Diethylaluminium chloride

Diethylaluminium chloride, abbreviated DEAC, is an organoaluminium compound. Although often given the chemical formula (C2H5)2AlCl, it exists as a dimer, [(C2H5)2AlCl]2 It is a precursor to Ziegler–Natta catalysts employed for the production of polyolefins. The compound is also a Lewis acid, useful in organic synthesis. The compound is a colorless waxy solid, but is usually handled as a solution in hydrocarbon solvents. It is highly reactive, even pyrophoric.

Structure and bonding

Compounds of the empirical formula AlR2Cl (R = alkyl, aryl) usually exist as dimers with the formula (R2Al)2(μ-Cl)2. The bridging ligands (indicated by "μ-") are halides, not the organic substituents. The aluminium adopts a tetrahedral geometry. Each Al(III) center follows the octet rule. In contrast, triethylaluminium and trimethylaluminium feature bridging alkyl groups and these compounds violate the octet rule. == Production ==

Production

Diethylaluminium chloride can be produced from ethylaluminium sesquichloride, (C2H5)3Al2Cl3, by reduction with sodium: :2 (C2H5)3Al2Cl3 + 3 Na → 3 (C2H5)2AlCl + Al + 3 NaCl It is also obtained from the reaction of triethylaluminium with hydrochloric acid: :(C2H5)3Al + HCl → (C2H5)2AlCl + C2H6 Reproportionation reactions can also be used: :2 (C2H5)3Al + AlCl3 → 3 (C2H5)2AlCl :(C2H5)3Al2Cl3 + (C2H5)3Al → 3 (C2H5)2AlCl == Uses ==

Uses

Diethylaluminium chloride and other organoaluminium compounds are used in combination with transition metal compounds as Ziegler–Natta catalysts for the polymerization of various alkenes. As a Lewis acid, diethylaluminium chloride also has uses in organic synthesis. For example, it is used to catalyze the Diels–Alder and ene reactions. Alternatively, it can react as a nucleophile or a proton scavenger. ==Safety==

Safety

Diethylaluminium chloride is not only flammable but pyrophoric. ==References==

Source: Wikipedia ↗

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