The Significance of Bromide in the Brust-Schiffrin Synthesis of Thiol Protected Gold Nanoparticles

Research output: Contribution to journalArticle

  • External authors:
  • Samuel G. Booth
  • Akihiro Uehara
  • Sin Yuen Chang
  • Camille La Fontaine
  • Toshiyuki Fujii
  • Yoshihiro Okamoto
  • Takahito Imai
  • Sven L. M. Schroeder

Abstract

The mechanism of the two-phase Brust-Schiffrin synthesis of alkane thiol protected metal nanoparticles is known to be highly sensitive to the precursor species and reactant conditions. In this work X-ray absorption spectroscopy is used in conjunction with liquid/liquid electrochemistry to highlight the significance of Brˉ in the reaction mechanism. The species [AuBr4]ˉ is shown to be a preferable precursor in the Brust-Schiffrin method as it is more resistant to the formation of Au(I) thiolate species than [AuCl4]ˉ. Previous literature has demonstrated that avoidance of the Au(I) thiolate is critical to achieving a good yield of nanoparticles, as [Au(I)X2]ˉ species are more readily reduced by NaBH4. We propose that the observed behavior of [AuBr4]ˉ species described herein explains the discrepancies in reported behavior present in the literature to date. This new mechanistic understanding should enable nanoparticle synthesis with a higher yield and reduce particle size polydispersity.

Bibliographical metadata

Original languageEnglish
JournalChemical Science
Early online date26 Sep 2017
DOIs
Publication statusPublished - 2017

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