| Attributs | Valeurs |
|---|
| type
| |
| Is Part Of
| |
| Subject
| |
| Title
| - Effect of the Excitation Wavelength on the Ultrafast Charge Recombination Dynamics ofDonor−Acceptor Complexes in Polar Solvents
|
| has manifestation of work
| |
| related by
| |
| Author
| |
| Abstract
| - The effect of the excitation wavelength on the charge recombination (CR) dynamics of several donor−acceptor complexes (DACs) composed of benzene derivatives as donors and of tetracyanoethylene orpyromellitic dianhydride as acceptors has been investigated in polar solvents using ultrafast time-resolvedspectroscopy. Three different wavelength effects have been observed. (1) With complexes exhibiting twowell-separated charge-transfer bands, the CR dynamics was found to be slower by a factor of about 1.5 uponexcitation in the high-energy band. This effect was measured in both fast and slow relaxing solvents and wasdiscussed in terms of different DAC geometries. (2) When the CR is faster than diffusive solvation, a slowingdown of the CR with increasing excitation wavelength accompanied by an increase of the nonexponentialcharacter of the dynamics was measured. This effect appears only when exciting on the red edge of thecharge-transfer absorption band. (3) When the driving force for CR is small, both nonequilibrium (hot) andthermally activated CR pathways can be operative. The results obtained with such a complex indicate thatthe relative contribution of these two paths depends on the excitation wavelength.
|
| article type
| |
| is part of this journal
| |
