Synthesis and Absolute Configuration of Novel Mono- and Dinuclear Cobalt(III) Complexes Containing S-Phenylalanine

Two diastereomers of bis(1,3-diaminopropane)(S-phenylalaninato)cobalt(III) were prepared by reaction of S-phenylalanine with carbonatobis(1,3-diaminopropane)cobalt(III). The diastereomers were separated on an optically active Sephadex QAE column and their absolute configurations assigned by means of circular dichroism. In addition, ¹HNMR spectra of the diastereomers were analyzed in terms of the population of the three predominant rotamers of the coordinated S-phenylalaninato ligand. One out of 24 theoretically possible diastereomers of the dinuclear species di- µ -hydroxo- tetrakis(S-phenylalaninato)dicobalt(III) was obtained by direct synthesis and its absolute configuration deduced from CD spectra.

Keywords:

• Absolute Configuration
• Circular Dichroism
• Cobalt(III) Complexes