Deprotonation-induced enhancement in fluorescence of 2- ( (2-hydroxybenzylidene) amino) phenol

Excited state dynamics of neutral and anionic forms of HBAP, a Schiff base, has been elucidated using time resolved fluorescence spectroscopy. HBAP exhibits very feeble fluorescence, associated with a lifetime of tens of picosecond, however, the anion exhibits significantly stronger fluorescence with lifetime of almost a nanosecond. Comparison with very recent publications on other Schiff bases, it is established that enhancement of fluorescence, induced by deprotonation, is a general phenomenon. (author)