Statistical treatment of recoil energy and angular distributions in the products of the reactions O(1D, 3P)+ICH3→OI+CH3

Abstract

Recently, good agreement was found between experimental and phase space theory (PST) results concerning the recoil energy and angular distributions in the products of the reactions O(¹D, ³P)+ICH₃→OI+CH₃. The details of the calculations are presented in this work. Three models are proposed which assume different degrees of intramolecular vibrational redistribution (IVR) for the intermediate complex OICH₃. It turns out that the reaction O(¹D)+ICH₃→OI+CH₃ might proceed through an osculating complex with a sufficiently short lifetime to excite only the vibrational modes of the complex which correlate with the stretching mode of OI and the umbrella mode of CH₃. Conversely, reaction O(³P)+ICH₃→OI+CH₃ proceeds via intersystem crossing between triplet and singlet surfaces through a long lifetime intermediate leading to an isotropic angular distribution of the products. Nevertheless, in opposition to the reaction O(¹D)+ICH₃→OI+CH₃, it appears difficult in this case to deduce the efficiency of the IVR process from the results obtained.