Production of\nNitrogen Dioxide, NO<sub>2</sub><sup>–</sup>, Anion from Dissociative\nElectron Attachment to Nitromethane\nbelow 1 eV and Its Temperature Dependence: Direct vs Dipole Bound\nMediated Processes

Reaction induced by slow electrons is implicated in a\nlarge field\nof research and applications. Below 3-4 eV, dissociative electron\nattachment efficiently fragments molecules via (1) shape resonance\nor (2) mediated by the formation of a dipole bound anion. While the\ntemperature dependence of process 1 is well-known, that of 2 is not\nclearly established. Nitromethane is the prototypical molecule for\nwhich the electron attachment leads to the formation of both a dipole\nbound and a covalent anion. We provide here a comprehensive study\nof the fragmentation of nitromethane by <1 eV electron and the\nunusual temperature effects attributed principally to process 2.