Four Ln(III) coordination polymers based on 1H-benzimidazole-5,6-dicarboxylate ligand: Synthesis, crystal structure, and luminescence

Abstract

Four Ln(III) coordination polymers, [La2(HBidc)3(H2O)]n (I), [Pr2(HBidc)3(H2O)]n (II), [Sm2(HBidc)3(H2O)]n (III), and [Gd2(HBidc)3(H2O)]n (IV), were synthesized hydrothermally by treating Ln(NO3)3 · 6H2O, NaOH, and H3Bidc (H3Bidc = 1H-benzimidazole-5,6-dicarboxylic acid) at 180°C and characterized by elemental analysis, IR spectra, and single-crystal X-ray structure analyses. Complexes I–IV are isostructural, and each complex contains two crystallographically independent Ln(III), one is seven-coordinated, while the other is eight-coordinated. X-ray crystallography reveals that the complex consists of 3D frameworks with the (34·44·52·66·710·8·9)(3·4·5)(3·4·5) topology. Furthermore, the photoluminescence properties of III has been studied.