FEMTOSECOND STUDIES OF CHARGE SEPARATION IN PHOTO-EXCITED DCM IN LIQUID SOLUTION

The solvatochromism of DCM in the fluorescent state has been studied u sing the femtosecond fluorescent up-conversion technique with a time-r esolution of almost-equal-to 150 fs. It is shown that intramolecular c harge separation is not complete within 300 fs after the excitation pu lse. A significant portion of the charge separation trajectory ( almos t-equal-to 30%) is controlled by the solvation process on a picosecond time scale. It is inferred that in photo-excited DCM the locally exci ted and charge transfer states mix in the strong adiabatic coupling li mit in the inverted region.