In a time-dependent view, the essential idea is that the elementary processes in isolated molecules and condensed phase occur in characteristic time scales that in turn, correlate and control the mechanisms observed at macroscopic level. Light pulses are the tools to induce and track different phenomena at molecular level. In particular, ultrashort laser pulses with durations in the femtoseconds (fs, 10-15 s) range, which is the scale of the nuclear movement, allow us to observe in real time the fundamental events in chemistry: nuclear reorganization, bond breaking and formation and intra-intermolecular energy transfer.
In our group, we use pump-probe methods based in fs pulses to induce and track photochemical and photophysical processes triggered by the electronic excitation in the UV-Vis region of model aromatic molecules isolated in the gas phase, micro-solvated in molecular clusters or in solution. These simple chromophores provide more complex molecular systems with the ability to be efficiently photoexcited by solar radiation, giving raise to phenomena as photosynthesis or photovoltaic generation. Understanding the role of the molecular electronic-vibrational coordinates in the evolution of the electronic excitation is key to model and control these processes.
