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Dysprosium(III) Fluoride
Dysprosium(III) fluoride is an inorganic compound of dysprosium with a chemical formula DyF3. Production Dysprosium(III) fluoride can be produced by mixing dysprosium(III) chloride or dysprosium(III) carbonate into 40% hydrofluoric acid. : : DyF3 can also be produced by hydrothermal reaction of dysprosium nitrate and sodium tetrafluoroborate at 200 °C. DyF3 can also be produced when dysprosium oxide and ammonium bifluoride are mixed and heated to 300 °C until the oxide is porous, and continued to heat to 700 °C. When hydrogen fluoride is introduced, a reaction occurs: : Properties Dysprosium(III) fluoride is a white, odorless solid that is insoluble in water. It has an orthorhombic crystal structure In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a r ... with the space ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysprosium(III) Chloride
Dysprosium(III) chloride (DyCl3), also known as dysprosium trichloride, is a compound of dysprosium and chlorine. It is a white to yellow solid which rapidly absorbs water on exposure to moist air to form a hexa hydrate, DyCl3·6H2O. Simple rapid heating of the hydrate causes partial hydrolysisF. T. Edelmann, P. Poremba, in: ''Synthetic Methods of Organometallic and Inorganic Chemistry'', (W. A. Herrmann, ed.), Vol. 6, Georg Thieme Verlag, Stuttgart, 1997. to an oxychloride, DyOCl. Preparation and reactions DyCl3 is often prepared by the " ammonium chloride route", starting from either Dy2O3 or the hydrated chloride DyCl3·6H2O. These methods produce (NH4)2 yCl5 :10 NH4Cl + Dy2O3 → 2 (NH4)2 yCl5 + 6 NH3 + 3 H2O :DyCl3·6H2O + ''2'' NH4Cl → (NH4)2 yCl5+ 6 H2O The pentachloride decomposes thermally according to the following equation: :(NH4)2 yCl5 → 2 NH4Cl + DyCl3 The thermolysis reaction proceeds via the intermediacy of (NH4) y2Cl7 Treating Dy2O3 with aqueou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Tetrafluoroborate
Sodium tetrafluoroborate is an inorganic compound with formula NaBF4. It is a salt that forms colorless or white water-soluble rhombic crystals and is soluble in water (108 g/100 mL) but less soluble in organic solvents. Sodium tetrafluoroborate is used in some fluxes used for brazing and to produce boron trifluoride. Preparation Sodium tetrafluoroborate can be prepared by neutralizing tetrafluoroboric acid with sodium carbonate or sodium hydroxide. :NaOH + HBF4 → NaBF4 + H2O :Na2CO3 + 2 HBF4 → 2 NaBF4 + H2O + CO2 Alternatively the chemical can be synthesized from boric acid, hydrofluoric acid, and sodium carbonate: :2H3BO3 + 8HF + Na2CO3 → 2NaBF4 + 7H2O + CO2 Reactions and uses On heating to its melting point, sodium tetrafluoroborate decomposes to sodium fluoride and boron trifluoride: :NaBF4 → NaF + BF3 It is a source of tetrafluoroborate anion, which is used in organic chemistry for the preparation of salts. Sodium tetrafluoroborate can be use ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fluorides
Fluoride (). According to this source, is a possible pronunciation in British English. is an inorganic, monatomic anion of fluorine, with the chemical formula (also written ), 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. Fluoride is the simplest fluorine anion. In terms of charge and size, the fluoride ion resembles the hydroxide ion. Fluoride ions occur on Earth in several minerals, particularly fluorite, but are present only in trace quantities in bodies of water in nature. Nomenclature Fluorides include compounds that contain ionic fluoride and those in which fluoride does not dissociate. The nomenc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Space Group
In mathematics, physics and chemistry, a space group is the symmetry group of an object in space, usually in three dimensions. The elements of a space group (its symmetry operations) are the rigid transformations of an object that leave it unchanged. In three dimensions, space groups are classified into 219 distinct types, or 230 types if chiral copies are considered distinct. Space groups are discrete cocompact groups of isometries of an oriented Euclidean space in any number of dimensions. In dimensions other than 3, they are sometimes called Bieberbach groups. In crystallography, space groups are also called the crystallographic or Fedorov groups, and represent a description of the symmetry of the crystal. A definitive source regarding 3-dimensional space groups is the ''International Tables for Crystallography'' . History Space groups in 2 dimensions are the 17 wallpaper groups which have been known for several centuries, though the proof that the list was complete was only ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Orthorhombic Crystal Structure
In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with a rectangular base (''a'' by ''b'') and height (''c''), such that ''a'', ''b'', and ''c'' are distinct. All three bases intersect at 90° angles, so the three lattice vectors remain mutually orthogonal. Bravais lattices There are four orthorhombic Bravais lattices: primitive orthorhombic, base-centered orthorhombic, body-centered orthorhombic, and face-centered orthorhombic. For the base-centered orthorhombic lattice, the primitive cell has the shape of a right rhombic prism;See , row oC, column Primitive, where the cell parameters are given as a1 = a2, α = β = 90° it can be constructed because the two-dimensional centered rectangular base layer can also be described with primitive rhombic axes. Note that the length a of the primitiv ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrogen Fluoride
Hydrogen fluoride (fluorane) is an inorganic compound with the chemical formula . This colorless gas or liquid is the principal industrial source of fluorine, often as an aqueous solution called hydrofluoric acid. It is an important feedstock in the preparation of many important compounds including pharmaceuticals and polymers, e.g. polytetrafluoroethylene (PTFE). HF is widely used in the petrochemical industry as a component of superacids. Hydrogen fluoride boils at near room temperature, much higher than other hydrogen halides. Hydrogen fluoride is an extremely dangerous gas, forming corrosive and penetrating hydrofluoric acid upon contact with moisture. The gas can also cause blindness by rapid destruction of the corneas. History In 1771 Carl Wilhelm Scheele prepared the aqueous solution, hydrofluoric acid in large quantities, although hydrofluoric acid had been known in the glass industry before then. French chemist Edmond Frémy (1814–1894) is credited with discoveri ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonium Bifluoride
Ammonium hydrogen fluoride is the inorganic compound with the formula or . 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. Structure Ammonium bifluoride, as its name indicates, contains an ammonium cation (), and a bifluoride or hydrogen(difluoride) anion (). The centrosymmetric triatomic bifluoride anion features the strongest known hydrogen bond, with a F− H length of 114 pm. and a bond energy greater than 155 kJ/mol. In solid , each ammonium cation is surrounded by four fluoride centers in a tetrahedron, with hydrogen-fluorine hydrogen bonds present between the hydrogen atoms of the ammonium ion and the fluorine atoms. Solutions contain tetrahedral cations and linear anions. Production and applications Ammonium bifluoride is a component of some etchants. It attacks silica component of glass: : Potassium bifluoride is a related more commonly used etc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysprosium Oxide
Dysprosium oxide (Dy2O3) is a sesquioxide compound of the rare earth metal dysprosium. It is a pastel yellowish-greenish, slightly hygroscopic powder having specialized uses in ceramics, glass, phosphors, lasers, as a Faraday rotator and dysprosium metal halide lamp A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...s. It can react with acids to produce the corresponding dysprosium(III) salts: :Dy2O3 + 6 HCl → 2 DyCl3 + 3 H2O References Dysprosium compounds Sesquioxides {{Inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysprosium Nitrate
Dysprosium(III) nitrate is an inorganic compound, a salt of dysprosium and nitric acid with the chemical formula Dy(NO3)3. The compound forms yellowish crystals, dissolves in water, forms a crystalline hydrate. Synthesis Anhydrous salt is obtained by the action of nitrogen dioxide on dysprosium(III) oxide: ::\mathsf The action of nitrogen dioxide on metallic dysprosium: ::\mathsf Physical properties Dysprosium(III) nitrate forms yellowish crystals. The anhydrous nitrate forms a crystalline hydrate in wet air with the ideal composition of , which melts in its own crystallization water at 88.6 °C. All hydrates (anhydrous, pentahydrate, and hexahydrate) are soluble in water and ethanol, hygroscopic. Chemical properties Hydrated dysprosium nitrate thermally decomposes to form , and further heating produces dysprosium oxide Dysprosium oxide (Dy2O3) is a sesquioxide compound of the rare earth metal dysprosium. It is a pastel yellowish-greenish, slightly hygroscopic powder havin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysprosium(III) Bromide
Dysprosium(III) bromide is an inorganic compound of bromine and dysprosium, with the chemical formula of DyBr3. Preparation Dysprosium(III) bromide can be obtained by reacting dysprosium with bromine:WebElementsChemical reactions of Dysprosium/ref> :2Dy + 3Br2 → 2DyBr3 Dysprosium bromide hexahydrate can be obtained by crystallization from its solution, which can be heated with ammonium bromide in vacuum to obtain the anhydrous form. Dysprosium(III) oxide and aluminium bromide (in the form of Al2Br6 at a high temperature react a DyAl3Br12, which decomposes to dysprosium(III) bromide at a lower temperature:杨冬梅, 于锦, 蒋军辉,等. 化学气相传输法制备无水溴化镝. 石油化工高等学校学报, 2003, 16(4). doi: 10.3969/j.issn.1006-396X.2003.04.004. : Dy2O3 + Al2Br6 → Al2O3 + 2 DyBr3 Properties Dysprosium(III) bromide is a white-gray hygroscopic solid that is soluble in water. It has a trigonal crystal structure of the bismuth(III) iodide Bismuth ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrofluoric Acid
Hydrofluoric acid is a Solution (chemistry), solution of hydrogen fluoride (HF) in water. Solutions of HF are colourless, acidic and highly Corrosive substance, corrosive. It is used to make most fluorine-containing compounds; examples include the commonly used pharmaceutical antidepressant medication fluoxetine (Prozac) and the material polytetrafluoroethylene, PTFE (Teflon). Elemental fluorine is produced from it. It is commonly used to Etching (microfabrication), etch glass and silicon wafers. Uses Production of organofluorine compounds The principal use of hydrofluoric acid is in organofluorine chemistry. Many organofluorine compounds are prepared using HF as the fluorine source, including Polytetrafluoroethylene, Teflon, fluoropolymers, fluorocarbons, and refrigeration, refrigerants such as freon. Many pharmaceuticals contain fluorine. Production of inorganic fluorides Most high-volume inorganic fluoride compounds are prepared from hydrofluoric acid. Foremost are Na3AlF6 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dysprosium(III) Carbonate
Dysprosium is the chemical element with the symbol Dy and atomic number 66. It is a rare-earth element in the lanthanide series with a metallic silver luster. Dysprosium is never found in nature as a free element, though, like other lanthanides, it is found in various minerals, such as xenotime. Naturally occurring dysprosium is composed of seven isotopes, the most abundant of which is 164Dy. Dysprosium was first identified in 1886 by Paul Émile Lecoq de Boisbaudran, but it was not isolated in pure form until the development of ion-exchange techniques in the 1950s. Dysprosium has relatively few applications where it cannot be replaced by other chemical elements. It is used for its high thermal neutron absorption cross-section in making control rods in nuclear reactors, for its high magnetic susceptibility () in data-storage applications, and as a component of Terfenol-D (a magnetostrictive material). Soluble dysprosium salts are mildly toxic, while the insoluble salts are consi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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