Probe molecules carbonium ions

Prins reaction, heteropolyacid catalysis, 41 156 Probe molecules, 42 119 acidic dissociation constant, 38 210 NMR solid acidity studies, 42 139-140 acylium ions, 42 139, 160 aldehydes, 42 162-163 alkyl carbenium ions, 42 154-157 allyl cation, 42 143-144 ammonia, 42 172-174 arenium ions, 42 150-154 carbonium ions, 42 157-160 chalcogenenonium ions, 42 161-162 cyclopentenyl cations, 42 140-143 indanyl cations, 42 144-147 ketones, 42 162,163-165 nitrogen-containing compounds, 42 165-170... 

Using the triphenylcarbonium ion as a probe it was possible to demonstrate (82) that mechanism A-l could obtain and to exclude A-2 and B from further consideration. It should be noted that if prior olefin adsorption were a necessary prerequisite for paraffin adsorption, then carbonium ions could not be formed from paraffin molecules in a system rigorously freed from olefin or olefin-forming impurities. As triphenylmethane itself is certainly not an olefin precursor, there remained only two possible sources of olefinic impurity to be considered namely, the catalyst surface and the reagents employed. The former was discounted on the grounds that it was highly improbable that either olefins or carbonium ions on the surface survived the ex-... 

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