75-24-1 Usage
Outline
Trimethylaluminum is called TMA for short. Trimethylaluminum was prepared by Buckton for the first time using methyl mercury and aluminum in 1865, but until the 1950s, TMA applications has been still limited to the scope of laboratory, its research and application was far less active than organic magnesium and organic lithium for a long time. In recent years, with the development of the research of polyolefins, TMA is as one of the cocatalyst, and starting raw materials for synthesis of cocatalyst catalysts methylalumoxane (of MAO) and modified methylaluminoxane (MMAO) in metallocene catalyst systems. In the organic chemical industry, especially polymer chemical industry, its importance began to appear.
At normal temperature and pressure, trimethyl aluminum is a colorless transparent liquid, highly reactive, spontaneous combustion in the air, and instantly be able to fire, reacts violently with alcohol and acids which have an active hydrogen, reacts violently with water, even in cold water explosive decomposition reaction can be produced, and also generates methane, and sometimes can catch fire. At 300 ℃ it slowly decompose to produce methane. It can form stable complexes with AsH3, PH3, ethers, tertiary amines and other Lewis bases, miscible in any proportion with alicyclic hydrocarbons such as hexane and heptane, aromatic hydrocarbon such as toluene, xylene. diluted to below 25% with a hydrocarbon-based solvent, trimethyl aluminum loses its spontaneous combustion.
Main application
There is an important use for trimethyl aluminum in organic catalytic chemistry, organic synthesis and polymer chemistry industry and other aspects.
Trimethylaluminum acts with water of a suitable form, may form highly reactive methylaluminoxane (MAO), which is one of the most important co-catalyst of the metallocene catalyst system. The maximum use of MAO is to form a coordination catalyst, such as with the halide of titanium, zirconium, hafnium to form a catalyst system, which can result in stereospecific polymerization, copolymerization, oligomerization of olefins. It can form catalyst with the compound of transition metal element such as nickel, cobalt, etc, which can result in lower poly, disproportionation, isomerization of olefins. Further, trimethyl aluminum itself may be used to catalyze the reaction.
TMA can be carried out oligomerization with ethylene to produce high-carbon aluminum alkyl, after oxidation and hydrolysis of the latter to form a straight-chain higher primary alcohols and advanced a-olefins. Organoaluminum is not only inexpensive, but also has high reaction activity, thus organoaluminum is commonly used for preparing other metals organic compounds, for example the reaction of TMA with stannic chloride can be prepared to produce methyl tin. TMA can also be used as mild reducing agent for high stereoselectivity reagents, vitamins, hormones and other drug synthetic. In recent years, the formation of a metal film is achieved by application of metal organic chemical vapor deposition method. As with the hydrogen carrying TMA, the substrate is heated for thermal decomposition to form a metal thin film of aluminum.
In the aerospace industry, and trimethyl aluminum can be used as liquid fuel of rockets. TMA can also be used as an important alkylating agent in organic synthesis of fine chemical industry.
As olefin polymerization catalyst, pyrophoric fuel, also used for making straight-chain primary alcohols and olefins, etc, it can be used for metal organic chemical vapor deposition.
The above information is edited by the lookchem of Yan Yanyong.
Category
Spontaneous Combustion items
Acute toxicity
Oral-rat LD50: 10000 mg/cubic meter/15 minutes
Flammability hazard characteristics
In case of air, chlorine, oxidizers, high temperature can be spontaneous, emit toxic aluminide gases.
Storage Characteristics
Treasury ventilation low-temperature drying, package with nitrogen charging, and stored separately from oxidants
Extinguishing agent
Dry sand, powder, mountain flour
Occupational standards
TWA 2 mg(AL)/cubic meter
Uses
Different sources of media describe the Uses of 75-24-1 differently. You can refer to the following data:
1. Trimethylaluminium can be used as catalyst for olefin polymerization, pyrophoric fuel, manufacture of straight-chain primary alcohols and olefins, to produce luminous trails in upper atmosphere to track rockets.
2. Trimethyl aluminum is a highly reactivereducing and alkylating agent. It is used in aZiegler-Natta catalyst for polymerization andhydrogenation.
3. Trimethylaluminum can be used in the pretreatment of Al2O3/p-type GaSb capacitors.
Definition
A colorless liquid produced by the sodium
reduction of dimethyl aluminum chloride.
It ignites spontaneously on contact with air
and reacts violently with water, acids,
halogens, alcohols, and amines. Aluminum
alkyls are used in the Ziegler process for
the manufacture of high-density polyethene.
Health Hazard
Different sources of media describe the Health Hazard of 75-24-1 differently. You can refer to the following data:
1. As it is pyrophoric and reacts explosivelywith moisture, skin contact can cause a dangerousburn. Contact with eyes can causeblindness. Because of its significant volatility,the risk of inhalation of this compoundis higher than with most other alkyls. Inhalationof its vapors can severely damage therespiratory tract.TLV-TWA: 2 mg(Al)/m3 (ACGIH).
2. Trimethylaluminum and related alkylaluminum reagents are pyrophoric materials that can react explosively with the moisture in tissues, causing severe burns. The heat of reaction can also ignite the methane gas generated, resulting in thermal burns. Alkylaluminum reagents are corrosive substances, and contact is extremely destructive to the eyes, skin, and mucous membranes. Inhalation of trimethylaluminum and other volatile alkylaluminum compounds may cause severe damage to the respiratory tract and can lead to fatal pulmonary edema.
Flammability and Explosibility
Trimethylaluminum is pyrophoric and burns violently on contact with air or water.
Other alkylaluminum reagents show similar behavior, although most are not as
volatile as trimethylaluminum. Water or CO2 fire extinguishers must not be used to
put out fires involving trialkylaluminum reagents. Instead, dry chemical powders
such as bicarbonate, Met-L-X?, or inert smothering agents such as sand or graphite
should be used to extinguish fires involving trialkylaluminum compounds.
storage
Safety glasses, impermeable gloves, and a fire-retardant laboratory coat
should be worn at all times when working with these compounds. Trialkylaluminum
reagents should be handled only under an inert atmosphere.
Check Digit Verification of cas no
The CAS Registry Mumber 75-24-1 includes 5 digits separated into 3 groups by hyphens. The first part of the number,starting from the left, has 2 digits, 7 and 5 respectively; the second part has 2 digits, 2 and 4 respectively.
Calculate Digit Verification of CAS Registry Number 75-24:
(4*7)+(3*5)+(2*2)+(1*4)=51
51 % 10 = 1
So 75-24-1 is a valid CAS Registry Number.
InChI:InChI=1/3CH3.Al/h3*1H3;/rC3H9Al/c1-4(2)3/h1-3H3
75-24-1Relevant articles and documents
27Al NMR study of the trimethylaluminum monomer-dimer equilibrium
Cerny, Z.,Fusek, J.,Kriz, O.,Hermanek, S.,Solc, M.,Casensky, B.
, p. 157 - 165 (1990)
The 27Al NMR signal from trimethylaluminum (TMA) in solution is shifted to lower field with: (i) increasing temperature; (ii) decreasing concentration of TMA; and (iii), more markedly, the increasing solvating power of the solvent.This shift reflects an i
C-H bond activation by hyperconjugation with Al-C bonds and by chelating coordination of the hydride ion
Uhl, Werner,Vinogradov, Andrej,Grimme, Stefan
, p. 11259 - 11264 (2007)
On treating di(tert-butyl)butadiyne with dimethylaluminum hydride under different reaction conditions two unprecedented organoelement compounds, containing cationic carbon atoms stable in solution at room temperature, were obtained. A vinyl cation (2) in which the cationic carbon atom is part of a C=C double bond was produced from 3 equiv of the hydride, whereas a large excess of the hydride yielded an aliphatic carbocation (3) by complete hydroalumination of all C-C multiple bonds. Each compound is zwitterionic with the hydride counterion effectively coordinated in a chelating manner by two strongly Lewis acidic aluminum atoms. In agreement with quantum-chemical calculations the C-H bond activation and the stabilization of the cationic species are further supported by a strong hyperconjugation with Al-C single bonds. This considerably diminishes the effective positive charge at the respective cationic carbon atoms.
Ln(AlMe4)3 as new synthetic precursors in organolanthanide chemistry: Efficient access to half-sandwich hydrocarbyl complexes
Dietrich, H. Martin,Zapilko, Clemens,Herdtweck, Eberhardt,Anwander, Reiner
, p. 5767 - 5771 (2005)
The homoleptic complexes Ln(AlMe4)3 (Ln = Y, La, Nd, Lu) were reacted with pentamethylcyclopentadiene to yield the corresponding half-sandwich complexes (C5Me5)Ln-(AlMe4) 2 in high yield and purity. NMR spectroscopic investigations revealed a highly dynamic nature of the bridging and terminal alkyl groups, even at -85°C. In the solid state, the tetramethylaluminato ligands coordinate differently to the metal center, as shown by an X-ray structure analysis of the lanthanum derivative. Due to the steric unsaturation of the large lanthanum metal center, one of the aluminate ligands adopts an unusual distorted μ:η3 coordination mode, while the second ligand bonds in a routine μ:η2 fashion. An alcoholysis reaction of (C 5Me5)Y(AlMe4)2 with HOCHtBu 2 gave the heteroleptic complex (C5Me5) Y(OCHtBu2)(AlMe4). (C5Me5) Nd(AlMe4)2 was reacted with dehydrated periodic mesoporous silica MCM-41, affording surface-grafted (C5Me5) Nd(AlMe4)2@MCM-41. The half-metallocene bis(aluminate) complexes were converted into donor-free [(C5Me5)LnMe 2l3 (Ln = Y, Lu) via stoichiometric THF-induced cleavage and reversibly regenerated by addition of trimethylaluminum. The organolanthanide complexes were fully characterized by NMR and FTIR spectroscopy and elemental analysis. The organometallic-inorganic hybrid materials were characterized by FTIR spectroscopy, elemental analysis, and nitrogen physisorption.
Trialkylaluminum N-Heterocyclic Olefin (NHO) Adducts as Catalysts for the Polymerization of Michael-Type Monomers
Watson, Ian C.,Zhou, Yuqiao,Ferguson, Michael J.,Kr?nzlein, Moritz,Rieger, Bernhard,Rivard, Eric
, p. 547 - 551 (2020)
The synthesis of new trialkylaluminum adducts with N-heterocyclic olefin (NHO) ligands is described. These well-defined complexes can catalyze the polymerization of various Michael-type monomers, such as 2-vinylpyridine, methylacrylate, and dimethylacryla
Preparation method of trimethylaluminum
-
Paragraph 0056-0057; 0089-0090; 0095-0096, (2021/03/30)
The invention provides a preparation method of trimethylaluminum, which comprises the following steps: in the presence of a catalyst and a solvent, reacting methyl aluminum dichloride or sesquimethylaluminum chloride or dimethylaluminum chloride with a system of metal M and chloromethane to generate trimethylaluminum and a chloride of metal M; wherein the catalyst is selected from metal or ions thereof which are arranged behind metal aluminum in an electrochemical sequence; the metal M is selected from alkali metals, alkaline earth metals, or combinations thereof. The catalyst can significantly increase the reaction rate, so that the reaction can be carried out under very simple experimental conditions such as near normal pressure, the reaction yield and the product purity are higher, no by-product metal aluminum or unreacted alkali metal or alkaline earth metal is contained in the product, and the product is more convenient to treat.
Preparation method of high-purity trimethylaluminum
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Paragraph 0024; 0025, (2020/12/15)
The invention provides a preparation method of high-purity trimethylaluminum. According to the method, aluminum trichloride is used as a raw material and reacts with a Grignard reagent of halomethanein a non-polar inert solvent to prepare high-purity trimethylaluminum. A solvent of the Grignard reagent is replaced by a non-polar solvent, and a complex of trimethylaluminum and an ether compound does not exist in the reaction process, so that the yield and the purity of trimethylaluminum are improved.
Clean process method for synthesizing trimethylaluminum
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Paragraph 0044-0064, (2020/05/30)
The invention relates to a clean process method for synthesizing trimethylaluminum. A trace amount of dimethyl aluminum chloride is generated in a reaction product of the following formula: 2Al + 3CH3Cl = CH3AlCl2.(CH3)2AlCl, a compound of formula MAl(CH3)4 is used to reduce the chlorine content of the trimethylaluminum, M is a Group IA element including lithium, sodium, and potassium; NaAl(CH3)4tetramethylaluminum sodium is adopted, and the dimethyl aluminum chloride is eliminated. Through removing the residual chlorine in the trimethylaluminum by using the tetramethylaluminum sodium, and recovering the tetramethylaluminum sodium, and converting the tetramethylaluminum sodium into methylaluminum chloride to be used as an initial raw material, the clean process method for synthesizing thetrimethylaluminum is a green process without three wastes.
