Photoinduced intramolecular and solvation dynamics of an organic chromophore in polar solvent

The ability of photofunctional organic molecules to perform chemical/mechanical work or convert photons into electrons results from a complex interplay between charge transfer and transient atomic rearrangements involving the local environment. These ultrafast structural dynamics have remained elusive experimentally, preventing a mechanistic understanding of the electronic-nuclear couplings. We will use the high X-ray photon flux and sub ps time resolution of the SwissFEL to realize the first X-ray scattering observation of solute-solvent dynamics following photoinduced charge transfer in an organic chromophore. The sensitivity of the scattering to changes in atomic distances will be exploited not only to track in real time the intra- and intermolecular structural dynamics but also to identify the electronic changes that trigger them. The results will pave the way for a better understanding of the factors governing the outcomes of photoreactions across chemistry and biology.