Synthesis,Structure And Properties Of Coordination Polymers Based On N-heterocyclic Aryl Polycarboxylate Ligands

Coordination polymers are porous materials formed by the combination of metals and organic ligands.Due to the structural diversity and designability,they are used in light emission,chemical sensing,heterogeneous catalysis,gas storage and gas separation Drug delivery and other fields have a wide range of applications,and in recent years it has become a hot research topic in the field of chemistry.In this thesis,two organic ligands of N-heteropolycarboxylic acid were selected,and 10 compounds with novel structure were synthesized under solvothermal conditions,and a series of structural characterization and fluorescence properties were studied.1,3-bis(carboxymethyl)benzimidazolium salt(HL1)was synthesized by the method reported in the literature,and it was used as a ligand to synthesize 5 compounds with lanthanide metal nitrate {[Ln(L1)(NO3)2H2O]n,Ln = Sm(1);Eu(2);Gd(3);Tb(4);Dy(5)}.X-ray single crystal diffractometer analysis shows that compounds 1-5 are crystallographically isomorphic and are all two-dimensional network structures.Compounds 1-5 were analyzed by powder X-ray diffraction(PXRD),infrared(IR),thermogravimetric(TGA),and fluorescence structures and properties.The test results show that compounds 1-5 have very good purity and high thermal stability.Compounds 1,2,4 and 5 show the corresponding luminescence characteristics of lanthanide ions,respectively.The fluorescence lifetime of compound 2 and the low-temperature phosphorescence spectrum of compound 3 at 77 k were also studied.Compounds 6-10 were synthesized using 1,3,5-triazolyl-4,4’,4’ ’-tribenzoic acid(H3L2)as ligand and transition metal nitrate: [Zn2(HL2)2(H2O)4·2DMF]n(6),[Ba(HL2)(H2O)2(DMF)]n(7),[Ni3(L2)2(H2O)4(μ2-O)2]n(8),[Mn3(L2)2(H2O)4(μ2-O)2]n(9),[Co3(L2)2(H2O)4(μ2-O)2]n(10).X-ray single crystal diffraction analysis showed that compounds 6-10 had different two-dimensional and three-dimensional structures.Compounds 8-10 are crystallographically isomorphic.PXRD,IR,TGA and other structural characterization analysis were carried out on compounds 6-10 respectively.The test results show that compound 6-10 has very good purity and thermal stability.The fluorescence properties of compound 6 were studied.Compound 6 showed an emission peak at 407 nm and emitted blue light.