{"term":{"id":"08789","title":"delocalization of electrons","longtitle":"IUPAC Gold Book - delocalization of electrons","doi":"10.1351\/goldbook.08789","code":"08789","status":"current","definitions":[{"id":1,"text":"Redistribution of electron density in a molecular entity as compared with a model assuming individual atoms in the same valence states connected by localized bonds.","notes":{"1":"Topological modes of the electron delocalization include: ribbon (one-dimensional) delocalization of \\(\\ce{\\uppi\\mbox{-}}\\) or \\(\\ce{\\upsigma\\mbox{-}electrons}\\) or both, which is typical of linear conjugated polymers that are therefore termed one-dimensional conductors;surface delocalization of \\(\\ce{\\uppi\\mbox{-}}\\) or \\(\\ce{\\upsigma\\mbox{-}electrons}\\) or both through an overlap of radially oriented orbitals of a cyclic molecule such as a molecule of cyclopropane or benzene;volume delocalization of \\(\\ce{\\upsigma\\mbox{-}electrons}\\) through an overlap of \\(\\ce{\\upsigma\\mbox{-}orbitals}\\) directed inside a molecular polyhedron, e.g., in tetrahedrane or carboranes.","2":"A delocalized electron is not associated with a particular atom or particular covalent bond but occupies an extended orbital spread over several to many atoms or the whole lattice.","3":"Extensive delocalization of electrons is typical of metals, semiconductors, graphite, conjugated polymers, polysilanes, boranes, conjugated compounds such as organic dyes and others."},"links":[{"term":"conductors","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08774"},{"term":"conjugated polymers","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08785"},{"term":"extent of electron delocalization","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08818"},{"term":"lattice","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08835"},{"term":"molecular orbital theory","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08841"},{"term":"polysilanes","url":"https:\/\/goldbook.iupac.org\/\/terms\/view\/08899"}],"sources":["PAC, 2022, 94, 15. 'Glossary of terms relating to electronic, photonic and magnetic properties of polymers (IUPAC Recommendations 2021)' on page 22 (https:\/\/doi.org\/10.1515\/pac-2020-0501)"]}],"altoutputs":{"html":"https:\/\/goldbook.iupac.org\/terms\/view\/08789\/html","xml":"https:\/\/goldbook.iupac.org\/terms\/view\/08789\/xml","plain":"https:\/\/goldbook.iupac.org\/terms\/view\/08789\/plain"},"citation":"Citation: 'delocalization of electrons' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. 10.1351\/goldbook.08789","license":"The IUPAC Gold Book is licensed under Creative Commons Attribution-ShareAlike CC BY-SA 4.0 International (https:\/\/creativecommons.org\/licenses\/by-sa\/4.0\/) for individual terms.","collection":"If you are interested in licensing the Gold Book for commercial use, please contact the IUPAC Executive Director at executivedirector@iupac.org .","disclaimer":"The International Union of Pure and Applied Chemistry (IUPAC) is continuously reviewing and, where needed, updating terms in the Compendium of Chemical Terminology (the IUPAC Gold Book). Users of these terms are encouraged to include the version of a term with its use and to check regularly for updates to term definitions that you are using.","accessed":"2026-04-18T09:00:13+00:00"}}