Using time-resolved cw EPR and pulsed EPR techniques, a study was made
of the characteristics of the photoexcited triplet state of C-60 adso
rbed in silica gel pores and embedded in a polymethylmethacrylate matr
ix. It was found that the time-resolved spectra from C-3(60) in these
matrices at room temperature retain the absorption/emission features o
f spectra from C-3(60) in frozen solution (less than or equal to 120 K
). Apparently, the combination of molecular rotation and pseudo rotati
on (resulting from interconversion between Jahn-Teller states) is not
fast enough to lead to complete averaging of the dipole-dipole interac
tion between the unpaired electrons. The study explored the effect of
introduction of solvent molecules in the silica gel pores on the C-3(6
0) spectrum and quenching of the triplet by electron donors.