Carbon Dioxide Hydrogenation to Formate Catalyzed by a Bench-Stable, Non-Pincer-Type Mn(I) Alkylcarbonyl Complex

[Image: see text] The catalytic reduction of carbon dioxide is a process of growing interest for the use of this simple and abundant molecule as a renewable building block in C1-chemical synthesis and for hydrogen storage. The well-defined, bench-stable alkylcarbonyl Mn(I) bis(phosphine) complex fac-[Mn(CH(2)CH(2)CH(3))(dippe)(CO)(3)] [dippe = 1,2-bis(diisopropylphosphino)ethane] was tested as an efficient and selective non-precious-metal precatalyst for the hydrogenation of CO(2) to formate under mild conditions (75 bar total pressure, 80 °C), in the presence of a Lewis acid co-catalyst (LiOTf) and a base (DBU). Mechanistic insight into the catalytic reaction is provided by means of density functional theory (DFT) calculations.