JP2016056126A - Novel condensed pyrrole-boron complex compound and method for producing the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a novel light-absorbing compound which absorbs near infrared light of a long wavelength region and can be used to realize more efficient application of near infrared light.SOLUTION: Provided is a benzodipyrrole derivative represented by a general formula I. (Arand Arare each independently a heteroaromatic group which may have a substituent; Rto Rare each independently a hydrogen atom, or a linear or branched alkoxy group having 1 to 8 carbon atoms which may have a substituent; and Band Bare each independently a hydrogen atom or a group selected from the group consisting of boryl groups which may have a substituent, where at least one of Band Bis a boryl group which may have a substituent.)SELECTED DRAWING: None

Description

  The present invention relates to a novel fused ring pyrrole boron complex compound useful as a near-infrared absorbing material, a method for producing the compound, and a solar cell using the compound.

  Near-infrared absorbing materials are applied in various fields such as near-infrared light filters, heat-absorbing films, ecological imaging, photodynamic therapy, near-infrared photodetectors, and thin-film solar cells. Most organic materials exhibiting near-infrared absorption characteristics have a near-infrared absorption characteristic of a relatively short wavelength from visible light to about 800 nm. For example, phthalocyanine is known as a dye material that forms a complex with a metal and usually exhibits blue to green, but a dye material called naphthalocyanine in which the benzene ring of phthalocyanine is replaced with a naphthalene ring is used in the near infrared region. It has a relatively narrow main absorption band (for example, near a wavelength of 800 nm) and emits light (see Patent Document 1 and Non-Patent Document 1).

  However, the light absorption characteristics required for near-infrared absorbing materials differ depending on the application, and in order to effectively use near-infrared light, it is important to use near-infrared light in a longer wavelength region after 800 nm. Therefore, development of a novel near-infrared absorbing material having a light absorption characteristic different from that of a naphthalocyanine-based dye material has been eagerly desired. For example, a novel compound in which an azulene ring is condensed and a production method thereof have been proposed (see Patent Document 2).

  On the other hand, in order to improve the performance of the photoelectric conversion device, it is essential to simultaneously maximize the open-circuit voltage and the short-circuit current density. In order to maximize the short-circuit current density, the active layer material needs to have suitable near-infrared absorption characteristics up to 1000 nm. At the same time, the active layer material must have an appropriate ionization potential and electron affinity in order to provide a high open-circuit voltage (see Non-Patent Document 2). However, donor-acceptor-linked molecules, which are conventional approaches for near-infrared absorbing materials, have limited acceptor unit types and exhibit sufficient near-infrared absorption characteristics while having appropriate electron levels. Creation of molecules was difficult.

JP 2009-29955 A JP 2011-116717 A

B. L. Wheeler et al., J. Am. Chem. Soc., Vol.106, p7404-7410, 1984 M. C. Scharber et al., Adv. Mater., Vol. 18, p789-794, 2006

  Accordingly, the present invention provides a new light-absorbing material that absorbs near-infrared light in the longer wavelength range up to 1000 nm, which has been considered difficult by conventional methods, and realizes more efficient use of near-infrared light. It is an object to do.

  As a result of intensive studies to solve the above problems, the present inventors have a characteristic that a certain kind of condensed pyrrole boron complex compound absorbs light in a wide range from a visible light to a long wavelength near infrared region. As a result, the present invention has been completed.

（式中、Ａｒ^１及びＡｒ^２は各々独立に、置換基を有してもよいヘテロアリール基を示し；Ｒ^ａ〜Ｒ^ｄは各々独立に、水素原子又は置換基を有してもよい炭素数１〜８の直鎖又は分岐鎖のアルコキシ基を示し；Ｂ^１及びＢ^２は各々独立に水素原子又は置換基を有してもよいボリル基からなる群から選択される基を示し、ただし、Ｂ^１及びＢ^２の少なくとも一方は置換基を有してもよいボリル基である）で表されるベンゾジピロール誘導体；
（２）Ａｒ^１またはＡｒ^２におけるヘテロアリール基を構成するヘテロ原子が、Ｂ^１又はＢ^２におけるボリル基のホウ素原子と配位結合を形成している、上記（１）に記載のベンゾジピロール誘導体；
（３）Ａｒ^１及びＡｒ^２は各々独立に、置換基を有してもよいキノキサリニル又はベンゾチアジアゾリルであって、当該置換基が、炭素数１〜８の直鎖又は分岐鎖のアルキルである、上記（１）又は（２）に記載のベンゾジピロール誘導体；
（４）Ａｒ^１及びＡｒ^２は各々独立に、８−（２−エチルヘキシル）−キノキサリン−５−イル、又は７−（２−エチルヘキシル）−２、１、３−ベンゾチアジアゾール−４−イルである、上記（１）又は（２）に記載のベンゾジピロール誘導体；
（５）Ｂ^１及びＢ^２におけるボリル基が−Ｂ（Ｒ^１）_２であって、ここで、Ｒ^１は各々独立に、ハロゲン、置換基を有してもよいアルキル、又は置換基を有してもよいアリールから選択される、上記（１）〜（４）のいずれか１に記載のベンゾジピロール誘導体；
（６）Ｒ^１がフェニルである、上記（５）に記載のベンゾジピロール誘導体；
（７）Ｂ^１及びＢ^２がいずれもボリル基である、上記（１）〜（６）のいずれか１に記載のベンゾジピロール誘導体；
（８）紫外可視吸収スペクトルにおいて６００〜２５００ ｎｍの範囲に吸収帯を有する、上記（１）〜（７）のいずれか１に記載のベンゾジピロール誘導体；
（９）イオン化ポテンシャルが４〜６ｅｖである、上記（１）〜（８）のいずれか１に記載のベンゾジピロール誘導体、及び
（１０）電子親和力が２〜５ｅｖである、上記（１）〜（９）のいずれか１に記載のベンゾジピロール誘導体
を提供するものである。 That is, the present invention in one aspect,
(1) General formula I:

(In the formula, Ar ¹ and Ar ² each independently represent a heteroaryl group which may have a substituent; R ^{a to} R ^d each independently represent a hydrogen atom or a carbon which may have a substituent; A linear or branched alkoxy group of 1 to 8; B ¹ and B ² each independently represents a group selected from the group consisting of a hydrogen atom or a boryl group which may have a substituent, , At least one of B ¹ and B ^{2 is} an optionally substituted boryl group);
(2) The benzodipyrrole according to (1) above, wherein the hetero atom constituting the heteroaryl group in Ar ¹ or Ar ² forms a coordinate bond with the boron atom of the boryl group in B ¹ or B ² Derivatives;
(3) Ar ¹ and Ar ² are each independently quinoxalinyl or benzothiadiazolyl which may have a substituent, and the substituent is a linear or branched alkyl having 1 to 8 carbon atoms. A benzodipyrrole derivative according to (1) or (2) above;
(4) Ar ¹ and Ar ² are each independently 8- (2-ethylhexyl) -quinoxalin-5-yl or 7- (2-ethylhexyl) -2,1,3-benzothiadiazol-4-yl. And the benzodipyrrole derivative according to (1) or (2) above;
(5) The boryl group in B ¹ and B ² is —B (R ¹ ) ₂ , wherein each R ¹ independently has a halogen, an alkyl having a substituent, or a substituent. A benzodipyrrole derivative according to any one of the above (1) to (4), which is selected from aryls that may be;
(6) The benzodipyrrole derivative according to (5), wherein R ¹ is phenyl;
(7) The benzodipyrrole derivative according to any one of (1) to (6), wherein both B ¹ and B ² are a boryl group;
(8) The benzodipyrrole derivative according to any one of (1) to (7) above, which has an absorption band in the range of 600 to 2500 nm in the ultraviolet-visible absorption spectrum;
(9) The benzodipyrrole derivative according to any one of the above (1) to (8), wherein the ionization potential is 4 to 6 ev, and (10) the above (1) to (1), wherein the electron affinity is 2 to 5 ev The benzodipyrrole derivative according to any one of (9) is provided.

（式中、Ａｒ^１及びＡｒ^２は各々独立に、置換基を有してもよいヘテロアリール基を示し；Ｒ^ａ〜Ｒ^ｄは各々独立に、水素原子又は置換基を有してもよい炭素数１〜８の直鎖又は分岐鎖のアルコキシ基を示し；Ｂ^１及びＢ^２は各々独立に水素原子又は置換基を有してもよいボリル基からなる群から選択される基を示し、ただし、Ｂ^１及びＢ^２の少なくとも一方は置換基を有してもよいボリル基である）
で表されるベンゾジピロール誘導体の製造方法であって、
一般式ＩＩ:

（式中、Ａｒ^１及びＡｒ^２並びにＲ^ａ〜Ｒ^ｄは上記式Ｉと同じ定義を有する）
で表される化合物とホウ素試剤を反応させて、一般式Ｉのベンゾジピロール誘導体を得る工程を含む、該製造方法；
（１２）Ａｒ^１またはＡｒ^２におけるヘテロアリール基を構成するヘテロ原子が、Ｂ^１又はＢ^２におけるボリル基のホウ素原子と配位結合を形成する、上記（１１）に記載の製造方法；
（１３）Ａｒ^１及びＡｒ^２は各々独立に、置換基を有してもよいキノキサリニル又はベンゾチアジアゾリルであって、当該置換基が、炭素数１〜８の直鎖又は分岐鎖のアルキルである、上記（１１）又は（１２）に記載の製造方法；
（１４）Ａｒ^１及びＡｒ^２は各々独立に、８−（２−エチルヘキシル）−キノキサリン−５−イル、又は７−（２−エチルヘキシル）−２，１，３−ベンゾチアジアゾール−４−イルである、上記（１１）又は（１２）に記載の製造方法；
（１５）Ｂ^１及びＢ^２におけるボリル基が−Ｂ（Ｒ^１）_２であって、ここで、Ｒ^１は各々独立に、ハロゲン、置換基を有してもよいアルキル、又は置換基を有してもよいアリールから選択される、上記（１１）〜（１４）のいずれか１に記載の製造方法；
（１６）Ｒ^１がフェニルである、上記（１５）に記載の製造方法；及び
（１７）Ｂ^１及びＢ^２がいずれもボリル基である、上記（１１）〜（１６）のいずれか１に記載の製造方法；
を提供するものである。 In another aspect, the present invention provides:
(11) General formula I:

(In the formula, Ar ¹ and Ar ² each independently represent a heteroaryl group which may have a substituent; R ^{a to} R ^d each independently represent a hydrogen atom or a carbon which may have a substituent; A linear or branched alkoxy group of 1 to 8; B ¹ and B ² each independently represents a group selected from the group consisting of a hydrogen atom or a boryl group which may have a substituent, , At least one of B ¹ and B ^{2 is} an optionally substituted boryl group)
A process for producing a benzodipyrrole derivative represented by:
Formula II:

(Wherein Ar ¹ and Ar ² and R ^{a to} R ^d have the same definition as in formula I above)
A process for obtaining a benzodipyrrole derivative of the general formula I by reacting a compound represented by formula (I) with a boron reagent;
(12) The production method according to (11) above, wherein the hetero atom constituting the heteroaryl group in Ar ¹ or Ar ² forms a coordinate bond with the boron atom of the boryl group in B ¹ or B ² ;
(13) Ar ¹ and Ar ² are each independently quinoxalinyl or benzothiadiazolyl which may have a substituent, and the substituent is a linear or branched alkyl having 1 to 8 carbon atoms. The production method according to (11) or (12) above,
(14) Ar ¹ and Ar ² are each independently 8- (2-ethylhexyl) -quinoxalin-5-yl or 7- (2-ethylhexyl) -2,1,3-benzothiadiazol-4-yl. The production method according to (11) or (12) above;
(15) The boryl group in B ¹ and B ² is —B (R ¹ ) ₂ , wherein each R ¹ independently has a halogen, an alkyl which may have a substituent, or a substituent. The production method according to any one of the above (11) to (14), which is selected from aryls that may be substituted;
(16) The production method according to the above (15), wherein R ¹ is phenyl; and (17) any one of the above (11) to (16), wherein both B ¹ and B ² are boryl groups. The manufacturing method as described;
Is to provide.

In a further aspect, the compound of the invention comprises
(18) A photoelectric conversion element comprising the benzodipyrrole derivative according to any one of (1) to (10) as an active layer material;
(19) A solar cell comprising the photoelectric conversion element according to (18) above, and (20) a solar cell module comprising the solar cell according to (19) above To do.

  Since the benzodipyrrole derivative of the present invention exhibits strong absorption in near infrared light, it can be used as a near infrared light absorbing material. For example, it is useful as a light absorbing material for a dye-sensitized solar cell element or an organic thin film solar cell element. In addition, photoabsorption materials used for photodynamic therapy (laser therapy, etc.), especially photodynamic therapy for cancer (sensitizers that form part of photodynamic therapy agents), light absorption used for molecular imaging or optical recording It can also be used as a material (such as a recording material). In addition, the benzodipyrrole derivative of the present invention has an advantage that it can be used as a near-infrared light absorbing material in either a solution state or a solid phase state (for example, a film-formed state).

  The photoelectric conversion element including the benzodipyrrole derivative of the present invention as a light absorbing material and the solar cell including the photoelectric conversion element expand the absorption wavelength region of the solar spectrum and are highly sensitized by long wavelength light such as infrared rays. Can improve the short circuit photocurrent and energy efficiency, and is extremely useful.

  In addition, the benzodipyrrole derivative of the present invention can absorb light in the near-infrared light region (mainly having a wavelength of 700 to 1100 nm), which is known to have relatively excellent cell tissue permeability. When used as a sensitizer in photodynamic therapy, for example, it is possible to treat a deeper lesion, or to reduce the possibility of giving side effects to normal cells on the surface layer.

FIG. 1 shows a UV-visible-NIR spectrum for the compound of the present invention.

  Hereinafter, embodiments of the present invention will be described. The scope of the present invention is not limited to these descriptions, and other than the following examples, the scope of the present invention can be appropriately changed and implemented without departing from the spirit of the present invention.

1. Definitions In this specification, “halogen atom” means a fluorine atom, a chlorine atom, a bromine atom, or an iodine atom.

In the present specification, “alkyl” may be any of an aliphatic hydrocarbon group composed of linear, branched, cyclic, or a combination thereof. The number of carbon atoms of the alkyl group is not particularly limited, for example, 1-20 carbon atoms _{(C 1-20),} several 3 to 15 carbon atoms _{(C 3-15),} 5 to 10 carbon atoms _{(C 5 to 10} ). When the number of carbons is specified, it means “alkyl” having the number of carbons within the range. For example, C _1-8 alkyl includes methyl, ethyl, n-propyl, isopropyl, n-butyl, isobutyl, sec-butyl, tert-butyl, n-pentyl, isopentyl, neo-pentyl, n-hexyl, isohexyl, n-heptyl, n-octyl and the like are included. In the present specification, the alkyl group may have one or more arbitrary substituents. Examples of the substituent include, but are not limited to, an alkoxy group, a halogen atom, an amino group, a mono- or di-substituted amino group, a substituted silyl group, and acyl. When the alkyl group has two or more substituents, they may be the same or different. The same applies to the alkyl part of other substituents containing an alkyl part (for example, an alkoxy group, an arylalkyl group, etc.).

  In the present specification, “alkenyl” refers to a linear or branched hydrocarbon group having at least one carbon-carbon double bond. For example, as non-limiting examples, vinyl, allyl, 1-propenyl, isopropenyl, 1-butenyl, 2-butenyl, 3-butenyl, 1,3-butanedienyl, 1-pentenyl, 2-pentenyl, 3-pentenyl 4-pentenyl, 1,3-pentanedienyl, 1-hexenyl, 2-hexenyl, 3-hexenyl, 4-hexenyl, 5-hexenyl and 1,4-hexanedienyl). The double bond may be either cis or trans conformation.

  In the present specification, “alkynyl” refers to a linear or branched hydrocarbon group having at least one carbon-carbon triple bond. For example, non-limiting examples include ethynyl, propynyl, 2-butynyl and 3-methylbutynyl.

  In the present specification, “cycloalkyl” refers to a monocyclic or polycyclic non-aromatic ring system composed of the above alkyl. The cycloalkyl can be unsubstituted or substituted by one or more substituents, which can be the same or different, and non-limiting examples of monocyclic cycloalkyl include cyclopropyl, cyclopentyl, cyclohexyl Non-limiting examples of polycyclic cycloalkyl include 1-decalinyl, 2-decalinyl, norbornyl, adamantyl and the like. In addition, the cycloalkyl may be a heterocycloalkyl containing one or more hetero atoms (for example, an oxygen atom, a nitrogen atom, or a sulfur atom) as ring-constituting atoms. Any —NH in the heterocycloalkyl ring may be protected, for example as a —N (Boc) group, —N (CBz) group and —N (Tos) group, a nitrogen atom in the ring or The sulfur atom may be oxidized to the corresponding N-oxide, S-oxide or S, S-dioxide. For example, non-limiting examples of monocyclic heterocycloalkyl include diazapanyl, piperidinyl, pyrrolidinyl, piperazinyl, morpholinyl, thiomorpholinyl, thiazolidinyl, 1,4-dioxanyl, tetrahydrofuranyl, tetrahydropyranyl, tetrahydrothiophenyl, lactam and Examples include lactones.

  As used herein, “cycloalkenyl” refers to a monocyclic or polycyclic non-aromatic ring system containing at least one carbon-carbon double bond. The cycloalkenyl may be unsubstituted or substituted by one or more substituents, which may be the same or different, and non-limiting examples of monocyclic cycloalkenyl include cyclopentenyl, cyclohexenyl And cyclohepta-1,3-dienyl, and non-limiting examples of polycyclic cycloalkenyl include norbornylenyl and the like. In addition, the cycloalkyl may be a heterocycloalkenyl which may be a heterocycloalkenyl containing one or more heteroatoms (for example, an oxygen atom, a nitrogen atom, or a sulfur atom) as a ring-constituting atom. Atoms may be oxidized to the corresponding N-oxide, S-oxide or S, S-dioxide.

  In the present specification, “aryl” may be any monocyclic or condensed polycyclic aromatic hydrocarbon group. “Heteroaryl” may be an aromatic heterocycle containing one or more heteroatoms (for example, an oxygen atom, a nitrogen atom, a sulfur atom, etc.) as a ring member atom of aryl (this is referred to as “heteroaromatic”). Sometimes called). When aryl or heteroaryl is both monocyclic and fused, it can be attached at all possible positions. Non-limiting examples of monocyclic aryl or heteroaryl include phenyl group (Ph), thienyl group (2- or 3-thienyl group), pyridyl group, furyl group, thiazolyl group, oxazolyl group, pyrazolyl group, 2-pyrazinyl, pyrimidinyl, pyrrolyl, imidazolyl, pyridazinyl, 3-isothiazolyl, 3-isoxazolyl, 1,2,4-oxadiazol-5-yl or 1,2,4-oxadi And azol-3-yl group. Non-limiting examples of fused polycyclic aryl or heteroaryl include 1-naphthyl group, 2-naphthyl group, 1-indenyl group, 2-indenyl group, 2,3-dihydroinden-1-yl group, 2,3-dihydroinden-2-yl group, 2-anthryl group, indazolyl group, quinolyl group, isoquinolyl group, 1,2-dihydroisoquinolyl group, 1,2,3,4-tetrahydroisoquinolyl group, Indolyl group, isoindolyl group, phthalazinyl group, quinoxalinyl group, benzofuranyl group, 2,3-dihydrobenzofuran-1-yl group, 2,3-dihydrobenzofuran-2-yl group, 2,3-dihydrobenzothiophen-1-yl Group, 2,3-dihydrobenzothiophen-2-yl group, benzothiazolyl group, benzothiadiazolyl group, benzimidazolyl , And a fluorenyl group or a thioxanthenyl group. In the present specification, the aryl group or heteroaryl group may have one or more arbitrary substituents on the ring. Examples of the substituent include, but are not limited to, an alkoxy group, a halogen atom, an amino group, a mono- or di-substituted amino group, a substituted silyl group, and acyl. When the aryl group or heteroaryl group has two or more substituents, they may be the same or different. The same applies to the aryl part or heteroaryl part of other substituents containing an aryl part or heteroaryl part (for example, an aryloxy group and an arylalkyl group).

  In the present specification, “arylalkyl” represents an alkyl substituted with the above aryl or heteroaryl. The arylalkyl may have one or more arbitrary substituents. Examples of the substituent include, but are not limited to, an alkoxy group, a halogen atom, an amino group, a mono- or di-substituted amino group, a substituted silyl group, and an acyl group. When the acyl group has two or more substituents, they may be the same or different. Non-limiting examples of arylalkyl include benzyl group, 2-thienylmethyl group, 3-thienylmethyl group, 2-pyridylmethyl group, 3-pyridylmethyl group, 4-pyridylmethyl group, 2-furylmethyl group, 3-furylmethyl group, 2-thiazolylmethyl group, 4-thiazolylmethyl group, 5-thiazolylmethyl group, 2-oxazolylmethyl group, 4-oxazolylmethyl group, 5-oxazolylmethyl group, 1-pyrazolylmethyl group 3-pyrazolylmethyl group, 4-pyrazolylmethyl group, 2-pyrazinylmethyl group, 2-pyrimidinylmethyl group, 4-pyrimidinylmethyl group, 5-pyrimidinylmethyl group, 1-pyrrolylmethyl group, 2-pyrrolylmethyl group, 3-pyrrolylmethyl group 1-imidazolylmethyl group, 2-imidazolylmethyl group, 4-imidazolylmethyl 3-pyridazinylmethyl group, 4-pyridazinylmethyl group, 3-isothiazolylmethyl group, 3-isoxazolylmethyl group, 1,2,4-oxadiazol-5-ylmethyl group Or a 1,2,4-oxadiazol-3-ylmethyl group etc. are mentioned.

  Similarly, in the present specification, “arylalkenyl” represents alkenyl substituted with the above aryl or heteroaryl.

  In the present specification, the “alkoxy group” is a structure in which the alkyl group is bonded to an oxygen atom, and examples thereof include a saturated alkoxy group that is linear, branched, cyclic, or a combination thereof. For example, methoxy group, ethoxy group, n-propoxy group, isopropoxy group, cyclopropoxy group, n-butoxy group, isobutoxy group, s-butoxy group, t-butoxy group, cyclobutoxy group, cyclopropylmethoxy group, n- Pentyloxy, cyclopentyloxy, cyclopropylethyloxy, cyclobutylmethyloxy, n-hexyloxy, cyclohexyloxy, cyclopropylpropyloxy, cyclobutylethyloxy or cyclopentylmethyloxy are preferred Take as an example.

  In the present specification, the “aryloxy group” is a group to which the aryl group or heteroaryl group is bonded via an oxygen atom. Examples of the aryloxy group include phenoxy group, 2-thienyloxy group, 3-thienyloxy group, 2-pyridyloxy group, 3-pyridyloxy group, 4-pyridyloxy group, 2-furyloxy group, and 3-furyl. Oxy group, 2-thiazolyloxy group, 4-thiazolyloxy group, 5-thiazolyloxy group, 2-oxazolyloxy group, 4-oxazolyloxy group, 5-oxazolyloxy group, 1-pyrazolyloxy group, 3-pyrazolyloxy group Group, 4-pyrazolyloxy group, 2-pyrazinyloxy group, 2-pyrimidinyloxy group, 4-pyrimidinyloxy group, 5-pyrimidinyloxy group, 1-pyrrolyloxy group, 2-pyrrolyloxy group, 3-pyrrolyloxy group, 1-imidazolyloxy group 2-imidazolyloxy group, 4-imidazolyloxy group, -Pyridazinyloxy group, 4-pyridazinyloxy group, 3-isothiazolyloxy group, 3-isoxazolyloxy group, 1,2,4-oxadiazol-5-yloxy group, or Examples include a 1,2,4-oxadiazol-3-yloxy group.

  In the present specification, “alkylene” is a divalent group consisting of a linear or branched saturated hydrocarbon, such as methylene, 1-methylmethylene, 1,1-dimethylmethylene, ethylene, 1-methylethylene, 1-ethylethylene, 1,1-dimethylethylene, 1,2-dimethylethylene, 1,1-diethylethylene, 1,2-diethylethylene, 1-ethyl-2-methylethylene, trimethylene, 1 -Methyltrimethylene, 2-methyltrimethylene, 1,1-dimethyltrimethylene, 1,2-dimethyltrimethylene, 2,2-dimethyltrimethylene, 1-ethyltrimethylene, 2-ethyltrimethylene, 1,1 -Diethyltrimethylene, 1,2-diethyltrimethylene, 2,2-diethyltrimethylene, 2-ethyl-2-methyltrimethyl , Tetramethylene, 1-methyltetramethylene, 2-methyltetramethylene, 1,1-dimethyltetramethylene, 1,2-dimethyltetramethylene, 2,2-dimethyltetramethylene, 2,2-di-n-propyl Trimethylene and the like.

  In the present specification, “alkenylene” is a divalent group consisting of an unsaturated hydrocarbon having at least one linear or branched carbon-carbon double bond, such as ethenylene. 1-methylethenylene, 1-ethylethenylene, 1,2-dimethylethenylene, 1,2-diethylethenylene, 1-ethyl-2-methylethenylene, propenylene, 1-methyl-2-propenylene, 2-methyl -2-propenylene, 1,1-dimethyl-2-propenylene, 1,2-dimethyl-2-propenylene, 1-ethyl-2-propenylene, 2-ethyl-2-propenylene, 1,1-diethyl-2-propenylene 1,2-diethyl-2-propenylene, 1-butenylene, 2-butenylene, 1-methyl-2-butenylene, 2-methyl-2-butenylene, , 1-dimethyl-2-butenylene, 1,2-dimethyl-2-butenylene, and the like.

  As used herein, the term “ring structure”, when formed by a combination of two substituents, means a heterocyclic or carbocyclic group, such group being saturated, unsaturated, or aromatic. Can be. Accordingly, it includes cycloalkyl, cycloalkenyl, aryl, and heteroaryl as defined above. Examples include cycloalkyl, phenyl, naphthyl, morpholinyl, piperidinyl, imidazolyl, pyrrolidinyl, pyridyl and the like. In the present specification, a substituent can form a ring structure with another substituent, and when such substituents are bonded to each other, those skilled in the art will recognize a specific substitution, such as bonding to hydrogen. Can be understood. Therefore, when it is described that specific substituents together form a ring structure, those skilled in the art can understand that the ring structure can be formed by an ordinary chemical reaction and can be easily generated. Both such ring structures and their process of formation are within the purview of those skilled in the art.

2. Benzodipyrrole Derivative The compound of the present invention is characterized by having a structure in which a pyrrole having a boryl group forms a condensed ring and a boryl group on the pyrrole ring forms a complex in the molecule. Are benzodipyrrole derivatives represented by the following general formula I.

In the formula, Ar ¹ and Ar ² each independently represent a heteroaryl group which may have a substituent. The heteroaryl group is not particularly limited as long as the heteroatom constituting the heteroaryl ring can form a coordinate bond with the boron atom in the boryl group on the pyrrole ring. Preferred quinoxalinyl or benzothiadiazolyl is preferred. The substituent is preferably linear or branched alkyl having 1 to 8 carbon atoms, and more preferably 2-ethylhexyl or octyl. Thus, preferred non-limiting examples of heteroaryl groups include 8- (2-ethylhexyl) -quinoxalin-5-yl and 7- (2-ethylhexyl) -2,1,3-benzothiadiazol-4-yl Can be mentioned.

Wherein, R ^a to R ^d each independently represent a linear or branched alkoxy group having 1 to 8 carbon atoms which may have a hydrogen atom or a substituent. Preferably, it is a hydrogen atom.

In the formula, B ¹ and B ² each independently represent a hydrogen atom or a group selected from the group consisting of a boryl group which may have a substituent. However, at least one of B ¹ and B ² is a boryl group which may have a substituent. Both B ¹ and B ² can also be a boryl group. The boryl group typically has a structure represented by —B (R ¹ ) ₂ , where R ¹ may preferably independently have a halogen or a substituent. It is selected from alkyl and aryl which may have a substituent. More preferably, either or both of R ¹ is phenyl.

  The compound of the present invention is characterized by showing strong absorption in near infrared light. More specifically, it has an absorption band in the range of 600 to 2500 nm in the ultraviolet-visible absorption spectrum, and preferably has a relatively large absorption band in the region of 650 to 1000 nm.

  Alternatively, the compounds of the present invention preferably have an ionization potential of 4-6 ev. Moreover, it preferably has an electron affinity of 2 to 5 ev. This is because when the compound of the present invention is used in a photoelectric conversion element, a solar cell, etc., it is an energy level effective for carrier extraction from the electrode material, and the photoelectric conversion efficiency can be maximized within this energy range. is there.

（式中、Ａｒ^１及びＡｒ^２並びにＲ^ａ〜Ｒ^ｄは上記式Ｉと同じ定義を有する）
で表される化合物とホウ素試剤を反応させることによって合成することができる。 3. Method for Producing Benzodipyrrole Derivatives As detailed in the examples below, the benzodipyrrole derivatives of the above general formula I which are compounds of the present invention are represented by the general formula II

(Wherein Ar ¹ and Ar ² and R ^{a to} R ^d have the same definition as in formula I above)
It can synthesize | combine by making the compound represented by these, and a boron reagent react.

  The solvent used in the reaction is preferably an aprotic polar solvent. Non-limiting examples of aprotic polar solvents include toluene, tetrahydrofuran (THF), N, N′-dimethylpropyleneurea (DMPU), acetonitrile, dimethylformamide (DMF), dimethyl sulfoxide (DMSO), N— And methylpyrrolidone (NMP). Preferably, it is toluene.

  The reaction temperature in the production method of the present invention can be appropriately set by those skilled in the art, but preferably the reaction is carried out under reflux.

  In addition, the reaction conditions such as the reaction time in the production method are described in detail as representative examples in the examples described below, but are not necessarily limited thereto, and those skilled in the art can Each can be appropriately selected based on general knowledge in organic synthesis.

  In addition, regarding the method for synthesizing the compound of the general formula II that is the raw material used in the production method of the present invention, those skilled in the art can fully understand based on general knowledge in organic synthesis. It is.

4). Photoelectric conversion element and solar cell As described above, the benzodipyrrole derivative of the present invention exhibits strong absorption in the near-infrared light region. Therefore, as a light absorbing material for a dye-sensitized solar cell element or an organic thin film solar cell element. Can be used. Therefore, another preferred embodiment of the present invention includes a photoelectric conversion element characterized by containing the benzodipyrrole derivative as an active layer material. Furthermore, this invention also includes the solar cell containing the said photoelectric conversion element, and a solar cell module provided with this solar cell.

  When the compound of the present invention is used as a light absorbing material, it can be used in either a solution state or a solid phase state (for example, a film-formed state). A method for bringing the compound into a solution state, a solid phase state, or a thin film state is not particularly limited, and a method known in the technical field can be employed.

  EXAMPLES Hereinafter, although an Example demonstrates this invention further in detail, this invention is not limited by these.

1. Synthesis [Synthesis Example 1: Synthesis of condensed pyrrole boron complexes QXBDPB1 and QXBDPB2]
A series of synthetic routes for the condensed pyrrole boron complex, which is the benzodipyrrole derivative of the present invention, is shown in Scheme 1. Details of the synthesis will be described individually below.

2,5-diethynyl-1,4-phenylenediamine (1), the starting material of 2,5-diethynyl-1,4-phenylenediamine (1) is a known literature (Clentsmith et al., Tetrahedron Lett, 2009, 50, 1469-1471).

Synthesis of 5-bromo-8- (2-ethylhexyl) -quinoxaline (2) Compound 2 (5-bromo-8- (2-ethylhexyl) -quinoxaline) was synthesized according to the following scheme 2.

A THF solution of 2-ethylhexylmagnesium bromide (0.89 M, 17.5 mL, 15.6 mmol) and a zinc chloride solution (1.00 M, 15.7 mL, 15.7 mmol) were added to a flask at 0 ° C. and stirred at room temperature for 1 hour. 4,7-Dibromoquinoxaline 4 (2.71 g, 9.41 mmol) and tetrakis (triphenylphosphine) palladium (0) (0.54 g, 0.47 mmol) were added and the mixture was refluxed for 1.5 hours. A saturated ammonium chloride solution was added to the reaction mixture and the reaction mixture was extracted with dichloromethane. The organic phase was dried over magnesium sulfate, filtered and concentrated under reduced pressure. The obtained crude product was purified by silica gel column chromatography (dichloromethane) to obtain a red liquid compound 2 (1.74 g, 58%).
¹ H NMR (500 MHz, CDCl ₃ ) δ 0.83-0.90 (m, 6H, CH ₃ ), 1.24-1.35 (m, 8H, CH ₂ ), 1.78-1.85 (m, 1H, CH), 3.12-3.17 ( m, 2H, CH ₂ ), 7.46-7.51 (m, 1H, ArH), 8.02 (d, J = 7.8, 1H, ArH), 8.87-8.90 (m, 1H, ArH), 8.94-8.96 (m, 1H , ArH); ¹³ C NMR (100 MHz, CDCl ₃ ) δ 10.54, 14.03, 22.89, 25.49, 28.52, 32.37, 34.69, 40.15, 121.05, 130.28, 132.90, 140.50, 141.70, 144.04. 144.74, 144.79; Anal. for C ₁₆ H ₂₁ BrN ₂ : C, 59.82: H, 6.59: N, 8.72. Found: C, 59.82: H, 6.76: N, 8.37.

2,5-Diethynyl-1,4-phenylenediamine 1 (278 mg, 1.78 mmol)、 5-bromo-8-(2-ethylhexyl)-quinoxaline 2 (1.26 g, 3.91 mmol)、tetrakis(triphenylphosphine)paladium(0) (42.7 mg, 0.043 mmol)、トリフェニルホスフィン (18.9 mg, 0.072 mmol)、 及びヨウ化銅 (14.0 mg, 0.074 mmol)を脱気したトリエチルアミン(15 mL)に添加した。混合物を１４時間還留し、その後、減圧下で濃縮した。ジクロロメタンを加え、不溶の固体をろ過除去した。ろ過物を減圧下で濃縮した。得られた粗生成物をシリカゲルカラムクロマトグラフィー（ジクロロメタン：ヘキサン＝２：１、５％トリエチルアミン）で精製し、赤色固体状の化合物3を得た(80 mg, 71 %)。
¹H NMR (400 MHz, CDCl₃) δ0.83-0.91 (m, 12H, CH₃), 1.2-1.35 (m, 16H, CH₂), 1.82-1.88 (m, 2H, CH), 3.14-3.33 (m, 4H, CH₂), 4.62 (s, 4H, NH₂), 6.93 (s, 2H, ArH), 7.57 (d, J = 7.6 Hz, 2H, ArH), 7.89 (d, J = 7.6 Hz, 2H, ArH), 8.89 (s, 4H, ArH). ¹³C NMR (125 MHz, CDCl₃) δ10.72, 14.10, 23.03, 25.77, 28.70, 32.59, 35.15, 40.48, 93.27, 93.48, 110.59, 116.40, 121.22, 129.79, 132.06, 141.05, 142.22, 142.56, 143.23, 144.04, 144.54; HRMS (FAB+) m/z 636.3926, calcd for C₄₂H₄₈N₆ 636.3940. Synthesis of 2,5-bis ((8- (2-ethylhexyl) -quinoxalin-5-yl) ethynyl) -1,4-phenylenediamine (3)

2,5-Diethynyl-1,4-phenylenediamine 1 (278 mg, 1.78 mmol), 5-bromo-8- (2-ethylhexyl) -quinoxaline 2 (1.26 g, 3.91 mmol), tetrakis (triphenylphosphine) paladium (0) (42.7 mg, 0.043 mmol), triphenylphosphine (18.9 mg, 0.072 mmol), and copper iodide (14.0 mg, 0.074 mmol) were added to degassed triethylamine (15 mL). The mixture was refluxed for 14 hours and then concentrated under reduced pressure. Dichloromethane was added and the insoluble solid was removed by filtration. The filtrate was concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography (dichloromethane: hexane = 2: 1, 5% triethylamine) to obtain compound 3 as a red solid (80 mg, 71%).
¹ H NMR (400 MHz, CDCl ₃ ) δ0.83-0.91 (m, 12H, CH ₃ ), 1.2-1.35 (m, 16H, CH ₂ ), 1.82-1.88 (m, 2H, CH), 3.14-3.33 (m, 4H, CH ₂ ), 4.62 (s, 4H, NH ₂ ), 6.93 (s, 2H, ArH), 7.57 (d, J = 7.6 Hz, 2H, ArH), 7.89 (d, J = 7.6 Hz , 2H, ArH), 8.89 ( s, 4H, ArH). 13 C NMR (125 MHz, CDCl 3) δ10.72, 14.10, 23.03, 25.77, 28.70, 32.59, 35.15, 40.48, 93.27, 93.48, 110.59, 116.40 , 121.22, 129.79, 132.06, 141.05, 142.22, 142.56, 143.23, 144.04, 144.54; HRMS (FAB +) m / z 636.3926, calcd for C ₄₂ H ₄₈ N ₆ 636.3940.

ヨウ化亜鉛(413 mg, 1.29 mmol)を化合物3(401 mg, 0.630 mol)のトルエン溶液(20 mL)に加えた。当該溶液を３時間還留し、水を添加し、得られた混合物をジクロロメタンで抽出した。抽出物を減圧下で濃縮した。得られた粗生成物をシリカゲルカラムクロマトグラフィー（ジクロロメタン、１％トリエチルアミン）で精製し、赤黒色固体状のQXBDPを得た(198 mg, 49 %)。
¹H NMR (400 MHz, CDCl₃) δ 0.85-0.94 (m, 12H, CH₃), 1.25-1.40 (m, 16H, CH₂), 1.83-1.90 (m, 2H, CH), 3.20 (d, J = 7.0 Hz, 4H, CH₂), 7.22 (s, 2H, ArH), 7.65 (d, J = 7.7 Hz, 2H, ArH), 7.71 (s, 2H, ArH), 8.35 (d, J = 7.7 Hz, 2H, ArH), 8.93 (s, 4H, ArH), 11.63 (s, 2H, NH). ¹³C NMR (100 MHz, CDCl₃) δ10.73, 14.15, 23.08, 25.73, 28.73, 32.60, 35.07, 40.38, 99.74, 127.05, 127.45, 130.36, 134.87, 137.78, 140.31, 140.35, 142.33, 142.61, 143.44; HRMS (FAB+) m/z 636.3924, calcd for C₄₂H₄₈N₆ 636.3940. Synthesis of QXBDP

Zinc iodide (413 mg, 1.29 mmol) was added to a toluene solution (20 mL) of compound 3 (401 mg, 0.630 mol). The solution was refluxed for 3 hours, water was added and the resulting mixture was extracted with dichloromethane. The extract was concentrated under reduced pressure. The obtained crude product was purified by silica gel column chromatography (dichloromethane, 1% triethylamine) to obtain red black solid QXBDP (198 mg, 49%).
¹ H NMR (400 MHz, CDCl ₃ ) δ 0.85-0.94 (m, 12H, CH ₃ ), 1.25-1.40 (m, 16H, CH ₂ ), 1.83-1.90 (m, 2H, CH), 3.20 (d, J = 7.0 Hz, 4H, CH ₂ ), 7.22 (s, 2H, ArH), 7.65 (d, J = 7.7 Hz, 2H, ArH), 7.71 (s, 2H, ArH), 8.35 (d, J = 7.7 Hz, 2H, ArH), 8.93 (s, 4H, ArH), 11.63 (s, 2H, NH). 13 C NMR (100 MHz, CDCl 3) δ10.73, 14.15, 23.08, 25.73, 28.73, 32.60, 35.07 , 40.38, 99.74, 127.05, 127.45, 130.36, 134.87, 137.78, 140.31, 140.35, 142.33, 142.61, 143.44; HRMS (FAB +) m / z 636.3924, calcd for C ₄₂ H ₄₈ N ₆ 636.3940.

トリフェニルボラン(46 mg, 0.19 mmol)をQXBDP (46 mg, 0.073 mmol)のトルエン溶液(4.0 mL)に加えた。当該溶液を５時間還留し、水を添加し、得られた混合物をジクロロメタンで抽出した。抽出物を減圧下で濃縮した。得られた粗生成物をシリカゲルカラムクロマトグラフィー（ジクロロメタン：ヘキサン＝１：１）で精製し、暗緑色固体状のQXBDPB2を得た(59 mg, 84 %)。
¹H NMR (400 MHz, CDCl₃) δ0.82-0.91 (m, 12H, CH₃), 1.24-1.35 (m, 16H, CH₂), 1.74-1.80 (m, 2H, CH), 3.11 (d, J = 7.2 Hz, 4H, CH₂), 6.66 (s, 2H, ArH), 7.02 (s, 2H, ArH), 7.21 (s, 20H, PhH), 7.69 (d, 2H, J = 7.9 Hz, ArH), 8.24 (d, J = 7.9 Hz, 2H, ArH), 8.60 (d, 2H, J = 1.4 Hz, ArH), 9.07 (d, 2H, J = 1.4 Hz, ArH).¹³C NMR (125 MHz, CDCl₃) δ10.64, 14.10, 23.01, 25.68, 28.65, 32.51, 35.17, 40.44, 100.62, 103.57, 125.74, 126.09, 126.76 (2C), 127.73 (4C), 129.61, 130.48, 132.87, 133.82×4, 135.54, 137.40, 138.83, 140.00, 143.96, 144.60, 148.21 (2C). Synthesis of QXBDPB2

Triphenylborane (46 mg, 0.19 mmol) was added to a toluene solution (4.0 mL) of QXBDP (46 mg, 0.073 mmol). The solution was refluxed for 5 hours, water was added and the resulting mixture was extracted with dichloromethane. The extract was concentrated under reduced pressure. The obtained crude product was purified by silica gel column chromatography (dichloromethane: hexane = 1: 1) to obtain QXBDPB2 as a dark green solid (59 mg, 84%).
¹ H NMR (400 MHz, CDCl ₃ ) δ0.82-0.91 (m, 12H, CH ₃ ), 1.24-1.35 (m, 16H, CH ₂ ), 1.74-1.80 (m, 2H, CH), 3.11 (d , J = 7.2 Hz, 4H, CH ₂ ), 6.66 (s, 2H, ArH), 7.02 (s, 2H, ArH), 7.21 (s, 20H, PhH), 7.69 (d, 2H, J = 7.9 Hz, ArH), 8.24 (d, J = 7.9 Hz, 2H, ArH), 8.60 (d, 2H, J = 1.4 Hz, ArH), 9.07 (d, 2H, J = 1.4 Hz, ArH). ¹³ C NMR (125 MHz, CDCl ₃ ) δ 10.64, 14.10, 23.01, 25.68, 28.65, 32.51, 35.17, 40.44, 100.62, 103.57, 125.74, 126.09, 126.76 (2C), 127.73 (4C), 129.61, 130.48, 132.87, 133.82 × 4 , 135.54, 137.40, 138.83, 140.00, 143.96, 144.60, 148.21 (2C).

トリフェニルボラン(18 mg, 0.076 mmol)をQXBDP(43 mg, 0.068 mmol)のトルエン溶液(4.0 mL)に加えた。当該溶液を８時間還留し、水を添加し、得られた混合物をジクロロメタンで抽出した。抽出物を減圧下で濃縮した。得られた粗生成物をシリカゲルカラムクロマトグラフィー（ジクロロメタン：ヘキサン＝１：１）で精製し、紫色固体状のQXBDPB1を得た(11 mg, 20 %)。
¹H NMR (400 MHz, CDCl₃) δ0.83-0.93 (m, 12H, CH₃), 1.25-1.38 (m, 16H, CH₂), 1.77-1.87 (m, 2H, CH), 3.16 (d, J = 6.6 Hz, 4H, CH₂), 6.72 (s, 1H, ArH), 6.85 (s, 1H, ArH), 7.22 (s, 10H, PhH), 7.38 (s, 1H, ArH), 7.56 (d, J = 7.7 Hz, 1H, ArH), 7.68 (s, 1H, ArH), 7.78 (d, J = 7.9 Hz, 1H, ArH), 8.18 (d, J = 7.7 Hz, 1H, ArH), 8.41 (d, J = 7.9 Hz, 1H, ArH), 8.64 (d, J = 2.4 Hz, 1H, ArH), 8.69 (s, 2H, ArH), 9.12 (d, J = 2.4 Hz, 1H, ArH), 11.41 (s, 1H, NH). ¹³C NMR (125 MHz, CDCl₃) δ10.66, 10.73, 14.13 (2C), 23.06 (2C), 25.67, 25.75, 28.67, 28.72, 32.54, 32.60, 35.03, 35.20, 40.35, 40.51, 99.25, 99.72, 100.60, 104.15, 125.65, 126.34, 126.89 (2C), 126.97, 127.62, 127.80 (4C), 129.58, 130.31, 130.50, 132.05, 133.74 (4C), 134.78, 135.73, 137.59, 137.63, 139.24, 140.02, 140.09, 140.36, 142.27, 142.59, 143.37, 144.03, 144.64, 148.07 (2C); HRMS (FAB+) m/z 800.4749, calcd for C₅₄H₅₇BN₆ 800.4738. Synthesis of QXBDPB1

Triphenylborane (18 mg, 0.076 mmol) was added to a toluene solution (4.0 mL) of QXBDP (43 mg, 0.068 mmol). The solution was refluxed for 8 hours, water was added and the resulting mixture was extracted with dichloromethane. The extract was concentrated under reduced pressure. The obtained crude product was purified by silica gel column chromatography (dichloromethane: hexane = 1: 1) to obtain purple solid QXBDPB1 (11 mg, 20%).
¹ H NMR (400 MHz, CDCl ₃ ) δ0.83-0.93 (m, 12H, CH ₃ ), 1.25-1.38 (m, 16H, CH ₂ ), 1.77-1.87 (m, 2H, CH), 3.16 (d , J = 6.6 Hz, 4H, CH ₂ ), 6.72 (s, 1H, ArH), 6.85 (s, 1H, ArH), 7.22 (s, 10H, PhH), 7.38 (s, 1H, ArH), 7.56 ( d, J = 7.7 Hz, 1H, ArH), 7.68 (s, 1H, ArH), 7.78 (d, J = 7.9 Hz, 1H, ArH), 8.18 (d, J = 7.7 Hz, 1H, ArH), 8.41 (d, J = 7.9 Hz, 1H, ArH), 8.64 (d, J = 2.4 Hz, 1H, ArH), 8.69 (s, 2H, ArH), 9.12 (d, J = 2.4 Hz, 1H, ArH), 11.41 (s, 1H, NH) . 13 C NMR (125 MHz, CDCl 3) δ10.66, 10.73, 14.13 (2C), 23.06 (2C), 25.67, 25.75, 28.67, 28.72, 32.54, 32.60, 35.03, 35.20 , 40.35, 40.51, 99.25, 99.72, 100.60, 104.15, 125.65, 126.34, 126.89 (2C), 126.97, 127.62, 127.80 (4C), 129.58, 130.31, 130.50, 132.05, 133.74 (4C), 134.78, 135.73, 137.59, 137.63, 139.24, 140.02, 140.09, 140.36, 142.27, 142.59, 143.37, 144.03, 144.64, 148.07 (2C); HRMS (FAB +) m / z 800.4749, calcd for C ₅₄ H ₅₇ BN ₆ 800.4738.

[Synthesis Example 2: Synthesis of condensed ring pyrrole BTBDP]
A compound BTBDP was synthesized in which the quinoxaline ring part of QXBDP obtained in Synthesis Example 1 was a benzothiadiazole ring. Details of the synthesis will be described individually below.

2-ethylhexylmagnesium bromideのＴＨＦ溶液(0.89 M, 22.5 mL, 20.0 mmol)、及び塩化亜鉛溶液(0.99 M, 20.5 mL, 20.3 mmol)を０℃のフラスコに添加し、室温で１時間撹拌した。4,7-Dibromo-2,1,3-benzothiadiazole 5 (5.30 g, 18.0 mmol) 及びtetrakis(triphenylphosphine)palladium(0) (1.03 g, 0.89 mmol)を添加し、混合物を２２時間還留した。塩化アンモニウム飽和溶液を反応混合物に加え、反応混合物をジクロロメタンで抽出した。有機相を硫酸マグネシウムで乾燥し、ろ過後、減圧下で濃縮した。得られた粗生成物をシリカゲルカラムクロマトグラフィー（酢酸エチル：ヘキサン＝１：６）で精製し、淡黄色液状の化合物6を得た(2.87 g, 49 %)。
¹H NMR (400 MHz, CDCl₃) δ 0.79-0.92 (m, 6H, CH₃), 1.24-1.40 (m, 8H, CH₂), 1.84-1.94 (m, 1H, CH), 3.00 (d, J = 7.2 Hz, 2H, CH₂), 7.20-7.24 (m, 1H, ArH), 7.74-7.80 (m, 1H, ArH); ¹³C NMR (100 MHz, CDCl₃) δ10.51, 14.01, 22.91, 25.58, 28.53, 32.45, 36.36, 39.27, 111.06, 128.62, 131.75, 135.09, 153.21, 154.85; Anal. Calcd for C₁₄H₁₉BrN₂S: C, 51.38: H, 5.85: N, 8.56. Found: C, 51.55: H, 5.99: N, 8.34. Synthesis of 4-bromo-7- (2-ethylhexyl) -2,1,3-benzothiadiazole (6)

A THF solution of 2-ethylhexylmagnesium bromide (0.89 M, 22.5 mL, 20.0 mmol) and a zinc chloride solution (0.99 M, 20.5 mL, 20.3 mmol) were added to a flask at 0 ° C. and stirred at room temperature for 1 hour. 4,7-Dibromo-2,1,3-benzothiadiazole 5 (5.30 g, 18.0 mmol) and tetrakis (triphenylphosphine) palladium (0) (1.03 g, 0.89 mmol) were added and the mixture was refluxed for 22 hours. A saturated ammonium chloride solution was added to the reaction mixture and the reaction mixture was extracted with dichloromethane. The organic phase was dried over magnesium sulfate, filtered and concentrated under reduced pressure. The resulting crude product was purified by silica gel column chromatography (ethyl acetate: hexane = 1: 6) to obtain Compound 6 (2.87 g, 49%) as a pale yellow liquid.
¹ H NMR (400 MHz, CDCl ₃ ) δ 0.79-0.92 (m, 6H, CH ₃ ), 1.24-1.40 (m, 8H, CH ₂ ), 1.84-1.94 (m, 1H, CH), 3.00 (d, J = 7.2 Hz, 2H, CH ₂ ), 7.20-7.24 (m, 1H, ArH), 7.74-7.80 (m, 1H, ArH); ¹³ C NMR (100 MHz, CDCl ₃ ) δ10.51, 14.01, 22.91 , 25.58, 28.53, 32.45, 36.36, 39.27, 111.06, 128.62, 131.75, 135.09, 153.21, 154.85; Anal.Calcd for C ₁₄ H ₁₉ BrN ₂ S: C, 51.38: H, 5.85: N, 8.56. Found: C , 51.55: H, 5.99: N, 8.34.

2,5-Diethynyl-1,4-phenylenediamine 1 (349 mg, 2.23 mmol)、 4-bromo-7-(2-ethylhexyl)-2,1,3-benzothiadiazole 6 (1.60 g, 4.89 mmol)、tetrakis(triphenylphosphine)paladium(0) (53.1 mg, 0.046 mmol)、トリフェニルホスフィン(24.3 mg, 0.093 mmol)、 及びヨウ化銅 (15.9 mg, 0.083 mmol)を脱気したトリエチルアミン(15 mL)に添加した。混合物を１４時間還留し、その後、減圧下で濃縮した。ジクロロメタンを加え、不溶の固体をろ過除去した。ろ過物を減圧下で濃縮した。得られた粗生成物をシリカゲルカラムクロマトグラフィー（ジクロロメタン：ヘキサン＝２：１、３％トリエチルアミン）で精製し、赤色固体状の化合物15を得た(1.19 g, 82 %)。
¹H NMR (400 MHz, CDCl₃) δ0.84-0.93 (m, 12H, CH₃), 1.26-1.37 (m, 16H, CH₂), 1.85-1.98 (m, 2H, CH), 3.06 (d, J = 7.1 Hz, 4H, CH₂), 4.35 (s, 4H, NH₂), 6.93 (s, 2H, ArH), 7.33 (d, J = 7.2 Hz, 2H, ArH), 7.69 (d, J = 7.2 Hz, 2H, ArH); ¹³C NMR (100 MHz, CDCl₃) δ10.65, 14.09, 23.01, 25.79, 28.66, 32.62, 36.90, 39.57, 92.49, 92.56, 110.42, 114.26, 116.90, 128.23, 131.39, 136.40, 140.68, 154.88, 154.90; Anal. Calcd for C₃₈H₄₄N₆S₂: C, 70.33: H, 6.83: N, 12.95. Found: C, 70.17: H, 7.01: N, 12.68. Synthesis of 2,5-bis ((7- (2-ethylhexyl) -2,1,3-benzothiadiazol-4-yl) ethynyl) -1,4-phenylenediamine (7)

2,5-Diethynyl-1,4-phenylenediamine 1 (349 mg, 2.23 mmol), 4-bromo-7- (2-ethylhexyl) -2,1,3-benzothiadiazole 6 (1.60 g, 4.89 mmol), tetrakis ( Triphenylphosphine) paladium (0) (53.1 mg, 0.046 mmol), triphenylphosphine (24.3 mg, 0.093 mmol), and copper iodide (15.9 mg, 0.083 mmol) were added to degassed triethylamine (15 mL). The mixture was refluxed for 14 hours and then concentrated under reduced pressure. Dichloromethane was added and the insoluble solid was removed by filtration. The filtrate was concentrated under reduced pressure. The obtained crude product was purified by silica gel column chromatography (dichloromethane: hexane = 2: 1, 3% triethylamine) to obtain compound 15 as a red solid (1.19 g, 82%).
¹ H NMR (400 MHz, CDCl ₃ ) δ0.84-0.93 (m, 12H, CH ₃ ), 1.26-1.37 (m, 16H, CH ₂ ), 1.85-1.98 (m, 2H, CH), 3.06 (d , J = 7.1 Hz, 4H, CH ₂ ), 4.35 (s, 4H, NH ₂ ), 6.93 (s, 2H, ArH), 7.33 (d, J = 7.2 Hz, 2H, ArH), 7.69 (d, J = 7.2 Hz, 2H, ArH); ¹³ C NMR (100 MHz, CDCl ₃ ) δ 10.65, 14.09, 23.01, 25.79, 28.66, 32.62, 36.90, 39.57, 92.49, 92.56, 110.42, 114.26, 116.90, 128.23, 131.39 , 136.40, 140.68, 154.88, 154.90; Anal.Calcd for C ₃₈ H ₄₄ N ₆ S ₂ : C, 70.33: H, 6.83: N, 12.95. Found: C, 70.17: H, 7.01: N, 12.68.

ヨウ化亜鉛(508 mg, 1.60 mmol)を化合物7(348 mg, 0.536 mol)のトルエン溶液(14 mL)に加えた。当該溶液を１．５日還留し、水を添加し、得られた混合物をジクロロメタンで抽出した。抽出物を減圧下で濃縮した。得られた粗生成物をシリカゲルカラムクロマトグラフィー（ジクロロメタン：ヘキサン＝１：１）で精製し、暗紫色固体状のBTBDPを得た(113 mg, 32 %)。
¹H NMR (400 MHz, CDCl₃) δ 0.86-0.95 (m, 12H, CH₃), 1.25-1.40 (m, 16H, CH₂), 1.93-2.00 (m, 2H, CH), 3.08 (d, J = 7.1 Hz, 4H, CH₂), 7.23 (s, 2H, ArH), 7.41-7.47 (m, 2H, ArH), 7.71 (s, 2H, ArH), 8.07 (d, J = 7.3 Hz, 2H, ArH), 10.60 (s, 2H, NH); ¹³C NMR (125 MHz, CDCl₃) δ 10.68, 14.13, 23.06, 25.80, 28.71, 29.69, 36.75, 39.57, 99.43, 99.93, 124.73, 127.46, 128.96, 133.92, 152.44, 152.66, 163.30, 163.73; HRMS (FAB+) m/z 648.3085, calcd for C₃₈H₄₄N₆S₂ 648.3069. Synthesis of BTBDP

Zinc iodide (508 mg, 1.60 mmol) was added to a toluene solution (14 mL) of compound 7 (348 mg, 0.536 mol). The solution was refluxed for 1.5 days, water was added and the resulting mixture was extracted with dichloromethane. The extract was concentrated under reduced pressure. The obtained crude product was purified by silica gel column chromatography (dichloromethane: hexane = 1: 1) to obtain BTBDP as a dark purple solid (113 mg, 32%).
¹ H NMR (400 MHz, CDCl ₃ ) δ 0.86-0.95 (m, 12H, CH ₃ ), 1.25-1.40 (m, 16H, CH ₂ ), 1.93-2.00 (m, 2H, CH), 3.08 (d, J = 7.1 Hz, 4H, CH ₂ ), 7.23 (s, 2H, ArH), 7.41-7.47 (m, 2H, ArH), 7.71 (s, 2H, ArH), 8.07 (d, J = 7.3 Hz, 2H , ArH), 10.60 (s, 2H, NH); ¹³ C NMR (125 MHz, CDCl ₃ ) δ 10.68, 14.13, 23.06, 25.80, 28.71, 29.69, 36.75, 39.57, 99.43, 99.93, 124.73, 127.46, 128.96, 133.92, 152.44, 152.66, 163.30, 163.73; HRMS (FAB +) m / z 648.3085, calcd for C ₃₈ H ₄₄ N ₆ S ₂ 648.3069.

Synthesis of BTBDP In the same manner as in Synthesis Example 1 above, BTBDP can be reacted with triphenylborane to obtain a compound into which a diphenylboryl group has been introduced.

2. Evaluation of Light Absorption Characteristics Near-infrared (NIR) absorption was measured for the condensed pyrrole boron complexes QXBDPB1 and QXBDPB2 obtained in Synthesis Example 1 above. The UV-visible-NIR spectrum in dichloromethane obtained for QXBDPB1, QXBDPB2 and QXBDP not forming a boron complex is shown in FIG. From FIG. 1, it can be seen that a large long wavelength shift is observed by introducing a diphenylboryl group (—B (Ph) ₂ ) to form a boron complex. Specifically, the absorption maximum due to the HOMO-LUMO transition was 507 nm for QXBDPB1 and 755 nm for QXBDPB2 compared to 507 nm for QXBDP. A wide NIR absorption band extends to around 100 nm. The results show that these condensed ring pyrrole boron complexes are useful as absorbing materials for near infrared light.

3. Preparation and evaluation of thin film laminated photoelectric conversion element A photoelectric conversion element was prepared by the following method. First, an indium tin oxide (ITO) transparent conductive film was deposited on a glass substrate. Then, an anode was formed by patterning the transparent conductive film into a stripe having a width of 4 nm using a normal photolithography technique and hydrochloric acid etching. After the glass substrate on which the anode of the ITO transparent conductive film was formed in this way was cleaned in the order of ultrasonic cleaning using a surfactant, water cleaning using ultra pure water, ultrasonic cleaning using ultra pure water, Drying was performed by nitrogen blowing, and finally ultraviolet ozone cleaning was performed.

Poly (3,4) -ethylenedioxythiophene / polystyrene sulfonate aqueous dispersion (PEDOT: PSS) (trade name “CLEVIOS ^™ PVP AI4083” manufactured by Heraeus) as a hole extraction layer on the substrate after washing Was applied by spin coating. Thereafter, the substrate was heated on the hot plate at 120 ° C. for 10 minutes in the atmosphere, and further heated on the hot plate at 180 ° C. for 10 minutes in nitrogen. The film thickness of the hole extraction layer was about 30 nm.

Next, a 0.2 wt% chloroform solution of the condensed pyrrole boron complex QXBDPB2 was prepared and filtered. On the hole extraction layer, the obtained filtrate was spin-coated at 3000 rpm in a nitrogen atmosphere to form a donor layer. Then, the glass substrate was placed in a vacuum evaporation apparatus was 40nm laminating fullerene (C ₆₀₎ as an acceptor layer by a vacuum evaporation method. On this acceptor layer, 2,9-bis (naphthalen-2-yl) -4,7-diphenyl-1,10-phenanthroline (NBphen) was further deposited in a thickness of 5 nm as a cathode buffer layer.

  Next, a cathode was formed on the cathode buffer layer. Specifically, a 4 mm wide striped shadow mask was brought into close contact with the anode ITO stripe on the cathode buffer layer. The substrate on which the mask was placed was placed in a vacuum deposition apparatus, and aluminum was deposited on the cathode buffer layer by vacuum deposition. The film thickness of the cathode was 80 nm.

  The multilayer element obtained as described above is disposed in a nitrogen glove box, a rear glass is disposed on the cathode side, and the rear glass and the glass substrate are bonded together using a photo-curing resin. The element was sealed. As described above, a photoelectric conversion element having a light receiving area portion having a size of 4 mm × 4 mm was produced.

The photoelectric conversion element manufactured as described above was irradiated with light of a solar simulator (AM1.5G) at an irradiation intensity of 100 mW / cm ² to measure voltage-current characteristics. As a result, the open circuit voltage (V _oc ) is 0.35 V, the short circuit current (J _sc ) is 1.72 mA / cm ² , the fill factor (FF) is 0.30, and the energy conversion efficiency (PCE) is 0.18%. there were. When the spectral sensitivity of photoelectric conversion at each wavelength was measured, photoelectric conversion was achieved in the region of 350 nm to 970 nm.

Claims (20)

Formula I:

(In the formula, Ar ¹ and Ar ² each independently represent a heteroaryl group which may have a substituent; R ^{a to} R ^d each independently represent a hydrogen atom or a carbon which may have a substituent; A linear or branched alkoxy group of 1 to 8; B ¹ and B ² each independently represents a group selected from the group consisting of a hydrogen atom or a boryl group which may have a substituent, , At least one of B ¹ and B ^{2 is} an optionally substituted boryl group)
A benzodipyrrole derivative represented by: The benzodipyrrole derivative according to claim 1, wherein the hetero atom constituting the heteroaryl group in Ar ¹ or Ar ² forms a coordinate bond with the boron atom of the boryl group in B ¹ or B ² . Ar ¹ and Ar ² are each independently quinoxalinyl or benzothiadiazolyl which may have a substituent, and the substituent is a linear or branched alkyl having 1 to 8 carbon atoms. Item 3. The benzodipyrrole derivative according to Item 1 or 2. Ar ¹ and Ar ² are each independently 8- (2-ethylhexyl) -quinoxalin-5-yl or 7- (2-ethylhexyl) -2,1,3-benzothiadiazol-4-yl. The benzodipyrrole derivative according to 1 or 2. The boryl group in B ¹ and B ² is —B (R ¹ ) ₂ , wherein each R ¹ independently has a halogen, an alkyl which may have a substituent, or a substituent. The benzodipyrrole derivative according to any one of claims 1 to 4, which is selected from good aryl. The benzodipyrrole derivative according to claim 5, wherein R ¹ is phenyl. B ¹ and B ² are both boryl group, benzodioxanyl pyrrole derivative according to any one of claims 1 to 6. The benzodipyrrole derivative according to any one of claims 1 to 7, which has an absorption band in a range of 600 to 2500 nm in an ultraviolet-visible absorption spectrum. The benzodipyrrole derivative according to any one of claims 1 to 8, wherein the ionization potential is 4 to 6 ev. The benzodipyrrole derivative according to any one of claims 1 to 9, which has an electron affinity of 2 to 5 ev. Formula I:

(In the formula, Ar ¹ and Ar ² each independently represent a heteroaryl group which may have a substituent; R ^{a to} R ^d each independently represent a hydrogen atom or a carbon which may have a substituent; A linear or branched alkoxy group of 1 to 8; B ¹ and B ² each independently represents a group selected from the group consisting of a hydrogen atom or a boryl group which may have a substituent, , At least one of B ¹ and B ^{2 is} an optionally substituted boryl group)
A process for producing a benzodipyrrole derivative represented by:
Formula II:

(Wherein Ar ¹ and Ar ² and R ^{a to} R ^d have the same definition as in formula I above)
A process for producing a benzodipyrrole derivative of the general formula I by reacting a compound represented by formula (I) with a boron reagent. The production method according to claim 11, wherein the hetero atom constituting the heteroaryl group in Ar ¹ or Ar ² forms a coordinate bond with the boron atom of the boryl group in B ¹ or B ² . Ar ¹ and Ar ² are each independently quinoxalinyl or benzothiadiazolyl which may have a substituent, and the substituent is a linear or branched alkyl having 1 to 8 carbon atoms. Item 13. The production method according to Item 11 or 12. Ar ¹ and Ar ² are each independently 8- (2-ethylhexyl) -quinoxalin-5-yl or 7- (2-ethylhexyl) -2,1,3-benzothiadiazol-4-yl. 11. The production method according to 11 or 12. The boryl group in B ¹ and B ² is —B (R ¹ ) ₂ , wherein each R ¹ independently has a halogen, an alkyl which may have a substituent, or a substituent. The production method according to claim 11, which is selected from good aryl. The production method according to claim 15, wherein R ¹ is phenyl. B ¹ and ^{B 2} both are boryl group, The process according to any one of claims 11 to 16. A photoelectric conversion element comprising the benzodipyrrole derivative according to any one of claims 1 to 10 as an active layer material. A solar cell comprising the photoelectric conversion element according to claim 18. A solar cell module comprising the solar cell according to claim 19.

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