Probing photoinduced proton coupled electron transfer process by means of two-dimensional resonant electronic-vibrational spectroscopy

TL;DR

This paper presents a theoretical model for photo-induced proton-coupled electron transfer (PPCET), analyzing its dynamics and pathways using advanced spectroscopy simulations to improve understanding of energy transfer in biological and photovoltaic systems.

Contribution

The study introduces a detailed quantum dynamical model of PPCET processes and employs 2DREVS spectroscopy to distinguish reaction pathways, advancing the analysis of complex energy transfer mechanisms.

Findings

Different transition pathways can be separated by TAS and 2DREVS.

The model enables analysis of PPCET dynamics under non-Markovian environments.

Simulations provide insights into reaction efficiency and pathway contributions.

Abstract

We develop a detailed theoretical model of photo-induced proton-coupled electron transfer (PPCET) processes, which are at the basis of solar energy harvesting in biological systems and photovoltaic materials. Our model enables to analyze the dynamics and the efficiency of a PPCET reaction under the influence of a thermal environment by disentangling the contribution of the fundamental electron transfer (ET) and proton transfer (PT) steps. In order to study quantum dynamics of the PPCET process under an interaction with non-Markovian environment we employ the hierarchical equations of motion (HEOM). We calculate transient absorption spectroscopy (TAS) and a newly defined two-dimensional resonant electronic-vibrational spectroscopy (2DREVS) signals in order to study the nonequilibrium reaction dynamics. Our results show that different transition pathways can be separated by TAS and 2DREVS.