Unusual hydrogen bonds in [AH3–H3O]+ radical cations (A = C, Si, Ge, Sn and Pb): Single-electron hydrogen bond, proton-hydride hydrogen bond and formation of [H2AOH2]+–H2 complexes

The hydrogen bond interaction in [AH3–H3O]+ radical cations for A = C, Si, Ge, Sn and Pb is studied at the CCSD(T)/6-311G++(3df,2pd)//MP2/6-31G++(d,p) level of theory. Two unusual hydrogen bond structures are found to be stable: the single-electron (SEHB) and the proton-hydride (PHHB) ones. The latter structures have been found to easily evolve to a [AH2H2O]+–H2 complex, from which H2 can be eliminated.