Xenon Difluoride

Edited By Team Careers360 | Updated on Jul 02, 2025 04:49 PM IST

In this article we will discuss different xenon compounds, xeof₂structure, xef₂ lewis structure, xenon structure.

Xenon difluoride has the chemical formula XeF₂. and The most important property of this compound is that it is a powerful fluorinating agent ( fluorinating agents are the compound that is capable of adding fluorine to any compound ). Xenon difluoride is also one of the stable compounds of xenon. As we can easily observe, xenon fluoride is an inorganic compound from its chemical formula. Xenon difluoride is a moisture-sensitive compound. Due to its sensitivity toward moisture, xenon fluoride will decompose when it comes in contact with water vapour or light. Xenon difluoride is solid with a dense and colourless texture.

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Xenon Difluoride
Xenon Structure
Q Xef2 polar or Nonpolar
Q Preparation of Xenon Difluoride
Q Structure of Xenon Difluoride
Q Xef2 h2o Gives
Q Xenon Molecular Weight
Chemical Properties

Xenon Structure

XeF₂ Lewis Structure

Lewis Structure

XeOF₂ Structure

XeOF2 Structure

Q Xef₂ polar or Nonpolar

The molecule xenon difluoride is nonpolar because of its linear shape geometry and also symmetry is present around I.e. both side of xenon atom

Q. Draw the structure of xef₂.

Structure of xef2

Q Xenon molar mass

Molar mass of xenon is 131.293 u

Q Preparation of Xenon Difluoride

Xe + F₂ → XeF₂

To proceed this reaction we have to provide energy, it may be in the form of electric discharge, radiation or heat. The product obtained I.e. XeF₂ is in solid state. And the product I.e. XeF₂ obtained in this reaction is in an impure state, so we use fractional distillation in the vacuum line to get XeF₂ in pure form.

It can also be formed from reacting between xenon and dioxygen difluoride

Q Structure of Xenon Difluoride

Xenon difluoride is a linear molecule that has a wavelength of 197 pm in vapour phase and in solid phase xenon difluoride has wavelength of 200pm.

When we observe its solid structure we can easily notice that both the fluorine atom will avoid the equatorial region and also according to VSEPR theory this molecule will have three pairs of unpaired electrons that will be present around the equatorial region of the xenon atom.

Under the pressure of 50 Gpa XeF₂ can be converted to XeF₄ and we have to note that XeF₄ is a semiconductor. The structure of XeF₄. will be the same as graphite. And if we further increase pressure I.e. above 90 Gpa then xenon difluoride will change into metallic 3d compound I.e. XeF₈

In the XeF molecule Xe—F bonds are weak. There is total bond energy of 267.8 kJ/mol in XeF₂ molecule.

Which constitute 184.1 kJ/mol for first bond energy and 83.68 kJ/mol for second bond energy.

One point to note here is that , XeF₂. is more stable than KrF₂ , Due to its bond energy I.e. only 92.05 kJ/mol.

Q Xef₂ h₂o Gives

XeF₂ is insoluble in water I.e.polar protic solvent. It is soluble in solvents like anhydrous hydrogen fluoride, and acetonitrile, BrF₅, BrF₃, IF₅ without oxidation or reduction. In hydrogen fluoride solubility of xenon difluoride XeF₂ is 167 g per 100 g HF.

2XeF₂(s)+2H₂O(l)→2Xe(g)+4HF(aq)+O₂(g).

Q Xef₂ Structure

Xenon difluoride is a linear molecule that has a wavelength of 197 pm in vapour phase and in solid phase xenon difluoride has wavelength of 200pm.When we observe its solid structure we can easily notice that both the fluorine atom will avoid the equatorial region and also according to VSEPR theory this molecule will have three pairs of unpaired electrons that will be present around the equatorial region of the xenon atom.

Q Xenon Molecular Weight

The molar mass or molecular weight of xenon atom ( xenon is an ideal gas ) is 131.293 u

Q Synthesis of Xenon Difluoride

Xe + F₂ → XeF₂

XeF₂ was discovered in 1962 by Chernick. First time it was formed by reaction between xenon and fluorine gas mixture in the electric discharge tube.

It can also be formed from reacting between xenon and dioxygen difluoride.

Q XeF

In the XeF molecule Xe—F bonds are weak. There is total bond energy of 267.8 kJ/mol in XeF₂ molecule.

Q Oxidation state of xe in xeof₄

Oxidation state of xe I.e. xenon in xeof₄ I.e. Xenon oxytetrafluoride is +6 due to higher electronegativity of fluorine.

Xenon difluoride is a linear molecule that has a wavelength of 197 pm in vapour phase and in solid phase xenon difluoride has wavelength of 200pm.

Q Oxidation number of xenon in xef₂

Oxidation state of xenon in XeF₂ is +2

Related topics link,

Q Solubility of XeF₂

There are many products which can be derived from xenon difluoride XeF₂

We can get XeF⁺ cation by reaction between xenon difluoride with strong fluorine acceptor it can be antimony pentafluoride (SbF₅)

XeF₂ + SbF₅ → XeF⁺ + SbF⁻₆

If we add xenon gas in the above solution formed then the colour of this solution will be changed from yellow to green and this will happens due to formation of paramagnetic Xe⁺₂ ion.

3Xe_(g) + Xe F⁺_(apf) + Sb F_5(l₎ ⇌ 2 Xe⁺_2(apf) + Sb F⁻_6(apf)

And the above reaction is reversible which means that if we remove xenon gas from the solution then xenon caution Xe⁺₂ will revert back to form xenon gas and XeF⁺. And the colour of the solution will also revert from green to pale yellow.

We can also precipitate dark green crystals from green solution with the help of liquid HF.

Xe⁺_{2 (apf}₎ + 4SbF⁻_{6 (apf)} → Xe⁺₂Sb₄F⁻₂₁₍_s) + 3 F⁻ _(apf)

Here the bond length between Xe—Xe is 309 pm and as we know that bond length is inversely proportional to bond strength, here in the case of Xe—Xe bond length is big I.e. 309 Pm and that’s why there is a weak bond between Xe—Xe.

Bonding in XeF₂. can be described by 3 centred and 4 electron bonds.

Another important use of XeF₂ is that it can be used as a ligand in HF solution.

My (AsF₆)2 + 4XeF₂ → [Mg(XeF₂)₄] (AsF₆)₂

In the above complex, six fluorine atoms are coordinated with magnesium atoms. And another four fluorine atom are attribute to the four xenon difluoride ligand and the other two are as a pair of cis-AsF⁻₆ ligands.

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Chemical Properties

Xenon difluoride gives substitution reaction when it is reacted with strong protonic acid like perchloric

acid.

The reaction in presence of protonic acid is given below.

It will react with NO to give nitrosyl fluoride.

It will react with sulphur trioxide.

Hydrogen will reduce XeF2 to Xe.

With fluorine, it will give higher fluoride.

It will undergo slow hydrolysis when dissolving in water.

It will reacts with SbF5 and AsF5 to form coordination complexes in which XeF2 acts as a donor of F −.

It will fluorinate ethylene to give 1,1–difluoroethane.

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Frequently Asked Questions (FAQs)

1. Why does xenon form compounds despite being a noble gas?

Xenon can form compounds because it has a relatively low ionization energy compared to other noble gases. This allows xenon to share or lose electrons more easily, especially with highly electronegative elements like fluorine. Additionally, xenon's large atomic size enables it to accommodate multiple ligands around it.

2. Why is XeF2 considered a powerful oxidizing agent?

XeF2 is a powerful oxidizing agent because of the high electronegativity of fluorine and the relatively weak Xe-F bond. It can easily release fluorine atoms, which can then oxidize other substances. The xenon atom in XeF2 is already in a high oxidation state (+2), making it eager to return to its more stable elemental form.

3. Why is XeF2 more stable than other xenon fluorides like XeF4 or XeF6?

XeF2 is more stable than XeF4 or XeF6 because it has fewer Xe-F bonds and more lone pairs on the xenon atom. The lone pairs contribute to the stability of the molecule by occupying space around the xenon atom and reducing electron-electron repulsion. Additionally, the linear geometry of XeF2 minimizes steric hindrance compared to the more complex structures of XeF4 and XeF6.

4. How does the electronegativity difference between xenon and fluorine affect the bonding in XeF2?

The large electronegativity difference between xenon (2.6) and fluorine (4.0) results in a highly polar covalent bond in XeF2. This polarity gives the Xe-F bond partial ionic character, with the fluorine atoms carrying a partial negative charge and the xenon atom carrying a partial positive charge. This polarity contributes to the molecule's reactivity and its ability to act as an oxidizing agent.

5. What is the oxidation state of xenon in XeF2?

In xenon difluoride (XeF2), the oxidation state of xenon is +2. This is because fluorine, being the most electronegative element, always has an oxidation state of -1 in compounds. Since there are two fluorine atoms, xenon must have an oxidation state of +2 to balance the charge.

6. How is xenon difluoride prepared in the laboratory?

Xenon difluoride is typically prepared by directly combining xenon gas with fluorine gas under controlled conditions. The reaction is usually carried out at high temperatures (around 400°C) and high pressures, often in the presence of a nickel catalyst. The equation for this reaction is: Xe + F2 → XeF2

7. How does the electron affinity of fluorine contribute to the stability of XeF2?

The high electron affinity of fluorine plays a crucial role in the stability of XeF2. Fluorine's strong tendency to gain electrons allows it to form a stable bond with xenon, despite xenon's usual inertness. The energy released when fluorine gains electrons partially offsets the energy required to remove electrons from xenon, making the formation of XeF2 energetically favorable. This balance between xenon's ionization energy and fluorine's electron affinity is key to the existence of XeF2.

8. Why is XeF2 stored in containers made of certain materials?

XeF2 is highly reactive and can corrode many common materials. It's typically stored in containers made of materials that resist fluorination, such as nickel or Monel metal (a nickel-copper alloy). Plastic containers made of fluoropolymers like PTFE (Teflon) are also used. These materials are chosen because they form a protective fluoride layer when exposed to XeF2, preventing further reaction.

9. What is the molecular geometry of xenon difluoride?

Xenon difluoride (XeF2) has a linear molecular geometry. The central xenon atom is bonded to two fluorine atoms in a straight line, with a bond angle of 180°. This linear structure is due to the presence of three lone pairs of electrons on the xenon atom, which arrange themselves to minimize repulsion.

10. How does the structure of XeF2 relate to VSEPR theory?

According to VSEPR (Valence Shell Electron Pair Repulsion) theory, XeF2 has an AX2E3 electron domain geometry. This means it has two bonding pairs (X) and three lone pairs (E) around the central atom (A). The three lone pairs arrange themselves in the equatorial positions, pushing the two bonding pairs to the axial positions, resulting in a linear geometry.

11. What is the hybridization of the xenon atom in XeF2?

The xenon atom in XeF2 exhibits sp3d hybridization. This hybridization involves one s orbital, three p orbitals, and one d orbital. Two of these hybrid orbitals are used for bonding with fluorine atoms, while the other three accommodate the lone pairs of electrons.

12. How does the bond length in XeF2 compare to that of F2?

The Xe-F bond in XeF2 is longer than the F-F bond in F2. The Xe-F bond length is approximately 1.98 Å, while the F-F bond length in F2 is about 1.42 Å. This difference is due to the larger size of the xenon atom compared to fluorine and the partial ionic character of the Xe-F bond.

13. What role does electron pair repulsion play in determining the shape of XeF2?

Electron pair repulsion plays a crucial role in determining the shape of XeF2. The three lone pairs on the xenon atom repel each other strongly, causing them to occupy the equatorial positions around the xenon. This forces the two bonding pairs to the axial positions, resulting in the linear geometry of XeF2. This arrangement minimizes the overall electron pair repulsion in the molecule.

14. How does XeF2 react with water?

XeF2 undergoes hydrolysis when it reacts with water. The reaction produces xenon gas, oxygen, and hydrogen fluoride. The equation for this reaction is:

15. How does XeF2 react with basic solutions?

When XeF2 reacts with basic solutions, it undergoes a disproportionation reaction. The xenon atom is both oxidized and reduced in this process. The reaction in a basic solution typically produces xenon gas, xenon trioxide, and fluoride ions:

16. How does XeF2 behave as a Lewis acid?

XeF2 can act as a Lewis acid by accepting electron pairs from Lewis bases. This is possible because the xenon atom in XeF2 has empty 5d orbitals that can accommodate additional electron pairs. For example, XeF2 can react with F- ions to form XeF3- complex ions:

17. How does the solubility of XeF2 vary in different solvents?

XeF2 shows interesting solubility behavior in different solvents:

18. What happens to XeF2 when it's heated?

When XeF2 is heated, it decomposes into its constituent elements. The decomposition reaction is:

19. How does the dipole moment of XeF2 compare to that of other molecules?

Despite being a polar molecule, XeF2 has a net dipole moment of zero. This is because the two Xe-F bonds are arranged linearly and in opposite directions, causing their individual dipoles to cancel out. This is similar to other linear molecules like CO2, but different from bent molecules like H2O, which do have a net dipole moment.

20. What is the nature of bonding in XeF2?

The bonding in XeF2 is primarily covalent but with significant ionic character. The large electronegativity difference between xenon and fluorine results in a highly polar covalent bond. Some descriptions of XeF2 include partial double bond character due to back-bonding from filled p orbitals on fluorine to empty d orbitals on xenon. This complex bonding situation contributes to the unique properties of XeF2.

21. What is the significance of XeF2 in understanding atomic structure?

The existence and properties of XeF2 have significant implications for our understanding of atomic structure:

22. What is the significance of the lone pairs in XeF2?

The three lone pairs on the xenon atom in XeF2 are crucial to its structure and reactivity. They:

23. How does the bond energy of Xe-F in XeF2 compare to other chemical bonds?

The Xe-F bond in XeF2 is relatively weak compared to many other chemical bonds. Its bond energy is approximately 130 kJ/mol, which is lower than the F-F bond in F2 (about 158 kJ/mol) and much lower than strong covalent bonds like C-C (about 348 kJ/mol). This relatively low bond energy contributes to the reactivity of XeF2 and its tendency to decompose at high temperatures.

24. What is the significance of XeF2 in the history of chemistry?

The synthesis of XeF2 in 1962 was a landmark in chemistry because it was one of the first compounds of a noble gas ever created. This discovery challenged the long-held belief that noble gases were completely inert and incapable of forming compounds. It led to a reevaluation of chemical bonding theories and opened up a new area of noble gas chemistry.

25. How does the stability of XeF2 compare to that of other noble gas compounds?

XeF2 is one of the most stable noble gas compounds. It's more stable than compounds of lighter noble gases (like krypton or argon) because xenon has lower ionization energy and can more easily form bonds. However, it's less stable than some compounds of radon, which can form even more easily due to its larger size and lower ionization energy.

26. What is the importance of XeF2 in semiconductor industry?

XeF2 has found important applications in the semiconductor industry, particularly in microfabrication processes. It's used as an isotropic gaseous etchant for silicon, silicon dioxide, and various metals. XeF2 is particularly useful because it can etch silicon without attacking many mask and structural materials like photoresist, silicon nitride, or aluminum. This selectivity makes it valuable in creating microelectromechanical systems (MEMS) and in chip manufacturing.

27. What is the role of XeF2 in understanding periodic trends?

XeF2 plays a crucial role in understanding periodic trends, particularly:

28. How does the formation of XeF2 relate to the concept of effective nuclear charge?

The formation of XeF2 is closely related to the concept of effective nuclear charge. Xenon, being a large atom, has its outer electrons relatively far from the nucleus and shielded by inner electrons. This results in a lower effective nuclear charge experienced by its valence electrons, making them more available for bonding. The relatively low effective nuclear charge of xenon's outer electrons contributes to its ability to form compounds like XeF2, despite being a noble gas.

29. Why is XeF2 considered a hypervalent compound?

XeF2 is considered a hypervalent compound because xenon exceeds its usual octet of electrons in its valence shell. In XeF2, xenon has 10 electrons in its valence shell (8 from its original configuration plus 2 from the bonds with fluorine). This expansion of the octet is possible due to xenon's ability to use its empty 5d orbitals for bonding.

30. How does the presence of XeF2 challenge the octet rule?

XeF2 challenges the octet rule because the central xenon atom has more than eight electrons in its valence shell. In XeF2, xenon has 10 valence electrons (8 from xenon, plus 2 from the two fluorine atoms). This expansion beyond the octet is possible due to xenon's ability to use its empty 5d orbitals for bonding. This hypervalent behavior of xenon in XeF2 demonstrates that the octet rule, while useful, is not universally applicable to all compounds.

31. What is the relationship between the structure of XeF2 and its infrared spectrum?

The linear structure of XeF2 is reflected in its infrared spectrum:

32. How does the reactivity of XeF2 compare to that of F2?

While both XeF2 and F2 are strong oxidizing agents, XeF2 is generally less reactive than F2. This is because the fluorine atoms in XeF2 are already in a partially reduced state (having gained some electron density from xenon), whereas in F2, the fluorine atoms are in their most oxidizing state. However, XeF2 is still a powerful oxidizer and can react with many substances that F2 can react with, often under milder conditions.

33. What is the role of XeF2 in organic synthesis?

XeF2 has found applications in organic synthesis as a mild and selective fluorinating agent. It can introduce fluorine atoms into organic molecules under relatively mild conditions. For example, it can convert alcohols to alkyl fluorides or carbonyl compounds to gem-difluorides. Its use in organic synthesis is valuable because it's less reactive and easier to handle than elemental fluorine, while still being an effective fluorinating agent.

34. How does XeF2 interact with other halogens?

XeF2 can react with other halogens, typically acting as a fluorinating agent. For example:

35. What is the significance of XeF2 in astrochemistry?

While XeF2 itself has not been detected in space, its existence on Earth has implications for astrochemistry: