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Publication Citation: Ligand Exchange Reactions in the Formation of Diphosphine-Protected Gold Clusters

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Author(s): Denis E. Bergeron; Orkid Coskuner; Jeffrey W. Hudgens; Carlos A. Gonzalez;
Title: Ligand Exchange Reactions in the Formation of Diphosphine-Protected Gold Clusters
Published: August 14, 2008
Abstract: Electrospray ionization mass spectrometry is employed to study the formation of L3- and L5-protected gold clusters (L3 = 1,3-Bis(diphenylphosphino)propane; L5 = 1,5-Bis(diphenylphosphino)pentane), and it is found that molecular complexes in which Au+ is bound to at least one triphenylphosphine ligand (PPh3) act as precursors, while complexes in which Au+ is bound only to the bidentate diphosphine ligands act as reaction bottlenecks.  Ligand exchange mechanisms and ion equilibria were established in the absence of a reducing agent, and a critical reaction was modeled with ab initio molecular dynamics simulations.  The displacement of one PPh3 by L3 on [Au(PPh3)2]+ was studied with Car Parrinello molecular dynamics and transition path sampling.  It is found that experiment and theory converge on a complete description of a reaction event critical in the synthesis of a particular set of monolayer protected nanoparticles.
Citation: Journal of Physical Chemistry C
Volume: 112
Issue: 33
Pages: pp. 12808 - 12814
Keywords: Electrospray ionization; gold nanoparticle; Car-Parrinello molecular dynamics; monolayer protected gold cluster
Research Areas:
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