13966-57-9Relevant academic research and scientific papers
SYNTHESIS OF ORGANO CHLOROSILANES FROM ORGANOSILANES
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Page/Page column 36; 37, (2019/04/16)
The invention relates to a process for the production of chlorosilanes by subjecting one or more hydndosilanes to the reaction with hydrogen chloride in the presence of at least one ether compound, and a process for the production of such hydndosilanes serving as starting materials.
Lewis Base Catalyzed Selective Chlorination of Monosilanes
Sturm, Alexander G.,Schweizer, Julia I.,Meyer, Lioba,Santowski, Tobias,Auner, Norbert,Holthausen, Max C.
supporting information, p. 17796 - 17801 (2018/11/23)
A preparatively facile, highly selective synthesis of bifunctional monosilanes R2SiHCl, RSiHCl2 and RSiH2Cl is reported. By chlorination of R2SiH2 and RSiH3 with concentrated HCl/ether solutions, the stepwise introduction of Si?Cl bonds is readily controlled by temperature and reaction time for a broad range of substrates. In a combined experimental and computational study, we establish a new mode of Si?H bond activation assisted by Lewis bases such as ethers, amines, phosphines, and chloride ions. Elucidation of the underlying reaction mechanisms shows that alcohol assistance through hydrogen-bond networks is equally efficient and selective. Remarkably, formation of alkoxysilanes or siloxanes is not observed under moderate reaction conditions.
Amorphous silicon: New insights into an old material
Spomer, Natalie,Holl, Sven,Zherlitsyna, Larissa,Maysamy, Fariba,Frost, Andreas,Auner, Norbert
, p. 5600 - 5616 (2015/03/30)
Amorphous silicon is synthesized by treating the tetrahalosilanes SiX4 (X=Cl, F) with molten sodium in high boiling polar and non-polar solvents such as diglyme or nonane to give a brown or a black solid showing different reactivities towards suitable reagents. With regards to their technical relevance, their stability towards oxygen, air, moisture, chlorine-containing reaction partners RCl (R=H, Cl, Me) and alcohols is investigated. In particular, reactions with methanol are a versatile tool to deliver important products. Besides tetramethoxysilane formation, methanolysis of silicon releases hydrogen gas under ambient conditions and is thus suitable for a decentralized hydrogen production; competitive insertion into the MeO-H versus the Me-OH bond either yields H- and/or methyl-substituted methoxy functional silanes. Moreover, compounds, such as MenSi(OMe)4-n (n=0-3) are simply accessible in more than 75% yield from thermolysis of, for example, tetramethoxysilane over molten sodium. Based on our systematic investigations we identified reaction conditions to produce the methoxysilanes MenSi(OMe)4-n in excellent (n=0:100%) to acceptable yields (n=1:51%; n=2:27%); the yield of HSi(OMe)3 is about 85%. Thus, the methoxysilanes formed might possibly open the door for future routes to silicon-based products. Amorphous silicon is easily synthesized from tetrahalosilanes SiX4 (X=Cl, F) and molten sodium in different solvents. Reactivity studies prove the resulting materials as versatile tools for the formation of technical important silanes, such as the silicon chloro-, alkoxy-, and methylalkoxy-substituted derivatives (see figure; bl=black, br=brown).
Process For Preparing Si-H-Containing Silanes
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Page/Page column 4-5, (2009/01/24)
Silanes of the general formula (1) [in-line-formulae]RaSiHbX4-b-a ??(1)[/in-line-formulae] are prepared by disproportionating at least one more highly chlorinated silane in the presence of a homogeneous catalyst in an apparatus with at least one reactive distillation column and at least one additional reactor selected from among prereactors and side reactors, where R is an alkyl, aryl, alkaryl or haloalkyl radical, X is a halogen atom, a is 0 or 1, and b is 2, 3 or 4.
An experimental and theoretical study of spin-spin coupling in chlorosilanes
Thorshaug, Knut,Swang, Ole,Dahl, Ivar M.,Olafsen, Anja
, p. 9801 - 9804 (2008/10/09)
An experimental and theoretical study of the absolute value of the one-bond spin-spin coupling constant |1J(Si,H)| in SiH nCl4-n (n = 0-4) dissolved in THF-d8 is presented. We found |1J(Si,H)| to increase with an increasing number of chlorine substituents, and the quantitative changes were found to differ from the values previously reported for the same compounds dissolved in cyclohexane-d12. We also report on the variations in | 1J(Si,H)| as a function of temperature, which we found to be linearly temperature dependent for the chlorine-substituted silanes and temperature independent for SiH4. Furthermore, the temperature dependence of |1J(Si,H)| varied between the different chlorosilanes. Solvent-solute interactions were studied by quantum chemical DFT calculations. The variations in chloro-silane bond lengths upon adduct formation and the different adduct interaction energies may explain the temperature dependences of the coupling constants.
Process for preparing organohydrongenosilanes
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Page/Page column 8, (2008/06/13)
Preparation of organylhydrogensilanes comprises comproportionating a mixture of organylhalosilanes in the presence of a catalyst, which contains at least one completely organically substituted ammonium or phosphonium unit. Preparation of organylhydrogensilanes comprises: comproportionating a mixture of organylhalosilanes by reaction of a organylhalosilane compound of formula (Z-R aSiCl 4-a) with organylhalosilane compound of formula (SiH bCl 4-b) to give a organylhalosilane compound of formula (Z-R aSiCl 3-a) and a organylhalosilane compound of formula (SiH b-yCl 4-b +y) in the presence of a catalyst which contains at least one completely organically substituted ammonium or phosphonium unit. R : alkyl, aryl, or alkaryl radical (optionally substituted with halo); a : 1-3; y, Z : 1-4; and b : 2-4.
Ion-enhanced etching of Si(100) with molecular chlorine: Neutral and ionic product yields as a function of ion kinetic energy and molecular chlorine flux
Materer,Goodman, Rory S.,Leone, Stephen R.
, p. 3261 - 3266 (2007/10/03)
Time-of-flight mass spectrometry (TOFMS) is used to measure neutral and ionic silicon etch products evolved during argon ion-enhanced etching of room temperature Si(100) with molecular chlorine. The yields of these neutral and ionic etch products are examined as a function of ion energy, ion flux, and molecular chlorine flux. For the neutral products, an Ar+ ion energy range of 275-975 eV is used, while the ionic product measurements are continued down to 60 eY The atomic Si, SiCl, and SiCl2 neutral etch products are measured without complications due to fragmentation by using 118-nm laser single-photon TOFMS. Atomic Si and SiCl are the major observed etch products. The ionic Si+ and SiCl+ etch products are also measured using TOFMS; however, the SiQ2+ species is not observed. The similarities between neutral and ionic Si and SiCl etch products as a function of various parameters suggest a model based on direct collisional desorption. For the observed neutral SiCl2 product, the absence of SiCl2+ suggests a different mechanism than that for Si and SiCl. For SiCl2, formation models based on thermal heating or reaction and desorption of neutral species at chemically active surface sites, which are ruled out for Si and SiCl, should be considered.
Surface Loss Coefficients for the Silyl Radical
Jasinski, Joseph M.
, p. 7385 - 7387 (2007/10/02)
Direct loss measurements for the heterogeneous reaction of the silyl radical, SiH3, obtained in a discharge flow reactor with mass spectrometric detection, are reported.From these measurements and the calculated gas-surface collision frequency, total surface loss coefficients, β, are determined for silyl on two different surfaces, one coated with a growing silicon-containing film and the other coated with Halocarbon wax.
