A theoretical study of reactions on the ClHCN surface

RHF+1+2/cc-pvdz calculations are reported for 14 minima and 9 transition states on the ClHCN ground state potential surface. The calculations predict the lowest energy route for the reaction Cl + HCN --> HCl + CN to be a simple, direct, collinear abstraction. A lower energy addition reaction leading to the HClCN adduct is predicted to exist, but no direct pathway from HClCN to HCl + CN could be found. For the reaction of H with ClCN the calculations predict three pathways. These are, in order of increasing barrier height, addition to the carbon, forming HClCN; addition to the nitrogen, forming cis-ClCNH, and abstraction via a slightly bent transition state, forming HCl + CN.