Photoinduced Charge Transfer versus Fragmentation Pathways in Lanthanum Cyclopentadienyl Complexes

This study compares two competing pathways of photoexcitations in gas-phase metal organic complexes: first, a sequence of phonon-assisted electronic transitions leading to dissipation of the energy of photoexcitations and, second, a sequence of light-driven electronic transitions &quot;leadingto photolysis. Phonon-assisted charge carrier dynamics is investigated by combination of the density matrix formalism and on-the-fly non adiabatic couplings. Light-driven fragmentation is modeled by a time-dependent excited-state molecular-dynamics (TDESMD) algorithm based on Rabi theory and principles similar to the trajectory surface hopping approximation. Numerical results indicate that, under the medium intensity of the laser field, light driven electronic transitions are more probable than phonon-assisted ones. The formation of multiple products is observed in TDESMD trajectories. Simulated mass spectra are extracted from TDESMD simulations and compared to experimental photoionization time-of-flight (PI-TOF) mass spectra. It is found that several features in the experimental mass spectra are reproduced by the simulations.</p