Abstract

TUCCERI, M.E.; CASTELLANO, E; CROCE, A.E  and  COBOS, C.J.. Rate Coefficients For The Reaction Of Chlorine Atoms With FS(O2)O AND FS(O2)OCl AT 298 K. An. Asoc. Quím. Argent. [online]. 2005, vol.93, n.4-6, pp.29-41. ISSN 0365-0375.

The kinetics of the recombination reaction Cl + FS(O2)O → FS(O2)OCl (1) has been studied by using an ArF excimer laser flash photolysis technique over the 25-950 mbar total pressure range of the bath gases He, N2 and CF4 at 298 K. The reaction was found to be essentially in the second-order regime. The derived limiting high-pressure rate coefficient is k1, ∞=(1.3 ±0.3)x10-10 cm3 molecule-1 s-1. For the reaction Cl + FS(O2)OCl → FS(O2)O + Cl2 (2) a rate coefficient of k 2 = (2.1 ±0.9)x10-11 cm3 molecule-1 s-1 was measured. The ratio between both rate coefficients of 0.16 agrees very well with data determined by Vasini and Schumacher. Quantum chemical calculations carried out at the G3MP2//B3LYP/6- 311+G(3df) level of theory allow to determine an standard heat of formation of -136.5 kcal mol-1 for FS(O2)OCl. Rate coefficient calculations in the framework of the phase space theory, performed on a G3MP2B3 electronic potential, indicate that central forces mainly dominate the present recombination reaction.

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