Femtosecond visible absorption study of excited-state dynamics of 9-cis retinal

Femtosecond time-resolved pump–probe absorption spectroscopy has been used to study the photophysics and photochemistry of 9-cis retinal in aerated hexane. Three excited singlet states (S3, S2, S1) and the lowest triplet state (T1) have been identified by the SVD analysis of the observed time-resolved absorption spectra. No evidence has been obtained for a 9-cis→all-trans isomerization reaction pathway that completes in the excited singlet manifold.