JPH05320352A - Dehydrogenative condensation catalyst for organosilicon monomer - Google Patents

Abstract

(57) [Summary] [Object] To provide a highly active dehydrogenative condensation catalyst which is easy to synthesize and easy to handle, and to obtain an organosilicon polymer efficiently from an organosilicon monomer in a short time. [Structure] A catalyst for dehydrogenative condensation of an organosilicon monomer has the formula Cp ₂ MX ₂ (wherein Cp each independently represents a substituted or unsubstituted η ⁵ -cyclopentadienyl group, The pentadienyl groups may be covalently bonded to each other via one or more atoms, M being T
i, Zr and Hf, and X represents F, Cl, Br and I. ) And a metallocene dihalide represented by the formula (Wherein A represents an alkali metal and Ar represents an aromatic hydrocarbon).

Description

Detailed Description of the Invention

[0001]

FIELD OF THE INVENTION The present invention relates to a catalyst used for producing an organosilicon polymer, and more particularly to a catalyst used for producing an organosilicon polymer by dehydrogenative condensation of an organosilicon monomer.

[0002]

BACKGROUND OF THE INVENTION Organosilicon polymers are used as electronic material devices, photoresist materials and photoinitiators, as well as carbonized silicon carbide fibers, silicon carbide binders, silicon carbide sheets, silicon carbide coatings and sintered silicon carbide. It is a polymer useful as a precursor for silicon materials.

Conventionally, organosilicon polymers have been synthesized by the Wurtz reaction of dihalosilane, dehydrogenative condensation of hydrosilane, or the like.

However, a method for preparing an organosilicon polymer by the Wurtz reaction of dihalosilane is known as dihalosilane 1
More than 2 moles of alkali metal is required per mole, and there is a risk of ignition of alkali metals, etc .; reaction conditions are extreme, types of side chains that can be produced are limited; molecular weight and molecular weight distribution Poor controllability; a large amount of salt is by-produced, and the yield of organosilicon polymer is 10 ~
It is as low as 50%; and a small amount of chlorine produced as a by-product remains in the organosilicon polymer (it is difficult to remove it), and the electrical properties of the organosilicon polymer deteriorate. Have.

On the other hand, in recent years, a dehydrogenative condensation reaction of hydrosilane using a transition metal complex catalyst has become known. For example, E. Henge (Hengge) et al., Cp ₂ TiMe ₂ as _{catalyst, Cp 2 ZrMe 2, Cp 2} Ti (n-
Bu) ₂ , Cp ₂ Zr (n-Bu) ₂ (where Cp represents a cyclopentadienyl group, Me represents a methyl group, and Bu represents a butyl group), and dimethyldisilane is converted into oligosilane or polysilane. It has been reported about the reaction of dehydrogenative condensation to (J. Organomet. Chem., 410, C1 to C4, 1991). As described above, a metallocene catalyst is mainly used as a catalyst used in the dehydrogenative condensation reaction. In addition, for example, Harrod et al. Use Cp ₂ TiM as a catalyst.
e ₂ , Cp ₂ ZrMe ₂ , Cp ₂ Ti (CH ₂ C
₆ H ₅ ) ₂ etc. are used to synthesize linear organosilicon polymers from organotrihydrosilane (J. Organo
met.Chem., 279, C11-C13,1985, CAN.J.CHEM.VOL.65,1804
-1809, 1987). Further, in JP-A-2-67288, a linear organosilicon polymer is synthesized by using Cp ₂ TiAr ₂ (where Ar is a substituted or unsubstituted phenyl group or naphthyl group) as a catalyst. .. These methods have advantages over the method using the Wurtz reaction in that they proceed under relatively mild conditions, the only by-product is hydrogen, which is easily separated, and the yield is as high as about 80%. ..

[0006]

In the method using the above-mentioned dehydrogenative condensation reaction, a transition metal complex catalyst is used, but these complexes require several steps of chemical reaction for synthesis,
Moreover, it was necessary to handle the catalyst used in an inert gas atmosphere.

Therefore, an object of the present invention is to provide a dehydrogenative condensation catalyst for an organosilicon monomer, which is easy to synthesize, can be handled in air, and is highly active.

[0008]

That is, the present invention provides, as a first component, a compound represented by the formula Cp ₂ MX ₂ (wherein Cp each independently represents a substituted or unsubstituted η ⁵ -cyclopentadienyl group, The two cyclopentadienyl groups may be covalently bonded to each other via one or more atoms, M being Ti,
Zr and Hf, and X represents F, Cl, Br and I. )
And a metallocene dihalide represented by

[0009]

[Chemical 2] (Here, A represents an alkali metal and Ar represents an aromatic hydrocarbon.) A catalyst for dehydrogenative condensation of an organosilicon monomer comprising an aromatic radical anion alkali metal salt represented by

The metallocene dihalide used as the first component is, for example, Cp ₂ TiCl ₂ , Cp ₂ ZrCl.
_{2, Cp 2 HfCl 2, Cp} 2 TiBr 2, Cp 2 Zr
Br ₂ , Cp ₂ HfBr ₂ , Cp ₂ TiI ₂ , Cp ₂ Z
rI ₂ , Cp ₂ HfI ₂ , Cp ^* ₂ TiCl ₂ , Cp ^*
₂ ZrCl ₂ , Cp ^* ₂ HfCl ₂ , Cp ^* ₂ TiB
r ₂ , Cp ^* ₂ ZrBr ₂ , Cp ^* ₂ HfBr ₂ , Cp
^* ₂ TiI ₂ , Cp ^* ₂ ZrI ₂ , Cp ^* ₂ HfI ₂ ,
Cp ^* CpTiCl ₂ , Cp ^* CpZrCl ₂ , C
p ^* CpHfCl ₂ , Cp ^* CpTiBr ₂ , Cp ^* C
pZrBr ₂ , Cp ^* CpHfBr ₂ , Cp ^* CpTi
I ₂ , Cp ^* CpZrI ₂ , Cp ^* CpHfI
₂ (where Cp ^* is

[0011]

[Chemical 3] Indicates. ), And the following formula:

[0012]

[Chemical 4]

[0013]

[Chemical 5] Etc. Here, as the atom for covalently bonding the two cyclopentadienyl groups of the metallocene dihalide used as the first component, for example, C, S
Examples thereof include i, O, N, Ge and the like. These first components are preferably synthesized separately and purified, but it is also possible to prepare raw materials for producing these components by adding them to the reaction system. Further, these components may be supported on a carrier before use.

The first component used in the present invention is G. Synthesized from cyclopentadienyl Grignard reagent and corresponding metal halides by Wilkinson et al. (J. Am. Chem. S.
oc. , 76, 4281-4284, 1954). Moreover, a commercial item can also be utilized.

In the aromatic radical anion alkali metal salt used as the second component, A represents an alkali metal, preferably Li, Na, K or Rb. Also,
Ar represents an aromatic hydrocarbon, preferably naphthalene,
Anthracene, phenanthrene, biphenyl, terphenyl, benzophenone, diphenylacetylene, benzylideneaniline and the like are shown. Examples of the aromatic radical anion alkali metal salt include, for example,

[0016]

[Chemical 6]

[0017]

[Chemical 7] Etc.

The second component used in the present invention can be easily obtained by dissolving the aromatic hydrocarbon in ether or the like under a nitrogen stream, adding the alkali metal little by little, and then stirring.

The catalyst of the present invention is one of organosilicon monomers having at least one hydrosilyl group, such as hydrosilane, dihydrosilane, trihydrosilane, or an organosilicon compound monomer having a hydrosilyl group, dihydrosilyl group, or trihydrosilyl group. The above is used for dehydrogenative condensation to produce an organosilicon polymer.

As the above-mentioned organosilicon compound monomer,
For example, the following compounds may be mentioned. MeSiH ₃ , Et
_{SiH 3, PhSiH 3, Me 3} SiSiH 3,

[0021]

[Chemical 8] ,as well as

[0022]

[Chemical 9] ,as well as

[0023]

[Chemical 10] , And _{H 3 Si-CH 2 -SiH 3} , H 3 Si-CH
_{(SiMe 3) -SiH 3, H} 3 Si-CH (Me) -
_{SiH 3, H 3 Si-CH} (Et) -SiH 3, H 3 S
i-CH (n-Pr) -SiH 3, H 3 Si-C (M
_{e) 2 -SiH 3, H 3} Si-CH (i-Pr) -Si
_{H 3, H 3 Si-C} (Me) (Et) -SiH 3, H 3
Si-C (Me) (SiMe 3) -SiH 3, H 3 Si
_{-C (Et) (SiMe 3)} -SiH 3, H 3 Si-C
_{(SiMe 3) 2 -SiH 3,} H 3 Si-CH 2 CH
_{(Me) -SiH 3, H 3} Si-CH 2 CH (Et) -
_{SiH 3, H 3 Si-CH} 2 C (Me) 2 -SiH 3,
_{H 3 Si-CH (Me)} CH (Me) -SiH 3, H 3
_{Si-CH 2 CH (SiMe 3} ) -SiH 3, H 3 Si
_{-CH 2 C (Me) (SiMe} 3) -SiH 3, H 3 S
_{i-CH 2 C (SiMe 3} ) 2 -SiH 3, H 3 Si-
_{CH (Me) CH (SiMe 3} ) -SiH 3, H 3 Si
_{-CH (SiMe 3) CH (SiMe} 3) -SiH 3,
_{H 3 Si- (CH 2) 3} -SiH 3, H 3 Si- (CH
₂ ) ₂ CH (Me) -SiH ₃ , H ₃ Si-CH (Si
_{Me 3) CH 2 CH 2 -SiH} 3, H 3 Si-CH 2 C
_{H (SiMe 3) CH 2 -SiH} 3, H 3 Si-CH =
_{CHCH 2 -SiH 3, H 3 Si-} (CH 2) 4 -Si
_{H 3, H 3 Si-CH} = CHCH = CH-SiH 3, H
_{3 Si-CH 2 CH = CHCH} 2 -SiH 3,

[0024]

[Chemical 11] And

[0025]

[Chemical formula 12] The dehydrogenative condensation reaction carried out using the catalyst of the present invention may be carried out in an open system or a closed system. The reaction may be carried out in a liquid phase or without a solvent, but is preferably a hydrocarbon solvent such as benzene, toluene, xylene, pentane or hexane, and / or tetrahydrofuran (THF), dioxane, It is carried out in the presence of a solvent such as diethyl ether, dibutyl ether, dimethoxyethane. Illustrating preferable reaction conditions, it is preferably 1.0 × 10 ^{−7 to} 100 with respect to the organosilicon monomer.
The metallocene dihalide represented by the formula Cp ₂ MX ₂ of the first component of mol%, particularly preferably 1.0 × 10 ⁻⁴ to 10 mol%, and preferably 1.0 × 1 with respect to the first component.
0 ⁻¹⁰ to 10 ⁵ mol%, particularly preferably 1.0 × 10 ⁻⁷
-10 ⁴ mol% of the second component aromatic radical anion using the above-mentioned catalyst consisting of an alkali metal salt, the reaction system hydrogen,
The reaction temperature is about −60 to 300 ° C., more preferably about 20 ° C. under a non-oxidizing gas atmosphere such as nitrogen, argon or helium.
The reaction time is about 5 minutes to 10 days, more preferably about 10 minutes to 48 hours. The temperature during the reaction,
By changing the reaction time, the catalyst, etc., the repeating unit of the polymer, the molecular weight, the dehydrogenation rate, and the degree of crosslinking can be changed. For example, when the reaction temperature is low and the reaction time is short, the molecular weight is low, and conversely, when the reaction temperature is high and the reaction time is long, the molecular weight is high.

The present invention is not limited by a particular theory, but the reason why the catalyst of the present invention exerts its effect is that the first component is a metallocene dihalide and the second component is an aromatic radical anion alkali metal salt. And the three reacting organosilicon monomers interact with each other to allow the reaction to proceed. At this time, the aromatic radical anion alkali metal salt as the second component acts as a reducing agent to reduce the metallocene dihalide and the reactive species. Is considered to occur.

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

[0028]

【Example】

[0029]

Example 1 5.0 g of phenylsilane as a monomer
(46 mmol), toluene 5 ml, Cp ₂ TiCl ₂
87 mg (0.33 mmol, 0.7 for monomer)
2 mol%) and 0.70 mmol of naphthalene radical anion lithium salt (7 ml of 0.1 mol toluene solution) were added to a pressure resistant reactor of 100 ml capacity equipped with a needle valve and a magnetic stirrer, and freeze deaeration was performed twice. The tube was sealed under a nitrogen atmosphere. This was heated in an oil bath at 50 ° C. for 5 hours, passed through a Florisil column (toluene solvent) to remove the catalyst, and then the solvent was distilled off under reduced pressure. 4.4 g of organosilicon polymer was obtained (yield 88%). The molecular weight by GPC analysis is _Mn (number average molecular weight) 720, M in terms of polystyrene.
_{It was w} (weight average molecular weight) of 1030. When the ¹ H-NMR spectrum of this organosilicon polymer was measured (the spectrum is shown in FIG. 1), 4.2 to 4.8 pp.
The peak due to hydrogen bonded to the silicon atom at m is
Peaks attributable to protons of the phenyl group were observed at 6.6 to 7.8 ppm (the peak of the methyl group of toluene as the residual solvent was found at 2.1 ppm. 0 ppm was the peak of the tetramethylsilane internal standard reagent). It is.).
Further, the IR spectrum of this organosilicon polymer was measured (the spectrum is shown in FIG. 2) 2107.
The peaks due to Si-H and Si-H ₂ are around cm ⁻¹ ,
A peak based on Si—H ₂ was observed near 911 cm ⁻¹ .

[0030]

Example 2 n-hexylsilane as a monomer 5.
3 g (46 mmol), diethyl ether 3 ml, Cp
₂ ZrCl ₂ 96 mg (0.33 mmol, 0.72 mol% with respect to monomer), anthracene radical anion sodium salt 0.70 mmol (0.1 mol benzene solution 7 ml), capacity equipped with needle valve and magnetic stirrer After adding to a 100 ml pressure resistant reactor and performing freeze deaeration twice, the tube was sealed under a nitrogen atmosphere. This was heated in an oil bath at 150 ° C for 10 hours, and then subjected to a Florisil column (toluene solvent).
After removing the catalyst by passing through the column, the solvent was distilled off under reduced pressure. 4.2
g of organosilicon polymer was obtained (yield 79%). GPC
The molecular weight by analysis is polystyrene equivalent _Mn 590, M
It was _w 770.

[0031]

Example 3 4.8 g (46 mmol) of 1,1,1-trimethyldisilane as a monomer, 5 ml of benzene,
Cp ₂ HfCl ₂ 125 mg (0.33 mmol, 0.72 mol% based on the monomer), phenanthrene radical anion potassium salt 0.70 mmol (0.1 mol)
The benzene solution (7 ml) was added to a pressure resistant reactor having a capacity of 100 ml equipped with a needle valve and a magnetic stirrer, and freeze deaeration was performed twice, and the tube was sealed under a nitrogen atmosphere. This was heated in an oil bath at 70 ° C. for 6 hours, passed through a Florisil column (toluene solvent) to remove the catalyst, and then the solvent was distilled off under reduced pressure.
4.0 g of organosilicon polymer was obtained (yield 83%).
The molecular weight by GPC analysis is M _n 48 in terms of polystyrene.
00 and _Mw 11800.

[0032]

Example 4 p-Tolylsilane as a monomer 5.6
g (46 mmol), xylene 5 ml, Cp ₂ ZrBr
₂ 126 mg (0.33 mmol, 0.72 mol% based on the monomer), biphenyl radical anion sodium salt 0.70 mmol (0.1 mol toluene solution 7)
ml) with a needle valve and a magnetic stirrer and a volume of 10
In addition to a 0 ml pressure resistant reactor, freeze deaeration was performed twice, and the tube was sealed under a nitrogen atmosphere. This was heated in an oil bath at 50 ° C. for 10 hours, passed through a Florisil column (toluene solvent) to remove the catalyst, and then the solvent was distilled off under reduced pressure. 5.2 g of organosilicon polymer was obtained (yield 93%). The molecular weights by GPC analysis were M _n 630 and M _w 880 in terms of polystyrene.

[0033]

Example 5 Cyclohexylsilane 5.2 g (46 mmol) as a monomer, THF 5 ml, Cp ₂ Zr
I ₂ 157 mg (0.33 mmol, 0.72 mol% based on the monomer), terphenyl radical anion potassium salt 0.70 mmol (0.1 mol THF solution 7 m
l) is a needle valve, capacity 100 equipped with a magnetic stirrer
In addition to a pressure resistant reactor of ml, freeze deaeration was performed twice, and the tube was sealed under a nitrogen atmosphere. This was heated in an oil bath at 110 ° C. for 8 hours, passed through a Florisil column (toluene solvent) to remove the catalyst, and then the solvent was distilled off under reduced pressure. 4.6 g of organosilicon polymer was obtained (88% yield). The molecular weight by GPC analysis was _Mn 290 and _Mw 540 in terms of polystyrene.

[0034]

Example 6 2-silylbutane 4.0 as a monomer
g (46 mmol), diethyl ether 5 ml, CpC
p ^* ZrCl ₂ 119 mg (0.33 mmol, 0.72 mol% with respect to monomer), benzophenone radical anion lithium salt 0.70 mmol (0.1 mol diethyl ether solution 7 ml) equipped with needle valve and magnetic stirrer In addition to the pressure resistant reactor having a capacity of 100 ml, freeze deaeration was performed twice, and the tube was sealed under a nitrogen atmosphere. This one
After heating in an oil bath at 30 ° C. for 7 hours and passing through a Florisil column (toluene solvent) to remove the catalyst, the solvent was distilled off under reduced pressure. 3.8 g of organosilicon polymer was obtained (yield 95
%). The molecular weight by GPC analysis is M in terms of polystyrene.
_n 650 and M _w 790.

[0035]

Example 7 5.6 g (46 mmol) of phenylmethylsilane as a monomer, 5 ml of toluene, Cp ₂ Z
rCl ₂ 96 mg (0.33 mmol, 0.72 mol% with respect to monomer), naphthalene radical anion sodium salt 0.70 mmol (0.1 mol benzene solution 7 ml), needle valve, volume 1 equipped with magnetic stirrer
In addition to a 00 ml pressure resistant reactor, freeze deaeration was performed twice, and the tube was sealed under a nitrogen atmosphere. 15 in an oil bath at 150 ° C
After heating for a period of time and passing through a Florisil column (toluene solvent) to remove the catalyst, the solvent was distilled off under reduced pressure. 4.7 g of organosilicon polymer was obtained (yield 84%). The molecular weight by GPC analysis is polystyrene-converted M _n 280, M _w 46
It was 0.

[0036]

Example 8 6.1 g (46 mmol) of 2-trimethylsilylethylsilane as a monomer and 5 m of toluene
1, Cp ₂ ZrCl ₂ 96 mg (0.33 mmol, 0.72 mol% based on the monomer), naphthalene radical anion sodium salt 0.70 mmol (0.1 mol)
THF solution (7 ml) was added to a pressure resistant reactor with a needle valve and a magnetic stirrer and a capacity of 100 ml, and freeze degassing was performed to 2
After the operation was repeated, the tube was sealed under a nitrogen atmosphere. This is heated in an oil bath at 80 ° C for 5 hours, and then Florisil column (toluene solvent)
After removing the catalyst by passing through the column, the solvent was distilled off under reduced pressure. 5.5
g of organosilicon polymer was obtained (yield 90%). GPC
The molecular weight by analysis is _Mn 950, M in terms of polystyrene
It was _w 1130.

[0037]

Example 9 5.5 g (46 mmol) of 2,2-dimethyltrisilane as a monomer, 5 ml of toluene, Cp
₂ ZrCl ₂ 96 mg (0.33 mmol, 0.72 mol% with respect to monomer), naphthalene radical anion sodium salt 0.70 mmol (0.1 mol benzene solution 7 ml) capacity equipped with needle valve and magnetic stirrer After adding to a 100 ml pressure resistant reactor and performing freeze deaeration twice, the tube was sealed under a nitrogen atmosphere. 6 in an oil bath at 80 ° C
After heating for a period of time and passing through a Florisil column (toluene solvent) to remove the catalyst, the solvent was distilled off under reduced pressure. 5.0 g of organosilicon polymer was obtained (yield 91%). The molecular weight by GPC analysis is M _n 3550, M _w 1 in terms of polystyrene.
It was 6300.

[0038]

Example 10: Disilylethane 4.1 as a monomer
g (46 mmol), toluene 5 ml, Cp ₂ ZrCl
₂ 96 mg (0.33 mmol, 0.
72 mol%), naphthalene radical anion lithium salt 0.70 mmol (0.1 mol diethyl ether solution 7
ml) with a needle valve and a magnetic stirrer and a volume of 10
In addition to a 0 ml pressure resistant reactor, freeze deaeration was performed twice, and the tube was sealed under a nitrogen atmosphere. This was heated in an oil bath at 60 ° C. for 5 hours, and then the solvent was distilled off under reduced pressure. 3.4 g of organosilicon polymer was obtained (yield 83%). The molecular weight by GPC analysis is polystyrene-converted _Mn 3400, _Mw 17200.
Met.

[0039]

Example 11 Phenylsilane 5.0 as a monomer
g (46 mmol), toluene 5 ml, Cp ₂ TiCl
0 ₂ 87 mg (0.33 mmol, based on the monomers.
72 mol%) and 0.70 mmol of lithium salt of naphthalene radical anion (7 ml of 0.1 mol xylene solution) were added to a pressure resistant reactor having a capacity of 100 ml equipped with a needle valve and a magnetic stirrer, and freeze deaeration was performed twice. The tube was sealed under a nitrogen atmosphere. This was heated in an oil bath at 50 ° C. for 5 hours, passed through a Florisil column (toluene solvent) to remove the catalyst, and then the solvent was distilled off under reduced pressure. 4.4 g of organosilicon polymer was obtained (yield 88%). The molecular weight by GPC analysis was M _n 890 and M _w 1260 in terms of polystyrene.

[0040]

Example 12 6.3 g (46 mmol) of 1,4-disilylbenzene as a monomer, 5 ml of toluene, Cp
₂ ZrCl ₂ 96 mg (0.33 mmol, 0.72 mol% with respect to monomer), naphthalene radical anion sodium salt 0.70 mmol (0.1 mol benzene solution 7 ml) capacity equipped with needle valve and magnetic stirrer After adding to a 100 ml pressure resistant reactor and performing freeze deaeration twice, the tube was sealed under a nitrogen atmosphere. 6 in an oil bath at 70 ° C
After heating for an hour, the solvent was distilled off under reduced pressure. 6.1 g of organosilicon polymer was obtained (yield 97%). The molecular weight by GPC analysis is _Mn 3510, M _w 17 in terms of polystyrene.
It was 790.

[0041]

Comparative Example 1 5.0 g of phenylsilane as a monomer
(46 mmol), benzene 5 ml, Cp ₂ ZrCl ₂
96 mg (0.33 mmol, 0.7 for monomer)
(2 mol%) was added to a pressure resistant reactor having a capacity of 100 ml equipped with a needle valve and a magnetic stirrer, freeze-deaerated twice, and then sealed under a nitrogen atmosphere. 1 in an oil bath at 150 ° C
Heated for 5 hours. No polymer was obtained and the phenylsilane monomer was recovered.

[0042]

[Comparative Example 2] 5.0 g of phenylsilane as a monomer
(46 mmol), benzene 5 ml, and naphthalene radical anion sodium salt 0.70 mmol (0.1 mol benzene solution 7 ml) were added to a 100 ml capacity pressure-resistant reactor equipped with a needle valve and a magnetic stirrer, and freeze deaeration was performed to 2 After the operation was repeated, the tube was sealed under a nitrogen atmosphere. 150 this
Heat in oil bath at 0 ° C. for 15 hours. No polymer was obtained and the phenylsilane monomer was recovered.

[0043]

Industrial Applicability As described above, the present invention can provide a highly active dehydrogenative condensation catalyst which is easy to synthesize and easy to handle. Further, the organosilicon polymer can be efficiently produced from the organosilicon monomer in a short time.

[Brief description of drawings]

¹ H of the organosilicon polymer obtained in Example 1
-NMR spectrum chart.

FIG. 2 IR of the organosilicon polymer obtained in Example 1.
Spectrum chart.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Ryuji Sato 1-3-1 Nishitsurugaoka, Oi-cho, Iruma-gun, Saitama Tonen Research Institute

Claims (1)

[Claims] 1. A first component of the formula Cp ₂ MX ₂ (wherein Cp is independently substituted or unsubstituted η ^5-
A cyclopentadienyl group is shown, and two cyclopentadienyl groups may be covalently bonded to each other via one or more atoms. M is Ti, Zr, Hf, X is F, C
l, Br and I are shown. ) A metallocene dihalide and a second component of the formula: (Here, A represents an alkali metal and Ar represents an aromatic hydrocarbon.) A catalyst for dehydrogenative condensation of an organosilicon monomer, which comprises an aromatic radical anion alkali metal salt represented by: