Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
5395401 | Computational and Theoretical Chemistry | 2011 | 7 Pages |
The weak dihydrogen-bonded interactions are found between HBBH (1Îg) and HM (M = Li, Na, K, BeH, MgH or CaH) using MP2 and CCSD(T) methods with 6-311++G(3df,2p) and aug-cc-pVTZ basis sets. The binding energies follow the order of HBBHâ¯HK > HBBHâ¯HNa > HBBHâ¯HLi > HBBHâ¯HCaH > HBBHâ¯HMgH > HBBHâ¯HBeH. The interactions in HBBHâ¯HM are weaker than those in HCCHâ¯HM. The calculated binding energies correlate with the Hâ¯H distance, the elongation of the BH bond and the charge density at the Hâ¯H bond critical point. The analyses of the natural bond orbital (NBO), atoms in molecules (AIM) and electron density shifts reveal the nature of the dihydrogen-bonded interaction. In these interactions, many of the lost densities from HM or the hydridic hydrogen of HM are shifted toward the BH bond or the H atom of the BH moiety. The polarization of the BB double-bond plays a role in the formation of the dihydrogen-bonded interaction. Thus, the concept of dihydrogen bond is extended to MHδââ¯+δHBBH system where the BH group can be as the proton donor.