The Electronic Structure of Cyclooctatetraene and the Modern Valence

Jun 1, 1995 - of cyclooctatetraene at its lowest-energy tub-shaped D2d geometry, as well as at ... Cyclooctatetraene, benzene, and cyclobutadiene are ...
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J. Phys. Chem. 1995,99, 10186-10195

10186

The Electronic Structure of Cyclooctatetraene and the Modern Valence-Bond Understanding of Antiaromaticity Peter B. Karadakov and Joseph Gerratt” School of Chemistry, University of Bristol, Cantock’s Close, Bristol BS8 1TS, United Kingdom

David L. Cooper Department of Chemistry, University of Liverpool, P.O. Box 147, Liverpool L69 3BX, United Kingdom

Mario Raimondi Dipartimento di Chimica Fisica ed Elettrochimica, Universita di Milano, Via Golgi 19, 20133 Milano, Italy Received: January 20, 1995; In Final Form: April 7, 1995@

Modern valence-bond (VB) theory, in its spin-coupled (SC) form, is used to investigate the electronic structure of cyclooctatetraene at its lowest-energy tub-shaped D2d geometry, as well as at two idealized planar geometries: a D8h regular octagon and a D4h octagon with alternating carbon-carbon bond lengths. It is ~ the eight SC orbitals comprising the active space represent equivalent, mostly found that at the D z geometry n-like, s”py(x