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[1] [2] [3] Introduced by Gilbert N. Lewis in his 1916 article The Atom and the Molecule, a Lewis structure can be drawn for any covalently bonded molecule, as well as coordination compounds. [4] Lewis structures extend the concept of the electron dot diagram by adding lines between atoms to represent shared pairs in a chemical bond.
[AlH 4] − − e − + n THF → AlH 3 ·nTHF + 1/ 2 H 2; 3 [AlH 4] − + Al − 3 e − + 4n THF → 4 AlH 3 ·nTHF; In reaction 2, the aluminium anode is consumed, limiting the production of aluminium hydride for a given electrochemical cell. The crystallization and recovery of aluminium hydride from electrochemically generated alane has ...
Aluminium borohydride, also known as aluminium tetrahydroborate, is the chemical compound with the formula Al(BH 4) 3. It is a volatile pyrophoric liquid which is used as a reducing agent in laboratories. Unlike most other metal–borohydrides, which are ionic structures, aluminium borohydride is a covalent compound. [2] [3]
A stable derivative of aluminium monoiodide is the cyclic adduct formed with triethylamine, Al 4 I 4 (NEt 3) 4. Also of theoretical interest but only of fleeting existence are Al 2 O and Al 2 S. Al 2 O is made by heating the normal oxide, Al 2 O 3, with silicon at 1,800 °C (3,272 °F) in a vacuum. Such materials quickly disproportionate to the ...
2 Al + 3 CH 3 CH 2 Cl → (CH 3 CH 2) 3 Al 2 Cl 3. The reaction resembles the synthesis Grignard reagents. The product, (CH 3 CH 2) 3 Al 2 Cl 3, is called ethylaluminium sesquichloride. The term sesquichloride refers to the fact that, on average, the Cl:Al ratio is 1.5. These sesquichlorides can be converted to the triorganoaluminium ...
The polymorphs differ in terms of the stacking of the layers. All forms of Al(OH) 3 crystals are hexagonal [disputed – discuss]: gibbsite is also known as γ-Al(OH) 3 [8] or α-Al(OH) 3 [citation needed] bayerite is also known as α-Al(OH) 3 [8] or β-alumina trihydrate [citation needed] nordstrandite is also known as Al(OH) 3 [8] doyleite
Most compounds considered to be Lewis acids require an activation step prior to formation of the adduct with the Lewis base. Complex compounds such as Et 3 Al 2 Cl 3 and AlCl 3 are treated as trigonal planar Lewis acids but exist as aggregates and polymers that must be degraded by the Lewis base. [10] A simpler case is the formation of adducts ...
[4] [5] An extended version of this model is used to describe the whole class of hypervalent molecules such as phosphorus pentafluoride and sulfur hexafluoride as well as multi-center π-bonding such as ozone and sulfur trioxide. There are also molecules such as diborane (B 2 H 6) and dialane (Al 2 H 6) which have three-center two-electron bond ...