Magnetic silica colloids for catalysis

Abstract

Monodisperse magnetizable colloidal silica particles in a stable dispersion have been functionalized with a homogeneous catalyst: a PCP-pincer Pd-complex. In a proof-of-principle experiment we demonstrate the catalytic activity of the colloids in a C-C bond formation reaction. Advantages of the magnetic silica carriers are the large surface-to-volume ratio and the easy recovery by magnetic separation. After magnetic separation, the catalyst-loaded particles are readily redispersed for further use. r

RuIII(OTf)SalophenCH2–NHSiO2–Fe: an efficient and magnetically recoverable catalyst for trimethylsilylation of alcohols and phenols with hexamethyldisilazane

“…Magnetic nanocatalysts have been used in a wide range of reactions with desired activities. Their surface can be functionalized during catalyst preparation …”

A Magnetically Recyclable Nanocomposite Catalyst for Olefin Epoxidation

“…[14] The magnetic behavior of the Mag-Mo-Nano catalyst was investigated using a superconducting quantum interference device (SQUID) magnetometer. The field-dependent magnetization curve at 300 K reveals that the catalyst is ferromagnetic with a saturation magnetization of 1.32 emu g À1 (Figure 4).…”

The Immobilization of a Transfer Hydrogenation Catalyst on Colloidal Particles

“…The intermediate size of colloidal objects combined with chemical surface reactivity make colloids in principle also a promising target for catalyst immobilization . In general, immobilization of catalysts onto solid supports provides a route toward hybrid catalytic systems to simultaneously combine the advantages and circumvent the disadvantages associated with purely homogeneous and heterogeneous catalysts.…”