Isomerization and dissociation of the acetonitrile molecular cation

Abstract The unimolecular dissociation of the acetonitrile molecular cation (CH 3 CN + ) has been investigated using mass-analyzed ion kinetic energy spectrometry. Kinetic energy release distribution was obtained for the H loss. Density functional theory calculations have been performed to investigate isomerization and dissociation of CH 3 CN + . The potential energy surface (PES) for the H loss has been constructed from the calculations at the UB3LYP/6-311++G(3df,3pd) level. The RRKM model calculations based on the obtained PES predict that CH 3 CN + interconverts to CH 2 CNH + and CH 2 NCH + followed by dissociation to a cyclic C 2 H 2 N + via a cyclic C 2 H 3 N + intermediate near the threshold. The present and previous experimental data for the dissociations of C 2 H 3 N + isomers are interpreted with the theoretical results.