Synthesis,Structures And Properties Of Zinc Coordination Polymers Based On Triazol-Carboxylate Ligands

As a new kind of multifunctional crystalline materials,coordination polymers have attracted extensive attention from chemists and material scientists due to their wide application prospects in many research fields such as gas storage/separation,heterogeneous catalysis,magnetic,fluorescence-based sensing,and so on.In this thesis,seven novel zinc coordination polymers were synthesized under hydrothermal/solvothermal conditions by using different Zn（II）salts with triazole ligand 3,5-dimethyl-1,2,4-triazole（Hdmtz）,bifunctional triazole-carboxylate ligands4-（1H-1,2,4-triazol-1-yl）benzoic acid（4-Htba）and 3-（4H-1,2,4-triazol-4-yl）benzoic acid（3-Htba）.The specific contents are as follows:1.A novel 3D zinc coordination polymer formulated as{[Zn₄（dmtz）₃（OH）₃（HCOO）]（NO₃）}_n（1）was synthesized under hydrothermal conditions and structurally characterized by single-crystal X-ray diffraction analysis,elemental analyses,and IR spectroscopy.Compound 1 show a（3,4,5）-connected 3D cation framework constructed byμ₃-bridging dmtz with hydroxyl and formate anions as the auxiliary ligands.In addition,the photocatalytic properties of compound 1 have been investigated and it exhibits selective photocatalytic degradation for methyl orange（MO）under UV light.2.A luminescent zinc porous coordination polymer with uncoordinated triazolate N-donors,namely[Zn（4-tba）₂]·（DMA）（2）（DMA=N,N-Dimethylacetamide）,was synthesized by using a triazolate-carboxylate bifunctional ligand 4-Htba.Single-crystal X-ray diffraction analyses showed that compound 2was connected by 4-tba ligands to form a three-dimensional porous structure with dia topology,and the activated 2a also shows selective adsorption of CO₂ over N₂.Moreover,compound 2 shows significant luminescence quenching of nitrobenzene and Fe³⁺,which can be used for sensing nitrobenzene and Fe³⁺.3.A series of Zn（II）coordination polymers,namely[Zn（3-tba）₂]·H₂O（3）,[Zn（3-tba）₂]·NMF（4）,[Zn（3-tba）₂]·0.5DMF（5）,[Zn（3-tba）₂]·DMA·H₂O（6）,and[Zn（3-tba）₂]·2NMP（7）（NMF=N-methylformamide,DMF=N,N-dimethyl-formamide,NMP=1-methyl-2-pyrrolidone）,were synthesized under hydrothermal/solvothermal conditions by using a V-shaped,bifunctional triazole-carboxylate ligand 3-Htba.Single-crystal X-ray diffraction analysis showed that the znic ion of compounds 3-7 adopts tetrahedral coordination geometry.Compounds 3-5 were two-dimensional layer structure,Compounds 3 and 5 were（4,4）lattice topology network structure,Compound 4 was single-nodal four-connected 4L7 topology network structure and point symbol was 6⁶.Compounds 6 and 7 were one-dimensional chain structure,and compound 7 was ladder chain.Meanwhile,the solid stete photoluminescence study indicates that compounds 3-7 have ligand-based fluorescence emission at room temperature.