Hydrothermal synthesis and crystal structure of a tungstovanadate: [4,4′-bipyH2][4,4′-bipyH]2[VW12O40] · 4,4′-bipy · 7.5H2O

Abstract

An organic-inorganic hybrid Keggin compound, [4,4′-bipyH2][4,4′-bipyH]2[VW12O40] · 4,4′-bipy · 7.5H2O (bipy-bipyridine) (1), has been prepared under hydrothermal conditions and characterized by IR spectroscopy, single crystal X-ray diffraction, thermal analysis, and ESR spectroscopy. 1 crystallized in the monoclinic space group P21/c with a = 18.7350(15) A, b = 14.0253(12) A, c = 26.434(2) A, β= 105.0810(10)°, V = 6706.6(10) A3 and Z = 4. The crystal structure of 1 consists of diprotonated and monoprotonated 4,4′-bipyridine cations, free 4,4′-bipyridine molecule, lattice water molecules, and a typical Keggin-type polyoxoanion [VW12O40]4−. The polyoxoanion is constructed by four {W3O16} trinuclear groups, each of which is made up of three edge-sharing {WO6} octahedra, and the {VO4} tetrahedron is in the center of the cage.