Like other organoaluminium chlorides, dimethylaluminium chloride is a Lewis acid. This property is exploited by the use of dimethylaluminium chloride to induce some Diels-Alder reactions.[3]
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 the prefix "μ-", are halides, not the organic substituents. The aluminium adopts a tetrahedral geometry and follows the octet rule.[4][5] By contrast, triethylaluminium and trimethylaluminium feature bridging alkyl groups and these compounds violate the octet rule.
Safety
Dimethylaluminium chloride is not only flammable but pyrophoric.
^Danheiser, Rick L.; Renslo, Adam R.; Amos, David T.; Wright, Graham T. (2003). "Preparation of Substituted Pyridines Via Regiocontrolled [4 + 2] Cycloadditions of Oximinosulfonates: Methyl 5-Methylpyridine-2-Carboxylate". Organic Syntheses. 80: 133. doi:10.15227/orgsyn.080.0133.
^McMahon, C. Niamh; Francis, Julie A.; Barron, Andrew R. (1997). "Molecular Atructure of [(tBu)2Al(μ-Cl)]2". Journal of Chemical Crystallography. 27 (3): 191–194. doi:10.1007/BF02575988. S2CID195242291.