13773-81-4

Usage

Uses

1. Used in Special Purpose Electric Bulbs:
Krypton(II) difluoride is used as a gas filler in special purpose electric bulbs, providing a stable and efficient light source.
2. Used in Metal-Vapor Discharge Tubes:
Krypton(II) difluoride is employed to initiate and sustain the arc in metal-vapor discharge tubes, such as mercury and sodium vapor lamps, enhancing their performance and efficiency.
3. Used in Surface Area Determination:
Krypton(II) difluoride is utilized in adsorption techniques to determine the surface areas of fine solids, which is crucial for various industrial and scientific applications.
4. Used in Chemical Research:
Due to its unique properties and reactivity, Krypton(II) difluoride is also used in chemical research to study its properties and potential applications in various fields.

Preparation

Krypton difluoride may be prepared by the reaction of krypton with fluorine in an electric discharge at low pressure and liquid oxygen temperature. Also it may be made by irradiating krypton with ultraviolet rays in a fluorine—argon gas mixture at liquid helium temperature (-196°F). Kr + F2 → KrF2 The product can be stored at -78°C without decomposition.

InChI:InChI=1/F2Kr/c1-3-2

Upstream product

• 75-71-8 Dichlorodifluoromethane 
• 13693-07-7 rhodium hexafluoride 
• 13693-05-5 platinum hexafluoride 
• 7782-41-4 fluorine 
• 102110-05-4 KrF₂CrF₄O 

Downstream Products

• 7783-54-2 nitrogen trifluoride 
• 13776-62-0 trans-1,2-difluorodiazine 
• 13709-42-7 neodymium(III) fluoride 
• 7790-91-2 chlorine trifluoride 
• 184851-42-1 chlorine pentafluoride 
• 10060-10-3 cerium tetrafluoride 
• 7664-39-3 hydrogen fluoride 
• 13709-56-3 PuF₄ 
• 13693-06-6 plutonium hexafluoride 
• 77744-91-3 KrF₂WOF₄ 
• 80937-33-3 oxygen 
• 7783-82-6 tungsten(VI) fluoride 
• 7783-81-5 uranium hexafluoride 
• 15195-58-1 manganese tetrafluoride 

Relevant academic research and scientific papers

X-ray crystal structures of α-KrF2, [KrF][MF6] (M = As, Sb, Bi), [Kr2F3][SbF6]·KrF2, [Kr2F3]2[SbF6] 2·KrF2, and [Kr2F3][AsF6]·[KrF][AsF6];

The crystal structures of α-KrF2 and salts containing the KrF+ and Kr2F3+ cations have been investigated for the first time using low-temperature single-crystal X-ray diffraction. The low-temperature α-phase of KrF2 crystallizes in the tetragonal space group I4/mmm with a = 4.1790(6) A, c = 6.489(1) A, Z = 2, V = 113.32(3) A3, R1 = 0.0231, and wR2 = 0.0534 at - 125 °C. The [KrF][MF6] (M = As, Sb, Bi) salts are isomorphous and isostructural and crystallize in the monoclinic space group P21/c with Z = 4. The unit cell parameters are as follows: β-[KrF][AsF6], a = 5.1753(2) A, b = 10.2019(7) A, c = 10.5763(8) A, β = 95.298(2)°, V = 556.02(6) A3, R1 = 0.0265, and wR2 = 0.0652 at - 120°C; [KrF][SbF6],a = 5.2922(6) A, b = 10.444(1) A, c = 10.796(1) A, β = 94.693-(4)°, V = 594.73(1) A3, R1 R, = 0.0266, wR2 = 0.0526 at - 113 °C; [KrF][BiF6], a = 5.336(1) A, b = 10.513(2) A, c = 11.046(2) A, β = 94.79(3)°, V = 617.6(2) A3, R1 = 0.0344, and wR2 = 0.0912 at - 130 °C. The Kr2F3+ cation was investigated in [Kr2F3][SbF6]·KrF2, [Kr2F3]2[SbF6] 2·KrF2, and [Kr2F3][AsF6]·[KrF][AsF6]. [Kr2F3]2[SbF6] 2·KrF2 crystallizes in the monoclinic P21/c space group with Z = 4 and a = 8.042(2) A, b = 30.815(6) A, c = 8.137(2) A, β = 111.945(2)°, V = 1870.1(7) A3, R1 = 0.0376, and wR2 = 0.0742 at -125 °C. [Kr2F3][SbF6]·KrF2 crystallizes in the triclinic P1 space group with Z = 2 and a = 8.032(3) A, b = 8.559(4) A, c = 8.948(4) A, α = 69.659(9)°, β = 63.75(1)°, γ = 82.60(1)°, V = 517.1(4) A3, R1 = 0.0402, and wR2 = 0.1039 at -113 °C. [Kr2F3][AsF6]·[KrF][AsF6] crystallizes in the monoclinic space group P21/c with Z = 4 and a = 6.247(1) A, b = 24.705(4) A, c = 8.8616(6) A, β = 90.304(6)°, V = 1367.6(3) A3, R1 = 0.0471 and wR2 = 0.0958 at -120 °C. The terminal Kr-F bond lengths of KrF+ and Kr2F3+ are very similar, exhibiting no crystallographically significant variation in the structures investigated (range, 1.765(3)-1.774(6) A and 1.780(7)-1.805(5) A, respectively). The Kr-F bridge bond lengths are significantly longer, with values ranging from 2.089(6) to 2.140(3) A in the KrF+ salts and from 2.027(5) to 2.065(4) A in the Kr2F3+ salts. The Kr-F bond lengths of KrF2 in [Kr2F3][SbF6]·KrF2 and [Kr2F3]2[SbF6] 2·KrF2 range from 1.868(4) to 1.888(4) A and are similar to those observed in α-KrF2 (1.894(5) A). The synthesis and Raman spectrum of the new salt, [Kr2F3][PF6]· nKrF2, are also reported. Electron structure calculations at the Hartree-Fock and local density-functional theory levels were used to calculate the gas-phase geometries, charges, Mayer bond orders, and Mayer valencies of KrF+, KrF2, Kr2F3+, and the ion pairs, [KrF][MF6] (M = P, As, Sb, Bi), and to assign their experimental vibrational frequencies.

Photolysis of Noble Gas-Fluorine Mixtures; Dimorphism in Krypton Fluoride Chemistry

The UV photolysis of krypton-fluorine mixtures at -196 deg C readily affords KrF2.Variable-temperature Raman studies on this material indicate a temperature-dependent phase transition at -80 deg C.The low-temperature UV photolysis of krypton-fluorine mixtures in the presence of Lewis acids (AsF5 or SbF5) only affords KrF2.Variable-temperature Raman studies on the resulting mixtures show that Kr2F3+SbF6-, α- and β-KrF+Sb2F11-, KrF+AsF6- and KrF+As2F11- are formed on warming the mixtures.

Synthesis and crystal structure of (Xe2F11+)2NiF6 2-

(Xe2F11+)2NiF6 2- has been prepared by the reaction between nickel difluoride, krypton difluoride, and xenon hexafluoride in anhydrous hydrogen fluoride. (Xe2F11+)2NiF6 2- crystallizes in the monoclinic space group I2/a with a = 17.477 (5) ?, b = 5.384 (6) ?, c = 21.300 (8) ?, β = 102.83 (3)°, V = 1954.2 ?3, Z = 4, and dc = 3.792 g cm-3. A structure determination using three-dimensional Mo Kα X-ray data resulted in conventional R and Rw factors of 0.070 and 0.094, respectively, for 1355 unique reflections for which I > 3σ(I). The anion NiF62- is essentially octahedral; Ni-F distances range from 1.77 (1) to 1.79 (1) ?. The Xe2Fu+ ion consists of two XeF5 groups bridged by an additional common fluorine atom. The bridge bond lengths are 2.35 (1) and 2.21 (1) ? with a bridge angle of 140.3 (6)°. (Xe2F11+)2NiF6 2- represents the first known crystal structure of a compound with two Xe2F11+ cations.

Synthesis and characterization of CrF4O, KrF2·CrF4O, and NO+CrF5O-

Chromium(VI) tetrafluoride oxide can be prepared in high yield and purity from CrO2F2 and KrF2 in HF solution. The vibrational spectra of gaseous, solid, and matrix-isolated CrF4O and its BrF5 and HF solutions are reported, as well as the 19F NMR spectra of the BrF5 and SO2ClF solutions. The data confirm for gaseous, matrix-isolated, and dissolved CrF4O a monomeric, square-pyramidal structure of symmetry C4v, and for solid CrF4O a fluorine-bridged polymeric structure. CrF4O is a strong Lewis acid, and with FNO it forms a stable NO+CrF5O- salt, which was characterized by vibrational spectroscopy. With KrF2 it forms an unstable 1:1 adduct that has in the solid phase an essentially covalent structure containing a Kr-F?Cr bridge but is completely dissociated in SO2ClF solution. With AsF5 it does not form a stable adduct at temperatures as low as -78°C, indicating that CrF4O is a weak Lewis base. It was also shown that CrF3O is a weak Lewis base and does not form a stable adduct at -78°C.

Formation of actinide hexafluorides at ambient temperatures with krypton difluoride

A second low-temperature agent, krypton difluoride, for generating volatile plutonium hexafluoride is reported (dioxygen difluoride is the only other reported agent). Plutonium hexafluoride is formed at ambient or lower temperature by the treatment of various solid substrates with krypton difluoride. Volatilization of uranium and neptunium from solid substrates using gaseous krypton difluoride is also reported for the first time. The formation of actinide hexafluorides has been confirmed for the reaction of krypton difluoride in anhydrous HF with UO2 and with uranium and neptunium fluorides at ambient temperatures. Treatment of americium dioxide with krypton difluoride did not yield americium hexafluoride under the conditions studied.