The resonance Raman spectrum of lycopene has been examined in acetone solvent and excitation profiles of the three fundamentals ngr;1, ngr;2, and ngr;3have been determined. The excitation data and the visible spectrum have been analyzed using twohyphen;mode and threehyphen;mode vibrational models, with the twohyphen;mode model involving virtual states of ngr;1and ngr;2giving the best fit to the data. This mode mixing or Duskinsky effect was not observed for bgr;hyphen;carotene. The singlehyphen;mode and threehyphen;mode theories which have been used to explain the corresponding data for bgr;hyphen;carotene are shown to be inconsistent with the experimental data of lycopene. Equations for calculating excitation profiles and visible spectra are given.
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