Mass-selected detection of N(2D) by resonance-enhanced multiphoton ionization following two-photon dissociation of NO

Abstract

Two-photon dissociation processes of NO have been studied using a pulsed laser system. NO was photolysed by laser light between 269 and 280 nm. One of the products, N(²D), was detected by a resonance-enhanced multiphoton-ionization technique combined with time-of-flight mass spectrometry. The yield of NO⁺ was also measured as a function of excitation laser wave-length. Efficient production of N(²D) was confirmed when NO was excited to the 6dπ^–(v= 1), 5dπ^–(v= 1) and 4dπ^–(v= 2) states. On the other hand, no signal could be observed when NO was excited to the 4dδ(v= 2) state. Production of N(²D)via the 5sσ(v= 3) state is inefficient, if not negligible. These results suggest that predissociation proceeds via the valence B′²Δ state. Contribution of the ndπ⁺ and ndσ states to the production of N(²D) was not confirmed.