Substituent-driven tuning of electronic structure and donor–acceptor interactions in Ru(II) piano-stool complexes: insights from DFT calculations
Molecular Physics, 2026 (SCI-Expanded, Scopus)
- Yayın Türü: Makale / Tam Makale
- Basım Tarihi: 2026
- Doi Numarası: 10.1080/00268976.2026.2674779
- Dergi Adı: Molecular Physics
- Derginin Tarandığı İndeksler: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Chemical Abstracts Core, Chimica, Compendex, INSPEC
- Anahtar Kelimeler: DFT, NBO, QTAIM, Ru(II) piano stool complexes, substituent effect
- İnönü Üniversitesi Adresli: Evet
Özet
In this work, the electronic structure and donor–acceptor interactions of Ru(II) piano-stool complexes bearing substituted aniline ligands (1–3) were examined using DFT in combination with NBO, ETS–NOCV, and QTAIM analyses. The NBO results indicate that the bonding in complexes arises from a combination of ligand-to-metal donation and metal-to-ligand back-donation, and intraligand delocalisation. ETS–NOCV analysis provides a complementary and more resolved description by decomposing the orbital interaction into a limited number of dominant charge-transfer channels, highlighting the primary role of Ru–arene interactions in the overall bonding framework. FMO analysis indicates that ligand substitution modulates the HOMO–LUMO gap, reflecting systematic changes in electronic softness and charge-transfer ability. QTAIM analysis shows that the Ru–N, Ru–Cl, and Ru–C(arene) interactions possess mixed closed-shell and covalent character, as evidenced by moderate electron densities at the BCPs, positive Laplacians, and slightly negative total energy densities. Variations in the |V(r)|/G(r) ratios further demonstrate that the covalent contribution to these bonds can be subtly tuned through ligand substitution. Together, the theoretical results highlight substituent modification as an effective strategy for tuning the electronic structure and donor–acceptor interactions in Ru(II) complexes and provide a molecular-level rationale for the design of ruthenium systems with electronic properties.