dipolar compounds

https://doi.org/10.1351/goldbook.D01753
Electrically neutral molecules carrying a positive and a negative charge in one of their major canonical descriptions. In most dipolar compounds the charges are delocalized; however the term is also applied to species where this is not the case. 1,2-Dipolar compounds have the opposite charges on adjacent atoms. The term 1,3-dipolar compounds is used for those in which a significant canonical resonance form can be represented by a separation of charge over three atoms (in connection with 1,3-dipolar cycloadditions). Subclasses of 1,3-dipolar compounds include:
  1. Allyl type X=Y+–Z−↔ X−–Y+=Z↔ X+–Y–Z−↔ X−=Y–Z+ (X, Z = C, N, or O; Y = N or O)
    See: azo imides, azomethine imides, azomethine ylides, azoxy compounds, carbonyl imides, carbonyl oxides, carbonyl ylides, nitro compounds, nitrones
  2. Propargyl type X≡N+–Z−↔ X−=N+=Z↔ X−=N–Z+↔ X–N=Z (X = C or O, Z = C, N, or O)
    See: azides, diazo compounds, nitrile imides, nitrile oxides, nitrile ylides, nitrilium betaines
  3. Carbene type X:–C=Z↔ X+=C–Z− (X = C or N; Z = C, N, or O)
    See: acyl carbenes, betaines, imidoyl carbenes, vinyl carbenes
Source:
PAC, 1995, 67, 1307. (Glossary of class names of organic compounds and reactivity intermediates based on structure (IUPAC Recommendations 1995)) on page 1333 [Terms] [Paper]
Citation: 'dipolar compounds' 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.D01753 RIS BibTex EndNote
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