JP2020189933A - Dibenzopyrromethene boron chelate compound, near infrared light absorption dye, photoelectric conversion element, near infrared light sensor and imaging element - Google Patents

Abstract

To provide a near infrared light absorbing material that has absorption properties in a near infrared region and shows high solubility in solvent, allowing deposition by a solution process, an organic thin film containing the near infrared light absorbing material, an organic electronic device containing the organic thin film, and an organic photoelectric conversion element containing the organic thin film.SOLUTION: The present invention provides a dibenzopyrromethene boron chelate compound represented by formula (1). (R1 to R12 independently represent an aliphatic hydrocarbon group, an aromatic group or a heterocyclic group or the like; Z1 and Z2 independently represent a bivalent linking group with two H atoms removed from an aromatic ring of an aromatic compound, or a bivalent linking group with two H atoms removed from a heterocycle of a heterocyclic compound; n independently represents an integer of 0 or greater).SELECTED DRAWING: None

Description

The present invention relates to a novel compound having a dibenzopyromethene boron chelate structure, a photoelectric conversion element, an optical sensor, and an imaging element. In particular, the present invention relates to a photoelectric conversion element having a main absorption band in the near infrared region and its use.

Near-infrared light-absorbing dyes having an absorption band in the near-infrared region of 780 to 2000 nm (International Electrotechnical Commission standard IEC60050-841; 1983) have been studied for application to various industrial applications. For example, the near-infrared light absorbing dye is an optical information recording medium such as a CD-R (Compact Disk-Recordable); a printing application such as a thermal CTP (Computer To Plate), flash toner fixing, and laser heat sensitive recording; It is used for applications such as blocking films. Furthermore, the near-infrared light-absorbing dye uses its property of selectively absorbing light in a specific wavelength range to form a near-infrared cut filter used for a PDP (plasma display panel) filter or the like, or a plant. It is also used in growth adjustment films and the like. The near-infrared light-absorbing dye can also be used as a near-infrared light-absorbing ink by dissolving or dispersing it in a solvent. The printed matter using the near-infrared light absorbing ink is difficult to visually recognize and can be read only by a near-infrared photodetector or the like. Therefore, it is used for printing for the purpose of preventing counterfeiting, for example. To.

As the near-infrared light absorbing material for forming such an invisible image, an inorganic near-infrared light absorbing material and an organic near-infrared light absorbing material are already known. Of these, rare earth metals such as ytterbium and copper-phosphate crystallized glass are known as inorganic near-infrared light absorbing materials. However, since the inorganic near-infrared light absorbing material does not have sufficient light absorption in the near-infrared region, a large amount of near-infrared light absorbing material is required per unit area of the invisible image. Therefore, when an invisible image is formed by an inorganic near-infrared light absorbing material, if a visible image is further formed on the surface of the invisible image, the unevenness of the invisible image on the lower side affects the visible image on the surface side.

On the other hand, the organic near-infrared light absorbing material has sufficient light absorption in the near-infrared region, so that the amount used per unit area of the invisible image can be small, and therefore the inorganic near-red There is no inconvenience as when using an external light absorbing material. Therefore, many organic near-infrared light absorbing materials have been developed to date.

For example, Patent Document 1 discloses a naphthalocyanine compound as an organic near-infrared light absorbing material. However, since naphthalocyanine compounds have a complicated production method and difficulty in adjusting the solubility, it is generally industrially possible to use a counterionic dye compound as a near-infrared light absorbing material. It is normal.
Further, Patent Document 2 discloses a naphthofluorescein compound as an example of a near-infrared fluorescent dye having a fluorescence wavelength in the near-infrared region.

On the other hand, organic electronic devices do not contain rare metals in their raw materials and can be stably supplied, as well as being flexible and can be manufactured by a wet film formation method, which are not found in inorganic materials. There is growing interest. Specific examples of organic electronic devices include organic EL elements, organic solar cell elements, organic photoelectric conversion elements, organic transistor elements, etc., and not only performance as devices but also applications utilizing the characteristics of organic materials are being studied. ing.

Non-Patent Document 1 reports on boron-dipyrromethene (hereinafter referred to as "BODIPY") as a dye having an absorption band to a fluorescent band in the red or near-infrared light region and having excellent fastness. ing.
Further, according to Patent Documents 3 to 5, by BO-chelating a compound having a BODIPY skeleton, the fastness of the compound to light can be further improved and the absorption wavelength can be shifted to the longer wavelength side. Are listed. However, a compound having a BODIPY skeleton generally has a significantly reduced solubility because the rigidity of the molecule is increased by BO chelation.

JP-A-2007-3944 Japanese Unexamined Patent Publication No. 2012-219258 JP-A-2016-166284 International Publication No. 2013/035303 International Publication No. 2018/079653

Chem. Soc. Rev. , 2014,43,4778-4823

The near-infrared light absorbing dyes currently used are required to have further improved durability. Moreover, considering the ease of processing for industrial use, it is necessary to maintain the near-infrared light absorption characteristics while having high solubility in a solvent.

An object of the present invention is to obtain a near-infrared light absorbing material, which has absorption characteristics in the near-infrared region and can form a thin film by a solution process by exhibiting high solubility in a solvent. An object of the present invention is to provide an organic thin film containing the organic thin film, an organic electrodevice containing the organic thin film, and an organic photoelectric conversion element containing the organic thin film.

As a result of studies to solve the above-mentioned problems, the present inventors have found that the above-mentioned problems can be solved by using a dibenzopyrromethene-boron chelate compound having an azomethine skeleton introduced into the molecule, and complete the present invention. I arrived.
That is, the present invention
[1] The following general formula (1)

(In the formula, R _{1 to} R ₈ are independently hydrogen atoms, aliphatic hydrocarbon groups, alkoxy groups, alkylthio groups, aromatic groups, heterocyclic groups, halogen atoms, hydroxyl groups, mercapto groups, nitro groups and substituted amino groups, respectively. , An unsubstituted amino group, a cyano group, a sulfo group, or an acyl group. R ₉ and R ₁₀ independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aromatic group, or a heterocyclic group, respectively. R ₁₁ and R ₁₂ independently represents an aliphatic hydrocarbon group, an aromatic group, or a heterocyclic group. Z ₁ and Z ₂ are divalent linkages obtained by independently removing two hydrogen atoms from the aromatic ring of an aromatic compound. A dibenzopyrromethene boron chelate compound represented by a group or a divalent linking group obtained by removing two hydrogen atoms from the heterocycle of a heterocyclic compound. N represents an integer of 0 or more independently.)
[2] The dibenzopyrromethene boron chelate compound according to the previous item [1], wherein n is 1.
[3] The dibenzopyrromethene boron chelate compound according to the above item [1] or [2], wherein R ₉ and R ₁₀ are hydrogen atoms.
[4] The dibenzopyrromethene boron chelate compound according to any one of the above items [1] to [3], wherein R ₁₁ and R ₁₂ are aromatic groups or heterocyclic groups.
[5] A near-infrared absorbing dye containing the dibenzopyrromethene boron chelate compound according to any one of the preceding items [1] to [4].
[6] An organic thin film containing the dibenzopyrromethene boron chelate compound according to any one of the above items [1] to [4].
[7] A photoelectric conversion element containing the dibenzopyrromethene boron chelate compound according to any one of the above items [1] to [4].
[8] A near-infrared light sensor including the photoelectric conversion element according to the previous item [7], and [9] an imaging element including the photoelectric conversion element according to the previous item [7].
Regarding.

Since the dibenzopyrromethene boron chelate compound of the present invention has absorption characteristics in the near infrared region and has high solubility, it is possible to form a film by coating with a solution. It can be applied to devices such as organic imaging elements, optical sensors, infrared sensors, etc., and cameras, video cameras, infrared cameras, etc. using them.

FIG. 1 shows a cross-sectional view illustrating an embodiment of the photoelectric conversion element of the present invention. FIG. 2 shows the absorption spectrum of the organic thin film of Example 3. FIG. 3 shows the absorption spectrum of the organic thin film of Example 4.

Hereinafter, the contents of the present invention will be described in detail. The description of the constituent elements described here is based on typical embodiments and specific examples of the present invention, while the present invention is not limited to such embodiments and specific examples. In the present invention, the near-infrared region refers to a wavelength region in the range of 780 to 2000 nm, and the near-infrared light absorbing material (dye) refers to a material having a main absorption wavelength in the near-infrared light region. , Near-infrared light emitting material (dye) means a material that emits light in the near infrared light region.

The dibenzopyrromethene boron chelate compound of the present invention is represented by the above formula (1). The above formula (1) shows only one of the resonance structures, and the compound of the present invention is not limited to the illustrated resonance structure.
R _{1 to} R ₈ in the formula (1) are independently hydrogen atom, aliphatic hydrocarbon group, alkoxy group, alkylthio group, aromatic group, heterocyclic group, halogen atom, hydroxyl group, mercapto group, nitro group, substitution. Represents an amino group, an unsubstituted amino group, a cyano group, a sulfo group, or an acyl group.

The aliphatic hydrocarbon group represented by R _{1 to} R ₈ in the above formula (1) is not limited to any of saturated or unsaturated linear, branched or cyclic, and has 1 to 30 carbon atoms. Preferably, 1 to 20 is more preferable. Here, specific examples of the saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an iso-butyl group and an allyl group. , T-Butyl group, n-Pentyl group, n-Hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-cetyl group, n-heptadecyl group. , N-butenyl group, 2-ethylhexyl group, 3-ethylheptyl group, 4-ethyloctyl group, 2-butyloctyl group, 3-butylnonyl group, 4-butyldecyl group, 2-hexyldecyl group, 3-octyl Examples thereof include an undecyl group, a 4-octyldodecyl group, a 2-octyldodecyl group, a 2-decyltetradecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group.
The aliphatic hydrocarbon group represented by R _{1 to} R ₈ in the formula (1) is preferably a linear or branched aliphatic hydrocarbon group, and is a saturated linear or branched alkyl group. Is more preferable, n-butyl group, n-hexyl group, n-octyl group, n-decyl group, n-dodecyl group, 2-ethylhexyl group, 2-methylpropyl group or 2-butyloctyl group. It is more preferable that it is an n-hexyl group, an n-octyl group or a 2-methylpropyl group.

The alkoxy group represented by R _{1 to} R ₈ in the above formula (1) is a substituent in which an oxygen atom and an alkyl group are bonded, and the alkyl group contained in the alkoxy group is, for example, R ₁ in the formula (1). to include alkyl groups described as specific examples in the section aliphatic hydrocarbon group represented by R _8.
The alkoxy group represented by R _{1 to} R ₈ in the formula (1) may have a substituent such as an alkoxy group.
The alkylthio group represented by R _{1 to} R ₈ in the above formula (1) is a substituent in which a sulfur atom and an alkyl group are bonded, and the alkyl group contained in the alkylthio group is, for example, R ₁ in the formula (1). to include alkyl groups described as specific examples in the section aliphatic hydrocarbon group represented by R _8.
The alkylthio group represented by R _{1 to} R ₈ in the formula (1) may have a substituent such as an alkylthio group.

The aromatic group represented by R _{1 to} R ₈ in the above formula (1) is a residue obtained by removing one hydrogen atom from the aromatic ring of the aromatic compound. Examples of the aromatic group represented by R _{1 to} R ₈ of the formula (1) include a phenyl group, a biphenyl group, a trill group, an indenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyrenyl group, a phenanthnyl group, a mesityl group and the like. Examples thereof include a phenyl group, a biphenyl group, a trill group, a naphthyl group or a mesityl group, and a phenyl group, a trill group or a mesityl group is more preferable.
The aromatic compound that can be an aromatic group may have a substituent, and the substituent that may have the substituent is not particularly limited.

The heterocyclic group represented by R _{1 to} R ₈ in the above formula (1) is a residue obtained by removing one hydrogen atom from the heterocycle of the heterocyclic compound. Examples of the heterocyclic group represented by R _{1 to} R ₈ of the formula (1) include a furanyl group, a thienyl group, a thienotienyl group, a pyrrolyl group, an imidazolyl group, an N-methylimidazolyl group, a thiazolyl group, an oxazolyl group, a pyridyl group and a pyrazil group. Group, pyrimidyl group, quinolyl group, indolyl group, benzopyrazyl group, benzopyrimidyl group, benzothienyl group, benzothiazolyl group, pyridinothiazolyl group, benzoimidazolyl group, pyridinoimidazolyl group, N-methylbenzoimidazolyl group, pyridino-N-methyl Imidazolyl group, benzoxazolyl group, pyridinooxazolyl group, benzothiazolyl group, pyridinothiazolyl group, benzoxaziazolyl group, pyridinooxadiazolyl group, carbazolyl group, phenoxadinyl group or phenothiazine Examples thereof include a thienyl group, a thienothienyl group, a thiazolyl group, a pyridyl group, a benzothiazolyl group, a benzothiadiazolyl group or a pyridinothiaazolyl group, and more preferably a thienyl group, a thiazolyl group and a pyridyl group.
The heterocyclic compound that can be a heterocyclic group may have a substituent, and the substituent that may have the substituent is not particularly limited.

Examples of the halogen atom represented by R _{1 to} R ₈ in the above formula (1) include a fluorine atom, a chlorine atom, a bromine atom and an iodine atom, and a fluorine atom or a chlorine atom is preferable, and a fluorine atom is more preferable.

The substituted amino group represented by R _{1 to} R ₈ in the above formula (1) is a substituent in which the hydrogen atom of the amino group is substituted with one or two substituents. As the substituent contained in the substituted amino group, an alkyl group or an aromatic group is preferable, and an aromatic group is more preferable. Specific examples of these substituents include the alkyl group described in the section of the aliphatic hydrocarbon group represented by R _{1 to} R _{8 in the} formula (1) and the aromatic represented by R _{1 to} R ₈ in the formula (1). The same as the group can be mentioned.
The acyl group represented by R _{1 to} R ₈ in the above formula (1) is a substituent in which a carbonyl group and an aromatic group or an alkyl group are bonded, and the alkyl group and the aromatic group contained in the acyl group are of the formula. Examples thereof include the alkyl group described in the section of the aliphatic hydrocarbon group represented by R _{1 to} R _{8 in} (1) and the same aromatic group represented by R _{1 to} R ₈ in the formula (1).

As R _{1 to} R ₈ in the formula (1), a hydrogen atom, an aromatic group, a heterocyclic group or a halogen atom is preferable independently, and a hydrogen atom, an aromatic group or a halogen atom is more preferable independently.
Further, it is preferable that R ₁ and R ₈ are the same, R ₂ and R ₇ are preferably the same, R ₃ and R ₆ are preferably the same, and R ₄ and R ₅ are the same. Is preferable.

R ₉ and R ₁₀ in the formula (1) independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aromatic group, or a heterocyclic group, respectively.
The aliphatic hydrocarbon group represented by R ₉ and R ₁₀ in the above formula (1) is not limited to any of saturated or unsaturated linear, branched or cyclic, and has 1 to 10 carbon atoms. Preferably, 1 to 6 are more preferable. Here, specific examples of the saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an iso-butyl group and an allyl group. , T-Butyl group, n-Pentyl group, n-Hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-cetyl group, n-heptadecyl group. , N-Butenyl group, 2-ethylhexyl group, 3-ethylheptyl group, 4-ethyloctyl group, 2-butyloctyl group, 3-butylnonyl group, 4-butyldecyl group, 2-hexyldecyl group, 3-octyl Examples thereof include an undecyl group, a 4-octyldodecyl group, a 2-octyldodecyl group, a 2-decyltetradecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group.
The aliphatic hydrocarbon group represented by R ₉ and R ₁₀ in the formula (1) is preferably a linear or branched aliphatic hydrocarbon group, and is a saturated linear or branched alkyl group. It is more preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group, an n-pentyl group or a 2-hexyl group, and an n-methyl group, an ethyl group or an n-propyl group. Is particularly preferable.

The aromatic group represented by R ₉ and R ₁₀ in the above formula (1) is a residue obtained by removing one hydrogen atom from the aromatic ring of the aromatic compound. Examples of the aromatic group represented by R _{9 to} R ₁₀ of the formula (1) include a phenyl group, a biphenyl group, a tolyl group, an indenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyrenyl group, a phenanthnyl group and a mesityl group. Although mentioned above, a phenyl group, a biphenyl group, a tolyl group, a naphthyl group or a mesityl group is preferable, and a phenyl group, a tolyl group or a mesityl group is more preferable.
The aromatic compound that can be an aromatic group may have a substituent, and the substituent that may have the substituent is not particularly limited.

The heterocyclic group represented by R ₉ and R ₁₀ in the above formula (1) is a residue obtained by removing one hydrogen atom from the heterocycle of the heterocyclic compound. Examples of the heterocyclic group represented by R _{9 to} R ₁₀ of the formula (1) include a furanyl group, a thienyl group, a thienotienyl group, a pyrrolyl group, an imidazolyl group, an N-methylimidazolyl group, a thiazolyl group, an oxazolyl group, a pyridyl group and a pyrazil group. Group, pyrimidyl group, quinolyl group, indolyl group, benzopyrazyl group, benzopyrimidyl group, benzothienyl group, benzothiazolyl group, pyridinothiazolyl group, benzoimidazolyl group, pyridinoimidazolyl group, N-methylbenzoimidazolyl group, pyridino-N-methyl Imidazolyl group, benzoxazolyl group, pyridinooxazolyl group, benzothiazolyl group, pyridinothiazolyl group, benzoxaziazolyl group, pyridinooxadiazolyl group, carbazolyl group, phenoxadinyl group and phenothiazine Examples thereof include a thienyl group, a thienotienyl group, a thiazolyl group, a pyridyl group or a benzothiazolyl group, and a thienyl group, a thiazolyl group or a pyridyl group is more preferable.
The heterocyclic compound that can be a heterocyclic group may have a substituent, and the substituent that may have the substituent is not particularly limited.

As R ₉ and R ₁₀ in the formula (1), a hydrogen atom, an aliphatic hydrocarbon group, an aromatic group or a heterocyclic group are preferable independently, and a hydrogen atom, an aliphatic hydrocarbon group or an aromatic group are independently obtained. Is more preferable, and a hydrogen atom is further preferable.

R ₁₁ and R ₁₂ in the formula (1) independently represent an aliphatic hydrocarbon group, an aromatic group, and a heterocyclic group, respectively.
The aliphatic hydrocarbon groups represented by R ₁₁ and R ₁₂ in the above formula (1) are not limited to saturated or unsaturated linear, branched or cyclic, and have 1 to 10 carbon atoms. Preferably, 1 to 6 are more preferable. Here, specific examples of the saturated or unsaturated linear, branched or cyclic aliphatic hydrocarbon group include a methyl group, an ethyl group, a propyl group, an isopropyl group, an n-butyl group, an iso-butyl group and an allyl group. , T-Butyl group, n-Pentyl group, n-Hexyl group, n-octyl group, n-decyl group, n-dodecyl group, n-tridecyl group, n-tetradecyl group, n-cetyl group, n-heptadecyl group. , N-Butenyl group, 2-ethylhexyl group, 3-ethylheptyl group, 4-ethyloctyl group, 2-butyloctyl group, 3-butylnonyl group, 4-butyldecyl group, 2-hexyldecyl group, 3-octyl Examples thereof include an undecyl group, a 4-octyldodecyl group, a 2-octyldodecyl group, a 2-decyltetradecyl group, a cyclopropyl group, a cyclobutyl group, a cyclopentyl group and a cyclohexyl group.

The aromatic group represented by R ₁₁ and R ₁₂ in the above formula (1) is a residue obtained by removing one hydrogen atom from the aromatic ring of the aromatic compound. Examples of the aromatic group represented by R _{11 to} R ₁₂ of the formula (1) include a phenyl group, a biphenyl group, a tolyl group, a fluorophenyl group, an indenyl group, a naphthyl group, an anthryl group, a fluorenyl group, a pyrenyl group, a phenanthnyl group and the like. Examples thereof include a methyl group, but a phenyl group, a biphenyl group, a tolyl group or a mesityl group is preferable, and a phenyl group, a tolyl group, a fluorophenyl group or a mesityl group is more preferable.
The aromatic compound that can be an aromatic group may have a substituent, and the substituent that may have the substituent is not particularly limited.

The heterocyclic group represented by R ₁₁ and R ₁₂ in the above formula (1) is a residue obtained by removing one hydrogen atom from the heterocycle of the heterocyclic compound. Examples of the heterocyclic group represented by R _{11 to} R ₁₂ of the formula (1) include a furanyl group, a thienyl group, a thienotienyl group, a pyrrolyl group, an imidazolyl group, an N-methylimidazolyl group, a thiazolyl group, an oxazolyl group, a pyridyl group and a pyrazil group. Group, pyrimidyl group, quinolyl group, indolyl group, benzopyrazyl group, benzopyrimidyl group, benzothienyl group, benzothiazolyl group, pyridinothiazolyl group, benzoimidazolyl group, pyridinoimidazolyl group, N-methylbenzoimidazolyl group, pyridino-N-methyl Imidazolyl group, benzoxazolyl group, pyridinooxazolyl group, benzothiazolyl group, pyridinothiazolyl group, benzoxaziazolyl group, pyridinooxadiazolyl group, carbazolyl group, phenoxadinyl group and phenothiazine Examples thereof include a thienyl group, a thienotienyl group, a thiazolyl group, a pyridyl group, an oxazolyl group or a benzothiazolyl group, and a thienyl group, a thiazolyl group or a benzothiazolyl group is more preferable.
The heterocyclic compound that can be a heterocyclic group may have a substituent, and the substituent that may have the substituent is not particularly limited.

As R ₁₁ and R ₁₂ in the formula (1), an aromatic group or a heterocyclic group is preferable independently, and an aromatic group is more preferable.

Z ₁ and Z ₂ in the formula (1) are divalent linking groups in which two hydrogen atoms are independently removed from the aromatic ring of the aromatic compound, or two hydrogen atoms are removed from the heterocycle of the heterocyclic compound. Represents a divalent linking group.
Examples of the aromatic compound which can be a divalent linking group obtained by removing one hydrogen atom from the aromatic ring of the aromatic compound represented by Z ₁ and Z ₂ in the above formula (1) include benzene, naphthalene, anthracene and pyrene. Examples thereof include fluorene and phenanthrene, and benzene or naphthalene is preferable, and benzene is more preferable.
The aromatic compound that can be a divalent linking group may have a substituent, and the substituent that may have the substituent is not particularly limited.

Examples of the aromatic compound that can be a divalent linking group obtained by removing one hydrogen atom from the heterocycle of the heterocyclic compound represented by Z ₁ and Z ₂ in the above formula (1) include thiophene, furan, pyrrole, and thiazole. Examples thereof include imidazole, oxazole, pyridine, pyrazine, pyrimidine and quinoline, with thiophene, thiazole or pyridine being preferable, and thiophene being more preferable.
The heterocyclic compound that can be a divalent linking group may have a substituent, and the substituent that may have the substituent is not particularly limited.

In the formula (1), n, which means the number of divalent linking groups Z ₁ and Z ₂ , each independently represents an integer of 0 or more, and 0 or 1 is preferable independently, and 1 is more preferable.

Next, a method for synthesizing the compound represented by the general formula (1) of the present invention will be described in detail.
The compound represented by the formula (1) can be synthesized, for example, by the synthetic scheme shown below. Compound (a) can be synthesized with reference to a known method (Patent Document 5), and the obtained compound (a) is reacted with a secondary amine derivative to obtain compound (b), and then tribromide. The compound represented by the formula (1) can be obtained by BO chelating by reacting with boron. The purification method of these compounds is not particularly limited, and for example, washing, recrystallization, column chromatography, vacuum sublimation and the like can be adopted, and these methods can be combined as necessary.

Specific examples of the compound represented by the formula (1) include the compounds represented by the formulas (1-1) to (1-128) below, but the present invention is not limited thereto. The structural formula shown as a specific example merely represents one of the resonance structures, and is not limited to the illustrated resonance structure.

The near-infrared light absorbing dye of the present invention contains a compound represented by the above formula (1).
The content of the compound represented by the formula (1) in the near-infrared light-absorbing dye of the present invention is as long as the near-infrared light absorption capacity required in the application using the near-infrared light-absorbing dye is exhibited. Although not particularly limited, it is usually 50% by mass or more, preferably 80% by mass or more, more preferably 90% by mass or more, still more preferably 95% by mass or more.
The near-infrared light absorbing dye of the present invention includes compounds other than the compound represented by the formula (1) (for example, a near-infrared light absorbing dye other than the compound represented by the formula (1)), additives and the like. It may be used together. The compounds and additives that can be used in combination are not particularly limited as long as the near-infrared light absorbing ability required in the application using the near-infrared light absorbing material is exhibited.

A thin film can be prepared using the compound of the present invention. The thin film may be composed only of the compound of the present invention, but may contain a separately known near-infrared light absorbing dye.

Examples of the thin film forming method of the present invention include a general dry film forming method and a wet film forming method. Specifically, it is a vacuum process such as resistance heating vapor deposition, electron beam deposition, sputtering, molecular lamination method, solution process casting, spin coating, dip coating, blade coating, wire bar coating, spray coating and other coating methods, and inkjet printing. , Screen printing, offset printing, printing methods such as letterpress printing, soft lithography methods such as microcontact printing, and the like.
For general near-infrared light absorbing dyes, a process of applying a compound in a solution state is desired from the viewpoint of ease of processing, but in the case of an organic electronics device in which an organic film is laminated, application is desired. It is not suitable because the solution may attack the organic film underneath.

In order to realize such a multi-layer laminated structure, it is appropriate to use a dry film deposition method, for example, a material capable of vapor deposition such as resistance heating vapor deposition. Therefore, a near-infrared light absorbing dye having a main absorption wavelength in the near-infrared region and capable of vapor deposition is preferable as the near-infrared photoelectric conversion material.

A method in which a plurality of the above methods are combined may be adopted for film formation of each layer. The thickness of each layer cannot be limited because it depends on the resistance value and charge mobility of each substance, but is usually in the range of 0.5 to 5000 nm, preferably in the range of 1 to 1000 nm, and more preferably 5. It is in the range of to 500 nm.

[Organic electronics device]
An organic electronic device including the compound of the present invention, a near-infrared light absorbing material, a near-infrared light emitting material, or an organic thin film using these can be produced. Examples of the organic electronics device include a thin film, an organic photoelectric conversion element, an organic solar cell element, an organic electroluminescence element (hereinafter, referred to as “organic EL element” or “organic light emitting element”), an organic light emitting transistor element, and an organic semiconductor. Examples include laser elements. In the present invention, we pay particular attention to organic photoelectric conversion elements and organic EL elements, which are expected to be used in near-infrared applications. Here, a near-infrared organic photoelectric conversion element used as a near-infrared light absorbing material, an organic EL element utilizing near-infrared emission characteristics, and an organic semiconductor laser element, which are one of the embodiments of the present invention, will be described.
Although not described in detail here, near-infrared light exceeding 700 nm has high transparency to living tissues. Therefore, since it can be used for observing in vivo tissues, it can be applied in various forms depending on the purpose in pathological elucidation, diagnosis, etc. in the medical field such as near-infrared fluorescent probe. ..

[Organic photoelectric conversion element]
Since the compound represented by the above formula (1) is a compound having near-infrared light absorption characteristics, it is expected to be used as a near-infrared organic photoelectric conversion element. In particular, it can be used as a photoelectric conversion layer in the organic photoelectric conversion element of the present invention. In the device, the maximum absorption of the absorption band of the response wavelength light with respect to light is preferably 780 nm or more and 2500 nm or less. Here, examples of the near-infrared organic photoelectric conversion element include a near-infrared light sensor, an organic imaging element, and a near-infrared light image sensor.

An organic photoelectric conversion element is an element in which a photoelectric conversion unit (film) is arranged between a pair of electrode films facing each other, and light is incident on the photoelectric conversion unit from above the electrode films. The photoelectric conversion unit generates electrons and holes in response to the incident light, and a semiconductor reads out a signal corresponding to the charge to indicate the amount of incident light according to the absorption wavelength of the photoelectric conversion film unit. Is. A transistor for reading may be connected to the electrode film on the side where light is not incident. When a large number of photoelectric conversion elements are arranged in an array, they are image pickup elements because they show incident position information in addition to the amount of incident light. Further, when the photoelectric conversion element arranged closer to the light source does not shield (transmit) the absorption wavelength of the photoelectric conversion element arranged behind the photoelectric conversion element when viewed from the light source side, a plurality of photoelectric conversion elements are laminated. You may use it.

In the organic photoelectric conversion element of the present invention, the compound represented by the formula (1) can be used as a constituent material of the photoelectric conversion unit.
The photoelectric conversion unit is one or a plurality of types selected from the group consisting of a photoelectric conversion layer, an electron transport layer, a hole transport layer, an electron block layer, a hole block layer, a crystallization prevention layer, an interlayer contact improvement layer, and the like. It is often composed of an organic thin film layer other than the photoelectric conversion layer. Although the compound of the present invention can be used in addition to the photoelectric conversion layer, it is preferable to use it as an organic thin film layer of the photoelectric conversion layer. The photoelectric conversion layer may be composed of only the compound represented by the formula (1), but includes a known near-infrared light absorbing material and others in addition to the compound represented by the formula (1). You may.

In the electrode film used in the organic photoelectric conversion element of the present invention, when the photoelectric conversion layer included in the photoelectric conversion unit described later has hole transportability or the organic thin film layer other than the photoelectric conversion layer has hole transportability. In the case of a hole transport layer, it plays a role of extracting holes from the photoelectric conversion layer and other organic thin film layers and collecting them, and the photoelectric conversion layer included in the photoelectric conversion unit has electron transportability. In some cases, or when the organic thin film layer is an electron transporting layer having electron transporting properties, it plays a role of extracting electrons from the photoelectric conversion layer and other organic thin film layers and discharging them. Therefore, the material that can be used as the electrode film is not particularly limited as long as it has a certain degree of conductivity, but the adhesion to the adjacent photoelectric conversion layer and other organic thin film layers, electron affinity, ionization potential, stability, etc. It is preferable to select in consideration of. Materials that can be used as the electrode film include conductive metal oxides such as tin oxide (NESA), indium oxide, indium tin oxide (ITO) and indium zinc oxide (IZO); gold, silver, platinum, chromium and aluminum. , Metals such as iron, cobalt, nickel and tungsten: Inorganic conductive substances such as copper iodide and copper sulfide: Conductive polymers such as polythiophene, polypyrrole and polyaniline: Carbon and the like. If necessary, a plurality of these materials may be mixed and used, or a plurality of these materials may be laminated in two or more layers. The conductivity of the material used for the electrode film is not particularly limited as long as it does not interfere with the light reception of the photoelectric conversion element more than necessary, but it is preferably as high as possible from the viewpoint of the signal strength of the photoelectric conversion element and the power consumption. For example, an ITO film having a conductivity of 300 Ω / □ or less functions sufficiently as an electrode film, but a commercially available substrate having an ITO film having a conductivity of several Ω / □ is also available. Therefore, it is desirable to use a substrate having such high conductivity. The thickness of the ITO film (electrode film) can be arbitrarily selected in consideration of conductivity, but is usually about 5 to 500 nm, preferably about 10 to 300 nm. Examples of the method for forming a film such as ITO include a conventionally known vapor deposition method, electron beam method, sputtering method, chemical reaction method, coating method and the like. The ITO film provided on the substrate may be subjected to UV-ozone treatment, plasma treatment, or the like, if necessary.

As the material of the transparent electrode film used for at least one of the electrode films on the side where light is incident, ITO, IZO, SnO ₂ , ATO (antimony-doped tin oxide), ZnO, AZO (Al-doped zinc oxide) , GZO (gallium-doped zinc oxide), TiO ₂ , FTO (fluorinated tin oxide) and the like. The transmittance of light incident through the transparent electrode film at the absorption peak wavelength of the photoelectric conversion layer is preferably 60% or more, more preferably 80% or more, and particularly preferably 95% or more. ..

Further, when a plurality of photoelectric conversion layers having different wavelengths to be detected are laminated, the electrode film used between the photoelectric conversion layers (this is an electrode film other than the pair of electrode films described above) is each photoelectric. It is necessary to transmit light having a wavelength other than the light detected by the conversion layer, and it is preferable to use a material that transmits 90% or more of the incident light, and a material that transmits 95% or more of the light is used for the electrode film. Is more preferable.

The electrode film is preferably plasma-free. By producing these electrode films in a plasma-free manner, the influence of plasma on the substrate on which the electrode film is provided can be reduced, and the photoelectric conversion characteristics of the photoelectric conversion element can be improved. Here, plasma-free means that plasma is not generated when the electrode film is formed, or the distance from the plasma generation source to the substrate is 2 cm or more, preferably 10 cm or more, more preferably 20 cm or more, and reaches the substrate. It means a state in which the plasma is reduced.

Examples of devices that do not generate plasma during film formation of the electrode film include an electron beam vapor deposition device (EB vapor deposition device) and a pulse laser vapor deposition device. The method of forming a transparent electrode film using an EB vapor deposition apparatus is referred to as an EB vapor deposition method, and the method of forming a transparent electrode film using a pulse laser vapor deposition apparatus is referred to as a pulse laser vapor deposition method.

As an apparatus capable of realizing a state in which plasma can be reduced during film formation (hereinafter referred to as a plasma-free film forming apparatus), for example, an opposed target sputtering apparatus, an arc plasma vapor deposition apparatus, or the like can be considered.

When the transparent conductive film is used as an electrode film (for example, the first conductive film), a DC short circuit or an increase in leakage current may occur. One of the reasons for this is that fine cracks generated in the photoelectric conversion layer are covered with a dense film such as TCO (Transient Conductive Oxide), and the conductivity between the film and the electrode film on the opposite side of the transparent conductive film is increased. it is conceivable that. Therefore, when a material such as Al, which is inferior in film quality, is used for the electrode, the leakage current is unlikely to increase. By controlling the film thickness of the electrode film according to the film thickness (crack depth) of the photoelectric conversion layer, an increase in leakage current can be suppressed.

Usually, when the conductive film is made thinner than a predetermined value, a rapid increase in resistance value occurs. The sheet resistance of the conductive film in the photoelectric conversion element for an optical sensor of the present embodiment is usually 100 to 10000 Ω / □, and the degree of freedom in film thickness is large. Further, the thinner the transparent conductive film, the smaller the amount of light absorbed, and generally the higher the light transmittance. When the light transmittance is high, the amount of light absorbed by the photoelectric conversion layer is increased and the photoelectric conversion ability is improved, which is very preferable.

The photoelectric conversion unit included in the organic photoelectric conversion element of the present invention may include an organic thin film layer other than the photoelectric conversion layer and the photoelectric conversion layer. An organic semiconductor film is generally used for the photoelectric conversion layer constituting the photoelectric conversion unit, but the organic semiconductor film may be one layer or a plurality of layers, and in the case of one layer, a p-type organic semiconductor film, n. A type organic semiconductor film or a mixed film thereof (bulk heterostructure) is used. On the other hand, in the case of a plurality of layers, there are about 2 to 10 layers, which is a structure in which any of a p-type organic semiconductor film, an n-type organic semiconductor film, or a mixed film (bulk heterostructure) thereof is laminated, and the layers are layers. A buffer layer may be inserted in. When the photoelectric conversion layer is formed by the above mixed film, the compound represented by the general formula (1) of the present invention is used as a p-type semiconductor material, and fullerenes and derivatives thereof, which are common as n-type semiconductor materials, are used. It is preferable to use.

In the organic photoelectric conversion element of the present invention, the organic thin film layer other than the photoelectric conversion layer constituting the photoelectric conversion unit is a layer other than the photoelectric conversion layer, for example, an electron transport layer, a hole transport layer, an electron block layer, and a hole block. It is also used as a layer, a crystallization prevention layer, an interlayer contact improvement layer, and the like. In particular, by using it as one or more thin film layers selected from the group consisting of an electron transport layer, a hole transport layer, an electron block layer and a hole block layer (hereinafter, also referred to as “carrier block layer”), even with weak light energy. This is preferable because an element that efficiently converts an electric signal can be obtained.

In addition, for example, organic image sensors are generally considered to aim at improving performance by reducing dark current for the purpose of high contrast and power saving, so a method of inserting a carrier block layer in the layer structure is used. preferable. These carrier block layers are generally used in the field of organic electronic devices, and each has a function of controlling the reverse movement of holes or electrons in the constituent film of the device.

The electron transport layer plays a role of transporting electrons generated in the photoelectric conversion layer to the electrode film and a role of blocking holes from moving from the electrode film of the electron transport destination to the photoelectric conversion layer. The hole transport layer plays a role of transporting generated holes from the photoelectric conversion layer to the electrode film and a role of blocking the movement of electrons from the electrode film of the hole transport destination to the photoelectric conversion layer. The electron block layer plays a role of hindering the movement of electrons from the electrode film to the photoelectric conversion layer, preventing recombination in the photoelectric conversion layer, and reducing dark current. The hole block layer has a function of hindering the movement of holes from the electrode film to the photoelectric conversion layer, preventing recombination in the photoelectric conversion layer, and reducing dark current.

FIG. 1 shows a typical element structure of the organic photoelectric conversion element of the present invention, but the present invention is not limited to this structure. In the example of the embodiment of FIG. 1, 1 is an insulating part, 2 is one electrode film, 3 is an electron block layer, 4 is a photoelectric conversion layer, 5 is a hole block layer, 6 is the other electrode film, and 7 is an insulating group. Represents a material or other organic photoelectric conversion element, respectively. Although the transistor for reading is not shown in the figure, it suffices if it is connected to the electrode film of 2 or 6, and if the photoelectric conversion layer 4 is transparent, the side opposite to the side on which light is incident is opposite. It may be formed on the outside of the electrode film of. The light incident on the organic photoelectric conversion element can be either from the upper part or the lower part unless the components other than the photoelectric conversion layer 4 extremely prevent the light of the main absorption wavelength of the photoelectric conversion layer from being incident. It may be from.

[About organic semiconductor laser devices]
Since the compound represented by the general formula (1) is a compound having near-infrared emission characteristics, it is expected to be used as an organic semiconductor laser device. That is, if the resonator structure is incorporated into the organic semiconductor laser device containing the compound represented by the general formula (1) and carriers can be efficiently injected to sufficiently increase the density of the excited state, the light is amplified. It is expected that this will lead to laser oscillation. Conventionally, only laser oscillation by photoexcitation is observed, and it is very difficult to inject high-density carriers required for laser oscillation by electroluminescence into an organic semiconductor device to generate a high-density excited state. Although it has been proposed, it is expected that highly efficient light emission (electroluminescence) may occur by using an organic semiconductor device containing the compound represented by the above general formula (1).

Hereinafter, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples. The structure of the compound described in the synthesis example was determined by mass spectrometry spectrum and nuclear magnetic resonance spectrum (NMR), if necessary. In the examples, ¹ H NMR was measured using JNM-ECS400 (manufactured by JEOL), the molecular weight was measured using ISQ LT GC-MS (manufactured by Thermo Fisher Scientific), and the value of λmax in the absorption spectrum was UV-1700 (manufactured by Shimadzu Corporation) was used for each.

Example 1 (Synthesis of the compound of the present invention)
The compound of the present invention represented by the formula (1-68) was synthesized by the following scheme.

(Step 1) Synthesis of Intermediate Compound Represented by Formula (2-2) in the above Scheme In a flask, the compound (0.55 mmol) represented by the above formula (2-1) and aniline (5.4 mmol). ) Was dissolved in toluene (36 mL), heated to 95 ° C., and stirred for 4 hours. The reaction mixture was allowed to cool, the solvent was concentrated and dried, and then the solvent was suspended and filtered through ethanol to obtain an intermediate compound represented by the formula (2-2) (0.34 mmol, yield 62% by mass). ). The measurement results of the molecular weight of the compound represented by the formula (2-2) were as follows.
EI-MS (m / z): 910 [M] ⁺

(Step 2) Synthesis of compound represented by formula (1-68) of the above specific example In a flask, an intermediate compound (0.29 mmol) represented by formula (2-2) obtained in step 1 is placed. It was dissolved in dichloromethane (25 mL). Boron tribromide (5.7 mL) was then added to the reaction system and stirred for 18 hours. The reaction solution was neutralized by adding it to a saturated aqueous sodium hydrogen carbonate solution, and then the organic layer was concentrated and dried. Methanol was added and suspension filtration was performed to obtain the compound of the present invention represented by the formula (1-68). (0.12 mmol, yield: 41% by mass).
The measurement results of the molecular weight of the compound represented by the formula (1-68) were as follows.
EI-MS (m / z): 842 [M] ^{+
1 1} H NMR (CDCl ₃ ) δ (ppm) = 8.46 (s, 2H), 7.92 (m, 6H), 7.78 (d, 4H), 7.71 (d, 2H), 7. 48 (s, 1H), 7.40 (t, 4H), 7.30-7.21 (m, 10H)

Example 2 (Synthesis of the compound of the present invention)
(Step 3) Synthesis of the compound of the present invention represented by the formula (1-101) of the above specific example In a flask, a di ((formylthiline) -methoxythionyl) difluorodibenzopyromethene-BF ₂ complex (0.033 mmol) ) And 3,5-dimethylaniline (0.30 mmol) were dissolved in toluene (2 mL), heated to 95 ° C., and stirred for 3 hours. The reaction mixture was allowed to cool, the solvent was concentrated and dried, and then suspension filtration was performed with ethanol to obtain an intermediate compound (0.020 mmol). The intermediate compound obtained above was dissolved in dichloromethane (2 mL) in a flask. Boron tribromide (0.5 mL) was then added to the reaction system and stirred for 7 hours. The reaction solution was neutralized by adding it to a saturated aqueous sodium hydrogen carbonate solution, and then the organic layer was concentrated and dried. Methanol was added and suspension filtration was performed to obtain the compound of the present invention represented by the formula (1-101). (0.11 mmol, yield: 33% by mass).
The measurement results of the molecular weight of the compound represented by the formula (1-101) were as follows.
EI-MS (m / z): 910 [M] ^{+
1 1} H NMR (CDCl ₃ ) δ (ppm) = 8.52 (s, 2H), 7.93 (dd, 2H), 7.65 (d, 2H), 7.45 (s, 1H), 7. 40 (d, 2H), 7.34 (d, 2H), 7.28 (d, 2H), 7.08 (s, 2H), 6.89 (s, 2H), 6.87 (s, 4H) ), 2.34 (s, 12H)

Comparative Example 1 (Synthesis of Compound for Comparison)
A comparative compound represented by the following formula (3-1) was obtained according to the method described in Patent Document 5.

(Measurement of solubility of the compound of the present invention and the compound for comparison in chloroform)
The solubility of the compound of the present invention and the compound for comparison obtained in Examples 1 and 2 and Comparative Example 1 in chloroform was measured, and the results are shown in Table 1.

While the compounds of the present invention (formulas (1-68) and (1-101)) obtained in Examples 1 and 2 all showed a solubility of 10 mg / mL or more. The comparative compound (formula (3-1)) obtained in Comparative Example 1 had a solubility of 2 mg / mL or less. From this result, it is clear that the compound of the present invention has a higher solubility than the comparative compound.

(Measurement of λmax of absorption spectrum of chloroform solution of compound of the present invention and compound for comparison)
Chloroform solutions (concentration 1.0 × ^10-5 mol / L) of the compounds obtained in Examples 1 and 2 and Comparative Example 1 were prepared, and the value of λmax obtained based on the measurement result of the absorption spectrum is shown in Table 2. It was shown to.

From the results in Table 2, the compounds of the present invention (formulas (1-68) and (1-101)) obtained in Examples 1 and 2 have longer wavelengths than the comparative compounds (formula (3-1)). It has λmax in the region, and it is clear that it can absorb near-infrared light more efficiently.

Example 3 (Preparation and evaluation of an organic thin film containing the compound of the present invention)
A 0.5 wt% chloroform solution was prepared using the compound represented by the formula (1-68) obtained in Example 1, 100 μL was applied onto a quartz substrate, and the mixture was spun at 1000 rpm for 30 seconds. The organic thin film of the present invention was obtained by coating. The absorption spectrum of the obtained organic thin film was measured, and the result is shown in FIG. The λmax of the organic thin film of Example 3 was 897 nm.

Example 4 (Preparation and evaluation of an organic thin film containing the compound of the present invention)
A 0.5 wt% chloroform solution was prepared using the compound represented by the formula (1-101) obtained in Example 2, 100 μL was applied onto a quartz substrate, and the mixture was spun at 1000 rpm for 30 seconds. The organic thin film of the present invention was obtained by coating. The absorption spectrum of the obtained organic thin film was measured, and the result is shown in FIG. The λmax of the organic thin film of Example 4 was 933 nm.

From the results of FIGS. 3 and 4, it is clear that the organic thin film containing the compound of the present invention exhibits good light absorption characteristics even in the near infrared light region.

The compound of the present invention has simple synthesis, high solubility in a solvent, film forming property by a solution process, and absorption characteristics in the near infrared region, and is very useful as a light absorbing dye in the near infrared region. is there.

(Fig. 1)
1 Insulation part 2 Upper electrode 3 Electronic block layer 4 Photoelectric conversion layer 5 Hole block layer 6 Lower electrode 7 Insulating base material or other photoelectric conversion element

Claims (9)

The following general formula (1)

(In the formula, R _{1 to} R ₈ are independently hydrogen atoms, aliphatic hydrocarbon groups, alkoxy groups, alkylthio groups, aromatic groups, heterocyclic groups, halogen atoms, hydroxyl groups, mercapto groups, nitro groups and substituted amino groups, respectively. , An unsubstituted amino group, a cyano group, a sulfo group, or an acyl group. R ₉ and R ₁₀ independently represent a hydrogen atom, an aliphatic hydrocarbon group, an aromatic group, or a heterocyclic group, respectively. R ₁₁ and R ₁₂ independently represents an aliphatic hydrocarbon group, an aromatic group, or a heterocyclic group. Z ₁ and Z ₂ are divalent linkages obtained by independently removing two hydrogen atoms from the aromatic ring of an aromatic compound. A dibenzopyrromethene boron chelate compound represented by a group or a divalent linking group obtained by removing two hydrogen atoms from the heterocycle of a heterocyclic compound. N represents an integer of 0 or more independently. The dibenzopyrromethene boron chelate compound according to claim 1, wherein n is 1. The dibenzopyrromethene boron chelate compound according to claim 1 or 2, wherein R ₉ and R ₁₀ are hydrogen atoms. The dibenzopyrromethene boron chelate compound according to any one of claims 1 to 3, wherein R ₁₁ and R ₁₂ are aromatic groups or heterocyclic groups. A near-infrared absorbing dye containing the dibenzopyrromethene boron chelate compound according to any one of claims 1 to 4. An organic thin film containing the dibenzopyrromethene boron chelate compound according to any one of claims 1 to 4. A photoelectric conversion element containing the dibenzopyrromethene boron chelate compound according to any one of claims 1 to 4. A near-infrared light sensor comprising the photoelectric conversion element according to claim 7. An image pickup device including the photoelectric conversion element according to claim 7.

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