Novel One-Dimensional Organic–Inorganic Polyoxometalate Hybrids Constructed from Heteropolymolybdate Units and Copper–Aminoacid Complexes

Abstract

Two unique organic–inorganic hybrid heteropolymolybdates with copper–aminoacid complexes [Cu(arg)2]2[(CuO6)Mo6O18(As3O3)2]·4 H2O (1) and [Cu(arg)2]3[TeMo6O24]·8H2O (2) (arg = l-arginine) have been prepared under the 110 °C hydrothermal environments and structurally characterized by elemental analyses, IR spectra, thermogravimetric (TG) analyses, and single-crystal X-ray diffraction. 1 stands for the first one-dimensional (1D) chain organic–inorganic hybrid arsenomolybdate constructed from lantern-shaped [(CuO6)Mo6O18(As3O3)2]4– units through dinuclear [Cu2(arg)4]4+ connectors, whereas 2 represents an unprecedented 1D chain organic–inorganic hybrid telluromolybdate built by Anderson-type [TeMo6O24]6– fragments via trinuclear [Cu3(arg)6]6+ bridges. Variable-temperature magnetic susceptibilities of 1 and 2 have been investigated and both illustrate the weak antiferromagnetic coupling within copper centers mediated by the carboxyl groups of arg ligands. Moreover, the solid-state electrochemical and electrocatalytic properties of 1 have been carried out in 1 mol L–1 H2SO4 aqueous solution by entrapping it in a carbon paste electrode. 1 displays apparent electrocatalytic activities toward the reduction of nitrite and bromate.