JP2018123093A - Dibenzopyrromethene boron chelate compound, near infrared light absorbing dye, photoelectric conversion element, near-infrared photosensor and imaging element - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide an organic compound having absorption characteristics in a near-infrared region, while showing high light durability, and has excellent photoelectric conversion performance, the organic compound to be used for a photoelectric conversion element, specifically an imaging element or a photosensor.SOLUTION: The present invention provides a dibenzopyrromethene boron chelate compound represented by formula (1) (Zis an unsubstituted/substituted naphthalene ring; R-Rindependently represent H, an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a halogen atom, a hydroxy group, an alkoxy group, a mercapto group, an alkylthio group, a nitro group, a substituted amino group, an amide group, an acyl group, a carboxyl group, an acyloxy group, a cyano group, a sulfo group, a sulfamoyl group, an alkyl sulfamoyl group, a carbamoyl group or an alkyl carbamoyl group).SELECTED DRAWING: Figure 1

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 use thereof.

  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 various industrial applications. For example, near-infrared light absorbing dyes are optical information recording media such as CD-R (Compact Disk-Recordable); printing applications such as thermal CTP (Computer To Plate), flash toner fixing, laser thermal recording; It is used for applications such as barrier films. Furthermore, near-infrared light-absorbing dyes selectively absorb light in a specific wavelength region, so that near-infrared cut filters used for PDP (plasma display panel) filters, etc., and plant growth It is also used for adjustment films. The near infrared light absorbing dye can also be used as a near infrared light absorbing ink by dissolving or dispersing in a solvent. The printed matter using the near-infrared light absorbing ink is difficult to recognize visually and can be read only by a near-infrared light detector or the like. For example, it is used for printing for the purpose of preventing counterfeiting. The

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

  In contrast, organic infrared light-absorbing materials have sufficient absorption of light in the infrared region, so less use is required per unit area of invisible images. There are no inconveniences when using materials. Therefore, many organic infrared light absorbing materials have been developed so far.

  For example, Patent Document 1 discloses a naphthalocyanine compound as an organic near infrared light absorbing material. However, since the naphthalocyanine-based compound has a complicated manufacturing method and difficulty in adjusting the solubility, the general industrial use of a counterionic dye compound as a near-infrared light absorbing material. It has become normal. Patent Document 2 discloses an aminium compound as an example of an infrared absorbing material having light absorption in the infrared light region. Patent Document 3 discloses a naphthofluorescein compound as an example of a near-infrared fluorescent dye having a fluorescence wavelength in the near-infrared region.

  Furthermore, Non-Patent Document 1 reports a boron dipyrromethene compound as an example of a near-infrared fluorescent dye having a fluorescence wavelength in the near-infrared light region. In Patent Document 4, it is reported that a dibenzopyromethene boron chelate compound has an absorption maximum wavelength on the long wavelength side, and in Patent Document 5, it is used as a sensitizer for organic thin-film solar cell elements. Non-Patent Document 2 reports a dinaphthopyromethene boron chelate compound that exhibits a peak top in the near-infrared wavelength region.

JP 2007-3944 A Japanese Patent Laid-Open No. 7-271081 JP 2012-219258 A JP 2010-184880 A JP 2012-199541 A

Tetrahedron 2011.7.37.3187-3193 J. et al. Org. Chem. 2016.8.11.1310-1315

Currently used near-infrared light-absorbing dyes have problems such as heat resistance, light resistance, and complicated manufacturing methods, and materials that can be industrially used and exhibit high durability are required. . In particular, for the purpose of sensing near infrared light, a photoelectric conversion element manufactured using an organic compound having strong absorption in the near infrared region is desired. A pyromethene boron chelate compound having relatively high heat resistance is a promising material that satisfies the above requirements, and as described above, there are reports, but it is insufficient as a material having an absorption band in the near infrared region. Although it has been reported that extension of the π conjugate length is effective as a technique for extending the wavelength of the absorption band, it is unstable against oxidation due to the shallowest energy level of the highest occupied orbit (HOMO). Thus, there is a problem that light resistance is lowered.
For example, in Non-Patent Document 1, the light absorption maximum is 711 nm, but in order to effectively use light in the near infrared region, a longer wavelength is required. Patent Document 4 and Patent Document 5 disclose use as a sensitizer for an organic thin film solar cell element, but the end of the photoelectric conversion wavelength reaches 800 nm, and photoelectric conversion in the near-infrared region. Not enough as a material.
Furthermore, although the dinaphthopyromethene boron chelate compound of Non-Patent Document 2 shows a light absorption maximum at 800 nm or more, the HOMO energy level becomes shallow and the stability against air oxidation is lowered.

  In view of the above-described problems, the object of the present invention is an organic compound that can be used industrially, has an absorption wavelength mainly in the near-infrared region, and has excellent photoelectric conversion performance. The object is to provide use as a photoelectric conversion element, in particular, an image pickup element and an optical sensor.

  In order to solve the above-mentioned problems, the present inventor has reduced the concentration by boron chelation with a naphthalene ring at the 3,5-positions of a boron dipyrromethene compound that exhibits sufficient performance when used in an organic photoelectric conversion element. A novel dibenzopyromethene boron chelate compound with a ring structure has been developed, and a thin film using this compound has a main absorption wavelength in the near infrared region, and in addition, a near infrared photoelectric conversion device using this has been realized As a result, the present invention has been completed.

That is, the present invention
[1] A dibenzopyromethene boron chelate compound represented by the following general formula (1):

(Z ¹ represents an unsubstituted or substituted naphthalene ring. R _{1 to} R ₈ each independently represents a hydrogen atom, an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a halogen atom, a hydroxy group, or an alkoxy group. , A mercapto group, an alkylthio group, a nitro group, a substituted amino group, an amide group, an acyl group, a carboxyl group, an acyloxy group, a cyano group, a sulfo group, a sulfamoyl group, an alkylsulfamoyl group, a carbamoyl group, and an alkylcarbamoyl group. )
[2] Dibenzopyromethene boron chelate compound represented by the following general formula (2),

(R _{1 to} R ₂₀ are each independently a hydrogen atom, aryl group, heteroaryl group, alkyl group, cycloalkyl group, halogen atom, hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group, substituted amino group, amide. Group, acyl group, carboxyl group, acyloxy group, cyano group, sulfo group, sulfamoyl group, alkylsulfamoyl group, carbamoyl group, alkylcarbamoyl group.)
[3] Dibenzopyromethene boron chelate compound represented by the following general formula (3),

(R ² and R ⁷ are each independently a hydrogen atom, aryl group, heteroaryl group, alkyl group, cycloalkyl group, halogen atom, hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group, substituted amino group, amide Group, acyl group, carboxyl group, acyloxy group, cyano group, sulfo group, sulfamoyl group, alkylsulfamoyl group, carbamoyl group, alkylcarbamoyl group.)
[4] A near-infrared light absorbing dye containing the dibenzopyromethene boron chelate compound according to any one of [1] to [3],
[5] A thin film containing the dibenzopyromethene boron chelate compound according to any one of [1] to [3]
[6] A photoelectric comprising the dibenzopyromethene boron chelate compound according to any one of [1] to [3], the near-infrared absorbing dye according to [4], or the thin film according to [5]. Conversion element,
[7] A near-infrared light sensor comprising the photoelectric conversion element according to [6] above,
[8] An imaging device comprising the photoelectric conversion device according to [6] above,
About.

  The dibenzopyromethene boron chelate compound of the present invention has absorption characteristics mainly in the near-infrared region and has excellent photoelectric conversion performance. Therefore, it uses organic imaging devices as well as devices such as optical sensors and infrared sensors and uses them. It can be applied to fields such as conventional cameras, video cameras, and infrared cameras.

Sectional drawing which illustrated embodiment of the photoelectric conversion element of this invention is shown. The ultraviolet visible near-infrared light absorption spectrum in the thin film of Example 3 is shown. The ultraviolet-visible near-infrared light absorption spectrum in the thin film of Example 4 is shown. The ultraviolet visible near-infrared light absorption spectrum in the thin film of the comparative example 1 is shown. The photocurrent responsiveness in the photoelectric conversion element of Example 5 is shown. The photocurrent responsiveness in the photoelectric conversion element of Example 6 is shown. The photocurrent responsiveness in the photoelectric conversion element of the comparative example 2 is shown.

  Hereinafter, the contents of the present invention will be described in detail. The explanation of the constituent elements described here is based on typical embodiments and specific examples of the present invention, but the present invention is not limited to such embodiments and specific examples. In the present specification, a numerical range represented by using “to” means a range including numerical values described before and after “to” as a lower limit value and an upper limit value. In the present invention, the near infrared region refers to a wavelength region in the range of 780 nm to 2000 nm, and the near infrared light absorbing material (dye) is a material having a main absorption wavelength in the near infrared light region. A near-infrared light-emitting material (pigment) means a material that emits light in the near-infrared light region.

  The dibenzopyromethene boron chelate compound which is one embodiment of the present invention is represented by the following formula (1).

(Z ¹ represents an unsubstituted or substituted naphthalene ring. R _{1 to} R ₈ each independently represents a hydrogen atom, an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a halogen atom, a hydroxy group, or an alkoxy group. , A mercapto group, an alkylthio group, a nitro group, a substituted amino group, an amide group, an acyl group, a carboxyl group, an acyloxy group, a cyano group, a sulfo group, a sulfamoyl group, an alkylsulfamoyl group, a carbamoyl group, and an alkylcarbamoyl group. )

Z ¹ in the above formula (1) may be any of ¹ , 2, 2, ^{1, 2, 3} of the naphthalene ring as the condensation position of the unsubstituted or substituted naphthalene ring.

  Examples of the aryl group in the above formula (1) include benzene, naphthalene, anthracene, phenanthrene, azulene, biphenyl, and terphenyl, which may have a substituent. Examples of the heteroaryl group include optionally substituted thiophene, furan, pyrrole, pyridine, indole, benzothiophene, benzofuran and the like. As the alkyl group, methyl group, ethyl group, propyl group, isopropyl group, normal butyl group, isobutyl group, tertiary butyl group, pentyl group, hexyl group, heptyl group, octyl group, nonyl group, decyl group, undecyl group And dodecyl group. Examples of the cycloalkyl group include a cyclopentyl group and a cyclohexyl group. Examples of the halogen atom include a fluorine atom, a chlorine atom, a bromine atom, and an iodine atom. Examples of the alkoxy group include those in which the above alkyl group is bonded to an oxygen atom, but the number, position, and number of branches of the oxygen atom are not limited. Examples of the substituted amino group include those in which a hydrogen atom of the amino group is substituted with the above organic group. Examples of the acyl group include those in which the aromatic group or alkyl group is bonded to a carbonyl group. Examples of the alkylsulfamoyl group include those in which a hydrogen atom of the sulfamoyl group is substituted with the above alkyl group. Examples of the alkylcarbamoyl group include those in which the hydrogen atom of the carbamoyl group is substituted with the above alkyl group.

R _{1 to} R ₈ are preferably a hydrogen atom, an alkyl group, an aryl group, a heteroaryl group, a halogen atom, an alkoxy group, or a substituted amino group, and a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group is more easily synthesized. From the viewpoint of thermal stability, a hydrogen atom, a substituted or unsubstituted aryl group having 6 to 18 ring carbon atoms, and a substituted or unsubstituted heteroaryl group having 5 to 20 ring atoms are particularly preferable.

  A dibenzopyromethene boron chelate compound which is one of the preferred embodiments of the present invention is represented by the following formula (2).

(R _{1 to} R ₂₀ in formula (2) are each independently a hydrogen atom, aryl group, heteroaryl group, alkyl group, cycloalkyl group, halogen atom, hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group. A substituted amino group, an amide group, an acyl group, a carboxyl group, an acyloxy group, a cyano group, a sulfo group, a sulfamoyl group, an alkylsulfamoyl group, a carbamoyl group, and an alkylcarbamoyl group.

R _{1 to} R ₂₀ in the formula (2) are preferably a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group, more preferably a hydrogen atom, an aryl group, or a heteroaryl group because of ease of synthesis, and thermal stability. In view of the above, a hydrogen atom, an aryl group having 6 to 18 carbon atoms, and a heteroaryl group having 5 to 20 ring atoms are particularly preferable.

The substituents R _{1 to} R ₈ on the isoindole ring may be the same or different, but from the viewpoint of synthesis, the substituents at the same substitution position on different isoindole rings are the same. It is preferable that In addition, the substituents R _{9 to} R _{20 of} the naphthalene ring may be the same or different, but from the viewpoint of synthesis, the substituents at the same substitution position on different naphthalene rings are the same. It is preferable that That is, in the above formula (2), R ₁ = R ₈ , R ₂ = R ₇ , R ₃ = R _6, R ₄ = R ₅ , R ₉ = R ₂₀ , R ₁₀ = R ₁₉ , R _{11 = R 18, R 12 = R} 17, R 13 = R 16, R 14 = a _{R 15} structure is preferred.

  The dibenzopyromethene boron chelate compound which is one of the more preferable embodiments of the present invention is represented by the following formula (3).

(R ₂ and R _{7 in} formula (3) are a hydrogen atom, an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, a halogen atom, a hydroxy group, an alkoxy group, a mercapto group, an alkylthio group, a nitro group, and a substituted amino group. Group, amide group, acyl group, carboxyl group, acyloxy group, cyano group, sulfo group, sulfamoyl group, alkylsulfamoyl group, carbamoyl group, alkylcarbamoyl group.)

Specific examples of R ₂ and R ₇ in the formula (3) are the same as R _{1 to} R ₈ in the formula (1), and the substituents R ₂ and R ₇ on the isoindole ring are the same. Although it may be present or different, it is preferable that R ₂ = R ₇ from the viewpoint of synthesis.

R ₂ and R ₇ are preferably a hydrogen atom, an alkyl group, an aryl group, or a heteroaryl group from the viewpoint of synthesis, and from the viewpoint of thermal stability, a hydrogen atom, an aryl group having 6 to 18 ring carbon atoms, or the number of ring atoms 5-20 heteroaryl groups are particularly preferred.

  Specific examples of the dibenzopyromethene boron chelate compounds represented by the above formulas (1) to (3) are shown below, but the present invention is not limited thereto. The structural formula shown as a specific example represents only one of the resonance structures, and is not limited to the illustrated resonance structure.

  The dibenzopyromethene boron chelate compound of the present invention can be synthesized by a known method. For example, it is obtained in the same manner as the following reaction step (Org. Lett., 2011, 4547). The structural formulas of various compounds obtained in the synthesis examples can be determined by measuring MS (mass spectrometry spectrum) and NMR (nuclear magnetic resonance spectrum) as necessary.

  The purification method of the dibenzopyromethene boron chelate compound of the present invention is not particularly limited, and known methods such as recrystallization, column chromatography, and vacuum sublimation purification can be employed. Moreover, you may use combining these methods as needed.

A thin film can be produced using the dibenzopyromethene boron chelate compound of the present invention. In the thin film or solid state, the light absorption band is preferably 780 nm to 2500 nm.
The thickness of the thin film varies depending on the application, but is usually 0.01 nm to 10 μm, preferably 0.05 nm to 3 μm, and more preferably 0.1 nm to 1 μm.
The dibenzopyromethene boron chelate compound of the present invention is characterized by high industrial applicability and good atmospheric stability. In addition, since the dibenzopyromethene boron chelate compound represented by the formula (1) is soluble and can be applied in a solution state, an organic compound is processed into a device by a physical deposition method such as vacuum evaporation or sputtering. This indicates that the organic compound processing process is easy.

  Since the dibenzopyromethene boron chelate compound of the present invention is a compound having near-infrared light absorption characteristics (hereinafter also referred to as “near-infrared absorbing dye”), it is expected to be used as a near-infrared organic photoelectric conversion element. Is done. In the element, the maximum absorption in the absorption band of the response wavelength light is preferably 780 nm to 2500 nm, more preferably 780 to 2000 nm, and particularly preferably 780 to 1500 nm. Here, examples of the near-infrared organic photoelectric conversion element include an imaging element, an optical sensor, and an optical image sensor.

The photoelectric conversion element of the present invention will be described. The dibenzopyromethene boron chelate compound of the present invention can be used as a photoelectric conversion element including a photoelectric conversion film. In particular, it can be suitably used as a material for the photoelectric conversion layer.
A photoelectric conversion element is an element in which a photoelectric conversion unit including a photoelectric conversion film is disposed between two opposing electrode films, which are an upper electrode and a lower electrode, and light is incident on the photoelectric conversion unit from above one electrode. It is incident. The photoelectric conversion unit generates electrons and holes according to the amount of incident light, and a signal corresponding to the charge is read out by a semiconductor to indicate the amount of incident light according to the absorption wavelength of the photoelectric conversion film unit. It is an element. In some cases, a transistor for reading is connected to the lower electrode film.
When a large number of the photoelectric conversion elements are arranged on the array, in addition to the amount of incident light, in addition to the incident position information, the photoelectric conversion element becomes an imaging element. In addition, regarding the incidence of light, when the photoelectric conversion element including the electrode existing in the rear part is not disturbed by the photoelectric conversion element existing in the front part, even if a plurality of photoelectric conversion elements are stacked. good. Furthermore, when the above-described plurality of photoelectric conversion elements absorb different visible lights, a multicolor imaging element is formed, and a full color photodiode is obtained.

A mode example of the photoelectric conversion element will be described with reference to FIG.
1, 1 is an insulating portion, 2 is an upper electrode, 3 is an electron block layer, 4 is a photoelectric conversion portion, 5 is a hole blocking layer, 6 is a lower electrode, 7 is an insulating base material, or photoelectric. Each conversion element is represented. Although the readout transistor is not shown in the drawing, it may be connected to the lower electrode, and further, it may be formed under the lower electrode if the semiconductor is transparent. The incident light may be incident from any of the upper and lower portions as long as the light other than the photoelectric conversion portion does not extremely disturb the absorption wavelength of the photoelectric conversion portion. The photoelectric conversion element of this invention can use the compound represented by the said Formula (1) as a constituent material of the said photoelectric conversion part.

  Here, the photoelectric conversion part is often composed of a plurality of layers such as 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, It is not limited to this. Although the compound of this invention can be used besides a photoelectric converting layer, it is preferable to use it as an organic thin film layer of a photoelectric converting layer. The photoelectric conversion layer may be composed only of the compound represented by the formula (1), but may contain a known near-infrared absorbing substance or the like in addition to the compound represented by the formula (1). Good.

  In general, an organic semiconductor film is used for the photoelectric conversion layer. However, the organic semiconductor film may be a single layer or a plurality of layers. In this case, a P-type organic semiconductor film, an N-type organic semiconductor film, Alternatively, a mixed film (bulk heterostructure) thereof is used. On the other hand, in the case of a plurality of layers, it is about 2-10 layers, and is a structure in which any one of a P-type organic semiconductor film, an N-type organic semiconductor film, or a mixed film (bulk heterostructure) is laminated. A buffer layer may be inserted in

  For organic semiconductor films, triarylamine compounds, benzidine compounds, pyrazoline compounds, styrylamine compounds, hydrazone compounds, triphenylmethane compounds, carbazole compounds, polysilane compounds, thiophene compounds, phthalocyanine compounds, cyanine compounds depending on the wavelength band to be absorbed , Merocyanine compound, oxonol compound, polyamine compound, indole compound, pyrrole compound, pyrazole compound, polyarylene compound, carbazole derivative, naphthalene derivative, anthracene derivative, phenanthrene derivative, phenylbutadiene derivative, styryl derivative, quinoline derivative, tetracene derivative, pyrene derivative Perylene derivatives, fluoranthene derivatives, quinacridone derivatives, coumarin derivatives, porphyrin derivatives and phosphorescent gold Complex (Ir complexes, Pt complexes, Eu complexes, etc.), or the like can be used.

Here, the hole transport layer transports the generated holes from the photoelectric conversion layer to the electrode, facilitates movement of holes from the photoelectric conversion layer to the electrode, and functions to block electron transfer from the electrode. Have The electron transport layer has a function of transporting generated electrons from the photoelectric conversion layer to the electrode, facilitating movement of electrons from the photoelectric conversion layer to the electrode, and a function of blocking movement of holes from the electrode. .
In addition, the hole blocking layer has a function of preventing movement of holes from the electrode to the photoelectric conversion layer, preventing recombination in the photoelectric conversion layer, and reducing dark current. The electron blocking layer has a function of preventing movement of electrons from the electrode to the photoelectric conversion layer, preventing recombination in the photoelectric conversion layer, and reducing dark current. In addition, the hole block layer and the electron block layer preferably have high transmittance at the absorption wavelength of the photoelectric conversion layer, or are preferably used as a thin film, in order not to prevent light absorption of the photoelectric conversion film.
Furthermore, in the photoelectric conversion layer, by receiving incident light, the generated electrons and holes are transported to the electrodes, and are sent as electrical signals to the readout circuit.

  The electrode film that can be used in the photoelectric conversion element is a hole-transporting photoelectric conversion film or a hole-transporting film included in the photoelectric conversion layer, which collects holes or collects electrons or is included in the photoelectric conversion layer. In order to take out electrons from the transportable photoelectric conversion film or the electron transport film and discharge the electrons, adjacent films such as a hole transport photoelectric conversion film and a hole transport film, or an electron transport photoelectric conversion film and an electron transport film Although it is selected in consideration of adhesion to adjacent films such as, electron affinity, ionization potential, stability, etc., it is not particularly limited, but tin oxide (NESA), indium oxide, indium tin oxide (ITO) , Conductive metal oxides such as zinc indium oxide (IZO), metals such as gold, silver, platinum, chromium, aluminum, iron, cobalt, nickel, tungsten, copper iodide, Inorganic conductive substances such as reduction copper, polythiophene, polypyrrole, and conductive polymers or carbon such as polyaniline. If necessary, a plurality of materials may be used, or two or more layers may be used. The resistance of the electrode is not limited, but is not limited as long as it does not interfere with the light reception of the element more than necessary. From the viewpoint of signal strength of the element and power consumption, the resistance is preferably low. For example, an ITO substrate having a sheet resistance value of 300Ω / □ or less functions as an element electrode, but since it is possible to supply a substrate of several Ω / □, it is desirable to use a low-resistance product. The thickness of ITO can be arbitrarily selected according to the resistance value, but is usually 5 to 500 nm, preferably 10 to 300 nm. Examples of film forming methods such as ITO include a vapor deposition method, an electron beam method, a sputtering method, a chemical reaction method, and a coating method. If necessary, UV-ozone treatment, plasma treatment or the like can be performed.

Particularly preferable as the material for the transparent electrode film are ITO, IZO, SnO ₂ , ATO (antimony-doped tin oxide), ZnO, AZO (Al-doped zinc oxide), GZO (gallium-doped zinc oxide), TiO ₂ , FTO (fluorine). Doped tin oxide). The light transmittance of the transparent electrode film is preferably 60% or more, more preferably 80% or more, more preferably 90% or more, at the absorption peak wavelength of the photoelectric conversion film included in the photoelectric conversion part including the transparent electrode film. More preferably, it is 95% or more.

  In addition, when a plurality of photoelectric conversion layers are stacked, the electrodes inside the stacked films need to transmit light having a wavelength other than the light detected by each photoelectric conversion film, and preferably 90%, more preferably, the absorbed light. Is preferably a material that transmits 95% or more of light.

  The electrode film is preferably made plasma-free. By forming the electrode film without plasma, the influence of plasma on the substrate can be reduced, and the photoelectric conversion characteristics can be improved. Here, plasma free means that no plasma is generated during the formation of the electrode film, 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 where the plasma to be reduced decreases.

  Examples of an apparatus that does not generate plasma during the formation of an electrode film include an electron beam vapor deposition apparatus (EB vapor deposition apparatus) and a pulse laser vapor deposition apparatus. Hereinafter, a method of forming a transparent electrode film using an EB vapor deposition apparatus is referred to as an EB vapor deposition method, and a 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 that can realize a state in which plasma can be reduced during film formation (hereinafter referred to as a plasma-free film formation apparatus), for example, an opposed target sputtering apparatus or an arc plasma deposition method can be considered.

  When a transparent conductive oxide (hereinafter referred to as “TCO”) is an electrode film, a DC short circuit or an increase in leakage current may occur. One reason for this is thought to be that fine cracks introduced into the photoelectric conversion film are covered with a dense film such as TCO, and conduction between the opposite electrode film is increased. For this reason, in the case of an electrode having a poor film quality such as Al, an increase in leakage current hardly occurs. By controlling the film thickness of the electrode film with respect to the film thickness (crack depth) of the photoelectric conversion film, an increase in leakage current can be largely suppressed.

  Usually, when the conductive film is made thinner than a certain range, the resistance value is rapidly increased. However, in the solid-state imaging device of this embodiment, the sheet resistance is preferably 100 to 10000Ω / □, and the film thickness can be reduced. The degree of freedom is large. Further, the thinner the transparent conductive thin film is, the less light is absorbed, and the light transmittance is generally increased. The increase in light transmittance is very preferable because it increases the light absorption in the photoelectric conversion film and increases the photoelectric conversion ability.

  The hole blocking layer is formed by laminating and mixing hole blocking substances alone or two or more kinds. As the hole blocking substance, phenanthroline derivatives such as bathophenanthroline and bathocuproin, silole derivatives, quinolinol derivative metal complexes, oxadiazole derivatives, oxazole derivatives, and the like are used. The compound is not particularly limited as long as it is a compound that can prevent flowing out of the element. The method for forming the hole blocking layer thin film of the organic photoelectric conversion element may be as described below. For the purpose of preventing leakage current, it is better that the film thickness is thin. However, since a sufficient amount of current is required for signal readout at the time of light incidence, the film thickness should be as thin as possible. In general, the power generation layer is preferably about 5 to 500 nm.

  Generally, the organic thin film of the organic photoelectric conversion device is formed by resistance heating vapor deposition which is a vacuum process, electron beam vapor deposition, sputtering, molecular lamination method, casting which is a solution process, spin coating, dip coating, blade coating, wire. Coating methods such as bar coating and spray coating, printing methods such as ink jet printing, screen printing, offset printing and letterpress printing, soft lithography methods such as microcontact printing, and a combination of these methods Can be adopted. The thickness of each layer depends on the resistance value and charge mobility of each substance and cannot be limited, but is selected from 0.5 to 5000 nm. Preferably it is 1-1000 nm, More preferably, it is 5-500 nm.

  Among the organic thin films constituting the organic photoelectric conversion element, one or more thin films such as a photoelectric conversion layer, a hole transport layer, a hole block layer, an electron transport layer, and an electron block layer, which are present between the electrodes, are described above. By including the organic compound represented by the general formula (1), it is possible to obtain an element that efficiently converts even a weak light energy into an electric signal.

(Light sensor, image sensor)
When light is incident from the transparent or translucent electrode side in a state where a voltage is applied between the electrodes or in a state where no voltage is applied, a photocurrent flows, whereby the photoelectric conversion element can be used as an optical sensor. Further, by integrating a plurality of the optical sensors into a module, it can be used as an image sensor including a plurality of photoelectric conversion elements. A module is a device including a plurality of photoelectric conversion elements. The module has a configuration in which a plurality of photoelectric conversion elements are integrated. Modules include image sensors. Here, the optical sensor includes a device such as an infrared light sensor.

  A near-infrared light sensor is a technology that receives light in the infrared region (infrared light), converts it into an electrical signal, takes out necessary information, and applies it, and a device that uses that technology. It has features such as being able to see an object without stimulating human vision and measuring the temperature of an object instantly from a distance without contact. By using an infrared film or an image sensor that is sensitive to the near infrared, it is possible to shoot an image that is different from an image that can be seen with the naked eye.

(Use)
The photoelectric conversion element of the present invention can be applied to the fields of cameras, digital still cameras, infrared cameras, and the like using devices such as an optical sensor using excellent photoelectric conversion performance and near infrared absorption characteristics.
Other applications include digital video cameras, surveillance cameras for the following applications (office buildings, parking lots, financial institutions and unmanned contractors, shopping centers, convenience stores, outlet malls, department stores, pachinko halls, karaoke boxes, game centers, Hospital), various other sensors (TV door phone, personal authentication sensor, factory automation sensor, home robot, industrial robot, piping inspection system), medical sensor (endoscope, fundus camera), video conference system, It can be used for applications such as videophones, mobile phones with cameras, safe driving systems for vehicles (back guide monitors, collision prediction, lane keeping systems), and video game sensors.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated still in detail, this invention is not limited to these examples. In Examples, “part” means “part by mass” unless otherwise specified, and “%” means “% by mass”. Moreover, the reaction temperature described the internal temperature in a reaction system unless there is particular notice.

The structural formulas of various compounds obtained in the synthesis examples were determined by measuring MS (mass spectrometry spectrum) and NMR (nuclear magnetic resonance spectrum) as necessary.
Moreover, unless otherwise specified, the application measurement of the current voltage in an Example was performed using the semiconductor parameter analyzer 4200-SCS (Keithley Instruments company). Irradiation of incident light was performed using PVL-3300 (Asahi Spectrometer) unless otherwise specified. The ionization potential measurement is a value measured using the atmospheric photoelectron spectroscopy AC-3 (registered trademark), unless otherwise specified.

Example 1 Synthesis of Compound (1)

Synthesis of Compound (A-2) Methyl 3-methoxy-2-naphthaenoate (3.02 g, 13.9 mmol) dissolved in dehydrated ethanol (14 mL) was added to hydrazine monohydrate (3.0 mL) under a nitrogen atmosphere. 61.7 mmol) and stirred at 80 ° C. overnight. After completion of the reaction, the solvent was distilled off and the precipitated solid was washed with hexane and filtered to obtain a gray solid (2.71 g, yield 90%).
¹ H NMR (500 MHz, CDCl ₃ ): δ (ppm) 9.06 (s, 1H), 8.77 (s, 1H), 7.91 (d, 1H), 7.75 (d, 1H, J = 8.15 Hz), 7.53 (t, 1H, J = 7.47 Hz), 7.23 (s, 1H), 4.23 (s, 2H), 4.07 (s, 3H). FAB-MS: m / z = 217 [M + H] ⁺

Synthesis of Compound (A-3) A-2 (1.01 g, 4.70 mmol) and 2-hydroxyacetophenone (0.7 mL, 5.81 mmol) were dissolved in dehydrated ethanol (13 mL) and refluxed overnight under a nitrogen atmosphere. I let you. After completion of the reaction, a white solid precipitated by filtration was obtained (1.49 g, yield 96%).
¹ H NMR (500 MHz, CDCl ₃ ): δ (ppm) 12.9 (s, 1H), 11.1 (s, 1H), 8.93 (s, 1H), 7.94 (d, 1H, J = 8.10 Hz), 7.76 (d, 1H, J = 8.20 Hz), 7.55 (ddd, 1H, J = 8.16, 6.94, 1.19 Hz), 7.47 ( dd, 1H, J = 7.95, 1.60 Hz), 7.43 (ddd, 1H, J = 8.09, 6.91, 1.16 Hz), 7.28-7.31 (m, 2H) 7.06 (dd, 1H, J = 8.33, 1.13 Hz), 6.87 (td, 1H, J = 7.57, 1.20 Hz), 4.19 (s, 3H), 2. 40 (s, 3H).
HRMS (FAB): m / z [M + H] + theory _{C 20 H 19 N 2 O 3} , 335.1396; Found, 335.1383.

Synthesis of Compound (A-4) Compound (A-3) (401 mg, 1.20 mmol) was dissolved in tetrahydrofuran (22 mL). To this solution was added lead tetraacetate (674 mg, 1.52 mmol) little by little, and the mixture was stirred at room temperature for 3 hours. After completion of the reaction, the solid precipitated by Kiriyama filtration with silica gel was removed, and the solvent was distilled off, followed by liquid separation with dichloromethane and distilled water. The organic phase was dried, the solvent was distilled off, and purification was performed by column chromatography (normal phase silica gel, ethyl acetate: hexane = 2: 3) to obtain a white solid (311 mg, 85%).
¹ HNMR (500 MHz, CDCl ₃ ): δ (ppm) 8.08 (s, 1H), 7.80 (d, 1H, J = 8.20 Hz), 7.75 (d, 1H, J = 8.25 Hz) ), 7.66 (dd, 1H, J = 7.65, 0.85 Hz), 7.56 (td, 1H, J = 7.50, 1.13 Hz), 7.52 (ddd, 1H, J = 8.22, 7.05, 1.30 Hz), 7.50 (td, 1H, J = 7.50, 1.28 Hz), 7.43 (dd, 1H, J = 7.60, 0.90 Hz) 7.37 (ddd, 1H, J = 8.16, 6.94, 1.19 Hz), 7.18 (s, 1H), 3.80 (s, 3H), 2.51 (s, 3H) .
HRMS (FAB): m / z [M + H] + theory _{C 20 H 17 O 3, 305.1178} ; Found, 305.1166.

Synthesis of Compound (A-5) Compound (A-4) (202 mg, 0.603 mmol) was dissolved in ethanol (10 mL) and acetic acid (2 mL), the solution was heated to 65 ° C., and then ammonium chloride (32.5 mg, 0.608 mmol) and ammonium acetate (296 mg, 3.84 mmol) were added. After stirring at 80 ° C. overnight, the mixture was quenched with a saturated aqueous sodium hydrogen carbonate solution and subjected to liquid separation treatment with dichloromethane and saturated brine. The organic phase was dried over sodium sulfate, the solvent was distilled off, and purification was performed by column chromatography (normal phase silica gel, benzene: hexane = 3: 1) to obtain a blue-violet solid (86.3 mg, yield). 51%).
¹ HNMR (500 MHz, CDCl ₃ ): δ (ppm) 8.40 (s, 2H), 7.98 (d, 2H, J = 8.05 Hz), 7.92 (d, 2H, J = 8.05 Hz) ), 7.85 (d, 2H, J = 8.10 Hz), 7.76 (d, 2H, J = 8.20 Hz), 7.66 (s, 1H), 7.48 (ddd, 2H, J = 8.09, 6.91, 1.16 Hz), 7.39 (ddd, 4H, J = 7.98, 6.95, 1.00 Hz), 7.29 (ddd, 2H, J = 7.91) , 6.94, 0.94 Hz), 7.23 (s, 2H), 3.78 (s, 6H).
HRMS (FAB): m / z [M + H] ⁺ theoretical value C ₃₉ H ₂₉ N ₂ O ₂ , 557.2229; found value, 557.2220.

Synthesis of Compound (A-6) Compound (A-5) (1.60 g, 2.88 mmol) was dissolved in dehydrated toluene (115 mL) under a nitrogen atmosphere, and triethylamine (1.1 mL, 7.94 mmol) was added. Allowed to stir. After heating to 80 ° C., boron trifluoride / diethyl ether complex (3.0 mL, 24.3 mmol) was added dropwise, and the mixture was stirred at 100 ° C. for 9 hours. Distilled water was added for quenching, and liquid separation treatment was performed with dichloromethane and distilled water. The organic phase was dried over sodium sulfate and the solvent was distilled off. Reprecipitation was performed with dichloromethane / hexane to obtain a dark blue solid (1.48 g, yield 85%). The identification data is described as a mixture of cis and trans isomers.
¹ HNMR (500 MHz, DMSO-d ₆ ): δ (ppm) 8.73 (s, 1H), 8.20 (d, 1H, J = 8.35 Hz), 8.20 (d, 1H, J = 8) .20 Hz), 7.98 (s, 1 H), 7.93 (s, 1 H), 7.84 (d, 1 H, J = 9.05 Hz), 7.84 (d, 1 H, J = 7.15 Hz) ), 7.82 (d, 1H, J = 7.10 Hz), 7.77 (d, 1H, J = 8.10 Hz), 7.55-7.59 (2H, m), 7.46-7 .50 (2H, m), 7.48 (s, 1H), 7.44 (s, 1H), 7.29-7.36 (2H, m), 7.32 (1H, d, J = 7) .95 Hz), 7.27 (1H, d, J = 7.20 Hz), 7.27 (2H, t, J = 7.50 Hz), 3.82 (s, 3H), 3.75 (s, 3H) )
HRMS (FAB): m / z [M] ⁺ theoretical value C ₃₉ H ₂₇ BF ₂ N ₂ O ₂ , 604.2134; found value, 604.2129.
Elemental analysis Theoretical value (% by weight) C ₃₉ H ₂₇ BF ₂ N ₂ O ₂ .0.7H ₂ O: C, 75.91; H, 4.64; N, 4.54. Found (wt%): C, 75.91; H, 4.48; N, 4.58.

Synthesis of Compound (1) Compound (A-6) (700.3 mg, 1.159 mmol) was dissolved in dehydrated dichloroethane (115 mL) and stirred at 0 ° C. under a nitrogen atmosphere. Boron tribromide (6.0 mL, 6.0 mmol) was added dropwise to this solution, and stirring was continued for 2 hours. The reaction was then heated to 40 ° C. and allowed to stir overnight. After completion of the reaction, the reaction solution was quenched by adding a saturated aqueous sodium hydrogen carbonate solution while cooling with ice. The aqueous phase was removed, the solvent was distilled off, and the solid precipitated with ethanol was washed, followed by filtration to obtain a dark green solid (611.2 mg, crude yield; 98%). Thereafter, a glossy red solid was obtained through sublimation purification.
Elemental analysis Theoretical value _{(wt%) C 37 H 21 BN 2} O 2 · 0.2H 2 O: C, 82.30; H, 3.99; N, 5.19. Found (wt%): C, 82.18; H, 3.85; N, 5.25.
HRMS (APCI): m / z (M + H) ⁺ theoretical value C ₃₇ H ₂₂ BN ₂ O ₂ , 537.1774; found value 537.1775.

Example 2 Synthesis of Compound (5)

Synthesis of Compound (A-7) Compound (A-2) (4.00 g, 18.5 mmol) and 2-bromo-4-methoxyacetophenone (4.70 g, 21.9 mmol) were mixed with dehydrated ethanol (50 mL) under a nitrogen atmosphere. ) And refluxed overnight. After completion of the reaction, a white solid precipitated by filtration was obtained (7.41 g, yield 97%).
¹ HNMR (500 MHz, CDCl ₃ ): δ (ppm) 13.2 (s, 1H), 11.1 (s, 1H), 8.91 (s, 1H, 7.93 (d, 1H, J = 8) .20 Hz), 7.75 (d, 1H, J = 8.20 Hz), 7.55 (ddd, 1H, J = 8.12, 6.98, 1.16 Hz), 7.44 (ddd, 1H, J = 8.12, 6.97, 1.14 Hz), 7.27 (s, 1H), 7.27 (d, 1H, J = 8.65 Hz, H _j ), 7.22 (d, 1H, J = 2.00 Hz), 6.97 (dd, 1H, J = 8.48, 2.08 Hz), 4.19 (s, 3H), 2.37 (s, 3H).
HRMS (FAB): m / z (M + H) + theoretical _{C 20 H 18 BrN 2 O 3} , 413.0501; Found, 413.0519.

Synthesis of Compound (A-8) Compound (A-7) (501 mg, 1.21 mmol) was dissolved in tetrahydrofuran (24 mL). To this solution was added lead tetraacetate (658 mg, 1.48 mmol) little by little, and the mixture was stirred at room temperature for 3 hours. After completion of the reaction, the solid precipitated by Kiriyama filtration with silica gel was removed, and the solvent was distilled off, followed by liquid separation with dichloromethane and distilled water. The organic phase was dried, the solvent was distilled off, and purification was performed by column chromatography (normal phase silica gel, ethyl acetate: hexane = 2: 3) to obtain a pale yellow solid (400 mg, 86%).
¹ HNMR (500 MHz, CDCl ₃ ): δ (ppm) 8.18 (s, 1H), 7.84 (d, 1H, J = 8.20 Hz), 7.75 (d, 1H, J = 8.10 Hz) ), 7.68 (dd, 1H, J = 8.20, 1.90 Hz), 7.58 (d, 1H, J = 8.20 Hz), 7.53 (1H, ddd, J = 8.22) 6.93, 1.28 Hz), 7.53 (d, 1 H, J = 1.9 Hz), 7.39 (ddd, 1 H, J = 8.17, 6.93, 1.20 Hz), 7.17 (S, 1H), 3.78 (s, 3H), 2.48 (s, 3H).
HRMS (FAB): m / z (M) + theoretical _{C 20 H 15 BrO 3, 382.0205} ; Found, 382.0219.

Synthesis of Compound (A-9) Compound (A-8) (304 mg, 0.794 mmol) was dissolved in ethanol (10 mL) and acetic acid (2 mL), and the solution was heated to 65 ° C., and then ammonium chloride (45.7 mg). , 0.854 mmol) and ammonium acetate (369 mg, 4.79 mmol). After stirring at 80 ° C. for 12 hours, the reaction mixture was quenched with a saturated aqueous sodium hydrogen carbonate solution and subjected to liquid separation treatment with dichloromethane and saturated brine. The organic phase was dried over sodium sulfate, the solvent was distilled off, and purification was performed by column chromatography (normal phase silica gel, benzene: hexane = 3: 1) to obtain a dark purple solid (124 mg, 44% yield). ).
¹ HNMR (500 MHz, CDCl ₃ ): δ (ppm) 8.31 (s, 2H), 8.04 (d, 2H, J = 1.40 Hz), 7.85 (d, 2H, J = 8.10 Hz) ), 7.81 (d, 2H, J = 8.50 Hz), 7.76 (d, 2H, J = 8.10 Hz), 7.56 (s, 1H), 7.50 (ddd, 2H, J = 8.10, 6.95, 1.14 Hz), 7.46 (dd, 2H, J = 8.50, 1.70 Hz), 7.40 (ddd, 2H, J = 8.07, 6.87). , 1.16 Hz), 7.23 (s, 2H), 3.77 (s, 6H).
HRMS (FAB): m / z (M + H) + theoretical _{C 39 H 27 Br 2 N 2} O 2, 713.0439; Found, 713.0405.

Synthesis of Compound (A-10) Compound (A-9) (162 mg, 0.226 mmol) is dissolved in dehydrated toluene (10 mL) under nitrogen atmosphere, and triethylamine (0.1 mL, 0.721 mmol) is added and stirred. It was. After heating to 80 ° C., boron trifluoride diethyl ether complex (0.25 mL, 2.03 mmol) was added dropwise, and the mixture was stirred at 100 ° C. for 5 hours. Distilled water was added to quench, and liquid separation treatment was performed with dichloromethane and saturated saline. The organic phase was dried over sodium sulfate and the solvent was distilled off. The product was washed with methanol, and a blue-violet solid was obtained by filtration (155 mg, yield 90%). The identification data is described as a mixture of cis and trans isomers.
¹ HNMR (500 MHz, DMSO-d ₆ ): δ (ppm) 8.84 (s, 1H), 8.16 (1H, d, J = 8.45 Hz), 8.16 (d, 1H, J = 8) .90 Hz), 7.98 (s, 1H), 7.94 (s, 1H), 7.84 (dd, 2H, J = 8.48, 3.78 Hz), 7.82 (d, 1H, J = 8.95 Hz), 7.77 (d, 1H, J = 7.90 Hz), 7.73 (dd, 1H, J = 8.82, 1.67 Hz), 7.73 (dd, 1H, J = 8.75, 1.40 Hz), 7.48-7.51 (m, 4H), 7.49 (s, 1H), 7.45 (s, 1H), 7.37-7.30 (m, 2H), 3.83 (s, 3H), 3.76 (s, 6H).
HRMS (FAB): m / z (M) ⁺ theoretical value C ₃₉ H ₂₅ BBr ₂ F ₂ N ₂ O ₂ , 760.0344; found value, 760.0307.

Synthesis of Compound (A-11) Compound (A-10) (1.46 g, 1.92 mmol) and phenylboronic acid (0.936 g, 7.68 mmol) were added to tetrahydrofuran (100 mL) and 2M aqueous potassium carbonate solution (23 mL). It was dissolved and freeze-deaerated three times. Pd (PPh ₃ ) ₄ (0.44 g, 0.381 mmol) was added in a glove bag under a nitrogen atmosphere, and the mixture was stirred at 70 ° C. overnight. After completion of the reaction, the reaction solution was quenched by adding distilled water and subjected to liquid separation treatment with dichloromethane. The organic phase was dried over sodium sulfate and the solvent was distilled off. Purification was performed by column chromatography (normal phase silica gel, benzene: hexane = 3: 1), and a deep red-purple solid was obtained by reprecipitation (dichloromethane / methanol) (1.02 g, yield 71%). The identification data is described as a mixture of cis and trans isomers.
¹ HNMR (500 MHz, DMSO-d ₆ ): δ (ppm) 8.82 (s, 1H), 8.31 (d, 1H, J = 8.50 Hz), 8.30 (d, 1H, J = 8) .55 Hz), 8.03 (s, 1 H), 7.9 (s, 1 H), 7.92 (dd, 2 H, J = 8.52, 1.47 Hz), 7.85 (d, 1 H, J = 8.35 Hz), 7.85 (d, 1H, J = 7.90 Hz), 7.84 (d, 1H, J = 8.15 Hz), 7.79 (d, 1H, J = 8.10 Hz) 7.65 (dd, 4H, J = 7.38, 1.28 Hz), 7.47-7.51 (m, 4H), 7.51 (s, 1H), 7.47 (s, 1H) , 7.43 (t, 1H, J = 7.67 Hz), 7.42 (t, 1H, J = 7.62 Hz), 7.30-7.37 (m, 4H), 3.85 ( , 3H), 3.78 (s, 3H).
FAB-MS: m / z = 756 (M) ⁺
Elemental analysis Theoretical value _{(wt%) C 51 H 35 BF 2} N 2 O 2: C, 80.96; H, 4.66; N, 3.70. Found (wt%): C, 80.85; H, 4.66; N, 3.69.

Synthesis of Compound (5) Compound (A-11) (701 mg, 0.927 mmol) was dissolved in dehydrated dichloroethane (92 mL) and stirred at 0 ° C. under a nitrogen atmosphere. Boron tribromide (5.0 mL, 5.0 mmol) was added dropwise to this solution, and stirring was continued for 2 hours. The reaction was then heated to 40 ° C. and allowed to stir overnight. After completion of the reaction, the reaction solution was quenched by adding a saturated aqueous sodium hydrogen carbonate solution while cooling with ice. The aqueous phase was removed, the solvent was distilled off, the solid precipitated with methanol was washed, and then a green solid was quantitatively obtained by filtration (665 mg). Then, a glossy green solid was obtained through sublimation purification.
FAB-MS: m / z = 688 (M) ⁺ .

(Example 3) Preparation and evaluation of thin film using compound (1) The compound (1) obtained in Example 1 was subjected to resistance heating vacuum deposition to a film thickness of 100 nm on a glass substrate previously washed, and the resulting organic The absorption spectrum was measured about the thin film. The obtained absorption spectrum is shown in FIG. As a result, the absorption maximum of the main absorption band in the thin film state of compound (1) was observed at 785 nm. The ionization potential was 5.3 eV.

(Example 4) Preparation and evaluation of thin film using compound (5) Compound (5) obtained in Example 2 was vacuum-deposited with resistance heating to a film thickness of 80 nm on a glass substrate previously washed, and the resulting organic The absorption spectrum was measured about the thin film. The obtained absorption spectrum is shown in FIG. As a result, the absorption maximum of the main absorption band in the thin film state of compound (2) was observed at 788 nm. The ionization potential was 5.3 eV.

(Comparative Synthesis Example 1) Synthesis of Comparative Compound B

Synthesis of Compound (A-13) Compound (A-12) (5.01 g, 30.1 mmol) and 2-hydroxyacetophenone (4.5 mL, 37.4 mmol) were dissolved in dehydrated ethanol (80 mL) under a nitrogen atmosphere. Refluxed overnight. After completion of the reaction, a white solid compound (A-13) precipitated by filtration was obtained (5.80 g, yield 68%).
¹ HNMR (500 MHz, CDCl ₃ ): δ (ppm) 12.9 (s, 1H), 11.0 (s, 1H), 8.36 (dd, 1H, J = 7.80, 1.80 Hz), 7.53 (ddd, 1H, J = 8.34, 7.26, 1.79 Hz), 7.47 (dd, 1H, J = 7.97, 1.58 Hz), 7.29 (td, 1H, J = 7.70, 1.50 Hz), 7.17 (td, 1H, J = 7.56, 0.88 Hz, H _d ), 7.05 (dd, 1H, J = 8.33, 1.13 Hz) ), 7.05 (dd, 1H, J = 8.23, 1.35 Hz), 6.87 (td, 1H, J = 7.59, 1.23 Hz), 4.10 (s, 3H), 2 .39 (s, 3H). FAB-MS: m / z = 285 (M + H) ⁺ .

Synthesis of Compound (A-14) Compound (A-13) (3.01 g, 10.6 mmol) was dissolved in tetrahydrofuran (190 mL). To this solution was added ice tetraacetate (5.72 g, 12.9 mmol) little by little, and the mixture was stirred at room temperature for 2 hours. After completion of the reaction, the solid precipitated by Kiriyama filtration with silica gel was removed, and the solvent was distilled off, followed by liquid separation with dichloromethane and distilled water. The organic phase was dried, and the solvent was distilled off to obtain a pale yellow solid compound (A-14) (2.61 g, yield 97%).
¹ HNMR (500 MHz, CDCl ₃ ): δ (ppm) 7.65-7.68 (m, 2H), 7.47-7.54 (m, 3H), 7.37 (dd, 1H, J = 6) .98, 1.78 Hz), 7.03 (td, 1H, J = 7.58, 0.95 Hz), 6.94 (d, 1H, J = 8.25 Hz), 3.64 (s, 3H) , 2.49 (s, 3H).
FAB-MS: m / z = 255 (M + H) ⁺ .

Synthesis of Compound (A-15) Compound (A-14) (1.00 g, 3.95 mmol) was dissolved in ethanol (55 mL) and acetic acid (11 mL), and the solution was heated to 65 ° C., and then ammonium chloride (216 mg). 4.03 mmol) and ammonium acetate (1.95 g, 25.4 mmol). After stirring at 80 ° C. overnight, the reaction mixture was quenched with saturated aqueous sodium hydrogen carbonate and subjected to liquid separation treatment with dichloromethane and saturated brine. The organic phase is dried over sodium sulfate, the solvent is distilled off, and the residue is purified by column chromatography (normal phase silica gel, dichloromethane: hexane = 1: 1) to give a bright dark green solid compound (A-15) (458 mg, 51% yield) was obtained.
¹ HNMR (500 MHz, CDCl ₃ ): δ (ppm) 7.94 (dd, 2H, J = 7.48, 1.53 Hz), 7.93 (d, 2H, J = 7.95 Hz), 7.84 (D, 2H, J = 8.15 Hz), 7.61 (s, 1H), 7.38 (td, 2H, J = 7.82, 1.35 Hz), 7.35 (t, 2H, J = 7.43 Hz), 7.24 (t, 2H, J = 7.58 Hz), 7.11 (td, 2H, J = 7.32, 0.70 Hz), 7.04 (d, 2H, J = 8) .25 Hz), 3.77 (s, 6H).
FAB-MS: m / z = 456 (M) ⁺ .

Synthesis of Compound (A-16) In a nitrogen atmosphere, Compound (A-15) (1.01 g, 2.21 mmol) was dissolved in dehydrated toluene (88 mL), and triethylamine (0.8 mL, 5.77 mmol) was added. Allowed to stir. After heating to 80 ° C., boron trifluoride diethyl ether complex (2.5 mL, 20.3 mmol) was added dropwise and allowed to stir at 100 ° C. for 3 hours. Distilled water was added for quenching, and liquid separation treatment was performed with dichloromethane and distilled water. The organic phase was dried over sodium sulfate and the solvent was distilled off. The obtained solid was washed with methanol, and a blue-violet solid compound (A-16) was obtained by filtration (1.10 g, yield 99%).
¹ HNMR (500 MHz, DMSO-d ₆ ): δ (ppm) 8.65 (s, 1H), 8.16 (d, 1H, J = 8.20 Hz), 8.15 (d, 1H, J = 8) 20 Hz), 7.54 (t, 2H, J = 7.37 Hz), 7.48 (td, 2H, J = 7.91, 1.63 Hz), 7.45 (d, 1H, J = 7. 60 Hz), 7.38 (d, 1H, J = 7.15 Hz), 7.29 (d, 1H, J = 8.10 Hz), 7.26 (d, 1H, J = 6.85 Hz) 7.28 (T, 1H, J = 8.15 Hz), 7.25 (t, 1H, J = 7.43 Hz), 7.20 (d, 1H, J = 8.25 Hz), 7.17 (d, 1H, J = 8.25 Hz), 7.07 (td, 1H, J = 7.50, 0.75 Hz), 7.01 (td, 1H, J = 7.49, 0.72) z), 3.72 (s, 6H), 3.66 (s, 6H).
FAB-MS: m / z = 504 (M) ⁺ .
Elemental analysis Theoretical value _{(wt%) C 31 H 23 BF 2} N 2 O 2: C, 73.83; H, 4.60; N, 5.55. Found (wt%): C, 73.54; H, 4.63; N, 5.55.

Synthesis of Comparative Compound (B) Compound (A-16) (700 mg, 1.39 mmol) was dissolved in dehydrated dichloroethane (138 mL) and stirred at 0 ° C. under a nitrogen atmosphere. Boron tribromide (7.0 mL, 7.0 mmol) was added dropwise to this solution, and stirring was continued for 2 hours. The reaction was then heated to 40 ° C. and allowed to stir overnight. After completion of the reaction, the reaction was quenched by adding saturated aqueous sodium bicarbonate while cooling with ice. The aqueous phase was removed, the solvent was distilled off, and the solid precipitated with methanol was washed, followed by filtration to obtain a blue-green solid (515 mg, crude yield 85%). Then, a glossy green solid was obtained through sublimation purification.
APCI-MS: m / z = 436 (M) ⁺ .

(Comparative example 1) Preparation and evaluation of thin film using comparative compound B Resistance compound was vacuum-deposited to a film thickness of 80 nm on a glass substrate previously washed with comparative compound B, and the absorption spectrum of the obtained organic thin film was measured. The obtained absorption spectrum is shown in FIG. As a result, the absorption maximum of the main absorption band in the thin film state of Comparative Compound B was observed at 757 nm. The ionization potential was 5.1 eV.

  Compared with Comparative Compound B shown in Comparative Example 1, the thin film using the dibenzopyromethene boron chelate compound of the present invention absorbs light in the near infrared region more efficiently and stabilizes HOMO energy. It can be confirmed that it has been achieved.

(Example 5) Production of photoelectric conversion element and evaluation thereof As a photoelectric conversion layer on ITO transparent conductive glass (manufactured by Geomat Co., Ltd., ITO film thickness 150 nm), compound (1) was vacuum-heated by resistance heating, and the film thickness was 100 nm. A film was formed. On top of that, aluminum was resistively heated and vacuum-deposited as an electrode to form a film having a thickness of 100 nm, thereby producing the photoelectric conversion element of the present invention. When the photocurrent response was measured when a voltage of 1 V was applied in a state where light irradiation with 800 nm and a half-value width of 20 nm was performed using ITO and aluminum as electrodes, the current in the dark was 8.49 × 10 ^{−. 9} a / cm ^2, the current in the light is ^{3.77 × 10 -6 a / cm 2} , the contrast ratio was 4.4 × 10 ^2. The photocurrent response of the obtained photoelectric conversion element is shown in FIG.

(Example 6) Production of photoelectric conversion element and evaluation thereof As a photoelectric conversion layer on ITO transparent conductive glass (manufactured by Geomatic Co., Ltd., ITO film thickness 150 nm), compound (5) was vacuum-heated by resistance heating, and the film thickness was 100 nm. A film was formed. On top of that, aluminum was resistively heated and vacuum-deposited as an electrode to form a film having a thickness of 100 nm, thereby producing the photoelectric conversion element of the present invention. When photocurrent response was measured when a voltage of 1 V was applied in a state where light irradiation with 800 nm and a half width of 20 nm was performed using ITO and aluminum as electrodes, the current in the dark was 1.09 × 10 ^{−. 9} A / cm ² , the current in the light place was 5.34 × 10 ⁻⁷ A / cm ² , and the light / dark ratio was 4.9 × 10 ² . FIG. 6 shows the photocurrent response of the obtained photoelectric conversion element.

(Comparative Example 2) Production of photoelectric conversion element and its evaluation Comparative compound B was vacuum heated by resistance heating as a photoelectric conversion layer on ITO transparent conductive glass (manufactured by Geomat Co., Ltd., ITO film thickness 150 nm) to a film thickness of 80 nm. A film was formed. On top of that, aluminum was resistively heated and vacuum-deposited as an electrode, and a film having a thickness of 100 nm was formed to produce a comparative photoelectric conversion element. When photocurrent response was measured when a voltage of 0.05 V was applied with ITO and aluminum being used as electrodes and irradiating with light of 775 nm and a half width of 20 nm, the current in the dark was 5.18 ×. 10 ⁻⁸ A / cm ² , the current in the light place was 9.47 × 10 ⁻⁷ A / cm ² , and the light / dark ratio was 18. The photocurrent response characteristic of the obtained photoelectric conversion element is shown in FIG. Further, when the photocurrent response when a voltage of 1 V was applied was measured, the current in the dark was 8.15 × 10 ⁻⁶ A / cm ² and the current in the bright was 1.42 × 10 6. ^{It was −5} A / cm ² and the light / dark ratio was 1.7.

  The photoelectric conversion element using the comparative compound B shown in Comparative Example 2 has a strong dark current leakage in the absence of light irradiation and a very poor contrast ratio, whereas the dibenzopyromethene boron chelate compound of the present invention. It can be confirmed that the photoelectric conversion element using the above has excellent photoelectric conversion characteristics since a three-digit light / dark ratio is obtained.

  The dibenzopyromethene boron chelate compound of the present invention has good near-infrared absorption characteristics and heat resistance that can be deposited, and exhibits excellent near-infrared photoelectric conversion characteristics, so that it is useful as an organic electronics device material.

1 Insulating part 2 Upper electrode 3 Electron blocking layer or hole transporting layer 4 Photoelectric conversion part 5 Hole blocking layer or electron transporting layer 6 Lower electrode 7 Insulating substrate, or other photoelectric conversion element

Claims (8)

A dibenzopyromethene boron chelate compound represented by the following general formula (1).

(Z ¹ in formula (1) represents an unsubstituted or substituted naphthalene ring. R _{1 to} R ₈ each independently represents a hydrogen atom, an aryl group, a heteroaryl group, an alkyl group, a cycloalkyl group, or a halogen atom. Hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group, substituted amino group, amide group, acyl group, carboxyl group, acyloxy group, cyano group, sulfo group, sulfamoyl group, alkylsulfamoyl group, carbamoyl group, Represents an alkylcarbamoyl group.) A dibenzopyromethene boron chelate compound represented by the following general formula (2).

(R _{1 to} R ₂₀ in formula (2) are each independently a hydrogen atom, aryl group, heteroaryl group, alkyl group, cycloalkyl group, halogen atom, hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group. A substituted amino group, an amide group, an acyl group, a carboxyl group, an acyloxy group, a cyano group, a sulfo group, a sulfamoyl group, an alkylsulfamoyl group, a carbamoyl group, and an alkylcarbamoyl group. A dibenzopyromethene boron chelate compound represented by the following general formula (3).

(R ₂ and R _{7 in} formula (3) are each independently a hydrogen atom, aryl group, heteroaryl group, alkyl group, cycloalkyl group, halogen atom, hydroxy group, alkoxy group, mercapto group, alkylthio group, nitro group. A substituted amino group, an amide group, an acyl group, a carboxyl group, an acyloxy group, a cyano group, a sulfo group, a sulfamoyl group, an alkylsulfamoyl group, a carbamoyl group, and an alkylcarbamoyl group.   The near-infrared absorption pigment | dye containing the dibenzopyromethene boron chelate compound as described in any one of Claims 1-3.   The thin film containing the dibenzopyromethene boron chelate compound as described in any one of Claims 1-3.   The photoelectric conversion element containing the dibenzopyromethene boron chelate compound as described in any one of Claims 1-3, the near-infrared absorption dye of Claim 4, or the thin film of Claim 5.   A near-infrared light sensor comprising the photoelectric conversion element according to claim 6. An imaging device comprising the photoelectric conversion device according to claim 6.

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