Affiliation:
1. Department of Chemistry – College of Science University of Baghdad Al-Jadirya Baghdad Iraq
2. Inorganic Chemistry, Department of Chemistry and Pharmacy University of Erlangen – Nuremberg Egerlandstr. 1 91058 Erlangen Germany
3. Computer Chemistry Center, Department of Chemistry and Pharmacy University of Erlangen – Nuremberg Nägelsbachstr. 25 91052 Erlangen Germany
4. Central Institute for Scientific Computing (ZISC) University of Erlangen – Nuremberg Martensstr. 5a 91058 Erlangen Germany
5. Fakultät Angewandte Mathematik, Physik und Allgemeinwissenschaften Technische Hochschule Nürnberg Georg Simon Ohm Keßlerplatz 12 90489 Nürnberg Germany
Abstract
AbstractHerein, 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 ∇2ρ(r), (2D‐3D) multidimensional off‐nucleus magnetic shielding (σzz(r) and σiso(r)), and scanning nucleus‐independent chemical shift (NICSzz 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 σzz(r) and σiso(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.
Subject
Physical and Theoretical Chemistry,Atomic and Molecular Physics, and Optics
Cited by
1 articles.
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