THE PHENOMENON OF CONGLOMERATE CRYSTALLIZATION .35. THE CRYSTAL AND MOLECULAR-STRUCTURE OF RACEMIC INITRO(1,8-DIAMINO-3,6-DITHIAOCTANE)COBALT(III)]CL (I) AND THE ABSOLUTE-CONFIGURATION OF MINO-3,6-DITHIAOCTANE)COBALT(III)]CLO4(II)()(546))

Compound I crystallizes as a racemate, as suggested earlier.(3,5,14) C rystals of II were prepared from externally resolved material. In both , the organic ligand is quadridentate with two tr ans-axial nitrogen a nd two cis sulphur donor atoms located trans to the two basal -NO2 lig ands. Likewise, in both, the counter-anion is hydrogen bonded to the t erminal -NH2 hydrogens and the cations are in the cis-alpha configurat ion, with those of the former having Lambda(delta lambda delta) and De lta(delta lambda delta) pairs related by the inversion centre; those o f the (+)(546) enantiomer of II are Lambda(delta lambda delta). These results fix the absolute configuration of II and establish the fact th at the synthetic procedure for the preparation of the precursors of th is compound, [Co(C6H16N2S2)(XY)]A (X = Y = NO2-;X = Y = Cl;X = Cl, Y = H2O, etc. and A = an anion), contain exclusively racemic Lambda(delta lambda delta) and Delta(delta lambda delta) pairs and no cis-beta or trans isomers. Packing in the case of I consists of infinite strings o f chloride-linked cations which are formed such that a given string co ntains [-Co(1)-Cl(1)-Co(1)-Cl(1)-](n) and of another string of.[-Co(2) -Cl(2)-Co(2)-Cl(2)-]n, and each chloride has three hydrogen bonds, two intra-string and a third linking adjacent strings. All Co(1) cations within the string defined by the current coordinates are Lambda(delta lambda delta; torsional angles = 42.3, -33.9 and 48.3 degrees) and all Co(2) cations within the string defined by the current coordinates ar e Delta(delta lambda delta; torsional angles = -27.1, 39.8 and -42.1 d egrees). Given the space group and the contents of the cell, it is cle ar that enantiomorphic pairs of infinite strings are present in the cr ystals. Crystals of enantiomorphic II were studied in order to show th e relationship between the CD spectrum and the absolute configuration of the cation.