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A zinc(II) coordination polymer, [Zn4(o-bda)4(p-pbim)4]n (1) (p-pbim = 4-pyridylbenzimidazole, o-bda2- = o-phenylenediacetic acid dianion), has been synthesized by hydrothermal method and characterized by elemental analysis, IR, TG, photoluminescence and X-ray single crystal diffraction. Complex 1 crystallizes in a monoclinic system and space group P21/n, with a = 14.231(3) Å, b = 16.257(4) Å, c = 16.794(4) Å, β = 100.262(1)°, and Z = 8; R1 for 6475 observed reflections [I > 2σ(I)] was 0.0420. Complex 1 shows a bi-chain structure fabricated by the tetranuclear zinc unit. Two zinc(II) ions are five coordinate with distorted trigonal-bipyramid geometry; the other two zinc(II) ions are four coordinate with distorted tetrahedral geometry. Complex 1 builds the 1-D bi-chain structure with two different subrings A and B, which are 32-member and 14-member rings, respectively. There exists a 2-D supramolecular network linked by hydrogen-bonding interactions (2.695 and 2.807 Å). A 3-D supramolecular network is further constructed by non-covalent interactions between the 1-D bi-chain structure. The TG/DTG shows that the chain skeleton is thermally stable to 356°C. Blue fluorescent emission of the complex was determined at 404 nm in the solid state with short decay lifetime of 1.67 ns. [ABSTRACT FROM AUTHOR]

The silver and acid hydrogen atoms in the crystal structure of [Ag(pa)(Hpa)]n (Hpa = 3-(1H-benzimidazol-2-yl) propionic acid-N) both lie on special positions of -1 site symmetry; the silver atom shows linear coordination [Ag-N = 2.109(3) Å, N-Ag-N = 180°]. The 'acid hydrogen' links molecules into a linear chain, and hydrogen bonds between the nitrogen-bound hydrogen atom and the carbonyl oxygen atom of an adjacent chain furnish a three-dimensional supramolecular structure. The compound, C20H19AgN4O4, belongs to the triclinic space group P1 [a = 6.536(7), b = 8.127(9), c = 9.051(1) Å; α = 81.692(2), β = 82.819(2), γ = 87.229(2)°], and there is one formula unit in the unit cell. [ABSTRACT FROM AUTHOR]