A photoluminescence study of fullerenes: total luminescence spectroscopy of C60 and C70

Abstract

Two-dimensional luminescence and luminescence excitation spectra of C[sub 60] and C[sub 70] fullerenes were recorded in glassy toluene solutions, polycrystalline toluene, and benzene matrices and in a Shpolskii type n-hexane matrix at 77 K. The energies of the lowest excited singlet states of C[sub 60] and C[sub 70] as well as of the lowest triplet state of C[sub 70] were determined experimentally and compared with respective values calculated using a modified INDO method. The calculated S[sub 1]-S[sub 2] energy difference in C[sub 70] was found to be quite large and the S[sub 1]-T[sub 1] splitting in both C[sub 60] and C[sub 70] very small. The spectra exhibit a pronounced dependence on the nature of the solvent used. 25 refs., 9 figs., 1 tab.