JPH05230219A - Production of alpha,omega-dihydropolysilane - Google Patents

Abstract

PURPOSE:To obtain the title polysilane useful as a functional polymer such as a nonlinear optical material by polymerizing a specified small-ring polysilane through ring opening in the presence of a polymerization catalyst in a solvent. CONSTITUTION:A small-ring polysilane of formula I (wherein R<1> to R<8> are each H, alkyl, aryl, alkenyl, alkinyl, alkoxy, silyl or halogen, and R<1> and R<2>, R<3> and R<4>, R<5> and R<6>, or R<7> and R<8> together with the corresponding bonded Si atom may be combined with each other to form a ring; and m is 0-1) is polymerized through ring opening in the presence of a polymerization catalyst (e.g. iodotrimethyl-silane) in a solvent (e.g. 1, 2-dichloroethane) to obtain the title polysilane of formula II (wherein n is 2 or greater).

Description

Detailed Description of the Invention

[0001]

The present invention relates to the following general formula [I]

[Chemical 3] (In the formula, R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group, an aryl group, an alkenyl group, an alkynyl group, an alkoxyl group, a silyl group. Or a halogen atom, R ¹ and R ² , R ³ and R ⁴ , R ⁵ and R ⁶
Alternatively, R ⁷ and R ⁸ may together with the silicon to which they are attached form a ring. m represents 0 or 1. n represents an integer of 2 or more. ) And a method for producing α, ω-dihydropolysilanes.

The α, ω-dihydropolysilanes obtained by the present invention are useful as synthetic intermediates for higher molecular weight polysilanes [US Pat. US500310
0]. Further, according to the present invention, various polysilanes useful as functional polymers such as nonlinear optical materials and conductive polymers can be synthesized [[Synthesis and application of organosilicon polymer] CMC (1989); Chemical Technology Research) Report, 8 , 5
69 (1989)].

[0003]

2. Description of the Related Art As a synthesis method of polysilanes represented by the general formula [I], (1) dichlorosilanes are reduced and condensed in the presence of an alkali metal such as sodium ["Synthesis and application of organosilicon polymer"]. CMC (1989)
p99].

(2) Method for dehydrogenative condensation of polyhydrosilanes in the presence of a transition metal catalyst [Can. J. Che
m. , 6 5,1804 (1987); J . Organo
met. Chem. , 2 7, C31 (1971) ].

(3) Method by anionic polymerization of disilabicyclooctadiene which is an equivalent of disilene [J. A
m. Chem. Soc. , 11 11,7641 (198
9)].

(4) Method by electrolytic reduction of dichlorosilanes [J. Chem. Soc. Chem. Commu
n. , 1160 (1990)].

(5) Method of reacting cyclotetrasilane with a catalytic amount of butyllithium [J. Am. Chem.
Soc. , 1 13, 1046 (1991)].

Among these methods, the methods (1) and (4) have the drawbacks that the functional groups that can be introduced into the side chain are limited and the molecular weight distribution is not uniform.

In the method (2), the substrates that can be used are limited to mono-substituted silanes, and the molecular weight distribution is not uniform.

In the method (3), since active alkyllithium is used as a reaction initiator, there is a drawback that the functional groups that can be introduced into the side chain are limited.

In the method (5), the substrates that can be used are extremely limited.

[0012]

DISCLOSURE OF THE INVENTION The present inventors have conducted studies on a highly selective and highly selective polysilane synthesis method which can be industrialized, and as a result, in the presence of a polymerization catalyst, small ring polysilanes such as octaethylsilane have been produced. The present invention has been completed by finding that α, ω-dihydropolysilanes represented by the above general formula [I] can be obtained by ring-opening polymerization.

[0013]

The present invention provides the following general formula [II] in the presence of a polymerization catalyst.

[0014]

[Chemical 4] (Wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ , R ⁸ and m have the same meanings as described above). It is a method for producing α, ω-dihydropolysilanes represented by the general formula [I] by polymerizing.

The small-ring polysilane represented by the above general formula [II] used in the present invention is prepared by condensing dichlorosilanes with lithium or sodium [J. Chem.
Soc. Chem. Commun. , 781 (198
3); Organometallics, 3 , 141
(1984); Chem. Lett. , 1711 (19
83); Organomet. Chem. , 2 1
2, 155 (1981); Polym. Prepr. Three
1,46 (1990); Organometallic
s, 2 , 1771 (1983)].

Examples of the small-ring polysilane represented by the general formula [II] include hexapropylcyclotrisilane, hexa (2,2-dimethylpropyl) cyclotrisilane, and hexa (1,1-dimethylethyl) cyclo. Trisilane, hexamesitylcyclotrisilane, octa (trimethylsilyl) cyclotetrasilane, octaethylcyclotetrasilane, octa (isopropyl) cyclotetrasilane, octaphenylcyclotetrasilane, 1,
2,3,4-tetramethyl-1,2,3,4-tetraphenylsilane, 1,2,3,4-tetrabromo-1,
2,3,4-tetraphenylcyclotetrasilane, 1,
2,3,4-tetramethoxy-1,2,3,4-tetraphenylcyclotetrasilane, 1,2,3,4-tetraphenylcyclotetrasilane, 1,2,3,4-tetravinyl-1, 2,3,4-tetraethylcyclotetrasilane, 1,2,3,4-tetraethynyl-1,2,3
4-tetraphenylcyclotetrasilane etc. can be mentioned.

In the present invention, it is an essential condition to carry out the reaction in the presence of a polymerization catalyst. As the polymerization catalyst, iodotrimethylsilane, iodotriethylsilane, trimethylsilyl trifluoromethanesulfonate, triethylsilyl trifluoromethanesulfonate, trimethylsilyl cyanide, bromotrimethylsilane, trimethylsilyl perchlorate, iodine, arsenic, trifluoromethanesulfonic acid, four Lewis acids such as titanium chloride, tin tetrachloride, and trifluoroborane diethyl ether complex can be used. Further, radical initiators such as azobis (isobutyronitrile) and triethylborane can be used alone or in combination with tributyltin hydride, diphenylmethylsilane, tris (trimethylsilyl) silane and the like. Further, a nucleophilic reaction agent such as tetrabutylammonium fluoride or tris (diethylamino) sulfonium difluorotrimethylsilicate can be used. The amount used may be a so-called catalytic amount.

The present invention uses a solvent, and as the solvent, dichloromethane, 1,2-dichloroethane, 1,
Halogenated hydrocarbons such as 1,1-trichloroethane, chlorobenzene, dichlorobenzene and chloroform can be used alone or in combination. Further, these solvents may be mixed with a solvent other than the halogenated hydrocarbon solvent and used. The reaction can be carried out in the range of −78 to 200 ° C., but it is desirable to carry out the reaction at room temperature to 100 ° C. in view of reaction efficiency. Further, it is desirable to carry out the reaction under ultrasonic irradiation in order to improve the yield.

The present invention will be described in more detail with reference to the following examples.

[0020]

【Example】

 Example 1

[0021]

[Chemical 5]

103 mg (0.030 mm) of octaethylcyclotetrasilane was added to 1,2-dichloroethane (1 ml) which had been freeze-degassed with liquid nitrogen under an argon atmosphere.
ol) was added, and freeze-deaeration was repeated three times. 30 μl (0.030 mmol) of 1,2-dichloroethane solution (1.0 M) of iodotrimethylsilane was added,
After the reaction vessel was sealed, ultrasonic irradiation was performed at room temperature for 10 hours. The reaction vessel was frozen with liquid nitrogen, the sealed portion was opened under an argon atmosphere, the reaction vessel was returned to room temperature, and then the solvent was distilled off under reduced pressure. Hexane (2 ml) and saturated aqueous sodium hydrogen carbonate (2 ml) were added, the mixture was stirred, and then the hexane layer was separated and dried over magnesium sulfate. The resulting crude product was applied to a silica gel column (EtOAc: Hexane =
1:20) to convert 1,1,2,
2,3,3,4,4,5,5,6,6,7,7,8,8
-Hexadecaethyloctasilane (selectivity 53%) and 1,1,2,2,3,3,4,4,5,5,6,6,6
7,7,8,8,9,9,10,10,11,11,1
2,12-Tetracosaethyldodecasilane (selectivity 47
%) Was obtained.

1, 1, 2, 2, 3, 3, 4, 4, 5,
5,6,6,7,7,8,8-Hexadecaethyloctasilane ¹ H NMR (CDCl ₃ ): δ 0.30 to 1.60
(M, 80H), 3.63 (quintet, J = 3.
2Hz, 2H)

IR (neat): 2980, 2070,
1460, 1005, 790, 700 cm ^-1 Anal. Calcd. for C ₃₂ H ₈₂ Si ₈ : C, 55.5
7; H, 11.95 Found: C, 55.58; H, 12.03.

1, 1, 2, 2, 3, 3, 4, 4, 5,
5,6,6,7,7,8,8,9,9,10,10,1
1,11,12,12-Tetracosaethyldodecasilane ¹ H NMR (CDCl ₃ ): δ 0.30 to 1.60
(M, 120H), 3.70 (quintet, J =
3.2Hz, 2H)

IR (neat): 2980, 2070,
1460, 1005, 790, 700 cm ^-1

Anal. Calcd. for C ₄₈ H ₁₂₂ Si ₁₂ : C, 55.6
2; H, 11.86 Found: C, 55.55; H, 12.16

Example 2

[0029]

[Chemical 6]

Example 1 In the same experimental procedure as the solvent 1,
Dichloromethane was used instead of 2-dichloroethane to obtain 103 mg of octaethyltetracyclosilane (0.30
mmol) and a catalytic amount of iodotrimethylsilane (0.0
30 mmol) reaction to obtain 1,1, at a conversion rate of 34%.
2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 6, 7, 7,
8,8-Hexadecaethyloctasilane (selectivity 80
%) And 1,1,2,2,3,3,4,4,5,5,5
6, 6, 7, 7, 8, 8, 9, 9, 10, 10, 11,
11,12,12-Tetracosaethyldodecasilane (selectivity 20%) was obtained. The product spectrum was consistent with that obtained in Example 1.

Example 3

[0032]

[Chemical 7]

Example 1 In the same experimental procedure as the solvent 1,
Dichloromethane was used instead of 2-dichloroethane to obtain 103 mg of octaethyltetracyclosilane (0.30
mmol) and a catalytic amount of trimethylsilyl trifluoromethanesulfonate (0.030 mmol) are reacted,
Conversion rate of 33%, 1,1,2,2,3,3,4,4,5
5,6,6,7,7,8,8-hexadecaethyloctasilane (selectivity 100%) was obtained. The product spectrum was consistent with that obtained in Example 1.

Example 4

[0035]

[Chemical 8]

Example 1 In the same experimental procedure as the solvent 1,
Dichloromethane was used instead of 2-dichloroethane to obtain 103 mg of octaethyltetracyclosilane (0.30
mmol) and a catalytic amount of iodine (0.015 mmol) are reacted at a conversion of 40% to 1,1,2,2,3,3,3.
4,4,5,5,6,6,7,7,8,8-hexadecaethyloctasilane (selectivity 69%) and 1,1,
2, 2, 3, 3, 4, 4, 5, 5, 6, 6, 6, 7, 7,
8,8,9,9,10,10,11,11,12,12
-Tetracosaethyldodecasilane (selectivity 31%) was obtained. The product spectrum was consistent with that obtained in Example 1.

Claims (1)

[Claims] 1. The following general formula: A ring-opening polymerization of a small-ring polysilane represented by the following formula in a solvent in the presence of a polymerization catalyst: The method for producing α, ω-dihydropolysilanes represented by the formula (wherein R ¹ , R ² , R ³ , R ⁴ , R ⁵ , R ⁶ , R ⁷ and R ⁸ are each independently a hydrogen atom, an alkyl group, Represents an aryl group, an alkenyl group, an alkynyl group, an alkoxyl group, a silyl group or a halogen atom, R ¹ and R ² , R ³ and R ⁴ , R ⁵ and R ⁶
Alternatively, R ⁷ and R ⁸ may together with the silicon to which they are attached form a ring. m represents 0 or 1. n represents an integer of 2 or more).