A roadmap toward the theory of vibrational polariton chemistry

The field of vibrational polariton chemistry was firmly established in 2016 when a chemical reaction rate at room temperature was modified within a resonantly tuned infrared cavity without externally driving the system. Despite intense efforts by scientists around the world to understand why the reaction rate changes, no convincing theoretical explanation exists. In this perspective, first, we briefly review this seminal experiment, as well as relevant experiments that have since followed that have hinted at the roles of reactant concentration, cavity frequency, and symmetry. Then, we analyze the relevance of leading theories, such as quantum electrodynamics-modified transition rate theories, the photonic solvent cage effect, the impact of dissipation from dark states, bond strengthening via intramolecular vibrational energy redistribution, and collectively enhanced local molecular properties. Finally, we construct a roadmap toward the theory of vibrational polariton chemistry by suggesting experiments to test theories and new paths for theorists. We believe that understanding the importance of the onset of the strong coupling regime, designing experiments to capture changes in reaction pathways, and further developing the theories of cavity-modified intramolecular vibrational energy redistribution and collectively enhanced local molecular properties are crucial next steps. We hope this perspective will be a valuable resource for guiding research in the field of vibrational polariton chemistry.