CHARACTERIZATION OF INTERMEDIATES ON THE O-1(2)-ENERGY SURFACE - A HIGH-LEVEL AB-INITIO STUDY(R2S POTENTIAL)

High-level ab initio correlated methods, including calculations at var ious Moller-Plesset, QCISD, and CCSD levels of theory, have been used to study the potential energy surface for the reaction of organic sulf ides with singlet oxygen. This has led to the identification and chara cterization of two discrete intermediates during the oxidation of sulf ides to sulfoxides. One intermediate has a persulfoxide structure (1) while the other is a structure involving a thiadioxirane ring (2). The se results are in excellent agreement with experimental results. The r elative importance of improving correlation treatment and basis set co mpleteness are assessed. (C) 1997 Elsevier Science B.V.