Multiple Fluorescence of 7 - Hydroxylepidone

The fluorescence spectra of the title compound have been measured in ethanol and in aqueous solutions of different p H . In ethanol the neutral molecule's fluorescence (at 360 nm) is observed, whereas in aqueous solutions emission occurs from the anion (at 428 nm) and from a " tautomer ic " species (at 460 nm), but not from the neutral molecule. An aqueous solution at p H 3, which contains about 3 0 % of ethanol gives a broad fluorescence band ranging from the near uv to the orange region o f the spectrum. Contrarily, 7-methoxylepidone has no fluorescence maximum in the visible part of the spectrum.