Molecular Photodynamics

Understanding the nature of molecular dynamics in detail, such as visualization of molecular bond breaking, charge-transfer processes, proton migration, Interatomic Coulombic decay (ICD), photoprotection, ring opening and isomerization phenomena induced by the interaction of photons with matter has become viable with the advent of ultrafast laser pulses [1].
Recently, experiments related to investigations of different ultrafast phenomena for various isolated organic molecules have been performed at FERMI by FELs-based time-resolved spectroscopy [2, 3] (for example, see Fig. 6).This class of spectroscopy is based on pump-probe techniques, where a pump pulse excites a sample and a probe pulse is used for probing the sample after an adjustable delay time.
Figure 6. A schematic overview of the relaxation mechanism of acetylacetone. The ground state S0 (darker blue), two singlet S2 (ππ*) (light blue) and S1 (nπ*) (orange), and two triplet T2 (nπ*) (light green) and T1 (ππ*) (green) states are shown. Excited state minima and minimum energy CIs (MECI) are indicated. Relative energies with respect to the electronic ground state minimum (S0min) are given. For details see [2].
[1]       N. Berrah. Phys. Chem. Chem. Phys. 19,19536 (2017).
[2]       R. J. Squibb et al. Nature Communications 9, 63 (2018).
[3]       S. Pathak et al. Nature Chemistry, 12, 795 (2020).