Tetranuclear Manganese Models of the OEC Displaying Hydrogen Bonding Interactions: Application to Electrocatalytic Water Oxidation to Hydrogen Peroxide.
Tetranuclear Manganese Models of the OEC Displaying Hydrogen Bonding Interactions: Application to Electrocatalytic Water Oxidation to Hydrogen Peroxide.
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DOI：
10.1021/jacs.7b03044
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发表时间：
2017-07-12
影响因子：
15
通讯作者：
Agapie T
中科院分区：
文献类型：
--
作者：
Han Z;Horak KT;Lee HB;Agapie T
为了发展光系统II(PSII)的放氧配合物(OEC)的结构和功能模型，我们报道了具有三个六配位和一个五配位的位置区分的四核锰配合物的合成。为了结合生物上相关的第二配位球相互作用，能够氢键的取代基被包括为带有苯氨基的吡唑类化合物。与低配位金属中心结合的末端阴离子配体OH−或Cl−的络合物通过氢键网络以一种类似于酶活性中心的方式被支撑。氢氧化物络合物被发现是形成O-O键的合格电催化剂，O-O键是与OEC相关的关键转化。在乙腈-水混合物中，在中性pH下，可以观察到电化学水氧化成过氧化氢，尽管法拉第的产率很低(15%)，这可能是由于与有机物的竞争反应。一致认为，在该簇合物存在下，9，10-二氢菲通过H原子的抽提和氧化以~50%的总法拉第产率被电化学氧化。
Toward the development of structural and functional models of the oxygen evolving complex (OEC) of photosystem II (PSII), we report the synthesis of site-differentiated tetranuclear manganese complexes featuring three six-coordinate and one five-coordinate Mn centers. To incorporate biologically relevant second coordination sphere interactions, substituents capable of hydrogen bonding are included as pyrazolates with phenylamino groups. Complexes with terminal anionic ligands, OH− or Cl−, bound to the lower coordinate metal center are supported through the hydrogen-bonding network in a fashion reminiscent to the enzymatic active site. The hydroxide complex was found to to be a competent electrocatalyst for O-O bond formation, a key transformation pertinent to the OEC. In an acetonitrile-water mixture, at neutral pH, electrochemical water oxidation to hydrogen peroxide was observed, albeit with low (15%) Faradaic yield, likely due to competing reactions with organics. In agreement, 9,10-dihydroanthracene is electrochemically oxidized in the presence of this cluster both via H-atom abstraction and oxygenation at ~50% combined Faradaic yield.
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影响因子：
15
作者：
Kanady, Jacob S.;Lin, Po-Heng;Carsch, Kurtis M.;Nielsen, Robert J.;Takase, Michael K.;Goddard, William A., III;Agapie, Theodor
通讯作者：
Agapie, Theodor
影响因子：
4.6
作者：
Chen, HY;Collomb, MN;Brudvig, GW
通讯作者：
Brudvig, GW
影响因子：
16.6
作者：
Brimblecombe, Robin;Swiegers, Gerhard F.;Spiccia, Leone
通讯作者：
Spiccia, Leone
影响因子：
4.6
作者：
Corbella, M;Costa, R;Rodriguez, V
通讯作者：
Rodriguez, V
影响因子：
56.9
作者：
Kanady, Jacob S.;Tsui, Emily Y.;Agapie, Theodor
通讯作者：
Agapie, Theodor