E. Hill, W. A. Boyd, Hemnalini Desai
May 17, 1996
Citations
0
Influential Citations
21
Citations
Journal
Journal of Organometallic Chemistry
Abstract
Abstract The infrared spectra of allyl- and methallyl-d 2 -magnesium bromides have two double bond streching bONds, corresponding to C CH 2 and C CD 2 groups in equilibrating allylic isomers. The methylene resonances in the 13 C NMR spectra of allylmagnesium bromide and chloride and methallylmagnesium bromide are broadened at low temperatures by an exchange process which appears to be the interconversion between the classical unsymmetrical allytic structures. Analogous changes are seen in the spectrum of 1,3-dimethylallylmagnesium chloride and in the proton NMR spectrum of allylmagnesium bromide. Rate constants and activation parameters for the exchange have been determined from the line broadenings. Unlike the Grignard reagent, the methylene resonances of diallylmagnesium in tetrahydrofuran are not significantly broadened at reduced temperature, and the deuterated reagent does not have two distinct double bond stretching bands in the IR spectrum.