DiChlorosilane, dimethyl

DIMETHYL CHLOROTHIOPHOSPHATE sea DIMETHYL THIOPHOSPHORYL-DIMETHYL DICHLOROSILANE DIMETHYL ETHER... 

Fluidized bed reactors do not have to perform poorly, but special conditions must be maintained for good performance. A basic process for silicone manufacturing, which is not practiced much anymore, is the reaction of silicon metal with methyl chloride to form dimethyl dichlorosilane ... 

Cu and Ag on Si(lll) surfaces. In the last example, we come back to surfaces. It is well known (44-46) that Cu catalyzes the formation of dimethyl-dichlorosilane from methylchloride and solid silicon, which is a crucial technological step in the synthesis of silicone polymers. Even today, the details of the catalytic mechanism are unclear. Cu appears to have unique properties for example, the congener Ag shows no catalytic activity. Thus, the investigation of the differences between Cu and Ag on Si surfaces can help in understanding the catalytic process. Furthermore, the bonding of noble metal atoms to Si surfaces is of great importance in the physics and chemistry of electronic devices. 

Column 2.5% SE-30 on 80-100 mesh Chromosorb G (acid-washed and dimethyl-dichlorosilane-treated), 2 m x 4 mm internal diameter glass column. It is essential that the support is fully deactivated. 

Dimethyl Silicone Elastomers They are having linear polymers of very high Molecular weight within the range of 30,000-7,00,000. In order to prepare these polymers, dimethyl dichlorosilane is made to dissolve in ether and the solution is then mixed with excess of water. 

In addition to the unconventional methods of the formation of siloxane bonds such as those discussed earlier, the non-hydrolytic reactions of chlorosilanes in the presence of dimethyl sulfoxide, 7 and the reaction of dichlorosilanes with metal oxides,111 a new method has recently been discovered which involves the condensation of alkoxysilanes with organohydrosilanes with the release of hydrocarbon.112... 

Prior to use, the cell and transfer line were silylated to deactivate the internal surfaces [170]. A 10% solution of dimethyl-dichlorosilane in toluene was used to rinse the cell, followed by successive rinses in toluene and methanol. The surfaces were then dried at room temperature in a stream of nitrogen. 

Dimethyl dichlorosilane [75-78-5] M 129.1, m -75.5°, b 68.5-68.7°/750mm, 70.5°/760mm, d 1.0885, n 1.4108. Other impurities are chlorinated silanes and methylsilanes. Fractionated through a 3/8in diameter 7ft Stedman column rated at 100 theoretical plates at almost total reflux. See purification of MeSiCl2. [JACS 70 3590 1948]. 

Cathodic reduction of dichlorosilanes in the presence of 2,3-dimethyl-l,3-butadiene provides cyclic silyl compounds (equation 96)120. 

The intermediate steps leading to the formation of polydimethyl siloxanes are composed of linear and/or cyclic dimethyl siloxanes formed by hydrolysis or methanolysis of dimethyl dichlorosilane ... 

As in other preparative methods for organosilicon compounds, the direct synthesis produces a mixture of methylchlorosilanes rather than the single compound shown in equation 3. Besides dimethyl-dichlorosilane, the mixture usually contains silicon tetrachloride, tri-chlorosilane, methyltrichlorosilane, methyldichlorosilane, trimethyl-chlorosilane, and even silicon tetramethyl. Under proper conditions, dimethyldichlorosilane is the principal product. Of the other compounds, methyltrichlorosilane usually is next in abundance this substance finds use in the cross-linked methyl silicone resins, or it can be methylated further by the Grignard method to increase the yield of dimethyldichlorosilane. There is no way of recycling it in the direct process, and so supplemental operations are required for the conversion. The interconversion of this and the other minor products of the direct synthesis, involving the exchange of methyl and chlorine groups as desired, has been a special study in itself.10... 

Catalytic hydrosilylation of alkenes performed in the presence of a chiral catalyst results in the formation of chiral silanes. Initially platinium catalysts of the type L PtCl2, L = (/ )-benzyl-(methyl)phenylphosphine (BMPP) or (/ )-methyl(phenyl)propylphosphine and 1,1-disubstituted prostereogenic alkenes, such as a-methylstyrene, 2,3-dimethyl-l-butene and 2-methyl-l-butene, were used however, the stereoselectivity was low4,5. A slightly higher stereoselectivity is obtained when dichlorobis[(/ )-benzyl(methyl)phenylphosphine]nickel [Ni(BMPP)2Cl2] is used as the catalyst. Note that two chiral silanes are formed in this reaction, both of which are products of anti-Markovnikov addition. The major product is the expected dichlorosilane 3, while the byproduct is an anomalous chlorosilane 4 both products were separated by fractional distillation and the major product methylated to give the trimethylsilanes 56 7. 

The hydrolysis of, for example, dimethyl dichlorosilane to cyclic dimethylsiloxanes and linear diols can be regarded as following a similar pattern, if OHs+Cl" is taken as the analogue of NH4+C1". Increase of acid concentration, or the use of a mutual solvent, increases the proportion of cyclic polymers their proportion is decreased by the use of insufficient, alkaline or scarce water in the foi-m of hydrated salts (see pp. 80 ff. in ref. 65). 

The methacryloyloxymethyl alkoxysilanes are easily available starting from methyl trichlorosilane, dimethyl dichlorosilane, or trimethyl chlorosilane (1), respectively (Scheme 1). Photochlorination of these precursor silanes almost exclusively leads to the chloromelhyl silanes. Alkoxylation with methanol or ethanol leads to the chloromethyl(methyl)alkoxysilanes (2). Nucleophilic substitution under phase transfer catalysis conditions and distillative isolation finally yields the methacryloyloxymethylsilanes (3), making the production independent of expensive hydrosilation technology. 

Hexamethylcyclotrisilazane and octamethylcyclotetra-silazane have been prepared by Brewer and Haber from the reaction of dry, gaseous ammonia with dimethyl-dichlorosilane in benzene. When the ammonolysis was carried out in liquid ammonia, the combined yield of silazanes was only slightly less, but the trimer was formed in greater proportion than the tetramer. Although the yield of cyclic silazanes was always high, it was difficult to reproduce the proportions of the individual compounds. The procedure given here is an adaptation of that of Brewer and Haber. 

Salicylic acid (677) and 432 afford 4-oxo-2,2-dimethyl-l,3-dioxa-2-silabenzocyclo-hexane (678) (equation 348)387. 1,8-dihydroxynaphthalene (679) and di-t-butyl-dichlorosilane (680) lead to 2,2-di-t-butyl-l,3-dioxanaphtho[1.8.8a-c/]-2H-2-siline (681)... 

Li Chrosorb RP-2 (support treated with dimethyl- dichlorosilane) Nucleosil Cg Porous 5, 10, 30... 

Capillaries are also made of stainless steel. Stainless steel interacts with many compounds and so is deactivated by treatment with dimethyl dichlorosilane (DMCS), producing a thin lining of fused silica to which stationary phases can be bonded. Stainless steel columns are more robust than fused silica columns and are used for applications requiring very high temperatures. 

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