Wang Yang, Li Bao, Qian Hujun, Wu Lixin
State Key Laboratory of Supramolecular Structure and Materials, Jilin University , Changchun 130012, P. R. China.
Inorg Chem. 2016 May 2;55(9):4271-7. doi: 10.1021/acs.inorgchem.6b00008. Epub 2016 Apr 13.
To create new types of organic ligands covalently grafted onto polyoxometalates and identify the reaction mechanism, we selected Cu(II) as the central heteroatom for the synthesis of a series of disklike Anderson-Evans clusters bearing different triol derivatives on both their faces via one-pot and/or step-by-step routes. By using a [(n-C4H9)4N]4[Mo8O26] precursor cluster and copper acetate as the starting materials, several organically modified χ isomers with Cu(II) heteroatom centers were obtained. Starting from a [(n-C4H9)4N]2[Mo2O7] subcluster, however, a half-malposition coordination fashion of triol ligands with a δ isomer on one face and a χ isomer on the other face of the Anderson-Evans cluster was obtained. By changing the reaction solvent from acetonitrile to methanol, we realized a secondary organic modification of the triol-grafted clusters and obtained a triol ligand/methanol codecoration on the Anderson-Evans polyoxometalate. In addition, by changing the reaction environment, we succeeded in modulating the transformation of triol ligands from one site to another on the polyoxometalate cluster. Importantly, by control of the reaction condition, the methanol molecules were also taken off from the cluster.
为了制备共价接枝到多金属氧酸盐上的新型有机配体并确定反应机理，我们选择Cu(II)作为中心杂原子，通过一锅法和/或分步路线合成了一系列在其两个面上带有不同三醇衍生物的盘状Anderson-Evans簇。以[(n-C4H9)4N]4[Mo8O26]前驱体簇和醋酸铜为起始原料，得到了几种具有Cu(II)杂原子中心的有机修饰χ异构体。然而，从[(n-C4H9)4N]2[Mo2O7]子簇开始，得到了一种三醇配体的半错位配位方式，在Anderson-Evans簇的一个面上为δ异构体，另一个面上为χ异构体。通过将反应溶剂从乙腈改为甲醇，我们实现了三醇接枝簇的二次有机修饰，并在Anderson-Evans多金属氧酸盐上获得了三醇配体/甲醇共修饰。此外，通过改变反应环境，我们成功地调控了三醇配体在多金属氧酸盐簇上从一个位点到另一个位点的转化。重要的是，通过控制反应条件，甲醇分子也从簇上脱离。
