Folding‐Induced Promotion of Proton‐Coupled Electron Transfers via Proximal Base for Light‐Driven Water Oxidation
Please always quote using this URN: urn:nbn:de:bvb:20-opus-312020
- Proton‐coupled electron‐transfer (PCET) processes play a key role in biocatalytic energy conversion and storage, for example, photosynthesis or nitrogen fixation. Here, we report a series of bipyridine‐containing di‐ to tetranuclear Ru(bda) macrocycles 2 C–4 C (bda: 2,2′‐bipyridine‐6,6′‐dicarboxylate) to promote O−O bond formation. In photocatalytic water oxidation under neutral conditions, all complexes 2 C–4 C prevail in a folded conformation that support the water nucleophilic attack (WNA) pathway with remarkable turnover frequencies of upProton‐coupled electron‐transfer (PCET) processes play a key role in biocatalytic energy conversion and storage, for example, photosynthesis or nitrogen fixation. Here, we report a series of bipyridine‐containing di‐ to tetranuclear Ru(bda) macrocycles 2 C–4 C (bda: 2,2′‐bipyridine‐6,6′‐dicarboxylate) to promote O−O bond formation. In photocatalytic water oxidation under neutral conditions, all complexes 2 C–4 C prevail in a folded conformation that support the water nucleophilic attack (WNA) pathway with remarkable turnover frequencies of up to 15.5 s\(^{−1}\) per Ru unit respectively. Single‐crystal X‐ray analysis revealed an increased tendency for intramolecular π‐π stacking and preorganization of the proximal bases close to the active centers for the larger macrocycles. H/D kinetic isotope effect studies and electrochemical data demonstrate the key role of the proximal bipyridines as proton acceptors in lowering the activation barrier for the crucial nucleophilic attack of H\(_{2}\)O in the WNA mechanism.…
Author: | Niklas Noll, Tobias Groß, Kazutaka Shoyama, Florian Beuerle, Frank WürthnerORCiDGND |
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URN: | urn:nbn:de:bvb:20-opus-312020 |
Document Type: | Journal article |
Faculties: | Fakultät für Chemie und Pharmazie / Institut für Organische Chemie |
Language: | English |
Parent Title (English): | Angewandte Chemie International Edition |
Year of Completion: | 2023 |
Volume: | 62 |
Issue: | 7 |
Article Number: | e202217745 |
Source: | Angewandte Chemie International Edition 2023, 62(7):e202217745. DOI: 10.1002/anie.202217745. |
DOI: | https://doi.org/10.1002/anie.202217745 |
Dewey Decimal Classification: | 5 Naturwissenschaften und Mathematik / 54 Chemie / 540 Chemie und zugeordnete Wissenschaften |
Tag: | Ruthenium complexes; artificial photosynthesis; folded macrocyles; homogeneous catalysis; photocatalysis |
Release Date: | 2023/06/16 |
EU-Project number / Contract (GA) number: | 787937 |
OpenAIRE: | OpenAIRE |
Licence (German): | CC BY: Creative-Commons-Lizenz: Namensnennung 4.0 International |