Paper Citing NAMD - Abstract
Pandey, Shubha; Baker, Gary A.; Sze, Leonhard; Pandey, Siddharth; Kamath, Ganesh; Zhao, Hua; Baker, Sheila N.
Ionic liquids containing fluorinated beta-diketonate anions: synthesis, characterization and potential applications
NEW JOURNAL OF CHEMISTRY, 37:909-919, 2013
Ionic liquids (ILs) sporting anions comprising the beta-diketonate functionality were prepared, fully characterized via ESI-MS, FTIR, and H-1/C-13 NMR, and tested in multiple scenarios. We present eight new salts based on four different beta-diketonate anions, each coupled with the choline or tetrabutylphosphonium cation. The thermal stabilities and transitions of these beta-diketonate salts were explored using DSC and TGA. Seven of the compounds displayed melting points at or below 100 degrees C and hence formally qualify as ILs. The inherent binding capability of the beta-diketonate moiety made possible a task-specific IL amenable to lanthanide recognition. For example, coordination with Eu3+ was accompanied by a striking three order-of-magnitude intensification of luminescence ('turn-on'). Additionally, these ILs display prominent acidochromism. That is, the intense visible color of beta-diketonate ILs is modulated in the presence of an acid source, permitting the visual transduction of local pH changes. Utility for carbon capture was also considered, however, these ILs were essentially incapable of binding CO2. Computational studies were better able to elucidate this behavior, revealing that the association of CO2 with the beta-diketonate anion is thermodynamically unfavored and sterically hindered. Despite this negative result for CO2 capture, these newly introduced beta-diketonate ILs show interesting and useful physicochemical properties applicable to a number of future applications.
