Resonance Raman and UV/visible absorption studies of protonated retinal schiff base phototransformations by irradiation with various laser lines

Binary mixtures of all‐ trans ‐ N ‐retinylidene‐ n ‐butylamine (NRB) in hexafluoroisopropanol (HFIP) were irradiated by various laser lines. The laser lines served both as sources of photoconversion and for Raman excitation. The photoproducts were studied by clectronic and resonacnce Raman Spectroscopy. The high specificity of resonance Raman spectroscopy was used to characterize different photoproducts at concentrations of the order uf 10 −5 m, present simultaneously in the same mixture. The results show that a partial break in conjugation occurs during the phototransformation. The electronic spectra of the photoproducts were compared with the electronic spectra of modified chromophores or pigments.