Abstract

While many photodissociation studies of stable molecules have been performed in recent years, it has proved difficult to extend these experiments to studies of reactive free radicals. This is largely due to the difficulty of implementing a clean, well-characterized source of free radicals. We have developed a novel approach to this problem by setting up an experiment in which free radicals are generated by laser photodetachment of a mass-selected anion beam, rather than the more conventional strategies in which radicals are formed by photolysis of a stable precursor or by a chemical reaction. The radicals are photodissociated with a second laser, and the photofragments are detected with high efficiency by using a microchannel plate detector. We can measure the total photodissociation cross section or, with a more sophisticated detector, look at the photofragment energy and angular distribution. Results will be presented for the N₃, NCO, and CH₂N0₂ radicals.

© 1992 Optical Society of America