Synthesis and Characterization of Luminescent Ionic Liquids

The preparation of metal-free luminescent Ionic Liquids (ILs) is a challenging topic from both synthetic and physical organic chemistry standpoints. Nevertheless, the combination of ILs characterized by fully tunable properties, with luminescent moieties opens a wide range of potential applications in material science (1). This concept has been exploited by us to develop a protocol based on the use of methylcarbonate ILs and luminescent species derived from amino acids (2). The following strategy was implemented: a) methylphosphonium and methylammonium methylcarbonate salts ([Pxxx1][MeOCO2] and [N1114][MeOCO2]; X=8, 4, respectively) were prepared by a straightforward, halide-free methodology; b) methylcarbonate salts were then subjected to a metathesis reaction with aminoacids bearing luminescent fragments (LAA). At the same time, the preparation of LAA was optimized with a focus on increasing the sustainability of preparative steps. Both the synthesis and the preliminary characterization of the new luminescent ILs will be discussed. The luminescence properties as well as the thermal analysis (TGA and DSC) of such compounds will be described.