URANYL(VI) AND LANTHANUM(III) COMPLEXES WITH FUNCTIONALIZED MACROCYCLIC AND MACROACYCLIC SCHIFF-BASES

Acyclic Schiff bases have been prepared by [2+1] condensation of 2,6-d iformyl-4-chlorophenol and H2NCH2[CH(2)XCH(2)]nCH2NH2(n=O H-2-I; X=NH, S, O n=1 H-2-II ... H-2-IV; X=O n=2 H-2-V; X=O n=3 H-2-VI). The relat ed uranyl(VI) and lanthanum(III) complexes have been synthesized by re action of the preformed ligands with the appropriate salt or by the te mplate procedure, in the presence of base. No base was employed in the preparation of lanthanum(III) complexes, La(H-2-II)(NO3)(3), La(H-2-I V)(NO3)(3) where the Schiff bases coordinate as neutral chelate ligand s. These acyclic complexes have been used for further condensation, an d symmetric and asymmetric cyclic complexes have been obtained by thei r reaction with the polyamines H2NCH2[CH(2)XCH(2)]nCH2NH2 or with 4,4' -diaminodibenzo-18-crown-6. By reaction with 4-aminobenzo-15-crown-5 o r 2-amino-methyl-15-crown-5, the same acyclic complexes give rise to f unctionalized complexes bearing crown-ether moieties. Analogously, the acyclic ligand H-3-IXX, prepared by condensation of 2,6-diformyl-4-ch lorophenol and tris(aminoethyl)amine, forms mono-and homodinuclear lan thanum(III) complexes, which may undergo further condensation when rea cted with primary functionalized amines.