Correlation between Quantumchemically Calculated LUMO Energies and the Electrochemical Window of Ionic Liquids with Reduction-Resistant Anions

Table 4

Comparison of calculated 𝐸_LUMO of several cations by B3LYP and PM3 calculations.

Cation	𝐸LUMO [eV] (DFT/B3LYP)	𝐸LUMO [eV] (semiempirical/PM3)
1-butylpyridinium	−6.46	−5.78
1-butyl-2-methylpyrazolium	−5.28	−5.41
1-butyl-2,3-dimethylimidazolium	−4.54	−4.84
trimethylpropylphosphonium	−2.95	−4.51
trimethylpropylammonium	−3.22	−4.45
1,1-butylmethylpyrrolidinium	−2.82	−4.21
1,1-butylmethylpiperidinium	−2.64	−4.16