Photophysical properties in aqueous solutions of C60 embedded in 2:1 γ-cyclodextrin/[60]fullerene inclusion complexes

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 C60 embedded in γ-cyclodextrin (γ-CD/C60) using laser flash photolysis. The results show that the triplet excited state characteristics of γ-CD/C60 in aqueous solutions are very similar to those observed for C60 in organic solvents. Moreover oxygen, in contrast with non-gaseous solutes, can reach the proximity of C60 embedded in 2:1 γ-CD inclusion complexes. In addition, photodestruction quantum yields have been determined for C60 in toluene and for C60 in γ-CD inclusion complexes in water.