Chlorine Gas as a Lewis Acid-Base Probe for Molten Salts of Divalent Metal Ions

In the context of energy applications for salts and, more specifically, in the case of molten salt reactors, the solvation of corrosion species, the nature and behavior of radiation-produced excess electrons, transient radicals, and molecular gas species all depend on the Lewis acid-base behavior of the constituent salt melt. Speciation of dissolved species and their transport properties are also influenced by the ability of the melt to form networks. This article focuses on the structural properties of melts composed of alkaline earth metal ions coupled with the Cl^- anion, and the quantum mechanical behavior of Cl₂, a typical product of the reaction of radiation-produced chlorine radicals in Cl^--based molten salts. We explore the effect of M²⁺ Lewis acidity on chlorobasicity, seen in this work as the availability of Cl^- ions to chemically react with Cl₂ to produce Cl₃^-.