Atomistic Simulation of the Structure of the Tetrabutylphosphonium Amino Acid Ionic Liquids

Ionic liquids (ILs) are a group of organic salts. The structure of ILs is similar to the table salt such as sodium chloride which contains crystals made of positive sodium ions and negative chlorine ions not molecules. While, salts do not melt below800 ◦C, most of ILs remain liquid at room temperature. However, RTILs are liquid generally up to 200 ◦C. ILs have a wide liquidus ranges. The low melting points of ILs are a result of the chemical composition. The combination of larger asymmetric organic cation and smaller inorganic counterparts lower the lattice energy and hence the melting point of the resulting ionic medium. Molecular dynamics (MD) simulation is a reliable approach to explore the relationship between microstructures and macroscopic properties of ionic liquids. In this study, we simulated a new type of task specific ILs, tetrabutylphosphonium amino acid ([P(C4)4][AA]).