Silane, also known as silicon tetrahydrogen, chemical formula is SiHfour, is a kind ofsilane。The structure of silicane is similar to that of methaneRegular tetrahedronStructure.
Silane is a colorless, flammable and toxic gas with strong odor.It is easily ignited in the air and reacts with oxidants. It is toxic after inhalation and has strong irritation to skin, eyes and mucous membranes.In case of prolonged exposure to fire or heat, the container may burst violently and explode.It is used to produce amorphous silicon[2]
Solubility: soluble in water, almost insoluble in ethanol, ether, benzene, chloroform, silicon chloroform and silicon tetrachloride
chemical property
The ignition and explosion of silane are the result of reaction with oxygen.Silane is extremely sensitive to oxygen and air.Silane with certain concentration will also explode with oxygen at - 180 ℃.The reaction of solid silane with liquid oxygen is very dangerous.When silane burns, the flame is dark yellow and reacts under the condition of sufficient oxygen:[1]
SiHfour+ 2Otwo=SiOtwo+ 2HtwoO，ΔH=-362 kcal/ mol
If oxygen is insufficient, incomplete oxidation reaction may occur:
SiHfour+ Otwo=SiOtwo+ 2Htwo，ΔH=-226 kcal/ mol
The high temperature generated by combustion also causes thermal decomposition reaction of some unreacted silane:
SiHfour=Si + 2Htwo，ΔH=-8.2 kcal/ mol
Calculate chemical data
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Reference value for drainage parameter calculation (XlogP): None
Topological molecule polar surface area (TPSA): 121
Number of heavy atoms: 7
Surface charge: 0
Complexity: 62.7
Number of isotope atoms: 0
Determine the number of atomic structure centers: 0
Number of uncertain atomic structure centers: 0
Determine the number of chemical bond structure centers: 0
Number of uncertain chemical bond structure centers: 0
Number of covalent bond units: 1
toxicology data
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Inhalation in ratsLC50: 9600ppm/4h;Mice inhaled LCLo: 9600ppm/4h.
application
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It is widely used in electronic industry, energy industry, glass industry, chemical industry, high-tech fields and other industries and fields, mainly used to produce liquid crystalsTFT、Solar cell、semiconductor, photosensitive materials, crystalline silicon solar panels, etc., and in many emerging fields such as silicon carbon anode, advanced ceramics, composite materials, biomaterials, etc.
Silane can be generated through pyrolysis reactionCrystalline silicon, generally only used for surface treatment, throughChemical vapor deposition(CVD) is an important special gas that cannot be replaced by many other silicon sources because of its high purity and fine control.
security information
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Safety terminology
S9：Keep container in a well-ventilated place.
Keep the container in a well ventilated place.
S16：Keep away from sources of ignition - No smoking.
Keep away from ignition sources and no smoking.
S33：Take precautionary measures against static discharges.
Take precautions against static electricity.
S36/37/38：Wear suitable protective clothing, gloves and eye/face protection.
Wear appropriate protective clothing, gloves and eye/face protection.
Risk terminology
R12：Extremely flammable.
Extremely flammable.
R17：Spontaneously flammable in air.
It is prone to spontaneous combustion in air.
R20：Harmful by inhalation.
Harmful by inhalation.
Properties and stability
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Avoid strong oxidants, strong alkalis and halogens.The gas density in standard state is 1.44g/L, and the relative density of liquid is 0.68 (- 185 ℃).Vapor pressure: 11mmHg (1mmHg=133322Pa) (- 160 ℃), 102mmHg (- 140 ℃), 470mmHg (- 120 ℃).Infrared spectrum wavelength 2191cm-1, 914cm-1.It is in gas state at room temperature, and there is no significant decomposition within several months during storage.Because silane is almost insoluble in grease, it can be stored in a container with a cork coated with grease.
Chemical properties: the chemical properties of silane are much more active than alkanes and are very easy to be oxidized.Spontaneous combustion may occur when contacting with air, and thick white amorphous silica fume may be emitted.It does not react with nitrogen below 25 ℃, and does not react with hydrocarbon compounds at room temperature.The reaction with oxygen is extremely intense, even at - 180 ℃.
Silane and chlorofluorocarbon fire extinguishing agents will react violently, so they cannot be used to extinguish the fire.The explosion limit is 0.8%~98%.
Storage method
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1. Store in a dry, cool and ventilated warehouse.Cylinders should be stored upright and fixed.
2. The cylinder shall be protected from extreme temperature and weather.It shall not be transported together with inflammables and oxidants, and shall be kept away from ignition sources.
