Derivatives of diazene (diimide),
HN=NH,
wherein both hydrogens are substituted by hydrocarbyl groups, e.g.
PhN=NPh
azobenzene or diphenyldiazene.
Source:
PAC, 1995, 67, 1307
(Glossary of class names of organic compounds and reactivity intermediates based on
structure (IUPAC Recommendations 1995))
on page 1321