Excimer Laser Photofragmentation of Organophosphonates. I. Detection of the PO Radical from Dimethyl Methyl Phosphonate (DMMP)

摘要

The argon fluoride (193 nm) and krypton fluoride (248 nm) lasers have been employed to photodissociate the chemical agent simulant DMMP at pressures up to 0.8 torr. Detection of the PO radical as a photolytic product was accomplished by laser-induced fluorescence. Both fluorescence and excitation spectra have been recorded and the A to X lifetime of PO has been determined to be 9 plus or minus 2 nsec. The multiphoton nature of the photodissociation is revealed by a near quadratic dependence of the PO laser-induced fluorescence on excimer laser power. The formation and detection of the PO radical is a critical element in the development of a chemical agent detection scheme involving pulsed ultraviolet laser photodissociation of agents.