New functionalized macrocyclic and macroacyclic Schiff bases: f-metal ions complexation and separation

New macrocyclic and macroacyclic Schiff bases have been obtained by condensation of 2,6-diformyl-4Z-phenols (Z = Cl, CH 3 , (CH 3 ) 3 C) with 4-N-dodecyldiethylenetriamine or the polyamines, l,5-diamino-3-azapentane, 1,5-diamino-3-thiapentane and octadecylamine. Their interaction with lanthanide(III) (Ln(III) = La, Ce, Sm, Eu, Tb, Dy, Yb) and the uranyl(VI) ions have been studied. The complexes, formulable as Ln ( H 2 L )( X ) 3 · nH 2 O or UO 2 L (H 2 L — unionized macrocyclic or macroacyclic ligands; X = NO 3 − , Cl − , n = 1, 0), have been synthesized by template procedure or by reaction of the appropriate metal salt with the preformed ligands. They have been characterized by elemental analysis, mass spectrometric measurements, infrared and nmr spectroscopy (decoupling and n.O.e. nuclear Overhauser effect, experiments). A study of the phase transfers of trivalent rare earths from nitrate and/or chloride media through an organic membrane to a receiving aqueous solution by the macrocyclic compounds has been undertaken and the results obtained for the extraction, transport and stripping of dysprosium(III), europium(III) and lanthanum(III) ions are reported. It was verified that these ligands are efficient in the extraction of lanthanide(III) ions without the addition of a synergic agent. A high selectivity has been observed for dysprosium(III) or europium(III) with respect to lanthanum(III) from a mixture of La, Eu and Dy.