Triethylaluminium

Triethylaluminium is an organoaluminium compound with the formula Al(C2H5)3. It consists of a tetrahedral aluminium center bound to three ethyl groups. The compound is a highly reactive, volatile liquid at room temperature and is notoriously pyrophoric, reacting vigorously with air and moisture.

Production and properties. Triethylaluminium is typically prepared and used under strictly anhydrous, inert conditions and stored in dry hydrocarbon solvents (such as n-hexane or similar) under inert gas. It hydrolyzes readily on contact with water or oxygen, releasing heat and forming aluminum hydroxide and ethane (C2H6). The material is reactive toward many inorganic and organic substrates and forms various alkylated aluminium species in situ.

Uses. TEA is a major reagent in organoaluminium chemistry and catalysis. It serves as a co-catalyst and alkylating agent in Ziegler–Natta-type polymerization systems for olefins, often in combination with titanium or other metal chlorides. It acts as a scavenger for impurities and helps to activate catalytic centers. TEA and related alkylaluminium compounds are also employed as precursors for aluminum oxide deposition in chemical vapor deposition and related techniques used in thin-film and catalyst-support fabrication.

Safety and handling. Because of its pyrophoric nature, triethylaluminium is handled under strictly inert atmosphere, typically with dry solvents and sealed, air-free apparatus. Exposure to air or moisture can ignite the material. Contact with water or steam rapidly generates flammable hydrocarbon and heat. Proper laboratory practices include the use of inert-gas transfers, appropriate shielding, and work in a fume hood with suitable fire suppression measures.