Structures, fluorescence and magnetism of a series of coordination polymers driven by a tricarboxypyridine ligand

Abstract

In this study, a tricarboxypyridine ligand 3-((5-carboxypyridin-3-yl)oxy)phthalic acid (H₃cppa) that combines three distinct types of functional groups (COOH, O-ether and N-pyridyl) was used to construct metal complexes by a hydrothermal reaction, and eight new complexes were constructed, namely, [Zn(μ₃-Hcppa)·2H₂O]_n (1), [Cd(μ₄-Hcppa)·H₂O]_n (2) [Cd(μ₂-H₂cppa)₂·2H₂O]_n (3), [Mn(μ₂-Hcppa)·(phen)·H₂O] (4), [Co₃(μ₃-cppa)₂·19H₂O]_n (5), [Co(μ₂-H₂cppa)₂·2H₂O]_n (6), [Co(μ₃-Hcppa)·(phen)·2H₂O]_n (7), and [Fe(μ₂-H₂cppa)₂·2H₂O]_n (8). The complexes were all characterized at room temperature by single crystal X-ray diffraction, infrared analysis and elemental analysis in the solid state; structure analyses reveal that complexes 1 and 2 have 2D network structures, complexes 3, 5, 6, 7, and 8 have a 1D chain structure and complex 4 has a 0D structure. In addition, luminescence behavior of complexes 1–3 was investigated and magnetic properties of complexes 4–8 were studied. The fluorescence test results show that the fluorescence intensities of complexes 1, 2 and 3 are lower than that of the ligand; the magnetic results indicate antiferromagnetic interactions in complexes 4, 5, 6, and 7 and weak ferromagnetic interactions in complex 8.