|
Tellurium Monoiodide
Tellurium iodide is an inorganic compound with the formula Te I. Two forms are known. Their structures differ from the other monohalides of tellurium. There are three subiodides of tellurium, α-TeI, β-TeI, and Te2I, and one tellurium tetraiodide. Preparation and properties TeI is a gray solid formed by the hydrothermal reaction of tellurium metal and iodine in hydroiodic acid. When this reaction is conducted near 270 °C gives the α-TeI, which is triclinic. When the same mixture is heated to 150 °C, one obtains the metastable monoclinic phase β-TeI. The compounds are related structurally to Te2I (see ditellurium bromide), but the additional iodide groups do not bridge to other Te centers. The corresponding monochloride and monobromide are molecular compounds with the formula Te2X2.Zhengtao Xu "Recent Developments in Binary Halogen–Chalcogen Compounds, Polyanions and Polycations" in Handbook of Chalcogen Chemistry: New Perspectives in Sulfur, Selenium and T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ditellurium Bromide
Ditellurium bromide is the inorganic compound with the formula Te2 Br. It is one of the few stable lower bromides of tellurium. Unlike sulfur and selenium Selenium is a chemical element with the symbol Se and atomic number 34. It is a nonmetal (more rarely considered a metalloid) with properties that are intermediate between the elements above and below in the periodic table, sulfur and tellurium, ..., tellurium forms families of polymeric subhalides where the halide/chalcogen ratio is less than 2. Preparation and properties Te2Br is a gray solid. Its structure consists of a chain of Te atoms with Br occupying a doubly bridged site. It is prepared by heating tellurium with the appropriate stoichiometry of bromine near 215 °C. The corresponding chloride and iodide, Te2Cl and Te2I, are also known. Other tellurium bromides include the yellow liquid Te2Br2, the orange solid TeBr4,Zhengtao Xu "Recent Developments in Binary Halogen–Chalcogen Compounds, Polyanions a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Selenium Monochloride
Selenium monochloride is an inorganic compound with the formula Se2Cl2. Although it is called selenium monochloride, a more descriptive name might be diselenium dichloride. It is a reddish-brown, oily liquid that hydrolyses slowly. It exists in chemical equilibrium with SeCl2, SeCl4, chlorine, and elemental selenium. Selenium monochloride is mainly used as a reagent for the synthesis of Se-containing compounds. Structure and properties Selenium monochloride has the connectivity Cl-Se-Se-Cl. With a nonplanar structure, it has C2 molecular symmetry, similar to hydrogen peroxide and sulfur monochloride. The Se-Se bond length is 2.23 Å, and the Se-Cl bond lengths are 2.20 Å. The dihedral angle is 87°. Preparation Early routes to selenium monochloride involved chlorination of elemental selenium. An improved method involves the reaction of a mixture of selenium, selenium dioxide, and hydrochloric acid:Fehér, F. "Diselenium Dichloride". In ''Handbook of Preparative Inorganic Che ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tellurium Tetraiodide
Tellurium tetraiodide ( Te I4) is an inorganic chemical compound. It has a tetrameric structure which is different from the tetrameric solid forms of TeCl4 and TeBr4. In TeI4 the Te atoms are octahedrally coordinated and edges of the octahedra are shared. TeI4 can be prepared from the elements or by reacting Te and iodomethane, CH3I. In the vapour TeI4 dissociates:''Inorganic Chemistry'',Egon Wiberg, Arnold Frederick Holleman Elsevier 2001 :TeI4 → TeI2 + I2 It is a conductor when molten, dissociating into the ions TeI3+ and I−. In solvents with donor properties such as acetonitrile Acetonitrile, often abbreviated MeCN (methyl cyanide), is the chemical compound with the formula and structure . This colourless liquid is the simplest organic nitrile (hydrogen cyanide is a simpler nitrile, but the cyanide anion is not clas ..., CH3CN ionic complexes are formed which make the solution conducting: :TeI4 + 2 CH3CN → (CH3CN)2TeI3+ + I− References Iodides Tellu ... [...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] |
Tellurium
Tellurium is a chemical element with the symbol Te and atomic number 52. It is a brittle, mildly toxic, rare, silver-white metalloid. Tellurium is chemically related to selenium and sulfur, all three of which are chalcogens. It is occasionally found in native form as elemental crystals. Tellurium is far more common in the Universe as a whole than on Earth. Its extreme rarity in the Earth's crust, comparable to that of platinum, is due partly to its formation of a volatile hydride that caused tellurium to be lost to space as a gas during the hot nebular formation of Earth.Anderson, Don L.; "Chemical Composition of the Mantle" in ''Theory of the Earth'', pp. 147-175 Tellurium-bearing compounds were first discovered in 1782 in a gold mine in Kleinschlatten, Transylvania (now Zlatna, Romania) by Austrian mineralogist Franz-Joseph Müller von Reichenstein, although it was Martin Heinrich Klaproth who named the new element in 1798 after the Latin 'earth'. Gold telluride minerals ar ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Iodide
An iodide ion is the ion I−. Compounds with iodine in formal oxidation state −1 are called iodides. In everyday life, iodide is most commonly encountered as a component of iodized salt, which many governments mandate. Worldwide, iodine deficiency affects two billion people and is the leading preventable cause of intellectual disability. Structure and characteristics of inorganic iodides Iodide is one of the largest monatomic anions. It is assigned a radius of around 206 picometers. For comparison, the lighter halides are considerably smaller: bromide (196 pm), chloride (181 pm), and fluoride (133 pm). In part because of its size, iodide forms relatively weak bonds with most elements. Most iodide salts are soluble in water, but often less so than the related chlorides and bromides. Iodide, being large, is less hydrophilic compared to the smaller anions. One consequence of this is that sodium iodide is highly soluble in acetone, whereas sodium chloride is not. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subhalide
In chemistry, subhalide usually refers to inorganic compounds that have a low ratio of halide to metal, made possible by metal–metal bonding (or element–element bonding for nonmetals), sometimes extensive. Many compounds meet this definition. Examples The normal halide of boron is . Boron forms many subhalides: several , including ; also BF. Aluminium forms a variety of subhalides. For gallium, adducts of are known. Phosphorus subhalides include , , and (structurally related to ). For bismuth, the compound originally described as bismuth monochloride was later shown to consist of clusters and chloride The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride salts ... anions. There are many tellurium subhalides, including , (X = Cl, Br, I), and two forms of TeI.Zhengtao Xu "Recent Deve ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hydrothermal Reaction
Hydrothermal synthesis includes the various techniques of crystallizing substances from high-temperature aqueous solutions at high vapor pressures; also termed "hydrothermal method". The term "hydrothermal" is of Geology, geologic origin. Geochemistry, Geochemists and mineralogists have studied hydrothermal phase equilibria since the beginning of the twentieth century. George W. Morey at the Carnegie Institution and later, Percy W. Bridgman at Harvard University did much of the work to lay the foundations necessary to containment of reactive media in the temperature and pressure range where most of the hydrothermal work is conducted. Hydrothermal synthesis can be defined as a method of synthesis of single crystals that depends on the solubility of minerals in hot water under high pressure. The crystal growth is performed in an apparatus consisting of a steel pressure vessel called an autoclave, in which a nutrient is supplied along with water. A temperature gradient is maintained b ... [...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] |
Hydroiodic Acid
Hydroiodic acid (or hydriodic acid) is an aqueous solution of hydrogen iodide (HI). It is a strong acid, one that is ionized completely in an aqueous solution. It is colorless. Concentrated solutions are usually 48% to 57% HI. Reactions Hydroiodic acid reacts with oxygen in air to give iodine: :4 HI + O2 → 2 + 2 I2 Like other hydrogen halides, hydroiodic acid adds to alkenes to give alkyl iodides. It can also be used as a reducing agent, for example in the reduction of aromatic nitro compounds to anilines. Cativa process The Cativa process is a major end use of hydroiodic acid, which serves as a co-catalyst for the production of acetic acid by the carbonylation of methanol. Illicit uses Hydroiodic acid is listed as a U.S. Federal DEA List I Chemical, owing to its use as a reducing agent related to the production of methamphetamine from ephedrine Ephedrine is a central nervous system (CNS) stimulant that is often used to prevent low blood pressure during anesthe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tellurium Dibromide
Ditellurium bromide is the inorganic compound with the formula Te2 Br. It is one of the few stable lower bromides of tellurium. Unlike sulfur and selenium, tellurium forms families of polymeric subhalide In chemistry, subhalide usually refers to inorganic compounds that have a low ratio of halide to metal, made possible by metal–metal bonding (or element–element bonding for nonmetals), sometimes extensive. Many compounds meet this definition. ...s where the halide/chalcogen ratio is less than 2. Preparation and properties Te2Br is a gray solid. Its structure consists of a chain of Te atoms with Br occupying a doubly bridged site. It is prepared by heating tellurium with the appropriate stoichiometry of bromine near 215 °C. The corresponding chloride and iodide, Te2Cl and Te2I, are also known. Other tellurium bromides include the yellow liquid Te2Br2, the orange solid TeBr4,Zhengtao Xu "Recent Developments in Binary Halogen–Chalcogen Compounds, Polyanions and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Iodide
Sodium iodide (chemical formula NaI) is an ionic compound formed from the chemical reaction of sodium metal and iodine. Under standard conditions, it is a white, water-soluble solid comprising a 1:1 mix of sodium cations (Na+) and iodide anions (I−) in a crystal lattice. It is used mainly as a nutritional supplement and in organic chemistry. It is produced industrially as the salt formed when acidic iodides react with sodium hydroxide. It is a chaotropic salt. Uses Food supplement Sodium iodide, as well as potassium iodide, is commonly used to treat and prevent iodine deficiency. Iodized table salt contains 10 ppm iodide. Organic synthesis Sodium iodide is used for conversion of alkyl chlorides into alkyl iodides. This method, the Finkelstein reaction, relies on the insolubility of sodium chloride in acetone to drive the reaction: ::R–Cl + NaI → R–I + NaCl Nuclear medicine Some radioactive iodide salts of sodium, including Na 125I and Na 131I, have radioph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
