Dimethylaluminium chloride
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3D model (JSmol)
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| ChemSpider | |
| ECHA InfoCard | 100.013.335 |
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PubChem CID
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| UNII | |
CompTox Dashboard (EPA)
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| Properties | |
| C4H12Al2Cl2 | |
| Molar mass | 185.00 g·mol−1 |
| Appearance | colorless liquid |
| Density | 0.996 g cm−3 |
| Melting point | −21 °C (−6 °F; 252 K) |
| Boiling point | 126–127 °C (259–261 °F; 399–400 K) |
| Hazards | |
| GHS labelling:[1] | |
 
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| Danger | |
| H225, H250, H260, H314 | |
| P210, P222, P223, P231, P231+P232, P233, P240, P241, P242, P243, P260, P264, P280, P301+P330+P331, P302+P335+P334, P302+P361+P354, P303+P361+P353, P304+P340, P305+P354+P338, P316, P321, P363, P370+P378, P402+P404, P403+P235, P405, P501 | |
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Dimethylaluminium chloride is an organoaluminium compound with the chemical formula [(CH3)2AlCl]2. It behaves similarly to diethylaluminium chloride but is more expensive. Hence, it is less commonly used.[2]
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
[edit]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
[edit]Dimethylaluminium chloride is not only flammable but pyrophoric.
References
[edit]- ^ "Aluminum, chlorodimethyl-". pubchem.ncbi.nlm.nih.gov.
- ^ Snider, Barry B. (2001). "Dimethylaluminum Chloride". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rd297. ISBN 0-471-93623-5.
- ^ 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.
- ^ Brendhaugen, Kristen; Haaland, Arne; Novak, David P.; Østvold, Terje; Bjørseth, Alf; Powell, D. L. (1974). "The Molecular Structure of Dimethylaluminium Chloride Dimer, [(CH3)2AlCl]2 Redetermined by Gas Phase Electron Diffraction". Acta Chemica Scandinavica. 28a: 45–47. doi:10.3891/acta.chem.scand.28a-0045.
- ^ 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. S2CID 195242291.