Fast Change in the Excited State Absorption Spectrum of TPM Dye Solutions

Abstract

Relaxation dynamics of Triphenylmethane dyes in the excited state has been extensively investigated using fluorescence and pump-probe techniques on nanosecond, picosecond and femtosecond time scales (see ref. in [1-3]). It is well established that the relaxation rate is determined by the solvent viscosity but the interpretation of the transient decays measured at a few wavelengths is not completely elucidated. Time evolution of transient absorption spectra of a TPM dye is reported here on subpicosecond and picosecond time scales. New transient bands in the blue are evidenced.