Three complexes of manganese(II) based on a new semirigid tetracarboxylate and N-containing ligands: Synthesis, crystal structures and magnetic properties

Three manganese(II) coordination polymers, namely [Mn(L)(0.5)(bipy)(0.5)(H2O)](n) (1), [Mn-2(L)(1,4-bimb)(H2O)(2)](n), (2) and [Mn(L)(0.5)(4,4'-bibp)(0.5)(H2O)(2)](n) (3), where H4L = 5,5'-([1,1'-biphenyl]-4,4'-diyl-bis(oxy))diisophthalic acid, bipy = 4,4'-bipyridine, 1,4-bimb = 1,4-bis(imidazol-1-ylmethyl) benzene and 4,4'-bibp = 4,4'-di(1H-imidazol-1-yl)-1,1'-biphenyl, have been successfully constructed using the hydrothermal method. To understand these compounds completely, single crystal X-ray diffraction, IR, powder X-ray diffraction (PXRD) and thermogravimetric studies have been carried out. Complexes 1 and 2 possess three-dimensional (3D) pillared-layer frameworks, and 2-fold and 3-fold interpenetration take place in 1 and 2, respectively. In complex 3, 2D layers are linked by hydrogen bonds, resulting in a 3D supramolecular architecture. Meanwhile, the magnetic behaviors of complexes 1 and 2 have been investigated and weak antiferromagnetic interactions between two Mn(II) centres within the polymers have been revealed. (C) 2015 Elsevier Ltd. All rights reserved.