TY  - JOUR
A1  - Titov, Evgenii
A1  - Granucci, Giovanni
A1  - Goetze, Jan Philipp
A1  - Persico, Maurizio
A1  - Saalfrank, Peter
T1  - Dynamics of Azobenzene Dimer Photoisomerization: Electronic and Steric Effects
JF  - The journal of physical chemistry letters
N2  - While azobenzenes readily photoswitch in solution, their photoisomerization in densely packed self-assembled monolayers (SAMs) can be suppressed. Reasons for this can be steric hindrance and/or electronic quenching, e.g., by exciton coupling. We address these possibilities by means of nonadiabatic molecular dynamics with trajectory surface hopping calculations, investigating the trans -> cis isomerization of azobenzene after excitation into the pi pi* absorption band. We consider a free monomer, an isolated dimer and a dimer embedded in a SAM-like environment of additional azobenzene molecules, imitating in this way the gradual transition from an unconstrained over an electronically coupled to an electronically coupled and sterically hindered, molecular switch. Our simulations reveal that in comparison to the single molecule the quantum yield of the trans -> cis photoisomerization is similar for the isolated dimer, but greatly reduced in the sterically constrained situation. Other implications of dimerization and steric constraints are also discussed.
Y1  - 2016
U6  - https://doi.org/10.1021/acs.jpciett.6b01401
SN  - 1948-7185
VL  - 7
SP  - 3591
EP  - 3596
PB  - American Chemical Society
CY  - Washington
ER  -