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Reaction Rates and Mechanisms in Condensed Phases from Enhanced Sampling

(119 Words, 1 Minutes)

Chemical reactions in liquids are shaped by their molecular environment. Solvent molecules can stabilise transition states, alter reaction barriers, participate in proton transfer, and change the balance between competing mechanisms. In the MME group, we develop molecular simulation approaches to quantify these effects directly from atomistic models.

Our work combines enhanced sampling methods, such as well-tempered metadynamics, with mean force integration and transition state theory to reconstruct free-energy landscapes and estimate reaction rate constants in explicit solvent. This allows us to study rare reactive events that are too slow to observe in conventional molecular dynamics, while retaining a molecular-level description of solvent structure and dynamics.

We apply these methods to reactions relevant to chemical manufacturing, polymer chemistry and molecular transformations in solution. Recent examples include solvent effects on radical β-scission reactions and the solvent-mediated mutarotation of sugars. In both cases, enhanced sampling reveals how the liquid environment controls not only the reaction rate, but also the microscopic pathway by which the reaction occurs.

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