Aluminium(I) oxide
Encyclopedia
Aluminium oxide is a compound of aluminium
Aluminium
Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

 and oxygen
Oxygen
Oxygen is the element with atomic number 8 and represented by the symbol O. Its name derives from the Greek roots ὀξύς and -γενής , because at the time of naming, it was mistakenly thought that all acids required oxygen in their composition...

 with the chemical formula
Chemical formula
A chemical formula or molecular formula is a way of expressing information about the atoms that constitute a particular chemical compound....

 Al2O. It can be made by heating the stable oxide Al2O3
Aluminium oxide
Aluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...

 with silicon at 1800 °C in a vacuum
Vacuum
In everyday usage, vacuum is a volume of space that is essentially empty of matter, such that its gaseous pressure is much less than atmospheric pressure. The word comes from the Latin term for "empty". A perfect vacuum would be one with no particles in it at all, which is impossible to achieve in...

.

Formation and Existence of Al2O

Al2O commonly exists as a gas since the solid state is not stable at room temperature and is only stable between 1050-1600°. Aluminum (I) Oxide is formed by heating Al and Al2O3 in vacuo while in the presence of SiO2 and C, and only by condensing the products. Information is not commonly available on this compound due to instability, complex high-temperature spectra, difficult detection, and identification. In reduction, Al2O is a major component of vapors of Al2O3. There are also 12 valence electrons in Al2O. Al2O molecules can be detected by mass spectroscopy, infrared emission, and ultraviolet absorption and emission in the gas phase. The molecule is linear at equilibrium in the ground state. In the language of valence bond theory, these molecules can be described as adopting sp2 orbital hybridisation, featuring one sigma and two pi bonds. The corresponding ground state for the valence electrons is 1σ2 1σ*224 1π*2, where the 1σ and 1σ* orbitals cancel, and the 1π and 1π* partially cancel. The overall configuration yields a divalent triplet molecule, with one lone electron focused on the oxygen atom and the other focused equally between the aluminium atoms.

Combination with SiO4 to make mullite powder

Common names include Kaopolite, and Kyanite. This is a rare mineral since it results from extremely high temperatures that have come in contact with specific alumina-silicate minerals. The mineral can be produced synthetically in electric arc furnaces from calcinated or Bayer processes using alumina and silica. This mineral has short, prismatic crystals, low porosity, good stability in ceramic bonds, volume stability, and low shrinkage. The applications include the lining of furnaces, electrode parts, kiln furniture, precision casting, and spark plugs.

Infrared Measurements of Al2O

Prominent absorptions are observed at 990.7 and 946.6 cm-1 which indicates the presence of a doublet. After diffusion absorptions are observed at 714.8 and 700 cm-1 which indicates a doublet and also at 689.4 cm-1 which indicates a triplet system with two equivalent oxygen atoms. In a more concentrated matrix, both doublet and triplet systems are detected at 715 cm-1. However, after diffusion, the triplet system enhances and the double system decreases.
The diffusion implies that Al2O is an aggregate species since it only appears in concentrated matrices which may be due to polymerization. The triplet may be due to a the presence of a dimer, (Al2O)2, however this should be viewed as relative since the vapor pressure of Al2O is uncertain

Aluminum as a metal fuel with oxidizers

This creates highly exothermic reactions. When Al2O3 is added to a pressure system, the reaction goes from steady, to accelerating, to unstable. This reaction indicates that unstable intermediates such as AlO or Al2O condense or do not form which prevent acceleration and convection down the pressure system.

Aluminum Oxides and Impact Explosions

Aluminum oxides are used as a catalysts and are products of aluminum combustion. Organic peroxides of aluminum have explosive properties and can result in explosions with careless handling. An explosion of Octogen - Octahydro-1,3,5,7-tetranitro-1,3,5,7-tetrazocine (HMX) and aluminum produce aluminum oxide (Al8/3O4).

See also

  • Aluminium
    Aluminium
    Aluminium or aluminum is a silvery white member of the boron group of chemical elements. It has the symbol Al, and its atomic number is 13. It is not soluble in water under normal circumstances....

  • Aluminium oxide
    Aluminium oxide
    Aluminium oxide is an amphoteric oxide with the chemical formula 23. It is commonly referred to as alumina, or corundum in its crystalline form, as well as many other names, reflecting its widespread occurrence in nature and industry...

  • Aluminium(II) oxide
    Aluminium(II) oxide
    Aluminium oxide or aluminium monoxide is a compound of aluminium and oxygen with the chemical formula AlO. It has been detected in the gas phase after explosion of aluminized grenades in the upper atmosphere and in stellar absorption spectra...

  • Oxide
    Oxide
    An oxide is a chemical compound that contains at least one oxygen atom in its chemical formula. Metal oxides typically contain an anion of oxygen in the oxidation state of −2....

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