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Neptunium(V) Fluoride
Neptunium(V) fluoride or neptunium pentafluoride is a chemical compound of neptunium and fluorine with the formula NpF5. Synthesis Neptunium(V) fluoride can be prepared by reacting neptunium(VI) fluoride with iodine: :\mathrm From the equation above, iodine pentafluoride is a byproduct. Properties Neptunium(V) fluoride thermally decomposes at 318 °C to produce neptunium(IV) fluoride and neptunium(VI) fluoride. Contrary to uranium(V) fluoride Uranium pentafluoride is the inorganic compound with the chemical formula UF5. It is a pale yellow paramagnetic solid. The compound has attracted interest because it is related to uranium hexafluoride, which is widely used to produce uranium fuel ..., neptunium(V) fluoride does not react with boron trichloride, but it reacts with lithium fluoride in anhydrous HF to produce LiNpF6. References Neptunium compounds Fluorides Actinide halides {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetragonal
In crystallography, the tetragonal crystal system is one of the 7 crystal systems. Tetragonal crystal lattices result from stretching a cubic lattice along one of its lattice vectors, so that the cube becomes a rectangular prism with a square base (''a'' by ''a'') and height (''c'', which is different from ''a''). Bravais lattices There are two tetragonal Bravais lattices: the primitive tetragonal and the body-centered tetragonal. The base-centered tetragonal lattice is equivalent to the primitive tetragonal lattice with a smaller unit cell, while the face-centered tetragonal lattice is equivalent to the body-centered tetragonal lattice with a smaller unit cell. Crystal classes The point groups that fall under this crystal system are listed below, followed by their representations in international notation, Schoenflies notation, orbifold notation, Coxeter notation and mineral examples.Hurlbut, Cornelius S.; Klein, Cornelis, 1985, ''Manual of Mineralogy'', 20th ed., p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine Pentafluoride
Iodine pentafluoride is an interhalogen compound with chemical formula IF5. It is one of the fluorides of iodine. It is a colorless liquid, although impure samples appear yellow. It is used as a fluorination reagent and even a solvent in specialized syntheses. Preparation It was first synthesized by Henri Moissan in 1891 by burning solid iodine in fluorine gas. This exothermic reaction is still used to produce iodine pentafluoride, although the reaction conditions have been improved. :I2 + 5 F2 → 2 IF5 Reactions IF5 reacts vigorously with water forming hydrofluoric acid and iodic acid: :IF5 + 3 H2O → HIO3 + 5 HF Upon treatment with fluorine, it converts to iodine heptafluoride: :IF5 + F2 → IF7 It has been used as a solvent for handling metal fluorides. For example, the reduction of osmium hexafluoride to osmium pentafluoride with iodine is conducted in a solution in iodine pentafluoride: :10 OsF6 + I2 → 10 OsF5 + 2 IF5 Primary amines react with iodine pentafluo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptunium Compounds
Neptunium compounds are compounds containg the element neptunium (Np). Neptunium has five ionic oxidation states ranging from +3 to +7 when forming chemical compounds, which can be simultaneously observed in solutions. It is the heaviest actinide that can lose all its valence electrons in a stable compound. The most stable state in solution is +5, but the valence +4 is preferred in solid neptunium compounds. Neptunium metal is very reactive. Ions of neptunium are prone to hydrolysis and formation of coordination compounds. Solution chemistry When it is in an aqueous solution, neptunium can exist in any of its five possible oxidation states (+3 to +7) and each of these show a characteristic color.Np(II), (III) and (IV) have been observed, see The stability of each oxidation state is strongly dependent on various factors, such as the presence of oxidizing or reducing agents, pH of the solution, presence of coordination complex-forming ligands, and even the concentration of ne ... [...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] |
Lithium Fluoride
Lithium fluoride is an inorganic compound with the chemical formula LiF. It is a colorless solid, that transitions to white with decreasing crystal size. Although odorless, lithium fluoride has a bitter-saline taste. Its structure is analogous to that of sodium chloride, but it is much less soluble in water. It is mainly used as a component of molten salts. Formation of LiF from the elements releases one of the highest energy per mass of reactants, second only to that of BeO. Manufacturing LiF is prepared from lithium hydroxide or lithium carbonate with hydrogen fluoride. Applications Precursor to LiPF6 for batteries Lithium fluoride is reacted with hydrogen fluoride (HF) and phosphorus pentachloride to make lithium hexafluorophosphate, an ingredient in lithium ion battery electrolyte. In molten salts Fluorine is produced by the electrolysis of molten potassium bifluoride. This electrolysis proceeds more efficiently when the electrolyte contains a few percent of LiF, possibly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Boron Trichloride
Boron trichloride is the inorganic compound with the formula BCl3. This colorless gas is a reagent in organic synthesis. It is highly reactive toward water. Production and structure Boron reacts with halogens to give the corresponding trihalides. Boron trichloride is, however, produced industrially by direct chlorination of boron oxide and carbon at 501 °C. :B2O3 + 3 C + 3 Cl2 → 2 BCl3 + 3 CO The carbothermic reaction is analogous to the Kroll process for the conversion of titanium dioxide to titanium tetrachloride. In the laboratory BF3 reacted with AlCl3 gives BCl3 via halogen exchange. BCl3 is a trigonal planar molecule like the other boron trihalides, and has a bond length of 175pm. A degree of π-bonding has been proposed to explain the short B− Cl distance although there is some debate as to its extent. It does not dimerize, although NMR studies of mixtures of boron trihalides shows the presence of mixed halides. The absence of dimerisation contrasts with the t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Uranium(V) Fluoride
Uranium pentafluoride is the inorganic compound with the chemical formula UF5. It is a pale yellow paramagnetic solid. The compound has attracted interest because it is related to uranium hexafluoride, which is widely used to produce uranium fuel. It crystallizes in two polymorphs, called α- and β-UF5. Synthesis and structure Uranium pentafluoride is an intermediate in the conversion of uranium tetrafluoride to volatile UF6: :2UF4 + F2 → 2UF5 :2UF5 + F2 → 2UF6 It can be produced by reduction of the hexafluoride with carbon monoxide at elevated temperatures. : 2UF6 + CO → 2UF5 + COF2 Other reducing agents have been examined. The α form is a linear coordination polymer consisting of chains of octahedral uranium centers in which one of the five fluoride anion forms a bridge to the next uranium atom. The structure is reminiscent of that for vanadium pentafluoride. In the β form, the uranium centers adopt a square antiprismatic structure. The β polymo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neptunium(IV) Fluoride
Neptunium(IV) fluoride or neptunium tetrafluoride is a inorganic compound with the formula NpF4. It is a green salt and is isostructural with UF4. Synthesis left, 162px, Alternative view of the structure of solid NpF4. Neptunium(IV) fluoride can be prepared by reacting neptunium(III) fluoride or neptunium dioxide with a gas mixture of oxygen and hydrogen fluoride at 500 °C: :\mathrm It can also be prepared by treating neptunium dioxide Neptunium(IV) oxide, or neptunium dioxide, is a radioactive, olive green cubic crystalline solid with the formula NpO2. It emits both α- and γ-particles. Production Industrially, neptunium dioxide is formed by precipitation of neptunium(IV) ... with HF gas: :\mathrm References Neptunium compounds Fluorides Actinide halides {{inorganic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodine
Iodine is a chemical element with the symbol I and atomic number 53. The heaviest of the stable halogens, it exists as a semi-lustrous, non-metallic solid at standard conditions that melts to form a deep violet liquid at , and boils to a violet gas at . The element was discovered by the French chemist Bernard Courtois in 1811 and was named two years later by Joseph Louis Gay-Lussac, after the Ancient Greek 'violet-coloured'. Iodine occurs in many oxidation states, including iodide (I−), iodate (), and the various periodate anions. It is the least abundant of the stable halogens, being the sixty-first most abundant element. As the heaviest essential mineral nutrient, iodine is required for the synthesis of thyroid hormones. Iodine deficiency affects about two billion people and is the leading preventable cause of intellectual disabilities. The dominant producers of iodine today are Chile and Japan. Due to its high atomic number and ease of attachment to organic compound ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pearson Symbol
The Pearson symbol, or Pearson notation, is used in crystallography as a means of describing a crystal structure, and was originated by W. B. Pearson. The symbol is made up of two letters followed by a number. For example: * Diamond structure, ''cF''8 * Rutile structure, ''tP''6 The two (italicised) letters specify the Bravais lattice. The lower-case letter specifies the crystal family, and the upper-case letter the centering type. The number at the end of the Pearson symbol gives the number of the atoms in the conventional unit cell.Nomenclature of Inorganic Chemistry IUPAC Recommendations 2005 IR-3.4.4, pp. 49–51; IR-11.5, pp. 241–242. |
Neptunium(VI) Fluoride
Neptunium(VI) fluoride (NpF6) is the highest fluoride of neptunium, it is also one of seventeen known binary hexafluorides. It is an orange volatile crystalline solid. It is relatively hard to handle, being very corrosive, volatile and radioactive. Neptunium hexafluoride is stable in dry air but reacts vigorously with water. At normal pressure, it melts at 54.4° C and boils at 55.18° C. It is the only neptunium compound that boils at a low temperature. Due to these properties, it is possible to easily separate neptunium from spent fuel. Preparation Neptunium hexafluoride was first prepared in 1943 by American chemist Alan E. Florin, who heated a sample of neptunium(III) fluoride on a nickel filament in a stream of fluorine and condensed the product in a glass capillary tube. Methods of preparation from both neptunium(III) fluoride and neptunium(IV) fluoride were later patented by Glenn T. Seaborg and Harrison S. Brown. Standard method The usual method of preparation i ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chemical Formula
In chemistry, a chemical formula is a way of presenting information about the chemical proportions of atoms that constitute a particular chemical compound or molecule, using chemical element symbols, numbers, and sometimes also other symbols, such as parentheses, dashes, brackets, commas and ''plus'' (+) and ''minus'' (−) signs. These are limited to a single typographic line of symbols, which may include Subscript and superscript, subscripts and superscripts. A chemical formula is not a chemical nomenclature, chemical name, and it contains no words. Although a chemical formula may imply certain simple chemical structures, it is not the same as a full chemical structural formula. Chemical formulae can fully specify the structure of only the simplest of molecules and chemical substances, and are generally more limited in power than chemical names and structural formulae. The simplest types of chemical formulae are called ''empirical formulae'', which use letters and numbers ind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
