M. Lachgar et al., Electron-stimulated desorption of O- from O-2 adsorbed on CD3CN: Substrate-mediated low-energy reaction pathways, CHEM P LETT, 305(5-6), 1999, pp. 408-412
Low-energy (0-15 eV) electron-stimulated desorption of O- from multilayer O
-2 proceeds via different O-2(-)* resonances at an onset energy near 6 eV.
Ln contrast, O-2 deposited on an acetonitrile (CD3CN) substrate shows a sig
nificant contribution towards lower energy with an onset near 2.6 eV, The a
bsolute intensity of this low-energy signal has a maximum at O-2 coverages
below 1 monolayer, suggesting a substrate-mediated reaction. It is proposed
that the ((2)Pi(CN)) resonance of acetonitrile acts as a low-energy electr
on acceptor. The energy required for low-energy desorption of O- is then pr
ovided by a reaction of the excited anionic complex (CD3CN . O-2)(-)* yield
ing O- and a thermodynamically favourable neutral species like methylisocya
nate (CD3NCO). (C) 1999 Elsevier Science B.V. All rights reserved.