X-RAY CRYSTALLOGRAPHIC AND PHYSICAL INVESTIGATION OF TRICYANOMETHANIDE AND DICYANAMIDE COMPLEXES OF COBALT(II) WITH IMIDAZOLE AND ITS METHYL-DERIVATIVES

Reaction of Co-II with N(CN)(2)(-) or C(CN)(3)(-) in the presence of imidazole (it) or its methyl derivatives (2-meiz and 4-meiz) gave eight compounds of Co-II: ligand stoichiometry 1:2, including two isomeric pairs (alpha and beta) for the complexes [Co{C(CN)(3)}(2)(2-meiz)(2)] and [Co{C(CN)(3)}(2)-(4-meiz)(2)]. The complexes were studied by electronic and i.r. spectroscopies. For alpha-[Co{C(CN)(3)}(2)(2-meiz)(2)] single-crystal X-ray analysis was performed; its crystal structure consists of one-dimensional chains, formed by C(CN); anions bridging between the Co-II atoms. The Co-II atom is nearly octahedrally coordinated by two tertiary nitrogens of 2-meiz and four nitrogens of C(CN)(3)(-). The spectra of these compounds and of the complexes with it, as well as that of alpha-[Co{C(CN)(3)}(2)(4-meiz)(2)], indicate all these compounds to have basically the same bridging polymeric octahedral structure. However, the spectra indicate distorted tetrahedral structures for the remaining compounds.