Halide exchange at a saturated carbon atom in dimethylformamide solvent. Comparison of experimental rates and Arrhenius parameters with values calculated by Ingold

Abstract

The rates of exchange of a strong electrolyte, tetraethylammonium chloride, with simple alkyl bromides in solvent dimethylformamide have been studied. The rate constants, activation energies, and Arrhenius log B terms are compared with those obtained by Hughes, Ingold, and Mackie, who studied reactions of the weak electrolyte lithium chloride in acetone. The results for dimethylformamide are also compared with the data calculated for Finkelstein substitutions in any solvent by de la Mare, Fowden, Hughes, Ingold, and Mackie. Special attention is given to the S_N2 and E2 reactions of t-butyl bromide with chloride ion. With one exception, Ingold's calculated values show remarkably good agreement with our experimental data.