Light interacting with molecules and materials is key to “photophysics”, e.g., spectroscopy, and “photochemistry”, i.e., the making and breaking of bonds after photoexcitation. Light-induced processes are ubiquitous and successful in chemistry but fundamental understanding of what electrons and atoms really do when optically excited, is still somewhat limited.

In this overview talk, we literally shed light on selected, photodriven processes and reactions relevant for photophysics and photochemistry, applying a combination of electronic structure and dynamics methods. In a first, “photophysical” example the creation of electron wavepackets in molecules by ultrashort laser pulses, and their attosecond dynamics and spectroscopic response will be followed with the help of time-dependent, correlated electronic structure methods. In a second example steps towards “photochemistry” are taken by considering photoswitching of azobenzene molecules in constraining environments. Here, non-adiabatic molecular dynamics with surface hopping allow for detailed insight into the mechanism of photoinduced trans-to-cis isomerization. As another photochemical process, photocatalytic water splitting in porous, carbon and nitrogen containing layered materials will be considered. Finally, if time permits, “photochemistry without light” will be discussed for the example of isomerization reactions of molecules in optical cavities, a new, emerging field in chemistry.

Seminar hosts: Neven Šantić i Damir Dominko