Crystal and molecular structures of three salts of Lambda-beta-1-[Co(R,R-picchxn)(R-phe)2+ (Picchxn=N,N'-di(2-picolyl)-1,2-diaminocyclohexane; phe=phenylalaninato(1-))

Single-crystal X-ray structures of Λ-β 1 -[Co( R , R -picchxn)( R -phe)]Br 2 , Λ-β 1 -[Co( R , R -picchxn)( R -phe)]Br 2 ÂÃ"šÃ‚· 3H 2 O and Λ-β 1 -[Co( R , R -picchxn)( R -phe)]I 2 are reported. In each structure there are three formula units in the asymmetric unit. Considerable disorder attends the anions and water molecules of crystallisation. In every case the conformer adopted by the coordinated aminoacidate is such that the phenylalaninato side chain is extended in order to minimize non-bonded steric interactions with the Co(tetradentate)fragment. Such an arrangement is in accord with the fact that this kind of diastereoisomer does not participate in any strong intramolecular ÃÂâ"šÂ¬-ÃÂâ"šÂ¬ or NH-ÃÂâ"šÂ¬ interaction.