Beat over the Old Ground with New Strategy: Engineering As···As Interaction in Arsenite-Based Dawson Cluster β‑[W18O54(AsO3)2]6–

By reaction of [As2W19O67(H2O)]14–, NiCl2·6H2O, and phen under hydrothermal conditions, a new organic–inorganic tungstoarsenate hybrid [Ni­(phen)3]4[As2W18O60]­{[Ni­(phen)2]­[H2As2W18O60]}·12H2O (where phen = 1,10-phenanthroline) (1) was obtained via self-assembly and characterized by elemental analysis, infrared (IR) spectroscopy, solid UV–vis absorption spectrum, and single-crystal X-ray diffraction (XRD). An unprecedented 18-tungstoarsenate Dawson cluster, β-[W18O54(AsO3)2]6–, encapsulating two pyramidal arsenite AsO33– anions as templates and exhibiting interesting intramolecular As···As interaction is first achieved. 1 displays a one-dimensional (1D) chain architecture constructed by alternating β-[W18O54(AsO3)2]6– and nickel­(II) complexes [Ni­(phen)2)]2+. The resulting hybrid can act as a photocatalyst to prompt the degradation of Rhodamine B (RhB) with excellent efficiency.

通过水热条件下使[As2W19O67(H2O)]14–、六水合氯化镍（NiCl2·6H2O）与1,10-邻菲啰啉（1,10-phenanthroline，简称phen）发生反应，经自组装过程得到一种新型有机-无机杂化钨砷酸盐[Ni(phen)3]4[As2W18O60]{[Ni(phen)2][H2As2W18O60]}·12H2O（记为化合物1）。采用元素分析、红外光谱（infrared, IR）、固体紫外-可见吸收光谱（ultraviolet–visible, UV–vis）以及单晶X射线衍射（single-crystal X-ray diffraction, XRD）对其进行了结构表征。本研究首次成功合成了前所未有的18-钨砷酸盐道森（Dawson）型簇合物β-[W18O54(AsO3)2]6–，该簇以两个锥型亚砷酸根（AsO33–）阴离子作为模板，展现出有趣的分子内As···As相互作用。化合物1呈现出一维（1D）链状结构，由交替排布的β-[W18O54(AsO3)2]6–与镍(II)配合物[Ni(phen)2]2+构筑而成。所得杂化材料可作为光催化剂，以优异的催化效率促进罗丹明B（Rhodamine B, RhB）的降解。