Syntheses in Aqueous Solution and Crystal Structure of a Triamido-Bridged Dicobalt(III) Complex with the Ligands 1,4,7-Triazacyclononane and 3-Thiapentane-1,5-diamine.

The reaction of Co(tacn)(daes)3+ [tacn = 1,4,7-triazacyclonane; daes = (3-thiapentane-1,5-diamine = di(2-aminoethyl)sulfide)] in 4 M NaOH yields nearly quantitively the triamido-bridged dicobalt(III) complex: 7--triazacyclononane-2kappa3N1,N4,N7-dicobalt(III) ion, in the following abbreviated as Co(tacn-mu-N)(daes-mu2-N1,N2)Co(tacn)3+: [GRAPHICS] The new dinuclear cation was isolated from the reaction mixture as a perchlorate salt in high yield (63%). The crystal and molecular structure of [Co(tacn-mu-N)(daeS-mu2-N1,N2)Co(tacn)](ClO4)3, H2O has been established by X-ray diffraction techniques at 122 K: a = 15.289(2), b = 21.392(2) and c = 17.834(4) angstrom, V = 5228(5) angstrom3, F(000) = 3344, Z = 8, space group Pbca, R(w) = 0.038 for 3124 unique reflections.