Yonsei Advanced Science Institute

Synthesis of dichloro cobalt (Ⅲ) complexes of a flexible N2O2-type tetradentate ligand, ethylenediamene-N, N'-di- -isobutyric acid (eddib), has yielded two geometrical isomers, s-cis-(Co (eddib) Cl2)-and uns-cis-(Co (eddib) Cl2)-.  A series of substitution reactions, (Co (eddib) Cl2)- →(CO (eddib) Cl H2O)→(Co (eddib) CO_3)-→(Co (eddib (H2O)2)+ have been run for each of the two geometrical isomers. The reaction between the s-cis-(Co (eddib) Cl2)- complex and L-alanine (L-als) or S-methyl-L-cysteine (L-mcy) gave the meridional s-cis-[Co (eddib)(aa))(aa= L-ala or L-mcy) complex. The S-methyl-L-cysteine was found to coordinate to cobalt (Ⅲ) ion via the nitrogen and oxygen donor atoms.