) (filled or partly filled) and L
) (completely or partly vacant) of a molecular entity
. Examination of the mixing of frontier molecular orbitals of reacting molecular entities
affords an approach to the interpretation of reaction behaviour; this constitutes
a simplified perturbation molecular orbital
theory of chemical behaviour.
PAC, 1994, 66, 1077
(Glossary of terms used in physical organic chemistry (IUPAC Recommendations 1994))
on page 1116
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. https://doi.org/10.1351/goldbook