non-Kekulé structure

https://doi.org/10.1351/goldbook.08190
Compound with unpaired electrons for which no Lewis structures are possible with all bonding electrons paired in single or double bonds.

Example 1:

Example 2:

Note: The isomer shown on the right (valence tautomer methylidenecyclopropane) is a Kekulé structure.

Source:
PAC, 2022, 94, 353. (Glossary of terms used in physical organic chemistry (IUPAC Recommendations 2021)) on page 472 [Terms] [Paper]
Citation: 'non-Kekulé structure' 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.08190 RIS BibTex EndNote
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