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 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. (C) 2014 Elsevier B.V. All rights reserved.