| Identifier | 3a |
|---|---|
| Cyclic voltammetry, oxidative scan of 10 mM 3a in 100 mM TBAPF₆ in DMF at 20 mV s⁻¹ | Single, irreversible oxidation feature with an anodic peak current of +0.30 V vs Fc/Fc⁺; the feature was attributed to the single-electron oxidation of 3a to the corresponding (Niᴵᴵᴵ)⁺ complex 4a |
| 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, together with an increasingly larger cathodic shift of the peak as more TBACl was added |
| Cyclic voltammetry with more than 0.75 equivalents TBACl in 100 mM TBAPF₆ in DMF at 20 mV s⁻¹ | Direct oxidation of the chloride anion began to dominate the CV |
| Cyclic voltammetry with and without added chloride in 100 mM TBAPF₆ in DMF, current normalized with respect to the square root of the scan rate | A catalytic current appeared; higher normalized currents were observed at slower scan rates; a cathodic shift of the peak current was observed as the scan rate decreased |
| Cyclic voltammetry, oxidative scans at different nickel concentrations | A linear relationship between the peak current and the nickel concentration was observed |
| Cyclic voltammetry, oxidative scan with excess aryl chloride 10a in 100 mM TBAPF₆ in DMF at 20 and 150 mV s⁻¹, current normalized with respect to scan rate | A decrease in peak current was observed; the same behavior was observed when the study was repeated with 1 equivalent TBACl |
| Cyclic voltammetry, reductive scan of 5 mM 3a in 100 mM NBu₄PF₆ in DMF at 150 mV s⁻¹ | Re₂, the initial reduction of 3a, was assigned to neutral Niᴵ(Ar) complex 12; the only reversible feature, Re₃/Ox₃, was assigned to Niᴵᴵ(Ar)₂ complex 13; the irreversible Re₁ feature was characteristic of NiᴵᴵCl₂ complex 18; Ox₂ and Ox₁ captured the reoxidation of Niᴵ complexes 12 and 14, respectively |
| Cyclic voltammetry, reductive scan with 20 equivalents aryl chloride 10a or aryl bromide 10b in 100 mM TBAPF₆ in DMF at 150 mV s⁻¹ | All previously observed redox features collapsed into a single new irreversible catalytic wave at more reducing potentials; Re₁, Re₂, and Re₃/Ox₃ disappeared completely; the new feature was tentatively assigned to a neutral Niᴵ species |
| Square-wave voltammetry with 20 equivalents aryl bromide 10b in 100 mM NBu₄PF₆ in DMF | The 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 the nickel concentration increased; the wave corresponded to the peak previously assigned to a neutral Niᴵ species; the signal broadened at higher nickel concentrations |
Olivia R. Taylor, Tanner J. Megna, Ana Bahamonde. “Challenging the kinetic likelihood of bimolecular bipyridine-nickelᴵᴵᴵ aryl dihalide reactions.” ChemRxiv (). https://doi.org/10.26434/chemrxiv.15007463/v2
The main paper refers to supporting information, but no separate supporting information file was found among the files available from the ChemRxiv record
| Identifier | 3b |
|---|---|
| Cyclic voltammetry of 10 mM 3b in DMF | The decrease in peak current observed for 3a with excess aryl chloride 10a was also observed; the CV traces were complicated by the presence of free bromide ion; inclusion of 1 equivalent NaPF₆ in the electrolyte solution mitigated this issue |