Dimethylaluminium chloride

Dimethylaluminium chloride
Identifiers
CAS Number	1184-58-3 ;
3D model (JSmol)	Interactive image;
ChemSpider	21171389;
ECHA InfoCard	100.013.335
EC Number	214-668-8;
PubChem CID	79147;
UNII	B548L3505Q;
CompTox Dashboard (EPA)	DTXSID5061580 ;
	InChI InChI=1S/2CH3.Al.ClH/h2*1H3;;1H/q;;+1;/p-1 Key: JGHYBJVUQGTEEB-UHFFFAOYSA-M;
	SMILES C[Al](C)Cl;
Properties
Chemical formula	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:
Pictograms
Signal word	Danger
Hazard statements	H225, H250, H260, H314
Precautionary statements	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). Infobox references

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

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.

References

^ "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.

[1] "Aluminum, chlorodimethyl-". pubchem.ncbi.nlm.nih.gov.

[2] Snider, Barry B. (2001). "Dimethylaluminum Chloride". Encyclopedia of Reagents for Organic Synthesis. doi:10.1002/047084289X.rd297. ISBN 0-471-93623-5.

[3] 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.

[4] 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.

[5] 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.

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