NMR of Organomagnesium Compounds
Since their discovery, the exact solution composition of Grignard compounds has been
the subject of considerable debate, and given the power of NMR in elucidating chemical
structure it is unsurprising that it was applied to the study of Grignard and other organomagnesium compounds from its earliest days. However, the complex nature of the solution behaviour of such compounds and the low magnetic field strengths then available often frustrated proper analysis of the data, and the first reported NMR studies were generally inconclusive. Worse, the interpretation of early NMR spectra was often based on preconceived (and as it is now realized incorrect) notions as to the nature of the compounds in solution, so caution must be exercised when considering much of the pre-1970’s data.
Although the advent of higher field NMR instruments and our increasing understanding
of the solution behaviour of organomagnesium reagents have greatly improved the veracity
of NMR studies, detailed NMR reports on such compounds remain relatively sparse. The bulk of the literature that has been published was done so prior to the 1980’s. The reasons
for the paucity of reported NMR studies are probably three-fold: (i) organomagnesium
reagents are generally highly sensitive, making the isolation of sufficiently pure samples
problematic; (ii) different preparations can apparently give quite different NMR spectra;
(iii) the exact solution behaviour depends on a number of factors, making it difficult to
draw any general conclusions.
This paper reviews the current state of the literature on the NMR of Grignard and other organomagnesium compounds.
Chemistry | Inorganic Chemistry | Organic Chemistry | Physical Chemistry
Heard, P. J. (2008) NMR of Organomagnesium Compounds, in The Chemistry of Organomagnesium Compounds (eds Z. Rappoport and I. Marek), John Wiley & Sons, Ltd, Chichester, UK. doi: 10.1002/9780470751879.ch3
Digital Commons Citation
Heard, Peter J., "NMR of Organomagnesium Compounds" (2007). Chemistry. Paper 13.