JP3089416B1 - Polycarbosilane and method for producing the same - Google Patents

Abstract

Abstract: PROBLEM TO BE SOLVED: To provide a divinylsilane partial structure (C = C-SiH-
Provided is a novel polycarbosilane having (C = C) in the main chain and a method for efficiently producing the same. SOLUTION: In the presence of a palladium catalyst, a trihydrosilane (R ¹ SiH ₃ ) is converted to a diyne compound (HC≡CR ² C).
≡CH) to form a novel polycarbosilane ((—SiR ¹ H—R ³ —R ² —R ⁴ ) having a divinylsilane partial structure (C ＝ C—SiH—C ＝ C) in the main chain.
-), Wherein R ³ and R ⁴ are the same or different divalent groups selected from —CH ＝ CH— (vinylene group) and> C ＝ CH ₂ (vinylidene group), and n is 2
Above integer).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for producing a polycarbosilane having a divinylsilane partial structure (C = C-SiH-C = C) in the main chain by reacting a trihydrosilane with a diyne compound, and It relates to a novel polycarbosilane obtained thereby. The polycarbosilane provided by the present invention has a C ＝ C bond and a Si—H bond that can be easily crosslinked and variously modified,
It can be used as a raw material for heat-resistant materials and as a preceramic for silicon carbide production. In addition, since the polycarbosilane of the present invention having an aromatic ring group or the like in the main chain exhibits a light emission phenomenon characteristic of its structure, it can be applied to various optical and electronic materials including electroluminescent devices. is there.

[0002]

2. Description of the Related Art A divinylsilane partial structure composed of C ＝ C bonds and Si—H bonds (C ＝ C—SiH—C ＝
A method for producing polycarbosilane having C) in the main chain has not been known so far.

[0003]

SUMMARY OF THE INVENTION The present invention relates to a method for producing a polycarbosilane having a divinylsilane partial structure (C = C-SiH-C = C) in the main chain, and a novel polycarbosilane obtained thereby. The task is to provide

[0004]

Means for Solving the Problems The present inventors have made intensive studies to solve the above-mentioned problems. As a result, trihydrosilanes easily react with a diyne compound in the presence of a palladium complex catalyst to form a divinylsilane moiety. Structure (C = C-SiH-
The present inventors have found a novel fact that a polycarbosilane having (C = C) in the main chain is obtained in good yield, and based on this, have completed the present invention. That is, the present invention, in the presence of a palladium catalyst, the general formula

[0005] R ¹ SiH ₃ (I) (wherein R ¹ represents a monovalent group selected from an alkyl group, an aryl group, an aralkyl group, and a monovalent heterocyclic group). Trihydrosilanes of the general formula

[0006] HC≡CR ² C≡CH (II) (wherein R ² is a divalent group selected from an alkylene group, an arylene group, and a divalent heterocyclic group). General formula characterized by reacting with diyne

(—SiR ¹ H—R ³ —R ² —R ⁴ —) _n (III) (wherein R ¹ and R ² represent the above formulas (I) and (II)
Same as inside. R ³ and R ⁴ are —CH ＝ C
H- (vinylene group) and> C = CH ₂ (vinylidene group) are the same or different divalent groups selected from each other. N represents an integer of 2 or more. ), And a novel polycarbosilane obtained by the method.

[0008]

According to the present invention, the trihydrosilane represented by the general formula (I) is reacted with a diyne compound represented by the general formula (II). A method for producing a polycarbosilane represented by the general formula (III) and a novel polycarbosilane obtained by the method are provided.

[0009] substituent R ¹ on silicon atoms containing in the general formula (I), an alkyl group, an aryl group, an aralkyl group or a monovalent heterocyclic group, and more particularly, is preferably a carbon number 1-20, more preferably 1-8 alkyl groups, preferably 6-20 carbon atoms, more preferably 6-6 carbon atoms.
10 aryl groups, preferably 7 to 20 carbon atoms, more preferably 7 to 10 aralkyl groups, or at least one heteroatom selected from nitrogen, oxygen, sulfur, selenium, silicon, boron, etc. And preferably a 3- to 10-membered, more preferably a 5- to 8-membered monovalent heterocyclic group. Specific examples thereof include methyl, ethyl, propyl, isopropyl, butyl, neopentyl, hexyl, octyl, decyl, phenyl, naphthyl, anthryl, benzyl, phenethyl, and pyridyl. Group, furyl group, thienyl group and the like. Therefore, when the trihydrosilanes represented by the general formula (I) having those substituents are exemplified,
Methylsilane, ethylsilane, propylsilane, isopropylsilane, butylsilane, neopentylsilane, hexylsilane, octylsilane, decylsilane, phenylsilane, naphthylsilane, anthrylsilane, benzylsilane, phenethylsilane, pyridylsilane, furylsilane, thienylsilane, etc. be able to.

On the other hand, R ² in the general formula (II) is a divalent group selected from an alkylene group, an arylene group and a divalent heterocyclic group, and preferably has 1 to 2 carbon atoms.
0, more preferably 1 to 8 alkylene groups, preferably 6 to 20, more preferably 6 to 12 arylene groups, or as a hetero atom, nitrogen, oxygen, sulfur,
At least one selected from selenium, silicon, boron, etc.
And preferably a 3- to 10-membered, more preferably 5- to 8-membered, divalent heterocyclic group. Specific examples thereof include a methylene group, an ethylene group, a tetramethylene group,
Pentamethylene group, hexamethylene group, octamethylene group, decamethylene group, dodecamethylene group, eicosamethylene group, phenylene group, naphthylene group, biphenylene group, anthrylene group, pyridylene group, furylene group, thienylene group, etc. Some of the hydrogen atoms in those groups are
It may be substituted with a group such as an alkyl group, an alkoxy group and a halogen atom. Accordingly, the diyne compounds represented by the general formula (II) which may have a substituent include 1,4-pentadiyne, 1,5-hexazine, 1,7-octadiyne, 1,8 -Nonadiyne,
1,9-decadiyne, 1,11-dodecadiin, 1,1
Examples include 3-tetradecadiyne, diethynylbenzene, diethynylnaphthalene, diethynylanthracene, diethynylpyridine, diethynylfuran, diethynylthiophene, and the like.

The molar ratio of the diyne compound represented by the general formula (II) to the trihydrosilanes to be subjected to the reaction is not particularly limited and can be arbitrarily selected, but taking into account the yield of polycarbosilane. If so, about 0.5 to 2 is desirable, and usually 0.7 to 1.5.

As the palladium catalyst used in the present invention, various catalysts including conventionally known ones such as a metal complex, a metal salt, a metal and a supported metal, and a system in which a ligand is added thereto can be used. . Specific examples thereof include dichlorobis (triphenylphosphine palladium), dichlorobis (methyldiphenylphosphine) palladium, diiodobis (diethylphenylphosphine) palladium, dichlorobis (tricyclohexylphosphine) palladium, diiodobis (tricyclohexylphosphine) palladium, dichlorobis ( Tributylphosphine) palladium, dichlorobis (tri-i-
Butylphosphine) palladium, dichlorobis (tri-
t-butylphosphine) palladium, dibromobis (tripropylphosphine) palladium, dichlorobis (tri-i-propylphosphine) palladium, dichlorobis (triethylphosphine) palladium, dichlorobis (trimethylphosphine) palladium, bis (tricyclohexylphosphine) palladium, tetrakis ( Triethylphosphine) palladium, dichlorobis (triphenylphosphite) palladium, dichlorobis (triethylphosphite) palladium, bis (t-butylisocyanide) palladium, bis (dibenzylideneacetone) palladium, tris (dibenzylideneacetone) dipalladium, dichlorobis ( Benzonitrile) palladium, dibromobis (benzonitrile) palladium, dichlorobis (aceto Tolyl) palladium, di -μ- chlorobis (.pi.-allyl) dipalladium, dichlorobis (pyridine) palladium, palladium acetate, palladium chloride, palladium iodide, palladium on charcoal and the like. Preferred among these are systems containing a phosphorus ligand, more preferably systems containing a phosphine ligand, and even more preferably systems containing a trialkylphosphine. Examples of ligands added to those systems as needed include triphenylphosphine, t-butyldiphenylphosphine, dicyclohexylphenylphosphine, tricyclohexylphosphine, tributylphosphine, tri-i-butylphosphine, and tri-phosphine. t-butyl phosphine, tripropyl phosphine, tri-i-propyl phosphine, triethyl phosphine, trimethyl phosphine, triphenyl phosphite, tributyl phosphite, trimethyl phosphite, t-butyl isocyanide, cyclohexyl isocyanide and the like. These catalyst systems can be used in combination of two or more kinds.

The amount of the palladium catalyst used can be appropriately determined, but is preferably in the range of usually 0.000001 to 0.5 as a molar ratio to the trihydrosilane.

The reaction of the present invention is carried out at a temperature of -100 ° C or higher, preferably -50 to 250 ° C, more preferably -20 to 150 ° C.
It is carried out at a reaction temperature of ° C. Although the method of the present invention can be carried out with or without a solvent, when a solvent is used, in addition to hydrocarbon solvents such as benzene, toluene and xylene and ether solvents such as tetrahydrofuran, the raw materials trihydrosilanes and diyne Various organic solvents other than those that react with the compound can be used.

The separation and purification of the desired product from the reaction mixture can be easily achieved by means commonly used in organic chemistry such as reprecipitation or chromatography.

According to the method of the present invention, the compound represented by the general formula (III)
Is provided. General formula (II
Specific examples of R ¹ and R ² in I) include compounds represented by general formula (I)
And those described above in the description of the general formula (II). By appropriately selecting the type of palladium catalyst in the polycarbosilane represented by the general formula (III), R ³ and R ⁴ are mainly those of a vinylene group, for example, vinylene relative to the total unit of R ³ and R ^4. Group is at least 60 unit% (the remainder is a vinylidene group), preferably 7
0% or more of the polycarbosilane of the general formula (III) can be obtained. In the general formula (III), n is an integer of 2 or more, preferably 2 to 50,000, more preferably 3 to 20,000. In the general formula (III),
The terminal on the silicon side is a hydrogen atom, an ethynyl organic group (HC≡
C—R ² —R ⁵ — (R ² is the same as that in the general formula (II), and R ⁵ is a vinylene group or a vinylidene group)) and the like.
The other end is a silyl group (—SiR ¹ H ₂ (R
¹ is the same as in general formula (I))). Also, as a method of obtaining a vinylidene group dominant,
(1) Use a sterically small ligand as the ligand of the palladium catalyst (in the reaction with monoyne, a sterically larger phosphine ligand is more likely to give a product having a vinylene structure); (2) Solvents and reactions (3) changing the types of the substituents R ¹ and R ² (in the reaction with monoyne,
^{When 1} is an alkyl group, a product having a vinylidene structure tends to be formed).

[0017]

Next, the present invention will be described in more detail with reference to examples, but the present invention is not limited to these examples.

Example 1 0.5 mmol of phenylsilane, 1,8-nonadiyne
0.5 mmol, and a solution of 0.5 ml of benzene,
Under nitrogen, palladium-tricyclohexylphosphine
Medium in benzene solution (tris (dibenzylideneacetone))
Dipalladium and tricyclohexylphosphine (4 equivalents
Benzene solution of the mixture of
Add 5 ml (0.001 mmol Pd) and add
For 2.5 hours. From the NMR measurement of the reaction solution,
Carbosilane, (-SiPhH-A ₁− (CH₂)₅−
A₁’-)_n(IIIa) (wherein A₁And A₁’
-CH = CH- and> C = CH, respectively₂Choose from
Divalent groups which are the same or different from each other,
CH- and> C = CH₂Is 94: 6), but almost constant
It was found to be formed quantitatively. Preparative GPC (toluene
(IIIa) (78% yield; weight)
Average molecular weight = 23,000, number average molecular weight = 6,300
(Based on polystyrene)).

The spectrum data and the like of (IIIa) are as follows. ¹ H-NMR (C ₆ D ₆ ) δ 1.0-1.6 (br
_{m, = C-C- (CH} 2) 3), 1.9-2.4 (br
_{m, = C-CH 2)} , 5.06 and 5.1-5.2
(Each d (J = 3.0 Hz) and brm (integral ratio is 13:87), SiH), 5.66 (d (J = 2.
^{3Hz), Si-C = C} H a H b), 5.8-6.0
(Br m, Si-CH = and Si-C = CH
^{a H b), 6.35 (br} dt (J = 18.5,6.
1 Hz, Si-CH = C H ), 7.1-7.4 and 7.6-7.9 (brm, benzene ring proton, respectively) ²⁹ Si-NMR (C ₆ D ₆ ) δ -26, -22 IR (neat) 2142 cm ⁻¹ (ν (Si−
H))

The polycarbosilane (III) obtained in Example 1
a) applying the toluene solution on a glass substrate,
Heating in vacuum (100 ° C., 1 hour) gave a thin film (light brown) of the poorly soluble crosslinked polymer (IVa) with high thermal stability. The results of the thermogravimetric analysis of (IVa) are shown below. Melting point> 300 ° C. Thermogravimetric analysis (in nitrogen stream) Td ₁ (1% weight loss temperature) 404 ° C. Td ₅ (5% weight loss temperature) 436 ° C. Residual weight (980 ° C.) 17%

Comparative Example 1 An experiment was conducted under the same conditions as in Example 1 except that a benzene solution of palladium-tricyclohexylphosphine was not added. As a result, no formation of (IIIa) was observed by NMR.

Example 2 A solution of 0.2 mmol of phenylsilane, 0.2 mmol of 1,8-nonadiyne and 0.13 ml of benzene was added to a solution of a palladium-tricyclohexylphosphine catalyst in a benzene solution (tris (dibenzylideneacetone) Palladium and tricyclohexylphosphine (4
Eq.) In a benzene solution of 0.02 MPd).
02 ml (0.0004 mmol Pd) was added and 4
After heating at 0 ° C. for 3 hours, it was left at room temperature for one day. From GPC and NMR measurements of the reaction mixture, weight average molecular weight = 10
Polycarbosilane having a number average molecular weight of 17,000 (based on polystyrene), (IIIa) (-CH = C
H- and> abundance ratio of C = CH ₂ 94: 6) was found to have almost quantitatively produced.

Example 3 A solution of palladium-tricyclohexylphosphine catalyst in benzene (tris (dibenzylideneacetone) 2) was added to a solution of 0.5 mmol of phenylsilane, 0.5 mmol of p-diethynylbene and 0.5 ml of benzene under nitrogen. Palladium and tricyclohexylphosphine (4
Eq.) Of the mixture in benzene, 0.02M Pd)
0.025 ml (0.0005 mmol Pd) was added and heated at 40 ° C. for 1 hour. From NMR measurement of the reaction solution, _{polycarbosilane, (- SiPhH-A 2 -p} -C
_{6 H 4 -A 2 '-)} n (IIIb) ( wherein, _{A 2} and A
₂ ′ are —CH ＝ CH— and> C ＝ CH ₂ , respectively.
The same or different divalent groups selected from
Abundance of -CH = CH- and> C = CH ₂ 80:20)
Was found to be produced almost quantitatively. Preparative GPC
(IIIb) was purified by (toluene solvent) (67%
Yield; weight average molecular weight = 23,000, number average molecular weight =
6,200 (based on polystyrene)).

The spectrum data and the like of (IIIb) are as follows. ¹ H-NMR (C ₆ D ₆ ) δ 5.3-5.4 and 5.4-5.5 (br m (integration ratio is 59: 4, respectively)
1), SiH), 5.7-5.9 and 6.1-6.3.
(Each _{br m, Si-C = CH} 2), 6.5-
6.8 (br m, Si-CH =), 7.0-7.9
(Br m, benzene ring proton and Si—CH ＝ C
H ) ²⁹ Si-NMR (C ₆ D ₆ ) δ -23, -21,-
20 IR (nujol) 2126 cm ⁻¹ (ν (Si−
H)) UV (THF) 308 nm (ε = 2.2 × 10 ⁴ ) Further, (IIIb) showed blue light emission by irradiation with ultraviolet light in a solid or solution state (393 in tetrahydrofuran).
The emission wavelength of the excitation light of nm is λmax = 445, 4
66 nm).

The polycarbosilane (II) obtained in Example 3
Ib) is to apply the toluene solution on a glass substrate and heat it in vacuum (100 ° C., 1 hour) to form a thin film (light brown) of the hardly soluble crosslinked polymer (IVb) having high thermal stability. Gave. The results of thermogravimetric analysis and the like of (IVb) are shown below. Melting point> 300 ° C. Thermogravimetric analysis (in nitrogen stream) Td ₁ (1% weight loss temperature) 444 ° C. Td ₅ (5% weight loss temperature) 504 ° C. Residual weight (980 ° C.) 78%

Example 4 0.2 mmol of phenylsilane, 0.2 mmol of p-diethynylbenzene and 0.15 of tetrahydrofuran
Under a nitrogen atmosphere, a solution of bis (tricyclohexylphosphine) palladium catalyst in tetrahydrofuran (0.02M Pd) was added to 0.01 ml (0.0002 m
mol Pd) was added and heated at 40 ° C. for 1 hour and further at 60 ° C. for 1 hour. GPC and NM of reaction solution
From R measured, the weight average molecular weight = 10,000, polycarbosilane having a number-average molecular weight = 3,000 (polystyrene standard), (IIIb) (- CH = CH- and> abundance ratio of C = CH ₂ is 74:26 ) Was found to be produced almost quantitatively.

[0027]

According to the method of the present invention, a polycarbosilane having a divinylsilane partial structure useful for the production of various materials can be efficiently and safely produced from trihydrosilanes and diyne compounds, and its purification is easy. It is. When the polycarbosilane of the present invention is used, for example, a heat-resistant material having excellent thermal stability can be formed by applying the solution and then heating and crosslinking. Therefore, the industrial significance of the present invention is great.

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) CA (STN) REGISTRY (STN)

Claims (2)

(57) [Claims] 1. A compound of the general formula R ¹ SiH ₃ (I) (wherein R ¹ is a monovalent group selected from an alkyl group, an aryl group, an aralkyl group, and a monovalent heterocyclic group) in the presence of a palladium catalyst. A trihydrosilane represented by the general formula HC≡CR ² C≡CH (II) (wherein R ² is an alkylene group, an arylene group, or a divalent heterocyclic group) And a divalent group represented by the formula: (-SiR ¹ H—R ³ —R ² —R ⁴ —) _n (III) (wherein , R ¹ and R ² are those of the above formulas (I) and (II)
Same as inside. R ³ and R ⁴ are —CH ＝ C
H- (vinylene group) and> C = CH ₂ (vinylidene group) are the same or different divalent groups selected from each other. N represents an integer of 2 or more. )). 2. A compound represented by the general formula (—SiR ¹ H—R ³ —R ² —R ⁴ —) _n (III) wherein R ¹ is an alkyl group, an aryl group, an aralkyl group, or a monovalent heterocyclic ring. R ² represents an alkylene group, an arylene group, or 2
It represents a divalent group selected from among the divalent heterocyclic groups. R ³ and R ⁴ represent —CH ＝ CH— (vinylene group) and> C
= Divalent groups which are the same or different from each other and are selected from CH ₂ (vinylidene group). N represents an integer of 2 or more. Polycarbosilane represented by).