Synthesis, structure and luminescent properties of coordination polymers with 1,2-benzenedicarboxylic acid and a series of flexible dicarboxylate ligands

Abstract

A series of lanthanide coordination polymers, namely, [Ln(ox)_0.5(phth)(H₂O)₂]·0.5H₂O (Ln = Tb (1), Sm (2); H₂ox = oxalic acid; H₂phth = 1,2-benzenedicarboxylic acid), [Ln(mal)_0.5(phth)(H₂O)₂]·H₂O (Ln = Eu (3), Sm (4); H₂mal = maleic acid), [Pr₃(mal′)(phth)₃(H₂O)₃]·H₂O (5) (H₂mal′ = malic acid) [Eu(ad)_0.5(phth)(H₂O)₂] (Ln = Eu (6), Sm (7); H₂ad = adipic acid), [Pr₂(ad)(phth)₂(H₂O)₄] (8) have been synthesized hydrothermally from the self-assembly of the lanthanide ions (Ln³⁺) with different types of flexible dicarboxylate ligands and the rigid 1,2-benzenedicarboxylate ligand. All coordination polymers were characterized by elemental analysis, IR spectroscopy, and single-crystal X-ray diffraction. Structural analyses reveal that the networks of all eight complexes exhibit a variety of coordination modes at the metal centers. The thermal stabilities for 1, 3, 5, 6, 8, photoluminescent properties for 1–4 and 6–7 were examined, and the results show that the complexes seem to be good candidates for novel hybrid inorganic–organic photoactive materials with excellent thermal stability.