Syntheses, structures and photoluminescent properties of lanthanide coordination polymers based on pyridyl functionalized imidazole dicarboxylic acid

Abstract

A series of lanthanide coordination polymers formulated as {[Ln2(HPIDC)2(H2O)8]·2(H2PIDC)·18H2O}n [Ln = Sm (1), Eu (2)], {[Dy2(HPIDC)2(H2O)9]·2(H2PIDC)·17H2O}n (3), {[Dy3(HPIDC)4(H2O)8]·(NO3)·6H2O}n (4), {[Dy2(HPIDC)2(bdc)(H2O)4]·8H2O}n (5), {[Ln(HPIDC)(bdc)]·H3O+·H2O}n [Ln = Er (6), Tm (7), Yb (8)] (H3PIDC = 2-(pyridin-4-yl)-1H-imidazole-4,5-dicarboxylic acid, H2bdc = 1,4-benzenedicarboxylic acid) based on pyridyl functionalized imidazole dicarboxylic acid ligand have been synthesized by hydrothermal methods and characterized by single crystal X-ray diffraction, powder X-ray diffraction, elemental analysis and thermogravimetric analysis. Compounds 1–3 are one-dimensional (1D) cationic chains linked by the H3PIDC ligands, and the free H2PIDC− act as counter ions in the crystal lattice. Compound 4 displays a 2D layer built up from 3-connected HPIDC2− ligands and 4-connected Dy(III) ions. While compounds 5–8 possess 2D network constructed from HPIDC2− and bdc2− ligands. The solid-state photoluminescent measurements show the photoluminescence of 1–5 are typical narrow emission bands of their lanthanide cations.