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Hafnium(IV) Nitrate
Hafnium(IV) nitrate is an inorganic compound, a salt of hafnium and nitric acid with the chemical formula Hf(NO3)4. Synthesis Hafnium nitrate can be prepared by the reaction of hafnium tetrachloride Hafnium(IV) chloride is the inorganic compound with the chemical formula, formula HfCl4. This colourless solid is the Precursor (chemistry), precursor to most hafnium organometallic compounds. It has a variety of highly specialized applications, m ... and dinitrogen pentoxide. Properties Hafnium nitrate is slightly volatile, and can be sublimed at 110 °C and 0.1 mmHg. Hafnium nitrate decomposes on heating (≥ 160°C) to HfO(NO3)2 and then to HfO2. Applications Hafnium nitrate can be used for the preparation of materials containing hafnium dioxide. References {{Nitrates Hafnium compounds Nitrates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thorium Nitrate
Thorium(IV) nitrate is a chemical compound, a salt of thorium and nitric acid with the formula Th(NO3)4. A white solid in its anhydrous form, it can form tetra- and pentahydrates. As a salt of thorium it is weakly radioactive. Preparation Thorium(IV) nitrate hydrate can be prepared by the reaction of thorium(IV) hydroxide and nitric acid: : Th(OH)4 + 4 HNO3 + 3 H2O → Th(NO3)4•5H2O Different hydrates are produced by crystallizing in different conditions. When a solution is very dilute, the nitrate is hydrolysed. Although various hydrates have been reported over the years, and some suppliers even claim to stock them, only the tetrahydrate and pentahydrate actually exist. What is called a hexahydrate, crystallized from a neutral solution, is probably a basic salt. The pentahydrate is the most common form. It is crystallized from dilute nitric acid solution. The tetrahydrate, Th(NO3)4•4H2O is formed by crystallizing from a stronger nitric acid solution. Concentrations of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zirconium Nitrate
Zirconium nitrate is a volatile anhydrous transition metal nitrate salt of zirconium with formula Zr(NO3)4. It has alternate names of zirconium tetranitrate, or zirconium(IV) nitrate. It has a UN number of UN 2728 and is class 5.1, meaning oxidising substance. Formation The anhydrous salt can be made from zirconium tetrachloride reacting with dinitrogen pentoxide. ZrCl4 + 4 N2O5 → Zr(NO3)4 + 4ClNO2 The product can be purified by sublimation in a vacuum. A contaminating substance in this is nitronium pentanitratozirconate. (NO2)Zr(NO3)5. Zirconium nitrate pentahydrate Zr(NO3)4·5H2O can be formed by dissolving zirconium dioxide in nitric acid and then evaporating the solution until it is dry. However it is easier to crystallise zirconyl nitrate trihydrate ZrO(NO3)2·3H2O from such a solution. Zirconium is highly resistant to nitric acid even in the presence of other impurities and high temperatures. So zirconium nitrate is not made by dissolving zirconium metal in nitric acid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Titanium Nitrate
Titanium nitrate is the inorganic compound with formula Ti(NO3)4. It is a colorless, diamagnetic solid that sublimes readily. It is an unusual example of a volatile binary transition metal nitrate. Ill defined species called titanium nitrate are produced upon dissolution of titanium or its oxides in nitric acid. Preparation Similarly to its original method, Ti(NO3)4 is prepared by the nitration of titanium tetrachloride using dinitrogen pentoxide or chlorine nitrate: :TiCl4 + 4 N2O5 → Ti(NO3)4 + 4 ClNO2 Hydrated titanium nitrate, the nitrate salt of the aquo complex i(H2O)6sup>3+, is produced upon dissolution of titanium compounds in nitric acid. Structure The complex has D2d symmetry, with four bidentate nitrate ligands. The N-O distances are 1·29 Å and 1·185 Å (noncoordinated). Physical properties In the infrared spectrum, it absorbs strongly at 1635 cm−1, assigned to a N-O vibrational mode. It is soluble in nonpolar solvents silico ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Compound
In chemistry, an inorganic compound is typically a chemical compound that lacks carbon–hydrogen bonds, that is, a compound that is not an organic compound. The study of inorganic compounds is a subfield of chemistry known as '' inorganic chemistry''. Inorganic compounds comprise most of the Earth's crust, although the compositions of the deep mantle remain active areas of investigation. Some simple carbon compounds are often considered inorganic. Examples include the allotropes of carbon (graphite, diamond, buckminsterfullerene, etc.), carbon monoxide, carbon dioxide, carbides, and the following salts of inorganic anions: carbonates, cyanides, cyanates, and thiocyanates. Many of these are normal parts of mostly organic systems, including organisms; describing a chemical as inorganic does not necessarily mean that it does not occur within living things. History Friedrich Wöhler's conversion of ammonium cyanate into urea in 1828 is often cited as the starting point of modern ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hafnium
Hafnium is a chemical element with the symbol Hf and atomic number 72. A lustrous, silvery gray, tetravalent transition metal, hafnium chemically resembles zirconium and is found in many zirconium minerals. Its existence was predicted by Dmitri Mendeleev in 1869, though it was not identified until 1923, by Dirk Coster and George de Hevesy, making it the penultimate stable element to be discovered (the last being rhenium in 1925). Hafnium is named after , the Latin name for Copenhagen, where it was discovered. Hafnium is used in filaments and electrodes. Some semiconductor fabrication processes use its oxide for integrated circuits at 45 nanometers and smaller feature lengths. Some superalloys used for special applications contain hafnium in combination with niobium, titanium, or tungsten. Hafnium's large neutron capture cross section makes it a good material for neutron absorption in control rods in nuclear power plants, but at the same time requires that it be removed from th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nitric Acid
Nitric acid is the inorganic compound with the formula . It is a highly corrosive mineral acid. The compound is colorless, but older samples tend to be yellow cast due to decomposition into oxides of nitrogen. Most commercially available nitric acid has a concentration of 68% in water. When the solution contains more than 86% , it is referred to as ''fuming nitric acid''. Depending on the amount of nitrogen dioxide present, fuming nitric acid is further characterized as red fuming nitric acid at concentrations above 86%, or white fuming nitric acid at concentrations above 95%. Nitric acid is the primary reagent used for nitration – the addition of a nitro group, typically to an organic molecule. While some resulting nitro compounds are shock- and thermally-sensitive explosives, a few are stable enough to be used in munitions and demolition, while others are still more stable and used as pigments in inks and dyes. Nitric acid is also commonly used as a strong oxidizing agen ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sigma Aldrich
Sigma-Aldrich (formally MilliporeSigma) is an American chemical, life science, and biotechnology company that is owned by the German chemical conglomerate Merck Group. Sigma-Aldrich was created in 1975 by the merger of Sigma Chemical Company and Aldrich Chemical Company. It grew through various acquisitions until it had over 9,600 employees and was listed on the Fortune 1000. The company is headquartered in St. Louis and has operations in approximately 40 countries. In 2015, the German chemical conglomerate Merck Group acquired Sigma-Aldrich for $17 billion. The company is currently a part of Merck's life science business and in combination with Merck's earlier acquired Millipore, operates as MilliporeSigma. History Sigma Chemical Company of St. Louis and Aldrich Chemical Company of Milwaukee were both American specialty chemical companies when they merged in August 1975. The company grew throughout the 1980s and 1990s, with significant expansion in facilities, acquisitions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
American Elements
American Elements is a global manufacturer and distributor of advanced materials with a more than 35,000-page online product catalog and compendium of information on the chemical elements, advanced materials, and high technology applications. The company's headquarters and educational programs are based in Los Angeles, California. Its research and production facilities are located in Salt Lake City, Utah; Monterrey, Mexico; Baotou, China; and Manchester, UK. History American Elements began as a toll chemical manufacturer and refiner serving U.S. mining companies by producing metal-based chemicals from their deposits. In 1998, its two largest customers, the Unocal/Molycorp rare-earth mine in Mountain Pass, California and the Rhodia rare-earth refinery in Freeport, Texas closed, ending domestic U.S. rare-earth production. In response, the company established mining joint ventures in Inner Mongolia, China and in 1999 became one of the first post-Cold War companies to export rare-eart ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hafnium Tetrachloride
Hafnium(IV) chloride is the inorganic compound with the chemical formula, formula HfCl4. This colourless solid is the Precursor (chemistry), precursor to most hafnium organometallic compounds. It has a variety of highly specialized applications, mainly in materials science and as a catalyst. Preparation HfCl4 can be produced by several related procedures: *The reaction of carbon tetrachloride and hafnium oxide at above 450 °C; :HfO2 + 2 CCl4 → HfCl4 + 2 COCl2 *Chlorination of a mixture of HfO2 and charcoal, carbon above 600 °C using chlorine gas or sulfur monochloride: :HfO2 + 2 Cl2 + C → HfCl4 + CO2 *halogenation, Chlorination of hafnium carbide above 250 °C. Separation of Zr and Hf Hafnium and zirconium occur together in minerals such as zircon, cyrtolite and baddeleyite. Zircon contains 0.05% to 2.0% hafnium dioxide HfO2, cyrtolite with 5.5% to 17% HfO2 and baddeleyite contains 1.0 to 1.8 percent HfO2.Newnham, Ivan Edgar "Purification of H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dinitrogen Pentoxide
Dinitrogen pentoxide is the chemical compound with the formula , also known as nitrogen pentoxide or nitric anhydride. It is one of the binary nitrogen oxides, a family of compounds that only contain nitrogen and oxygen. It exists as colourless crystals that melt at 41 °C. Its boiling point is 47 °C, and sublimes slightly above room temperature, yielding a colorless gas.Peter Steele Connell The Photochemistry of Dinitrogen Pentoxide'. Ph. D. thesis, Lawrence Berkeley National Laboratory. Dinitrogen pentoxide is an unstable and potentially dangerous oxidizer that once was used as a reagent when dissolved in chloroform for nitrations but has largely been superseded by nitronium tetrafluoroborate (). is a rare example of a compound that adopts two structures depending on the conditions. The solid is a salt, nitronium nitrate, consisting of separate nitronium cations and nitrate anions ; but in the gas phase and under some other conditions it is a covalently-bo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
HfO2
Hafnium(IV) oxide is the inorganic compound with the formula . Also known as hafnium dioxide or hafnia, this colourless solid is one of the most common and stable compounds of hafnium. It is an electrical insulator with a band gap of 5.3~5.7 eV. Hafnium dioxide is an intermediate in some processes that give hafnium metal. Hafnium(IV) oxide is quite inert. It reacts with strong acids such as concentrated sulfuric acid and with strong bases. It dissolves slowly in hydrofluoric acid to give fluorohafnate anions. At elevated temperatures, it reacts with chlorine in the presence of graphite or carbon tetrachloride to give hafnium tetrachloride Hafnium(IV) chloride is the inorganic compound with the chemical formula, formula HfCl4. This colourless solid is the Precursor (chemistry), precursor to most hafnium organometallic compounds. It has a variety of highly specialized applications, m .... Structure Hafnia typically adopts the same structure as zirconia (ZrO2). Unlike TiO2, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrochemical And Solid-State Letters
''Electrochemical and Solid-State Letters'' (ESL) was a peer-reviewed scientific journal that began publication in 1998 as a joint publication of the Electrochemical Society and the IEEE Electron Devices Society The Institute of Electrical and Electronics Engineers (IEEE) is a 501(c)(3) professional association for electronic engineering and electrical engineering (and associated disciplines) with its corporate office in New York City and its operation .... The final issue was published in 2012. The journal is now preserved as an archive, and has been replaced by '' ECS Electrochemistry Letters'' and '' ECS Solid State Letters''. Abstracting and indexing The journal was abstracted and indexed in: According to the '' Journal Citation Reports'', the journal has a 2013 impact factor of 2.149, ranking it 12th out of 27 journals in the category "Electrochemistry" and 70th out of 251 journals in the category "Materials Science, Multidisciplinary". History The Society's rapid-pub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
