Synthesis, structural characterization, and theoretical treatment of an unusual organozirconium hydroxide with the [Zr6(μ4-O)(μ-O)4(μ-OH)8] core

A novel organozirconium hydroxide, [(Cp*Zr)(6)(mu(4)-O)(mu-O)(4)(mu-OH)(8)].2(C7H8) (2), was prepared by the hydrolysis of Cp*ZrCl3. For the preparation of 2 the reagents KOH and water and the two-phase system ammonia/toluene were used. The crystal structure reveals that 2 is an octahedron comprising Cp*Zr fragments arranged around an interstitial oxygen atom that preferentially occupies two off-center positions, 0.933(13) Angstrom apart from each other. The six Cp*Zr fragments are bridged by a total of 12 mu-O and mu-OH groups. Molecular mechanical and ab initio calculations were carried out in order to analyze the stability and the bonding environment of the off-center structure by comparing to that with the ideal mu(6)-0 arrangement.