# Excited State Dynamics of CO2 Reduction Catalyst under Vibrational Strong Coupling

## TL;DR

This paper explores how vibrational strong coupling affects the excited state dynamics of a CO2 reduction catalyst using advanced spectroscopy techniques.

## Contribution

The study introduces a novel approach to investigate vibrational strong coupling effects on molecular processes using angle-resolved time-dependent transmission spectra.

## Key findings

- Distinct infrared polaritonic signatures of CO dynamical Stokes shift were observed.
- Solvation-induced vibrational dynamic Stokes shift of CO modes remained largely unchanged under vibrational strong coupling.
- Perturbed free induction decay in the cavity was linked to polariton dynamics.

## Abstract

Molecular polaritons, formed by coupling molecular electronic
or
vibrational transitions to photonic modes in microcavities, have gained
interest for their potential to influence chemical dynamics. Here,
we investigate the effects of vibrational strong coupling (VSC) on
solvation-induced time-dependent Stokes shifts using transient infrared
(IR) transmission spectroscopy. The electronic excited-state dynamics
of the Re­(bpy-COOH)­(CO)3Cl complex (ReC0A) is monitored
via angle-resolved time-dependent transmission spectra of vibrational
polaritons following 400 nm excitation inside a Fabry–Perot
cavity. Our results reveal distinct infrared polaritonic signatures
of the CO dynamical Stokes shift, which we interpret using simulations
based on a time-dependent excited-state absorption model. We observed
negligible change of the solvation-induced vibrational dynamic Stokes
shift of the CO modes under VSC. We also investigate the perturbed
free induction decay in the cavity and its connection to polariton
dynamics. This setup allows us to probe and test potential fundamental
VSC effects on molecular processes relevant to the reactivity and
charge transfer.