Name | Trimethylaluminium |
Synonyms | TMA trimethyl-alane Trimethylalumine trimethyl-aluminu Trimethylaluminum Trimethylaluminium Trimethylaluminum solution Trimethylaluminiummincolorlessliquid TrimethylaluminumelecgrPURATREMcolorlessliq trimethylaluminum steel flask 0.3 L (net ~150 G) |
CAS | 75-24-1 |
EINECS | 200-853-0 |
InChI | InChI=1/3CH3.Al/h3*1H3;/rC3H9Al/c1-4(2)3/h1-3H3 |
InChIKey | JLTRXTDYQLMHGR-UHFFFAOYSA-N |
Molecular Formula | C3H9Al |
Molar Mass | 72.09 |
Density | 0.81g/mLat 25°C |
Melting Point | 15 °C |
Boling Point | 126 °C |
Flash Point | 40°F |
Water Solubility | REACTS |
Solubility | Soluble in aromatic, saturated aliphatic and cycloaliphatic hydrocarbons. |
Vapor Presure | 69.3 mmHg ( 60 °C) |
Appearance | Liquid |
Specific Gravity | 0.688 |
Color | Clear colorless |
Odor | Corrosive odor and "taste" may be detectable from trimethylaluminum fires |
Exposure Limit | ACGIH: TWA 50 ppm (Skin)OSHA: TWA 500 ppm(1800 mg/m3)NIOSH: IDLH 1100 ppm; TWA 50 ppm(180 mg/m3) |
BRN | 3587197 |
Storage Condition | 0-6°C |
Sensitive | Air & Moisture Sensitive |
Physical and Chemical Properties | At room temperature and atmospheric pressure, trimethyl aluminum is a colorless transparent liquid, with strong reactivity, spontaneous combustion in the air, instant ignition, intense reaction with alcohol and acid with active hydrogen, and intense reaction with water, even in cold water, an explosive decomposition reaction can be produced, and methane and sometimes a fire can be generated. Methane is slowly decomposed at 300 °c. Stable complexes are formed with AsH3, PH 3, ethers, tertiary amines and other Lewis bases. It can be miscible with aliphatic hydrocarbons such as hexane and heptane and aromatic hydrocarbons such as toluene and xylene in any proportion. Trimethylaluminum, which is released to less than 25% of the alkene using a hydrocarbon-based solvent, loses its pyrophoricity. |
Risk Codes | R11 - Highly Flammable R14 - Reacts violently with water R17 - Spontaneously flammable in air R34 - Causes burns R50/53 - Very toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R65 - Harmful: May cause lung damage if swallowed R67 - Vapors may cause drowsiness and dizziness R14/15 - R63 - Possible risk of harm to the unborn child R48/20 - R51/53 - Toxic to aquatic organisms, may cause long-term adverse effects in the aquatic environment. R20 - Harmful by inhalation R62 - Possible risk of impaired fertility |
Safety Description | S26 - In case of contact with eyes, rinse immediately with plenty of water and seek medical advice. S36/37/39 - Wear suitable protective clothing, gloves and eye/face protection. S45 - In case of accident or if you feel unwell, seek medical advice immediately (show the label whenever possible.) S61 - Avoid release to the environment. Refer to special instructions / safety data sheets. S62 - If swallowed, do not induce vomitting; seek medical advice immediately and show this container or label. S6A - S43A - S24/25 - Avoid contact with skin and eyes. S16 - Keep away from sources of ignition. S43 - In case of fire use ... (there follows the type of fire-fighting equipment to be used.) S60 - This material and its container must be disposed of as hazardous waste. S33 - Take precautionary measures against static discharges. S25 - Avoid contact with eyes. S24 - Avoid contact with skin. |
UN IDs | UN 3399 4.3/PG 1 |
WGK Germany | 3 |
RTECS | BD2204000 |
FLUKA BRAND F CODES | 1-10 |
TSCA | Yes |
HS Code | 29319090 |
Hazard Class | 4.3 |
Packing Group | I |
Toxicity | TLV-TWA (ACGIH) 2 mg (Al)/m3 |
It is a colorless transparent liquid at normal temperature and pressure. Spontaneous combustion in air. Water, oxidants, halogenated hydrocarbons, alcohols or other oxygen-containing organic matter can be a strong reaction. It is dissolved in aliphatic hydrocarbons such as ethane and heptane, and aromatic hydrocarbons such as toluene and dimethylbenzene. Trimethylaluminum is stable at room temperature and decomposes slowly at temperatures above 100 °c.
The aluminum powder reacts with methyl iodide to produce methyl aluminum iodide, and then reacts with potassium sodium tetramethylene in a dried decane solution to produce crude trimethyl aluminum. The mixture of crude trimethylaluminum and Decane is subjected to reduced pressure or atmospheric pressure distillation to obtain a high purity product.
high-purity trimethylaluminum is used as a raw material for the MOCVD process for the deposition of aluminum films. It is also useful as a catalyst for the polymerization of olefins.
skin contact with trimethylaluminum can cause tissue damage and burns. Aluminum oxide smoke is harmful to human body when spontaneous combustion occurs in the air. This smoke can irritate and corrode the eyes, skin, and mucous membranes of the respiratory tract. After inhalation, the trachea and lungs are injured, which can cause pulmonary edema in severe cases. It is attached to the skin and can destroy tissue. If it is not treated in time, it can cause severe burns. Staff should be protected. Fire-extinguishing facilities such as fire-resistant asbestos covers, carbon dioxide fire retardants and dry powder fire extinguishing agents must be provided in the workplace, but water, carbon tetrachloride or bromochloromethane fire extinguishing agents must not be used.
NIST chemical information | information provided by: webbook.nist.gov (external link) |
EPA chemical substance information | information provided by: ofmpeb.epa.gov (external link) |
Overview | trimethylaluminum (TMA), in 1865 Buckton first used methyl mercury and aluminum reaction to produce trimethylaluminum, but until the 20th century, the application of TMA has still been limited to the laboratory range, and has long been far less active than the research and application of organomagnesium and organolithium. In recent years, with the development of polyolefin research, TMA as one of the cocatalysts of traditional catalysts and the cocatalysts of methylaluminoxane (MAO) and modified methylaluminoxane (MMAO) the starting materials, in the organic chemical industry, especially the importance of polymer chemical industry began to appear. |
Main uses | important uses of trimethylaluminum in organic catalytic chemistry, organic synthesis and polymer chemical industry. The interaction of trimethylaluminum with appropriate water forms highly active trimethylaluminoxane (MAO), which is one of the most important cocatalysts in metallocene catalytic systems, its largest use is to form a coordination catalyst, such as a catalytic system formed with halides of titanium, zirconium and hafnium, which can make olefins undergo Stereospecific Polymerization, copolymerization and oligomerization; an olefin can be oligomerized, disproportionated, and isomerized by a catalyst composed of a compound of a transition metal element such as nickel or cobalt. In addition, trimethylaluminum itself can also be used to catalyze the reaction. TMA can be oligomerized with ethylene to produce high carbon alkyl aluminum, which is oxidized and hydrolyzed to form linear higher primary alcohols and higher a-olefins. Organic aluminum is not only cheap, and high reactivity, so the commonly used organic aluminum to take other metal organic compounds, such as TMA and tin chloride reaction can be prepared by methyl tin. TMA can also be used as a mild reducing agent for the synthesis of high stereoselectivity reagents, vitamins, hormones and other drugs. In recent years, the formation of metal thin film, is the application of metal organic chemical vapor deposition method to achieve. If TMA is carried by hydrogen gas, a metal aluminum thin film can be formed by thermal decomposition on a heating substrate. In the aerospace industry, trimethyl aluminum can be used as a liquid fuel for rocket. TMA can also be used as an important alkylating agent in the fine organic synthetic chemistry industry. |
preparation | aluminum reduction method TMA can be prepared by direct reduction of methylmercury with aluminum, however, due to the instability and toxicity of Alkyl mercury, the reaction has no practical value, and the production of mercury makes the handling of the product more difficult. TMA can also be obtained by the aluminum reduction method of methyl halide (mainly methyl iodide), and the reaction scheme is as follows: the reaction temperature of this method is 69~72 C, and the theoretical conversion rate is 50% ~ 65%. The reaction time is too long (more than 20 h), and methyl iodide is expensive and extremely unstable, which limits the utility of this reaction. |
hazard characteristics | can form explosive mixture with air; Flammable, pay attention to the risk of dust explosion; after the flame is put out, it may re-burn; Pay attention to the risk of spontaneous combustion; Contact with water may cause strong or explosive reaction; The container exposed to the fire may leak out the contents through the pressure safety valve; expansion or explosive decomposition may occur when heated or exposed to a flame. |
Application | trimethylaluminum is used as a catalyst for olefin polymerization, as a pilot fuel, and also for the preparation of straight-chain primary alcohols and olefins, it can be used for metal-organic compound vapor deposition. |
production method | 1. This product can be made by heating metal aluminum and dimethyl mercury; Or made from metal aluminum and Halomethane trihalogenated trimethyldialuminum, and then reacted with metal sodium. 2. EtZnX(X = Br, I) produced by the reaction of Zn, EtBr and Etti in the presence of a Cu salt and a catalyst is converted to diethylzinc by heating, and can be separated and purified by distillation. Aluminum powder reacts with methyl iodide to produce methyl aluminum iodide, which reacts with potassium-sodium alloy in dry decane solution to produce crude trimethyl aluminum. The mixture of crude trimethylaluminum and Decane is subjected to reduced pressure or atmospheric pressure distillation to obtain a high purity product. |
category | spontaneous combustion articles |
toxicity grade | poisoning |
Acute toxicity | inhalation-rat LC50: 10000 mg/m3/15 min |
flammability hazard characteristics | spontaneous combustion in air, chlorine, oxidant and high temperature; release of toxic aluminides gas |
storage and transportation characteristics | The warehouse is ventilated and dried at low temperature; The package is filled with nitrogen; Stored separately from the oxidant |
extinguishing agent | dry sand, dry powder, stone powder |
Occupational Standard | TWA 2 mg (AL) /m3 |
spontaneous combustion temperature |