JPS6368590A - Cyclotetrasilanes and production thereof - Google Patents

Abstract

NEW MATERIAL:The compound of formula (R1-R24 are 1-20C alkyl, alkenyl or aryl provided that at least one combination of R1-R3, R4-R6, R7-R9, R10-R12, R13-R15, R16-R18, R19-R21 and R22-R24 is >=2C R). EXAMPLE:Octakis(ethyldimethylsilyl)cyclotetrasilane. USE:A raw material for polymer, photoresist or raw material for ceramics. PREPARATION:At least one kind of dihalogenated silane selected from 8 kinds of dihalogenated silanes of formulas (R1R2R3Si)2SiX2, (R4R5R6Si)2SiX2, (R7R8 R9Si)2SiX2, (R10R11R12Si)2SiX2, (R13R14R15Si)2SiX2, (R16R17R18Si)2SiX2, (19R20R21Si)2 SiX2 and (R22R23R24Si)2SiX2 is made to react with an alkali metal or alkaline earth metal.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention provides a novel compound, octakissilylcyclotetrasilane, and a method for producing the same.

In recent years, technological advances in organosilicon chemistry have been active, and various highly strained cyclopolysilane compounds have recently been synthesized.For example, ((CHs)tsi)h
(Journal of the American Chemical Society (J, Am; Ches, Soc,), 71
(1949) 963), (L-Bu (CHx) SL) 4 (Bu is a butyl group, (Journal Organometallic Chemistry (J, Organomet, ches,), 77 (1
974) Cf3), (MeszSi)z (Mes is mesityl group, (Science), 21 Rainbow (1
981) 1343) , (ArzSi) s (Ar
is 2,6-dimethylphenyl group, Journal of American Chemical Society (J, Am, Che
m, Soc, ), 104 (1982) 1152),
((t-BuCHt)zsi) 3+ ((t-BuC
Hz)zsi) z(Chemical Communication (C
hem, Commun, ), (1983) 781)
, (t-BuzSi)s+ (t-BuzSi)z(Angew, Chsm,), 9
6 (1984) 1311), etc. Furthermore, as a cyclopolysilane containing a silyl group in the side chain, only octakis(trimethylsilyl)cyclotetrasilane ((CHi) zsi ) tsi) 4 is known. (Organometallics
(1982) 1410).

These highly strained cyclopolysilanes have large strain energy and are highly thermally reactive, and are used as reaction reagents with various molecules. Also, 5t in cyclopolysilane
-3+ bond is easily decomposed by light irradiation (approximately 200 to 400 nm) and releases silylene (:5iRz);
Various photoreactions can be performed using this. In particular, cyclopolysilane having a silyl group in its side chain has many 5t-5+ bonds, and is expected to have extremely high photoreactivity. Furthermore, by ring-opening polymerization, it can be used as a raw material for polymers.
It can be expected to have a wide range of uses as a photoresist and as a raw material for SiC ceramics.

(((C)Is) zsi ) zsi) is a known cyclopolysilane containing a silyl group in the side chain described above.
a is methoxytris(trimethylsilyl)silane ((
(Cfh)zsi) 350CL) is synthesized by thermal decomposition.

However, in this pyrolysis method, the raw material [(CH
z)xSi) tsiOcH* is difficult to obtain, expensive, and difficult to call an industrial method, and
The yield of si) zsi) a is also low and insufficient.

The inventors of the present invention have made earnest efforts to improve the above-mentioned conventional problems and have arrived at the present invention. That is, the present invention provides a method for producing novel cyclotetrasilanes having a silyl group in the side chain, using an easily available organosilicon compound as a raw material.

The cyclotetrasilanes having a silyl group in the side chain of the present invention are those shown by the following formula (+). That is, SiR+Rzlh SiRmRsRaRzJz! R
zzSi-Si 5i-SiRJaRqRz
lIh. R1*Si-Si-5i-5iR+. RzR
+zSiR+iR+J+self SiR+3RzR+5 (However, R, to RZ4 are A/I/
*/I/ 5, an alkenyl group or an aryl group, and R+ to R1, R1 to R4, R1 to R
9.R.

. ~R+z, R+z~RIS, R16~R+
s −, RIq to L+, Lz to L4, each 3
In each combination of R5's, at least one of them is an R group having 2 or more carbon atoms. Also, R, ~R
24 may be the same or different. ) Specific examples of the R group include methyl group, ethyl group, n-propyl 5.1so
-propyl group, n-butyl group, 1so-butyl group, t-
Butyl group, n-pentyl i, neo-pentyl group, n-
Hexyl group, n-octyl group, hexadecyl group, vinyl group, allyl group, n-butenyl group, phenyl group, tolyl group, naphthyl group and their derivatives, i.e. halogen, hydroxyl group, aldehyde group, carboxyl group, amino group, etc. Examples include those included in substituents. As mentioned above, all three alkyl groups bonded to one silyl group are not all methyl groups, and at least one has 2 carbon atoms.
That's all.

Specific examples of such cyclotetrasilanes include:
Examples include octakis(ethyldimethylsilyl)cyclotetrasilane, octakis(tri-n-butylsilyl)cyclotetrasilane, octakis(tri-n-hexylsilyl)cyclotetrasilane, and octakis(triphenylsilyl)cyclotetrasilane.

The cyclotetrasilanes of the present invention are more stable than conventional cases in which the three alkyl groups mentioned above are all methyl groups, and for example, the reaction with oxygen in air (Si-
0-Si bonds) are slow and easy to store. This effect is greater as the R group becomes bulkier, and this is thought to be due to steric hindrance of the R group. Furthermore, the solubility in 8% ig medium is significantly improved compared to the case where all methyl groups are used.

Next, the cyclotetrasilanes of the present invention are produced by the following method.

That is, it can be produced by reacting at least one type of dihalogenated silane selected from eight types of dihalogenated silanes represented by the following formula (n) with an alkali metal or an alkaline earth metal.

(R+RzRsSi)zsiXz, (RaRsR*
Si) 2SiXz.

(RJ*RqSi) zsiXz, (R+++Rz
R+zSi)zsiXz, (R+ffR+aR+5Si
)zsiXz, (R+aR+J+5Si)zsiX
z, (R+qRtoRzISr)tsrXt or (
RzJzJzaSi) zsiXt
(■) Here, R3 to La are an alkyl group, an alkenyl group, or an aryl group having 20 or less carbon atoms. Also, X is a halogen atom, such as fluorine, chlorine, bromine,
Examples include iodine, but among these, bromine is preferable because of the yield of cyclotetrasilanes. Specific exemplary compounds represented by formula (II) include, for example, bis(ethyldimethylsilyl)dibromosilane.

Further, alkali metals or alkaline earth metals are used in the reaction, and among these, sodium, potassium, or magnesium is preferred from the viewpoint of yield and economy. The required amount may be the amount required according to the reaction formula described below, but in reality it is preferable to use an amount slightly in excess of the stoichiometry.6 Regarding the reaction mode, there is no particular restriction, but usually It is carried out in the liquid phase, and the solvents are toluene, benzene,
Xylene, hexane, heptane, tetrahydrofuran, etc. can be used. Reaction temperature is preferably 20 to 200°
C1 reaction time preferably ranges from 10 minutes to 30 hours. After the completion of the reaction, the produced salts are separated and removed by filtration, etc., and then a poor solvent (hexane, alcohol, etc.) is used to precipitate the desired cyclotetrasilanes, which is the most preferable method. It is preferable that all the imprinting be carried out in an inert gas such as nitrogen, argon, helium or the like. As a specific reaction example, for example, 4 (CJs(CH3)zsi) zsiBrz +
8Na → ((G2H5(CH3) tsi ] z
si) a+8NaBr
■ can be mentioned.

Further, the dihalogenated silanes used as starting materials in the present invention can be produced by various methods, and the production method is not limited in the present invention, but the following method is the most economical and easy method. can be given. That is, specifically, for example, PhzSiCIz + 2R+RzRiSiC1+2M
g→(RJJzSi)zSiPhz +2MgC1□
■It is. The reaction (2) is usually carried out in a liquid phase in the presence of a solvent, and the reaction temperature is preferably from 20 to 100°C.The reaction time is preferably from 30 minutes to 5 hours.

After the reaction is completed, the produced salt is separated and removed by filtration or the like to obtain disilyldiphenylsilane. The disilyldiphenylsilane is further converted to disilyldibromosilane by the reaction (2), but this reaction is carried out in the presence of a solvent as in (2).
The temperature of the reaction carried out in the liquid phase is preferably between 20 and 10
The 0°01 reaction time is preferably 30 minutes to 10 hours. After the 0° reaction is completed, the produced aluminum salt is separated and removed by filtration or the like to obtain the desired disilyldibromosilane. It is preferable that all operations in (1) and (2) be carried out in an inert gas such as tin, argon, helium or the like.

Note that PJSiCIz and RIR2RzSiC1, which are the raw materials for producing the dihalogenated silanes described above, can be produced relatively easily by a direct reaction between metal silicon and a halogenated hydrocarbon, and are easily available.

Hereinafter, the present invention will be explained by examples.

<Example 1> Octakis(ethyldimethylsilyl)cyclotetrasilane was synthesized according to the following reaction route.

PhzSiCI2+2CzHs(CHz)zsicl
+2Mg→(CzHs(CH3) zsi ) zsi
Phz + 2MgCLz ■”lBr
5 +5iBrz ■-
4 (CJs(CH3)zsi) zSiBrz+8
Na -” ((CJs(CHz)zsi) zsi)
4+ 8NaBr ■゛(11 bis(
Synthesis of ethyldimethylsilyl)diphenylsilane (■°
) Ethyldimethylchlorosilane (78 g, 0.63
so1), magnesium (29g, 1.20g-ato
m), HMPA (300 ml) was placed, and while stirring at room temperature, diphenyldichlorosilane (72 g, 0.0
．． After stirring the reaction mixture at room temperature for 2 hours, a THF (140a+1) solution of 28 mol) was added dropwise over 1 hour.
Hexane (500ml) was added. The precipitated salt was filtered off along with unreacted magnesium. The filtrate was diluted with 5χ hydrochloric acid (
100+*l), washed with water, and dried over anhydrous magnesium sulfate. ? The solvent 8 was removed by distillation under reduced pressure.

Bis(ethyldimethylsilyl)diphenylsilane is collected
Fi75g (yield 74χ) was obtained as a colorless liquid.

The physical properties of this product were as follows.

[Z-point] 190-192°C/ 7mmHg
('HNMR) (CC1,) δ0.14 (S, 12)
1. Me) 0.52 to 1.18 (m, 10H, Et) 7
．． 37 (+m, 10H, Ph) [Elemental analysis value] (Actual measurement value) C, 67, 46; H,
9,00χ (calculated value) C as CzoHtzSit
, 67, 34; ) 1,9.04χ (2) Synthesis of bis(ethyldimethylsilyl)dibromosilane (■° reaction) Add the bis(
ethyldimethyl)diphenylsilane (18g, 0.04
4 mol), aluminum bromide (1.8 g, 0.007
mol) and benzene (200 ml) were added thereto, and hydrogen bromide was passed therein for 5 hours at room temperature while stirring. Hexane (500 ml) was added to the reaction mixture, and the precipitated aluminum salt was filtered off. 0.5 ml of acetone was added to the filtrate and distilled. Bis(ethylmethylsilyl)dibromosilane was obtained as a colorless liquid in a yield of 112 g (yield 67χ).

The physical properties of this product were as follows.

[Boiling point] 170-172°C 15mmHg[:'H
IIMR) (CC1,) δ 0.26 (S, 12H,
Me) 0.69-1.3 (m, 5H, Et) [Elemental analysis value] (Actual measurement value) C, 34,27; H, 7,2
3χ (calculated value) C+zH3oSiJrz as C,3
4, 45; H, 7, 23 Sodium (0.61g, 26mg
-at.

ff+) Add totoluene (30III+), 110
Bis(ethyldimethylsilyl)dibromosilane obtained in (2) (4.0 g, 1
1.1CAMol) dissolved in toluene (20 ml) was added dropwise over 1 hour with stirring. 19 of the reaction mixture
The mixture was heated to reflux for an hour and cooled to room temperature. Hexane (IS
Oml) was added, and the formed salt was precipitated and separated by filtration. The filtrate was concentrated and a mixed solution of ethanol/pentane (9/1) was added to precipitate octakis(ethyldimethylsilyl)cyclotetrasilane. Yield 0.23g (yield 20χ).

The physical properties of this product are as follows.

[Shape] White columnar crystal [Melting point] 335-347°C CU V ] (C-hexane) 3
00 nm (t 1900) [I R) 2950 (
s), 2925(s), 2900(s), 2875(s)
).

1460(m), 1250(s), 1240(
s), 1000(s).

830(11), 800(S), 775811-'(
II) ('IN? II?) (C, DA) 60.54
(s, 6LMe) 1.10 (a+, 5H, Et) [”SiNMR] (C6D &, TMS) δ-89, 8 (
(ELMezSi)zSi )-5,12(EtMez
Si) [Exact MS (El)) (Actual measurement value) + s/z
808.4117 (calculated value) CstHs*Si+ x
m/z 808.4118 Yoshizato ■ Shika The present invention provides novel cyclotetrasilanes that are industrially useful, and in particular are expected to be used in the future, and a method for producing the same. The manufacturing process uses raw materials that are relatively easy to use as starting materials, providing an economical manufacturing method.

Claims (2)

[Claims] (1) Cyclotetrasilanes represented by formula (I). ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (However, R_1 to R_2_4 are alkyl groups, alkenyl groups, or aryl groups having 20 or less carbon atoms, and R_1 to R_3, R_4 to R_6, R_7
to R_9, R_1_0 to R_1_2, R_1_3 to R_1_5, R_1_6 to R_1_8, R_1_9
In each combination of three R_ groups, R_2_1 to R_2_2 to R_2_4, at least one is an R group having 2 or more carbon atoms. Also, R_1~
R_1_5 may be the same or different. ) (2) At least one type of dihalogenated silane selected from eight types of dihalogenated silanes represented by formula (II) and (R_1R_2R_3Si)_2SiX_2, (R_4
R_5R_6Si)_2SiX_2, (R_7R_8R
_9Si)_2SiX_2, (R_1_0R_1_1R
_1_2Si)_2SiX_2, (R_1_3R_1_
4R_1_5Si)_2SiX_2, (R_1_6R_
1_7R_1_8Si)_2SiX_2, (R_1_9
R_2_0R_2_1Si)_2SiX_2 or (
R_2_2R_2_3R_2_4Si)_2SiX_2
(II) (However, R_1 to R_2_4 have 20 carbon atoms.
The following alkyl group, alkenyl group or aryl group, where X is a halogen atom, R_1 to R_1
_5 may be the same or different. ) A method for producing cyclotetrasilanes represented by formula (I), which comprises reacting with an alkali metal or an alkaline earth metal. ▲There are mathematical formulas, chemical formulas, tables, etc.▼ (I) (However, R_1 to R_2_4 are alkyl groups, alkenyl groups, or aryl groups with 20 or less carbon atoms.)