Ultrafast Dynamics in Light-Driven Molecular Rotary Motors Probed by Femtosecond Stimulated Raman Spectroscopy
Christopher R Hall, Jamie Conyard, Ismael A Heisler, Garth Jones, James Frost, Wesley R Browne, Ben L Feringa, Stephen R Meech
JOURNAL OF THE AMERICAN CHEMICAL SOCIETY | AMER CHEMICAL SOC | Published : 2017
Photochemical isomerization in sterically crowded chiral alkenes is the driving force for molecular rotary motors in nanoscale machines. Here the excited-state dynamics and structural evolution of the prototypical light-driven rotary motor are followed on the ultrafast time scale by femtosecond stimulated Raman spectroscopy (FSRS) and transient absorption (TA). TA reveals a sub-100-fs blue shift and decay of the Franck-Condon bright state arising from relaxation along the reactive potential energy surface. The decay is accompanied by coherently excited vibrational dynamics which survive the excited-state structural evolution. The ultrafast Franck-Condon bright state relaxes to a dark excited..View full abstract
Awarded by EPSRC
Awarded by ERC
Awarded by Engineering and Physical Sciences Research Council
S.R.M. is grateful to EPSRC for financial support (EP/J009148/01, EP/M00197/1), and B.L.F. thanks the ERC (Advanced Investigator Grant 227897). J.F. thanks EPSRC for the award of a studentship. The calculations presented in this Paper were carried out on the High Performance Computing Cluster supported by the Research and Specialist Computing Support service at the University of East Anglia.