Abstract:
The excited state dynamics of quinine sulphate (QS), quinidine (Qd) and 6-methoxyquinoline (6MQ) has been studied as a function of pH in steady state and nanosecond time resolved fluorescence experiments. The solvent relaxation process is a dominant process for all the molecules studied, irrespective of pH. Moreover, 6MQ undergoes a proton transfer reaction in the excited state at pH 7 whereas QS and Qd do not exhibit excited state protonation.