Dinitrogen difluoride

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Dinitrogen difluoride [1]
(Z)-Dinitrogen-difluoride.png
cis-dinitrogen difluoride
(E)-Dinitrogen-difluoride.png
trans-dinitrogen difluoride
(Z)-Dinitrogen-difluoride-3D-balls.png
(E)-Dinitrogen-difluoride-3D-balls.png
Names
IUPAC name
cis- or trans-dinitrogen difluoride
Other names
cis- or trans-difluorodiazene
Identifiers
3D model (JSmol)
ChemSpider
PubChem CID
  • (cis):InChI=1S/F2N2/c1-3-4-2/b4-3-
    Key: DUQAODNTUBJRGF-ONEGZZNKBY
  • (trans):InChI=1/F2N2/c1-3-4-2/b4-3+
    Key: DUQAODNTUBJRGF-ONEGZZNKBY
  • InChI=1S/F2N2/c1-3-4-2/b4-3+ Yes check.svgY
    Key: DUQAODNTUBJRGF-ARJAWSKDSA-N Yes check.svgY
  • (cis):F\N=N\F
  • (trans):F\N=N/F
Properties
FN=NF
Molar mass 66.011 g·mol−1
AppearanceColorless gas
Density 2.698 g/L
Melting point cis: less than−195 °C (−319.0 °F; 78.1 K)
trans: −172 °C (−278 °F)
Boiling point cis:−105.75 °C (−158.35 °F; 167.40 K)
trans: −111.45 °C (−168.61 °F)
cis: 0.16 D
trans: 0 D
Thermochemistry
cis: 69.5 kJ/mol
trans: 82.0 kJ/mol
Related compounds
Other anions
Azide
Other cations
Related compounds
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Dinitrogen difluoride is a chemical compound with the formula N2F2. It is a gas at room temperature, and was first identified in 1952 as the thermal decomposition product of the fluorine azide (FN3). It has the structure F−N=N−F and exists in both cis and trans isomers, as typical for diimides.

Contents

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.[ clarification needed ] 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] [ page needed ]

2 N2F2 + SiO2 → SiF4 + 2 N2O

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]

N2F4hv→Br2N2F2 + byproducts

Reactions

The cis form of difluorodiazene will react with strong fluoride ion acceptors such as antimony pentafluoride to form the linear [6] [N≡N−F]+ cation (fluorodiazonium cation [6] ) which forms a salt with the formula [N≡N−F]+[SbF6]− (fluorodiazonium hexafluoroantimonate(V)).

F−N=N−F + SbF5 → [N≡N−F]+[SbF6]−

Analogous reaction of cis-difluorodiazene with arsenic pentafluoride gives white solid salt with the formula [N≡N−F]+[AsF6]− [6] (fluorodiazonium hexafluoroarsenate(V)).

F−N=N−F + AsF5 → [N≡N−F]+[AsF6]−

In the solid phase, the observed N≡N and N−F bond distances in the [N≡N−F]+ cation are 1.089(9) and 1.257(8) Å respectively, among the shortest experimentally observed N-N and N-F bonds.

Related Research Articles

In chemistry, noble gas compounds are chemical compounds that include an element from the noble gases, group 18 of the periodic table. Although the noble gases are generally unreactive elements, many such compounds have been observed, particularly involving the element xenon.

Antimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a strong Lewis acid and a component of the superacid fluoroantimonic acid, formed upon mixing liquid HF with liquid SbF5 in 1:1 ratio. It is notable for its strong Lewis acidity and the ability to react with almost all known compounds.

<span class="mw-page-title-main">Xenon difluoride</span> Chemical compound

Xenon difluoride is a powerful fluorinating agent with the chemical formula XeF
2, and one of the most stable xenon compounds. Like most covalent inorganic fluorides it is moisture-sensitive. It decomposes on contact with water vapor, but is otherwise stable in storage. Xenon difluoride is a dense, colourless crystalline solid.

<span class="mw-page-title-main">Selenium tetrafluoride</span> Chemical compound

Selenium tetrafluoride (SeF4) is an inorganic compound. It is a colourless liquid that reacts readily with water. It can be used as a fluorinating reagent in organic syntheses (fluorination of alcohols, carboxylic acids or carbonyl compounds) and has advantages over sulfur tetrafluoride in that milder conditions can be employed and it is a liquid rather than a gas.

<span class="mw-page-title-main">Tantalum(V) fluoride</span> Chemical compound

Tantalum(V) fluoride is the inorganic compound with the formula TaF5. It is one of the principal molecular compounds of tantalum. Characteristic of some other pentafluorides, the compound is volatile but exists as an oligomer in the solid state.

<span class="mw-page-title-main">Gold(V) fluoride</span> Chemical compound

Gold(V) fluoride is the inorganic compound with the formula Au2F10. This fluoride compound features gold in its highest known oxidation state. This red solid dissolves in hydrogen fluoride but these solutions decompose, liberating fluorine.

<span class="mw-page-title-main">Dioxygenyl</span> Chemical compound

The dioxygenyl(or dioxyl) ion, O+
2, is a rarely-encountered oxycation in which both oxygen atoms have a formal oxidation state of +1/2. It is formally derived from oxygen by the removal of an electron:

<span class="mw-page-title-main">Manganese(IV) fluoride</span> Chemical compound

Manganese tetrafluoride, MnF4, is the highest fluoride of manganese. It is a powerful oxidizing agent and is used as a means of purifying elemental fluorine.

<span class="mw-page-title-main">Rhenium heptafluoride</span> Chemical compound

Rhenium heptafluoride is the compound with the formula ReF7. It is a yellow low melting solid and is the only thermally stable metal heptafluoride. It has a distorted pentagonal bipyramidal structure similar to IF7, which was confirmed by neutron diffraction at 1.5 K. The structure is non-rigid, as evidenced by electron diffraction studies.

Arsenic trifluoride is a chemical compound of arsenic and fluorine with the chemical formula AsF3. It is a colorless liquid which reacts readily with water.

<span class="mw-page-title-main">Iridium(V) fluoride</span> Chemical compound

Iridium(V) fluoride, IrF5, is a chemical compound of iridium and fluorine. A highly reactive yellow low melting solid, it has a tetrameric structure, Ir4F20, which contains octahedrally coordinated iridium atoms. This structure is shared with RuF5 and OsF5. It can be prepared by the controlled decomposition of IrF6 or the reduction of IrF6 with silicon powder or H2 in anhydrous HF.

<span class="mw-page-title-main">Bismuth pentafluoride</span> Chemical compound

Bismuth pentafluoride is an inorganic compound with the formula BiF5. It is a white solid that is highly reactive. The compound is of interest to researchers but not of particular value.

<span class="mw-page-title-main">Pentazenium</span> Polytomic cation (N–N–N–N–N)

In chemistry, the pentazenium cation is a positively-charged polyatomic ion with the chemical formula N+5 and structure N−N−N−N−N. Together with solid nitrogen polymers and the azide anion, it is one of only three poly-nitrogen species obtained in bulk quantities.

Chromium pentafluoride is the inorganic compound with the chemical formula CrF5. It is a red volatile solid that melts at 34 °C. It is the highest known chromium fluoride, since the hypothetical chromium hexafluoride has not yet been synthesized.

<span class="mw-page-title-main">Molybdenum(V) fluoride</span> Chemical compound

Molybdenum(V) fluoride is an inorganic compound with the formula MoF5. It is a hygroscopic yellow solid. Like most pentafluorides, it exists as a tetramer.

<span class="mw-page-title-main">Fluorine azide</span> Chemical compound

Fluorine azide or triazadienyl fluoride is a yellow green gas composed of nitrogen and fluorine with formula FN3. Its properties resemble those of ClN3, BrN3, and IN3. The bond between the fluorine atom and the nitrogen is very weak, leading to this substance being very unstable and prone to explosion. Calculations show the F–N–N angle to be around 102° with a straight line of 3 nitrogen atoms.

Difluoroamino sulfur pentafluoride is a gaseous chemical compound of fluorine, sulfur, and nitrogen. It is unusual in having a hexa-coordinated sulfur atom with a link to nitrogen. Other names for this substance include difluoro(pentafluorosulfur)amine, pentafluorosulfanyldifluoramine, and pentafluorosulfanyl N,N-difluoramine.

<span class="mw-page-title-main">Chlorine trifluoride oxide</span> Chemical compound

Chlorine oxide trifluoride or chlorine trifluoride oxide is a corrosive liquid molecular compound with formula ClOF3. It was developed secretly as a rocket fuel oxidiser.

<span class="mw-page-title-main">Hexafluoroarsenate</span> Chemical compound

The hexafluoroarsenate anion is a chemical species with formula AsF−6. Hexafluoroarsenate is relatively inert, being the conjugate base of the notional superacid hexafluoroarsenic acid.

Protactinium compounds are compounds containing the element protactinium. These compounds usually have protactinium in the +5 oxidation state, although these compounds can also exist in the +2, +3 and +4 oxidation states.

References

  1. ↑ Lide, David R. (1998). Handbook of Chemistry and Physics (87th ed.). Boca Raton, FL: CRC Press. pp. 4–73, 5–15, 9–46. ISBN   0-8493-0594-2.
  2. ↑ Christe, Karl O.; Dixon, David A.; Grant, Daniel J.; Haiges, Ralf; Tham, Fook S.; Vij, Ashwani; Vij, Vandana; Wang, Tsang-Hsiu; Wilson, William W. (2010-08-02). "Dinitrogen Difluoride Chemistry. Improved Syntheses of cis - and trans -N 2 F 2 , Synthesis and Characterization of N 2 F + Sn 2 F 9 − , Ordered Crystal Structure of N 2 F + Sb 2 F 11 − , High-Level Electronic Structure Calculations of cis -N 2 F 2 , trans -N 2 F 2 , F 2 N═N, and N 2 F + , and Mechanism of the trans−cis Isomerization of N 2 F 2". Inorganic Chemistry. 49 (15): 6823–6833. doi:10.1021/ic100471s. ISSN   0020-1669.
  3. ↑ Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Butterworth-Heinemann. ISBN   978-0-08-037941-8.
  4. 1 2 Sykes, A. G. (1989-07-17). Advances in Inorganic Chemistry. Academic Press. p. 171. ISBN   9780080578828 . Retrieved 21 June 2014.
  5. ↑ Leon M. Zaborowski; et al. (1973), Aaron Wold and John K. Ruff (ed.), Chlorodifluoroamine and Difluorodiazene - B. Difluorodiazene (Dinitrogen difluoride), Inorganic Syntheses (in German), vol. 14, McGraw-Hill Book Company, Inc., pp. 34–39
  6. 1 2 3 Cacace, Fulvio; Grandinetti, Felice; Pepi, Federico (1995). "Gaseous Fluorodiazonium Ions. Experimental and Theoretical Study on Formation and Structure of FN2+". Inorganic Chemistry. 34 (6): 1325–1332. doi:10.1021/ic00110a007.
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