Substituent effects on the stability of cyclic - unsaturated remote N-heterocyclic Hammick carbenes using density functional theory

SÖĞÜTLÜ İ., Soltanzadeh M., Mert H., Mert N., Vessally E.

Journal of Molecular Structure, vol.1230, 2021 (SCI-Expanded) identifier identifier

  • Publication Type: Article / Article
  • Volume: 1230
  • Publication Date: 2021
  • Doi Number: 10.1016/j.molstruc.2020.129821
  • Journal Name: Journal of Molecular Structure
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Academic Search Premier, Chemical Abstracts Core, INSPEC
  • Keywords: Hammick carbene, DFT, Stability, NHCs, Nucleophilicity
  • Van Yüzüncü Yıl University Affiliated: Yes


© 2020We investigated the structure, stability and chemical properties of novel singlet (s) and triplet (t) Hammick carbenes with different fused aromatic rings, at (U)B3LYP/6‐311+G*, (U)M06-2X/6‐311+G*, (U)B3LYP/AUG-cc-pVTZ and (U)M06-2X/AUG-cc-pVTZ levels of theory. It is observed that: (1) All singlet and triplet structures appear as minima on their energy surfaces and each singlet carbene displays more thermodynamic stability than its corresponding triplet state; (2) Regarding to the relationship among carbenic center and substituted heteroatom, the order of thermodynamic stability based on singlet-triplet energy differences (ΔΕs-t) for fused rings is ortho-pyrrole > furan > thiophene > phosphole in a “W” arrangement; (3) The highest kinetic stability based on band gap (ΔΕHOMO-LUMO) is demonstrated by substituted ortho-pyrrole carbene in a "W" arrangement; (4) Regardless of how orchestrated, the order of stabilization for fused rings is pyrrole > furan > thiophene > phosphole; (5) The ortho-phosphole ring in a “W” arrangement destabilizes carbene more than benzene ring.