Photoexcited fullerene species in Triton-X100 micelles

Photoexcited states of fullerene C-60 have been studied using laser flash photolysis and near-IR spectroscopy. In order to stabilise these species the C-60 molecules were incorporated into aqueous micelles of reduced Triton-X100 (TX100-R). Mechanistic studies show that C-60(.-) can be formed in the presence of an electron donor, such as sodium ascorbate, via the triplet state C-3(60). With this donor at 0.25 mmol dm(-3), a maximum lifetime for C.- of tau approximate to 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 C-60(.-) decay pathway the micelle lifetimes were investigated using stopped-flow spectrophotometry. Finally, a mechanism for C-60(.-) formation/decay is proposed that is consistent with all these results.