Hydrogen bonding of H 2O to the hydroxo ligands of Cp* 2Zr(OH) 2: implications for proton and oxygen exchange processes. The crystal and molecular structure of the hydrate Cp* 2Zr(OH) 2 · (H 2O)

Abstract

The molecular structure of Cp* 2Zr(OH) 2 · (H 2O) (Cp* = η 5-C 5Me 5) has been determined by single-crystal X-ray diffraction. The asymmetric unit of Cp* 2Zr(OH) 2 · (H 2O) consists of a hydrogen-bonded dimeric structure in which two water molecules serve to link two Cp* 2Zr(OH) 2 moieties together. The hydrogen bonding of H 2O to the hydroxo ligands of Cp* 2Zr(OH) 2, rather than direct coordination of H 2O to the zirconium centre, provides support for the mechanisms proposed previously to rationalize the fact that proton exchange between Cp* 2Zr(OH) 2 and labelled H 2O is more facile than that for oxygen exchange.