Structural Flexibility Slows Down Charge Transfers in Diaminoterephthalate-C60Dyads

Autor: Timmer, Daniel, Hergert, Germann, Gerhards, Luca, Lünemann, Daniel C., Schröder, Nils, Greven, Tobias, van der Vlugt, Jarl Ivar, De Sio, Antonietta, Solov’yov, Ilia A., Christoffers, Jens, Lienau, Christoph
Zdroj: The Journal of Physical Chemistry - Part C; February 2024, Vol. 128 Issue: 6 p2380-2391, 12p
Abstrakt: In recent years, research has emphasized the significant influence of vibronic couplings on charge separation in donor–acceptor molecules and thin films. Diaminoterephthalates (DATs), known for their versatile optical and electronic properties, are intriguing donor materials. Efficient, vibronically assisted charge separation in DAT-acceptor dyads has been suggested. This study therefore investigates charge separation dynamics in DAT-linker-fullerene dyads in a polar solvent by using transient absorption spectroscopy. The results demonstrate photoinduced electron transfers with close to unity efficiency, occurring within 10–80 ps for benzene and biphenyl linkers. Surprisingly, there is a lack of orientational alignment between the donor and acceptor units, indicating a notable conformational flexibility that hinders electron transfer. Time-dependent density functional calculations support this finding. The obtained insights are crucial for developing and comprehending charge-transfer dyads under strong vibronic coupling conditions.
Databáze: Supplemental Index