In such procedures, the dimethylmagnesium exists as the ether adduct, not the polymer.[4]
Addition of
1,4-dioxane causes precipitation of solid MgX2(μ-dioxane)2, a
coordination polymer.[4] This precipitation drives the
Schlenk equilibrium toward (CH3)2Mg. Related methods have been applied to other dialkylmagnesium compounds.[3]
Dimethylmagnesium can also be prepared by combining
dimethylmercury and magnesium.[5][6]
Properties
The structure of this compound has been determined by
X-ray crystallography. The material is a polymer with the same connectivity as
silicon disulfide, featuring tetrahedral magnesium centres, each surrounded by bridging methyl groups. The Mg-C distances are 224 pm.[7]Dimethylberyllium adopts the same structure.[8]
References
^Cope, A. C. (1935). "The Preparation of Dialkylmagnesium Compounds from Grignard Reagents". J. Am. Chem. Soc. 57 (11): 2238–2240.
doi:
10.1021/ja01314a059.
^
Anteunis, M. (1962). "Studies of the Grignard Reaction. II. Kinetics of the Reaction of Dimethylmagnesium with Benzophenone and of Methylmagnesium Bromide-Magnesium Bromide with Pinacolone". J. Org. Chem.27 (2): 596–598.
doi:
10.1021/jo01049a060.