Dinitrogen difluoride
Template:Short description <templatestyles src="Chembox/styles.css"/>
Template:Chembox AllOtherNamesTemplate:Chembox headerbarTemplate:Chembox IndexlistTemplate:Chembox JmolTemplate:Chembox ChEMBLTemplate:Chembox ECHATemplate:Chembox E numberTemplate:Chembox IUPHAR ligandTemplate:Chembox UNIITemplate:Chembox CompToxTemplate:Chembox headerbarTemplate:Chembox headerbarTemplate:Chembox headerbarTemplate:Chembox Datapage checkTemplate:Chembox Footer| Template:Chembox image sbs cell | |
| Template:Chembox image sbs cell | |
| Template:Longitem | Template:Unbulleted list |
| ChEBI | Template:Unbulleted list |
| ChemSpider | Template:Unbulleted list |
| DrugBank | Template:Unbulleted list |
| EC Number | Template:Unbulleted list |
| KEGG | Template:Unbulleted list |
| Template:Longitem | Template:Unbulleted list |
| RTECS number | Template:Unbulleted list |
| Script error: No such module "collapsible list". | |
| Script error: No such module "collapsible list". | |
| Template:Longitem | FN=NF |
| Molar mass | Template:Chem molar mass |
| Appearance | Colorless gas |
| Density | 2.698 g/L |
| Melting point | Template:Chembox CalcTemperatures |
| Boiling point | Template:Chembox CalcTemperatures |
| Template:Longitem | cis: 0.16 D trans: 0 D |
| Template:Longitem | cis: 69.5 kJ/mol trans: 82.0 kJ/mol |
| Template:Longitem | Azide |
| Template:Longitem | Template:Ubl |
| Template:Longitem | Template:Ubl |
Template:Chembox Footer/trackingScript error: No such module "TemplatePar".Template:Short description
Dinitrogen difluoride is a chemical compound with the formula Template:Chem2. It is a gas at room temperature, and was first identified in 1952 as the thermal decomposition product of the fluorine azide (Template:Chem2). It has the structure Template:Chem2 and exists in both cis and trans isomers, as typical for diimides.
Isomers
The cis isomer has C2v symmetry and the trans isomer has C2h symmetry. These isomers can interconvert, but the process is slow enough at low temperature that the two can separated by low-temperature fractionation.Script error: No such module "Unsubst". The trans isomer is less thermodynamically stable[2] but can be stored in glass vessels. The cis isomer attacks glass over a time scale of about 2 weeks to form silicon tetrafluoride and nitrous oxide:[3]Script error: No such module "Unsubst".
Preparation
Most preparations of dinitrogen difluoride give mixtures of the two isomers, but they can be prepared independently.
An aqueous method involves N,N-difluorourea with concentrated potassium hydroxide. This gives a 40% yield with three times more of the trans isomer.[4]
Difluoramine forms a solid unstable compound with potassium fluoride (or rubidium fluoride or caesium fluoride) which decomposes to dinitrogen difluoride.[4]
It can also be prepared by photolysis of tetrafluorohydrazine and bromine:[5]
Reactions
The cis form of difluorodiazene will react with strong fluoride ion acceptors such as antimony pentafluoride to form the linear[6] Template:Chem2 cation (fluorodiazonium cation[6]) which forms a salt with the formula Template:Chem2 (fluorodiazonium hexafluoroantimonate(V)).
Analogous reaction of cis-difluorodiazene with arsenic pentafluoride gives white solid salt with the formula Template:Chem2[6] (fluorodiazonium hexafluoroarsenate(V)).
In the solid phase, the observed Template:Chem2 and Template:Chem2 bond distances in the Template:Chem2 cation are 1.089(9) and 1.257(8) Å respectively, among the shortest experimentally observed N-N and N-F bonds.
References
<templatestyles src="Reflist/styles.css" />
Script error: No such module "Check for unknown parameters".Template:Nitrogen compounds