CRYSTAL AND MOLECULAR-STRUCTURE OF (-)589-CIS-DINITROBIS(2S)-2-AMINO-4-AZAPENTANE)COBALT(III) CHLORIDE, (-)589-CIS-[CO(NO2)2(N2-ME-(S)-PN)2]CL

The crystal and molecular structure of (-)589-cis-[Co(NO2)2(N2-Me-(S)-pn)2]Cl has been determined from three-dimensional X-ray counter data. The complex forms orthorhombic crystals with a = 13.568 (1) Å, b = 15.498 (3) Å, c = 7.596 (1) Å, and Z = 4, in space group P212121. The structure has been refined by block-diagonal matrix least-squares methods with anisotropic temperature factors to an R value of 0.039 for 2246 independent reflections with Fo> 3σ(Fo). Six nitrogen atoms of the diamine and nitro groups are bonded nearly octahedrally to the central cobalt atom. The complex cation has approximately symmetry 2 (C2). The complex cation has the absolute configuration A, and the conformations of the chelate rings are both δ, the two N-methyl and the two C-methyl groups being in equatorial positions with respect to the chelate rings. The absolute configurations of the two asymmetric nitrogen atoms are both R. The N-methyl groups are cis to one another, and the C-methyl groups are trans to each other. © 1979, American Chemical Society. All rights reserved.