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  • aromatic
  • In the co: ventional preparation of alkyl-substituted aromatic compounds by the Friedel-Crafts reaction, an aromatic compound such as benzene is reacted with an allryl halide, such as n-amyl chloride, in the presence of chloride and a suitable solvent such as carbon disulfide. (google.com)
  • Unexpectedly I have discovered that when this same reaction is applied to-organosilicon compounds containing silicon-bonded chloroalkyl radicals, instead of forming a product containing a .silyl -alkyl' radical attached to an aromatic nucleus, the product is a silylalkyl arylcarbithioate. (google.com)
  • and an aromatic compound having the following formula disulfidi- In Formulae 3 and 4, R, R, X, a-and b have Patented Aug. 13, 1957 the meaning discussed above in connection with Formula 1. (google.com)
  • The aromatic compounds within the scope of Formula 4 are also well known in the art and those containing halogen are prepared, for example, by the halogenation of benzene or various alkyl benzenes. (google.com)
  • In'the preparation of the silylalkyl arylcarbithioates of Formula 1 by reaction between an a-chloroalkyl silane within the scope of Formula 3, an aromatic compound withinthe scope of Formula 4, aluminum chloride and carbon disulfide,- the proportions of the ingredients are not critical and may vary within wide limits. (google.com)
  • The amount of carbon disulfide or of the aromatic compound within the scope of Formula 4 may also vary within extremely wide limits because of the fact that either of these two ingreclients may be employed as a solvent for the reaction mixture. (google.com)
  • cyclic
  • The cyclic compound which best mimics the action of the natural pheromones presumably has a conformation similar to that which the pheromone adopts when bound to the receptor site. (lsu.edu)
  • Cyclomethicones are a group of methyl siloxanes, a class of liquid silicones (cyclic polydimethylsiloxane polymers) that possess the characteristics of low viscosity and high volatility as well as being skin emollients and in certain circumstances useful cleaning solvents. (wikipedia.org)
  • atoms
  • The scarcity of silicon-sulfur compounds in the reaction products is undoubtedly due to the instability of these compounds and to the affinity of SiF2 for atoms other than sulfur. (rice.edu)
  • The researchers first grow a thin layer of the material using molecular beam epitaxy, a process widely used in the semiconductor industry in which evaporated atoms of indium, gallium and arsenic react with each other within a vacuum to form a single-crystal compound. (cellular-news.com)
  • Higher energy lone pairs of electrons on oxygen atoms either hyperconjugate to vicinal silanol/siloxane antibonding orbitals or backdonate electron density via donor-acceptor pi-type bonding with participation of pd or p hybrids on silicon atoms. (cdc.gov)
  • silica
  • In one embodiment, the silicon compounds are attached to the surface of a substrate comprising silica, such as a glass substrate, to provide a functionalized surface on the substrate, to which molecules, including polypeptides and nucleic acids, may be attached. (google.co.uk)
  • In one embodiment, after covalent attachment of a functionalized silicon compound to the surface of a solid silica substrate to form a functionalized coating on the substrate, an array of nucleic acids may be covalently attached to the substrate. (google.co.uk)
  • Evonik Industries and Jiangsu Zhongneng Polysilicon Technology Development Co. Ltd., a wholly owned subsidiary of GCL-Poly Energy Holdings Limited, have signed a letter of intent to establish a joint venture for the production of fumed silica and ultra-pure silicon tetrachloride in China. (coatingsworld.com)
  • Silicon tetrachloride is a byproduct of PCS production, and the joint venture will purchase this to produce AEROSIL fumed silica and Siridion STC HP ultra-pure silicon tetrachloride. (coatingsworld.com)
  • By making the planned investment we are aiming to further strengthen our market position for fumed silica and ultra-pure silicon tetrachloride and to promote growth, particularly in the attractive Chinese market,' said Klaus Engel, CEO of Evonik Industries. (coatingsworld.com)
  • This cooperation can combine Evonik's advanced technologies of producing silica and ultra-pure silicon tetrachloride with Jiangsu Zhongneng's leading technologies of silicon material production. (coatingsworld.com)
  • Most free silicon is used in the steel refining, aluminium-casting, and fine chemical industries (often to make fumed silica). (wikipedia.org)
  • In 1787 Antoine Lavoisier suspected that silica might be an oxide of a fundamental chemical element, but the chemical affinity of silicon for oxygen is high enough that he had no means to reduce the oxide and isolate the element. (wikipedia.org)
  • silicon tetrafluoride had already been prepared long before in 1771 by Carl Wilhelm Scheele by dissolving silica in hydrofluoric acid. (wikipedia.org)
  • reaction
  • Monochlorides of esters of phospheric acid also react with hexamethyldisilazane under heterocyclic fission of the Si-N-compound, while the reaction of trimethyl-N-methylamino-silane results in the substitution of the H-atom attached to the N-atom without any fission of the Si-N-compound. (dtic.mil)
  • Methanol converts it to trimethoxymethylsilane: MeSiCl3 + 3 CH3OH → MeSi(OCH3)3 + 3 HCl Reduction of methyltrichlorosilane with alkali metals forms a highly crosslinked material called poly(methylsilyne): n MeSiCl3 + 3n Na →[MeSi]n + 3n NaCl The reaction illustrates the susceptibility of silicon halides to reductive coupling. (wikipedia.org)
  • Si-I. Silicon tetrabromide is synthesized by the reaction of silicon with hydrogen bromide at 600 °C. Si + 4 HBr → SiBr4 + 2 H2 Side products include dibromosilane (SiH2Br2) and tribromosilane (SiHBr3). (wikipedia.org)
  • The reaction involves a copper-catalyzed reaction of alkyl halides with silicon metal, which takes place in a fluidized bed reactor. (wikipedia.org)
  • The alpha-silicon effect is the destabilizing effect of a silicon atom (relative to a carbon atom) next to a reaction center with a partial positive charge. (wikipedia.org)
  • Addition of alkali to the β-substituted compound on the other hand leads to an elimination reaction with liberation of ethylene. (wikipedia.org)
  • amorphous silicon
  • Polysilicon is distinct from monocrystalline silicon and amorphous silicon. (wikipedia.org)
  • Although it can be deposited by LPCVD, plasma-enhanced chemical vapour deposition (PECVD), or solid-phase crystallization of amorphous silicon in certain processing regimes, these processes still require relatively high temperatures of at least 300 °C. These temperatures make deposition of polysilicon possible for glass substrates but not for plastic substrates. (wikipedia.org)
  • Therefore, a relatively new technique called laser crystallization has been devised to crystallize a precursor amorphous silicon (a-Si) material on a plastic substrate without melting or damaging the plastic. (wikipedia.org)
  • In 1811, Gay-Lussac and Thénard are thought to have prepared impure amorphous silicon, through the heating of recently isolated potassium metal with silicon tetrafluoride, but they did not purify and characterize the product, nor identify it as a new element. (wikipedia.org)
  • In 1823, Jöns Jacob Berzelius prepared amorphous silicon using approximately the same method as Gay-Lussac (reducing potassium fluorosilicate with molten potassium metal), but purifying the product to a brown powder by repeatedly washing it. (wikipedia.org)
  • semiconductor
  • Although many of the techniques applied by the team are already used in silicon fabrication, they have only rarely been used to make compound semiconductor transistors. (cellular-news.com)
  • But when you are talking about integrating billions of tiny transistors onto a chip, then we need to completely reformulate the fabrication technology of compound semiconductor transistors to look much more like that of silicon transistors,' del Alamo says. (cellular-news.com)
  • The products are then sliced into thin silicon wafers and used for the production of solar cells, integrated circuits and other semiconductor devices. (wikipedia.org)
  • Even more visibly, the relatively small portion of very highly purified silicon used in semiconductor electronics ( (wikipedia.org)
  • ionic
  • The medium effects are consistent with an ionic mechanism, wherein hydride transfer occurs prior to silicon-oxygen bond formation. (osti.gov)
  • This means that ionic compounds use too much energy to make. (wikipedia.org)
  • substrate
  • They are used as thin films or as nanoparticles, obtained by means of epitaxial growth on a silicon substrate. (wikipedia.org)
  • Short, high-intensity ultraviolet laser pulses are used to heat the deposited a-Si material to above the melting point of silicon, without melting the entire substrate. (wikipedia.org)
  • Clusters
  • The cubic cages are cubane-type clusters, with silicon centers at the corners of a cube oxygen centres spanning each of the twelve edges. (wikipedia.org)
  • Oxygen
  • Siloxanes also include branched compounds, the defining feature of which is that each pair of silicon centres is separated by one oxygen atom. (wikipedia.org)
  • The word siloxane is derived from the words silicon, oxygen, and alkane. (wikipedia.org)
  • Over 90% of the Earth's crust is composed of silicate minerals, making silicon the second most abundant element in the Earth's crust (about 28% by mass) after oxygen. (wikipedia.org)
  • octet rule
  • Although silicon tetrahalides obey the octet rule, they add Lewis basic ligands to give adducts with the formula SiBr4L and SiBr4L2 (where L is a Lewis base). (wikipedia.org)
  • In these structures, the chemical bonds to silicon conform to the octet rule. (wikipedia.org)
  • Bonds
  • First page The Reactivity with Alkali of Chlorine-Carbon Bonds Alpha, Beta and Gamma to Silicon Leo H. Sommer, Edwin Dorfman, Gershon M. Goldberg, Frank C. Whitmore J. Am. Chem. (wikipedia.org)
  • Aluminium
  • Effects of Silicon on the Toxicity of Aluminium to Soybean. (degruyter.com)
  • Commercially relevant aluminium alloys containing silicon have at least element added. (wikipedia.org)
  • Note that tectosilicates can only have additional cations if some of the silicon is replaced by a lower-charge cation such as aluminium. (wikipedia.org)
  • By electrolyzing a mixture of sodium chloride and aluminium chloride containing approximately 10% silicon, he was able to obtain a slightly impure allotrope of silicon in 1854. (wikipedia.org)
  • DERIVATIVES
  • They give an excellent overview of current research into many areas of tin and silicon, encompassing both inorganic and organometallic derivatives and fundamental and applied studies. (docme.ru)
  • 1989
  • f80.00 ISBN 0 19 855580 6 In October 1989, the 1st International Chemical Conference on Silicon and Tin, which was organized by the Asian Network for Analyticd and Inorganic Chemistry (ANAIC), was held at the Institute of Advanced Studies, University of Malaya in Kuala Lumpur. (docme.ru)
  • ceramics
  • Pyrolysis of SiBr4 followed by treatment with ammonia yields silicon nitride (Si3N4) coatings, a hard compound used for ceramics, sealants, and the production of many cutting tools. (wikipedia.org)
  • Formula
  • The present invention provides a silicon-containing polymer which contains a repeating unit shown by the general formula (1-3) and one or more repeating units. (patents.com)
  • In aqueous solution, the hydronium cation (H3O+) is traditionally equated with a solvated proton, and as such, the formula for this compound is often written as H 2SiF 6. (wikipedia.org)
  • methyl
  • Compound (21) was also obtained using the same method from 2-(5-acetoxypentyl)-3-methyl-cyclohexan-one (63). (lsu.edu)
  • alkyl
  • This can be explained by a stronger increase in electron density on the silicon atom by the alkyl groups. (wikipedia.org)
  • boron
  • He retained part of Davy's name but added "-on" because he believed that silicon was a nonmetal similar to boron and carbon. (wikipedia.org)
  • Chloride
  • Chloride is used to reduce the tendency of silicon to react in the gas phase and thus to increase the growth rate of the process. (wikipedia.org)
  • surface
  • or grown on a silicon surface MnSi1.73 was investigated as thermoelectric material and as an optoelectronic thin film. (wikipedia.org)
  • temperatures
  • however, samarium compounds can withstand significantly higher temperatures, above 700 °C (1,292 °F), without losing their magnetic properties, due to the alloy's higher Curie point. (wikipedia.org)
  • form
  • The functionalized silicon compounds may be covalently attached to surfaces to form functionalized surfaces which may be used in a wide range of different applications. (google.co.uk)
  • Myriad silicate anions can exist, and each can form compounds with many different cations. (wikipedia.org)
  • applications
  • M-units: (CH3)3SiO0.5, D-units: (CH3)2SiO, T-units: (CH3)SiO1.5 Because silicones are heavily used in biomedical and cosmetic applications, their toxicology has been intensively examined. (wikipedia.org)