Palladium-coated nickel nanoclusters: new Hiyama cross-coupling catalysts.
The advantages of bimetallic nanoparticles as C-C coupling catalysts are discussed, and a simple, bottom-up synthesis method of core-shell Ni-Pd clusters is presented. This method combines electrochemical and 'wet chemical' techniques, and enables the preparation of highly monodispersed structured bimetallic nanoclusters. The double-anode electrochemical cell is described in detail. The core-shell Ni-Pd clusters were then applied as catalysts in the Hiyama cross-coupling reaction between phenyltrimethoxysilane and various haloaryls. Good product yields were obtained with a variety of iodo- and bromoaryls. We found that, for a fixed amount of Pd atoms, the core-shell clusters outperform both the monometallic Pd clusters and the alloy bimetallic Ni-Pd ones. THF is an excellent solvent for this process, with less than 2% homocoupling by-product. The roles of the stabiliser and the solvent are discussed.
Van 't Hoff Institute of Molecular Sciences, University of Amsterdam, Nieuwe Achtergracht 166, 1018 WV Amsterdam, The Netherlands.
Laura
L
Durán Pachón
Mehul B
MB
Thathagar
Frantisek
F
Hartl
Gadi
G
Rothenberg
D002384:Catalysis; D004563:Electrochemistry / Q000295:instrumentation; D008956:Models, Chemical; D015394:Molecular Structure; D049329:Nanostructures / Q000737:chemistry*; D009532:Nickel / Q000737:chemistry*; D017646:Organosilicon Compounds / Q000737:chemistry; D010165:Palladium / Q000737:chemistry*
D017646:Organosilicon Compounds; C410706:phenyltrimethoxysilane; D010165:Palladium; D009532:Nickel