Synthesis and properties of lanthanide and actinide complexes with new macrocyclic and macroacyclic ligands containing long aliphatic chains ?

Lanthanide and actinide complexes with Schiff bases have been widely studied and, for several of the prepared complexes, structure determinations have been carried out. In particular, potentially pentadentate Schiff bases derived from substituted salicylaldehyde and triamines coordinate such metal ions in the equatorial plane. The addition of lateral chains to these ligands considerably enhances the solubility of the related complexes in organic solvents. Thus we have prepared the Schiff bases by condensation of 2,6-diformyl-4-substituted phenols with polyamines and octadecylamine or N-dodecyldiethylenetriamine and studied their interaction with lanthanide(III) and uranyl(VI) ions. The complexes have been obtained by template procedure or by reaction of the metal ions with the preformed ligands. They have been characterized by elemental analysis, infrared spectra and NMR spectroscopy (decoupling and n.O.e. experiments). The complexes with the above simple pentadentate ligands have also been investigated in detail.