TIME-RESOLVED FLUORESCENCE OF A HEMICYANINE DYE - DYNAMICS OF ROTAMERISM AND RESOLVATION

We observed the time-resolved fluorescence spectra of a hemicyanine dy e with no CC double bond and one CC single bond and of a homologous dy e with blocked rotamerism of the CC single bond. Using the more rigid dye, we determined the dynamics of resolvation. Taking that reference, we analyzed the dynamics of rotamerism around the CC single bond. We found that the Franck-Condon geometry equilibrates with a polar-twiste d rotamer which is deactivated by fast nonradiative decay. The rotamer ism occurs during the relaxation of the solvation shell.