Silane caution

The authors caution that MeSiH is formed. It should therefore be ensured that this volatile silane (b.p. 1(fC) can escape from the reaction vessel. ... 

Caution/ See warnings concerning the use of impure chlorotrimethyl-silane Note 8) and finely dispersed alkali metals Notes 1, 9,11, and 19). 

A mixture of powdered Mg (0.1 g atom), cyclohexa-1,3-diene (0.1 mol), and TMSCI (0.35 mol) in HMPA (CAUTION—CANCER SUSPECT AGENT) (100 ml) was heated under reflux with stirring for 65 h. After this time, the Mg had disappeared, and the medium had separated into two phases. On cooling, the mixture was poured on to cold saturated ammonium chloride solution, and thoroughly extracted with ether. The combined ethereal extracts were washed with brine and dried. Concentration and distillation gave the silane (0.065 mol, 65%) as a mixture of stereoisomers, b.p. 121-124 °C/25mmHg. 

MRH Bromine 1.21/91, carbon tetrachloride 2.89/83, chlorine 3.85/82 Silane burns in contact with bromine, chlorine or covalent chlorides (carbonyl chloride, antimony pentachloride, tin(IV) chloride, etc.) [1], Extreme caution is necessary when handling silane in systems with halogenated compounds, as a trace of free halogen may cause violent explosions [2],... 

Caution. When working with silane and silyl compounds it is essential that the vacuum line is of particularly sound construction. Explosions can result if fractures occur during manipulation of these compounds. 

Dimethylaminomethyl)-l,2-bis(trimethylsilyloxy)-cyclopentene. In a 500-ml three-necked flask, equipped with a football stirrer, a reflux condenser and a 100-ml pressure-equalising dropping funnel (maintained under oxygen-free nitrogen), are added toluene (200 ml) (2) and sodium (4.0 g, 174 mmol). The toluene is brought to reflux on an oil bath (bath temperature 135 °C) and the mixture stirred until a fine suspension of sodium is produced. Dimethyl 2-(dimethylaminomethyl)pentanedioate (10.6 g, 48 mmol) and chlorotrimethyl-silane (20.0 g, 184 mmol, CAUTION) (distilled from calcium hydride, under nitrogen, immediately prior to use) in dry toluene (80 ml) are added dropwise... 

It is apparent that all glass and other apparatus used for the preparation of derivatives must be perfectly clean in order to prevent contamination. If septa are used to close reaction vessels, they should be used repeatedly only with caution in order that substances accidentally adsorbed on the septum do not cause the same difficulties. The surface of glass vessels is modified in special instances only when the reagents used for the derivatives are extremely sensitive to the activity of the glass. Silanization is a common modification of the surface of glass vessels. It is performed, e.g., by treatment with a 5% solution of dichlorodimethylsilane in toluene [22]. The silanized glass is then rinsed with methanol and dried. Other silanization agents can also be applied. 

Caution. Heat is liberated during the course of the reaction with bromo-silane, and it may be necessary to cool the bottom of the reactor to — 78°. The brown residue remaining in the bottom of the reactor after sublimation of the product is pyrophoric and should be destroyed by the slow addition of n-butanol to the reactor. 

Caution. The selenium and tellurium compounds in these preparations are toxic and vile smelling. Rapid decomposition, particularly for the silanes, wUI occur on exposure to air and/or moisture. Manipulations should be carried out... 

To trimethyl(vinyl)silane (26.0 g, 259 mmol) and tert-butyl peroxybenzoate (1.02 g, 5 mmol) in MeOH (100 mL) was slowly added NaHSOs (52.6 g, 505 mmol) in HjO (100mL) at rt. The mixture was refluxed for 48 h, carefully concentrated (CAUTION peroxides ) and H2O was removed by azeotropic distillation with MeOH (3 x) by rotary evaporation. The residue was extracted with MeOH (3 x with a total of 250 mL), and the resulting soln was taken to dryness and dried at 150 °C under reduced pressure giving sodium 2-(trimethylsilyl)ethanesulfonate yield 37.0 g (70%). 

CAUTION The silane reagent is volatile and corrosive. Use in a good fume hood. Do not breathe the vapor. 

Caution. Silane is a flammable gas, its mixtures with oxygen are explosive, arid it often spontaneously violently inflames in air. It must he handled with greai care in a vacuum line. Of course, the same precautions apply to silane-di. 

Caution. In order to present air from accidentally entering the system, stop the addition of SiCU EtiO sotution while a small amount of liquid is still present in the addition funnel. This is important since silane will inflame or explode upon exposure to oxygen. 

Special caution had to be taken to record their PE spectra (Figure 15), because mixtures of silanes Si Hw with air, if ignited, explode violently causing harm and damage117. 

Numerous thermal analysis studies have been performed by other groups on resin composites, which are used for small anterior restorations that do not experience substantial stress and with caution for posterior teeth because of concern about wear [1-3]. The polymer matrix contains the oligomer bis-GMA (bisphenol A-glycidyl methacrylate) or urethane dimethacrylate, and triethylene glycol dimethacrylate is a diluent. Filler particles are silane-coated for chemical bonding with tire matrix. Free-radical polymerization is carried out by chemical... 

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