Reactive quenching studies of Xe (6s, /sup 3/P/sub 2/) metastable atoms by chlorine containing molecules

The XeCl* emission spectrum has been used to study the reactions of Xe (6s, /sup 3/P/sub 2/) metastable atoms with 20 chlorine containing reagents. Although the total quenching rate constants are large, only Cl/sub 2/, the mixed halogens and Group VI chlorides have high product branching fractions for XeCl* excimer formation. From analysis of the low pressure XeCl* emission spectra, the ratios for XeCl (III,1/2 or B,1/2) and XeCl (II,3/2 or C,3/2) formation were determined. Using results presented in the following paper, the vibrational energy distributions of the XeCl* molecules also can be estimated. A wide difference, depending upon reagent, is observed for the vibrational energy disposal. The short wavelength limit of the XeCl (B--X) emission can be used to assign upper limits to D/sup 0//sub 0/ (R--Cl) and this work gives D/sup 0//sub 0/ (SCl--Dl) < or =44.7; D/sup 0//sub 0/ (ClS/sub 2/--Cl) < or =46.2, D/sup 0//sub 0/ (SOCl--Cl) < or =53.9; D/sup 0//sub 0/ (SO/sub 2/--Cl) < or =58.5, and D/sup 0//sub 0/ (PCl/sub 2/--Cl) < or =77.7 kcal mole/sup -1/. For purposes of comparison, the XeCl* emission spectra also were obtained from the reaction of Xe (6s, /sup 3/P/sub 1/) resonance atoms with Cl/sub 2/, PCl/submore » 2/, CCl/sub 4/, and COCl/sub 2/. The branching ratios and energy disposal for Xe ( /sup 3/P/sub 2/) and Xe ( /sup 3/P/sub 1/) reactions appear to be qualitatively similar. Based upon all of these data, the dynamics of the reactions between Xe ( /sup 3/P/sub 2/) and the chlorine containing reagents are discussed and compared to the models in the literature used previously for the reactions of alkali metal atoms with halogen containing molecules. Characteristic XeI* and XeBr* spectra from Xe ( /sup 3/P/sub 2/) atom reactions are included in an Appendix.« less