Diels-Alder Reactions in Water Are Determined by Microsolvation

Luis Ruiz Pestana, Hongxia Hao, Teresa Head-Gordon

Research output: Contribution to journalArticlepeer-review

10 Scopus citations

Abstract

Nanoconfined aqueous environments and the recent advent of accelerated chemistry in microdroplets are increasingly being investigated for catalysis. The mechanisms underlying the enhanced reactivity in alternate solvent environments and whether the enhanced reactivity due to nanoconfinement is a universal phenomenon are not fully understood. Here, we use ab initio molecular dynamics simulations to characterize the free energy of a retro-Diels-Alder reaction in bulk water at very different densities and in water nanoconfined by parallel graphene sheets. We find that the broadly different global solvation environments accelerate the reactions to a similar degree with respect to the gas-phase reaction, with activation free energies that do not differ by more than kbT from each other. The reason for the same acceleration factor in the extremely different solvation environments is that it is the microsolvation of the dienophile's carbonyl group that governs the transition-state stabilization and mechanism, which is not significantly disrupted by either the lower density in bulk water or the strong nanoconfinement conditions used here. Our results also suggest that significant acceleration of Diels-Alder reactions in microdroplets or on-water conditions cannot arise from local microsolvation when water is present but instead must come from highly altered reaction environments that drastically change the reaction mechanisms.

Original languageEnglish (US)
Pages (from-to)606-611
Number of pages6
JournalNano Letters
Volume20
Issue number1
DOIs
StatePublished - Jan 8 2020
Externally publishedYes

Keywords

  • ab initio molecular dynamics
  • isocommitor analysis
  • microdroplet chemistry
  • nanoconfinement chemistry
  • on-water chemistry

ASJC Scopus subject areas

  • Bioengineering
  • Chemistry(all)
  • Materials Science(all)
  • Condensed Matter Physics
  • Mechanical Engineering

Fingerprint

Dive into the research topics of 'Diels-Alder Reactions in Water Are Determined by Microsolvation'. Together they form a unique fingerprint.

Cite this