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Xenon Hexafluoride
Xenon hexafluoride is a noble gas compound with the formula XeF6. It is one of the three binary fluorides of xenon that have been studied experimentally, the other two being XeF2 and XeF4. All of them are exergonic and stable at normal temperatures. XeF6 is the strongest fluorinating agent of the series. It is a colorless solid that readily sublimes into intensely yellow vapors. Preparation Xenon hexafluoride can be prepared by heating of XeF2 at about 300 °C under 6 MPa (60 atmospheres) of fluorine. With as catalyst, however, this reaction can proceed at 120 °C even in xenon-fluorine molar ratios as low as 1:5. Structure The structure of XeF6 required several years to establish in contrast to the cases of and . In the gas phase the compound is monomeric. VSEPR theory predicts that due to the presence of six fluoride ligands and one lone pair of electrons the structure lacks perfect octahedral symmetry, and indeed electron diffraction combined with high-level cal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Krypton Hexafluoride
Krypton hexafluoride is an inorganic chemical compound of krypton and fluorine with the chemical formula . It is still a hypothetical compound. Calculations indicate it is unstable. History In 1933, Linus Pauling predicted that the heavier noble gases would be able to form compounds with fluorine and oxygen. He also predicted the existence of krypton hexafluoride. Calculations suggest it would have octahedral molecular geometry. So far, out of all possible krypton fluorides, only 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 ... () has actually been synthesized. References Krypton compounds Fluorides Nonmetal halides Hexafluorides Fluorinating agents Hypothetical chemical compounds {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahedron
In geometry, a tetrahedron (: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular Face (geometry), faces, six straight Edge (geometry), edges, and four vertex (geometry), vertices. The tetrahedron is the simplest of all the ordinary convex polytope, convex polyhedra. The tetrahedron is the three-dimensional case of the more general concept of a Euclidean geometry, Euclidean simplex, and may thus also be called a 3-simplex. The tetrahedron is one kind of pyramid (geometry), pyramid, which is a polyhedron with a flat polygon base and triangular faces connecting the base to a common point. In the case of a tetrahedron, the base is a triangle (any of the four faces can be considered the base), so a tetrahedron is also known as a "triangular pyramid". Like all convex polyhedra, a tetrahedron can be folded from a single sheet of paper. It has two such net (polyhedron), nets. For any tetrahedron there exists a sphere (called th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caesium Heptafluoroxenate
Caesium heptafluoroxenate is an inorganic compound of caesium, and fluorine, and xenon with the chemical formula . It consists of caesium cations and heptafluoroxenate(VI) anions . Preparation Caesium heptafluoroxenate can be prepared by dissolving caesium fluoride in liquid xenon hexafluoride: : Properties Caesium heptafluoroxenate is a yellow solid that is stable at room temperature. It is a very strong oxidizer. The compound decomposes at 50 °C to produce caesium octofluoroxenate: : Uses Caesium heptafluoroxenate is used to isolate xenon hexafluoride Xenon hexafluoride is a noble gas compound with the formula XeF6. It is one of the three binary fluorides of xenon that have been studied experimentally, the other two being XeF2 and XeF4. All of them are exergonic and stable at normal temperatur ... from a reaction mixture. References {{Noble gas compounds Caesium compounds Fluorine compounds Xenon compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rubidium
Rubidium is a chemical element; it has Symbol (chemistry), symbol Rb and atomic number 37. It is a very soft, whitish-grey solid in the alkali metal group, similar to potassium and caesium. Rubidium is the first alkali metal in the group to have a density higher than Properties of water, water. On Earth, natural rubidium comprises two isotopes: 72% is a stable isotope Rb, and 28% is slightly radioactive Rb, with a half-life of 48.8 billion years – more than three times as long as the estimated age of the universe. German chemists Robert Bunsen and Gustav Kirchhoff discovered rubidium in 1861 by the newly developed technique, Atomic emission spectroscopy#Flame emission spectroscopy, flame spectroscopy. The name comes from the Latin word , meaning deep red, the color of its emission spectrum. Rubidium's compounds have various chemical and electronic applications. Rubidium metal is easily vaporized and has a convenient spectral absorption range, making it a frequent target for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Caesium
Caesium (IUPAC spelling; also spelled cesium in American English) is a chemical element; it has Symbol (chemistry), symbol Cs and atomic number 55. It is a soft, silvery-golden alkali metal with a melting point of , which makes it one of only five elemental metals that are liquid at or near room temperature. Caesium has physical and chemical properties similar to those of rubidium and potassium. It is pyrophoricity, pyrophoric and reacts with water even at . It is the least electronegativity, electronegative stable element, with a value of 0.79 on the Pauling scale. It has only one stable isotope, caesium-133. Caesium is mined mostly from pollucite. Caesium-137, a fission product, is extracted from waste produced by nuclear reactor technology, nuclear reactors. It has the largest atomic radius of all elements whose radii have been measured or calculated, at about 260 picometres. The German chemist Robert Bunsen and physicist Gustav Kirchhoff discovered caesium in 1860 by the new ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Potassium Fluoride
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. Preparation Potassium fluoride is prepared by reacting potassium carbonate with hydrofluoric acid. Evaporation of the solution forms crystals of potassium bifluoride. The bifluoride on heating yields potassium fluoride: : : Platinum or heat resistant plastic containers are often used for these operations. Potassium chloride converts to KF upon treatment with hydrogen fluoride. In this way, potassium fluoride is recyclable. Crystalline properties KF crystallizes in the cubic NaCl crystal structure. The lattice parameter at room temperature is 0.266 nm. Applications in organic chemistry In organic c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Fluoride
Sodium fluoride (NaF) is an inorganic compound with the formula . It is a colorless or white solid that is readily soluble in water. It is used in trace amounts in the fluoridation of drinking water to prevent tooth decay, and in toothpastes and topical pharmaceuticals for the same purpose. In 2022, it was the 221st most commonly prescribed medication in the United States, with more than 1million prescriptions. It is also used in metallurgy and in medical imaging. Uses Dental caries Fluoride salts are often added to municipal drinking water (as well as to certain food products in some countries) for the purpose of maintaining dental health. The fluoride enhances the strength of teeth by the formation of fluorapatite, a naturally occurring component of tooth enamel. Although sodium fluoride is used to fluoridate water and is the standard by which other water-fluoridation compounds are gauged, hexafluorosilicic acid (H2SiF6) and its salt sodium hexafluorosilicate (Na2Si ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrosonium Octafluoroxenate(VI)
Nitrosonium octafluoroxenate(VI) is a chemical compound of xenon with nitrogen, oxygen, and fluorine, having formula . It is an ionic compound containing well-separated nitrosonium cations (NO+) and octafluoroxenate(VI) anions (). The molecular geometry of the octafluoroxenate(VI) ion is square antiprismatic, having Xe–F bond lengths of 1.971 Å, 1.946 Å, 1.958 Å, 2.052 Å, and 2.099 Å. It is synthesized by the reaction of xenon hexafluoride Xenon hexafluoride is a noble gas compound with the formula XeF6. It is one of the three binary fluorides of xenon that have been studied experimentally, the other two being XeF2 and XeF4. All of them are exergonic and stable at normal temperatur ... () with nitrosyl fluoride (NOF): : + 2 NOF → Other compounds containing the octafluoroxenate(VI) ion include its alkali metal salts, including Cs2XeF8 and Rb2XeF8, which are stable up to 400 °C. References Xenon(VI) compounds Fluoro complexes ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitrosonium
The nitrosonium ion is , in which the nitrogen atom is bonded to an oxygen atom with a bond order of 3, and the overall diatomic species bears a positive charge. It can be viewed as nitric oxide with one electron removed. This ion is usually obtained as the following salts: , ( nitrosylsulfuric acid, more descriptively written ) and . The and salts are slightly soluble in acetonitrile . NOBF4 can be purified by sublimation at 200–250 °C and . Synthesis and spectroscopy is isoelectronic with CO, and . It arises via protonation of nitrous acid: :HONO + H+ NO+ + H2O In its infrared spectrum of its salts, νNO is a strong peak in the range 2150-2400 cm−1. Chemical properties Hydrolysis reacts readily with water to form nitrous acid: : For this reason, nitrosonium compounds must be protected from water or even moist air. With base, the reaction generates nitrite: : As a diazotizing agent reacts with aryl amines, , to give diazonium salts, . The resu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Square Antiprism
In geometry, the square antiprism is the second in an infinite family of antiprisms formed by an even number, even-numbered sequence of triangle sides closed by two polygon caps. It is also known as an ''anticube''. If all its faces are regular polygon, regular, it is a semiregular polyhedron or uniform polyhedron. A nonuniform ''D''4-symmetric variant is the cell of the Noble polyhedron, noble square antiprismatic 72-cell. Points on a sphere When eight points are distributed on the surface of a sphere with the aim of maximising the distance between them in some sense, the resulting shape corresponds to a square antiprism rather than a cube (geometry), cube. Specific methods of distributing the points include, for example, the Thomson problem (minimizing the sum of all the reciprocal (mathematics), reciprocals of distances between points), maximising the distance of each point to the nearest point, or minimising the sum of all reciprocals of squares of distances between points ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis Acid
A Lewis acid (named for the American physical chemist Gilbert N. Lewis) is a chemical species that contains an empty orbital which is capable of accepting an electron pair from a Lewis base to form a Lewis adduct. A Lewis base, then, is any species that has a filled orbital containing an electron pair which is not involved in bonding but may form a dative bond with a Lewis acid to form a Lewis adduct. For example, NH3 is a Lewis base, because it can donate its lone pair of electrons. Trimethylborane CH3)3Bis a Lewis acid as it is capable of accepting a lone pair. In a Lewis adduct, the Lewis acid and base share an electron pair furnished by the Lewis base, forming a dative bond. In the context of a specific chemical reaction between NH3 and Me3B, a lone pair from NH3 will form a dative bond with the empty orbital of Me3B to form an adduct NH3•BMe3. The terminology refers to the contributions of Gilbert N. Lewis. From p. 142: "We are inclined to think of substances as ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Xenon Dioxydifluoride
Xenon dioxydifluoride is an inorganic chemical compound with the formula XeO2F2. At room temperature it exists as a metastable solid, which decomposes slowly into xenon difluoride, but the cause of this decomposition is unknown. Preparation Xenon dioxydifluoride is prepared by reacting xenon trioxide with xenon oxytetrafluoride Xenon oxytetrafluoride () is an inorganic chemical compound. It is an unstable colorless liquid with a melting point of that can be synthesized by partial hydrolysis of , or the reaction of with silica or : : + → + + A high-yield synth .... : References {{Inorganic-stub Nonmetal halides Oxyfluorides Xenon(VI) compounds ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
