Department of Chemistry and Chemical Engineering, California Institute of Technology, 1200 East California Boulevard MC 127-72, Pasadena, CA 91125, USA.
Science. 2011 Aug 5;333(6043):733-6. doi: 10.1126/science.1206036.
Within photosynthetic organisms, the oxygen-evolving complex (OEC) of photosystem II generates dioxygen from water using a catalytic Mn(4)CaO(n) cluster (n varies with the mechanism and nature of the intermediate). We report here the rational synthesis of a Mn(3)CaO(4) cubane that structurally models the trimanganese-calcium-cubane subsite of the OEC. Structural and electrochemical comparison between Mn(3)CaO(4) and a related Mn(4)O(4) cubane alongside characterization of an intermediate calcium-manganese multinuclear complex reveals potential roles of calcium in facilitating high oxidation states at manganese and in the assembly of the biological cluster.
在光合作用生物中，光系统 II 的氧气产生复合物（OEC）利用催化的 Mn(4)CaO(n) 簇（n 根据中间产物的机制和性质而变化）将水分解为氧气。我们在这里报告了一种 Mn(3)CaO(4) 立方烷的合理合成，该立方烷结构上模拟了 OEC 的三锰-钙-立方烷亚基。Mn(3)CaO(4)与相关的 Mn(4)O(4)立方烷的结构和电化学比较以及对中间钙-锰多核配合物的表征揭示了钙在促进锰的高氧化态和生物簇组装中的潜在作用。
