Density functional methods in the study of oxygen transfer reactions

The oxygen transfer reactions from heterocyclic compounds such as oxaziridine, methyldioxirane and ethylene oxide to ethylene and phosphine have been studied using different computational methods, and the results have been compared to those obtained with CASPT2 and CBS-QB3 methods. The results show that the generalized gradient approximation (GGA) functionals BLYP and PBEPBE, highly underestimate the barriers. On the other hand, the hybrid meta-GGA functionals (BB1K, M05 and M05-2X) and BHandHLYP tend to overestimate the barriers. Finally, the B3LYP and OPBE functionals provide reasonable barriers. Nevertheless, none of the tested functionals describes all the studied reactions with the same accuracy.