Fragmentation of propionitrile (CH₃CH₂CN) by low energy electrons

Propionitrile (CH₃CH₂CN, PN) is a molecule relevant for interstellar chemistry. There is credible evidence that anions, molecules, and radicals that may originate from PN could also be involved in the formation of more complex organic compounds. In the present investigation, dissociative electron attachment to CH₃CH₂CN has been studied in a crossed electron-molecular beam experiment in the electron energy range of about 0-15 eV. In the experiment, seven anionic species were detected: C₃H₄N^-, C₃H₃N^-, C₃H₂N^-, C₂H₂N^-, C₂HN^-, C₂N^-, and CN^-. The anion formation is most efficient for CN^- and anions originating from the dehydrogenation of the parent molecule. A discussion of possible reaction channels for all measured negative ions is provided. The experimental results are compared with calculations of thermochemical thresholds of the detected anions.