Transition Metal Complexes of Oxamide Oxime, 1. Synthesis and X-Ray Crystal Structure of Tris(oxamide oxime-N1,N1′)cobalt(III) Triiodide [Co(H2oxao)3]I3

Abstract

Tris(oxamide oxime-N1,N1′)cobalt(III) triiodide, [Co(H2oxao)3]I3, has been synthesized, and its structure determined by single crystal X-ray diffraction at room temperature. The trigonal structure (rhombohedral space group R 3̄ c) was refined by full matrix least-squares to a final R (Rw) of 4.1 (3.5)% for 51 parameters and 911 observed independent reflections. The structure consists exclusively of quasi-octahedral chiral cobaloxime cations, [Co(H2oxao)3]3+, and iodide anions. This structure is isotypic to that of the homologous Ni-based salt analyzed previously in which, as a matter of specific difference, one H2O molecule of crystallization per formula unit is present. Moreover, whereas nickel in the latter salt was identified as NiII on the basis of magnetic data, preliminary voltammetric data clearly reveals Com in the present salt.