Isocyanides as hydrogen bond acceptors

A theoretical study of the capability of hydrogen isocyanide (HNC) as a hydrogen bond acceptor has been carried out. The geometry, interaction energy and electronic properties of the corresponding complexes with HF, HCl, HBr, H₂O, NH₃, HCCH, HCN and HNC itself indicate that it is able to form strong hydrogen bonds. A search in the Cambridge Structural Database has shown the presence of isocyanides involved in hydrogen bonds in solid phase. Finally, the comparison of the properties of HNC with its isomer, hydrogen cyanide, shows strong similarities between both compounds. Received: 13 October 1997 / Accepted: 11 December 1997