Four out of six theoretically possible isomers of the (1,3-diaminopropane)bis(S-tyrosinato)cobalt(III) complex, having the cis(O) configuration, were isolated, and the trans(O) isomer was only defined in the eluate. The isomers were separated on an optically active Sephadex QAE column. Geometrical and absolute configurations of the isomers were determined by electronic absorption, circular dichroic and H-1 NMR spectra. The effect of the aromatic side group of the coordinated S-tyrosinato ligand on the stereoselective formation of the obtained isomers was examined
