Cyclam-based dendrimers as ligands for lanthanide ions.

Détails

ID Serval
serval:BIB_D2D6CA7814E4
Type
Article: article d'un périodique ou d'un magazine.
Collection
Publications
Titre
Cyclam-based dendrimers as ligands for lanthanide ions.
Périodique
Dalton Transactions
Auteur⸱e⸱s
Saudan C., Ceroni P., Vicinelli V., Maestri M., Balzani V., Gorka M., Lee S.K., van Heyst J., Vögtle F.
ISSN
1477-9226
Statut éditorial
Publié
Date de publication
2004
Peer-reviewed
Oui
Numéro
10
Pages
1597-1600
Langue
anglais
Résumé
We have investigated the complexation of lanthanide ions (Nd3+, Eu3+, Gd3+, Tb3+, Dy3+) with three cyclam-based ligands (cyclam = 1,4,8,11-tetraazacyclotetradecane), namely 1,4,8,11-tetrakis(naphthylmethyl)cyclam (1), and two dendrimers consisting of a cyclam core appended with four dimethoxybenzene and eight naphthyl units (2) and twelve dimethoxybenzene and sixteen naphthyl units (3). In the free ligands the fluorescence of the naphthyl units is strongly quenched by exciplex formation with the cyclam nitrogens. Complexation with the metal ions prevents exciplex formation and revives the intense naphthyl fluorescence. Fluorescence and NMR titration experiments have revealed the formation of complexes with different metal/ligand stoichiometries in the case of 1, 2 and 3. Surprisingly, the large dendrimer 3 gives rise to a stable [M(3)3]3+ species. Energy transfer from the lowest singlet and triplet excited states of the peripheral naphthyl units to the lower lying excited states of Nd3+, Eu3+, Tb3+, Dy3+ coordinated to the cyclam core does not take place.
Pubmed
Web of science
Création de la notice
19/05/2008 12:00
Dernière modification de la notice
20/08/2019 16:52
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