title: Interrogating the catalytic mechanism of nanoparticle mediated Stille coupling reactions employing bio-inspired Pd nanocatalysts.
abstract: To address issues concerning the global environmental and energy state, new catalytic technologies must be developed that translate ambient and efficient conditions to heavily used reactions. To achieve this, the structure/function relationship between model catalysts and individual reactions must be critically discerned to identify structural motifs responsible for the reactivity. This is especially true for nanoparticle-based systems where this level of information remains limited. Here we present evidence indicating that peptide-capped Pd nanoparticles drive Stille C-C coupling reactions via Pd atom leaching. Through a series of reaction studies, the materials are shown to be optimized for reactivity under ambient conditions where increases in temperature or catalyst concentration deactivate reactivity due to the leaching process. A quartz crystal microbalance analysis demonstrates that Pd leaching occurs during the initial oxidative addition step at the nanoparticle surface by aryl halides. Together, this suggests that peptide-based materials may be optimally suited for use as model systems to isolate structural motifs responsible for the generation of catalytically reactive materials under ambient synthetic conditions.
authors: Department of Chemistry, University of Kentucky, 101 Chemistry-Physics Building, Lexington, Kentucky 40506-0055, USA.
authors: Dennis B
authors: DB
authors: Pacardo
authors: Joseph M
authors: JM
authors: Slocik
authors: Kyle C
authors: KC
authors: Kirk
authors: Rajesh R
authors: RR
authors: Naik
authors: Marc R
authors: MR
authors: Knecht
mesh_terms: D040761:Biomimetic Materials / Q000737:chemistry*; D002384:Catalysis; D046911:Macromolecular Substances / Q000737:chemistry; D008422:Materials Testing; D008956:Models, Chemical; D008968:Molecular Conformation; D049329:Nanostructures / Q000737:chemistry* / Q000648:ultrastructure*; D010165:Palladium / Q000737:chemistry*; D010316:Particle Size; D013499:Surface Properties
chemical_list: D046911:Macromolecular Substances; D010165:Palladium