Fluorescence spectra and lifetimes of tropolone incorporated into the bicyclo[2.2.1]heptane frame

Abstract

Steady state and time-resolved fluorescence studies of tropolone, incorporated into the rigid bicyclo[2.2.1]heptane frame (5-hydroxytricyclo[7.2.1.0^2,8]dodeca-2,5,7-trien-4-one (HTCD)), were carried out in solution and in rigid matrices. It was found that the molecules can give rise to two different types of fluorescence, the “normal” fluorescence and the “tautomer” fluorescence. The electronically excited tautomer is formed by proton transfer from the hydroxyl group to the carbonyl group via intramolecular hydrogen bonding in the excited state. The relative fluorescence intensities from the excited species are very sensitive to the solvent and temperature.