1,2-Carbagerma-closo-dodecaborate as a Germanium Ligand in Coordination Chemistry - Synthesis, Structure and Reactivity

A much improved synthesis for the carbagerma‐closo‐dodecaborate anion [GeCB10H11]– is described in the form of [Bu3NH][GeCB10H11] (1). In reactions with transition metal electrophiles, three transition metal complexes {[Bu3NH][(C6H6)Ru(Cl)2(GeCB10H11)] (2), [Bu3NH][Cp*Ir(Cl)(GeCB10H11)2] (3) and [Me3NH][(PPh3)2Ir(CO)(GeCB10H11)2] (4)} with metal–germanium bonds were synthesized. The carbagermaborate anion, in the form of the salt [Et3NH][GeCB10H11], and the coordination compounds 2–4 were structurally characterized by single‐crystal X‐ray diffraction. Computations were carried out for the anions in 1–4 to aid NMR assignments. An improved synthesis of carbagerma‐closo‐dodecaborate is presented. Coordination compounds with this type of germylene ligands are structurally characterized, and the ligand properties are discussed by using the results of quantum chemical calculations.