Matrix Infrared Spectra and DFT Computations of CH₂CNH and CH₂NCH Produced from CH₃CN by Laser-Ablation Plume Radiation

摘要

The smallest ketenimine and hydrogen cyanide N-methylide (CH2CNH and CH2NCH) are provided from the argon/acetonitrile matrix samples exposed to radiation from laser ablation of transition-metals. New infrared bands are observed in addition to better determination of the vibrational characteristics for the previously reported bands, and the 13C substituted isotopomers (13CH2 13CNH and 13CH2N13CH) are also generated. Density functional frequency calculations and the D and 13C isotopic shifts substantiate the vibrational assignments. CH2CNH is probably produced through single-step conversion of CH3CN, whereas CH2NCH through two-step conversion via 2H-azirine. Inter-conversions between these two products evidently do not occur during photolysis and annealing.