When copper(1) chloride was used as a catalyst in the reaction of silicon with phenol, a high selectivity for triphenoxysilane (HSi(OPh)3) (94%) was obtained, the other product being tetraphenoxysilane (Si(OPh)4). Addition of a small amount of propyl chloride to the feed for poisoning metallic copper enhanced the selectivity for HSi(OPh)3 without affecting the rate of silicon consumption. This result indicates that HSi(OPh)3 is an exclusive primary product and that Si(OPh)4 is formed by the secondary reaction between HSi(OPh)3 and phenol. The reaction mechanism involving surface silylene intermediate is proposed for the formation of HSi(OPh)3 as the sole primary product. The intermediacy of surface silylene was confirmed by adding ethylene in the silicon-phenol reaction to give rise to the trapped product ethyldiphenoxysilane, obtained in a 5.8% selectivity.
ASJC Scopus subject areas
- Physical and Theoretical Chemistry
- Organic Chemistry
- Inorganic Chemistry
- Materials Chemistry