The synthesis and structural comparison are reported herein for a series of late first-row transition metal complexes using a macrocyclic pyridinophane ligand, N,N'-di-tert-butyl-2,11-diaza[3.3](2,6)pyridinophane ((tBu)N4). The (tBu)N4 ligand enforces a distorted octahedral geometry in complexes [((tBu)N4)M-II(MeCN)(2)](OTf)(2) (M = Fe-II, Co-II, Ni-II, Cu-II), [((tBu)N4)Zn-II(MeCN)(OTf)](OTf), and [((tBu)N4)Fe-III(OMe)(2)](OTf), with elongated axial M-N-amine distances compared to the equatorial M-N-py distances. The geometry of [((tBu)N4)Cu-I(MeCN)](OTf) is pentacoordinate with weak axial interactions with the amine N-donors of (tBu)N4. Complexes [((tBu)N4)M(MeCN)(2)](OTf)(2) (M = Fe, Co) exhibit magnetic properties that are intermediate between those expected for high spin and low spin complexes. Electrochemical studies of ((tBu)N4)M complexes suggest that (tBu)N4 is suitable to stabilize Co-I, Ni-I, Co-III, Fe-III solvato-complexes, while the electrochemical oxidation of ((tBu)N4)NiCl2 complex leads to formation of a Ni-III species, supporting the ability of the (tBu)N4 ligand to stabilize first row transition metal complexes in various oxidation states. Importantly, the [((tBu)N4)M-II(MeCN)(2)](2+) complexes exhibit two available cis coordination sites and thus can mediate reactions involving exogenous ligands. For example, the [((tBu)N4)Cu-II(MeCN)(2)](2+) species acts as an efficient Lewis acid and promotes an uncommon hydrolytic coupling of nitriles. In addition, initial UV-vis and electron paramagnetic resonance (EPR) studies show that the [((tBu)N4)Fe-II(MeCN)(2)](2+) complex reacts with oxidants such as H2O2 and peracetic acid to form high-valent Fe transient species. Overall, these results suggest that the ((tBu)N4)M-II systems should be able to promote redox transformations involving exogenous substrates.