C-Branched chiral (racemic) macrocyclic amino acids: Structure of their Ni(ii), Zn(ii) and Cu(ii) complexes

Abstract

A new procedure for the synthesis of macrocyclic embedded bis-α-amino acids and their use as cation-ligands is described. These compounds are able to form stable Cu(ii), Zn(ii) and Ni(ii) complexes as long as they have a flexible tether between the two nitrogen atoms. For a given macrocycle, the X-ray diffraction studies revealed diastereomerically pure complexes having different geometries depending on the metal ion.