Quantum-Chemical and Molecular Dynamics Investigations of Magnesium Chloride Complexes in Dimethoxyethane Solutions

摘要

Quantum-chemical calculations and classical and ab initio molecular dynamics simulations have been performed to study the Mg~(2+)-conducting electrolytes based on Mg(TFSI)_(2)/MgCl_(2) solutions in dimethoxyethane. It has been shown that depending on the TFSI/Cl~(–) ratio, the Mg_(2)Cl_(2)~(2+) or Mg_(3)Cl_(4)~(2+) complexes are preferred as stable ion aggregates. In the initial stages of the ion association process, MgCl~(+), MgCl_(2), and Mg_(2)Cl_(3)~(+) are formed as intermediate species. Calculations of harmonic frequencies and simulations of the IR spectrum of the electrolyte from the ab initio MD trajectories have been used to identify the spectral range of vibrations of ion aggregates found in the modeled electrolyte. The results have been discussed in the context of experimental data.