Abstract
The rate kP of ionic and polar reactions in solutions is known to be sensitive to the applied pressure P. In the present work, structural and dielectric contributions to kP are expressed explicitly as functions of P. The pressure dependence of the volume and the dielectric constant of the solvent are described by the Tait equation. The model predicts the relation ln (kP/k0)=–νP/B–µ ln(1 +P/B) where ν, µ and B are adjustable parameters. This expression fits remarkably well the kinetic data of 11 ionic and polar reactions up to 45 kbar. The resulting activation volume is ΔV[graphic omitted]P=ΔV[graphic omitted]∞+(ΔV[graphic omitted]0–ΔV[graphic omitted]∞)/(1 +P/B) where the limiting values of ΔV[graphic omitted]P at zero and infinite pressures are expressed in terms of intrinsic volume changes in the reactants and in the surrounding solvent, and by the strength of the electrostatic interaction. The results suggest that for ionic and polar reactions, the structural and the dielectric contributions to the activation volume can be separated objectively, using a single solvent. The meaning and the significance of the various parameters are discussed.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callMore From: Journal of the Chemical Society, Faraday Transactions 1: Physical Chemistry in Condensed Phases
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
