Abstract

The collision-free and collisional UV multiple- photon dissociation of dimethyl methyl phosphonate (DMMP) vapor, utilizing the ArF (193-nm) and KrF (248-nm) excimer lasers, resulted in production of ground state PO X(²∏)radicals. PO was detected using a Nd:YAG/dye laser system by laser-induced fluorescence of the (²∑⁺) ↔ X(²∏) system near 248 nm (0,0). Time-resolving the fluorescence with a fast photodetector yielded a radiative lifetime of 9 ± 2 nsec for the A (²∑⁺) state and a quenching rate by nitrogen of 1.6 × 10⁻¹⁰ cc/molecule sec. PO was also observed to react with oxygen, and the rate constant for the PO + O₂ → product reaction was measured in pseudofirst-order conditions to be 1.0 × 10⁻¹⁰ cc/molecule sec at 298 K.

© 1985 Optical Society of America