Accession Number : ADA139081

Title :   The Influence of Specific Reactant-Solvent Interactions on Intrinsic Activation Entropies for Outer-Sphere Electron Transfer Reactions.

Descriptive Note : Technical rept.,


Personal Author(s) : Hupp,J T ; Weaver,M J

PDF Url : ADA139081

Report Date : Nov 1983

Pagination or Media Count : 22

Abstract : The physical basis of the solvent contribution to the intrinsic activation entropy, Delta S* Sub int, for outer-sphere electron-transfer reactions in homogeneous solution is examined in terms of the entropic parameters for the constituent electrochemical half reactions. A relationship for calculating Delta S* Sub int is derived which takes into account specific reactant-solvent interactions for the isolated redox centers by employing electrochemical reaction entropy data. This relation yields rather larger and more structure-sensitive values of Delta S* Sub int than those deduced on the basis of the usual dielectric continuum treatment. These considerations indicate that the more negative values of Delta S* Sub int typically extracted from experimental kinetic data arise largely from the modification to the specific reactant-solvent interactions within the precursor complex caused by the proximity of the other redox center. (Author)

Descriptors :   *Reactants(Chemistry), *Solvents, *Chemical reactions, *Entropy, *Electron transfer, Reaction kinetics, Activation energy, Homogeneity, Solutions(Mixtures), Oxidation reduction reactions, Electrochemistry, Barriers, Value, Mathematical analysis

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE