Synthesis, characterization, magnetic and electrochemical properties of a new 3D hexa-copper-substituted germanotungstate

• Transition-metal substituted polyoxometalates.
• Hexa-copper-substituted germanotungstate.
• Six-connected 3D network.
• Electrocatalytic reduction of nitrite, bromate and hydrogen peroxide.

An inorganic–organic hybrid hexa-copper-substituted germanotungstate Na2[Cu(dap)2]2[Cu(dap)2] {[Cu6(H2O)2(dap)2][B-α-GeW9O34]2}·4H2O (1) (dap=1,2-diaminopropane) has been hydrothermally prepared and characterized by elemental analyses, inductively coupled plasma atomic emission spectrometry (ICP–AES) analyses, IR spectra, powder X-ray diffraction (PXRD), thermogravimetric analysis (TGA) and single-crystal X-ray diffraction. 1 displays the six-connected 3D network with the long topological (O′Keefe) vertex symbol is 4·4·64·4·4·4·4·64·4·4·4·64·4·4·4 and the short vertex (Schläfli) symbol of 41263. Magnetic measurements indicate that there are the overall ferromagnetic exchange interactions in the belt-like hexa-CuII cluster in 1. Furthermore, the electrochemical behavior and electrocatalysis of 1 modified carbon paste electrode (1-CPE) have been studied. The reductions of nitrite, bromate and hydrogen peroxide are principally mediated by the WVI-based wave.

A hexa-CuII sandwiched germanotungstate has been synthesized and structurally characterized. The magnetic, solid-state electrochemical and electrocatalytic properties have been investigated. Figure optionsDownload as PowerPoint slide