Reduction of [Cp*2Mo2O5] in aqueous medium: Structure and properties of a triangular mixed oxo-hydroxo-bridged product, [Cp*3Mo3(μ-O)2(μ-OH) 4](X)2 (X = CF3CO2 or CF 3SO3)

Demirhan F.; Çaǧatay B.; Demir D.; Baya M.; Daran J.-C.; Poli R.

Reduction of [Cp2Mo2O5] in aqueous medium: Structure and properties of a triangular mixed oxo-hydroxo-bridged product, [Cp3Mo3(μ-O)2(μ-OH) 4](X)2 (X = CF3CO2 or CF 3SO3)

Date

2006

Authors

Publisher

Wiley-VCH Verlag

Abstract

The reduction of [Cp*2Mo2O5] with Zn in a MeOH/H2O solution acidified with either CF3COOH or CF3SO3H leads to the formation of the [Cp* 3Mo3(μ-O)2(μ-OH)4] 2+ ion as its trifluoroacetate or trifluoromethanesulfonate salt. The structure of the compound was confirmed by X-ray analyses. The anions establish hydrogen-bonding interactions with all four bridging OH groups. Density functional calculations afford bonding parameters in close agreement with the observed structure and indicate that the cluster is best described as a valence-delocalized Mo313+ species. The five metal electrons are distributed among an α-type (z2) orbital, which accounts for most of the metal-metal attraction, and two essentially metal-metal nonbonding e-type (xy) orbitals with a slight Mo(μ-O) π*-type contribution. Because of the C2 symmetry, the latter orbitals are not degenerate. The calculations show that the unpaired electron is located in a molecular orbital with equal contribution from two Mo atoms, in agreement with the experimental observation of coupling of the unpaired electron to two Mo atoms in the isotropic EPR spectrum. © Wiley-VCH Verlag GmbH & Co. KGaA, 2006.