Difluorides are chemical compounds with two

fluorine Fluorine is a chemical element; it has Chemical symbol, symbol F and atomic number 9. It is the lightest halogen and exists at Standard temperature and pressure, standard conditions as pale yellow Diatomic molecule, diatomic gas. Fluorine is extre ...

atoms per molecule (or per formula unit). Metal difluorides are all ionic. Despite being highly ionic, the

alkaline earth metal The alkaline earth metals are six chemical elements in group (periodic table), group 2 of the periodic table. They are beryllium (Be), magnesium (Mg), calcium (Ca), strontium (Sr), barium (Ba), and radium (Ra).. The elements have very similar p ...

difluorides generally have extremely high lattice stability and are thus

insoluble In chemistry, solubility is the ability of a substance, the solute, to form a solution with another substance, the solvent. Insolubility is the opposite property, the inability of the solute to form such a solution. The extent of the solub ...

in water. The exception is

beryllium difluoride Beryllium fluoride is the inorganic compound with the formula Be F2. This white solid is the principal precursor for the manufacture of beryllium metal. Its structure resembles that of quartz, but BeF2 is highly soluble in water. Properties Ber ...

. In addition, many

transition metal In chemistry, a transition metal (or transition element) is a chemical element in the d-block of the periodic table (groups 3 to 12), though the elements of group 12 (and less often group 3) are sometimes excluded. The lanthanide and actinid ...

difluorides are water-soluble. Calcium difluoride is a notable compound. In the form of the mineral

fluorite Fluorite (also called fluorspar) is the mineral form of calcium fluoride, CaF2. It belongs to the halide minerals. It crystallizes in isometric cubic habit, although octahedral and more complex isometric forms are not uncommon. The Mohs scal ...

it is the major source of commercial fluorine. It also has an eponymic crystal structure, which is an end member of the spectrum starting from

bixbyite Bixbyite is a manganese iron oxide mineral with chemical formula: . The iron/manganese ratio is quite variable and many specimens have almost no iron. It is a metallic dark black with a Mohs hardness of 6.0 – 6.5. It is a somewhat rare mineral ...

and progressing through

pyrochlore Pyrochlore () is a mineral group of the niobium end member of the pyrochlore supergroup. Pyrochlore is also a term for the crystal structure ''F''dm. The name is from the Greek , ''fire'', and , ''green'' because it typically turns green on ignit ...

List of the difluorides

Examples of the difluorides include:

Alkaline earth metal difluorides

The alkaline earth metals all exhibit the oxidation state +2, and form difluorides. The difluoride of

radium Radium is a chemical element; it has chemical symbol, symbol Ra and atomic number 88. It is the sixth element in alkaline earth metal, group 2 of the periodic table, also known as the alkaline earth metals. Pure radium is silvery-white, ...

is however not well established due to the element's high radioactivity. *

Beryllium difluoride Beryllium fluoride is the inorganic compound with the formula Be F2. This white solid is the principal precursor for the manufacture of beryllium metal. Its structure resembles that of quartz, but BeF2 is highly soluble in water. Properties Ber ...

Magnesium fluoride Magnesium fluoride is an ionically bonded inorganic compound with the formula . The compound is a colorless to white crystalline salt and is transparent over a wide range of wavelengths, with commercial uses in optics that are also used in space ...

Calcium fluoride Calcium fluoride is the inorganic compound of the elements calcium and fluorine with the formula CaF2. It is a white solid that is practically insoluble in water. It occurs as the mineral fluorite (also called fluorspar), which is often deeply col ...

Strontium difluoride Strontium fluoride, SrF2, also called strontium difluoride and strontium(II) fluoride, is a fluoride of strontium. It is a brittle white crystalline solid. In nature, it appears as the very rare mineral strontiofluorite. Preparation Strontium fl ...

Barium fluoride Barium fluoride is an inorganic compound with the formula . It is a colorless solid that occurs in nature as the rare mineral frankdicksonite. Under standard conditions it adopts the fluorite structure and at high pressure the structure. Like ...

* Radium fluoride :

Lanthanide difluorides

* Neodymium difluoride * Samarium difluoride *

Europium difluoride Europium(II) fluoride is an inorganic compound with a chemical formula EuF2. It was first synthesized in 1937.Zhao Yongzhi, Ma Ying, Hou Shaochun, Zhang Wenjuan, Wang Jingjing, Ding Yanrong, Hao Yifan氟化亚铕研究现状 (''lit''. Research Prog ...

* Dysprosium difluoride *

Thulium difluoride Thulium(II) fluoride is one of the fluoride salts of the lanthanide metal thulium, with the chemical compound of TmF2. It can react with zirconium tetrafluoride at 900 °C to form TmZrF6, which has a hexagonal structure. In addition, low-tempe ...

Ytterbium difluoride Ytterbium(II) fluoride is a binary inorganic compound of ytterbium and fluorine with the chemical formula . Synthesis Ytterbium(II) fluoride can be obtained by reacting ytterbium(III) fluoride with ytterbium or hydrogen. :: :: Physical properti ...

Transition metal difluorides

Compounds of the form MF₂: *

Cadmium difluoride Cadmium fluoride (CdF2) is a mostly water-insoluble source of cadmium used in oxygen-sensitive applications, such as the production of metallic alloys. In extremely low concentrations (ppm), this and other fluoride compounds are used in limited me ...

Chromium(II) fluoride Chromium(II) fluoride is an inorganic compound with the formula CrF2. It exists as a blue-green iridescent solid. Chromium(II) fluoride is sparingly soluble in water, almost insoluble in alcohol, and is soluble in boiling hydrochloric acid, but is ...

* Cobalt difluoride *

Copper(II) fluoride Copper(II) fluoride or cupric fluoride is an inorganic compound with the chemical formula CuF2. The anhydrous form is a white, ionic, crystalline, hygroscopic salt with a distorted rutile-type crystal structure, similar to other fluorides of che ...

Iron(II) fluoride Iron(II) fluoride or ferrous fluoride is an inorganic compound with the molecular formula FeF2. It forms a tetrahydrate FeF2·4H2O that is often referred to by the same names. The anhydrous and hydrated forms are white crystalline solids.Dale L. ...

Manganese(II) fluoride Manganese(II) fluoride is the chemical compound composed of manganese and fluoride with the formula MnF2. It is a light pink solid, the light pink color being characteristic for manganese(II) compounds. It is made by treating manganese and diverse ...

* Mercury difluoride * Nickel difluoride * Palladium difluoride * Platinum difluoride * Silver difluoride * Vanadium difluoride *

Zinc difluoride Zinc fluoride is an inorganic chemical compound with the chemical formula . It is encountered as the anhydrous form and also as the tetrahydrate, (rhombohedral crystal structure). It has a high melting point and has the rutile structure containi ...

Post-transition metal difluorides

Lead difluoride Lead(II) fluoride is the inorganic compound with the formula Pb F2. It is a white solid. The compound is polymorphic, at ambient temperatures it exists in orthorhombic (PbCl2 type) form, while at high temperatures it is cubic ( Fluorite type). ...

Tin(II) fluoride Tin(II) fluoride, commonly referred to commercially as stannous fluoride (from Latin ', 'tin'), is a chemical compound with the formula SnF2. It is a colourless solid used as an ingredient in toothpastes. Oral health benefits Stannous fluoride is ...

Nonmetal and metalloid difluorides

Dinitrogen difluoride Dinitrogen difluoride is a chemical compound with the formula . It is a gas at room temperature, and was first identified in 1952 as the thermal decomposition product of the fluorine azide (). It has the structure and exists in both ''cis'' an ...

Oxygen difluoride Oxygen difluoride is a chemical compound with the formula . As predicted by VSEPR theory, the molecule adopts a bent molecular geometry. It is a strong oxidizer and has attracted attention in rocketry for this reason. With a boiling point of &minus ...

Dioxygen difluoride Dioxygen difluoride is a compound of fluorine and oxygen with the molecular formula O2F2. It can exist as an orange-red colored solid which melts into a red liquid at . It is an extremely strong oxidant and decomposes into oxygen and fluorine e ...

Selenoyl difluoride Selenoyl fluoride, selenoyl difluoride, selenium oxyfluoride, or selenium dioxydifluoride is a chemical compound with the formula SeO2F2. Structure The shape of the molecule is a distorted tetrahedron with the O-Se-O angle being 126.2°, the O-Se ...

Sulfur difluoride Sulfur difluoride is an inorganic compound with the chemical formula SF2. It can be generated by the reaction of sulfur dichloride and potassium fluoride or mercury(II) fluoride at low pressures: :SCl2 + 2 KF → SF2 + 2 KCl :SCl2 + HgF2 → SF2 + ...

Disulfur difluoride Disulfur difluoride is an inorganic compound with the chemical formula . It is a halide of sulfur. Structure Disulfur difluoride has a chain structure . The angle between the and planes is 87.9°, while the angles of and are equivalent, and ...

Thionyl difluoride Thionyl fluoride is the inorganic compound with the formula . This colourless gas is mainly of theoretical interest, but it is a product of the degradation of sulfur hexafluoride, an insulator in electrical equipment. The molecule adopts a distort ...

Germanium difluoride Germanium difluoride (GeF2) is a chemical compound of germanium and fluorine. It is a white solid with a melting point of 110 °C, and can be produced by reacting germanium tetrafluoride with germanium powder at 150–300 °C. Structure ...

Noble gas difluorides

*Helium difluoride (hypothetical) Wu, R. Q
"HeF2 and ArF2 molecules from first-principles study"
/ref> * Argon difluoride (predicted) *

Krypton difluoride Krypton difluoride, KrF2 is a chemical compound of krypton and fluorine. It was the first compound of krypton discovered. It is a volatile, colourless solid at room temperature. The structure of the KrF2 molecule is linear, with Kr−F distances ...

Xenon difluoride Xenon is a chemical element; it has symbol Xe and atomic number 54. It is a dense, colorless, odorless noble gas found in Earth's atmosphere in trace amounts. Although generally unreactive, it can undergo a few chemical reactions such as th ...

Radon difluoride Radon difluoride () is a compound of radon, a radioactive noble gas. Radon reacts readily with fluorine to form a solid compound, but this decomposes on attempted vaporization and its exact composition is uncertain. Calculations suggest that it ...

Bifluorides

The

bifluoride The bifluoride ion is an inorganic anion with the chemical formula . The anion is colorless. Salts of bifluoride are commonly encountered in the reactions of fluoride salts with hydrofluoric acid. The commercial production of fluorine involves ...

s contain the two fluorine atoms in a covalently bound HF₂⁻

polyatomic ion A polyatomic ion (also known as a molecular ion) is a covalent bonded set of two or more atoms, or of a metal complex, that can be considered to behave as a single unit and that usually has a net charge that is not zero, or in special c ...

rather than as F⁻ anions. *

Ammonium bifluoride Ammonium bifluoride is an inorganic compound with the formula or . It is produced from ammonia and hydrogen fluoride. This colourless salt is a glass-industrial etching, etchant and an intermediate in a once-contemplated route to hydrofluoric acid ...

Potassium bifluoride Potassium bifluoride is the inorganic compound with the formula . This colourless salt consists of the potassium cation () and the bifluoride anion (). The salt is used as an etchant for glass. Sodium bifluoride is related and is also of commerci ...

* Sodium bifluoride

Organic difluorides

Ethanedioyl difluoride Oxalyl fluoride is the organofluorine compound with the formula (COF)2. It is a fluorine, fluorinated derivative of oxalic acid. This colorless liquid is prepared by reaction of sodium fluoride with oxalyl chloride. Oxalyl fluoride is being inve ...

* Ethylidene difluoride * Carbonyl difluoride * Carbon dibromide difluoride (dibromodifluoromethane) *

Carbon dichloride difluoride Dichlorodifluoromethane (R-12) is a colorless gas popularly known by the genericized brand name Freon (as Freon-12). It is a chlorofluorocarbon halomethane (CFC) used as a refrigerant and aerosol spray propellant. In compliance with the Montreal ...

(dichlorodifluormethane) * Methyl difluoride *

Methylphosphonyl difluoride Methylphosphonyl difluoride (DF), also known as EA-1251 or difluoro, is a chemical weapon precursor. Its chemical formula is CH3POF2. It is a Schedule 1 substance under the Chemical Weapons Convention. It is used for production of sarin and so ...

Polyvinylidene difluoride Polyvinylidene fluoride or polyvinylidene difluoride (PVDF) is a highly non-reactive thermoplastic fluoropolymer produced by the polymerization of vinylidene difluoride. Its chemical formula is (C2H2F2)''n''. PVDF is a specialty plastic used i ...

References

Bibliography

* * * {{Chemistry index Fluorides