M. Fujio, H. Morimoto, Hyun-Joong Kim
Dec 1, 1997
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0
Influential Citations
7
Citations
Journal
Bulletin of the Chemical Society of Japan
Abstract
The solvolysis rates of 2,2,2-trifluoro-1-(3-chlorophenyl)-1-(substituted phenyl)ethyl and 2,2,2-trifluoro-1-(3,5-dichlorophenyl)-1-(substituted phenyl)ethyl tosylates or bromides were conductimetrically measured at 25.0 °C in 80% aqueous ethanol. The 3-chlorophenyl-fixed series showed a bilinear Yukawa–Tsuno correlation with ρ = −4.81 and r = 1.41 for substituents more deactivating than 3,5-dimethyl, and with ρ = −6.19 and r = 1.57 for the substituent range more activating than 4-methyl. The bilinear correlation was interpreted in terms of the changing coplanarity of the two aryl rings. The 3,5-dichlorophenyl-fixed substrates gave an excellent linear Yukawa–Tsuno correlation for the substituents ranging from 4-MeO to 4-Cl with ρ = −5.95 and r = 1.69. The variable aryl rings in this series show the largest extent of resonance interaction with the extraordinary deactivated carbenium ion center by α-CF3 and α-(3,5-dichlorophenyl) groups in the transition state. The optimization of the geometries of 2,2,2-tr...