(Pentamethylcyclopentadienyl)silanetriol: Synthesis, derivatization, and X-ray crystal structure of its hemihydrate

Hydrolysis of Cp*SiCl3 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 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.