Cheap and abundant bioavailable nitrogen is responsible for disruptions in the global nitrogen cycle, causing negative effects such as eutrophication and hypoxic zones, in addition to producing large anthropogenic sinks of nitrous oxide (a potent greenhouse gas). Nature is capable of converting these pollutants into more innocuous species via the reductase family of metalloenzymes. Inspired by Nature, our group has been active in developing methodologies that control the flux of protons and electrons for biologically relevant reactions by utilizing redox-active pyridinediimine (PDI) scaffolds merged with secondary coordination spheres that are “charge-responsive” and capable of performing hydrogen bond (H-bond) directed reactions. The research presented will focus on our efforts toward the reduction of the nitrogen oxyanions nitrite and nitrate, and the selective coupling of NO to form N2O. Specifically, rate accelerations and the mechanism of nitrogen oxyanion reduction will be discussed in relation to the ligand-based design concepts of redox activity, pKa, sterics, and the secondary coordination influence.