Tricyclopropylcarbinyl cations

The tricyclopropylcarbinyl cation 16 is among the earliest stable carbocations to have been prepared 2,503. It is stable even in neat sulfuric acid. Earlier studies reported the UV absorptions for this cation at 270 nm with extinction coefficient exceeding 20,000. The... 

Arnett and Hofelich measured heats of reaction of a variety of alcohols with SbF5/FS03H in sulfuryl chloride fluoride to form their respective carbocations at constant temperature (-40 °C). In this superacid medium there were no ion-pair complications126 and hence reliable calorimetric data were obtained for various cyclopropyl and phenyl substituted cations. The heats of reaction for the formation of tricyclopropylcarbinyl cation (-59.2 kcalmol ), trityl cation (-49.0 kcalmol1) and ferr-butyl cation (-35.5 kcalmol1) show that the relative order of the stabilization of the cationic center is cyclopropyl >... 

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