Hydrogen-Bridged Digermyl and Germylsilyl Cations

The synthesis of the digermyl and germylsilyl hydronium borates 7[B­(C6F5)4] and 8[B­(C6F5)4] is reported. Spectroscopic (IR, NMR) and structural data supported by the results of density functional calculations indicate in both cases a symmetric or almost symmetric E–H–E′ three-center–two-electron linkage (7, E = E′ = Ge; 8, E = Si, E′ = Ge). The [B­(C6F5)4]− and the [HCB11H5Br6]− salts of both cations are active in catalytic hydrodefluorination reactions of alkyl and benzyl fluorides. No significant effect of the element atom E on the determined turnover numbers was found.