Abstract

Infrared kinetic spectroscopy is being developed using a pulsed excimer laser for ultraviolet photolysis and a color center laser spectrometer as an infrared probe in the 2.3–3.0-μm region. Sub­microsecond time resolution is possible with the 14-ns excimer laser pulses and the InSb detectors currently employed. Previous work on the Br, OH, and NH₂ radicals has led to the development of three monitoring schemes based on the use of either balanced detectors, magnetic rotation, or short-time monitoring. Kinetic studies of the NH₂ + NO reaction have measured the branching ratio of the two primary product channels by monitoring a number of precursors and products. Current work on the C₂H radical produced by photolysis of acetylene has indicated an ~ 1-μs lifetime for this radical, demonstrating the ability to detect short-lived species. Other work includes the production of highly reactive O(¹D) atoms by the photolysis of O₃, providing a method for generating free radicals from stable molecules by hydrogen atom abstraction. Additional studies on the spectroscopy and kinetics of other free radicals are discussed.

© 1986 Optical Society of America