JP2002105090A - Reactive phosphine oxides and semiconductor ultrafine particles having the same as a ligand - Google Patents

Abstract

PROBLEM TO BE SOLVED: To obtain new semiconductor ultrafine particles having a light absorbing and emitting ability and a high refractive index controlled by quantum effects. SOLUTION: The phosphine oxides are obtained by binding a radically reactive group. The semiconductor ultrafine particles have the phosphine oxides as a ligand.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to ultrafine semiconductor particles having a radical-reactive phosphine oxide bonded thereto.
The semiconductor ultrafine particles of the present invention have a controlled absorption / emission ability by a quantum effect and a high refractive index. Therefore, it can be used, for example, in the form of a resin composition in which it is dispersed, as a light refraction member such as an optical waveguide, an optical lens or an optical prism, or as a raw material for a luminous body such as a display or a lighting fixture.

[0002]

2. Description of the Related Art An amorphous thermoplastic resin represented by a styrene resin, an acrylic resin, or an aromatic polycarbonate resin, or a curable resin such as an unsaturated polyester resin or diallyl phthalate resin has a good wavelength in the visible region. High transparency, and low specific gravity, moldability and mass productivity, or toughness, flexibility,
It is a general-purpose transparent resin material having excellent characteristics such as excellent balance of mechanical properties such as impact resistance. When a high refractive index is imparted to such a transparent resin material, it becomes useful as a material for, for example, a thin and lightweight optical lens, a prism, or a core portion of an optical waveguide.

As means for increasing the refractive index of a transparent resin material, a monomer containing an element having a large atomic number such as bromine or sulfur has conventionally been used. For example, T. Ok
Ubo et al .; Mater. Sci. , 34, 337
Page (1999) shows 2,5-bis (mercaptomethyl)
A high refractive index polymer material using -1,4-dithiane as a high refractive index monomer has been reported. However, there are only drawbacks such as lack of light stability due to chemical reactivity possessed by elements such as halogen and sulfur, and environmental pollution which is a source of dioxins especially when a halogen element such as bromine is used. In addition, there is a problem that the industrial application field is extremely limited due to the use of such non-general-purpose special monomers, and styrene resins such as polystyrene and acrylic resins such as polymethyl methacrylate (commonly known as PMMA). There is a strong demand for a technique for increasing the refractive index using a transparent resin made of a general-purpose radical polymerizable monomer such as a resin.

In general-purpose resins containing a hydrophilic structure (carbonyl group, ester bond, carbonate bond) in the molecular structure, such as an acrylic resin or an aromatic polycarbonate resin, water absorption may be a problem. . As a new application utilizing the characteristics of the general-purpose transparent resin material as an optical material, there is a polymer optical fiber (hereinafter abbreviated as POF) using an amorphous thermoplastic resin such as an acrylic resin. The core part (the center part in the optical fiber cross section) of the POF needs to have a higher refractive index than the clad part (the outer peripheral part), and the larger the difference in the refractive index, the larger the aperture corresponding to the maximum angle at which light can propagate. The number (NA) can be increased, which is advantageous from the viewpoint of suppressing optical loss due to bending of the POF and performance degradation due to optical coupling. However, conventionally, if an attempt is made to use a general-purpose amorphous thermoplastic resin such as an acrylic resin such as PMMA or an aromatic polycarbonate resin such as bisphenol A polycarbonate as the clad material,
Since there was practically no general-purpose amorphous thermoplastic resin material that can be used in combination with these as a high refractive index core material (usually a refractive index difference from the cladding is 0.1 or more), A material having a low refractive index by blending an expensive fluororesin or the like has to be used.

On the other hand, a high refractive index material such as a semiconductor or a metal is dispersed or dissolved in an amorphous matrix as particles smaller than the wavelength of light (practically, near ultraviolet to visible region) to form a high refractive index transparent material. The method of obtaining has long been known with lead glass or the like. Red glass in which cadmium selenide (CdSe) is dissolved is used as a color filter. As a related art related to an amorphous resin material, for example, European Patent No. 922245 (1999)
Discloses a material in which ultra-fine particles of CdSe are dispersed in poly (4-vinylpyridine) at 10% by volume, and a technique utilizing the coordination force of pyridine residues in the polymer molecule to the surface of a CdSe crystal is disclosed. For this reason, it has been difficult to use the general-purpose amorphous resin as a matrix resin.

Similarly, a technique for dispersing semiconductor ultrafine particles in a polymer matrix by utilizing the coordination force of a polymer having a pyridine residue in a molecule is disclosed in S. K. W. Haggata et al. For example, a material in which CdSe and zinc selenide (ZnSe) ultrafine particles are dispersed by about 31% by weight and 25% by weight, respectively, is S.S. W. Haggata et al .;
J. Mater. Chem. , 7, p. 1969 (19
97), cadmium sulfide (CdS) and zinc sulfide (Z
nS) A material in which ultrafine particles are dispersed by about 25% by weight and 18% by weight, respectively. W. Haggata et al .; Ma
ter. Chem. 6, Volume 1771 (1996), respectively. However, the upper limit of the addition amount of the semiconductor ultrafine particles is not limited to the above-mentioned level, and the effect of increasing the refractive index is not satisfactory, and the use of the above-mentioned general-purpose amorphous resin as a matrix is not possible. Technology was also difficult.

Further, C.I. Becker et al; SPIE, 3
469, 88 (1998) discloses a material in which ultrafine silica particles surface-treated with a silane coupling agent are dispersed at 10% by volume in a PMMA matrix, but the effect of increasing the refractive index is not satisfactory. Was. Recently J. L
ee et al; Adv. Mater. , Vol. 12, p. 1102 (2000), a luminescent material in which ultrafine CdSe / ZnS core / shell particles coordinated with trioctylphosphine (abbreviated as TOPO) are dispersed in polylauryl methacrylate (abbreviated as PLMA) resin. Have been. Phosphine oxides such as TOPO are used in semiconductor nanocrystals as ligands having excellent coordination ability and chemical stability. However, this technology uses TOPO having a relatively long alkyl chain having 8 carbon atoms. PLM having a side chain having 12 carbon atoms
A is based on the compatibility with a specific resin matrix A, and it has been difficult even with this technique to use a general-purpose amorphous resin such as PMMA or polystyrene as the matrix.

[0008]

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and an object of the present invention is to provide a phosphine oxide to which a radical reactive group is bonded and a semiconductor to which the phosphine oxide is bonded as a ligand. There are two points in providing ultrafine particles.

[0009]

Means for Solving the Problems In order to achieve the above object, the present inventors have synthesized a phosphine oxide having a radical reactive group bonded thereto, and used such a phosphine oxide as a ligand for semiconductor ultrafine particles. As a result of intensive studies on, it has been found that, in particular, a compound in which a radical polymerizable group such as a methacryloyl group is ester-bonded to a phosphine oxide having a hydroxyl group terminal can be very suitably obtained, and the present invention has been reached. .

That is, a first gist of the present invention resides in phosphine oxides having a radical reactive group bonded thereto. A second gist of the present invention resides in semiconductor ultrafine particles containing the phosphine oxides as a ligand.

[0011]

DESCRIPTION OF THE PREFERRED EMBODIMENTS [Phosphine oxides bonded to radical-reactive groups] The semiconductor ultrafine particles of the present invention are mainly composed of semiconductor crystals described later, and have phosphines bonded to radical-reactive groups on their surfaces. It binds oxides as essential ligands.

The structure of the radical reactive group bonded to the phosphine oxides is not limited, and examples thereof include a carbon-carbon double bond, a carbon-carbon triple bond, and a cyclopropane ring. Radical reactive groups suitable for the purpose of the present invention are structures having radical polymerizability, for example, an acryloyl group, a methacryloyl group, or a carbon-carbon double bond conjugated to a carbonyl group such as a crotonoyl group, a propargylcarbonyl group A carbon-carbon triple bond conjugated to two carbonyl groups such as a maleoyl residue and a fumaroyl residue at both ends; a 4-vinylbenzyl group;
Carbon-carbon double bond conjugated with an aromatic ring such as vinylbenzyl group, vinylnaphthylmethyl group, vinylpyridylmethyl group, carbon-carbon triple bond conjugated with an aromatic ring such as propargylphenyl group, propargylnaphthyl group, propargylpyridyl group Bonding, a structure in which a vinyl group such as a vinyloxycarbonyl group, a vinyloxy group, or a vinylamino group is bonded to an atom having a high electronegativity, and a structure in which an allyl group such as an allyloxy group or an allylamino group is bonded to an atom having a high electronegativity. No. Among them, preferred from the viewpoint of radical polymerizability are a carbon-carbon double bond conjugated to a carbonyl group such as an acryloyl group and a methacryloyl group, and a carbon-carbon double bond conjugated at both ends to two carbonyl groups such as a maleoyl residue. A carbon-carbon double bond conjugated to an aromatic ring such as a heavy bond, a vinylbenzyl group, a structure in which a vinyl group such as a vinyloxycarbonyl group or a vinyloxy group is bonded to an atom having a high electronegativity, and an allyl group such as an allyloxy group. It has a structure bonded to an atom having a high electronegativity, and among them, a carbon-carbon double bond conjugated to a carbonyl group such as an acryloyl group, a methacryloyl group, and a maleoyl residue is most preferable.

As a preferred structure of a phosphine oxide having a radical reactive group bonded thereto, the following general formula (2) is exemplified.

[0014]

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In the general formula (2), R ^rad is a radical selected from any of an acryloyl group, a methacryloyl group, a maleoyl group, and a vinylphenyl group (for example, a 4-vinylphenyl group and a 3-vinylphenyl group). R ¹ and R ^{2 each} independently represent an alkyl group, an acyl group, an aryl group having 10 or less carbon atoms or the aforementioned R ^rad , and L represents a carbon atom attached to a phosphorus atom of a phosphine oxide group (O = P). An aliphatic group having 2 to 16 carbon atoms bonded by an atom (where L represents an oxygen-containing bond such as an ether bond, an ester bond, a carbonate bond, a ketone bond, or an amide bond, a urethane bond, a urea bond, etc.) Nitrogen-containing bonds, etc.
A non-aromatic bond containing any heteroatom may be contained).

The phosphine represented by the general formula (2)
R in the structure of the oxides¹And R^TwoIs R^radBoombox
Semiconductor ultrafine particles of the present invention as long as the reactivity is not impaired.
Which contributes to the improvement of compatibility when
Preferably R^{ra d}Similar radical reactive groups
Need not be. However, in the general formula (2),
And R¹And R^TwoAs R^radRadical reactivity
The use of groups is a radically polymerizable,
Solubility and ease of synthesis of phosphine oxides
Sometimes it is always preferred.

Examples of general structures used for R ¹ and R ² in the general formula (2) include a methyl group, an ethyl group,
n-propyl group, n-butyl group, n-hexyl group, n-
Linear alkyl groups such as octyl group and n-decyl group; branched alkyl groups such as isopropyl group, isobutyl group, tert-butyl group and isohexyl group; cyclic alkyl groups such as cyclopentyl group and cyclohexyl group; and aryl groups such as benzyl group. Alkyl group, unsaturated group such as vinyl group or allyl group, formyl group, acetyl group, propionyl group,
Aromatic acyl groups such as butyryl group, valeryl group, hexanoyl group, octanoyl group, decanoyl group, isobutyryl group, pivaloyl group, isovaleryl group, etc., benzoyl group, isophthaloyl group, terephthaloyl group, salicyloyl group, etc. , Phenyl group,
And an aryl group such as a naphthyl group and a pyridyl group. The preferred structure among these varies as described above depending on the chemical structure of the matrix resin used in the formation of the resin composition in the future, but when it is desired to increase the semiconductor crystal content in the resin composition, the R ¹ and R ^{1 2} is preferably not larger chemical structure than necessary as long as having a compatibility with the resin to the matrix. In this sense, preferred structures of R ¹ and R ² include a methyl group, an ethyl group, an n-propyl group,
linear alkyl groups such as n-butyl group, isopropyl group, isobutyl group, branched alkyl group such as tert-butyl group,
An alkyl group having an aryl group such as a benzyl group bonded thereto, an aliphatic acyl group such as a formyl group, an acetyl group, a propionyl group, and a butyryl group, and an aromatic acyl group such as a benzoyl group, among which a methyl group, an ethyl group, and an n- Propyl group, n-
A linear alkyl group such as a butyl group, an alkyl group having an aryl group such as a benzyl group bonded thereto, an aliphatic acyl group such as an acetyl group, and the like are more preferable. Particularly, the acetyl group can be introduced very easily by acetylation with acetic anhydride. Optimal because of its small chemical structure.

In the general formula (2), L represents 1 carbon atom.
Although it may contain from 6 to 6 branched side chains, it is preferably linear. If the carbon number of L is less than 2, R
The mobility of the ^rad- bonded molecular chain may be extremely reduced, and the distance between the phosphine oxide group, which is a coordinating functional group, and the molecular terminal is short. The other effect as a ligand for protecting the compound may also be reduced. Conversely, if L has more than 16 carbon atoms, the R ^rad may be buried in such an aliphatic structure and its radical reactivity may be extremely reduced. The carbon number of the L is preferably 2 to 14, more preferably 3 to 12, and most preferably 3 to 10.

Preferred examples of L include a straight-chain methylene chain having 2 to 16 carbon atoms, an oxyalkylene group having an oxygen atom bonded to the end of the straight-chain methylene chain having 2 to 16 carbon atoms, and the following general formula (3) ), An n-propylene group bonded to a polybutylene glycol chain represented by the following general formula (4), and a polypropane represented by the following general formula (5). Acid chains and the like.

[0020]

## STR3 ## _{- (CH 2) 3 -O- (} CH 2 CH 2 O) x -T (3) - (CH 2) 3 -O- (CH 2 CH 2 CH 2 CH 2 O) y -T ( _{4) - (CH 2 CH 2} COO) z -T (5) is T where in the general formula (3) to (5) represents one of R ^1, R ^2, and R ^rad in the general formula (2) , X is an integer of 0 to 6, y is an integer of 0 to 3, z is 1
Represents an integer of 5 to 5, respectively.

L in the general formula (3) or (4) is 3-
L can be constructed by ring-opening polymerization of ethylene oxide or tetrahydrofuran starting from a hydroxypropyl group, and L in the above general formula (5) can be obtained by utilizing the Michael addition reaction of acrylic acid, acrylate or acrylonitrile. Can be built. Preferred examples of the structure of the general formula (2) include the following general formula (1).

[0022]

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However, R ¹ , R ² and R ^rad in the general formula (1) are all the same as those in the general formula (2). As a particularly preferred structure of the general formula (1), a molecular structure represented by the following formula (6), in which R ¹ , R ² and R ^rad are all acryloyl groups or methacryloyl groups, is exemplified.

[0024]

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In the formula (6), A represents a hydrogen atom or a methyl group. In addition, those having one or two alkyl chains represented by the following general formula (7) or (8) are also suitably used as the phosphine oxide to which the radical reactive group of the present invention is bonded.

[0026]

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[0027]

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However, R ¹ in the general formula (7) or (8)
Or, R ^rad is the same as in the case of the general formula (1), and R represents an alkyl group having 12 or less carbon atoms. The R is preferably a methyl group, an ethyl group, an n-propyl group, an n-butyl group,
A linear group having 8 or less carbon atoms such as an n-hexyl group and an n-octyl group, more preferably a methyl group, an ethyl group,
It is a straight-chained one having 6 or less carbon atoms such as a butyl group or an n-hexyl group, and most preferably a straight-chained one having 4 or less carbon atoms such as a methyl group, an ethyl group, or an n-butyl group. Two Rs in the general formula (8) may be the same or different from each other.

[Method for synthesizing phosphine oxides of the present invention] A method for synthesizing the phosphine oxides of the general formula (1) will be described as an example. Such phosphine oxides can be obtained by alkylating a hydroxyl group of tris (3-hydroxypropyl) phosphine oxide (hereinafter abbreviated as HPPO, for example, a compound supplied by Nippon Chemical Industry Co., Ltd. under the trade name Hishicolin PO-500), acylation, Or arylation. Among these, a preferable synthesis method in terms of ease of synthesis is alkylation or acylation of the hydroxyl group, and acylation is most preferable.

For example, the above-mentioned acylation is carried out by acetic anhydride, acrylic anhydride, methacrylic anhydride, maleic anhydride,
Benzoic anhydride, or acid anhydrides such as mixed anhydrides obtained from these acid anhydrides and any carboxylic acid, acetyl chloride, butyryl chloride, benzoyl chloride, acryloyl chloride, methacryloyl chloride,
An acylating agent such as an acid halide such as crotonoyl chloride is converted to an HP under the presence of an organic base such as pyridine (which may be suitably used as a solvent) or triethylamine or an inorganic base such as potassium carbonate or potassium hydroxide.
A method of condensing with a hydroxyl group of PO, a method of converting HPPO with a carboxylic acid ester such as ethyl acrylate or methyl methacrylate and a suitable transesterification catalyst (for example, a strong acid such as sulfuric acid or p-toluenesulfonic acid, a strongly acidic ion exchange resin, tetrabutyl ortho A method of transesterification in the presence of a Lewis acid such as titanate, a method of converting HPPO with a carboxylic acid (excess amount) such as acrylic acid or methacrylic acid and a suitable acid catalyst (for example, sulfuric acid or p
-A strong acid such as toluenesulfonic acid) by the Fischer method or the like to obtain the corresponding ester by heating and dehydration. The preferred method among these is for HPPO,
It is a method of condensing acid anhydrides such as acetic anhydride, acrylic anhydride, methacrylic anhydride and maleic anhydride in a pyridine solvent. The point is that a target compound having a usable purity can be obtained.

For example, in the above alkylation, an alkyl halide such as methyl iodide, ethyl iodide, benzyl bromide or 4-vinylbenzyl chloride is added to an appropriate base (for example, sodium hydroxide, water). The condensation is carried out in the presence of an inorganic base such as potassium oxide, potassium carbonate or sodium hydride, or an organic base such as pyridine, triethylamine or 9-BBN.

In any of the reactions, N, N-dimethylformamide (commonly known as DMF), N, N
Amide-based aprotic solvents such as -dimethylacetamide and N-methylpyrrolidone, or dimethylsulfoxide (commonly referred to as DMSO) are preferably used. DMF and DMSO are more preferred, and DMF is optimal in that it can be removed by distillation. In addition, water may be added to the solvent as long as the reaction of acylating or alkylating HPPO to a hydroxyl group is not extremely inhibited.

In the general formula (1), when R ¹ , R ² , and R ^rad have different structures, the equivalents of a plurality of corresponding reagents are controlled and used in the acylation or alkylation reaction. There is a need. In this case, purification may be performed after the reaction of each reagent, or purification may be performed at the end by reacting each reagent without particular purification. When multiple acylation or alkylation reagents are allowed to act, HPPO
Although the desired reaction does not necessarily proceed selectively to the three hydroxyl groups, the phosphine oxide mixture produced by the reaction is preferably used as long as the object of the present invention is finally achieved in the production of the resin composition of the present invention. It may be used as it is as a ligand of the semiconductor ultrafine particles of the present invention without going through a separation / purification step by chromatography or the like.

That is, for example, R ¹ and R ² are acetyl groups,
R ^rad is intended to be a methacryloyl group, and one equivalent of HP
First, 1/3 equivalent of methacrylic anhydride was allowed to act on PO in a solvent containing a large excess of pyridine, and then 2/3 equivalent of acetic anhydride was allowed to act on the reaction solution. There is a possibility that a compound in which one or two groups are bonded or a small amount of a compound in which three methacryloyl groups in which A is a methyl group in the formula (2) is mixed is formed. The mixture of phosphine oxides obtained by concentrating such a reaction solution under reduced pressure is used as a ligand for semiconductor ultrafine particles as described later without separating and purifying the mixture, and thus obtained semiconductor ultrafine particles of the present invention are obtained by the above resin composition. It is often the case that the object of the present invention can be achieved as a result of using the material as a raw material.

The phosphine oxide represented by the general formula (7) or (8) is obtained by using, as a raw material, a phosphine oxide obtained by substituting one or two 3-hydroxypropyl groups of HPPO with R. And are similarly synthesized. In order to prevent an undesired radical reaction from proceeding to the synthesis reaction of the phosphine oxides of the present invention, an optional radical scavenger such as methylhydroquinone or 2,6-di-tert-butyl-4-methylphenol may be added. Alternatively, the reaction may be shielded from light.

[Semiconductor Ultrafine Particles] The semiconductor ultrafine particles of the present invention are mainly composed of a semiconductor crystal as described later, and are bonded with a phosphine oxide having a radical reactive group bonded thereto as a ligand. Therefore, it is desirable that the semiconductor ultrafine particles of the present invention also have radical reactivity.

The semiconductor crystal may be a semiconductor single crystal, a mixed crystal in which a plurality of semiconductor crystal compositions are phase-separated, or a mixed semiconductor crystal in which phase separation is not observed, and may have a core-shell structure described later. . The particle size of such a semiconductor crystal is usually 0.5 to 20 nm as a weight average particle size, and preferably 1 to 1 in terms of electromagnetic characteristics such as light absorption and light emission.
5 nm, more preferably 2 to 12 nm, and most preferably 2 to 10 nm. The light absorption and emission characteristics of the semiconductor crystal due to the quantum effect are controlled by the particle size, which can usually be determined by observation with a transmission electron microscope (TEM). When the atomic number of the element contained in the semiconductor crystal is small and it is difficult to obtain a contrast by an electron beam, it can be estimated by observation with an atomic force microscope (AFM) or by light scattering or neutron scattering measurement in a solution.

Although there is no limitation on the particle size distribution of the semiconductor crystal,
In the case of utilizing the light emission characteristics due to the quantum effect of a semiconductor crystal,
By changing the distribution, the required emission wavelength width can be changed. In the case where the wavelength width needs to be narrowed, the particle size distribution is narrowed, but the standard deviation is usually within ± 40%, preferably within ± 30%, more preferably within ± 20%, and most preferably. Is within ± 10%. In the case of a particle size distribution exceeding the standard deviation range, it is difficult to sufficiently achieve the purpose of narrowing the emission band wavelength width due to the quantum effect.

The semiconductor ultrafine particles of the present invention are formed by the quantum effect.
Absorption and emission may have non-linearity.
It is also useful as a nonlinear optical material. [Composition of semiconductor crystal]
Although the semiconductor crystal composition is not particularly limited,
And those having a high refractive index are desirable in application. Ingredient
Examples of physical compositions include carbon, silicon, germanium,
Simple substance of element of group 14 of the periodic table such as tin, phosphorus (black phosphorus)
Periodic Table of the Periodic Elements of Group 15 Elements, Selenium, Tellurium, etc.
A simple substance of group 16 elements, and a plurality of elements such as silicon carbide (SiC)
A compound composed of an element of Group 14 of the periodic table, tin (IV) oxide (S
nO_Two), Tin sulfide (II, IV) (Sn (II) Sn (IV) S_Three),
Tin (IV) sulfide (SnS_Two), Tin (II) sulfide (SnS),
Tin (II) selenide (SnSe), Tin (II) telluride (S
nTe), lead (II) sulfide (PbS), lead (II) selenide
(PbSe), lead (II) telluride (PbTe), etc.
Compound of group 14 element and periodic table group 16 element, nitriding
Boron (BN), boron phosphide (BP), boron arsenide
(BAs), Aluminum nitride (AlN), Al phosphide
Minium (AlP), aluminum arsenide (AlAs),
Aluminum antimonide (AlSb), gallium nitride
(GaN), gallium phosphide (GaP), gallium arsenide
(GaAs), gallium antimonide (GaSb), nitrogen
Indium phosphide (InN), Indium phosphide (InN)
P), indium arsenide (InAs), indium antimonide
Group 13 elements such as indium (InSb) and Periodic Table
Compounds with Group 15 elements (or III-V compounds)
Body), aluminum sulfide (Al_TwoS_Three), Aluminum selenide
Ni (Al_TwoSe_Three), Gallium sulfide (Ga_TwoS_Three),
Gallium lenide (Ga _TwoSe_Three), Gallium telluride (G
a_TwoTe_Three), Indium oxide (In)_TwoO_Three), Sulfide
Um (In_TwoS_Three), Indium selenide (In)_TwoS
e_Three), Indium telluride (In)_TwoTe_Three) And other periodic tables
Compounds of Group 13 elements and Group 16 elements of the periodic table;
Lithium (I) (TlCl), thallium (I) bromide (Tl
Br), thallium (I) iodide (TlI), etc.
Compound of group 13 element and group 17 element of the periodic table, zinc oxide
(ZnO), zinc sulfide (ZnS), zinc selenide (Zn
Se), zinc telluride (ZnTe), cadmium oxide
(CdO), cadmium sulfide (CdS), cadmium selenide
CdSe, Cadmium Telluride (CdT)
e), mercury sulfide (HgS), mercury selenide (HgS)
e), mercury telluride (HgTe), etc.
Compound of element and element of group 16 of the periodic table (or group II-VI
Compound semiconductor), arsenic sulfide (III) (As_TwoS_Three), Sele
Arsenic (III) (As_TwoSe_Three), Arsenic (III) telluride
(As_TwoTe_Three), Antimony (III) sulfide (Sb
_TwoS_Three), Antimony (III) selenide (Sb_TwoSe_Three),
Antimony (III) telluride (Sb _TwoTe_Three), Bis sulfide
Trout (III) (Bi_TwoS_Three), Bismuth (III) selenide
(Bi _TwoSe_Three), Bismuth (III) telluride (Bi)_TwoTe
_Three) And other elements of the Periodic Table Group 16 and the Periodic Table Group 16
Compound, copper (I) oxide (Cu_TwoO), copper (I) selenide
(Cu_TwoSe) and other elements of Periodic Table 11 and Periodic Table 16
Compounds with group III elements, copper (I) chloride (CuCl), copper bromide
(I) (CuBr), copper (I) iodide (CuI), chloride
Periodic Table 11 of silver (AgCl), silver bromide (AgBr), etc.
Compound of group 17 element and group 17 element of the periodic table, nickel oxide
(II) Periodic Table Group 10 elements such as (NiO) and Periodic Table 1
Compounds with Group 6 elements, cobalt (II) oxide (CoO),
Group 9 elements of the periodic table such as cobalt (II) sulfide (CoS)
Compounds with Group 16 elements of the periodic table, triiron tetroxide (Fe
_ThreeO_Four), Periodic table group 8 elements such as iron (II) (FeS)
Of manganese with Group 16 element of the periodic table, manganese oxide (II)
(MnO) and other Group 7 elements of the Periodic Table and Group 16 elements
With molybdenum (IV) sulfide (MoS_Two), Oxidation
Tungsten (IV) (WO_Two) And other elements of Group 6 of the periodic table
Compound with Group 16 element of the periodic table, vanadium (II) oxide
(VO), vanadium (IV) oxide (VO_Two), Tan oxide
Tal (V) (Ta_TwoO_Five) And other periodic table elements
Compounds with Group 16 elements, titanium oxide (TiO 2_Two, Ti_Two
O_Five, Ti_TwoO_Three, Ti_FiveO₉And other elements of the Periodic Table 4
Compound with Group 16 element of the periodic table, magnesium sulfide (M
gS), periodic table of magnesium selenide (MgSe), etc.
Compound of group 2 element and group 16 element of the periodic table, cadmium oxide
Medium (II) Chromium (III) (CdCr_TwoO_Four),selenium
Cadmium (II) chromium (III) (CdCr_TwoS
e_Four), Copper (II) chromium (III) (CuCr)_TwoS_Four),
Mercury (II) selenide chromium (III) (HgCr_TwoSe_Four)
Such as chalcogen spinels, barium titanate (Ba)
TiO_Three) And the like. G. Schmid
Adv. Mater. , 4, p. 494 (199
Reported in 1) (BN)₇₅(BF_Two)_FifteenF_FifteenAnd
D. Fenske et al .; Angew. Chem. Int.
Ed. Engl. 29, 1452 (1990).
Reported Cu₁₄₆Se₇₃(Triethyl phosphite
N)_{twenty two}Semiconductor cluster with a fixed structure like
Are similarly exemplified.

Among these, those having a high refractive index and practically important suitable for a method for producing semiconductor ultrafine particles to be described later can be represented by a composition formula, for example, SnS ₂ , SnS, SnSe, S
14th Periodic Table of nTe, PbS, PbSe, PbTe, etc.
Compounds of Group 16 elements and Group 16 elements of the periodic table, GaN, Ga
P, GaAs, GaSb, InN, InP, InAs,
III-V compound semiconductors such as InSb, Ga ₂ O ₃ , Ga ₂
S ₃ , Ga ₂ Se ₃ , Ga ₂ Te ₃ , In ₂ O ₃ , In ₂ S ₃ ,
Compounds of Group 13 elements of the periodic table and elements of Group 16 of the periodic table, such as In ₂ Se ₃ and In ₂ Te ₃ , ZnO, ZnS, ZnS
e, ZnTe, CdO, CdS, CdSe, CdTe,
HgO, HgS, HgSe, II- VI group compound such as HgTe _{semiconductor, As 2 O 3, As 2} S 3, As 2 Se 3, As 2 T
_{e 3, Sb 2 O 3,} Sb 2 S 3, Sb 2 Se 3, Sb 2 Te 3,
A compound of a Group 15 element of the Periodic Table and a Group 16 element of the Periodic Table, such as Bi ₂ O ₃ , Bi ₂ S ₃ , Bi ₂ Se ₃ , and Bi ₂ Te ₃ , Mg
It is a compound of an element of Group 2 of the periodic table such as S or MgSe and an element of Group 16 of the periodic table. Among them, GaN, GaP, In
N, InP, Ga ₂ O ₃ , Ga ₂ S ₃ , In ₂ O ₃ , In
_{Since 2} S ₃ , ZnO, ZnS, CdO, CdS, etc. do not contain highly toxic negative elements, they are preferable in terms of environmental pollution resistance and safety to living organisms. In this respect, ZnO and ZnS are more preferable, and a high refractive index is used. Zn in terms of safety, economy of raw materials, etc.
S is most preferred. Further, CdSe and ZnSe are important in terms of stable luminous ability.

The semiconductor crystal, which is the main component of the semiconductor ultrafine particles of the present invention, is, for example, A.I. R. Kortan et al .; Am.
Chem. Soc. 112, 1327 (199
0) or US Pat. No. 5,985,173 (199).
As reported in 9), if a so-called core-shell structure composed of an inner core and an outer shell is used for the purpose of improving the light emission characteristics of the semiconductor crystal, the quantum effect of the semiconductor crystal forming the core is increased. In some cases, the luminescent ability of the resin composition of the present invention is improved, and thus the resin composition of the present invention may be suitable for use in applications utilizing such luminescent ability. In this case, a semiconductor crystal structure having a larger band gap energy than the semiconductor crystal structure of the core is used as a shell, so that energy loss via a surface level or a crystal lattice defect level that attenuates the luminous efficiency of the core crystal is achieved. In some cases can be prevented. The semiconductor crystal structure suitably used for such a shell has a bandgap in a bulk state of 2.0 eV or more at a temperature of 300 K, such as boron nitride (BN), depending on the bandgap energy of the core semiconductor crystal. Boron arsenide (BA
s), gallium nitride (GaN) and gallium phosphide (Ga)
P) and other compounds of the periodic table group 13 elements and the periodic table group 15 elements (III-V compound semiconductors), zinc oxide (Zn)
O), zinc sulfide (ZnS), zinc selenide (ZnS)
e), zinc telluride (ZnTe), cadmium oxide (C
dO), cadmium sulfide (CdS) and other compounds of the Periodic Table Group 12 and Group 16 elements (II-VI compound semiconductors), magnesium sulfide (MgS), and magnesium selenide (MgSe). A compound of a Group 2 element of the Table and a Group 16 element of the Periodic Table is preferably used. Among these, the semiconductor crystal composition that is a more preferable shell is B
Group III-V compound semiconductors such as N, BAs, GaN, Zn
The bandgap of a bulk state of a II-VI compound semiconductor such as O, ZnS, ZnSe, and CdS, and a compound of a periodic table group 16 element and a periodic table group 16 element such as MgS and MgSe at a temperature of 300 K is 2. 3 eV or more, most preferably BN, BAs, GaN, Zn
The band gap of a bulk state of O, ZnS, ZnSe, MgS, MgSe, etc. is 2.5 eV or more at a temperature of 300K.

Any of the semiconductor crystal compositions exemplified above may include, for example, Al, Mn, Cu, Zn, A as a small amount of a doping material (meaning the intentionally added impurity) as necessary.
Elements such as g, Cl, Ce, Eu, Tb, and Er may be added. The addition of such a doping substance may greatly improve the light emitting characteristics of the semiconductor crystal. Examples of semiconductor crystal seeds that exhibit a favorable effect by the addition of such a doping substance include ZnO and ZnS, and ZnS is particularly preferable in this respect. A particularly preferred doping system is ZnS doped with Mn ²⁺ as described in the aforementioned US Pat. No. 5,985,173.

The semiconductor ultrafine particles of the present invention mainly composed of a semiconductor crystal exhibiting a photoelectric effect may be used as a solar cell material used for photovoltaic power generation. [Auxiliary Organic Ligand] The semiconductor ultrafine particles of the present invention use an organic component other than the phosphine oxides having the above-mentioned radical reactive group bonded to the surface of the semiconductor crystal as an auxiliary organic ligand or the like. It may be bonded or adsorbed / held. Such an auxiliary organic ligand, for example, when using the semiconductor ultrafine particles of the present invention as a resin composition raw material,
It is desirable to have an organic structure compatible with the matrix resin.

Coordination functional groups in such auxiliary organic ligands
And usually a functional group containing a Group 15 or 16 element of the periodic table
Group. As a specific example, a primary amino group (—N
H_Two) A secondary amino group (-NHR; wherein R is a methyl group,
Carbon such as ethyl group, propyl group, butyl group and phenyl group
A hydrocarbon group of the number 6 or less; the same applies hereinafter), tertiary amino
Group (-NR¹R^Two; However, R¹And R^TwoIs independently a methyl group,
Carbon number of tyl group, propyl group, butyl group, phenyl group, etc.
6 or less; the same applies to the following), a nitrile group,
A functional group having a nitrogen-containing multiple bond such as an isocyanate group,
Nitrogen-containing nitrogen-containing aromatic rings such as pyridine and triazine rings
Functional group, primary phosphine group (-PH_Two) Secondary phosph
Infin group (-PHR), Tertiary phosphine group (-PR
¹R^Two) Primary phosphine oxide group (-PH_Two= O),
Secondary phosphine oxide group (-PHR = O), tertiary phosphine
Fin oxide group (-PR¹R^Two= 0) primary phosphine
Selenide group (-PH_Two= Se) Secondary phosphine seleni
Group (-PHR = Se), tertiary phosphine selenide group
(-PR¹R^Two= Periodic table of phosphorus-containing functional groups such as Se)
Functional group containing group 15 element, hydroxyl group (-OH), methyl
Ruether group (-OCH_Three), Phenyl ether group (-
OC₆H_Five), Carboxyl group (-COOH)
Functional group, mercapto group (also called thiol group; -S
H), a methylsulfide group (-SCH_Three), Ethylsul
Fido group (-SCH_TwoCH_Three), Phenyl sulfide group
(-SC₆H_Five), Methyl disulfide group (—S—S—C
H_Three), A phenyl disulfide group (—S—S—C
₆H_Five), Thioacid group (—COSH), dithioacid group (—CS
SH), xanthate group, xanthate group, isothio
Cyanate group, thiocarbamate group, thiophene ring, etc.
Sulfur-containing functional groups, similarly -SeH, -SeCH _Three, -S
eC₆H_FiveSelenium-containing functional groups such as -TeH, -T
eCH_Three, -TeC₆H_FivePeriod of tellurium-containing functional groups such as
Examples include functional groups containing Group 16 elements. this
Among them, nitrogen is preferably used such as a pyridine ring.
Containing functional group, tertiary phosphine group, tertiary phosphineoxy
And tertiary phosphine selenide groups and other phosphorus-containing functional groups
Functional groups containing elements of group 15 of the periodic table, mercapto
Periodic Table of Sulfur-Containing Functional Groups such as Groups and Methyl Sulfides
A functional group containing a Group 16 element,
Phosphorus-containing functionalities such as fin groups and tertiary phosphine oxide groups
Group or a sulfur-containing functional group such as a mercapto group
It is preferably used.

Although the specific coordination chemical structure of an organic ligand for a semiconductor crystal typified by a nanocrystal has not been sufficiently elucidated, the surface of the semiconductor ultrafine particles used in the present invention has the above-described ligand. The functional group does not necessarily have to keep the same structure. For example, in the case of a mercapto group (SH), a structure in which a covalent bond is formed with a metal element M (for example, zinc or cadmium in a II-VI compound semiconductor, gallium or indium in a III-V compound semiconductor) existing at the terminal of a semiconductor crystal. (For example, a structure of SM), and in the case of a phosphine oxide group (P = O), a structure in which a covalent bond with a metal element M is formed (for example, P
-OM) can be considered.

[Manufacturing Method of Semiconductor Crystal] The semiconductor crystal may be formed by an arbitrary method such as a conventional semiconductor crystal manufacturing method described below. (A) High vacuum process such as molecular beam epitaxy or CVD. By this method, high-purity semiconductor ultrafine particles whose composition is highly controlled can be obtained, but toxic gases such as phosphine and arsine may be used as raw materials, and expensive production equipment is required. There are restrictions on the above usage. (B) A method in which a raw material aqueous solution is present as reverse micelles in a nonpolar organic solvent and crystals are grown in the reverse micelle phase (hereinafter referred to as reverse micelle method). S. Zou
Int. J. Quant. Chem. , 72, 4
39 (1999). A well-known reverse micelle stabilization technique can be used in a general-purpose reactor, relatively inexpensive and chemically stable salts can be used as raw materials, and the reaction is performed at a relatively low temperature that does not exceed the boiling point of water. It is a suitable method for production. However, the light emission characteristics may be inferior to those of the following hot soap method. (C) A method of injecting a thermally decomposable raw material into a high-temperature liquid-phase organic medium to grow crystals (hereinafter referred to as a hot soap method). B. This is a method reported in a document by Murray et al. As compared with the reverse micelle method, a semiconductor crystal having excellent particle size distribution and purity can be obtained, and the product has excellent light emission characteristics and is generally soluble in an organic solvent. For the purpose of desirably controlling the reaction rate in the process of crystal growth in the liquid phase in the hot soap method, a coordinating organic compound having a coordinating power suitable for a semiconductor constituent element is selected as a liquid phase component.
Examples of such coordinating organic compounds include trialkyl phosphines such as tributyl phosphine, trihexyl phosphine and trioctyl phosphine, and trialkyl phosphines such as tributyl phosphine oxide, trihexyl phosphine oxide, trioctyl phosphine oxide and tridecyl phosphine oxide. Examples thereof include phosphine oxides, ω-aminoalkanes such as octylamine, decylamine, dodecylamine, tetradecylamine, hexadecylamine, and octadecylamine, and dialkyl sulfoxides such as dimethyl sulfoxide and dibutyl sulfoxide. Among them, trialkyl phosphine oxides such as tributyl phosphine oxide and trioctyl phosphine oxide, and ω- having 12 or more carbon atoms such as dodecylamine, hexadecylamine and octadecylamine.
Aminoalkanes and the like are preferable, and among them, trialkylphosphine oxides such as trioctylphosphine oxide and ω having 16 or more carbon atoms such as hexadecylamine are preferable.
-Aminoalkanes are optimal. (D) A solution reaction involving semiconductor crystal growth similar to the hot soap method described above, but a method in which an acid-base reaction is performed at a relatively low temperature as a driving force has been known for a long time (for example, PA Jackson). J. Cryst. Growth
h, 3-4, 395 (1968)). Recently, Diaz et al .; Phys. Chem. B, 103
Vol., Page 9854 (1999) illustrates the synthesis of cadmium sulfide (CdS) nanocrystals using cadmium (II) carboxylate and sodium sulfide as raw materials and dimethyl sulfoxide (DMSO) as a solvent.

In the preferred liquid phase production methods exemplified in the above (b) to (d), a batch method in which a fixed amount of raw material is charged in a fixed volume reactor, or a liquid phase is prepared in a tubular reactor by a predetermined method. The method can be applied to any flow method in which raw materials are continuously supplied while flowing at a constant speed to secure a constant reaction residence time. The reaction system is preferably in an atmosphere of a dry noble gas such as dry argon or an inert gas such as dry nitrogen for the purpose of preventing thermal oxidation and hydrolysis due to mixing with the air. In any case, the particle size of the generated ultrafine particles can be monitored, for example, by appropriately extracting a small amount of the reaction solution and measuring the absorption spectrum or emission spectrum.

The semiconductor raw materials usable in the liquid phase production method include a substance containing a positive element selected from Groups 2 to 15 of the periodic table and a negative element selected from Groups 15 to 17 of the periodic table. Substances. It is known that the Group 15 element of the periodic table also constitutes a semiconductor as a trivalent positive element, for example, bismuth sulfide or bismuth telluride described in the Dictionary of Physical and Chemical Sciences (4th edition, Iwanami Shoten, 1987). ing.

When there are a plurality of semiconductor raw materials, these may be mixed in advance, or may be individually injected into the reaction liquid phase. These raw materials may be used as a solution using an appropriate diluting solvent. Examples of positive element-containing substances that are semiconductor raw materials include magnesium, titanium, vanadium, tantalum,
Simple substance such as chromium, molybdenum, tungsten, manganese, iron, cobalt, nickel, copper, zinc, cadmium, mercury, boron, aluminum, gallium, indium, tin, lead, antimony, bismuth, diethylmagnesium, and di-n-butylmagnesium Periodic Table of the Periodic Tables of the Periodic Tables of the Periodic Tables of the Group 2 Elements such as Dihalides of Group 2 Elements, such as dialkylated compounds, methylmagnesium chloride, methylmagnesium bromide, methylmagnesium iodide and ethynylmagnesium chloride. Group 2 element dihalides, titanium tetrachloride (IV), titanium tetrabromide (I
V), halides of Group 4 elements of the periodic table such as titanium tetraiodide (IV), vanadium dichloride (II), vanadium tetrachloride (IV), vanadium dibromide (II), vanadium tetrabromide (IV) ), Vanadium diiodide (II), vanadium tetraiodide (IV), tantalum pentachloride (V), tantalum pentabromide (V), tantalum pentaiodide (V), etc. Chloride, chromium (III) tribromide, chromium (III) triiodide, molybdenum tetrachloride (IV), molybdenum tetrabromide (IV), molybdenum tetraiodide (IV), tungsten tetrachloride (IV), tetraodor Periodic table No. 6
Halides of Group 7 elements, such as halides of manganese dichloride (II), manganese dibromide (II), and manganese diiodide (II), halides of Group 7 elements, iron dichloride (II), and iron trichloride (III), iron (II) dibromide, iron (III) tribromide, iron (II) diiodide, iron (III) triiodide, etc., halides of Group VIII elements, cobalt dichloride (II), cobalt dibromide (II), cobalt diiodide (II) and other halides of Group 9 elements of the periodic table, nickel dichloride (II), nickel dibromide (II), nickel diiodide Periodic table such as (II) Halide of Group 10 element, Periodic table 11 such as copper (I) iodide
Group element halide, dimethyl zinc, diethyl zinc,
Di-n-propyl zinc, diisopropyl zinc, di-n-
Dialkylated compounds of Group 12 elements of the periodic table such as butyl zinc, diisobutyl zinc, di-n-hexyl zinc, dicyclohexyl zinc, dimethyl cadmium, diethyl cadmium, dimethyl mercury (II), diethyl mercury (II), dibenzyl mercury (II) , Methyl zinc chloride, methyl zinc bromide,
Alkyl halides of Group 12 elements such as methylzinc iodide, ethylzinc iodide, methylcadmium chloride, methylmercury (II) chloride, zinc dichloride, zinc dibromide, zinc diiodide, cadmium dichloride , Cadmium dibromide, cadmium diiodide, mercury (II) dichloride, zinc chloroiodide, cadmium chloroiodide, mercury chloroiodide (II), zinc bromoiodide, cadmium bromoiodide, bromide Dihalides of Group 12 elements of the periodic table such as mercury (II) iodide, trimethylboron, tri-n-propylboron, triisopropylboron, trimethylaluminum, triethylaluminum, tri-n-butylaluminum, tri-n
Hexyl aluminum, trioctyl aluminum,
Tri-n-butylgallium (III), trimethylindium (III), triethylindium (III), tri-n
Trialkylated compounds of Group 13 elements of the periodic table such as -butylindium (III), dimethylaluminum chloride, diethylaluminum chloride, di-n-butylaluminum chloride, diethylaluminum bromide, diethylaluminum iodide, di-n-chloride Dialkyl monohalides of Group 13 elements of the periodic table, such as butylgallium (III) and di-n-butylindium (III) chloride, methyl aluminum dichloride, ethyl aluminum dichloride, ethyl aluminum dibromide, and ethyl diiodide Aluminum, n-butyl aluminum dichloride, n-butyl gallium dichloride (II
I), monoalkyl dihalides of Group 13 elements of the periodic table such as n-butylindium (III) dichloride, boron trichloride, boron tribromide, boron triiodide, aluminum trichloride, aluminum tribromide, Aluminum iodide, gallium (III) trichloride, gallium (III) tribromide, gallium (III) triiodide, indium (III) trichloride, indium (III) tribromide, indium (III) triiodide, Gallium (III) bromide dichloride, gallium (III) iodide dichloride,
Gallium diiodide (III) chloride, indium (III) dichloride, and the like, trihalides of Group 13 elements of the periodic table, germanium tetrachloride (IV), germanium tetrabromide (IV), germanium tetraiodide ( IV), tin dichloride (I
I), tin tetrachloride (IV), tin dibromide (II), tin tetrabromide (I
V), tin (II) diiodide, tin (IV) tetrabromide, tin (II) dichloride (IV), tin (IV) tetraiodide, lead (II) dichloride, lead (II) dibromide ), Halides of elements of group 14 of the periodic table such as lead (II) diiodide, trimethylantimony (III), triethylantimony (III), tri-n-butylantimony (III), trimethylbismuth (III), triethyl Bismuth (III), tri-n-butyl bismuth (III) and other trialkylated compounds of Group 15 elements of the periodic table, methyl antimony dichloride (III), methyl antimony dibromide (II)
I), methyl antimony diiodide (III), ethyl antimony diiodide (III), methyl bismuth dichloride (III),
Monoalkyldihalides of Group 15 elements such as ethyl bismuth (III) diiodide, arsenic trichloride (II
I), arsenic tribromide (III), arsenic triiodide (III), antimony trichloride (III), antimony tribromide (III), antimony triiodide (III), bismuth (III) trichloride, Examples include trihalides of Group 15 elements of the periodic table, such as bismuth (III) bromide and bismuth (III) triiodide.

Of these, particularly preferred as the raw material for the hot soap method are diethylmagnesium and di-n-
Dialkylated compounds of Group 2 elements of the Periodic Table such as butylmagnesium, alkyl halides of Group 2 elements of the Periodic Table such as methylmagnesium chloride, methylmagnesium bromide and methylmagnesium iodide, dimethylzinc, diethylzinc,
Di-n-propyl zinc, diisopropyl zinc, di-n-
Butyl zinc, diisobutyl zinc, di-n-hexyl zinc, dimethyl cadmium, dialkyl compounds of Group 12 elements such as diethyl cadmium, methyl zinc chloride, methyl zinc bromide, methyl zinc iodide, methyl zinc iodide, ethyl zinc iodide,
Alkyl halides of Group 12 elements of the periodic table such as methylcadmium chloride, aluminum triiodide, gallium (III) trichloride, gallium (III) tribromide, gallium (III) triiodide, indium (III) trichloride , Indium (III) tribromide, indium (III) triiodide
And the like, among which dimethyl zinc, diethyl zinc, di-n-propyl zinc, diisopropyl zinc, di-n-butyl zinc, dimethyl cadmium,
Dialkylated compounds of Group 12 elements of the periodic table such as diethylcadmium, gallium (III) trichloride, indium trichloride (I
Most suitable are trihalides of Group 13 elements such as II).

Note that germanium tetrachloride (IV), germanium tetrabromide (IV), germanium tetraiodide (IV), tin dichloride (II), tin tetrachloride (IV), tin dibromide (II), Tin (IV) tetrabromide, Tin (II) diiodide, Tin (IV) tetrabromide, Tin (IV) dichloride (IV), Tin (IV) tetraiodide, Lead (I) chloride
The halides of Group 14 elements of the periodic table such as I), lead (II) dibromide, and lead (II) diiodide are ultrafine particles of a single semiconductor of the Group 14 elements of the periodic table such as germanium and tin alone. May be used as a raw material for

Examples of the negative element-containing substance which is a semiconductor raw material include periodic table 15 to 17 such as nitrogen, phosphorus, arsenic, antimony, bismuth, oxygen, sulfur, selenium, tellurium, fluorine, chlorine, bromine and iodine. Elemental group element, ammonia, phosphine (PH ₃ ), arsine (AsH ₃ ),
A hydride of a Group 15 element of the periodic table such as stibine (SbH ₃ ), a silylated product of a Group 15 element of the periodic table such as tris (trimethylsilyl) amine, tris (trimethylsilyl) phosphine, tris (trimethylsilyl) arsine, hydrogen sulfide, selenium Periodic table of hydrogen fluoride, hydrogen telluride, etc.
Periodic Table 1 of hydrides of group elements, bis (trimethylsilyl) sulfide, bis (trimethylsilyl) selenide, etc.
Alkali metal salts of Group 16 elements such as silylated compounds of Group 6 elements, sodium sulfide, sodium selenide, etc., tributylphosphine sulfide, trihexylphosphine sulfide, trioctylphosphine sulfide, tributylphosphine selenide, trihexylphosphine selenide , Trialkylphosphine chalcogenides such as trioctylphosphine selenide, hydrides of Group 17 elements of the periodic table such as hydrogen fluoride, hydrogen chloride, hydrogen bromide, hydrogen iodide, trimethylsilyl chloride, trimethylsilyl bromide, trimethylsilyl iodide, etc. Periodic Table No. 17
Group-containing silylated products. Among them, in terms of reactivity, stability and operability of compounds, phosphorus, arsenic, antimony, bismuth, sulfur, selenium, tellurium, iodine and the like, a simple substance of Group 15 to 17 elements of the periodic table, tris (trimethylsilyl) Phosphine, tris (trimethylsilyl) arsine, etc., a silylated compound of Group 15 element of the periodic table, hydrogen sulfide,
Hydrides of Group 16 elements such as hydrogen selenide and hydrogen telluride; silylates of Group 16 elements such as bis (trimethylsilyl) sulfide and bis (trimethylsilyl) selenide; sodium sulfide; sodium selenide; Alkali metal salts of Group 16 elements of the periodic table, tributylphosphine sulfide, trihexylphosphine sulfide, trioctylphosphine sulfide, tributylphosphine selenide, trihexylphosphine selenide,
Trialkyl phosphine chalcogenides such as trioctyl phosphine selenide, and silylated products of Group 17 elements of the periodic table such as trimethylsilyl chloride, trimethylsilyl bromide, and trimethylsilyl iodide are preferably used. Periodic elements such as simple substances of elements of groups 15 and 16 of the periodic table, tris (trimethylsilyl) phosphine, tris (trimethylsilyl) arsine, and the like, silylated products of group 15 elements of the periodic table, bis (trimethylsilyl) sulfide, bis (trimethylsilyl) selenide, etc. Table 16 Alkali metal salts of Group 16 elements such as silylated products of Group 16 elements, sodium sulfide, sodium selenide, etc., tributylphosphine sulfide, trioctylphosphine sulfide, tributylphosphine selenide, Trialkyl phosphine chalcogenide such as trioctylphosphine selenide, etc. are particularly preferably used.

In the hot soap method, which is a particularly preferred liquid phase production method, there is no limitation on the supply rate of the raw material compound to the reaction liquid phase. In some cases, it is preferable to inject a predetermined amount in a short time of about 60 seconds. The appropriate crystal growth reaction time (residence time in the case of the flow method) after the injection of the raw material solution varies depending on the type of semiconductor, the desired particle size, or the reaction temperature, but typical conditions are 200 to 350. ° C
The reaction temperature is about 1 minute to 10 hours.

In such a hot soap method, after completion of the growth reaction of the semiconductor crystal, isolation and purification are usually performed. As this method, concentration of liquid phase components or precipitation method is suitable. A preferred representative procedure of the precipitation method is as follows. That is, after cooling to a temperature not reaching the solidification temperature of the reaction solution, lower alcohols such as toluene and n-butanol are added to such an extent that precipitation does not occur, thereby suppressing solidification at room temperature. Poor solvents such as methanol,
This is a procedure in which semiconductor ultrafine particles are precipitated by mixing with lower alcohols such as ethanol, n-propanol, isopropyl alcohol, and n-butanol, or water, and then separated by physical means such as centrifugation or decantation. . It is possible to further increase the degree of purification by dissolving the precipitate thus obtained in toluene or hexane again and repeating the procedure of precipitation and separation. The precipitation solvent may be a mixed solvent. In some cases, such a purification step is preferably performed in an atmosphere of an inert gas such as nitrogen or argon to avoid side reactions such as oxidation.

[Coordination of Desired Ligand to Semiconductor Crystal Surface] A phosphine oxide or a phosphine oxide in which a radical reactive group of the present invention is bonded to a semiconductor crystal obtained by any of the production methods as exemplified above. A preferred method for coordinating the auxiliary organic ligands (hereinafter, these are collectively simply referred to as “organic ligands”) will be exemplified. In addition, in order to prevent an undesired radical reaction from proceeding in any reaction for coordinating the organic ligand, methylhydroquinone or 2,6-di-
An arbitrary radical scavenger such as tert-butyl-4-methylphenol may be added, or the reaction may be shielded from light. (A) Method by Ligand Exchange Reaction The organic solvent-soluble semiconductor ultrafine particles synthesized by the hot soap method or the like are dissolved in a relatively weakly coordinating organic solvent such as toluene, methylene chloride, or pyridine. The reaction is performed by adding a desired organic ligand (preferably having a strongly coordinating functional group such as a phosphine oxide group or a mercapto group). As a result, ligand exchange in which the added organic ligand replaces the originally existing ligand proceeds, but the coordination force of these ligands is adjusted to leave the desired organic ligand. There is a need to. When pyridine is used as a solvent, pyridine is a weak but coordinating solvent molecule, so that ligand exchange proceeds first, and then ligand exchange by the added desired organic ligand proceeds. It may be.

The ligand exchange reaction is usually carried out at -10 to 20.
The reaction is carried out in a temperature range of about 0 ° C., and is preferably set to 0 to avoid thermal deterioration of organic substances and incomplete exchange reaction.
The temperature is about 170 ° C, more preferably about 10 to 140 ° C, and most preferably about 20 to 120 ° C. The reaction time of each step depends on the raw materials and the temperature, but is usually 1 minute to 100 minutes.
Time, preferably 5 minutes to 70 hours, more preferably 10 minutes
Minutes to 50 hours, most preferably about 10 minutes to 30 hours. Further, in order to avoid side reactions such as oxidation, it is desirable to carry out the reaction in an inert gas atmosphere such as nitrogen or argon.
Further, in some cases, not only the ligand exchange reaction but also the post-treatment step for producing ultrafine particles is preferably performed under light-shielding conditions. After the ligand exchange reaction, any method such as filtration, combined use of precipitation and centrifugation, distillation, and sublimation may be used to isolate the product. Particularly effective is the hot soap described above. It is a combination of precipitation and centrifugation as described in the method. At this time, the solubility of the semiconductor ultrafine particles changes due to ligand exchange,
It is usually necessary to adjust the type and mixing ratio of the re-dissolving solvent and the precipitating solvent accordingly. (B) Addition of an organic ligand to a reaction liquid phase of a hot soap method This is a method of adding a desired organic ligand to a reaction liquid phase for synthesis of a semiconductor crystal by the above-described hot soap method. Organic ligands suitable for such a method are organic ligands having a strongly coordinating functional group such as a phosphine group, a phosphine oxide group, or a mercapto group, and particularly those having a phosphine oxide group are optimal. .

The addition of the coordinating organic ligand to the reaction liquid phase of the hot soap method is preferably carried out at a later stage of the hot soap method reaction. The reason is that after a semiconductor crystal having a desired size is generated, a coordinating organic ligand is coordinated on the surface thereof. The timing of the addition of the desired organic ligand is selected according to the particle size of the semiconductor crystal determined by the desired light-absorbing / emitting ability, but usually the particle size of the semiconductor crystal is 0.5 to
10 nm, preferably 1 to 9 nm, more preferably 2 to
It is at the time when it has grown to 8 nm, most preferably about 3 to 7 nm. In order to suppress undesired thermal decomposition of the desired organic ligand and to secure sufficient coordination reactivity, the reaction temperature during the addition is usually 20 to 300 ° C., preferably 40 to 300 ° C.
To 250 ° C, more preferably 60 to 200 ° C, most preferably about 80 to 150 ° C. In such a method, a post-treatment similar to that described in the above (a), that is, a step of isolating the semiconductor ultrafine particles to be generated is usually performed. Again, a combination of precipitation and centrifugation is particularly preferred.

[Use of Semiconductor Ultrafine Particles] Since the above semiconductor ultrafine particles of the present invention usually have radical polymerizability, a general-purpose radical polymerizable monomer such as styrene or methyl methacrylate is mixed with the semiconductor ultrafine particles. By promoting the radical polymerization, a resin composition having good transparency is produced. Such a resin composition is used for an optical waveguide, a light refraction member, a display, a lighting device, and the like by utilizing characteristics such as a high light transmittance, a high refractive index, and a light absorbing and emitting ability.

[0059]

EXAMPLES Hereinafter, specific embodiments of the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples unless it exceeds the gist thereof.
The raw material reagents are Aldric unless otherwise specified.
The product of Company h was used without purification. However, the purified toluene was washed with concentrated sulfuric acid, water, saturated aqueous sodium hydrogen carbonate, and water in that order, dried over anhydrous magnesium sulfate, and then filtered through filter paper.
Obtained distilled from diphosphorus pentaoxide (P ₂ O _5). Further, as the methanol and n-butanol used in the synthesis example of the semiconductor ultrafine particles, both anhydrous grades (99.8%) supplied from Aldrich were used.

[Measurement Apparatus and Conditions, etc.] (1) Nuclear magnetic resonance spectrum (NMR): JNM-EX270 type FT-NMR manufactured by JEOL Ltd. ( ¹ H: 270 MH)
z). Unless otherwise specified, deuterated chloroform was used as a solvent, and tetramethylsilane was measured at 23 ° C. with 0 ppm as a control. (2) Infrared absorption spectrum (FT-IR): FT / IR-8000 type FT-IR manufactured by JASCO Corporation. Measured at 23 ° C. (3) X-ray diffraction (XRD) spectrum: RINT 1500 manufactured by Rigaku Corporation (X-ray source: copper Kα ray, wavelength 1.541)
8Å). Measured at 23 ° C. (4) Transmission electron microscope (TEM) observation: H-9000UHR transmission electron microscope manufactured by Hitachi, Ltd. (acceleration voltage: 300 kV, vacuum degree during observation: about 7.6 × 10 ⁻⁹ Torr)
r). (5) Photoexcitation luminescence (PL) spectrum: F-2500 type spectrofluorometer manufactured by Hitachi, Ltd. under the conditions of scan speed 60 nm / min, excitation side slit 5 nm, fluorescence side slit 5 nm, and photomultiplier voltage 400 V. The measurement was performed using a quartz cell having an optical path length of 1 cm.

Example 1 [Synthesis of phosphine oxide bonded to methacryloyl group] Tris (3-hydroxypropyl) phosphine oxide (hereinafter abbreviated as HPPO, 3.96 g; 0.0177 mol, a product of Nippon Chemical Industry Co., Ltd.) Name Hishicolin PO-
Methacrylic anhydride (8.4) was stirred in pyridine (100 mL) at room temperature under a dry nitrogen atmosphere.
4g; 0.0547 mol) and DMF (40 mL) were added. After stirring at room temperature for about 3.5 hours, the mixture was heated at 60 ° C. for about 1 hour, and the resulting transparent uniform solution was left at room temperature for about 67 hours. In a ¹ H-NMR spectrum of a non-volatile residue obtained by concentrating a part of the reaction solution under reduced pressure, two protons of an olefin derived from an acryloyl group (5.56 pp.
m and 6.11 ppm) and methyl protons, and HP
Proton of methylene group derived from PO (1.92 to 2.05)
ppm, 4.21 ppm: methylene group adjacent to the ester group oxygen). However, a methylene group proton adjacent to the unreacted hydroxyl group of HPPO was observed at 3.70 ppm, and from the comparison of the integral value with the signal at 4.21 ppm,
Under these reaction conditions, the conversion of hydroxyl groups of HPPO to methacrylic acid ester proceeded, but it was considered that about 25% of all hydroxyl groups remained unreacted. In the FT-IR spectrum of the concentrated residue, a very strong absorption band of a carbonyl group attributed to an ester bond (1715c
m ^-1 ) was observed, while the broad absorption band of hydroxyl groups from 3100 to 3700 cm ^-1 was weakly observed, indicating that a small amount of hydroxyl groups remained without being converted to methacrylic acid esters. Supported. Therefore,
Acetic anhydride (1.40 g; 0.0137 mol) was added, and the mixture was allowed to stand at room temperature to convert unreacted hydroxyl groups to acetate, and concentrated under reduced pressure to remove volatile components. In this way, a mixed phosphine oxide was obtained in which it is estimated that about 25% of the phosphine oxide ester bonded to a methacryloyl group in which A is a methyl group in the formula (2) is an acetate ester (this product is hereinafter referred to as MPO). Abbreviated).

Synthesis Example 1 [Synthesis of Ultra Fine CdSe Particles] Trioctylphosphine oxide (a colorless transparent Pyrex (registered trademark) glass three-necked flask equipped with an air-cooled Liebig reflux tube and a thermocouple for controlling the reaction temperature was placed in the flask. Hereinafter, TOPO is abbreviated; 4 g), and stirred under a magnetic stirrer in a dry argon gas atmosphere.
Heated to 0 ° C. Separately, selenium (simple black powder; 0.1 g) was mixed with tributylphosphine (hereinafter abbreviated as TBP; 6.014 g) in a glove box in a dry nitrogen atmosphere.
Dimethyl cadmium (Strem)
A raw material solution A in which Chemical Company; 97%; 0.216 g) was mixed and dissolved was sealed in a rubber stopper (septum supplied from Aldrich), wrapped tightly with aluminum foil, and prepared in a light-shielded glass bottle. A part (2.0 mL) of the raw material solution A was injected into the flask containing the TOPO at once with a syringe, and this time was regarded as the reaction start time. Twenty minutes after the start of the reaction, the heat source was removed and about 50
When cooled to ° C., purified toluene (2 mL) was added with a syringe to dilute, and methanol (10 mL) was injected to generate an insoluble matter. This insoluble material is centrifuged (3000r
pm), the supernatant was removed by decantation and separated, and vacuum dried at room temperature for about 14 hours to obtain a solid powder.

In the XRD spectrum of this solid powder, the 002 face and the 1st face of the Wurtzite type CdSe crystal
From the observation of diffraction peaks belonging to 10 planes, Cd
Generation of Se nanocrystals was confirmed. The average particle size of the CdSe nanocrystals was about 4 nm according to TEM observation. This CdSe nanocrystal gave a red emission band (peak wavelength: 595 nm, half width: 43 nm) when irradiated with excitation light having a wavelength of 366 nm in a purified toluene solution.

Synthesis Example 2 [CdSe having ZnS shell]
Synthesis of semiconductor ultrafine particles mainly composed of nanocrystals] B. O. Dabbousi et al .; Phys. Che
m. B, 101, 9463 (1997). This will be described below. TOPO in a brown glass three-necked flask in a dry argon gas atmosphere
(15 g) was added, and the mixture was stirred under reduced pressure at a temperature of 130 to 150 ° C. in a molten state for about 2 hours. During this time, an operation of returning to atmospheric pressure with dry argon gas was performed several times in order to replace the remaining air and moisture. Approx. 1 with the temperature set to 100 ° C
After a lapse of time, the solid powder of CdSe nanocrystals obtained in Synthesis Example 1 (0.094 g) was trioctylphosphine (1.5%).
g, hereinafter abbreviated as TOP) solution to obtain a transparent solution containing CdSe nanocrystals. This was further stirred for about 80 minutes under reduced pressure of 100 ° C., and then the temperature was set to 180 ° C. and the pressure was restored to the atmospheric pressure with dry argon gas. Separately, in a dry nitrogen atmosphere glove box, 1N concentration of diethyl zinc n-
Hexane solution (1.34 mL; 1.34 mmol) and bis (trimethylsilyl) sulfide (0.239 g;
1.34 mmol) was dissolved in TOP (9 mL) to prepare a glass bottle sealed with a septum used in Synthesis Example 1, wrapped tightly with aluminum foil, and shielded from light. This raw material solution B was mixed with the above 180
The solution was dropped into a transparent solution containing CdSe nanocrystals at 20 ° C. over 20 minutes. After the temperature was lowered to 90 ° C., stirring was continued for about 1 hour. After allowing to stand at room temperature for about 14 hours, the mixture was again heated and stirred at 90 ° C. for 3 hours. The heat source was removed and n-butanol (8 mL) was added to the reaction and cooled to room temperature to give a clear red solution.

This red solution did not have the odor of the sulfur compound such as bis (trimethylsilyl) sulfide as the raw material, but instead had the leek-like odor peculiar to selenium. Since the solution of the CdSe nanocrystals obtained in Synthesis Example 1 did not have such a selenium odor, the intended sulfide generation reaction on the surface of the CdSe nanocrystals and the selenium atom due to sulfur atoms on the nanocrystal surface It is presumed that selenium was liberated by some mechanism such as a substitution reaction of CdSe, and it was considered that semiconductor ultrafine particles mainly composed of CdSe nanocrystals having a ZnS shell were generated as described in the above-mentioned literature (hereinafter referred to as CdSe). / ZnS).

A portion (8 mL) of this red solution was added dropwise to methanol (16 mL) at room temperature under a stream of dry nitrogen to give
A red insoluble substance was obtained by a precipitation operation in which stirring was continued for 0 minutes. This red insoluble matter was separated by centrifugation and decantation in the same manner as in Synthesis Example 1, and purified toluene (14 mL)
Was re-dissolved. Using this re-dissolved toluene solution, a similar series of purification operations including precipitation, centrifugation, and decantation was performed again to obtain a solid product. This solid product was washed by shaking with 1 mL of purified methanol, and then separated by decantation. This solid product gives a clear red purified toluene solution, which is irradiated with excitation light having a wavelength of 468 nm to emit an orange emission band (having a peak wavelength of 59 nm).
7 nm, half width at 41 nm). This emission was clearly higher in emission intensity than the case of the CdSe nanocrystal obtained in Synthesis Example 1 at the same solution concentration.
It was considered that the conversion to the CdSe nanocrystal having a ZnS shell and the contribution of the non-light emitting process via the surface state and the like were suppressed.

Example 2 [Synthesis of Ultrafine Semiconductor Particles Containing Phosphine Oxide with Methacryloyl Group as Ligand] Ultrafine semiconductor particles CdSe / ZnS obtained in Synthesis Example 2 were dissolved in purified toluene, After the MPO obtained in Step 1 (about 5 times the weight of the used CdSe / ZnS) was added and allowed to act sufficiently, the separation and purification of semiconductor ultrafine particles was performed by the same precipitation, centrifugation, and decantation as in Synthesis Example 2. Thus, semiconductor ultrafine particles having MPO bonded as a ligand are obtained (hereinafter, abbreviated as CdSe / ZnS-MPO). The binding of the MPO is confirmed by observing the MPO-derived absorption band in the FT-IR spectrum of the sufficiently purified semiconductor ultrafine particles.

[0068]

According to the present invention, the phosphine oxides provided with a radical reactive group provided by the present invention provide the semiconductor ultrafine particles of the present invention obtained by bonding the phosphine oxides. Such semiconductor ultrafine particles usually have radical polymerizability. . Therefore, by mixing a general-purpose radical polymerizable monomer such as styrene or methyl methacrylate with the semiconductor ultrafine particles and then allowing the radical polymerization to proceed, a resin composition having good transparency is produced. Such a resin composition utilizes a characteristic such as a high light transmittance, a high refractive index, or a light absorbing and emitting ability, an optical waveguide,
It is used for light refraction members, displays and lighting equipment.

Claims (4)

[Claims] 1. A phosphine oxide having a radical reactive group bonded thereto. 2. The phosphine oxide according to claim 1, represented by the following general formula (1). Embedded image (However, in the general formula (1), R ^rad is a radical reactive group, and R ¹ and R ² independently represent an alkyl group, an acyl group, an aryl group having 10 or less carbon atoms, or the above-mentioned R ^rad .) 3. The radical-reactive group is an acryloyl group,
The phosphine oxide according to claim 1 or 2, which is selected from a methacryloyl group, a maleoyl residue, and a vinylphenyl group. 4. Ultrafine semiconductor particles comprising the phosphine oxide according to claim 1 as a ligand.