1 High-Temperature Kinetics of the Reaction between Chlorine Atoms and Hydrogen Sulfide Yide Gao, I. M. Alecu, A. Goumri, and Paul Marshall* Department of Chemistry, University of North Texas, 1155 Union Circle #305070, Denton, Texas 76203-5070, USA * To whom correspondence should be addressed. E-mail: marshall@unt.edu Tel (940) 565-2294 Abstract The rate constant k 1 for Cl + H2 S has been measured over 290-914 K using the laser flash photolysis/resonance fluorescence technique. Atomic chlorine was generated by pulsed 193 nm photolysis of CCl 4 and C6 H5 Cl and monitored by time-resolved resonance fluorescence at 130-140 nm. The data are summarized as k 1 = (2.90 ± 0.10) × 10 -11 exp(2.38 ± 0.11 kJ mol -1 /RT) cm 3 molecule -1 s -1 where the uncertainties in the Arrhenius parameters are ± 2σ. 95% confidence limits for k 1 are ±6%. These extended range measurements confirm a negative activation energy for the reaction.