Luminescent compounds

Abstract

Polycyclic aromatic hydrocarbons represented by the following general formula (I) wherein X is one of nitrogen, phosphorus, arsenic, antimony, bismuth, sulphur, selenium, tellurium; R independently represents an aromatic group and/or an aliphatic group; Q is one of a cyclic aliphatic hydrocarbon, a cyclic aromatic hydrocarbon, a polycyclic hydrocarbon, a polycyclic aromatic hydrocarbon, and/or a fused polycyclic aromatic hydrocarbon; wherein the substituents independently comprise one or more of a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, a carbon atom, an oxygen atom (e.g. an alkylated oxygen atom), a nitrogen atom (e.g. an alkylated nitrogen atom), a cyano group, a nitro group, an alkyl group and/or anaryl group; p is an integer of 1 to 2; q is an integer of 1 to 4; Y.sup.1 and Y.sup.2 independently represent one or more of a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, a carbon atom, an oxygen atom (e.g. an alkylated oxygen atom), a nitrogen atom (e.g. an alkylated nitrogen 20 atom), a cyano group, a nitro group, an alkyl group and/oranaryl group; and x is an integer of 0, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 or more. ##STR00001##

Claims

1. Polycyclic aromatic hydrocarbon derivatives, represented by the following general formula: ##STR00022## wherein X is one of phosphorus, arsenic, antimony, bismuth, sulphur, selenium or tellurium; R independently represents an aromatic group or an aliphatic group; p is an integer of 1 to 2; q and s are independently integers of 1 to 4; Y.sup.1, Y.sup.2, and Y.sup.3 independently represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, a carbon atom, an OH, a carboxylic acid group, a glycol, an alkoxy, a thioalkoxy, an amino, an acetate, an amide, a thioamide, a thioester, an azo, a silyl group, an alkylated nitrogen atom, a cyano group, a nitro group, a branched or straight chain alkyl group which may be further functionalized and/or an aryl group which may be further functionalized.

2. Polycyclic aromatic hydrocarbon derivatives, wherein the polycyclic aromatic hydrocarbon derivatives are triphenylene derivatives represented by the following general formula: ##STR00023## wherein X is one of phosphorus, arsenic, antimony, bismuth, sulphur, selenium or tellurium; R independently represents an aromatic group or an aliphatic group; A independently represents a hydrogen atom, an aryl group, an alkyl group comprising 1 to 20 carbons or an alkyl ether; J independently represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, a carbon atom, an OH, an alkylated oxygen atom, a carboxylic acid group, a glycol, an alkoxy, a thioalkoxy, an amino, an acetate, an amide, a thioamide, a thioester, an azo, a silyl group, an alkylated nitrogen atom, a cyano group, a nitro group, a branched or straight chain alkyl group which may be further functionalized or an aryl group which may be further functionalized.

3. Polycyclic aromatic hydrocarbon derivatives, wherein the polycyclic aromatic hydrocarbon derivatives are triphenylene derivatives represented by the following general formula: ##STR00024## wherein X is independently one of phosphorus, arsenic, antimony, bismuth, sulphur, selenium or tellurium; R.sup.1 and R.sup.2 independently represents an aromatic group or an aliphatic group; p and q are independently an integer of 1 to 2; s is an integer of 1 to 4; Y.sup.1, Y.sup.2, and Y.sup.3 independently represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, a carbon atom, an OH, a carboxylic acid group, a glycol, an alkoxy, a thioalkoxy, an amino, an acetate, an amide, a thioamide, a thioester, an azo, a silyl group, an alkylated nitrogen atom, a cyano group, a nitro group, a branched or straight chain alkyl group which may be further functionalized and/or an aryl group which may be further functionalized.

4. Polycyclic aromatic hydrocarbon derivatives, wherein the polycyclic aromatic hydrocarbon derivatives are triphenylene derivatives represented by the following general formula: ##STR00025## wherein X is independently one of phosphorus, arsenic, antimony, bismuth, sulphur, selenium or tellurium; R.sup.1 and R.sup.2 independently represents an aromatic group or an aliphatic group; A independently represents a hydrogen atom, an aryl group, an alkyl group comprising 1 to 20 carbons or an alkyl ether; J independently represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, a carbon atom, an OH, an alkylated oxygen atom, a carboxylic acid group, a glycol, an alkoxy, a thioalkoxy, an amino, an acetate, an amide, a thioamide, a thioester, an azo, a silyl group, an alkylated nitrogen atom, a cyano group, a nitro group, a branched or straight chain alkyl group which may be further functionalized or an aryl group which may be further functionalized.

5. Polycyclic aromatic hydrocarbon derivatives represented by the following general formula: ##STR00026## wherein X is independently one of phosphorus, arsenic, antimony, bismuth, sulphur, selenium or tellurium; R.sup.1, R.sup.2, R.sup.3 independently represent an aromatic group or an aliphatic group; p, q, and s are each independently an integer of 1 to 2; Y.sup.1, Y.sup.2, and Y.sup.3 independently represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, a carbon atom, an OH, an alkylated oxygen atom, a carboxylic acid group, a glycol, an alkoxy, a thioalkoxy, an amino, an acetate, an amide, a thioamide, a thioester, an azo, a silyl group, an alkylated nitrogen atom, a cyano group, a nitro group, a branched or straight chain alkyl group which may be further functionalized and/or an aryl group which may be further functionalized.

6. Polycyclic aromatic hydrocarbon derivatives, wherein the polycyclic aromatic hydrocarbon derivatives are triphenylene derivatives and represented by the following general formula: ##STR00027## wherein X is independently one of phosphorus, arsenic, antimony, bismuth, sulphur, selenium or tellurium; R.sup.1, R.sup.2, R.sup.3 independently represent an aromatic group or an aliphatic group; A independently represents a hydrogen atom, an aryl group, an alkyl group comprising 1 to 20 carbons or an alkyl ether; J independently represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, a carbon atom, an OH, an alkylated oxygen atom, a carboxylic acid group, a glycol, an alkoxy, a thioalkoxy, an amino, an acetate, an amide, a thioamide, a thioester, an azo, a silyl group, an alkylated nitrogen atom, a cyano group, a nitro group, a branched or straight chain alkyl group which may be further functionalized or an aryl group which may be further functionalized.

7. The polycyclic aromatic hydrocarbon derivatives according to claim 1, wherein X is a sulphur atom.

8. The polycyclic aromatic hydrocarbon derivatives according to claim 1, wherein R comprises a phenyl group.

9. The polycyclic aromatic hydrocarbon derivatives according to claim 1, wherein R comprises a heterocyclic group.

10. The polycyclic aromatic hydrocarbon derivatives according to claim 1, wherein R comprise a polycyclic aromatic hydrocarbon.

11. The polycyclic aromatic hydrocarbon derivatives according to claim 10, wherein R comprise one of naphthalene, anthracene, or pyrene.

12. The polycyclic aromatic hydrocarbon derivatives according to claim 1 selected from the structures Compound 1 and Compound 2: ##STR00028##

13. A device comprising the polycyclic aromatic hydrocarbon derivatives according to claim 1.

14. A device according to claim 13, wherein the device is an organic electroluminescent device, an OPV (organic photovoltaic) device, a thin-film transistor, or a liquid crystal display.

15. A device of claim 14, wherein the organic electroluminescent device comprises a pair of electrodes and one or more layers interposed therebetween, wherein the one or more layers comprise one or more of the polycyclic aromatic hydrocarbon derivatives.

16. A device of claim 13, wherein the polycyclic aromatic hydrocarbon derivatives exhibit a Stokes shift of between 200 cm.sup.1 to 36,000 cm.sup.1 when dissolved in ethyl acetate and measured at ambient temperature.

17. A device of claim 13, wherein the polycyclic aromatic hydrocarbon derivatives exhibit a conductivity value of 5.010.sup.13 S cm.sup.1 and 110.sup.2 S cm.sup.1.

Description

(1) Embodiments of the invention will now be described by way of example only with reference to the accompanying drawings in which:

(2) FIG. 1 is a representative structure of a series of triphenylene derivatives according to some embodiments of the invention;

(3) FIG. 2 is a schematic synthetic route of the prior art to the precursors of the triphenylene derivatives according to embodiments of the invention;

(4) FIG. 3 is a schematic synthetic route for the synthesis of triphenylene derivatives according to embodiments of the invention, as shown in FIG. 1;

(5) FIG. 4 are examples of triphenylene derivatives according to examples of the invention;

(6) FIG. 5 is an absorption and emission spectra of Compound 1;

(7) FIG. 6 is a graph showing electrical conductivity and photoconductivity data for Compound 1;

(8) FIG. 7 is an OLED according to a further aspect of the invention.

(9) Referring now to FIG. 1, there is shown a representative structure of a triphenylene derivative series 100 according to some embodiments of the invention. In this series, the R group is changed to provide analogues of the triphenylene derivative series 100. The R group may be selected to alter the luminescent and/or other advantageous properties of the triphenylene derivative series 100.

(10) Referring now to FIG. 2, there is shown a schematic synthetic route 200 of the prior art (N. Boden et. al. J. Mater. Chem., 1995, 5, 2275) to produce Precursor 1, which is an amine (2,3,6,7,10,11-hexakis(pentyloxy)-1-triphenylenylamine). The full procedures to synthesise Precursor 1, starting from catechol 201, is found in the prior art and are incorporated herein by reference.

(11) Referring now to FIG. 3, there is shown a schematic synthetic route 300 for the formation of the triphenylene derivative series 100 of the present invention. There is shown Precursor 1, an acyl chloride 301, a triphenylene amide intermediate 302, and the triphenylene derivative series 100. The acyl chloride 301 comprises an R group, which is incorporated into the oxazole moiety of the triphenylene derivative series 100. The R group may be an alkyl group, or an aryl group, i.e. the carbon atom bonded to the oxazole moiety in the triphenylene derivative series 100 may be either sp.sup.2 or sp.sup.3 hybridised.

(12) Advantageously, the method of FIG. 3 enables a huge number of analogues of the triphenylene derivate 100 to be synthesised by varying the R group of the acyl chloride 301 in the method 300. The triphenylene derivative series 100 of the present invention exhibit a number of desirable properties, in particular desirable luminescent characteristics. Advantageously, the R group may be altered to tune these properties. More advantageously, within the known parameters of this invention, the R group may be specifically selected to enable the tuning of the desirable luminescent characteristics. This is demonstrated in detail in the section below.

(13) To further exemplify the invention, reference is also made to the following non-limiting Example.

(14) All compound names were generated using Chem Draw software.

(15) Referring to FIG. 4 there is shown Examples (Compound 1) of the triphenylene derivative series 100. The methods for synthesising Compound 1 is described below.

Example 1Method of Synthesising Compound 1

(16) Compound 1 was synthesised using the following method. A solution of Precursor 1 (100 mg, 0.132 mmol), benzoyl chloride (92 mg, 0.658 mmol) and N,N-diisopropylethylamine (0.1 mL, 0.574 mmol) in PhMe (5 mL) was heated to and held at reflux for 18 h under N.sub.2. The reaction was cooled to room temperature and then evaporated to dryness in vacuo purified via flash column chromatography (silica, 60% CH.sub.2Cl.sub.2: 40% n-hexane) to afford Compound 302 (R=Ph) as a brown solid (19 mg, 18%).

(17) Compound 302 (R=Ph) had the following characterisation data: .sup.1H NMR H: (300 MHz, CDCl.sub.3) 8.55 (1H, s), 8.45 (1H, s), 8.07 (2H, d, J 7.5), 7.78 (1H, s), 7.74 (1H, s), 7.72 (1H, s), 7.71 (1H, s), 7.59 (1H, d, J 7.0), 7.54 (2H, t, J 7.4), 4.15 (10H, d, J 52.3), 3.67-3.54 (2H, m), 2.00-1.85 (8H, m), 1.70-1.37 (20H, m), 1.34-1.06 (8H, m), 1.02-0.90 (12H, m), 0.83 (3H, t, J 7.0), 0.75 (3H, t, J 7.1) ppm. .sup.13C NMR C: (100 MHz, CDCl.sub.3) 174.6, 151.0, 149.7, 148.7, 148.4, 148.4, 144.0, 135.1, 131.7, 130.9, 128.5, 127.9, 126.6, 124.7, 124.2, 123.0, 122.6, 122.0, 110.3, 108.1, 107.7, 106.8, 106.7, 73.4, 70.1, 70.0, 69.5, 69.3, 68.8, 32.1, 30.1, 29.9, 29.6, 29.4, 29.3, 28.7, 28.5, 28.5, 28.1, 22.9, 22.7, 22.6, 14.3, 14.3, 14.1 ppm. MALDI m/z: 863.3 ([M]+100%).

(18) A solution of Compound 302 (R=Ph) (100 mg, 0.116 mmol) and Lawesson's Reagent (175 mg, 0.658 mmol) in PhMe (5 mL) was heated to and held at reflux for 48 h under N.sub.2. The reaction was cooled to room temperature and then evaporated to dryness in vacuo. The solid was then heated and held at 240 C. for 15 mins under N.sub.2. The crude black solid was then cooled to room temperature and purified via flash column chromatography (silica, 40% CH.sub.2Cl.sub.2: 60% n-hexane) to afford Compound 1 as a green solid (17 mg, 19%).

(19) The name for Compound 1 is 2,3,6,11,12-pentakis(pentyloxy)-8-phenyltriphenyleno[1,2-d]thiazole.

(20) Compound 1 had the following characterisation data: .sup.1H NMR H: (300 MHz, CDCl.sub.3) 10.51 (1H, s), 8.24-8.22 (2H, m), 7.92-7.89 (3H, m), 7.76 (1H, s), 7.53-7.52 (3H, m), 4.43-4.26 (10H, m), 2.10-1.95 (10H, m), 1.66-1.57 (10H, m), 1.53-1.47 (10H, m), 1.03-1.00 (15H, m) ppm. .sup.13C NMR OC: (100 MHz, CDCl.sub.3) 166.4, 152.5, 151.5, 150.2, 149.3, 148.3, 134.7, 130.9, 130.0, 129.3, 127.6, 125.7, 125.4, 124.7, 123.8, 119.0, 112.4, 108.9, 107.2, 106.9, 100.9, 70.3, 70.2, 69.7, 69.2, 69.1, 29.7, 29.6, 29.6, 29.5, 29.4, 28.8, 28.8, 28.8, 23.1, 23.0, 23.0, 23.0 23.0, 14.5, 14.5, 14.5, 14.5 ppm. MALDI m/z: 791.56 ([M]+ 100%).

Example 2Method of Synthesising Compound 2

(21) Compound 2 was synthesised using the following method. A solution of Precursor 1 (100 mg, 0.132 mmol), 4-cyanobenzoyl chloride (109 mg, 0.658 mmol) and N,N-diisopropylethylamine (0.1 mL, 0.574 mmol) in PhMe (5 mL) was heated to and held at reflux for 18 h under N.sub.2. The reaction was cooled to room temperature and then evaporated to dryness in vacuo. The crude brown solid was added to a solution of Lawesson's Reagent (175 mg, 0.658 mmol) in PhMe (5 mL) was heated to and held at reflux for 48 h under N.sub.2. The reaction was cooled to room temperature and then evaporated to dryness in vacuo. The solid was then heated and held at 240 C. for 15 mins under N.sub.2. The crude black solid was then cooled to room temperature and purified via flash column chromatography (silica, 40% CH.sub.2Cl.sub.2: 60% n-hexane) to afford Compound 2 as a yellow solid (5 mg, 5%).

(22) The name for Compound 2 is 4-(2,3,6,11,12-pentakis(pentyloxy)triphenyleno[1,2-d]thiazol-8-yl)benzonitrile.

(23) Compound 2 had the following characterisation data: .sup.1H NMR H: (300 MHz, CDCl.sub.3) 10.38 (1H, s), 8.31 (2H, d, J 8.4), 7.97-7.88 (4H, m), 7.79 (1H, d, J 8.5), 4.41-4.26 (10H, m), 2.06-1.95 (10H, m), 1.61-1.55 (10H, m), 1.51-1.44 (10H, m), 1.03-0.97 (15H, m) ppm. MALDI m/z: 816.9 ([M]+90%), 817.9 ([M+H]+ 100%).

(24) Properties of Triphenylene Derivative Series 100

(25) The triphenylene derivative series 100 of the present invention exhibits a number of advantageous properties that are useful in many applications. Some of these advantageous properties are demonstrated and described below in a non-limiting way.

(26) Referring now to FIG. 5, there is shown an absorption and emission spectra 500 of Compound 1. Compound 1 was dissolved in ethyl acetate, and the absorption and emission was measured. The absorption maxima was shown to be 274 nm, and the emission maxima was shown to be 492 nm.

(27) FIG. 6 is a graph 600 showing electrical conductivity and photoconductivity data for Compound 1. The electrical conductivity 601 was measured at different temperatures for Compound 1. The photoconductivity 602 was measured at different temperatures for Compound 1 whilst irradiating with UV light at 350 nm.

(28) Large Stokes Shift

(29) It should be noted that by Stokes shift, we also mean a pseudo Stokes shift. The IUPAC definition of the Stokes shift requires that the difference in the band maxima of the absorption and luminescence arise from the same electronic transition. However, it is widely referred to in the literature in general terms to mean the difference in excitation and emission wavelengths, regardless of electronic transition.

(30) Emission Across the Entire Visible Spectrum, which Varies with R Group Structure

(31) Advantageously, the emission spectra of the compounds of the invention span a large portion of the visible spectrum. The R group need not be limited to those disclosed, and may be any alkyl or aryl group. In particular, variation of the R group with, for example, a different aromatic hydrocarbon group has been shown to result in a shift in the emission spectra. The shift in emission, and consequently the resulting visible colour of a specific triphenylene derivative, within the triphenylene derivative series 100, may be predicted with a good level of certainty for variation of the R group. Advantageously, this provides a huge number of analogues, for example wherein R is an aryl group, so that the emission is a colour within the visible spectrum, and this visible colour may be tuned by slight structural alteration to the R group of the triphenylene derivative series 100 of the present invention.

(32) Application of Triphenylene Derivative Series 100 in Electroluminescent Devices

(33) The triphenylene derivatives of the present invention may also be used in a functional layer of an OLED (Organic Light Emitting Diode). It has been shown that the triphenylene derivatives of the present invention may exhibit excellent emitting, charge transporting, and/or charge blocking abilities.

(34) Referring now to FIG. 7 there is shown an OLED 700. The OLED 700 comprises the following successive layers: a substrate 701, an anode 702, an optional hole transport layer 703, an optional electron blocking layer 704, an emissive layer 705, an optional hole blocking layer 706, an optional electron transport layer 707, and a cathode 708.

(35) Each layer described above may comprise any suitable material known to those skilled in the art, and may comprise more than one type of material or layer. For example, the substrate 701 may comprise glass, quartz, polymers, and so on. The thickness is not critical and may be, for example, between 25 to 1000 microns depending on the application of the device. The anode 702 may comprise any electrically conductive material, e.g. metal, or a conductive metal oxide such as ITO (indium tin oxide). The hole transport layer 703 may comprise, for example, 1,4-bis[(1-naphthyphenyl)-amino]biphenyl (NPD). The emissive layer 705 may comprise aluminium tris(8-hydroxyquinoline). The hole blocking layer 706 may comprise 2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (bathocuproine, BCP). The electron transport layer 707 may comprise, for example, metal chelates such as, for example, aluminium tris(8-hydroxyquinoline). The cathode 708 may comprise any metal, for example, aluminium, lithium, magnesium, and/or calcium.

(36) The emissive layer 705 comprises the triphenylene derivatives of the present invention, e.g. the triphenylene derivative series 100.

(37) The OLED 700 is fabricated in the following manner: The anode 702 is patterned upon the clean substrate 701. The substrate 701, which is patterned with the anode 702, is treated with oxygen for 1 to 5 minutes. The substrate 701, which is patterned with the anode 702, is placed in a thermal evaporator and the pressure is reduced to below 610.sup.6 torr. The hole transport layer 703, the electron blocking layer 704, the emissive layer 705, the hole blocking layer 706, the electron transport layer 707, and the cathode 708 are successively formed in the listed order by thermal evaporation.

(38) It will be appreciated by those skilled in the art that several variations to the aforementioned embodiments are envisaged without departing from the scope of the invention. For example, the R group of the triphenylene derivative series 100 and Precursor 1 need not be restricted to C.sub.5H.sub.11, and may be any stable alkyl or aryl group capable of alkylating the phenol moiety of the triphenylene moiety.

(39) Advantageously, the triphenylene derivative series 100 of the present invention may be further functionalised, for example, by derivatisation of functional groups within the R group. This provides the possibility of using the triphenylene derivative of the present invention as biotags or probes, for example.

(40) It will also be appreciated by those skilled in the art that any number of combinations of the aforementioned features and/or those shown in the appended drawings provide clear advantages over the prior art and are therefore within the scope of the invention described herein.