Institute of Inorganic Chemistry, University of Zurich, Winterthurerstrasse 190, 8057 Zurich, Switzerland.
Inorg Chem. 2013 May 20;52(10):6055-61. doi: 10.1021/ic4004017. Epub 2013 May 3.
The synthesis of the two penta-pyridyl type ligands pyridine-2,6-diylbis(dipyridin-2-ylmethanol) (PPy, 1) and bis-2,2''-bipyridine-6-yl(pyridine-2-yl)methanol (aPPy, 2) is described. Both ligands coordinate rapidly to the 3d element cations Mn(II), Fe(II), Co(II), Ni(II), Cu(II), and Zn(II), thereby yielding complexes of the general composition MBr(1) and MBr(2), respectively. Further, the X-ray structures of selected complexes with ligands 1 and 2 are described. They show metal center dependent structural features and complexes with 2 exhibiting distinctly distorted octahedral geometries. Moreover, photocatalytic water reduction with [Co(II)Br(PPy)]Br (1c) and [Co(II)Br(aPPy)]Br (2c) as water reducing catalysts (WRC) was investigated. Both complexes showed catalytic activity in water when in presence of ascorbic acid as sacrificial electron donor and Re(py)(bpy)(CO)3 (3) as photosensitizer (PS). Turnover numbers, TONs (H2/Co), up to 11,000 were achieved. Complex 2c was more active than 1c, whereas none of the other complexes showed any activity.
两种五齿配体吡啶-2,6-二基双（二吡啶-2-基甲醇）（PPy，1）和双-2,2''-联吡啶-6-基（吡啶-2-基）甲醇（aPPy，2）的合成。这两种配体都能快速与 3d 元素阳离子 Mn(II)、Fe(II)、Co(II)、Ni(II)、Cu(II)和 Zn(II)配位，从而分别得到[MBr(1)]+和[MBr(2)]+的配合物。此外，还描述了配体 1 和 2 的部分配合物的 X 射线结构。它们显示出与金属中心相关的结构特征，并且 2 配位的配合物表现出明显的扭曲八面体几何形状。此外，还研究了[Co(II)Br(PPy)]Br（1c）和[Co(II)Br(aPPy)]Br（2c）作为水还原催化剂（WRC）的光催化水还原。当以抗坏血酸作为牺牲电子供体和Re(py)(bpy)(CO)3（3）作为光敏剂（PS）存在时，这两种配合物在水中都表现出催化活性。达到了高达 11000 的周转数，TONs（H2/Co）。2c 比 1c 更活跃，而其他配合物均无活性。
