Cation radicals of N-substituted phenothiazines

Article abstract of DOI:10.1007/BF01169261

The reaction of N-substituted phenothiazines with certain acceptors (halogenated solvents CHCl₃, CH₂Br₂, CCl₄, o-chloranil, AlCl₃, SnCl₄, concentrated H₂SO₄, concentrated HNO₃ in HClO₄) has been studied by EPR spectroscopy. The hyperfine structure in the EPR spectra of the cation radicals is analyzed. To interpret the EPR spectra obtained in terms of the MNDO-PM3 method we carried out a calculation of the electronic structure of phenothiazine cation radicals containing N-CH₃ and N-CH₂R substituents. In these radical systems, there are significant steric hindrances to conformational rotation of the CH₂ substituent around the N-C bond leading to a conformation with magnetically non-equivalent protons in the methylene group. 1996 Plenum Publishing Corporation.