A series of seven bis(pyridinedipyrrolide)zirconium complexes, Zr( R 1 PDP R 2 ) 2 , where [ R 1 PDP R 2 ] 2− is the doubly deprotonated form of [2,6-bis(5-R 1 -3-R 2 -1H-pyrrol-2-yl)pyridine], were prepared and characterized in solution by NMR, UV/vis absorption, and emission spectroscopy and cyclic voltammetry. The molecular structures were determined by single-crystal X-ray crystallography. All complexes exhibit remarkably long emission lifetimes (τ = 190−576 μs) with high quantum efficiencies (Φ PL = 0.10−0.38) upon excitation with visible light in a benzene solution. The substituents on the pyrrolide rings were shown to have significant effects on the photoluminescence and electrochemical properties of these compounds. The R 2 substituents (R 2 = H, Me, Ph, or C 6 F 5 ) show only limited effects on the absorption and emission profiles of the complexes but allow systematic tuning of the ground-and excited-state redox potentials over a range of almost 600 mV. The R 1 substituents (R 1 = H, Me, Ph, or 2,4,6-Me 3 Ph) influence both the optical and electrochemical properties through electronic effects. Additionally, the R 1 substituents have profound consequences for the structural flexibility and overall stability of the compounds. Distortions of the Zr(PDP) 2 core from idealized D 2d symmetry in the solid state can be traced to the steric profiles of the R 1 substituents and correlate with the observed Stokes shifts for each compound. The complex with the smallest ligand system, Zr( H PDP H ) 2 , coordinates two additional solvent molecules in a tetrahydrofuran (THF) solution, which allowed the isolation of photoluminescent, eight-coordinate Zr( H PDP H ) 2 (THF) 2 . The photoredox catalytic dehalogenation of aryl iodides and aryl chlorides using the most reducing derivative, Zr( Me PDP Me ) 2 , highlights the potential of Zr(PDP) 2 photosensitizers to promote challenging reductive transformations under mild conditions upon excitation with green light.