Rare earth(iii) complexes with indole-derived acetylacetones I: synthesis and characterization of rare earth(iii) complexes

Abstract

Binary and ternary complexes of rare earth (RE)(III) with HL 1(1-indoleacetylacetone) and HL 3(3-indoleacetylacetone) were synthesized and their compositions were determined by elemental analysis and confirmed by thermal analysis. The coordination between RE(III) and the ligands was studied by IR, UV and 1HNMR. The complexes are shown to be formed by substitution of the proton in the enol form of β-diketones. The existence of the NH group in RE(III)-L 3 complexes and its absence in RE(III)-L 1 complexes were confirmed by both IR and 1HNMR. All the experimental results showed that complexes with HL 1 are less stable than those with HL 3, in which there are larger conjugative systems.