Persistent Planar Tetracoordinate Carbon in Global Minima Structures of Silicon-Carbon Clusters

Leyva-Parra L.; Inostroza D.; Yañez O.; Cruz J.C.; Garza J.; García V.; Tiznado W. · Atoms (2022) · DOI: 10.3390/atoms10010027

Resumen

Recently, we reported a series of global minima whose structures consist of carbon rings decorated with heavier group 14 elements. Interestingly, these structures feature planar tetracoordinate carbons (ptCs) and result from the replacement of five or six protons (H+ ) from the cyclopentadienyl anion (C5 H5− ) or the pentalene dianion (C8 H62− ) by three or four E2+ dications (E = Si–Pb), respec-tively. The silicon derivatives of these series are the Si3 C5 and Si4 C8 clusters. Here we show that ptC persists in some clusters with an equivalent number of C and Si atoms, i.e., Si5 C5, Si8 C8, and Si9 C9 . In all these species, the ptC is embedded in a pentagonal C5 ring and participates in a three-center, two-electron (3c-2e) Si-ptC-Si σ-bond. Furthermore, these clusters are π-aromatic species according to chemical bonding analysis and magnetic criteria.

Instituciones: Universidad Nacional Mayor de San Marcos