Quantum mechanics

Reaction rate constant

Ground state

Metallurgy

Materials science

Enthalpy

Entropy (arrow of time)

Coupling (piping)

Atomic physics

Kinetic energy

Molecule

Thermodynamics

Physics

Organic chemistry

Molecular dynamics

Condensed matter physics

Computational chemistry

Kinetics

Thermodynamic integration

Coupling strength

Chemistry

Transition state theory

Molecular vibration

Nanophotonics

Vibrational strong coupling (VSC) is currently emerging as a tool to control chemical dynamics. Here we study the impact of strong coupling strength, given by the Rabi splitting energy ( ħ Ω R ), on the thermodynamic parameters associated with the transition state of the desilylation reaction of the model molecule 1-phenyl-2-trimethylsilylacetylene. Under VSC, the enthalpy and entropy of activation determined from the temperature-dependent kinetic studies varied nonlinearly with the coupling strength. The thermodynamic parameters of the noncavity reaction did not show noticeable variation, ruling out concentration effects other than the enhanced ħ Ω R for the changes observed under VSC. The difference between the total free energy change under VSC and in noncavity was relatively smaller possibly because the enthalpy and entropy of activation compensate each other. This thermodynamic study gives more insight into the role of collective strong coupling on the transition state that leads to modified dynamics and branching ratios.

Ground state chemistry under vibrational strong coupling: dependence of thermodynamic parameters on the Rabi splitting energy