Interpretation of the electron spin resonance spectrum of the tetraphenylethylene radical anion

Abstract

The e.s.r. spectrum of the radical anion of tetraphenylethylene has been interpreted in terms of 5 sets of 4 equivalent protons. This interpretation has been explained in terms of asymmetry in each of the phenyl rings due to steric effects. The assignment of splitting constants has been based on refined molecular orbital calculations where asymmetry has been introduced by variation of the appropriate Coulomb integrals.