Verstärkung der Fluoreszenz von Chelaten der Seltenen Erden durch zusätzliche Koordination

It is shown that the fluorescence of various Eu-chelates (dibenzoylmethide, benzoylacetonate, acetylacetonate and β-naphthoylacetonate) is much enhanced by additional coordination of ophenanthroline or α.α'-dipyridil. Complexes of the composition Eu (β-diketone)3-Phen, Eu(β- diketone)3-Dip etc. could be isolated and the absorption and the fluorescence in various solvents was studied. Compared to the trischelates the temperature dependence of the additional coordinated chelates is remarkably reduced.