General Description
A colorless, mildly acidic volatile liquid. Flash point 0°F. Boiling point 78°F. A serious fire hazard. Mildly toxic by ingestion. Emits acrid smoke and fumes when heated to high temperatures. Less dense than water and insoluble in water, but soluble in most organic solvents. Used as an aviation fuel and as an internal standard for nmr analytical instruments.
Reactivity Profile
Hydrides, such as TETRAMETHYLSILANE, are reducing agents and react rapidly and dangerously with oxygen and with other oxidizing agents, even weak ones. Thus, they are likely to ignite on contact with alcohols. Hydrides are incompatible with acids, alcohols, amines, and aldehydes.
Air & Water Reactions
Highly flammable. TETRAMETHYLSILANE(75-76-3) is insoluble in water.
Health Hazard
May cause toxic effects if inhaled or absorbed through skin. Inhalation or contact with material may irritate or burn skin and eyes. Fire will produce irritating, corrosive and/or toxic gases. Vapors may cause dizziness or suffocation. Runoff from fire control or dilution water may cause pollution.
Fire Hazard
HIGHLY FLAMMABLE: Will be easily ignited by heat, sparks or flames. Vapors may form explosive mixtures with air. Vapors may travel to source of ignition and flash back. Most vapors are heavier than air. They will spread along ground and collect in low or confined areas (sewers, basements, tanks). Vapor explosion hazard indoors, outdoors or in sewers. Runoff to sewer may create fire or explosion hazard. Containers may explode when heated. Many liquids are lighter than water.
Chemical Properties
Tetramethylsilane (TMS) is the simplest tetraalkylsilane. It is a colorless, highly volatile liquid with a characteristic organometallic odor. TMS is chemically stable, insoluble in water, and soluble in most organic solvents.
In nuclear magnetic resonance (NMR) spectroscopy, TMS is widely used as an internal standard for chemical shift measurements. Chemical shift is a relative value and is generally referenced to TMS, whose chemical shift is defined as 0 ppm. The protons in TMS experience a strong shielding effect, requiring a relatively high external magnetic field to achieve resonance. As a result, few compounds exhibit signals at a higher field than TMS, making it an ideal reference standard for NMR analysis.
Uses
NMR reference standard. In semiconductor applications (chemical vapor deposition). Tetramethylsilane (TMS) is used as a chemical shift reference for proton, carbon-13, and silicon-29 analysis in organic solvents and is given 0 as its chemical shift position.
Uses
Tetramethylsilane is used as a building block in organometallic chemistry. It acts as a by-product in the production of methyl chlorosilanes. Also, it serves as a precursor to silicon dioxide or silicon carbide. It is used as internal reference standard for the calibration of chemical sift for 1, 13 and 29 NMR spectroscopy. In addition, it is used as an aviation fuel.
Definition
ChEBI: Tetramethylsilane is an organosilicon compound that is silane in which the hydrogens have been replaced by methyl groups.
Preparation
At present, the synthesis method of Tetramethylsilane mainly comprises two methods, namely, tetrachlorosilane or tetraethoxysilane is reacted with methyl magnesium iodide to prepare the tetramethylsilane. The second one is prepared by reacting chloromethane and silicon powder in the presence of copper catalyst and then carrying out fine fractionation.
Hazard
Flammable, high fire risk.
Purification Methods
Distil it from conc H2SO4 (after shaking with it) or LiAlH4, through a 5ft vacuum-jacketed column packed with glass helices into an ice-cooled condenser, then percolate it through silica gel to remove traces of halide. [Beilstein 4 IV 3875.]
Toxics Screening Level
Tetramethysilane had an ITSL of 1300 μg/m3 annual average.
