Two novel zipper-like compounds of the usual and bivanadyl capped Keggin clusters connected by propeller-shaped complexes

Abstract

By choosing asymmetric L ligands (L = 1-(imidazol-1-yl)-4-(1,2,4-triazol-1-ylmethyl)benzene), Cu²⁺/Co²⁺ cations and Keggin clusters as starting materials, two new POM-based zipper-like compounds, {Cu(L)₄[HPMo₁₂O₄₀]}·4H₂O (1) and {[Co(L)₄][HPMo₈V^V₄O₄₀(V^IVO)₂]} (2), have been hydrothermally synthesized and characterized by elemental analyses, single-crystal X-ray diffraction, XPS, powder X-ray diffraction, IR spectroscopy, and TG analyses. A structural feature of 1 and 2 is that there exists a 1D + 1D → 3D interdigitated architecture achieved using molecular zippers, in which overhanging mono-coordinated L arms act as teeth. Compound 2 shows bifunctional electrocatalytic activities toward not only reduction of normal iodated inorganic molecules (IO₃⁻) ascribed to Mo-centers, but also oxidation of biological molecules such as ascorbic acid (AA) ascribed to V-centers.