Pt. need surgery, hemodent:
A- zinc chloride
B- aluminum chloride***
Aluminum chloride (AlCl3) also known as aluminum trichloride, or aluminum (III) chloride, is a salt of aluminum and chlorine.
The anhydrous form has a particular structure: although it is a halide of a highly electropositive metal, the chemical bonds are mainly covalent and not ionic as one might expect. This has the consequence that AlCl3 has low melting and sublimation temperatures (178 ° C for the latter), and that in the liquid state, it poorly conducts electricity unlike ionic halides such as sodium chloride .
This compound exists in the solid state in the form of a hexacoordinated network.
It melts to form a tetracoordinated dimer, Al2Cl6 which can vaporize but dissociates at higher temperature to form a BF3-like AlCl3 species.
Aluminum chloride is very deliquescent and can explode on contact with water as a result of hydration.
It hydrolyzes partially in the presence of water to form hydrogen chloride (hydrochloric acid).
In aqueous solution, AlCl3 is totally ionized and the solution conducts electrical current well.
AlCl3 is probably the most commonly used Lewis acid and among the most potent.
This compound has many applications in the chemical industry, especially as a catalyst for Friedel and Crafts reactions, both alkylation and acylation.
It is also used for polymerization or isomerization reactions of organic compounds.
There is also an aluminum chloride (I) (AlCl), but it is very unstable and is only known in the gaseous state.
Physico-chemical properties:
In the solid state, aluminum chloride crystallizes according to the type structure YCl3, with the Al3 ions forming a face-centered cubic lattice.
Aluminum chloride is a strong Lewis acid capable of reacting according to Lewis acid-base reactions with even weak Lewis bases such as benzophenone or mesitylene. In the presence of a chloride ion, it reacts to form AlCl4-.
Partial hydrolysis in the presence of water forms hydrogen chloride and / or hydrochloric acid. Aqueous solutions of aluminum chloride behave in the same way as solutions of other salts containing hydrated Al3 ions.
For example, in the presence of the appropriate amount of soda, it forms a gelatinous precipitate of aluminum hydroxide:
AlCl3 (aq) 3 NaOH (aq) → Al (OH) 3 (s) 3 NaCl (aq).
Crystal structure:
In the solid state, aluminum chloride crystallizes in a RhCl3 type structure, with a C 2 / m monoclinic space group. Its mesh parameters are a = 5.914 Å, b = 10.234 Å and c = 6.148 Å with β = 108.25 °.
In the mesh, the aluminum occupies the Wyckoff position 4g (y = 0.166) and the chlorine positions 4i (x = 0.215 and z = 0.226) and 8j (x = 0.252, y = 0.321, z = 0.225).
The structure obtained is a structure in sheets in the plane (a, c), aluminum being placed in the center of aluminum octahedra, and honeycomb in the plane (a, b).
Preparation:
Aluminum chloride is produced industrially by the direct reaction of aluminum and chlorine elements:
2 Al + 3 Cl2 → 2 AlCl3
Or from aluminum and hydrochloric acid:
2 Al + 6 HCl → 2 AlCl3 + 3 H2
This reaction is exothermic.
Aluminum chloride (AlCl3) also known as aluminum trichloride, or aluminum (III) chloride, is a salt of aluminum and chlorine.
The anhydrous form has a particular structure: although it is a halide of a highly electropositive metal, the chemical bonds are mainly covalent and not ionic as one might expect. This has the consequence that AlCl3 has low melting and sublimation temperatures (178 ° C for the latter), and that in the liquid state, it poorly conducts electricity unlike ionic halides such as sodium chloride .
This compound exists in the solid state in the form of a hexacoordinated network.
It melts to form a tetracoordinated dimer, Al2Cl6 which can vaporize but dissociates at higher temperature to form a BF3-like AlCl3 species.
Aluminum chloride is very deliquescent and can explode on contact with water as a result of hydration.
It hydrolyzes partially in the presence of water to form hydrogen chloride (hydrochloric acid).
In aqueous solution, AlCl3 is totally ionized and the solution conducts electrical current well.
AlCl3 is probably the most commonly used Lewis acid and among the most potent.
This compound has many applications in the chemical industry, especially as a catalyst for Friedel and Crafts reactions, both alkylation and acylation.
It is also used for polymerization or isomerization reactions of organic compounds.
There is also an aluminum chloride (I) (AlCl), but it is very unstable and is only known in the gaseous state.
Physico-chemical properties:
In the solid state, aluminum chloride crystallizes according to the type structure YCl3, with the Al3 ions forming a face-centered cubic lattice.
Aluminum chloride is a strong Lewis acid capable of reacting according to Lewis acid-base reactions with even weak Lewis bases such as benzophenone or mesitylene. In the presence of a chloride ion, it reacts to form AlCl4-.
Partial hydrolysis in the presence of water forms hydrogen chloride and / or hydrochloric acid. Aqueous solutions of aluminum chloride behave in the same way as solutions of other salts containing hydrated Al3 ions.
For example, in the presence of the appropriate amount of soda, it forms a gelatinous precipitate of aluminum hydroxide:
AlCl3 (aq) 3 NaOH (aq) → Al (OH) 3 (s) 3 NaCl (aq).
Crystal structure:
In the solid state, aluminum chloride crystallizes in a RhCl3 type structure, with a C 2 / m monoclinic space group. Its mesh parameters are a = 5.914 Å, b = 10.234 Å and c = 6.148 Å with β = 108.25 °.
In the mesh, the aluminum occupies the Wyckoff position 4g (y = 0.166) and the chlorine positions 4i (x = 0.215 and z = 0.226) and 8j (x = 0.252, y = 0.321, z = 0.225).
The structure obtained is a structure in sheets in the plane (a, c), aluminum being placed in the center of aluminum octahedra, and honeycomb in the plane (a, b).
Preparation:
Aluminum chloride is produced industrially by the direct reaction of aluminum and chlorine elements:
2 Al + 3 Cl2 → 2 AlCl3
Or from aluminum and hydrochloric acid:
2 Al + 6 HCl → 2 AlCl3 + 3 H2
This reaction is exothermic.
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