The nature of [PdCl 2(C 2H 4)(H 2O)] as an active species in the Wacker process: New insights from Ab initio molecular dynamics simulations

Gábor Kovács, András Stirling, Agustí Lledós, Gregori Ujaque

Research output: Contribution to journalArticle

20 Citations (Scopus)

Abstract

First-principles molecular dynamics coupled with metadynamics have been used to gain a deeper insight into the reaction mechanism of the Wacker process by determining the nature of the active species. An explicit and dynamic representation of the aqueous solvent, which was essential for modeling this reaction, was efficiently included into the simulations. Prompted by our earlier results, which showed that the configuration of the catalytically active species [PdCl 2(H 2O)(C 2H 4)] was crucial in the subsequent steps of the Wacker process, herein we focused on the preceding equilibria that led to the formation of both the cis and trans isomers. Starting from the initial catalyst, [PdCl 4] 2-, the free-energy barriers for the forward and backward reactions were calculated. These results confirmed the relevance of the trans intermediate in the reaction mechanism, whilst conversely, they showed that the cis configuration played no role in it. This sole participation of the trans intermediate has some very important implications; besides the mechanistic interpretation of the initial steps in the Wacker reaction mechanism, the analysis of these equilibria provides additional information about the chemical nature of these ligand-substitution processes.

Original languageEnglish
Pages (from-to)5612-5619
Number of pages8
JournalChemistry - A European Journal
Volume18
Issue number18
DOIs
Publication statusPublished - Apr 27 2012

    Fingerprint

Keywords

  • Wacker process
  • ab initio calculations
  • ligand effects
  • molecular dynamics
  • water chemistry

ASJC Scopus subject areas

  • Catalysis
  • Organic Chemistry

Cite this