Insertion of Cp*GeCl into a Tungsten−Chlorine Bond and Crystal Structures of the Germylenes Cp*GeCl, [Cp*GeBr]2, and [Cp*Ge][BF4] (Cp* = Pentamethylcyclopentadienyl)

Insertion of the chlorogermylene Cp*GeCl ( 2 ) (Cp* = pentamethylcyclopentadienyl) into the W−Cl bond of CpW(CO) 3 Cl ( 1 ) (Cp = cyclopentadienyl) affords the germyl complex CpW(CO) 3 GeCl 2 Cp* ( 3 ). Treatment of GeCp* 2 with 1 equiv of HBr gives the bromogermylene [Cp*GeBr] 2 ( 5 ). The crystal structures of the halogermylenes 2 and 5 are described. 2 is monomeric in the solid-state, whereas 5 has a dimeric structure, which is characterized by two germylene units associated through asymmetric bromo bridges. In both compounds the pentamethylcyclopentadienyl group is bonded to the germanium atom in an asymmetric η 2 fashion. In comparison, the crystal structure of [Cp*Ge][BF 4 ] ( 6 ) reveals the presence of BF 4 anions and Cp*Ge cations, in which the Cp* ligand is η 5 bonded to the germanium atom.