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Recent studies have shown a divergence in reactivity between (PPRP)CoI2 precatalysts (R = H, Cl, CF3), appearing to be contingent on the central phosphorus substituent. This study reports the synthesis and characterization of a manifold of PPXP and (PPXP)CoI2 complexes (X = NEt2, NiPr2, OEt, OiPr, OCH2CF3, OCH(CF3)2, (-)-mentholate, and Me) to probe the impact of substituent (X) on electronic character of the metal complex. A combination of spectroscopic techniques, including NMR, Cyclic Voltammetry, Electron Paramagnetic Resonance, and DFT-simulated IR allowed for further understanding of the electronic environment of the cobalt center as a function of central phosphorus substituent. Preliminary kinetic studies allowed for a direct comparison of catalytic activity towards hydroboration of styrene via kobs. This work serves as a holistic approach to understanding precise ligand tuning to optimize catalytic activity for this PPXP system.