A Highly Active N‐Heterocyclic Carbene Manganese(I) Complex for Selective Electrocatalytic CO2 Reduction to CO

Abstract We report here the first purely organometallic fac ‐[Mn I (CO) 3 (bis‐ Me NHC)Br] complex with unprecedented activity for the selective electrocatalytic reduction of CO 2 to CO, exceeding 100 turnovers with excellent faradaic yields ( η CO ≈95 %) in anhydrous CH 3 CN. Under the same conditions, a maximum turnover frequency (TOF max ) of 2100 s −1 was measured by cyclic voltammetry, which clearly exceeds the values reported for other manganese‐based catalysts. Moreover, the addition of water leads to the highest TOF max value (ca. 320 000 s −1 ) ever reported for a manganese‐based catalyst. A Mn I tetracarbonyl intermediate was detected under catalytic conditions for the first time.