Self-assembly mechanism of a bimetallic europium triple-stranded helicate.
Fiche publication
Date publication
février 2003
Journal
Journal of the American Chemical Society
Auteurs
Membres identifiés du Cancéropôle Est :
Dr VAN DORSSELAER Alain, Dr ELHABIRI Mourad
Tous les auteurs :
Hamacek J, Blanc S, Elhabiri M, Leize E, Van Dorsselaer A, Piguet C, Albrecht-Gary AM
Lien Pubmed
Résumé
We report the self-assembly process of a supramolecular edifice based on the coordination of europium(III) by a ditopic strand L bearing tridentate bis(benzimidazolyl)pyridine subunits. Varying the metal/ligand ratio and using a fruitful combination of electrospray mass spectrometry and absorption spectrophotometry, we characterized three major complexes (EuL(2), Eu(2)L(2), and Eu(2)L(3)) in acetonitrile. Kinetic investigations showed an alternative "braiding" and "keystone" mechanism leading to Eu(2)L(3). The formation mechanism of the dinuclear triple-stranded helicate, which is mainly governed by electrostatic interactions, goes via the "side-by-side" Eu(2)L(2) intermediate. Our thermodynamic and kinetic data allow the prediction of the apparent "magic" self-assembly of Eu(2)L(3) which is fast and efficient only under a strict set of conditions.
Référence
J. Am. Chem. Soc.. 2003 Feb;125(6):1541-50