CARBOXYLATE-BRIDGED BINUCLEAR IRON-SULFUR CLUSTERS FLOURESCENT PROBE, PREPARATION METHOD AND APPLICATION THEREOF

Abstract

The present invention provides a carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe having the structure of Formula I. The preparation method comprises the following steps: anthracenylmethanamine and p-methoxycarbonylphenyl isocyanate have an addition reaction to get a substitutional methyl benzoate, which is hydrolyzed to get a corresponding carboxylic acid; react the resulting carboxylic acid with alkali to get carboxylate, and then coordinate with binuclear iron precursor to obtain the fluorescent probe. Compared with the prior art, the invention firstly provides the carboxylate-bridged binuclear iron-sulfur clusters of metal complex which similar to the central structure of bio-enzyme. The metal complex, as a fluorescent probe, has good selectivity to the fluorinion detection. The fluorescence titration experiment is simple and easy to operate and the fluorescence changes are sensitive.

##STR00001##

Claims

1. Carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe of formula I, ##STR00004## wherein, R is methyl or ethyl.

2. A preparation method of the carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe according to claim 1, comprising the following steps: (1) addition reaction: react anthracen-9-ylmethanamine with p-methoxycarbonylphenyl isocyanate at a temperature of 0-40 C. for 1-48 hours to get addition product; (2) hydrolysis reaction: react the addition product obtained in step (1) with alkaline aqueous solution at a temperature of 0-100 C. for 1-24 hours, then adjust pH to 6-7 with acidic aqueous solution to get hydrolyzate; (3) neutralization reaction: react the hydrolyzate obtained in step (2) with alkali at a temperature of 0-80 C. for 1-24 hours to get ligand; (4) coordination reaction: react the ligand obtained in step (3) with binuclear iron precursor at a temperature of 0-80 C. for 1-48 hours; wherein the binuclear iron precursor is [Cp*Fe(-SR).sub.2(MeCN).sub.2FeCp*] [PF.sub.6].sub.2; in which, Cp* is pentamethylcyclopentadienyl, R is Me or Et.

3. The preparation method of the carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe according to claim 2, wherein at step (1), the molar ratio of anthracen-9-ylmethanamine to p-methoxycarbonylphenyl isocyanate is 1:1-2:1, and the reaction's solvent is at least one of dichloromethane, toluene, tetrahydrofuran, acetonitrile, ethyl acetate, acetone and ether.

4. The preparation method of the carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe according to claim 2, wherein at step (2), the concentration of the alkaline aqueous solution is 1-5 mol/L, and the ratio of the volume of alkaline aqueous solution to the mass of p-methoxycarbonylphenyl isocyanate is 5:1-50:1 mL/g.

5. The preparation method of the carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe according to claim 2, wherein at step (3), the alkali is at least one of potassium t-butoxide, sodium t-butoxide, triethylamine, sodium hydride, sodium hydroxide, potassium hydroxide, sodium methoxide, and sodium ethoxide; the mass molar of the alkali to the hydrolyzate is 1:1-2:1.

6. The preparation method of the carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe according to claim 2, wherein at step (4), the molar ratio of the added binuclear iron precursor to the ligand is 1:1-1:2; and solvent for the coordination reaction is at least one of dichloromethane, tetrahydrofuran, acetonitrile, and acetone.

7. An application for fluorinion detection of the carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe according to claim 1.

Description

BRIEF DESCRIPTION OF DRAWINGS

[0024] FIG. 1 shows the fluorescence spectra of fluorescent probe 5a reacts with different amount of F.sup.;

[0025] FIG. 2 shows the fluorescence spectra of fluorescent probe 5b reacts with different amount of F.sup.;

[0026] FIG. 3 shows the fluorescence spectra of fluorescent probe 5a reacts with different anions;

[0027] FIG. 4 shows the fluorescence spectra of fluorescent probe 5b reacts with different anions;

[0028] FIG. 5 shows the monocrystal structure of fluorescent probe 5a;

[0029] the bond length (), bond angle and dihedral angle () of 5a: Fe(1)-Fe(2) 2.5996(10), Fe(1)-S(1) 2.2031(15), Fe(1)-S(2) 2.2115(15), Fe(1)-O(1) 1.971(3), Fe(2)-S(1) 2.2025(16), Fe(2)-S(2) 2.2085(15), Fe(2)-O(2) 1.972(3), Fe(2)-S(1)-Fe(1) 53.83(4), Fe(2)-S(2)-Fe(1) 53.92(4), C(25)-O(2)-Fe(2) 122.7(3), C(25)-O(1)-Fe(1) 122.7(3), O(1)-Fe(1)-Fe(2) 84.85(10), O(1)-Fe(1)-S(2)89.81(11), O(1)-Fe(1)-S(1) 90.57(11), O(2)-Fe(2)-Fe(1) 84.91(10), O(2)-Fe(2)-S(2) 89.7(1), S(1)-Fe(1)-S(2) 107.37 (6), Fe(2)-S(1)-Fe(1) 72.32(5), Fe(2)-S(2)-Fe(1) 72.05(5), S(2)-Fe(1)-Fe(2) 53.92(4), S(2)-Fe(2)-Fe(1) 54.03(4), O(2)-C(25)-O(1) 124.7(4), Cp*(1)-Cp*(2) 55.94(15), S(1)Fe(2)Fe(1)-Fe(2)O(2)O(1)Fe(1) 86.7(7), O(2)C(25)O(1)-Fe(2)O(2)O(1)Fe(1) 4.4(4), C(34)C(35)C(40)C(41)C(42)C(47)-O(1)C(25)O(2) 70.3(4).

[0030] FIG. 6 shows the monocrystal structure of fluorescent probe 5b;

[0031] the bond length (), bond angle and dihedral angle () of 5b: Fe(1)-Fe(2) 2.6208(8), Fe(1)-S(1) 2.2067(13), Fe(1)-S(2) 2.2097(13), Fe(1)-O(1) 1.972(3), Fe(2)-S(1) 2.2008(12), Fe(2)-S(2) 2.1976(12), Fe(2)-O(2) 1.976(3), O(1)-C(25) 1.266(5), O(2)-C(25) 1.265(5), O(3)-C(32) 1.205(5), N(1)-C(32) 1.390(5), N(1)-C(29) 1.390(5), N(2)-C(32) 1.356(5), N(2)-C(33) 1.442(5), Fe(2)-S(1)-Fe(1) 72.39(4), Fe(2)-S(2)-Fe(1), C(25)-O(2)-Fe(2) 123.0(2), C(25)-O(1)-Fe(1) 122.7(2), O(1)- Fe(1)-Fe(2) 84.97(8), O(1)-Fe(1)-S(2) 89.78(8), O(1)-Fe(1)-S(1) 90.17(8), O(2)-Fe(2)-Fe(1) 84.57(8), O(2)-Fe(2)-S(1) 89.52(9), O(2)-Fe(2)-S(2) 90.02(9), S(1)-Fe(1)-Fe(2) 53.70(3), S(1)-Fe(2)-Fe(1) 53.91(3), S(1)-Fe(1)-S(2) 106.96(5), Fe(2)-S(1)-Fe(1) 72.39(4), Fe(2)-S(2)-Fe(1) 72.40(4), S(2)-Fe(1)-Fe(2) 53.59(3), S(2)-Fe(2)-Fe(1) 54.02(3), O(2)-C(25)-O(1) 124.8(3), Cp*(1)-Cp*(2) 54.03(12), S(1)Fe(2)Fe(1)-Fe(2)O(2)O(1)Fe(1) 90.0(7), O(2)C(25)O(1)-Fe(2)O(2)O(1)Fe(1) 1.2(4). C(34)C(35)C(40)C(41)C(42)C(47)-O(1)C(25)O(2) 84.91(3).

DETAILED DESCRIPTIONS OF THE PREFERRED EMBODIMENTS

[0032] The present invention is described in combination with embodiments in details, but the following embodiments are only preferred modes of execution without limiting the present invention in any way. Those person skilled in the art can make equivalent replacements or changes to the present invention, which according to the technical solutions and inventive concepts within the disclosed technical scope of the present invention, shall fall into the protection scope of the present invention.

[0033] The reaction mechanism of the preparation method of carboxylate-bridged binuclear iron-sulfur clusters fluorescent probe is as follows:

##STR00003##

[0034] (1) addition reaction

[0035] react anthracen-9-ylmethanamine with p-methoxycarbonylphenyl isocyanate to get a corresponding carboxylic ester;

[0036] (2) hydrolysis reaction

[0037] react the product solution obtained in step (1) with alkaline aqueous solution to obtain an hydrolyzate 3;

[0038] (3) neutralization reaction

[0039] react the hydrolyzate 3 obtained in step (2) with alkali to get a carboxylate;

[0040] (4) coordination reaction

[0041] react the carboxylate obtained in step (3) with binuclear iron precursor 4a or 4b to get fluorescent probes 5a or 5b.

Embodiment 1

Synthesis of Carboxylate-Bridged Binuclear Iron-Sulfur Clusters Fluorescent Probe 5a

[0042] To a solution of anthracen-9-ylmethanamine (1 g) in CH.sub.2Cl.sub.2 (180 mL) was added p-methoxycarbonylphenyl isocyanate (0.86 g) and then the resulting solution was stirred at room temperature for 24 h. The mixture was filtered to get filter cake and washed with CHCl.sub.3 to give solid. To a solution of the solid in EtOH (10 mL) was added NaOH solution (2 M, 10 mL) and the resulting solution was stirred at 75 C. for 12 h. After being adjusted to pH=6 with diluted hydrochloric acid (3 M), the solution was filtered and washed with H.sub.2O (5 mL) and EtOH (5 mL) to give crude solid. The solid was crystallized from DMSO-acetone to give hydrolyzate 3 (0.92 g, 52%).

[0043] .sup.1H NMR (400 MHz, DMSO-d.sup.6): 11.24 (br, 1H), 8.99 (s, 1H), 8.61 (br, 1H), 8.54 (d, J.sub.HH=8 Hz, 2H), 8.11 (br, 2H), 7.72 (br, 2H), 7.54-7.61 (m, 4H), 7.35 (br, 3H), 5.31 (br, 2H). .sup.13C NMR (100 MHz, DMSO-D.sup.6): 155.08, 141.50, 131.08, 130.97, 129.78, 128.83, 127.11, 126.22, 125.17, 124.60, 115.93, 35.17.

[0044] ESI-HRMS (m/z): [M-H].sup. 369.1317; calcd. value for C.sub.23H.sub.18N.sub.2O.sub.3: 369.1326.

[0045] To a solution of hydrolyzate 3 (72 mg) in THF (30 mL) was added t-BuOK (22 mg) and then the resulting solution was reacted at 50 C. for 2 h. After the solution was removed in vacuum, CH.sub.3CN (30 mL) and binuclear iron precursor 4a (150 mg) were added. The resulting solution was allowed to react for 48 h at room temperature under argon, the solution was filtered, and CH.sub.3CN was removed in vacuum. Then, the residue was extracted with CH.sub.2Cl.sub.2 (3 mL). After filtration and removal of the CH.sub.2Cl.sub.2 in vacuum, the residue was extracted with THF (3 mL). After filtration and removal of the THF, the residue was washed with Et.sub.2O (2 mL2) to give light green solid 5a ((108 mg, 60%).

[0046] .sup.1H NMR (400 MHz, CD.sub.2Cl.sub.2): 8.43 (s, 1H), 8.32 (br, 2H), 7.99 (br, 2H), 7.44-7.50 (m, 4H), 7.13 (br, 2H), 6.95 (br, 2H), 6.72 (s, 1H), 5.25 (br, 2H), 1.79 (s, 6H), 1.43 (s, 30H). IR (KBr, cm.sup.1): 3419 (m), 2921 (s), 1695 (m), 1597 (m), 1550 (m), 1516 (s), 1397 (s), 1375 (m), 1318 (w), 1216 (w), 1178 (m), 1018 (m), 955 (w), 842 (s), 778 (m), 735 (m).

[0047] ESI-HRMS (m/z): [M-PF.sub.6].sup.+ 845.2170; calcd. value for C.sub.45H.sub.53Fe.sub.2N.sub.2O.sub.3S.sub.2: 845.2196.

Embodiment 2

Synthesis of Carboxylate-Bridged Binuclear Iron-Sulfur Clusters Fluorescent Probe 5b

[0048] 4b was used as the binuclear precursor, and the other procedures were the same as those in Embodiment 1, to get 5b (105 mg, 58%).

[0049] .sup.1H NMR (400 MHz, CD.sub.2Cl.sub.2): 8.44 (s, 1H), 8.33 (d, =8 Hz, 2H), 8.01 (d, J.sub.HH=8 Hz, 2H), 7.46-7.51 (m, 4H), 7.14 (d, J.sub.HH=8 Hz, 2H), 6.93 (d, J.sub.HH=8 Hz, 2H), 6.73 (s, 1H), 5.33 (br, 2H), 5.26 (br, 1H), 1.93 (t, =8 Hz, 6H), 1.63 (q, J.sub.HH=8 Hz, 4H), 1.46 (s, 30H). IR (KBr, cm.sup.1): 3421 (m), 3056 (w), 2981 (m), 2925 (s), 1698 (s), 1597 (s), 1519 (s), 1448 (w) 1403 (s), 1375 (m), 1319 (m), 1231 (m), 1178 (m), 1073 (w), 1018 (s), 845 (s), 778 (m), 736 (m).

ESI-HRMS (m/z): [M-PF.sub.6].sup.+ 873.2506; calcd. value for C.sub.47H.sub.57Fe.sub.2N.sub.2O.sub.3S.sub.2: 873.2509.

Embodiment 3

The Effect of the Amount of Fluoride Ion on the Fluorescent Probe 5a Fluorescent Emission

[0050] 3 mL of 10.sup.5 mol/L 5a(prepared as described in embodiment 1) tetrahydrofuran solution was taken each time to a cuvette, then 0.2 eq, 0.4 eq, 0.6 eq, 0.8 eq, 1.0 eq, 1.2 eq, 1.4 eq, 1.6 eq, 1.8 eq, 2.0 eq, 2.2 eq, 2.4 eq, 2.6 eq, 2.8 eq and 3.0 eq of tetrabutylammonium fluoride aqueous solutions were added ordinally to test their fluorescence emission spectra, and get the results as shown in FIG. 1. It can be seen from this figure, with the increase of the fluoride ions, the fluorescence of the system was significantly enhanced.

[0051] The effect of the amount of fluoride ion on the fluorescent probe 5b fluorescence emission can be obtained by the same way, as shown in FIG. 2.

Embodiment 4

The Effect of Different Anions on the Fluorescent Probe 5a Fluorescent Emission

[0052] 3 mL of 10.sup.5 mol/L 5a (prepared as described in embodiment 1) tetrahydrofuran solution was taken each time to a cuvette, then 3 eq of F.sup., Br.sup., H.sub.2PO.sub.4.sup., HSO.sub.4.sup., Ac.sup., NO.sub.3.sup. and I.sup. were added ordinally, and under the effect of 370 nm exciting light to test the fluorescence emission spectra, and get the results as shown in FIG. 3. As can be seen from this figure, the system could selectively identify fluorinion.

[0053] The effect of different anions on the fluorescent probe 5b fluorescent emission could be obtained by the same way, as shown in FIG. 4.