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)3Cl (1) (Cp = cyclopentadienyl) affords the germyl complex CpW(CO)3GeCl2Cp* (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 η2 fashion. In comparison, the crystal structure of [Cp*Ge][BF4] (6) reveals the presence of BF4 anions and Cp*Ge cations, in which the Cp* ligand is η5 bonded to the germanium atom.