			15min:

SPECTROSCOPIC AND KINETIC MEASUREMENTS OF ORGANIC PEROXY RADICALS BY DUAL-WAEVELENGTH CAVITY RING DOWN SPECTROSCOPY.

DMITRY G. MELNIK AND TERRY A. MILLER, Laser Spectroscopy Facility, Department of Chemistry, The Ohio State University, 120 W. 18th Avenue, Columbus, Ohio 43210.

The weakly-absorbing A leftarrow X transition of organic peroxy radicals in the NIR provides an excellent opportunity for quantitative species-specific measurements. Previously we used the dual-wavelength cavity ring-down spectroscopy (CRDS) technique to accurately measure the absolute peak absorption cross-section of ethyl peroxy radical, C₂H₅O₂. In the present work, we extend the capabilities of the dual-wavelength technique to studying kinetics of the self-reaction of ethyl peroxy by utilizing a high duty-factor, time-resolved CW-CRDS. An extension of this technique to study cross-reactions between different species will be discussed.