Dissociation Kinetics of an Ethylene-Dinitrilo-N,N'-Diacetato-N,N'-DI-3-Propionato Complex of Europium(III)

Abstract
The kinetics of dissociation of EuENDPDA was studied by a stopped-flow technique with a Cu2+ scavenger. The dissociation data indicated that EuENDPDA follows a similar dissociative mechanism as EuEDTA and other Eu-aminopolycarboxylate complexes. Both acid-dependent and acid-independent paths are present with a 100-fold increase in the acid catalyzed rate compared to that of EuEDTA. These results are discussed in terms of the relative stability of 5- and 6-membered chelate rings in the complexes.