Monthly Archives: October 2022

Solvent-specific effects in ultrafast processes

I thought that ion-specific effects on solution structure and thermodynamics of complex solutes (e.g., proteins) are difficult task. Nevertheless, being long in classical MD simulations, I forgot that quantum chemistry offers way more electronic states (not only the ground state) where the system can live (even simultaneously). This opens yet another complexity of the studied systems.-)

Transition metal complexes, such as ReCl(CO)3(bpy) (bpy = 2,2-bipyridine), offer numerous electronic states, which evolution can be well traced by time-resolved spctroscopy techniques. Following the experimental setup and observation (fluorescence and time-resolved IR) we applied computationally demanding hybrid QM/MM nonadiabatic dynamics on spin-mixed potential energy surfaces. We analyzed fluorescence and inter-system crossing kinetics in acetonitrile and dimethylsulfoxide, finding that responsible time constants are solvent specific. Moreover, we found that the faster time constant correlates with geometry relaxation and the slower with solvent reorientation dynamics.

Congratulations to Adam for converting his MSc thesis in this nice paper and thanks to all collaborators for this nice experience. Enjoy the reading!
[1] Šrut, A., Mai, S., Sazanovich, I. V, Heyda, J., Vlček, A., González, L., & Záliš, S. (2022). Nonadiabatic excited-state dynamics of ReCl(CO) 3 (bpy) in two different solvents. Physical Chemistry Chemical Physics.