Electron spin resonance study of a stable benzo[b]furanyl radical

Abstract

The structure of radicals of type (II) formed by the thermal decomposition of 2,2′-dioxo-3,3′-diphenyl-2,2′,3,3′tetrahydrobibenzo[b]furan-3-yl (I) has been studied. The approximate values of the coupling constants were determined using methyl or deuterium substitution and the e.s.r. spectra of (II) and some of its derivatives were computer-simulated. Spin densities were calculated by the INDO and McLachlan–Honeybourne methods. The calculated coupling constants were compared with those obtained by computer simulation.