Activation of the aromatic system by the SO2CF3 group: Kinetics study and structure–reactivity relationships

✍ Scribed by Nizar El Guesmi; Taoufik Boubaker; Régis Goumont

• Publisher: John Wiley and Sons
• Year: 2010
• Tongue: English
• Weight: 228 KB
• Volume: 42
• Category: Article
• ISSN: 0538-8066
• DOI: 10.1002/kin.20446

✦ Synopsis

Abstract

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