A metal–organic framework based on Wells–Dawson polyoxometalates [As2W18O62]6 − template

A metal–organic framework based on Wells–Dawson polyoxometalate [As2W18O62]6 −, Co2(bpy)3(ox)(As2W18O62)·2(H2bpy)·2H2O (1) (bpy = 4,4′-bipyridine, ox = oxalate), has been synthesized hydrothermally by reacting Co(NO3)2, 4,4′-bipyridine, oxalate and K6As2W18O62. Single-crystal X-ray diffraction reveals that compound 1 contains a 3D cationic host framework composed of oxalate-bridged binuclear secondary building unit and 4,4′-bipyridine linkers. The channels of the 3D host framework are occupied by Wells–Dawson [As2W18O62]6 − templates. Thermogravimetric analysis shows the host framework keeps high thermal stability up to 450 °C. Furthermore, the electrochemistry property of 1 has been studied. The result indicates 1 has good electrocatalytic activity toward the reduction of nitrite.

Graphical abstractA 3D metal-framework is constructed by Wells–Dawson polyoxometalates [As2W18O62]6 − template. Compound 1 contains 3D cationic host framework constructed from oxalate-bridged binuclear secondary building unit and 4,4′-bipyridine linkers, and the channel of which are occupied by Wells–Dawson [As2W18O62]6 − templateFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► Polyoxometalates-templated metal–organic framework have attracted extensive interest due to their intriguing structure topologies and application in catalyst and sorption. ► We again confirmed that POMs is effective template to construct MOFs and the pore can be controlled by the choice of suitable POM. ► TG analysis exhibits that POMs can improve the thermal stability of the host framework. ► Compound 1 shows good electrocatalytic activity towards the reduction of nitrite.