三氮烷是一种含有三个氮原子的氮烷（饱和氮氢化合物），可以看作氨分子中两个氢原子被氨基所取代的产物，它的结构简式为NH₂-NH-NH₂。

Triazane (also systematically named 1,1,2,3,3-pentahydrido-1,2,3-triazy-[3]catena), or aminohydrazine is an inorganic compound with the chemical formula NH
2NHNH
2 (also written [H
2NN(H)
2NH
2] or [N
3H
5]). Triazane is the third simplest acyclic azane (the simplest are ammonia and hydrazine). It can be synthesised from hydrazine but is unstable and cannot be isolated in the free base form, only as salt forms such as triazanium sulfate. Attempts to convert triazanium salts to the free base release only diazene and ammonia. Triazane was first synthesised as a ligand of the silver complex ion: tris(μ-triazane-κN,N)disilver(2+).