Applying Supramolecular Chemistry to the Synthesis and Characterization of Uranium Bearing Hybrid Materials

This dissertation focuses on the synthesis and characterization of uranium-containing metal-organic hybrid materials. These materials self-assemble under aqueous conditions aided by supramolecular interactions which help define the solid state structures. This work set out to create families of uranium-bearing hybrid materials which may be utilized in discerning the limits of supramolecular inorganic-organic chemistry as a means of crystal engineering. As the many forces which achieve the organization of molecules and ions in the solid state (including hydrogen bonds, pi-pi and halogen-halogen interactions, and weaker interactions) are not all apparent when attempting syntheses of new materials, known supramolecular synthons are a convenient way of summarizing major interactions. As these synthons are explored in the synthesis of metal-organic hybrid materials, researchers may begin to move away from chance results and towards creating desired structure types. Until our efforts, supramolecular chemistry has been significantly underdeveloped in actinide systems.;We first demonstrate the utility of applying supramolecular chemistry to uranium in a system where the [UO2X4]2- anion interacts predictably with linear bipryidinium cations to form a previously observed transition metal synthon (M-Cl2˙˙˙H-N). The resulting bifurcated "ribbon motif" was realized in many such phases, absent only when the organic tecton diverged from the linear prototypes seen in other work.;While the above uranium-bearing tectons are diverse and may provide a route to many new phases and families of materials, they too have their limitations; namely they semi-regularly produce a 'ribbon' motif within the solid state and limit our predictive efforts to 1-D.;We next show that limited metal-ligand coordination yields a second method for creating new uranium-bearing tectons, which have the added benefit of utilizing additional supramolecular synthons, such as halogen-halogen interactions. This second approach exploits our knowledge of hard-soft acid base (HSAB) theory to choose a ligand, 4-halobenzoic acid, that coordinates to uranium on one side, while presenting a supramolecular entity outward. This coordination creates a tecton that presents a 'face' capable of halogen-halogen interactions with sister tectons in the solid state.;Both methods represent a significant step in utilizing crystal engineering to create families of uranyl-bearing hybrid materials.