Polar and steric effects of substituents in aromatic nucleophilic substitution. Reactions of 4-, 5-, and 6-substituted 1-chloro-2-nitrobenzenes with sodium thiophenoxide in methanol
The kinetics of the reactions of 4-, 5-, and 6-substituted 1-chloro-2-nitrobenzenes with sodium thiophenoxide in methanol have been determined, and the thermodynamic parameters, energy and entropy of activation, calculated. For the 5-substituted series a plot of log k against σ-values gave a ρ-value...
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| Autores principales: | , , , |
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| Formato: | JOUR |
| Acceso en línea: | http://hdl.handle.net/20.500.12110/paper_00456470_v_n_p963_Porto |
| Aporte de: |
| Sumario: | The kinetics of the reactions of 4-, 5-, and 6-substituted 1-chloro-2-nitrobenzenes with sodium thiophenoxide in methanol have been determined, and the thermodynamic parameters, energy and entropy of activation, calculated. For the 5-substituted series a plot of log k against σ-values gave a ρ-value + 5·15. The σ4-Subst values corresponding to this reaction have been estimated by regression. For the 6-substituted-series a plot of log k6-Subst against σ4-Subst parameters gave a ρ-value + 3.46 showing that the polar influence of an ortho-substitutent predominates over its steric effects. |
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