- Effects of hydrogen chloride addition to the direct reaction of methylene chloride with elemental silicon
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Direct synthesis of bis(chlorosilyl)methanes has been reinvestigated by reacting elemental silicon simultaneously with methylene chloride and hydrogen chloride in the presence of copper catalyst using a stirred reactor equipped with a spiral band agitator at a carefully controlled temperature between 260 and 340°C. Bis(dichlorosilyl)methane and (dichlorosilyl)(trichlorosilyl)methane were obtained as the major products and bis(trichlorosilyl)methane as a minor product along with trichlorosilane and tetrachlorosilane derived from the reaction between elemental silicon and hydrogen chloride. The decomposition of methylene chloride was suppressed and the production of polymeric carbosilanes reduced by adding hydrogen chloride to the methylene chloride reactant. The optimum mixing ratio of methylene chloride and hydrogen chloride for the direct synthesis of bis(silyl)methanes was 1 : 4. The deactivation problem of elemental silicon owing to decompositions of methylene chloride and polycarbosilanes was eliminated. Cadmium was a good promoter for the reaction, while zinc was found to be an inhibitor for this particular reaction.
- Yeon, Seung Ho,Han, Joon Soo,Yoo, Bok Ryul,Jung, Il Nam
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- ORGANIC CHLOROHYDROSILANE AND METHOD FOR PREPARING THEM
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Provided is an organic chlorohydrosilane, a useful starting material for preparing silicon polymers and a method for preparing the same. More particularly, the present invention enables the synthesis of various novel organic chlorohydrosilanes in high yield by an exchange reaction between an Si—H bond of a chlorosilane which can be obtained in an inexpensive and easy manner and an Si—Cl bond of an another organic chlorosilane using a quaternary organic phosphonium salt compound as a catalyst. Since the catalyst can be recovered after its use and reused, the present invention is very economical and thus effective for mass-producing silicon raw materials.
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- Phosphine-Catalyzed Si-C Coupling of Bissilylmethanes: Preparation of Cyclic (Cl2SiCH2)2 and Linear Cl 2Si(CH2SiCl3)2 via Silylene and Silene Intermediates
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Cyclic and linear carbosilanes, (Cl2SiCH2) 2 (2) and Cl2Si(CH2SiCl3) 2 (3), were produced from phosphine-catalized Si-C coupling reactions of bissilylmethanes, HCl2SiCH2SiX1X 2Cl (X1, X2 = Cl (1), X1 = H, X 2 = Cl (7), and X1 = Me, X2 = Cl (8)). The formation of compounds 2 and 3 suggested competing reaction pathways, involving dichlorosilene [CH2=SiCl2] and dichlorosilylene [:SiCl2] intermediates. Each intermediate was either proposed by the product isolation of the trimerized product (3) or confirmed by trapping experiments with 2,3-dimethylbutadiene and methylene chloride.
- Hong, Soon Hyun,Hyun, Sang Il,Jung, Il Nam,Han, Won-Sik,Kim, Min-Hye,Yun, Hoseop,Nam, Suk-Woo,Kang, Sang Ook
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experimental part
p. 687 - 691
(2010/05/15)
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