Two novel pillar-layered Mn(II) coordination networks based on aromatic carboxylic acids with aminodiacetate functionality

By utilizing 2-aminodiacetic terephthalic acid (H4adtp) and N-(4-carboxyphenyl)iminodiacetic acid (H34-cpida), two coordination polymers formulated as [Mn(H2adtp)(H2O)]n (1) and [Mn3(4-cpida)2(H2O)2]n (2) have been synthesized under solvothermal conditions without any secondary linker. 1 is a three-dimensional (3D) supramolecular pillar-layered structure, where double hydrogen bonding two H2adtp ligands act as one pillar. 2 is a genuine 3D pillar-layered framework with phenyl moiety as strut. Aminodiacetate functionalities in 1 and 2 demonstrate unprecedented ability in connecting the metal ions into 2D layers. Magnetism studies indicate that two complexes both exhibit dominant antiferromagnetic behaviors. In addition, the fitting of magnetic susceptibility (χM) of 1 is performed based on the model of the alternating –J1J2– coupling chain and considering molecular-field approximation.