Removal of residual metal catalysts with iron/iron oxide nanoparticles from coordinating environments.
The application of Fe@FexOy nanoparticles was examined for the sequestration of catalytic metal impurities from organic reaction products. An X-ray photoelectron spectroscopy (XPS) study of the recovered particles confirmed Fe@FexOy sequestered Co2+, Cu2+, Ni2+, RhX+, Pd2+, Ag+, and Pt4+ by coordination of the metal ion to the iron oxide surfaces and followed by subsequent reduction of the surface-bonded ions to their metallic state. Fe@FexOy metal sequestration was found to be effective for catalyst impurities in the absence of strongly coordinating environments but was inhibited by the presence of phosphines. Sequestration of phosphine-coordinated metal impurities was achieved through the addition of either cysteamine or 3-mercaptopropionic acid to the Fe@FexOy during sequestration. This approach was applied to model syntheses using Grubbs' Catalyst (first generation), Pd(PPh3)4, Pd2(dba)3, and Wilkinson's Catalyst (RhCl(PPh3)3).
Macdonald
Janet E
JE
Department of Chemistry, University of Alberta, Edmonton, Alberta Canada, T6G 2G2.
Veinot
Jonathan G C
JG