Cobalt(II) complexes with dicyanamide - from binuclear entities to chains

One binuclear complex [Co(bpm*)(2)(dca)](2)(ClO4)(2) (1) and two 1D chain Co-II complexes, {[Co(bpm)(2)(dca)](ClO4)}(n) (2) and [Co(dmf)(2)(dca)(2)](n). (3), (bpm*: bis[(3,5-dimethyl)pyrazolyl]methane; bpm: bis(pyrazolyl)methane; dca: dicyanamide; dmf: N,N-dimethyl formamide) have been prepared and structurally characterized. The cobalt atoms are hexa-coordinated forming a slightly distorted octahedral coordination. Compound 1 crystallizes in the monoclinic system, space group P2(1)/c, a = 9.849(3) Angstrom, b = 21.944(7)Angstrom, c = 13.814(5) Angstrom, beta = 94.824(6) Z = 4, R-1 = 0.0672, wR(2) = 0.1395. 1 is a binuclear complex linked by two dca ligands, and each Co-II ion is coordinated by two terminal bpm* ligands. Compound 2 crystallizes in the orthorhombic system, space group Cmcm, a = 10.377(4) Angstrom, b = 13.594(5) Angstrom, c = 15.999(6) A, Z = 4, R-1 = 0.0609, wR(2) = 0.1328. The structure of 2 can be described as a one-dimensional zigzag chain of Co-II ions bridged by one dca ligand. Each Co-II ion in the chain is coordinated by two bpm ligands. Compound 3 crystallizes in the monoclinic system, space group C-2, a = 13.559(15) Angstrom, b = 7.393(8) Angstrom, c = 8.110(9) Angstrom, beta = 112.228(15), Z = 2, R-1 = 0.0260, wR(2) = 0.0760. 3 has a one-dimensional linear chain of Coll ions bridged by two dca ligands, in which each Co-II ion is coordinated with two dmf molecules.