Reaction of triphenylphosphine with methyl iodide. Transfer thermodynamic quantities and various extended Brönsted treatments

Abstract

The enthalpies of solution and the apparent molar volumes have been determined in various solvents for the reactants and products of the reaction of triphenylphosphine with methyl iodide in various solvents. The rate constants, activation enthalpies, activation volumes, and the reaction enthalpies have also been determined for these reactions. Three types of extended Brönsted plots, i.e., ΔV^‡versusΔV°, δΔH^‡versusδΔH° with solvent variation, and ΔH^‡versusΔH° with variation of the nucleophile, do not show any general pattern of behaviour. The physical meaning of the various Brönsted slopes is discussed.