Synthesis, Crystal Structure, and Magnetic Properties of a New Coordination Polymer Framework [CoII(4,4′-bpy)(N3)2]n

A new cobalt(II) coordination polymer containing 4,4'-bipyridine and azide as bridging ligand,[Co-II(4,4 '-bpy)(N-3)(2)](n) (1) was synthesized under mild hydrothermal conditions and was characterized by single-crystal X-ray diffraction studies and magnetic susceptibility measurements. It exhibits an acentric structure, in which cobalt(II) ions are linked through end-to-end (EE) azido groups. The 4,4'-bpy ligands are coordinated oil the axial positions of the octahedral environment reinforcing the intermetallic connections and resulting in a network. Circular dichroism spectra of the compound exhibit a maximum negative Cotton effect at 260 nm, which indicates the chiral nature of 1. Variable temperature magnetic susceptibility measurements in the temperature range 2-300 K reveal the existence of antiferromagnetic couplings in the framework.