- Synthesis of alkyl fluorosilanes by the reaction of alkyl chlorosilanes with pyridinium poly(hydrogen fluoride) at room temperature
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Dimethyl difluorosilane (DFS) has been prepared in high yield (80-90percent) by the reaction of dimethyl dichloro-silane with pyridinium poly(hydrogen fluoride) at room temperature (25-35 deg C).The gas has been characterised by IR and 19F NMR spectroscopy, molecular weight measurements and elemental analysis.The method has been extended to the preparation in high yields of monomethyl and trimethyl fluorosilanes.
- Muddukrishna, K. R.,Padma, D. K.
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- Depolymerization of end-of-life poly(dimethylsilazane) with boron trifluoride diethyl etherate to produce difluorodimethylsilane as useful commodity
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A straightforward protocol for the depolymerization of end-of-life poly(dimethylsilazane) using boron trifluoride diethyl etherate as depolymerization reagent to convert the Si-N to Si-F bonds was set-up. The application of the depolymerization reagent affords difluorodimethylsilane as major products, which can be a suitable synthon for the synthesis of new polymers (e.g., poly(dimethylsiloxanes) and allow an overall recycling of the [Me2Si]-unit.
- D?hlert, Peter,Pfrommer, Johannes,Enthaler, Stephan
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- Synthetic method of lithium battery aid 3-cyanopropyldimethylfluorosilane
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The invention relates to the technical field of synthesis of organosilicon compounds, in particular to a synthetic method of a lithium battery aid 3-cyanopropyldimethylfluorosilane. The synthetic method comprises dropwise adding 4-chlorobutytonitrile into a sodium water-free solvent, allowing to react to obtain a suspension of N=CCH2CH2CH2Na, and carrying out any one of two process routes to obtain 3-cyanopropyldimethylfluorosilane, wherein the route 1 includes subjecting N=CCH2CH2CH2Na to reaction with dimethyldichlorosilane to obtain 3-cyanopropyldimethylchlorosilane, and fluorinating to obtain 3-cyanopropyldimethylfluorosilane, and the route 2 includes fluorinating dimethyldichlorosilane to obtain dimethyldifluorosilane, and subjecting the dimethyldifluorosilane to reaction with N=CCH2CH2CH2Na to obtain the 3-cyanopropyldimethylfluorosilane. The synthetic method has the advantages that the raw materials are easy to attain, the cost is low, the purity is higher, reacting is easy, andthe synthetic method is economical and feasible.
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Paragraph 0014; 0042; 0045; 0049; 0052
(2019/07/11)
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- NONAQUEOUS ELECTROLYTE COMPOSITIONS COMPRISING SILYL OXALATES
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Disclosed herein are electrolyte compositions comprising a fluorinated solvent, at least one silyl oxalate represented by the formulas RR′Si(C2O4), wherein R and R′ are each the same or different from each other and independently selected from C1-C8 alkyl, C2-C8 alkenyl, C2-C8 alkynyl, or C6-C10 aryl radical, optionally comprising at least one substituent selected from halogen, hydroxyl, alkoxy, carbonyl, and carboxyl groups; and LiPF6. Also disclosed herein are electrolyte compositions comprising a fluorinated solvent and a lithium oxalato phosphate salt represented by the formula LiPF(6-2q)(C2O4)q, wherein q is 1, 2 or 3; wherein the oxalato phosphate salt comprises at least a portion that is derived from at least one silyl oxalate as defined herein. The electrolyte compositions are useful in electrochemical cells, such as lithium ion batteries.
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Paragraph 0272-0276
(2019/08/20)
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- Synthesis and kinetics of disassembly for silyl-containing ethoxycarbonyls using fluoride ions
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In this study, a series of silyl-containing ethoxycarbonates and ethoxycarbamates on electron poor anilines and phenols were synthesized and their kinetics of disassembly determined in real-time upon exposure to fluoride ion sources at room temperature. The results provide a greater understanding of stability and kinetics for silyl-containing protecting groups that eliminate volatile molecules upon removal, which will allow for simplification of orthogonal protection in complex organic molecules.
- Camerino, Eugene,Daniels, Grant C.,Wynne, James H.,Iezzi, Erick B.
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p. 1884 - 1888
(2018/02/06)
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- Thermal and hydrolytic decomposition mechanisms of organosilicon electrolytes with enhanced thermal stability for lithium-ion batteries
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The high flammability and thermal instability of conventional carbonate electrolytes limit the safety and performance of lithiumion batteries (LIBs) and other electrochemical energy storage devices. Organosilicon solvents have shown promise due to their reduced flammability and greater chemical stability at high temperatures. A series of organosilicon electrolytes with different functional substituents were studied to understand the structural origins of this enhanced stability. The thermal and hydrolytic stability of organosilicon and carbonate solvents with LiPF6 was probed by storage at high temperatures and with added water. Quantitative monitoring of organosilicon and carbonate electrolyte decomposition products over time using NMR spectroscopy revealed mechanisms of degradation and led to the discovery of a key PF5-complex that forms in organosilicon electrolytes to inhibit further salt breakdown. Increased knowledge of specific structural contributions to electrolyte stability informs the development of future electrolyte solvents to enable the safer operation of high-performing lithium-ion batteries.
- Guillot, Sarah L.,Pe?a-Hueso, Adrian,Usrey, Monica L.,Hamers, Robert J.
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p. A1907 - A1917
(2018/02/28)
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- Effect of Silyl Ether-functinoalized Dimethoxydimethylsilane on Electrochemical Performance of a Ni-rich NCM Cathode
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Dimethoxydimethylsilane (DODSi) is used as an interface stabilizing additive through a selective HF scavenging reaction for layered Ni-rich oxide cathodes. Ex situ NMR analyses demonstrated that DODSi effectively removes HF from the electrolyte based on the matched chemical reactivity of Si with F? and O with H+. The cells employing DODSi exhibit higher specific capacity with retention than those cycled with a DODSi-free electrolyte even under in situ HF generating conditions. Scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and inductively coupled plasma-mass spectroscopy (ICP-MS) analyses indicate that DODSi effectively protects the Ni-rich oxide cathodes against HF corrosion, resulting in improved surface stability of Ni-rich cathodes.
- Jang, Seol Heui,Yim, Taeeun
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p. 3402 - 3406
(2017/12/15)
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- Transformations of diallylsilanes under the action of electrophilic reagents
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Reactions of dimethyl-, diphenyl-, and (chloromethyl)methyldiallylsilanes with acetic, trifluoroacetic, triflic acids and complex BF3 · 2AcO{cyrillic}H are studied. Depending on the structure of the starting diallylsilane and the nature of the
- Suslova, Elena N.,Albanov, Alexandr I.,Shainyan, Bagrat A.
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experimental part
p. 420 - 426
(2009/04/14)
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- Si-disubstituted diallylsilanes in homolytic thiylation and electrophilic fragmentation reactions
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Approaches to Si-disubstituted 1-thia-5-silacyclooctanes based on homolytic addition of hydrogen sulfide to diallylsilanes R2Si(CH 2CH=CH2)2 and on intramolecular cyclization of Si-disubstituted (allyl)(γ-sulfanylpropyl)silanes have been studied. In the former case the reactivity of the silanes decreases in the order R = MeO > F > Me > Ph, whereas in the latter case the reactivity order is slightly different: Me > MeO ≈ F ? Ph. The reactions of diphenyl-and dimethyldiallylsilanes with the complex BF3?2AcOH occur in a different manner: The former involves rearrangement to form fluoro(2-methylpent- 4-enyl)diphenylsilane, while the latter, elimination of the two allyl groups to fluorodimethylsilane and propene.
- Suslova,Albanov,Shainyan
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experimental part
p. 1675 - 1681
(2009/02/06)
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- Synthesis and applications of tert-alkoxysiloxane linkers in solid-phase chemistry
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Straightforward syntheses of two tert-alkoxysilyl chloride functionalised resins 3 and 31 that allow facile attachment of 1°, 2°, 3° alcohols and phenols to the solid-phase have been achieved. Resin 3 displayed useful loading levels (0.7 mmol/g), and it was stable to storage in activated form. Siloxanes from reaction of 3 with alcohols and phenols were compatible with a variety of reaction conditions commonly used in solid-phase synthesis.
- Meloni, Marco M.,White, Peter D.,Armour, Duncan,Brown, Richard C.D.
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p. 299 - 311
(2007/10/03)
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- Method of producing amide compound
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Provided is a method of producing a highly pure amide compound in a high yield, wherein a silazane compound and/or a silane compound having at least one silicone-nitrogen bond are added to a reaction mixture obtained by reacting an acylfluoride group-containing compound with an amino compound, wherein the amide compound is present together with hydrogen fluroide and/or the amine hydrofluoride, thereby removing the hydrogen fluoride and/or the amine hydrofluoride from the reaction mixture.
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- ORGANOSILICON AND ORGANOPHOSPHORUS COMPOUNDS WITH PSEUDOHALIDE GROUPS. VI. SYNTHESIS OF ALKOXYDIMETHYLSILYL AZIDES AND SOME OF THEIR PROPERTIES
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By reaction of sodium azide with alkoxydimethylsilyl chlorides in hexamethylphosphoramide previously unknown alkoxydimethylsilyl azides were prepared and some of their properties were studied.Silyl azides reacting with zinc difluoride, acyl halides, phosphorus acid chlorides, and perfluoro-2-aza-2-butene can replace halogen by both alkoxy and azido groups (depending on the nature of the halogen-containing compound).
- Krolevets, A. A.,Chmykhov, V. N.,Glotov, E. N.,Gontar', A. F.,Martynov, B. I.
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p. 597 - 599
(2007/10/02)
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- The synthesis and properties of (CH2F)SiH3 and related monofluoromethylsilanes
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The reduction of (CFCl2)SiCl3 by LiAlH4, Me3SnH, and (nBu)3SnH has been studied.The compound (CH2F)SiH3 (I) and all the compounds of the series (CFCl2-mHm)SiCl3-nHn, m = 0, 1 and n = 0-3 were detected and characterized by NMR spectroscopy.Conditions for the synthesis of I, (CHFCl)SiH3 (IX) and (CFCl2)SiH3 (V) with acceptable yields have been optimized.These novel compounds were studied by 1H, 19F, 13C and 29Si NMR spectroscopy; their infrared and Raman spectra were recorded and assigned with the assistance of a normal coordinate analysis of 1 and its isotopomer (CD2F)SiD3.The thermolyses of I, IX and (CHF2)SiH3 (X) which start at about 120, 200 and 180 deg C, respectively, have been studied.Whereas I decomposes by a migration of F from C to Si, compound X undergoes elimination of the carbene CHF, insertion of which into SiH bonds ultimately gives CH3Si derivatives.
- Buerger, H.,Moritz, P.
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p. 293 - 308
(2007/10/02)
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- Preparative electrochemical oxidation of cyclic peralkylsilanes
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The electrochemical oxidation of cyclic peralkylsilanes undergo ring opening followed by further Si-Si bond cleavage and reaction with BF4- to form α,ω-difluorosilanes, F-(SiR2)(n)-F, as major products.
- Becker,Shakkour,West
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p. 5633 - 5636
(2007/10/02)
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- REACTIONS OF ORGANYLTRIFLUORO- AND DIORGANYLDIFLUOROSILANES WITH 1,1,3,3-TETRAMETHYLDISILOXANE
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1,1,3,3-Tetramethyldisiloxane is decomposed by organyltrifluoro- and diorganyldifluorosilanes already at 20 deg C in the presence of catalysts with formation of hitherto unknown 1,1-dimethyl-3,3-diorganyl-3-fluoro- and 1,1-dimethyl-3-organyl-3,3-difluorodisiloxanes of general formula R4-nSiFn-1OSiH(CH3)2 (n = 2-3) in yields of 50-70 percent.On storing these decomposition products easily disproportionate in various directions, in which their propensity to disproportionation is determined by the nature of the substituents at the silicon atoms and the number of fluorine atoms in the molecule.
- Basenko, S. V.,Gebel', I. A.,Vitkovskii, V. Yu.,Mirskov, R. G.,Voronkov, M. G.
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p. 1042 - 1046
(2007/10/02)
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- ORGANOSILICON AND ORGANOPHOSPHORUS COMPOUNDS WITH PSEUDOHALOGEN GROUPS. 1. SYNTHESIS OF ALKOXYDIMETHYLSILYL CYANIDES AND THEIR REACTIONS WITH METAL FLUORIDES
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Alkoxydimethylsilyl cyanides were syntesized by the exchange reaction of the corresponding alkoxydimethylchlorosilanes with trimethylsilyl cyanide, and also by the reaction of the former compounds with HCN in the presence of triethylamine (the latter method were preferential).Reactions of silyl cyanides with SbF3 and ZnF2 were studied.It was found that the reaction of silyl cyanides with SbF3 leads to the formation of Me2SiF2 and the corresponding alkoxydimethylfluorosilanes, which were also obtained by countersynthesis from alkoxydimethylsilylchlorosilanes and metal fluorides (SbF3, ZnF2, CsF).Dimethylfluorosilyl cyanide was obtained by the reaction of silyl cyanides with ZnF2.
- Krolevets, A. A.,Antipova, V. V.,Martynov, I. V.
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p. 1410 - 1415
(2007/10/02)
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- CHLOR-FLUOR -AUSTAUSCHREAKTIONEN MIT TRIALKYLFLUOR-PHOSPHORANEN
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Trialkyldifluorophosphoranes R3PF2 (R = iPr, nBu) were found to react with chlorides or organoelement chlorides, EClm or ERm-zClz (EIV, m = 4, z = 1,2; EV, m = 3, z = 1,2) of elements belonging to main groups IV and V with chlorine/fluorine exchange to form the halophosphonium salts +Cl- (X = F, Cl) and the fluoro derivatives, EFm or ERm-zFz.With AlCl3 ionic products of composition are obtained.The transition metal chlorides, NiCl2, PdCl2 NiCl2(PMe3)2, and CoCl2 were found to be less reactive.Chlorine/fluorine exchange has been observed only the case of CoCl2.
- Bartsch, R.,Schmutzler, R.,Spiegel, G. U.,Stelzer, O.
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p. 107 - 118
(2007/10/02)
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- A RAPID, EFFICIENT AND SELECTIVE CONVERSION OF ALDEHYDES AND ACETALS TO THEIR 1,3-DITHIANE DERIVATIVES WITH 2,2-DIMETHYL-2-SILA-1,3-DITHIANE1
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Aldehydes and acetals are cleanly and rapidly converted to the corresponding dithianes with 2,2-dimethyl-2-sila-1,3-dithiane and stochiometric amounts of boron trifluoride etherate even in the presence of ketones, which do not react competitively with the reagent.
- Soderquist, John A.,Miranda, Edgar I.
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p. 6305 - 6306
(2007/10/02)
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- OBSERVATIONS AND COMMENTS ON THE THERMAL BEHAVIOR OF 7-SILANORBORNADIENES
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Evidence for a radical mechanism in the termal decomposition of a 7-silanorbornadiene is presented.It is demonstrated that 2-carboxy-7-silanorbornadienes undergo a formal 1,5-migration of silicon to form O-silyl enol ethers.An earlier suggested rearrangement of a 7-silanorbornadiene to a silepin or silanorcardiene is excluded.A recent report of thermal and photochemical epimerization of 7-silanorbornadienes is shown to be incorrect.
- Barton, Thomas J.,Goure, William F.,Witiak, Joanne L.,Wulff, William D.
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- Reactions of Lithio-aminofluorosilanes with Covalent Element Halides
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Halides of boron, germanium, phosphorus, and arsenic react with lithio-aminofluorosilanes (1a-e) with elimination of lithium halide and substitution (to 2a, b, 3c, 4b, 5b, 5d, 6b).Depending on the bulkiness of the substituents and the reaction conditions, halosilanes are also cleaved off and four-membered rings (8d, 10b, 11b, 13b, 14b) are formed.The reaction of 1e with (Me3Si)2NPF2 leads to the formation of the aminoiminophosphane 9e.A 1,3-migration of a silyl group from the alkyl- to the arylamino-nitrogen is observed in this reaction. 5d reacts with lithiated (2,4,6-trimethylphenyl)(trimethylsilyl)amine to give 15d and LiF.The aminoiminophosphane 16d is obtained by thermal difluorosilane elimination from 15d.An aminoiminodifluorophosphane (12b) is formed in the reaction of 1b with PF5, isobutene, tert-butyldifluorophenylsilane, and LiF being claved off.
- Neemann, Jutta,Klingebiel, Uwe
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p. 527 - 535
(2007/10/02)
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- Oxidative Desilylation of Alkylsilanes with Triphenylcarbenium Ion. Control of Transition-State Geometry
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Ten acylic, cyclic, and aralkyl-type silanes were treated with triphenylcarbenium tetrafluoroborate in dichloromethane to measure rates of oxidative desilylation: RCH2CH2SiR3+Ph3C(1+)BF4(1-)->Ph3CH+RCH=CH2+R3SiF+BF3.The divergence of rates, from Ph2CHCH2SiMe3, which was inert, through dimethylsilacyclopentane (k2=4E-6), to dimethylsilacyclohexane (k2=2.2E-3), can not be rationalized on purely electronic grounds.A transition state requiring anticoplanar arrangement of the silicon moiety and β-hydrogen to be extruded is proposed.Dimethylsilacyclobutane, which reacts extremely rapidly (k2 approx. 2E-2), suffers allylic cleavage of the initially formed fluoro(2-propenyl)dimethylsilane.As the olefin products suffer decomposition or polymerization under the reaction conditions, this desilylation is of minimal preparative value.
- Washburne, Stephen S.,Szendroi, Robert
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p. 691 - 693
(2007/10/02)
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- Synthesis and Nuclear Magnetic Resonance Spectroscopic Studies of Alkylene / Alkylidenebis(phosphonic Dihalides) and -bis(fluorophosphoranes)
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Chlorine-fluorine exchange in the bis(phosphonic dichlorides) Cl2P(O)-X-P(O)Cl2 (1a - c) with AsF3 furnishes the bis(phosphonic difluorides) F2P(O)-X-P(O)F2 (2a - c).Reaction of 2a - c with SF4 leads to bis(tetrafluorophosphoranes) F4P-X-PF4 (3a - c) (X = CH2, CH2CH2, trans-CH=CH).Additional methods of synthesis are indicated for compound 3a (X = CH2) which are based on the cleavage of the Si-C bond with PF5 in the Si-C bonded precursors 2 and Me3SiCH2PF4.The NMR spectra of compounds 2 and 3 are discussed.
- Althoff, Wolfgang,Fild, Manfred,Schmutzler, Reinhard
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p. 1082 - 1090
(2007/10/02)
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