Air-Stable and Highly Active Dendritic Phosphine Oxide- Stabilized Palladium Nanoparticles: Preparation, Characterization and Applications in the Carbon-Carbon Bond Formation and Hydrogenation Reactions
作者:Lei Wu、Zhi-Wei Li、Feng Zhang、Yan-Mei He、Qing-Hua Fan
DOI:10.1002/adsc.200700441
日期:2008.4.7
compared with the commonly used homogeneous catalyst tetrakis(triphenylphosphine)palladium [Pd(PPh3)4]. In addition, the results obtained from the bulky dendritic substrate suggest that the Pd nanoparticles might act as reservoir of catalytically active species, and that the reaction is actually catalyzed by the soluble Pd(0) and/or Pd(II) species leached from the nanoparticle surface.
在膦树状大分子配体存在下,使用氢在四氢呋喃中还原双(乙酰丙酮)钯[Pd(acac)2 ],形成树状大分子稳定的钯纳米颗粒。通过TEM,31 P NMR和31表征所得的Pd纳米颗粒P MAS NMR。结果表明,树枝状膦配体被氧化为氧化膦。这些树状聚合物稳定的Pd纳米颗粒被证明是Suzuki和Stille偶联反应和氢化的有效催化剂。树状楔用作稳定剂以防止纳米颗粒聚集,并且用作促进Pd催化剂的分离和/或再循环的载体。在铃木偶联反应的情况下,与常用的均相催化剂四(三苯基膦)钯[Pd(PPh 3)4相比,这些Pd纳米颗粒显示出高催化效率(TON高达65,000)和空气稳定性。]。此外,从庞大的树突状基质获得的结果表明,Pd纳米颗粒可能充当催化活性物质的储存库,并且该反应实际上是由从水中浸出的可溶性Pd(0)和/或Pd(II)物质催化的。纳米颗粒表面。