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

Three new Co 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 · n H 2 O ( 2 ), and [Co 2 ( L ) 2 ( p -BDC)(N 3 ) 2 ] n ·2 n MeOH ( 3 ) [ o -BDC = 1,2-benzenedicarboxylate, m -BDC = 1,3-benzenedicarboxylate, p -BDC = 1,4-benzenedicarboxylate, and L = di(1 H -imidazol-1-yl)methane], have been constructed from di(1 H -imidazol-1-yl)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 π···π 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.