Aluminium tri-sec-butoxide
[CAS 2269-22-9]

Identification

• Classification: Organic raw materials >> Organometallic compound >> Organic aluminum
• Name: Aluminium tri-sec-butoxide
• Synonyms: Aluminum sec-butoxide
• Molecular Formula: 3(C₄H₉O).Al
• Molecular Weight: 246.32
• CAS Registry Number: 2269-22-9
• EC Number: 218-871-2
• SMILES: CCCC[O-].CCCC[O-].CCCC[O-].[Al+3]

Properties

• Boiling point: 341.3 - 348.9 °C (Expl.)
• Flash point: 27.8 °C (Expl.)
• Solubility: water: decomposes (Expl.)
• Refraction index: 1.439 (Expl.)

Safety Data

• Hazard Symbols: GHS02;GHS06;GHS07 DangerGHS02
• Risk Statements: H226-H302-H311-H312-H319-H335-H336
• Safety Statements: P210-P233-P240-P241-P242-P243-P261-P262-P264-P264+P265-P270-P271-P280-P301+P317-P302+P352-P303+P361+P353-P304+P340-P305+P351+P338-P316-P317-P319-P321-P330-P337+P317-P361+P364-P362+P364-P370+P378-P403+P233-P403+P235-P405-P501

Hazard Classification

Hazard	Class	Category Code	Hazard Statement
Flammable liquids	Flam. Liq.	3	H226
Acute toxicity	Acute Tox.	4	H302
Acute toxicity	Acute Tox.	4	H312
Eye irritation	Eye Irrit.	2	H319
Specific target organ toxicity - single exposure	STOT SE	3	H335
Specific target organ toxicity - single exposure	STOT SE	3	H336
Acute toxicity	Acute Tox.	3	H311
Serious eye damage	Eye Dam.	1	H318
Skin corrosion	Skin Corr.	1A	H314
Skin irritation	Skin Irrit.	2	H315
Skin corrosion	Skin Corr.	1B	H314

• Transport Information: UN 1992

chemBlink Chemical Story

Aluminium tri-sec-butoxide, CAS 2269-22-9, is an aluminium alkoxide with three sec-butoxy groups attached to aluminium. PubChem gives the formula C12H27AlO3 for the idealized alkoxide representation, while supplier records commonly write it as Al[OCH(CH3)C2H5]3. Its importance comes from the high reactivity of metal-alkoxide bonds toward water and from their ability to generate aluminium-oxygen networks under controlled conditions.

In sol-gel chemistry, hydrolysis replaces alkoxide groups with hydroxyl groups, and subsequent condensation forms Al-O-Al linkages. Repeating these reactions converts a molecular precursor into an inorganic oxide network. Because the transformation can begin in solution, chemists can control mixing, coating, particle formation and film deposition before the final alumina structure is produced by drying and heat treatment.

Sigma-Aldrich describes aluminium tri-sec-butoxide as a metal-organic precursor and specifically notes use as a sol-gel precursor for alumina thin films. Aluminium alkoxides are also widely used as starting materials for high-purity alumina, mixed oxides and surface coatings. Reaction rate is crucial: uncontrolled contact with moisture can cause rapid hydrolysis and precipitation, whereas carefully chosen water content, solvent, temperature and chelating additives can slow the process and improve uniformity.

The compound is also described as a chelating or reactive aluminium reagent in synthesis. Its Lewis-acidic aluminium center and exchangeable alkoxide ligands allow it to participate in coordination and catalytic chemistry. However, its best-known materials role remains as a molecular route to aluminium oxide.

This is a classic example of precursor chemistry. The sec-butoxy groups are not intended to remain in the final ceramic; they make aluminium processable in an organic-compatible molecular form. Hydrolysis and condensation then remove the organic groups and build the Al-O framework. A liquid molecular reagent can therefore become the starting point for an inorganic film or oxide material.

References:
1. PubChem, Aluminum sec-butoxide, CID 61289, CAS 2269-22-9.
2. U.S. FDA GSRS, Aluminum sec-butoxide, UNII FE7IK35OPN.
3. Sigma-Aldrich, Aluminum-tri-sec-butoxide, product 201073.
4. Brinker CJ, Scherer GW. Sol-Gel Science. Academic Press, 1990.

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