The key intermediate in dinitrogen cleavage by Mo(N[t-Bu]Ar)(3), 1 (Ar = 3,5-C6H3Me2), has been characterized by a pair of single crystal X-ray structures. For the first time, the X-ray crystal structure of (mu-N-2)[Mo(N[t-BU]Ar)(3)](2), 2, and the product of homolytic fragmentation of the N-N bond, N Mo(N[t-BujAr)(3), are reported. The structural features of 2 are compared with previously reported EXAFS data. Moreover, contrasts are drawn between theoretical predictions concerning the structural and magnetic properties of 2 and those reported herein. In particular, it is shown that 2 exists as a triplet (S = 1) at 20 degrees C. Further insight into the bonding across the MoNNMo core of the molecule is obtained by the synthesis and structural characterization of the one- and two-electron oxidized congeners, (mu-N-2)[Mo(N[t-Bu]Ar)312[B(Ar F)41, 2[B(Ar F)41 (Ar-F = 3,5-C6H3(CF3)(2)) and (mu-N-2)[Mo(N[t-Bu]Ar)(3)](2)[B(Ar-F)(4)](2), 2[B(Ar-F)(4)](2), respectively. Bonding in these three molecules is discussed in view of X-ray crystallography, Raman spectroscopy, electronic absorption spectroscopy, and density functional theory. Combining X-ray crystallography data with Raman spectroscopy studies allows the N-N bond polarization energy and N-N internuclear distance to be correlated in three states of charge across the MoNNMo, core. For 2[B(Ar F)41, bonding is symmetric about the mu-N-2 ligand and the N-N polarization is Raman active; therefore, 2[B(Ar-F)(4)] meets the criteria of a Robin-Day class III ixed-valent compound. The redox couples that interrelate 2, 2(+), and 2(2+) are studied by cyclic voltammetry and spectroelectrochemistry. Insights into the electronic structure of 2 led to the discovery of a photochemical reaction that forms N Mo(N[t-Bu]Ar)(3) and Mo(N[t-Bu]Ar)(3) through competing N-N bond cleavage and N-2 extrusion reaction pathways. The primary quantum yield was determined to be Phi(p) = 0.05, and transient absorption experiments show that the photochemical reaction is complete in less than 10 ns.