A novel 2D organic–inorganic hybrid based on [P2W18O62]6− polyoxoanion and Cu–bbi coordination polymers

A novel 2D compound based on Wells–Dawson polyoxometalates, [Cu3(bbi)6(P2W18O62)] (bbi = 1,1′-(1,4-butanediyl)bis(imidazole)) (1) has been hydrothermally synthesized and characterized by elemental analyse, IR, TG, PXRD and single crystal X-ray diffraction. In compound 1, each Cu2+ ion is connected with four adjacent Cu2+ ions by bbi ligands along four different directions and each bbi ligand is two-coordinated by two Cu2+ ions, which results in an unusual 2D interlink lock-liked layer. Interestingly, two kinds of macrocycles exist in the structure, in which six smaller 33-membered rings are placed end to end to form the larger ones (66-membered macrocycles). The [P2W18O62]6− polyoxoanions as bidentate ‘guest’ is incorporated into the larger macrocycles. These 2D layers are further packed into 3D framework through strong supramolecular interactions. Additionally, electrochemical and electrocatalysis behavior of 1-CPE have been studied in detail.