Electron spin resonance spectroscopy of pyrrole radical cations

Abstract

The ESR spectra are reported for the radical cations of the following pyrrole derivatives in fluid solution: 2,5-di-t-butyl- and 2,5-diphenyl-pyrrole; N-amino-, N-phthalimido- and N-(4-aminophenyl)-2,5-dimethylpyrrole; 1,4-bis-(2,5-dimethylpyrrol-1-yl)-, 1,4-bis-(2,5-diethylpyrrol-1-yl)-, and 1-(2,5-diethylpyrrol-1-yl)-4-(2,5-dimethylpyrrol-1-yl)-benzene; 1,4-bis-(2,5-dimethylpyrrol-1-yl)-2,3,5,6-tetramethylbenzene; 1,4-bis-(2,5-dimethylpyrrol-1-yl)butane, bis-(2,5-dimethylpyrrol-1-yl)methane, and bi-(2,5-dimethylpyrrol-1-yl); and 8b,8c-diazapyracyclene. The spectra are discussed in terms of the nuclear and electronic structures of the compounds.