Theoretical study of N(C)-H H-B multi-dihydrogen bonds

The optimized geometries, frequencies and interaction energy corrected with basis set superposition error (BSSE) of the multi-dihydrogen bond complexes C4H4NHBH 4 and CH≡CH BH 4 have been calculated at both the B3LYP/6-311++G** and the MP2/6-311++G** levels. The calculations were performed to study the nature of the N-H H3-B and C-H H2-B red shift multi dihydrogen bond in complex C4H4NH BH 4 and CH≡CH BH 4 The BSSE-corrected multi-dihydrogen bond interaction energy of complex I (C4H4NH BH 4 ) and complex II (CH≡CH BH 4 ) is 76.62 and 33.79 kJ/mol (MP2/6-311++G**), respectively. From the natural bond orbital (NBO) analysis, we detailedly discussed the orbital interactions, electron density transfers, rehybridizations and the essential of the correlative bond length changes in the two complexes. In addition, solvent effect on the geometric structures, vibration frequencies and interaction energy of the monomer and complexes was studied in detail. It is relevant to the relatively dielectric constants (ε).