IUPAC > Gold Book > alphabetical index > A > alternancy symmetry
icon

IndexesDownload


alternancy symmetry

A topological property of the molecular graphs of alternant hydrocarbons which allows the carbon atoms to be divided into two subsets in such a way that no two atoms of the same subset are adjacent. A consequence of this property is the symmetrical arrangement of the energy levels of bonding and antibonding Hückel MOs relative to the level of a nonbonding orbital (energy level of the p AO of a carbon atom).
Source:
PAC, 1999, 71, 1919 (Glossary of terms used in theoretical organic chemistry) on page 1922
Interactive Link Maps
First LevelSecond LevelThird Level
GraphGraphGraph
Cite as:
IUPAC. Compendium of Chemical Terminology, 2nd ed. (the "Gold Book"). Compiled by A. D. McNaught and A. Wilkinson. Blackwell Scientific Publications, Oxford (1997). XML on-line corrected version: http://goldbook.iupac.org (2006-) created by M. Nic, J. Jirat, B. Kosata; updates compiled by A. Jenkins. ISBN 0-9678550-9-8. doi:10.1351/goldbook.
Last update: 2014-02-24; version: 2.3.3.
DOI of this term: doi:10.1351/goldbook.AT06985.
Original PDF version: http://www.iupac.org/goldbook/AT06985.pdf. The PDF version is out of date and is provided for reference purposes only. For some entries, the PDF version may be unavailable.
Current PDF version | Version for print | History of this term
picture