Nitrogen (II) fluoride

Structural formula
General
Surname	Nitrogen (II) fluoride
other names	Nitrous tetrafluoride Tetrafluorohydrazine
Molecular formula	N 2 F 4
Brief description	colorless gas
External identifiers / databases
CAS number 10036-47-2 EC number 233-114-6 ECHA InfoCard 100.030.091 PubChem 24845 Wikidata Q382867
properties
Molar mass	104.01 g mol −1
Physical state	gaseous
density	4.6 kg m −3
Melting point	−164.5 ° C
boiling point	−73 ° C
Vapor pressure	2.40 M Pa (20 ° C)
safety instructions
GHS hazard labeling no classification available
As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions .

Nitrogen (II) fluoride , also called dinitrogen tetrafluoride , is a chemical compound of the elements nitrogen and fluorine with the empirical formula N ₂ F ₄ . Here nitrogen has the oxidation state +2. The compound belongs to the group of nitrogen halides .

presentation

Nitrogen (II) fluoride can be prepared by reduction of nitrogen trifluoride synthesized are. For this purpose, it is converted in a redox reaction at an elevated temperature with a metal , for example copper , which is oxidized to copper (I) fluoride .

${\displaystyle \mathrm {2\ NF_{3}\ +\ 2\ M\ {\xrightarrow {375\cdot C}}\ N_{2}F_{4}\ +\ 2\ MF} }$

properties

At room temperature it is a colorless gas that condenses at −73 ° C and solidifies at −164.5 ° C.

Two conformers exist in equilibrium , the gauche and the trans form. Analogous to hydrazine , the trans form, in which the fluorine atoms are on a gap, is energetically more favorable - in this case by about 2 k J mol ⁻¹ . The inversion barrier between the two conformations is 12.5 kJ mol ⁻¹ .

The bond length between the nitrogen atoms is 148  pm , the NF bond length 139 pm.

Nitrogen (II) fluoride is very reactive and a powerful fluorinating agent . The NN single bond can easily be cleaved by radicals due to the -I effects due to the fluorine substituents. It can react violently with flammable substances such as hydrogen . Hydrolytically it is less stable than nitrogen trifluoride.

use

Nitrogen (II) fluoride oxidizes elemental lithium to lithium fluoride and nitride .

${\displaystyle \mathrm {10\ Li\ +\ N_{2}F_{4}\longrightarrow \ 4\ LiF\ +\ 2\ Li_{3}N} }$

Individual evidence

1. ^ ^{A b c d e f} A. F. Holleman , E. Wiberg , N. Wiberg : Textbook of Inorganic Chemistry . 101st edition. Walter de Gruyter, Berlin 1995, ISBN 3-11-012641-9 .
2. ^ Nitrogen (II) fluoride at webelements.com
3. ↑ Entry on dinitrogen tetrafluoride in the GESTIS substance database of the IFA , accessed on February 28, 2017(JavaScript required) .
4. ↑ This substance has either not yet been classified with regard to its hazardousness or a reliable and citable source has not yet been found.