Time-resolved spectroscopy of 4-hydroxy-1-naphthalenesulphonate in alcohol—water mixtures

The initial proton transfer dynamics of 4-hydroxy-1-naphthalenesulphonate has been studied in alcohol—water (7:3) mixtures at room temperature by using picosecond time-resolved emission spectroscopy. Consecutive processes of dissociation, recombination, re-dissociation have been observed in methanol—water and ethanol—water mixtures. However, no recombination has been found in the 1-propanol—water mixture. The need for a particular solvent structure for the proton hydration is discussed.