PHOTOCHEMISTRY OF FULLERENES - EXCITED-STATE BEHAVIOR OF C-60 AND C-70 AND THEIR REDUCTION IN POLY(METHYL METHACRYLATE) FILMS

The singlet and triplet excited states of C60 and C70 have been characterized in poly(methyl methacrylate) (PMMA) films by using picosecond and nanosecond laser flash photolysis techniques. The absorption properties and lifetimes of these excited states are very similar to those observed in solutions. When complexed with dimethylaniline (DMA) in the PMMA films, these fullerenes exhibit decreased lifetimes in their excited states. Photoinduced electron transfer between C60 (or C70) and DMA in the PMMA film was carried out with 532-nm laser pulse excitation. The polymeric environment facilitated the stabilization of electron-transfer products.