Iron-imidazole ligation is ubiquitous in non-heme enzymes especially those involved in oxidative stress response. In chapter 1, we have demonstrated that N4 ligands with these donors are not straightforward in regards to coordination chemistry and afford eight-coordinate systems depending on geometrical constraints imposed by the ligand. These molecules are structurally robust and, like biological non-heme Fe-Im systems, exhibit reversible electrochemistry. Synthetic modifications rendered these systems to coordinate in the expected fashion and have allowed us to construct a variety of Fe(II)-N4-L systems that replicate structural and spectroscopic features of metalloenzymes such as superoxide reductase (SOR).The coordination chemistry of nitric oxide (NO) is very rich and much of its chemistry is related to metal coordination. In chapter 2, we report the synthesis/characterization of {CoNO}8 and {CoNO}9 systems. The structure, spectroscopy, and reactivity of these CoNO compounds demonstrate that they could be useful in NO or HNO delivery.