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Tris(trimethylsilyl)silane
Tris(trimethylsilyl)silane is the organosilicon compound with the formula (Me3Si)3SiH (where Me = CH3). It is a colorless liquid that is classified as a hydrosilane since it contains an Si-H bond. The compound is notable as having a weak Si-H bond, with a bond dissociation energy estimated at 84 kcal/mol. For comparison, the Si-H bond in trimethylsilane is 94 kcal/mol. With such a weak bond, the compound is used as a reagent to deliver hydrogen atoms. The compound has been described as an environmentally benign analogue of tributyltin hydride. Reactions The compound can be prepared by protonation of tris(trimethylsilyl)silyl lithium, which is derived from tetrakis(trimethylsilyl)silane: :(Me3Si)4Si + MeLi → (Me3Si)3SiLi + Me4Si :(Me3Si)3SiLi + HCl → (Me3Si)3SiH + LiCl Alternatively, the reaction of trimethylsilyl chloride and trichlorosilane Trichlorosilane (TCS) is an inorganic compound with the formula HCl3Si. It is a colourless, volatile liquid. Purif ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Organosilicon Compound
Organosilicon chemistry is the study of organometallic compounds containing carbon–silicon bonds, to which they are called organosilicon compounds. Most organosilicon compounds are similar to the ordinary organic compounds, being colourless, flammable, hydrophobic, and stable to air. Silicon carbide is an ''inorganic'' compound. History In 1863, Charles Friedel and James Crafts made the first organochlorosilane compound. The same year, they also described a "polysilicic acid ether" in the preparation of ethyl- and methyl-o-silicic acid. Extensive research in the field of organosilicon compounds was pioneered in the beginning of 20th century by Frederic S. Kipping. He also had coined the term "silicone" (resembling ''ketones'', though this is erroneous) in relation to these materials in 1904. In recognition of Kipping's achievements, the Dow Chemical Company had established an award in the 1960s that is given for significant contributions to the field of silicon chemistry ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetrakis(trimethylsilyl)silane
Tetrakis(trimethylsilyl)silane is the organosilicon compound with the formula (Me3Si)4Si (where Me = CH3). It is a colorless sublimable solid with a high melting point. The molecule has tetrahedral symmetry. The compound is notable as having silicon bonded to four other silicon atoms, like in elemental silicon. Preparation and reactions The compound is prepared by the reaction of trimethylsilyl chloride, silicon tetrachloride, and lithium: :4 Me3SiCl + SiCl4 + 8 Li → (Me3Si)4Si + 8 LiCl The compound is a precursor to tris(trimethylsilyl)silyl lithium by reaction with methyl lithium:{{cite journal, title=Tris(trimethylsilyl)silane, author=Joachim Dickhaut, Bernd Giese, journal=Org. Synth., year=1992, volume=70, page=164, doi=10.15227/orgsyn.070.0164 :(Me3Si)4Si + MeLi → (Me3Si)3SiLi + Me4Si The organolithium compound (Me3Si)3SiLi is a versatile reagent, e.g. to tris(trimethylsilyl)silane ((Me3Si)3SiH). See also * Tris(trimethylsilyl)methane Tris(trimethyl ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bond Dissociation Energy
The bond-dissociation energy (BDE, ''D''0, or ''DH°'') is one measure of the strength of a chemical bond . It can be defined as the standard enthalpy change when is cleaved by homolysis to give fragments A and B, which are usually radical species. The enthalpy change is temperature-dependent, and the bond-dissociation energy is often defined to be the enthalpy change of the homolysis at 0 K (absolute zero), although the enthalpy change at 298 K ( standard conditions) is also a frequently encountered parameter. As a typical example, the bond-dissociation energy for one of the C−H bonds in ethane () is defined as the standard enthalpy change of the process : , : ''DH''°298() = Δ''H°'' = 101.1(4) kcal/mol = 423.0 ± 1.7 kJ/mol = 4.40(2) eV (per bond). To convert a molar BDE to the energy needed to dissociate the bond ''per molecule'', the conversion factor 23.060 kcal/mol (96.485 kJ/mol) for each eV can be used. A variety of experi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Reagent
In chemistry, a reagent ( ) or analytical reagent is a substance or compound added to a system to cause a chemical reaction, or test if one occurs. The terms ''reactant'' and ''reagent'' are often used interchangeably, but reactant specifies a substance ''consumed'' in the course of a chemical reaction. ''Solvents'', though involved in the reaction mechanism, are usually not called reactants. Similarly, ''catalysts'' are not consumed by the reaction, so they are not reactants. In biochemistry, especially in connection with enzyme-catalyzed reactions, the reactants are commonly called substrates. Definitions Organic chemistry In organic chemistry, the term "reagent" denotes a chemical ingredient (a compound or mixture, typically of inorganic or small organic molecules) introduced to cause the desired transformation of an organic substance. Examples include the Collins reagent, Fenton's reagent, and Grignard reagents. Analytical chemistry In analytical chemistry, a reag ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tributyltin Hydride
Tributyltin hydride is an organotin compound with the formula (C4H9)3SnH. It is a colorless liquid that is soluble in organic solvents. The compound is used as a source of hydrogen atoms in organic synthesis. Synthesis and characterization The compound is produced by reduction of tributyltin oxide with polymethylhydrosiloxane: : 2 " eSi(H)Osub>n" + (Bu3Sn)2O → " eSi(OH)Osub>n" + 2 Bu3SnH It can also be synthesized by a reduction of tributyltin chloride with lithium aluminium hydride. The hydride is a distillable liquid that is mildly sensitive to air, decomposing to (Bu3Sn)2O. Its IR spectrum exhibits a strong band at 1814 cm−1 for ''ν''Sn−H. Applications It is a specialized reagent in organic synthesis. Combined with azobisisobutyronitrile (AIBN) or by irradiation with light, tributyltin hydride converts organic halides (and related groups) to the corresponding hydrocarbon. This process occurs via a radical chain mechanism involving the radical Bu3S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trimethylsilyl Chloride
Trimethylsilyl chloride, also known as chlorotrimethylsilane is an organosilicon compound ( silyl halide), with the formula , often abbreviated or TMSCl. It is a colourless volatile liquid that is stable in the absence of water. It is widely used in organic chemistry. Preparation TMSCl is prepared on a large scale by the '' direct process'', the reaction of methyl chloride with a silicon-copper alloy. The principal target of this process is dimethyldichlorosilane, but substantial amounts of the trimethyl and monomethyl products are also obtained. The relevant reactions are (Me = methyl, ): x\ \ce \longrightarrow \begin \ce, \\ pt \ce, \\ pt \ce,\\ pt \text \end Typically about 2–4% of the product stream is the monochloride, which forms an azeotrope with . Reactions and uses TMSCl is reactive toward nucleophiles, resulting in the replacement of the chloride. In a characteristic reaction of TMSCl, the nucleophile is water, resulting in hydrolysis to give the hexa ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trichlorosilane
Trichlorosilane (TCS) is an inorganic compound with the formula HCl3Si. It is a colourless, volatile liquid. Purified trichlorosilane is the principal precursor to ultrapure silicon in the semiconductor industry. In water, it rapidly decomposes to produce a siloxane polymer while giving off hydrochloric acid. Because of its reactivity and wide availability, it is frequently used in the synthesis of silicon-containing organic compounds. Production Trichlorosilane is produced by treating powdered metallurgical grade silicon with blowing hydrogen chloride at 300 °C in a hydrochlorination process. Hydrogen is also produced, as described in the chemical equation: :Si + 3 HCl → HCl3Si + H2 Yields of 80-90% can be achieved. The main byproducts are silicon tetrachloride (chemical formula SiCl4), hexachlorodisilane (Si2Cl6) and dichlorosilane (H2SiCl2), from which trichlorosilane can be separated by distillation. It is also produced from silicon tetrachloride in a dir ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Carbosilanes
Carbosilanes are organosilicon compounds where the structures feature alternating silicon and carbon atoms, i.e., linkages. They represent molecular analogues of silicon carbide. The compounds exploit the tendency of both carbon and silicon to form tetrahedral structures. The inventory of carbosilanes is large. Synthesis and structure The compounds originally were obtained as products of the pyrolysis Pyrolysis is a process involving the Bond cleavage, separation of covalent bonds in organic matter by thermal decomposition within an Chemically inert, inert environment without oxygen. Etymology The word ''pyrolysis'' is coined from the Gree ... of simple organosilicon precursors such as the methylsilanes. More efficient precursors contain premade {{chem2, \sSi\sC\sSi\sC\s subunits. References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
