Four- and two-electron rules for diatropic and paratropic ring currents in monocyclic pi systems.
The pi ring current in an even-eletron monocycle is dominated by the HOMO-LUMO transition, and hence corresponds to circulation of four electrons in a diatropic (4n + 2)-electron, but two in a paratropic (4n)-electron cycle.
Seiner
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E
School of Chemistry, University of Exeter, Stocker Road, Exeter, UK EX4 4QD. E.Steiner@exeter.ac.uk
Fowler
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