Lithium Aluminum Hydride CAS 16853-85-3 Information
| CAS |
16853-85-3 |
| Molecular formula |
LiAlH4 |
| Molecular weight |
37.954298 |
| EIENCS |
240-877-9 |
| Form |
tablets (~0.5 g each) |
| Melting point |
125 °C (dec.)(lit.) |
| boling point |
0°C |
| Density |
0.97 g/mL at 20 °C |
| Solubility |
Reacts |
| PKA |
/ |
| Color |
White to light gray |
| Storage temp |
Store below +30°C. |
What is Lithium Aluminum Hydride CAS 16853-85-3?
Thermal decomposition reaction: It is metastable at room temperature and decomposes into Li₃AlH₆ and LiH over long storage time. This process can be accelerated by co-catalytic elements such as titanium, iron and vanadium. The reaction mechanism during heating is divided into three steps:
3LiAlH₄ → Li₃AlH₆ + 2Al + 3H₂↑ (R1, usually begins with melting, temperature range 150-170 ° C)
2Li₃AlH₆ → 6LiH + 2Al + 3H₂↑ (R2, occurs at about 200 ° C)
2LiH + 2Al → 2LiAl + H₂↑ (R3, reversible reaction, equilibrium pressure 25 kilopascals at 500 ° C)
Other reactions: It immediately undergoes an explosive and violent reaction upon contact with water and releases hydrogen gas. This reaction can be used to determine the content of lithium aluminum hydride in samples or to prepare hydrogen gas in the laboratory. It can react with ammonia, halides, etc. It can also undergo hydroalumination reactions on alkenes and alkynes to obtain the corresponding intermediates, which can then react with electrophilic reagents. It can reduce halogenated alkanes to alkanes (halogenated product activity: iodinated product > brominated product > chlorinated product); The hydrogenation of carbon-carbon double bonds is usually not possible.
Lithium Aluminum Hydride CAS 16853-85-3 Use
Organic synthesis: It is a very important reducing agent in organic synthesis, especially suitable for the reduction of esters, carboxylic acids and amides. It can reduce aldehydes, ketones, acids, anhydrides, esters, quinones, acyl chlorides, etc. to alcohols, reduce nitriles to primary amines, and reduce halogenated hydrocarbons to hydrocarbons. However, it usually cannot hydrogenate carbon-carbon double bonds. It can also act on double and triple bond compounds to achieve hydroalumination reactions and can also participate in reactions as a base.
Other fields: It is used as a reducing agent in medicine, fragrances, pesticides, dyes and other fine organic syntheses; It can release a large amount of heat energy when burning and is used as an additive for the fuel of missiles and launch vehicles.
Lithium Aluminum Hydride CAS 16853-85-3 safety
Danger: It will decompose into hydrogen gas when exposed to water or moist air. When heated, in contact with moisture, water, alcohols or acids, it will undergo exothermic reactions and release hydrogen gas, leading to combustion or explosion. It reacts violently with strong oxidants and explodes.
Both solids and solutions are highly flammable.
It has a strong irritant effect on mucous membranes, upper respiratory tract, eyes and skin. After being inhaled by the human body, it can cause inflammation, edema, spasm, chemical pneumonia or pulmonary edema in the larynx and bronchi, leading to death. Contact may cause a burning sensation, coughing, wheezing, laryngitis, shortness of breath, headache, nausea and vomiting, etc.
Storage precautions: Store in a cool, dry, well-ventilated warehouse, away from sources of ignition and heat. The warehouse temperature should not exceed 25℃, and the relative humidity should not exceed 75%. The packaging should be sealed and stored separately from oxidants, acids, alcohols, etc. Mixed storage is strictly prohibited. The storage area should be equipped with appropriate materials to contain spills.
Emergency response:
Emergency response for leakage: Isolate the contaminated area of the leakage and restrict access; Cut off the source of fire; It is recommended that emergency response personnel wear self-contained positive pressure breathing apparatus and fire protection suits. Do not come into direct contact with the leak. When there is a small leakage, avoid raising dust. Use spark-free tools to collect it in a dry, clean and covered container and transfer it to a safe place. When there is a large-scale leakage, cover it with plastic sheeting or canvas to reduce scattering. Contact the relevant technical department to determine the removal method.
First aid measures:
Skin contact: Immediately remove contaminated clothing and rinse with plenty of running water for at least 15 minutes. Seek medical attention.
Eye contact: Immediately lift the eyelids and rinse thoroughly with plenty of running water or physiological saline for at least 15 minutes. Seek medical attention.
Inhalation: Quickly move to a place with fresh air and keep the airway clear. If breathing is difficult, administer oxygen; If breathing stops, perform artificial respiration immediately and seek medical attention.
Ingestion: If swallowed by mistake, rinse mouth with water, give milk or egg white to drink, and seek medical attention.
