- Metastable Ion Study of Organosilicon Compounds VI - Triethoxymethylsilane and Tetraethoxysilane
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The fragmentations of triethoxymethylsilane ((C2H5O)3SiCH3 (1)) and tetraethoxysilane ((C2H5O)4Si (3)) induced by electron impact were investigated by mass-analysed ion kinetic energy (MIKE) spectrometry and a deuterium-labelling study.These molecular ions begin to fragment by the loss of methyl, ethyl and/or ethoxy radicals.Almost complete scrambling of methylene hydrogen takes place in these resultant intermediate ions, prior to the elimination of acetaldehyde molecule.The fragmentations of +. and +. were compared with those of the corresponding carbon analogues, 1,1,1-triethoxyethane ((C2H5O)3CCH3 (2)) and tetraethoxymethane ((C2H5O)4C (3)), respectively.
- Tabei, Eiichi,Mori, Shigeru,Okada, Fumio,Tajima, Susumu,Ogino, Kazuo,et al.
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- THE PROCESS FOR THE PREPARATION AND USE OF HAIR TREATMENT COMPOSITIONS CONTAINING ORGANIC C1-C6 ALKOXY SILANES
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The subject of the present application is a method for the preparation and use of an agent for the treatment of keratinous material, in particular human hair, comprising the following steps: (1) Mixing one or more organic C1-C6 alkoxy silanes with water,(2) optionally, partial, or complete removal from the reaction mixture of the C1-C6 alcohols liberated by the reaction in step (1),(3) if necessary, addition of one or more cosmetic ingredients,(4) Filling of the preparation into a packaging unit,(5) Storage of the preparation in the packaging unit for a period of at least about 5 days; and(6) Application of the preparation on the keratinous material.
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- METHOD FOR TREATING HAIR, COMPRISING THE APPLICATION OF AN ORGANIC SILICON COMPOUND, AN ALKALISING AGENT AND A FILM-FORMING POLYMER
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It is an object of the present disclosure to provide a method for treating keratinous material, in particular human hair, comprising the following steps: Application of a water-containing agent (a) to the keratinous material, wherein the agent (a) has and contains a pH of at least 9.6:(a1) at least one organic silicon compound selected from the group including silanes having one, two or three silicon atoms, and(a2) at least one alkalizing agent selected from the group including ammonia, alkanolamines and basic amino acids, andApplication of an agent (b) to the keratinous material, wherein the agent (b) includes:(b1) at least one film-forming polymer.
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- Sustainable Catalytic Synthesis of Diethyl Carbonate
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New sustainable approaches should be developed to overcome equilibrium limitation of dialkyl carbonate synthesis from CO2 and alcohols. Using tetraethyl orthosilicate (TEOS) and CO2 with Zr catalysts, we report the first example of sustainable catalytic synthesis of diethyl carbonate (DEC). The disiloxane byproduct can be reverted to TEOS. Under the same conditions, DEC can be synthesized using a wide range of alkoxysilane substrates by investigating the effects of the number of ethoxy substituent in alkoxysilane substrates, alkyl chain, and unsaturated moiety on the fundamental property of this reaction. Mechanistic insights obtained by kinetic studies, labeling experiments, and spectroscopic investigations reveal that DEC is generated via nucleophilic ethoxylation of a CO2-inserted Zr catalyst and catalyst regeneration by TEOS. The unprecedented transformation offers a new approach toward a cleaner route for DEC synthesis using recyclable alkoxysilane.
- Putro, Wahyu S.,Ikeda, Akira,Shigeyasu, Shinji,Hamura, Satoshi,Matsumoto, Seiji,Lee, Vladimir Ya.,Choi, Jun-Chul,Fukaya, Norihisa
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p. 842 - 846
(2020/12/07)
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- Nucleophile induced ligand rearrangement reactions of alkoxy- and arylsilanes
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The ligand-redistribution reactions of aryl- and alkoxy-hydrosilanes can potentially cause the formation of gaseous hydrosilanes, which are flammable and pyrophoric. The ability of generic nucleophiles to initiate the ligand-redistribution reaction of commonly used hydrosilane reagents was investigated, alongside methods to hinder and halt the formation of hazardous hydrosilanes. Our results show that the ligand-redistribution reaction can be completely inhibited by common electrophiles and first-row transition metal pre-catalysts.
- Docherty, Jamie H.,Dominey, Andrew P.,Thomas, Stephen P.
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p. 3330 - 3335
(2019/05/10)
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- Preparation method of methyl triethoxysilane
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The invention discloses a preparation method of methyl triethoxysilane. The prepaeration method comprises the following steps of continuously adding an ethanol solution of sodium ethoxide into methyltrichlorosilane to perform alcoholysis; performing pressure-relief sucking and filtering, removing filter residue, rectifying, separating, purifying, and the like. The preparation method has the advantages that the reaction conditions are mild, the technology is easy to operate, the equipment investment is small, the scale production is convenient, the yield rate of the product is high, and the content of chloride in the product is low.
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Paragraph 0021-0026
(2019/02/04)
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- Synthesis of Polycyclic and Cage Siloxanes by Hydrolysis and Intramolecular Condensation of Alkoxysilylated Cyclosiloxanes
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The controlled synthesis of oligosiloxanes with well-defined structures is important for the bottom-up design of siloxane-based nanomaterials. This work reports the synthesis of various polycyclic and cage siloxanes by the hydrolysis and intramolecular condensation of monocyclic tetra- and hexasiloxanes functionalized with various alkoxysilyl groups. An investigation of monoalkoxysilylated cyclosiloxanes revealed that intramolecular condensation occurred preferentially between adjacent alkoxysilyl groups to form new tetrasiloxane rings. The study of dialkoxy- and trialkoxysilylated cyclotetrasiloxanes revealed multistep intramolecular condensation reactions to form cubic octasiloxanes in relatively high yields. Unlike conventional methods starting from organosilane monomers, intramolecular condensation enables the introduction of different organic substituents in controlled arrangements. So-called Janus cubes have been successfully obtained, that is, Ph4R4Si8O12, in which R=Me, OSiMe3, and OSiMe2Vi (Vi=vinyl). These findings will enable the creation of siloxane-based materials with diverse functions.
- Sugiyama, Tomoaki,Shiba, Hiroya,Yoshikawa, Masashi,Wada, Hiroaki,Shimojima, Atsushi,Kuroda, Kazuyuki
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p. 2764 - 2772
(2019/02/01)
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- A process for the production of alkoxy silane (by machine translation)
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The invention belongs to the field of chemical industry, relates to a production process of alkoxy silane, in order to improve the purity of the product. The production process comprises the following steps: A, eliminates the water mellowly enters into the reaction equipment, an esterification reaction with the organic silane; B, after the esterification reaction of the material entering the evaporation apparatus, and distilled to remove the material in a small amount of alcohol; C, in and after the distillation product to get the alkoxysilane; production process the start-up phase, the steps of adding excessive mellow A, the reaction apparatus in the backflow of appears mellowly; in the case of when the mellow backflow, add organochlorosilane, joins the quantity mellowly is reduced to the amount of consumption by the reaction. The invention relates to a simple process for the production of the realization of the alkoxy silane, in particular methyl triethoxy silane production. Relative to the other process reduces the rectifying tower, the circulation evaporator replace, increased water removal system and in the fixed-bed and system. In the reaction process through the control of the temperature, pressure and feed rate, the obtained alkoxy silane in the HCl content of 10 ppm following, purity 99.0% wt or more. (by machine translation)
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Paragraph 0033; 0034
(2017/07/15)
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- Synthesis of dimethylmanganese(II) complexes bearing N-heterocyclic carbenes and nucleophilic substitution reaction of tetraalkoxysilanes by diorganomanganese(II) complexes
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Reactions of manganese(II) dichlorides bearing a N-heterocyclic carbene ligand (L), [MnCl(μ-Cl)(L)]2(1a, L?=?1,3-diisopropyl-4,5-dimethylimidazole-2-ylidene (IiPr); 1b, L?=?1,3-bis(2,4,6-trimethylphenyl)imidazole-2-ylidene (IMes); 1c, L?=?1,3-bis(2,6-diisopropylphenyl)imidazole-2-ylidene (IPr)) with MeLi afford the dinuclear dimethylmanganese(II) complexes, [MnMe(μ-Me)(L)]2(2a, L?=?IiPr; 2b, L?=?IMes; 2c, L?=?IPr). Complexes 2a-c achieve nucleophilic substitution of Si(OEt)4to selectively form MeSi(OEt)3. Related arylmanganese(II) complexes analogously react with Si(OEt)4to afford ArSi(OEt)3and Ar2Si(OEt)2(Ar?= Ph, 2,6-Me2(C6H3)). Kinetic studies support an associative mechanism for the observed transformation of Si(OEt)4, in which both the manganese species and Si(OEt)4are involved in the rate-limiting step.
- Hashimoto, Takayoshi,Kawato, Yuko,Nakajima, Yumiko,Ohki, Yasuhiro,Tatsumi, Kazuyuki,Ando, Wataru,Sato, Kazuhiko,Shimada, Shigeru
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- Br?nsted acid-promoted formation of stabilized silylium ions for catalytic friedel-crafts C-H silylation
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A counterintuitive approach to electrophilic aromatic substitution with silicon electrophiles is disclosed. A strong Br?nsted acid that would usually promote the reverse reaction, i.e., protodesilylation, was found to initiate the C-H silylation of electron-rich (hetero)arenes with hydrosilanes. Protonation of the hydrosilane followed by liberation of dihydrogen is key to success, fulfilling two purposes: to generate the stabilized silylium ion and to remove the proton released from the Wheland intermediate.
- Chen, Qing-An,Klare, Hendrik F. T.,Oestreich, Martin
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supporting information
p. 7868 - 7871
(2016/07/07)
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- Mechanism of the Iron(II)-Catalyzed Hydrosilylation of Ketones: Activation of Iron Carboxylate Precatalysts and Reaction Pathways of the Active Catalyst
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A detailed mechanistic study of the catalytic hydrosilylation of ketones with the highly active and enantioselective iron(II) boxmi complexes as catalysts (up to >99% ee) was carried out to elucidate the pathways for precatalyst activation and the mechanism for the iron-catalyzed hydrosilylation. Carboxylate precatalysts were found to be activated by reduction of the carboxylate ligand to the corresponding alkoxide followed by entering the catalytic cycle for the iron-catalyzed hydrosilylation. An Eyring-type analysis of the temperature dependence of the enantiomeric ratio established a linear relationship of ln(S/R) and T-1, indicating a single selectivity-determining step over the whole temperature range from -40 to +65°C (ΔΔG?sel,? 233? K = 9 ± 1 kJ/mol). The rate law as well as activation parameters for the rate-determining step were derived and complemented by a Hammett analysis, radical clock experiments, kinetic isotope effect (KIE) measurements (kH/kD = 3.0 ± 0.2), the isolation of the catalytically active alkoxide intermediate, and DFT-modeling of the whole reaction sequence. The proposed reaction mechanism is characterized by a rate-determining σ-bond metathesis of an alkoxide complex with the silane, subsequent coordination of the ketone to the iron hydride complex, and insertion of the ketone into the Fe-H bond to regenerate the alkoxide complex.
- Bleith, Tim,Gade, Lutz H.
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supporting information
p. 4972 - 4983
(2016/05/10)
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- Chlorosilane alcoholysis acid removing agent and regeneration method thereof
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The invention discloses a chlorosilane alcoholysis acid removing agent and a regeneration method thereof. The regeneration method is characterized in that at a temperature of -10-130 DEG C, a substituting agent and an acid removing agent are added into a reactor in advance, chlorosilane is gradually added, the liquid phase obtained through filtration separation is subjected to rectification after the alcoholysis reaction is completed so as to obtain a silane finished product and the excessive substitution agent, the excessive substitution agent is recycled, and the acid removing agent obtained through filtration separation is recycled after being regenerated. According to the present invention, the yield of the silane prepared by using the process is more than or equal to 95%, and the recovery rate of the acid removing agent is more than or equal to 95%.
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Paragraph 0017
(2017/04/28)
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- COSMETIC TREATMENT METHOD COMPRISING THE APPLICATION OF A COATING BASED ON AN AEROGEL COMPOSITION OF LOW BULK DENSITY
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The present invention relates to a cosmetic treatment method comprising the formation of a coating on keratin fibres characterized in that it comprises: 1) the preparation of an aerogel precursor composition comprising:—at least one organic solvent chosen from acetone, C1-C4 alcohols, C1-C6 alkanes, C1-C4 ethers, which may or may not be perfluorinated, and mixtures thereof and at least one precursor compound that contains:—at least one atom chosen from silicon, titanium, aluminium and zirconium,—at least one hydroxyl or alkoxy function directly attached to the atom chosen from silicon, titanium, aluminium and zirconium by an oxygen atom, and,—optionally an organic group directly attached to the atom chosen from silicon, titanium, aluminium and zirconium by a carbon atom, 2) the removal of the solvent or solvents resulting in the formation of an aerogel composition having a bulk density less than or equal to 0.35 g/cm3, 3) the application to the keratin fibres of the aerogel composition resulting from step 2) or of the aerogel precursor composition resulting from step 1). Advantageously, the molar ratio between the precursor compounds and the solvent is at most 1/20.
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Paragraph 0067
(2014/02/15)
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- COMPOUNDS WITH GUANIDINE STRUCTURE AND USES THEREOF AS ORGANOPOLYSILOXANE POLYCONDENSATION CATALYSTS
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A compound having a guanidine structure and uses thereof as organopolysiloxane polycondensation catalysts are described.
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- CYCLIC AMINO COMPOUNDS FOR LOW-K SILYLATION
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Disclosed herein are mono-functional silylating compounds that may exhibit enhanced silylating capabilities. Also disclosed are method of synthesizing and using these compounds. Finally methods to determine effective silylation are also disclosed.
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- Some regularities of chlorosilanes etherification
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The influence of reagents, solvent polarity, and temperature on the etherification of chlorosilanes ClCH2SiCl3, VinSiCl 3, PrSiCl3, and Ph3SiCl with ethanol was studied. Influence of reaction temperature on the ratio of the synthesized alkoxysilane and related side-product siloxane is revealed. Use of excess alcohol is shown to increase the content of siloxane. Introduction of FeCl 3 does not affect the synthesis. Solvents are shown to influence the reaction rate: the rate constant increases with increasing ε parameter of the solvent. The rate constant of etherification of chlorosilanes with ethanol falls in the series: ClCH2SiCl3 > VinSiCl3 > PrSiCl3. An explanation of the regularities is suggested.
- Belyakova,Komarov,Bykovchenko,Ershov,Chernyshev,Storozhenko
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body text
p. 1650 - 1655
(2011/05/13)
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- Mechanism of olefin hydrosilylation catalyzed by [RuCl(NCCH3)5]+: A DFT study
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The hydrosilylation reaction between methyldimethoxysilane and methylvinyldimethoxysilane, catalyzed by the cationic species chloropenta(acetonitrile)ruthenium(II)+ (C1), was investigated with density functional theory (DFT). The Chalk-Harrod,
- Tuttle, Tell,Wang, Dongqi,Thiel, Walter,K?hler, Jutta,Hofmann, Marco,Weis, Johann
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p. 2282 - 2290
(2008/01/27)
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- Process for making haloalkylalkoxysilanes
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A haloalkylalkoxysilane is prepared by reacting an olefinic halide with an alkoxysilane in which the alkoxy group(s) contain at least two carbon atoms in the presence of a catalytically effective amount of ruthenium-containing catalyst. The process can be used to prepare, inter alia, chloropropyltriethoxysilane which is a key intermediate in the manufacture of silane coupling agents.
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- Use of an organometallic compound to protect and/or strengthen a keratin material, and treatment process
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The use of a composition comprising at least one organometallic compound which may be obtained by partial or total hydrolysis, and partial or total condensation, of at least one metallic precursor, to at least one of protect and strengthen a keratin material.
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- Effect of substituents on the silicon atom on etherification of organochlorosilanes with ethanol
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The kinetics of etherification of organochlorosilanes with various substituents on the silicon atom with ethanol were studied. The etherification rate is mostly controlled by the inductive constants of the substituents and increases as the electron-acceptor power of the substituents increases. The ρ* value in the Taft equation for etherification of organochlorosilanes with ethanol was determined.
- Chernyshev,Belyakova,Komarov,Bykovchenko
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p. 1038 - 1040
(2007/10/03)
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- Process for preparing low-chloride or chloride-free alkoxysilanes
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A process for preparing an alkoxysilane with an acidic chloride content of less than 10 ppm by weight, comprising: reacting a chlorosilane with an alcohol in a water-free and solvent-free phase to form a product mixture containing alkoxysilane and residual acidic chloride, with removal of resultant hydrogen chloride from the product mixture, then adding liquid or gaseous ammonia, in an amount corresponding to a stoichiometric excess, based on the content of acidic chloride, to form an ammonia-containing product mixture, treating the ammonia-containing product mixture at a temperature between 10 and 50 DEG C., wherein the ammonia and acidic chloride undergo neutralization, to form a crude product, and optionally, then separating off a salt formed in the course of neutralization, from the crude product, and recovering the alkoxysilane by distilling the crude product.
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- Utilization of bottoms of the direct synthesis of methylchlorosilanes in production of the crude mixtures of phenylethoxysilanes by continuous organomagnesium Procedure
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Utilization of the bottoms after distillation of methylchlorosilanes in continuous organomagnesium synthesis of organosilicon raw materials for production of polyphenylsiloxane resins and lacquers and enamels based on them was analyzed.
- Klokov
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p. 476 - 478
(2007/10/03)
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- Reaction of Tetraalkoxysilanes with Alkyl(aryl)chlorosilanes
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Alkyl(aryl)trichloro- or dialkyl(diaryl)dichlorosilanes react with tetraalkoxysilanes Si(OMe)4, Si(OEt)4, and Si(OBu)4 to give partially etherfied alkyl(aryl)chlorosilanes RSiCl2(OAlk), RSiCl(OAlk)2, and R2SiCl(OAlk).
- Chernyshev, E. A.,Komalenkova, N. G.,Tagachenkov, A. A.,Bykovchenko, V. G.
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p. 241 - 243
(2007/10/03)
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- Polyfunctional carbosilanes and organosilicon compounds. Synthesis via grignard reactions
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The THF solutions of (triethoxysilyl)methyl magnesium chloride are stable at low temperatures. At 20°C, the Grignard reagent underwent intermolecular condensation, providing a simple synthesis of cyclic carbosilanes derivatives. The cross-coupling reaction with organic halides also afforded a facile route to a variety of trifunctional organosilicon compounds.
- Brondani, Dalci J.,Corriu, Roben J. P.,El Ayoubi, Sabar,Moreau, Joel J. E.,Man, Michel Wong Chi
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p. 2111 - 2114
(2007/10/02)
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- Redistribution reactions of alkoxy- and siloxysilanes, catalyzed by dimethyltitanocene
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Dimethyltitanocene is an excellent catalyst for the redistribution of alkoxy- and siloxyhydrosilanes.The redistribution reactions of triethoxysilane, diethoxymethylsilane, 1,3,5,7-tetramethylcyclotetrasiloxane, pentamethyldisiloxane, and H-(SiMe2O)n-SiMe2H (n = 1 to 3) are described.The mechanism of these reactions is discussed in terms of TiH mediated displacements.The possibility of both Ti(III) and (IV) mediated displacements are considered and a mechanism involving the former, which fits all of the experimental data, is proposed.
- Xin, Shixuan,Aitken, Clare,Harrod, John. F.,Ying Mu,Samuel, E.
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p. 471 - 476
(2007/10/02)
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- ETHERIFICATION OF METHYLTRICHLOROSILANE WITH ALIPHATIC ALCOHOLS.
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The authors report the results of a study of etherification of MTCS with C//2-C//4 aliphatic alcohols. It is shown experimentally that the rate of etherification of MTCS falls with increase of the molecular weight of the aliphatic alcohol. Etherification is slower with alcohols of branched structure than with the corresponding alcohols of normal structure. The rate of etherification of MTCS decreases with decrease of the number of chlorine atoms in the organochlorosilane molecule, and the final stage is reversible.
- Utkin,Pavlova,Kolobkov,Vasil'ev
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p. 601 - 605
(2007/10/02)
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- Preparation of organically modified silicon dioxides
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Process for the preparation of modified, porous silicon dioxides by the hydrolytic polycondensation of tetraalkoxysilanes or polyalkoxysiloxanes in the heterogenous phase in the presence of an organoalkoxysilane.
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