[reaction: see text] Surprisingly, the anti-aromatic paratropic ring current of the planar D(4)(h) transition state of 1,3,5,7-cyclooctatetraene (COT) survives almost all the way to the equilibrium tub-shaped D(2)(d) 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.
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