A Water‐Soluble Highly Oxidizing Cobalt Molecular Catalyst Designed for Bioinspired Water Oxidation. Issue 20 (16th March 2022)

• Record Type: Journal Article
• Authors: Su, Yun‐Fei; Luo, Wen‐Zhi; Lin, Wang‐Qiang; Su, Yi‐Bing; Li, Zi‐Jian; Yuan, Yong‐Jun; Li, Jian‐Feng; Chen, Guang‐Hui; Li, Zhaosheng; Yu, Zhen‐Tao; Zou, Zhigang
• Is Part Of: Angewandte Chemie international edition. Volume 61:Issue 20(2022)
• Page Start: n/a
• Page End: n/a
• Publication Date: 2022-03-16
• Subjects: Cobalt Complex -- Density Functional Calculations -- High Oxidation State -- High-Spin Systems -- Water Oxidation Catalysts; Chemistry -- Periodicals; 540
• DOI: 10.1002/anie.202201430
• Languages: English
• ISSNs: 1433-7851

Abstract

Abstract: Herein, we present a stable water‐soluble cobalt complex supported by a dianionic 2, 2′‐([2, 2′‐bipyridine]‐6, 6′‐diyl)bis(propan‐2‐ol) ligand scaffold, which is a rare example of a high‐oxidation species, as demonstrated by structural, spectroscopic and theoretical data. Electron paramagnetic resonance (EPR) spectroscopy and magnetic susceptibility measurements revealed that the Co IV center of the mononuclear complex in the solid state resides in the high spin state (sextet, S =5/2). The complex can effectively catalyze water oxidation via a single‐site water nucleophilic attack pathway with an overpotential of only 360 mV in a phosphate buffer with a pH of 6. The key intermediate toward water oxidation was speculated based on theoretical calculations and was identified by in situ spectroelectrochemical experiments. The results are important regarding the accessibility of high‐oxidation state metal species in synthetic models for achieving robust and reactive oxidation catalysis. Abstract : A stable water‐soluble cobalt(IV) complex supported by a dianionic 2, 2′‐([2, 2′‐bipyridine]‐6, 6′‐diyl)bis(propan‐2‐ol) ligand scaffold is very active in the catalysis of water oxidation at an overpotential of only 360 mV at pH=6.