Diazine

{{Short description|Organic compound (C4H4N2); benzene with two CH groups replaced by N}}

{{Distinguish|Diazene|Diazane}}

In organic chemistry, diazines are a group of organic compounds having the molecular formula {{chem2|C4H4N2}}. Each contains a benzene ring in which two of the C-H fragments have been replaced by isolobal nitrogen.{{Cite book|chapter-url=https://www.sciencedirect.com/science/article/pii/B9780080571164500237|chapter=Aromatic and Heteroaromatic Rings|date=1991-01-01|publisher=Academic Press|doi=10.1016/B978-0-08-057116-4.50023-7 |isbn=978-0-12-451160-6|language=en |title=The Handbook of Infrared and Raman Characteristic Frequencies of Organic Molecules |last1=Lin-Vien |first1=Daimay |last2=Colthup |first2=Norman B. |last3=Fateley |first3=William G. |last4=Grasselli |first4=Jeanette G. |pages=277–306 }} There are three structural isomers:

• pyridazine (1,2-diazine) 45px
• pyrimidine (1,3-diazine) 45px
• pyrazine (1,4-diazine) 45px