Siloxane network formation from the Si 8 O 20 8− silicate species and dimethyldichlorosilane

Abstract

Organic-silica hybrids were synthesized from the Si 8 O 20 8− silicate anion by the reaction with an excess of dimethyldichlorosilane. The structure of the hybrids has been found to comprise the Si 8 O 20 8− structure as a building block, linked by the (CH 3 ) 2 Si unit. 29 Si NMR signals from terminal groups in the hybrids have been assigned. When the amount of dimethyldichlorosilane present for the reaction is increased, the number of terminal groups decreases, indicating that cross-linking of Si 8 O 20 8− with dimethyldichlorosilane proceeds to form three-dimensional siloxane networks in the hybrids. Copyright­© 1999 John Wiley & Sons, Ltd.