Synthesis, crystal structures, and magnetic properties of three cobalt(II) coordination polymers constructed from 3,5-pyridinedicarboxylic acid or 3,4-pyridinedicarboxylic acid ligands

Abstract

Three 2D new coordination polymers Co 2 (L 1 ) 2 (1,10-Phenanthroline) 2 (DMF) 0.5 (H 2 O) (1), (H 2 L 1 = Pyridine-3,5-dicarboxylic acid) Co(L 1 )(2,2-bipyridine) (2), and Co(L 2 )(2,2-bipyridine) (DMF) (3) (H 2 L 2 = Pyridine-3,4-dicarboxylic acid) were synthesized through a solvothermal reaction of cobalt nitrate and pyridine carboxylic acid ligand with the auxiliary ligand (1,10-Phenanthroline or 2,2-bipyridine). They were characterized by X-ray diffraction and elemental analysis, infrared spectroscopy, thermogravimetry analysis, and magnetism. Compounds 1–3 featured 2D hexagonal (6,3) networks which linked into 3D supramolecular architectures through π–π interaction. In addition, compounds 1 and 2 showed the antiferromagnetic exchange interactions, and the magnetic property of compound 3 exhibited ferromagnetic exchange interactions.