Theoretical treatment of ion–molecular charge transfer reactions involving dimer radical ions

Abstract

For the first time spin evolution of radical ions participating in ion–molecular charge transfer reactions involving dimer radical ion and neutral monomer molecule (dimer–monomer charge transfer reaction) has been studied quantitatively. The peculiarity of the problem is that only a fragment (monomer) of a radical ion is changed in the course of the reaction. For this case the kinetic equations of the encounter theory for spin density matrix of a radical ion have been obtained. Calculations of EPR spectra of radical ions in the presence of dimer–monomer charge transfer reaction have been performed. The cases of small and large hyperfine coupling constants, slow and fast charge transfer reactions have been studied in detail. The shifts and broadening of the EPR spectral lines in these cases have been calculated.