Pyrrole compound, method for production thereof and photoelectric converter

Abstract

To provide a pyrrole compound demonstrating suitable absorption properties as a photoelectric conversion material for red light, and a method for synthesizing the pyrrole compound.SOLUTION: The present invention provides a pyrrole compound represented by a formula (1) and a method for producing the same. In the formula (1), Ar represents an aromatic hydrocarbon or heteroaromatic group, where the aromatic hydrocarbon and heteroaromatic group may be optionally substituted with a substituent selected from an alkyl group, a haloalkyl group, an optionally substituted aryl group, a dialkylamino group, a diarylamino group and a halogen atom. X1 and X2 independently represent a hydrogen atom, an alkyl group, a haloalkyl group, an aryl group, a heteroaryl group, an aralkyl group, a trialkylsilyl group or the like.SELECTED DRAWING: None

Description

[Technical field]

[0001] The present invention relates to a pyrrole compound, a method for producing the same, and a photoelectric conversion element. [Background technology]

[0002] Photoelectric conversion elements are used in imaging elements such as optical sensors and photovoltaic devices such as solar cells. A photoelectric conversion element using an organic photoelectric conversion material is disclosed in Patent Document 1 and the like.

[0003] As photoelectric conversion elements, elements using silicon semiconductors are widely used, and silicon photodiodes are mainly used as imaging elements. Since such silicon photodiodes have sensitivity over the entire visible light range, color images are captured by distributing each pixel as a light receiving section for each RGB color using a color filter with RGB arranged in a mosaic pattern on top of the photodiode. In this method, the efficiency of light utilization is low due to the loss of incident light in the color filter, and it is feared that this will become an obstacle to increasing the sensitivity of imaging elements. Therefore, an imaging element in which organic photoelectric conversion layers of each color of RGB are laminated (hereinafter referred to as a laminated organic imaging element) has been proposed (see, for example, Non-Patent Document 1). In this method, there is no light loss due to the color filter compared to when a color filter is used, and the efficiency of light utilization is several times higher. In general, in devices such as cameras, miniaturization of pixels is required to achieve high pixel counts. However, as pixels become more miniaturized, there is a problem that the amount of light that hits each pixel decreases. Therefore, laminated organic imaging elements with high light utilization efficiency are expected to be used in high-sensitivity devices.

[0004] The photoelectric conversion layer of the stacked organic imaging element is required to have high light absorption and wavelength selectivity suitable for the color of each RGB layer. In particular, it is desirable to show absorption characteristics similar to the color matching function of the color space system. For example, since the wavelength of the maximum point of the color matching function of red is 600 nm, it is preferable that the red photoelectric conversion material shows maximum absorption near 600 nm. Patent Document 2 and Non-Patent Document 2 describe a red photoelectric conversion element using boron subnaphthalocyanine chloride (hereinafter, SubNc) as the photoelectric conversion material for the R layer (red photoelectric conversion layer), and it is reported that a single layer film shows maximum absorption at a wavelength of about 680 nm, and that the external quantum efficiency of the photoelectric conversion element also shows a maximum value at a wavelength of about 680 nm in an element with a photoelectric conversion layer thickness of 50 nm, but a material showing maximum absorption near 600 nm is required as the red photoelectric conversion material.

[0005] Patent Document 3 describes a semiconductor device containing a pyrrole derivative, but it differs from the pyrrole compound of the present invention in that it does not have a substituent on the indolion group. [Prior art documents] [Patent documents]

[0006] [Patent Document 1] Patent No. 4148374 [Patent Document 2] JP 2017-73426 A [Patent Document 3] JP 6192656 A [Non-patent literature]

[0007] [Non-Patent Document 1] Japanese Journal of Applied Physics, 2011, Vol. 50, p. 024103 [Non-Patent Document 2] IEICE Transactions C Vol. J101-C No.9 pp.352-361 Summary of the Invention [Problem to be solved by the invention]

[0008] The present invention aims to provide a pyrrole compound that exhibits absorption characteristics more suitable as a red photoelectric conversion material than existing materials, i.e., that exhibits a maximum absorption in the vicinity of 600 nm, and to provide a method for simply synthesizing the pyrrole compound. [Means for solving the problem]

[0009] Means for Solving the Problems The present inventors have conducted extensive research to solve the above problems and have discovered that a novel pyrrole compound exhibits a maximum absorption in the vicinity of 600 nm, thereby completing the present invention.

[0010] That is, the present invention is [1] A pyrrole compound represented by the following formula (1):

[0011] [ka]

[0012] In formula (1), Ar represents an aromatic hydrocarbon or a heteroaromatic group, and the aromatic hydrocarbon and the heteroaromatic group are Alkyl groups having 1 to 18 carbon atoms; Haloalkyl groups having 1 to 8 carbon atoms; an aryl group having 6 to 14 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms; Dialkylamino group having 2 to 18 carbon atoms; A diarylamino group having 12 to 18 carbon atoms; and It may be substituted with one or more substituents selected from the group consisting of halogen atoms. X 1 and X 2each independently represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms, a heteroaryl group having 3 to 18 carbon atoms, an aralkyl group having 7 to 19 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms, a methoxymethyl group, an acetyl group, a benzoyl group, or a trityl group, and the aryl group, aralkyl group, and heteroaryl group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 6 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom. represents a pyrrole compound represented by the formula: [2] In formula (1), Ar represents an aromatic hydrocarbon having 6 to 18 carbon atoms or a heteroaromatic ring having 3 to 18 carbon atoms, and the aromatic hydrocarbon and the heteroaromatic ring are Alkyl groups having 1 to 18 carbon atoms; Haloalkyl groups having 1 to 8 carbon atoms; an aryl group having 6 to 18 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms; Dialkylamino group having 2 to 18 carbon atoms; A diarylamino group having 12 to 18 carbon atoms; and The pyrrole compound according to [1], which may be substituted with one or more substituents selected from the group consisting of halogen atoms. [3] The pyrrole compound according to [1], wherein the pyrrole compound represented by formula (1) is represented by the following formula (1-a), (1-b) or (1-c):

[0013] [ka] In formulas (1-a), (1-b) and (1-c), R 1 ~R 8 are each independently Hydrogen atom, Alkyl groups having 1 to 18 carbon atoms; Haloalkyl groups having 1 to 8 carbon atoms; an aryl group having 6 to 18 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms; Dialkylamino group having 2 to 18 carbon atoms; A diarylamino group having 12 to 18 carbon atoms; or represents a halogen atom, X 1 and X 2 each independently represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a haloalkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 3 to 18 carbon atoms, an aralkyl group having 7 to 19 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms, a methoxymethyl group, an acetyl group, a benzoyl group, or a trityl group, and the aryl group, aralkyl group, and heteroaryl group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 6 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom. [4] In formula (1), R 1 ~R 8 is a phenyl group which may be substituted with an alkyl group having 1 to 18 carbon atoms or an alkyl group having 1 to 4 carbon atoms. [5] In formula (1), X 1 and X 2 each independently represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a trialkylsilyl group having 3 to 12 carbon atoms.

[0014] The present invention also provides a method for producing a method for manufacturing a semiconductor device comprising the steps of: [6] The following formula (2)

[0015] [ka]

[0016] (in formula (2), Ar represents an aromatic hydrocarbon or a heteroaromatic group, and the aromatic hydrocarbon and the heteroaromatic group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 18 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 18 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom) in the presence of a halogenating agent, to obtain a carboxylic acid compound represented by the general formula (1-H):

[0017] [ka]

[0018] (wherein Ar has the same meaning as defined above); [7] The following formula (1-H)

[0019] [ka]

[0020] (in formula (1-H), Ar represents an aromatic hydrocarbon or a heteroaromatic group, and the aromatic hydrocarbon and the heteroaromatic group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 18 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 18 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom) in the presence of a base, to obtain a pyrrole compound represented by the general formula (1-X):

[0021] [ka]

[0022] In formula (1-X), Ar has the same meaning as above. X 1 and X 2each independently represents an alkyl group having 1 to 30 carbon atoms, a haloalkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 3 to 18 carbon atoms, an aralkyl group having 7 to 19 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms, a methoxymethyl group, an acetyl group, a benzoyl group, or a trityl group, and the aryl group, the aralkyl group, and the heteroaryl group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 6 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom.

[0023] The present invention also provides a method for producing a semiconductor device comprising the steps of: [8] A photoelectric conversion element comprising the pyrrole compound according to any one of the above [1] to [5]; [9] A photoelectric conversion element comprising a photoelectric conversion layer containing the pyrrole compound according to any one of the above [1] to [5];

[10] The photoelectric conversion element according to [9] above, wherein the photoelectric conversion layer further contains a fullerene derivative;

[11] The fullerene derivative is

[60] fullerene (C 60 ) or

[70] fullerene (C 70 The photoelectric conversion element according to

[10] above,

[12] A material for a photoelectric conversion device, comprising the pyrrole compound according to any one of the above [1] to [5];

[13] The present invention relates to the material for photoelectric conversion elements according to the above item

[12] , which is a material for a photoelectric conversion layer. Effect of the Invention

[0024] The pyrrole compound (1) of the present invention has a maximum absorption in the red light region and has photoelectric conversion ability, and therefore is expected to be used as an organic electronic material, typically an organic photoelectric conversion element for red light. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0025] In this specification, a numerical range indicated using "~" indicates a range including the numerical values ​​described before and after "~" as the minimum and maximum values, respectively. In addition, unless specifically stated otherwise, the units of the numerical values ​​described before and after "~" are the same. In the numerical ranges described in stages in this specification, the upper limit or lower limit of a certain numerical range may be replaced with the upper limit or lower limit of a numerical range of another stage. In addition, in the numerical ranges described in this specification, the upper limit or lower limit of the numerical range may be replaced with a value shown in the examples. In addition, the upper limit and lower limit values ​​described individually can be combined arbitrarily.

[0026] The present invention will be described in detail below.

[0027] Ar and X in the pyrrole compound (1) of the present invention 1 , X 2 , R 1 , R 2 , R 3 , R 4 , R 5 , R 6 , R 7 and R 8 The definition of is explained below.

[0028] The aromatic hydrocarbon represented by Ar is not particularly limited, and specific examples thereof include benzene, naphthalene, biphenyl, anthracene, phenanthrene, triphenylene, and the like. A phenyl group is preferred in terms of ease of synthesis of the pyrrole compound (1).

[0029] The heteroaromatic group represented by Ar is not particularly limited, and specific examples thereof include furan, thiophene, pyrrole, selenophene, benzofuran, benzothiophene, indole, benzoselenophene, thieno[2,3-b]thiophene, and thieno[3,2-b]thiophene. Thiophene is preferred in terms of ease of synthesis of the pyrrole compound (1).

[0030] Ar may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 12 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 18 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom. The alkyl group having 1 to 18 carbon atoms may be any of linear, branched, or cyclic alkyl groups, and specific examples thereof include a methyl group, a cyclohexylmethyl group, an ethyl group, a 2-cyclopentylethyl group, a propyl group, a 2-methylpropyl group, a 2,2-dimethylpropyl group, a 3-cyclopropylpropyl group, a 1-methylethyl group, a cyclopropyl group, a butyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 2-butyl group, a 3-methylbutan-2-yl group, a tert-butyl group, a cyclobutyl group, a pentyl group, a 2-methylpentyl group, a 3-ethylpentyl group, a 2,4-dimethylpentyl group, a 2-pentyl group, a 2-methylpentan-2-yl group, a 4,4-dimethylpentan-2-yl group, a 3-pentyl group, a 3-ethylpentan-3-yl group, a cyclopentyl group, a 2,5-dimethylcyclopentyl group, a 3-ethyl cyclopentyl, hexyl, 2-methylhexyl, 3,3-dimethylhexyl, 4-ethylhexyl, 2-hexyl, 2-methylhexan-2-yl, 5,5-dimethylhexan-2-yl, 3-hexyl, 2,4-dimethylhexan-3-yl, cyclohexyl, 4-ethylcyclohexyl, 4,4-dimethylcyclohexyl, heptyl, 2-heptyl, 3- Examples of the alkyl group include a heptyl group, a 4-heptyl group, a bicyclo[2.2.1]heptyl group, an octyl group, a 2-octyl group, a 3-octyl group, a 4-octyl group, a cyclooctyl group, a bicyclo[2.2.2]octyl group, a hexadecyl group, a heptadecyl group, and an octadocyl group. From the viewpoint of ease of synthesis of the pyrrole compound (1), an alkyl group having 1 to 12 carbon atoms is preferred, and a tert-butyl group is more preferred.The haloalkyl group having 1 to 4 carbon atoms may be any of linear, branched, or cyclic haloalkyl groups, and specific examples thereof include a trifluoromethyl group, a difluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a 3,3,3-trifluoropropyl group, a 1,1-difluoropropyl group, a perfluoroisopropyl group, a 2,2,2-trifluoro ... Examples of the fluoroalkyl group include a fluoro-1-(trifluoromethyl)ethyl group, a perfluorocyclopropyl group, a 2,2,3,3-tetrafluorocyclopropyl group, a perfluorobutyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, a 3,3,4,4,4-pentafluorobutyl group, a 4,4,4-trifluorobutyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, a 2-chloroethyl group, and a 3-bromopropyl group. From the viewpoint of ease of synthesis of the pyrrole compound (1), a fluoroalkyl group is preferred, and a trifluoromethyl group is more preferred.Examples of the aryl group having 6 to 14 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-biphenylyl group, a 3-biphenylyl group, a 4-biphenylyl group, a 3,5-terphenylyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthrenyl group, a 2-phenanthrenyl group, a 3-phenanthrenyl group, a 4-phenanthrenyl group, a 9-phenanthrenyl group, a 1-fluorenyl group, a 2-fluorenyl group, a 3-fluorenyl group, a 4-fluorenyl group, a 9,9-dimethyl-9H-fluoren-1-yl group, a 9,9-dimethyl-9H-fluoren-2-yl group, a 9,9-dimethyl-9H-fluoren-3-yl group, a 9,9-dimethyl- Examples include 9H-fluoren-4-yl group, 1-pyrenyl group, 2-pyrenyl group, 9-pyrenyl group, 1-triphenylenyl group, 2-triphenylenyl group, o-tolyl group, m-tolyl group, p-tolyl group, 2,6-xylyl group, 3,5-xylyl group, 2,4,6-trimethylphenyl group, 2,3,5-trimethylphenyl group, 2,3,6-trimethylphenyl group, 2,4,5-trimethylphenyl group, and the like. From the viewpoint of ease of synthesis of the pyrrole compound (1), a phenyl group, a 1-naphthyl group, an o-tolyl group, a m-tolyl group, a p-tolyl group, a 2,6-xylyl group, or a 3,5-xylyl group is preferred, a phenyl group, an o-tolyl group, a m-tolyl group, or a p-tolyl group is more preferred, and a phenyl group or an o-tolyl group is even more preferred. In the dialkylamino group having 2 to 18 carbon atoms, two alkyl groups may be linear or branched, and the two alkyl groups may be bonded together to form a ring. Specific examples of the dialkylamino group include a dimethylamino group, a diethylamino group, a 1-pyrrolidinyl group, a 1-piperidinyl group, a dibutylamino group, a dihexylamino group, and a dioctylamino group. From the viewpoint of ease of synthesis of the pyrrole compound (1), a dimethylamino group or a 1-piperidinyl group is preferred.The diarylamino group having 12 to 18 carbon atoms may be a ring formed by bonding two aryl groups, and specific examples thereof include a diphenylamino group, a 1-naphthyl(phenyl)amino group, a 2-naphthyl(phenyl)amino group, and a 9-carbazoyl group, and the like, with the diphenylamino group and the 9-carbazoyl group being preferred in terms of ease of synthesis of the pyrrole compound (1).The halogen atom may be a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom, and the bromine atom is preferred in terms of ease of synthesis of the pyrrole compound (1).

[0031] X 1 and X 2The alkyl group having 1 to 18 carbon atoms represented by the formula (I) may be any of a linear, branched, or cyclic alkyl group, and specific examples thereof include a methyl group, a cyclohexylmethyl group, an ethyl group, a 2-cyclopentylethyl group, a propyl group, a 2-methylpropyl group, a 2,2-dimethylpropyl group, a 3-cyclopropylpropyl group, a 1-methylethyl group, a cyclopropyl group, a butyl group, a 2-methylbutyl group, a 3-methylbutyl group, a 2-butyl group, a 3-methylbutan-2-yl group, a tert-butyl group, a cyclobutyl group, a pentyl group, a 2-methylpentyl group, a 3-ethylpentyl group, a 2,4-dimethylpentyl group, a 2-pentyl group, a 2-methylpentan-2-yl group, a 4,4-dimethylpentan-2-yl group, a 3-pentyl group, a 3-ethylpentan-3-yl group, a cyclopentyl group, a 2,5-dimethylcyclopentyl group, a 3-ethylcyclopentyl group, a hexyl group, 2-methylhexyl, 3,3-dimethylhexyl, 4-ethylhexyl, 2-hexyl, 2-methylhexan-2-yl, 5,5-dimethylhexan-2-yl, 3-hexyl, 2,4-dimethylhexan-3-yl, cyclohexyl, 4-ethylcyclohexyl, 4,4-dimethylcyclohexyl, heptyl, 2-heptyl, 3-heptyl, 4-heptyl, bicyclo[2.2 Examples of the alkyl group include a bicyclo[2.2.2]octyl group, a hexadecyl group, a heptadecyl group, and a cyclooctyl group. From the viewpoint of ease of synthesis of the pyrrole compound (1), an alkyl group having 1 to 12 carbon atoms is preferred, a methyl group, a tert-butyl group, or a hexyl group is more preferred, and a tert-butyl group is even more preferred.

[0032] X 1 and X 2The haloalkyl group having 1 to 8 carbon atoms represented by the formula (I) may be any of linear, branched, or cyclic haloalkyl groups, and specific examples thereof include a trifluoromethyl group, a difluoromethyl group, a perfluoroethyl group, a 2,2,2-trifluoroethyl group, a 1,1-difluoroethyl group, a 2,2-difluoroethyl group, a perfluoropropyl group, a 2,2,3,3,3-pentafluoropropyl group, a 2,2,3,3-tetrafluoropropyl group, a 3,3,3-trifluoropropyl group, a 1,1-difluoropropyl group, a perfluoroisopropyl group, a 1,1,1,3,3,3-hexafluoroisopropyl group, a 2, ...1,1,1,3,3,3 Examples of the fluoroalkyl group include a fluoro-1-(trifluoromethyl)ethyl group, a perfluorocyclopropyl group, a 2,2,3,3-tetrafluorocyclopropyl group, a perfluorobutyl group, a 2,2,3,3,4,4,4-heptafluorobutyl group, a 3,3,4,4,4-pentafluorobutyl group, a 4,4,4-trifluorobutyl group, a chloromethyl group, a bromomethyl group, an iodomethyl group, a 2-chloroethyl group, a 3-bromopropyl group, a trifluorohexyl group, and a trifluorooctyl group. From the viewpoint of ease of synthesis of the pyrrole compound (1), a fluoroalkyl group is preferred, and a 2,2,2-trifluoroethyl group is more preferred.

[0033] X 1 and X 2Examples of the aryl group having 6 to 14 carbon atoms represented by the formula (I) include a phenyl group, a 1-naphthyl group, a 2-naphthyl group, a 2-biphenylyl group, a 3-biphenylyl group, a 4-biphenylyl group, a 3,5-terphenylyl group, a 1-anthryl group, a 2-anthryl group, a 9-anthryl group, a 1-phenanthrenyl group, a 2-phenanthrenyl group, a 3-phenanthrenyl group, a 4-phenanthrenyl group, a 9-phenanthrenyl group, a 1-fluorenyl group, a 2-fluorenyl group, a 3-fluorenyl group, a 4-phenanthrenyl group, a 9-phenanthrenyl group, a 1-fluorenyl group, a 2-fluorenyl group, a 3-fluorenyl group, a 4-phenanthrenyl group, a 5-fluorenyl group, a 6-fluorenyl group, a 7-fluorenyl group, a 8-fluorenyl group, a 9-fluorenyl group, a 1-fluorenyl group, a 2-fluorenyl group, a 3-fluorenyl group, a 4-fluoren ... Examples of the pyrrole group include a fluorenyl group, a 4-fluorenyl group, a 9,9-dimethyl-9H-fluoren-1-yl group, a 9,9-dimethyl-9H-fluoren-2-yl group, a 9,9-dimethyl-9H-fluoren-3-yl group, a 9,9-dimethyl-9H-fluoren-4-yl group, a 1-pyrenyl group, a 2-pyrenyl group, a 9-pyrenyl group, a 1-triphenylenyl group, and a 2-triphenylenyl group. Of these, a phenyl group is preferred in terms of ease of synthesis of the pyrrole compound (1).

[0034] X 1 and X 2Examples of the heteroaryl group having 3 to 18 carbon atoms represented by the formula (I) include a 2-furanyl group, a 3-furanyl group, a 2-thienyl group, a 3-thienyl group, a 1-pyrrolyl group, a 2-pyrrolyl group, a 3-pyrrolyl group, a 2-pyridyl group, a 3-pyridyl group, a 4-pyridyl group, a 2-quinolyl group, a 3-quinolyl group, a 4-quinolyl group, a 5-quinolyl group, a 6-quinolyl group, a 7-quinolyl group, an 8-quinolyl group, a 2-benzofuranyl group, a 3-benzofuranyl group, a 2-benzothienyl group, a 3-benzothienyl group, a 1-indolyl group, a 2-indolyl group, a 3-indolyl group, a 1-carbazoyl group, a 2-carbazoyl group, and a 3-carbazoyl group. , 4-carbazolyl group, 9-phenyl-9H-carbazol-1-yl group, 9-phenyl-9H-carbazol-2-yl group, 9-phenyl-9H-carbazol-3-yl group, 9-phenyl-9H-carbazol-4-yl group, dibenzofuran-2-yl group, dibenzofuran-3-yl group, dibenzofuran-4-yl group, dibenzothiophen-2-yl group, dibenzothiophen-3-yl group, dibenzothiophen-4-yl group and the like can be exemplified. From the viewpoint of ease of synthesis of the pyrrole compound (1), a 2-furanyl group, a 2-thienyl group or a pyridyl group is preferred, and a 2-thienyl group is more preferred.

[0035] X 1 and X 2 Examples of the aralkyl group having 7 to 15 carbon atoms represented by the following formula include a phenylmethyl group and a phenylethyl group, and the phenylmethyl group is preferred in terms of ease of synthesis of the pyrrole compound (1).

[0036] X 1 and X 2The aryl group, aralkyl group and heteroaryl group represented by the formula (I) may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 6 carbon atoms, a diarylamino group having 12 to 18 carbon atoms and a halogen atom. The alkyl group having 1 to 4 carbon atoms may be any of a linear, branched or cyclic alkyl group, and specific examples thereof include a methyl group, an ethyl group, a propyl group, a 1-methylethyl group, a cyclopropyl group, a butyl group, a 2-butyl group, a tert-butyl group and a cyclobutyl group. In terms of ease of synthesis of the pyrrole compound (1), a methyl group or a tert-butyl group is preferred. In the dialkylamino group having 2 to 8 carbon atoms, the two alkyl groups may be either linear or branched, and the two alkyl groups may be united to form a ring, and specific examples thereof include dimethylamino, diethylamino, 1-pyrrolidinyl, 1-piperidinyl, and dibutylamino groups, and the dimethylamino or 1-piperidinyl group is preferred in terms of ease of synthesis of the pyrrole compound (1). Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom, and the bromine atom is preferred in terms of ease of synthesis of the pyrrole compound (1).

[0037] X 1 and X 2 Examples of the trialkylsilyl group having 3 to 12 carbon atoms represented by the formula (I) include a trimethylsilyl group, an ethyldimethylsilyl group, a dimethylpropylsilyl group, an isopropyldimethylsilyl group, a tert-butyldimethylsilyl group, a triethylsilyl group, a diethylpropylsilyl group, a diethylisopropylsilyl group, a tripropylsilyl group, a tri(isopropyl)silyl group, a tributylsilyl group, and a tri(isobutyl)silyl group. In terms of high solubility of the pyrrole compound (1), a tert-butyldimethylsilyl group, a triethylsilyl group, or a tri(isopropyl)silyl group is preferred, and a tert-butyldimethylsilyl group is more preferred.

[0038] R 1 ~R 8Examples of the alkyl group having 1 to 18 carbon atoms represented by the formula (I) include the same alkyl groups having 1 to 18 carbon atoms as exemplified for Ar. In terms of good solubility of the pyrrole compound (1), an alkyl group having 1 to 12 carbon atoms is preferred, and a tert-butyl group is more preferred.

[0039] R 1 ~R 8 Examples of the haloalkyl group having 1 to 4 carbon atoms represented by the formula (I) include the same haloalkyl groups having 1 to 4 carbon atoms as exemplified for Ar. In terms of ease of synthesis of the pyrrole compound (1), a fluoroalkyl group is preferred, and a trifluoromethyl group is more preferred.

[0040] R 1 ~R 8 Examples of the aryl group having 6 to 14 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms, represented by the formula (I), include the same aryl groups having 6 to 14 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms as exemplified by Ar. In terms of ease of synthesis of the pyrrole compound (1), a phenyl group, a 1-naphthyl group, an o-tolyl group, a m-tolyl group, a p-tolyl group, a 2,6-xylyl group or a 3,5-xylyl group is preferred, a phenyl group, an o-tolyl group, a m-tolyl group or a p-tolyl group is more preferred, and a phenyl group or an o-tolyl group is even more preferred.

[0041] R 1 ~R 8 Examples of the dialkylamino group having 2 to 18 carbon atoms represented by the following formula (I) include the same dialkylamino groups having 2 to 18 carbon atoms as exemplified for Ar. In terms of ease of synthesis of the pyrrole compound (1), a dimethylamino group or a 1-piperidinyl group is preferred.

[0042] R 1 ~R 8Examples of the dialkylamino group having 2 to 18 carbon atoms represented by the following formula (I) include the same dialkylamino groups having 2 to 18 carbon atoms as exemplified for Ar. In terms of ease of synthesis of the pyrrole compound (1), a dimethylamino group or a 1-piperidinyl group is preferred.

[0043] R 1 ~R 8 Examples of the diarylamino group having 12 to 18 carbon atoms represented by the following formula can be mentioned as the diarylamino group having 12 to 18 carbon atoms exemplified as Ar. In terms of ease of synthesis of the pyrrole compound (1), a diphenylamino group or a 9-carbazoyl group is preferred.

[0044] R 1 ~R 8 Examples of the halogen atom represented by the formula (I) include the same halogen atoms as those exemplified for Ar, and a bromine atom is preferred in terms of ease of synthesis of pyrrole compound (1).

[0045] The pyrrole compound (1) of the present invention is not particularly limited, and specific examples thereof include the compounds having the structures shown in the following (1-1) to (1-57).

[0046] [ka]

[0047] [ka]

[0048] [ka]

[0049] [ka]

[0050] [ka] In this specification, Me represents a methyl group.

[0051] Among the compounds represented by (1-1) to (1-57), the pyrrole compound (1) of the present invention is preferably a compound represented by (1-1), (1-2), (1-4), (1-5), (1-6), (1-7), (1-14), (1-15), (1-16), (1-31), (1-32), (1-33), (1-37), (1-40), (1-43), (1-44), (1-46), (1-47), (1-48), (1-49), (1-56) or (1-57), in terms of ease of synthesis, and more preferably a compound represented by (1-2), (1-4), (1-14), (1-44), (1-47) or (1-56).

[0052] Next, a method for producing the pyrrole compound (1-X) of the present invention (hereinafter referred to as the production method of the present invention) will be described.

[0053] The pyrrole compound (1-X) of the present invention can be produced by steps 1 and 2A or steps 1 and 2B shown in the following reaction scheme.

[0054] [ka]

[0055] [ka]

[0056] [ka]

[0057] In the formula, Ar represents an aromatic hydrocarbon or a heteroaromatic group, and the aromatic hydrocarbon and the heteroaromatic group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 18 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 18 carbon atoms which may be substituted with an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 18 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, a cyano group, and a halogen atom. X 1 and X 2 each independently represents a hydrogen atom, an alkyl group having 1 to 18 carbon atoms, a haloalkyl group having 1 to 8 carbon atoms, an aryl group having 6 to 14 carbon atoms, a heteroaryl group having 3 to 18 carbon atoms, an aralkyl group having 7 to 15 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms, a methoxymethyl group, an acetyl group, a benzoyl group, or a trityl group, and the aryl group, aralkyl group, and heteroaryl group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 8 carbon atoms, and a halogen atom.

[0058] Step 1 is a step of reacting compound (2) to produce a pyrrole compound (1-H).

[0059] Examples of the substituent in the compound (2) used in the step 1 include the same as the substituent in the pyrrole compound represented by the general formula (1). Ar is preferably benzene or thiophene, more preferably benzene.

[0060] Specific examples of the compound (2) used in step 1 include compounds having the structures shown in the following (2-1) to (2-15).

[0061] [ka]

[0062] Among the compounds represented by (2-1) to (2-15), compounds represented by (2-1), (2-4), (2-7), (2-8), (2-10), (2-11) or (2-12) are preferred in terms of ease of synthesis, and compounds represented by (2-7), (2-8), (2-10) or (2-11) are particularly preferred. Compound (2) can be produced by a general method well known to those skilled in the art, and for example, compound (2) can be obtained in good yield by following the method disclosed in Angewandte Chemie International Edition, 2015, Vol. 54, pp. 2995-2999. Also, commercially available products may be used.

[0063] In step 1, it is preferable to react compound (2) with a halogenating agent and then with a Lewis acid catalyst.

[0064] Specific examples of the halogenating agent used in step 1 include oxalyl chloride, phosphoryl chloride, sulfuryl chloride, phosphorus trichloride, phosphorus pentachloride, phosphorus tribromide, etc. Oxalyl chloride is preferred in terms of the good yield of the synthesis of the pyrrole compound (1-H).

[0065] Specific examples of the Lewis acid catalyst used in step 1 include metal halides, such as aluminum chloride, iron trichloride, and iron tribromide. Aluminum chloride is preferred because it provides a good synthesis yield for the pyrrole compound (1-H).

[0066] The molar ratio of compound (2) to the halogenating agent used in step 1 is not particularly limited, and in terms of good yield, the molar ratio of compound (2):halogenating agent is preferably in the range of 1:1 to 1:100, and more preferably in the range of 1:2 to 1:20, in terms of good reaction yield.

[0067] Step 1 can be carried out in a solvent. There is no particular limit to the solvent that can be used, and any solvent that does not inhibit the reaction may be used. Specific examples of such solvents include aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, anisole, and tetralin; aliphatic hydrocarbons such as pentane, hexane, heptane, octane, and cyclohexane; ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether (CPME), tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1,4-dioxane, and dimethoxyethane; halogenated solvents such as chloroform, dichloromethane, chlorobenzene, and orthodichlorobenzene; and amides such as N,N-dimethylformamide (DMF), dimethylacetamide (DMAc), and N-methylpyrrolidone; and the like, which may be mixed in any ratio. There is no particular limit to the amount of solvent used. Among these, halogenated solvents, amides or mixed solvents thereof are preferred in terms of the good reaction yield of the pyrrole compound (1-H) of the present invention, and chloroform, DMF or mixed solvents thereof are more preferred.

[0068] The reaction temperature for carrying out step 1 is not particularly limited, and the reaction can usually be carried out at a temperature appropriately selected from -80 to 140°C. In terms of a good reaction yield of the pyrrole compound (1-H) of the present invention, the reaction is preferably carried out at a temperature appropriately selected from 0 to 80°C, and more preferably at a temperature appropriately selected from 10 to 40°C.

[0069] The pyrrole compound (1-H) of the present invention can be obtained by carrying out a normal treatment after completion of the reaction in step 1. If necessary, it may be purified by recrystallization, column chromatography, sublimation, preparative HPLC, or the like.

[0070] Steps 2A and 2B are steps for producing a pyrrole compound (1-X) by reacting a pyrrole compound (1-H).

[0071] The substituents in the pyrrole compound (1-H) used in step 2 can be the same as those in the pyrrole compound represented by formula (1). Ar is preferably benzene or thiophene, more preferably benzene; X 1 is preferably a methyl group, a phenyl group, a phenylmethyl group, a tert-butyldimethylsilyl group, a triethylsilyl group, or a tri(isopropyl)silyl group, and more preferably a tert-butyldimethylsilyl group.

[0072] Steps 2A and 2B are preferably carried out in the presence of a base.

[0073] Specific examples of the base used in steps 2A and 2B include metal hydroxides such as sodium hydroxide, potassium hydroxide, and calcium hydroxide; metal carbonates such as sodium carbonate, potassium carbonate, lithium carbonate, and cesium carbonate; metal acetates such as potassium acetate and sodium acetate; metal phosphates such as potassium phosphate and sodium phosphate; metal fluorides such as sodium fluoride, potassium fluoride, and cesium fluoride; metal alkoxides such as sodium methoxide, potassium methoxide, sodium ethoxide, potassium isopropyl oxide, and potassium tert-butoxide; tertiary alkylamines such as trimethylamine, triethylamine, diisopropylethylamine, and tributylamine; cyclic azines such as pyridine, pyrazine, quinoline, and imidazole; and the like. These bases may be used alone or in combination of two or more types as appropriate. Imidazole is preferred in terms of the good yield of the synthesis of the pyrrole compound (1-X).

[0074] Steps 2A and 2B can be carried out in a solvent. There is no particular limit to the solvent that can be used, and any solvent that does not inhibit the reaction may be used. Specific examples of such solvents include aromatic hydrocarbons such as benzene, toluene, xylene, mesitylene, anisole, and tetralin; aliphatic hydrocarbons such as pentane, hexane, heptane, octane, and cyclohexane; ethers such as diethyl ether, diisopropyl ether, dibutyl ether, cyclopentyl methyl ether (CPME), tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1,4-dioxane, and dimethoxyethane; halogenated solvents such as chloroform, dichloromethane, chlorobenzene, and orthodichlorobenzene; and amides such as N,N-dimethylformamide (DMF), dimethylacetamide (DMAc), and N-methylpyrrolidone (NMP). These may be mixed and used in any ratio. There is no particular limit to the amount of solvent used. Among these, amides are preferred in that they provide a good reaction yield of the pyrrole compound (1-X) of the present invention, and DMF is more preferred.

[0075] The reaction temperature when carrying out steps 2A and 2B is not particularly limited, and the steps can usually be carried out at a temperature appropriately selected from -80 to 140°C. In terms of a good reaction yield of the pyrrole compound (1-H) of the present invention, the steps are preferably carried out at a temperature appropriately selected from 20°C to 80°C, and more preferably at a temperature appropriately selected from 10°C to 40°C.

[0076] The pyrrole compound (1-X) of the present invention can be obtained by carrying out a normal treatment after the completion of the reactions of steps 2A and 2B. If necessary, it may be purified by recrystallization, column chromatography, sublimation, preparative HPLC, or the like.

[0077] Further, a photoelectric conversion element containing the pyrrole compound (1) of the present invention (hereinafter referred to as "the photoelectric conversion element of the present invention") will be described.

[0078] The photoelectric conversion element of the present invention includes a substrate, a negative electrode layer, a photoelectric conversion layer, and a positive electrode layer. If necessary, a hole transport layer and / or an electron blocking layer may be provided between the negative electrode layer and the photoelectric conversion layer, and an electron transport layer and / or a hole blocking layer may be provided between the positive electrode layer and the photoelectric conversion layer.

[0079] In the photoelectric conversion element of the present invention, the pyrrole compound (1) of the present invention may be used in any layer, but is preferably used in the photoelectric conversion layer.

[0080] The photoelectric conversion layer may contain a fullerene derivative. The fullerene derivative is, for example,

[60] fullerene (C 60 ),

[70] Fullerene (C 70 ), Phenyl-C 61 -Methyl butyrate (

[60] PCBM), phenyl-C 71 -Methyl butyrate (

[70] PCBM), phenyl-C 85 3-methylbutyrate (

[84] PCBM), and

[60] fullerene (C 60 ) or

[70] fullerene (C 70 ) is preferred.

[0081] When the photoelectric conversion layer contains a fullerene derivative, the volume ratio of the pyrrole compound (1) of the present invention to the fullerene derivative is preferably 1:0.01 or more and 1:100 or less, more preferably 1:0.1 or more and 1:10 or less.

[0082] In the photoelectric conversion element of the present invention, a hole transport layer may be provided between the negative electrode and the photoelectric conversion layer, and an electron transport layer may be provided between the positive electrode and the photoelectric conversion layer, in order to improve carrier transportability. The hole transport layer is not particularly limited, and has either hole injection or transport, or electron barrier properties, and may be either an organic or inorganic material, and specifically includes triazole derivatives, oxadiazole derivatives, imidazole derivatives, polyarylalkane derivatives, pyrazoline derivatives and pyrazolone derivatives, phenylenediamine derivatives, arylamine derivatives, amino-substituted chalcone derivatives, oxazole derivatives, styrylanthracene derivatives, fluorenone derivatives, hydrazone derivatives, stilbene derivatives, silazane derivatives, aniline-based copolymers, and conductive polymer oligomers. The electron transport layer is not particularly limited, and has either electron injection or transport or hole blocking properties. Specific examples include nitro-substituted fluorene derivatives, diphenylquinone derivatives, thiopyran dioxide derivatives, carbodiimides, fluorenylidene methane derivatives, anthraquinodimethane, and anthrone derivatives or oxadiazole derivatives. In addition, for the purpose of suppressing dark current generation, an electron blocking layer may be provided between the negative electrode and the photoelectric conversion layer, and a hole blocking layer may be provided between the positive electrode and the photoelectric conversion layer. Examples of the electron blocking layer include triarylamines such as 2,7-bis(9-carbazolyl)-9,9-spirobifluorene (Spiro-2CBP) and 3,7-bis[4-(9H-carbazol-9-yl)phenyl]-2,6-diphenylbenzo[1,2-b:4,5-b']difuran (CZBDF). Examples of the hole blocking layer include naphthalenetetracarboxylic acid diimides such as N,N'-di(4-pyridyl)-1,4,5,8-naphthalenetetracarboxylic acid diimide, tris(8-quinolinolato)aluminum (Alq3), etc. The hole transport layer may also function as the electron blocking layer, and the electron transport layer may also function as the hole blocking layer.

[0083] There is no particular limitation on the method for producing the photoelectric conversion layer, hole transport layer, electron transport layer, hole blocking layer and electron blocking layer (hereinafter referred to as "organic layers") of the photoelectric conversion element of the present invention, but film formation by vacuum deposition is possible. Film formation by vacuum deposition can be performed by using a general-purpose vacuum deposition device. The degree of vacuum in the vacuum chamber when forming a film by vacuum deposition is 1×10, which can be achieved by a commonly used diffusion pump, turbomolecular pump, cryopump, etc., taking into consideration the production takt time and production cost for producing an organic electroluminescent device. -6 Pa or more 1×10 -2 The deposition rate is preferably 0.005 nm / sec or more and 1.0 nm / sec or less, depending on the thickness of the film to be formed. Film formation can also be performed by a spin coating method, an inkjet method, a casting method, a dipping method, or the like using a general-purpose device.

[0084] The positive electrode layer and the negative electrode layer of the photoelectric conversion element of the present invention are connected to a power source via an electrical conductor such as a conducting wire. Either the positive electrode layer or the negative electrode layer can be in contact with the substrate of the photoelectric conversion element of the present invention. For convenience, the electrode in contact with the substrate is called the lower electrode. In the photoelectric conversion element of the present invention, either the positive electrode layer or the negative electrode layer may be the lower electrode.

[0085] As for the positive electrode layer and the negative electrode layer (hereinafter referred to as "electrode") of the photoelectric conversion element of the present invention, at least one of them, which is the light receiving surface, is preferably light transmissive. As the light transmissive electrode, a general transparent electrode material can be used, and examples thereof include metal oxides such as indium-tin oxide (ITO), indium-zinc oxide (IZO), tin oxide, aluminum or indium-doped tin oxide, magnesium-indium oxide, or nickel-tungsten oxide, metal nitrides such as gallium nitride, metal selenides such as zinc selenide, or metal sulfides such as zinc sulfide. Metal oxides are preferred in terms of good light transmissivity and electrical conductivity, and ITO, IZO, and tin oxide are more preferred. In addition, the electrode can be modified with plasma-deposited fluorocarbon.

[0086] For the other electrode that is not the light receiving surface, in addition to the transparent electrode materials exemplified above, an opaque or reflective electrode material can be used. Examples of the opaque or reflective electrode material include gold, silver, iridium, molybdenum, palladium, platinum, sodium, sodium-potassium alloy, magnesium, lithium, magnesium / copper mixture, magnesium / silver mixture, magnesium / aluminum mixture, magnesium / indium mixture, aluminum, aluminum / aluminum oxide (Al2O3) mixture, indium, lithium / aluminum mixture, and rare earth metals.

[0087] There is no particular limitation on the method for producing the electrodes of the photoelectric conversion element of the present invention, but film formation by vacuum deposition, sputtering, electron beam deposition, chemical reaction methods (such as the sol-gel method), coating methods, etc. are possible.

[0088] The photoelectric conversion element of the present invention is formed on a substrate. The substrate may be light-transmitting or opaque depending on the intended light receiving direction. Light-transmitting is preferred for receiving light through the substrate, and examples of the substrate include transparent glass, quartz, and plastic. Examples of opaque substrates include silicon and silicon oxide. The substrate may also be a composite structure including multiple material layers.

[0089] The method for producing the photoelectric conversion element of the present invention is not particularly limited, but the element can be produced by successively forming an electrode layer, an organic layer, and an electrode layer on a substrate. Alternatively, an organic layer and an electrode layer may be successively formed on a substrate on which an electrode layer has been formed in advance.

[0090] The pyrrole compound (1) of the present invention has a maximum absorption in the red light region and has photoelectric conversion ability, and therefore is expected to be used as an organic electronic material, typically an organic photoelectric conversion element for red light. EXAMPLES

[0091] The present invention will be described in more detail below with reference to examples and comparative examples, but the present invention should not be construed as being limited to these. [1 H-NMR measurement] 1 H-NMR measurements were performed using a Bruker AVANCE III 400 or AVANCE III HD 400 NMR. 1 H-NMR was measured using a deuterated solvent as the measurement solvent and tetramethylsilane (TMS) as the internal standard. [Thin film preparation and film thickness measurement] The thin film was prepared by vacuum deposition using ELORA-500 (manufactured by ULVAC KIKOU). The substrate was cleaned with isopropyl alcohol and then cleaned with oxygen plasma. The film thickness was measured using a stylus film thickness measuring instrument DektakXT (manufactured by BRUKER). [Absorption spectrum measurement] The absorption spectrum was measured using a spectrophotometer V-750 (manufactured by JASCO Corporation). The measurement was performed at a scan speed of 400 nm / min. The measurement sample was a thin film prepared on a quartz substrate by vacuum deposition. [Light current measurement] The photocurrent was measured using a solar cell spectral response measurement device (manufactured by Soma Optical Co., Ltd.). The irradiated light intensity was 50 μW / cm 2 Measurements were performed. [Dark current measurement] The dark current was measured using a Source Measure Unit 2636B (manufactured by Keithley).

[0092] The reagents used were commercially available.

[0093] Synthesis reference example-1

[0094] [ka]

[0095] 3,6-bis(4-tert-butylphenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (3.0g, 7.5mmol), potassium carbonate (10g, 75mmol), and tetrabutylammonium hydrogen sulfate (0.12g, 0.38mmol) were suspended in DMF (150mL) and stirred at 120°C for 30 minutes. tert-Butyl bromoacetate (9.6mL, 68mmol) was added dropwise to the reaction solution, and the mixture was stirred at 120°C for 4 hours. The reaction solution was filtered to remove insoluble matter, and low boiling points were distilled off under reduced pressure from the obtained filtrate. The obtained solid was extracted with chloroform, and the extract was dried over sodium sulfate, and then the sodium sulfate was removed by filtration. The low boiling fractions were removed from the obtained filtrate by distillation under reduced pressure to obtain 2,5-bis(tert-butyloxycarbonylmethyl)-3,6-bis(4-tert-butylphenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (3.8 g, 79%). 1 H-NMR(400Hz,CDCl3)δ(ppm):7.73(d,J=8.6Hz,4H),7.51(d,J=8.6Hz,4H),4.44(s,4H),1.37(s,18H),1.34(s,18H). Synthesis reference example-2

[0096] [ka]

[0097] 2,5-bis(tert-butyloxycarbonylmethyl)-3,6-bis(4-tert-butylphenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (3.7g, 5.9mmol) was dissolved in chloroform (30mL), trifluoroacetic acid (15mL) was added, and the mixture was stirred at room temperature for 18 hours. The resulting precipitate was filtered off, and the resulting solid was washed with water and chloroform to obtain 2,5-bis(carboxylmethyl)-3,6-bis(4-tert-butylphenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (carboxylic acid compound (2-3)) (2.6g, 86%). 1H-NMR(400Hz,DMSO-d6)δ(ppm):13.2(brs,2H),7.75(d,J=8.7Hz,4H),7.62(d,J=8.7Hz,4H),4.47(s,4H),1.33(s,18H). Synthesis Example 1

[0098] [ka]

[0099] 2,5-Bis(carboxylmethyl)-3,6-di(4-tert-butylphenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (2.5g, 4.8mmol) was suspended in chloroform (100mL), oxalyl chloride (4.2mL, 48mmol) and DMF (1mL) were added, and the mixture was stirred at room temperature for 30 minutes. After removing low boiling points from the reaction solution by vacuum distillation, the obtained solid was dissolved in chloroform (100mL), aluminum chloride (7.7g, 58mmol) was added, and the mixture was stirred for 18 hours. The reaction solution was quenched with a saturated aqueous potassium hydrogen sulfate solution, and then insoluble matter was removed by filtration. The residue was washed with water and chloroform to obtain 3,11-di-tert-butyl-5,13-dihydroxy-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (pyrrole compound (1-58)) (1.7 g, 63%). 1 H-NMR(400Hz,CDCl3)δ(ppm):10.3(brs,2H),8.91(d,J=8.6Hz,2H),7.93(d,J=1.7Hz,2H),7.78(dd,J=8.6,1.7Hz,2H),7.43(s,2H),1.40(s,18H). Synthesis Example 2

[0100] [ka]

[0101] 3,11-Di-tert-butyl-5,13-dihydroxy-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (1.2 g, 2.4 mmol) was dissolved in DMF (25 mL), and tert-butylchlorodimethylsilane (1.6 g, 11 mmol) and imidazole (1.4 g, 21 mmol) were added and the mixture was stirred at room temperature for 16 hours. Low boiling fractions were distilled off from the reaction solution under reduced pressure, and the resulting solid was washed with water and hexane, then dissolved in chloroform and purified by silica pad filtration to obtain 3,11-di-tert-butyl-5,13-bis(tert-butyldimethylsiloxy)-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (pyrrole compound (1-2)) (1.1 g, 63%). 1 H-NMR(400Hz,CDCl3)δ(ppm):9.04(d,J=8.5Hz,2H),7.93(d,J=1.9Hz,2H),7.71 (dd,J=8.5,1.9Hz,2H),7.45(s,2H),1.41(s,18H),1.11(s,18H),0.32(s,12H). Synthesis reference example-3

[0102] [ka]

[0103] 3,6-bis(4-chlorophenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (15g, 42mmol), potassium carbonate (59g, 0.42mol), and tetrabutylammonium hydrogen sulfate (1.5g, 4.3mmol) were suspended in DMF (1.3L) and stirred at 120°C for 30 minutes. tert-Butyl bromoacetate (57mL, 0.39mol) was added dropwise to the reaction solution and stirred at 120°C for 4 hours. The reaction solution was filtered to remove insoluble matter, and low boiling points were distilled off from the obtained filtrate under reduced pressure. The obtained solid was washed with methanol and water and dried under reduced pressure to obtain 2,5-bis(tert-butyloxycarbonylmethyl)-3,6-bis(4-chlorophenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (15g, 60%). 1 H-NMR(400Hz,CDCl3)δ(ppm):7.72(d,J=8.5Hz,4H),7.49(d,J=8.5Hz,4H),4.38(s,4H),1.40(s,18H). Synthesis reference example-4

[0104] [ka]

[0105] 2,5-bis(tert-butyloxycarbonylmethyl)-3,6-bis(4-chlorophenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (15g, 25mmol) was suspended in trifluoroacetic acid (80mL) and water (10mL) and stirred at room temperature for 14 hours. Water (200mL) was added at 0°C, and the resulting precipitate was filtered off to obtain a solid, which was washed with water, chloroform, and hexane and dried under reduced pressure to obtain 2,5-bis(carboxylmethyl)-3,6-bis(4-chlorophenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (carboxylic acid compound (2-10)) (11g, 89%). 1 H-NMR(400Hz,DMSO-d6)δ(ppm):13.19(brs,2H),7.83(d,J=8.6Hz,4H),7.69(d,J=8.6Hz,4H),4.48(s,4H). Synthesis Example 3

[0106] [ka]

[0107] 2,5-Bis(carboxylmethyl)-3,6-di(4-chlorobutylphenyl)-1,4-diketopyrrolo[3,4-c]pyrrole (9.7g, 20mmol) was suspended in chloroform (300mL), oxalyl chloride (18mL, 0.21mol) and DMF (5mL) were added, and the mixture was stirred at room temperature for 20 hours. After removing low boiling points from the reaction solution by vacuum distillation, the obtained solid was dissolved in chloroform (300mL), aluminum chloride (33g, 0.25mol) was added, and the mixture was heated at 60℃ for 16.5 hours. The reaction solution was quenched with hydrochloric acid (1 mol / L, 300 mL), and the resulting precipitate was collected by filtration to obtain a solid. The solid was washed with water, acetone, and chloroform, and dried under reduced pressure to obtain 3,11-dichloro-5,13-dihydroxy-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (pyrrole compound (1-56)) (8.9 g, 99%). 1 H-NMR (400Hz,Acetone-d6+D2O+K2CO3)δ(ppm):8.95(d,J=8.7Hz,2H),8.24(s,2H),7.59(d,J=8.7Hz,2H),7.13(s,2H). Synthesis Example 4

[0108] [ka]

[0109] 3,11-dichloro-5,13-dihydroxy-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (3.0g, 6.8mmol) was dissolved in DMF (35mL), tert-butylchlorodimethylsilane (4.6g, 30mmol) and imidazole (4.1g, 60mmol) were added, and the mixture was stirred at room temperature for 16 hours. Low boiling points were removed from the reaction solution by vacuum distillation, and the obtained solid was washed with water, ethanol and hexane, then dissolved in chloroform, purified by silica pad filtration, and the solvent was removed by vacuum distillation. The resulting residue was washed with toluene and hexane and dried under reduced pressure to obtain 3,11-di-tert-butyl-5,13-bis(tert-butyldimethylsiloxy)-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (pyrrole compound (1-14)) (1.6 g, 34%). 1 H-NMR(400Hz,CDCl3)δ(ppm):8.93(d,J=8.5Hz,2H),7.77(d,J=1.2Hz,2H),7.51(dd,J=8.5Hz,1.2Hz,2H),7.39(s,2H),1.10(s,18H),0.34(s,12H). Synthesis Example 5

[0110] [ka]

[0111] 3,11-Di-tert-butyl-5,13-bis(tert-butyldimethylsiloxy)-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (0.10 g, 0.14 mmol), palladium acetate (4.0 mg, 18 μmol), 2-dicyclohexylphosphino-2',4',6'-triisopropylbiphenyl (XPhos) (16 mg, 34 μmol), potassium carbonate (99 mg, 0.72 mmol) and 2-methylphenylboronic acid (49 mg, 0.36 mmol) were suspended in THF (2 mL) and water (0.4 mL) and refluxed for 16 hours. The reaction solution was added to a mixture of methanol and water, and the resulting precipitate was collected by filtration. The solid thus obtained was washed with water, methanol, chloroform, and hexane, and then dried under reduced pressure to obtain 3,11-bis(2-methylphenyl)-5,13-dihydroxy-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (pyrrole compound (1-47)) (70 mg, 89%). 1 H-NMR(400Hz,DMSO-d6)δ(ppm):10.36(brs,2H),9.00(d,J=8.3Hz,2H),7.85(s,2H),7.78(d,J=8.3Hz,2H),7.47(s,2H),7.36(m,8H),2.31(s,6H). Synthesis Example 6

[0112] [ka]

[0113] 3,11-Bis(2-methylphenyl)-5,13-dihydroxy-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (42 mg, 76 μmol) was dissolved in DMF (2 mL), tert-butylchlorodimethylsilane (61 mg, 0.40 mmol) and imidazole (50 mg, 0.73 mmol) were added, and the mixture was stirred at room temperature for 16 hours. Low boiling points were distilled off from the reaction solution under reduced pressure, and the resulting solid was washed with water, ethanol and hexane, and then dried under reduced pressure to obtain 3,11-bis(2-methylphenyl)-5,13-bis(tert-butyldimethylsiloxy)-8H,16H-benzo[7',8']indolizino[2',1':3,4]pyrrolo[2,1-a]isoquinolizine-8,16-dione (pyrrole compound (1-5)) (47 mg, 79%). 1 H-NMR(400Hz,CDCl3)δ(ppm):9.18(d,J=8.2Hz,2H),7.89(d,J=1.4Hz,2H),7.64(dd,J= 8.2Hz,1.4Hz,2H),7.51(s,2H),7.33(m,8H),2.36(s,6H),1.06(s,18H),0.34(s,12H). Evaluation example 1 A thin film of the pyrrole compound (1-2) of the present invention was prepared on a quartz substrate by vacuum deposition, and the absorption spectrum of the thin film was measured. The maximum absorption wavelength in the visible light region (400 to 700 nm) was 620 nm, and the half-width of the maximum absorption peak was 106 nm.

[0114] Comparative Example 1 A thin film of SubNc was prepared on a quartz substrate by vacuum deposition, and the absorption spectrum of the thin film was measured. The maximum absorption wavelength in the visible light region (400 to 700 nm) was 680 nm, and the half-width of the maximum absorption peak was 109 nm.

[0115] Evaluation example 2 A photoelectric conversion element containing the pyrrole compound of the present invention as a constituent component was produced, and its performance was evaluated.

[0116] The substrate used was a glass substrate with an ITO transparent electrode on which an ITO film with a width of 2 mm was patterned in a stripe shape. This substrate was washed with isopropyl alcohol and then oxygen plasma washed. On the washed substrate, 2,7-bis(carbazol-9-yl)-9,9-spirobifluorene (Spiro-2CBP, film thickness 30 nm) was applied as a hole transport layer, and the pyrrole compound (1-2) of the present invention and

[60] fullerene (C 60 ) co-evaporated film (thickness 320 nm, equivalent film thickness ratio 1:1), and

[60] fullerene (C 60 A metal mask was then placed on the substrate so as to be perpendicular to the ITO stripes, and aluminum was vacuum-deposited at a deposition rate of 0.3 nm / sec to form a positive electrode layer. After deposition, the multilayer film was sealed in a nitrogen atmosphere glove box with oxygen and moisture concentrations of 1 ppm or less, and then cooled to 400° C. for 24 hours. 2 The photoelectric conversion element was produced using a glass sealing cap and an epoxy type UV-curable resin (manufactured by Nagase ChemteX Corporation).

[0117] The light current (irradiation light wavelength: 600 nm) and dark current were measured when a voltage of 10 V was applied to the photoelectric conversion element, and the light / dark ratio was calculated to be 1.0 × 10 2 This demonstrates that the photoelectric conversion element of the present invention operates as a photoelectric conversion element having sensitivity in the red light region.

[0118] From Evaluation Examples 1 and 2, it was shown that the pyrrole compound of the present invention has a maximum absorption wavelength closer to 600 nm than SubNc shown in Comparative Example 1, and has photoelectric conversion ability, and is therefore useful as a red photoelectric conversion material. [Industrial Applicability]

[0119] The pyrrole compound (1) of the present invention can be used as an organic photodiode material, an organic thin-film solar cell material, an organic semiconductor laser material, an organic EL display material, a photonic crystal material, or other electronic material.

Claims

1. A pyrrole compound represented by general formula (1): 【Chemistry 1】 In formula (1), Ar represents an aromatic hydrocarbon or a heteroaromatic group, and the aromatic hydrocarbon and the heteroaromatic group are an alkyl group having 1 to 18 carbon atoms; A haloalkyl group having 1 to 8 carbon atoms; an aryl group having 6 to 18 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms; A dialkylamino group having 2 to 18 carbon atoms; A diarylamino group having 12 to 18 carbon atoms; and It may be substituted with one or more substituents selected from the group consisting of halogen atoms. X １ and X ２ each independently represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a haloalkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 3 to 18 carbon atoms, an aralkyl group having 7 to 19 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms, a methoxymethyl group, an acetyl group, a benzoyl group, or a trityl group; The aryl group, aralkyl group and heteroaryl group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 6 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom.

2. In formula (1), Ar represents an aromatic hydrocarbon having 6 to 18 carbon atoms or a heteroaromatic ring having 3 to 18 carbon atoms, and the aromatic hydrocarbon and the heteroaromatic ring are each an alkyl group having 1 to 18 carbon atoms; A haloalkyl group having 1 to 8 carbon atoms; an aryl group having 6 to 18 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms; A dialkylamino group having 2 to 18 carbon atoms; A diarylamino group having 12 to 18 carbon atoms; and The pyrrole compound according to claim 1, which is optionally substituted with one or more substituents selected from the group consisting of halogen atoms.

3. The pyrrole compound according to claim 1, wherein the pyrrole compound represented by formula (1) is represented by the following formula (1-a), (1-b) or (1-c): 【Chemistry 2】 In formulas (1-a), (1-b) and (1-c), R １ ~R ８ are each independently Hydrogen atom; an alkyl group having 1 to 18 carbon atoms; A haloalkyl group having 1 to 8 carbon atoms; an aryl group having 6 to 18 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms; A dialkylamino group having 2 to 18 carbon atoms; A diarylamino group having 12 to 18 carbon atoms; or represents a halogen atom, X １ and X ２ each independently represents a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, a haloalkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 3 to 18 carbon atoms, an aralkyl group having 7 to 19 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms, a methoxymethyl group, an acetyl group, a benzoyl group, or a trityl group; The aryl group, aralkyl group and heteroaryl group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 6 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom.

4. In formula (1), R １ ~R ８ The pyrrole compound according to claim 3, wherein is a phenyl group which may be substituted with an alkyl group having 1 to 18 carbon atoms or an alkyl group having 1 to 4 carbon atoms.

5. In formula (1), X １ and X ２ The pyrrole compound according to claim 1, wherein each of the is independently a hydrogen atom, an alkyl group having 1 to 30 carbon atoms, or a trialkylsilyl group having 3 to 12 carbon atoms.

6. General formula (2) 【Chemistry 3】 In formula (2), Ar represents an aromatic hydrocarbon or a heteroaromatic compound, and the aromatic hydrocarbon and the heteroaromatic compound are an alkyl group having 1 to 18 carbon atoms; A haloalkyl group having 1 to 8 carbon atoms; an aryl group having 6 to 18 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms; A dialkylamino group having 2 to 18 carbon atoms; A diarylamino group having 12 to 18 carbon atoms; and (which may be substituted with one or more substituents selected from the group consisting of halogen atoms) in the presence of a halogenating agent to obtain a carboxylic acid compound represented by the general formula (1-H): 【Chemistry 4】 (wherein Ar has the same meaning as defined above)

7. General formula (1-H) 【Chemistry 5】 In formula (1-H), Ar represents an aromatic hydrocarbon or a heteroaromatic compound, and the aromatic hydrocarbon and the heteroaromatic compound are an alkyl group having 1 to 18 carbon atoms; A haloalkyl group having 1 to 8 carbon atoms; an aryl group having 6 to 18 carbon atoms which may be substituted by an alkyl group having 1 to 4 carbon atoms; A dialkylamino group having 2 to 18 carbon atoms; A diarylamino group having 12 to 18 carbon atoms; and (which may be substituted with one or more substituents selected from the group consisting of halogen atoms) in the presence of a base to obtain a pyrrole compound represented by the general formula (1-X): 【Chemistry 6】 In formula (1-X), Ar has the same meaning as above. X １ and X ２ each independently represents an alkyl group having 1 to 30 carbon atoms, a haloalkyl group having 1 to 30 carbon atoms, an aryl group having 6 to 18 carbon atoms, a heteroaryl group having 3 to 18 carbon atoms, an aralkyl group having 7 to 19 carbon atoms, a trialkylsilyl group having 3 to 12 carbon atoms, a methoxymethyl group, an acetyl group, a benzoyl group, or a trityl group, and the aryl group, the aralkyl group, and the heteroaryl group may be substituted with one or more substituents selected from the group consisting of an alkyl group having 1 to 4 carbon atoms, a dialkylamino group having 2 to 6 carbon atoms, a diarylamino group having 12 to 18 carbon atoms, and a halogen atom.

8. A photoelectric conversion element comprising the pyrrole compound according to any one of claims 1 to 5.

9. A photoelectric conversion element comprising a photoelectric conversion layer containing the pyrrole compound according to any one of claims 1 to 5.

10. The photoelectric conversion element according to claim 9 , wherein the photoelectric conversion layer further contains a fullerene derivative.

11. The fullerene derivative is [60]fullerene (C ６０ ) or [70]fullerene (C ７０ The photoelectric conversion element according to claim 10 .

12. A material for a photoelectric conversion device, comprising the pyrrole compound according to any one of claims 1 to 5.

13. The material for a photoelectric conversion element according to claim 12 , which is a material for a photoelectric conversion layer.

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