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) (H(2)4apa = 4-aminophthalic acid, bpy = 4,4'-bipyridine, H(2)3npa = 3-nitrophthalic acid, H(2)3adpa = 3-(4-amino-1,3-dioxoisoindolin-2-yl)phthalic acid, btx = 1,4-bis(1,2,4-triazole-1-ylmethyl)benzene, H(2)4npa = 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 (H(2)3apa) 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 mu(1,3) 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 2300 K reveal antiferromagnetic interactions in 14 between the Co(II) ions transmitted by mu(1,3) carboxylate groups (C) 2013 Elsevier Ltd. All rights reserved.