EN
Absorption spectroscopy was used to study the aqueous solution structure of Eu(III) complexes with DTPA (diethylenetriaminepentaacetic acid) and TTHA (triethylenetetraaminehexaacetic acid). Analysis of the oscillator strengths of the 4f ↔ 4f transitions and of the Judd-Ofelt intensity parameters, τ_{λ}, was performed in order to investigate the formation and the type of bonding in Eu(III)-DTPA and Eu(III)-TTHA species occurring in solution. The correlation of these results with those from other methods made it possible to suggest a relatively complete model of Eu(III)-polyaminocarboxylate coordination.