Abstract
A novel ONNO-type tetradentate ligand, 1,3-diaminopropane-N,N'-di-α-(β-methyl)-pentanoic acid (H2apmp) and its cobalt(Ⅲ) complexes, [Co(apmp)X2]n+, (X=Cl-, NO2-, H2O, X2=CO32-, en, L-phenylalanine) have been synthesized. During the preparation of the dichloro cobalt(Ⅲ) complex of apmp, [Co(apmp)Cl2]-, the ligand has coordinated to the cobalt(Ⅲ) ion in a geometric selectivity to give only the uns-cis isomer and, during the substitution reaction between L-phenylalanine and [Co(apmp)Cl2]-, the L-phenylalanine has coordinated to the cobalt(Ⅲ) ion in a geometric selectivity to give only an uns-cis-meridional isomer. It is of interest that this is a rare case of the [Co(ONNO ligand)X2]n+-type complex preparations, which gives only an uns-cis isomer with geometric selectivity.