Abstract
We investigate the mechanism of water oxidation catalyzed by the CuII(pyalk)2 complex, combining density functional theory with experimental measurements of turnover frequencies, UV-visible spectra, H/D kinetic isotope effects (KIEs), electrochemical analysis, and synthesis of a derivative complex. We find that only in the cis form does CuII(pyalk)2 convert water to dioxygen. In a series of alternating chemical and electrochemical steps, the catalyst is activated to form a metal oxyl radical species that undergoes a water-nucleophilic attack defining the rate-limiting step of the reaction. The experimental H/D KIE (3.4) is in agreement with the calculated value (3.7), shown to be determined by deprotonation of the substrate nucleophile upon O-O bond formation. The reported mechanistic findings are particularly valuable for rational design of complexes inspired by CuII(pyalk)2.
| Original language | English |
|---|---|
| Pages (from-to) | 7952-7960 |
| Number of pages | 9 |
| Journal | ACS Catalysis |
| Volume | 8 |
| Issue number | 9 |
| DOIs | |
| Publication status | Published - Sep 7 2018 |
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Keywords
- catalysis
- copper
- density functional theory
- electrocatalysis
- water oxidation
- water-nucleophilic attack
ASJC Scopus subject areas
- Catalysis
- Chemistry(all)
Cite this
Water-Nucleophilic Attack Mechanism for the CuII(pyalk)2 Water-Oxidation Catalyst. / Rudshteyn, Benjamin; Fisher, Katherine J.; Lant, Hannah M.C.; Yang, Ke R.; Mercado, Brandon Q.; Brudvig, Gary W; Crabtree, Robert H.; Batista, Victor S.
In: ACS Catalysis, Vol. 8, No. 9, 07.09.2018, p. 7952-7960.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Water-Nucleophilic Attack Mechanism for the CuII(pyalk)2 Water-Oxidation Catalyst
AU - Rudshteyn, Benjamin
AU - Fisher, Katherine J.
AU - Lant, Hannah M.C.
AU - Yang, Ke R.
AU - Mercado, Brandon Q.
AU - Brudvig, Gary W
AU - Crabtree, Robert H.
AU - Batista, Victor S.
PY - 2018/9/7
Y1 - 2018/9/7
N2 - We investigate the mechanism of water oxidation catalyzed by the CuII(pyalk)2 complex, combining density functional theory with experimental measurements of turnover frequencies, UV-visible spectra, H/D kinetic isotope effects (KIEs), electrochemical analysis, and synthesis of a derivative complex. We find that only in the cis form does CuII(pyalk)2 convert water to dioxygen. In a series of alternating chemical and electrochemical steps, the catalyst is activated to form a metal oxyl radical species that undergoes a water-nucleophilic attack defining the rate-limiting step of the reaction. The experimental H/D KIE (3.4) is in agreement with the calculated value (3.7), shown to be determined by deprotonation of the substrate nucleophile upon O-O bond formation. The reported mechanistic findings are particularly valuable for rational design of complexes inspired by CuII(pyalk)2.
AB - We investigate the mechanism of water oxidation catalyzed by the CuII(pyalk)2 complex, combining density functional theory with experimental measurements of turnover frequencies, UV-visible spectra, H/D kinetic isotope effects (KIEs), electrochemical analysis, and synthesis of a derivative complex. We find that only in the cis form does CuII(pyalk)2 convert water to dioxygen. In a series of alternating chemical and electrochemical steps, the catalyst is activated to form a metal oxyl radical species that undergoes a water-nucleophilic attack defining the rate-limiting step of the reaction. The experimental H/D KIE (3.4) is in agreement with the calculated value (3.7), shown to be determined by deprotonation of the substrate nucleophile upon O-O bond formation. The reported mechanistic findings are particularly valuable for rational design of complexes inspired by CuII(pyalk)2.
KW - catalysis
KW - copper
KW - density functional theory
KW - electrocatalysis
KW - water oxidation
KW - water-nucleophilic attack
UR - http://www.scopus.com/inward/record.url?scp=85050479541&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85050479541&partnerID=8YFLogxK
U2 - 10.1021/acscatal.8b02466
DO - 10.1021/acscatal.8b02466
M3 - Article
AN - SCOPUS:85050479541
VL - 8
SP - 7952
EP - 7960
JO - ACS Catalysis
JF - ACS Catalysis
SN - 2155-5435
IS - 9
ER -