Potassium fluorosilicate

Last updated
Potassium fluorosilicate
Names
Preferred IUPAC name
Potassium fluorosilicate
Other names
Potassium hexafluorosilicate(IV)
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.037.163 OOjs UI icon edit-ltr-progressive.svg
EC Number
PubChem CID
RTECS number
  • VV8400000
UNII
UN number 2655
  • InChI=1S/F6Si.2K/c1-7(2,3,4,5)6;;/q-2;2*+1
    Key: UUHPPUWEDCVPCO-UHFFFAOYSA-N
  • F[Si-2](F)(F)(F)(F)F.[K+].[K+]
Properties
K2[SiF6]
Molar mass 220.28 gmol−1 [1]
Density 2.27gcm−3, [1] 2.719gcm−3 [2]
Slightly soluble in water
Structure
cubic
Fm3m
a = 0.8134 nm
0.538.2 nm3
4
Hazards
GHS labelling:
GHS-pictogram-skull.svg
Danger
H301, H311, H331
P261, P264, P270, P271, P280, P301+P310, P302+P352, P304+P340, P311, P312, P321, P322, P330, P361, P363, P403+P233, P405, P501
Related compounds
Other cations
Ammonium hexafluorosilicate
Sodium fluorosilicate

Fluorosilicic acid

Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).

Potassium fluorosilicate is a chemical compound with the chemical formula K2[SiF6].

Contents

When doped with Potassium hexafluoromanganate(IV) ((K2[MnF6]) it forms a narrow band red producing phosphor, (often abbreviated PSF or KSF), of economic interest due to its applicability in LED lighting and displays.

Natural occurrence

Occurs naturally as Hiereatite, found in the Aeolian islands (Sicily/Italy). [3] A hexagonal form Demartinite has also been found at the rim of volcanic fumaroles in the same islands. [4]

Structure and properties

According to analysis by (Loehlin, 1984) it has space group Fm3m, with a0 = 0.8134 nm, V = 0.538.2 nm3 at 295K. The Si-F bond length is 0.1683 nm. [2] At high temperatures and pressures -beta and -gamma phases exist. [5]

Application

Potassium fluorosilicate has applications in porcelain manufacture, the preservation of timber, aluminium and magnesium smelting, and the manufacture of optical glass. [1]

Red phosphor

When doped with potassium hexafluoromanganate(IV) (K2[MnF6]), a narrow band red phosphor is produced, emitting at around 630 nm. This substance has application improving the white light quality of white LEDs that use a blue emitting LED in combination with the yellow cerium doped yttrium aluminium garnet phosphor (YAG), Y3Al5O12:Ce3+. [6]

Synthesis routes to the phosphor include co-crystallisation and co-precipitation. For example, K2[MnF6] in (40%) hydrofluoric acid with potassium fluoride can be mixed with SiO2 dissolved in (40%) hydrofluoric acid to co-precipitate the phosphor. [5]

The acronyms KSF or PSF are used for potassium fluorosilicate phosphors. [7]

See also

Related Research Articles

<span class="mw-page-title-main">Silicon</span> Chemical element, symbol Si and atomic number 14

Silicon is a chemical element; it has symbol Si and atomic number 14. It is a hard, brittle crystalline solid with a blue-grey metallic luster, and is a tetravalent metalloid and semiconductor. It is a member of group 14 in the periodic table: carbon is above it; and germanium, tin, lead, and flerovium are below it. It is relatively unreactive.

<span class="mw-page-title-main">Phosphor</span> Luminescent substance

A phosphor is a substance that exhibits the phenomenon of luminescence; it emits light when exposed to some type of radiant energy. The term is used both for fluorescent or phosphorescent substances which glow on exposure to ultraviolet or visible light, and cathodoluminescent substances which glow when struck by an electron beam in a cathode-ray tube.

Fluoride is an inorganic, monatomic anion of fluorine, with the chemical formula F
, whose salts are typically white or colorless. Fluoride salts typically have distinctive bitter tastes, and are odorless. Its salts and minerals are important chemical reagents and industrial chemicals, mainly used in the production of hydrogen fluoride for fluorocarbons. Fluoride is classified as a weak base since it only partially associates in solution, but concentrated fluoride is corrosive and can attack the skin.

<span class="mw-page-title-main">Hydrofluoric acid</span> Solution of hydrogen fluoride in water

Hydrofluoric acid is a solution of hydrogen fluoride (HF) in water. Solutions of HF are colorless, acidic and highly corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material PTFE (Teflon). Elemental fluorine is produced from it. It is commonly used to etch glass and silicon wafers.

<span class="mw-page-title-main">Potassium fluoride</span> Ionic compound (KF)

Potassium fluoride is the chemical compound with the formula KF. After hydrogen fluoride, KF is the primary source of the fluoride ion for applications in manufacturing and in chemistry. It is an alkali halide salt and occurs naturally as the rare mineral carobbiite. Solutions of KF will etch glass due to the formation of soluble fluorosilicates, although HF is more effective.

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

Hydrogen fluoride (fluorane) is an inorganic compound with chemical formula HF. It is a very poisonous, colorless gas or liquid that dissolves in water to yield an aqueous solution termed hydrofluoric acid. It is the principal industrial source of fluorine, often in the form of hydrofluoric acid, and is an important feedstock in the preparation of many important compounds including pharmaceuticals and polymers, e.g. polytetrafluoroethylene (PTFE). HF is also widely used in the petrochemical industry as a component of superacids. Due to strong and extensive hydrogen bonding, it boils at near room temperature, much higher than other hydrogen halides.

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

Tantalum pentoxide, also known as tantalum(V) oxide, is the inorganic compound with the formula Ta
2
O
5
. It is a white solid that is insoluble in all solvents but is attacked by strong bases and hydrofluoric acid. Ta
2
O
5
is an inert material with a high refractive index and low absorption, which makes it useful for coatings. It is also extensively used in the production of capacitors, due to its high dielectric constant.

<span class="mw-page-title-main">Hexafluorosilicic acid</span> Octahedric silicon compound

Hexafluorosilicic acid is an inorganic compound with the chemical formula H
2
SiF
6
. Aqueous solutions of hexafluorosilicic acid consist of salts of the cation and hexafluorosilicate anion. These salts and their aqueous solutions are colorless.

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

Ammonium bifluoride is the inorganic compound with the formula [NH4][HF2] or [NH4]F·HF. It is produced from ammonia and hydrogen fluoride. This colourless salt is a glass-etchant and an intermediate in a once-contemplated route to hydrofluoric acid.

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

Aluminium fluoride is an inorganic compound with the formula AlF3. It forms hydrates AlF3·xH2O. Anhydrous AlF3 and its hydrates are all colorless solids. Anhydrous AlF3 is used in the production of aluminium metal. Several occur as minerals.

<span class="mw-page-title-main">Hexafluorophosphate</span> Anion with the chemical formula PF6–

Hexafluorophosphate is an anion with chemical formula of [PF6]. It is an octahedral species that imparts no color to its salts. [PF6] is isoelectronic with sulfur hexafluoride, SF6, and the hexafluorosilicate dianion, [SiF6]2−, and hexafluoroantimonate [SbF6]. In this anion, phosphorus has a valence of 5. Being poorly nucleophilic, hexafluorophosphate is classified as a non-coordinating anion.

<span class="mw-page-title-main">Fluorapatite</span> Phosphate mineral

Fluorapatite, often with the alternate spelling of fluoroapatite, is a phosphate mineral with the formula Ca5(PO4)3F (calcium fluorophosphate). Fluorapatite is a hard crystalline solid. Although samples can have various color (green, brown, blue, yellow, violet, or colorless), the pure mineral is colorless, as expected for a material lacking transition metals. Along with hydroxylapatite, it can be a component of tooth enamel, but for industrial use both minerals are mined in the form of phosphate rock, whose usual mineral composition is primarily fluorapatite but often with significant amounts of the other.

<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">Bismuth trifluoride</span> Chemical compound

Bismuth(III) fluoride or bismuth trifluoride is a chemical compound of bismuth and fluorine. The chemical formula is BiF3. It is a grey-white powder melting at 649 °C.

<span class="mw-page-title-main">Fluorine</span> Chemical element, symbol F and atomic number 9

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

<span class="mw-page-title-main">Bararite</span> Halide mineral

Bararite is a natural form of ammonium fluorosilicate (also known as hexafluorosilicate or fluosilicate). It has chemical formula (NH4)2SiF6 and trigonal crystal structure. This mineral was once classified as part of cryptohalite. Bararite is named after the place where it was first described, Barari, India. It is found at the fumaroles of volcanoes (Vesuvius, Italy), over burning coal seams (Barari, India), and in burning piles of anthracite (Pennsylvania, U.S.). It is a sublimation product that forms with cryptohalite, sal ammoniac, and native sulfur.

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

Potassium heptafluorotantalate is an inorganic compound with the formula K2[TaF7]. It is the potassium salt of the heptafluorotantalate anion [TaF7]2−. This white, water-soluble solid is an intermediate in the purification of tantalum from its ores and is the precursor to the metal.

Fluorine forms a great variety of chemical compounds, within which it always adopts an oxidation state of −1. With other atoms, fluorine forms either polar covalent bonds or ionic bonds. Most frequently, covalent bonds involving fluorine atoms are single bonds, although at least two examples of a higher order bond exist. Fluoride may act as a bridging ligand between two metals in some complex molecules. Molecules containing fluorine may also exhibit hydrogen bonding. Fluorine's chemistry includes inorganic compounds formed with hydrogen, metals, nonmetals, and even noble gases; as well as a diverse set of organic compounds. For many elements the highest known oxidation state can be achieved in a fluoride. For some elements this is achieved exclusively in a fluoride, for others exclusively in an oxide; and for still others the highest oxidation states of oxides and fluorides are always equal.

<span class="mw-page-title-main">Fluorochemical industry</span> Industry dealing with chemicals from fluorine

The global market for chemicals from fluorine was about US$16 billion per year as of 2006. The industry was predicted to reach 2.6 million metric tons per year by 2015. The largest market is the United States. Western Europe is the second largest. Asia Pacific is the fastest growing region of production. China in particular has experienced significant growth as a fluorochemical market and is becoming a producer of them as well. Fluorite mining was estimated in 2003 to be a $550 million industry, extracting 4.5 million tons per year.

<span class="mw-page-title-main">Fluorocarbonate</span> Class of chemical compounds

A carbonate fluoride, fluoride carbonate, fluorocarbonate or fluocarbonate is a double salt containing both carbonate and fluoride. The salts are usually insoluble in water, and can have more than one kind of metal cation to make more complex compounds. Rare-earth fluorocarbonates are particularly important as ore minerals for the light rare-earth elements lanthanum, cerium and neodymium. Bastnäsite is the most important source of these elements. Other artificial compounds are under investigation as non-linear optical materials and for transparency in the ultraviolet, with effects over a dozen times greater than Potassium dideuterium phosphate.

References

  1. 1 2 3 4 "44495 Potassium hexafluorosilicate, 99.999% (metals basis)", www.alfa.com
  2. 1 2 Loehlin, J. H. (1984), "Redetermination of the structure of potassium hexafluorosilicate, K2SiF6", Acta Crystallogr., C40 (3): 570, Bibcode:1984AcCrC..40..570L, doi:10.1107/S0108270184004893
  3. "Hieratit", www.mineralienatlas.de
  4. GRAMACCIOLIß, CARLO MARIA; CAMPOSTRINI, ITALO (2007), "DEMARTINITE, A NEW POLYMORPH OF K2SiF6 FROM LA FOSSA CRATER, VULCANO, AEOLIAN ISLANDS, ITALY", The Canadian Mineralogist, 45 (5): 1275–1280, Bibcode:2007CaMin..45.1275G, doi:10.2113/gscanmin.45.5.1275
  5. 1 2 Verstraete, Reinert; Sijbom, Heleen F.; Joos, Jonas J.; Korthout, Katleen; Poelman, Dirk; Detavernier, Christophe; Smet, Philippe F. (2018), "Red Mn4+-Doped Fluoride Phosphors: Why Purity Matters" (PDF), ACS Applied Materials & Interfaces, 10 (22): 18845–18856, doi: 10.1021/acsami.8b01269 , PMID   29750494
  6. SIJBOM, HELEEN F.; VERSTRAETE, REINERT; JOOS, JONAS J.; POELMAN, DIRK; SMET, PHILIPPE F. (1 Sep 2017), "K2SiF6:Mn4+ as a red phosphor for displays and warm-white LEDs: a review of properties and perspectives", Optical Materials Express, 7 (9): 3332, Bibcode:2017OMExp...7.3332S, doi: 10.1364/OME.7.003332
  7. Happich, Julien (20 Nov 2017), "Differentiate or loose! Yole's analysis on LED phosphors and QDs", www.eenewseurope.com