Assemblies of Copper Bis(triazole) Coordination Polymers Using the Same Keggin Polyoxometalate Template

Four inorganic−organic hybrid compounds, [CuI4(bte)4(SiW12O40)] (1), [CuII2(bte)4(SiW12O40)]·4H2O (2) [bte = 1,2-bis(1,2,4-triazol-1-yl)ethane], [CuI4(btb)2(SiW12O40)]·2H2O (3), and [CuII2(btb)4(SiW12O40)]·2H2O (4) [btb = 1,4-bis(1,2,4-triazol-1-yl)butane], were hydrothermally synthesized through use of the same Keggin polyoxometalate as the template and tuning the molar ratio of the bis(triazole) ligand to the CuII ion. The ratio of the bis(triazole) ligand to CuII has a crucial influence on the structures of this series. Single-crystal X-ray diffraction analyses indicate that compound 1 is constructed by tetranuclear ring-connecting chains and polymerized [Cu(bte)]+ chains, between which SiW12 anions are inserted to form a three-dimensional (3D) structure. Compound 2 shows a (44·62) two-dimensional grid sheet. The discrete SiW12 anions are sandwiched by the sheets, just like “hamburgers”. Compound 3 presents channel-like [Cu2(btb)]2+ polymerized chains, which are further connected by SiW12 anions to construct a 3D framework. Compound 4 exhibits a (66) 3D Cu-btb framework with hexagonal channels, into which the tetradentate SiW12 anions are incorporated. The thermal stabilities of the compounds are discussed.