Synthesis, crystal structures and magnetic properties of three porous coordination polymers based on a semirigid tripodal carboxylate ligand

Abstract

Three new coordination polymers, namely, {[Cu2(bcpmba)(μ4-OH)]·2H2O}n (1), [Mn(Hbcpmba)]n (2), and [Co2(bcpmba)(μ3-OH)·H2O]n (3) (H3bcpmba = 3,5-bi(4-carboxy-phenylene-methylene-oxy)-benzoic acid) have been prepared under solvothermal conditions. The complexes were characterized by physico-chemical and spectroscopic methods. All of the compounds 1–3 contain one-dimensional (1D) chains extended via the bcpmba3− bridge to generate 2D porous layers which are further connected by bcpmba3− ligands to form 3D porous coordination polymers. The result shows configurations of the ligand have an important influence on the structure. Magnetic susceptibility measurements indicate that compounds 1–3 exhibit antiferromagnetic coupling between adjacent metal ions, with the corresponding J value of − 2.76 cm−1 for compound 2. Three porous coordination polymers, namely, {[Cu2(bcpmba)(μ4-OH)]·2H2O}n (1), [Mn(Hbcpmba)]n (2) and [Co2(bcpmba)(μ3-OH)·H2O]n (3) have been synthesized by employing a semi-rigid aromatic multicarboxylate acid (3,5-bi(4-carboxy-phenylene-methylene-oxy)-benzoic acid, H3bcpmba) under solvothermal conditions. Porous coordination polymers 1–3 consisted of 1D chain extended via the bridge of bcpmba3– to generate 2D porous layers and further connected by bcpmba3– to provide a 3D porous frameworks. The results reveal that different coordination modes of the ligand play an important role in the self-assembly processes to form metal-organic frameworks with different structures. Moreover, compounds 1–3 exhibited antiferromagnetic properties.