Photodissociation of vibrationally excited OH/OD radicals

Autor: Shiou-Min Wu, David H. Parker, André J. A. van Roij, J. J. ter Meulen, Gerrit C. Groenenboom, Liesbeth M. C. Janssen, Dragana Č. Radenović, Mark van der Loo
Rok vydání: 2008
Předmět:
Zdroj: Molecular Physics, 106, 2-4, pp. 557-572
Molecular Physics, 106, 557-572
ISSN: 0026-8976
Popis: This paper describes a joint experimental and theoretical study of the photodissociation of vibrationally excited hydroxyl radicals. OH and OD radicals produced in a pulsed electric discharge supersonic beam are state-selected and focused by a hexapole and then photo-dissociated by a single laser tuned to various H/D or O atom (2 + 1) resonance enhanced multiphoton ionization (REMPI) wavelengths between 243 nm and 200 nm. The angle velocity distributions of the resulting O+ and D+ photofragment ions were recorded using velocity map imaging. Photodissociation to the O(3PJ) + H(2S) limit is shown to take place by one-photon excitation to the repulsive 1 2Σ− state. The experimental data shows that vibrationally excited OH/OD which are formed in the discharge are dissociated, and a vibrational temperature of ≈2000 K was estimated for the beam source. An analysis in the high-energy recoil sudden limit is used to predict the O(3PJ) fine structure branching ratios and alignment information in the molecular and l...
Databáze: OpenAIRE