Vom Fluorsilan zum Siloxan — 1,3-Silylgruppenwanderung am Si3CSiO-Gerüst/ From a Fluorosilane to a Siloxane — 1,3-Migration of Silyl Groups in the Si3CSiO System

Abstract The nature of the products which are formed in the reaction of tris(trimethylsilyl)Methylfluorosilanes (Me3Si)3C -SiF2R with KOH depends on the bulkiness of the substituents R. The condensed siloxane is obtained for R = F . The crystal structure determination of this siloxane (Me3Si)3C -SiF2-O -SiF2-C (SiMe3)3 shows that the Si -O - Si unit is linear. A fluorosilanol as well as a siloxane could be isolated for R = Me. 1,3-Migration of one or two trimethylsilyl groups from the carbon to the oxygen takes place for R = phenyl, rm-butyl or silylamine, with formation of siloxanes which are isomeres o f the expected silanols.