Construction of a PbII coordination polymer from a semi-rigid ditopic 2,2-biimidazole derivative: synthesis,crystal structure and characterization

<!?tlsb=-0.04pt>A new Pb^II coordination polymer, poly0.75(aqua)μ₃-4,4′-(1H,1′H-2,2′-biimidazole]-1,1′-diyl)dibenzoato-κ⁵O,O′;N;O′′,O′′′]]lead(II)] 1.25-hydrate], {Pb(C₂₀H₁₂N₄O₄)(H₂O)_0.75]·1.25H₂O}_n or {Pb(L)(H₂O)_0.75]·1.25H₂O}_n ( 1 ) H₂L = 4,4′-(1H,1′H-2,2′-biimidazole]-1,1′-diyl)dibenzoic acid], was synthesized under solvothermal reaction conditions and characterized using microanalysis, IR spectroscopy and thermogravimetric analysis. Single-crystal structure analysis reveals that a two-dimensional corrugated layer structure is formed in 1 and that neighbouring layers are further extended into a three-dimensional structure by hydrogen-bonding interactions. In addition, a fluorescence sensing experiment towards Cu²⁺ based on the polymeric Pb^II complex was carried out.