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Updated: Jan 19, 2026
Nucleophilic Substitution: SN1 and SN2 Reactions
Published on: April 30, 2023
Studies on Long-Lived (Pentafluorosulfanyl)phenyl-Substituted Carbocations
Arjun Narayanan1, Kazufumi Kohno1, Archith Nirmalchandar1
1Donald P. and Katherine B. Loker Hydrocarbon Research Institute and Department of Chemistry , University of Southern California , Los Angeles , California 90089-1661 , United States.
Abstract:
A variety of long-lived carbocations containing the p-(pentafluorosulfanyl)phenyl and m-(pentafluorosulfanyl)phenyl groups have been characterized by low-temperature NMR spectroscopy. In the case of potential nonclassical carbocations substituted with the p-(pentafluorosulfanyl)phenyl substituent, deviations from linearity when the Hammett parameter (σC) is plotted versus 13C NMR shifts of the carbocationic center were observed. Plotting the experimentally derived 13C NMR shifts versus σC or σ+ of classical 4-phenyl-X substituted carbocations also provides a means to accurately back-calculate the σ+ and σC parameters of the -SF5 substituent.
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