Zhifeng Zhao

Inorganic–organic hybrids constructed from heteropolymolybdate anions and copper–organic fragments: syntheses, structures and properties

A series of inorganic–organic complexes based on polymolybdate anions and copper–organic subunits, [Cu(H2O)(bim)2]{[Cu(Hbim)2][P2Mo5O23]}·2H2O (1), [Cu(Hbim)2]{[Cu(bim)(H2O)2]2[Cu(bim)2]2[(P2Mo5O23)2]}·20H2O (2), [Cu(phen)(H2O)][Cu(bim)2]2[P2Mo5O23]·H2O (3) and Mg[Cu(bim)(H2O)]2[P2Mo5O23]·4H2O (4) (bim = 2,2′-biimidazole, phen = 1,10-phenanthroline), have been synthesized under hydrothermal conditions and their crystal structures have been determined by single-crystal X-ray diffraction analysis. All of these compounds contain the [P2Mo5O23]6− polyoxoanions as building units. The structure determination shows that the polyoxoanion of compound 1 is mono-supported by one copper complex subunit. In compound 2, the [P2Mo5O23]6−cluster is supported by two distinct [Cu(bim)(H2O)2]2+ and [Cu(bim)2]2+ fragments. Compound 3 presents a tri-supported polyoxometalate cluster structure, where each [P2Mo5O23]6− anion is decorated by two [Cu(bim)2]2+ and one [Cu(phen)(H2O)]2+ cations. In compound 4, the [P2Mo5O23]6− anion is supported by four symmetry [Cu(bim)(H2O)]2+ units. The cyclic voltammetry results for 1–4 indicate the known fingerprint of the [P2Mo5O23]6− anion. Although compounds 1–4 contain similar polyoxometalate anions, the mean peak potentials are slightly different, due to their different chemical environments. The magnetic behaviours of 1–4 were also investigated, in the temperature range of 2–300 K.

Three novel coordination polymers constructed from [Cu(CN)] chains

Three new coordination polymers based on [Cu(CN)] chains, [Cu(CN)]3(phen) (1), [Cu(CN)]2(4,4′-bipy) (2) and [Cu(CN)]4(bpp)2 (3) (phen = 1,10′-phenanthroline, bipy = 4,4′-bipyridine and bpp = 1,3-bis(4-pyridyl)propane), have been synthesized by hydrothermal methods and characterized by elemental analysis, IR, X-ray powder diffraction (XRPD) and single crystal X-ray diffraction. Complex 1 features a noncovalence-induced 2D layer and further forms a 3D supramolecular framework by π⋯π interactions. Complex 2 generates an interesting 3D coordination polymer of 2-fold interpenetration with (4.62)(42.610.83) topology. Complex 3 displays 2-fold parallel interpenetration with (4.62)(43.611.72.85)(44.611)(45.615.7) topology. The thermal stability and photoluminescent properties of 1–3 in the solid state at ambient temperature were also investigated.

Synthesis, crystal structure, and properties of a new 1-D “heteropoly blue”-modified nickel complex

A new reduced molybdenum phosphate, [Ni(bpy)2(H2O)2]{[Ni(H2O)2][Ni0.5(MoO2)6(OH)3(PO4)(HPO4)3[Ni(bpy)2(H2O)]2][Ni0.5(MoO2)6(OH)3(PO4)(H2PO4)2(HPO4)]} · 14H2O (1) (2,2′-bpy = 2,2-bipyridine), has been hydrothermally synthesized and characterized by elemental analysis, IR, UV-Vis, TG, and single-crystal X-ray diffraction. Compound 1 crystallizes in the triclinic system, space group P-1, with lattice parameters a = 17.0459(9) Å, b = 19.2643(11) Å, c = 19.9357(11) Å, β = 79.9500(10)°, V = 5804.9(6) Å, Z = 2, and R 1(wR 2) = 0.0460(0.1228). Structural analysis indicates that neighboring Ni[P4Mo6]2 and nickel-complex polyanions are interconnected by [Ni(H2O)2] subunits via P–O–Ni(2) bridges, generating a 1-D infinite chain “heteropoly blue” structure. Furthermore, 1 shows photoluminescence in the solid state at room temperature. Compound 1 was used as a solid bulk modifier to fabricate a carbon paste electrode (1-CPE) by direct mixing. The electrochemical and electrocatalytic behaviors of 1-CPE have been studied.