Three Lanthanide Coordination Polymers Based on Novel Rigid Tetracarboxylate Ligand: Syntheses, Crystal Structures, and Luminescence Properties

摘要

Three lanthanide coordination polymers [Ln(bcpb)0.5(NO3)(DEF)2](Ln=Y(1),Tb(2),Eu(3),H4 bcpb=2,5-bis(2,4-dicarboxyphenyl) pyridine and DEF=N,N-diethylformamide)) have been solvothermally synthesized under hydrothermal conditions with a novel H4 bcpb ligand and trivalent lanthanide nitrates.Single-crystal X-ray diffraction analysis reveals that compounds 1~3 are isostructural and crystallize in the monoclinic system,space group P21/n.Crystal data for 1:C20H26N4O9 Y,Mr=555.36,a=13.022(9),b=17.778(12),c=10.861(8) ?,β=100.208(3)o,V=2475(3) ?3,Z=4;Crystal data for 2:C20H26N4O9 Tb,Mr=625.37,a=13.0476(4),b=17.8037(7),c=10.9398(3) ?,β=100.008(4)o,V=2496.4(12) ?3,Z=4;Crystal data for 3:C20H26N4O9 Eu,Mr=618.41,a=13.055(4),b=17.833(5),c=10.893(3) ?,β=100.133(4)o,V=2496.4(12) ?3,Z=4.The compounds were characterized by thermogravimetric analysis(TGA),IR spectroscopy,and X-ray single-crystal diffraction.Compounds 1~3 all feature 2D networks with-ABAB- fashions.The luminescent properties of compounds 1~3 and free H4 bcpb ligand were investigated at room temperature.The results show that the H4 bcpb ligand can efficiently transfer energy to the Tb(Ⅲ) ions,while the energy is not fully transferred from the H4 bcpb ligand to the Eu(Ⅲ) ions.