This dissertation discusses the synthesis, characterization and electronic delocalization of bis(imino)pyridine (I2P) complexes of the Group 13 metals Al, Ga and In. This work aims to understand the electronic communication between redox-active ligands bridged by a main group metal and apply this research for storing multiple electrons in nonaqueous redox-flow battery applications. The introduction to this dissertation details the background on redox-active ligands, mixed valency and redox flow batteries. A future outlook on this field is presented. The work presented here has contributed to our understanding of delocalization of charge in organic molecules, and how delocalization is affected by increasing charge, appending electron-donating or withdrawing functional groups or varying the metal bridge. Evidence for a symmetric nonaqueous redox flow battery is presented. In Chapter 2, ligand-based mixed valency is introduced. Water stable organic mixed valence (MV) compounds were prepared by reaction of reduced bis(imino)pyridine ligands (I2P) with the trichloride salts of Al, Ga, and In. Coordination of two tridentate ligands to each ion affords octahedral complexes that are accessible with five ligand charge states: [(I2P0)(I2P−)M]2+, [(I2P−)2M]+, (I2P−)(I2P2−)M, [(I2P2−)2M]−, [(I2P2−)(I2P3−)M]2−, and for M = Al only, [(I2P3−)2M]3−. In solid-state structures the anionic members of the redox series are stabilized by intercalation of Na+ cations within the ligands. The MV members of the redox series, (I2P−)(I2P2−)M and [(I2P2−)(I2P3−)M]2−, show characteristic intervalence transitions, in the near-infrared region between 6800 - 7400 and 7800 - 9000 cm-1, respectively. Cyclic voltammetry (CV), NIR spectroscopic, and X-ray structural studies support the assignment of Class II for compounds [(I2P2−)(I2P3−)M]2− and Class III for M = Al and Ga in (I2P−)(I2P2−)M. All compounds containing a singly reduced I2P− ligand exhibit a sharp, low energy transition in the region 5100 - 5600 cm−1 that corresponds to a [pi]* - [pi]* transition. CV studies demonstrate that the electron transfer events in each of the redox series, Al, Ga, and In span 2.2, 1.4 and 1.2 V, respectively. In Chapter 3, ligand-based mixed valent (MV) complexes of Al(III) incorporating electron donating (ED) and electron withdrawing (EW) substituents on bis(imino)pyridine ligands (I2P) are presented. The MV states (I2P−)(I2P2−)Al and [(I2P2−)(I2P3−)Al]2− prepared containing EW groups are both assigned as Class II/III. The MV states prepared with incorporation of ED functional groups are Class III and Class II/III in the (I2P−)(I2P2−)Al and [(I2P2−)(I2P3−)Al]2− charge states, respectively. The assignments of the delocalized electronic structures were made using cyclic voltammetry (CV), and near infra-red (NIR) spectroscopy. The MV ligand charge states (I2P−)(I2P2−)Al and [(I2P2−)(I2P3−)Al]2− show intervalence charge transfer (IVCT) transitions at 6850-7740 and 7410-9780 cm−1, respectively. Alkali metal cations in solution had no effect on the IVCT bands of [(I2P2−)(I2P3−)Al]2− complexes containing ED -PhNMe2 substituents or EW -PhF5 substituents on the I2P ligands. Localization of charge in [(I2P2−)(I2P3−)Al]2− was observed when -PhOMe substituents are included on the I2P ligands, so that those complexes are Class II/III with K+ and Class III with K:(18-crown-6)+. In Chapter 4, the application of these redox-active octahedral Al(III) complexes as analytes for symmetric nonaqueous redox flow batteries is presented. Redox flow batteries (RFBs) operate by storing electrons on soluble molecular anolytes and catholytes, however large increases in the energy density of RFBs could be achieved if multiple electrons could be stored in each molecular analyte. Others have suggested and employed various transition element - redox active ligands combinations to realize multi-electron storage in anolytes, and a challenge with those efforts has been the analyte's stability over extended charging and discharging of multi-electron cycles. We reported an organoaluminum analyte in which four electrons can be stored on organic ligands, and for which charging and discharging cycles performed in a symmetric nonaqueous RFB configuration remain stable for over 100 cycles at 70% state of charge and 97% Coulombic efficiency. Stability is promoted by the kinetic inertness of the anolyte to trace water in solvents and by the redox stability of the Al(III) ion to the applied current. Proof-of principle experiments performed with an asymmetric NRFB configuration further demonstrate that up to four electrons can be stored in the cell with no degradation of the analyte over multiple cycles that show 96% Coulombic efficiency.