PROTON-TRANSFER REACTION OF 4-HYDROXY-1-NAPHTHALENESULPHONATE IN METHANOL-WATER AND ETHANOL-WATER MIXTURES

The excited state proton transfer rate of 4-hydroxy-1-naphthalenesulph onate has been studied in methanol-water and ethanol-water mixtures. T he lifetimes of the probe are measured at six different temperatures b etween 5 and 60 degrees C. The decay is single exponential in the long time regime and proton transfer rates have been found to increase wit h the square of the concentration of water in alcohol-water mixtures. The decay has been explained by a new model proposing a water dimer to be the effective proton acceptor in the proton transfer process.