1. Bioinspired Nickel Complexes Supported by an Iron Metalloligand.
- Author
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Prat JR, Gaggioli CA, Cammarota RC, Bill E, Gagliardi L, and Lu CC
- Subjects
- Carbon Dioxide chemistry, Ligands, Biomimetic Materials chemistry, Coordination Complexes chemistry, Iron chemistry, Nickel chemistry
- Abstract
Nature utilizes multimetallic sites in metalloenzymes to enable multielectron chemical transformations at ambient conditions and low overpotentials. One such example of multimetallic cooperativity can be found in the C-cluster of Ni-carbon monoxide dehydrogenase (CODH), which interconverts CO and CO
2 . Toward a potential functional model of the C-cluster, a family of Ni-Fe bimetallic complexes was synthesized that contain direct metal-metal bonding interactions. The complexes were characterized by X-ray crystallography, various spectroscopies (NMR, EPR, UV-vis, Mössbauer), and theoretical calculations. The Ni-Fe bimetallic system has a reversible Fe(III)/Fe(II) redox couple at -2.10 V (vs Fc+ /Fc). The Fe-based "redox switch" can turn on CO2 reactivity at the Ni(0) center by leveraging the Ni→Fe dative interaction to attenuate the Ni(0) electron density. The reduced Ni(0)Fe(II) species mediated the formal two-electron reduction of CO2 to CO, providing a Ni-CO adduct and CO3 2- as products. During the reaction, an intermediate was observed that is proposed to be a Ni-CO2 species.- Published
- 2020
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