Zinc azide Zn(N3)2 is an inorganic compound composed of zinc cations (Zn2+) and azide anions (N−3). It is a white, explosive solid that can be prepared by the protonolysis of diethylzinc with hydrazoic acid:
3D model (JSmol)
|Molar mass||149.4 g/mol|
|Density||2.559 g/cm3 (alpha polymorph)|
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Zinc azide is a coordination polymer which crystallizes in three polymorphs, all of which feature tetrahedral zinc centers and bridging azide ligands. α-Zn(N3)2 crystallizes in the monoclinic space group and is stable, while the other two polymorphs are metastable. P21/n. β-Zn(N3)2 is trigonal, space group P3221, and γ-Zn(N3)2 is monoclinic, space group C2.
It is easily hydrolyzed, and attempts to prepare it in aqueous solution resulted in the precipitation of basic azides Zn(OH)
x (x = 0.9–1.0). Both the α- and β-forms were found to be very friction- and shock-sensitive, violently exploding in blue flashes, but can be made to decompose slowly by gentle heating, giving off nitrogen gas. In a sealed glass tube with inert atmosphere, this yields zinc nitride, Zn3N2.