N–H bond dissociation energies, reduction potentials and pKas of multisubstituted anilines and aniline radical cations
- 1 January 1995
- journal article
- Published by Royal Society of Chemistry (RSC) in Journal of the Chemical Society, Perkin Transactions 2
- No. 1,p. 61-65
- https://doi.org/10.1039/p29950000061
Abstract
The one-electron reduction potential and the pKa of 10 ortho-, meta- and para-substituted aniline radical cations have been determined by means of pulse radiolysis. The N–H bond dissociation energies of the corresponding anilines were also determined using a thermodynamic cycle. All three properties of the aniline radical cations and the corresponding anilines were shown to be linearly dependent on the sum of the Brown substituent constants, Σσ+. A conditional scale for ortho substituents was also derived (σo += 0.73σp +). The results from this work along with previously published results have been used to derive a linear free energy relationship between one-electron reduction potentials of benzene radical cations and the substituent pattern. In addition an equation for the calculation of X–Y bond dissociation energies of arbitrarily substituted molecules with the general formula Ph–X–Y is proposed.Keywords
This publication has 15 references indexed in Scilit:
- Redox and Acidity Properties of 4-Substituted Aniline Radical Cations in WaterJournal of the American Chemical Society, 1994
- Remote substituent effects on polar and non-polar covalent bondsJournal of the Chemical Society, Perkin Transactions 2, 1994
- Redox chemistry of substituted benzenes: the one-electron reduction potentials of methoxy-substituted benzene radical cationsThe Journal of Physical Chemistry, 1993
- O–H bond strengths and one-electron reduction potentials of multisubstituted phenols and phenoxyl radicals. Predictions using free energy relationshipsJournal of the Chemical Society, Perkin Transactions 2, 1993
- Electronegativity, hardness, and chemical binding in simple molecular systemsInorganic Chemistry, 1992
- A survey of Hammett substituent constants and resonance and field parametersChemical Reviews, 1991
- Rate Constants for Reactions of Inorganic Radicals in Aqueous SolutionJournal of Physical and Chemical Reference Data, 1988
- Critical Review of rate constants for reactions of hydrated electrons, hydrogen atoms and hydroxyl radicals (⋅OH/⋅O− in Aqueous SolutionJournal of Physical and Chemical Reference Data, 1988
- Theoretical and experimental evaluation of IFER for MSE (interactive free energy relationship for multiple-substituent effects). Mechanistic significance of the reaction constant and cross-interaction constantJournal of the American Chemical Society, 1984
- Rate Constants and Equilibrium Constants for Electron Transfer Reactions of Aromatic Molecules in SolutionPublished by American Chemical Society (ACS) ,1968