title: Sigma aromaticity of the bimetallic Au5Zn+ cluster.
abstract: Experimental and theoretical evidence for a "sigma aromatic" bimetallic cluster is presented. A mass spectrometric analysis of AuNZn+ (N = 2-44) photofragments shows Au5Zn+ to be very abundant, proving its high stability. Calculations predict that Au5Zn+ has a planar geometry and six valence s electrons occupying delocalized sigma-bonded molecular orbitals in a manner similar to that of aromatic organic compounds, except for their nodal properties in the molecular plane. The delocalized sigma electrons provide diamagnetic ring currents, suggesting Au5Zn+ is aromatic.
authors.affiliation: Laboratorium voor Vaste-Stoffysica en Magnetisme, Departement Natuurkunde en Sterrenkunde, K.U.Leuven, Celestijnenlaan 200D, B-3001 Leuven, Belgium.
authors.forename: Hiromasa
authors.initials: H
authors.lastname: Tanaka
authors.forename: Sven
authors.initials: S
authors.lastname: Neukermans
authors.forename: Ewald
authors.initials: E
authors.lastname: Janssens
authors.forename: Roger E
authors.initials: RE
authors.lastname: Silverans
authors.forename: Peter
authors.initials: P
authors.lastname: Lievens