994-30-9Relevant articles and documents
CO2 laser excitation of triethylsilane: Time resolved luminescence of diethylsilyl radical
Papagiannakopoulos,Lazarou
, p. 857 - 867 (1994)
The infrared multiphoton excitation of triethylsilane in the gas phase, with a pulsed CO2 laser at high intensities (I>700 MW/cm2), produced an intense luminescence. The spectrum and time profile of this luminescence was studied as a function of pressure, and laser frequency. The radiative lifetime of this emission was 357±10 ns, and the quenching rates by Cl2 and NO were determined from lifetime measurements. A reasonable mechanism for the interpretation of this luminescence involves the initial infrared multiphoton decomposition of triethylsilane, followed by the secondary infrared multiphoton excitation of the primary photofragment diethylsilyl radical, which subsequently undergoes relaxation to an excited electronic state. The addition of O2 resulted in a new chemiluminescence at shorter wavelengths, which corresponds to the SiO* chromophore group.
Oxidation of Triorganosilanes and Related Compounds by Chlorine Dioxide
Grabovskiy,Kabal’nova
, p. 2391 - 2402 (2022/01/22)
Abstract: Oxidation of triethylsilane, tert-butyldimethylsilane, dimethylphenylsilane, triphenylsilane, 1,1,1,2tetramethyl-2-phenyldisilane, tris(trimethylsilyl)silane, hexamethyldisilane, tetrakis(trimethylsilyl)silane, 1,1,3,3tetraisopropyldisiloxane with chlorine dioxide was carried out. The reaction products of studied triorganosilanes with chlorine dioxide in an acetonitrile solution were the corresponding silanols and siloxanes. A mechanism explaining the formation of products and the observed regularities of the oxidation of silanes with chlorine dioxide has been proposed. A thermochemical analysis of some possible pathways in the gas phase using methods G4, G3, M05, and in an acetonitrile solution by the SMD-M05 method was carried out. The oxidation process can occur both with the participation of ionic and radical intermediates, depending on the structure of the oxidized substrate and medium.
Neutral-Eosin-Y-Photocatalyzed Silane Chlorination Using Dichloromethane
Fan, Xuanzi,Xiao, Pin,Jiao, Zeqing,Yang, Tingting,Dai, Xiaojuan,Xu, Wengang,Tan, Jin Da,Cui, Ganglong,Su, Hongmei,Fang, Weihai,Wu, Jie
supporting information, p. 12580 - 12584 (2019/08/16)
Chlorosilanes are versatile reagents in organic synthesis and material science. A mild pathway is now reported for the quantitative conversion of hydrosilanes to silyl chlorides under visible-light irradiation using neutral eosin Y as a hydrogen-atom-transfer photocatalyst and dichloromethane as a chlorinating agent. Stepwise chlorination of di- and trihydrosilanes was achieved in a highly selective fashion assisted by continuous-flow micro-tubing reactors. The ability to access silyl radicals using photocatalytic Si?H activation promoted by eosin Y offers new perspectives for the synthesis of valuable silicon reagents in a convenient and green manner.
Rh(iii)-Catalysed solvent-free hydrodehalogenation of alkyl halides by tertiary silanes
Almenara,Azpeitia,Garralda,Huertos
supporting information, p. 16225 - 16231 (2018/11/30)
Efficient catalytic reduction of CDCl3 and other alkyl halides, including persistent organic pollutants, by different tertiary silanes using the unsaturated silyl-hydrido-Rh(iii) complex {Rh(H)[SiMe2(o-C6H4SMe)](PPh3)2}[BArF4] as a pre-catalyst is accomplished. The reactions are performed in a solvent-free manner. On account of experimental evidence, a simplified catalytic cycle is suggested for the hydrodehalogenation of CDCl3.
DMF-activated chlorosilane chemistry: Molybdenum-catalyzed reactions of R3SiH, DMF and R′3SiCl to initially form R′3SiOSiR′3 and R3SiCl
Gonzalez, Paulina E.,Sharma, Hemant K.,Pannell, Keith H.
, p. 376 - 381 (2017/06/30)
The room temperature reactions between R3SiH (R3?=?Et3, PhMe2, Ph2Me) and R′3SiCl (R′3?=?Me3, PhMe2, Ph2Me), with an excess of dimethylformamide (DMF) in the presence of (Me3N)Mo(CO)5 as a catalyst, result in the initial formation of R3SiCl, R′3SiOSiR′3 and Me3N as detected by 29Si, 13C, 1H NMR spectroscopy and GC/MS. As the reaction proceeds, the more so if the reaction temperature is raised, mixed disiloxanes R3SiOSiR′3 and ultimately lesser amounts of R3SiOSiR3 may be detected. A mechanism involving the activation of chlorosilanes by the nucleophilic DMF is proposed to produce transient imminium siloxy ion pairs, [Me2N[dbnd]CHCl]+[R′3SiO]? ? [Me2N[dbnd]CH(OSiR′3)]+Cl? which react with R3SiH to form Me2NCH2OSiR′3 and R3SiCl. A secondary reaction of Me2NCH2OSiR′3 with R′3SiCl produces the symmetrical disiloxane R′3SiOSiR′3 and ClCH2NMe2. The final stage of the reaction is the reduction of ClCH2NMe2 by R3SiH, a reaction which is reported for the first time. The newly created chlorosilane R3SiCl can become involved in the initial DMF activation chemistry thereby forming the other disiloxanes observed as the reaction proceeds.
B(C6F5)3-Catalyzed Selective Chlorination of Hydrosilanes
Chulsky, Karina,Dobrovetsky, Roman
supporting information, p. 4744 - 4748 (2017/04/11)
The chlorination of Si?H bonds often requires stoichiometric amounts of metal salts in conjunction with hazardous reagents, such as tin chlorides, Cl2, and CCl4. The catalytic chlorination of silanes often involves the use of expensive transition-metal catalysts. By a new simple, selective, and highly efficient catalytic metal-free method for the chlorination of Si?H bonds, mono-, di-, and trihydrosilanes were selectively chlorinated in the presence of a catalytic amount of B(C6F5)3 or Et2O?B(C6F5)3 and HCl with the release of H2 as a by-product. The hydrides in di- and trihydrosilanes could be selectively chlorinated by HCl in a stepwise manner when Et2O?B(C6F5)3 was used as the catalyst. A mechanism is proposed for these catalytic chlorination reactions on the basis of competition experiments and density functional theory (DFT) calculations.
An Isolable Potassium Salt of a Borasilene–Chloride Adduct
Suzuki, Yuko,Ishida, Shintaro,Sato, Sota,Isobe, Hiroyuki,Iwamoto, Takeaki
supporting information, p. 4593 - 4597 (2017/04/11)
Among the variety of isolable compounds with multiple bonds involving silicon, examples of compounds that contain silicon–boron double bonds (borasilenes) still remain relatively rare. Herein, we report the synthesis of the potassium salt of a chloride adduct of borasilene 1 ([2]?), which was obtained as an orange crystalline solid. Single-crystal X-ray diffraction analysis and reactivity studies on [2]? confirmed the double-bond character of the Si=B bond as well as the reduced Lewis acidity, which is due to the coordination of Cl? to the boron center. A thermal reaction of [2]? afforded a bicyclic product by formal intramolecular C?H insertion across the Si=B bond of 1, which was corroborated by a theoretical study.
[...] compound
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Paragraph 0041, (2020/10/21)
PROBLEM TO BE SOLVED: To provide a method of manufacturing a dichloromonohydrosilane compound that is capable of manufacturing a dichloromonohydrosilane compound useful as a synthesis raw material for various silane compounds such as a silane coupling agent or a functional silicone oil by using inexpensive and easily available monohydrosilane compound at a low cost since it does not require a special reaction device for conducting reactions under pressure.SOLUTION: There is provided a method of manufacturing dichloromonohydrosilane compound represented by the general formula (3) HSiRCl, where Ris an unsubstituted or a substituted monovalent hydrocarbon group having a substituent at other than α position of a silicon atom, by reacting a trichloroorganosilane compound represented by the general formula (1) RSiCl, where Ris as defined above, and a monohydrosilane compound represented by the general formula (2) HSiRCl, where Ris an unsaturated or a substituted monovalent hydrocarbon group and m is 1, 2 or 3.
S-F and S-C activation of SF6 and SF5 derivatives at rhodium: Conversion of SF6 into H2S
Zamostna, Lada,Braun, Thomas,Braun, Beatrice
supporting information, p. 2745 - 2749 (2014/03/21)
The degradation of SF6 and SF5 organyls by S-F and S-C bond-activation reactions at [{Rh(μ-H)(dippp)}2] under mild conditions is reported. Fluorido and thiolato species were identified as products or intermediates, and were characterized by X-ray diffraction analysis and multinuclear NMR spectroscopy. An unprecedented cyclic process for the conversion of the potent greenhouse gas SF6 into H2S was developed. Activation of the stable greenhouse gas SF6: The rhodium hydrido complex [{Rh(μ-H)(dippp)}2] effected defluorination at the sulfur atom of SF6 and organic SF5 compounds under mild conditions. The reduction of SF6 in the presence of HSiEt3 led exclusively to the thiolato complex [Rh2(μ-H)(μ-SSiEt 3)(dippp)2] and FSiEt3 (see Scheme). A cyclic process was developed for the conversion of SF6 into H2S.
Reduction of alkyl halides by triethylsilane based on a cationic iridium bis(phosphinite) pincer catalyst: Scope, selectivity and mechanism
Yang, Jian,Brookhart, Maurice
scheme or table, p. 175 - 187 (2009/10/01)
A highly efficient procedure for the reduction of a broad range of alkyl halides by triethylsilane based on a cationic iridium bis(phosphinite) pincer catalyst has been discovered and developed. This reduction chemistry is chemoselective and has unique selectivities compared with conventional radical-based processes and the aluminum trichloride/ triethylsilane (AlCl 3/Et3SiH) and triphenylmethyl tetrakis[pentafluorophenyl] borate/triethylsilane {[Ph3C] [B(C6F5) 4]/Et3SiH} systems. Reductions use three equivalents of triethylsilane relative to the halide and can be carried out with very low catalyst loadings and in a solvent-free manner, which may provide an environmentally attractive and safe alternative to many currently practiced methods for reduction of alkyl halides. Mechanistic studies reveal a unique catalytic cycle. The cationic iridium hydride 2,6-bis[di-(tert-butyl) phosphinyloxy)phenyl-(hydrido)iridium, (POCOP)IrH+ {POCOP= 2,6-[OP(t-Bu)2]2C6H3} binds and activates the silane. This complex serves as a potent silylating reagent to generate silyl halonium ions, Et3SiXR+, which are reduced by the neutral iridium dihydride to yield alkane product and regenerate the cationic (POCOP)IrH+, thus closing the catalytic cycle. All key intermediates have been identified by in situ NMR monitoring and kinetic studies have been completed. An application of this reduction system to the catalytic hydrodehalogenation of a metal chloride complex is also described.
