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Silicon Disulfide
Silicon disulfide is the inorganic compound with the formula Si S2. Like silicon dioxide, this material is polymeric, but it adopts a 1-dimensional structure quite different from the usual forms of SiO2. Synthesis, structure, and properties The material is formed by heating silicon and sulfur or by the exchange reaction between SiO2 and Al2S3. The material consists of chains of edge-shared tetrahedra, Si(μ-S)2Si(μS)2, etc. Like other silicon sulfur-compounds (e.g., bis(trimethylsilyl)sulfide) SiS2 hydrolyzes readily to release H2S. In liquid ammonia it is reported to form the imide Si(NH)2 and NH4SH, but a recent report has identified crystalline (NH4)2 iS3(NH3)�2NH3 as a product which contains the tetrahedral thiosilicate anion, SiS3(NH3). Reaction with ethanol gives the alkoxide tetraethyl orthosilicate and H2S. With bulky tert-butanol, alcoholysis gives tris(tert-butoxy)silanethiol: :3 (CH3)3COH + SiS2 → CH3)3COsub>3SiSH + H2S Reaction with sodium sulfid ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahedral
In geometry, a tetrahedron (plural: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertex corners. The tetrahedron is the simplest of all the ordinary convex polyhedra and the only one that has fewer than 5 faces. The tetrahedron is the three-dimensional case of the more general concept of a Euclidean simplex, and may thus also be called a 3-simplex. The tetrahedron is one kind of 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 nets. For any tetrahedron there exists a sphere (called the circumsphere) on which all four vertices lie, and another sph ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrahedra
In geometry, a tetrahedron (plural: tetrahedra or tetrahedrons), also known as a triangular pyramid, is a polyhedron composed of four triangular faces, six straight edges, and four vertex corners. The tetrahedron is the simplest of all the ordinary convex polyhedra and the only one that has fewer than 5 faces. The tetrahedron is the three-dimensional case of the more general concept of a Euclidean simplex, and may thus also be called a 3-simplex. The tetrahedron is one kind of 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 nets. For any tetrahedron there exists a sphere (called the circumsphere) on which all four vertices lie, and anothe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sulfides
Sulfide (British English also sulphide) is an inorganic anion of sulfur with the chemical formula S2− or a compound containing one or more S2− ions. Solutions of sulfide salts are corrosive. ''Sulfide'' also refers to chemical compounds large families of inorganic and organic compounds, e.g. lead sulfide and dimethyl sulfide. Hydrogen sulfide (H2S) and bisulfide (SH−) are the conjugate acids of sulfide. Chemical properties The sulfide ion, S2−, does not exist in aqueous alkaline solutions of Na2S. Instead sulfide converts to hydrosulfide: :S2− + H2O → SH− + OH− Upon treatment with an acid, sulfide salts convert to hydrogen sulfide: :S2− + H+ → SH− :SH− + H+ → H2S Oxidation of sulfide is a complicated process. Depending on the conditions, the oxidation can produce elemental sulfur, polysulfides, polythionates, sulfite, or sulfate. Metal sulfides react with halogens, forming sulfur and metal salts. :8 MgS + 8 I2 → S8 + 8& ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inorganic Silicon Compounds
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 o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thiosilicate
In chemistry and materials science, thiosilicate refers to materials containing anions of the formula . Derivatives where some sulfide is replaced by oxide are also called thiosilicates, examples being materials derived from the oxohexathiodisilicate . Silicon is tetrahedral in all thiosilicates and sulfur is bridging or terminal. Formally such materials are derived from silicon disulfide in analogy to the relationship between silicon dioxide and silicates. Thiosilicates are typically encountered as colorless solids. They are characteristically sensitive to hydrolysis. They are from the class of chalcogenidotetrelates. Materials science The LISICON (LIthium Super Ionic CONductor) include thiosilicates, which are fast ion conductors. Thiosilicates and related thiogermanates are also of interest for infrared Infrared (IR), sometimes called infrared light, is electromagnetic radiation (EMR) with wavelengths longer than those of visible light. It is therefore invisible to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aluminum Sulfide
Aluminum sulfide or aluminium sulphide is a chemical compound with the formula Al2 S3. This colorless species has an interesting structural chemistry, existing in several forms. The material is sensitive to moisture, hydrolyzing to hydrated aluminum oxides/hydroxides. This can begin when the sulfide is exposed to the atmosphere. The hydrolysis reaction generates gaseous hydrogen sulfide (H2S). Crystal structure More than six crystalline forms of aluminum sulfide are known and only some are listed below. Most of them have rather similar, wurtzite-like structures, and differ by the arrangement of lattice vacancies, which form ordered or disordered sublattices. The β and γ phases are obtained by annealing the most stable α-Al2S3 phase at several hundred degrees Celsius. Compressing aluminum sulfide to 2–65 bar results in the δ phase where vacancies are arranged in a superlattice of tetragonal symmetry. Unlike Al2O3, in which the Al(III) centers occupy octahedral holes, th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Magnesium Sulfide
Magnesium sulfide is an inorganic compound with the formula Mg S. It is a white crystalline material but often is encountered in an impure form that is brown and non-crystalline powder. It is generated industrially in the production of metallic iron. Preparation and general properties MgS is formed by the reaction of sulfur or hydrogen sulfide with magnesium. It crystallizes in the rock salt structure as its most stable phase, its zinc blende and wurtzite structures can be prepared by molecular beam epitaxy. The chemical properties of MgS resemble those of related ionic sulfides such as those of sodium, barium, or calcium. It reacts with oxygen to form the corresponding sulfate, magnesium sulfate. MgS reacts with water to give hydrogen sulfide and magnesium hydroxide. Applications In the BOS steelmaking process, sulfur is the first element to be removed. Sulfur is removed from the impure blast furnace iron by the addition of several hundred kilograms of magnesium powder by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sodium Sulfide
Sodium sulfide is a chemical compound with the formula Na2 S, or more commonly its hydrate Na2S·9 H2O. Both the anhydrous and the hydrated salts in pure crystalline form are colorless solids, although technical grades of sodium sulfide are generally yellow to brick red owing to the presence of polysulfides and commonly supplied as a crystalline mass, in flake form, or as a fused solid. They are water-soluble, giving strongly alkaline solutions. When exposed to moist air, Na2S and its hydrates emit hydrogen sulfide, an extremely toxic, flammable and corrosive gas which smells like rotten eggs. Some commercial samples are specified as Na2S·''x''H2O, where a weight percentage of Na2S is specified. Commonly available grades have around 60% Na2S by weight, which means that ''x'' is around 3. These grades of sodium sulfide are often marketed as 'sodium sulfide flakes'. Structure Na2S adopts the antifluorite structure, which means that the Na+ centers occupy sites of the fluoride ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tris(tert-butoxy)silanethiol
Tris(''tert''-butoxy)silanethiol is a silicon compound containing three ''tert''-butoxy groups and a rare Si–S–H functional group. This colourless compound serves as an hydrogen donor in radical chain reactions. It was first prepared by alcoholysis of silicon disulfide Silicon disulfide is the inorganic compound with the formula Si S2. Like silicon dioxide, this material is polymeric, but it adopts a 1-dimensional structure quite different from the usual forms of SiO2. Synthesis, structure, and properties Th ... and purified by distillation: :3 (CH3)3COH + SiS2 → CH3)3COsub>3SiSH + H2S Since 1962 it was thoroughly studied including its acid-base properties and coordination chemistry with metal ions. It coordinates to metal ions via the sulfur and oxygen donor atoms.A. Pladzyk, A. Ozarowski, Ł. Ponikiewski: Crystal and electronic structures of Ni(II) silanethiolates containing flexible diamine ligands. Inorg. Chim. Acta 440 (2016) 84-93. References {{ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetraethyl Orthosilicate
Tetraethyl orthosilicate, formally named tetraethoxysilane (TEOS), ethyl silicate is the organic chemical compound with the formula Si(OC2H5)4. TEOS is a colorless liquid. It degrades in water. TEOS is the of orthosilicic acid, Si(OH)4. It is the most prevalent alkoxide of silicon. TEOS is a tetrahedral molecule. Like its many analogues, it is prepared by alcoholysis of silicon tetrachloride: :SiCl4 + 4 EtOH → Si(OEt)4 + 4 HCl where Et is the ethyl group, C2H5, and thus EtOH is ethanol. Applications TEOS is mainly used as a crosslinking agent in silicone polymers and as a precursor to silicon dioxide in the semiconductor industry. TEOS is also used as the silica source for synthesis of some zeolites. Other applications include coatings for carpets and other objects. TEOS is used in the production of aerogel. These applications exploit the reactivity of the Si-OR bonds. TEOS has historically been used as an additive to alcohol based rocket fuels to decrease the heat ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkoxide
In chemistry, an alkoxide is the conjugate base of an alcohol and therefore consists of an organic group bonded to a negatively charged oxygen atom. They are written as , where R is the organic substituent. Alkoxides are strong bases and, when R is not bulky, good nucleophiles and good ligands. Alkoxides, although generally not stable in protic solvents such as water, occur widely as intermediates in various reactions, including the Williamson ether synthesis. Transition metal alkoxides are widely used for coatings and as catalysts. Enolates are unsaturated alkoxides derived by deprotonation of a bond adjacent to a ketone or aldehyde. The nucleophilic center for simple alkoxides is located on the oxygen, whereas the nucleophilic site on enolates is delocalized onto both carbon and oxygen sites. Ynolates are also unsaturated alkoxides derived from acetylenic alcohols. Phenoxides are close relatives of the alkoxides, in which the alkyl group is replaced by a derivative ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ammonia
Ammonia is an inorganic compound of nitrogen and hydrogen with the formula . A stable binary hydride, and the simplest pnictogen hydride, ammonia is a colourless gas with a distinct pungent smell. Biologically, it is a common nitrogenous waste, particularly among aquatic organisms, and it contributes significantly to the nutritional needs of terrestrial organisms by serving as a precursor to 45% of the world's food and fertilizers. Around 70% of ammonia is used to make fertilisers in various forms and composition, such as urea and Diammonium phosphate. Ammonia in pure form is also applied directly into the soil. Ammonia, either directly or indirectly, is also a building block for the synthesis of many pharmaceutical products and is used in many commercial cleaning products. It is mainly collected by downward displacement of both air and water. Although common in nature—both terrestrially and in the outer planets of the Solar System—and in wide use, ammonia is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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