Two 2D frameworks of inorganic-organic hybrids based on Keggin-type tungstogermanates and {CuI(CuII)-bimb}n polymer chains

Abstract

Two new 2D frameworks of inorganic-organic hybrids, CuI4(bimb)4GeW12O40·2H2O (1) and CuII3Cl2(bimb)3(H2O)4GeW12O40·5H2O (2) were successfully synthesized under hydrothermal conditions by adjusting the stoichiometry of starting materials and pH values with the same starting materials. They were characterized by single crystal X-ray diffraction analysis, IR spectrum and magnetic measurements. Both of them are constructed by coordination polymer chains {CuI(CuII)-bimb}n and {GeW12O40} anions as building blocks. Compound 1 crystallizes in P-1 space group and exhibits a two-dimensional (2D) (3,4)-binodal layer, composed of wavelike {CuI-bimb}n polymer chains bridged by tetradentate [GeW12O40]4− polyanions, with a Schläfli symbol of (83)·(62·84). Compound 2 crystallizes in noncentrosymmetric space group P1 and exhibits a 2D (4,4) layer composed of one-dimensional (1D) tri-chains {CuII3(bimb)3Cl2(H2O)4}∞ constructed by unique three-nuclearity cluster {CuII3Cl2(H2O)4}4+ and bib molecules, bridged by bidentate [GeW12O40]4− anions. Magnetic measurements reveal that ferromagnetic interactions exist among the three-nuclearity cluster {Cu3Cl2O2(H2O)4} in 2.