Fluorescence spectroscopy of fullerene derivative C70(CH3)8 in a toluene solid solution at 5 K

Highly resolved fluorescence and excitation fluorescence spectra for C70(CH3)8 were recorded in a solid toluene solution at 5 K. The addition of eight methyl groups to the fullerene cage induces a blue shift of about 1300 cm−1 of the C70 fluorescence. By comparison with the spectra of C70 in toluene, the observed structures are assigned to arise from a partially dipole allowed S1→S0 transition and a dipole allowed S2→S0 transition only separated by 65 cm−1.