Fluorescence excitation spectra of the S1 states of isolated trienes

Abstract
First observation of fluorescence for simple, linear trienes is reported. S1←S0 fluorescence excitation spectra of hexatriene and octatriene indicate large differences between the S0 and S1 potential energy surfaces. Activation energy of −1 for the S1 state nonradiative decay is tentatively ascribed to isomerization.