Three compounds were obtained from the reactions of Co(NCS)2 with pyrazine and 4,4‘-bipyridine in different solvents:  Co(NCS)2(pyz)2 (1) has a 2D sheet structure, monoclinic, C2/m, a = 10.039(2) Å, b = 10.382(2) Å, c = 7.190(1) Å, β = 118.64(1)°, Z = 2; Co(NCS)2(H2O)2(4,4‘-bipy)·4,4‘-bipy (2) has linear Co−bipy−Co chains connected by hydrogen bonds between H2O and noncoordinated 4,4‘-bipy molecules to form stair type sheets, triclinic, P1̄, a = 7.450(1) Å, b = 9.020(1) Å, c = 10.122(1) Å, α = 107.74(1)°, β = 104.02(1)°, γ = 97.16(1)°, Z = 1; Co(NCS)2(4,4‘-bipy)2·2(CH3CH2)2O (3) has ether molecules intercalated between layers formed by Co(NCS)2 and coordinated 4,4‘-bipyridine ligands, monoclinic, P2/c, a = 11.483(2) Å, b = 11.397(3) Å, c = 13.609(1) Å, β = 107.55(1)°, Z = 2. Compounds 2 and 3 thermally decompose to form the same products. The identities of the decomposition products are discussed.

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&onemacr;, 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.