Theoretical investigation of the reactions of O(P-3) with CH3F and CH2F2

The reactions of O(P-3) with CH3F and CH2F2 have been studied using ab init io G2(MP2) theory. The direct hydrogen abstraction mechanism was revealed f or the first time. Two nearly degenerate transition states (of (3)A" and (3 )A' symmetries) were located for each reaction. The rate constants and the equilibrium constants of two reactions were also predicted over a wide temp erature range of 200-3000 K. Comparison of theoretical calculations with th e limited experimental results were made and discussed. (C) 1999 Elsevier S cience B.V. All rights reserved.