New insights into the formation chemistry of chalcogenate-protected metal nanoparticles (NPs) synthesized via the well-known Brust-Schiffrin two-phase method are presented here. On the basis of Raman, NMR, and surface plasmon resonance characterizations, it is concluded that, before the formation of any metal-chalcogen bonds, metal nucleation centers/NPs are first formed inside the inverse micelles of the tetrabutylammonium bromide in the organic solvent, where the metal ions are reduced by NaBH(4). The ensuing formation of the metal-chalcogen bonds between the naked metal NPs inside the micelles and the organo-chalcogen ligands in the organic solvent is the mechanism by which the further growth of the metal core can be controlled. This proposed mechanism is further examined in the formation of Ag and Cu NPs.
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http://dx.doi.org/10.1021/ja1105078 | DOI Listing |
Phys Chem Chem Phys
June 2024
Institute of Information Photonics Technology, School of Physics and Optoelectronic Engineering, Beijing University of Technology, Beijing 100124, P. R. China.
The Brust-Schiffrin two-phase method is a facile way to prepare thiolate-protected metal nanoparticles, but its mechanism remains controversial. In this work, we demonstrate the use of the Brust-Schiffrin method based on coordination compound theory. We confirmed that the formation of stable complexes is the driving force for a series chemical reaction in the organic phase.
View Article and Find Full Text PDFNanoscale
October 2020
College of Materials Science and Engineering, Qingdao University of Science and Technology, Qingdao 266042, P. R. China.
The two-phase Brust-Schiffrin (B-S) method has been widely used for synthesizing small-sized Au nanoparticles (NPs) of size 2-6 nm, as well as Au nanoclusters (NCs) of size <2 nm. However, size tuning of Au NCs at the atomic level by this method is challenging probably due to a lack of in-depth understanding of its mechanism. Herein, we report the identification of two roles of tetraoctylammonium bromide (TOAB) in the two-phase B-S method: TOAB not only transfers Au(iii) precursors but also transfers the reducing agent NaBH from the aqueous to the organic phase.
View Article and Find Full Text PDFBioconjug Chem
November 2018
Department of Chemical and Biomolecular Engineering , University of Delaware, 150 Academy Street , Newark , Delaware 19716 , United States.
Histone-inspired polymer assemblies (polyplexes) can regulate gene expression and subcellular transport in plasmids by harnessing the cellular machinery normally used for histone proteins. When grafted to polyplexes, histone tails promote nuclear accumulation, trigger plasmid DNA (pDNA) release, and enhance transcription. Herein, we developed multifunctional gold nanoparticles (AuNPs) decorated by histone motifs as histone-inspired scaffolds with improved pDNA binding, easy bioimaging, and increased potential for gene delivery and chromatin analysis applications.
View Article and Find Full Text PDFACS Appl Mater Interfaces
August 2018
Key Laboratory for Micro-/Nano-Optoelectronic Devices of Ministry of Education, School of Physics and Electronics , Hunan University, Changsha 410082 , China.
The gold nanoparticles highly grafted by a liquid crystalline polymer (LCP) with azobenzene mesogens as the side chain (denoted as Au@TE-PAzo NPs) are successfully designed and synthesized by the two-phase Brust-Schiffrin method. The chemical structures of the monomer and polymer ligands have been confirmed by nuclear magnetic resonance, and the molecular weight of the polymer is determined by gel permeation chromatography. The combined analysis of transmission electron microscopy and thermogravimetric analysis shows that the size of the nanoparticles is 2.
View Article and Find Full Text PDFChem Sci
December 2017
School of Chemistry , University of Manchester, Manchester , M13 9PL , UK . Email:
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 Br in the reaction mechanism. The species [AuBr] 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 [AuCl].
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