Grignard reagents crystal structure

Unlike Grignard reagents, crystal structures of dicoordinated organomagnesium compounds are known. These are formed when sterically hindered ligands cause excessive crowding in the environment around the Mg atom and prevent the coordination of any solvent molecules. The X-ray structure of bis[tris(trimethylsilyl)methyl]magnesium [Compound 19] indicates that the compound is linear (C—Mg—C=180°) and is centrosymmetric around the Mg atom [21]. 

Analyses of Grignard reagents] crystal structures. 117-144, 295-297. 502 bimetallic magnesium species, 136-139 dicoordinate diorganomagnesium. 124-127... 

A number of Grignard reagents have been subjected to X-ray structure determination.23 Ethylmagnesium bromide has been observed in both monomeric and dimeric forms in crystal structures.24 Figures 7.1a and b show, respectively, the crystal structure... 

Use of Amido Grignard Reagents in Inorganic Chemistry—Synthesis and Crystal Structure of Anti (Ragaini et al., 1997)... 

Crystal structures of Grignard reagents do not necessarily correspond to their structure in solution. In general, the crystal structures (61—64) indicate the reagents are ligated with THF or diethyl ether and are frequendy observed to be dimers. The Mg atoms in the dimers do not have a Mg—Mg bond instead the dimers are typically held together by a halide bridge. 

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