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

Hydrolysis of Cp*SiCl 3 affords the silanetriol Cp*Si(OH) 3 ( 1) as an amorphous solid. Reaction of 1 with Me 3 SiCl/NEt 3 and with N(SnMe 3 ) 3 leads to Cp*Si(OSiMe 3 ) 3 ( 2 ) and Cp*Si(OSnMe 3 ) 3 ( 3 ), respectively. From a concentrated solution of 1 in diethyl ether, the hemihydrate Cp*Si(OH) 3 ·0.5 H 2 O ( 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.