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Names | |
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Preferred IUPAC name Lithium aluminate | |
Systematic IUPAC name Lithium(1+) aluminate | |
Other names Lithium metaaluminate Lithium aluminum oxide | |
Identifiers | |
3D model (JSmol) | |
ChemSpider | |
ECHA InfoCard | 100.031.291 |
EC Number |
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MeSH | Lithium+aluminate |
PubChem CID | |
CompTox Dashboard (EPA) | |
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Properties | |
AlLiO2 | |
Molar mass | 65.92 g·mol−1 |
Appearance | white crystalline powder |
Density | 2.615 g/cm3, solid |
Melting point | 1,625 [1] °C (2,957 °F; 1,898 K) |
insoluble | |
Thermochemistry | |
Std molar entropy (S⦵298) | 53.35 J/mol·K [2] |
Std enthalpy of formation (ΔfH⦵298) | -1188.670 kJ/mol [2] |
Gibbs free energy (ΔfG⦵) | -1126.276 kJ/mol [2] |
Hazards | |
Safety data sheet (SDS) | External MSDS |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa). |
Lithium aluminate (LiAlO
2), also called lithium aluminium oxide, is an inorganic chemical compound, an aluminate of lithium. In microelectronics, lithium aluminate is considered as a lattice matching substrate for gallium nitride. [3] [4] In nuclear technology, lithium aluminate is of interest as a solid tritium breeder material, for preparing tritium fuel for nuclear fusion. [5] Lithium aluminate is a layered double hydroxide (LDH) with a crystal structure resembling that of hydrotalcite.[ dubious – discuss ][ clarification needed ] Lithium aluminate solubility at high pH (12.5 – 13.5) is much lower than that of aluminium oxides. In the conditioning of low- and intermediate level radioactive waste (LILW), lithium nitrate is sometimes used as additive to cement to minimise aluminium corrosion at high pH and subsequent hydrogen production. [6] Indeed, upon addition of lithium nitrate to cement, a passive layer of LiH(AlO
2)
2 · 5 H
2O is formed onto the surface of metallic aluminium waste immobilised in mortar. The lithium aluminate layer is insoluble in cement pore water and protects the underlying aluminium oxide covering the metallic aluminium from dissolution at high pH. It is also a pore filler. [7] This hinders the aluminium oxidation by the protons of water and reduces the hydrogen evolution rate by a factor of 10. [8]
Lithium aluminate also finds its use as an inert electrolyte support material in molten carbonate fuel cells, where the electrolyte may be a mixture of lithium carbonate, potassium carbonate, and sodium carbonate. [9]
In 1906 Weyberg described his newly synthesized compound, lithium hydrogen aluminate. This was the first known synthesis of this unique compound. He asserted that this new compound had the corresponding chemical formula: [10]
In 1915 Allen and Rogers asserted that an insoluble aluminate of lithium is formed when aluminum is dissolved in a solution of lithium hydroxide. This air-dried substance had an atomic ratio of 2Li:5Al and the chemical formula: [11]
In 1929 Prociv recreated Allen and Rogers experiment and through a series of conductometric measurements on the saturated solution of the substance concluded that lithium and aluminum were present in the ratio of 0.8Li:2Al, which, he says, is an atomic ratio of approximately 1Li:2Al. According to him lithium aluminate may also be precipitated by the addition of a solution of lithium hydroxide to a solution of aluminum salt or by adding a solution of lithium salt to a solution of an alkali aluminate. Thus there was disagreement between Allen/Rogers and Prociv as to the composition of lithium aluminate. This may have been attributed to variations between their precipitation conditions. [11]
In 1932 Dobbins and Sanders described the formation of lithium aluminate by the addition of dilute ammonia to a solution containing lithium and aluminum salt, in the presence of phelphtalein as an indicator. In their preparation of acid lithium aluminate they dissolved strips of amalgamated aluminum in normal and tenth normal solutions of lithium hydroxide. The lithium aluminate was precipitated by the addition of a solution of lithium hydroxide to a solution of aluminum salts, or by adding a solution of lithium salt to a solution of alkaline aluminate. In all cases the composition of the compound of lithium aluminate was expressed by the formula: [12]
They claimed that the formed compound contained lithium and aluminum in the atomic ratio of 2Li:5Al. Their chemical formula was simplified into the modern formulation for lithium aluminate:
The fundamental compound of lithium aluminate has found attention in two different fields: nuclear physics and solid-state chemistry. At least five different phases of lithium aluminate have been found. [13] The lithium aluminate crystal structure may be found in either α, β, or γ phases. [14]
Nuclear physicists are interested in the γ-LiAlO
2 modification of lithium aluminate, because of its good performance under high neutron and electron radiation. This modification also exhibits the essential chemical, thermo physical and mechanical stability at high temperature along with the required irradiation behavior. This phase appears to be a promising lithium ceramic, suitable as an in site tritium breeding material in future fusion reactors. [13]
Solid-state chemists investigating preparational routes to lithium aluminate discovered its interesting acid-base chemistry. The α-LiAlO
2 modification (but neither β-LiAlO
2 or γ-LiAlO
2) reacts with molten benzoic acid leading to nearly total Li+
proton exchange thus forming LiHAl
2O
4 There is a lot of interest in the chemical reactivity among the three modifications of LiAlO
2. The reasons for the α-LiAlO
2 modification being highly reactive and the β-LiAlO
2 or γ-LiAlO
2 modifications being totally unreactive is currently a mystery. [13]
Lithium aluminate powder preparation was based on the solid-state reactions between Al
2O
3 and lithium-containing compounds like Li
2CO
3, LiOH, Li
2O, LiAc, and reactions occurred at temperatures between 400Deg C to 1000 Deg C. Due to the evaporation of lithium at high temperatures and contamination from grinding operations, pure lithium aluminate with controlled particle size has been difficult to synthesize. [15]
Synthesis of lithium aluminate has been essentially performed by several methods: in the solid state, by wet chemical, sol-gel, with the use of templates, various precursors, and combustion processes. The main product in a solid state reaction is the α-LiAlO
2 phase; in a wet chemical reaction, the main product is a solid solution of α-LiAlO
2 and γ-LiAlO
2 phases. [14] The α-LiAlO2 modification (low temperature phase), with a hexagonal structure, undergoes transformation to the γ-modification (High temperature phase), with a tetragonal structure, at about 900 °C. The metastable β-modification, with a monoclinic structure, is assumed to transform to the γ-modification at about 900 °C. [15]
The compound is unknown in the natural environment. However, a related compound, LiAl5O8, is known as the very recently discovered (as of 2020) and very rare mineral chukochenite. [16] [17]
Berkelium is a synthetic chemical element; it has symbol Bk and atomic number 97. It is a member of the actinide and transuranium element series. It is named after the city of Berkeley, California, the location of the Lawrence Berkeley National Laboratory where it was discovered in December 1949. Berkelium was the fifth transuranium element discovered after neptunium, plutonium, curium and americium.
Hydroxide is a diatomic anion with chemical formula OH−. It consists of an oxygen and hydrogen atom held together by a single covalent bond, and carries a negative electric charge. It is an important but usually minor constituent of water. It functions as a base, a ligand, a nucleophile, and a catalyst. The hydroxide ion forms salts, some of which dissociate in aqueous solution, liberating solvated hydroxide ions. Sodium hydroxide is a multi-million-ton per annum commodity chemical. The corresponding electrically neutral compound HO• is the hydroxyl radical. The corresponding covalently bound group –OH of atoms is the hydroxy group. Both the hydroxide ion and hydroxy group are nucleophiles and can act as catalysts in organic chemistry.
Lithium carbonate is an inorganic compound, the lithium salt of carbonic acid with the formula Li
2CO
3. This white salt is widely used in processing metal oxides. It is on the World Health Organization's List of Essential Medicines for its efficacy in the treatment of mood disorders such as bipolar disorder.
Sodium hydroxide, also known as lye and caustic soda, is an inorganic compound with the formula NaOH. It is a white solid ionic compound consisting of sodium cations Na+ and hydroxide anions OH−.
Aluminium hydroxide, Al(OH)3, is found in nature as the mineral gibbsite and its three much rarer polymorphs: bayerite, doyleite, and nordstrandite. Aluminium hydroxide is amphoteric, i.e., it has both basic and acidic properties. Closely related are aluminium oxide hydroxide, AlO(OH), and aluminium oxide or alumina, the latter of which is also amphoteric. These compounds together are the major components of the aluminium ore bauxite. Aluminium hydroxide also forms a gelatinous precipitate in water.
Manganese dioxide is the inorganic compound with the formula MnO
2. This blackish or brown solid occurs naturally as the mineral pyrolusite, which is the main ore of manganese and a component of manganese nodules. The principal use for MnO
2 is for dry-cell batteries, such as the alkaline battery and the zinc–carbon battery. MnO
2 is also used as a pigment and as a precursor to other manganese compounds, such as KMnO
4. It is used as a reagent in organic synthesis, for example, for the oxidation of allylic alcohols. MnO
2 has an α-polymorph that can incorporate a variety of atoms in the "tunnels" or "channels" between the manganese oxide octahedra. There is considerable interest in α-MnO
2 as a possible cathode for lithium-ion batteries.
The Bayer process is the principal industrial means of refining bauxite to produce alumina (aluminium oxide) and was developed by Carl Josef Bayer. Bauxite, the most important ore of aluminium, contains only 30–60% aluminium oxide (Al2O3), the rest being a mixture of silica, various iron oxides, and titanium dioxide. The aluminium oxide must be further purified before it can be refined into aluminium.
Lithium aluminium hydride, commonly abbreviated to LAH, is an inorganic compound with the chemical formula Li[AlH4] or LiAlH4. It is a white solid, discovered by Finholt, Bond and Schlesinger in 1947. This compound is used as a reducing agent in organic synthesis, especially for the reduction of esters, carboxylic acids, and amides. The solid is dangerously reactive toward water, releasing gaseous hydrogen (H2). Some related derivatives have been discussed for hydrogen storage.
Sodium aluminate is an inorganic chemical that is used as an effective source of aluminium hydroxide for many industrial and technical applications. Pure sodium aluminate (anhydrous) is a white crystalline solid having a formula variously given as NaAlO2, NaAl(OH)4 (hydrated), Na2O·Al2O3, or Na2Al2O4. Commercial sodium aluminate is available as a solution or a solid.
Other related compounds, sometimes called sodium aluminate, prepared by reaction of Na2O and Al2O3 are Na5AlO4 which contains discrete AlO45− anions, Na7Al3O8 and Na17Al5O16 which contain complex polymeric anions, and NaAl11O17, once mistakenly believed to be β-alumina, a phase of aluminium oxide.
In chemistry, an aluminate is a compound containing an oxyanion of aluminium, such as sodium aluminate. In the naming of inorganic compounds, it is a suffix that indicates a polyatomic anion with a central aluminium atom.
Lithium oxide (Li
2O) or lithia is an inorganic chemical compound. It is a white solid. Although not specifically important, many materials are assessed on the basis of their Li2O content. For example, the Li2O content of the principal lithium mineral spodumene (LiAlSi2O6) is 8.03%.
Uranium compounds are compounds formed by the element uranium (U). Although uranium is a radioactive actinide, its compounds are well studied due to its long half-life and its applications. It usually forms in the +4 and +6 oxidation states, although it can also form in other oxidation states.
Aluminium hydride is an inorganic compound with the formula AlH3. Alane and its derivatives are part of a family of common reducing reagents in organic synthesis based around group 13 hydrides. In solution—typically in ethereal solvents such tetrahydrofuran or diethyl ether—aluminium hydride forms complexes with Lewis bases, and reacts selectively with particular organic functional groups, and although it is not a reagent of choice, it can react with carbon-carbon multiple bonds. Given its density, and with hydrogen content on the order of 10% by weight, some forms of alane are, as of 2016, active candidates for storing hydrogen and so for power generation in fuel cell applications, including electric vehicles. As of 2006 it was noted that further research was required to identify an efficient, economical way to reverse the process, regenerating alane from spent aluminium product.
Lithium titanates are chemical compounds of lithium, titanium and oxygen. They are mixed oxides and belong to the titanates. The most important lithium titanates are:
Scandium compounds are compounds containing the element scandium. The chemistry of scandium is almost completely dominated by the trivalent ion, Sc3+, due to its electron configuration, [Ar] 3d14s2. The radii of M3+ ions in the table below indicate that the chemical properties of scandium ions have more in common with yttrium ions than with aluminium ions. In part because of this similarity, scandium is often classified as a lanthanide-like element.
Aluminium triacetate, formally named aluminium acetate, is a chemical compound with composition Al(CH
3CO
2)
3. Under standard conditions it appears as a white, water-soluble solid that decomposes on heating at around 200 °C. The triacetate hydrolyses to a mixture of basic hydroxide / acetate salts, and multiple species co-exist in chemical equilibrium, particularly in aqueous solutions of the acetate ion; the name aluminium acetate is commonly used for this mixed system.
Lithium iridate, Li2IrO3, is a chemical compound of lithium, iridium and oxygen. It forms black crystals with three slightly different layered atomic structures, α, β, and sometimes γ. Lithium iridate exhibits metal-like, temperature-independent electrical conductivity, and changes its magnetic ordering from paramagnetic to antiferromagnetic upon cooling to 15 K.
Aluminium (British and IUPAC spellings) or aluminum (North American spelling) combines characteristics of pre- and post-transition metals. Since it has few available electrons for metallic bonding, like its heavier group 13 congeners, it has the characteristic physical properties of a post-transition metal, with longer-than-expected interatomic distances. Furthermore, as Al3+ is a small and highly charged cation, it is strongly polarizing and aluminium compounds tend towards covalency; this behaviour is similar to that of beryllium (Be2+), an example of a diagonal relationship. However, unlike all other post-transition metals, the underlying core under aluminium's valence shell is that of the preceding noble gas, whereas for gallium and indium it is that of the preceding noble gas plus a filled d-subshell, and for thallium and nihonium it is that of the preceding noble gas plus filled d- and f-subshells. Hence, aluminium does not suffer the effects of incomplete shielding of valence electrons by inner electrons from the nucleus that its heavier congeners do. Aluminium's electropositive behavior, high affinity for oxygen, and highly negative standard electrode potential are all more similar to those of scandium, yttrium, lanthanum, and actinium, which have ds2 configurations of three valence electrons outside a noble gas core: aluminium is the most electropositive metal in its group. Aluminium also bears minor similarities to the metalloid boron in the same group; AlX3 compounds are valence isoelectronic to BX3 compounds (they have the same valence electronic structure), and both behave as Lewis acids and readily form adducts. Additionally, one of the main motifs of boron chemistry is regular icosahedral structures, and aluminium forms an important part of many icosahedral quasicrystal alloys, including the Al–Zn–Mg class.
Gallium compounds are compounds containing the element gallium. These compounds are found primarily in the +3 oxidation state. The +1 oxidation state is also found in some compounds, although it is less common than it is for gallium's heavier congeners indium and thallium. For example, the very stable GaCl2 contains both gallium(I) and gallium(III) and can be formulated as GaIGaIIICl4; in contrast, the monochloride is unstable above 0 °C, disproportionating into elemental gallium and gallium(III) chloride. Compounds containing Ga–Ga bonds are true gallium(II) compounds, such as GaS (which can be formulated as Ga24+(S2−)2) and the dioxan complex Ga2Cl4(C4H8O2)2. There are also compounds of gallium with negative oxidation states, ranging from -5 to -1, most of these compounds being magnesium gallides (MgxGay).
Neptunium compounds are compounds containing the element neptunium (Np). Neptunium has five ionic oxidation states ranging from +3 to +7 when forming chemical compounds, which can be simultaneously observed in solutions. It is the heaviest actinide that can lose all its valence electrons in a stable compound. The most stable state in solution is +5, but the valence +4 is preferred in solid neptunium compounds. Neptunium metal is very reactive. Ions of neptunium are prone to hydrolysis and formation of coordination compounds.