Structures and luminescent properties of three new lanthanide (III) coordination polymers based on 2-(pyridin-3-yl)-1H-imidazole-4, 5-dicarboxylate

Three new lanthanide (III) coordination polymers based on 2-(pyridine-3-yl)-1H-4, 5-imidazoledicarboxylic acid (H3PyIDC) with or without oxalate (Ox) coligand, namely, {[Sm(μ3-HPyIDC)(H2O)3]·Cl·H2O}n (1), {[Tb(μ1-H2PyIDC)(μ2-Ox)(H2O)3]·H2O}n (2), and {[Sm(μ4-HPyIDC)(μ2-Ox)0.5(H2O)]·- 2H2O}n (3), have been successfully synthesized. Compound 1 has a two-dimensional (2D) network structure with (4,4) topology based on binuclear [Sm2(COO)2] as secondary building units (SBUs). Compound 2 possesses a 1D lanthanide-oxalate zigzag chain with μ1-H2PyIDC− ligands hanging on both sides. Compound 3 features an unprecedented uninodal 10-connected 3D open framework with (312·424·58·6) topology based on binuclear [Sm2O2] SUBs. The results revealed that the structural diversity is mainly attributed to the different coordination modes of the H3PyIDC ligand as well as the introduction of Ox2 − auxiliary ligand. Moreover, the thermal stabilities and luminescence properties of the selected complexes were also investigated.