Theoretical study on dissociation of Grignard reagents with several substituents in THF

Abstract

Magnesium has interesting properties suitable for acting negative electrodes in rechargeable battery. The electrodeposition from THF solution with Grignard reagent is one of the potential methods to make good electrodes. In this study, dissociation of Grignard reagents in solution was analysed using values from quantum mechanical (QM) calculations. Geometry optimizations were performed for Grignard reagents with several substituents, such as methyl, ethyl n-propyl, n-pentyl, n-octyl, and phenyl groups. As we observed ionic conductivities of these reagents dissolved in THF, a PLS regression was applied in order to explain the observed property on the basis of calculated values such as dissociation energies of Mg-Br and Mg-C bonds and their distances, molecular volumes, maximum radius of molecules, r(max), and orbital energies of HOMO and LUMO as explanatory variables. The GA-PLS analysis selected r(max) and LUMO energies as explanatory variables for the PLS regression. The correlation equation from the PLS analysis was used to analyse the mechanism of magnesium deposition in THF with Grignard solution.