A Series of Lanthanide−Organic Frameworks Based on 2-Propyl-1H-imidazole-4,5-dicarboxylate and Oxalate: Syntheses, Structures, Luminescence, and Magnetic Properties

Abstract

A family of self-assembly lanthanide−organic coordination polymers with both rigid and flexible ligands formulated as {[Ln2(Hpimda)2(μ4-C2O4)·2H2O]·4H2O}n (Ln = Sm (1), Eu (2), Tb (3), Dy (4), Ho (5), Er (6), H3pimda = 2-propyl-1H-imidazole-4,5-dicarboxylic acid) has been synthesized from the reactions of H3pimda with trivalent lanthanide salts in the presence of oxalate as coligand. X-ray diffraction analysis reveals that these complexes are isomorphous and isostructural, and each forms a novel three-dimensional (3D) frameworks structure, in which the metalloligands' two-dimensional (2D) networks were constructed from the lanthanide ion, 2-propyl-imidazole-dicarboxylate as well as oxalate ligands, and the oxalate further acts as a pillar to link the [Ln(Pimda)(oxo)] 2D grids to generate the 3D open frameworks, leaving one-dimensional channels, which are occupied by water clusters displaying an intricate array. The luminescence emission spectra of the complexes vary depending on which lanthanide ion is pr...