Details

Autor(en) / Beteiligte

• Chagas, Julio C. V.
• Milanez, Bruno D.
• Oliveira, Vytor P.
• Pinheiro Jr, Max
• Ferrão, Luiz F. A.
• Aquino, Adelia J. A.
• Lischka, Hans
• Machado, Francisco B. C.

Titel

A multi‐descriptor analysis of substituent effects on the structure and aromaticity of benzene derivatives: π‐Conjugation versus charge effects

Ist Teil von

• Journal of computational chemistry, 2024-05, Vol.45 (12), p.863-877

Ort / Verlag

Hoboken, USA: John Wiley & Sons, Inc

Erscheinungsjahr

2024

Quelle

Wiley-Blackwell Journals

Beschreibungen/Notizen

• This work provides a detailed multi‐component analysis of aromaticity in monosubstituted (X = CH3, CH2−, CH2+, NH2, NH−, NH+, OH, O−, and O+) and para‐homodisubstituted (X = CH3, CH2, NH2, NH, OH, and O) benzene derivatives. We investigate the effects of substituents using single‐reference (B3LYP/DFT) and multireference (CASSCF/MRCI) methods, focusing on structural (HOMA), vibrational (AI(vib)), topological (ELFπ), electronic (MCI), magnetic (NICS), and stability (S0–T1 splitting) properties. The findings reveal that appropriate π‐electron‐donating and π‐electron‐accepting substituents with suitable size and symmetry can interact with the π‐system of the ring, significantly influencing π‐electron delocalization. While the charge factor has a minimal impact on π‐electron delocalization, the presence of a pz orbital capable of interacting with the π‐electron delocalization is the primary factor leading to a deviation from the typical aromaticity characteristics observed in benzene. One can manipulate the electronic structure properties of a specific molecule to attain desired properties through the strategic introduction of substituent effects. This study offers insights into how substituents impact π‐electron delocalization. While charge effects primarily play a role in the σ domain of electrons, π‐electron conjugation resulting from substituent effects significantly influences the aromaticity of the benzene ring moiety.