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Activation of the aromatic system by the SO 2 CF 3 group: Kinetics study and structure–reactivity relationships
Author(s) -
Guesmi Nizar El,
Boubaker Taoufik,
Goumont Régis
Publication year - 2010
Publication title -
international journal of chemical kinetics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.341
H-Index - 68
eISSN - 1097-4601
pISSN - 0538-8066
DOI - 10.1002/kin.20446
Subject(s) - chemistry , hammett equation , reaction rate constant , substituent , kinetics , reactivity (psychology) , methanol , chemical kinetics , activation energy , medicinal chemistry , computational chemistry , organic chemistry , medicine , physics , alternative medicine , pathology , quantum mechanics
The rate constants for the reaction of 2,6‐bis(trifluoromethanesulfonyl)‐4‐nitroanisole with some substituted anilines have been measured by spectrophotometric methods in methanol at various temperatures. The data are consistent with the S N Ar mechanism. The effect of substituents on the rate of reaction has been examined. Good linear relationships were obtained from the plots of log k 1 against Hammett σ para constants values at all temperature with negative ρ values (−1.68 to −1.11). Activation parameters Δ ≠ H varied from 41.6 to 54.3 kJ mol −1 and Δ ≠ S from −142.7 to −114.6 J mol −1 K −1 . The δΔ ≠ H and δΔ ≠ S reaction constants were determined from the dependence of Δ ≠ H and Δ ≠ S activation parameters on the σ substituent constants, by analogy with the Hammett equation. A plot of Δ ≠ H versus Δ ≠ S for the reaction gave good straight line with 177°C isokinetic temperature. © 2010 Wiley Periodicals, Inc. Int J Chem Kinet 42: 203–210, 2010