Time-resolved electron spin resonance study of spin–lattice relaxation in the radical anion of 2,3,5,6-tetraisopropylnitrobenzene

Abstract

Radicals present in the flash-photolysis of 2,3,5,6-tetraisopropylnitrobenzene in various solvents were identified. In amine solvents transient spectra were observed from two isomers of the radical anion. These spectra exhibited electron spin polarization (CIDEP) and an attempt was made to measure the hyperfine dependence of the spin–lattice relaxation of the most abundant radical from analysis of the decay of the polarized signals. Within experimental error these relaxation rates but not the linewidths can be accounted for by modulation of the anisotropic g-interaction, of electron-nuclear dipolar couplings and of the spin–rotation interaction.