In this study, using a computational approach, we are pursuing to find a proper answer about the possible application of fused-TIs as superbases through the calculation and discussion of standard thermochemistry parameters, like Gas-phase Basicity (GB) and Proton Affinity (PA(. In some studied cases, the role of aromaticity/anti-aromaticity fluctuations supposed to be more important than mesomeric effects. In this sense, Nucleus-independent Chemical Shift (NICS) and Anisotropy of the Induced Current Density (ACID) were utilized in this study to probe into the aromaticity-related parameters of the proposed molecules. Results revealed the highest GB/PA values for the molecules having cyclobutadiene in between of two troponimines. Additional investigation was performed into the other candidates of cyclobutadiene-fused troponimines by substituting several electron donors along with the changing position of donors. Some novel superbases offered record-holding GB/PA values so that PA magnitudes higher than 300 kcal mol-1 are now feasible for non-phosphorous Neutral Organic Superbases (NOS).

Keywords