Photophysical properties in aqueous solutions of C$_{60}$ embedded in 2:1 $\gamma$-cyclodextrin/[60]fullerene inclusion complexes
Résumé
To resolve conflicting results in the literature, we determine quantitatively the properties of the lowest triplet excited state of water soluble 2:1 host:guest complexes of C$_{60}$ embedded in $\gamma$-cyclodextrin ($\gamma$-CD/C$_{60}$) using laser flash photolysis. The results show that the triplet excited state characteristics of $\gamma$-CD/C$_{60}$ in aqueous solutions are very similar to those observed for C$_{60}$ in organic solvents. Moreover oxygen, in contrast with non-gaseous solutes, can reach the proximity of C$_{60}$ embedded in 2:1 $\gamma$-CD inclusion complexes. In addition, photodestruction quantum yields have been determined for C$_{60}$ in toluene and for C$_{60}$ in $\gamma$-CD inclusion complexes in water.