Pursuing Electrochemical Dinitrogen Fixation at a Rhenium Center

The Haber-Bosch process (HB) is an industrial process that converts atmospheric N2 to ammonia (NH3), which is a critical component of fertilizer. Despite the massive benefit that this process has brought to society, it is also detrimental to the environment. HB uses a lot of energy to maintain the reaction conditions required for NH3 production, and it also produces CO2 as a byproduct. We aim to develop catalysts capable of doing the same work as HB, but at a lower cost to the environment. A rhenium(V) dioxo has been synthesized using a ligand scaffold modeled off previous work in the field. This dioxo is air-stable and has been structurally characterized by XRD, and the two oxo ligands were revealed to be trans to each other, a rare configuration. This trans-dioxo configuration proved unreactive with a variety of reagents, but the molecule can be chemically reduced in the presence of acid to a tentatively assigned N2-bridged Re-Re dimer. Cyclic voltammetry of the dioxo in the presence of acid indicated the possibility of PCET or PCET-like reactivity and electrolyzing results in a reduction from rhenium(V) to rhenium(I), and the replacement of the two axial oxo ligands, leading to a molecule that is in a better position to fix dinitrogen. This work demonstrates the plausibility of using a rhenium oxo precursor for N2 fixation, opening these stable molecules to investigation.Bachelor of Scienc