Cyano‐Capped Porphyrins Embedded With First‐Row Transition Metals and Evaluation for Electrocatalytic Syngas Production

Herein, we present and discuss the synthesis and characterization of cobalt‐, nickel‐ and copper‐based tetraphenylporphyrin complexes comprising cyano groups at the ortho position of the meso ‐phenyl rings. Interestingly, these complexes were obtained in a straightforward manner, in sharp contrast with the unsuccessful preparation of the analogous iron derivative. As a proof‐of‐concept, we further demonstrate that the readily prepared complexes, which are based on first‐row and Earth's crust abundant metals, are active in the environmentally‐relevant CO 2 reduction, enabling syngas (H 2 /CO) production under electrochemical conditions. The presence of hanging, dative cyano groups nearby the electrocatalytically active site provides opportunities for second coordination sphere engineering aimed at optimizing activity and product selectivity.