Zinc azide

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:

Zinc azide

Names
IUPAC name Zinc(II) azide
Other names Zinc diazide
Identifiers
CAS Number	14215-28-2 N[EPA]
3D model (JSmol)	Interactive image
ChemSpider	26583533
PubChem CID	131722987
CompTox Dashboard (EPA)	DTXSID301337045
InChI InChI=1S/2N3.Zn/c2*1-3-2;/q2*-1;+2 Key: QFDUTPNKBRXHTC-UHFFFAOYSA-N
SMILES [N-]=[N+]=[N-].[N-]=[N+]=[N-].[Zn+2]
Properties
Chemical formula	Zn(N3)2
Molar mass	149.4 g/mol
Appearance	White solid
Density	2.559 g/cm3 (α polymorph)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). Infobox references

Zn(C₂H₅)₂ + 2 HN₃ → Zn(N₃)₂ + 2 C₂H₆

Properties

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)_2−x(N₃)_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.