Spectral and Basic Properties of Flavones in the Ground and Excited States

Varenikov, A. S., Serdiuk, I. E., Roshal, A. D. (2013). Spectral and Basic Properties of Flavones in the Ground and Excited States. French-Ukrainian Journal of Chemistry, 1(1), 153–157.

Dependence between structures of R-oxyflavones and their spectral and basic properties has been investigated. It was found that pKa of flavones, depending on positions of hydroxy and methoxy groups, increase by 6-8 orders of magnitude upon excitation and reaches 3.7-6.6 units. Due to high pKa* value carbonyl group can serve as a proton acceptor in the excited-state intramolecular proton transfer as far as in the formation of phototautomers of 7- and 4'-hydroxyflavones in protic solvents.