Kinetic solvent isotope effects [k(H2O)/k(D2O)] for benzyl nitrate, 4-chlorobutan-l-ol and piperidylsulphamoyl chloride. The significance of activation parameters to the mechanism of the reaction

Abstract

Kinetic solvent isotope effects (KSIE =k[H₂O]/k[D₂O]) are reported for benzyl nitrate, 4-chlorobutan-l-ol and piperidylsulphamoyl chloride. The dependences of first-order rate constants on temperature are analysed to obtain related standard activation parameters. The significance of these parameters is discussed in relation to the mechanism of reaction. Where the solvolysis involves direct solvent participation on going from initial to transition state (e.g. an S_N2 reaction), an implicit extrathermodynamic assumption in the analysis dispenses with the information which would otherwise lead to details of the reaction mechanism.