The dimethylsilylcyclopentadienide anion undergoes cleavage of the silicon-cyclopentadienyl bond upon attempted complexation with transition metals. Complexes bearing such ligands can be obtained by metallation of the cyclopentadienyl ligand in tricarbonyl(η5-cyclopentadienyl)manganese, ferrocene and ruthenocene, followed by reaction with chlorodimethylsilane. The silicon-hydrogen function can react