Aromatic nucleophilic replacement. Part XVI. Reactions of o-fluoro- and p-fluoro-nitrobenzene and 1-fluoro-3,5-dinitrobenzene with sulphite ions, and of o- and p-fluoronitrobenzene with isopropoxide ions

Rate constants and Arrhenius parameters for the reactions of o- and p-fluoronitrobenzenes and of 1-fluoro-3,5-dinitrobenzene with sulphite ions in 60% aqueous ethanol and for the reactions of o- and p-fluoronitrobenzene with isopropoxide ions in absolute isopropyl alcohol have been measured. The results for the sulphite ion reactions have been interpreted in terms of a transition state lying closer to the reactants than to the Wheland intermediate, and those for the isopropoxide ion in terms of differential solvation of initial and transition states, with steric exclusion of solvation occuring in the transiton state of the ortho-isomer.