~14N/~15N isotope effect on the electron transfer process between phenothiazine and its radical cation

摘要

An appreciable equilibrium isotope effect has been observed for electron transfer from phenothiazine (PT) to the radica cation of its ~15N-substituted analogue ([~15N]PT+.),i.e. formula (ell) via electron paramagnetic resonance analysis of the mixed radical cations formed from mixing the [~15N]phenothiazine radical cation hexachloroantimonate and phenothiazine in acetonitrile (k=0.77±0.01 at 25 deg.C), and by physical separation of the neutral phenothiazines from the radical cation salts in the equilibrium mixture (k=0.83±0.01 at 25 deg. C).