Diazine

Diazine refers to a group of organic compounds having the molecular formula C4H4N2. Each contains a benzene ring in which two of the carbon atoms have been replaced by nitrogen. There are three isomers:
 * pyrazine (1,4-diazine)    [[image:pyrazine_simple_structure.svg]]
 * pyrimidine (1,3-diazine)    [[image:pyrimidine_simple_structure.svg]]
 * pyridazine (1,2-diazine)    [[image:pyridazine_simple_structure.svg]]

Diazene, (spelled -ene, not -ine) refers to compounds with the formula RN=NR, also called azo compounds.