Ultrafast intramolecular relaxation of C60

Transient absorption spectra of C60 molecules trapped in cryogenic rare gas matrices and dissolved in room temperature toluene have been measured with a time resolution of 90 fs. An absorption build-up with a characteristic rise time of 200 fs is measured, which is solvent-, temperature- and probe wavelength-independent. It is attributed to the population of an intermediate state by the decay of the initially excited singlet state(s) by vibrational and electronic relaxation. The data are discussed in the light of results from the literature and a general picture of intramolecular relaxation in C60 is proposed.