A variety of long-lived carbocations containing the -(pentafluorosulfanyl)phenyl and -(pentafluorosulfanyl)phenyl groups have been characterized by low-temperature NMR spectroscopy. In the case of potential nonclassical carbocations substituted with the -(pentafluorosulfanyl)phenyl substituent, deviations from linearity when the Hammett parameter (σ) is plotted versus C NMR shifts of the carbocationic center were observed. Plotting the experimentally derived C NMR shifts versus σ or σ of classical 4-phenyl-X substituted carbocations also provides a means to accurately back-calculate the σ and σ parameters of the -SF substituent.
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