Syntheses, Characterizations And Properties Of Coordination Polymer Based On Aromatic Polycarboxylates And N-containing Heterocyclic Ring Ligands

Due to the potential applications of coordination polymers in the fields of light, electricity, magnetism, catalysis, gas adsorption, etc., they have become one of the hot research realms in functional materials. So far, a large number of coordination polymers have been prepared by using various organic ligands, such as carboxylate acids, imidazoles, and pyridine derivatives. Because of the versatile coordination modes, aromatic carboxylate linkers are considered to be excellent structural constructors and most used to construct coordination polymers. Herein, based on the current research in the field of coordination chemistry, we designed and synthesized three novel aromatic polycarboxylate ligands and nine complexes through hydrothermal synthesis methods; furthermore, the thermal stabilities and photoluminescence of them were studied.The main contents of this paper include the following three parts:1. Synthesis of three organic ligands:4-Nitro-2,6-Bi(4-Carboxyphenyl)phenol(L1) and4-tert-Butyl-2,6-Bi(4-Carboxyphenyl)phenol(L2) were synthesized by coupling, hydrolysis and other multi-step reaction using4-Nitro-phenol,4-tert-Butyl-phenol and p-methoxycarbonylphenyl boronic acid as raw materials;2-(3-Carboxyphenyl)-pyrimidine-4,6-dicarboxylic acid(L3) was synthesized by substitution, coupling, oxidation and other multi-step reaction using acetylacetone, urea, m-methoxycarbonylphenyl boronic acid as raw materials. And their structures were determined by1H NMR,13C NMR, IR, elemental analysis.2. Synthesis of nine coordination Polymers:(1)Six new lanthanide coordination polymers were synthesized via hydrothermal using ligand L3and rare earths metal salts Dy(NO3)3·6H2O, Er(NO3)3·6H2O、Ho(NO3)3·6H2O, Tm(NO3)3-6H2O、 Tb(NO3)3·6H2O、 Sm(NO3)3·6H2O.(2)Two new transition metal coordination polymers were synthesized via hydrothermal using L1, L3as the main ligand, 1,4-bimidazole butane(bib) as the second ligand and transition metal salts Cd(NO3)2·4H2O、 CdCl2-2.5H2O.(3)0ne new coordination polymers[Cd(L4)(H2O)2]n were synthesized via solvothermal using ligand L4and metal salts Cd(NO3)2-4H2O3. Characterization and Property of coordination polymers:Polymers1-9were characterized by element analyses, IR spectroscopy, Powder X-ray diffraction (PXRD) and single-crystal X-ray diffraction. The thermal stabilities of polymers1-5、8were analyzed and the results showed that8has a better thermal stability. Moreover, we found that only complexes1,3and8can show a certain degree of fluorescence.