Dihydroimidazol-2-ylidene is a hypothetical

organic compound In chemistry, organic compounds are generally any chemical compounds that contain carbon-hydrogen or carbon-carbon bonds. Due to carbon's ability to catenate (form chains with other carbon atoms), millions of organic compounds are known. T ...

with formula C₃H₆N₂. It would be a heterocyclic compound, formally derived from

imidazolidine Imidazolidine is a heterocyclic compound (CH2)2(NH)2CH2. The parent imidazolidine is lightly studied, but related compounds substituted on one or both nitrogen centers are more common. Generally, they are colorless, polar, basic compounds. Imida ...

with two hydrogen atoms removed from carbon number 2, leaving two vacant

chemical bond A chemical bond is a lasting attraction between atoms or ions that enables the formation of molecules and crystals. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds, or through the sharing of ...

s — which makes it a

carbene In organic chemistry, a carbene is a molecule containing a neutral carbon atom with a valence of two and two unshared valence electrons. The general formula is or where the R represents substituents or hydrogen atoms. The term "carbene" ma ...

. Although carbenes in general are extremely short-lived, some derivatives of this compound are surprisingly stable, and form an important class of the

persistent carbene A persistent carbene (also known as stable carbene) is a type of carbene demonstrating particular stability. The best-known examples and by far largest subgroup are the ''N''-heterocyclic carbenes (NHC) (sometimes called Arduengo carbenes), for ex ...

s. They include the first stable carbenes postulated (but not isolated) by Hans-Werner Wanzlick around 1960. Wanzlick1

They also include an example of the (saturated) imidazolin-2-ylidene (

) reported by A.J. Arduengo in 1995.

References

Carbenes Imidazolines Hypothetical chemical compounds {{heterocyclic-stub