Syntheses, structures, and properties of novel one dimensional copper cyanide coordination polymers

Three new one-dimensional copper coordination polymers have been prepared and fully characterized by single-crystal X-ray diffraction, IR spectroscopy, thermogravimetric analysis, and magnetic susceptibility measurements. The structure of Cu(CN)₂(bpy)] (1) (bpy = 2,2-bipyridyl) (monoclinic P2₁/c, a = 8.9761(7) Å, b = 16.731(1) Å, c = 8.0224(6) Å, β = 114.437(1)°) consists of Cu(II) metal centers coordinated by three cyanide ligands and chelated by one bpy to form the monomers Cu(CN)₃(bpy) with distorted square pyramidal geometry. Each monomer shares two cyanide ligands with two adjacent monomers to form infinite -Cu(II)-CN-Cu(II)-CN-Cu zigzag chains along the c-axis. The one-dimensional structure of Cu(CN)(bpy)] (2) (hexagonal P3₂, a = 14.4883(6) Å, b = 12.921(1) Å) is built of tetrahedral Cu(CN)₂bpy metal complexes in which Cu(I) metal centers are coordinated by one nitrogen and one carbon from two different CN ligands, and two nitrogens from one bpy. The two CN ligands act as bridging ligands between adjacent monomers to form helical chains along the 3₂ screw axis. The crystal structure of Cu₂Cl(CN)(bpy)] (3) (orthorhombic Pbca, a = 17.853(2) Å, b = 6.9724 (9) Å, c = 18.7357 (9) Å) consists of two monomers, CuCl₂(CN) and Cu(bpy)(CN) that share a cyanide ligand to form Cu₂Cl₂(CN)(bpy) dimers. The dimers link to each other by sharing Cl ligands leading to the formation of infinite Cu-Cl-Cu chain decorated by the complex Cu(CN)(bpy). Variable-temperature magnetic measurement shows an overall ferromagnetic behavior for compound 1. The magnetic pathway of compound 1 is through the cyanide bridge connecting apical and equatorial positions of adjacent copper (II) ions.