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Electrocatalytic Water Oxidation by a Homogeneous Copper Catalyst Disfavors Single-Site Mechanisms

Electrocatalytic Water Oxidation by a Homogeneous Copper Catalyst Disfavors Single-Site Mechanisms

Sara J. Koepke, Kenneth M. Light, Peter E. VanNatta, Keaton M. Wiley, and Matthew T. Kieber-Emmons* 
Department of Chemistry, University of Utah, Salt Lake City, Utah 84112-0850, United States
J. Am. Chem. Soc., Article ASAP
DOI: 10.1021/jacs.7b03278
Publication Date (Web): May 30, 2017
Copyright © 2017 American Chemical Society
*matthew.kieber-emmons@utah.edu

http://pubs.acs.org/doi/abs/10.1021/jacs.7b03278


本論文では、銅錯体による水の酸化触媒反応において、二核銅錯体 [(L)Cu(II)]2-(μ-OH)2}(OTf)2 (L =
Me2TMPA = bis((6-methyl-2-pyridyl)methyl)(2-pyridylmethyl)-
amine(上図右上)が反応活性中間体であるということを報告しています。この二核の反応中間体は分光学的手法や電気化学的手法さらに計算化学的手法により同定されています。

これまでの銅錯体による水の酸化触媒の反応中間体には、同じような水の酸化触媒であるRu錯体やIr錯体のように単核Cu(IV)O/Cu(III)−O• 錯体を反応中間体として経由し反応が進行すると報告されていました。

DFT計算によってこの二核錯体は
・分子間の水の求核攻撃
・還元によって生成する {[LCu(III)]2-(μ-O)2}2+
がO-O結合生成のためのpath としてエネルギー的に起こりうるということを明らかにしています。


同じ水の酸化反応において、二核錯体を経由することでこれまでに報告されてきていたものと違った反応機構になるというのが面白いと思いました。


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