Syntheses, Structures, and Characterizations of a Series of Polymers Constructed by Two V-Shape Dipyridine-Containing Ligands

Two flexible V-shape ligands, namely, 1,3-bis(pyridine-4-ylmethoxy)benzene (4-bpmb) and 1,3-bis(pyridine-2-ylmethoxy)benzene (2-bpmb), have been synthesized and employed for constructing eight novel coordination polymers, {[Zn(4-bpmb)(H2O)(NO3)(2)]center dot(4-bpmb)}(n) (1), {[Cd(4-bpmb)(H2O)(NO3)(2)]center dot(4-bpmb)}(n) (2), {[Hg(4-bpmb)(H2O)(NO3)(2)]center dot(4-bpmb)}(n) (3), {[Zn-4(2-bpmb)(4)Cl-8]center dot C5H5N}(n) (4), {[Hg(2-bpmb)Cl-2]center dot 2H(2)O}(n) (5), [Cu-4(mu-CH3COO)(8)(2-bpmb)(2)](n) (6), [Ag(2-bpmb)(NO3)](n) (7), {[Cu(2-bpmb)(H2O)(2)]center dot(NO3)(2)}(n) (8). These complexes were characterized by elemental analyses and IR spectra and structurally determined by powder and single crystal X-ray diffraction analyses. The photoluminescence properties of complexes 1-3 are studied. The results revealed that the 4-bpmb ligands react with II B group transitional metallic nitrates to give three isostructural 1D wavelike chains (complexes 1-3), which are further decorated by equimolar 4-bpmb molecules to form the wavelike double-stranded chain structures via hydrogen bonds. In the packing model of complex 3, a 2D layer network is observed considering the interaction between mercury atoms and nitrate anions from the adjacent chains. The 2-bpmb ligands reacting with the corresponding transition metal salts generate three 1D helical chains, as expected (complexes 4-6). Complex 7 has a 2D layer structure produced by nitrate anions bridging with 1D opposite homohanded helical chains. Complex 8 displays a straight chain due to the coordination or two O atoms of 2-bpmb ligand with copper cations.