The photophysics of salicylic acid derivatives in aqueous solution
نویسندگان
چکیده
J. Phys. Or es (SADs) in aqueous solutions was investigated in a wide range of pH by time-correlated single photon counting (lex1⁄4 350nm, tresp1⁄4 300ps) and fluorescence up-conversion (lex1⁄4 266nm, tresp1⁄4 300 fs) techniques. The acid–base equilibrium constants in the ground (pKa) and the excited states (pK a ), the fluorescence quantum yields as well as the lifetimes of anionic, neutral, and cationic forms of SADs were determined. Evidence of ultrafast excited-state intramolecular proton transfer (ESIPT) leading to the formation of the proton-transferred excited state of SADs was obtained from the fluorescence up-conversion measurement. The nature of the ESIPT process is discussed. Copyright 2008 John Wiley & Sons, Ltd.
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