Syntheses, Crystal Structures and Magnetic Properties of Ni(Ⅱ) and Mn(Ⅱ) Coordination Polymers Constructed from 5-(2'-Carboxylphenyl) Nicotate and 2,2'-Biimidazole

Two coordination polymers, namely {[Ni(cpna)(H2biim)(H2O)]·H2O}n(1) and {[Mn(cpna)(H2biim)]·H2O}n(2)(H2cpna = 5-(2'-carboxylphenyl) nicotic acid, H2biim = 2,2'-biimidazole),have been hydrothermally synthesized and characterized by elemental analysis, IR, TG, magnetic properties, and single-crystal X-ray diffraction. Compound 1 exhibits a one- dimensional(1D) step-like chain structure, which further builds a three-dimensional(3D) supramolecular architecture via O–H···O and N–H···O hydrogen-bonding and π-π stacking interactions. Compound 2 possesses a one-dimensional(1D) double chain structure, which is further assembled into a 3D supramolecular framework by N–H···O hydrogen bonding and π-π stacking interactions. Magnetic susceptibility measurement indicates that compound 1 shows a weak antiferromagnetic coupling between the nearest Ni(II) centers, with g = 2.11 and J = –1.87 cm–1.