A MP2(full) and CCSD(T) theoretical investigation on the dihydrogen-bonded interactions between HNa and RBBH (RÂ =Â F, Cl, H, CN, NC and CO)

► The dihydrogen-bonded complex includes the electron-deficient BB π-system. ► The substituent effect on the dihydrogen-bonded interaction is investigated. ► The loss of H2 occurs from neutral dihydrogen-bonded complex by substituent effect.