Modification of ground-state chemical reactivity via light-matter coherence in infrared cavities

Reaction-rate modifications for chemical processes due to strong coupling between reactant molecular vibrations and the cavity vacuum have been reported; however, no currently accepted mechanisms explain these observations. In this work, reaction-rate constants were extracted from evolving cavity transmission spectra, revealing resonant suppression of the intracavity reaction rate for alcoholysis of phenyl isocyanate with cyclohexanol. We observed up to an 80% suppression of the rate by tuning cavity modes to be resonant with the reactant isocyanate (NCO) stretch, the product carbonyl (CO) stretch, and cooperative reactant-solvent modes (CH). These results were interpreted using an open quantum system model that predicted resonant modifications of the vibrational distribution of reactants from canonical statistics as a result of light-matter quantum coherences, suggesting links to explore between chemistry and quantum science.

Automated summary

Reaction-rate modifications due to the strong coupling between molecular vibrations and the cavity vacuum have been investigated, but the mechanisms behind these observations are still unknown. This study extracted reaction-rate constants from evolving cavity transmission spectra, showing resonant suppression of the intracavity reaction rate for a specific alcoholysis reaction. By tuning the cavity modes to be resonant with the reactant and product vibrations, as well as cooperative modes, up to 80% suppression of the reaction rate was observed. An open quantum system model was used to interpret these results, suggesting the role of light-matter quantum coherences in modifying the vibrational distribution of reactants and highlighting the connection between chemistry and quantum science.