Chelation of a proton by oxidized diphosphines

The chelation of a proton by oxidized diphosphines is studied for the first time both experimentally and theoretically. As a proof of concept the rare case where two different H-bond systems exist in one compound, H[7,8-(OPiPr2)2-7,8-nido-C2B9H10] is reported. Based on NBO, QTAIM and ELF calculations, the P–O⋯H+⋯O–P interactions were characterized as strong hydrogen bonds.