High acidity of polycyano azatriquinanes—theoretical prediction by the DFT calculations

It is shown by the B3LYP/6-311+G(2d,p)//B3LYP/6-31G(d) calculations that the hexacyano derivative of aza-acepentalene is an extremely powerful superacid both in the gas phase and in DMSO as evidenced by the ΔHacid = 255.1 kcal mol−1 and pKa (DMSO) = −26.5. Its synthesis is strongly recommended, in particular, since the related conjugate base hexachloro aza-acepentalenide anion was prepared recently.