A LUMINESCENCE STUDY OF EU(III) AND TB(III) COMPLEXES WITH AMINOPOLYCARBOXYLIC ACID LIGANDS

The luminescence of Eu(III) and TB(III) complexes with eight aminopoly carboxylic acids (APA) in aqueous solution is reported. The ratio of t he luminescence intensity of the Eu(III) ion (eta = I615 nm/I593 nm) w as analysed and a linear temperature dependence was found. An analysis of the Tb(III) luminescence intensity (lambda = 545 nm) yielded a lin ear correlation between the Tb(III) intensity and the hydration number of the Tb-APA complex. On the basis of the luminescence intensities, a theoretical model has been proposed within the electrostatic dipole approximation. In the model the luminescence intensity of a given elec tronic transition is dependent on the dipole moment.