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

Abstract

Abstract. Electron impact to trifluoroacetamide (CF3CONH2, 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, H2O and HNCO as deduced from their directly observed ionic counterparts (M -H2O) − , (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, H2O 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.

Carboxylation Enhances Fragmentation of Furan upon Resonant Electron Attachment

“…The DEA reaction resulting in hydrogen loss from a molecule itself , or from the hydroxyl moiety of a carboxylic group is a well-known process. ,, In the present case, it occurs primarily at an electron energy of ∼1.2 eV as demonstrated in the energy dependent ion yields in Figure . In 2FA, there are four hydrogen atoms which may be cleaved from the parent ion.…”

Advances in positron and electron scattering*

“…Triple-differential cross sections for the ionization of NH 3 by positron impact in coplanar and perpendicular geometrical arrangements were presented by Toth et al [26]. The first high resolution measurement of He * − formation in helium droplets was reported by Al Maalouf et al [27], the study of the radiative electron attachment and photodetachment processes for the C 2 H/C 2 H − and C 4 H/C 4 H − molecules by Khamesian et al, the theoretical study of a positron-attachment to vibrational excited states for non-polar carbon disulphide molecule by Takeda et al [28] and low energy electron induced reactions in fluorinated acetamide yielding neutral stable molecules have been reported by Kopyra et al [29].…”