Bio-inspired Electrocatalysts for Water Oxidation

Galia Maayan
Schulich Faculty of Chemistry, Technion – Israel Institute of Technology, Haifa, Israel
gm92@technion.ac.il

Enzymatic catalysis is largely based on cooperativity between a metal center and functional organic molecules located at its surrounding folds. Inspired by this biological concept, we are developing molecules that aim to mimic enzymatic cooperativity. Thus, we use two different approaches for the design of intramolecular catalytic systems in which both the catalytic group(s) and the non-reacting components are tethered in close proximity to each other, aiming to address current challenges in the catalytic activation of small molecules. Our first approach is to mimic the structure of the oxygen evolving center, a manganese complex near photosystem II in plants and bacteria, within the context of its protein environment, aiming to mimic its function. In my talk I will present such complexes and demonstrate the role of the organic ligands, surrounding the metallic catalytic core, in the electrocatalytic water oxidation activity. [1-4] Our second approach is to incorporate several functional side chains within peptoids, N-substituted glycine oligomers, for mimicking a second coordination sphere about embedded metal centers. Peptoids can be efficiently generated by a solid-phase method that enables the inclusion of innumerable functional groups at specified N-positions along their spine. Thus, they can be used as a tool for studying the cooperativity between catalytic groups placed on one scaffold. In my talk I will show how we utilized this approach for the construction of peptoids that catalyze oxidation transformation, specifically electrochemical water oxidation, with high turn-over-numbers via intramolecular cooperativity. [5-9]

[1] G. Maayan*, N. Gluz, G. Christou, Nat. Catal. 2018, 1, 48-54
[2] T. Ghosh, G. Maayan, Angew. Chem. Int. Ed. 2019, 58, 2785–2790
[3] N. Gluz, G. Christou and G. Maayan, Chem. Eur. J. 2021, 27, 6034–6043
[4] N. Gluz, G. Ruan, G. Maayan, Chem. Catal 2024, 4 (3), 100955
[5] T. Ghosh, P. Ghosh and G. Maayan, ACS Catal. 2018, 8 (11) 10631-10640
[6] G. Ruan and G. Maayan J. Am. Chem. Soc. 2021, 143 (28) 10614–10623
[7] G. Ruan, L. Engelberg, P. Ghosh and G. Maayan, Chem. Commun. 2021, 57, 939.
[8] S. Pahar and G. Maayan, Chem Sci. 2024, 15, 12928-12938.
[9] G. Ruan, N. Fridman and G. Maayan,”, Inorg. Chem. 2025, in press.