Diode laser spectroscopy for monitoring the yield of metastable Cl from photodissociation of simple molecules

摘要

Time resolved spectroscopy of the atomic fine structure transition of Cl,2P1/2ndash;2P3/2at 882.35 cmminus;1is applied to derive relative yields of the metastable level2P1/2of Cl(Clast;) from the photodissociation by excimer laser radiation of KrF or ArF. Molecules such as HCl, CH3Cl, CH2Cl2, phenyl chloride, and PCl3are studied, getting for the first time the possibility of systematic comparison of yields for Clast; and also of earlier results on heavier halogens obtained by other authors using different methods. Most yields determined in the present work are close to a value as calculated from the statistical weights of the two fine structure levels of Cl. This finding is related in a simple diabatic picture to the small spinndash;orbit interaction in Cl compared to that in iodine. Additionally some rate constants for the collisional quenching of the metastable Cl by the parent molecule are derived.