# Isodiazene

> Mediated Wiki article. Canonical URL: https://mediated.wiki/source/Isodiazene
> Markdown URL: https://mediated.wiki/source/Isodiazene.md
> Source: https://en.wikipedia.org/wiki/Isodiazene
> Source revision: 1353371671
> License: Creative Commons Attribution-ShareAlike 4.0 International (https://creativecommons.org/licenses/by-sa/4.0/)

In [organic chemistry](/source/Organic_chemistry), an **isodiazene**, also known by the incorrectly constructed (but commonly used) name **1,1-diazene** or systematic name **diazanylidene**,[1] is an organic derivative of the parent isodiazene (H2N+=N–, also called 1,1-diimide) with general formula R1R2N+=N–. The functional group has two major resonance forms, a diazen-2-ium-1-ide form, and an aminonitrene form:

Although isodiazenes are formally [isoelectronic](/source/Isoelectronicity) with [ketones and aldehydes](/source/Carbonyl_compounds), the reactivity of this exotic functional group is very different.

In the absence of other reactants, they facilely undergo reactions in which N2 is eliminated.[2] Consequently, most isodiazenes can only be isolated in a matrix at cryogenic temperatures.[3] They are generally used to "snip out" nitrogen atoms from molecules, typically leaving two [radicals](/source/Radical_(chemistry)) that then [couple](/source/Coupling_reaction).[4]

## Preparation

There are multiple methods for the preparation of isodiazene [intermediates](/source/Reaction_intermediate):

- Oxidation of the hydrazine (R2N–NH2)[2] with [mercuric oxide](/source/Mercuric_oxide).[5]
- 1,1-Elimination of MX from R2N–NMX (M = Na, K; X = SO2Ar).[2]
- Treatment of [secondary amines](/source/Secondary_amines) with nitrene sources including [electrophilic amination](/source/Electrophilic_amination) reagents;[4] [Angeli's salt](/source/Angeli's_salt);[6][page needed] sulfuryl azides, especially [sulfuryl diazide](/source/Sulfuryl_diazide); "anomeric [amides](/source/Amide)" of the form RC(=O)N(O′)2; or an [iminoiodinane](/source/Iminoiodinane).[4]
- Reduction of nitrosamines with dithionite.[4][7]

## Stable isodiazenes

A small number of highly hindered derivatives with tertiary R groups (e.g., R1= R2 = *t-*Bu, stable at –127 °C, decomposes at –90 °C; R1—R2 = C(CH3)2CH2CH2CH2(CH3)2C, stable up to –78 °C) are isolable by preparation and chromatography or filtration at low temperature as red solutions.[8]

Isodiazenes have been observed to serve as ligands in transition metals complexes, including those of molybdenum and vanadium.[9]

## Atypical reactions

Elimination of N2 from cyclic isodiazenes is concerted, not radical:

If the reaction were radical, then a [cyclobutane](/source/Cyclobutane) would be expected. Also, the reaction exhibits [stereospecificity](/source/Stereospecificity) consistent with [Woodward and Hoffman's rules](/source/Woodward-Hoffman_rules):[2]

Isodiazenes participate in cycloaddition reactions with alkenes to generate *N*-aminoaziridines.[2]

## See also

- [Diazene](/source/Diazene)
- [Ylide](/source/Ylide)
- [Nitrene](/source/Nitrene)

## References

1. Kuznetsov, M A & Ioffe, B V (31 August 1989). "The present state of the chemistry of aminonitrenes and oxynitrenes". *Russian Chemical Reviews*. **58** (8): 732–746. [Bibcode:1989RuCRv..58..732K](https://ui.adsabs.harvard.edu/abs/1989RuCRv..58..732K). [doi:10.1070/rc1989v058n08abeh003474](https://doi.org/10.1070/rc1989v058n08abeh003474). [S2CID 250826036](https://api.semanticscholar.org/CorpusID:250826036)

1. Hanson, James Edward (21 June 2007). *I. Matrix Isolation of 1,1-Diazenes. II. Distance, Temperature, and Dynamic Solvent Effects on Electron Transfer Reactions*. California Institute of Technology. pp. 2–31. [doi:10.7907/1F5A-AC10](https://doi.org/10.7907/1F5A-AC10)

1. Bi Xihe; Wei Hao; Lu Hongjian; Song Song (Dec 9, 2025 [July 9, 2025]). "Skeletal editing of cyclic scaffolds". *CCS Chemistry*. **8**: 647-650. [doi:10.31635/ccschem.025.202506288](https://doi.org/10.31635/ccschem.025.202506288)

1. Xu Yi-An; Xiang Shao-Hua; Che Jin-Teng; Wang Yong-Bin; Tan Bin (2024). "Skeletal editing of cyclic molecules using nitrenes". *Chinese Journal of Chemistry*. **42**: 2660-2661. Wiley. [doi:10.1002/cjoc.202400342](https://doi.org/10.1002/cjoc.202400342)

1. Carey, Francis A. & Sundberg, Richard J. (2007). *Advanced Organic Chemistry. Part B: Reactions and Synthesis*. 5th ed. New York, NY: Springer. ISBN 9781601195494. [OCLC 223941000](https://www.worldcat.org/oclc/223941000)

1. Burwell, Frederick Powell (June 1970). Untitled PhD thesis on nitroso-substituted nitrogenous rings (Part I: "The synthesis and reduction of *cis*- and *trans*-1nitroso-2,4diphenyl­azetidine"; Part II: "The attempted synthesis of 1nitroso-2,7diphenyl­hexahydroazepine"). [Polytechnic Institute of Brooklyn](/source/Polytechnic_Institute_of_Brooklyn).

1. McIntyre, Daniel K. & Dervan, Peter B. (November 1982). "1,1-Di-tert-butyldiazene". *Journal of the American Chemical Society*. **104** (23): 6466–6468. [Bibcode:1982JAChS.104.6466M](https://ui.adsabs.harvard.edu/abs/1982JAChS.104.6466M). [doi:10.1021/ja00387a061](https://doi.org/10.1021/ja00387a061)

1. Dilworth, J.R. (January 2017). "Diazene, diazenido, isodiazene and hydrazido complexes". *Coordination Chemistry Reviews*. **330**: 53–94. [doi:10.1016/j.ccr.2016.09.006](https://doi.org/10.1016/j.ccr.2016.09.006)

---
Adapted from the Wikipedia article [Isodiazene](https://en.wikipedia.org/wiki/Isodiazene) by Wikipedia contributors ([contributor history](https://en.wikipedia.org/wiki/Isodiazene?action=history)). Available under [Creative Commons Attribution-ShareAlike 4.0 International](https://creativecommons.org/licenses/by-sa/4.0/). Changes may have been made.