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

Abstract

Three manganese(II) coordination polymers, namely [Mn(L)0.5(bipy)0.5(H2O)]n (1), [Mn2(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′-diylbis(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.