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Trimethylstibine
Trimethylstibine is an organoantimony compound with the formula Sb(CH3)3. It is a colorless pyrophoric and toxic liquid. It is synthesized by treatment of antimony trichloride and methyl Grignard reagent.Sabina C. Grund, Kunibert Hanusch, Hans J. Breunig, Hans Uwe Wolf "Antimony and Antimony Compounds" in Ullmann's Encyclopedia of Industrial Chemistry, 2006, Wiley-VCH, Weinheim. It is produced by anaerobic bacteria in antimony-rich soils. In contrast to trimethylphosphine, trimethylstibine is a weaker Lewis base. It is used in the production of some III-V semiconductor Semiconductor materials are nominally small band gap insulators. The defining property of a semiconductor material is that it can be compromised by doping it with impurities that alter its electronic properties in a controllable way. Because of t ...s. References Organoantimony compounds {{organic-compound-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylamine
Trimethylamine (TMA) is an organic compound with the formula N(CH3)3. It is a colorless, hygroscopic, and flammable tertiary amine. It is a gas at room temperature but is usually sold as a 40% solution in water. (It is also sold in pressurized gas cylinders.) TMA is a nitrogenous base and can be readily protonated to give the trimethylammonium cation. Trimethylammonium chloride is a hygroscopic colorless solid prepared from hydrochloric acid. Trimethylamine is a good nucleophile, and this reaction is the basis of most of its applications. TMA is widely used in industry: it is used in the synthesis of choline, tetramethylammonium hydroxide, plant growth regulators or herbicides, strongly basic anion exchange resins, dye leveling agents, and a number of basic dyes. At higher concentrations it has an ammonia-like odor, and can cause necrosis of mucous membranes on contact. At lower concentrations, it has a "fishy" odor, the odor associated with rotting fish. In humans, ingesti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylphosphine
Trimethylphosphine is a neutral organophosphorus compound with the formula P(CH3)3, commonly abbreviated as PMe3. This colorless liquid has a strongly unpleasant odor, characteristic of alkylphosphines. The compound is a common ligand in coordination chemistry. Structure and bonding It is a pyramidal molecule with approximate ''C''3''v'' symmetry. The C–P–C bond angles are approximately 98.6°. The C–P–C bond angles are consistent with the notion that phosphorus predominantly uses the 3p orbitals for forming bonds and that there is little sp hybridization of the phosphorus atom. The latter is a common feature of the chemistry of phosphorus. As a result, the lone pair of trimethylphosphine has predominantly s-character as is the case for phosphine, PH3. PMe3 can be prepared by the treatment of triphenyl phosphite with methylmagnesium chloride: : 3 CH3MgCl + P(OC6H5)3 → P(CH3)3 + 3 C6H5OMgCl The synthesis is conducted in dibutyl ether, from which the more volatile PMe3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylarsine
Trimethylarsine (abbreviated TMA or TMAs) is the chemical compound with the formula (CH3)3As, commonly abbreviated As Me3 or TMAs. This organic derivative of arsine has been used as a source of arsenic in microelectronics industry, a building block to other organoarsenic compounds, and serves as a ligand in coordination chemistry. It has distinct "garlic"-like smell. Trimethylarsine had been discovered as early as 1854. Structure and preparation AsMe3 is a pyramidal molecule. The As-C distances average 1.519 Å, and the C-As-C angles are 91.83° Trimethylarsine can be prepared by treatment of arsenic oxide with trimethylaluminium: :As2O3 + 1.5 lMe3sub>2 → 2 AsMe3 + 3/n (MeAl-O)n Occurrence and reactions Trimethylarsine is the volatile byproduct of microbial action on inorganic forms of arsenic which are naturally occurring in rocks and soils at the parts-per-million level. Trimethylarsine has been reported only at trace levels (parts per billion) in landfill gas from Germany, C ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triphenylstibine
Triphenylstibine is the chemical compound with the formula Sb(C6H5)3. Abbreviated SbPh3, this colourless solid is often considered the prototypical organoantimony compound. It is used as a ligand in coordination chemistry and as a reagent in organic synthesis. Like the related molecules triphenylphosphine and triphenylarsine, SbPh3 is pyramidal with a propeller-like arrangement of the phenyl groups. The Sb-C distances average 2.14-2.17 Å and the C-Sb-C angle are 95°. SbPh3 was first reported in 1886, being prepared from antimony trichloride by the reaction: :6 Na + 3 C6H5Cl + SbCl3 → (C6H5)3Sb + 6 NaCl An alternative method treats phenylmagnesium bromide Phenylmagnesium bromide, with the simplified formula , is a magnesium-containing organometallic compound. It is commercially available as a solution in diethyl ether or tetrahydrofuran (THF). Phenylmagnesium bromide is a Grignard reagent. It is o ... with SbCl3. References {{reflist Organoantimony compounds Phenyl c ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pyrophoric
A substance is pyrophoric (from grc-gre, πυροφόρος, , 'fire-bearing') if it ignites spontaneously in air at or below (for gases) or within 5 minutes after coming into contact with air (for liquids and solids). Examples are organolithium compounds and triethylborane. Pyrophoric materials are often water-reactive as well and will ignite when they contact water or humid air. They can be handled safely in atmospheres of argon or (with a few exceptions) nitrogen. Fire Classes#Metal, Class D fire extinguisher#Class D dry powder and other agents for metal fires, fire extinguishers are designated for use in fires involving pyrophoric materials. A related concept is hypergolic propellant, hypergolicity, in which two compounds spontaneously ignite when mixed. Uses The creation of spark (fire), sparks from metals is based on the pyrophoricity of small metal particles, and pyrophoric alloys are made for this purpose. The sparking mechanisms in lighters and various toys, using fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimony Trichloride
Antimony trichloride is the chemical compound with the formula SbCl3. It is a soft colorless solid with a pungent odor and was known to alchemists as butter of antimony. Preparation Antimony trichloride is prepared by reaction of chlorine with antimony, antimony tribromide, antimony trioxide, or antimony trisulfide. It also may be made by treating antimony trioxide with concentrated hydrochloric acid. Reactions SbCl3 is readily hydrolysed and samples of SbCl3 must be protected from moisture. With a limited amount of water it forms antimony oxychloride releasing hydrogen chloride: :SbCl3 + H2O → SbOCl + 2 HCl With more water it forms which on heating to 460° under argon converts to . SbCl3 readily forms complexes with halides, but the stoichiometries are not a good guide to the composition, for example the contains a chain anion with distorted SbIII octahedra. Similarly the salt contains a polymeric anion of composition with distorted octahedral SbIII. With nitrogen donor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Grignard Reagent
A Grignard reagent or Grignard compound is a chemical compound with the general formula , where X is a halogen and R is an organic group, normally an alkyl or aryl. Two typical examples are methylmagnesium chloride and phenylmagnesium bromide . They are a subclass of the organomagnesium compounds. Grignard compounds are popular reagents in organic synthesis for creating new carbon-carbon bonds. For example, when reacted with another halogenated compound in the presence of a suitable catalyst, they typically yield and the magnesium halide as a byproduct; and the latter is insoluble in the solvents normally used. In this aspect, they are similar to organolithium reagents. Pure Grignard reagents are extremely reactive solids. They are normally handled as solutions in solvents such as diethyl ether or tetrahydrofuran; which are relatively stable as long as water is excluded. In such a medium, a Grignard reagent is invariably present as a complex with the magnesium atom conn ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Antimony
Antimony is a chemical element with the symbol Sb (from la, stibium) and atomic number 51. A lustrous gray metalloid, it is found in nature mainly as the sulfide mineral stibnite (Sb2S3). Antimony compounds have been known since ancient times and were powdered for use as medicine and cosmetics, often known by the Arabic name kohl. The earliest known description of the metal in the West was written in 1540 by Vannoccio Biringuccio. China is the largest producer of antimony and its compounds, with most production coming from the Xikuangshan Mine in Hunan. The industrial methods for refining antimony from stibnite are roasting followed by reduction with carbon, or direct reduction of stibnite with iron. The largest applications for metallic antimony are in alloys with lead and tin, which have improved properties for solders, bullets, and plain bearings. It improves the rigidity of lead-alloy plates in lead–acid batteries. Antimony trioxide is a prominent additive for halo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylphosphine
Trimethylphosphine is a neutral organophosphorus compound with the formula P(CH3)3, commonly abbreviated as PMe3. This colorless liquid has a strongly unpleasant odor, characteristic of alkylphosphines. The compound is a common ligand in coordination chemistry. Structure and bonding It is a pyramidal molecule with approximate ''C''3''v'' symmetry. The C–P–C bond angles are approximately 98.6°. The C–P–C bond angles are consistent with the notion that phosphorus predominantly uses the 3p orbitals for forming bonds and that there is little sp hybridization of the phosphorus atom. The latter is a common feature of the chemistry of phosphorus. As a result, the lone pair of trimethylphosphine has predominantly s-character as is the case for phosphine, PH3. PMe3 can be prepared by the treatment of triphenyl phosphite with methylmagnesium chloride: : 3 CH3MgCl + P(OC6H5)3 → P(CH3)3 + 3 C6H5OMgCl The synthesis is conducted in dibutyl ether, from which the more volatile PMe3 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lewis Base
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 (Me3B) is 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 pos ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
III-V Semiconductor
Semiconductor materials are nominally small band gap insulators. The defining property of a semiconductor material is that it can be compromised by doping it with impurities that alter its electronic properties in a controllable way. Because of their application in the computer and photovoltaic industry—in devices such as transistors, lasers, and solar cells—the search for new semiconductor materials and the improvement of existing materials is an important field of study in materials science. Most commonly used semiconductor materials are crystalline inorganic solids. These materials are classified according to the periodic table groups of their constituent atoms. Different semiconductor materials differ in their properties. Thus, in comparison with silicon, compound semiconductors have both advantages and disadvantages. For example, gallium arsenide (GaAs) has six times higher electron mobility than silicon, which allows faster operation; wider band gap, which allo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
