Observation and control of coherent torsional dynamics in a quinquethiophene molecule.
By applying femtosecond pump-probe spectroscopy to a substituted quinquethiophene molecule in solution, we observe in the time domain the coherent torsional dynamics that drives planarization of the excited state. Our interpretation is based on numerical modeling of the ground and excited state potential energy surfaces and simulation of wavepacket dynamics, which reveals two symmetric excited state deactivation pathways per oscillation period. We use the acquired knowledge on torsional dynamics to coherently control the excited state population with a pump-dump scheme, exploiting the non-stationary Franck-Condon overlap between ground and excited states.
Cirmi
Giovanni
G
Dipartimento di Fisica, Politecnico di Milano, Piazza L. da Vinci 32, 20133 Milano, Italy.
Brida
Daniele
D
Gambetta
Alessio
A
Piacenza
Manuel
M
Della Sala
Fabio
F
Favaretto
Laura
L
Cerullo
Giulio
G
Lanzani
Guglielmo
G
D056004:Molecular Dynamics Simulation; D013876:Thiophenes / Q000737:chemistry*; D013997:Time Factors; D014732:Vibration
D013876:Thiophenes