IMX Talks - Photoinduced symmetry-breaking charge-transfer

A substantial number of symmetric molecular architectures, including the reaction centre of photosynthetic bacteria, undergo photoinduced charge transfer along one of several energetically equivalent pathways, resulting in a breaking of the symmetry. Some of our efforts toward a better understanding of the origin and dynamics of these processes will be presented.
Two types of photoinduced symmetry-breaking charge-transfer process occurring in symmetric molecular systems will be addressed. The first concerns charge separation between two identical molecules, and the second charge transfer in multipolar molecules containing two or more identical donor-acceptor branches.
The experimental approaches to visualise symmetry breaking in real time using ultrafast spectroscopy will be presented and the main factors governing these processes will be discussed.
Dereka, B.; Rosspeintner, A.; Li, Z.; Liska, R.; Vauthey, E., Direct Visualization of Excited-State Symmetry Breaking Using Ultrafast Time-Resolved Infrared Spectroscopy. J. Am. Chem. Soc. 2016, 138, 4643-4649.
Aster, A.; Licari, G.; Zinna, F.; Brun, E.; Kumpulainen, T.; Tajkhorshid, E.; Lacour, J.; Vauthey, E., Tuning Symmetry Breaking Charge Separation in Perylene Bichromophores by Conformational Control. Chem. Sci. 2019, 10, 10629-10639.
Vauthey, E. Watching Excited-State Symmetry Breaking in Multibranched Push–Pull Molecules. J. Phys. Chem. Lett. 2022, 13, 2064-2071.