The Cu7Sc cluster is a stable σ-aromatic seven-membered ring

Tibor Höltzl, Ewald Janssens, Nele Veldeman, Tamás Veszprémi, Peter Lievens, Minh Tho Nguyen

Research output: Contribution to journalArticle

40 Citations (Scopus)


Density functional theory calculations demonstrate that the global minimum of the Cu7Sc potential energy surface is a seven-membered ring of copper atoms with scandium in its center, yielding a planar D7h, structure. Nucleus-independent chemical shifts [NICS(1)zz and NICS(2)zz] show that this cluster has aromatic character, which is consistent with the number of 4s electrons of copper and scandium plus the 3d electrons of scandium satisfying Hückel's rule. According to a canonical MO decomposition of NICS(1)zz and NICS(2)zz, the MOs consisting of the 4s atomic orbi tals are mainly responsible for the aromatic behavior of the cluster. The electron localizability indicator (ELI-D) and its canonical MO decomposition (partial ELI-D) suggest that a localized basin is formed in Cu7Sc by the copper atoms whereas the two circular localized domains are situated below and above the ring. The planar Cu 7Sc cluster can thus be considered as a σ-aromatic species. These findings agree with the phenomenological shell model.

Original languageEnglish
Pages (from-to)833-838
Number of pages6
Issue number6
Publication statusPublished - Apr 21 2008


  • Aromaticity
  • Cluster compounds
  • Electron localizability indicator
  • Electronic structure
  • Seven-membered ring

ASJC Scopus subject areas

  • Atomic and Molecular Physics, and Optics
  • Physical and Theoretical Chemistry

Fingerprint Dive into the research topics of 'The Cu<sub>7</sub>Sc cluster is a stable σ-aromatic seven-membered ring'. Together they form a unique fingerprint.

  • Cite this

    Höltzl, T., Janssens, E., Veldeman, N., Veszprémi, T., Lievens, P., & Nguyen, M. T. (2008). The Cu7Sc cluster is a stable σ-aromatic seven-membered ring. ChemPhysChem, 9(6), 833-838.