Harnessing Benzoyl‐Urea Secondary‐Sphere Hydrogen‐Bonding to Enhance Oxygen Evolution Catalysis by Cobalt Corroles

Secondary‐sphere control is leveraged to boost cobalt corrole oxygen‐evolution catalysis. We install a pendant benzoyl‐urea unit on a corrole scaffold to position a hydrogen‐bond donor above the metal site. The ligand is obtained via an isolable N‐benzoyl‐dicyclohexylurea intermediate, converted to the FB corrole, and metalated to Co(III); a pentafluorophenyl analog lacking the urea serves as control. X‐ray/time‐dependent density functional theory (TD‐DFT) show axial pyridine ligation lifts the pendant carbonyl toward the catalytic pocket with reduced saddling. In MeCN, CV features reversible Co (III/II) couples at −0.62 V (urea) and −0.52 V (control) versus FeCp 2 +/0 , plus ligand‐centered oxidations; spectro‐electrochemistry/EPR ( g iso = 1.9986) confirm a corrole‐radical [Co III (corrole •2‐ )(py) 2 ] + . Water addition unveils catalytic waves ~1.12V(urea) and 1.21 V (control), versus FeCp 2 +/0 . Under CPE (1.78 V, vs. Ag/AgCl), the urea–bearing complex delivers 83.9% Faradaic efficiency , TOF 1.19 s −1 (vs. 59.6% , 0.47 s −1 for control); a KIE = 1.3 implicates PCET. DFT supports WNA at a Co‐oxyl, [Co III (corrole •2‐ )(O •‐ )(py)], with the pendant carbonyl H‐bonding to the incoming H 2 O (O···H = 1.71 Å), thereby lowering the activation barrier relative to a truncated analog. These results establish benzoyl‐urea secondary‐sphere engineering as a concise, general strategy to enhance charge utilization and OO bond formation in cobalt corrole oxygen evolution reaction catalysis.