HIGH-PRESSURE PICOSECOND TIME-RESOLVED FLUORESCENCE STUDIES ON THE EXCITED INTRAMOLECULAR CHARGE-TRANSFER KINETICS OF 4-(9-ANTHRYLMETHYL)-N,N-DIMETHYLANILINE IN ALCOHOL

Picosecond time-resolved fluorescence spectroscopy has been used to ex amine the dynamic solvent effect on the excited intramolecular charge- transfer (ICT)-state formation in 4-(9-anthrylmethyl)-N,N-dimethylanil ine (AMDMA) in linear alcohol solvents as a function of pressure. The non-exponential population decay of the local excited (LE)-state emiss ion is analyzed by fitting to a double exponential function. As solven t viscosity increases, the rate of the ICT-state formation of AMDMA be comes noticeably faster than the solvent relaxation time, which is gau ged by the longitudinal relaxation time of the solvent (tau(L)). The p ressure effect on the ICT reaction of AMDMA in the excited state can b e accounted for in terms of the pressure-tuning effect of the solvent viscosity.In addition, the time-dependent Stokes shift (TDSS) of the I CT emission is measured at high pressures.