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Hirofumi Sato

Publications and source records attributed to Hirofumi Sato.

2 recordsLinked to original sources

On transition path times for condensed-phase non-adiabatic electron transfer reactions under a two-parabola model

Condensed-phase non-adiabatic electron transfer (ET) reactions play an important role in various areas of science. The characteristics of the microscopic transition processes involved in these reactions and their dynamic behavior remain poorly understood. In this study, we performed non-adiabatic simulations based on the Zhu-Nakamura theory, combining the two-parabola model with Kramers-like Langevin dynamics. We numerically analyzed the dependence of the macroscopic reaction time and the timescale of the microscopic transition process on the diabatic coupling between the diabatic states and on the friction parameter in Langevin dynamics. Although the microscopic transfer process is generally regarded as instantaneous in the non-adiabatic regime, we found that the timescale of the microscopic transition process can still be a non-negligible fraction of the macroscopic reaction time.

physics.chem-ph

Fluctuation-induced acceleration of inter-ligand exciton transfer in bis(dipyrrinato)Zn(II) complex

Exciton transfer dynamics between chromophores depends on excitonic coupling, which is governed by relative orientation between the chromophores. While the excitonic coupling is treated as a static parameter in many cases, structural dynamics can introduce time-dependence on the excitonic coupling. However, influence of the dynamics of excitonic coupling on the exciton transfer has been scarcely understood. In the present study, exciton transfer under dynamical fluctuation in excitonic coupling was investigated via combined use of non-adiabatic molecular dynamics simulations, exciton density analysis, and a simple two-state model, for inter-ligand exciton transfer in bis(dipyrrinato)Zn(II) as the example case. The reaction coordinate for the exciton transfer was obtained a posteriori via regression analysis where the target and explanatory variables are diabatic energy gaps and atomic displacements, respectively. The results suggest that dynamical angular fluctuation between the two dipyrrinato ligands breaks the symmetry to incidentally increase the excitonic coupling, accelerating the exciton transfer between the ligands.

physics.chem-ph