Fluorescent dye, preparation method therefor and use thereof
10889719 ยท 2021-01-12
Assignee
Inventors
Cpc classification
C09B23/0066
CHEMISTRY; METALLURGY
G01N21/6428
PHYSICS
C09B23/0025
CHEMISTRY; METALLURGY
C09B23/0033
CHEMISTRY; METALLURGY
International classification
Abstract
Disclosed are a fluorescent dye, a preparation method and an application thereof. The fluorescent dye has a structure of formula (I), where X and Y are independently selected from O, S, C(CH.sub.3).sub.2 and NR.sub.6; R.sub.2 and R.sub.3 are independently hydrogen or a functional group; R.sub.1, R.sub.4, R.sub.5 and R.sub.6 are independently selected from functional groups; and Z.sup. is a negative ion. The fluorescent dye has an ability to permeate the living cell membrane, so that it can be used in the fluorescence imaging of living cell microstructures, and can also be used in the STED super-resolution fluorescence imaging and laser scanning confocal microscopy of live cells.
Claims
1. A fluorescent dye of formula (I): ##STR00129## wherein X and Y are independently selected from O, S, C(CH.sub.3).sub.2 and NR.sub.6; R.sub.1 is (CH.sub.2).sub.n1CH.sub.3, (CH.sub.2).sub.nR.sub.7, (CH.sub.2).sub.mC.sub.6H.sub.5 or (CH.sub.2).sub.mC.sub.6H.sub.4R.sub.7; R.sub.2 and R.sub.3 are independently selected from H, F, Cl, Br, I, (CH.sub.2).sub.n1CH.sub.3, (CH.sub.2).sub.nR.sub.8, CH.sub.2C.sub.6H.sub.5, CH.sub.2C.sub.6H.sub.4R.sub.8, O(CH.sub.2).sub.n1CH.sub.3, O(CH.sub.2).sub.nR.sub.8, OCH.sub.2C.sub.6H.sub.5, OCH.sub.2C.sub.6H.sub.4R.sub.8 and CN; R.sub.4, R.sub.5 and R.sub.6 are independently selected from (CH.sub.2).sub.n1CH.sub.3, (CH.sub.2).sub.nR.sub.8, CH.sub.2C.sub.6H.sub.5 and CH.sub.2C.sub.6H.sub.4R.sub.8; wherein R.sub.7 is C.sub.6H.sub.5, C.sub.6H.sub.4R.sub.9, SO.sub.3R.sub.10 or COOR.sub.11; R.sub.8 is SO.sub.3R.sub.10 or COOR.sub.11; n and m are integers respectively selected from 1-18 and 0-18; R.sub.9 is arsonic acid, boric acid, carboxylic acid, sulfonic acid, amino, hydroxyl, sulfhydryl or C.sub.1-C.sub.18 alkyl; R.sub.10 is N(R.sub.12R.sub.13R.sub.14R.sub.15); R.sub.11 is a C.sub.1-C.sub.18 alkyl; R.sub.12, R.sub.13, R.sub.14 and R.sub.15 are independently selected from H, C.sub.1-C.sub.18 alkyl and (CH.sub.2).sub.pOH, and p is an integer selected from 0-18; and Z.sup. is a halide anion or OTs.sup..
2. A method of preparing the fluorescent dye of claim 1, comprising: preparing a compound of formula (III) and Lawesson's reagent; dissolving the compound of formula (III) and the Lawesson's reagent in a first solvent; and subjecting the reaction mixture to substitution reaction under heating in an inert gas to produce a compound of formula (II); and subjecting the compound of formula (II) and a nucleophilic reagent R.sub.1Z to addition reaction to produce the fluorescent dye of formula (I); ##STR00130## wherein X and Y are independently selected from O, S, C(CH.sub.3).sub.2 and NR.sub.6; R.sub.1 is (CH.sub.2).sub.n1CH.sub.3, (CH.sub.2).sub.nR.sub.7, (CH.sub.2).sub.mC.sub.6H.sub.5 or (CH.sub.2).sub.mC.sub.6H.sub.4R.sub.7; R.sub.2 and R.sub.3 are independently selected from H, F, Cl, Br, I, (CH.sub.2).sub.n1CH.sub.3, (CH.sub.2).sub.nR.sub.8, CH.sub.2C.sub.6H.sub.5, CH.sub.2C.sub.6H.sub.4R.sub.8, O(CH.sub.2).sub.n1CH.sub.3, O(CH.sub.2).sub.nR.sub.8, OCH.sub.2C.sub.6H.sub.5, OCH.sub.2C.sub.2H.sub.4R.sub.8 and CN; R.sub.4, R.sub.5 and R.sub.6 are independently selected from (CH.sub.2).sub.n1CH.sub.3, (CH.sub.2).sub.nR.sub.8, CH.sub.2C.sub.6H.sub.5 and CH.sub.2C.sub.6H.sub.4R.sub.8; wherein R.sub.7 is C.sub.6H.sub.5, C.sub.6H.sub.4R.sub.9, SO.sub.3R.sub.10 or COOR.sub.11; R.sub.8 is SO.sub.3R.sub.10 or COOR.sub.11; n and m are integers respectively selected from 1-18 and 0-18; Re is arsonic acid, boric acid, carboxylic acid, sulfonic acid, amino, hydroxyl, sulfhydryl or C.sub.1-C.sub.18 alkyl; R.sub.10 is N(R.sub.12R.sub.13R.sub.14R.sub.15); R.sub.11 is a C.sub.1-C.sub.18 alkyl; R.sub.12, R.sub.13, R.sub.14 and R.sub.15 are independently selected from H, C.sub.1-C.sub.18 alkyl and (CH.sub.2).sub.pOH, and p is an integer selected from 0-18; and Z.sup. is a halide anion or OTs.sup..
3. The method of claim 2, wherein the first solvent is a mixed solution of dichloromethane and anhydrous tetrahydrofuran; and/or a temperature of the substitution reaction is 40-50 C.; and/or a temperature of the addition reaction is 25-60 C.; and/or a molar ratio of the compound of formula (III) to the Lawesson's reagent is 1:1; and/or a molar ratio of the compound of formula (II) to the nucleophilic reagent R.sub.1Z is 1:2-5.
4. The method of claim 2, wherein the compound of formula (III) is prepared by the steps of: preparing a compound of formula (VI) and a compound of formula (VII); subjecting the compound of formula (VI) and a nucleophilic reagent R.sub.4Z to addition reaction to produce a compound of formula (V); subjecting the compound of formula (VII) and a nucleophilic reagent of R.sub.5Z to addition reaction to produce a compound of formula (IV); mixing the compound of formula (V) and the compound of formula (IV) with a squaric acid solution, and reacting the reaction mixture in the presence of a catalyst to obtain the compound of formula (III); ##STR00131##
5. The method of claim 4, wherein a solvent in the squaric acid solution is ethanol; and/or the catalyst is triethyl orthoformate; and/or a molar ratio of the compound of formula (V) to the compound of formula (IV) to the squaric acid is 1:(0.8-1.2):(0.8-1.2).
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
DETAILED DESCRIPTION OF EMBODIMENTS
(3) The invention will be further described below with reference to the embodiments to make the technical problems to be solved, technical solutions and beneficial effects of the invention clearer. It should be understood that the embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
(4) In a first aspect, the invention provides a fluorescent dye of formula (I):
(5) ##STR00003##
(6) wherein X and Y are independently selected from O, S, C(CH.sub.3).sub.2 and NR.sub.6; R.sub.2 and R.sub.3 are independently selected from hydrogen and functional groups; R.sub.1, R.sub.4, R.sub.5 and R.sub.6 are independently selected from functional groups, and Z.sup. is a negative ion.
(7) The preparation of the fluorescent dye provided herein is started by modifying one of the oxygen atoms of the squaric acid ring in the squaraine dye, and the specific process is described as follows. Lawesson's reagent, as a commonly-used chemical reagent to convert oxygen into sulfur, is used herein to substitute an oxygen atom on the squaric acid ring with a sulfur atom. The resulting product is reacted with an alkylating agent react to form a stable product, which is subsequently used to prepare the desired fluorescent dye of formula (I). The method introduces a substituent to the squaric acid ring in the middle of the squaraine dye, which can not only change the charge structure of the squaraine dye, but also improve the synthesis and application of the dye. In addition, this method can avoid the occurrence of the unstable alkoxy group on the squaric acid ring, and the resulting fluorescent dye is capable of permeating the membrane of living cells, and thus it is suitable for the fluorescence imaging of living cell microstructures, STED super-resolution fluorescence imaging and laser scanning confocal imaging of living cells.
(8) In an embodiment, Z.sup. is a halide anion or OTs.sup..
(9) In an embodiment, R.sub.1 is (CH.sub.2).sub.nCH.sub.3, (CH.sub.2).sub.nR.sub.7, (CH.sub.2).sub.mC.sub.6H.sub.5 or (CH.sub.2).sub.mC.sub.6H.sub.4R.sub.7; R.sub.2 and R.sub.3 are independently selected from H, F, Cl, Br, I, (CH.sub.2).sub.nCH.sub.3, (CH.sub.2).sub.nR.sub.8, CH.sub.2C.sub.6H.sub.5, CH.sub.2C.sub.6H.sub.4R.sub.8, O(CH.sub.2).sub.n1CH.sub.3, O(CH.sub.2).sub.nR.sub.8, OCH.sub.2C.sub.6H.sub.8, OCH.sub.2C.sub.6H.sub.4R.sub.8 and CN; R.sub.4, R.sub.5 and R.sub.6 are independently selected from (CH.sub.2).sub.n1CH.sub.3, (CH.sub.2).sub.nR.sub.8, CH.sub.2C.sub.6H.sub.5 and CH.sub.2C.sub.6H.sub.4R.sub.8; where R.sub.7 and R.sub.8 are independently selected from functional groups, n and m are integers respectively selected from 1-18 and 0-18.
(10) In an embodiment, R.sub.7 is C.sub.6H.sub.5, C.sub.6H.sub.4R.sub.9, SO.sub.3R.sub.10 or COOR.sub.11; R.sub.8 is SO.sub.3R.sub.10 or COOR.sub.11; where R.sub.9, R.sub.10 and R.sub.11 are independently selected from functional groups.
(11) In an embodiment, R.sub.9 is arsonic acid, boric acid, carboxylic acid, sulfonic acid, amino, hydroxyl, sulthydryl or a C.sub.1-C.sub.18 alkyl; R.sub.10 is N(R.sub.12R.sub.13R.sub.14R.sub.15); R is a C.sub.1-C.sub.18 alkyl; where R.sub.12, R.sub.13, R.sub.14 and R.sub.15 are independently selected from H, C.sub.1-C.sub.18 alkyl and (CH.sub.2).sub.pOH, p is an integer selected from 0-18.
(12) In the formula (I), X and Y are independently selected from C(CH.sub.3).sub.2, O, S, NCH.sub.3 and NCH.sub.2CH.sub.3 among the preferred molecular structures, which are listed below (I.sub.na-X.sub.na, and n is an integer):
(13) ##STR00004##
(14) In a second aspect, the invention provides a method for preparing the above fluorescent dye, comprising:
(15) S01
(16) preparing a compound of formula (III) and Lawesson's reagent;
(17) S02
(18) dissolving the compound of formula (III) and the Lawesson's reagent in a first solvent; and subjecting the reaction mixture to substitution reaction under heating in an inert gas to produce a compound of formula (II); and
(19) S03
(20) subjecting the compound of formula (II) and a nucleophilic reagent of R.sub.1Z to addition reaction to produce the fluorescent dye of formula (I);
(21) ##STR00005##
(22) The key technology of the preparation method is to substitute the oxygen atom on the ring at the middle of the squaraine dye with a sulfur atom, where a key reagent used is Lawesson's reagent. Then the sulful-containing universal intermediate (sulfur-substituted squaraine dye) is used for the subsequent preparation of squaraine dyes with different substituents.
(23) In an embodiment, in step (S02), the first solvent is a mixed solution of dichloromethane and anhydrous tetrahydrofuran; a temperature of the substitution reaction is 40-50 C.; and a molar ratio of the compound of formula (III) to the Lawesson's reagent is 1:1.
(24) In an embodiment, in step (S03), a temperature of the addition reaction is 25-60 C.; and a molar ratio of the compound of formula (II) to the nucleophilic reagent R.sub.1Z is 1: 2-5.
(25) In an embodiment, the compound of formula (III) is prepared by the following steps:
(26) E01
(27) preparing a compound of formula (VI) and a compound of formula (VII);
(28) E02
(29) subjecting the compound of formula (VI) and a nucleophilic reagent R.sub.4Z to addition reaction to produce a compound of formula (V);
(30) E03
(31) subjecting the compound of formula (VII) and a nucleophilic reagent R.sub.5Z to addition reaction to produce a compound of formula (IV);
(32) E04
(33) mixing the compound of formula (V) and the compound of formula (IV) with a squaric acid solution, and reacting the reaction mixture in the presence of a catalyst to obtain the compound of the formula (III);
(34) ##STR00006##
(35) In an embodiment, in step (E04), a solvent in the squaric acid solution is ethanol; the catalyst is triethyl orthoformate; and a molar ratio of the compound of formula (V) to the compound of formula (IV) to squaric acid in the squaric solution is 1:(0.8-1.2):(0.8-1.2).
(36) Specifically, the fluorescent dye of the invention is prepared as follows.
(37) (1) Compound I.sub.ne such as 2,3,3-trimethyl-5-R.sub.2(R.sub.3)-3H-indoline and benzoindoline carrying R.sub.4 or R.sub.5, and related substituted benzothiazole, benzoxazole and benzimidazole (is reacted with R.sub.4(R.sub.5)CH.sub.2Z to obtain a corresponding quaternary ammonium salt I.sub.nd-X.sub.nd, where Z is a halide anion or OTs.sup.; a reaction temperature is 80-148 C.; a reaction time is 6-36 h; and a reaction solvent is toluene, o-dichlorobenzene, ethanol or acetonitrile; and a molar ratio of the compound I.sub.ne to R.sub.4(R.sub.5)CH.sub.2Z is 1:1-1:4. In the case that Z is chlorine or bromine, a small amount of KI may be added as a catalyst in the reaction to accelerate the reaction.
(38) (2) Synthesis of Corresponding Squaraine Dyes
(39) a. Synthesis of symmetrical squaraine dyes (XY, I.sub.nc-IV.sub.nc)
(40) 1 mol of 1,2-dihydroxy-3,4-cyclobutenedione is dissolved in a certain amount of absolute ethanol, to which the catalytic amount of triethyl orthoformate is added. The reaction mixture is refluxed under nitrogen until the solids are completely dissolved.
(41) Then 2.2-2.5 mol of indoline quaternary ammonium salt is added, and the reaction mixture is refluxed sequentially until it is turned into dark blue. Then the refluxing is stopped, and the reaction mixture is cooled to room temperature, dried under vacuum and purified to give a corresponding blue solid.
(42) b. Synthesis of Asymmetrical Squaraine Dyes (XY, V.sub.nc-X.sub.nc)
(43) 1 mol of 1,2-dihydroxy-3,4-cyclobutenedione is dissolved in a certain amount of absolute ethyl alcohol, to which catalytic amount of triethyl orthoformate is added. The reaction mixture is refluxed under nitrogen until the solids are completely dissolved. 1 mol of quaternary ammonium salt A is added, and the reaction mixture is refluxed until the reaction is completed. Then 1-1.2 mol of quaternary ammonium salt B is added, and the reaction mixture is continuously heated until the raw materials are completely consumed. The reaction mixture is cooled to room temperature, dried under vacuum and purified by column chromatography to give a corresponding blue solid.
(44) c. Sulfur-Substitution of the Oxygen Atom on the Squaric Acid in the Middle of a Squaraine Dye (I.sub.nb-X.sub.nb)
(45) 1 mol of dye I.sub.nc-X.sub.nc is added to a 100 mL round-bottomed flask, to which 30 mL of a mixed solvent of anhydrous dichloromethane and anhydrous tetrahydrofuran is added. After the solid dye is completely dissolved, 1 mol of a sulfurizing reagent capable of substituting an oxygen atom with a sulfur atom is added, and the reaction mixture is heated at 40 C. under argon protection for 2-5 h. Then the reaction mixture is dried under vacuum, where it should be noted that some protective measures should be adopted to prevent odor from spreading. Then the resulting residue is washed with a mixed solution of anhydrous diethyl ether and n-hexane, dissolved and purified by column chromatography to give a corresponding blue solid (I.sub.nb-X.sub.nb).
(46) d. Preparation of the Target Dyes
(47) 1 mol of sulfur-substituted squaraine dye (I.sub.nb-X.sub.nb) is added to 20 mL of anhydrous acetonitrile, to which 2-5 mol of a corresponding electrophilic reagent (R.sub.1X) is added. Then the reaction mixture is heated at a temperature from room temperature to 60 C. When the reaction is determined to be completed by TLC, the reaction mixture is dried under vacuum and purified by silica gel column chromatography to give a corresponding target dye (I.sub.na-X.sub.na) with a yield of 30-80%.
(48) In a third aspect, the invention provides an application of the above fluorescent dye in the fluorescence imaging of living cells and the fluorescent labeling and the STED super-resolution fluorescence imaging of intracellular microstructure. Due to the ability to permeate living cell membranes, the above fluorescent dye can be used in the fluorescence imaging of living cell microstructures, and in the STED super-resolution fluorescence imaging and laser scanning confocal imaging of live cells.
(49) The invention will be described in detail below with reference to preferred embodiments.
Example 1
(50) In this example, in formula (I), X and Y were both C(CH.sub.3).sub.2, based on which, structures of ten representative dyes respectively varying in R.sub.1-R.sub.5 were shown as follows:
(51) ##STR00007## ##STR00008## ##STR00009##
(52) 1. Synthetic routes of dyes I.sub.1a-I.sub.6a were shown as follows:
(53) ##STR00010##
(54) where the structural formulas of T.sub.n(n=1-6) were respectively shown as follows:
(55) ##STR00011##
(56) The dyes I.sub.1a-I.sub.6a were specifically prepared as follows.
(57) (1) 1 mol of 2,3,3-trimethyl-3H-indoline and 2 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 5 h, and then cooled to room temperature. The reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.1d), which was dried and then stored for use.
(58) (2) 1 mol of squaric acid was added to 50 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved. Then 2.2 mol of the quaternary ammonium salt (I.sub.1d) was added, and the reaction mixture was continuously refluxed. After the reaction was confirmed to be completed by TLC, the reaction mixture was cooled, dried under vacuum and purified by column chromatography to give a blue solid dye (I.sub.1c).
(59) (3) 1 mol of the dye (I.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, and then the reaction was stopped. The reaction mixture was dried under vacuum and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (I.sub.1b).
(60) (4) 1 mol of the sulfur-substituted squaraine dye (I.sub.1b) was added to dry acetonitrile, to which a bromo-substituted intermediate T.sub.nBr (T.sub.n was selected from T.sub.1-T.sub.6) was added. The reaction mixture was stirred at a temperature from room temperature to 60 C., dried under vacuum and purified by column chromatography to give a corresponding target dye (I.sub.1a-I.sub.6a).
(61) The compounds I.sub.1a-I.sub.6a were characterized as follows.
(62) I.sub.1a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.38 (t, 3H, CH.sub.3, J=8.0 Hz), 1.41 (t, 6H, CH.sub.3, J=8.0 Hz), 1.83 (s, 12H, CH.sub.3), 3.17 (q, 2H, CH.sub.2, J=8.0 Hz), 4.29 (q, 4H, CH.sub.2, J=8.0 Hz), 6.48 (s, 2H, CH), 7.07 (d, 2H, ArH, J=8.0 Hz), 7.18 (t, 2H, ArH, J=8.0 Hz), 7.35 (q, 4H, ArH, J=8.0 Hz);
(63) .sup.13C-NMR (100 MHz, CDCl.sub.3): 12.26, 13.31, 27.71, 31.04, 40.40, 50.14, 87.64, 110.40, 122.61, 124.61, 128.12, 142.02, 142.61, 173.45, 186.68, 204.15;
(64) HRMS-ESI: m/z calcd M.sup.+ for C.sub.32H.sub.37N.sub.2OS.sup.+, 497.2621; found, 497.2625.
(65) I.sub.2a: HRMS-ESI: m/z calcd [M+H].sup.+ for C.sub.33H.sub.37N.sub.2O.sub.3S.sup.+, 541.2447; found, 541.2452.
(66) I.sub.3a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.41 (t, 6H, CH.sub.3, J=8.0 Hz), 1.83 (s, 12H, CH.sub.3), 3.70 (s, 2H, CH.sub.2), 4.29 (q, 4H, CH.sub.2, J=8.0 Hz), 6.48 (s, 2H, CH), 7.07 (m, 4H, ArH), 7.18 (t, 2H, ArH, J=8.0 Hz), 7.35 (q, 4H, ArH, J=8.0 Hz), 7.42 (m, 3H, ArH);
(67) .sup.13C-NMR (100 MHz, CDCl.sub.3): 12.26, 27.71, 28.61, 40.40, 50.14, 87.64, 110.40, 122.61, 124.61, 126.65, 127.71, 128.12, 128.29, 140.83, 142.02, 142.61, 173.45, 186.68, 204.15;
(68) HRMS-ESI: m/z calcd M.sup.+ for C.sub.32H.sub.37N.sub.2OS.sup.+, 559.2778; found, 559.2781.
(69) I.sub.2a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.37H.sub.38N.sub.3O.sub.3S.sup.+, 604.2628; found, 604.2633.
(70) I.sub.5a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.43 (t, 6H, CH.sub.3, J=8.0 Hz), 1.70 (m, 14H, CH.sub.3& CH.sub.2), 1.85 (m, 2H, CH.sub.2), 2.01 (m, 2H, CH.sub.2), 2.72 (t, 2H, CH.sub.2, J=8.0 Hz), 3.11 (m, 2H, CH.sub.2), 3.28 (m, 2H, CH.sub.2), 3.63 (t, 2H, CH.sub.2, J=8.0 Hz), 4.22 (q, 4H, CH2, J=8.0 Hz), 5.72 (s, 2H, CH), 7.17 (d, 2H, ArH, J=8.0 Hz), 7.29 (m, 2H, ArH), 7.39 (m, 4H, ArH), 7.46 (m, 2H, ArH), 7.96 (d, 2H, ArH, J=8.0 Hz), 9.69 (s, 1H, NH);
(71) .sup.13C-NMR (100 MHz, CDCl.sub.3): 12.57, 25.19, 26.17, 27.59, 30.00, 32.27, 37.24, 40.74, 41.80, 50.64, 88.32, 111.49, 120.01, 122.58, 126.41, 128.87, 131.19, 137.11, 140.59, 141.01, 142.53, 142.61, 171.82, 171.96, 172.01, 173.08, 173.43, 174.12, 175.65;
(72) HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.51ASN.sub.3O.sub.2S.sub.3.sup.+, 824.2354; found, 824.2358.
(73) I.sub.6a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.42H.sub.48N.sub.3O.sub.2S.sup.+, 658.3462; found, 658.3466.
(74) 2. The synthetic route of dye I.sub.7a was shown as follows:
(75) ##STR00012##
(76) The dye I.sub.7a was specifically synthesized as follows.
(77) (1) 1 mol of 2,3,3-trimethyl-3H-indoline and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 12 h and cooled to room temperature. Then the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.2d), which was dried and then stored for use.
(78) (2) 1 mol of squaric acid was added to 50 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 2.2 mol of the quaternary ammonium salt (I.sub.2d) was added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum and purified by column chromatography to give a blue solid dye (I.sub.2c).
(79) (3) 1 mol of the dye (I.sub.2c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After the reaction mixture was stirred at 40 C. for 3 h, the reaction was stopped. The reaction mixture was dried under vacuum and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (I.sub.2b).
(80) (4) 1 mol of the sulfur-substituted squaraine dye (I.sub.2b) was added to a dry acetonitrile solvent, to which 2.5 mol of iodoethane was added. The reaction mixture was thermally stirred at room temperature for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum and purified by column chromatography to give a target dye (I.sub.7a).
(81) The compound (I.sub.7a) was characterized as follows:
(82) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.39 (t, 3H, CH.sub.3, J=8.0 Hz), 1.83 (s, 12H, CH.sub.3), 3.19 (q, 2H, CH.sub.2, J=8.0 Hz), 3.58 (m, 6H, CH.sub.2&OH), 3.98 (m, 4H, CH.sub.2), 6.48 (s, 2H, CH), 7.07 (d, 2H, ArH, J=8.0 Hz), 7.18 (t, 2H, ArH, J=8.0 Hz), 7.35 (q, 4H, ArH, J=8.0 Hz);
(83) .sup.13C-NMR (100 MHz, CDCl.sub.3): 13.31, 27.71, 31.04, 40.40, 53.14, 59.81, 87.64, 110.40, 122.61, 124.56, 128.12, 142.02, 142.63, 173.45, 186.68, 204.10;
(84) HRMS-ESI: m/z calcd M.sup.+ for C.sub.32H.sub.37N.sub.2O.sub.3S.sup.+, 529.2519; found, 529.2523.
(85) 3. The synthetic route of dye I.sub.8a was shown as follows:
(86) ##STR00013##
(87) The dye I.sub.8a was specifically prepared as follows.
(88) (1) 1 mol of 2,3,3-trimethyl-3H-indoline and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 12 h and cooled to room temperature. Then the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.2d), which was dried and stored for use.
(89) (2) 1 mol of 2,3,3-trimethyl-3H-indoline and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.3d), which was dried and stored for use.
(90) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (I.sub.2d) and 1.2 mol of the quaternary ammonium salt (I.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum and purified by column chromatography to give a blue solid dye (be).
(91) (4) 1 mol of the dye (I.sub.3) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After the reaction mixture was stirred at 40 C. for 3 h, the reaction was stopped. Then the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (bb).
(92) (5) 1 mol of the sulfur-substituted squaraine dye (bb) was added to a dry acetonitrile solvent, to which 2.5 mol of benzyl bromide was added. After thermally stirred at room temperature for 2 h, the reaction was cooled to room temperature, dried under vacuum and purified by column chromatography to give a target dye (I.sub.8a).
(93) The compound (I.sub.8a) was characterized as follows: HRMS-ESI: m/z calcd M.sup.+ for C.sub.42H.sub.41N.sub.2O.sub.2S.sup.+, 637.2883; found, 637.2886.
(94) 4. The synthetic route of dye I.sub.9a was shoen as follows:
(95) ##STR00014## ##STR00015##
(96) The dye I.sub.9a was specifically prepared as follows.
(97) (1) 1 mol of 2,3,3-trimethyl-5-bromo-3H-indoline and 3 mol of ethylene glycol tosylate were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.4d), which was dried and stored for use.
(98) (2) 1 mol of 2,3,3-trimethyl-5-methyl-3H-indoline and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.5d), which was dried and stored for use.
(99) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (I.sub.4d) and 1.2 mol of the quaternary ammonium salt (I.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum and purified by column chromatography to give a blue solid dye (I.sub.4c).
(100) (4) 1 mol of the dye (I.sub.4c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After the reaction mixture was stirred at 40 C. for 3 h, the reaction was stopped. The reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (I.sub.4b).
(101) (5) 1 mol of the sulfur-substituted squaraine dye (I.sub.4b) was added to a dry acetonitrile solvent, to which 2.5 mol of benzyl bromide was added. The reaction mixture was thermally stirred for 2 h at room temperature. After cooled to room temperature, the reaction mixture was dried under vacuum and purified by column chromatography to give a target dye (I.sub.9a).
(102) The compound (I.sub.9a) was characterized as follows:
(103) HRMS-ESI: m/z calcd M.sup.+ for C.sub.42H.sub.48BrN.sub.2O.sub.5S.sup.+, 771.2462; found, 771.2484.
(104) 5. The synthetic route of dye I.sub.9a was shown as follows:
(105) ##STR00016## ##STR00017##
(106) The dye I.sub.9a was specifically prepared as follows.
(107) (1) 1 mol of 2,3,3-trimethyl-5-methoxy-3H-indoline (I.sub.4e) and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.6d) which was dried and stored for use.
(108) (2) 1 mol of 2,3,3-trimethyl-5-benzyloxy-3H-indoline (I.sub.5e) and 3 mol of 4-vinyl benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.7d) which was dried and stored for use.
(109) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completed dissolved. Then 0.8 mol of the quaternary ammonium salt (I.sub.6d) and 1.2 mol of quaternary ammonium salt (I.sub.7d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum and purified by column chromatography to give a blue solid dye (I.sub.5c).
(110) (4) 1 mol of the dye (I.sub.5c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran to which 2 mol of Lawesson's reagent was added. After the reaction mixture was stirred at 40 C. for 3 h, the reaction was stopped. The reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (I.sub.5b).
(111) (5) 1 mol of the sulfur-substituted squaraine dye (I.sub.5b) was added to a dry acetonitrile solvent to which 2.5 mol of benzyl bromide was added. The reaction mixture was thermally stirred at room temperature for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum and purified by column chromatography to give a target dye (I.sub.10a).
(112) The compound (I.sub.10a) was characterized as follows:
(113) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.83 (s, 12H, CH.sub.3), 2.86 (t, 1H, CH, J=8.0 Hz), 3.56 (t, 2H, CH.sub.2, J=8.0 Hz), 3.65 (s, 1H, OH), 3.83 (s, 3H, CH.sub.3), 3.98 (t, 2H, CH.sub.2, J=8.0 Hz), 4.33 (s, 2H, CH.sub.2), 4.87 (s, 2H, CH.sub.2), 5.16 (s, 2H, CH.sub.2), 5.23 (m, 1H, CH.sub.2), 5.74 (m, 1H, CH.sub.2), 5.82 (s, 1H, CH), 5.92 (s, 1H, CH), 6.69 (m, 1H, CH), 7.19 (m, 4H, ArH), 7.38 (m, 4H, ArH), 7.54 (m, 2H, ArH), 7.86 (m, 3H, ArH), 8.10 (m, 2H, ArH);
(114) .sup.13C-NMR (100 MHz, CDCl.sub.3): 22.93, 24.70, 27.71, 49.60, 53.14, 55.83, 58.20, 59.81, 70.79, 74.62, 94.64, 107.80, 110.41, 111.52, 114.31, 124.61, 126.80, 127.11, 128.12, 129.73, 131.80, 133.72, 134.30, 135.91, 142.02, 142.61, 148.70, 149.11, 152.93, 160.30, 163.42, 173.45, 186.68;
(115) HRMS-ESI: m/z calcd M.sup.+ for C.sub.48H.sub.47N.sub.2O.sub.4S.sup.+, 747.3251; found, 747.3256.
Example 2
(116) Listed herein were merely partial representative structures, where in the formula (I), X and Y were both O, based on which, structures of ten representative dyes respectively varying in R.sub.1-R.sub.5 were shown below.
(117) ##STR00018## ##STR00019## ##STR00020##
(118) 1. Synthetic routes of dyes II.sub.1a-II.sub.6a were shown as follows:
(119) ##STR00021##
(120) where the structural formulas of S.sub.n (n=16) were respectively shown as follows:
(121) ##STR00022##
(122) The dyes II.sub.1a-II.sub.6a were specifically prepared as follows.
(123) (1) 1 mol of 2-methylbenzoxazole and 2 mol of iodoethane were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 5 h, and then cooled to room temperature. The reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.1d) which was dried and then stored for use.
(124) (2) 1 mol of squaric acid was added to 50 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved. Then 2.2 mol of the quaternary ammonium salt (II.sub.1d) was added, and the reaction mixture was continuously refluxed. After the reaction was confirmed to be completed by TLC, the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (II.sub.1c).
(125) (3) 1 mol of the dye (II.sub.1c) was added to 25 mL of mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (II.sub.1b).
(126) (4) 1 mol of the sulfur-substituted squaraine dye (II.sub.1b) was added to dry acetonitrile, to which a corresponding bromo intermediate S.sub.nBr (S.sub.n was selected from S.sub.1-S.sub.6) was added. The reaction mixture was stirred at a temperature from room temperature to 60 C., dried under vacuum, and purified by column chromatography to give a corresponding target dye (II.sub.1a-II.sub.6a).
(127) The compounds II.sub.1a-II.sub.6a were characterized as follows:
(128) II.sub.1a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.01 (t, 3H, CH.sub.3, J=8.0 Hz), 1.42 (t, 6H, CH.sub.3, J=8.0 Hz), 1.69 (m, 2H, CH.sub.2), 3.24 (t, 2H, CH.sub.2, J=8.0 Hz), 4.37 (q, 4H, CH2, J=8.0 Hz), 6.69 (s, 2H, CH), 7.09 (d, 2H, ArH, J=8.0 Hz), 7.26 (t, 2H, ArH, J=8.0 Hz), 7.38 (q, 4H, ArH, J=8.0 Hz);
(129) .sup.13C-NMR (100 MHz, CDCl.sub.3): 12.11, 14.20, 25.51, 34.04, 40.40, 87.64, 110.40, 122.61, 124.61, 128.12, 142.02, 142.61, 173.45, 186.68, 204.15;
(130) HRMS-ESI: m/z calcd M.sup.+ for C.sub.27H.sub.27N.sub.2O.sub.3S.sup.+, 459.1737; found, 459.1741.
(131) II.sub.2a: HRMS-ESI: m/z calcd [M.sup.+H].sup.+ for C.sub.26H.sub.25N.sub.2O.sub.6S.sub.2, 525.1076; found, 525.1081.
(132) II.sub.3a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.39 (t, 6H, CH.sub.3, J=8.0 Hz), 4.41 (q, 4H, CH2, J=8.0 Hz), 4.62 (s, 2H, CH.sub.2), 6.17 (s, 2H, CH.sub.2), 6.57 (s, 2H, CH), 7.01 (m, 4H, ArH), 7.30 (m, 3H, ArH), 7.38 (m, 4H, ArH);
(133) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.27, 43.20, 46.01, 82.53, 101.20, 108.79, 112.40, 122.61, 124.61, 128.12, 133.10, 142.02, 142.61, 148.73, 156.31, 173.45, 186.68, 202.09;
(134) HRMS-ESI: m/z calcd M.sup.+ for C.sub.32H.sub.27N.sub.2O.sub.5S.sup.+, 551.1635; found, 551.1638.
(135) II.sub.4a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.31H.sub.26N.sub.3O.sub.5S.sup.+, 552.1588; found, 552.1592.
(136) II.sub.5a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.40 (t, 6H, CH3, J=8.0 Hz), 4.43 (q, 4H, CH.sub.2, J=8.0 Hz), 4.72 (s, 2H, CH.sub.2), 6.63 (s, 2H, CH), 7.10 (m, 3H, ArH), 7.43 (m, 6H, ArH), 7.62 (m, 4H, ArH), 7.91 (m, 2H, ArH);
(137) .sup.13C-NMR (100 MHZ, CDCl.sub.3): 13.98, 42.40, 46.13, 83.35, 101.12, 107.63, 112.27, 123.52, 125.10, 128.12, 134.03, 142.71, 144.15, 148.10, 155.30, 174.69, 186.04, 204.11;
(138) HRMS-ESI: m/z calcd M.sup.+ for C.sub.35H.sub.29N.sub.2O.sub.3S.sup.+, 557.1893; found, 557.1897.
(139) II.sub.6a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.32H.sub.33N.sub.2O.sub.3S.sup.+, 525.2206; found, 525.2210.
(140) 2. The synthetic route of dye II.sub.7a was shown as follows:
(141) ##STR00023##
(142) The dye II.sub.7a was specifically synthesized as follows.
(143) (1) 1 mol of 2-methylbenzoxazole and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 12 h and cooled to room temperature. Then the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.2d), which was dried and stored for use.
(144) (2) 1 mol of squaric acid was added to 50 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, then 2.2 mol of the quaternary ammonium salt (II.sub.2d) was added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (II.sub.2c).
(145) (3) 1 mol of the dye (I.sub.2c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (II.sub.2b).
(146) (4) 1 mol of the sulfur-substituted squaraine dye (II.sub.2b) was added to a dry acetonitrile solvent, to which 2.5 mol of cyclopropyl bromide was added. The reaction mixture was thermally stirred at room temperature for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum and purified by column chromatography to give a target dye (II.sub.7a).
(147) The compound II.sub.7a was characterized as follows:
(148) .sup.1H-NMR (400 MHz, CDCl.sub.3): 0.48 (m, 2H, CH.sub.2), 0.76 (m, 2H, CH.sub.2), 1.36 (m, 1H, CH), 3.56 (s, 2H, OH), 3.63 (q, 4H, CH.sub.2, J=8.0 Hz), 3.98 (q, 4H, CH.sub.2, J=8.0 Hz), 6.34 (s, 2H, CH), 7.02 (d, 2H, ArH, J=8.0 Hz), 7.21 (t, 2H, ArH, J=8.0 Hz), 7.38 (q, 4H, ArH, J=8.0 Hz);
(149) .sup.13C-NMR (100 MHz, CDCl.sub.3): 6.89, 10.23, 42.38, 58.71, 86.67, 109.30, 122.11, 125.53, 127.91, 142.17, 143.28, 174.30, 187.10, 203.93;
(150) HRMS-ESI: m/z calcd M.sup.+ for C.sub.27H.sub.25N.sub.2O.sub.5S.sub.+, 489.1479; found, 489.1482.
(151) 3. The synthetic route of dye II.sub.8a was shown as follows:
(152) ##STR00024##
(153) The dye II.sub.8a was specifically prepared as follows.
(154) (1) 1 mol of 2-methylbenzoxazole and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 12 h and cooled to room temperature. Then the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (I.sub.2d), which was dried and stored for use.
(155) (2) 1 mol of 2-methylbenzoxazole and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.3d) which was dried and stored for use.
(156) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (II.sub.2d) and 1.2 mol of the quaternary ammonium salt (II.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (II.sub.3c).
(157) (4) 1 mol of the dye (II.sub.3c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (II.sub.3b).
(158) (5) 1 mol of the sulfur-substituted squaraine dye (II.sub.3b) was added to a dry acetonitrile solvent, to which 2.5 mol of 2-furan methyl chloride was added. After thermally stirred at room temperature for 2 h, the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (II.sub.8a).
(159) The compound II.sub.8a was characterized as follows:
(160) HRMS-ESI: m/z calcd M.sup.+ for C.sub.34H.sub.27N.sub.2O.sub.5S.sup.+, 575.1635; found, 575.1639.
(161) 4. The synthetic route of dye II.sub.9a was shown as follows:
(162) ##STR00025## ##STR00026##
(163) The dye II.sub.9a was specifically prepared as follows.
(164) (1) 1 mol of 2-methyl-5-bromobenzoxazole and 3 mol of ethylene glycol tosylate were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.4d) which was dried and stored for use.
(165) (2) 1 mol of 2-methyl-5-methylbenzoxazole and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.4d), which was dried and stored for use.
(166) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (II.sub.4d) and 1.2 mol of the quaternary ammonium salt (II.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (II.sub.4c).
(167) (4) 1 mol of the dye (II.sub.4c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (II.sub.4b).
(168) (5) 1 mol of the sulfur-substituted squaraine dye (II.sub.4b) was added to a dry acetonitrile solvent, to which 2.5 mol of
(169) ##STR00027##
was added. The reaction mixture was thermally stirred at room temperature for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum, and purified by column chromatography to give a target dye (II.sub.9a).
(170) The compound II.sub.9a was characterized as follows:
(171) .sup.1H-NMR (400 MHz, CDCl.sub.3): 2.35 (s, 3H, CH3), 3.06 (t, 2H, CH.sub.2, J=8.0 Hz), 3.41 (m, 6H, CH.sub.2), 3.58 (s, 2H, OH), 3.67 (m, 4H, CH.sub.2), 4.06 (m, 4H, CH.sub.2), 5.41 (s, 2H, CH.sub.2), 5.93 (S, 1H, CH), 6.15 (s, 1H, CH), 7.13 (m, 3H, ArH), 7.29 (m, 5H, ArH), 7.46 (m, 3H, ArH);
(172) .sup.13C-NMR (100 MHz, CDCl.sub.3): 21.61, 33.90, 44.38, 45.29, 60.31, 66.12, 69.40, 73.14, 84.33, 108.07, 116.80, 122.11, 125.53, 131.07, 143.26, 146.82, 159.42, 174.30;
(173) HRMS-ESI: m/z calcd M.sup.+ for C.sub.36H.sub.36BrN.sub.2O.sub.7S.sup.+, 719.1421; found, 719.1425.
(174) 5. The synthetic route of dye II.sub.10a was shown as follows:
(175) ##STR00028## ##STR00029##
(176) The dye II.sub.10a was specifically prepared as follows.
(177) (1) 1 mol of 2-methyl-5-methoxybenzoxazole (II.sub.4e) and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.6d) which was dried and stored for use.
(178) (2) 1 mol of 2-methyl-5-benzyloxybenzoxazole (II.sub.5e) and 3 mol of 4-vinylbenzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.7d) which was dried and stored for use.
(179) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved. Then 0.8 mol of the quaternary ammonium salt (II.sub.6d) and 1.2 mol of quaternary ammonium salt (II.sub.7d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (II.sub.5c).
(180) (4) 1 mol of the dye (II.sub.5c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (III.sub.5b).
(181) (5) 1 mol of the sulfur-substituted squaraine dye (II.sub.5b) was added to a dry acetonitrile solvent, to which 2.5 mol of propargyl bromide was added. The reaction mixture was thermally stirred at room temperature for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum, and purified by column chromatography to give a target dye (II.sub.10a).
(182) The compound II.sub.10a was characterized as follows:
(183) HRMS-ESI: m/z calcd M.sup.+ for C.sub.43H.sub.37N.sub.2O.sub.5S.sup.+, 693.2418; found, 693.2423.
Example 3
(184) Listed herein were only partially representative structures, where in the formula (I), XYO, based on which, structures of ten representative dyes respectively varying in R.sub.1-R.sub.5 were shown as follows:
(185) ##STR00030## ##STR00031## ##STR00032##
(186) 1. Synthetic routes of dyes III.sub.1a-III.sub.6a were shown as follows:
(187) ##STR00033##
(188) where the structural formulas of U.sub.n (n=16) were respectively shown as follows:
(189) ##STR00034##
(190) The dyes III.sub.1a-III.sub.6a were specifically prepared as follows.
(191) (1) 1 mol of 2-methylbenzothiazole and 2 mol of iodopropane were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 5 h, and then cooled to room temperature. The reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.1d), which was dried and then stored for use.
(192) (2) 1 mol of squaric acid was added to 50 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved. Then 2.2 mol of the quaternary ammonium salt (III.sub.1d) was added, and the reaction mixture was continuously refluxed. After the reaction was confirmed to be completed by TLC, the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (III.sub.1c).
(193) (3) 1 mol of the dye (III.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (III.sub.1b).
(194) (4) 1 mol of the sulfur-substituted squaraine dye (III.sub.1b) was added to a dry acetonitrile solvent, to which a bromo-substituted intermediate U.sub.nBr (U.sub.n was selected from U.sub.1-U.sub.6) was added. The reaction mixture was stirred at a temperature from room temperature to 60 C., dried under vacuum, and purified by column chromatography to give a corresponding target dye (III.sub.1a-III.sub.6a).
(195) The compounds III.sub.1a-III.sub.6a were characterized as follows:
(196) III.sub.1a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.29H.sub.31N.sub.2OS.sub.3.sup.+, 519.1593; found, 519.1598.
(197) III.sub.2a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.04 (t, 6H, CH3, J=8.0 Hz), 1.39 (m, 4H, CH.sub.2), 1.43 (s, 9H, CH.sub.3), 4.30 (t, 4H, CH.sub.2, J=8.0 Hz), 6.31 (s, 2H, CH), 7.17 (d, 2H, ArH, J=8.0 Hz), 7.39 (t, 2H, ArH, J=8.0 Hz), 7.58 (q, 4H, ArH, J=8.0 Hz);
(198) .sup.13C-NMR (100 MHz, CDCl.sub.3): 11.40, 22.71, 32.83, 46.02, 52.64, 89.50, 109.81, 122.47, 125.10, 127.65, 142.11, 144.36, 176.22, 185.04, 202.90;
(199) HRMS-ESI: m/z calcd M.sup.+ for C.sub.30H.sub.33N.sub.2OS.sub.3.sup.+, 533.1750; found, 533.1754.
(200) III.sub.3a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.33H.sub.30N.sub.2O.sub.4S.sub.4, 646.1088; found, 647.1093.
(201) III.sub.4a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.03 (t, 6H, CH.sub.3, J=8.0 Hz), 1.37 (m, 4H, CH.sub.2), 2.43 (s, 3H, CH.sub.3), 4.27 (t, 4H, CH.sub.2, J=8.0 Hz), 4.59 (s, 2H, CH.sub.2), 6.23 (s, 2H, CH), 7.10 (m, 3H, ArH), 7.17 (m, 3H, ArH), 7.39 (t, 2H, ArH, J=8.0 Hz), 7.58 (q, 4H, ArH, J=8.0 Hz);
(202) .sup.13C-NMR (100 MHz, CDCl.sub.3): 10.79, 21.33, 21.71, 43.09, 53.10, 91.06, 108.98, 122.11, 124.83, 128.07, 138.10, 141.80, 143.01, 145.24, 177.35, 184.20, 203.81;
(203) HRMS-ESI: m/z calcd M.sup.+ for C.sub.34H.sub.33N.sub.2OS.sub.3.sup.+, 581.1750; found, 581.1754.
(204) III.sub.5a: HRMS-ESI: m/z calcd [M.sup.+Cl].sup.+ for C.sub.32H.sub.31ClN.sub.3OS.sub.3.sup.+, 604.1312; found, 604.1316.
(205) III.sub.6a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.01 (t, 6H, CH.sub.3, J=8.0 Hz), 1.41 (m, 4H, CH.sub.2), 4.31 (t, 4H, CH2, J=8.0 Hz), 5.16 (s, 2H, CH.sub.2), 6.33 (s, 2H, CH), 7.13 (m, 5H, ArH), 7.38 (m, 4H, ArH), 7.61 (m, 3H, ArH);
(206) .sup.13C-NMR (100 MHz, CDCl.sub.3): 10.90, 22.70, 36.62, 54.04, 90.63, 109.30, 122.56, 123.90, 127.61, 138.40, 142.07, 144.12, 146.37, 178.51, 187.40;
(207) HRMS-ESI: m/z calcd M.sup.+ for C.sub.32H.sub.30N.sub.3OS.sub.3.sup.+, 568.1546; found, 568.1551.
(208) 2. The synthetic route of dye III.sub.7a was shown as follows:
(209) ##STR00035##
(210) The dye III.sub.7a was specifically synthesized as follows.
(211) (1) 1 mol of 2-methylbenzothiazole and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 12 h and cooled to room temperature. Then the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.2d) which was dried and then stored for use.
(212) (2) 1 mol of squaric acid was added to 50 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 2.2 mol of the quaternary ammonium salt (III.sub.2d) was added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (III.sub.2c).
(213) (3) 1 mol of the dye (III.sub.2c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (III.sub.2b).
(214) (4) 1 mol of the sulfur-substituted squaraine dye (III.sub.2b) was added to a dry acetonitrile solvent, to which 2.5 mol of 4-butoxy benzyl bromide was added. The reaction mixture was stirred at 60 C. for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum, and purified by column chromatography to give a target dye (III.sub.7a).
(215) The compound III.sub.7a was characterized as follows:
(216) HRMS-ESI: m/z calcd M.sup.+ for C.sub.35H.sub.35N.sub.2O.sub.4S3.sup.+, 643.1753; found, 643.1757.
(217) 3. The synthetic route of dye III.sub.8a was shown as follows:
(218) ##STR00036## ##STR00037##
(219) The dye III.sub.8a was specifically prepared as follows.
(220) (1) 1 mol of 2-methylbenzothiazole and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 12 h and cooled to room temperature. Then the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.2d), which was dried and stored for use.
(221) (2) 1 mol of 2-methylbenzothiazole and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.3d), which was dried and stored for use. (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (III.sub.2d) and 1.2 mol of the quaternary ammonium salt (III.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (III.sub.3c).
(222) (4) 1 mol of the dye (III.sub.3c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (III.sub.3b).
(223) (5) 1 mol of the sulfur-substituted squaraine dye (III.sub.3b) was added to a dry acetonitrile solvent, to which 2.5 mol of triethylene glycol p-toluenesulfonate was added. After stirred at 50 C. for 2 h, the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (III.sub.8a).
(224) The compound III.sub.8a was shown as follows:
(225) .sup.1H-NMR (400 MHz, CDCl.sub.3): 2.98 (t, 2H, CH2, J=8.0 Hz), 3.58 (m, 12H, CH.sub.2), 4.01 (t, 2H, CH.sub.2, J=8.0 Hz), 5.42 (s, 2H, CH.sub.2), 5.94 (s, 1H, CH), 6.13 (s, 1H, CH), 7.11 (m, 4H, ArH), 7.32 (m, 4H, ArH), 7.48 (m, 2H, ArH), 7.59 (m, 3H, ArH);
(226) .sup.13C-NMR (100 MHz, CDCl.sub.3): 32.81, 54.55, 55.60, 61.31, 63.07, 69.73, 70.34, 73.48, 89.50, 109.13, 117.60, 122.74, 124.16, 126.53, 130.90, 143.11, 147.75, 158.30, 173.64;
(227) HRMS-ESI: m/z calcd M.sup.+ for C.sub.35H.sub.35N.sub.2O.sub.5S.sub.3.sup.+, 659.1703; found, 659.1709.
(228) 4. The synthetic route of dye III.sub.9a was shown as follows:
(229) ##STR00038##
(230) The dye III.sub.9a was specifically prepared as follows.
(231) (1) 1 mol of 2-methyl-bromobenzothiazole and 3 mol of diethylene glycol tosylate were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.4d) which was dried and stored for use.
(232) (2) 1 mol of 2-methyl-methylbenzothiazole and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink solid quaternary ammonium salt (III.sub.5d) which was dried and stored for use.
(233) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (III.sub.4d) and 1.2 mol of the quaternary ammonium salt (III.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (III.sub.4c).
(234) (4) 1 mol of the dye (III.sub.4c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. The reaction mixture was stirred at 40 C. for 3 h, dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (III.sub.4b).
(235) (5) 1 mol of the sulfur-substituted squaraine dye (III.sub.4b) was added to a dry acetonitrile solvent, to which 2.5 mol of cyclohexyl bromide was added. The reaction mixture was thermally stirred at room temperature for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum, and purified by column chromatography to give a target dye (III.sub.9a).
(236) The compound III.sub.9a was characterized as follows:
(237) HRMS-ESI: m/z calcd M.sup.+ for C.sub.38H.sub.38BrN.sub.2O.sub.3S.sub.3.sup.+, 745.1222; found, 745.1225.
(238) 5. The synthetic route of dye III.sub.10a was shown as follows:
(239) ##STR00039## ##STR00040##
(240) The dye III.sub.10a was specifically prepared as follows.
(241) (1) 1 mol of 2-methyl-5-methoxybenzothiazole (III.sub.4e) and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (Hied) which was dried and stored for use.
(242) (2) 2-methyl-5-benzyloxybenzothiazole and 3 mol of 4-vinylbenzyl bromide were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.7d) which was dried and stored for use.
(243) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (III.sub.6d) and 1.2 mol of quaternary ammonium salt (III.sub.7d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (III.sub.5c).
(244) (4) 1 mol of the dye (III.sub.5c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran to produce a solution, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (III.sub.5b).
(245) (5) 1 mol of the sulfur-substituted squaraine dye (III.sub.5b) was added to a dry acetonitrile solvent, to which 2.5 mol of alkyne 2-thienylmethyl p-toluenesulfonate was added. The reaction mixture was stirred at 35 C. for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum, and purified by column chromatography to give a target dye (III.sub.10a).
(246) The compound III.sub.10a was characterized as follows:
(247) .sup.1H-NMR (400 MHz, CDCl.sub.3): 3.67 (s, 1H, OH), 3.83 (m, 5H, CH2&CH.sub.3), 4.01 (t, 2H, CH.sub.2, J=8.0 HZ), 4.13 (s, 2H, CH.sub.2), 5.18 (m, 3H, CH.sub.2&CH.sub.2), 5.42 (s, 2H, CH.sub.2), 5.66 (m, 1H, CH.sub.2), 5.97 (S, 1H, CH), 6.16 (s, 1H, CH), 6.63 (m, 1H, CH), 7.02 (m, 6H, ArH), 7.33 (m, 2H, ArH), 7.45 (m, 8H, ArH), 7.67 (m, 2H, ArH);
(248) .sup.13C-NMR (100 MHz, CDCl.sub.3): 31.30, 52.91, 54.82, 55.80, 63.15, 70.88, 90.61, 111.03, 114.32, 116.49, 118.34, 122.74, 124.16, 125.18, 126.53, 128.50, 130.90, 133.65, 143.11, 147.44, 158.30, 173.64;
(249) HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.37N.sub.2O.sub.4S.sub.4.sup.+, 785.1631; found, 785.1635.
Example 4
(250) Listed herein were only partially representative structures, where in formula (I), XYNCH.sub.2CH.sub.3, based on which, structures of ten representative dyes respectively varying in R.sub.1-R.sub.5 were shown below:
(251) ##STR00041## ##STR00042## ##STR00043##
(252) 1. Synthetic routes of dyes IV.sub.1a-IV.sub.6a were shown as follows:
(253) ##STR00044## ##STR00045##
(254) where the structural formulas of V.sub.n (n=16) were respectively shown as follows:
(255) ##STR00046##
(256) The dyes IV.sub.1a-IV.sub.6a were specifically prepared as follows.
(257) (1) 1 mol of 2-methyl-3-N-ethylbenzimidazole and 2 mol of 1-bromo-2-methoxyethane were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 35 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.1d), which was dried and then stored for use.
(258) (2) 1 mol of squaric acid was added to 50 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 2.2 mol of the quaternary ammonium salt prepared above was added. The reaction mixture was continuously refluxed. After the reaction was confirmed to be completed by TLC, the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IV.sub.1c).
(259) (3) 1 mol of the dye (IV.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IV.sub.1b).
(260) (4) 1 mol of the sulfur-substituted squaraine dye (IV.sub.1b) was added to a dry acetonitrile solvent, to which a bromo-substituted intermediate V.sub.nBr (V.sub.n was selected from V.sub.1-V.sub.6) was added. The reaction mixture was stirred at a temperature for a certain period of time, dried under vacuum, and purified by column chromatography to give a corresponding target dye (IV.sub.1a-IV.sub.6a).
(261) The compounds IV.sub.1a-IV.sub.6a were characterized as follows:
(262) IV.sub.1a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.30 (t, 6H, CH.sub.3, J=8.0 Hz), 2.28 (s, 3H, CH.sub.3), 3.29 (s, 6H, CH.sub.3), 3.57 (t, 4H, CH.sub.2, J=8.0 Hz), 4.01 (m, 6H, CH.sub.2), 4.25 (t, 4H, CH.sub.2, J=8.0 HZ), 6.15 (S, 2H, CH), 7.11 (d, 2H, ArH, J=8.0 Hz), 7.20 (t, 2H, ArH, J=8.0 Hz), 7.38 (q, 4H, ArH, J=8.0 Hz);
(263) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.71, 26.80, 44.13, 44.85, 50.35, 59.02, 69.25, 89.87, 110.08, 114.53, 123.16, 124.57, 128.21, 144.24, 158.10, 172.87, 203.65;
(264) HRMS-ESI: m/z calcd M.sup.+ for C.sub.33H.sub.39N.sub.4S.sup.+, 587.2687; found, 587.2691.
(265) IV.sub.2a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.38H.sub.41N.sub.4O.sub.4S.sup.+, 649.2843; found, 649.2848.
(266) IV.sub.3a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.29 (t, 6H, CH.sub.3, J=8.0 Hz), 3.26 (s, 6H, CH.sub.3), 3.55 (t, 4H, CH.sub.2, J=8.0 Hz), 3.98 (t, 4H, CH.sub.2, J=8.0 Hz), 4.25 (q, 4H, CH.sub.2, J=8.0 Hz), 4.59 (s, 2H, CH.sub.2), 5.15 (m, 1H, CH.sub.2), 5.58 (m, 1H, CH.sub.2), 6.34 (s, 2H, CH), 6.60 (m, 1H, CH), 7.13 (m, 4H, ArH), 7.24 (m, 3H, ArH), 7.44 (m, 5H, ArH);
(267) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.33, 14.87, 42.10, 44.61, 51.11, 59.80, 70.36, 90.54, 110.17, 114.42, 117.49, 123.16, 124.57, 128.21, 129.32, 144.24, 157.12, 171.98;
(268) HRMS-ESI: m/z calcd M.sup.+ for C.sub.39H.sub.43N.sub.4O.sub.3S.sup.+, 647.3050; found, 647.3053.
(269) IV.sub.4a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.40H.sub.47N.sub.4O.sub.3S.sup.+, 663.3363; found, 647.3067.
(270) IV.sub.5a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.27 (t, 6H, CH.sub.3, J=8.0 Hz), 1.53 (m, 8H, CH.sub.2), 1.80 (m, 2H, CH.sub.2), 2.35 (m, 1H, CH), 3.26 (s, 6H, CH.sub.3), 3.58 (t, 4H, CH.sub.2, J=8.0 Hz), 3.99 (t, 4H, CH.sub.2, J=8.0 Hz), 4.05 (s, 2H, CH.sub.2), 4.28 (q, 4H, CH.sub.2, J=8.0 Hz), 6.31 (s, 2H, CH), 7.13 (d, 2H, ArH, J=8.0 Hz), 7.25 (m, 2H, ArH), 7.41 (q, 4H, ArH, J=8.0 Hz);
(271) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.75, 25.35, 28.13, 39.70, 44.89, 50.97, 60.01, 70.25, 91.54, 109.73, 116.49, 122.80, 127.45, 129.52, 145.69, 157.63, 173.40;
(272) HRMS-ESI: m/z calcd M.sup.+ for C.sub.38H.sub.47N.sub.4O.sub.4S.sup.+, 655.3313; found, 655.3315.
(273) IV.sub.6a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.43H.sub.51N.sub.4O.sub.9S.sup.+, 799.3371; found, 799.3375.
(274) 2. The synthetic routes of dye IV.sub.7a was shown as follows:
(275) ##STR00047##
(276) The dye IV.sub.7a was specifically synthesized as follows.
(277) (1) 1 mol of 2-methyl-3-N-ethylbenzimidazole and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.2d), which was dried and then stored for use.
(278) (2) 1 mol of squaric acid was added to 50 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 2.2 mol of the quaternary ammonium salt (IV.sub.2d) prepared above was added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IV.sub.2c).
(279) (3) 1 mol of the dye (IV.sub.2c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran to, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IV.sub.2b).
(280) (4) 1 mol of the sulfur-substituted squaraine dye (IV.sub.2b) was added to a dry acetonitrile solvent, to which 2.5 mol of 4-(methylthio)benzyl chloride was added. The reaction mixture was thermally stirred at room temperature for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum, and purified by column chromatography to give a target dye (IV.sub.7a).
(281) The compound IV.sub.7a was characterized as follows:
(282) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.26 (t, 6H, CH.sub.3, J=8.0 Hz), 2.53 (s, 3H, CH.sub.3), 3.66 (t, 4H, CH.sub.2, J=8.0 Hz), 4.03 (t, 4H, CH.sub.2, J=8.0 Hz), 4.25 (q, 4H, CH.sub.2, J=8.0 Hz), 4.69 (s, 2H, CH.sub.2), 6.29 (S, 2H, CH), 7.12 (m, 6H, ArH), 7.27 (m, 3H, ArH), 7.47 (m, 3H, ArH);
(283) .sup.13C-NMR (100 MHz, CDCl.sub.3): 13.79, 42.04, 43.99, 51.58, 63.74, 92.32, 108.45, 117.18, 119.30, 123.06, 127.09, 129.74, 137.70, 146.54, 158.65, 174.04;
(284) HRMS-ESI: m/z calcd M.sup.+ for C.sub.36H.sub.39N.sub.4O.sub.3S.sub.2.sup.+, 639.2458; found, 639.2461.
(285) 3. The synthetic route of dye IV.sub.8a was shown as follows:
(286) ##STR00048##
(287) The dye IV.sub.8a was specifically prepared as follows.
(288) (1) 1 mol of 2-methyl-3-N-ethylbenzimidazole and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.2d), which was dried and stored for use.
(289) (2) 1 mol of 2-methyl-3-N-ethylbenzimidazole and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.3d), which was dried and stored for use.
(290) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (IV.sub.2d) and 1.2 mol of the quaternary ammonium salt (IV.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IV.sub.3c).
(291) (4) 1 mol of the dye (IV.sub.3c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IV.sub.3b).
(292) (5) 1 mol of the sulfur-substituted squaraine dye (IV.sub.3b) was added to a dry acetonitrile solvent, to which 4 mol of allyl bromide was added. The reaction mixture was thermally stirred at room temperature for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum, and purified by column chromatography to give a target dye (IV.sub.5a).
(293) The compound IV.sub.5a was characterized as follows:
(294) HRMS-ESI: m/z calcd M.sup.+ for C.sub.36H.sub.37N.sub.4O.sub.2S.sup.+, 589.2632; found, 589.2638.
(295) 4. The synthetic route of dye IV.sub.9a was shown as follows:
(296) ##STR00049## ##STR00050##
(297) The dye IV.sub.9a was specifically prepared as follows.
(298) (1) 1 mol of 2-methyl-3-N-ethyl-5-bromobenzimidazole and 3 mol of diethylene glycol tosylate were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.4d), which was dried and stored for use.
(299) (2) 1 mol of 2-methyl-3-N-ethyl-5-methylbenzimidazole and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.5d), which was dried and stored for use.
(300) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (IV.sub.4d) and 1.2 mol of the quaternary ammonium salt (IV.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IV.sub.4c).
(301) (4) 1 mol of the dye (IV.sub.4c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IV.sub.4b).
(302) (5) 1 mol of the sulfur-substituted squaraine dye (IV.sub.4b) was added to a dry acetonitrile solvent, to which 2 mol of phenyl 2-bromoacetate was added. After stirred at 40 C. for 2 h, the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (IV.sub.9a).
(303) The compound IV.sub.9a was characterized as follows:
(304) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.28 (m, 6H, CH.sub.3), 2.49 (s, 3H, CH.sub.3), 3.56 (m, 6H, CH.sub.2), 3.98 (S, 2H, CH.sub.2), 4.27 (m, 6H, CH.sub.2), 4.89 (s, 2H, CH.sub.2), 5.95 (s, 1H, CH), 6.14 (s, 1H, CH), 7.09 (m, 3H, ArH), 7.22 (m, 7H, ArH), 7.36 (m, 4H, ArH), 7.48 (m, 2H, ArH);
(305) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.08, 21.93, 36.74, 42.16, 47.51, 53.90, 57.15, 61.78, 69.23, 88.71, 95.44, 107.80, 110.72, 114.63, 117.15, 119.03, 121.52, 123.04, 127.71, 129.94, 137.83, 146.40, 158.65, 173.11;
(306) HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.44BrN.sub.4O.sub.5S.sup.+, 819.2210; found, 819.2214.
(307) 5. The synthetic route of dye IV.sub.10a was shown as follows:
(308) ##STR00051## ##STR00052##
(309) The dye IV.sub.10a was specifically prepared as follows.
(310) (1) 1 mol of 2-methyl-3-N-ethyl-5-methoxybenzimidazole (IV.sub.4e) and 3 mol of bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.6d) which was dried and stored for use.
(311) (2) 1 mol of 2-methyl-3-N-ethyl-5-benzyloxybenzimidazole (IV.sub.5e) and 3 mol of 4-vinylbenzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.7d) which was dried and stored for use.
(312) (3) 1 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 0.8 mol of the quaternary ammonium salt (IV.sub.6d) and 1.2 mol of quaternary ammonium salt (IV.sub.7d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IV.sub.5c).
(313) (4) 1 mol of the dye (IV.sub.5c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IV.sub.5b).
(314) (5) 1 mol of the sulfur-substituted squaraine dye (IV.sub.5b) was added to a dry acetonitrile solvent, to which 2.5 mol of ethyl bromoacetate was added. The reaction mixture was stirred at 40 C. for 2 h. After cooled to room temperature, the reaction mixture was dried under vacuum, and purified by column chromatography to give a target dye (IV.sub.10a).
(315) The compound IV.sub.10a was characterized as follows:
(316) HRMS-ESI: m/z calcd M.sup.+ for C.sub.47H.sub.49N.sub.4O.sub.6S.sup.+, 797.3367; found, 797.3371.
Example 5
(317) The asymmetric dyes were further respectively substituted with different groups at the middle position to obtain asymmetric target dyes (V.sub.1a-V.sub.10a), which were shown as follows with XO and YNCH.sub.2CH.sub.3 in formula (I):
(318) ##STR00053## ##STR00054## ##STR00055##
(319) 1. The synthetic routes of dyes V.sub.1a-V.sub.6a were shown as follows:
(320) ##STR00056##
(321) where the structural formulas of Y.sub.n(n=16) were respectively shown as follows:
(322) ##STR00057##
(323) The dyes V.sub.1a-V.sub.6a were specifically prepared as follows.
(324) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (V.sub.4e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.1d), which was dried and then stored for use.
(325) (2) 1 mol of 2-methylbenzoxazole (V.sub.5e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.1d), which was dried and stored for use.
(326) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.1d) and 1 mol of the quaternary ammonium salt (V.sub.1d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (V.sub.1c).
(327) (4) 1 mol of the dye (V.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (V.sub.1b).
(328) (5) 1 mol of the sulfur-substituted squaraine dye (V.sub.5b) was added to a dry acetonitrile solvent, to which 2.5 mol of a bromo-substituted intermediate Y.sub.nBr (Y.sub.n was selected from Y.sub.1-Y.sub.6) was added. The reaction mixture was stirred at room temperature or under heating for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a corresponding target dye (V.sub.1a-V.sub.6a).
(329) The compounds V.sub.1a-V.sub.6a were characterized as follows:
(330) V.sub.1a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.30 (m, 6H, CH.sub.3), 1.59 (s, 6H, CH.sub.3), 4.36 (m, 4H, CH.sub.2), 4.79 (S, 2H, CH.sub.2), 5.98 (s, 1H, CH), 6.22 (s, 1H, CH), 7.08 (m, 2H, ArH), 7.23 (m, 4H, ArH), 7.37 (m, 3H, ArH), 7.59 (m, 3H, ArH);
(331) .sup.13C-NMR (100 MHz, CDCl.sub.3): 13.81, 14.45, 24.74, 42.20, 46.51, 55.09, 89.63, 96.44, 108.70, 111.52, 115.01, 117.85, 120.03, 121.48, 124.90, 127.71, 130.94, 137.13, 141.65, 152.97, 158.72, 173.10, 187.23;
(332) HRMS-ESI: m/z calcd M.sup.+ for C.sub.34H.sub.32FN.sub.2O.sub.2S.sup.+, 819.2210; found, 819.2215.
(333) V.sub.2a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.34H.sub.32ClN.sub.2O.sub.2S.sup.+, 567.1868; found, 567.1871.
(334) V.sub.3a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.33 (m, 6H, CH.sub.3), 1.57 (s, 6H, CH.sub.3), 4.35 (m, 4H, CH.sub.2), 4.72 (S, 2H, CH.sub.2), 5.91 (m, 1H, CH.sub.2), 6.01 (s, 1H, CH), 6.19 (m, 1H, CH.sub.2), 6.23 (S, 1H, CH), 6.28 (m, 1H, CH), 7.09 (m, 3H, ArH), 7.23 (m, 3H, ArH), 7.49 (m, 2H, ArH);
(335) .sup.13C-NMR (100 MHz, CDCl.sub.3): 12.79, 13.88, 25.10, 45.63, 51.90, 55.61, 91.44, 98.28, 109.15, 112.42, 115.11, 118.60, 120.56, 122.41, 126.03, 131.12, 135.84, 142.80, 152.52, 155.90, 174.22;
(336) HRMS-ESI: m/z calcd M.sup.+ for C.sub.31H.sub.31N.sub.2O.sub.3S.sup.+, 511.2050; found, 511.2054.
(337) V4a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.35H.sub.33N.sub.2O.sub.3S.sup.+, 561.2206; found, 561.2211.
(338) V.sub.5a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.30 (m, 6H, CH.sub.3), 1.58 (s, 6H, CH.sub.3), 3.22 (q, 4H, CH.sub.2, J=8.0 HZ), 4.15 (m, 6H, CH.sub.2), 5.99 (s, 1H, CH), 6.18 (s, 1H, CH), 7.15 (m, 3H, ArH), 7.28 (m, 6H, ArH), 7.48 (m, 3H, ArH), 8.89 (s, 1H, NH);
(339) .sup.13C-NMR (100 MHz, CDCl.sub.3): 13.03, 14.17, 24.90, 27.87, 34.75, 45.60, 56.51, 90.24, 99.05, 109.10, 112.89, 114.03, 117.50, 109.84, 121.40, 127.31, 130.48, 134.80, 143.77, 150.92, 156.10, 172.62;
(340) HRMS-ESI: m/z calcd M.sup.+ for C.sub.37H.sub.37AsN.sub.3O.sub.3S.sub.3.sup.+, 742.1208; found, 742.1213.
(341) V.sub.6a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.39H.sub.41BN.sub.3O.sub.5S.sup.+, 674.2854; found, 674.2858.
(342) 2. The synthetic route of dye V.sub.7a was shown as follows:
(343) ##STR00058##
(344) The dye V.sub.7a was specifically synthesized as follows.
(345) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (V.sub.4e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.3d), which was dried and stored for use.
(346) (2) 1 mol of 2-methylbenzoxazole (V.sub.5e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.4d), which was dried and stored for use.
(347) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.3d) and 1 mol of the quaternary ammonium salt (V.sub.4d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. The reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (V.sub.2C).
(348) (4) 1 mol of the dye (V.sub.2c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (V.sub.2b).
(349) (5) 1 mol of the sulfur-substituted squaraine dye (V.sub.2b) was added to a dry acetonitrile solvent, to which 2.5 mol of a 3-bromopropyl triethoxysilane intermediate was added. The mixture was stirred under heating for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (V.sub.7a).
(350) The compound V.sub.7a was characterized as follows:
(351) .sup.1H-NMR (400 MHz, CDCl.sub.3): 0.48 (t, 2H, CH.sub.2, J=8.0 Hz), 1.20 (t, 9H, CH.sub.3, J=8.0 Hz), 1.51 (s, 6H, CH.sub.3), 2.10 (m, 2H, CH.sub.2), 3.24 (q, 2H, CH.sub.2, J=8.0 Hz), 3.68 (m, 6H, CH.sub.2), 3.88 (m, 8H, CH.sub.2), 6.03 (s, 1H, CH), 6.21 (s, 1H, CH), 7.12 (m, 3H, ArH), 7.29 (m, 3H, ArH), 7.46 (m, 2H, ArH);
(352) .sup.13C-NMR (100 MHz, CDCl.sub.3): 15.70, 17.38, 18.49, 23.35, 35.80, 45.22, 55.07, 58.40, 62.65, 91.53, 99.70, 110.01, 112.60, 114.03, 115.94, 118.20, 121.35, 123.09, 127.40, 130.25, 136.50, 143.91, 149.73, 154.10, 173.30;
(353) HRMS-ESI: m/z calcd M.sup.+ for C.sub.36H.sub.47N.sub.20?SSi.sup.+, 679.2868; found, 679.2872.
(354) 3. The synthetic route of dye V.sub.8a was shown as follows:
(355) ##STR00059## ##STR00060##
(356) The dye V.sub.8a was specifically prepared as follows.
(357) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (V.sub.4e) and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.5d), which was dried and stored for use.
(358) (2) 1 mol of 2-methylbenzoxazole (V.sub.5e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.5d), which was dried and stored for use.
(359) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.5d) and 1 mol of the quaternary ammonium salt (V.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (V.sub.3c).
(360) (4) 1 mol of the dye (V.sub.5c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (V.sub.3b).
(361) (5) 1 mol of the sulfur-substituted squaraine dye (V.sub.3b) was added to a dry acetonitrile solvent, to which 2.5 mol of a 4-(2-trimethylsilyl ethynyl benzyl bromide) intermediate was added. The mixture was stirred under heating for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (V.sub.8a).
(362) The compound V.sub.8a was characterized as follows:
(363) HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.43N.sub.2O.sub.3SSi.sup.+, 707.2758; found, 707.2763.
(364) 4. The synthetic route of dye V.sub.9a was shown as follows:
(365) ##STR00061## ##STR00062##
(366) The dye V.sub.9a was specifically prepared as follows.
(367) (1) 1 mol of 2,3,3-trimethyl-5-bromo-3H-indoline (V.sub.6e) and 3 mol of ethanol, 2-(2-hydroxyethoxy)-, 1-(4-Methylbenzenesulfonate) were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.7d) which was dried and stored for use.
(368) (2) 1 mol of 2-methyl-5-methylbenzoxazole (V.sub.7e) and 3 mol of benzyl bromide were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (Vsd) which was dried and stored use.
(369) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.7d) and 1 mol of the quaternary ammonium salt (V.sub.8d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (V.sub.4c).
(370) (4) 1 mol of the dye (V.sub.4c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (V.sub.4b).
(371) (5) 1 mol of the sulfur-substituted squaraine dye (V.sub.4b) was added to a dry acetonitrile solvent, to which 2.5 mol of a 4-phenoxybenzyl bromide intermediate was added. The reaction mixture was stirred under heating for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to a give target dye (V.sub.9a).
(372) The compound V.sub.9a was characterized as follows:
(373) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.50 (s, 6H, CH.sub.3), 2.38 (s, 3H, CH.sub.3), 3.59 (m, 6H, CH.sub.2), 4.15 (t, 2H, CH.sub.2, J=8.0 Hz), 4.63 (s, 2H, CH.sub.2), 4.88 (s, 2H, CH.sub.2), 6.04 (s, 1H, CH), 6.28 (s, 1H, CH), 7.07 (m, 4H, ArH), 7.21 (m, 8H, ArH), 7.36 (m, 4H, ArH), 7.51 (m, 3H, ArH), 7.79 (m, 1H, ArH);
(374) .sup.13C-NMR (100 MHz, CDCl.sub.3): 21.17, 25.35, 42.80, 52.42, 55.91, 61.33, 66.80, 70.43, 89.58, 98.04, 110.25, 111.82, 112.51, 114.26, 115.75, 117.60, 119.31, 121.52, 123.14, 124.26, 127.30, 130.65, 132.81, 136.70, 145.22, 149.43, 154.49, 174.20;
(375) HRMS-ESI: m/z calcd M.sup.+ for C.sub.48H.sub.44BrN.sub.2O.sub.5S.sup.+, 839.2149; found, 839.2153.
(376) 5. The synthetic route of dye V.sub.10a was shown as follows:
(377) ##STR00063## ##STR00064##
(378) The dye V.sub.10a was specifically prepared as follows.
(379) (1) 1 mol of 2,3,3-trimethyl-5-methoxy-3H-indoline (V.sub.8e) and 2 mol of octadecyl bromide were added to 20 mL of dry 1,2-dichlorobenzene, to which potassium iodide was added as a catalyst. Then the reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.9d) which was dried and stored for use.
(380) (2) 1 mol of 2-methyl-5-benzyloxybenzoxazole (V.sub.9e) and 3 mol of bromoheptane were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.10d) which was dried and stored for use.
(381) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.9d) and 1 mol of quaternary ammonium salt (V.sub.10d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (V.sub.5c).
(382) (4) 1 mol of the dye (V.sub.5c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (V.sub.5b).
(383) (5) 1 mol of the sulfur-substituted squaraine dye (V.sub.5b) was added to a dry acetonitrile solvent, to which 2.5 mol of a propargyl bromide intermediate was added. The reaction mixture was stirred under heating for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (V.sub.10a).
(384) The compound V.sub.10a was characterized as follows:
(385) HRMS-ESI: m/z calcd M.sup.+ for C.sub.58H.sub.77N.sub.2O.sub.4S.sup.+, 897.5599; found, 897.5603.
Example 6
(386) The asymmetric dyes were further respectively substituted with different groups at the middle position to obtain asymmetric target dyes (VI.sub.1a-VI.sub.10a) which were shown as follows with XC(CH.sub.3).sub.2 and YS in formula (I):
(387) ##STR00065## ##STR00066## ##STR00067## ##STR00068##
(388) 1. Synthetic routes of dyes VI.sub.1a-VI.sub.6a were shown as follows:
(389) ##STR00069##
(390) where the structural formulas of A.sub.n (n=16) were respectively shown as follows:
(391) ##STR00070##
(392) The dyes VI.sub.1a-VI.sub.6a were specifically prepared as follows.
(393) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (V.sub.4e), 3 mol of ethyl iodide and 0.1 mol of potassium iodide were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.1d) which was dried and stored for use.
(394) (2) 1 mol of 2-methylbenzothiazole (VI.sub.1e), 3 mol of ethyl iodide and 0.1 mol of potassium iodide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 48 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.1d) which was dried and stored for use.
(395) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.1d) and 1 mol of the quaternary ammonium salt (VI.sub.1d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VI.sub.1c).
(396) (4) 1 mol of the dye (VI.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VI.sub.1b).
(397) (5) 1 mol of the sulfur-substituted squaraine dye (VI.sub.1b) was added to dry acetonitrile, to which 2.5 mol of a bromo-substituted intermediate A.sub.nBr (A.sub.n was selected from A.sub.1-A.sub.6) was added. The reaction mixture was stirred at room temperature or under heating for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a corresponding target dye (VI.sub.1a-VI.sub.6a).
(398) The compounds VI.sub.1a-VI.sub.6a were characterized as follows:
(399) VI.sub.1a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.48 (s, 6H, CH.sub.3), 3.49 (m, 2H, CH.sub.2), 3.76 (s, 6H, CH.sub.2, CH&CH.sub.3), 5.42 (s, 2H, CH.sub.2), 6.06 (s, 1H, CH), 6.31 (s, 1H, CH), 7.11 (m, 4H, ArH), 7.28 (m, 9H, ArH), 7.49 (m, 5H, ArH);
(400) .sup.13C-NMR (100 MHz, CDCl.sub.3): 24.90, 33.41, 41.34, 52.26, 55.05, 58.13, 90.06, 99.53, 108.70, 111.42, 113.95, 116.07, 117.94, 120.15, 123.81, 126.34, 130.40, 133.18, 136.60, 143.13, 148.35, 155.02, 173.73, 205.40;
(401) HRMS-ESI: m/z calcd M.sup.+ for C.sub.42H.sub.36N.sub.3O.sub.3S.sub.2.sup.+, 694.2193; found, 694.2196.
(402) VI.sub.2a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.38N.sub.3O.sub.3S.sub.2.sup.+, 720.2349; found, 720.2353.
(403) VI.sub.3a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.58 (s, 6H, CH.sub.3), 3.46 (m, 8H, CH.sub.2), 3.78 (m, 5H, CH2&CH), 5.44 (s, 2H, CH.sub.2), 6.13 (s, 1H, CH), 6.37 (s, 1H, CH), 7.10 (m, 4H, ArH), 7.24 (m, 4H, ArH), 7.33 (m, 5H, ArH), 7.52 (m, 5H, ArH);
(404) .sup.13C-NMR (100 MHz, CDCl.sub.3): 24.90, 33.41, 41.34, 52.26, 55.05, 58.13, 90.06, 99.53, 108.70, 111.42, 113.95, 116.07, 117.94, 120.15, 123.81, 126.34, 130.40, 133.18, 136.60, 143.13, 148.35, 155.02, 173.73, 205.40;
(405) HRMS-ESI: m/z calcd M.sup.+ for C.sub.45H.sub.42N.sub.3O.sub.5S.sub.2.sup.+, 768.2560; found, 768.2565.
(406) VI.sub.4a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.36N.sub.3O.sub.3S.sub.2.sup.+, 718.2193; found, 768.2597.
(407) VI.sub.5a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.57 (s, 6H, CH.sub.3), 3.50 (m, 2H, CH.sub.2), 3.79 (m, 3H, CH&CH.sub.2), 5.42 (s, 2H, CH.sub.2), 6.16 (s, 1H, CH), 6.39 (s, 1H, CH), 7.08 (m, 4H, ArH), 7.23 (m, 9H, ArH), 7.35 (m, 5H, ArH), 7.50 (m, 5H, ArH);
(408) .sup.13C-NMR (100 MHz, CDCl.sub.3): 25.75, 33.90, 42.46, 53.02, 54.11, 91.39, 98.80, 108.61, 110.20, 111.87, 113.52, 116.10, 117.33, 118.92, 120.25, 122.19, 123.50, 126.81, 131.04, 133.50, 136.93, 143.10, 148.42, 155.08, 174.11;
(409) HRMS-ESI: m/z calcd M.sup.+ for C.sub.47H.sub.38N.sub.3O.sub.3S.sub.2.sup.+, 756.2349; found, 756.2353.
(410) VI.sub.6a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.37N.sub.3O.sub.5S.sub.2, 751.2175; found, 752.2179.
(411) 2. The synthetic route of dye VI.sub.7a was shown as follows:
(412) ##STR00071##
(413) The dye VI.sub.7a was specifically synthesized as follows.
(414) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (V4e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.2d) which was dried and stored for use.
(415) (2) 1 mol of 2-methylbenzoxazole (VI.sub.1e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.2d) which was dried and stored for use.
(416) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.2d) and 1 mol of the quaternary ammonium salt (VI.sub.2d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VI.sub.2c).
(417) (4) 1 mol of the dye (VI.sub.2c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson s reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VI.sub.2b).
(418) (5) 1 mol of the sulfur-substituted squaraine dye (VI.sub.2b) was added to dry acetonitrile, to which 2.5 mol of an N-chloromethyl phthalimide intermediate was added. The reaction mixture was stirred under heating for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VI.sub.7a).
(419) The compound VI.sub.7a was characterized as follows:
(420) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.49 (s, 6H, CH.sub.3), 3.66 (m, 6H, CH.sub.2), 3.95 (m, 2H, CH.sub.2), 5.33 (s, 2H, CH.sub.2), 6.15 (s, 1H, CH), 6.38 (s, 1H, CH), 7.10 (m, 3H, ArH), 7.18 (m, 2H, ArH), 7.37 (m, 5H, ArH), 7.49 (m, 2H, ArH);
(421) .sup.13C-NMR (100 MHz, CDCl.sub.3): 24.75, 44.80, 54.25, 55.83, 61.62, 63.30, 88.90, 98.11, 109.15, 111.09, 114.41, 115.20, 118.73, 121.65, 124.29, 126.30, 130.04, 133.81, 136.60, 145.89, 147.55, 153.90, 173.07;
(422) HRMS-ESI: m/z calcd M.sup.+ for C.sub.36H.sub.32N.sub.3O.sub.5S2.sup.+, 650.1778; found, 650.1783.
(423) 3. The synthetic route of dye VI.sub.8a was shown as follows:
(424) ##STR00072## ##STR00073##
(425) The dye VIsa was specifically prepared as follows.
(426) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (V.sub.4e) and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.5d) which was dried and stored for use.
(427) (2) 1 mol of 2-methylbenzothiazole (VI.sub.1e) and 2 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.3d) which was dried and stored for use.
(428) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.5d) and 1 mol of the quaternary ammonium salt (VI.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VI.sub.4c).
(429) (4) 1 mol of the dye (VI.sub.4c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VI.sub.3b).
(430) (5) 1 mol of the sulfur-substituted squaraine dye (VI.sub.3b) was added to dry acetonitrile, to which 2.5 mol of a 2-chloroethoxyethyl phthalimide intermediate was added. The reaction mixture was stirred at 60 C. for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VI.sub.8a).
(431) The compound VIsa was characterized as follows:
(432) HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.40N.sub.3O.sub.5S.sub.2.sup.+, 754.2404; found, 754.2408.
(433) 4. The synthetic route of dye VI.sub.9a was shown as follows:
(434) ##STR00074##
(435) The dye VI.sub.9a was specifically prepared as follows.
(436) (1) 1 mol of 2,3,3-trimethyl-5-bromo-3H-indoline (V.sub.6e) and 3 mol of ethanol, 2-(2-hydroxyethoxy)-, 1-(4-Methylbenzenesulfonate) were added to 20 mL of dry 1,2-dichlorobenzene. The reaction was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.7d) which was dried and stored for use.
(437) (2) 1 mol of 2, 5-dimethylbenzothiazole (VI.sub.2e) and 3 mol of benzyl bromide were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.4d) which was dried and stored for use.
(438) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.7d) and 1 mol of the quaternary ammonium salt (VI.sub.4d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VI.sub.4c).
(439) (4) 1 mol of the dye (VI.sub.4c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VI.sub.4b).
(440) (5) 1 mol of the sulfur-substituted squaraine dye (VI.sub.4b) was added to dry acetonitrile, to which 2.5 mol of 2-aminoethoxyethyl p-toluenesulfonate was added. The reaction mixture was stirred at 35 C. for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VI.sub.9a).
(441) The compound VI.sub.9a was characterized as follows:
(442) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.52 (s, 6H, CH.sub.3), 2.43 (s, 3H, CH.sub.3), 3.03 (m, 4H, CH.sub.2), 3.73 (m, 10H, CH.sub.2), 4.09 (t, 2H, CH.sub.2, J=8.0 Hz), 5.13 (s, 2H, CH.sub.2, J=8.0 Hz), 6.14 (s, 1H, CH), 6.39 (s, 1H, CH), 7.06 (m, 2H, ArH), 7.19 (m, 6H, ArH), 7.44 (m, 3H, ArH);
(443) .sup.13C-NMR (100 MHz, CDCl.sub.3): 20.89, 24.70, 33.81, 41.60, 50.33, 54.60, 61.52, 69.04, 73.11, 89.45, 100.16, 108.04, 111.35, 113.26, 114.90, 118.37, 121.50, 125.18, 126.90, 131.50, 134.96, 136.82, 144.03, 147.78, 152.60, 173.15;
(444) HRMS-ESI: m/z calcd M.sup.+ for C.sub.39H.sub.43BrN.sub.3O.sub.4S.sub.2.sup.+, 760.1873; found, 760.1878.
(445) 5. The synthetic route of dye VI.sub.10a was shown as follows:
(446) ##STR00075##
(447) The dye VI.sub.10a was specifically prepared as follows.
(448) (1) 1 mol of 2,3,3-trimethyl-5-methoxy-3H-indoline (V.sub.8e) and 2 mol of octadecyl bromide were added to 20 mL of dry 1,2-dichlorobenzene, to which potassium iodide was added as a catalyst. Then the reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.9d) which was dried and stored for use.
(449) (2) 1 mol of 2-methyl-5-benzyloxybenzoxazole (VI.sub.3e) and 3 mol of bromoheptane were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.5d) which was dried and stored for use.
(450) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.9d) and 1 mol of the quaternary ammonium salt (VI.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VI.sub.5c).
(451) (4) 1 mol of the dye (VI.sub.5c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VI.sub.5b).
(452) (5) 1 mol of the sulfur-substituted squaraine dye (VI.sub.5b) was added to dry acetonitrile, to which 2 mol of a butane sultone intermediate was added. The reaction mixture was stirred at 35 C. for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VI.sub.10a).
(453) The compound VI.sub.10a was characterized as follows:
(454) HRMS-ESI: m/z calcd [M+H].sup.+ for C.sub.58H.sub.81N.sub.2O.sub.6S.sub.3, 997.5179; found, 997.5185.
Example 7
(455) The asymmetric dyes were further respectively substituted with different groups at the middle position to obtain asymmetric dyes (VII.sub.1a-VII.sub.10a) which were shown as follows with XC(CH.sub.3).sub.2 and YNC.sub.2H.sub.5 in formula (I):
(456) ##STR00076## ##STR00077## ##STR00078##
(457) 1 The synthetic routes of dyes VII.sub.1a-VII.sub.6a were shown as follows:
(458) ##STR00079##
(459) where the structural formulas of W.sub.n (n=16) were respectively shown as follows:
(460) ##STR00080##
(461) The dyes VII.sub.1a-VII.sub.6a were specifically prepared as follows.
(462) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (V.sub.1e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.1d) which was dried and stored for use.
(463) (2) 1 mol of 2-methyl-1-N-ethylbenzimidazole (VII.sub.1e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VII.sub.1d) which was dried and stored for use.
(464) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.1d) and 1 mol of the quaternary ammonium salt (VII.sub.1d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VII.sub.1c).
(465) (4) 1 mol of the dye (VII.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VII.sub.1b).
(466) (5) 1 mol of the sulfur-substituted squaraine dye (VII.sub.1b) was added to dry acetonitrile, to which 2.5 mol of a bromo-substituted intermediate W.sub.nBr (W.sub.n was selected from W.sub.1-W.sub.6) was added. The reaction mixture was stirred at room temperature or under heating for a certain period of time until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a corresponding target dye (VII.sub.1a-VII.sub.6a).
(467) The compounds VII.sub.1a-VII.sub.6a were characterized as follows:
(468) VI.sub.1a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.33 (m, 6H, CH.sub.3), 1.44 (t, 3H, CH.sub.3, J=8.0 Hz), 1.55 (s, 6H, CH.sub.3), 3.16 (t, 2H, CH.sub.2, J=8.0 Hz), 4.12 (m, 6H, CH.sub.2), 4.59 (q, 2H, CH.sub.2, J=8.0 Hz), 6.17 (s, 1H, CH), 6.39 (s, 1H, CH), 7.11 (m, 3H, ArH), 7.24 (m, 3H, ArH), 7.47 (m, 2H, ArH);
(469) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.13, 25.70, 33.85, 43.40, 44.36, 47.90, 56.02, 89.90, 99.25, 108.50, 111.71, 114.15, 117.08, 120.46, 123.21, 124.45, 128.75, 143.56, 158.18, 172.70, 203.50;
(470) HRMS-ESI: m/z calcd M.sup.+ for C.sub.31H.sub.35ClN.sub.3OS.sup.+, 532.2184; found, 532.2188.
(471) VII.sub.2a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.31H.sub.36N.sub.3O.sub.2S.sup.+, 514.2523; found, 514.2527.
(472) VII.sub.3a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.44H.sub.46N.sub.3O.sub.2S.sup.+, 680.3305; found, 680.3308.
(473) VII.sub.4a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.38H.sub.40N.sub.3O.sub.3S.sub.2.sup.+, 650.2506; found, 650.2510.
(474) VII.sub.5a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.36H.sub.38N.sub.3O.sub.3S.sub.2.sup.+, 592.2628; found, 592.2632.
(475) VII.sub.6a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.36H.sub.37IN.sub.3OS.sup.+, 686.1697; found, 686.1701.
(476) 2. The synthetic route of dye VII.sub.7a was shown as follows:
(477) ##STR00081##
(478) The dye VII.sub.7a was specifically synthesized as follows.
(479) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (Vie) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.2d) which was dried and stored for use.
(480) (2) 1 mol of 1-N-ethyl-2-methylbenzimidazole (VII.sub.1e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VII.sub.2d) which was dried and stored for use.
(481) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.2d) and 1 mol of the quaternary ammonium salt (VII.sub.2d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VII.sub.2c).
(482) (4) 1 mol of the dye (VII.sub.2c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VII.sub.2b).
(483) (5) 1 mol of the sulfur-substituted squaraine dye (VII.sub.2b) was added to dry acetonitrile, to which 2.5 mol of cyclohexylmethyl bromide was added. The reaction mixture was stirred under heating until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VII.sub.7a).
(484) The compound VII.sub.7a was characterized as follows:
(485) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.29 (m, 5H, CH.sub.3&CH.sub.2), 1.49 (m, 8H, CH.sub.2), 1.65 (m, 7H, CH.sub.3&CH), 2.83 (d, 2H, CH.sub.2, J=8.0 Hz), 3.68 (m, 4H, CH.sub.2), 3.92 (m, 6H, CH.sub.2), 6.15 (s, 1H, CH), 6.38 (s, 1H, CH), 7.10 (m, 3H, ArH), 7.27 (m, 3H, ArH), 7.49 (m, 2H, ArH);
(486) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.37, 25.80, 26.92, 32.64, 34.85, 42.40, 52.85, 63.30, 90.05, 100.61, 109.44, 112.17, 113.30, 115.90, 117.35, 120.82, 123.08, 124.19, 127.40, 143.31, 158.25, 173.90;
(487) HRMS-ESI: m/z calcd M.sup.+ for C.sub.36H.sub.44N.sub.3O.sub.3S.sup.+, 598.3098; found, 598.3103.
(488) 3. The synthetic route of dye VII.sub.8a was shown as follows:
(489) ##STR00082##
(490) The dye VII.sub.8a was specifically prepared as follows.
(491) (1) 1 mol of 2,3,3-trimethyl-3H-indoline (V.sub.1e) and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (Vsd) which was dried and stored for use.
(492) (2) 1 mol of 1-N-ethyl-2-methylbenzimidazole (VII.sub.1e) and 2 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VII.sub.3d) which was dried and stored for use.
(493) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.5d) and 1 mol of the quaternary ammonium salt (VII.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VII.sub.3e).
(494) (4) 1 mol of the dye (VII.sub.3c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VII.sub.3b).
(495) (5) 1 mol of the sulfur-substituted squaraine dye (VII.sub.3b) was added to dry acetonitrile, to which 2.5 mol of 2-p-toluenesulfonate glyceryl was added. The reaction mixture was stirred under heating until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VII.sub.8a).
(496) The compound VII.sub.8a was characterized as follows:
(497) HRMS-ESI: m/z calcd M.sup.+ for C.sub.38H.sub.42N.sub.3O.sub.4S.sup.+, 636.2891; found, 636.2896.
(498) 4. The synthetic route of dye VII.sub.9a was shown as follows:
(499) ##STR00083##
(500) The dye VII.sub.9a was specifically prepared as follows.
(501) (1) 1 mol of 2,3,3-trimethyl-5-bromo-3H-indoline V.sub.6e) and 3 mol of ethanol, 2-(2-hydroxyethoxy)-, 1-(4-Methylbenzenesulfonate) were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.7d) which was dried and stored for use.
(502) (2) 1 mol of 2,5-dimethylbenzothiazole (Vibe) and 3 mol of benzyl bromide were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VII.sub.4d) which was dried and stored for use.
(503) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.7d) and 1 mol of the quaternary ammonium salt (VII.sub.4d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VII.sub.4c).
(504) (4) 1 mol of the dye (VII.sub.4c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VII.sub.4b).
(505) (5) 1 mol of the sulfur-substituted squaraine dye (VII.sub.4b) was added to dry acetonitrile, to which 2.5 mol of N-methyl-nitroimidazole methyl bromide was added. The reaction mixture was stirred under heating until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to a give target dye (VII.sub.9a).
(506) The compound VII.sub.9a was characterized as follows:
(507) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.31 (t, 3H, CH.sub.3, J=8.0 Hz), 1.58 (s, 6H, CH.sub.3), 2.45 (s, 3H, CH.sub.3), 3.72 (m, 11H, CH.sub.3&CH.sub.2), 4.12 (m, 4H, CH.sub.2), 6.19 (s, 1H, CH), 6.42 (s, 1H, CH), 7.12 (m, 4H, ArH), 7.33 (m, 5H, ArH), 7.48 (m, 3H, ArH);
(508) .sup.13C-NMR (100 MHz, CDCl.sub.3): 15.35, 21.60, 26.93, 32.08, 44.10, 50.42, 53.95, 61.30, 67.05, 70.61, 89.10, 99.53, 109.60, 112.45, 113.03, 113.95, 115.50, 117.81, 118.30, 120.26, 123.70, 124.18, 129.40, 143.38, 158.72, 174.60;
(509) HRMS-ESI: m/z calcd M.sup.+ for C.sub.42H.sub.44BrN.sub.6O.sub.5S.sub.+, 823.2272; found, 823.2275.
(510) 5. The synthetic route of dye VII.sub.10a was shown as follows:
(511) ##STR00084## ##STR00085##
(512) The dye VII.sub.10a was specifically prepared as follows.
(513) (1) 1 mol of 2,3,3-trimethyl-5-methoxy-3H-indoline (V.sub.8e) and 2 mol of bromopropane were added to 20 mL of dry 1,2-dichlorobenzene, to which potassium iodide was added as a catalyst. Then the reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.9d) which was dried and stored for use.
(514) (2) 1 mol of 2-methyl-5-benzyloxybenzoxazole (VII.sub.3e) and 3 mol of bromopropane were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VII.sub.5d) which was dried and stored for use.
(515) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.9d) and 1 mol of the quaternary ammonium salt (VII.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VII.sub.5c).
(516) (4) 1 mol of the dye (VII.sub.5c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VII.sub.5b).
(517) (5) 1 mol of the sulfur-substituted squaraine dye (VI.sub.5b) was added to dry acetonitrile, to which 2.5 mol of methyltriazole methyl bromide was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VII.sub.10a).
(518) The compound VII.sub.10a was characterized as follows:
(519) HRMS-ESI: m/z calcd M.sup.+ for C.sub.43H.sub.49N.sub.6O.sub.3S.sup.+, 729.3581; found, 729.3585.
Example 8
(520) The asymmetric dyes were further respectively substituted with different groups at the middle position to obtain exemplary asymmetric target dyes (VIII.sub.1a-VIII.sub.10a) which were shown as follows with XS and YO in formula (I):
(521) ##STR00086## ##STR00087## ##STR00088##
(522) 1. The synthetic routes of dyes VII.sub.1a-VIII.sub.6a were shown as follows:
(523) ##STR00089##
(524) where the structural formulas of E.sub.n (n=16) were respectively shown as follows:
(525) ##STR00090##
(526) The dyes VII.sub.1a-VII.sub.6a were specifically prepared as follows.
(527) (1) 1 mol of 2-methylbenzothiazole (III.sub.4e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.1d) which was dried and stored for use.
(528) (2) 1 mol of 2-methylbenzoxazole (II.sub.4e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.1d) which was dried and stored for use.
(529) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (III.sub.1d) and 1 mol of the quaternary ammonium salt (II.sub.1d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VIII.sub.1c).
(530) (4) 1 mol of the dye (VIII.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VIII.sub.1b).
(531) (5) 1 mol of the sulfur-substituted squaraine dye (VII.sub.1b) was added to dry acetonitrile, to which 2.5 mol of a bromo-substituted intermediate E.sub.nBr (E.sub.n was selected from E.sub.1-E.sub.6) was added. The reaction mixture was stirred at room temperature or under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a corresponding target dye (VIII.sub.1a-VIII.sub.6a).
(532) The compounds VII.sub.1a-VIII.sub.6a were characterized as follows:
(533) VIII.sub.1a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.26H.sub.26N.sub.3O.sub.2S.sub.2.sup.+, 476.1461; found, 476.1464.
(534) VIII.sub.2a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.44 (m, 6H, CH.sub.3), 3.15 (m, 4H, CH.sub.2), 4.45 (m, 4H, CH.sub.2), 6.18 (s, 1H, CH), 6.45 (s, 1H, CH), 7.10 (m, 4H, ArH), 7.35 (m, 5H, ArH), 7.47 (m, 3H, ArH), 9.72 (t, 1H, CHO, J=8.0 Hz);
(535) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.39, 15.60, 29.93, 43.08, 50.49, 53.10, 90.30, 99.05, 108.61, 111.35, 112.20, 113.09, 115.87, 117.12, 118.75, 120.40, 123.16, 124.90, 127.04, 143.49, 158.45, 175.07, 203.50;
(536) HRMS-ESI: m/z calcd M.sup.+ for C.sub.27H.sub.25N.sub.2O.sub.7S.sub.2.sup.+, 489.1301; found, 489.1304.
(537) VIII.sub.3a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.32H.sub.27N.sub.2O.sub.4S.sub.2.sup.+, 567.1407; found, 567.1411.
(538) VIII.sub.4a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.32H.sub.27N.sub.2O.sub.4S.sub.2.sup.+, 567.1407; found, 567.1415.
(539) VIII.sub.5a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.27H.sub.27N.sub.2O.sub.4S.sub.2.sup.+, 507.1407; found, 507.1412.
(540) VII.sub.6a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.31H.sub.26N.sub.5O.sub.2S.sub.2.sup.+, 564.1522; found, 564.1526.
(541) 2. The synthetic route of dye VIII.sub.7a was shown as follows:
(542) ##STR00091##
(543) The dye VIII.sub.7a was specifically prepared as follows.
(544) (1) 1 mol of 2-methylbenzothiazole (III.sub.4e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.2d) which was dried and stored for use.
(545) (2) 1 mol of 2-methylbenzoxazoic (II.sub.4e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.2d) which was dried and stored for use.
(546) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (III.sub.2d) and 1 mol of the quaternary ammonium salt (II.sub.2d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed to be completed by TLC. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VIII.sub.2c).
(547) (4) 1 mol of the dye (VIII.sub.2c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VII.sub.2b).
(548) (5) 1 mol of the sulfur-substituted squaraine dye (VII.sub.2b) was added to dry acetonitrile, to which 2.5 mol of a bromomethyltriphenylamine intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VIII.sub.7a).
(549) The compound VIII.sub.7a was characterized as follows:
(550) .sup.1H-NMR (400 MHz, CDCl.sub.3): 3.64 (m, 5H, CH.sub.2&OH), 3.72 (m, 2H, CH.sub.2), 3.99 (m, 2H, CH.sub.2), 4.49 (s, 2H, CH.sub.2), 6.13 (s, 1H, CH), 6.37 (s, 1H, CH), 7.10 (m, 2H, ArH), 7.15 (m, 4H, ArH), 7.29 (m, 5H, ArH), 7.34 (m, 6H, ArH), 7.47 (m, 5H, ArH);
(551) .sup.13C-NMR (100 MHz, CDCl.sub.3): 42.70, 51.82, 54.65, 63.05, 64.40, 88.12, 98.63, 109.90, 112.07, 112.99, 113.65, 115.18, 117.78, 118.40, 120.26, 123.50, 124.61, 126.93, 127.42, 130.03, 138.17, 143.45, 156.90, 173.87;
(552) HRMS-ESI: m/z calcd M.sup.+ for C.sub.43H.sub.36N.sub.3O.sub.4S.sub.2.sup.+, 722.2142; found, 722.2147.
(553) 3. The synthetic route of dye VII.sub.8a was shown as follows:
(554) ##STR00092##
(555) The dye VII.sub.8a was specifically prepared as follows.
(556) (1) 1 mol of 2-methylbenzoxazole (II.sub.1e) and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.5d) which was dried and stored for use.
(557) (2) 1 mol of 2-methylbenzothiazole (III.sub.1e) and 2 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.3d) which was dried and stored for use.
(558) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (II.sub.3d) and 1 mol of the quaternary ammonium salt (II.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VIII.sub.3c).
(559) (4) 1 mol of the dye (VIII.sub.3c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VIII.sub.3b).
(560) (5) 1 mol of the sulfur-substituted squaraine dye (VIII.sub.3b) was added to dry acetonitrile, to which 2.5 mol of a chloromethyl triphenylphosphine intermediate was added. The reaction mixture was stirred under heating for a certain period of time until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VIII.sub.8a).
(561) The compound VIII8a was characterized as follows:
(562) HRMS-ESI: m/z calcd M.sup.+ for C.sub.48H.sub.38N.sub.2O.sub.3PS.sub.2.sup.+, 785.2056; found, 785.2062.
(563) 4. The synthetic route of dye VIII.sub.9a was shown as follows:
(564) ##STR00093## ##STR00094##
(565) The dye VIII.sub.9a was specifically prepared as follows.
(566) (1) 1 mol of 2-methyl-5-bromobenzothiazole (III.sub.6e) and 3 mol of ethanol, 2-(2-hydroxyethoxy)-, 1-(4-Methylbenzenesulfonate) were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.7d) which was dried and stored for use.
(567) (2) 1 mol of 2,5-dimethylbenzoxazole (II.sub.2e) and 3 mol of benzyl bromide were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.4d) which was dried and stored for use.
(568) (3) 2 mol of squaric acid was added to 100 mL of absolute wthanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (III.sub.7d) and 1 mol of the quaternary ammonium salt (II.sub.4d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VIII.sub.9c).
(569) (4) 1 mol of the dye (VIII.sub.9c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VIII.sub.9b).
(570) (5) 1 mol of the sulfur-substituted squaraine dye (VIII.sub.9b) was added to dry acetonitrile, to which 2.5 mol of a 2-chloroethyl diphenylphosphine intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to a give target dye (VIII.sub.9a).
(571) The compound VIII9a was characterized as follows:
(572) HRMS-ESI: m/z calcd M.sup.+ for C.sub.48H.sub.45BrN.sub.2O.sub.4PS.sub.2.sup.+, 887.1736; found, 887.1741.
(573) 5. The synthetic route of dye VII.sub.10a was shown as follows:
(574) ##STR00095## ##STR00096##
(575) The dye VIII.sub.10a was specifically prepared as follows.
(576) (1) 1 mol of 2-methyl-5-benzyloxy-benzothiazole (II.sub.8e) and 2 mol of 3-furanmethyl chloride were added to 20 mL of dry 1,2-dichlorobenzene, to which potassium iodide was added as a catalyst. Then the reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.9d) which was dried and stored for use.
(577) (2) 1 mol of 2-methyl-5-methoxybenzoxazole (II.sub.3e) and 3 mol of naphthylmethyl bromide were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.5d) which was dried and stored for use.
(578) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (II.sub.9d) and 1 mol of quaternary ammonium salt (III.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction mixture was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (VIII.sub.10c).
(579) (4) 1 mol of the dye (VIII.sub.10c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (VII.sub.10b).
(580) (5) 1 mol of the sulfur-substituted squaraine dye (VIII.sub.10b) was added to dry acetonitrile, to which 2.5 mol of a propargyl bromide intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (VIII.sub.10a).
(581) The compound VIII.sub.10a was characterized as follows:
(582) .sup.1H-NMR (400 MHz, CDCl.sub.3): 2.83 (t, 1H, CH, J=8.0 Hz), 3.82 (s, 3H, CH.sub.3), 4.33 (d, 2H, CH.sub.2, J=8.0 Hz), 5.16 (s, 2H, CH.sub.2), 5.40 (s, 2H, CH.sub.2), 5.53 (s, 2H, CH.sub.2), 6.16 (s, 1H, CH), 6.38 (s, 1H, CH), 6.73 (d, 1H, ArH, J=4.0 Hz), 7.08 (m, 4H, ArH), 7.17 (m, 3H, ArH), 7.29 (m, 10H, ArH), 7.58 (m, 3H, ArH);
(583) .sup.13C-NMR (100 MHz, CDCl.sub.3): 22.70, 45.02, 53.65, 55.80, 70.87, 73.05, 76.40, 89.21, 98.33, 108.41, 111.07, 113.60, 116.55, 117.01, 120.29, 124.42, 125.93, 127.70, 130.51, 133.72, 134.10, 138.29, 141.16, 143.05, 156.50, 173.31;
(584) HRMS-ESI: m/z calcd M.sup.+ for C.sub.47H.sub.35N.sub.2O.sub.5S.sub.2.sup.+, 771.1982; found, 771.1987.
Example 9
(585) The asymmetric dyes were further respectively substituted with different groups at the middle position to obtain exemplary asymmetric target dyes (IX.sub.1a-IX.sub.10a) which were shown as follows with XS and YNCH.sub.2CH.sub.3 in formula (I):
(586) ##STR00097## ##STR00098## ##STR00099##
(587) 1. The synthetic route of dyes IX.sub.1a-IX.sub.6a was shown as follows:
(588) ##STR00100## ##STR00101##
(589) where the structural formulas of D.sub.n (n=16) were respectively shown as follows:
(590) ##STR00102##
(591) The dyes IX.sub.1a-IX.sub.6a were specifically prepared as follows.
(592) (1) 1 mol of 2-methyl-N-ethylbenzimidazole (V.sub.4e) and 4 mol of iodoethane were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 36 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.1d) which was dried and stored for use.
(593) (2) 1 mol of 2-methylbenzothiazole (III.sub.1e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.1d) which was dried and stored for use.
(594) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.1d) and 1 mol of the quaternary ammonium salt (III.sub.1d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IX.sub.1c).
(595) (4) 1 mol of the dye (IX.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IX.sub.1b).
(596) (5) 1 mol of the sulfur-substituted squaraine dye (IX.sub.1b) was added to dry acetonitrile, to which 2.5 mol of a bromo-substituted intermediate D.sub.nBr (D.sub.n was selected from D.sub.1-D.sub.6) was added. The reaction mixture was stirred at room temperature or under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a corresponding target dye (IX.sub.1a-IX.sub.6a).
(597) The compounds IX.sub.1a-IX.sub.6a were characterized as follows:
(598) IX.sub.1a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.35 (m, 6H, CH.sub.3), 1.49 (m, 6H, CH.sub.3), 3.17 (t, 2H, CH.sub.2, J=8.0 HZ), 4.26 (m, 2H, CH.sub.2), 4.51 (m, 4H, CH.sub.2), 6.13 (s, 1H, CH), 6.44 (s, 1H, CH), 7.06 (m, 3H, ArH), 7.19 (m, 2H, ArH), 7.38 (m, 3H, ArH);
(599) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.30, 15.49, 16.60, 29.52, 42.27, 48.05, 55.30, 91.40, 101.51, 110.41, 112.70, 115.53, 117.02, 120.91, 125.37, 131.15, 138.80, 141.64, 143.03, 156.15, 173.70;
(600) HRMS-ESI: m/z calcd M.sup.+ for C.sub.28H.sub.30N.sub.3OS.sub.2.sup.+, 488.1825; found, 488.1828.
(601) IX.sub.2a: HRMS-ESI: m/z calcd [M+Na].sup.+ for C.sub.29H.sub.29N.sub.3NaO.sub.3S.sub.2.sup.+, 554.1543; found, 554.1547.
(602) IX.sub.3a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.33H.sub.32N.sub.3OS.sub.2.sup.+, 550.1981; found, 550.1985.
(603) IX.sub.4a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.33H.sub.31N.sub.4O.sub.3S.sub.2.sup.+, 595.1832; found, 595.1838.
(604) IX.sub.5a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.40H.sub.44N.sub.5O.sub.2S.sub.2.sup.+, 690.2931; found, 690.2936.
(605) IX.sub.6a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.41H.sub.46BN.sub.4O.sub.4S.sub.2.sup.+, 733.3048; found, 733.3053.
(606) 2. The synthetic route of dye IX.sub.7a was shown as follows:
(607) ##STR00103## ##STR00104##
(608) The dye IX.sub.7a was specifically prepared as follow.
(609) (1) 1 mol of 2-methyl-N-ethylbenzimidazole (IV.sub.1e) and 4 mol of 2-bromoethanol were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 36 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (IV.sub.2d) which was dried and stored for use.
(610) (2) 1 mol of 2-methylbenzothiazole (Hie) and 4 mol of 2-bromoethanol were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 36 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (II.sub.2d) which was dried and stored for use.
(611) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (IV.sub.2d) and 1 mol of the quaternary ammonium salt (II.sub.2d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IX.sub.7c).
(612) (4) 1 mol of the dye (IX.sub.7c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IX.sub.7b).
(613) (5) 1 mol of the sulfur-substituted squaraine dye (IX.sub.7b) was added to dry acetonitrile, to which 2.5 mol of an iodoethane intermediate was added. The reaction mixture was stirred at room temperature for 1 h. After the reaction was confirmed by TLC to be completed, the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (IX.sub.7a).
(614) The compound IX.sub.7a was characterized as follows:
(615) HRMS-ESI: m/z calcd M.sup.+ for C.sub.28H.sub.30N.sub.3O.sub.2.sup.+, 520.1723; found, 520.1727.
(616) 3. The synthetic route of dye IX.sub.8a was shown as follows:
(617) ##STR00105## ##STR00106##
(618) The dye IX.sub.8a was specifically prepared as follows.
(619) (1) 1 mol of 2-methyl-3-N-ethylbenzimidazole (V.sub.4e) and 3 mol of 2-bromoethanol were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 36 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.5d) which was dried and stored for use.
(620) (2) 1 mol of 2-methylbenzothiazole (II.sub.1e) and 2 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white quaternary ammonium salt solid (II.sub.3d) which was dried and stored for use.
(621) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.5d) and 1 mol of the quaternary ammonium salt (II.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IX.sub.8c).
(622) (4) 1 mol of the dye (IX.sub.8c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran. After the solid dye was completely dissolved, 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IX.sub.8b).
(623) (5) 1 mol of the sulfur-substituted squaraine dye (IX.sub.5b) was added to dry acetonitrile, to which 2.5 mol of an iodoethane intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a corresponding target dye (IX.sub.8a).
(624) The compound IX.sub.8a was characterized as follows:
(625) HRMS-ESI: m/z calcd M.sup.+ for C.sub.28H.sub.30N.sub.3O.sub.3S.sub.2.sup.+, 520.1723; found, 520.1725.
(626) 4. The synthetic route of dye IX.sub.9a was shown as follows:
(627) ##STR00107## ##STR00108##
(628) The dye IX.sub.9a was specifically prepared as follows.
(629) (1) 1 mol of 2,5-dimethyl-N-ethylbenzimidazole (V.sub.6e) and 3 mol of benzyl bromide were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 30 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white quaternary ammonium salt solid (V.sub.7d) which was dried and stored for use.
(630) (2) 1 mol of 2-methyl-5-bromobenzothiazole (VI.sub.2e) and 3 mol of ethanol, 2-(2-hydroxyethoxy)-, 1-(4-Methylbenzenesulfonate) were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.4d) which was dried and stored for use.
(631) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.7d) and 1 mol of the quaternary ammonium salt (VI.sub.4d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IX.sub.9c).
(632) (4) 1 mol of the dye (IX.sub.9c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IX.sub.9b).
(633) (5) 1 mol of the sulfur-substituted squaraine dye (IX.sub.9b) was added to dry acetonitrile, to which 2.5 mol of a
(634) ##STR00109##
intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a corresponding target dye (IX.sub.9a).
(635) The compound IX.sub.9a was characterized as follows:
(636) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.31 (t, 3H, CH.sub.3, J=8.0 Hz), 2.36 (s, 3H, CH.sub.3), 3.01 (t, 2H, CH.sub.2, J=8.0 Hz), 3.55 (m, 14H, CH.sub.2&OH), 4.08 (m, 4H, CH.sub.2), 5.51 (s, 2H, CH.sub.2), 6.15 (s, 1H, CH), 6.41 (s, 1H, CH), 7.08 (m, 3H, ArH), 7.21 (m, 5H, ArH), 7.50 (m, 3H, ArH);
(637) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.80, 21.52, 33.27, 44.05, 53.30, 52.02, 61.33, 66.14, 70.71, 70.45, 89.83, 100.14, 109.73, 112.80, 113.65, 115.12, 117.74, 118.60, 120.59, 122.81, 125.53, 128.81, 131.37, 133.31, 138.08, 139.75, 141.64, 143.90, 153.05, 154.72, 174.49;
(638) HRMS-ESI: m/z calcd M.sup.+ for C.sub.38H.sub.41BrN.sub.3O.sub.5S.sub.2.sup.+, 762.1666; found, 762.1671.
(639) 5. The synthetic route of dye IX.sub.10a was shown as follows:
(640) ##STR00110## ##STR00111##
(641) The dye IX.sub.10a was specifically prepared as follows.
(642) (1) 1 mol of 2-methyl-5-methoxybenzothiazole (II.sub.8e) and 2 mol of p-hexylbenzyl bromide were added to 20 mL of dry 1,2-dichlorobenzene, to which potassium iodide was added as a catalyst. Then the reaction mixture was refluxed under nitrogen protection for 36 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a dark gray quaternary ammonium salt solid (II.sub.9d) which was dried and stored for use.
(643) (2) 1 mol of 2-methyl-5-benzyloxybenzoxazole (VI.sub.3e) and 3 mol of bromopropane were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.5d) which was dried and stored for use.
(644) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (II.sub.9d) and 1 mol of the quaternary ammonium salt (VI.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (IX.sub.10c), which was dried and stored for use.
(645) (4) 1 mol of the dye (IX.sub.10c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (IX.sub.10b).
(646) (5) 1 mol of the sulfur-substituted squaraine dye (IX.sub.10b) was added to dry acetonitrile, to which 2.5 mol of a propargyl bromide intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (IX.sub.10a).
(647) The compound IX.sub.10a was characterized as follows:
(648) HRMS-ESI: m/z calcd M.sup.+ for C.sub.49H.sub.52N.sub.3O.sub.3S.sub.2.sup.+, 794.3445; found, 794.3449.
Example 10
(649) The asymmetric dyes X.sub.1a-X.sub.10a with XO and YNCH.sub.2CH.sub.3 in formula (I) were shown as follows:
(650) ##STR00112## ##STR00113## ##STR00114##
(651) 1. The synthetic route of dyes X.sub.1a-X.sub.6a was shown as follows:
(652) ##STR00115## ##STR00116##
(653) where the structural formulas of G.sub.n (n=1-6) were respectively shown as follows:
(654) ##STR00117##
(655) The dyes X.sub.1a-X.sub.6a were specifically prepared as follows.
(656) (1) 1 mol of 2-methyl-N-ethylbenzimidazole (VI.sub.1e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.1d) which was dried and stored for use.
(657) (2) 1 mol of 2-methylbenzoxazole (III.sub.1e) and 3 mol of iodoethane were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.1d) which was dried and stored for use.
(658) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (III.sub.1d) and 1 mol of the quaternary ammonium salt (VI.sub.1d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (X.sub.1c).
(659) (4) 1 mol of the dye (X.sub.1c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (X.sub.1b).
(660) (5) 1 mol of the sulfur-substituted squaraine dye (X.sub.1b) was added to dry acetonitrile, to which 2.5 mol of a bromo-substituted intermediate G.sub.nBr (G.sub.n was selected from G.sub.1-G.sub.6) was added. The reaction mixture was stirred at room temperature or under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a corresponding target dye (X.sub.1a-X.sub.6a).
(661) The compounds X.sub.1a-X.sub.6a were characterized as follows:
(662) X.sub.1a: .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.32 (m, 6H, CH.sub.3), 1.46 (m, 6H, CH.sub.3), 3.16 (q, 2H, CH.sub.2, J=8.0 Hz), 4.25 (q, 2H, CH.sub.2, J=8.0 Hz), 4.55 (m, 4H, CH.sub.2), 6.11 (s, 1H, CH), 6.41 (s, 1H, CH), 7.11 (m, 2H, ArH), 7.24 (m, 3H, ArH), 7.47 (m, 3H, ArH);
(663) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.17, 15.20, 16.35, 29.52, 44.27, 50.19, 51.08, 88.50, 100.37, 109.01, 113.80, 114.49, 116.60, 117.93, 121.24, 122.80, 128.17, 133.05, 137.74, 142.28, 153.30, 173.91;
(664) HRMS-ESI: m/z calcd M.sup.+ for C.sub.28H.sub.30N.sub.3O.sub.2S.sup.+, 472.2053; found, 472.2057.
(665) X.sub.2a: HRMS-ESI: m/z calcd [M+Na].sup.+ for C.sub.29H.sub.29N.sub.3NaO.sub.4S, 538.1771; found, 538.1775.
(666) X.sub.3a: HRMS-ESI: m/z calcd M.sup.+ for C.sub.33H.sub.32N.sub.3O.sub.2S.sup.+, 534.2210; found, 534.2215.
(667) X.sub.4a: HRMS-ESI: m/zcalcd M.sup.+ for C.sub.33H.sub.31N.sub.4O.sub.4S.sup.+, 579.2061; found, 579.2066.
(668) X.sub.5a: HRMS-ESI: m/zcalcd M.sup.+ for C.sub.40H.sub.46N.sub.5O.sub.3S.sup.+, 676.3316; found, 676.3320.
(669) X.sub.6a: HRMS-ESI: m/zcalcd M.sup.+ for C.sub.41H.sub.46BN.sub.4O.sub.5S.sup.+, 717.3276; found, 717.3281.
(670) 2. The synthetic route of dye X.sub.7a was shown as follows:
(671) ##STR00118## ##STR00119##
(672) The dye X.sub.7a was specifically prepared as follows.
(673) (1) 1 mol of 2-methyl-N-ethylbenzimidazole (VI.sub.1e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.2d) which was dried and stored for use.
(674) (2) 1 mol of 2-methylbenzoxazoic (III.sub.1e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.10d) which was dried and stored for use.
(675) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformat was added e as a catalyst. The mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (III.sub.10d) and 1 mol of the quaternary ammonium salt (VI.sub.2d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (X.sub.7c).
(676) (4) 1 mol of the dye (X.sub.7c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (X.sub.7b).
(677) (5) 1 mol of the sulfur-substituted squaraine dye (X.sub.7b) was added to dry acetonitrile, to which 2.5 mol of an iodoethane intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (X.sub.7a).
(678) The compound X.sub.7a was characterized as follows:
(679) HRMS-ESI: m/zcalcd M.sup.+ for C.sub.28H.sub.30N.sub.3O.sub.4S.sup.+, 504.1952; found, 504.1956.
(680) 3. The synthetic route of dye X.sub.8a was shown as follows:
(681) ##STR00120## ##STR00121##
(682) The dye X.sub.8a was specifically prepared as follows.
(683) (1) 1 mol of 2-methy 1-N-ethylbenzimidazole (VI.sub.1e) and 3 mol of 2-bromoethanol were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.3d) which was dried and stored for use.
(684) (2) 1 mol of 2-methylbenzothiazole (II.sub.1e) and 2 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (V.sub.5d) which was dried and stored for use.
(685) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (V.sub.5d) and 1 mol of the quaternary ammonium salt (VI.sub.3d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (X.sub.8c).
(686) (4) 1 mol of the dye (X.sub.8c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (X.sub.8b).
(687) (5) 1 mol of the sulfur-substituted squaraine dye (X.sub.8b) was added to dry acetonitrile, to which 2.5 mol of a benzyl bromide intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (X.sub.8a).
(688) The compound X.sub.8a was characterized as follows:
(689) HRMS-ESI: m/zcalcd M.sup.+ for C.sub.38H.sub.34N.sub.3O.sub.3S.sup.+, 612.2315; found, 612.2320.
(690) 4. The synthetic route of dye X.sub.9a was shown as follows:
(691) ##STR00122## ##STR00123##
(692) The dye X.sub.9a was specifically prepared as follows.
(693) (1) 1 mol of 2,5-dimethyl-N-ethylbenzimidazole (VI.sub.6e) and 3 mol of benzyl bromide were added to 20 mL of dry toluene. The reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.7d) which was dried and stored for use.
(694) (2) 1 mol of 2-methyl-5-bromobenzoxazole (III.sub.4e) and 3 mol of ethanol, 2-(2-hydroxy ethoxy)-, 1-(4-Methylbenzenesulfonate) were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 12 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (III.sub.4d) which was dried and stored for use.
(695) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (III.sub.4d) and 1 mol of the quaternary ammonium salt (VI.sub.7d) were added. The reaction mixture was continuously refluxed until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (X.sub.9c).
(696) (4) 1 mol of the dye (X.sub.9c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (X.sub.9b).
(697) (5) 1 mol of the sulfur-substituted squaraine dye (X.sub.9b) was added to dry acetonitrile, to which 2.5 mol of a diethylene glycol monobenzenesulfonate intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to a give target dye (X.sub.9a).
(698) The compound X.sub.9a was characterized as follows:
(699) .sup.1H-NMR (400 MHz, CDCl.sub.3): 1.31 (t, 3H, CH.sub.3, J=8.0 Hz), 2.36 (s, 3H, CH.sub.3), 3.03 (t, 2H, CH.sub.2, J=8.0 Hz), 3.70 (m, 12H, CH.sub.2&OH), 4.01 (t, 2H, CH.sub.2, J=8.0 Hz), 4.22 (q, 2H, CH.sub.2, J=8.0 Hz), 6.09 (s, 1H, CH), 6.42 (s, 1H, CH), 7.12 (m, 3H, ArH), 7.29 (m, 5H, ArH), 7.50 (m, 3H, ArH);
(700) .sup.13C-NMR (100 MHz, CDCl.sub.3): 14.37, 21.20, 33.35, 44.03, 49.75, 53.29, 61.13, 67.02, 70.50, 73.07, 89.63, 99.40, 110.05, 113.43, 114.69, 116.51, 117.07, 121.25, 122.91, 125.12, 128.06, 129.77, 133.53, 135.08, 138.47, 142.48, 153.35, 174.90;
(701) HRMS-ESI: m/zcalcd M.sup.+ for C.sub.38H.sub.41BrN.sub.3O.sub.6S.sup.+, 746.1894; found, 746.1898.
(702) 5. The synthetic route of dye X.sub.10a was shown as follows:
(703) ##STR00124## ##STR00125##
(704) The dye X.sub.10a was specifically prepared as follows.
(705) (1) 1 mol of 2-methyl-5-methoxybenzoxazole (III.sub.6e) and 3 mol of 4-chlorobenzyl chloride were added to 20 mL of dry 1,2-dichlorobenzene. The reaction mixture was heated under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white quaternary ammonium salt solid (III.sub.9d) which was dried and stored for use.
(706) (2) 1 mol of N-ethyl-2-methyl-5-benzyloxy-3H-indoline (VI.sub.3e) and 2 mol of p-methoxybenzyl bromide were added to 20 mL of dry 1,2-dichlorobenzene, to which potassium iodide was added as a catalyst. Then the reaction mixture was refluxed under nitrogen protection for 24 h. After cooled to room temperature, the reaction mixture was washed with anhydrous diethyl ether and crystallized with propanone to give a white to pink quaternary ammonium salt solid (VI.sub.5d) which was dried and stored for use.
(707) (3) 2 mol of squaric acid was added to 100 mL of absolute ethanol, to which triethyl orthoformate was added as a catalyst. The reaction mixture was refluxed under nitrogen protection until the squaric acid was completely dissolved, and then 1 mol of the quaternary ammonium salt (III.sub.9d) and 1 mol of the quaternary ammonium salt (VI.sub.5d) were added. The reaction mixture was continuously refluxed until the reaction mixture was confirmed by TLC to be completed. Then the reaction mixture was cooled, dried under vacuum, and purified by column chromatography to give a blue solid dye (X.sub.10c).
(708) (4) 1 mol of the dye (X.sub.10c) was added to 25 mL of a mixed solvent of dry dichloromethane and tetrahydrofuran, to which 2 mol of Lawesson's reagent was added. After stirred at 40 C. for 3 h, the reaction mixture was dried under vacuum, and purified by column chromatography to give a bluish green centrally sulfur-substituted squaraine dye (X.sub.10b).
(709) (5) 1 mol of the sulfur-substituted squaraine dye (X.sub.10b) was added to dry acetonitrile, to which 2.5 mol of a propargyl bromide intermediate was added. The reaction mixture was stirred under heating until the reaction was confirmed by TLC to be completed. Then the reaction mixture was cooled to room temperature, dried under vacuum, and purified by column chromatography to give a target dye (X.sub.10a).
(710) The compound X.sub.10a was characterized as follows:
(711) HRMS-ESI: m/zcalcd M.sup.+ for C.sub.48H.sub.41ClN.sub.3O.sub.5S.sup.+, 806.2450; found, 806.2454.
Example 11
(712) Ten representative dyes (shown as the following formulas I.sub.0a-X.sub.0a) respectively from the above Examples 1-10 were tested for the living cell membrane permeability, intracellular localization ability, fluorescence imaging and super-resolution imaging effect. The experiment was specifically described as follows.
(713) 1. The ten dyes shown as I.sub.0a-X.sub.0a were accurately weighed separately, and then dissolved in DMSO solvent to prepare a corresponding 1 mM dye solution (mother liquor), which was stored in a refrigerator for use.
(714) 2. After macrophages were resuscitated and passaged according to standard experimental methods, the previously prepared dye solutions were respectively added to the cell suspension to a final concentration of 1 M. After cultured at 37 C. and 5% carbon dioxide for 30 min, the cells were observed under a laser confocal microscope, where the excitation wavelength was selected to 633 nm, and the fluorescence generated under 645 nm or higher was collected. The results of the living cell confocal laser scanning imaging involving the above ten representative dyes were shown in
(715) 3. The dyes IX.sub.0a and X.sub.0a were simultaneously used for the STED super-resolution imaging of macrophages, and the results were shown in
(716) It can be seen from
(717) ##STR00126## ##STR00127## ##STR00128##
(718) Described above are merely preferred embodiments of the application, and are not intended to limit the application. Various modifications, replacements, improvements and changes made by those skilled in the art without departing from the spirit of the application should fall within the scope of the application.