Intramolecular interactions in bis(pentamethylcyclopentadienyl) complexes: X-ray structures of (η 5 -C 5 Me 5 ) 2 Zr(OH)(Cl) and (η 5 -C 5 Me 5 ) 2 Zr(OH) 2

The structure of (η5-C5Me5)2Zr(OH)(Cl)(1) and (η5-C5Me5)2Zr(OH)2(2) have been determined by X-ray diffraction; location of all hydrogen atoms in (1) has established the presence of significant intramolecular non-bonding contacts and (2) is the first early transition metal dihydroxo complex to be structurally characterized.