Synthesis of N,N '-bis[(benzo-15-crown-5)-oylmethyl]diaminoglyoxime and its metal complexes

A new macrocyclic ligand (LH2) has been synthesised by the reaction of 4'-o mega-aminoacetyl(benzo-15-crown-5) with anti-dichloroglyoxime (EE-diimidoyl dichloride-dihydroxyethane). The crystalline complexes of the ligand (LH2) with Cu(II), Ni(II) and Co(II) has also been isolated. Protonation constant s of the ligand and overall formation constants have been calculated from p otentiometric data using the program TITFIT. Both amino and hydroxyimino gr oups provide donor atoms together with hydroxyl ions at higher pH values. T he order of formation constants of the mononuclear complexes is Cu(II)> U(V I)O-2>Ni(II)> Co(II)> Mn(II).