Cyclam-based dendrimers as ligands for lanthanide ions.

Details

Serval ID
serval:BIB_D2D6CA7814E4
Type
Article: article from journal or magazin.
Collection
Publications
Title
Cyclam-based dendrimers as ligands for lanthanide ions.
Journal
Dalton Transactions
Author(s)
Saudan C., Ceroni P., Vicinelli V., Maestri M., Balzani V., Gorka M., Lee S.K., van Heyst J., Vögtle F.
ISSN
1477-9226
Publication state
Published
Issued date
2004
Peer-reviewed
Oui
Number
10
Pages
1597-1600
Language
english
Abstract
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
Create date
19/05/2008 11:00
Last modification date
20/08/2019 15:52
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