The equilibriurm constants for mixed binuc1 eM camp 1 ex fG rmGion between certain bivalne transition metal-EDTA complexes and various cyano­ comp 1 exes in aqueous sol ut ion have been obtained from spectrophotometric measurements. The results can be interpreted to obtain the order of strenght of binuclear complex formation with metal (II) which is: Cu» Ni) Co with aminocarboxylate complexes:4_NTA)EDDA 4_HEDTA > E'01~ > PDTA)CDTA2_; and with cyano-complexes; Fe{CN)6>Ru( (CN)6 >Fe(CN)6 ) Fe(CN)5(NO) . 


A H KHAN ,W C E HIGGINSON ,SR S MURRAY ,