A Phenomenological Symmetry Rule for Chemical Reactivity Under Vibrational Strong Coupling

Area of Science:

• Chemical Physics
• Quantum Chemistry
• Spectroscopy

Background:

• Symmetry is a known factor influencing chemical reaction pathways.
• Vibrational strong coupling (VSC) effects on chemical reactions and equilibria are significant but not fully understood.
• The precise role of symmetry in VSC requires further investigation.

Purpose of the Study:

• To explore the role of vibrational symmetry in chemical reactivity.
• To investigate the impact of symmetry on equilibrium constants in charge transfer complexes under VSC.
• To establish a general symmetry rule for predicting VSC outcomes.

Main Methods:

• Studied equilibrium constants of trimethyl benzene isomers with varying point groups.
• Described the VSC system using a direct product of irreducible representations for complexes and cavity.
• Analyzed how new irreducible representations of coupled vibrations affect reaction coordinates.

Main Results:

• A general symmetry rule emerged from studying charge transfer complexes.
• The irreducible representation of the coupled vibration showed differential projection on the reaction coordinate.
• Observed changes in equilibrium constants correlated with symmetry-based predictions.

Conclusions:

• Symmetry plays a crucial role in dictating chemical reactivity under VSC.
• The developed symmetry rule provides a framework for predicting VSC-induced chemical outcomes.
• This work elucidates the fundamental connection between symmetry, VSC, and chemical equilibrium.