Hepta- and octacoordinate boron in molecular wheels of eight- and nine-atom boron clusters: observation and confirmation.

Abstract

Clusters of atoms can adopt different atomic arrangements from bulk materials. They often exhibit novel structures and properties, which provide opportunities for a new types of chemical bonding and stoichiometry. Herein we report experimental and theoretical evidence that 8- and 9-atom boron clusters are perfectly planar molecular wheels, with a hepta- or octacoordinated central boron atom, respectively, despite the predominance of three-dimensional structures normally found in bulk boron and its compounds.