The Role of Benzonitrile Chlorination Explored by Dissociative Electron Attachment

The dissociative electron attachment process to ortho‐ and para‐chlorobenzonitrile was investigated in the 0–12 eV energy range with a crossed‐beam time‐of‐flight mass spectrometer, supported by quantum chemical scattering calculations. The major dissociation channel corresponds to Cl − formation, accompanied by M─Cl − , CN − , M─CN − , and minor fragments. A key distinction between the two isomers is the observation of a parent anion at near‐zero energy in the ortho‐chlorobenzonitrile, whereas it is absent in the para‐chlorobenzonitrile. Calculations on the basis of the Schwinger Multichannel method reproduce the main resonant features and provide a consistent representation of the electron attachment pathways. The results highlight how dipole‐bound states and orbital coupling shape fragmentation dynamics, with implications for halogenated nitrile chemistry in astrophysical environments.