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and 3-bpo (2,5-bis(3pyridyl)-1,3,4-oxadiazole) or 4-bpo (2,5-bis(4-pyridyl)-1,3,4-oxadiazole) and characterized by elemental analysis, IR spectroscopy, TG analysis, and single crystal X-ray diffraction. The 4-bpo molecules are connected into an infinite double-chain in compound 1 as a bidentate ligand. Compound 2 contains large hexagonal prism shaped molecular cages defined by copper ions and 4-bpo molecules which wrap Keggin ions inside. In compound 3 {Cu 2 (3-bpo) 2 } molecular rings connect with Keggin ions to form a 1D chain. By inspection of the structures, the geometry and the coordination mode of bpo ligands play important roles in the formation of 1-3. The catalytic performance of 1-3 was investigated for epoxidation of styrene using tert-butyl hydroperoxide (TBHP) as the oxidant. Compounds 1-3 present promising activity as heterogeneous catalysts while compound 1 exhibits the best yield of styrene epoxide.

Blue needle—shaped crystals of [Cu(bpy)(H2O)2(C4H4O4)]· 2H2O were obtained by slow evaporation of a methanolic aqueous solution containing a fresh Cu(C4H4O4)· 2H2O precipitate, 4, 4′—bipyridine, and ammonia. Within the complex, the six—coordinated Cu atoms are linked by bis—monodentate gauche succinate anions into chains propagating helically around the [001] axis. The chains are interconnected by 4, 4′—bipyridine ligands into a 3D framework with the crystal H2O molecules located in the channels along the [100], [010] and [110] directions. The Cu2+ ions are in distorted octahedral coordination of two nitrogen and four oxygen atoms (equatorial bonds: Cu—N 1.986(5), 2.015(5)Å; Cu—O 1.950(6), 1.954(6)Å; axial bonds Cu—O: 2.524(9), 2.539(8)Å). Furthermore, the thermal and magnetic behavior of the compound will be discussed. Crystal data: hexagonal, P61 (no. 169), a = 11.066(2)Å, c = 24.965(5)Å, V = 2647.5(8)Å3, Z = 6, R = 0.0528 and wR2 = 0.1103 for 1426 observed reflections (Fo2 > 2σ(Fo2)) out of 2170 unique reflections.

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