Novel squarylium compound, near-infrared absorbing dye, and thin film

Abstract

The invention relates to a novel squarylium compound, a near-infrared absorbing pigment and a thin film. Provided is a compound having high heat resistance and absorbing in the near-infrared light region. A squarylium compound represented by general formula (1). In the # imgabs0 formula, L1 and L2 each represent a single bond, an alkenylene group, a divalent aromatic hydrocarbon group, or a divalent aromatic heterocyclic group, R1 and R2 each represent an alkyl group, an alkenyl group, an alkynyl group, a cycloalkyl group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, Ar1 and Ar2 each represent a hydrogen atom, an amino group, an aromatic hydrocarbon group, or an aromatic heterocyclic group, and m and n each represent an integer of 1 or 2.

Description

Technical Field

[0001] The present invention relates to novel squarylium compounds, and near-infrared absorbing pigments and thin films containing the compounds. Background Art

[0002] In recent years, regarding pigment compounds, although the requirements for fastness, particularly light resistance and weather resistance, and the demand for dyes rather than pigments (functions in a film or molecularly dispersed state) are increasing, molecular design for adjusting each physical property is still in a state of helplessness. Therefore, exploration of pigment compounds based on new skeletons is underway.

[0003] Near-infrared absorbing pigments are pigments that have absorption in the near-infrared region (700 nm - 2000 nm) with a longer wavelength than visible light, and exhibit strong light absorption obtained from charge transfer of organic pigments and metal complexes. Since near-infrared light has high biological penetrability and is contained in sunlight in large amounts, various developments have been carried out using light in the near-infrared region, and applications are expected in a wide range of fields such as photoelectric conversion elements such as organic thin-film solar cells and dye-sensitized solar cells, neutral density (ND) filters, the security field, agricultural films, dimming filters (thermal insulation / semiconductor sensors), and photodynamic therapy.

[0004] As near-infrared absorbing materials, inorganic materials and organic materials are included. As inorganic materials, rare earth metals such as ytterbium and copper phosphate crystallized glass are known. However, since the absorption of light in the near-infrared region by inorganic materials is insufficient, a large amount of materials is required. On the other hand, regarding organic materials, since they have sufficient light absorption in the near-infrared region, development as near-infrared absorbing materials has been vigorously carried out.

[0005] As organic near-infrared absorbing materials, to date, although organic pigments having phthalocyanine, rhodamine, etc. as the mother nucleus have been synthesized, their types and quantities are limited. In addition, most of them also absorb visible light (Patent Document 1), so there are few organic pigments that can be applied to uses requiring transparency such as near-infrared absorbing films.

[0006] In addition, near-infrared absorbing pigments can be dissolved or dispersed in a solvent to be used as a solution or dispersion. When forming a film by coating a pigment solution, the solubility of the pigment is required, and in the case of film formation, the molecular structure contributes greatly. Therefore, it is desired to develop a near-infrared absorbing pigment that satisfies the following conditions: absorbs near-infrared light and has less absorption in the visible light region, has solubility suitable for coating film when used after dissolution, has high heat resistance, and is easy to handle.

[0007] Patent Document 1: Japanese Patent Application Laid-Open No. 2011-116717

[0008] Patent Document 2: WO 2017 / 104283 Summary of the Invention

[0009] An object of the present invention is to provide a compound having absorption in the near-infrared region and having high heat resistance. Another object of the present invention is to provide a near-infrared absorbing dye and a film using the compound.

[0010] In order to solve the above problems, the inventors focused on the dithienopyrrole skeleton in the development of novel near-infrared absorbing dyes and conducted in-depth research. As a result, it was found that a squarylium compound having a dithienopyrrole skeleton is useful as a near-infrared absorbing dye for solving the above problems. That is, the present invention has the following gist.

[0011] [1] A squarylium compound represented by the following general formula (1):

[0012] [Chemical Formula 1]

[0013]

[0014] In the formula, L 1 and L 2 each independently represents a single bond, a linear or branched alkenylene having 2 to 20 carbon atoms which may have a substituent, a divalent aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent.

[0015] R 1 and R 2 each independently represents 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, 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, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent.

[0016] Ar 1 and Ar 2 each independently represents a hydrogen atom, an amino group having 6 to 36 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent.

[0017] m and n each independently represent an integer of 1 or 2.

[0018] [2] The squarylium compound according to [1], wherein in the general formula (1), Ar 1 and Ar 2 each independently represent a hydrogen atom or a group represented by the following general formula (2).

[0019]

Chemical formula 2

[0020]

[0021] In the formula, R 3 and R 4 each independently represent 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, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent,

[0022] R 3 and R 4 can bond to each other to form a ring,

[0023] Z 1 represents an oxygen atom or a sulfur atom,

[0024] x and y each independently represent an integer of 0 or 1.

[0025] [3] The squarylium compound according to [1] or [2], wherein in the general formula (1), R 1 and R 2 each independently are a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent.

[0026] [4] A near-infrared absorbing dye comprising the squarylium compound according to any one of [1] to [3].

[0027] [5] A film comprising the squarylium compound according to any one of [1] to [3].

[0028] According to the squarylium compound of the present invention, a near-infrared absorbing dye having main absorption characteristics in the near-infrared region and high heat resistance can be obtained. In addition, a film made of this squarylium compound can be applied to organic electronic devices such as solar cells having excellent photoelectric conversion performance. Description of the Drawings

[0029] Figure 1 is the ultraviolet-visible near-infrared absorption spectrum of the compound (A-1) obtained in Example 1. Detailed Embodiments

[0030] Hereinafter, embodiments of the present invention will be described in detail. The following description is an example of the embodiments of the present invention, and the present invention is not limited to these contents. The novel compound having a squarylium skeleton of the present invention can be used in organic electronic devices such as near-infrared absorbing dyes, thin films containing the compound, and photoelectric conversion elements containing them.

[0031] 〈Squarylium Compound〉

[0032] The squarylium compound of the present invention is a compound represented by the general formula (1). Hereinafter, the squarylium compound of the present invention will be specifically described.

[0033] In the general formula (1), L 1 and L 2 each independently represents a single bond, a linear or branched alkenylene group having 2 to 20 carbon atoms which may have a substituent, a divalent aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent, or a divalent aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent. In addition, regarding L 1 and L 2 , the case where they are single bonds means that the squarylium skeleton is directly bonded to the dithienopyrrole skeleton in the general formula (1).

[0034] As the "linear or branched alkenylene group having 2 to 20 carbon atoms which may have a substituent" represented by L 1 and L 2 , specifically, alkenylene groups obtained by removing one hydrogen atom from alkenyl groups such as vinyl group, 1-propenyl, 2-propenyl, 1-butenyl, 2-butenyl, 1-pentenyl, 2-pentenyl, 1-hexenyl, isopropenyl and isobutenyl can be mentioned.

[0035] As the "divalent aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent" represented by L 1 and L 2 , specifically, divalent aromatic hydrocarbon groups (arylene groups) obtained by removing one hydrogen atom from aromatic hydrocarbon groups such as phenyl, biphenyl, terphenyl, naphthyl, anthryl, phenanthryl, fluorenyl, indenyl, pyrenyl, perylenyl, fluoranthenyl and benzo[9,10]phenanthryl can be mentioned. In addition, in the present invention, "aromatic hydrocarbon group" includes "fused polycyclic aromatic group".

[0036] As the "divalent aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent" represented by L 1 and L 2The "divalent aromatic heterocyclic group having 5 to 36 ring-forming atoms capable of having substituents" in the representation specifically includes divalent aromatic heterocyclic groups obtained by removing one hydrogen atom from monovalent heterocyclic groups such as pyridyl, pyrimidinyl, triazinyl, thienyl, furanyl group, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, quinolinyl, isoquinolinyl, naphthyridinyl, acridinyl, phenanthrolinyl, benzofuranyl, benzothienyl, oxazolyl, indolyl, carbazolyl, benzoxazolyl, thiazolyl, benzothiazolyl, quinoxalinyl, benzimidazolyl, dibenzofuranyl, dibenzothienyl, dithienopyrrolyl, iminostilbenyl, and carbolinyl.

[0037] As for L 1 and L 2The "substituent" in the "linear or branched alkenylene having 2 to 20 carbon atoms capable of having substituents", "divalent aromatic hydrocarbon group having 6 to 36 carbon atoms capable of having substituents", or "divalent aromatic heterocyclic group having 5 to 36 ring-forming atoms capable of having substituents" specifically includes: halogen atoms such as fluorine atom, chlorine atom, bromine atom, iodine atom; cyano group; hydroxyl group; nitro group; nitroso group; carboxyl group; phosphoric acid group; carboxylic acid ester groups such as methyl ester group, ethyl ester group; linear or branched alkyl groups having 1 to 19 carbon atoms such as methyl group, ethyl group, n-propyl group, isopropyl group, n-butyl group, isobutyl group, sec-butyl group, tert-butyl group, n-pentyl group, isopentyl group, n-hexyl group, 2-ethylhexyl group, heptyl group, octyl group, isooctyl group, nonyl group, decyl group; linear or branched alkenyl groups having 2 to 18 carbon atoms such as vinyl group, 1-propenyl group, allyl group, 1-butenyl group, 2-butenyl group, 1-pentenyl group, 1-hexenyl group, isopropenyl group, isobutenyl group; alkoxy groups having 1 to 20 carbon atoms such as methoxy group, ethoxy group, propoxy group, tert-butoxy group, pentyloxy group, hexyloxy group; aromatic hydrocarbon groups having 6 to 19 carbon atoms such as phenyl group, naphthyl group, anthryl group, phenanthryl group, pyrenyl group; aromatic heterocyclic groups having 5 to 19 ring-forming atoms such as pyridyl group, pyrimidinyl group, triazinyl group, thienyl group, furyl group, pyrrolyl group, imidazolyl group, pyrazolyl group, triazolyl group, quinolinyl group, isoquinolinyl group, naphthyridinyl group, acridinyl group, phenanthrolinyl group, benzofuryl group, benzothienyl group, oxazolyl group, indolyl group, carbazolyl group, benzoxazolyl group, thiazolyl group, benzothiazolyl group, quinoxalinyl group, benzimidazolyl group, dibenzofuryl group, dibenzothienyl group, dithienopyrrolyl group, iminostilbene group, and carbolinyl group; amino groups having 0 to 20 carbon atoms, which are unsubstituted amino group (-NH2), mono-substituted amino groups such as ethylamino group, acetylamino group, phenylamino group, or di-substituted amino groups such as diethylamino group, diphenylamino group, acetylphenylamino group; unsubstituted sulfanyl group (mercapto group: -SH), sulfanyl groups having 0 to 20 carbon atoms such as methylsulfanyl group, ethylsulfanyl group, propylsulfanyl group, hex-5-ene-3-sulfanyl group, phenylsulfanyl group, biphenylsulfanyl group; amide groups having 0 to 20 carbon atoms, which are unsubstituted amide group (-C(=O)NH2), mono-substituted amide groups such as acetamide group, acetylamide group, benzamide (-C(=O)NHR a1 ), or di-substituted amide groups such as diethylamide group, dihexylamide group, diphenylamide group (-C(=O)NR a1 R a2 )(wherein, R a1 and R a2 represent linear or branched alkyl groups having 1 to 20 carbon atoms, or aromatic hydrocarbon groups having 6 to 20 carbon atoms); and so on. In addition, for these "substituents", it can contain only one, or can contain multiple. When containing multiple, they can be the same or different from each other. In addition, these "substituents" can further have the exemplified substituents.

[0038] In the general formula (1), R 1 and R 2 each independently represent 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, 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, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent.

[0039] As the "linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent" represented by R 1 and R 2 , specifically, methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, n-hexyl (Hex), 2-ethylhexyl (2-EtHex), heptyl, octyl, isooctyl, nonyl, decyl and the like can be mentioned.

[0040] As the "linear or branched alkenyl group having 2 to 20 carbon atoms which may have a substituent" represented by R 1 and R 2 , specifically, vinyl, 1-propenyl, allyl, 1-butenyl, 2-butenyl, 1-pentenyl, 1-hexenyl, isopropenyl, isobutenyl, and linear or branched alkenyl groups having 2 to 20 carbon atoms obtained by bonding multiple of these alkenyl groups and the like can be mentioned.

[0041] As the "linear or branched alkynyl group having 2 to 20 carbon atoms which may have a substituent" represented by R 1 and R 2 , specifically, ethynyl, 1-propynyl, 2-propynyl, 1-butynyl, 2-butynyl, 1-methyl-2-propynyl, 1-pentynyl, 2-pentynyl, 1-methyl-n-butynyl, 2-methyl-n-butynyl, 3-methyl-n-butynyl, 1-hexynyl and the like can be mentioned.

[0042] As the "cycloalkyl group having 3 to 10 carbon atoms which may have a substituent" represented by R 1 and R 2 , specifically, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl and the like can be mentioned.

[0043] As R 1 and R2 In the “aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents” represented, specifically, examples thereof include phenyl, biphenyl, terphenyl, naphthyl, anthryl group, phenanthryl, fluorenyl, indenyl, pyrenyl, perylenyl, fluoranthenyl, and benzo[9,10]phenanthryl.

[0044] As the “R 1 and R 2 In the “aromatic heterocyclic group having 5 to 36 ring-constituting atoms which may have substituents” represented, specifically, examples thereof include pyridyl, pyrimidinyl, triazinyl, thienyl, furanyl group, pyrrolyl, imidazolyl, pyrazolyl, triazolyl, quinolinyl, isoquinolinyl, naphthyridinyl, acridinyl, phenanthrolinyl, benzofuranyl, benzothienyl, oxazolyl, indolyl, carbazolyl, benzoxazolyl, thiazolyl, benzothiazolyl, quinoxalinyl, benzimidazolyl, dibenzofuranyl, dibenzothienyl, dithienopyrrolyl, iminostilbenyl, and carbolinyl.

[0045] As the “R 1 and R 2 The “substituent” in the “linear or branched alkyl group having 1 to 20 carbon atoms which may have substituents”, “linear or branched alkenyl group having 2 to 20 carbon atoms which may have substituents”, “linear or branched alkynyl group having 2 to 20 carbon atoms which may have substituents”, “cycloalkyl group having 3 to 10 carbon atoms which may have substituents”, “aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents”, or “aromatic heterocyclic group having 5 to 36 ring-constituting atoms which may have substituents” represented, examples thereof include the same substituents as the “substituent” in the “linear or branched alkenylene group having 2 to 20 carbon atoms which may have substituents” represented by L 1 and L 2

[0046] In the general formula (1), Ar 1 and Ar 2 each independently represents a hydrogen atom, an amino group having 6 to 36 carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents, or an aromatic heterocyclic group having 5 to 36 ring-constituting atoms which may have substituents.

[0047] As the “Ar 1 and Ar 2 ​The "amino group having 6 to 36 carbon atoms which may have substituents" in the represented "amino group having 6 to 36 carbon atoms which may have substituents" specifically includes, for example, ethylamino, acetylamino, phenylamino, etc. as monosubstituted amino groups; and diethylamino, dipropylamino, dibutylamino, diphenylamino, acetylphenylamino, bis(2-ethylhexyl)amino, etc. as disubstituted amino groups.

[0048] As the "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents" represented by Ar 1 and Ar 2 The "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents" includes the same groups as the "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents" represented by R 1 and R 2 represented.

[0049] As the "aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents" represented by Ar 1 and Ar 2 The "aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents" includes the same groups as the "aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents" represented by R 1 and R 2 represented.

[0050] As the "substituent" in the "amino group having 6 to 36 carbon atoms which may have substituents", "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents", or "aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents" represented by Ar 1 and Ar 2 includes the same substituents as the "substituent" in the "linear or branched alkenylene group having 2 to 20 carbon atoms which may have substituents" represented by L 1 and L 2 represented.

[0051] In the general formula (1), m and n each independently represent an integer of 1 or 2. That is, when m is 1, n is 1 or 2, and when n is 1, m is 1 or 2. In the present invention, for the convenience of compound synthesis, it is preferred that m and n are the same.

[0052] In the present invention, L 1 and L 2Preferably a single bond, a divalent aromatic hydrocarbon group having 6 to 36 carbon atoms capable of having substituents, or a divalent aromatic heterocyclic group having 5 to 36 ring-forming atoms capable of having substituents, more preferably a single bond or a divalent aromatic heterocyclic group having 5 to 36 ring-forming atoms capable of having substituents. In addition, in L 1 and L 2 is a group having substituents, the "substituent" is preferably a hydroxyl group, a linear or branched alkyl group having 1 to 19 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, or an aromatic hydrocarbon group having 6 to 19 carbon atoms.

[0053] In the present invention, R 1 and R 2 are preferably a linear or branched alkyl group having 1 to 20 carbon atoms capable of having substituents, an aromatic hydrocarbon group having 6 to 36 carbon atoms capable of having substituents, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms capable of having substituents. In addition, in R 1 and R 2 is a group having substituents, the "substituent" is preferably a linear or branched alkyl group having 1 to 19 carbon atoms, a linear or branched alkenyl group having 2 to 18 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 19 carbon atoms, an amino group having 0 to 20 carbon atoms, or an amide group having 0 to 20 carbon atoms.

[0054] The compound represented by the general formula (1) is preferably symmetric with the squarylium skeleton as the center. In addition, in this specification, "symmetric" means that the compound has a structure that is the same on the left and right with the squarylium skeleton as the center. That is, in the general formula (1), L 1 and L 2 , R 1 and R 2 , m and n, and Ar 1 and Ar 2 are all preferably the same structure. However, when the compound is applied to various uses, sometimes the compound of the present invention becomes asymmetric due to modifying one of the structures on the left and right of the squarylium skeleton, but even in such a case, the compound of the present invention can be applied.

[0055] In the present invention, Ar 1 and Ar 2 are preferably each independently a hydrogen atom or a group represented by the general formula (2).

[0056] In the general formula (2), R 3 and R 4Each independently represents a linear or branched alkyl group having 1 to 20 carbon atoms which may have substituents, a cycloalkyl group having 3 to 10 carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents.

[0057] As the "linear or branched alkyl group having 1 to 20 carbon atoms which may have substituents" represented by R 3 and R 4 in the "linear or branched alkyl group having 1 to 20 carbon atoms which may have substituents", specifically, groups the same as the "linear or branched alkyl group having 1 to 20 carbon atoms which may have substituents" represented by the aforementioned R 1 and R 2 can be cited.

[0058] As the "cycloalkyl group having 3 to 10 carbon atoms which may have substituents" represented by R 3 and R 4 in the "cycloalkyl group having 3 to 10 carbon atoms which may have substituents", specifically, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, cyclooctyl, cyclodecyl, cyclododecyl, etc. can be cited.

[0059] As the "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents" represented by R 3 and R 4 in the "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents", groups the same as the "aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents" represented by the aforementioned R 1 and R 2 can be cited.

[0060] As the "aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents" represented by R 3 and R 4 in the "aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents", groups the same as the "aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents" represented by the aforementioned R 1 and R 2 can be cited.

[0061] As the "aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents" represented by R 3 and R 4The "substituent" in the "linear or branched alkyl group having 1 to 20 carbon atoms capable of having substituents", "cycloalkyl group having 3 to 10 carbon atoms capable of having substituents", "aromatic hydrocarbon group having 6 to 36 carbon atoms capable of having substituents", or "aromatic heterocyclic group having 5 to 36 ring-forming atoms capable of having substituents" can be exemplified by the same substituents as the "substituent" in the "linear or branched alkenylene group having 2 to 20 carbon atoms capable of having substituents" represented by L 1 and L 2 represents.

[0062] R 3 and R 4 can bond to each other to form a ring. Specifically, R 3 and R 4 can also bond to each other through a single bond, a vinylene bond (―CH=CH―), or a bond sandwiching an oxygen atom, a sulfur atom, a selenium atom, or a nitrogen atom to form a ring.

[0063] In the present invention, R 3 and R 4 are preferably a linear or branched alkyl group having 1 to 20 carbon atoms capable of having substituents, an aromatic hydrocarbon group having 6 to 36 carbon atoms capable of having substituents, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms capable of having substituents. In addition, when R 3 and R 4 are groups having substituents, the "substituent" is preferably a linear or branched alkyl group having 1 to 19 carbon atoms, a linear or branched alkenyl group having 2 to 18 carbon atoms, an alkoxy group having 1 to 20 carbon atoms, an aromatic hydrocarbon group having 6 to 19 carbon atoms, an amino group having 0 to 20 carbon atoms, or an amide group having 0 to 20 carbon atoms.

[0064] In the general formula (2), Z 1 represents an oxygen atom or a sulfur atom. In addition, in the general formula (2), x and y each independently represent an integer of 0 or 1. That is, when x is 0, y is 0 or 1, and when x is 1, y is 0 or 1. In the present invention, it is preferable that x is 0 and y is 0, x is 0 and y is 1, or x is 1 and y is 0.

[0065] Hereinafter, specific examples of the squarylium compound represented by the general formula (1) of the present invention are shown, but the present invention is not limited to these compounds. In addition, some hydrogen atoms, carbon atoms, etc. have been omitted in the following exemplified compounds. Furthermore, in the following exemplified compounds, one of the possible isomers is shown, and the squarylium compound according to the present invention also includes all other isomers. In addition, the squarylium compound according to the present invention can also be a mixture of two or more isomers. In addition, in the following exemplified compounds, 2-ethylhexyl (2EtHex) is sometimes labeled as R b1 , and n-hexyl (-C6H 13 ) is labeled as R b2 .

[0066] [Chemical Formula 3]

[0067]

[0068] [Chemical Formula 4]

[0069]

[0070] [Chemical Formula 5]

[0071]

[0072] [Chemical Formula 6]

[0073]

[0074] [Chemical Formula 7]

[0075]

[0076] [Chemical Formula 8]

[0077]

[0078] [Chemical Formula 9]

[0079]

[0080] [Chemical Formula 10]

[0081]

[0082] [Chemical Formula 11]

[0083]

[0084] [Chemical Formula 12]

[0085]

[0086] [Chemical Formula 13]

[0087]

[0088]

Chemical Formula 14

[0089]

[0090]

Chemical Formula 15

[0091]

[0092]

Chemical Formula 16

[0093]

[0094]

Chemical Formula 17

[0095]

[0096]

Chemical Formula 18

[0097]

[0098]

Chemical Formula 19

[0099]

[0100]

Chemical Formula 20

[0101]

[0102]

Chemical Formula 21

[0103]

[0104]

Chemical Formula 22

[0105]

[0106]

Chemical Formula 23

[0107]

[0108]

Chemical Formula 24

[0109]

[0110]

Chemical Formula 25

[0111]

[0112]

Chemical Formula 26

[0113]

[0114] Chemical Formula 27

[0115]

[0116] Chemical Formula 28

[0117]

[0118] Chemical Formula 29

[0119]

[0120] Chemical Formula 30

[0121]

[0122] Chemical Formula 31

[0123]

[0124] The compound of the present invention represented by the general formula (1) can be synthesized by a known method. As an example, the synthesis method of compound (A-1) will be described. First, after brominating the following compound (1a) (4-(2-ethylhexyl)-4H-dithieno[3,2-b:2’,3’-d]pyrrole) to obtain a brominated compound, a coupling reaction is carried out with an amine compound represented by the following compound (2a), whereby the following compound (3a) is obtained. Then, by reacting compound (3a) with squaric acid, compound (A-1) can be synthesized. In addition, compound (1a) can be synthesized by a known method.

[0125] Chemical Formula 32

[0126]

[0127] As a purification method of the compound of the present invention represented by the general formula (1), purification can be carried out by column chromatography, recrystallization and reprecipitation based on solvents, washing, etc. In addition, the identification of the compound can be carried out by nuclear magnetic resonance analysis (NMR) and mass spectrometry.

[0128] In addition, in the compound represented by the general formula (1), the cation is delocalized and present as follows.

[0129] Chemical Formula 33

[0130]

[0131] 〈Near-infrared absorbing pigment〉

[0132] The squarylium compound represented by the general formula (1) has absorption in the near-infrared region and high heat resistance, and thus can be used as a near-infrared absorbing dye. That is, the near-infrared absorbing dye of the present invention contains the squarylium compound represented by the general formula (1). As the near-infrared absorbing dye, the compound represented by the general formula (1) and a known near-infrared absorbing material can be used in combination. In addition, a near-infrared absorbing dye composition containing the compound represented by the general formula (1), a solvent, an additive, etc. can also be prepared for various uses. Furthermore, the near-infrared absorbing dye can also be used as a near-infrared absorbing ink solution by dissolving or dispersing it in a solvent.

[0133] 〈Near-infrared Absorbing Material〉

[0134] The compound represented by the general formula (1) can be used as a near-infrared absorbing material for organic electronic devices and the like. In addition, a near-infrared absorbing composition obtained by dissolving or dispersing the compound in various media (the medium can be a liquid such as an organic solvent or a solid such as a polymer material) can also be used for various purposes. Furthermore, a film can be formed from the compound or the composition, and then the film can be used for the above purposes.

[0135] The compound represented by the general formula (1) has solubility suitable for solution processes. In particular, it is also possible to consider using a composition containing the compound in a solution process to manufacture organic electronic devices. In this specification, "solution process" refers to a process of simply forming a film, an element, etc. by coating a composition in the form of a solution, a dispersion, an emulsion, etc. obtained by dissolving or dispersing a compound in an organic solvent or the like.

[0136] In addition, the solubility of the compound can be evaluated as follows: Add the compound to an organic solvent, stir it at room temperature (25 ± 5 °C) or place it in an ultrasonic cleaner for about 1 or 2 minutes, and then visually measure the solubility (or saturated solubility). Since sufficient solubility is required in the manufacturing process of elements using solution processes, it is preferable to have a higher solubility.

[0137] 〈Thin Film〉

[0138] A thin film can be made using a near-infrared absorbing dye composition containing the squarylium compound represented by the general formula (1). That is, the thin film of the present invention is a thin film using the compound represented by the general formula (1) and contains the compound.

[0139] When coating a near-infrared absorbing pigment composition in a solution process to form a thin film, the composition can contain additives, binder polymers, etc. The coating solution can be prepared by dissolving or dispersing only the compound in a solvent, or by dissolving or dispersing the compound and a binder polymer in a solvent. Specific examples of binder polymers include organic or inorganic high molecular compounds such as poly-N-vinylcarbazole, polyarylate, polystyrene, polyester, polysiloxane, polymethyl acrylate, polymethyl methacrylate, polyether, polycarbonate, polyamide, polyimide, polyamideimide, parylene, polyethylene, polyethylene ether, polypropylene ether, polyphenylene ether, polyethersulfone, polyaniline and its derivatives, polythiophene and its derivatives, polyphenylene vinylene and its derivatives, polyphenylene acetylene and its derivatives, polyfluorene and its derivatives, and polythienylethylene and its derivatives.

[0140] As methods for forming a thin film, generally, the following can be mentioned: vapor deposition methods such as resistance heating evaporation, electron beam evaporation, sputtering, and molecular layer deposition as vacuum processes; solution methods such as spin coating, drop casting, dip coating, and spraying; relief printing methods such as flexographic printing and resin letterpress printing, planographic printing methods such as offset printing, dry offset printing, pad printing, intaglio printing methods such as gravure printing, screen printing methods such as silk screen printing, stencil printing methods such as mimeograph printing and Risograph printing, inkjet printing, microcontact printing, etc.; and methods combining multiple of these methods.

[0141] Solvents that can be 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; halogenated alkane organic solvents such as dichloromethane, chloroform, 1,2-dichloroethane, 1,1,2-trichloroethane, and dichloromethane; nitrile solvents such as benzonitrile and acetonitrile; ether solvents such as diethyl ether, tetrahydrofuran (THF), dioxane, diisopropyl ether, cyclopentyl methyl ether, ethylene glycol dimethyl ether, ethylene glycol diethyl ether, and 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, isopropyl alcohol, 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); chloroform (trichloromethane), etc., but are not limited to these solvents. In addition, the above solvents can be used alone or in combination of two or more, and the solvent to be used can also be selected according to the structure of the compound.

[0142] The film thickness of the thin film varies depending on its use, but is usually preferably 1 nm to 50 μm, more preferably 5 nm to 20 μm, and still more preferably 10 nm to 10 μm.

[0143] 〈Organic Electronic Device〉

[0144] An organic electronic device can be fabricated using the compound represented by the general formula (1). Examples of organic electronic devices include photoelectric conversion elements such as solar cells and photosensors, thin film transistors, and organic EL elements. Hereinafter, as an embodiment of the organic electronic device of the present invention, focusing on an organic photoelectric conversion element particularly expected to be developed for near-infrared applications, a photoelectric conversion element using the compound of the present invention as a near-infrared light absorbing material will be described.

[0145] In addition, although detailed description is omitted in this specification, near-infrared light with a wavelength exceeding 700 nm has high permeability to biological tissues. Therefore, it can also be used for the observation of in-vivo tissues, and can be applied in various forms according to the purpose in pathological analysis, diagnosis, etc. in medical fields such as near-infrared fluorescence probes.

[0146] [Photoelectric Conversion Element]

[0147] A photoelectric conversion element is an element in which a photoelectric conversion unit is disposed between a pair of opposed electrodes. The compound of the present invention represented by the general formula (1) has near-infrared light absorption characteristics, so it can be expected to be used as a photoelectric conversion element and can be considered for use in the photoelectric conversion unit of the 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.

[0148] Specifically, the compound represented by the general formula (1) can be used as a constituent material of the photoelectric conversion unit of the photoelectric conversion element. The photoelectric conversion unit is mostly composed of a photoelectric conversion layer and one or more thin film layers selected from an electron transport layer, a hole transport layer, an electron blocking layer, a hole blocking layer, and an interlayer contact improvement layer, etc., other than the photoelectric conversion layer. The compound of the present invention is useful as a light absorbing material, a photoelectric conversion material, a charge transport material, etc., so it can also be considered for use in the thin film layers other than the above-mentioned photoelectric conversion layer, but is preferably used as the thin film layer of the photoelectric conversion layer. Especially when the compound of the present invention is used as a light absorbing material, a photoelectric conversion material, etc. in an organic thin film solar cell, it can be expected to efficiently capture solar energy and utilize it for photoelectric conversion. The photoelectric conversion layer can be composed only of the compound represented by the general formula (1), or can also be composed of a known light absorbing material, other additives, etc. in addition to the compound represented by the general formula (1). In addition, the photoelectric conversion layer can contain a plurality of compounds represented by the general formula (1).

[0149] The material that can be used as the electrode of the photoelectric conversion element is not particularly limited as long as it has a certain degree of conductivity. However, it is preferably selected considering the adhesion, electron affinity, ionization potential, and stability between the adjacent photoelectric conversion layer or other layers.

[0150] Specific examples of the conductive material for the electrode include conductive transparent oxide semiconductors such as indium tin oxide (ITO) doped with tin, 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 substances such as copper iodide and copper sulfide; conductive polymers such as polythiophene, polypyrrole, and polyaniline; and carbon. These materials can also be used in combination as needed.

[0151] In the electrode, the conductive support used as the transparent electrode film on at least one side of the light incident side needs to have light transmittance capable of transmitting the light participating in the photoelectric conversion. In addition, since the conductive support is a member having the function of extracting current from the photoelectric conversion layer, a conductive substrate is preferred. Examples of the material for the conductive support include ITO, FTO (fluorine-doped tin oxide), etc.

[0152] The photoelectric conversion layer usually uses an organic semiconductor film, and the organic semiconductor film can be one layer or multiple layers. In the case of one layer, a p-type organic semiconductor layer, an n-type organic semiconductor layer, or a mixed layer thereof can be used. On the other hand, in the case of multiple layers, a structure of about 2 to 10 layers and stacked with any one of a p-type organic semiconductor layer, an n-type organic semiconductor layer, or a mixed film layer thereof can also have a buffer layer inserted between the layers. The compound of the present invention can be considered for use as a p-type semiconductor material or an n-type semiconductor material.

[0153] <Near-infrared cut-off filter>

[0154] The near-infrared absorbing material can also be used in a near-infrared cut-off filter that uses the property of selectively absorbing light in a specific wavelength region, a film for plant growth regulation, etc. The compound of the present invention and the composition containing the compound can be considered for use as a material constituting a near-infrared cut-off filter, etc., because of their high near-infrared absorption ability and excellent heat resistance. As a specific use of the near-infrared cut-off filter, examples include color filters used in semiconductors, electronic devices, various sensors, liquid crystal display devices, or imaging elements, etc.

[0155] [Color filter]

[0156] When the compound of the present invention represented by the general formula (1) is used as a near-infrared absorbing dye in a color filter, a two-layer configuration method of forming a color filter layer and a near-infrared cut-off filter layer on a substrate, or a one-layer configuration method of forming a layer having the functions of both a color filter and a near-infrared cut-off filter on a substrate can be used. In the case of the one-layer configuration, a thin-film filter can be produced by making this layer an optical filter layer.

[0157] In the case of the one-layer configuration optical filter layer, the colorant for the color filter includes: a near-infrared absorbing dye composition containing at least one compound represented by the general formula (1) and other components commonly used in the manufacture of the color filter. As other components, pigments such as dyes or pigments, resin components, organic solvents, and additives such as photoinitiators can be cited. In addition, these components can be selected and discarded, and other components can be added as needed.

[0158] Regarding a general color filter, for example, in the case of a method using a photolithography process, it can be obtained by the following method: mixing pigments such as dyes and pigments with resin components and solvents, then coating the prepared liquid on a substrate such as glass or resin, using a photomask to cause it to undergo photopolymerization, making a colored pattern of a pigment-resin composite film that is soluble / insoluble in the solvent, cleaning it, and then heating it. In addition, in the electrodeposition method and the printing method, a mixture obtained by mixing a pigment with a resin and other components is also used to make a colored pattern.

[0159] Examples of the dye or pigment in the colorant for the color filter include: red pigments such as C.I. Pigment Red 177, 209, 242, 254, 255, 264, 269, C.I. Pigment Orange 38, 43, 71; other red lake pigments; yellow pigments such as C.I. Pigment Yellow 138, 139, 150; red dyes such as C.I. Acid Red 88, C.I. Basic Violet 10; basic dyes such as C.I. Basic Blue 3, 7, 9, 54, 65, 75, 77, 99, 129; acid dyes such as C.I. Acid Blue 9, 74; disperse dyes such as Disperse Blue 3, 7, 377; spiro dyes; cyanine-based, indigo-based, phthalocyanine-based, anthraquinone-based, methylene-based, triarylmethane-based, indanthrone-based, oxazine-based, dioxazine-based, azo-based, xanthene-based; other blue lake pigments, etc., and there is no particular limitation.

[0160] In the manufacturing process of the colorant for the color filter and the color filter, it is necessary to dissolve or disperse the compound of the present invention represented by the general formula (1) well in an organic solvent containing a resin or the like. Therefore, it is preferable that the solubility or dispersibility of the compound in the organic solvent is high. The organic solvent is not particularly limited, and specifically, the same organic solvent as that used in the film formation can be used.

[0161] As the resin component in the colorant for a color filter, as long as it has the properties required in the manufacturing process and use of the resulting color filter resin film, known resins can be used. Examples of the resin component include acrylic resins, polyolefin resins, styrene resins, polyimide resins, polyurethane resins, polyester resins, epoxy resins, vinyl ether resins, phenolic (novolac) resins, other transparent resins, photocurable resins, or thermosetting resins, and monomer or oligomer components constituting these resins can be appropriately combined and used. In addition, copolymers obtained by combining monomers constituting these resins can also be used. In the case of a liquid colorant, the content of the resin component in the colorant for a color filter is preferably 5 to 95% by mass, more preferably 10 to 50% by mass, based on the mass of the colorant.

[0162] In addition, other additives such as surfactants, dispersants, defoamers, and leveling agents can be added according to the use. The amount of use of these additives is preferably an appropriate amount, preferably in a range that reduces or increases the solubility to more than required and does not affect the effects of other additives of the same type used in the manufacture of products such as color filters. The additives can be added at any time during the process of preparing the colorant.

[0163] As other additives in the colorant for a color filter of the present invention in addition to the above additives, components required for the polymerization and curing of resins such as photoinitiators and crosslinking agents can be cited. In addition, surfactants, dispersants, etc. required for stabilizing the properties of the components in the liquid colorant for a color filter can be cited. All of them can use known substances for color filter manufacturing and are not particularly limited. The total amount of the additives in the total solid components of the colorant for a color filter is preferably 5 to 60% by mass, more preferably 10 to 40% by mass, based on the mass of the colorant.

[0164] Examples

[0165] Hereinafter, the present invention will be described more specifically by way of examples, but the present invention is not limited to the following examples. In addition, the identification of the compounds obtained in the examples was carried out using 1 H-NMR (manufactured by JEOL Ltd., trade name: JNM-ECZ400S / L1 type). In addition, for the obtained compounds, ultraviolet-visible-near-infrared (UV-VIS-NIR) absorption spectra were measured using LAMBDA750-UV / VIS / NIR-SPECTROMETAR (trade name, manufactured by Perkin Elmer JAPAN Co., Ltd.), and thermal analysis was carried out using Thermoplus EVO2-TG-DTA8122 Smartloader (trade name, manufactured by Rigaku Corporation).

[0166] [Example 1]

[0167] <Synthesis of Compound (A-1)>

[0168] 3,3'-Dibromo-2,2'-bithiophene (2.0 g, 6.17 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.), sodium tert-butoxide (1.3 g, 13.6 mmol, manufactured by Kanto Chemical Co., Inc.), and dehydrated toluene (100 mL) were added to a reaction vessel, and degassing and argon replacement were carried out. Tris(dibenzylideneacetone)dipalladium(0) (283 mg, 0.309 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and 2,2'-bis(diphenylphosphino)-1,1'-binaphthalene (769 mg, 1.23 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) were added to the above reaction vessel under an argon stream, and finally 2-ethylhexylamine (1.00 mL, 6.17 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the mixture was stirred at 103 °C for 6 hours and 5 minutes for reaction. After cooling to room temperature, the reaction solution was filtered through Celite, and the solvent in the filtrate was removed by distillation under reduced pressure. Purification was carried out by silica gel column chromatography (SiO2 / hexane:ethyl acetate (20:1)) to obtain the following compound (3) as a yellow oily compound (yield: 1.97 g, yield: 100%).

[0169] <Results of NMR Analysis>

[0170] 1 1H-NMR (400 MHz, CDCl3): δ (ppm) = 0.86 - 0.92 (m, 6H), 1.28 - 1.33 (m, 8H), 1.95 (m, 1H), 4.06 (d, 2H), 6.99 (d, 2H), 7.12 (d, 2H)

[0171] The following compound (3) (100.0 mg, 0.343 mmol) and 3 mL of tetrahydrofuran were added to a reaction container under an argon gas flow, and N-bromosuccinimide (61.1 mg, 0.343 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added while stirring in ice-cooling to allow the reaction to proceed. After the reaction was stopped, extraction was performed with ethyl acetate, washed with water three times, washed with brine once, and dried over magnesium sulfate. Filtration and reduced pressure distillation were performed, and toluene was added without completely distilling off the solvent. Then, sodium tert-butoxide (49.5 mg, 0.515 mmol, manufactured by Kanto Chemical Co., Ltd.) was added, and degassing and argon replacement were performed. Tris(dibenzylideneacetone)dipalladium(0) (15.7 mg, 0.017 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and tri-tert-butylphosphine (33% by mass xylene solution) (42.1 mg, 0.069 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added under an argon gas stream, and finally di(4-methylphenyl)amine (67.7 mg, 0.343 mmol) was added, and the mixture was stirred at 92°C for 4 hours and 55 minutes to react. After cooling to room temperature, the reaction solution was filtered with diatomaceous earth, and the solvent in the filtrate was removed by distillation under reduced pressure. Purification was performed using silica gel column chromatography (SiO2 / hexane:toluene (8:1)). A fluorescent yellow-green oily compound (4) was obtained (yield: 64.1 mg, yield: 38%).

[0172] Compound (4) (64 mg, 0.131 mmol), squaric acid (7.5 mg, 0.066 mmol, manufactured by Sigma-Aldrich Co. LLC) and 6 mL of n-butanol: toluene (1:1) were added to a reaction vessel under an argon gas stream, and heated and stirred at 95-97°C for 4 hours and 45 minutes. After cooling to room temperature, the solvent was distilled off under reduced pressure. After ultrasonic cleaning with methanol, filtration and vacuum drying (70°C) were performed to obtain the following compound (A-1) (blue-purple solid, yield: 27.2 mg).

[0173] <NMR analysis results>

[0174] 1 H-NMR (400MHz, CDCl3): δ (ppm) = 0.83-0.88 (m, 12H), 1.23-1.43 (m, 16H), 2.3 6(m, 12H), 1.90(m, 2H), 3.89(d, 4H), 6.21(s, 2H), 7.16(d, 16H), 7.74(s, 2H)

[0175]

Chemical formula 34

[0176]

[0177] 〈Absorption spectrum measurement〉

[0178] Prepare a dimethyl sulfoxide solution (concentration 1.0×10 -5 mol / L), and UV-visible near-infrared absorption spectra were measured. The absorption spectrum obtained is as follows Figure 1 In addition, the absorption maximum wavelength (nm) and molar absorption coefficient (M) obtained based on the results of ultraviolet-visible-near infrared absorption spectra were -1 cm -1 ) are shown in Table 1.

[0179] Thermal Analysis

[0180] The decomposition temperature (5% weight loss temperature) of the obtained compound (A-1) was measured. The measurement results are shown in Table 2.

[0181] [Example 2]

[0182] <Synthesis of Compound (A-3)>

[0183] The above compound (3) (668.5 mg, 2.29 mmol) and 10.0 mL of tetrahydrofuran were added to a reaction container, and N-bromosuccinimide (408.2 mg, 2.29 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added while stirring in ice-cold under an argon gas stream to react. After the reaction was terminated, extraction was performed with ethyl acetate, washed with water 3 times, washed with brine once, and dried over magnesium sulfate. Filtration and vacuum distillation were performed to obtain a yellow earth-colored oily crude product. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane:toluene (20:1)). 5.0 mL of dehydrated toluene and sodium tert-butoxide (130.8 mg, 1.36 mmol, manufactured by Kanto Chemical Co., Ltd.) were added to the obtained fraction, and vacuum degassing and argon replacement were performed. Tris(dibenzylideneacetone)dipalladium(0) (207.7 mg, 0.227 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and tri-tert-butylphosphine (33% by mass xylene solution) (1.0 mL, 0.567 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added under an argon gas stream, and finally di(4-methoxyphenyl)amine (260.0 mg, 1.13 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added. After stirring at 88°C for 1 hour and 30 minutes, the mixture was cooled to room temperature and filtered with celite. The solvent in the filtrate was removed by distillation under reduced pressure, and then purified by silica gel column chromatography (SiO2 / hexane:ethyl acetate (10:1)) to obtain the following compound (5) (yield: 334.4 mg, yield: 28%).

[0184] <NMR analysis results>

[0185] 1H-NMR (400 MHz, CDCl3): δ (ppm) = 0.82 - 0.89 (m, 6H), 1.20 - 1.35 (m, 8H), 1.88 (m, 1H), 3.79 (s, 6H), 3.95 (m, 2H), 6.61 (s, 1H), 6.81 (d, 4H), 6.94 (d, 1H), 7.03 (d, 1H), 7.10 (d, 4H)

[0186] Under an argon stream, the above compound (5) (344.4 mg, 0.645 mmol), squaric acid (35.0 mg, 0.307 mmol, manufactured by Sigma - Aldrich Co., LLC), and 16 mL of n - butanol:toluene (1:1) were added to a reaction vessel, and the mixture was heated and stirred at 99 °C for 1 hour and 10 minutes. After the raw materials disappeared, it was cooled to room temperature, and the solvent was removed by distillation under reduced pressure. After ultrasonic cleaning with methanol, filtration and vacuum drying (75 °C) were carried out, whereby the following compound (A - 3) (red - purple solid, yield: 232.3 mg, yield: 68%) was obtained.

[0187] [[Chemical formula 35]]

[0188]

[0189] <NMR analysis results>

[0190] 1 H-NMR (400 MHz, THF - d8): δ (ppm) = 0.82 - 0.88 (m, 12H), 1.20 - 1.36 (m, 16H), 1.88 (m, 2H), 3.75 (s, 12H), 4.02 (d, 4H), 6.20 (s, 2H), 6.87 (d, 8H), 7.23 (d, 8H), 7.71 (s, 2H)

[0191] 〈Absorption spectrum measurement〉

[0192] A dimethyl sulfoxide solution (concentration 2.3×10 -5 mol / L) of the obtained compound (A - 3) was prepared, and ultraviolet - visible - near - infrared absorption spectrum measurement was carried out. The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values obtained from the results of ultraviolet - visible - near - infrared absorption spectrum measurement are shown in Table 1.

[0193] 〈Thermal analysis〉

[0194] The decomposition temperature (5% weight loss temperature) of the obtained compound (A - 3) was measured. The measurement results are shown in Table 2.

[0195] 〈Solubility evaluation〉

[0196] The obtained compound (A-3) was weighed in a transparent sample tube, and chloroform was added to prepare a 5 mass % solution. The prepared solution was placed in an ultrasonic cleaning machine at room temperature (25 ± 2 ° C) for 1 minute, and the solubility was evaluated by visually confirming whether there was a dissolved residue. The results are shown in Table 3. In addition, the judgment criteria are as shown below.

[0197] Completely dissolved: ○

[0198] Suspended matter residue: △

[0199] Insoluble: ×

[0200] [Example 3]

[0201] <Synthesis of Compound (A-10)>

[0202] The above compound (3) (326.1 mg, 1.12 mmol) and 6.0 mL of tetrahydrofuran were added to a reaction container, and N-bromosuccinimide (199.1 mg, 1.12 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added while stirring in ice-cooling under an argon gas stream to react. After the reaction was terminated, extraction was performed with ethyl acetate, washed with water 3 times, washed with brine once, and dried over magnesium sulfate. Filtration and vacuum distillation were performed to obtain a yellow earth-colored oily crude product. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane:toluene (15:1)). 5 mL of dehydrated toluene and sodium tert-butoxide (39.0 mg, 0.41 mmol, manufactured by Kanto Chemical Co., Ltd.) were added to the obtained fraction, and vacuum degassing and argon replacement were performed. Tris(dibenzylideneacetone)dipalladium(0) (12.3 mg, 0.014 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and tri-tert-butylphosphine (33% by mass xylene solution) (50.8 mg, 0.083 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added under an argon gas stream, and finally 2-ethylhexylamine (100 mg, 0.27 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added. After stirring at 88°C for 3 hours and 30 minutes, the mixture was cooled to room temperature and filtered with diatomaceous earth. The solvent in the filtrate was removed by reduced pressure distillation, and then purified by silica gel column chromatography (SiO2 / hexane:toluene (15:1)) to obtain the following compound (6) (yield: 42.0 mg, yield: 7%).

[0203] In an argon gas stream, the above compound (6) (40.0 mg, 0.075 mmol), squaric acid (4.3 mg, 0.038 mmol, manufactured by Sigma-Aldrich Co., LLC), and 6 mL of n-butanol:toluene (1:1) were added to a reaction vessel, and the mixture was heated and stirred at 99 °C for 2 hours and 15 minutes. After the raw materials disappeared, the mixture was cooled to room temperature, and the solvent was removed by distillation under reduced pressure. After ultrasonic cleaning with methanol, filtration and vacuum drying (75 °C) were carried out to obtain the following compound (A-10) (black-purple solid, yield: 17.6 mg, yield: 41%). The structure of compound (A-10) was confirmed by NMR.

[0204] [Chemical Formula 36]

[0205]

[0206] 〈Absorption Spectrum Measurement〉

[0207] A dimethyl sulfoxide solution (concentration 1.0×10 -5 mol / L) of the obtained compound (A-10) was prepared, and ultraviolet-visible-near-infrared absorption spectrum measurement was carried out. The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values obtained based on the results of the ultraviolet-visible-near-infrared absorption spectrum measurement are shown in Table 1.

[0208] 〈Thermal Analysis〉

[0209] The decomposition temperature (5% weight loss temperature) of the obtained compound (A-10) was measured. The measurement results are shown in Table 2.

[0210] [Example 4]

[0211] 〈Synthesis of Compound (A-17)〉

[0212] The above compound (3) (500.0 mg, 1.72 mmol) and 15.0 mL of tetrahydrofuran were added to a reaction container, and N-bromosuccinimide (305.3 mg, 1.72 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added while stirring under ice-cooling under an argon gas flow to carry out the reaction. The reaction was stopped with 30 mL of water, and then extracted with 20 mL of ethyl acetate, washed with water 3 times, washed with brine once, and dried with magnesium sulfate. Filtration and vacuum distillation were performed to obtain a yellow earth-colored oily crude product. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane:chloroform (20:1)) to obtain a fraction containing a monobrominate. The obtained monobrominate, 5 mL of dehydrated toluene and sodium tert-butoxide (38.9 mg, 0.405 mmol, manufactured by Kanto Chemical Co., Ltd.) were added to a 50 mL flask, and vacuum degassing and argon replacement were performed. Tris(dibenzylideneacetone)dipalladium(0) (12.4 mg, 0.014 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and tri-tert-butylphosphine (33% by mass xylene solution) (33.1 mg, 0.054 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added under an argon gas stream, and finally carbazole (45.1 mg, 0.270 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added. After stirring at 92°C for 1 hour and 50 minutes and cooling to room temperature, the reaction solution was filtered with diatomaceous earth, the solvent in the filtrate was removed by vacuum distillation, and then purified by silica gel column chromatography (SiO2 / hexane: toluene (15:1)). The following compound (7) was obtained (yield: 81.1 mg, yield: 35%).

[0213] <NMR analysis results>

[0214] 1 H-NMR (400MHz, CDCl3): δ (ppm) = 0.85-0.94 (m, 6H), 1.27-1.38 (m, 8H), 1.95 (m, 1H), 4.12 (d, 2 H), 7.05(d, 1H), 7.19(s, 1H), 7.21(d, 2H), 7.32(t, 2H), 7.44(t, 2H), 7.50(d, 2H), 8.11(d, 2H)

[0215] Under an argon stream, the above compound (7) (45.0 mg, 0.10 mmol), squaric acid (5.6 mg, 0.050 mmol, manufactured by Sigma-Aldrich Co., LLC), and 6 mL of n-butanol:toluene (1:1) were added to a reaction vessel, and the mixture was heated and stirred at 99 °C for 3 hours. After the raw materials disappeared, the mixture was cooled to room temperature, and the solvent was removed by distillation under reduced pressure. After ultrasonic cleaning with methanol, filtration and vacuum drying (75 °C) were carried out to obtain the following compound (A-17) (black solid, yield: 17.9 mg, yield: 37%). The structure of compound (A-17) was confirmed by NMR.

[0216] [Chemical Formula 37]

[0217]

[0218] 〈Absorption Spectrum Measurement〉

[0219] A dimethyl sulfoxide solution (concentration 1.0×10 -5 mol / L) of the obtained compound (A-17) was prepared, and ultraviolet-visible-near-infrared absorption spectrum measurement was carried out. The absorption maximum wavelength (nm) and molar absorptivity (M -1 cm -1 ) values obtained from the results of ultraviolet-visible-near-infrared absorption spectrum measurement are shown in Table 1.

[0220] 〈Thermal Analysis〉

[0221] The decomposition temperature (5% weight loss temperature) of the obtained compound (A-17) was measured. The measurement results are shown in Table 2.

[0222] [Example 5]

[0223] 〈Synthesis of Compound (A-19)〉

[0224] The above compound (3) (148.8 mg, 0.51 mmol) and 4.0 mL of tetrahydrofuran were added to a reaction container, and N-bromosuccinimide (90.9 mg, 0.51 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added while stirring in ice-cold under an argon gas stream to react. After the reaction was terminated, extraction was performed with ethyl acetate, washed with water 3 times, washed with brine once, and dried over magnesium sulfate. Filtration and vacuum distillation were performed to obtain a yellow earth-colored oily crude product. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane:chloroform (15:1)). 5 mL of dehydrated toluene and sodium tert-butoxide (23.4 mg, 0.24 mmol, manufactured by Kanto Chemical Co., Ltd.) were added to the obtained fraction, and vacuum degassing and argon replacement were performed. Tris(dibenzylideneacetone)dipalladium(0) (7.4 mg, 0.008 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and tri-tert-butylphosphine (33% by mass xylene solution) (19.9 mg, 0.032 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added under an argon gas stream, and finally, iminostilbene (31.3 mg, 0.16 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added. After stirring at 97°C for 1 hour and 55 minutes, the mixture was cooled to room temperature and filtered with diatomaceous earth. After removing the solvent from the filtrate by vacuum distillation, the mixture was purified by silica gel column chromatography (SiO2 / hexane:toluene (15:1)) to obtain the following compound (8) (yield: 45.8 mg, yield: 21%).

[0225] Under an argon gas stream, the above compound (8) (30.0 mg, 0.062 mmol), squaric acid (2.4 mg, 0.021 mmol, manufactured by Sigma-Aldrich Co. LLC) and 6 mL of n-butanol: toluene (1:1) were added to the reaction vessel, and heated with stirring at 99°C for 3 hours. After the raw materials disappeared, the mixture was cooled to room temperature and the solvent was removed by distillation under reduced pressure. After ultrasonic cleaning with methanol, the mixture was filtered and vacuum dried (75°C) to obtain the following compound (A-19) (black solid, yield: 4.3 mg, yield: 7%). The structure of compound (A-19) was confirmed by NMR.

[0226]

Chemical formula 38

[0227]

[0228] 〈Absorption spectrum measurement〉

[0229] Prepare a solution of the obtained compound (A-19) in N-methylpyrrolidone (concentration 1.0×10 -5mol / L), an ultraviolet-visible near-infrared absorption spectrum measurement was performed. The absorption maximum wavelength (nm) and molar absorptivity (M -1 cm -1 )) values are shown in Table 1.

[0230] [Example 6]

[0231] 〈Synthesis of Compound (A-21)〉

[0232] The above compound (3) (298.8 mg, 1.03 mmol) and 4.0 mL of tetrahydrofuran were added to a reaction vessel, and while stirring in ice-cold under an argon stream, N-bromosuccinimide (182.4 mg, 1.03 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added and the reaction was carried out. After stopping the reaction with water, extraction was performed with ethyl acetate, washed 3 times with water and 1 time with brine, and dried using magnesium sulfate. Filtration and distillation under reduced pressure were carried out to remove, and a yellowish-brown oily crude product was obtained. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane:toluene (20:1)) to obtain a fraction containing the monobromo body. The obtained monobromo body, 5 mL of dimethylformamide and 2M aqueous potassium carbonate solution (2.0 mL) were added to a 50 mL flask, and vacuum degassing and argon replacement were carried out. Under an argon stream, tetrakis(triphenylphosphine)palladium(0) (15.6 mg, 0.014 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and finally dimethoxytriphenylamine tetramethyldioxaborane (139.8 mg, 0.324 mmol) was added. After stirring at 79 °C for 1 hour and 20 minutes, it was cooled to room temperature, and the reaction was stopped with water. After extraction with ethyl acetate, it was washed 3 times with water and 1 time with brine, and dried using magnesium sulfate. After filtration and distillation under reduced pressure to remove, purification was carried out by silica gel column chromatography (SiO2 / hexane:ethyl acetate (8:1)) to obtain the following compound (9) (yield: 177.8 mg, yield: 29%).

[0233] 〈NMR Analysis Results〉

[0234] 1 1H-NMR (400 MHz, CDCl3): δ (ppm) = 0.86 - 0.92 (m, 6H), 1.24 - 1.29 (m, 8H), 1.95 (m, 1H), 3.80 (s, 6H), 4.05 (m, 2H), 6.84 (d, 4H), 6.94 (d, 2H), 7.00 (s, 1H), 7.09 (m, 6H), 7.44 (d, 2H)

[0235] Under an argon stream, the above compound (9) (177.8 mg, 0.30 mmol), squaric acid (17.0 mg, 0.15 mmol, manufactured by Sigma - Aldrich Co., LLC), and 6 mL of n - butanol:toluene (1:1) were added to a reaction vessel, and the mixture was heated and stirred at 97 °C for 2 hours and 35 minutes. After the raw materials disappeared, it was cooled to room temperature, and the solvent was removed by distillation under reduced pressure. After ultrasonic cleaning with methanol, filtration and vacuum drying (75 °C) were carried out, whereby the following compound (A - 21) (reddish - purple solid, yield: 138.0 mg, yield: 73%) was obtained. The structure of compound (A - 21) was confirmed by NMR.

[0236] [Chemical Formula 39]

[0237]

[0238] 〈Absorption Spectrum Measurement〉

[0239] A dimethyl sulfoxide solution (concentration 2.0×10 -6 mol / L) of the obtained compound (A - 21) was prepared, and ultraviolet - visible - near - infrared absorption spectrum measurement was carried out. The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values obtained from the results of ultraviolet - visible - near - infrared absorption spectrum measurement are shown in Table 1.

[0240] 〈Thermal Analysis〉

[0241] The decomposition temperature (5% weight loss temperature) of the obtained compound (A - 21) was measured. The measurement results are shown in Table 2.

[0242] 〈Solubility Evaluation〉

[0243] Except for using compound (A - 21) instead of compound (A - 3), solubility evaluation was carried out in the same manner as in Example 2. The results are shown in Table 3.

[0244] [Example 7]

[0245] 〈Synthesis of Compound (A - 29)〉

[0246] The above compound (3) (200 mg, 0.69 mmol) and 3.0 mL of tetrahydrofuran were added to a reaction container, and N-bromosuccinimide (116.0 mg, 0.65 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added while stirring under an argon gas stream in ice-cooling. The reaction was stopped with water, and then extracted with ethyl acetate, washed with water 3 times, washed with brine once, and dried with magnesium sulfate. Filtration and vacuum distillation were performed to obtain a yellow earth-colored oily crude product. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane:toluene (20:1)) to obtain a fraction containing a monobrominate. The obtained monobrominate, 5 mL of dehydrated toluene and sodium tert-butoxide (27.2 mg, 0.28 mmol, manufactured by Kanto Chemical Co., Ltd.) were added to a 50 mL flask, and vacuum degassing and argon replacement were performed. Tris(dibenzylideneacetone)dipalladium(0) (8.7 mg, 0.010 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and tri-tert-butylphosphine (33% by mass xylene solution, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) (23.2 mg, 0.038 mmol) were added under an argon gas stream, and the mixture was stirred at 84°C for 4 hours and 30 minutes. After cooling to room temperature, the reaction solution was filtered through diatomaceous earth. After removing the solvent from the filtrate by reduced pressure distillation, the mixture was purified by silica gel column chromatography (SiO2 / hexane:toluene (15:1)) to obtain the following compound (10) (yield: 40.0 mg, yield: 20%).

[0247] <NMR analysis results>

[0248] 1 H-NMR (400MHz, CDCl3): δ (ppm) = 0.88-0.93 (m, 12H), 1.30-1.36 (m, 16H), 1.97 (m, 2H), 4.06 (d, 4H), 6.97 (d, 2H), 7.06 (s, 2H), 7.12 (d, 2H)

[0249] The following compound (10) (40.0 mg, 0.11 mmol), squaric acid (6.3 mg, 0.056 mmol, manufactured by Sigma-Aldrich Co. LLC) and 6 mL of n-butanol: toluene (1:1) were added to the reaction vessel under an argon flow, and heated and stirred at 99°C for 3 hours under an argon flow. After the raw materials disappeared, the mixture was cooled to room temperature and the solvent was distilled off under reduced pressure. After ultrasonic cleaning with methanol, the mixture was filtered and vacuum dried (75°C), thereby obtaining the following compound (A-29) (black purple solid, yield: 7.1 mg, yield: 16%).

[0250]

Chemical formula 40

[0251]

[0252] <NMR analysis results>

[0253] 1 H-NMR (400 MHz, THF-d8): δ (ppm) = 0.80 - 1.00 (m, 24H), 1.21 - 1.48 (m, 32H), 2.01 (m, 4H), 4.16 (d, 8H), 7.03 (d, 2H), 7.11 (s, 2H), 7.23 (s, 2H), 7.34 (s, 2H), 7.91 (d, 2H)

[0254] <Absorption spectrum measurement>

[0255] A dimethyl sulfoxide solution (concentration 1.2×10 -5 mol / L) of the obtained compound (A-29) was prepared, and ultraviolet-visible-near-infrared absorption spectrum measurement was carried out. The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values obtained based on the results of the ultraviolet-visible-near-infrared absorption spectrum measurement are shown in Table 1.

[0256] [Example 8]

[0257] <Synthesis of compound (A-53)>

[0258] Referring to Reference Example 1, aniline (manufactured by Kishida Chemical Co., Ltd.) was used instead of 2-ethylhexylamine, and the reaction was carried out in the same manner to obtain the following compound (11). Then, referring to Reference Example 4, the same reaction was carried out to obtain the following compound (12).

[0259] The above compound (12) (110 mg, 0.263 mmol) and 10 mL of tetrahydrofuran were added to a reaction vessel. While stirring in ice-cold under an argon stream, N-bromosuccinimide (46.9 mg, 0.263 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and the reaction was carried out. The reaction was stopped using water, and then extraction was performed with ethyl acetate. It was washed 3 times with water and 1 time with brine, and dried using magnesium sulfate. Filtration and distillation under reduced pressure were carried out to remove the solvent, and a yellowish-brown oily crude product was obtained. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane:toluene (8:1)) to obtain a fraction containing the monobromo compound. The obtained monobromo compound, 6 mL of dimethylformamide, and 2 mL of 2M aqueous potassium carbonate solution were added to a 50 mL flask, and vacuum degassing and argon replacement were carried out. Under an argon stream, tetrakis(triphenylphosphine)palladium(0) (15.2 mg, 0.013 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and finally 1-(tert-butoxycarbonyl)-2-pyrroleboronic acid (55.6 mg, 0.263 mmol) was added. After stirring at 81 °C for 5 hours and 50 minutes, an aqueous potassium hydroxide solution was added. After the reaction stopped, filtration was carried out using diatomaceous earth. The filtrate was extracted with ethyl acetate, washed 3 times with water and 1 time with brine, and dried using magnesium sulfate. Filtration and distillation under reduced pressure were carried out to remove the solvent, and purification was carried out by silica gel column chromatography (SiO2 / hexane:ethyl acetate (5:1)) to obtain the following compound (13) (yield: 81.8 mg, yield: 64%).

[0260] [Chemical Formula 41]

[0261]

[0262] 〈NMR Analysis Results〉

[0263] 1 1H-NMR (400 MHz, CDCl3): δ (ppm) = 6.31 (m, 1H), 6.50 (m, 1H), 6.85 (m, 1H), 7.18 (s, 1H), 7.33 (m, 4H), 7.45 (t, 2H), 7.54 (m, 4H), 7.64 (d, 2H), 8.11 (d, 2H), 8.36 (s, 1H)

[0264] In an argon gas stream, the above compound (13) (81.8 mg, 0.168 mmol), squaric acid (9.6 mg, 0.084 mmol, manufactured by Sigma-Aldrich Co., LLC), and 6 mL of n-butanol:toluene (1:1) were added to a reaction vessel, and the mixture was heated and stirred at 99 °C for 1 hour and 30 minutes. After the raw materials disappeared, the mixture was cooled to room temperature, and the solvent was removed by distillation under reduced pressure. After ultrasonic cleaning with methanol, filtration and vacuum drying (75 °C) were carried out to obtain the following compound (A-53) (brown solid, yield: 75.5 mg, yield: 85%).

[0265] [Chemical Formula 42]

[0266]

[0267] <NMR analysis results>

[0268] 1 1H-NMR (400 MHz, DMSO-d8): δ (ppm) = 7.01 (d, 2H), 7.32 (m, 4H), 7.40 - 7.49 (m, 6H), 7.51 (d, 2H), 7.58 (d, 4H), 7.65 (m, 4H), 7.71 (s, 2H), 7.77 (d, 4H), 8.21 (d, 4H), 8.44 (s, 2H)

[0269] 〈Absorption spectrum measurement〉

[0270] A dimethyl sulfoxide solution (concentration 0.5 × 10 -5 mol / L) of the obtained compound (A-53) was prepared, and ultraviolet-visible-near-infrared absorption spectrum measurement was carried out. The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values obtained based on the results of the ultraviolet-visible-near-infrared absorption spectrum measurement are shown in Table 1.

[0271] 〈Thermal analysis〉

[0272] The decomposition temperature (5% weight loss temperature) of the obtained compound (A-53) was measured. The measurement results are shown in Table 2.

[0273] [Example 9]

[0274] 〈Synthesis of compound (A-57)〉

[0275] The above compound (3) (458 mg, 1.57 mmol) and 8.0 mL of tetrahydrofuran were added to a reaction vessel, and while stirring in ice-cold under an argon stream, N-bromosuccinimide (279 mg, 1.57 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added. The reaction was stopped with water, and then, extraction was performed with ethyl acetate, washed 3 times with water and 1 time with brine, and dried using magnesium sulfate. Filtration and distillation under reduced pressure were carried out to remove, and a yellowish-brown oily crude product was obtained. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane: chloroform (20:1)) to obtain a fraction containing the monobromo product. The obtained monobromo product, 10 mL of dimethylformamide, and 2 M aqueous potassium carbonate solution (2.0 mL) were added to a 50 mL flask, and vacuum degassing and argon replacement were performed. Under an argon stream, tetrakis(triphenylphosphine)palladium(0) (91 mg, 0.078 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added, and finally, triphenylamine-4-boronic acid (453 mg, 1.57 mmol) was added. After stirring at 82 °C for 3 hours, it was cooled to room temperature, and the reaction was stopped with water. After extraction with ethyl acetate, it was washed 3 times with water and 1 time with brine, and dried using magnesium sulfate. Filtration and distillation under reduced pressure were carried out to remove, and purification was performed by silica gel column chromatography (SiO2 / hexane: ethyl acetate (5:1)) to obtain the following compound (14) (yield: 674 mg, yield: 81%).

[0276] 〈NMR analysis results〉

[0277] 1 1H-NMR (600 MHz, THF-d8): δ (ppm) = 0.85 - 0.92 (m, 6H), 1.26 - 1.39 (m, 8H), 1.94 (m, 1H), 4.15 (d, 2H), 6.99 (d, 2H), 7.03 (d, 2H), 7.05 (d, 1H), 7.07 - 7.08 (m, 4H), 7.16 (d, 1H), 7.22 - 7.25 (m, 4H), 7.34 (s, 1H), 7.53 (d, 2H)

[0278] Under an argon stream, the above compound (14) (270 mg, 0.51 mmol), squaric acid (29 mg, 0.25 mmol, manufactured by Sigma-Aldrich Co., LLC), and 15 mL of n-butanol: toluene (1:2) were added to a reaction vessel, and heated and stirred at 99 °C for 2 hours and 15 minutes. After the raw materials disappeared, it was cooled to room temperature, and the solvent was removed by distillation under reduced pressure. After ultrasonic cleaning with methanol, filtration and vacuum drying (75 °C) were carried out to obtain the following compound (A-57) (purple solid, yield: 233 mg, yield: 81%). The structure of compound (A-57) was confirmed by NMR.

[0279]

Chemical formula 43

[0280]

[0281] 〈Absorption spectrum measurement〉

[0282] Prepare a dimethyl sulfoxide solution (concentration 1.0×10 -5 mol / L), and ultraviolet-visible-near-infrared absorption spectra were measured. The absorption maximum wavelength (nm) and molar absorption coefficient (M) obtained based on the results of ultraviolet-visible-near-infrared absorption spectra were -1 cm -1 ) are shown in Table 1.

[0283] Thermal Analysis

[0284] The decomposition temperature (5% weight loss temperature) of the obtained compound (A-57) was measured. The measurement results are shown in Table 2.

[0285] [Example 10]

[0286] <Synthesis of Compound (A-58)>

[0287] The above compound (3) (708 mg, 2.43 mmol) and 10.0 mL of tetrahydrofuran were added to the reaction container, and N-bromosuccinimide (432 mg, 2.43 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added while stirring in ice-cold under an argon gas stream. After the reaction was terminated, extraction was performed with ethyl acetate, washed with water 3 times, washed with brine once, and dried with magnesium sulfate. Filtration and vacuum distillation were performed to obtain a yellow earthy oily crude product. The obtained crude product was purified by silica gel column chromatography (SiO2 / hexane:toluene (20:1)). 25 mL of dehydrated toluene and sodium tert-butoxide (304 mg, 3.16 mmol, manufactured by Kanto Chemical Co., Ltd.) were added to the obtained fraction, and vacuum degassing and argon replacement were performed. Tris(dibenzylideneacetone)dipalladium(0) (111 mg, 0.12 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) and tri-tert-butylphosphine (33% by mass xylene solution) (0.4 mL, 0.496 mmol, manufactured by Fujifilm Wako Pure Chemical Industries, Ltd.) were added under an argon gas stream, and finally bis(4-dimethylaminophenyl)amine (621 mg, 2.43 mmol, manufactured by Tokyo Chemical Industry Co., Ltd.) was added. After stirring at 98°C for 1 hour and 10 minutes, the mixture was cooled to room temperature and filtered with diatomaceous earth. After removing the solvent from the filtrate by vacuum distillation, the mixture was purified by silica gel column chromatography (SiO2 / hexane:ethyl acetate (4:1)) to obtain the following compound (15) (yield: 422 mg, yield: 32%).

[0288] 〈NMR Analysis Results〉

[0289] 1 1H-NMR (600 MHz, THF-d8): δ (ppm) = 0.82 - 0.90 (m, 6H), 1.18 - 1.34 (m, 8H), 1.93 (s, 1H), 2.87 (d, 12H), 4.00 (d, 2H), 6.54 (s, 1H), 6.63 (d, 4H), 6.99 (q, 6H)

[0290] Under an argon stream, the above compound (15) (420 mg, 0.771 mmol), squaric acid (44 mg, 0.385 mmol, manufactured by Sigma - Aldrich Co., LLC), and 20 mL of n-butanol:toluene (3:2) were added to a reaction vessel, and the mixture was heated and stirred at 99 °C for 3 hours. After the raw materials disappeared, it was cooled to room temperature, and the solvent was removed by distillation under reduced pressure. After ultrasonic cleaning with methanol, filtration and vacuum drying (75 °C) were carried out, whereby the following compound (A-58) (black solid, yield: 168 mg, yield: 47%) was obtained.

[0291]

Chemical Formula 44

[0292]

[0293] 〈NMR Analysis Results〉

[0294] 1 1H-NMR (400 MHz, CDCl3): δ (ppm) = 0.84 - 0.86 (m, 12H), 1.25 (m, 16H), 1.88 (d, 2H), 2.96 (s, 24H), 3.85 (d, 4H), 5.95 (s, 2H), 6.66 - 6.68 (d, 8H), 7.16 - 7.18 (d, 8H), 7.61 (s, 2H)

[0295] 〈Absorption Spectrum Measurement〉

[0296] A dimethyl sulfoxide solution (concentration 4.8×10 -6 mol / L) of the obtained compound (A-58) was prepared, and ultraviolet-visible-near-infrared absorption spectrum measurement was carried out. The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values obtained from the results of ultraviolet-visible-near-infrared absorption spectrum measurement are shown in Table 1.

[0297] 〈Thermal Analysis〉

[0298] The decomposition temperature (5% weight loss temperature) of the obtained compound (A-58) was measured. The measurement results are shown in Table 2.

[0299] <Solubility Evaluation>

[0300] The solubility evaluation was carried out in the same manner as in Example 2, except that compound (A-58) was used instead of compound (A-3). The results are shown in Table 3.

[0301] [Comparative Example 1]

[0302] <Absorption Spectrum Measurement>

[0303] As a comparative compound, the following compound (B-1) described in Patent Document 2 was synthesized, and a dimethyl sulfoxide solution of this compound (concentration: 1.4×10 -5 mol / L) was prepared, and ultraviolet-visible-near-infrared absorption spectrum measurement was performed. The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values obtained from the results of the ultraviolet-visible-near-infrared absorption spectrum measurement are shown in Table 1.

[0304] [Chemical Formula 45]

[0305]

[0306] [Comparative Example 2]

[0307] <Absorption Spectrum Measurement>

[0308] As a comparative compound (compound (B-2)), a commercially available near-infrared absorbing dye (trade name: IR813 / p-Toluenesulfonate, manufactured by Tokyo Chemical Industry Co., Ltd.) was prepared. A dimethyl sulfoxide solution of compound (B-2) (concentration: 1.0×10 -5 mol / L) was prepared, and ultraviolet-visible-near-infrared absorption spectrum measurement was performed. The absorption maximum wavelength (nm) and molar extinction coefficient (M -1 cm -1 ) values obtained from the results of the ultraviolet-visible-near-infrared absorption spectrum measurement are shown in Table 1.

[0309] <Thermal Analysis>

[0310] The decomposition temperature (5% weight loss temperature) of the commercially available compound (B-2) was measured. The measurement results are shown in Table 2.

[0311] [Table 1]

[0312]

[0313]

[0314] As shown in Table 1, it can be seen that the compounds of the present invention obtained in Examples 1 to 10 have a high molar extinction coefficient in the near-infrared region at a higher wavelength compared to the compounds of the Comparative Examples, and can effectively absorb near-infrared light. Thus, by using the compounds of the present invention that can effectively absorb near-infrared light, for example, in the production of photoelectric conversion elements, etc., it is also possible to expect to produce elements with high conversion efficiency at a low concentration, which can reduce costs. In addition, as Figure 1 shown, it can be seen that the absorption of the compounds of the present invention in the visible light region is less.

[0315]

Table 2

[0316]

[0317] As shown in Table 2, the compounds of the present invention have higher thermal durability than the compounds (B-2) of the Comparative Examples. Thus, based on the compounds of the present invention with high heat resistance, an improvement in the durability of photoelectric conversion elements and near-infrared absorption films can be expected. In addition, the heat resistance evaluation of a color filter is generally carried out by observing whether there is a change in hue at a temperature of 200 °C or higher. The compounds of the present invention all have a decomposition temperature of 250 °C or higher, so it can be expected that they are suitable as constituent materials for color filters.

[0318]

Table 3

[0319] Compound Solubility Example 2 A-3 ○ Example 6 A-21 ○ Example 10 A-58 ○

[0320] As shown in Table 3, the compounds of the present invention have good solubility in organic solvents, so it is also possible to expect to dissolve or disperse the compounds in a solvent to make a coating solution for utilization.

[0321] The compounds of the present invention are expected to be applied as near-infrared absorbing pigments having absorption in the near-infrared region and high heat resistance in a wide range of fields such as photoelectric conversion elements such as solar cells and near-infrared light sensors, and near-infrared absorbing materials such as neutral density (ND) filters, the security field, agricultural films, and dimming filters (heat insulation · semiconductor sensors), as well as in light mechanics therapy.

Claims

1. A squarylium compound represented by the following general formula (1): [Chemical Formula 1] In the formula, L 1 and L 2 each independently represents a single bond, a linear or branched alkenylene having 2 to 20 carbon atoms which may have substituents, a divalent aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents, or a divalent aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents. R 1 and R 2 each independently represents a linear or branched alkyl group having 1 to 20 carbon atoms which may have substituents, a linear or branched alkenyl group having 2 to 20 carbon atoms which may have substituents, a linear or branched alkynyl group having 2 to 20 carbon atoms which may have substituents, a cycloalkyl group having 3 to 10 carbon atoms which may have substituents, an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have substituents, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have substituents, Ar 1 and Ar 2 each independently represents a hydrogen atom, an amino group having 6 to 36 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent, m and n each independently represent an integer of 1 or 2.

2. The squarylium compound according to claim 1, wherein In the general formula (1), Ar 1 and Ar 2 each independently represents a hydrogen atom or a group represented by the following general formula (2). [Chemical Formula 2] In the formula, R 3 and R 4 each independently represents 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, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent. R 3 and R 4 which are capable of bonding to each other to form a ring, Z 1 represents an oxygen atom or a sulfur atom, x and y each independently represent an integer of 0 or 1.

3. The squarylium compound according to claim 1 or 2, wherein In the general formula (1), R 1 and R 2 are each independently a linear or branched alkyl group having 1 to 20 carbon atoms which may have a substituent, an aromatic hydrocarbon group having 6 to 36 carbon atoms which may have a substituent, or an aromatic heterocyclic group having 5 to 36 ring-forming atoms which may have a substituent.

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

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

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