Thorium tetrafluoride

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Thorium(IV) fluoride
Kristallstruktur Uran(IV)-fluorid.png
3D model (JSmol)
ECHA InfoCard 100.033.857
EC Number 237-259-6
PubChem CID
Molar mass 308.03 g/mol
Appearancewhite crystals
Density 6.3 g/cm3
Melting point 1,110 °C (2,030 °F; 1,380 K)
Boiling point 1,680 °C (3,060 °F; 1,950 K)
Monoclinic, mS60
C12/c1, No. 15
Flash point Non-flammable
Related compounds
Other anions
Thorium(IV) chloride
Thorium(IV) bromide
Thorium(IV) iodide
Other cations
Protactinium(IV) fluoride
Uranium(IV) fluoride
Neptunium(IV) fluoride
Plutonium(IV) fluoride
Related compounds
Thorium dioxide
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Infobox references

Thorium(IV) fluoride (Th F4) is an inorganic chemical compound. It is a white, hygroscopic powder which can be produced by reacting thorium with fluorine gas. At temperatures above 500 °C, it reacts with atmospheric moisture to produce ThOF2. [1]

Thorium Chemical element with atomic number 90

Thorium is a weakly radioactive metallic chemical element with the symbol Th and atomic number 90. Thorium is silvery and tarnishes black when it is exposed to air, forming thorium dioxide; it is moderately hard, malleable, and has a high melting point. Thorium is an electropositive actinide whose chemistry is dominated by the +4 oxidation state; it is quite reactive and can ignite in air when finely divided.

Fluorine Chemical element with atomic number 9

Fluorine is a chemical element with the symbol F and atomic number 9. It is the lightest halogen and exists as a highly toxic pale yellow diatomic gas at standard conditions. As the most electronegative element, it is extremely reactive, as it reacts with almost all other elements, except for helium and neon.

Chemical compound Substance composed of multiple elements

A chemical compound is a chemical substance composed of many identical molecules composed of atoms from more than one element held together by chemical bonds. Two atoms of the same element bonded in a molecule do not form a chemical compound, since this would require two different elements.



Despite its (mild) radioactivity, thorium fluoride is used as an antireflection material in multilayered optical coatings. It has excellent optical transparency in the range 0.35–12 µm, and its radiation is primarily due to alpha particles, which can be easily stopped by a thin cover layer of another material. [2] [3]

Alpha particle helium-4 nucleus; a particles consisting of two protons and two neutrons bound together

Alpha particles, also called alpha ray or alpha radiation, consist of two protons and two neutrons bound together into a particle identical to a helium-4 nucleus. They are generally produced in the process of alpha decay, but may also be produced in other ways. Alpha particles are named after the first letter in the Greek alphabet, α. The symbol for the alpha particle is α or α2+. Because they are identical to helium nuclei, they are also sometimes written as He2+
or 4
indicating a helium ion with a +2 charge. If the ion gains electrons from its environment, the alpha particle becomes a normal helium atom 4

Thorium fluoride was used[ when? ] in manufacturing carbon arc lamps, which provided high-intensity illumination for movie projectors and search lights. [4] [5]

See also

Related Research Articles

Lanthanum Chemical element with atomic number 57

Lanthanum is a chemical element with the symbol La and atomic number 57. It is a soft, ductile, silvery-white metal that tarnishes slowly when exposed to air and is soft enough to be cut with a knife. It is the eponym of the lanthanide series, a group of 15 similar elements between lanthanum and lutetium in the periodic table, of which lanthanum is the first and the prototype. It is also sometimes considered the first element of the 6th-period transition metals, which would put it in group 3, although lutetium is sometimes placed in this position instead. Lanthanum is traditionally counted among the rare earth elements. The usual oxidation state is +3. Lanthanum has no biological role in humans but is essential to some bacteria. It is not particularly toxic to humans but does show some antimicrobial activity.

Protactinium Chemical element with atomic number 91

Protactinium is a chemical element with the symbol Pa and atomic number 91. It is a dense, silvery-gray actinide metal which readily reacts with oxygen, water vapor and inorganic acids. It forms various chemical compounds in which protactinium is usually present in the oxidation state +5, but it can also assume +4 and even +3 or +2 states. Concentrations of protactinium in the Earth's crust are typically a few parts per trillion, but may reach up to a few parts per million in some uraninite ore deposits. Because of its scarcity, high radioactivity and high toxicity, there are currently no uses for protactinium outside scientific research, and for this purpose, protactinium is mostly extracted from spent nuclear fuel.

Thorium dioxide Chemical compound

Thorium dioxide (ThO2), also called thorium(IV) oxide, is a crystalline solid, often white or yellow in color. Also known as thoria, it is produced mainly as a by-product of lanthanide and uranium production. Thorianite is the name of the mineralogical form of thorium dioxide. It is moderately rare and crystallizes in an isometric system. The melting point of thorium oxide is 3300 °C – the highest of all known oxides. Only a few elements (including tungsten and carbon) and a few compounds (including tantalum carbide) have higher melting points. All thorium compounds are radioactive because there are no stable isotopes of thorium.

Calcium fluoride is the inorganic compound of the elements calcium and fluorine with the formula CaF2. It is a white insoluble solid. It occurs as the mineral fluorite (also called fluorspar), which is often deeply coloured owing to impurities.

Cadmium sulfide chemical compound

Cadmium sulfide is the inorganic compound with the formula CdS. Cadmium sulfide is a yellow solid. It occurs in nature with two different crystal structures as the rare minerals greenockite and hawleyite, but is more prevalent as an impurity substituent in the similarly structured zinc ores sphalerite and wurtzite, which are the major economic sources of cadmium. As a compound that is easy to isolate and purify, it is the principal source of cadmium for all commercial applications. Its vivid yellow color led to its adoption as a pigment for the yellow paint "cadmium yellow" in the 18th century.

Tungsten(VI) fluoride, also known as tungsten hexafluoride, is an inorganic compound with the formula WF6. It is a toxic, corrosive, colorless gas, with a density of about 13 g/L (roughly 11 times heavier than air.) It is one of the densest known gases under standard conditions. WF6 is commonly used by the semiconductor industry to form tungsten films, through the process of chemical vapor deposition. This layer serves as a low-resistivity metallic "interconnect". It is one of seventeen known binary hexafluorides.

Magnesium fluoride chemical compound

Magnesium fluoride is an inorganic compound with the formula MgF2. The compound is a white crystalline salt and is transparent over a wide range of wavelengths, with commercial uses in optics that are also used in space telescopes. It occurs naturally as the rare mineral sellaite.

Caesium fluoride chemical compound

Caesium fluoride or cesium fluoride is an inorganic compound usually encountered as a hygroscopic white solid. It is used in organic synthesis as a source of the fluoride anion.

Chlorine trifluoride is an interhalogen compound with the formula ClF3. This colorless, poisonous, corrosive, and extremely reactive gas condenses to a pale-greenish yellow liquid, the form in which it is most often sold (pressurized at room temperature). The compound is primarily of interest as a component in rocket fuels, in plasmaless cleaning and etching operations in the semiconductor industry, in nuclear reactor fuel processing, and other industrial operations.

Beryllium fluoride chemical compound

Beryllium fluoride is the inorganic compound with the formula BeF2. 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.

Tungsten(III) oxide (W2O3) is a compound of tungsten and oxygen. It has been reported (2006) as being grown as a thin film by atomic layer deposition at temperatures between 140 and 240 °C using W2(N(CH3)2)6 as a precursor. It is not referred to in major textbooks. Some older literature refers to the compound W2O3 but as the atomic weight of tungsten was believed at the time to be 92, i.e., approximately half the modern accepted value of 183.84, the compound actually being referred to was WO3.

Silver(II) fluoride chemical compound (AgF₂)

Silver(II) fluoride is a chemical compound with the formula AgF2. It is a rare example of a silver(II) compound. Silver usually exists in its +1 oxidation state. It is used as a fluorinating agent.

Antimony pentafluoride is the inorganic compound with the formula SbF5. This colourless, viscous liquid is a valuable Lewis acid and a component of the superacid fluoroantimonic acid, the strongest known acid formed when mixing liquid HF with liquid SbF5 in a 2:1 ratio. It is notable for its Lewis acidity and its ability to react with almost all known compounds.

Aluminium fluoride chemical compound

Aluminium fluoride refers to inorganic compounds with the formula AlF3·xH2O. They are all colorless solids. Anhydrous AlF3 is used in the production of aluminium metal. Several occur as minerals.

Arsenic triselenide chemical compound

Arsenic triselenide (As2Se3) is an inorganic chemical compound, a selenide of arsenic.

Zirconium silicate, also zirconium orthosilicate, ZrSiO4, is a chemical compound, a silicate of zirconium. It occurs in nature as zircon, a silicate mineral. Powdered zirconium silicate is also known as zircon flour.

Zinc phosphide chemical compound

Zinc phosphide (Zn3P2) is an inorganic chemical compound. It is a grey solid, although commercial samples are often dark or even black. It is used as a rodenticide. Zn3P2 is a semiconductor with a direct band gap of 1.5 eV and may have applications in photovoltaic cells. A second zinc phosphide is known, with the stoichiometry ZnP2.

Beryllium iodide chemical compound

Beryllium iodide is the chemical compound with the formula BeI2. It is very hygroscopic and reacts violently with water, forming hydroiodic acid.

Sodium bifluoride chemical compound

Sodium bifluoride is the inorganic compound with the formula NaHF2. It is a salt of sodium cation (Na+) and bifluoride anion (HF2). It is a white, water-soluble solid that decomposes upon heating. Sodium bifluoride is non-flammable, hygroscopic, and has a pungent smell. Sodium bifluoride has a number of applications in industry.

Compounds of thorium any chemical compound having at least one thorium atom

Many compounds of thorium are known: this is because thorium and uranium are the most stable and accessible actinides and are the only actinides that can be studied safely and legally in bulk in a normal laboratory. As such, they have the best-known chemistry of the actinides, along with that of plutonium, as the self-heating and radiation from them is not enough to cause radiolysis of chemical bonds as it is for the other actinides. While the later actinides from americium onwards are predominantly trivalent and behave more similarly to the corresponding lanthanides, as one would expect from periodic trends, the early actinides up to plutonium have relativistically destabilised and hence delocalised 5f and 6d electrons that participate in chemistry in a similar way to the early transition metals of group 3 through 8: thus, all their valence electrons can participate in chemical reactions, although this is not common for neptunium and plutonium.


  1. Dale L. Perry, Sidney L. Phillips (1995). Handbook of inorganic compounds. CRC Press. p. 412. ISBN   0-8493-8671-3.
  2. Rancourt, James D. (1996). Optical thin films: user handbook. SPIE Press. p. 196. ISBN   0-8194-2285-1.
  3. W. Heitmann and E. Ritter (1968). "Production and properties of vacuum evaporated films of thorium fluoride". Appl. Opt. 7 (2): 307–9. doi:10.1364/AO.7.000307. PMID   20062461.
  4. McKetta, John J. (1996). Encyclopedia of Chemical Processing and Design: Thermoplastics to Trays, Separation, Useful Capacity. CRC Press. p. 81. ISBN   0-8247-2609-X.
  5. Thorium tetrafluoride International Bio-Analytical Industries, Inc.