The solvatochromism of the molecules flavone (F), 5-hydroxyflavone (5HF), 3-methoxyflavone (3MF), 3-hydroxyflavone (3HF), 5,7-dihydroxyflavone (chrysin), and 2`,3,4`,5,7-pentahydroxyflavone (morin) is investigated with the aid of the pure solvent scales of Catalán in about twenty-five solvents. The solvent polarizability contribution accounts for the major part of the solvatochromism of the flavonoids mentioned above, and it brings about a bathochromic shift. Only, the 3HF emission depends likewise on the solvent basicity as much as the solvent polarizability. Neither the emission nor the absorption of 3HF exhibits a zwitterionic nature. The solvatochromism of the absorption band for the remaining molecules does not show any zwitterionic nature, though morin shows a clear-cut charge-transfer character on photoexcitation.
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