Abstract
The singlet and the triplet excited states parameters of psoralen and derivatives, 4,6,4′-trimethylangelicin and 4,5′,8-trimethylpsoralen, show an extreme sensivity to solvent polarity in dioxane/water mixtures. The internal conversion rate constant is the non-radiative deactivation path dominating their photophysical behaviour. The minimum values of this radiationless rate constant correspond to a more allowed radiative transition and to a longer fluorescence wavelength. Thus, the singlet-triplet energy gap decreases and intersystem crossing is promoted. This work shows that dioxane/water mixtures can display the same solvent-induced changes in the electronic structure of psoralens during solvation as those induced by the biological microenvironment sensed by the drug localization in serum lipoproteins.
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© 1996 Springer Science+Business Media New York
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Sa e Melo, T., Sousa, C. (1996). Solvent-Dependent Excited State Properties of Psoralens. In: Kohen, E., Hirschberg, J.G. (eds) Analytical Use of Fluorescent Probes in Oncology. NATO ASI Series, vol 286. Springer, Boston, MA. https://doi.org/10.1007/978-1-4615-5845-3_43
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DOI: https://doi.org/10.1007/978-1-4615-5845-3_43
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