Size and Electronic Effects on Redox Potentials and Electrocatalytic Processes Performed by Corrole-Chelated Metal Complexes

The future of our planet critically depends on the introduction of new or improved strategies for developing non-polluting energy production. Leading approaches are the electrocatalytic production of hydrogen gas, development of fuel cells relying on efficient reduction of oxygen and either gaseous or liquid fuels, as well as efficient reduction of carbon dioxide. Metal complexes chelated by N4 macrocycles serve as excellent catalysts in many of these processes, performed at both homogeneous and heterogeneous conditions. Our contributions to those aspect focused on introducing metallocorroles as catalysts for reduction of protons, oxygen and carbon dioxide, as well as for water oxidation 1-5. The common motif in these and other publications was to take advantage of the relatively easy functionalization of the macrocyclic periphery for the tuning of properties and reactivity. A significant game changer was the recently reported synthetic access to corroles with meso -CF 3 substituents and even to the parent corrole with no substituents whatsoever 6. These developments allow for a focus on the size effect, which according to both hypothesis and fast accumulating results has a very strong effect (“smaller is better”) on the performance of electrodes modified by the corresponding metal complexes 7-9. References Sinha, N. Fridman, Y. Diskin-Posner, L. J. W. Shimon and Z. Gross “Superstructured Metallocorroles for Electrochemical CO 2 Reduction”, Chem. Commun. 2019 , 55 , 11912-11915. Sinha, A. Mahammed, N. Fridman and Z. Gross “Water Oxidation Catalysis by Mono- and Binuclear Iron Corroles” ACS Catal. 2020 , 10 ,3764-3772. Sudhakar, A. Mahammed, Q.-C. Chen, N. Fridman, B. Tumanskii and Z. Gross “Copper Complexes of CF 3 ‐Substituted Corroles for Affecting Redox Potentials and Electrocatalysis” ACS Appl. Energy Mater. 2020 , 3 , 2828-2836. Yadav, I. Nigel-Etinger, A. Kumar, A. Mizrahi, A. Mahammed, N. Fridman, S. Lipstman,I. Goldberg, and Z. Gross “Hydrogen Evolution Catalysis, by Terminal Molybdenum-Oxo Complexes”, Iscience 2021 , 24 , 102924. -C. Chen, S. Fite, N. Fridman, B. Tumanskii, A. Mahammed, and Z. Gross “Hydrogen Evolution Catalyzed by Corrole-Chelated Nickel Complexes, Characterized in all Catalysis-relevant Oxidation States”, ACS Catalysis 2022 , 12 , 4310−4317. Kumar, P. Yadav, M. Majdoub, I. Saltsman, N. Fridman, S. Kumar, A. Kumar,A. Mahammed and Z. Gross “Corroles: The Hitherto Elusive Parent Macrocycle and its Metal Complexes” Angew. Chem. 2021 , 60 , 25097-25103. Mahammed and Z. Gross “Milestones and Most Recent Advances in Corrole’s Science and Technology”, J. Am. Chem. Soc. 2023 , 145 , 12429–12445 Raslin, J. Douglin, A. Kumar, M. Fernandez-Dela-Mora, D. Dekel and Z. Gross “Size and electronic effects on the performance of (corrolato)cobalt-modified electrodes for ORR catalysis”. Inorg. Chem. 2023 , 62 , 14147–14151. Kumar, S. Fite, A. Raslin, S. Kumar, A. Mizrahi, A. Mahammed, and Z. Gross “Beneficial Effects on the Cobalt-Catalyzed Hydrogen Evolution Reaction Induced by Corrole Chelation”. ACS Catal. 2023 , 13 , 13344-13353. Figure 1