Novel quinoid bithiophene compounds and near-infrared absorbing dyes

Abstract

To provide a near-infrared absorbing dye which has absorption in the near-infrared light region and has solubility and high light resistance suitable for a coating film.SOLUTION: The invention provides a compound represented by the general formula (1) in the figure.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a novel quinoid bithiophene compound and a near-infrared absorbing dye. [Background technology]

[0002] In recent years, there has been an increasing need for dye compounds with robustness, particularly light resistance and weather resistance, and demand for dyes rather than pigments (functions in films and molecular dispersion states), but molecular design to adjust various physical properties has reached a dead end. For this reason, the search for organic dye compounds with novel skeletons is underway.

[0003] Near-infrared absorbing dyes are dyes that absorb light in the longer wavelength region (700-2000 nm) than visible light, and exhibit strong light absorption based on charge transfer in organic dyes and metal complexes. Near-infrared light is highly biotransparent and is abundant in sunlight, so various developments utilizing near-infrared light have been carried out, and they are expected to be applied in a wide range of fields, including photoelectric conversion elements such as organic thin-film solar cells and dye-sensitized solar cells, neural density (ND) filters, color filters, security, agricultural films, light control filters (thermal blocking and semiconductor sensors), and photodynamic therapy.

[0004] Many of the near-infrared absorbing dyes available to date have low light resistance, which has been an issue. Furthermore, when using near-infrared absorbing dyes for the above applications, they are subject to various constraints. For example, organic dyes that absorb near-infrared light have been synthesized using phthalocyanine, rhodamine, or other parent nuclei. However, the number and variety of these dyes is limited, and many of them also absorb visible light (Patent Document 1), so few are suitable for applications requiring transparency, such as near-infrared absorbing films.

[0005] Furthermore, when a dye solution is applied to form a film for use as a photoelectric conversion element, the dye must be soluble, and the molecular structure plays a major role in forming the film. Therefore, there is a need for the development of a near-infrared absorbing dye that absorbs near-infrared light, has relatively little absorption in the visible light region, has suitable solubility in coating films, is highly durable, and is easy to handle, and has absorption in the near-infrared region.

[0006] Color filters are also used in near-infrared absorbing dye liquid crystal and electroluminescent (EL) display devices, as well as CCD and CMOS image sensors. Color filters are manufactured by laminating colored layers onto a light-transmitting substrate such as glass or transparent resin using methods such as dyeing, pigment dispersion, printing, and electrodeposition. Improving the performance of color filters makes it possible to reduce the brightness of the light source, enabling display devices to operate at lower voltages.

[0007] Conventional color filters function as filters that transmit only the three primary colors of blue, green, and red in the visible light region, but they have a weak ability to block light in the near-infrared region, allowing near-infrared light to pass through. For this reason, a method has been proposed in which a near-infrared cut filter layer is used in combination with a color filter layer to eliminate the effects of near-infrared light, and only red, green, and blue light is taken into the pixels for photoelectric conversion.Patent Document 2 describes a method in which an inorganic multilayer film is provided below a color filter layer as a near-infrared cut filter layer.

[0008] Meanwhile, from the viewpoint of weight reduction and noise reduction of recent solid-state imaging devices, there is a demand for thinner near-infrared cut filter layers. For example, Patent Document 3 describes an optical filter layer that functions as both a color filter and a near-infrared cut filter by using a colored resin composition containing an organic color pigment and an infrared absorbing dye. By changing from the conventional two-layer structure to a single-layer structure, a thinner filter can be produced.

[0009] Dyes that can be used for the above-mentioned applications are required to have common properties such as optimal spectral absorption, good fastness such as light resistance, moisture resistance, and chemical resistance, and high solubility.

[0010] Bithiophene compounds bridged with electron-withdrawing groups have been synthesized (Non-Patent Documents 1 and 2). However, although the absorption due to these CTs is observed in the long wavelength region, the absorption coefficients of these compounds are often very small due to forbidden transitions, and they are insufficient as materials with an absorption band in the near-infrared region. [Prior art documents] [Patent documents]

[0011] [Patent Document 1] Japanese Patent Application Laid-Open No. 2011-116717 [Patent Document 2] International Publication No. 2014 / 041742 [Patent Document 3] International Publication No. 2017 / 002910 [Non-patent literature]

[0012] [Non-Patent Document 1] The Journal of Physical Chemistry C 2014, Vol. 118, No. 15, P. 7844-7855 [Non-patent document 2] Macromolecular Chemistry and Physics 2012, Vol. 213, Vol. 12, P. 1216-1224 Summary of the Invention [Problem to be solved by the invention]

[0013] The problem to be solved by the present invention is to provide a near-infrared absorbing dye that has absorption in the near-infrared region, and has solubility suitable for coating films and high light resistance. [Means for solving the problem]

[0014] In order to solve the above problems, the inventors have focused on the bithiophene skeleton in the development of a novel near-infrared absorbing dye, and as a result of extensive investigations, have found that the compound of the present invention is useful as a near-infrared absorbing dye that solves the above problems.

[0015] 1. A compound represented by the following general formula (1):

[0016] [ka]

[0017] [In the formula, R 1 ~R 4 are each independently a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent; a linear or branched alkynyl group having 2 to 20 carbon atoms which may have a substituent; or a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent, X 1 and X 2 each independently represents a divalent group.

[0018] 2. X in the general formula (1) 1 and X 2 A compound represented by the following general formula (2) or (3):

[0019] [ka]

[0020] [In the formula, R 5 and R 6 are each independently a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent; or an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent, Y represents a carbon atom, a silicon atom, or a germanium atom.

[0021] [ka]

[0022] [wherein Z is an oxygen atom, CR 7 R 8 or NR 9 represents R 7 and R 8 are each independently nitrile groups, an acyl group having 1 to 18 carbon atoms which may have a substituent; or an alkoxycarbonyl group having 1 to 18 carbon atoms which may have a substituent, R 9 teeth, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent; or an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent; represents.]

[0023] 3. In the general formula (1), R 1 ~R 4 is a compound which is a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent.

[0024] 4. A near-infrared absorbing dye comprising the compound described above.

[0025] 5. A thin film comprising the compound described above.

[0026] 6. A color filter containing the near-infrared absorbing dye.

[0027] 7. A near-infrared cut filter containing the near-infrared absorbing dye. [Effects of the Invention]

[0028] The compound having a bithiophene skeleton according to the present invention can provide a near-infrared absorbing dye having a main absorption characteristic in the near-infrared region, and having solubility and high light resistance suitable for a coating film, and a thin film made of the compound. [Brief explanation of the drawings]

[0029] [Figure 1] Absorption spectrum of Example 2 DETAILED DESCRIPTION OF THE INVENTION

[0030] The novel compound having a bithiophene skeleton of the present invention can be used in near-infrared absorbing dyes and thin films containing the compound, and in photoelectric conversion elements and color filters used in liquid crystal displays, image sensors, etc.

[0031] The compounds of the present invention represented by the general formula (1) will be specifically explained below, but the present invention is not limited thereto.

[0032] In general formula (1), R 1 ~R 4 are each independently a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent; a linear or branched alkynyl group having 2 to 20 carbon atoms which may have a substituent; Alternatively, it represents a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent.

[0033] In general formula (1), R 1 ~R 4Specific examples of the "straight-chain or branched alkyl group having 1 to 20 carbon atoms" in the "straight-chain or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" represented by the formula (1) include a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group, an s-butyl group, a t-butyl group, an n-pentyl group, an isopentyl group, an n-hexyl group, a 2-ethylhexyl group, a heptyl group, an octyl group, an isooctyl group, a nonyl group, and a decyl group.

[0034] In general formula (1), R 1 ~R 4 Specific examples of the "straight-chain or branched alkenyl group having 2 to 20 carbon atoms" in the "straight-chain or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent" represented by the formula (1) include a vinyl group, a 1-propenyl group, an allyl group, a 1-butenyl group, a 2-butenyl group, a 1-pentenyl group, a 1-hexenyl group, an isopropenyl group, an isobutenyl group, and a straight-chain or branched alkenyl group having 2 to 20 carbon atoms in which a plurality of these alkenyl groups are bonded.

[0035] In general formula (1), R 1 ~R 4 Specific examples of the "cycloalkyl group having 3 to 10 carbon atoms" in the "cycloalkyl group having 3 to 10 carbon atoms which may have a substituent" represented by the formula (1) include a cyclopropyl group, a cyclobutyl group, a cyclopentyl group, a cyclohexyl group, a cycloheptyl group, a cyclooctyl group, a cyclodecyl group, and a cyclododecyl group.

[0036] In the general formula (1), examples of the "substituent" in the "optionally substituted linear or branched alkyl group of 1 to 20 carbon atoms," "optionally substituted linear or branched alkenyl group of 2 to 20 carbon atoms," "optionally substituted linear or branched alkynyl group of 2 to 20 carbon atoms," or "optionally substituted cycloalkyl group of 3 to 10 carbon atoms" include specifically a halogen atom such as a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom; a cyano group; a hydroxyl group; a nitro group; a nitroso group; a carboxyl group; a phosphate group; Carboxylic acid ester groups such as methyl ester groups and ethyl ester groups; linear or branched alkyl groups having 1 to 19 carbon atoms, such as methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, s-butyl, t-butyl, n-pentyl, isopentyl, n-hexyl, 2-ethylhexyl, heptyl, octyl, isooctyl, nonyl, and decyl; linear or branched alkenyl groups having 2 to 18 carbon atoms, such as vinyl, 1-propenyl, allyl, 1-butenyl, 2-butenyl, 1-pentenyl, 1-hexenyl, isopropenyl, and isobutenyl; Alkoxy groups having 1 to 20 carbon atoms, such as a methoxy group, an ethoxy group, a propoxy group, a t-butoxy group, a pentyloxy group, or a hexyloxy group; Aromatic hydrocarbon groups having 6 to 19 carbon atoms, such as phenyl, naphthyl, anthryl, phenanthryl, and pyrenyl groups; pyridyl group, pyrimidinyl group heterocyclic groups having 5 to 19 ring atoms, such as a triazinyl group, a thienyl group, a furyl (furanyl) group, a pyrrolyl group, an imidazolyl group, a pyrazolyl group, a triazolyl group, a quinolyl group, an isoquinolyl group, a naphthyldinyl group, an acridinyl group, a phenanthrolinyl group, a benzofuranyl group, a benzothienyl group, an oxazolyl group, an indolyl group, a carbazolyl group, a benzoxazolyl group, a thiazolyl group, a benzothiazolyl group, a quinoxalinyl group, a benzimidazolyl group, a pyrazolyl group, a dibenzofuranyl group, a dibenzothienyl group, or a carbonyl group; An amino group having 0 to 20 carbon atoms, which may be an unsubstituted amino group (-NH2), a mono-substituted amino group such as an ethylamino group, an acetylamino group, or a phenylamino group, or a di-substituted amino group such as a diethylamino group, a diphenylamino group, or an acetylphenylamino group; Thio groups having 0 to 20 carbon atoms, such as unsubstituted thio groups (thiol groups: —SH), methylthio groups, ethylthio groups, propylthio groups, hex-5-ene-3-thio groups, phenylthio groups, and biphenylthio groups; These "substituents" may be contained in only one or in multiple numbers, and when multiple "substituents" are contained, they may be the same or different. Furthermore, these "substituents" may further have the substituents exemplified above.

[0037] In general formula (1), R 1 ~R 4 is preferably a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent.

[0038] In general formula (1), X 1 and X 2 represents an independent divalent group.

[0039] X in general formula (1) 1 and X 2 is preferably represented by the general formula (2) or (3).

[0040] In general formula (2), R 5 and R 6 are each independently a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent; Alternatively, it represents an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent.

[0041] In general formula (2), R 5 and R 6In the "straight-chain or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" represented by the formula (1), the "straight-chain or branched alkyl group having 1 to 20 carbon atoms" includes, for example, 1 ~R 4 Examples of the alkyl group include the same as the "straight or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" represented by the following formula:

[0042] In general formula (2), R 5 and R 6 The "cycloalkyl group having 3 to 10 carbon atoms" in the "cycloalkyl group having 3 to 10 carbon atoms which may have a substituent" represented by the formula (1) is, for example, R 1 ~R 4 Examples of the cycloalkyl group include the same as the "cycloalkyl group having 3 to 10 carbon atoms which may have a substituent" represented by the following formula:

[0043] In general formula (2), R 5 and R 6 Specific examples of the "aromatic hydrocarbon group having 6 to 36 carbon atoms" in the "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent" represented by the formula (1) include aryl groups such as a phenyl group, a naphthyl group, a biphenyl group, an anthryl group, a phenanthryl group, a pyrenyl group, a triphenylenyl group, an indenyl group, and a fluorenyl group. Here, the "aromatic hydrocarbon group" in the present invention has the same meaning as an aryl group and includes a condensed polycyclic aromatic group, and among these, a phenyl group, a naphthyl group, and a biphenyl group are preferred.

[0044] In general formula (2), R 5 and R 6Examples of the "substituent" in the "straight-chain or branched alkyl group of 1 to 20 carbon atoms which may have a substituent," "cycloalkyl group of 3 to 10 carbon atoms which may have a substituent," or "aromatic hydrocarbon group of 6 to 36 carbon atoms which may have a substituent" represented by the above formula include the same as the "substituent" in the "straight-chain or branched alkyl group of 1 to 20 carbon atoms which may have a substituent" in general formula (1).

[0045] In the general formula (2), Y represents a carbon atom, a silicon atom, or a germanium atom.

[0046] In the general formula (3), Z is an oxygen atom, CR 7 R 8 or NR 9 Z represents CR 7 R 8 or NR 9 When Z is an oxygen atom, it has the same electronic effect as a ketone group.

[0047] In general formula (3), R 7 and R 8 are each independently nitrile groups, an acyl group having 1 to 18 carbon atoms which may have a substituent; Alternatively, it represents an alkoxycarbonyl group having 1 to 18 carbon atoms which may have a substituent.

[0048] In general formula (3), R 7 and R 8 Specific examples of the "acyl group having 1 to 18 carbon atoms" in the "acyl group having 1 to 18 carbon atoms which may have a substituent" represented by the formula (I) include an acetyl group, a propionyl group, a butyryl group, an isobutyryl group, a valeryl group, an isovaleryl group, a benzoylacetyl group, and a benzoyl group, and when it contains an alkyl chain, it includes those in which hydrogen atoms are partially fluorinated and those in which hydrogen atoms are completely substituted with fluorine atoms (perfluorinated).

[0049] In general formula (3), R 7 and R 8 Specific examples of the "alkoxycarbonyl group having 1 to 18 carbon atoms" in the "alkoxycarbonyl group having 1 to 18 carbon atoms which may have a substituent" represented by the formula (I) include a methoxycarbonyl group, an ethoxycarbonyl group, etc.

[0050] In general formula (3), R 9 teeth, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent; or an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent; Represents.

[0051] In general formula (3), R 9 In the "straight-chain or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" represented by the formula (1), the "straight-chain or branched alkyl group having 1 to 20 carbon atoms" includes, for example, 1 ~R 4 Examples of the alkyl group include the same as the "straight or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" represented by the following formula:

[0052] In general formula (3), R 9 The "cycloalkyl group having 3 to 10 carbon atoms" in the "cycloalkyl group having 3 to 10 carbon atoms which may have a substituent" represented by the formula (1) is, for example, R 1 ~R 4 Examples of the cycloalkyl group include the same as the "cycloalkyl group having 3 to 10 carbon atoms which may have a substituent" represented by the following formula:

[0053] In general formula (3), R 9 The "aromatic hydrocarbon group having 6 to 36 carbon atoms" in the "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent" represented by the general formula (2) is, for example, R5 and R 6 Examples of the aromatic hydrocarbon group include the same as the "optionally substituted aromatic hydrocarbon group having 6 to 36 carbon atoms" represented by the following formula:

[0054] In general formula (3), R 7 ~R 9 Examples of the "substituent" in the "optionally substituted acyl group having 1 to 18 carbon atoms," "optionally substituted alkoxycarbonyl group having 1 to 18 carbon atoms," "optionally substituted linear or branched alkyl group having 1 to 20 carbon atoms," "optionally substituted cycloalkyl group having 3 to 10 carbon atoms," or "optionally substituted aromatic hydrocarbon group having 6 to 36 carbon atoms" represented by the above formula include the same as the "substituent" in the "optionally substituted linear or branched alkyl group having 1 to 20 carbon atoms" in general formula (1).

[0055] Specific examples of the compound represented by the general formula (1) of the present invention are shown below, but the present invention is not limited to these. Furthermore, the following exemplary compounds are shown with some hydrogen atoms, carbon atoms, etc. omitted, and are examples of possible isomers, but all other isomers are included. Furthermore, each may be a mixture of two or more isomers.

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[0085] The compound of the present invention represented by the general formula (1) can be synthesized by known methods.

[0086] For example, the introduction of an acceptor into 4H-cyclopenta[2,1-b:3,4-b']dithiophen-4-one, such as compound (A-6) of the present invention, is carried out by the method described in Non-Patent Document 1. The introduction of an alkyl group into 4H-cyclopenta[2,1-b:3,4-b']dithiophene, such as compound (A-35) of the present invention, is carried out by the method described in Non-Patent Document 2, to obtain compounds represented by formulas (4) and (5) below. Subsequently, a bromination reaction is carried out by a known method, and the resulting monobromo compounds, represented by formulas (6) and (7), are subjected to Suzuki-Miyaura cross-coupling reaction with the boronic acid ester compound represented by formula (8) below, followed by further bromination. The resulting compound is dimerized by a Stille coupling reaction and then oxidized with an oxidizing agent to synthesize the compound represented by general formula (1) of the present invention.

[0087] [ka]

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[0090] The compound of the present invention represented by the general formula (1) can be purified by column chromatography, recrystallization with a solvent, reprecipitation, or washing. These compounds can be identified by nuclear magnetic resonance analysis (NMR) or mass spectrometry.

[0091] The compound represented by the general formula (1) of the present invention can be used as a near-infrared absorbing dye, and can be used in combination with a known near-infrared absorbing substance in addition to the organic compound represented by the general formula (1) of the present invention. Furthermore, the near-infrared absorbing dye composition can contain a solvent, additives, and the like and be used. Furthermore, the near-infrared absorbing dye can be used as a near-infrared absorbing ink by dissolving or dispersing it in a solvent.

[0092] The compound of the present invention represented by the general formula (1) can be used for near-infrared absorbing materials, organic electronic devices, etc. The compound can also be used for various applications as a composition dissolved or dispersed in various media (the medium may be a liquid such as an organic solvent or a solid such as a polymeric material). A film can also be formed from the compound or the composition, and the film can be used for the above applications.

[0093] The compound of the present invention represented by the general formula (1) has a solubility suitable for solution processing. In particular, it is conceivable to use the compound of the present invention represented by the general formula (1) as a composition in a solution process to manufacture an organic electronic device. As used herein, the term "solution process" refers to a process of easily producing an element or the like by applying a composition in the form of a solution, dispersion, emulsion, or the like in which a compound is dissolved in an organic solvent or the like.

[0094] A thin film can be prepared using the near-infrared absorbing dye composition of the present invention containing the compound represented by the general formula (1).

[0095] When coating is performed by a solution process, the near-infrared absorbing dye composition may contain additives, a binder polymer, etc. A coating liquid can be prepared by dissolving or dispersing only the compound or the compound and a binder polymer in a solvent, and specific examples of the binder polymer include organic or inorganic polymer compounds such as poly-N-vinylcarbazole, polyarylate, polystyrene, polyester, polysiloxane, polymethyl acrylate, polymethyl methacrylate, polyether, polycarbonate, polyamide, polyimide, polyamideimide, polyparaxylene, polyethylene, polyethylene ether, polypropylene ether, polyphenylene oxide, polyethersulfone, polyaniline and derivatives thereof, polythiophene and derivatives thereof, polyphenylene vinylene and derivatives thereof, polyphenylene ethynylene and derivatives thereof, polyfluorene and derivatives thereof, and polythienylene vinylene and derivatives thereof.

[0096] Methods for forming thin films generally include gas phase methods such as vacuum processes such as resistance heating evaporation, electron beam evaporation, sputtering, and molecular lamination; solution methods such as spin coating, drop casting, dip coating, and spraying; relief printing methods such as flexographic printing and resin relief printing, lithographic printing methods such as offset printing, dry offset printing, and pad printing, intaglio printing methods such as gravure printing, screen printing methods such as silkscreen printing, stencil printing methods such as mimeograph printing and lithographic printing, inkjet printing, and microcontact printing; and printing methods such as a combination of these methods.

[0097] The solvents used in film formation include aromatic organic solvents such as benzene, toluene, xylene, mesitylene, tetralin (1,2,3,4-tetrahydronaphthalene), monochlorobenzene, o-dichlorobenzene, m-dichlorobenzene, p-dichlorobenzene, and nitrobenzene; alkyl halide organic solvents such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, and dichloromethane; nitrile solvents such as benzonitrile and acetonitrile; diethyl ether, tetrahydrofuran (hereinafter abbreviated as THF), dioxane, diisopropyl ether, cyclopentyl methyl ether, ethylene glycol dimethyl ether, and ethylene glycol diethyl ether. Examples of solvents include, but are not limited to, ether solvents such as propylene glycol monomethyl ether (PGME); ester solvents such as ethyl acetate, n-butyl acetate, and propylene glycol monomethyl ether acetate (PGMEA); alcohol solvents such as methanol, isopropanol, n-butanol, propylene glycol, 1,3-butanediol, 1,4-butanediol, 2,3-butanediol, cyclohexanol, and 2-n-butoxyethanol; ketones such as acetone and cyclohexanone; amides such as N,N-dimethylformamide (DMF) and N-methylpyrrolidone (NMP); dimethyl sulfoxide (DMSO); and chloroform (trichloromethane). These solvents may be used alone or in combination, and the solvent to be used can be selected based on the structure.

[0098] The thickness of the thin film varies depending on the application, but is generally preferably 1 nm to 10 μm, more preferably 5 nm to 3 μm, and even more preferably 10 nm to 1 μm.

[0099] [Evaluation of solubility] The solubility of the compound of the present invention represented by the general formula (1) is evaluated by adding the compound of the present invention to an organic solvent, stirring at room temperature (25±5°C) for about 1-2 minutes or subjecting it to an ultrasonic cleaner, and then visually evaluating the solubility (or saturated solubility). The solubility must be sufficient for the manufacturing process of devices and the like by solution processing, and high solubility is preferred.

[0100] [Lightfastness evaluation] The lightfastness test may be performed by irradiating a sample with light for a certain period of time using a tester that simulates sunlight, including ultraviolet light, and measuring the changes in hue and absorbance before and after the test. In the present invention, irradiation was performed using a xenon fade meter, and the change in absorbance at the absorption maximum wavelength was measured using a UV-visible spectrophotometer. For industrial use as a dye, high lightfastness is preferred.

[0101] [Organic Electronics Devices] The compound of the present invention represented by general formula (1) can be used to prepare organic electronic devices, such as photoelectric conversion elements such as solar cells and photosensors, thin film transistors, and organic EL elements. As an embodiment of the present invention, attention is focused on organic photoelectric conversion elements which are expected to be particularly used in near-infrared applications, and a photoelectric conversion element using a near-infrared light absorbing material will be described. Although not described in detail here, near-infrared light exceeding 700 nm has high transmittance through biological tissues, and therefore can be used to observe tissues in vivo. Therefore, near-infrared fluorescent probes and other applications in the medical field, such as pathological elucidation and diagnosis, can be applied in various ways depending on the purpose.

[0102] [Photoelectric conversion element] A photoelectric conversion element is an element in which a photoelectric conversion part is disposed between a pair of opposing electrodes. The compound represented by general formula (1) of the present invention has near-infrared light absorption properties, and is therefore expected to be used as a photoelectric conversion element, and can be used as the photoelectric conversion part of a photoelectric conversion element. The photoelectric conversion element can be used as an imaging element such as a solar cell, a near-infrared light sensor, or a near-infrared light image sensor.

[0103] The compound represented by the general formula (1) can be used as a constituent material of the photoelectric conversion part of a photoelectric conversion element. The photoelectric conversion part often comprises a photoelectric conversion layer and one or more thin film layers other than the photoelectric conversion layer selected from the group consisting of an electron transport layer, a hole transport layer, an electron blocking layer, a hole blocking layer, and an interlayer contact improving layer. The compound of the present invention is considered to be useful as a light absorbing material, a photoelectric conversion material, a charge transport material, etc., but is preferably used as a thin film layer of the photoelectric conversion layer. In particular, when used as a light absorbing material, a photoelectric conversion material, etc. of an organic thin film solar cell, it is possible to efficiently use solar energy. collection The photoelectric conversion layer may be composed of only the compound represented by the general formula (1), or may contain known light-absorbing materials and other additives in addition to the compound represented by the general formula (1).

[0104] Materials that can be used as electrodes of a photoelectric conversion element are not particularly limited as long as they have a certain degree of conductivity, but it is preferable to select a material taking into consideration adhesion to adjacent photoelectric conversion layers and other layers, electron affinity, ionization potential, stability, etc.

[0105] Specific examples of conductive materials used for electrodes include conductive transparent oxide semiconductors such as tin-doped indium oxide (ITO), fluorine-doped tin oxide (FTO), and indium-tin composite oxide; metals such as gold, silver, platinum, chromium, aluminum, iron, cobalt, nickel, and tungsten; inorganic conductive materials such as copper iodide and copper sulfide; conductive polymers such as polythiophene, polypyrrole, and polyaniline; and carbon. These materials may be used in combination as needed.

[0106] The conductive support, which is a transparent electrode film used on at least one of the electrodes on the light-incident side, must be translucent enough to transmit light that contributes to photoelectric conversion. Furthermore, the conductive support is preferably a conductive substrate, since it is a member that functions to extract current from the photoelectric conversion layer. Examples of materials include ITO and FTO (fluorine-doped tin oxide).

[0107] The photoelectric conversion part may include a photoelectric conversion layer and a thin film other than the photoelectric conversion layer. An organic semiconductor film is generally used for the photoelectric conversion layer, and the organic semiconductor film may be one layer or multiple layers. In the case of a single layer, a p-type organic semiconductor layer, an n-type organic semiconductor layer, or a mixed layer thereof is used. On the other hand, in the case of multiple layers, the organic semiconductor film has a structure in which either a p-type organic semiconductor layer, an n-type organic semiconductor layer, or a mixed film layer thereof is laminated, with a buffer layer optionally inserted between the layers. The compound of the present invention may be used as a p-type semiconductor material or an n-type semiconductor material.

[0108] Examples of thin film layers other than the photoelectric conversion layer that constitute the photoelectric conversion part include an electron transport layer, a hole transport layer, an electron blocking layer, a hole blocking layer, and an interlayer contact improving layer, and it is also considered that the compound of the present invention can be used in each of these layers.

[0109] <Near-infrared cut filter applications> Near-infrared absorbing materials are also used in near-infrared cut filters, plant growth regulating films, etc., which utilize their property of selectively absorbing light in a specific wavelength range. The compound of the present invention and a composition containing the compound have high near-infrared absorption ability and excellent light resistance, and therefore can be considered for use as a material for constituting near-infrared cut filters, etc. Specific applications of near-infrared cut filters include semiconductor applications, electronic device applications, various sensor applications, and color filters used in liquid crystal display devices, image sensors, etc.

[0110] [Color filter] When the compound represented by general formula (1) of the present invention is used as a near-infrared absorbing dye in a color filter, it can be provided on a substrate by a method of forming two layers, a color filter layer and a near-infrared cut filter layer, or by a method of forming a single layer having both the functions of a color filter and a near-infrared cut filter. In the case of a single-layer structure, a thin filter can be produced by using it as an optical filter layer.

[0111] When a single-layer optical filter layer is used, the colorant for a color filter contains a composition containing at least one near-infrared absorbing dye represented by general formula (1) and other components commonly used in the manufacture of color filters. These include other additives such as other dyes or pigments, resin components, organic solvents, and photopolymerization initiators. These components may be selected or omitted, and other components may be added as needed. A typical color filter can be obtained, for example, by photolithography, where a liquid prepared by mixing a dye or pigment with a resin component and a solvent is applied to a substrate such as glass or resin, photopolymerization is performed using a photomask, and a colored pattern of a dye-resin composite film that is soluble or insoluble in the solvent is produced, followed by washing and heating. Also, in electrodeposition and printing methods, a colored pattern is produced using a mixture of a dye with a resin or other components.

[0112] Examples of dyes or pigments for color filters include red pigments such as CI Pigment Red 177, 209, 242, 254, 255, 264, 269, and CI Pigment Orange 38, 43, and 71; other red lake pigments; yellow pigments such as CI Pigment Yellow 138, 139, and 150; red dyes such as CI Acid Red 88 and CI Basic Violet 10; basic dyes such as CI Basic Blue 3, 7, 9, 54, 65, 75, 77, 99, and 129; acid dyes such as CI Acid Blue 9 and 74; disperse dyes such as Disperse Blue 3, 7, and 377; spiron dyes; cyanine dyes, indigo dyes, phthalocyanine dyes, anthraquinone dyes, methine dyes, triarylmethane dyes, indanthrenes, oxazine dyes, dioxazine dyes, azo dyes, and xanthene dyes; and other blue lake pigments, but these are not particularly limited.

[0113] In the manufacturing process of the colorant and the color filter, it is necessary to dissolve or disperse well in an organic solvent containing a resin, etc. Therefore, it is preferable that the colorant has high solubility or dispersibility in the organic solvent. The organic solvent is not particularly limited, but specifically, the same solvent as that used in the film formation can be used.

[0114] As the resin component in the colorant for color filters, any known resin can be used as long as it has the properties required for the manufacturing method of the color filter resin film formed using it and for use. Examples include acrylic resin, polyolefin resin, styrene resin, polyimide resin, polyurethane resin, polyester resin, epoxy resin, vinyl ether resin, phenol (novolac) resin, other transparent resin, photocurable resin, or thermosetting resin. These monomer or oligomer components can be used in appropriate combination. Copolymers of these resins can also be used in combination. The resin content in these colorant for color filters is 5 to 95% when the colorant is liquid. mass %, and more preferably 10 to 50 mass %.

[0115] Furthermore, surfactants, dispersants, antifoaming agents, leveling agents, and other additives can be added depending on the intended use. The content of the additives is preferably an appropriate amount, and is preferably within a range that does not decrease the solubility or increase it more than necessary, or that does not affect the effects of other additives of the same type used in the production of products such as color filters, and can be added at any timing during the preparation of the colorant.

[0116] Other additives in the colorant for color filters of the present invention include components necessary for polymerizing and curing resins, such as photopolymerization initiators and crosslinking agents, as well as surfactants and dispersants necessary for stabilizing the properties of components in the liquid colorant for color filters. Any of these additives may be known for use in color filter production, and are not particularly limited. The total mixing ratio of these additives to the total solid content of the colorant for color filters is preferably 5 to 60% by mass, more preferably 10 to 40% by mass. [Example]

[0117] The present invention will be described in more detail below with reference to examples, but the present invention is not limited to the following examples. 1 The data were analyzed by H-NMR (H-NMR (JEOL Ltd., nuclear magnetic resonance spectrometer, JNM-ECZ400S / L1 model), mass spectrometry (JEOL Ltd., JMS-T100LP), and elemental analysis (J Science Lab Co., Ltd., JM10).

[0118] [Example 1] <Synthesis of Compound (A-1)> A reaction vessel was charged with 4H-cyclopenta[1,2-b:5,4-b']dithiophen-4-one (2.07 g, 0.0108 mol, manufactured by BLD Pharmatech Ltd.) and 50 mL of anhydrous tetrahydrofuran under an argon atmosphere and stirred at -2 °C in a salt ice bath. A solution of N-bromosuccinimide (1.86 g, 0.0105 mol, manufactured by Tokyo Chemical Industry Co., Ltd.) in 50 mL of anhydrous tetrahydrofuran was added dropwise over 40 minutes. The mixture was stirred at 0 °C for 5 hours, then allowed to warm naturally and allowed to stand overnight. The solvent was evaporated, and the resulting crude product was purified by silica gel column chromatography (SiO2 / hexane to hexane:chloroform = (1:2)). The fraction containing the target product was concentrated to give a reddish-brown solid (2.55 g). This solid was further purified by silica gel column chromatography (SiO2 / hexane to hexane:chloroform = (1:1) (volume ratio)) to obtain the compound represented by the following formula (9) as a reddish-brown solid (yield: 1.19 g, yield: 41%).

[0119] [ka]

[0120] A reaction vessel was charged with 2,6-di-t-butyl-4-bromophenol (2.01 g, 0.00705 mol, Tokyo Chemical Industry Co., Ltd.), bis(pinacolato)diboron (2.44 g, 0.00961 mol, Kishida Chemical Co., Ltd.), potassium acetate (1.89 g, 0.0193 mol, Fujifilm Wako Pure Chemical Industries, Ltd.), and 85 mL of dehydrated 1,4-dioxane under an argon atmosphere. The mixture was degassed in an ultrasonic cleaner (hereafter referred to as "ultrasonic") for 20 minutes. [1,1'-bis(diphenylphosphino)ferrocene]palladium(II) dichloride·dichloromethane adduct (260 mg, 0.318 mmol, Sigma-Aldrich) was added and heated and stirred at 84°C for 22 hours. After completion of the reaction, the reaction solution was cooled to room temperature and filtered through Celite. The residue was washed with chloroform, and the filtrate was evaporated to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO / hexane to hexane:chloroform = (1:1.5) (volume ratio)) to obtain the compound represented by the following formula (10) as a white solid (yield: 1.44 g, 62%).

[0121] [ka]

[0122] A reaction vessel was charged with the compound of formula (9) (1.21 g, 0.00446 mol), the compound of formula (10) (1.48 g, 0.00445 mol), 60 mL of tetrahydrofuran, and 30 mL of purified water under an argon atmosphere. The mixture was degassed by ultrasonic irradiation for 20 minutes. Sodium carbonate (950 mg, 0.00896 mol, Kishida Chemical Co., Ltd.) and tetrakis(triphenylphosphine)palladium(0) (267 mg, 0.231 mmol, Kanto Chemical Co., Inc.) were added and heated at 64°C for 6.5 hours. After the reaction was completed, the reaction solution was cooled to room temperature, and then 100 mL of ethyl acetate and 100 mL of tap water were added. The organic layer was separated and washed twice with 100 mL of water and with saturated brine. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was removed by evaporation to obtain the crude product. This crude product was purified by silica gel column chromatography (SiO2 / hexane to hexane:ethyl acetate=5:1 (volume ratio)) to obtain the compound of the following formula (11) as a black purple solid (yield: 1.64 g, yield: 93%).

[0123] A reaction vessel was charged with the compound of formula (11) below (832 mg, 0.00210 mol), N-bromosuccinimide (411 mg, 0.00231 mmol, Tokyo Chemical Industry Co., Ltd.), and 30 mL of dehydrated tetrahydrofuran, and the mixture was stirred at room temperature for 2.5 hours under an argon atmosphere. After the reaction was completed, the solvent was distilled off to obtain the crude product as a black-purple solid. The crude product was purified by silica gel column chromatography (SiO2 / hexane to hexane:chloroform = 1:1.5 (volume ratio)), and the fraction containing the target product was concentrated. When crystals precipitated, they were filtered, and the compound of formula (12) below was obtained as a black-purple solid (yield: 604 mg, 61%).

[0124] <NMR analysis results> 1 H-NMR (400MHz, CDCL3): δ(ppm)=1.47(s,18H), 5.37(s,1H), 6.99(s,1H), 7.08(s,1H), 7.33(s, 2H)

[0125] [ka]

[0126] The compound of formula (12) (384 mg, 0.808 mmol), bis(tributyltin) (215 μL, 0.426 mmol, Sigma-Aldrich), and 5 mL of dehydrated tetrahydrofuran were added to a reaction vessel under an argon atmosphere, and the mixture was degassed by ultrasonication for 20 minutes. Tris(dibenzylideneacetone)palladium(0) (38.8 mg, 0.0424 mmol, Sigma-Aldrich) and a 33 wt% xylene solution of tri-t-butylphosphine (Fujifilm Wako Pure Chemical Industries, Ltd.) (117 mg, 0.578 mmol) were added, and the mixture was heated to reflux at 63 °C for 9 hours. After the reaction was completed, the reaction solution was cooled to room temperature, and the solvent was distilled off to obtain a crude product. 20 mL of acetone was added to the crude product, and the mixture was ultrasonicated. After filtration, the filter cake was washed with acetone to obtain a black solid. 500 mL of chloroform was added to this black solid, and the mixture was subjected to ultrasonic irradiation at 50°C for 30 minutes, followed by silica gel filtration. The filtrate was concentrated to obtain a black-green solid. Acetone was added to this solid, and the mixture was subjected to ultrasonic irradiation and filtration to obtain the compound of the following formula (13) as a black-green solid (yield: 99.4 mg, 31%).

[0127] <NMR analysis results> 1 H-NMR (400MHz, CDCL3): δ(ppm)=1.48(s,36H), 5.38(s,2H), 7.03(s,2H), 7.10(s,2H), 7.35(s, 4H) <Mass spectrometry results> TOF-MS(ESI) m / z calculation for C 46 H 46 O4S4(M + ):790.23,found:790.25

[0128] [ka]

[0129] The compound of formula (13) (21.0 mg, 0.0265 mmol) and 80 mL of 1,2-dichlorobenzene were added to a reaction vessel, and the mixture was sonicated and heated with a heat gun to dissolve the raw materials. The insoluble material was filtered, and 7.5 g of 10% potassium hydroxide aqueous solution and potassium ferricyanide (85 mg, 0.258 mmol, Fujifilm Wako Pure Chemical Industries, Ltd.) were added to the filtrate under an argon atmosphere, and the mixture was stirred at room temperature for 5 hours. After the reaction was completed, the reaction solution was filtered, and the residue was washed with water and acetone to obtain the compound of formula (A-1) below as a brown solid.

[0130] <Mass spectrometry results> TOF-MS(ESI) m / zcalc.for C 46 H 44 O4S4([M+H] + ):789.22,found:789.21

[0131] [ka]

[0132] <Absorption spectrum measurement> The obtained compound (A-1) was dissolved in 1,2-dichlorobenzene (concentration 1.0 × 10 -5 The ultraviolet-visible absorption spectrum was measured using an ultraviolet-visible spectrophotometer (Hitachi, Ltd., U-3000). The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values ​​are shown in Table 2.

[0133] [Example 2] <Synthesis of Compound (A-6)> A reaction vessel was charged with 30 mL of dehydrated tetrahydrofuran under an argon atmosphere and cooled to -2°C in a salt ice bath. Titanium tetrachloride (2.89 mL, 0.00265 mol, Fujifilm Wako Pure Chemical Industries, Ltd.) was added to the reaction vessel with stirring. 30 mL of a solution of 4H-cyclopenta[1,2-b:5,4-b']dithiophen-4-one (598 mg, 0.00311 mol, BLD Pharmatech Ltd.) and dihexyl malonate (4.40 mL, 0.0153 mol, Tokyo Chemical Industry Co., Ltd.) in dehydrated tetrahydrofuran and pyridine (3.86 mL, 0.0478 mol, Nacalai Tesque, Inc.) were then added. The salt ice bath was then removed, the mixture was allowed to warm naturally, and the mixture was stirred at room temperature for 5 hours. After the reaction was completed, 100 mL of water and 200 mL of chloroform were added to the reaction solution, and the layers were separated. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was then evaporated to obtain a crude product (red oil). The crude product was purified by silica gel column chromatography (SiO2 / hexane:chloroform = 50:1 to 1:1 (volume ratio)). The fraction containing the target product was concentrated, 100 mL of tap water was added, and the mixture was cooled in an ice bath. The precipitated solid was filtered, and the filter cake was washed with tap water to obtain a reddish-black solid. This solid was dissolved in 150 mL of acetone, dried over anhydrous magnesium sulfate, and the solvent was evaporated to obtain the compound of formula (14) below as a reddish-black solid (yield: 1.54 g).

[0134] A compound of formula (14) (1.42 g, 0.00302 mol) and 44 mL of anhydrous tetrahydrofuran were added to a reaction vessel under an argon atmosphere. A solution of N-bromosuccinimide (536 mg, 0.00301 mol, manufactured by Tokyo Chemical Industry Co., Ltd.) in 30 mL of anhydrous tetrahydrofuran was added dropwise over 4 hours with stirring at room temperature, followed by stirring for 30 minutes. After completion of the reaction, the solvent was distilled off to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO2 / hexane:chloroform = 50:1 to 1:1.5 (volume ratio)) to obtain the compound of formula (15) as a dark purple solid (yield: 966 mg, 57%).

[0135] <NMR analysis results> 1H-NMR (400MHz, CDCL3): δ(ppm)=0.87(m,6H), 1.27-1.45(m,12H), 1.72(m,4H), 4.31(m,4H)7.02(d,1H), 7.20(d,1H), 7.38(s, 1H)

[0136] [ka]

[0137] A reaction vessel was charged with the compound of formula (15) (903 mg, 1.72 mmol), the boronic acid ester of formula (10) (572 mg, 1.72 mmol), 43 mL of tetrahydrofuran, and 21 mL of purified water under an argon atmosphere. The mixture was then degassed by ultrasonic irradiation for 20 minutes. Sodium carbonate (366 mg, 3.45 mmol, Kishida Chemical Co., Ltd.) and tetrakis(triphenylphosphine)palladium(0) (101 mg, 0.087 mmol, Kanto Chemical Co., Inc.) were added, and the mixture was heated and stirred at 62°C for 3.5 hours. After the reaction was completed, the reaction solution was cooled to room temperature, and then 200 mL of ethyl acetate and 150 mL of tap water were added for phase separation. The aqueous layer was extracted twice with 100 mL of ethyl acetate. The resulting organic layer was dried over anhydrous magnesium sulfate, and the solvent was removed by evaporation to obtain the crude product. This crude product was purified by silica gel column chromatography (SiO2 / hexane to hexane:ethyl acetate = 20:1 (volume ratio)), and then purified again by silica gel column chromatography (NH-SiO2 / hexane to hexane:ethyl acetate = 2:1 (volume ratio)) to obtain the compound of the following formula (16) as a purple oily substance (yield: 803 mg, 72%).

[0138] The compound of formula (16) below (684 mg, 1.05 mmol), 50 mL of dehydrated tetrahydrofuran, and N-bromosuccinimide (189 mg, 1.06 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a reaction vessel and stirred at room temperature for 2.5 hours under an argon atmosphere. After the reaction was completed, the solvent was distilled off from the reaction solution to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO2 / hexane to hexane:chloroform = 1:2 (volume ratio)), and the compound of formula (17) below was obtained as a purple oil (yield: 679 mg, 89%).

[0139] <NMR analysis results> 1 H-NMR (400MHz, CDCL3): δ(ppm)=0.85-0.92(m,6H), 1.28-1.41(m,12H), 1.47(s,1) 8H), 1.73(m,4H), 4.32(m,4H), 5.32(s,1H), 7.21(s,1H), 7.32(s,2H), 7.43(s, 1H)

[0140] [ka]

[0141] A reaction vessel was charged with the compound of formula (17) (499 mg, 0.684 mmol), 20 mL of dehydrated tetrahydrofuran, and bis(tributyltin) (172 μL, 0.340 mmol, manufactured by Sigma-Aldrich) under an argon atmosphere, and the mixture was degassed by ultrasonication for 15 minutes. A 33 wt % xylene solution of tri-t-butylphosphine (manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (98.0 mg, 0.160 mmol) and tris(dibenzylideneacetone)dipalladium(0) (33.6 mg, 0.0367 mmol, manufactured by Sigma-Aldrich) were then added, and the mixture was heated and stirred at 62°C for 2 hours. Furthermore, a 33 wt% xylene solution of tri-t-butylphosphine (116 mg, 0.189 mmol) and tris(dibenzylideneacetone)dipalladium(0) (31.6 mg, 0.156 mmol) were added, and the mixture was heated and stirred at 62 °C for 13.5 hours. After the reaction was completed, the reaction solution was cooled to room temperature, and the solvent was distilled off to obtain a crude product. The resulting crude product was purified by silica gel column chromatography (SiO2 / hexane to hexane:chloroform = 1:2 (volume ratio)), and the fraction containing the target compound was concentrated to obtain a dark green solid (760 mg). 10 mL of methanol was added to this solid, and the mixture was subjected to ultrasonic waves and filtered to obtain the compound of formula (18) below as a dark green solid (yield: 301 mg, 68%).

[0142] <NMR analysis results> 1 H-NMR (400MHz, CDCL3): δ(ppm)=0.86-0.92(m,12H), 1.28-1.45(m,24H), 1.48(s,3) 6H), 1.75(m,8H), 4.35(m,8H), 5.32(s,2H), 7.28(s,2H), 7.34(s,4H), 7.41(s, 2H) <Mass spectrometry results> TOF-MS(ESI) m / z calculation for C 76 H 98 O 10 S4([M] + ):1298.60,found:1298.59 <Elemental analysis results> Anal.Calcd.For C 76 H 98 O10 S4:C,70.23;H,7.60;N,0.Found:C,70.58;H,7.58;N,0.18.

[0143] [ka]

[0144] The compound of formula (18) (226 mg, 0.174 mmol) was added to a reaction vessel, followed by 10 mL of dehydrated 1,2-dichlorobenzene and lead(IV) oxide (419 mg, 1.75 mmol, manufactured by Kanto Chemical Co., Inc.), and ultrasonic waves were applied for 30 minutes. Lead(IV) oxide was added again in the same manner, and ultrasonic waves were applied for 60 minutes twice (additional lead(IV) oxide: 858 mg, 3.58 mmol). The reaction was terminated by ultrasonic waves for 4 hours. The reaction solution was filtered through Celite, and the filtrate was evaporated to obtain the crude product as a black-brown solid. 60 mL of chloroform was added to this solid, and the insoluble matter was filtered through Celite. The filtrate was further filtered using a syringe filter. The solvent was evaporated from the filtrate, and 5 mL of acetone was added to the filtrate, and ultrasonic waves were applied. The filtrate was then washed with acetone, yielding the compound of formula (A-6) below as a black solid (yield: 187 mg, 83%).

[0145] <Mass spectrometry results> TOF-MS(ESI) m / z calculation for C 76 H 96 O 10 S4([M+H] + ):1297.59,found:1297.57 <Elemental analysis results> Anal.Calcd.For C 76 H 96 O 10 S4:C,70.34;H,7.46;N,0.Found:C,70.05;H,7.41;N,0.12.

[0146] [ka]

[0147] <Solubility Evaluation> The obtained compound (A-6) was weighed into a transparent sample tube, and a 5 wt% solution was prepared using tetrahydrofuran. The solution was then placed in an ultrasonic cleaner at room temperature (25±2°C) for 1 minute, and the presence or absence of residual solution was visually confirmed to evaluate the solubility. The results are shown in Table 1. The evaluation criteria were expressed as ○ for complete dissolution (25±2°C), △ for residual turbidity (25±2°C), and × for insolubility (25±2°C).

[0148] <Absorption spectrum measurement> Instead of compound (A-1), a 1,2-dichlorobenzene solution of compound (A-6) (concentration 5.0 × 10 -6 The ultraviolet-visible absorption spectrum was measured in the same manner as in Example 1, except that a solution of 1000 mol / L was prepared and the measurement was carried out using an ultraviolet-visible spectrophotometer (Shimadzu Corporation, UV-3600). The results are shown in Table 2. The absorption spectrum of compound (A-6) is shown in Figure 1.

[0149] [Example 3] Synthesis of Compound (A-35) Under an argon atmosphere, 4H-cyclopenta[2,1-b:3,4-b']dithiophene (1.08 g, 6.06 mmol, Tokyo Chemical Industry Co., Ltd.), 125 mL of dimethyl sulfoxide dehydrated over molecular sieves, 1-bromohexane (2.12 mL, 15.2 mmol, Tokyo Chemical Industry Co., Ltd.), and potassium iodide (28.0 mg, 0.169 mmol, Junsei Chemical Co., Ltd.) were added to a reaction vessel and cooled to 2 °C in an ice bath. Potassium hydroxide (905 mg, 16.1 mmol, Fujifilm Wako Pure Chemical Industries Co., Ltd.) pre-ground in a mortar was added to the reaction solution, the ice bath was removed, and the mixture was stirred for 5 hours while warming to room temperature. Potassium hydroxide (71.0 mg, 1.27 mmol) was then added and the mixture was stirred for an additional 15 minutes at room temperature. The mixture was left to stand overnight, and potassium hydroxide (112 mg, 2.00 mmol) was added and stirred at room temperature for 7 hours. After the reaction was completed, 250 mL of tap water and 200 mL of ethyl acetate were added and the mixture was separated. The organic layer was washed with 200 mL of tap water, saturated brine, and saturated aqueous ammonium chloride solution. The separated organic layer was dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain the crude product as a brown oil. This crude product was purified by silica gel column chromatography (SiO2 / hexane) to obtain the compound of formula (19) below as a yellow oil (yield: 1.59 g, 76%).

[0150] A compound represented by the following formula (19) (295 mg, 0.851 mmol), 5 mL of tetrahydrofuran, and N-bromosuccinimide (151 mg, 0.849 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a reaction vessel and stirred at 0°C in an ice bath for 4 hours. After completion of the reaction, the solvent was distilled off from the reaction solution to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO / hexane) to obtain a mixture containing the monobromo compound, dibromo compound, and compound represented by the following formula (19), which is the target compound of the following formula (20), as a yellow oily substance (yield: 343 mg (monobromo compound: 60 wt%)).

[0151] [ka]

[0152] The compound represented by formula (20) (161 mg, 0.234 mmol), 5 mL of tetrahydrofuran, and 2.5 mL of purified water were added to a reaction vessel and ultrasonically degassed for 15 minutes. Sodium carbonate (67.8 mg, 0.640 mmol, Kishida Chemical Co., Ltd.) and tetrakis(triphenylphosphine)palladium(0) (19.0 mg, 0.0164 mmol, Kanto Chemical Co., Inc.) were added and heated with stirring at 60°C for 1.5 hours. The compound represented by formula (10) (28.1 mg, 0.0845 mmol) was added and heated with stirring at 60°C for 50 minutes. After the reaction was completed, the reaction solution was cooled to room temperature, and then 50 mL of tap water and 50 mL of ethyl acetate were added and the mixture was separated. The organic layer was dried over anhydrous magnesium sulfate, and the solvent was evaporated to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO2 / hexane to hexane:ethyl acetate=20:1 (volume ratio)) to obtain the compound of the following formula (21) (yield: 112 mg, yield: 87%).

[0153] The compound of the following formula (21) (99.8 mg, 0.181 mol), 2 mL of tetrahydrofuran, and N-bromosuccinimide (32.9 mg, 0.185 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) were added to a reaction vessel and stirred at room temperature for 25 minutes. After completion of the reaction, the solvent was distilled off from the reaction solution to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO2 / hexane) to obtain the compound of the following formula (22) (yield: 89.4 mg, 78%).

[0154] <NMR analysis results> 1 H-NMR (400MHz, CDCL3): δ(ppm)=0.82(t,6H), 0.92-0.98(m,4H), 1.12-1.22(m,12H), 1.49(s,18H), 1.79-1.83(m,4H)5.27(s,1H), 6.93(s,1H), 6.99(s,1H), 7.40(s,2H)

[0155] [ka]

[0156] The compound of formula (22) (90.9 mg, 0.137 mmol), bis(tributyl)tin (35 μL, 0.0693 mmol, Sigma-Aldrich), and 5 mL of dehydrated tetrahydrofuran were added to a reaction vessel and degassed by ultrasonication for 15 minutes under an argon stream. A 33 wt% xylene solution of tri-t-butylphosphine (Fujifilm Wako Pure Chemical Industries, Ltd.) (18.5 mg, 0.0302 mmol) and tris(dibenzylideneacetone)dipalladium(0) (6.4 mg, 0.00699 mmol, Sigma-Aldrich) were added and heated to reflux at 61°C for 2 hours. After the reaction was completed, the reaction solution was cooled to room temperature and the solvent was distilled off to obtain the crude product. The crude product was purified twice by silica gel column chromatography (SiO / hexane to hexane:ethyl acetate (or chloroform) = 10:1 (volume ratio)) to obtain an orange-brown solid. This solid was dissolved in 1 mL of chloroform, and then reprecipitated by adding 1 mL of methanol. The solid was collected by filtration to obtain the compound of the following formula (23) as a yellow-brown solid (yield: 33.6 mg, 45%).

[0157] <NMR analysis results> 1 H-NMR (400MHz, THF-d8): δ(ppm)=0.81(m,12H), 0.98-1.04(m,8H), 1.14-1.22(m,24H), 1.47(s,36H), 1.92-1.94(m,8H)6.35(s,2H), 7.15(s,2H), 7.16(s,2H), 7.42(s,4H) <Mass spectrometry results> TOF-MS(ESI) m / z calculation for C 70 H 98 O2S4([M] + ):1098.65,found:1098.66 <Elemental analysis results> Anal.Calcd.For C 70 H 98 O2S4:C,76.45;H,8.98;N,0.Found:C,76.51;H,8.87;N,0.23.

[0158] [ka]

[0159] The compound represented by formula (23) (10.5 mg, 0.00955 mmol), 5 mL of 1,2-dichlorobenzene, potassium ferricyanide (21.8 mg, 0.0662 mmol, Fujifilm Wako Pure Chemical Industries, Ltd.), and 1.3 mL (0.145 mmol) of aqueous potassium hydroxide solution (potassium hydroxide 308 mg / purified water 50 mL) were added to a reaction vessel and stirred at room temperature for 5 hours. After completion of the reaction, 20 mL of tap water and 30 mL of 1,2-dichlorobenzene were added to the reaction solution, and the mixture was separated. The organic layer was evaporated to obtain a crude product. 5 mL of acetone was added to the crude product, which was then washed with ultrasound to obtain the compound of formula (A-35) below as a reddish-brown solid (yield: 7.8 mg, 74%).

[0160] <Mass spectrometry results> TOF-MS(ESI) m / zcalc.for C 70 H 96 O2S4([M+H] + ):1097.64:,found:1097.67 <Elemental analysis results> Anal.Calcd.For C 70 H 96 O2S4:C,76.59;H,8.81;N,0.Found:C,76.74;H,8.84;N,0.26.

[0161] [ka]

[0162] <Solubility Evaluation> Except for using compound (A-35) instead of compound (A-6), the solubility evaluation was carried out in the same manner as in Example 1. The results are shown in Table 1.

[0163] <Absorption spectrum measurement> Instead of compound (A-1), a dichloromethane solution of compound (A-35) (concentration 1.0 × 10 -6The ultraviolet-visible absorption spectrum was measured in the same manner as in Example 1, except that a solution of 1000 ppm (1000 mol / L) was prepared and measured using an ultraviolet-visible spectrophotometer (Shimadzu Corporation, UV-3600). The results are shown in Table 2.

[0164] [Example 4] Synthesis of Compound (A-27) 3,3'-Dibromo-5,5'-bis(trimethylsilyl)-2,2'-bithiophene (5.05 g, 0.0108 mol, Tokyo Chemical Industry Co., Ltd.) was added to a reaction vessel and the atmosphere was replaced with argon. Anhydrous tetrahydrofuran (100 mL) was added and the vessel was cooled to below -70°C in a dry ice-acetone bath. A hexane solution (1.55 M) of n-butyllithium (15 mL, 0.0232 mol, Kanto Chemical Co., Inc.) was added dropwise over 22 minutes, and the mixture was stirred at below -70°C for 2 hours. Dichlorodibutylsilane (3.8 mL, 0.0137 mol) was added dropwise to the reaction mixture over 4 minutes, and the mixture was allowed to warm to room temperature over 2 hours and 25 minutes, completing the reaction. Tap water and ethyl acetate were added to the reaction mixture, and the organic layer was separated. The organic layer was washed twice with tap water. The separated organic layer was dried over anhydrous magnesium sulfate, and the solvent was removed by distillation to obtain the crude product. This crude product was purified twice by silica gel column chromatography (SiO2 / hexane) to obtain the compound of the following formula (24) as a pale yellow oily substance (yield: 4.44 g, yield: 81.0%).

[0165] A compound of formula (24) (3.31 g, 6.53 mmol), 186 mL of chloroform, and trifluoroacetic acid (1.26 mL, 13.1 mmol) were added to a reaction vessel and stirred at room temperature for 25 minutes. After the reaction was completed, tap water was added to the reaction solution and the layers were separated. The organic layer was washed with saturated brine, dried over anhydrous magnesium sulfate, and the solvent was distilled off to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO / hexane) to obtain the compound of formula (25) as a yellow oil (yield: 2.15 g, 108%).

[0166] [ka]

[0167] The reaction vessel was purged with argon, and a 12 mL solution of the compound of formula (25) (1.62 g, 0.00528 mol) in dehydrated tetrahydrofuran was added. The temperature was then adjusted to below −70°C in a dry ice-acetone bath. A 1.58 M hexane solution of n-butyllithium (3.1 mL, 0.00490 mol, manufactured by Kanto Chemical Co., Inc.) was added dropwise over 5 minutes, and the mixture was stirred at −70°C or below for 3 hours and 20 minutes. A 2.5 mL solution of trimethyltin chloride (1.08 g, 0.00542 mol, manufactured by Tokyo Chemical Industry Co., Ltd.) in dehydrated tetrahydrofuran was added dropwise over 10 minutes, and the mixture was stirred at −70°C or below for 2 hours. The reaction vessel was then removed from the dry ice-acetone bath, allowed to warm naturally, and left to stand overnight. After stirring at room temperature for 4 hours, the solvent was distilled off to obtain a crude product. 100 mL of hexane was added to this crude product, the precipitate was filtered, and the solvent in the filtrate was distilled off to obtain a dark green oily substance containing the compound of the following formula (26) (yield: 2.11 g, HPLC purity: 79%).

[0168] A compound of formula (26) (2.11 g, HPLC purity 79%, 0.00355 mol), 2,6-di-t-butyl-4-bromophenol (1.11 g, 0.00389 mol, manufactured by Tokyo Chemical Industry Co., Ltd.), and 30 mL of dehydrated tetrahydrofuran were added to a reaction vessel under an argon atmosphere. The mixture was degassed by ultrasonic irradiation for 15 minutes. Tetrakis(triphenyl)phosphinepalladium(0) (0.209 g, 0.000181 mol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the mixture was heated to reflux at 63°C for 2 hours and 40 minutes. The reaction solution was cooled to room temperature and then allowed to stand overnight. After heating to reflux at 63°C for 50 minutes, tetrakis(triphenyl)phosphinepalladium(0) was added in the same manner, and the mixture was heated to reflux at 63°C for 8 hours and 25 minutes. After the reaction was completed, the reaction solution was cooled to room temperature, and the solvent was evaporated to obtain a crude product. This crude product was purified twice by silica gel column chromatography (SiO2 / hexane to hexane:chloroform=5:1) to obtain the compound of the following formula (27) as an orange-yellow solid (yield: 1.11 g, 61%).

[0169] <NMR analysis results> 1H-NMR (400MHz, CDCL3): δ(ppm)=0.85(t,6H), 0.91-0.94(m,4H), 1.30-1.40(m,8H), 1.49(s,18H), 5.26(s,1H), 7.06(d,1H), 7.11(s,1H), 7.19(d,1H), 7.41(s,2H)

[0170] [ka]

[0171] The compound of formula (27) (1.11 g, 0.00217 mol) and 80 mL of anhydrous tetrahydrofuran were added to a reaction vessel, and a solution of N-bromosuccinimide (0.427 g, 0.00240 mol, manufactured by Tokyo Chemical Industry Co., Ltd.) in 10 mL of anhydrous tetrahydrofuran was added under ice bath conditions, followed by stirring for 20 minutes. After completion of the reaction, the solvent was distilled off from the reaction solution to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO2 / hexane to hexane:chloroform = 30:1) to obtain the compound of formula (28) below as an orange solid (yield: 986 mg, 77%).

[0172] <NMR analysis results> 1 H-NMR (400MHz, CDCL3): δ(ppm)=0.85(t,6H), 0.89-0.92(m,4H), 1.30-1.38(m,8H), 1.48(s,18H), 5.28(s,1H), 7.00(s,1H), 7.09(s,1H), 7.39(s,2H)

[0173] [ka]

[0174] The compound of formula (28) (986 mg, 1.67 mmol) and 50 mL of dehydrated tetrahydrofuran were added to a reaction vessel under an argon atmosphere, and the mixture was degassed by ultrasonication for 15 minutes. Bis(tributyl)tin (425 μL, 0.841 mmol, Sigma-Aldrich), tris(dibenzylideneacetone)palladium(0) (78.5 mg, 0.0857 mmol, Sigma-Aldrich), and a 33 wt% xylene solution of tri-t-butylphosphine (Fujifilm Wako Pure Chemical Industries, Ltd.) (230 mg, 0.375 mmol) were added, and the mixture was heated to reflux at 63 °C for 7 hours. The reaction solution was cooled to room temperature and allowed to stand overnight, and then tris(dibenzylideneacetone)palladium(0) (81.3 mg, 0.0888 mmol, Sigma-Aldrich) and a 33 wt% xylene solution of tri-t-butylphosphine (223 mg, 0.364 mmol) were added, and the mixture was again heated under reflux at 63°C for 9 hours and 30 minutes. After completion of the reaction, the reaction solution was cooled to room temperature, and the solvent was distilled off to obtain a crude product. This crude product was purified by silica gel column chromatography (SiO2 / toluene) to obtain a brown oily substance. 50 mL of methanol was added to this brown oily substance, and the mixture was filtered by ultrasonic irradiation for 60 minutes. 10 mL of hexane was added to the residue, and the mixture was filtered by ultrasonic irradiation for 50 minutes to obtain the compound of formula (29) below as an orange solid (yield: 285 mg, 34%).

[0175] <NMR analysis results> 1 H-NMR (400MHz, THF-d8): δ(ppm)=0.86(t,12H), 0.97-1.00(m,8H), 1.29-1.4 5(m,16H), 1.47(s,36H), 6.37(s,2H), 7.20(s,2H), 7.21(s,2H), 7.42(s,4H)

[0176] [ka]

[0177] The compound of formula (29) (31.1 mg, 0.0305 mmol), 5 mL of dehydrated 1,2-dichlorobenzene, and lead(IV) oxide (71.5 mg, 0.299 mmol) were added to a reaction vessel under an argon atmosphere, and the mixture was subjected to ultrasonic irradiation for 50 minutes. The addition of lead(IV) oxide was repeated twice, resulting in a total of 80 minutes of ultrasonic irradiation (additional lead(IV) amount: 232.8 mg, 0.973 mmol). After the reaction was completed, the reaction solution was filtered to remove the lead(IV) oxide, and the filtrate was distilled to obtain the crude product. 5 mL of methanol was added to the crude product, and the mixture was subjected to ultrasonic irradiation and filtration to obtain the compound of formula (A-27) below as a black solid (yield: 20 mg).

[0178] [ka]

[0179] <Solubility Evaluation> Except for using compound (A-27) instead of compound (A-6), the solubility was evaluated in the same manner as in Example 1. The results are shown in Table 1.

[0180] <Absorption spectrum measurement> Except for using compound (A-27) instead of compound (A-1), ultraviolet-visible absorption spectrum measurement was carried out in the same manner as in Example 1. The results are shown in Table 2.

[0181] [Comparative Example 1] The solubility evaluation was carried out in the same manner as in Example 1, except that copper (II) phthalocyanine (β-type (manufactured by Tokyo Chemical Industry Co., Ltd.)), a comparative compound represented by the following formula (B-1), was used instead of compound (A-6). The results are shown in Table 1.

[0182] [ka]

[0183] Comparative Example 2 The solubility evaluation was carried out in the same manner as in Example 1, except that IR-813 p-toluenesulfonate (manufactured by Tokyo Chemical Industry Co., Ltd.), a comparative compound (B-2) represented by the following formula, was used instead of compound (A-6). The results are shown in Table 1.

[0184] [ka]

[0185] [Table 1]

[0186] As is clear from Table 1, the compounds of the present invention in the examples exhibited higher solubility than the conventionally known near-infrared absorbing dyes.

[0187] [Table 2]

[0188] The results in Table 2 clearly show that the compounds of the present invention have a high molar absorption coefficient in the near-infrared region and can efficiently absorb near-infrared light. Being able to efficiently absorb near-infrared light is expected to enable the production of elements that exhibit high conversion efficiency at low concentrations, for example, in the production of photoelectric conversion elements, enabling cost reductions. Furthermore, Figure 1 shows that the absorption in the visible light region is relatively low.

[0189] [Example 5] Light resistance evaluation <Creating a coating> A coating solution was prepared by dissolving 10 mg of near-infrared absorbing dye (A-6) in 5 mL of polymer solution (2.5 g of polyvinyl butyral resin BM-S [Lot. IE-C50] / 25 mL of ethanol / 25 mL of toluene). 0.2 mL of the solution was dropped onto a glass substrate (Matsunami slide glass S9111 (76 × 52 mm, t0.8-1.0 mm)) and spin-coated at 500 rpm (10 sec) and 2000 rpm (30 sec) using a spin coater to form a coating film.

[0190] The coating film was measured using a xenon fade meter / ATLAS Ci3000 + Xenon Weather Ometer (manufactured by Atlas Co., Ltd.) at an irradiance of 300-400 nm and 60 W / m 2 The irradiation was carried out under the conditions of a test chamber temperature of 38°C, humidity of 50%, and black panel (BP) temperature of 63°C, and the change in absorbance at the maximum absorption wavelength was measured using a UV-visible spectrophotometer. The absorbance at the maximum absorption wavelength of an unirradiated coating film was set to 1, and the absorbance after 50 hours, 100 hours, and 150 hours of irradiation is shown in Table 3.

[0191] [Comparative Examples 3 and 4] The light resistance of coating films prepared using comparative compound (B-1) or comparative compound (B-2) instead of near-infrared absorbing dye (A-6) was evaluated in the same manner as in Example 5. The results are also shown in Table 3.

[0192] [Table 3]

[0193] As is clear from Table 3, the compounds of the present invention exhibited higher light resistance than the conventionally known near-infrared absorbing dyes. The compound of the present invention has good solubility and light resistance, and can be used as a near-infrared absorbing dye in photoelectric conversion elements, color filters, and the like. [Industrial Applicability]

[0194] The compounds of the present invention are expected to be applied in a wide range of fields as near-infrared absorbing dyes that absorb light in the near-infrared region, have high solubility in solvents, film-forming properties by solution processing, and high light resistance, as photoelectric conversion elements such as solar cells and near-infrared photosensors, as near-infrared absorbing materials such as neural density (ND) filters, color filters, security films, agricultural films, and light control filters (heat shielding / semiconductor sensors), and as photosensitizing dyes for photodynamic therapy.

Claims

1. A compound represented by the following general formula (1): 【Chemistry 1】 [In the formula, R １ ~R ４ are each independently a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent; a linear or branched alkynyl group having 2 to 20 carbon atoms which may have a substituent; or a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent, X １ and X ２ each independently represents a divalent group.

2. X in the general formula (1) １ and X ２ The compound according to claim 1, wherein is represented by the following general formula (2) or (3): 【Chemistry 2】 [In the formula, R ５ and R ６ are each independently a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent; or an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent, Y represents a carbon atom, a silicon atom, or a germanium atom. 【Transformation 3】 [wherein Z is an oxygen atom, CR ７ R ８ or NR ９ represents R ７ and R ８ are each independently nitrile groups, an acyl group having 1 to 18 carbon atoms which may have a substituent; or an alkoxycarbonyl group having 1 to 18 carbon atoms which may have a substituent, R ９ teeth, a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent; a cycloalkyl group having 3 to 10 carbon atoms which may have a substituent; an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent; represents.]

3. In the general formula (1), R １ ~R ４ The compound according to claim 1 or 2, wherein is a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent.

4. A near-infrared absorbing dye comprising the compound according to any one of claims 1 to 3.

5. A thin film comprising the compound according to any one of claims 1 to 3.

6. A color filter comprising the near-infrared absorbing dye according to claim 4 .

7. A near-infrared cut filter comprising the near-infrared absorbing dye according to claim 4 .

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