A cyanide-bridged di-manganese carbonyl complex that photochemically reduces CO2 to CO

Abstract

Manganese(I) tricarbonyl complexes such as [Mn(bpy)(CO)₃L] (L = Br, or CN) are known to be electrocatalysts for CO₂ reduction to CO. However, due to their rapid photodegradation under UV and visible light, these monomeric manganese complexes have not been considered as photocatalysts for CO₂ reduction without the use of a photosensitizer. In this paper, we report a cyanide-bridged di-manganese complex, {[Mn(bpy)(CO)₃]₂(μ-CN)}ClO₄, which is both electrocatalytic and photochemically active for CO₂ reduction to CO. Compared to the [Mn(bpy)(CO)₃CN] electrocatalyst, our CN-bridged binuclear complex is a more efficient electrocatalyst for CO₂ reduction using H₂O as a proton source. In addition, we report a photochemical CO₂ reduction to CO using the dimanganese complex under 395 nm irradiation.