The Influence of a Single Transition Metal Atom on the Reactivity of Main Group Metal Clusters in the Gas Phase

Collision induced dissociation experiments of the metalloid clusters [(CO)(5)CrGe9R3](-) 2 and [(CO)(3)CrGe9R3](-) 3 are presented, showing that 2 can lose Cr(CO)(5) or CO to give [Ge9R3](-) 1 or 3, respectively. Further dissociation from 3 leads first of all to the metalloid cluster [CrGe9R3](-) 4, from which different elimination routes start. Thereby significant differences with respect to the chromium free cluster [Ge9R3](-) 1 are observed, where beside C-H also Si-C and Si-Si bond dissociation at low threshold energy take place, showing that 4, with its additional chromium atom, is an ideal model system for a single atom catalyst.