Paramagnetic Ring Current in Cyclooctatetraene: Evidence from 1H Nuclear Magnetic Resonance Shifts of Fused Benzo Derivatives

Abstract

The ¹H n.m.r. aromatic spectral regions of benzocyclooctatetraene and several related compounds have been analyzed using the LAOCOON 3 program. Assignments are based on the analysis of the ¹³C satellite spectrum of the parent compound. Results are interpreted in terms of appreciable π-electron delocalization in the 8π-electron eight-membered rings giving rise to measurable paramagnetic anisotropic effects.