A new three-dimensional cadmium(II) coordination polymer based on bis[4-(2-methylimidazol-1-yl)phenyl]methanone: synthesis, structure and properties

A twofold interpenetrated two-dimensional zinc(II) coordination polymer for the highly sensitive detection of nitrofurantoin in aqueous medium

A novel ZnII coordination polymer, namely, poly[{μ2-bis[4-(2-methyl-1H-imidazol-1-yl)phenyl]methanone-κ2N3:N3'}(μ2-5-bromobenzene-1,3-dicarboxylato-κ2O1:O3)zinc(II)], [Zn(C8H3BrO4)(C21H18N4O)]n or [Zn(Br-BDC)(MIPMO)]n, (I), has been synthesized by the solvothermal method using 5-bromoisophthalic acid (Br-H2BDC), bis[4-(2-methyl-1H-imidazol-1-yl)phenyl]methanone (MIPMO) and Zn(NO3)2·6H2O. Structure analysis showed that compound (I) displays twofold parallel interwoven sql nets. Fluorescence experiments confirmed that the compound can sensitively and selectively detect nitrofurantoin (NFT) in aqueous medium. In addition, the possible fluorescence quenching mechanisms of compound (I) toward NFT are investigated.

A new two-dimensional cadmium(II) coordination polymer based on Cd6(CHADC)6 clusters (H2CHADC is cyclohexane-1,2-dicarboxylic acid): synthesis, structure and properties

The highly effective recognition and detection of metal ions and anions in water has attracted much attention with respect to environmental safety. Herein, a novel Cd-based coordination polymer, poly[[4,4'-bis(2-methylimidazol-1-yl)biphenyl]bis(cyclohexane-1,2-dicarboxylato)dicadmium(II)], [Cd₂(C₈H₁₀O₄)₂(C₂₀H₁₈N₄)]_n or [Cd(CHADC)(4,4'-BMIBP)_0.5]_n, (I), has been synthesized employing cis-cyclohexane-1,2-dicarboxylic acid (H₂CHADC) and 4,4'-bis(2-methyl-1H-imidazol-1-yl)biphenyl (4,4'-BMIBP). Single-crystal X-ray analysis reveals that (I) presents a 6-connected hxl two-dimensional layer based on Cd₆(CHADC)₆ clusters with the point symbol (3⁶·4⁶·5³). Furthermore, (I) has been characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis and fluorescence spectroscopy, and exhibits good stability and excellent photoluminescence properties. Coordination polymer (I) was chosen as a fluorescent probe to sense different target analytes and shows an obvious selective recognition response to Fe³⁺ cations and Cr₂O₇^2-/CrO₄^2- anions through luminescence-quenching effects in aqueous solution. The sensing mechanism was investigated and showed that the detection mechanism was resonance energy transfer between (I) and the Fe³⁺, Cr₂O₇^2- and CrO₄^2- ions.