Term: sudden polarization
https://doi.org/10.1351/goldbook.ST07110

Definition:
The occurrence of a large intramolecular charge separation in the singlet excited state of polyenes and their derivatives twisted about a double bond. Non-symmetrical substitution or geometrical distortion is effective in polarizing the system. An example is the stabilization of the zwitterionic structure of 90° twisted ethene with one methylene group pyramidalized: ST07110.png

Related Terms:
1) intramolecular (http://doi.org/10.1351/goldbook.I03130).
2) charge separation (http://doi.org/10.1351/goldbook.C00999).
3) excited state (http://doi.org/10.1351/goldbook.E02257).
4) methylene (http://doi.org/10.1351/goldbook.M03881).

Image: Not defined (https://goldbook.iupac.org/img/inline/ST07110.png) 

Source: PAC, 1999, 71, 1919. 'Glossary of terms used in theoretical organic chemistry' on page 1964 (https://doi.org/10.1351/pac199971101919)

Citation: 'sudden polarization' 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.ST07110

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