Salt effects on a proton transfer reaction of excited 1-naphthol in a solid/liquid interface layer A picosecond time-resolved total internal reflection fluorescence study

Analyses of the excited-state proton transfer reaction of 1-naphthol in sapphire/water interface layers have been performed using fluorescence decay data obtained by a picosecond time-resolved total internal reflection fluorescence spectroscopy. The rate constant of the excited-state proton transfer reaction, k(1), of 1-naphthol in an interface layer was reduced as compared to that in a bulk aqueous solution. Addition of NaCl to aqueous solution of 1-naphthol resulted in a decrease in k(1) for both in the interface layer and in the bulk solution, suggesting that a proton acceptor from excited 1-naphthol is not a single water molecule but a water cluster and that water clusters in an interface layer are also destroyed by NaCl.