Dihydroimidazol-2-ylidene is a hypothetical

organic compound Some chemical authorities define an organic compound as a chemical compound that contains a carbon–hydrogen or carbon–carbon bond; others consider an organic compound to be any chemical compound that contains carbon. For example, carbon-co ...

with formula C₃H₆N₂. It would be a

heterocyclic compound A heterocyclic compound or ring structure is a cyclic compound that has atoms of at least two different elements as members of its ring(s). Heterocyclic organic chemistry is the branch of organic chemistry dealing with the synthesis, proper ...

, 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 the association of atoms or ions to form molecules, crystals, and other structures. The bond may result from the electrostatic force between oppositely charged ions as in ionic bonds or through the sharing of electrons a ...

s — which makes it a

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

. 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 an organic molecule whose natural resonance structure has a carbon atom with octet rule, incomplete octet (a carbene), but does not exhibit the tremendous instability typically associated with ...

s. They include the first stable carbenes postulated (but not isolated) by

Hans-Werner Wanzlick Hans-Werner Wanzlick (1917-1988) was a German chemist. A Professor of chemistry at Technische Universität Berlin he is notable for work on persistent carbenes and for proposing the Wanzlick equilibrium between saturated imidazolin-2-ylidenes a ...

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