Answers are grounded in this paper and cite their sources.
The rate of separation into free ions of a geminate ion pair generated by photoinduced electron transfer between 9,lO-anthraquinone excited to the lowest triplet state and 1,2,4-trimethoxybenzenein 1,1,2,2-tetrachloroethane has been measured at different temperatures by nanosecond time-resolved resonance Raman spectroscopy (TR3). The intrinsic activation energy for the separation amounts to 0.04 eV, suggesting that the center-to-center interionic distance in the geminate ion pair is about 7.5 A. The activation barrier is due to a loss of electrostatic stabilization upon separation to a distance of about 9.5 A, where a solvent molecule or part of it can interpenetrate to increase the solvation energy. This suggests that the geminate ion pair is a loose ion pair but is not truly solvent separated.
No takes yet. Share an insight, caveat, or question.
Vauthey et al. (1994) studied this question.
Synapse has enriched 10 related papers. Consider them for comparative context: