Stereochemical studies of cobalt ethylenediamine complexes and their tetrathionate salts: Interactions between complex configuration and tetrathionate conformation

A range of chiral coordination complexes of the formulae cis-[Co(en)2XY] where X, Y = hal, NH3, NO2, ox, SCN have been prepared as the halide or pseudohalide salts, and the novel examples have been structurally characterised and their stereochemical behaviour studied. Salt metathesis of certain of these species to the corresponding tetrathionates is described, and the tetrathionates structurally characterised and the stereochemical relationship between the conformations of the chiral complexes and the pseudochiral tetrathionates analysed. The patterns of cation–cation and cation–anion interactions are discussed in the context of the reported ability of the tetrathionate ion to induce conglomerate crystallisation in such species, and tetrathionate chirality in the literature.

Chirality can be transmitted through chains of Co(en)2XY cations via hydrogen bonding with tetrathionate anions which themselves take up chiral conformations. The conditions under which such interactions may lead to conglomerate crystallisation are discussed.Figure optionsDownload as PowerPoint slide