Dissociative multiphoton ionization of NO2 studied by time-resolved imaging
SourceJournal of Chemical Physics, 121, 16, (2004), pp. 7776-7783
Article / Letter to editor
Display more detailsDisplay less details
Molecular and Laser Physics
Journal of Chemical Physics
SubjectMolecular and Laser Physics
We have studied dissociative multiphoton ionization of NO2 by time-resolved velocity map imaging in a two-color pump-probe experiment using the 400 and 266 nm harmonics of a regeneratively amplified titanium-sapphire laser. We observe that most of the ion signal appears as NO+ with similar to0.28 eV peak kinetic energy. Approximately 600 fs period oscillations indicative of wave packet motion are also observed in the NO+ decay. We attribute the signal to two competitive mechanisms. The first involving three-photon 400 nm absorption followed by dissociative ionization of the pumped state by a subsequent 266 nm photon. The second involving one-photon 400 nm absorption to the B-2(2) state of NO2 followed by two-photon dissociative ionization at 266 nm. This interpretation is derived from the observation that the total NO+ ion signal exhibits biexponential decay, 0.72 exp(-t/90+/-10)+0.28 exp(-t/4000+/-400), where t is the 266 nm delay in femtoseconds. The fast decay of the majority of the NO+ signal suggests a direct dissociation via the bending mode of the pumped state. (C) 2004 American Institute of Physics.
Upload full text
Use your RU credentials (u/z-number and password) to log in with SURFconext to upload a file for processing by the repository team.