Low energy electron induced reactions in fluorinated acetamide – probing negative ions and neutral stable counterparts*

Electron impact to trifluoroacetamide (CF 3 CONH 2 , TFAA) in the energy range 0–12 eV leads to a variety of negative fragment ions which are formed via dissociative electron attachment (DEA). The underlying reactions range from single bond cleavages to remarkably complex reactions that lead to loss of the neutral units HF, H 2 O and HNCO as deduced from their directly observed ionic counterparts (M – H 2 O) − , (M – HF) − and (M – HNCO) − . Also formed are the pseudo-halogen ions CN − and OCN − . All these reactions proceed dominantly via a resonance located near 1 eV, i.e., electrons at subexcitation energies trigger reactions involving multiple bond cleavages. The electron induced generation of the neutral molecules HF, H 2 O and HNCO in condensed TFAA films is probed by temperature controlled thermal desorption spectrometry (TDS) which can be viewed as a complementary techniques to gas-phase experiments in DEA to directly probe the neutral counterparts.