Low energy (0-4 eV) electron impact to N_2O clusters: Dissociative electron attachment, ion-molecule reactions, and vibrational Feshbach resonances

摘要

Electron attachment to clusters of N_2 O in the energy range of 0-4 eV yields the ionic complexes [(N_2 O)_nO] -, [(N _2 O)_n NO] -, and (N_2 O) n-. The shape of the ion yields of the three homologous series differs substantially reflecting the different formation mechanisms. While the generation of [(N_2 O) _nO] - can be assigned to dissociative electron attachment (DEA) of an individual N_2 O molecule in the target cluster, the formation of [(N_2 O)_n NO] - is interpreted via a sequence of ion molecule reactions involving the formation of O- via DEA in the first step. The nondecomposed complexes (N_2 O) n- are preferentially formed at very low energies (below 0.5 eV) as a result of intramolecular stabilization of a diffuse molecular anion at low energy. The ion yields of [(N_2 O) _nO] - and (N_2 O) n- versus electron energy show sharp peaks at the threshold region, which can be assigned to vibrational Feshbach resonances mediated by the diffuse anion state as already observed in an ultrahigh resolution electron attachment study of N_2 O clusters [E. Leber, S. Barsotti, J. B?mmels, J. M. Weber, I. I. Fabrikant, M.-W. Ruf, and H. Hotop, Chem. Phys. Lett. 325, 345 (2000)].