A B3LYP and MP2 theoretical investigation on unusual cation-pi interaction between the singlet state HB=BH ((1)Delta(g)) and H , Li , Na , Be2 or Mg2

作者：Wu Yao jin; Ren Fu de^*; Li Bao cheng

来源：Journal of Molecular Structure (Theochem), 2009, 909(1-3): 79-85.

DOI：10.1016/j.theochem.2009.05.029

• B=B double bond
• Cation-pi interaction
• Electron density shifts

The nature of unusual cation-pi interaction has been investigated by carrying out B3LYP and MP2(full) theoretical calculations of the complexes of cations (H , Li , Na , Be2 and Mg2 ) with the electron-deficient B=B double bond. The interaction energies have been calculated using MP2(full) and B3LYP methods at 6-311 G(2df,2p) and aug-cc-pVTZ levels, with the order of HB=BH center dot center dot center dot H > HB=BH center dot center dot center dot Be2 > HB=BH center dot center dot center dot Mg2 >> HB=BH center dot center dot center dot Li > HB=BH center dot center dot center dot Na . Furthermore, the interaction energies between HB=BH ((1)Delta(g)) and cations are stronger than those of the HC CH complexes with the corresponding cations. The analyses of natural bond orbital (NBO), atoms in molecules (AIM) theory and electron density shifts have revealed that the origin of the cation-pi interaction is that many of the lost densities from the n-orbital of B=B are shifted toward the cation, leading to the electron densities accumulation and the formation of the cation-pi interaction. Differently from the other complexes, the complex of H is indicative of covalent interaction, as is agreement with the interaction between HC CH and H .

• 出版日期2009-9-15
• 单位中北大学