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Difluoride
Difluorides are chemical compounds with two fluorine atoms per molecule (or per formula unit). Metal difluorides are all ionic compound, ionic. Despite being highly ionic, the alkaline earth metal difluorides generally have extremely high lattice stability and are thus solubility, insoluble in water. The exception is beryllium difluoride. In addition, many transition metal difluorides are water-soluble. CaF2, Calcium difluoride is a notable compound. In the form of the mineral fluorite 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 and progressing through pyrochlore. 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 is however not well established due to the element's high radioactivity. * Beryllium difluoride * Magne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 extremely Reactivity (chemistry), reactive as it reacts with all other Periodic table, elements except for the light Noble gas, noble gases. It is highly toxicity, toxic. Among the elements, fluorine ranks Abundance of the chemical elements, 24th in cosmic abundance and 13th in crustal abundance. Fluorite, the primary mineral source of fluorine, which gave the element its name, was first described in 1529; as it was added to metal ores to lower their melting points for smelting, the Latin verb meaning gave the mineral its name. Proposed as an element in 1810, fluorine proved difficult and dangerous to separate from its compounds, and several early experimenters died or sustained injuries from their attempts. Only in 1886 did French chemist He ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 properties Ytterbium(II) fluoride is a gray solid and crystallizes in the so-called 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 ... type analogous to calcium fluoride with a unit cell ''a'' axis of 559.46 pm. In the crystal structure of ytterbium(II) fluoride, the Yb2+ cation is surrounded by eight F− anions in the form of a cube, which is tetrahedrally surrounded by four Yb2+. References Fluorides Lanthanide halides Ytterbium(II) compounds Fluorite crystal structure {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 fluoride is prepared by the action of hydrofluoric acid on strontium carbonate. Structure The solid adopts the fluorite structure. In the vapour phase the SrF2 molecule is non-linear with an F−Sr−F angle of approximately 120°. This is an exception to VSEPR theory which would predict a linear structure. Ab initio calculations have been cited to propose that contributions from d orbitals in the shell below the valence shell are responsible. Another proposal is that polarization of the electron core of the strontium atom creates an approximately tetrahedral distribution of charge that interacts with the Sr−F bonds.Core Distortions and Geometries of the Difluorides and Dihydrides of Ca, Sr, and Ba Bytheway I, Gillespie RJ, Tang TH, Bad ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 not attacked by hot distilled sulfuric acid or nitric acid. Like other chromous compounds, chromium(II) fluoride is oxidized to chromium(III) oxide in air. Preparation and structure The compound is prepared by passing anhydrous hydrogen fluoride over anhydrous chromium(II) chloride. The reaction will proceed at room temperature but is typically heated to 100-200 °C to ensure completion: :CrCl2 + 2 HF → CrF2 + 2 HCl Like many difluorides, CrF2 adopts a structure like rutile with octahedral molecular geometry about Cr(II) and trigonal geometry at F−. Two of the six Cr–F bonds are long at 2.43 Å, and four are short near 2.00 Å. This distortion is a consequence of the Jahn–Teller effect that arises from the d4 elect ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Beryllium fluoride has distinctive optical properties. In the form of fluoroberyllate glass, it has the lowest refractive index for a solid at room temperature of 1.275. Its dispersive power is the lowest for a solid at 0.0093, and the nonlinear coefficient is also the lowest at 2 × 10−14. Structure and bonding The structure of solid BeF2 resembles that of cristobalite. Be2+ centers are four coordinate and tetrahedral and the fluoride centers are two-coordinate. The Be-F bond lengths are about 1.54 Å. Analogous to SiO2, BeF2 can also adopt a number of related structures. An analogy also exists between BeF2 and AlF3: both adopt extended structures at mild temperature. Gaseous and liquid BeF2 Gaseous beryllium fluoride adopts a lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 chemical formulae MF2 (where M is a metal). The dihydrate, , is blue in colour. Structure Copper(II) fluoride has a monoclinic crystal structure and cannot achieve a higher-symmetry structure. It forms rectangular prisms with a parallelogram base. Each copper ion has four neighbouring fluoride ions at 1.93 Å separation and two further away at 2.27 Å. This distorted octahedral +2coordination is a consequence of the Jahn–Teller effect in d9 copper(II), and leads to a distorted rutile structure similar to that of chromium(II) fluoride, , which is a d4 compound. Uses Cupric fluoride catalyzes the decomposition of nitric oxides in emission control systems. Copper (II) fluoride can be used to make fluorinated aromatic hydrocarbons ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 medical treatment protocols. Fluoride compounds also have significant uses in synthetic organic chemistry. The standard enthalpy has been found to be −167.39 kcal. mole−1 and the Gibbs energy of formation has been found to be −155.4 kcal. mole−1, and the heat of sublimation was determined to be 76 kcal. mole−1. Preparation Cadmium fluoride is prepared by the reaction of gaseous fluorine or hydrogen fluoride with cadmium metal or its salts, such as the chloride, oxide, or sulfate. It may also be obtained by dissolving cadmium carbonate in 40% hydrofluoric acid solution, evaporating the solution and drying in a vacuum at 150 °C. Another method of preparing it is to mix cadmium chloride and ammonium fluoride solutions, followe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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-temperature Mössbauer spectroscopy Mössbauer spectroscopy is a spectroscopic technique based on the Mössbauer effect. This effect, discovered by Rudolf Mössbauer (sometimes written "Moessbauer", German: "Mößbauer") in 1958, consists of the nearly recoil-free emission and a ... and some theoretical studies of thulium(II) fluoride have also been reported. References {{Lanthanide halides Thulium compounds Fluorides Fluorite crystal structure Lanthanide halides ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Progress of Europium(II) Fluoride). ''Chinese Rare Earths'', 2017. 38 (5): 134-140. (in Chinese) Production Europium(II) fluoride can be produced by reducing europium(III) fluoride with metallic europium or hydrogen gas.Georg Brauer: ''Handbuch der Präparativen Anorganischen Chemie''. 3., umgearb. Auflage. Band I. Enke, Stuttgart 1975, , S. 255. :\mathrm :\mathrm Properties Europium(II) fluoride is a bright yellowish solid with a fluorite structure. EuF2 can be used to dope a trivalent rare-earth fluoride, such as LaF3, to create a vacancy-filled structure with increased conductivity over a pure crystal. Such a crystal can be used as a fluoride-specific semipermeable membrane in a fluoride selective electrode A fluoride selective electrode ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 compounds of manganese(II) in hydrofluoric acid. Like some other metal difluorides, MnF2 crystallizes in the rutile structure, which features octahedral Mn centers. Uses MnF2 is used in the manufacture of special kinds of glass and laser A laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. The word ''laser'' originated as an acronym for light amplification by stimulated emission of radi ...s. It is a canonical example of uniaxial antiferromagnet (with Neel temperature of 68 K) which has been experimentally studied since early on. References Manganese(II) compounds Fluorides Metal halides {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 Beryllium fluoride has distinctive optical properties. In the form of fluoroberyllate glass, it has the lowest refractive index for a solid at room temperature of 1.275. Its dispersive power is the lowest for a solid at 0.0093, and the nonlinear coefficient is also the lowest at 2 × 10−14. Structure and bonding The structure of solid BeF2 resembles that of cristobalite. Be2+ centers are four coordinate and tetrahedral and the fluoride centers are two-coordinate. The Be-F bond lengths are about 1.54 Å. Analogous to SiO2, BeF2 can also adopt a number of related structures. An analogy also exists between BeF2 and AlF3: both adopt extended structures at mild temperature. Gaseous and liquid BeF2 Gaseous beryllium fluoride adopts a lin ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 sought after by collectors as it typically forms euhedral isometric crystals exhibiting various cubes, octahedra, and dodecahedra. It is commonly associated with beryl, quartz, spessartine, hematite, pseudobrookite, hausmannite, braunite and topaz in pneumatolytic or hydrothermal veins and cavities and in metamorphic rocks. It can also be found in lithophysal cavities in rhyolite. Typical localities are Jhabua and Chhindwara districts, India and the Thomas Range in Juab County, Utah. It is also reported from San Luis Potosi, Mexico; northern Patagonia, Argentina; Girona, Catalonia, Spain; Sweden, Germany, Namibia, Zimbabwe, and South Africa. Bixbyite was named for the American mineralogist Maynard Bixby (1853–1935), responsible ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
