Persistence of Paratropic Ring Currents in Nonplanar, Tub-Shaped Geometries of 1,3,5,7-Cyclooctatetraene

Abstract

Surprisingly, the anti-aromatic paratropic ring current of the planar D4h transition state of 1,3,5,7-cyclooctatetraene (COT) survives almost all the way to the equilibrium tub-shaped D2d COT structure (plane-to-plane distance, d = 0.76 A); the current vanishes at ca. 80% of the geometric change and ca. 90% of the energy change from planar to tub geometry.