Uranium-mediated reductive conversion of CO2 to CO and carbonate in a single-vessel, closed synthetic cycle

Abstract

The new neopentyl (Neop)-substituted tris(aryloxide) U(III) complex [((^Neop,MeArO)₃tacn)U^III] reacts with CO₂ to form CO and the bridging carbonate complex [{((^Neop,MeArO)₃tacn)U^IV}₂(μ-CO₃)]. The uranium(IV) bridging oxo [{((^Neop,MeArO)₃tacn)U^IV}₂(μ-O)] has been determined to be the intermediate in this reaction. For the first time, both U(IV) complexes can be reduced back to the U(III) starting material. Thus, with KC₈ as reductant, [((^Neop,MeArO)₃tacn)U^III] engages in a synthetic cycle, in which CO₂ is converted to CO and CO₃²⁻.