Eric Johnson, University of Utah
The ability to reduce O2 in mild conditions holds many important implications such as: use as an economical fuel cell, pharmaceutical synthesis, biomass degradation and conversion of small molecules to fuels. We are building the [M(μ-OH) (oxapyme)M(H2O)]+ molecules and symmetrical counterparts for use in O2 reduction reactions (M = Cobalt, Nickel, Iron). The precursors to the [M(μ-OH)(oxapyme)M(H2O)]+ have been synthesized as follows. 2-[5-(2-Nitro-phnyl)-[1,3,4]oxadiazol- 2-yl]-phenylamine serves as the backbone of the complex, allowing for two distinct ligands to be attached to each side. Initial yields for this synthesis averaged at 6%. To be able to complete the synthesis this needed to be significantly raised. The literature procedure was modified in various ways until new reaction conditions were found that allowed for 40% yield. Other precursors include 2,2’-(1,3,4)Oxadiazole-2,5-diyl-bis-aniline which also serves as a ligand backbone but differs in that it allows for preparation of a symmetrical ligand have been synthesized with a 51% yield. The first ligand Bis-pyridine-2-ylmethyl-amino has been produced with a 60% yield. The second ligand Methyl-pyridine-2-ylmethyl-amino has been synthesized with an approximate yield of 75%. These yields are high enough to finish the synthesis of the ligand and subsequently coordinate the metals. Upon completion, the electrochemical properties of the compounds that differ in the metal composition and the ligand (symmetrical versus asymmetrical) will be determined using studies such as cyclic voltammetry. Once the metal and ligand that are most apt at oxygen reduction is determined, more advanced studies will be undertaken to identify the reaction mechanism and intermediates.