Chemical Education Today
Letters The Electrophilic Aromatic Substitution of Fluorobenzene In the June 2003 issue, Joel Rosenthal and David Schuster published a paper entitled “The Anomalous Reactivity of Fluorobenzene in Electrophilic Aromatic Substitution and Related Phenomena” (1). The authors and the reviewers, apparently, were not aware of my publication in this Journal in 1966 entitled “The Activating Effect of Fluorine in Electrophilic Aromatic Substitution” (2). In that paper I referred to four electrophilic aromatic substitution reactions in which the para position of fluorobenzene was more reactive than any one position of benzene, and indicated that those and three additional reactions are discussed in a paper by Leon Stock and H. C. Brown (3). I also mentioned that fluorodurene is nitrated 2.31 times faster than durene itself. F
fluorodurene; rate = 2.31
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Furthermore, in the second edition of Physical Organic Chemistry (4), Louis P. Hammett writes at length on the effects of substituents on the properties of benzene derivatives and explains how their effects can be summarized by the σ values of the Hammett equation. Literature Cited 1. Rosenthal, J.; Schuster, D. J. Chem. Educ. 2003, 80, 679– 690. 2. Ault, A. J. Chem. Educ. 1966, 43, 329–330. 3. Stock, L. M.; Brown, H. C. J. Am. Chem. Soc. 1962, 84, 1668– 1673. 4. Hammett, L. P. Physical Organic Chemistry. Reaction Rates, Equilibria, and Mechanisms, 2nd ed.; McGraw-Hill: New York, 1970. Addison Ault
durene; rate = 1
Journal of Chemical Education
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Department of Chemistry Cornell College Mount Vernon, IA 52314-1098
[email protected] Vol. 81 No. 5 May 2004
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www.JCE.DivCHED.org
