HuagongsheHuagongshe Chemistry Print Report · For research reference only
Lithium aluminum hydride
LAH · LiAlH4 · LITHIUM ALUMINIUM TETRAHYDRIDE · LITHIUM ALUMINIUM HYDRIDE · LiAlH · Lithium aluminum tetrahydride · LITHIUM TETRAHYDROALUMINATE · LITHIUM ALANATE
Identifiers & Physical Properties
| CAS No. | 16853-85-3 |
|---|---|
| Molecular formula | AlH4.Li |
| Average molar mass | 38 g/mol |
| Monoisotopic mass | 38.02884331 g/mol |
| SMILES | [AlH4-].[Li+] |
| InChIKey | OCZDCIYGECBNKL-UHFFFAOYSA-N |
| PubChem CID | 28112 |
| ChEBI | CHEBI:30142 |
| EC No. | 240-877-9 |
| DTXSID | DTXSID70893441 |
Chemical & Physical Properties
| Topological polar surface area | 0 |
|---|---|
| Hydrogen bond donors | 0 |
| Hydrogen bond acceptors | 1 |
| Rotatable bonds | 0 |
| Heavy atoms | 2 |
| Formal charge | 0 |
| Complexity | 0 |
| Chemical classes | Metals -> Metal HydridesFlammable agents - 2nd degree |
| Odor | NoneOdorless solid |
| Density | 0.917 at 59 °F (USCG, 1999) - Less dense than waterwill float0.920.92 @25 °C0.97 g/mL at 20 °C |
| Color/Form | Microcrystalline powder when puregray when aluminum impurity present. Monoclinic crystals.Gray-white monoclinic crystals |
| Solubility | Solubility (parts/100 parts solvent): 30 (ether)13 (tetrahydrofuran)10 (dimethylcellosolve)2 (dibutyl ether)0.1 (dioxane).reacts with H2O, ethanolseth, tetrahydrofuran |
| Decomposition | Decomposes to lithium hydride, aluminum metal and hydrogen above 125 °C without melting.Decomposes above 125 °C, slowly loses hydrogen at 120 °C, decomposes in moist air. |
| Melting point | Decomposes >125 °C125 °C (dec.)(lit.) |
| Physical Description | Lithium aluminum hydride appears as a white powder that turns gray on standing. If spread out over a large flat combustible surface, friction can cause ignition. Used to make other chemicals, as a polymerization catalyst, as a hydrogen source, and as a propellant.Gray to white crystals[HSDB] |
| Stability/Shelf Life | Stable in dry air at room temperature.Sometimes turns gray on standingLow melting solids or colorless, volatile liquids. /Alkylaluminum halides/Less sensitive than trialkylaminums to oxidation upon exposure to air. /Alkylaluminum halides/ |
| Other Experimental Properties | Reacts rapidly with water and alcoholsreduces aldehydes, ketones, acid chlorides and esters to alcoholsreduces nitriles to aminesaromatic nitro compounds to azo-compounds. Does not attack olefinic double bonds unless they are conjugated with a phenyl group and a carbonyl or nitrile group.Gray when aluminum impurity presentStable in dry air at room temperature, decomposes above 125 °C, slowly loses hydrogen at 120 °C, decomposes in moist air, may ignite on grinding in air.Heat of formation: -116.3 (crystalline) kJ/mol @ 298.15 KGibbs energy of formation: -44.7(crystalline) kJ/mol @ 298.15 Kstandard molar entropy: 78.7 J/mol K @ 298.15 Kmolar heat capacity at constant pressure: 83.2 J/mol K @ 298.15 K |
| Boiling point | 0°C |
| Bulk density | 400kg/m3 |
| Flash point | 99 °F |
| Storage conditions | Store below +30°C. |
| pKa (acidity coefficient) | 3.86 |
| Physical state | tablets (~0.5 g each) |
| Color | White to light gray |
| Specific gravity | 0.917 |
| Specific heat capacity | Cp(crystal): 2.19 J/(g·K), at 25℃ |
| Sensitivity | Air & Moisture Sensitive |
| Hydrolytic Sensitivity | 8: reacts rapidly with moisture, water, protic solvents |
| Merck | 14,350 |
| Exposure limits | TLV-TWA 2 mg(Al)/m3 (ACGIH). |
| Stability | Stable. Reacts violently with water, liberating hydrogen. Incompatible with strong oxidizing agents, alcohols, acids. |
| InChI | 1S/Al.Li.4H/q-1+1 |
| InChIKey | OCZDCIYGECBNKL-UHFFFAOYSA-N |
| SMILES | [Li].[AlH3] |
| CAS DataBase Reference | 16853-85-3(CAS DataBase Reference) |
| EWG's Food Scores | 1 |
| FDA UNII | 77UJC875H4 |
| NIST Chemistry Reference | Lithium tetrahydroaluminate(16853-85-3) |
| EPA Substance Registry System | Lithium aluminum hydride (16853-85-3) |
| UNSPSC Code | 26111700 |
| NACRES | NA.23 |
| GHS pictogram | GHS02,GHS05,GHS06 |
| Signal word | Danger |
| GHS hazard statements | H330-H301-H314-H260 |
| GHS precautionary statements | P501-P223-P260-P270-P231+P232-P271-P264-P280-P284-P370+P378-P335+P334-P303+P361+P353-P301+P330+P331-P363-P301+P310+P330-P304+P340+P310-P305+P351+P338+P310-P403+P233-P402+P404-P405 |
| Personal protective equipment (PPE) | Eyeshields, Faceshields, Gloves, type P3 (EN 143) respirator cartridges |
| Hazard symbols | F,C,Xi,Xn,F+,T |
| Risk statements (R) | 15-34-14/15-11-36/37-19-40-10-67-66-22-12-35-37-65-48/20-63-36/38-61-60 |
| Safety statements (S) | 43-7/8-6A-45-43B-36/37/39-33-26-16-24/25-27-29-62-53 |
| UN transport number | UN 1410 4.3/PG I (LITHIUM ALUMINIUM HYDRIDE) |
| Water hazard class (WGK) | 2 |
| RTECS number | BD0100000 |
| F | 10-21 |
| TSCA inventory status | TSCA listed |
| Customs code | 2850 00 20 |
| Hazard class | 4.3Eye Dam. 1Skin Corr. 1AWater-react 1 |
| Packing group | I |
| Storage class | 4.3 - Hazardous materials which set free flammable gases upon contact with water |
| Hazardous substances data | 16853-85-3(Hazardous Substances Data) |
| Toxicity | TLV-TWA (ACGIH) 2 mg (Al)/m3 |
| REACH registrations | Active |
| Excepted quantities | Not Permitted as Excepted Quantity |
Safety & Regulations
| GHS classification | DangerH220 (13.3%): Extremely flammable gas [Danger Flammable gases]P203, P210, P222, P223, P231+P232, P260, P264, P264+P265, P280, P301+P330+P331, P302+P335+P334, P302+P361+P354, P304+P340, P305+P354+P338, P316, P317, P321, P363, P370+P378, P377, P381, P402+P404, P403, P405, and P501 (click each P-code to see the statement)Aggregated GHS information provided per 279 reports by companies from 4 notifications to the ECHA C&L Inventory. Each notification may be associated with multiple companies.H260: In contact with water releases flammable gases which may ignite spontaneously [Danger Substances and mixtures which in contact with water, emit flammable gases] |
|---|---|
| Regulatory information | Chemical: Aluminate(1-), tetrahydro-, lithium, (T-4)-Status: Active Update: 11-11-2013 https://echa.europa.eu/registration-dossier/-/registered-dossier/11218Aluminate(1-), tetrahydro-, lithium, (T-4)-: HSNO Approval: HSR001279 Approved with controlsThe New Jersey Worker and Community Right to Know Act requires public and private employers to provide information about hazardous substances at their workplaces. (N.J.S.A. 34:5A-1 et. seq.) |
| Other safety information | IMAP assessments - Aluminate(1-), tetrahydro-, lithium, (T-4)-: Human health tier I assessment |
| DOT label | Dangerous When Wet |
| Fire hazards | Behavior in Fire: Decomposes at 257 °F to form hydrogen gas. The heat generated may cause ignition and/or explosion. (USCG, 1999)· Produce flammable gases on contact with water. |
| Fire potential | Evolves hydrogen & ignites on contact with water.Decomposition begins at 257 °F (125 °C) & releases heat. Combustion may produce irritants & toxic gases.Flammable, dangerous fire risk. May ignite spontaneously on grinding or rubbing, or from static sparks.Lithium aluminum hydride has the additional fire hazard in that it is used in the flammable solvents diethyl ether and tetrahydrofuran.Lithium aluminum hydride should not be used to dry methyl ethers or tetrahydrofuranfires from this are very common.Lithium aluminum hydride with carbon dioxide in sodium bicarbonate at high temp is a fire hazard. |
| Health hazards | Contact of solid with eyes and skin causes severe burns similar to those caused by caustic soda. (USCG, 1999)· Inhalation or contact with vapors, substance or decomposition products may cause severe injury or death. |
| Hazards summary | Contact with solid causes caustic burns to eyes and skin. [CHRIS] Inhalation of high concentrations can cause pulmonary edema[HSDB] Reacts with moisture on the skin or in the eyes and respiratory tract to form a corrosive alkali solution (lithium hydroxide)[CHEMINFO] |
| DOT ID and guide | 1411 1381410 138 |
| Reactive group | Metal Hydrides, Metal Alkyls, Metal Aryls, and Silanes |
| RCRA requirements | D003A solid waste containing Lithium aluminum hydride may become characterized as a hazardous waste when subjected to testing for reactivity as stipulated in 40 CFR 261.23, and if so characterized, must be managed as a hazardous waste. |
| Reactivity Alerts | Strong Reducing Agent |
| Reactivity Profile | LITHIUM ALUMINUM HYDRIDE is a powerful reducing agent. React violently on contact with many oxidizing agents. Ignites by friction, especially if powdered. Reacts vigorously with hydroxy compounds such as water, alcohols, carboxylic acids [Mellor 2 Supp. 2:142. 1961]. Caused a violent explosion when used to dry diethylene glycol dimethyl ether: Ignition may have been caused by heat from reaction with impurity water or perhaps decomposition of peroxides in the ether. About 75% of the ether had been removed when the explosion occurred [MCA Case History 1494. 1968]. Reduces carbon dioxide or sodium hydrogen carbonate to methane and ethane at elevated temperatures. These flammable or explosive gases can form when CO2 extinguishers are used to fight hydride fires. Forms explosive complexes with ether, dimethylamine and various tetrazoles. Tetrazoles include, 2-methyl, 2-ethyl, 5-ethyl, 2-methyl-5-vinyl, 5-amino-2-ethyl [US Pat. 3 396 170, 1968]. |
| Fire fighting | Excerpt from ERG Guide 138 [Substances - Water-Reactive (Emitting Flammable Gases)]: |
| Accidental release measures | · CALL 911. Then call emergency response telephone number on shipping paper. If shipping paper not available or no answer, refer to appropriate telephone number listed on the inside back cover.· ELIMINATE all ignition sources (no smoking, flares, sparks or flames) from immediate area. |
| First aid | In case of accidental contact with the skin, wipe off excess with a dry paper towel. Wash the affected area with a large volume of water to prevent localized heating of the skin. (USCG, 1999)General First Aid: |
| Firefighting Hazards | It /lithium aluminum hydride/ reacts with water to form lithium hydroxide, a corrosive material, aluminum hydroxide and hydrogen, a flammable gas. The heat of this reaction may be sufficient to ignite the hydrogen. The lithium and aluminum hydroxides are corrosive. |
| Exposure control and personal protection | · Wear positive pressure self-contained breathing apparatus (SCBA). |
| Fire fighting procedures | Fire must be extinguished with powdered limestone or dry chemical.A fire once started cannot be extinguished by ordinary methodssmothering by dolomite powder is recommended.Fires should be extinguished with dry chemicals"Lith-X," the trademark for a graphite-base dry chemical extinguishing agent, is available for such fires.Sand can be used as a fire extinguisher for lithium aluminum hydride.For more Fire Fighting Procedures (Complete) data for LITHIUM ALUMINUM HYDRIDE (7 total), please visit the HSDB record page. |
| Storage conditions | Store in a cool, dry, well-ventilated location. Separate from ketones, aldehydes, nitrogenous organic compounds.Extremely reactive with air, moisture and compounds containing active hydrogen and therefore must be kept under a blanket of inert gas. /Aluminum alkyls/In general, materials ... toxic as stored or which can decompose into toxic components ... Should be stored in cool ... ventilated place, out of ... sun, away from ... fire hazard ... be periodically inspected and monitored. Incompatible materials should be isolated ...All possibility of contact with water must be avoided. Solution containing not more than 20% of these compounds in non-reactive solvents, however, can be handled without risk of spontaneous ignition. /Aluminum alkyls/For more Storage Conditions (Complete) data for LITHIUM ALUMINUM HYDRIDE (6 total), please visit the HSDB record page. |
| Nonfire spill response | Excerpt from ERG Guide 138 [Substances - Water-Reactive (Emitting Flammable Gases)]: |
| Disposal methods | Aluminum compounds are treated under anhydrous conditions to prevent violent reactions, recover solvent, and form Al compounds suitable for landfill by reaction with anhydrous hydrolysis agent, eg calcium hydroxide. /Aluminum compounds/SRP: The most favorable course of action is to use an alternative chemical product with less inherent propensity for occupational exposure or environmental contamination. Recycle any unused portion of the material for its approved use or return it to the manufacturer or supplier. Ultimate disposal of the chemical must consider: the material's impact on air qualitypotential migration in soil or watereffects on animal, aquatic, and plant lifeand conformance with environmental and public health regulations. |
| Preventive Measures | Burning lithium aluminum hydride is not extinguished by nitrogentherefore, for large-scale utilization of lithium aluminum hydride, use of an inert gas such as argon is necessry to prevent a potentially hazardous situation.The principal physical property of lithium hydrides important to their safe handling is the large amount of hydrogen contained in a relatively small volume. Two g of lithium hydride treated with water will liberate 200 cu ft of hydrogen. ... In the handling of lithium hydrides, water in any form must be eliminated. ... Chief hazards in handling are dust production, static electricity, and fire. /Lithium hydrides/Care is necessary in handling ... . A rubber mallet is recommended for /pulverizing instead of a mortar and pestle/.Personnel protection: Avoid breathing dusts, and fumes from burning material. ... Do not handle broken packages unless wearing appropriate personal protective equipment. Wash away any material which may have contacted the body with copious amounts of water or soap and water.For more Preventive Measures (Complete) data for LITHIUM ALUMINUM HYDRIDE (9 total), please visit the HSDB record page. |
| Isolation and Evacuation | Excerpt from ERG Guide 138 [Substances - Water-Reactive (Emitting Flammable Gases)]:Immediate precautionary measure |
| Minimum Risk Level | Intermediate Oral: 1.0 mg/kg/day (L134) Chronic Oral: 1.0 mg/kg/day (L134) |
| Treatment | EYES: irrigate opened eyes for several minutes under running water. INGESTION: do not induce vomiting. Rinse mouth with water (never give anything by mouth to an unconscious person). Seek immediate medical advice. SKIN: should be treated immediately by rinsing the affected parts in cold running water for at least 15 minutes, followed by thorough washing with soap and water. If necessary, the person should shower and change contaminated clothing and shoes, and then must seek medical attention. INHALATION: supply fresh air. If required provide artificial respiration. |
| Health effects | Aluminum targets the nervous system and causes decreased nervous system performance and is associated with altered function of the blood-brain barrier. The accumulation of aluminum in the body may cause bone or brain diseases. High levels of aluminum have been linked to Alzheimer's disease. A small percentage of people are allergic to aluminium and experience contact dermatitis, digestive disorders, vomiting or other symptoms upon contact or ingestion of products containing aluminium. (L739, L740) |
| Adverse effects | Neurotoxin - Other CNS neurotoxin |
| Exposure routes | Oral (L739)inhalation (L739) |
| Toxicity summary | IDENTIFICATION AND USE: Lithium aluminum hydride is a gray-white monoclinic crystalline material which is soluble in ether, tetrahydrofuran, dimethylcellosolvepartially soluble in dibutyl ether and insoluble in dioxane. This chemical is an intermediate in the production of other hydrides. It is used as a reducing agent for over 60 different functional groups, especially for pharmaceutical, perfume, and fine organic chemicalsconverts esters, aldehydes and ketones to alcohols and nitriles to aminessource of hydrogenpropellantcatalyst in polymerizations. HUMAN EXPOSURE AND TOXICITY: Causes severe eye and skin burns. It may be harmful if inhaled. This chemical is irritating to skin, eyes, and respiratory system. Symptoms of overexposure include spasms, inflammation and edema of larynx, and bronchi, pulmonary edema, coughing, wheezing, laryngitis, nausea, and vomiting. Solid will burn skin and eyes. The hydrides of aluminum can react with moisture and leave behind hydroxide. The hydrides of lithium in the presence of moisture are readily converted to hydroxides which are highly irritating to the skin by caustic and thermal action. Similar effects can occur on contact with eyes and respiratory mucous membranes. ANIMAL STUDIES: No animal studies could be located.The main target organs of aluminum are the central nervous system and bone. Aluminum binds with dietary phosphorus and impairs gastrointestinal absorption of phosphorus. The decreased phosphate body burden results in osteomalacia (softening of the bones due to defective bone mineralization) and rickets. Aluminum's neurotoxicity is believed to involve several mechanisms. Changes in cytoskeletal protein functions as a results of altered phosphorylation, proteolysis, transport, and synthesis are believed to be one cause. Aluminum may induce neurobehavioral effects by affecting permeability of the blood-brain barrier, cholinergic activity, signal transduction pathways, lipid peroxidation, and impair neuronal glutamate nitric oxide-cyclic GMP pathway, as well as interfere with metabolism of essential trace elements because of similar coordination chemistries and consequent competitive interactions. It has been suggested that aluminum's interaction with estrogen receptors increases the expression of estrogen-related genes and thereby contributes to the progression of breast cancer (A235), but studies have not been able to establish a clear link between aluminum and increased risk of breast cancer (A15468). Certain aluminum salts induce immune responses by activating inflammasomes. (L739, A235, A236) |
| Signs and Symptoms | Inhalating aluminum dust causes coughing and abnormal chest X-rays. A small percentage of people are allergic to aluminium and experience contact dermatitis, digestive disorders, vomiting or other symptoms upon contact or ingestion of products containing aluminium. (L739, L740) |
| Human Toxicity Excerpts | /HUMAN EXPOSURE STUDIES/ Contamination of aluminum with lithium was suggested as a mechanism for encephalopathy because psychotic patients treated with lithium salts exhibit tremors, early or after several years. Lithium may be a neurotoxin alone, as suggested by the observation that volunteers given lithium carbonate in doses of 1225 +/- 300 mg/day for 7 days when tested in the company of distractors made more errors recalling words than when they received a placebo. Although lithium and aluminum may act similarly, more studies are needed to determine whether lithium contamination contributes to occupational aluminum toxicity. /Lithium contaminated aluminum//SIGNS AND SYMPTOMS/ Causes severe eye and skin burns. May be harmful if inhaled. Irritating to skin, eyes, and respiratory system. Symptoms of overexposure include spasms, inflammation and edema of larynx, and bronchi, pulmonary edema, coughing, wheezing, laryngitis, nausea, and vomiting./SIGNS AND SYMPTOMS/ From an industrial point of view lithium itself and its salts present no hazard but lithium hydride and its derivatives lithium tetrahydroaluminate and lithium tetrahydroborate are corrosive and irritant. |
| Carcinogen Classification | Not listed by IARC. IARC classified aluminum production as carcinogenic to humans (Group 1), but did not implicate aluminum itself as a human carcinogen. (L135) A link between use of aluminum-containing antiperspirants and increased risk of breast cancer has been proposed (A235), but studies have not been able to establish a clear link (A15468). |
| Toxicity Data | LC50 (mammal) = 70 mg/m3 |
| State Drinking Water Standards | (CA) CALIFORNIA 1000 ug/l /Aluminum/ |
| State drinking water guidelines | (AZ) ARIZONA 73 ug/l /Aluminum/(CA) CALIFORNIA 200 ug/l /Aluminum/(ME) MAINE 1430 ug/l /Aluminum/ |
| Federal drinking water guidelines | EPA 50-200 ug/l /Aluminum/ |
| F | 10-21 |
| Personal protective equipment (PPE) | Eyeshields, Faceshields, Gloves, type P3 (EN 143) respirator cartridges |
| Water hazard class (WGK) | 2 |
| TSCA inventory status | TSCA listed |
| RTECS number | BD0100000 |
| UN transport number | UN 1411 4.3/PG I (LITHIUM ALUMINIUM HYDRIDE, ETHEREAL) |
| Customs code | 2850 00 20 |
| Toxicity | TLV-TWA (ACGIH) 2 mg (Al)/m3 |
| Risk statements (R) | 15-34-14/15-11-36/37-19-40-10-67-66-22-12-35-37-65-48/20-63-36/38-61-60 |
| Signal word | Danger |
| GHS pictogram | GHS02,GHS05,GHS06 |
| Hazard symbols | F,C,Xi,Xn,F+,T |
| Safety statements (S) | 43-7/8-6A-45-43B-36/37/39-33-26-16-24/25-27-29-62-53 |
| Hazard class | 4.3Eye Dam. 1Skin Corr. 1AWater-react 1 |
| Storage class | 4.3 - Hazardous materials which set free flammable gases upon contact with water |
| Packing group | I |
| GHS hazard statements | H330-H301-H314-H260 |
| Excepted quantities | Not Permitted as Excepted Quantity |
| REACH registrations | Active |
| GHS precautionary statements | P501-P223-P260-P270-P231+P232-P271-P264-P280-P284-P370+P378-P335+P334-P303+P361+P353-P301+P330+P331-P363-P301+P310+P330-P304+P340+P310-P305+P351+P338+P310-P403+P233-P402+P404-P405 |
| Hazardous substances data | 16853-85-3(Hazardous Substances Data) |
Applications & Uses
Description
Lithium aluminum hydride (LiAlH4) is a promising compound for hydrogen storage, with a high gravimetric and volumetric hydrogen density and a low decomposition temperature. Similar to other metastable hydrides, LiAlH4 does not form by direct hydrogenation at reasonable hydrogen pressures; therefore, there is considerable interest in developing new routes to regenerate the material from the dehydrogenated products LiH and Al. It can also be used as a reducing agent in the preparation of reduced graphene oxide (rGO).
Uses
Lithium aluminum hydride is among the most important industrial reducingagents. It is used extensively in organic syntheses and also in catalytichydrogenation. Reactant or reagent for: 1. The preparation of thermoplastic polyester polyamides from oleic acid 2. Lithium-polymer batteries 3. Hydrodefluorination of gem-difluoromethylene derivatives 4. Asymmetric aldol reactions 5. Synthesis of Li-Al-N-H composites with hydrogen absorption / desorption properties 6. LAH is a powerful reducing agent for many different reduction reactions such as that of ketones to alcohols
Uses
It is used as a powerful reducing agent inorganic synthesis. Except for olefinic doublebonds, almost all organic functional groupsare reduced by lithium aluminum hydride(Sullivan and Wade 1980). It is used extensivelyin pharmaceutical synthesis and in catalytichydrogenation.
General Description
A white powder that turns gray on standing. If spread out over a large flat combustible surface, friction can cause ignition. Used to make other chemicals, as a polymerization catalyst, as a hydrogen source, and as a propellant.
Preparation & Synthesis
Preparation
Lithium aluminum hydride is prepared by reaction of lithium hydride with aluminum chloride in diethylether: 4LiH + AlCl3 →(C2H5)2O→LiAlH4+3LiCl