EPR measurements on the diffusionless homogeneous electron-self exchange kinetics of the nitrobenzene–nitrobenzene radical anion couple in nitrobenzene as solvent†

Abstract

Electron-self exchange rate constants of the nitrobenzene–nitrobenzene radical anion couple (NB/NB^˙–) and their temperature dependence have been measured by EPR-linebroadening effects in the so-called ‘fast exchange limit’. Nitrobenzene itself serves as solvent. The first order rate constants of these diffusionless reactions vary between 2.8 × 10⁸ and 9.7 × 10⁸ s^–1 within a temperature range of 296–353 K.

The results are compared on the basis of Marcus theory of electron transfer reactions with corresponding results of the same redox couple in solvents like DMF and CH₃CN.