| |||
| |||
Names | |||
---|---|---|---|
Other names Azide radical Triazirene (cyclic) | |||
Identifiers | |||
| |||
3D model (JSmol) |
| ||
ChEBI |
| ||
ChemSpider |
| ||
770 | |||
PubChem CID | |||
CompTox Dashboard (EPA) |
| ||
| |||
| |||
Properties | |||
N3 | |||
Molar mass | 42.021 g·mol−1 | ||
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Trinitrogen also known as the azide radical is an unstable molecule composed of three nitrogen atoms. Two arrangements are known: a linear form with double bonds and charge transfer, and a cyclic form. Both forms are highly unstable, though the linear form is the more stable of the two. [1] More-stable derivatives exist, such as when it acts as a ligand, and it may participate in azido nitration, which is a reaction between sodium azide and ammonium cerium nitrate. [2] [3]
The linear form of N3 was discovered in 1956 by B. A. Thrush [4] by photolysis of hydrogen azide. [5] As a linear and symmetric molecule, it has D∞h symmetry, with a nitrogen–nitrogen bond length averaging 1.8115 Å. The first excited electronic state, A2Σu, is 4.56 eV above the ground state. [1]
The cyclic form was identified in 2003 by N. Hansen and A. M. Wodtke using ultraviolet photolysis of chlorine azide. Although the reaction yielded mostly the linear form, about 20% of the molecules were cyclic. [4] [1] The ring has C2v symmetry [1] —an isosceles triangle—in contrast to the linear form that has equal N–N bond-lengths.