Jutzi P, Wegener D, Stammler H-G, Karaulov A, Hursthouse MB. Anionic dicarbollyl complexes of germanium(II) and tin(II) — missing links in a series of [pi]-complexes with Group 14 elements as central atoms. Inorganica Chimica Acta. 1992;198-200:369-375.On the basis of the isolobal concept, comparable series of structurally different [pi]-complexes with Group 14 elements as central atoms and with cyclopentadienyl or dicarbollyl systems as ligands can be organized. We describe for the first time anionic [pi]-complexes in which one or two dicarbollyl (B9H9C2Me2) ligands are coordinated to a divalent germanium or tin centre. Thus, reaction of the phosphonium salt Ph3MeP+TlB9H9C2Me2- (4) with the element dichlorides GeCl2 and SnCl2, respectively, in a 1:1 ratio leads to the ionic compounds Ph3MeP+ClGeB9H9C2Me2- (5) and Ph3MeP+ClSnB9H9C2Me2- (6), respectively. In a 2:1 ratio of the same reactants, the ionic compounds (Ph3MeP+)2Ge(B9H9C2Me2)22- (7) and (Ph3MeP+)2Sn(B9H9C2Me2)22- (8), respectively, are formed. Some further chemistry of the starting material Tl+TlB9H9C2Me2- is also described. The characterization of the new complexes is based on 1H, 13C, 11B and 119Sn NMR data and on X-ray crystal structure investigations (5 and 7)
