Can the BB multiple bonds be as the stronger hydrogen-bond proton acceptors than the CC multiple bonds: A comparative theoretical investigation on unusual intermolecular T-shaped X [sbnd]H…π interaction between HF and HB [dbnd]BH ( [formula omitted]), HB [dbnd]BH ( 1Δ g), OCB [tbnd]BCO, H 2C [dbnd]CH 2 or HC [tbnd]CH

Abstract

The unusual T-shaped X H…π hydrogen bonds between HF and BB or CC multiple bonds are compared using the (U)MP2 and DFT ((U)B3LYP functional) methods with the 6-311++G(2df,2p) and aug-cc-pVTZ basis sets. The binding energies follow the order of HB BH ( 1Δ g)…HF > H 2C CH 2…HF > HC CH…HF > OCB BCO…HF > HB BH ( 3 Σ g - )…HF. NBO analysis and the results of the AIM charge density and electron density shifts confirm that, although BB multiple bonds are more electron-deficient than CC multiple bonds, HB BH ( 1Δ g) can be as the stronger T-shaped X H…π hydrogen-bond proton acceptor than the CC multiple-bond monomers.