Knowledge Bank

Ab initio calculations have been carried out to characterize Grignard reagents $CH3MgX$ and $CH3MgMgX(X=F,Cl,Br)$. Positions and intensities of IR spectra have been predicted for these species as well as for other possible products of matrix $reactions1$ of magnesium with $CH3X$ at the uniform theoretical level $(SCF/6-31G\ast )$. Relative stabilities have been discussed on the basis of the MP2 theory. For the fluorine species unusual complexes of Grignard reagents with magnesium have been studied with the help of the density functional approach. Comparison with previous $findings2,3$ has been discussed as well as with preliminary experimental results of cryogenic syntheses of such substances.