Hückel and Möbius annulenes: relationships between their Hückel-level orbitals and their Hückel-level energies

The problem of convenient access to quantitative Hückel-level descriptions of Möbius and Hückel annulenes for undergraduate lectures about aromaticity is discussed. Frost circle, Zimmerman circle, double circle and Langler semicircular mnemonics are described. The relationship between spectra (compl...

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Bibliographic Details
Published in:Química Nova 2000-12, Vol.23 (6), p.841-844
Main Authors: Langler, Richard Francis, Salgado, Guillermo, Mendizabal, Carlos
Format: Article
Language:English
Subjects:
aromaticity
CHEMISTRY, MULTIDISCIPLINARY
circle mnemonics
Hückel theory
Online Access:Get full text
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Summary:The problem of convenient access to quantitative Hückel-level descriptions of Möbius and Hückel annulenes for undergraduate lectures about aromaticity is discussed. Frost circle, Zimmerman circle, double circle and Langler semicircular mnemonics are described. The relationship between spectra (complete sets of secular equation roots) for an isoconjugate pair of Hückel and Möbius annulenes and the corresponding acyclic polyene with one less carbon is fully developed. In addition to providing an alternative path to exact spectrum roots, this relationship provides immediate access to almost half of the eigenfunctions for an isoconjugate annulene pair. The remaining eigenfunctions may be obtained very easily.
ISSN:0100-4042
1678-7064
1678-7064
DOI:10.1590/S0100-40422000000600020