Selected AB4(2-/-) (A = C, Si, Ge; B = Al, Ga, In) ions: a battle between covalency and aromaticity, and prediction of square planar Si in SiIn4(2-/-).

ABSTRACT: CAl(4)(2-/-) (D(4h), (1)A(1g)) is a cluster ion that has been established to be planar, aromatic, and contain a tetracoordinate planar C atom. Valence isoelectronic substitution of C with Si and Ge in this cluster leads to a radical change of structure toward distorted pentagonal species. We find that this structural change goes together with the cluster acquiring partial covalency of bonding between Si/Ge and Al(4), facilitated by hybridization of the atomic orbitals (AOs). Counter intuitively, for the AAl(4)(2-/-) (A = C, Si, Ge) clusters, hybridization in the dopant atom is strengthened from C, to Si, and to Ge, even though typically AOs are more likely to hybridize if they are closer in energy (i.e. in earlier elements in the Periodic Table). The trend is explained by the better overla

SUBMITTER: Alexandrova AN 

PROVIDER: S-EPMC3478443 | biostudies-literature | 2012 Nov

REPOSITORIES: biostudies-literature