Cobalt(II)-Azido Coordination Polymers with Dicarboxylate and Di(1H-imidazol-1-yl)methane Ligands Exhibiting Ferromagnetic Behaviors

Three new Con(II)-azido complexes, [Co-3(L)(2)(o-BDC)(2)-(N-3)(2)](n) (1) [Co-3(L)(2)(m-BDC)(2)(N-3)(2)](n) center dot nH(2)O (2), and [Co-2(L)(2)(p-BDC)(N-3)(2)](n) center dot 2nMeOH (3) [o-BDC = 1,2-benzenedicarboxylate, m-BDC = 1,3-benzenedicarboxylate, p-BDC = 1,4-benzenedicarboxylate, and L = di(1H-imidazol-1-yl)methane], have been constructed from di(1H-imidazol-1-y)methane, azido, and different aromatic dicarboxylates under hydrothermal conditions. Complex 1 takes a dia topology with the Co-3 units as connecting nodes, and complex 2, is a two-dimensional sql layer that further extends to a three-dimensional (3D) supramolecular network via pi center dot center dot center dot pi interaction between m-BDC ligands, while complex 3 forms a 3D pcu network based on Co-2 units as nodes. The investigaton of magnetic properties of complexes 1-3 demonstrates that they all display ferromagnetic coupling between Co-II ions but antiferromagnetic interaction between Co-3 or Co-2 units.