One- and two-dimensional coordination polymers constructed from bicapped Keggin mixed molybdenum-vanadium heteropolyoxoanions and polynuclear copper(I) clusters bridged by asymmetrical bipyridine (2,4′-bipy and 2,3′-bipy) ligands

Two novel trimetallic coordination polymers containing bridging bicapped Keggin mixed Mo/V polyoxoanions and asymmetrical aromatic amine bridging ligands 2,3'-bipyridine (2,3'-bipy) or 2,4'-bipyridine (2,4'-bipy), [Cu-I (6)(2,3'-bipy)(6)(2,3'-bipy-2'-O)(2)] [(V2Mo5MO7O38)-Mo-IV-M-V-O-VI(PO4)] [2,3'-bipy-2'-OH = 3-(pyridin-2-yl)pyridin-2-ol] (1) and [Cu-5(I)(2,4'-bipy)(6)(OH)][(PMo8V3VO40)-V-VI-V-V-O-IV((VO)-O-IV)(2)]center dot 1.5H(2)O\ (2), have been prepared under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction. Gillard type hydration for the 2,3'-bipy ligand was observed during synthesis of 1, which happens on the 2'-carbon atom C, rather than on the alpha-carbon atom of the coordinated nitrogen atom in the 2,3'-bipy ligand. Complex 1 is constructed from an alternatively arranged bivanadyl capped alpha-Keggin polymolybdate anion [(V2MO5Mo7O38)-M-IV-Mo-V-O-VI(PO4)](4-) and double 2,3'-bipy ligand bridged trinuclear copper(I) cluster [Cu-3(I)(2,3'-bipy)(3)(2,3'-bipy-2'-O)](2+), forming a one-dimensional (1D) ribbon structure. The two-dimensional (2D) extended layer structure of 2 is composed of another type of bicapped Keggin mixed molybdenum-vanadium polyoxoanion [PMoVI (8V3VO40)-V-V-O-IV((VO)-O-IV)(2)](4-) and copper(I) coordination polymer cation chain [Cu-5(I)(2,4'-bipy)(6)(OH)](4+); the latter consists of a 2,4'-bipy ligand bridged hexanuclear copper(I) cluster [Cu(I)5+(2,4-bipy)(6)](5+) linked by double hydroxyl groups.