Thermal stability of ionic liquids on the molecular level
Ionic liquids (ILs) are valuable solvents with promising properties. Impurities may strongly deteriorate the solvent ability of the IL. At higher temperature, ILs may contaminate themselves by their own decomposition products. The complete decomposition mechanisms are currently unknown.Copyright: © Institute of Technical Thermodynamics of RWTH Aachen University
In a joint research effort of the University of Rostock and RWTH Aachen University, IL decomposition mechanisms are investigated both experimentally, e.g. with thermogravimetry, and with computational chemistry methods. The latter can analyze reaction pathways and rate with our in-house code Chemical Trajectory analYzer (ChemTraYzer). Automatically deduced molecule geometries are then processed by high-level ab initio methods. Possible decomposition reactions in gas and liquid are investigated using Transition State Theory (TST). The figure shows a Transition State (TS) for an elimination reaction in ethyl-methyl-imidazoliumacetate ([C2C1Im][OAc]). The improved understanding of such reaction mechanisms enables the future design of stable and tailored ILs.