LAUSR

Metal–imido complexes are critical intermediates in transition metal-catalyzed C–H amination reactions. Discerning the factors that control their reactivity, however, remains largely open for exploration, particularly for the territory of cobalt–imido’s. Herein we describe a systematic computational exploration of this new frontier via the C–H activation mechanisms of typical well-defined cobalt–imido complexes, whose formal oxidation states cover an extremely wide range from Co(II) to Co(V). Hydrogen atom abstraction (HAA) is found to be the rate-limiting step in all these systems, with the open-shell electronic states of radical character consistently bearing kinetic advantage over the closed-shell ones. Surprisingly, there is no correlation found between the cobalt oxidation state and the HAA reactivity. To render a more accessible HAA channel, the dichotomous EER/anti-EER electron-shift scenarios for the open-shell electronic structure are dependent on the cobalt oxidation states [Co(III), different f...