Next, we proceed to a comparison of the results concerning the diphenyl-substituted groups. LSV results for DiPh and DiMeOPh cations under CO2 atmosphere are presented in Figure 4.5 (left). Concurrently, Figure 4.5 (right) exhibits the electron density maps calculated for these two cations. The outcomes of the calculated charge analysis align with the 13C NMR findings depicted in Figure 4.3 (indicated by orange letters). These results suggest a reduced co-catalytic activity for the DiMeOPh cation in comparison to the DiPh cation, owing to its increased electron richness. This is well-confirmed by the LSV results which shows a lower apparent activity for the diphenyl methoxy substituted imidazolium cation. While comparing outcomes within the same functional groups can be straightforward, assessing results across different functional families requires careful consideration. In Figure 4.6 (left), we present the LSV results obtained from MM and DiPh cations during CO2 reduction under consistent salinity conditions. Based on the electron density maps generated from DFT calculations (Figure 4.6 right), it becomes apparent that DiPh displays a somewhat higher Figure 4.4. (left) The comparison of LSVs for 0.5 mol% MM-NTf2 (red) and TetraMe-NTf2 (black) for CO2 reduction in anhydrous acetonitrile. (right) Electron density map (from VDD charge analysis) which shows MM is more electron poor, thus a more acidic cation.
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