A density functional theory study of the mechanisms of oxidation of ethylene by technetium oxo complexes

► Dioxylate is favored over metallaoxetane in LTcO3 (L = O−, Cl, CH3, OCH3, Cp, NPH3). ► The reactions of TcO4 and TcO3Cp with ethylene do not form epoxides. ► The reactions of LTcO3 (L = Cl, CH3, OCH3, NPH3) form epoxides.