Synthesis and characterization of sym-cis- and unsym-cis- (ethylenediamine-N,N '-di-3-propionato)cobalt(III) complexes with symmetrical N,N '-substituted diamines

A series of octahedral sym-cis and unsym-cis cobalt(III) complexes involving tetradentate ethylenediamine-N,N'-di-3-propionate ion (eddp) and symmetrical diamines, [ethylenediamine (en), N,N'-dimethylethylenediamine (dmen) and N,N'-diethylethylenediamine (deen)] were prepared by reaction of sodium unsym-cis-(ethylenediamine-N,N'-di-3-propionato)(carbonato)cobaltate(III) dihydrate with the corresponding diamine. The stereochemistry of the complexes prepared was investigated through ion-exchange chromatography, electronic absorption, infrared and H-1 NMR spectroscopy