Microprobe Analysis of Polystyrene-Attached Catalysts

Polymer-Attached Catalysts

“…The distribution of species containing atoms other than C and H may be readily determined in polystyrene copolymer beads by the use of electron microprobe analysis. Cross-sections of the phosphinated polystyrene beads are scanned, and the resulting surface analyses of samples prepared by the differing methods described above reveal that the phosphine distribution is completely different in each case [31]. 31p NMR spectroscopy is also a useful tool for characterizing organophosphorus ligands attached to a polymeric support [18].…”

“…By cross-sectional analysis of polymer beads using an electron probe microanalyzer, it has been shown that the rhodium atoms in a polymersupported Wilkinson's complex are distributed in a layer 16 11m deep from the surface of the beads [71]. Thus, polystyrene works not only as a polymer matrix to decrease its mobility but also as a ligand for the metal.…”

Characterization of functionalized polymers: synthesis of cyanomethylated polystyrenes and reaction chemistry with palladium(II)

“…In order to confirm this penetration effect, samples of 2 and 7 were embedded in an epoxy matrix and sectioned for X-ray spectroscopic analysis by using an electron microprobe equipped with an energy dispersive spectrometer (EDS). 16,17 The relative abundance of chlorine was measured in the first instance in background-corrected counts taken in 20-s intervals at 100-µ steps across each bead section. Plots of the relative chlorine content across each bead are shown in Figures 3 and 4 showing that the chloromethyl groups only undergo extensive reaction at the edges of the bead.…”

“…Such information can, however, be acquired by the application of electron microprobe analysis or allied surface techniques. 16,17 In this paper we describe the synthesis of cyanomethylated polystyrene and its reaction with palladium(II) chloride. A combination of CP/MAS NMR and DRIFT techniques has been employed to analyze reaction products and electron microprobe analysis has shed light on matrix effects observed during reactivity studies.…”

Polymer-Bound Phosphine Catalysts

“…In polymers with small pores «50 A), penetration was limited to the outer bead areas. (58) In attaching the metal to the support, it was found that the metal was distributed in the outer portions of the bead if a deficiency of the metal was used. With excess metal the distribution was similar to that of the phosphine groups.…”