Aluminium isopropoxide

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Aluminium isopropoxide
Names
IUPAC name
Aluminium isopropoxide
Other names
2-Propanol aluminium salt
AIP
Aluminium isopropanolate
Aluminum propan-2-olate
Aluminium sec-propanolate
Aluminium triisopropoxide
Triisopropoxyaluminium
Properties
C9H21O3Al
Molar mass 204.25 g/mol
Appearance Colorless solid
Density 1.035 g/cm3
Melting point 119 °C (246 °F; 392 K)
Boiling point 135 °C (10 mm Hg)
131 °C (7.5 mm Hg)
125.5 °C (5.5 mm Hg)
113 °C (2.5 mm Hg)
106 °C (1.5 mm Hg)
94 °C (0.5 mm Hg)
Hydrolyzes
Solubility Reacts with carboxylic acids
Soluble in benzene, carbon disulfide, CCl4, chloroform, ethanol, THF, toluene
Moderate soluble in isopropanol
Insoluble
Vapor pressure 1.33-47.33 mmHg (at 119 - 173.9 °C)[1]
Hazards
Safety data sheet Sigma-Aldrich
Flash point 16 °C
Lethal dose or concentration (LD, LC):
11,300 mg/kg (rat oral)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
Infobox references

Aluminium isopropoxide or aluminium triisopropoxide is a chemical compound, a salt of isopropanol with aluminium. It is widely used as a reducing agent for reducing ketones and aldehydes to their corresponding alcohols. It has the chemical formula C9H21O3Al. The general formula used for the compound is Al(O-i-Pr)3, where i-Pr is the isopropyl group (CH(CH3)2).

Properties

Chemical

Aluminium isopropoxide readily hydrolyzes in water to isopropanol and aluminium(III) hydroxide.

Physical

Aluminium isopropoxide is a colorless solid, slightly soluble in alcohols, but more soluble in THF and carbon disulfide. It has the tendency to supercool.

The structure of this compound is complex, possibly time-dependent, and may depend on solvent.

Availability

Aluminium isopropoxide is sold by chemical suppliers. There doesn't appear to be any sellers on eBay or Amazon.

Preparation

Aluminium isopropoxide can be prepared by reacting a mixture or aluminium metal with anhydrous isopropanol, in the presence of a catalyst, such as mercury(II) chloride. The resulting aluminium triisopropoxide is extracted from the reaction mass via factional distillation under vacuum. Some mercury may distill and condense in the resulting isopropoxide, though it can be removed with a syringe. For better purity, aluminium triisopropoxide should be recrystallized, in a dry environment.[2] NileRed made a video on how to make this compound.[3]

It's believed that a gallium-aluminium alloy can be used instead of the aluminium + HgCl2 route.

Projects

  • Reduce ketones and aldehydes to their respective alcohols and viceversa

Handling

Safety

Aluminium isopropoxide is water-sensitive and contact with skin should be avoided. Wear gloves and protection goggles when handling the compound.

Storage

Should be stored in air-tight containers or in a desiccator.

Disposal

Can be destroyed by burning it outside. Hydrolysis gives isopropanol, which is non-toxic but flammable.

References

  1. Wilhoit; Journal of Physical Chemistry; vol. 61; (1957); p. 114
  2. https://www.thevespiary.org/rhodium/Rhodium/Vespiary/talk/files/1457-rre-aluminum-alpropixet807f.pdf
  3. https://www.youtube.com/watch?v=SuoWnueBJaY

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