Selective Nitrite Reduction at Heterobimetallic CoMg Complexes
- Creators
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Uyeda, Christopher
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Peters, Jonas C.
Abstract
Heme-containing nitrite reductases bind and activate nitrite by a mechanism that is proposed to involve interactions with Brønsted acidic residues in the secondary coordination sphere. To model this functionality using synthetic platforms that incorporate a Lewis acidic site, heterobimetallic CoMg complexes supported by diimine–dioxime ligands are described. The neutral (μ-NO_2)CoMg species 3 is synthesized from the [(μ-OAc)(Br)CoMg]+ complex 1 by a sequence of one-electron reduction and ligand substitution reactions. Data are presented for a redox series of nitrite adducts, featuring a conserved μ-(η^1-N:η^1-O)-NO_2 motif, derived from this synthon. Conditions are identified for the proton-induced N–O bond heterolysis of bound NO_2– in the most reduced member of this series, affording the [(NO)(Cl)CoMg(H_2O)]+ complex 6. Reduction of this complex followed by protonation leads to the evolution of free N_2O. On the basis of these stoichiometric reactivity studies, the competence of complex 1 as a NO_2– reduction catalyst is evaluated using electrochemical methods. In bulk electrolysis experiments, conducted at −1.2 V vs SCE using Et_3NHCl as a proton source, N_2O is produced selectively without the competing formation of NH_3, NH_2OH, or H_2.
Additional Information
© 2013 American Chemical Society. Received: May 29, 2013; Published: July 18, 2013. This work was supported by the National Science Foundation Center for Chemical Innovation on Solar Fuels (CCI Solar, Grant CHE-0802907) and the Gordon and Betty Moore Foundation. We thank Larry M. Henling for assistance with crystallography, Angelo Di Bilio for assistance with EPR measurements, and David Lacy for assistance with IR spectroelectrochemical experiments.Attached Files
Supplemental Material - ja4053653_si_001.pdf
Supplemental Material - ja4053653_si_002.cif
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Additional details
- Eprint ID
- 41360
- DOI
- 10.1021/ja4053653
- Resolver ID
- CaltechAUTHORS:20130917-100711754
- NSF
- CHE-0802907
- Gordon and Betty Moore Foundation
- Created
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2013-09-17Created from EPrint's datestamp field
- Updated
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2021-11-10Created from EPrint's last_modified field
- Caltech groups
- CCI Solar Fuels