Dichlorodimethylsilane → Silane, dichlorobis(3,3,4,4,5,5,6,6,6-nonafluorohexyl)-

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Reaction Conditions

Reaction Steps

3 moles C4F9CH=CH2 and 4.8 g isopropanolic chloroplatinic acid solution (concentration=10%) were placed in a flask and heated under reflux while stirring. 2.5 moles trichlorosilane was dripped in from an addition funnel over a period of 3 hours, and the reaction was then heated under reflux for another 5 hours. At this point, analysis by gas chromatography confirmed the disappearance of the C4F9CH=CH2, and C4F9CH2CH2SiCl3 was isolated by distillation at ambient pressure. The boiling point of this trichlorosilane was 162° C. 2 moles of this C4F9CH2CH2SiCl3, 3.5 moles Me2SiHCl, and 2.6 g tetra(n-butyl)ammonium chloride were placed in a flask and heated under reflux for 3 days while stirring. A mixture of chlorosilanes was then obtained by distillation in vacuo. Analysis by gas chromatography confirmed the main components of this reaction product to be C4F9CH2CH2SiCl3, C4F9CH2CH2SiHCl2, Me2SiHCl, and Me2SiCl2. The C4F9CH2CH2SiCl3 and C4F9CH2CH2SiHCl2 fraction was separated by distillation in vacuo, and the C4F9CH2CH2SiCl3 and C4F9CH2CH 2 SiHCl2 mixture was introduced into a flask along with 5 g isopropanolic chloroplatinic acid solution (concentration=10%). This was heated to 80° C., and C4F9CH=CH2 was added while stirring. This addition was discontinued when the peak for C4F9CH2CH2SiHCl2 disappeared in gas chromatographic analysis. Precision distillation in vacuo then afforded (C4F9CH2CH2)2SiCl2 (bp=128° C./20 mmHg).

Provenance & Evidence