Compound characterization data — Taylor et al., 2026

(dtbbpy)NiII(Ar)(Cl)
Identifier	3a
Cyclic voltammetry, oxidative scan in DMF at 20 mV s⁻¹	single, irreversible oxidation feature with an anodic peak current at +0.30 V vs Fc/Fc+
Cyclic voltammetry, oxidative scans at 20–2000 mV s⁻¹	no reversibility was observed at any of the scan rates tested; no reoxidation feature was observed
Cyclic voltammetry with 0–0.75 equivalents TBACl in 100 mM TBAPF6 in DMF at 20 mV s⁻¹	completely irreversible trace, with no observable NiIII return reduction feature, and an increasingly larger cathodic shift of the peak as more TBACl was added
Cyclic voltammetry, current normalized to the square root of scan rate	higher normalized currents at slower scan rates; cathodic shift of the peak current as the scan rate decreased
Cyclic voltammetry with excess aryl chloride 10a	decrease in peak current
Cyclic voltammetry, reductive scan of 5 mM 3a in 100 mM NBu4PF6 in DMF at 150 mV s⁻¹ with 20 equivalents ArCl 10a or ArBr 10b	previously observed redox features collapsed into a single new irreversible catalytic wave at more reducing potentials
Square-wave voltammetry with 20 equivalents aryl bromide 10b in 100 mM NBu4PF6 in DMF	redox features observed without aryl halide were almost completely suppressed; small residual signals attributable to NiII(Ar)Cl and NiII(Ar)2 remained detectable at lower nickel concentrations; the dominant feature was a new irreversible reduction wave that increased in intensity and shifted to more cathodic potentials as nickel concentration increased

(dtbbpy)NiII(Ar)(Br)
Identifier	3b
Cyclic voltammetry in DMF	traces were complicated by the presence of free bromide ion; inclusion of 1 equivalent NaPF6 in the electrolyte solution mitigated this issue