A Relationship between the Circular Dichroism and the Configuration of Asymmetric Nitrogen in trans(N,EthyIene)-chloro- l -aminocarboxylato-η2-ethyleneplatinum(II)

The circular dichroism (CD) peaks of trans(N, ethylene)[PtCl(l-am)(C2H4)] (l-am, l-amino carboxylate) in acetonitrile (AN) at 33000 and 37000 cm−1 are characteristic of those complexes with asymmetric nitrogen. The CD sign depends on the substituents on the asymmetric nitrogen, and the additivity law holds for methyl and benzyl derivatives of l-prolinato, l-hydroxyprolinato, and l-valinato complexes. The quadrant rule is applicable to the contribution of the substituents on the nitrogen. On the preparation of the benzyl-l-valinato complex from Zeise’s salt in a weakly acid medium the nitrogen exhibits a marked stereoselectivity to give R configuration.