Modeling the heating and cooling of a chromophore after photoexcitation
Elizete Ventura, Silmar A. do Monte, Mariana T. do Casal, Max Pinheiro, Josene M. Toldo, Mario Barbatti
Abstract
nonadiabatic dynamics of cytosine, a prototypical chromophore undergoing ultrafast internal conversion, in three solvents-argon matrix, benzene, and water-spanning an extensive range of interactions. We implemented an analytical energy-transfer model to analyze these data and extract heating and cooling times. The model accounts for nonadiabatic effects, and excited- and ground-state energy transfer, and can analyze data from any dataset containing kinetic energy as a function of time. Cytosine heats up in the subpicosecond scale and cools down within 25, 4, and 1.3 ps in argon, benzene, and water, respectively. The time constants reveal that a significant fraction of the benzene and water heating occurs while cytosine is still electronically excited.