CRYSTAL AND MOLECULAR-STRUCTURE OF THE ASYMMETRIC COBALOXIME, TRANS-BIS(2,3-BUTANEDIONE DIOXIMATO(1-)-N,N')IODOPYRIDINECOBALT(III) - (CO(HDMG)2I(PY))

The three-dimensional structure of the asymmetric cobaloxime, trans-bis(2,3-butanedione dioximato)iodopyridinecobalt(III), [Co(Hdmg)2I(py)] (Hdmg- = dimethylglyoximate; py = pyridine), has been determined by X-ray diffraction at ambient temperature. The monoclinic structure (P2(1)/n) was refined by full matrix least-squares to a final R(w) = 0.037 for 3233 observed independent reflections. The structure consists of interesting neutral cobaloxime molecules in which the coordination geometry around Co(III) resembles very closely that observed in cyanocobalamine or vitamin B-12.