Exploring the Electrochemistry of Iron Dithiolene and Its Potential for Electrochemical Homogeneous Carbon Dioxide Reduction

In this work, the dithiolene complex iron(III) bis‐maleonitriledithiolene [Fe(mnt)(2)] is characterised and evaluated as a homogeneous CO(2) reduction catalyst. Electrochemically the Fe(mnt)(2) is reduced twice to the trianionic Fe(mnt)(2) (3−) state, which is correspondingly found to be active towards CO(2). Interestingly, the first reduction event appears to comprise overlapping reversible couples, attributed to the presence of both a dimeric and monomeric form of the dithiolene complex. In acetonitrile Fe(mnt)(2) demonstrates a catalytic response to CO(2) yielding typical two‐electron reduction products: H(2), CO and CHOOH. The product distribution and yield were governed by the proton source. Operating with H(2)O as the proton source gave only H(2) and CO as products, whereas using 2,2,2‐trifluoroethanol gave 38 % CHOOH faradaic efficiency with H(2) and CO as minor products.