Patent Description:
Luminescent compounds are widely used in industrial and research applications as, for example, dyes, probes, sensors, and in electronic devices. These molecules emit light under external energy excitation from sources such as light and/or electrical current.

In photoluminescence, under light irradiation a luminescent compound will absorb light of a specific wavelength and re-emit light of a different wavelength. The type of photoemission observed depends on the molecular structure of the compound.

The difference between the maximum excitation wavelength and the emission wavelength of a luminescent compound is known as the Stokes shift. For use as dyes, probes and/or sensors in industrial applications, it is advantageous for luminescent compounds to possess a large Stokes shift, often defined as greater than <NUM>-<NUM> i.e. a comparatively large difference between the excitation wavelength and emission wavelength. This is advantageous because it minimises the reabsorption of light from the emission of the molecule.

A drawback of many fluorescent dyes with large Stokes shifts is their relatively low brightness, this being defined as the product of the molar extinction coefficient and fluorescence quantum yield. Additionally, dyes with large Stokes shifts often suffer from poor photostability (<NPL>).

Organometallic complexes that are luminescent often have a large Stokes shift. However, these contain metal centres, e.g. osmium, ruthenium, iridium, rhenium and so on, which are rare, expensive, the complexes are often difficult to synthesise and often toxic. Luminescent organic molecules are often easier to synthesise, but usually exhibit a Stokes shift of relatively smaller magnitude.

In contrast, in electroluminescence, a luminescent compound will emit light in response to an electric current. One of the main applications for this phenomenon is in electronic devices containing OLEDs (Organic Light Emitting Diodes). The OLED material is a layer of a luminescent organic compound, which is situated between two electrodes, one of which is typically transparent. This technology is used in digital displays in electronic devices such as televisions screens, computer monitors, mobile phones, electroluminescent lighting panels and so on.

It is advantageous for luminescent compounds for use in electroluminescent applications to exhibit high brightness. Brightness is defined as the product of the molar extinction coefficient (E) and fluorescence quantum yield (Φ) divided by <NUM>. Consequently, it is advantageous for luminescent compounds to exhibit a high molar extinction coefficient (E) (defined by the Beer-Lambert law, in which A is absorbance, c is the molar concentration of the luminescent compound, and I is the path length), and also a high quantum yield (Φ) as a measure of efficiency.

It is well known that polycyclic aromatic hydrocarbons exhibit luminescent properties. One such class of compound is triphenylene and its derivatives. For example, triphenylene may be functionalised with alkoxy chains appended to the periphery of the molecule. In addition, these derivatives exhibit discotic liquid crystalline (DLC) behaviour (<NPL>). Discotic liquid crystalline behaviour is characterised in that disc-shaped molecules form stacks or columns in a mesophase, which allows charge transfer through π stacking, enabling the material to be electrically semiconductive in the stacking direction. This DLC behaviour, combined with the luminescent properties, is particularly useful for application in technologies such as electronic devices using OLEDs (Organic Light Emitting Diodes), LEDs (Light Emitting Diodes), and for use in solar cells.

It is also known for luminescent compounds to exhibit photoconductivity, in which compounds exhibit increased electrical conductivity in the presence of light by converting the light energy into current. It is known to utilise compounds with good photoconductivity in devices such as solar cells.

Although many luminescent triphenylene derivatives have been synthesised and characterised (<NPL>, for example), it remains a challenge to provide triphenylene derivatives with the advantageous properties described above, i.e. large Stokes shift, high brightness, high molar extinction coefficient, and high quantum yield. Furthermore, it remains a challenge to provide a range of luminescent compounds that emit wavelengths throughout the visible spectrum. Specifically, blue emitters are a particular challenge to provide (<NPL>).

Furthermore, it remains a challenge to provide luminescent triphenylene derivatives wherein the absorption and the emission energies can be predicted and tuned by design and synthesis to result in specific and desired visible colours (<NPL>).

<NPL> discloses triphenylenoimidazole discotic liquid crystals.

Accordingly, a first aspect of the invention provides polycyclic aromatic hydrocarbon derivatives according to Claim <NUM>.

Also described (but not claimed) are polycyclic aromatic hydrocarbon derivatives represented by the following general formula:
<CHM>.

Q may represent C<NUM>H<NUM>. In embodiments, Q is a polycyclic aromatic hydrocarbon, for example, Q may be one of naphthalene, anthracene, phenanthrene, tetracene, chrysene, triphenylene, pyrene, pentacene, benzo[a]pyrene, corannulene, benzo[ghi]perylene, coronene, ovalene, fullerene, and/or benzo[c]fluorene. Q may be any isomer of the polycyclic aromatic hydrocarbons described, for example, <NUM>-napthalene, <NUM>-napthalene, <NUM>-anthracene, <NUM>-anthracene. The polycyclic aromatic hydrocarbon group may be substituted with other moieties such as aryl groups, alkyl groups, heteroatoms, and/or other electron withdrawing or electron donating groups.

Q is bonded to other six membered rings, e.g. aromatic six membered rings, and/or substituted aromatic six membered rings. The number of six membered rings bonded to Q is represented by the integer x wherein x is <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> or more.

In an embodiment, Q is an aromatic six-membered ring, and x is <NUM>.

Also described (but not claimed) are the polycyclic aromatic hydrocarbon derivatives represented by the following general formula:
<CHM>.

For example, D may be a linear or branched alkyl chain, an aryl group, or a combination thereof.

The (described but not claimed) polycyclic aromatic hydrocarbon derivatives may be represented by the following general formula:
<CHM>.

The polycyclic aromatic hydrocarbon derivatives of Claim <NUM> are represented by the following general formula:
<CHM>.

In embodiments, the polycyclic aromatic hydrocarbon derivative may be a triphenylene derivative. In alternative embodiments, the polycyclic aromatic hydrocarbon derivative may comprise a fused polycyclic aromatic hydrocarbon comprising six <NUM>-membered rings.

Y<NUM>, Y<NUM>, and Y<NUM> may be one or more of hydrogen atoms, deuterium atoms, oxygen atoms, fluorine atoms, chlorine atoms, carbon atoms, cyano groups, nitro groups carboxylic acid groups,, glycol, alkoxy, thioalkoxy, amino, acetate, amide, thioamide, thioester, azo, and/or silyl groups. Additionally or alternatively, Y<NUM>, Y<NUM>, and Y<NUM> may comprise an alkyl group. The alkyl group(s) may be a straight chain, or may comprise a branched chain. Additionally or alternatively, Y<NUM>, Y<NUM>, and Y<NUM> may comprise an aryl group, The aryl group(s) may be unsubstituted. The integer p may be <NUM> to <NUM>. The integer q may be <NUM>, <NUM>, <NUM>, or <NUM>. The integer s may be <NUM>, <NUM>, <NUM>, or <NUM>.

Also described (but not claimed) are polycyclic aromatic hydrocarbon derivatives, represented by the following general formula:
<CHM>.

A further aspect of the invention provides polycyclic aromatic hydrocarbon derivatives according to Claim <NUM>, represented by the following general formula:
<CHM>.

In embodiments, A may be C<NUM>H<NUM> and/or C<NUM>H<NUM>. In embodiments, A represents a polyethylene glycol (PEG) group (e.g. C<NUM>H<NUM>OC<NUM>H<NUM>OC<NUM>H<NUM>OCH<NUM>.

A further aspect of the invention provides polycyclic aromatic hydrocarbons according to Claim <NUM> represented by the following general formula:
<CHM>.

In embodiments, the polycyclic aromatic hydrocarbons are triphenylene derivatives represented by the following general formula:
<CHM>.

A yet further aspect of the invention provides polycyclic aromatic hydrocarbons according to Claim <NUM> represented by the following general formula:
<CHM>.

In (described but not claimed) embodiments, A comprises further functionality, for example, A may further comprise fluorine atoms, chlorine atoms, cyano groups, nitro groups, glycol, alkoxy, thioalkoxy, polyethylene glycol, amino, acetate, carboxylic acid, amide, thioamide, thioester, azo, and/or silyl groups.

In embodiments, J comprises or represents an aryl group, e.g. a phenol group. Additionally or alternatively, J comprises a halogen atom, e.g. fluorine, chlorine, bromine, or iodine.

In embodiments, R, R<NUM>, R<NUM>, or R<NUM> may be an alkyl group, for example, a straight or branched alkyl chain. In embodiments, at least one of R, R<NUM>, R<NUM>, R<NUM> may be a methyl, ethyl, propyl, butyl group.

The group R, R<NUM>, R<NUM>, or R<NUM>, may independently be an aromatic group and/or an aliphatic group.

In embodiments wherein R, R<NUM>, R<NUM>, or R<NUM> is an aromatic group, the aromatic group may be one of, or a combination of, an aromatic hydrocarbon group, and/or an aromatic heterocyclic group.

In embodiments wherein R, R<NUM>, R<NUM>, or R<NUM> is an aromatic hydrocarbon group, the aromatic hydrocarbon group may comprise one of, or a combination of, a phenyl ring and/or a substituted phenyl ring. There may be one, two, three, four, or five additional substituents on the phenyl ring. The substituents are bonded directly to the phenyl ring, and may be one of, or a combination of, fluorine, chlorine, bromine, iodine, a hydroxyl group, an amine group, a nitro group, an alkoxy group, a carboxylic acid, an amide, a cyano group, a trifluoromethyl, an ester, an alkene an alkyne, an azide, an azo, an isocyanate, a ketone, an aldehyde, an alkyl group consisting of a hydrocarbon chain, or a hydrocarbon ring, an alkyl group consisting of other heteroatoms such as fluorine, chlorine, bromine, iodine, oxygen, nitrogen, and/or sulphur. The alkyl group may comprise a hydroxyl group, an amine group, a nitro group, an ether group, a carboxylic acid, an amide, a cyano group, trifluoromethyl, an ester, an alkene an alkyne, an azide, an azo, an isocyanate, a ketone, an aldehyde, for example. The substituents may be another aromatic group, for example, R may comprise a phenyl substituted with a further phenyl ring. In embodiments, the R group may be a phenyl ring, substituted with a second phenyl ring, which in turn is substituted with a third phenyl ring.

In embodiments wherein R, R<NUM>, R<NUM>, or R<NUM> is an aromatic group, the aromatic group may be a polycyclic aromatic hydrocarbon, for example, naphthalene, anthracene, phenanthrene, tetracene, chrysene, triphenylene, pyrene, pentacene, benzo[a]pyrene, corannulene, benzo[ghi]perylene, coronene, ovalene, fullerene, and/or benzo[c]fluorene. The R group may be bonded to the polycyclic aromatic hydrocarbon derivative, e.g. the triphenylene derivative, by any isomer of the polycyclic aromatic hydrocarbons described, for example, <NUM>-napthalene, <NUM>-napthalene, <NUM>-anthracene, <NUM>-anthracene. The polycyclic aromatic hydrocarbon group may be substituted with other moieties such as aryl groups, alkyl groups, heteroatoms, and/or other electron withdrawing or electron donating groups.

In embodiments, wherein R, R<NUM>, R<NUM>, or R<NUM> is an aromatic heterocyclic group, the heterocyclic group may be a three membered ring, a four membered ring, a five membered ring, a six membered ring, a seven membered ring, an eight membered ring, a nine membered ring, a ten membered ring, or a fused ring. In embodiments, the heterocyclic group may be furan, benzofuran, isobenzofuran, pyrrole, indole, isoindole, thiophene, benzothiophene, benzo[c]thiophene, imidazole, benzimidazole, purine, pyrazole, indazole, oxazole, benzoxazole, isoxazole, benzisoxazole, thiazole, benzothiazole, pyridine, quinoline, isoquinoline, pyrazine, quinoxaline, acridine, pyrimidine, quinozoline, pyridazine, cinnoline, phthalazine, <NUM>,<NUM>,<NUM>-triazine, <NUM>,<NUM>,<NUM>-triazine, <NUM>,<NUM>,<NUM>-triazine. pyridine or thiophene.

In embodiments wherein R, R<NUM>, R<NUM>, or R<NUM> is an aliphatic group, the aliphatic group may be one of, or a combination of, an n-alkyl chain, a branched alkyl chain, an alkyl chain comprising unsaturated moieties, an alkyl chain comprising heteroatoms, for example, fluorine, chlorine, bromine, iodine, oxygen, sulphur, nitrogen. The alkyl chain may comprise unsaturated portions, comprising alkenes, or aromatic moieties. The alkyl chain may comprise functional groups for further derivatisation of the polycyclic aromatic hydrocarbon derivative, e.g. the triphenylene derivative. For example, the functional groups may be one or more of an azide, a carbonyl group, an alcohol, a halogen, or an alkene.

The polycyclic aromatic hydrocarbon, e.g. triphenylene, derivatives may be used, for example, as luminescent dyes for use in devices.

A further aspect of the invention provides a device comprising the polycyclic aromatic hydrocarbon, e.g. triphenylene, derivatives. The device may be an electronic device, for example, an organic electroluminescent device, a thin-film transistor and/or an OPV (organic photovoltaic) device. The electronic device may comprise a digital display, the digital display comprising polycyclic aromatic hydrocarbon, e.g. triphenylene, derivatives of the present invention, for example, a liquid crystal display. The digital display may be in a television screen, a computer monitor, a mobile phone screen, a games console, for example. The organic electroluminescent device may comprise 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, e.g. triphenylene, derivatives.

The device may be for the use of detecting species, for example, ions, e.g. metal ions. For example, the polycyclic aromatic hydrocarbon derivative, e.g. the triphenylene derivative, may comprise a moiety that is capable of binding to a species, e.g. an ion. The moiety may be tagged to or integrated into, i.e. covalently bonded to, the polycyclic aromatic hydrocarbon derivative, e.g. the triphenylene derivative. Binding of a species to a polycyclic aromatic hydrocarbon derivative, e.g. a triphenylene derivative, may elicit a luminescent response. The luminescent response may be recorded to quantitatively or qualitatively measure the presence of the species, e.g. in solution. The moiety may be a crown ether, a multidentate ligand, a bidentate ligand or a monodentate ligand. The polycyclic aromatic hydrocarbon, e.g. triphenylene, derivative, e.g. comprising a moiety that is capable of binding to a species, may be spin coated onto a dipstick. The dipstick may comprise a UV LED (light emitting diode). The LED may be illuminated in the presence of specific species upon binding to the polycyclic aromatic hydrocarbon, e.g. triphenylene, derivative, e.g. ions, metal ions. The LED illumination may be specific to a specific species that is bound to the polycyclic aromatic hydrocarbon, e.g. triphenylene, derivative, i.e. a specific wavelength of light, wavelength A, is emitted by the LED upon binding to a specific species, species A, and a different wavelength of light, wavelength B, is emitted by the LED upon binding to a specific species, species B.

The device may be used in biofluorescent microscopy techniques. The device may comprise the polycyclic aromatic hydrocarbon, e.g. triphenylene, derivatives as a luminescent dye that may be used to label biological, or non-biological samples, which may include DNA or proteins or antigens or biomarkers.

The device may comprise a polymer, or a pre-polymer, and/or a resin composition for use in printing, for example, for use in 3D printing plastic products comprising the polycyclic aromatic hydrocarbon, e.g. triphenylene, derivatives. The polycyclic aromatic hydrocarbon, e.g. triphenylene, derivatives may be used as a dopant in the device.

The polycyclic aromatic hydrocarbon, e.g. triphenylene, derivative(s) of the device may emit light in the visible spectrum, i.e. between <NUM> and <NUM>. The triphenylene derivative(s) of the device may exhibit a Stokes shift of between <NUM>-<NUM> to <NUM>,<NUM>-<NUM>, for example, between <NUM>,<NUM>-<NUM> to <NUM>,<NUM>-<NUM>. The polycyclic aromatic hydrocarbon derivatives, e.g. triphenylene derivative(s), of the device may exhibit a conductivity value of <NUM> x <NUM>-<NUM> S cm-<NUM> and <NUM> x <NUM>-<NUM> S cm-<NUM>, for example, between <NUM> x <NUM>-<NUM> S cm-<NUM> and <NUM> x <NUM>-<NUM> S cm-<NUM>. The polycyclic aromatic hydrocarbon, e.g. triphenylene, derivative(s) of the device may) exhibit a photoconductivity when irradiated at <NUM> of between <NUM> x <NUM>-<NUM> S cm-<NUM> and <NUM> x <NUM>-<NUM> S cm-<NUM>, for example, between <NUM> x <NUM>-<NUM> S cm-<NUM> and <NUM> × <NUM>-<NUM> cm-<NUM>.

Also described (but not claimed) is a method of synthesising polycyclic aromatic hydrocarbons, e.g. triphenylene derivatives, (P1) comprising the general formula:
<CHM>.

In embodiments, the polycyclic aromatic hydrocarbon derivative may be a triphenylene derivative.

In this embodiment, (SM1) represents a polycyclic aromatic hydrocarbon core and (P1) represents a polycyclic aromatic hydrocarbon derivative. A' may be an alkyl chain, for example, an alkyl chain comprising three or more carbon atoms, e.g. four, five, six, seven, or more carbon atoms. The method may involve the polycyclic aromatic hydrocarbon core (SM1) undergoing an intramolecular rearrangement to produce a polycyclic aromatic hydrocarbon derivative (P1).

A yet further aspect of the invention provides a method of synthesising polycyclic aromatic hydrocarbon derivatives, e.g. triphenylene derivatives, according to Claim <NUM> (P2) comprising the general formula:
<CHM>.

Compound (F2) represents the polycyclic aromatic hydrocarbon core, wherein group G may be a carbon atom, e.g. an alkyl chain, or an aryl group. (E) represents the reagent, wherein R is an aromatic group and/or an aliphatic group, and group Z may be one of a derivatised oxygen atom, e.g. an OH group; a chlorine atom, or a bromine atom, or any good leaving group. Reagent (E) may be an acyl chloride or a carboxylic acid. The method may involve Step (i) the polycyclic aromatic hydrocarbon core (F2) and the reagent (E) undergoing an intermolecular coupling reaction to produce the polycyclic aromatic hydrocarbon intermediate (G2). The polycyclic aromatic hydrocarbon intermediate (G2) may undergo Step (ii) a thionation reaction followed by an intramolecular cyclisation reaction to afford the polycyclic aromatic hydrocarbon derivatives (P2).

In embodiments, the polycyclic aromatic hydrocarbon derivative (P2) may be a triphenylene derivative.

Step (ii) of the method may be performed using a thionating agent, for example, Lawesson's reagent, ammonium phosphorodithioate or thiophosphoryl chloride with triethylamine.

The method of synthesising triphenylene derivatives (P3) may comprise the general formula according to Claim <NUM>:
<CHM>.

(F3) represents the triphenylene core, G may be an alkyl or aryl group, (E) represents the reagent, R is an aromatic group and/or an aliphatic group, Z is e.g. an OH group, a derivatised oxygen atom, a chlorine atom, or a bromine atom, or any good leaving group, and wherein the triphenylene core (F3) and the reagent (E) undergo Step (i) an intermolecular coupling reaction to produce the triphenylene intermediate (G3).

The triphenylene intermediate (G3) may undergo Step (ii) a thionation reaction followed by an intramolecular cyclisation reaction to afford the triphenylene derivatives (P3).

Step (ii) of the method may be performed using a thionating agent, for example, Lawesson's reagent ammonium phosphorodithioate or thiophosphoryl chloride with triethylamine.

For example, the method of synthesising triphenylene derivatives (M) may comprise the formula:
<CHM>.

A yet further aspect of the invention provides a method of synthesising polycyclic aromatic hydrocarbons, e.g. triphenylene derivatives, (P4), according to Claim <NUM>, the method comprising the following general formula:
<CHM>.

The method of synthesising triphenylene derivatives (P5) according to Claim <NUM> may comprise the general formula:
<CHM>.

(F5) represents the triphenylene core, G is an alkyl, hydrogen atom or aryl group, (E) represents the reagent, R is an aromatic group and/or an aliphatic group, Z is one of a derivatised oxygen atom, a chlorine atom, or a bromine atom, and wherein the triphenylene core (F5) and the reagent (E) undergo Step (i) an intermolecular coupling reaction to produce the triphenylene intermediate (G5). The triphenylene intermediate (G5) may undergo Step (ii) a thionation reaction followed by an intramolecular cyclisation reaction to afford the triphenylene derivatives (P5).

The triphenylene core (F5) of the method of synthesising triphenylene derivatives (P5) may comprise the formula (N):
<CHM>.

A yet further aspect of the invention provides a method of synthesising of synthesising polycyclic aromatic hydrocarbon derivatives (P6) according to Claim <NUM> comprising the general formula:
<CHM>.

The method of synthesising triphenylene derivatives (P7) according to Claim <NUM> may comprise the general formula:
<CHM>.

(F7) represents the triphenylene core, G is an alkyl or aryl group, (E) represents the reagent, R is an aromatic group and/or an aliphatic group, Z is one of an oxygen atom, e.g. an OH group, a derivatised oxygen atom, a chlorine atom, or a bromine atom, and wherein the triphenylene core (F7) and the reagent (E) undergo Step (i) an intermolecular coupling reaction to produce the triphenylene intermediate (G7). The triphenylene intermediate (G7) may undergo Step (ii) a thionation reaction followed by an intramolecular cyclisation reaction to afford the triphenylene derivatives (P7).

The thionation reaction may be performed using a thionating agent, for example, Lawesson's reagent ammonium phosphorodithioate or thiophosphoryl chloride with triethylamine.

The triphenylene core (F7) of the method of synthesising triphenylene derivatives (P7) may comprise the formula (P):
<CHM>.

The method may further comprise a reagent to replace, in situ, group Z with a good leaving group.

The reagent (E) may be a carboxylic acid, for example, benzoic acid or a substituted benzoic acid. The method may further comprise the use of a reagent and/or catalyst to form the triphenylene intermediate, e.g. (J3), from the triphenylene core, e.g. (H3). For example, the reagent may be dicyclohexylcarbodiimide (DCC) or <NUM>-ethyl-<NUM>-(<NUM>-dimethylaminopropyl)carbodiimide (EDC).

Step (i) of the method may further comprise a species to replace group Z with a good leaving group, for example, the species may be (diacetoxyiodo)benzene).

Alternatively, the reagent (E) may be an acyl chloride, for example, benzyl chloride or a substituted benzyl chloride.

Step (i) of the method may comprise heating the triphenylene core in a solvent, e.g. toluene, wherein Compound (E) is an acyl chloride, i.e. Z is a chlorine atom.

Step (i) and Step (ii) may be performed as separate steps, or may be performed in one single step, in a 'one pot' synthesis.

It is to be understood that the polycyclic aromatic derivatives may be further functionalised to produce analogues. For example, the polycyclic aromatic hydrocarbon derivatives, e.g. the triphenylene derivatives, may undergo bromination, e.g. using Br<NUM>, to add a bromine atom to one or more aromatic carbon atoms. The bromine atom may act as a functional group to undergo further chemical transformations, e.g. to functionalise the polycyclic aromatic hydrocarbon derivatives with a phenol group. In embodiments, J may represent a bromine atom and/or a phenol group. The bromine atom and/or phenyl group may be used to further functionalise the polycyclic aromatic hydrocarbon derivative.

Additionally or alternatively, the alkyl groups of one or more of the alkoxy groups (e.g. the OC<NUM>H<NUM> groups) may be de-alkylated to form hydroxyl (e.g. phenol) groups (e.g. using boron tribromide).

The polycyclic aromatic hydrocarbon derivatives may act as bio-labels or bio-probes.

For the avoidance of doubt, the terms "may", "and/or", "e.g.", "for example" and any similar term as used herein should be interpreted as non-limiting such that any feature so-described need not be present. Indeed, any combination of optional features is expressly envisaged without departing from the scope of the invention, whether or not these are expressly claimed.

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

Referring now to <FIG>, there is shown a schematic synthetic route <NUM> of the prior art (<NPL>) to produce Precursor <NUM>, which is an amine (<NUM>,<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-hexakis(pentyloxy)-<NUM>-triphenylenylamine). The full procedures to synthesise Precursor <NUM>, starting from catechol <NUM>, is found in the prior art and are incorporated herein by reference.

Referring now to <FIG>, there is shown a schematic synthetic route <NUM> for the formation of the triphenylene derivative series <NUM> of the present invention. There is shown Precursor <NUM>, an acyl chloride <NUM>, a triphenylene amide intermediate <NUM>, and the triphenylene derivative series <NUM>. The acyl chloride <NUM> comprises an R group, which is incorporated into the oxazole moiety of the triphenylene derivative series <NUM>. 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 <NUM> may be either sp<NUM> or sp<NUM> hybridised.

Advantageously, the method of <FIG> enables a huge number of analogues of the triphenylene derivate <NUM> to be synthesised by varying the R group of the acyl chloride <NUM> in the method <NUM>. The triphenylene derivative series <NUM> 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.

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

All compound names were generated using ChemDraw (RTM) software.

Referring to <FIG> there is shown Examples (Compound <NUM>) of the triphenylene derivative series <NUM>. The methods for synthesising Compound <NUM> is described below.

Compound <NUM> was synthesised using the following method. A solution of Precursor <NUM> (<NUM>, <NUM> mmol), benzoyl chloride (<NUM>, <NUM> mmol) and N,N-diisopropylethylamine (<NUM>, <NUM> mmol) in PhMe (<NUM>) was heated to and held at reflux for <NUM> under N<NUM>. The reaction was cooled to room temperature and then evaporated to dryness in vacuo purified via flash column chromatography (silica, <NUM> % CH<NUM>Cl<NUM>: <NUM> % n- hexane) to afford Compound <NUM> (R=Ph) as a brown solid (<NUM>, <NUM> %).

Compound <NUM> (R=Ph) had the following characterisation data: <NUM>H NMR δH: (<NUM>, CDCl<NUM>) <NUM> (<NUM>, s), <NUM> (<NUM>, s), <NUM> (<NUM>, d, J<NUM>), <NUM> (<NUM>, s), <NUM> (<NUM>, s), <NUM> (<NUM>, s), <NUM> (<NUM>, s), <NUM> (<NUM>, d, J<NUM>), <NUM> (<NUM>, t, J<NUM>), <NUM> (<NUM>, d, J<NUM>), <NUM>-<NUM> (<NUM>, m), <NUM> - <NUM> (<NUM>, m), <NUM> - <NUM> (<NUM>, m), <NUM> - <NUM> (<NUM>, m), <NUM> - <NUM> (<NUM>, m), <NUM> (<NUM>, t, J<NUM>), <NUM> (<NUM>, t, J7. <NUM>) ppm. <NUM>C NMR δC: (<NUM>, CDCl<NUM>) <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM> ppm. MALDI m/z: <NUM> ([M]+ <NUM>%).

A solution of Compound <NUM> (R=Ph) (<NUM>, <NUM> mmol) and Lawesson's Reagent (<NUM>, <NUM> mmol) in PhMe (<NUM>) was heated to and held at reflux for <NUM> under N<NUM>. The reaction was cooled to room temperature and then evaporated to dryness in vacuo. The solid was then heated and held at <NUM> for <NUM> mins under N<NUM>. The crude black solid was then cooled to room temperature and purified via flash column chromatography (silica, <NUM> % CH<NUM>Cl<NUM>: <NUM> % n- hexane) to afford Compound <NUM> as a green solid (<NUM>, <NUM> %).

The name for Compound <NUM> is <NUM>,<NUM>,<NUM>,<NUM>,<NUM>-pentakis(pentyloxy)-<NUM>-phenyltriphenyleno[<NUM>,<NUM>-d]thiazole.

Compound <NUM> had the following characterisation data: <NUM>H NMR δH: (<NUM>, CDCl<NUM>) <NUM> (<NUM>, s), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>, m), <NUM> (<NUM>, s), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>,m), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>, m) ppm. <NUM>C NMR δC: (<NUM>, CDCl<NUM>) <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM><NUM>, <NUM>, <NUM>, <NUM>, <NUM> ppm. MALDI m/z: <NUM> ([M]+ <NUM>%).

Compound <NUM> was synthesised using the following method. A solution of Precursor <NUM> (<NUM>, <NUM> mmol), <NUM>-cyanobenzoyl chloride (<NUM>, <NUM> mmol) and N,N-diisopropylethylamine (<NUM>, <NUM> mmol) in PhMe (<NUM>) was heated to and held at reflux for <NUM> under N<NUM>. 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 (<NUM>, <NUM> mmol) in PhMe (<NUM>) was heated to and held at reflux for <NUM> under N<NUM>. The reaction was cooled to room temperature and then evaporated to dryness in vacuo. The solid was then heated and held at <NUM> for <NUM> mins under N<NUM>. The crude black solid was then cooled to room temperature and purified via flash column chromatography (silica, <NUM> % CH<NUM>Cl<NUM>: <NUM> % n- hexane) to afford Compound <NUM> as a yellow solid (<NUM>, <NUM> %).

The name for Compound <NUM> is <NUM>-(<NUM>,<NUM>,<NUM>,<NUM>,<NUM>-pentakis(pentyloxy)triphenyleno[<NUM>,<NUM>-d]thiazol-<NUM>-yl)benzonitrile.

Compound <NUM> had the following characterisation data: <NUM>H NMR δH: (<NUM>, CDCl<NUM>) <NUM> (<NUM>, s), <NUM> (<NUM>, d, J <NUM>), <NUM>-<NUM> (<NUM>, m), <NUM> (<NUM>, d, J <NUM>), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>, m), <NUM>-<NUM> (<NUM>, m) ppm. MALDI m/z: <NUM> ([M]+ <NUM>%), <NUM> ([M+H]+ <NUM>%).

The triphenylene derivative series <NUM> 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.

Referring now to <FIG>, there is shown an absorption and emission spectra <NUM> of Compound <NUM>. Compound <NUM> was dissolved in ethyl acetate, and the absorption and emission was measured. The absorption maxima was shown to be <NUM>, and the emission maxima was shown to be <NUM>.

<FIG> is a graph <NUM> showing electrical conductivity and photoconductivity data for Compound <NUM>. The electrical conductivity <NUM> was measured at different temperatures for Compound <NUM>. The photoconductivity <NUM> was measured at different temperatures for Compound <NUM> whilst irradiating with UV light at <NUM>.

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.

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 <NUM>, 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 <NUM> of the present invention.

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.

Referring now to <FIG> there is shown an OLED <NUM>. The OLED <NUM> comprises the following successive layers: a substrate <NUM>, an anode <NUM>, an optional hole transport layer <NUM>, an optional electron blocking layer <NUM>, an emissive layer <NUM>, an optional hole blocking layer <NUM>, an optional electron transport layer <NUM>, and a cathode <NUM>.

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 <NUM> may comprise glass, quartz, polymers, and so on. The thickness is not critical and may be, for example, between <NUM> to <NUM> microns depending on the application of the device. The anode <NUM> may comprise any electrically conductive material, e.g. metal, or a conductive metal oxide such as ITO (indium tin oxide). The hole transport layer <NUM> may comprise, for example, <NUM>,<NUM>-bis[(<NUM>-naphthyphenyl)-amino]biphenyl (NPD). The emissive layer <NUM> may comprise aluminium tris(<NUM>-hydroxyquinoline). The hole blocking layer <NUM> may comprise <NUM>,<NUM>-dimethyl-<NUM>,<NUM>-dipphenyl-<NUM>,<NUM>-phenanthroline (bathocuproine, BCP). The electron transport layer <NUM> may comprise, for example, metal chelates such as, for example, aluminium tris(<NUM>-hydroxyquinoline). The cathode <NUM> may comprise any metal, for example, aluminium, lithium, magnesium, and/or calcium.

The emissive layer <NUM> comprises the triphenylene derivatives of the present invention, e.g. the triphenylene derivative series <NUM>.

The OLED <NUM> is fabricated in the following manner:.

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 as defined in the appended claims. For example, the R group of the triphenylene derivative series <NUM> and Precursor <NUM> need not be restricted to C<NUM>H<NUM>, and may be any stable alkyl or aryl group capable of alkylating the phenol moiety of the triphenylene moiety.

Advantageously, the triphenylene derivative series <NUM> 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.

Claim 1:
The polycyclic aromatic hydrocarbon derivatives, represented by the following general formula (B):
<CHM>
wherein X is sulphur;
R independently represents an aromatic group and/or an aliphatic group;
p is an integer of <NUM> to <NUM>;
q and s are independently integers of <NUM> to <NUM>;
Y<NUM>, Y<NUM>, and Y<NUM> independently represent a hydrogen atom, a deuterium atom, a fluorine atom, a chlorine atom, a bromine atom, 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, an alkyl group (e.g. branched or straight chain alkyl group) and/or an aryl group.