Redistribution of the
valence-shell
electron density throughout a molecular entity as compared with some localized models (individual
atoms in their
valence states, separated bonds or fragments). Different topological modes of the electron
delocalization include:
- ribbon delocalization of either π- or σ-electrons (i.e., electrons occupying respectively π- and σ-orbitals)
- surface delocalization of σ-electrons occurring through an overlap of radially oriented
σ-orbitals of a cyclic molecule, as is the case of cyclopropane; and
- volume delocalization of σ-electrons through an overlap of
σ-orbitals directed inside a molecular polyhedron, as is the case in tetrahedrane.
Source:
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.
https://doi.org/10.1351/goldbook.
