(Pentamethylcyclopentadienyl)silanetriol: Synthesis, Derivatization, and X-ray Crystal Structure of Its Hemihydrate

Abstract

Hydrolysis of Cp*SiCl3 affords the silanetriol Cp*Si(OH)3 (1) as an amorphous solid. Reaction of 1 with Me3SiCl/NEt3 and with N(SnMe3)3 leads to Cp*Si(OSiMe3)3 (2) and Cp*Si(OSnMe3)3 (3), respectively. From a concentrated solution of 1 in diethyl ether, the hemihydrate Cp*Si(OH)3·0.5 H2O (4) is obtained as colorless crystals. An X-ray crystal structure analysis of 4 reveals that Cp*Si(OH)3 and water molecules are hydrogen-bonded to form a multilayer arrangement with the pentamethylcyclopentadienyl groups forming the hydrophobic outer sheets and the silanetriol groups together with the water molecules forming the hydrophilic inner sheets.