JP2001131185A - Boron compounds - Google Patents

Abstract

PROBLEM TO BE SOLVED: To increase the degree of freedom in the material design, for example, the selectivity of ligands and selectivity of metals more than in the case of conventional organometallic complex. SOLUTION: Boron is allowed to react with ligands of an organic compound to form a complex. This compound and a metallic element different from boron or a halogen element are used to produce a salt of the metallic element and the halogen atom. As necessary, a polymer bearing a prescribed recurring units, a polymer substance of high molecular weight or a gigantic molecular-weight body can be produced. Thus, materials having the ligands of different nurnbers can be synthesized and a plurality of different kinds of metals and halogens form the salts whereby the effect of the mutual actions between the metals and the organic ligands can be controlled more broadly and the degree of freeness can be rapidly increased in the material designs.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a novel boron compound suitably used for various organic films.

[0002]

2. Description of the Related Art In recent years, attempts to realize a new functional element through thinning of organic molecules have become active. For example, research on organic EL (electrochloroluminescence) elements formed by vapor deposition and other optical elements has been conducted. It is becoming active. Among the organic molecules used in such an organic thin film device, an organic metal complex emits fluorescence in a solid state and has an excellent charge transporting ability, so that an organic EL device, an organic photoreceptor for electrophotography, and an organic solar cell are used. Are widely applied to photovoltaic elements and the like. Specifically, an organic EL device, a solar cell, and the like using an aluminum quinolinolyl complex represented by the following general formula [4] are reported.

[0003]

Embedded image

In the above-mentioned organic thin film element, not only the charge transporting ability at the time of thin film formation but also film forming property, stability after film formation and heat resistance are required. Further, when used as a light emitting material of an organic EL element, light emitting ability is required. Since the emission color and the charge transport ability are greatly influenced by the central metal or the ligand, the selection of the central metal or the ligand is very important in designing a molecule.

However, the metal complex represented by the aluminum metal complex represented by the general formula [4] described above often has a fixed coordination number, and the degree of freedom in molecular design is limited. And hindered the development of new materials.

The conventional metal complex represented by the general formula [4] is coordinated to one kind of central metal.

[Problems to be solved by the invention]

As described above, conventional organometallic complexes are not good charge-transporting materials and luminescent materials due to the limited number of ligands. An object of the present invention is to improve the selectivity of a ligand by using boron as a central metal, improve the degree of freedom in material design by allowing coordination with another metal, and improve a suitable material. It is to develop.

[Means for Solving the Problems]

[0008] The present invention made to achieve the above object is a novel boron compound represented by the above general formulas [1] to [3].

That is, the boron compound of the present invention comprises a complex formed with an organic compound of boron as shown in the general formula [1] and one or more different metal elements or molecules, ions, cations, atoms, It has a structure that forms a salt with a polymer.

Alternatively, it takes a structure represented by the general formula [2], has boron as a central metal, and forms a complex with an organic compound.

Alternatively, the complex represented by the general formula [3] may be formed to form a complex formed with boron and an organic compound and a salt formed with one or more negative ions, atoms, molecules, anions or polymers. .

In some cases, it exists as a multimer, a high molecular weight, or a macromolecule having a part of at least one of the general formulas [1] to [3] and having a certain repeating unit.

By using the boron compound of the present invention, materials having different numbers of ligands as shown by the general formulas [1] to [3] can be synthesized, and a plurality of different kinds of metals or The effect of the interaction between the metal and the organic ligand to form a complex with ions, molecules, atoms, and a polymer can be controlled more widely, and the degree of freedom in material design can be greatly improved.

In the boron compound of the present invention, the ligands of R _{1 to} R ₄ represented by the general formulas [1] to [3] interact with the central metal to form a charge (hole or electron). Take a structure that can be involved in giving and receiving. The ligand is an unsubstituted or substituted alkyl group having 1 to 150 carbon atoms having at least one conjugation in a part of the molecular structure, an unsubstituted or substituted aryl group having 6 to 150 carbon atoms, an unsubstituted or substituted heterocyclic group. Or a silicon compound. The ligand is preferably
Unsubstituted or substituted saturated alkyl groups such as methane, ethane, propane and butane having 1 to 150 carbon atoms, and 1 to 15 carbon atoms such as ethylene, propene, butene and acetylene.
0 unsubstituted or substituted unsaturated alkyl groups, cyclopentane, cyclobutane, cyclopentane, cyclohexane,
Cyclic hydrocarbons such as cycloheptane, quinolinol, and quinolinol derivatives such as methylquinolinol, sulfoquinolinol, dichloroquinolinol, difluoroquinolinol, diiodoquinolinol, dibromoquinolinol, thiooxin, selenooxin, dihydroxyazobenzene, trihydroxyazobenzene, and mordanto blue 31, eriochrome red B, super chrome garnet Y, phenol azonaphthol, etc., exemplified azo compounds, morin, flavonol, fustin, trihydroxyflavorane, flavonoid derivatives such as quercetin, salicylidene-o-aminophenol, 2-
Hydroxy-5-sulfoaniline-N-salicylidene,
Amino compounds such as 2-hydroxy-5-methylbenzaldehyde-thiosemicarbazone, azomethine compounds represented by 2-hydroxy-5-chlorobenzaldehyde-thiosemicarbazone, diaminonaphthalene, phenylenediamine, diaminonaphthalene, and diaminobenzidine; Cationic dyes such as rhodamine B, rhodamine 3B, rhodamine S, acridine red, thiobromine and braviosin; anionic dyes such as fluorescein, eosin and erythrosine; anthraquinones such as aminohydroxyanthraquinone, quinizarin, tetrahydroxyanthraquinone, diaminonitroanthraquinone and derivatives thereof , Salicylic acid, benzothiazole, nitronaphthylamine, benzene, naphthalene, anthracene,
Perylene, cyclopentadiene, benzyne, thiadiazole, pyridazine, piperazine, pyrrolidine, pyrazoline, oxazole, triazole, furan, pyran,
Dioxane, pyrimidine, triazine, pyrrodiline,
Dioxolan, thiazole, morpholine, pyrazine,
Trithiane, norborane, benzofuran, benzimidazole, tinoline, fluorene, phenanthroline, adamantane, indole, indene, benzothiazole, isoquinoline, quinoxaline, dibenzofuran, phenanthrene, phenanthiazine, pyrene, thionaphthalene, purine, coumarin, azulene, carbazole, Flavones, pyrroles, benzopyridines, aziridines, pyrarols, imidazoles, oxadiazoles, acridines, quinolines, benzoquinolinols, acridines, phenanthrenes, thiophenes, bithiophenes, dietes, phenylene vinylenes, helicenes and the like, and derivatives thereof. By selecting these ligands and coordination numbers, it is possible to control electronic properties, optical properties, and light-emitting properties, so that it becomes very easy to select desired material properties. For example, if a ligand having a strong electron donating property is coordinated with the ligand, a molecule having a hole transporting ability can be obtained.

The boron compound according to the present invention contains, in its structure, a metal other than boron or a molecule, atom, ion,
The polymer M may be included. Preferably, the organic compound of boron and M have a bond, and more preferably take an electrical bond. The organic compound of boron and the metal M are not necessarily 1: 1.
The connection is not limited to the one-to-many, the one-to-many, the plurality-to-one, or the many-to-many. Specifically, Li, Na,
Alkali metals such as K and Rb, Be, Mg, Ca, Sr,
Alkaline earth metals such as Ba and Ra, C, Si, Al,
Typical elements exemplified by Zn, Mn, Fe, Cd, Cu,
Transition elements exemplified by Au, Ag, Sn, Ge, etc.,
Lanthanoids represented by Eu, Tb, etc., ammonia, aniline, ethylamine, diethylamine, diphenylamine, diphenylguanine, amines such as tetramethylguanidine, triethanolamine, triethylamine, tributylamine, piperidine, pyridine,
Butylamine and the like.

The boron compound in the present invention is an atom or a molecule of a mono- or polyvalent anion represented by Ri in the structure, and specifically, a halogen element such as F, Cl, Br, I, formic acid , Acetic acid, nitric acid and other monovalent negative ions, oxalic acid, adipic acid, phthalic acid and other divalent acids such as dicarboxylic acid and sulfuric acid, 1,3,5-tricarboxylic acid, phosphoric acid, etc. It is a typical trivalent negative ion. Amino acids, etc.

As a method for forming the organic thin film of the boron compound of the present invention, a usual film forming method such as a spin coating method, a casting method, a vapor deposition method, an LB method, a water surface spreading method, and an electric field method can be adopted. . Among them, the vapor deposition method is simple and suitable for forming a laminate of organic thin films, and is particularly preferable. The thickness of such an organic thin film is appropriately set depending on the characteristics of a device to be usually formed, and can be appropriately selected from 0.1 nm to 10 micrometers.

Further, when forming an organic thin film,
A polymer material can be added for the purpose of stabilizing the film. However, the content can be appropriately adjusted as long as the properties inherent in the boron compound of the present invention are exhibited.

Further, for the purpose of assisting the intrinsic properties of the boron compound of the present invention, an additive can be added. However, in this case, the content is preferably 50% or less for the purpose of not impairing the performance of the boron compound of the present invention.

Further, the boron compound of the present invention can be added to and contained in a low molecular weight material for the purpose of assisting the intrinsic properties of the boron compound of the present invention. However, in this case, the content is preferably 50% or less for the purpose of not impairing the performance of the boron compound of the present invention.

When an organic thin film device is prepared by using the boron compound of the present invention, an organic thin film formed by the above-mentioned film forming method can be basically used as a single layer. Alternatively, an element having an advanced composite function can be realized by laminating composite material thin films. Hereinafter, the structure and operation principle of an organic thin-film element prepared using the boron compound of the present invention will be briefly described. Organic EL device

An organic thin film having a two-layer structure of a light emitting layer containing a fluorescent dye and a hole transporting layer or an electron transporting layer, or a three-layered structure having a light emitting layer between the hole transporting layer and the electron transporting layer or a multilayer structure of more layers. It is characterized in that the laminated structure has a structure in which at least one is sandwiched between two electrodes which are transparent electrodes. In each case, electrons and holes are injected into the light-emitting layer and recombine to emit light. The electron transport layer and the hole transport layer have a function of increasing the injection efficiency and the recombination efficiency. Fluorescent material

Luminescence is generated by various external stimuli such as light, heat, electric field, and electrons. Here,
Fluorescent materials have both fluorescent and phosphorescent meanings. It may be used as a pure substance, or may be used as a mixture with a solvent or a solid. Solar cell

A two-layer structure in which a charge generation layer containing a dye that absorbs light to generate electrons and holes is laminated with a hole transport layer or an electron transport layer, or between a hole transport layer and an electron transport layer. It has a three-layer structure in which charge generation layers are stacked or a stacked structure of three or more layers. The organic layer is characterized in that it has a structure in which at least one of these organic layers is sandwiched between two electrodes that are transparent enough to transmit light. In either case, charge separation occurs and a photoelectric conversion effect occurs. Photoelectric conversion element

A laminated structure in which an organic layer containing a dye that absorbs light and generates photoelectrons is sandwiched between electrodes and the like. It is characterized in that at least one of the electrodes has a structure sandwiched between two electrodes which are transparent enough to transmit light. Organic photoreceptor for electrophotography

A two-layer structure is provided in which a charge generation layer containing a dye that absorbs light to generate electrons and holes and a charge transport layer that transports holes or electrons are stacked on a metal or a conductive substance. An electric charge is uniformly applied to the surface by corona discharge, and a part of the electric charge is released onto the conductive material by photoconductivity resulting from the image exposure to form a charge latent image on the surface. Next, a toner having an opposite charge is sprayed and adsorbed on the latent image portion to perform development.
This is transferred to paper and heated and fixed to obtain an image. Nonlinear optical element

There are cases where a thin film on a substrate or a single thin film is used alone, but a multilayer film in which two or more layers are laminated, or a thin film in which two or more kinds of substances are alternately arranged in the light propagation direction, Alternatively, by irradiating a strong light such as a laser beam to a thin film in which substances having different processing states are arranged with the same substance, polarization proportional to the second or third power of the light intensity or higher order is generated. A harmonic that is twice, three times or more the angular frequency of the incident light is obtained. It can also be applied to optical modulators, electro-optical elements, photorefractive elements, and the like. Optical amplifier

A structure in which one or more organic thin films having at least one layer containing a dye responding to incident light are laminated. The organic layer takes a structure sandwiched between electrodes or mirrors. However, one may be transparent. As the mirror, a translucent or Bragg mirror may be used in some cases. This is an element that amplifies incident light energy by using energy such as electricity or light.

[0029]

EXAMPLES Examples of the present invention are described below in Examples 1 and 2, which are synthesis examples of the present invention. Examples 3 and 4 show examples in which an organic EL device was prepared using the boron compound of the present invention. Example 1 (synthesis)

Lithium borohydride was reacted with 8-quinolinol. A substance precipitated by the reaction was filtered. The collected material was purified by the Soxhlet reflux method to obtain a boron compound represented by the following structural formula [5]. FIG. 1 shows a proton NMR spectrum. FIG. 2 shows carbon NMR.

[0031]

Embedded image Example 2 (synthesis)

Lithium borohydride was reacted with 2-methyl 8-quinolinol. A substance precipitated by the reaction was filtered. The collected material was purified by the Soxhlet reflux method to obtain a boron compound represented by the following structural formula [6]. FIG. 3 shows a proton NMR spectrum. FIG. 4 shows carbon NMR.

[0033]

Embedded image Example 3 (organic EL device)

On the ITO glass, as a hole transport layer, a triphenylamine derivative represented by the following structural formula [7] and a polyvinyl carbazole represented by the following structural formula [8]:
One solution was spin-coated, and a boron compound represented by the structural formula [5] was vacuum-deposited as an electron transport layer and a light-emitting layer to prepare a two-layer element. The thickness of each layer is 50 nm, 60 nm
It is. Thereafter, fifteen electrodes each having an area of 0.13 cm ^{2 made} of an alloy of magnesium and silver (volume ratio of 10: 1) were formed on the organic thin film, thereby forming an organic EL device of this example.

[0035]

Embedded image

[0036]

Embedded image Example 4 (organic EL element)

Instead of using the boron derivative represented by the structural formula [5], an organic EL device using the boron derivative represented by the structural formula [6] was also prepared. All the devices emitted blue light and had high luminance, high efficiency, and long life.

As described in detail above, according to the boron compound of the present invention, a good device can be produced. In addition, the degree of freedom in molecular design is very high, and the range of material selection is widened. Therefore, if the boron compound of the present invention is used, it is possible to prepare an element corresponding to many uses, and there is a very large industrial value.

[Brief description of the drawings]

FIG. 1 shows a proton NMR spectrum of a boron compound represented by a structural formula [4].

FIG. 2 is a diagram showing a carbon NMR spectrum of a boron compound represented by a structural formula [4].

FIG. 3 shows a proton NMR spectrum of the boron compound represented by the structural formula [5].

FIG. 4 is a diagram showing a carbon NMR spectrum of a boron compound represented by a structural formula [5].

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Toodoro 3-3-1202, Tenjincho, Fuchu-shi, Tokyo Room (72) Hironori Suzuki 5-2-2 Mikawa, Mito-shi, Ibaraki F-term (Reference) 3K007 AB00 AB02 AB03 AB04 CA01 CB01 DA00 DB03 EB00 FA01 4H048 AA01 AB92 AB99 VA20 VA32 VA50 VA51 VA75 VB10

Claims (4)

[Claims] 1. A tetra-ligand compound of boron represented by the following general formula [1]. Embedded image In the formula, B is boron, and R _{1 to} R ₄ may be the same or different, and at least one is an organic compound having a conjugation such as σ or π. M is a metal, or a molecule, an atom,
Ions and cations. n and m are integers. 2. A three-ligand compound of boron, which is represented by the following general formula [2]. Embedded image In the formula, B is boron, and R _{1 to} R ₃ may be the same or different, and at least one is an organic compound having a conjugation such as σ or π. Dotted lines indicate coordination. 3. A two-coordinate compound of boron, represented by the following general formula [3]. Embedded image In the formula, B is boron, and R _{1 and} R ₂ may be the same or different, and at least one is an organic compound having a conjugation such as σ or π. n and m are integers. Ri is
An atom or molecule, an ion, or an anion. Dotted lines indicate coordination. 4. A multimer, high molecular weight polymer, copolymer or macromolecule having at least a part of the structure represented by any one of the general formulas [1] to [3] as a skeleton.