- PROCESSES FOR SYNTHESIZING UNSYMMETRICAL DISILOXANES
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Described herein are methods for making alkenyl disiloxanes, comprising combining an alkenyl halosilane with an alkyl halosilane and adding the mixture to water, an acidic aqueous solution, or a basic aqueous solution. The ratio of the alkenyl halosilane to the alkyl halosilane is about 10:1 to about 1:10. The alkenyl halosilane and the alkyl halosilane are mixed at about 20 °C to about 45 °C. The reaction product is separated and washed with saturated alkali carbonate solution.
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Paragraph 0044-0046
(2021/06/22)
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- Organic silicon low boiling processing method
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The invention discloses a treatment method of an organic silicon low-boiling-point substance and particularly relates to a method of treating an organic silicon low-boiling-point substance by utilizing reverse dropwise adding of concentrated hydrochloric acid. The method comprises the following steps: a, adding the organic silicon low-boiling-point substance into a reaction kettle with a filled column and stirring, and then, dropwise adding concentrated hydrochloric acid from the middle part of the filled column while stirring to carry out reaction; 1.5-1 hour after dropwise adding the concentrated hydrochloric acid, heating a reaction system to 40 DEG C-50 DEG C to continuously react for 1-2 hours; b, ventilating tail gas generated by reaction into a hydrochloric acid absorbing device, an organic absorbing device and a tetramethylsilane condensing and recycling device in sequence; c, after the reaction in the step a is finished, standing for a certain time, and discharging the hydrochloric acid from the reaction kettle; and d, heating the reaction kettle, keeping the temperature in the kettle at 60 DEG C-70 DEG C for carrying out distillation to obtain tetramethylsilane. According to the treatment method disclosed by the invention, three products of the tetramethylsilane, the hydrochloric acid and hydrolysate can be obtained, so that a novel method is provided for treating the organic silicon low-boiling-point substance.
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Paragraph 0034 - 0036
(2017/03/22)
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- Dendritic, nanosized building block for Siloxane-based materials: A spherosilicate dendrimer
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A spherosilicate dendrimer (DMS-1) with closely spaced reaction sites (Si-H groups) on the dendrimer surface has been synthesized by stepwise silylation of double-four-ring silicate with chlorotriethoxysilane (ClSi(OEt)3) and subsequently with chlorodimethylsilane (ClSiHMe2). DMS-1 consists of a maximum of 40 Si atoms in the interior frameworks and 24 reactive Si-H groups on the surface. Because DMS-1 is spherical and about 1.5 nm in diameter, it can be regarded as the smallest well-defined silica-based nanoparticle. DMS-1 also forms molecular crystals and is soluble in typical organic solvents. A molecularly ordered silica-based hybrid can be prepared by heating a cast film of DMS-1 at 180 °C for 5 days. The surface of DMS-1 can be modified by hydrosilylation with 1-hexadecene, triethoxyvinylsilane, and allylic-terminated tetraethylene glycol monomethyl ether. More than 20 Si-H groups out of 24 react with these reagents. The solubilities of the products depend on the modification. DMS-1 is not only a building block for nanohybrids, but also the smallest and most precisely designed siloxane-based nanoparticle.
- Kawahara, Kazufumi,Hagiwara, Yoshiaki,Kuroda, Kazuyuki
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experimental part
p. 13188 - 13196
(2012/02/06)
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- Studies on the synthesis and thermal properties of alkoxysilane-terminated organosilicone dendrimers
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Silicone core dendrimers bearing terminaldialkoxy andtrialkoxy silane groups were prepared in a three-step synthesis. Initially, the Si-H terminated multifunctional silicone dendrimer, i.e. tetrakis(dimethylsiloxy)silane, was prepared by the reaction of tetraethoxysilane and dimethylethoxysilane. Tetrakis(dimethylsiloxy)silane on reaction with allylglycidylether in the presence of Speier's catalystunderpressure (100 psi) yieldedepoxy- terminateddendrimerin veryhigh yield (95%).Theepoxy-terminated dendrimer was reacted with aminopropylalkoxysilanes to yield the next-generation dendrimer bearing dialkoxy and trialkoxy silane groups. The dendrimers were characterized by the usual physico-chemical techniques, i.e. elemental analysis, FT-IR, 1H, 13C and 29Si NMR. Thermal studies (Thermogravimetric analysis and Thermomechanical analysis) of the alkoxy terminated dendrimers and its cured products were also carried out. Copyright
- Saxena, Kanak,Bisaria,Saxena
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experimental part
p. 251 - 256
(2010/11/16)
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- Electrochemical synthesis of symmetrical difunctional disilanes as precursors for organofunctional silanes
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Difunctional disilanes of the general type XR2SiSiR2X (1-5) (X = OMe, H; R = Me, Ph, H) have been synthesized by electrolysis of the appropriate chlorosilanes XR2SiCl in an undivided cell with a constant current supply and in the absence of any complexing agent. Reduction potentials of the chlorosilane starting materials derived from cyclic voltammetry measurements were used to rationalize the results of preparative electrolyses. Organofunctional silanes of the general formula MeO(Me 2)SiC6H4Y (6a-c, 7) were subsequently obtained by the reaction of sym-dimethoxytetramethyldisilane (1) with NaOMe in the presence of p-functional aryl bromides BrC6H4Y (Y = OMe, NEt2, NH2).
- Grogger, Christa,Loidl, Bernhard,Stueger, Harald,Kammel, Thomas,Pachaly, Bernd
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p. 105 - 110
(2007/10/03)
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- Optical disk-based assay devices and methods
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Optical disk-based assay devices and methods are described, in which analyte-specific signal elements are disposed on an optical disk substrate. In preferred embodiments, the analyte-specific signal elements are disposed readably with the disk's tracking features. Also described are cleavable signal elements particularly suitable for use in the assay device and methods. Binding of the chosen analyte simultaneously to a first and a second analyte-specific side member of the cleavable signal element tethers the signal-responsive moiety to the signal element's substrate-attaching end, despite subsequent cleavage at the cleavage site that lies intermediate the first and second side members. The signal responsive moiety reflects, absorbs, or refracts incident laser light. Described are nucleic acid hybridization assays, nucleic acid sequencing, immunoassays, cell counting assays, and chemical detection. Adaptation of the assay device substrate to function as an optical waveguide permits assay geometries suitable for continuous monitoring applications.
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- Process for the preparation of 1,3-dihalo-1,1,3,3-tetra(organyl) disiloxanes
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1,3-dihalo-1,1,3,3-tetra(organyl)disiloxanes of the general formula XR2Si—O—SiR2X??(1) are prepared by reacting hydrogen halide with the corresponding 1,3-dihydro-1,1,3,3-tetra(organyl)disiloxanes of the general formula HR2Si—O—SiR2H??(2), in which R is an alkyl or halogen substituted alkyl group and X is halogen, in the presence of a catalyst selected from transition metals of the 8th subgroup of the periodic table of the elements, or compounds or complexes of these transition metals.
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- Optical disk-based assay devices and methods
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Optical disk-based assay devices and methods are described, in which analyte-specific signal elements are disposed on an optical disk substrate. In preferred embodiments, the analyte-specific signal elements are disposed readably with the disk's tracking features. Also described are cleavable signal elements particularly suitable for use in the assay device and methods. Binding of the chosen analyte simultaneously to a first and a second analyte-specific side member of the cleavable signal element tethers the signal-responsive moiety to the signal element's substrate-attaching end, despite subsequent cleavage at the cleavage site that lies intermediate the first and second side members. The signal responsive moiety reflects, absorbs, or refracts incident laser light. Described are nucleic acid hybridization assays, nucleic acid sequencing, immunoassays, cell counting assays, and chemical detection. Adaptation of the assay device substrate to function as an optical waveguide permits assay geometries suitable for continuous monitoring applications.
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- Ion-molecular reactions of free ethylsilicenium ions with alcohols in the gas phase
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Ion-molecular reactions of free ethylsilicenium ions with methanol and isobutanol in the gas phase were studied radiochemically. Within the reaction time the ethylsilicenium ion completely isomerizes into the dimethylsilicenium ion. The reaction mechanism was suggested.
- Kochina,Shchukin,Nefedov,Sinotova
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p. 885 - 888
(2007/10/03)
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- A novel catalytic system for the Mannich-type reaction of silyl enolates: Stereoselective synthesis of β-aminoketones
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Water and a catalytic amount of iPr2NH effectively induces the Mannich- type reaction of ketone dimethylsilyl enolates with aromatic and α,β- unsaturated N-sulfonylimines, to afford β-aminoketones in good to excellent yields with high levels of
- Miura, Katsukiyo,Tamaki, Kentaro,Nakagawa, Takahiro,Hosomi, Akira
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p. 1958 - 1960
(2007/10/03)
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- Siloxane basicity toward strong acid in nonpolar solution
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The relative basicities of ten siloxanes and an ether were studied in benzene by determining from visible spectroscopic measurements the thermodynamic constants for the competition between the substrate and a reference base (4-chloro-2-nitroaniline) for acid (trifluoromethanesulfonic acid): RB-HA + S ? RB + S·HA. The Keq values were considered as a measure of basicity with the following order established and explained by inductive effects in the protonated species: permethyl linear siloxanes (Me3Si(OSiMe2)nOSiMe3, n = 0-3) > dibutyl ether > HMe2SiOSiMe2H > branched siloxanes ((Me3SiO)3SiMe, (Me3SiO)4Si) > cyclic siloxanes ((Me2SiO)n, n = 3-5). The ΔH and ΔS values were positive and increased with higher basicity; this behavior was attributed to differential solvation of ion pairs.
- Shepherd, Brian D.
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p. 5581 - 5583
(2007/10/02)
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- GENERATION AND REARRANGEMENT OF A 1-NORBORNENE IN PYROLYSIS OF 1-SILA-OXYNORBORNANES
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Gas phase pyrolysis of 1-sila-2-oxynorbornenes yields a nortricyclene which is proposed to arise from a β-elimination to form a 1-norbornene, which isomerizes to a 2-norbornacylidene which undergoes γ-CH insertion.
- Barton, Thomas J.,Yeh Ming-Hsiung
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p. 6421 - 6424
(2007/10/02)
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- Determination of the Molecular Structures of Bis(methylsilyl) Ether and Bis(dimethylsilyl) Ether in the Gas Phase by Electron Diffraction
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The molecular structures of the title compounds, O(SiH2Me)2 and O(SiHMe2)2, in the gas phase, have been determined by electron diffraction.The monomethylsilyl ether has at least two conformers, the major one (64percent) having the methyl groups twisted by 124(4) and 58(8) deg away from the positions in which the Si-C bonds are trans to O-Si bonds.Other important parameters (ra) are: r(Si-C) 186.4(3), r(Si-O) 164.2(3) pm; SiOSi 143.0(6) and OSiC 109.7(5) deg.In the dimethylsilyl ether the silyl groups are twisted by 101(8) and 41(4) deg away from the symmetrical position in which both Si-H bonds are cis to O-Si bonds, so that the dimethylsilyl groups are staggered with respect to each other.Principal parameters (ra) are: r(Si-C) 186.4(3), r(Si-O) 163.5(2) pm; SiOSi 148.4(9), OSiC 110.1(6), and CSiC 107.4(17) deg.
- Rankin, David W. H.,Robertson, Heather E.
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p. 265 - 270
(2007/10/02)
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- THE SILICON-OXYGEN DOUBLE-BONDED INTERMEDIATES. A NEW METHOD FOR THE FORMATION OF ORGANOSILANONES
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The kinetics and mechanism of thermal decomposition of R1R2(H)SiOOR3 silylperoxides have been studied.It has been shown that peroxides generated diorganosilanones, R1R2Si=O, with a high yield in the temperature range 130-180 deg C.A mechanism is suggested for the silanone formation.The interaction of silanones with cyclosiloxanes, triethylsilane, α-methylstyrene has been investigated as well as the cyclisation of silanones.
- Tomadze, A. V.,Yablokova, N. V.,Yablokov, V. A.,Razuvaev, G. A.
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- Studies of silyl and germyl Group VI species. Part IV. Dimethyl- and tetramethyl-disilyl chalcogenides and related species
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The symmetrically substituted disilyl chalcogenides (MenH3-nSi)2E where E = O, S, Se, Te; n = 0 -> 3, have been prepared and characterized spectroscopically and by cleavage reactions.The synthetic routes include reactions of halogenosilanes with water, mercury(II) sulfide, lithium telluride, and complex thio- and seleno-aluminates.The spectroscopic properties of the (MeH2Si)2E and (Me2HSi)2E species, which have not been reported previously, are discussed in some detail.
- Drake, John E.,Glavincevski, Boris M.,Hemmings, Raymond T.
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p. 2161 - 2166
(2007/10/02)
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- INSERTION OF DIMETHYLSILYLENE INTO O-H AND N-H SINGLE BONDS
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Dimethylsilylene, generated by photolysis of dodecamethylcyclohexasilane, inserts efficiently into O-H single bonds of alcohols to yield alkoxydimethyl-silanes.Use of ethanol-O-d1 yields ethoxydimethylsilane-Si-d1.Dimethylsilylene also inserts into O-H single bonds of water or D2O to yield respectively tetramethyldisiloxane or tetramethyldisiloxane-Si2-d2.Dimethylsilylene also inserts into N-H bonds of primary and secondary amines to yield aminodimethylsilanes.This reaction provides an efficient route to difunctional silanes.
- Gu, Tai-Yin Yang,Weber, William P.
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