| In this thesis,two types of bis-pyridine-bis-amide are designed as the main ligands(the first type is aliphatic hydrocarbon-based bis-pyridine-bis-amide ligand,and the second type is thiophene-based bis-pyridine-bis-amide ligands with different lengths),ten multidentate organic carboxylic acids are selected as auxiliary ligands,fourteen coordination polymers(CPs)were designed and synthesized with Zn(?)or Ag(?)as the central metals by changing the synthesis conditions.The complexes were characterized by X-ray single crystal diffraction,infrared spectroscopy,and powder X-ray diffraction.The fluorescence sensing properties,electrochemical properties and dye adsorption properties were systematically studied.1.From the perspective of ligand fluorescence,two luminescent ligands were selected as the main ligand and auxiliary ligand,that is,the N,N'-bis(3-pyridinecarboxamide)-1,4-butane(3-dpyb)and tetradentate carboxylic acid ligand 4,4'-oxydiphthalic acid(H4odpa),respectively,two CPs were designed and synthesized with Zn(?)or Ag(?)as the central metal by controlling solvent system.The two CPs had good luminescence properties and could be effectively used in the detection of anions,cations,organic solvents,and organic pesticides.Besides,the mechanism for the detection of analytes was analyzed.[Zn2(3-dpyb)2(odpa)2(H2O)3]·4H2O(1)[Ag(3-dpyb)(H3odpa)]-H2O(2)Single crystal X-ray diffraction analysis shows that complex 1 has a 3D structure while complex 2 exhibits a 1D chain structure.The structural diversity of CPs 1 and 2 reveals that metal ions have an important influence on the structures of the complexes.Complexes 1 and 2 exhibit good fluorescence property,so the fluorescence sensing performance of complexes 1 and 2 were investigated.The results revealed that complex 1 showed fluorescence sensing behaviours and selectivity for cations(Fe3+,Bi3+),anions(MnO4-,Cr2O72-),and toxic organic solvents(AH,Hacac,NB).Complex 2 had fluorescence selectivity for organic solvents(Hacac,NB),pesticides(2,6-DCN),and metal cations(Fe2+,Hg2+and Fe3+),indicating that complexes 1 and 2 have significant fluorescence sensing properties.After the stability of testing,it is found that the complexes 1 and 2 can be recycled for many times,so they could be used as highly sensitive and selective multifunctional fluorescence sensors.The experimental mechanism was due to photoelectron transfer and electron transfer on the ligands.2.The fluorescent thiophene bis-pyridine-bis-amide ligand N,N'-bis(4-pyridinecarboxamide)-3,4-thiophene(4-bpft)was introduced into the construction of the complexes.By tuning the substituents,angle and number of the carboxyl groups of auxiliary carboxylic acid,seven Zn(?)-CPs were designed and synthesized under hydrothermal conditions.The auxiliary carboxylic acid ligands are isophthalic acid(1,3-H2bdc),5-methylisophthalic acid(5-H2mip),5-hydroxyisophthalic acid(H2hip),5-aminoisobenzene dicarboxylic acid(5-H2aip),5-nitroisophthalic acid(5-H2nip),terephthalic acid(1,4-H2bdc)and 3,4',5-biphenyltricarboxylic acid(3,4 ',5-H3bpt).In addition,the fluorescent recognition effect of the complexes on different analytes was performed.[Zn2(4-bpft)2(1,3-bdc)2]·2H2O(3)[Zn(4-bpft)(5-mip)](4)[Zn(4-bpft)(5-hip)](5)[Zn(4-bpft)(5-aip)](6)[Zn(4-bpft)(5-nip)](7)[Zn(4-bpft)(1,4-bdc)](8)[Zn2(4-bpft)(3,4',5-bpt)(OH)](9)The auxiliary carboxylic acid ligands in complexes 3-7 are based on different substituted isophthalic acid.Structural analysis showed that complexes 3-7 had a similar 1D chain structures,there are only certain differences in the coordination mode of Zn ions.Complexes 8 and 9 were both 2D layered structures,however,due to the differences in the both geometric configuration of the auxiliary carboxylic acid ligands and the numbers of carboxyl groups,two compounds exhibited different structural characteristics.In addition,the fluorescence sensing properties of complex 3 to Hg(?),adenine,and guanine,the fluorescence properties of complex 4 and 5 to Hg(?),and the fluorescence properties of complex 8 to AA were studied.Besides,the electrochemical behavior and the dye adsorption performance of complex 8 were also investigated.3.Five Zn(?)-complexes were synthesized under hydrothermal conditions by choosing a semi-rigid thiophene-containing bis-pyridine-bis-amide ligand N,N'-bis(3-pyridylamide)-3,4-thiophene(3-bpat)as the main ligand,isophthalic acid(1,3-H2bdc),5-methylisophthalic acid(5-H2mip),5-hydroxyisophthalic acid(H2hip),3,3',5,5'-azobenzenetetracarboxylic acid(H4abtc),and 1,3,5-trimesic acid(1,3,5-Hsbtc)were chosen as the auxiliary ligands.The effects of different carboxylic acid ligands on the structures and performance were further studied.[Zn2(3-bpat)2(1,3-bdc)2]·2H2O(10)[Zn(3-bpat)(5-mip)](11)[Zn(3-bpat)(5-hip)]·H2O(12)[Zn(3-bpat)(1,3,5-btc)(H2O)2]·2H2O(13)[Zn(3-bpat)(abtc)]·H2O(14)The structure analysis revealed that the complexes 10,12 and 14 were all 1D chain structures,and two Zn ions in complexes 10 and 12 are connected by a carboxylic acid ligand to form a 1D chain,and the 3-bpat ligands are arranged symmetrically on both sides.In complex 14,the Zn ions were linked by carboxylic acid ligands to form a 1D chain,and the 3-bpat ligands were only suspended on one side of the chain.In complex 11,two adjacent Zn(II)ions were connected by carboxylic acid ligands to form a 1D chain,and two 1D chains are connected by 3-bpat ligands to form a 2D layer.The complex 13 was a 3D structure,there were two Zn ions connected by two 3-bpat to form a ring,and the rings were further expanded into the 3D structure by abtc4-ligands coordinating with the Zn ions.Furthermore,the fluorescence properties of the complexes 10-12 were researched.The results revealed that both Fe3+and MnO4-could quench the luminescence of 10-12;the fluorescence sensing performance of complex 14 was investigated.At the same time,the electrocatalysis and dye adsorption performance of complex 14 were carried out,and the results indicated that 14 exhibited excellent electrocatalytic activity on the oxidation of AA and had good adsorption performance on MB,GV,and NR dyes. |
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