Ralph Puchta

Herein, we report designing a new Δ (delta‐shaped) proton sponge base of 4,12‐dihydrogen‐4,8,12‐triazatriangulene (compound 1 ) and calculating its proton affinity ( PA ), aromatic stabilization, natural bond orbital (NBO), electron density ρ (r), Laplacian of electron density ∇ 2 ρ (r), (2D‐3D) multidimensional off ‐nucleus magnetic shielding ( σ zz (r) and σ iso (r)), and scanning nucleus‐independent chemical shift (NICS zz and NICS). Density functional theory (DFT) at B3LYP/6‐311+G(d,p), ωB97XD/6‐311+G(d,p), and PW91/def2TZVP were used to compute the magnetic shielding variables. In addition, relevant bases like pyridine, quinoline, and acridine were also studied and compared. The protonation of compound 1 yields a highly symmetric carbocation of three Hückel benzenic rings. Comparing our findings of the studied molecules showed that compound 1 precedes others in PA , aromatic isomerization stabilization energy, and basicity. Therefore, the basicity may be enhanced when a conjugate acid gains higher aromatic features than its unprotonated base. Both multidimensional σ zz (r) and σ iso (r) off ‐nucleus magnetic shieldings outperformed electron‐based techniques and can visually monitor changes in aromaticity that occur by protonation. The B3LYP/6‐311+G(d,p), ωB97XD/6‐311+G(d,p), and PW91/def2TZVP levels showed no significant differences in detailing isochemical shielding surfaces.