| In the past few decades,coordination polymers(CPs)have attracted more and more attention from researchers with their tunable crystalline structure and excellent functionality,and have shown great application potential in the fields of drug delivery gas storage and separation,heterogeneous catalysis,and sensing.With the rapid development of the national economy,chemical products are widely used in production and life,and some chemical products that are difficult to degrade enter the ecological environment,causing serious pollution to the water and atmosphere and soil on which human beings depend.In particular,water pollution is particularly serious,so the detection of contaminants in water is very important.Due to the excellent fluorescence performance of complexes,fluorescence sensing detection of contaminants in water by complexes is a very efficient and convenient method.Constructing coordination polymers with specific functional active sites is a challenge,and exploring the structure-activity relationship between the design and synthesis,crystal structure and properties of coordination polymers is the foundation for the future development of coordination polymers.Among many organic ligands,polycarboxylic acid ligands are favored in the synthesis of coordination polymers with their strong coordination ability and multiple coordination methods.To prepare functionalized coordination polymers,polycarboxylic acid ligands are often combined with structures with multiple active sites.In this paper,three pyridine polycarboxylic acid organic ligands were selected to coordinate with different metal central ions,and 14 cases of coordination polymer materials were designed and synthesized,their single crystal structure was determined,and infrared spectroscopy,X-ray powder diffraction and thermal stability analysis were performed.In view of the current detection needs of antibiotics and anions in water,a series of fluorescence sensing performance tests were carried out on some compounds.The specific contents are as follows:(1)Using 3-(pyridin-3-yloxy)phthalic acid(H2PPA)as the organic ligand,In(Ⅲ),La(Ⅲ),and Tb(Ⅲ)as the central metal ion,under the condition of only replacing the metal element Next,three examples of low-dimensional CPs materials {[In(PPA)(H2O)Cl]·H2O}n(1)、[La2(PPA)2(ox)1/2(H2O)4]n(2)and[Tb2(PPA)2(ox)1/2(H2O)4]n(3).Compounds 1-3 are all two-dimensional layered structures.The fluorescence sensing test of compounds 1-3 showed that compounds 1 and 2 had a sensitization effect on sparfloxacin,with obvious fluorescence enhancement,and the detection limits were 1.806×10-8 mol/L and 4.817×10-8 mol/L,respectively.Compound 3 showed quenching phenomenon to CrO42-,and the lowest detection limit was 5.620×10-7 M.1-3 all have high sensitivity and selectivity,and can be used as fluorescence detectors for sparfloxacin and CrO42-.(2)Four compounds were synthesized using 4-(pyridin-3-yl)phthalic acid(H2PYPA)as the main ligand and 4-(1H-tetrazol-5-yl)pyridine(Httpd)as auxiliary ligands:only PYPA2-coordinated isomeric compounds[Zn(PYPA)]n(4)and[Ni(PYPA)]n(5);Isomeric compounds[Co3(PYPA)2(ttpd)2]n(6)and[Ni3(PYPA)2(ttpd)4]n(7)plus second ligand-assisted coordination.Compounds 4-7 are three-dimensional structural compounds.The basic characterization and fluorescence sensing performance tests of compound 4 were carried out,and it was found that 4 had a sensitization effect on sparfloxacin and the detection limit was 1.220 ×10-7 mol/L,and showed a fluorescence quenching phenomenon on CrO42-,and the detection limit was 1.350×10-6 mol/L,can efficiently and selectively detect sparfloxacin and CrO42-by fluorescence.Therefore,compound 4 can be used as a sensitive and rapid fluorescent sensor for the detection of sparfloxacin and CrO42-.(3)Seven coordination polymer structures were constructed by 4-(5-carboxypyridin-3-yl)phthalic acid(H3DBPA)and different metal elements under water/solvothermal method.Among them,[Ln(DBPA)(H2O)2]n(Ln=Eu(8),Pr(9),Gd(10),Nd(11))are four isomorphic rare earth coordination polymers.and three cases of heterogeneous coordination polymers:[[Ba(HDBPA)(H2O)2]n(12)、[Mn(HDBPA)(H2O)]n(13)and[Ni(HDBPA)(H2O)2]n(14).Compounds 8-11 and 13 are two-dimensional layered structures,compound 12 is a three-dimensional network structure,and compound 14 is a one-dimensional chain structure.The solid-state luminescence properties of 8 were detected,showing the characteristic red fluorescence of Eu(Ⅲ)ions.Compounds 8 and 12 can be used as fluorescent probes to detect contaminants in water,and 8 pairs of CrO42-have good fluorescence quenching detection ability,and the detection limit is 1.635 ×10-6 mol/L.12 There was obvious sensitization to the antibiotic norfloxacin,and the minimum detection limit was 7.144×10-1 mol/L.The high selectivity and sensitivity of 8 and 12 pairs of detectors make it a good CrO42-and norfloxacin fluorescence sensing detector. |
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