Site-Selective Surface Modification of 2D Superatomic Re₆Se₈

Area of Science:

• Materials Science
• Nanotechnology
• Surface Chemistry

Background:

• Two-dimensional (2D) materials offer unique properties for various applications.
• Surface functionalization is key to tailoring these properties.
• Superatomic materials provide a novel platform for advanced functionalities.

Purpose of the Study:

• To develop a site-selective surface functionalization method for 2D superatomic Re₆Se₈Cl₂ monolayers.
• To create new, functionalized 2D superatomic materials.
• To demonstrate control over material properties through surface modification.

Main Methods:

• Activation of bulk Re₆Se₈Cl₂ via lithium intercalation.
• Exfoliation in N-methylformamide (NMF) to yield Li₂Re₆Se₈Cl₂.
• Thermal elimination of LiCl to form monolayer Re₆Se₈(NMF)_2-x nanosheets.
• Covalent surface functionalization using radical-based chemistry enabled by unpaired electrons.

Main Results:

• Successful synthesis of four new surface-functionalized 2D superatomic materials: Re₆Se₈I₂, Re₆Se₈(SPh)₂, Re₆Se₈(SPhNH₂)₂, and Re₆Se₈(SC₁₆H₃₃)₂.
• Preservation of the in-plane structure of the 2D Re₆Se₈ material after functionalization, confirmed by TEM, chemical analysis, and spectroscopy.
• Demonstrated control over vacancy defect density and material solubility by varying the functionalizing groups.

Conclusions:

• The developed method allows for site-selective surface functionalization of 2D superatomic materials.
• This approach enables systematic tuning of physical properties, chemical reactivity, and solution processability.
• The findings open avenues for designing novel 2D superatomic materials with tailored functionalities for diverse applications.