Photoexcited fullerene species in Triton-X100 micelles
Photoexcited states of fullerene C60 have been studied using laser flash photolysis and near-IR spectroscopy. In order to stabilise these species the C60 molecules were incorporated into aqueous micelles of reduced Triton-X100 (TX100-R). Mechanistic studies show that C60− can be formed in the presence of an electron donor, such as sodium ascorbate, via the triplet state 3C60. With this donor at 0.25 mmol dm−3, a maximum lifetime for C60− of τ ≈ 400 s was obtained. For the parent micelles the c.m.c.s. were measured using dye solubilisation and the aggregation structures were investigated by small-angle neutron scattering (SANS). The levels of additives used here did not significantly affect either of these micellar properties. To see if aggregate breakdown is an important step in the C60− decay pathway the micelle lifetimes were investigated using stopped-flow spectrophotometry. Finally, a mechanism for C60− formation/decay is proposed that is consistent with all these results.