The $\bar{A}-\bar{X}$ Systems of the Alkyl-O and Alkyl-S Radicals

Abstract

Rotationally cold spectra $(<5K)$ of the $\bar{A}-\bar{X}$ systems of $CH_{3}O, C_{2}H_{6}O. iC_{3}H_{7}O$ and $CH_{3}S$ have been observed by LIF. These radicals were produced by UV laser photolysis of a suitable precursor seeded in a rare-gas free-jet expansion. The ``hot'' fragments are rapidly cooled by collisions in the expansion and are subsequently probed with a Nd:YAG-pumped dyelaser system. Details of this experimental technique will be presented and the analysis of the $CH_{3}S$ data will be discussed.