One-Dimensional Coordination Polymers of Cobalt with 4,4‘-Bipyridine:  Syntheses and Structures

Several new one-dimensional coordination polymers were obtained by reactions of different simple cobalt salts with 4,4'-bipyridine. Co(SO(4))(H(2)O)(3)(4,4'-bipy).2H(2)O (1) was obtained by reacting CoSO(4) with 4,4'-bipy in a water/ethanol solvent system: hexagonal, P6(5), a = 11.435(2) Å, c = 20.886(4) Å, Z = 6. CoCl(2)(DMSO)(2)(4,4'-bipy) (2) was crystallized from the reaction of an aqueous solution of CoCl(2) with a DMSO solution of 4,4'-bipy: orthorhombic, Pbcn, a = 11.470(2) Å, b = 11.390(2) Å, c = 14.753(1) Å, Z = 4. Reaction of Co(CH(3)COO)(2) with 4,4'-bipy in water/acetonitrile under hydrothermal conditions yielded Co(CH(3)COO)(2)(4,4'-bipy) (3): triclinic, P, a = 7.996(1) Å, b = 9.128(1) Å, c = 10.676(1) Å, alpha = 109.79(1) degrees, beta = 99.90(1) degrees, gamma = 100.98(1) degrees, Z = 2. 1 and 2 have structures containing linear Co-bipy-Co chains. In 1, the chains are connected by a network of hydrogen bonds. The structure of 3 contains linear double Co-bipy-Co chains bridged by CH(3)COO(-) groups. The reaction chemistry observed in different solvent systems and under hydrothermal conditions is discussed.