On the mechanism of water oxidation by a bimetallic manganese catalyst: a density functional study.
On the mechanism of water oxidation by a bimetallic manganese catalyst: a density functional study.
复制标题
DOI：
10.1039/c0dt01362e
复制
发表时间：
2011-03
影响因子：
4
通讯作者：
W. Sameera;C. McKenzie;J. McGrady
中科院分区：
文献类型：
--
作者：
W. Sameera;C. McKenzie;J. McGrady
密度泛函理论被用来探索可能的机制，导致水的氧化由McKenzie和同事开发的锰催化剂。在此基础上，我们提出关键活性中间体是混合价Mn（III）（μ-O）Mn（IV）-O甲氧基自由基物种，氧中心是水亲核进攻的位点。混合价物种与同分异构的金刚石核Mn（IV）（μ-O）（2）Mn（IV）结构处于平衡状态，该结构充当活性物种的储存库。这种化学性质似乎是五齿配体所独有的，因为这些配体移动了Mn（III）（μ-O）Mn（IV）-O同分异构体和Mn（IV）（μ-O）（2）Mn（IV）同分异构体之间的平衡位置，使得溶液中存在大量的前者。
Density functional theory is used to explore possible mechanisms that lead to water oxidation by a bimetallic manganese catalyst developed by McKenzie and co-workers. On the basis of our calculations we propose that the key active intermediate is a mixed valent Mn(III)(μ-O)Mn(IV)-O˙ oxyl radical species, the oxyl centre being the site of nucleophilic attack by water. The mixed-valent species is in equilibrium with an isomeric diamond-core Mn(IV)(μ-O)(2)Mn(IV) structure, which acts as reservoir for the active species. The chemistry appears to be unique to pentadentate ligands because these shift the position of the equilibrium between the Mn(III)(μ-O)Mn(IV)-O˙ and Mn(IV)(μ-O)(2)Mn(IV) isomers, such that significant concentrations of the former are present in solution.