Titre : |
Vers de nouveaux matériaux basés sur les fullerènes |
Type de document : |
texte imprimé |
Auteurs : |
Carlo Thilgen, Auteur ; François Diederich, Auteur |
Année de publication : |
2003 |
Article en page(s) : |
p. 114-118 |
Note générale : |
Bibliogr. |
Langues : |
Français (fre) |
Catégories : |
Capteurs (technologie) Chimie organique Chiralité Fullerènes Matériaux
|
Tags : |
Fullerènes Chiralité Fonctionnalisation dirigée espaceur Senseurs ions Diades fullerène-porphyrine Sensibilisateur photooxydation support solide |
Index. décimale : |
620.1 Mécanique de l'ingénieur (mécanique appliquée) et matériaux |
Résumé : |
Regio- and stereoselective tether-directed remote functionalization was used to prepare three-dimensional building blocks for supramolecular construction and advanced materials. A C60-ionophore conjugate was prepared selectively as trans-1 regioisomer in a K+-templated Bingel addition of a bismalonate derived from dibenzo[18]crown-6. It can act as an ion sensor and the close proximity of complexed potassium ions to the fullerene sphere induces anodical shifts in the redox potentials of the latter. A similar but even more pronounced effect is seen in a C70 cage which is sandwiched between two crown ethers. Favorable C60-porphyrin ground state interactions were detected by steady-state and time-resolved absorption and luminescence spectroscopy of a trans-1 type, doubly bridged dyad as well as in a fullerene connected to two porphyrins by single linkages. In toluene, both the zinc-porphyrin- and the fullerene-centered excited states are deactivated to a lower-lying charge-transfer (CT) state which emits in the infrared (IR) spectral region. Enantiopure bis-adducts of C60 with the chiral cis-3 functionalization pattern were prepared by regio- and stereoselective Bingel macrocyclizations using non-racemic chiral tethers. Configurational assignment was possible by a combination of computational and 1 H NMR-spectroscopic conformational analysis and it was confirmed by a comparison of its circular dichroism (CD) spectra with the measured and calculated spectra of another C60 adduct with the same Pi-chromophore. Finally, a polysiloxane-supported fullerene derivative was prepared and proven to act as a heterogeneous sensitizer for the selective photooxidation of sulfides to sulfoxides by 1O2. |
En ligne : |
https://new.societechimiquedefrance.fr/numero/vers-de-nouveaux-materiaux-bases-s [...] |
Format de la ressource électronique : |
Pdf |
Permalink : |
https://e-campus.itech.fr/pmb/opac_css/index.php?lvl=notice_display&id=4618 |
in L'ACTUALITE CHIMIQUE > N° 4-5 (04-05/2003) . - p. 114-118