Structures and Properties of Planar Ge 3 O 3 Cluster and Its Buckled Honeycomb Two-Dimensional Nanostructure.

The discovery of graphene and its excellent properties inspired the search for more two-dimensional (2D) materials. Understanding the structures and properties of the smallest repeating units as well as crystal 2D materials is helpful for designing 2D materials. As germanium tends to form three-dimensional structures, the preparation of germanium-based 2D nanomaterials is still a challenge. Herein, we report a Ge 3 O 3 cluster with the potential to construct a germanium oxide 2D nanostructure. We conduct a combined anion photoelectron spectroscopy and theoretical study on Ge 3 O 3 -/0 . The structure of Ge 3 O 3 - is a C s symmetric nonplanar six-membered ring, while that of Ge 3 O 3 is a D 3h symmetric planar six-membered ring. Chemical bonding analyses reveal that Ge 3 O 3 exhibits π aromaticity. First-principle results suggest that a buckled honeycomb 2D nanostructure with a wide band gap of 3.14 eV may be produced based on Ge 3 O 3 , which is promising in optoelectronic applications especially in blue, violet, and ultraviolet regions.