Syntheses, structural diversities and magnetic properties of four new Co(II) coordination polymers with phthalic acid derivatives

Four new 3D Co(II) coordination polymers, [Co(4apa)(H2O)] (1), [Co(bpy)(3npa)] (2), [Co(bpy)1.5(3adpa)] (3) and [Co(btx)0.5(4npa)(H2O)2] (4) (H24apa = 4-aminophthalic acid, bpy = 4,4′-bipyridine, H23npa = 3-nitrophthalic acid, H23adpa = 3-(4-amino-1,3-dioxoisoindolin-2-yl)phthalic acid, btx = 1,4-bis(1,2,4-triazole-1-ylmethyl)benzene, H24npa = 4-nitrophthalic acid), have been synthesized and characterized by single crystal X-ray diffraction, PXRD and magnetic susceptibility measurements. An interesting in situ acylation reaction of 3-aminophthalic acid (H23apa) has been found in the formation of coordination polymer 3. The Co(II) ions of each polymer lie in distorted octahedral environments and are bridged by μ1,3 carboxylate groups to form 2D (1), 1D (2 and 3) and dimer (4) structures, which are further assembled through ligands into different 3D structures due to the influence of the substituent groups. Studies of the temperature dependence of the magnetic susceptibilities in the range 2–300 K reveal antiferromagnetic interactions in 1–4 between the Co(II) ions transmitted by μ1,3 carboxylate groups.

Graphical abstractFour 3D Co(II) coordination polymers with phthalic acid derivatives as ligands have been synthesized and characterized by single crystal X-ray diffraction, PXRD and magnetic susceptibility measurements. Analyses of the temperature dependence of the magnetic susceptibilities reveal antiferromagnetic interactions between the μ1,3 carboxylate groups bridging the Co(II) ions in these four complexes.Figure optionsDownload full-size imageDownload as PowerPoint slide