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(SO4)(H2O)(3)(4,4'-bipy). 2H(2)O (1) was obtained by reacting CoSO4 with 4,4'-bipy in a water/ethanol solvent system: hexagonal, P6(5), a = 11.435(2) Angstrom, c = 20.886(4) Angstrom, Z = 6. CoCl2(DMSO)(2)(4,4'-bipy) (2) was crystallized from the reaction of an aqueous solution of CoCl2 with a DMSO solution of 4,4'-bipy: orthorhombic, Pbcn, a = 11.470(2) Angstrom, b = 11.390(2) Angstrom, c = 14.753(1) Angstrom, Z = 4. Reaction of Co(CH3COO)(2) with 4,4'-bipy in water/acetonitrile under hydrothermal conditions yielded Co(CH3COO)2(4,4'-bipy) (3): triclinic, P (1) over bar, a = 7.996(1) Angstrom, b = 9.128(1) Angstrom, 10.676(1) Angstrom, 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 CH3COO- groups. The reaction chemistry observed in different solvent systems and under hydrothermal conditions is discussed.