The Synthesis, Structures And Photoluminescence Of Lanthanide Organic Frameworks Based On Aromatic Polycarboxylic ACID

The hydrothermal reaction between Ln(III) ions,1,4-benzenedicarboxylic acid and oxalic acid led to six novel3-D lanthanide-based organic frameworks. Two novel3-D mix-ligands compounds constructed by Ln(III) ions,2,2’-bipyridine-3,3’-dicarboxylic acid and oxalic acid were synthesized under hydrothermal conditions. The compounds were characterized by elemental analysis, IR spectra, UV-vis spectra, powder X-ray diffraction, and TG-DTA methods. Additional, the photoluminescence and sensing properties of these compounds have been studied.(1) Six novel3D lanthanide-based organic frameworks with the formula of [Ln2(BDC)2(ox)(H2O)4]-2H2O (Ln-Tb1, Dy2, Gd3) and Ln2(BDC)2(ox)(H20)2(Ln=Ho4, Er5, Yb6; H2BDC=1,4-benzenedicarboxylate; H2ox=oxalic acid) have been synthesized successfully by hydrothermal method and complexes1and4were structurally characterized. The compounds were characterized by elemental analysis, IR spectra, UV-vis spectra, powder X-ray diffraction, and TG-DTA methods. Compounds1-6display two types of3D networks under the same condition according to lanthanide constraction effect. Compounds1-3are isostructural and crystallize in the monoclinic crystal system, space group P21/c, while compounds4-6are also isostructural crystallizing in triclinic with the space group P-1. Compounds1and2exhibit characteristic emissions of Tb(Ⅲ) and Dy(Ⅲ) ions and the luminescent lifetime of compound1is0.54ms.(2) Two novel3-D mix-ligand compounds constructed by Ln(Ⅲ) ions,2,2’-bipyridine-3,3’-dicarboxylic acid and oxalic acid were synthesized under hydrothermal conditons, namely [Ln4(μ3-OH)4(bpdc)3(ox)(H2O)5]·nH2O(Ln=Dy (1), n=13; Er (2), n=11). Both of the compounds were structurally characterized and characterized by elemental analysis, IR spectra, UV-vis spectra, powder X-ray diffraction, and TG-DTA methods. Compounds1and2are crystallize in the monoclinic crystal system, space group P21/n. Compound1exhibits characteristic emissions of Dy(Ⅲ) ions and the luminescent sensing properties have been studied.