The synthesis of Metal-Organic Frameworks, or MOFs, can be easily changed or manipulated simply by changing the solvent medium. The research focused primarily on the role ionic liquids (ILs) had in MOF synthesis. ILs can be defined as salts that are liquid at room temperature. IL ligands were found one of three ways in the final structure; either acting as the anion, cation, or neither and just acting as a medium for a reaction. This research primarily revolved around Cambridge Structural Database (CSD). The purpose of CSD was a way to look more closely at these crystalline structures from previous research papers and create certain figures that are different from the ones used in the originals to formulate a better understanding of the role of the IL in the MOFs. Keywords to the research, searched in databases such as Scifinder Scholar, and Google Scholar to try and find research papers with a suitable structure that could be found via CSD. The suitable structures found in the research papers were searched in CSD, so they could be transferred to its associated software Mercury. By using Mercury, new structures were created to convey and highlight the role of the IL and differences in connections from structure to structure. One structure in particular was synthesized by Ribbeck et al. They were able to crystalize the 3D Frameworks of lanthanide ions with pentaflouroethyltricyanoborate with the ionic liquid ethyl-methyl-imidazolium or emim. In this specific case, the ionic liquid emim plays the role of the anion in the 3D crystalline structure; linking together the metal in an unique way. Another of the papers analyzed discussed the ionothermal synthesis of compounds [emim][Mn(btc)] and [pmim][Mn(btc)] with the latter having different structures dependent upon the IL. In the case of these compounds, the IL not only acted as a medium, but the IL’s anion was part of the final structure and contributed to the structural differences between compounds. Throughout the research in the final product, the IL could act as an anion, a cation, or not appear in the final product at all. However, no matter how the ionic liquid played into the final structure, every structure varied by bridging ligand, types of connections from ligand to metal (such as monodentate or bidentate, etc.), the metal coordination number, the metal geometry, the ligand plane, and the net of the centroids. After gathering the data together, this information was used to create structures and find similarities between each of the papers and the MOFs within them.
Forbes, Sydney; Wills, Aaron; and Eppley, Hilary, "Conceptualizing and Analyzing Metal-Organic Frameworks and the Role of the Ionic Liquid" (2020). Annual Student Research Poster Session. 41, Scholarly and Creative Work from DePauw University.
Sydney Forbes; Aaron Wills; Hilary Eppley, PhD
Department of Biochemistry, DePauw University, Greencastle, IN
Supported by: DePauw University Faculty Development Committee