π → π* transition

https://doi.org/10.1351/goldbook.P04386
An electronic transition described approximately as a promotion of an electron from a 'bonding' $\ce{\uppi\! orbital}$ to an 'antibonding' $\ce{\uppi\! orbital}$ designated as $\ce{\uppi\!^{\ast}}$.
Source:
PAC, 1996, 68, 2223. (Glossary of terms used in photochemistry (IUPAC Recommendations 1996)) on page 2266 [Terms] [Paper]
Citation: 'π → π* transition' in IUPAC Compendium of Chemical Terminology, 5th ed. International Union of Pure and Applied Chemistry; 2025. Online version 5.0.0, 2025. https://doi.org/10.1351/goldbook.P04386 RIS BibTex EndNote
Div. IIIPDFTextXMLJSON