Molecularly “clicking” active moieties to germanium-based inorganic 2D materials

Abstract

Two dimensional materials beyond graphene are in forefront research. Two dimensional analogues of graphene of group 14, germanene, are of high importance for their electronic and optical properties. The commonly used deintercalation fabrication approach has reached a major bottleneck in the field due to the lack of versatility derived from the limited library of precursors available for 2D-Ge functionalization with terminal groups. Thus, a chemical procedure that would allow for the on-demand synthesis of functional 2D-Ge derivatives with tuned physicochemical features for task-specific applications is of utmost importance to advance in the field. To fill this gap, click chemistry is herein presented as a straightforward “one-pot” synthetic strategy to simply reach functional 2D-Ge derivatives by covalently assembling ad hoc thiol-rich active molecular components (R′–SH) upon commercially available allyl 2D-Ge (2D-Ge–CH₂CHCH₂) by taking advantage of a photoinduced thiol–ene click reaction. Consequently, the combination of molecular engineering and Ge-based 2D materials through click chemistry supposes a step forward towards the achievement of a new family of smart 2D-Ge–CH₂CH₂CH₂S–R′ derivatives with different (supra)molecular responsiveness, which goes beyond the state-of-the-art in the field. This approach of functionalization of 2D monoelemental post-graphene material germanene is highly innovative and shall provide universal way of functionalization of germananes.