Molecular Nanowire Bonding to Epitaxial Single ‐Layer MoS2 by an On‐Surface Ullmann Coupling Reaction

The combination of single ‐layer MoS2 with organic molecules by surface assisted Ullmann coupling provides a new and promising methodology to build hybrid systems of organic molecules and two ‐dimensional (2D) materials. The present results demonstrate how molecules can be attached to the corner sites, paving the way to new detailed studies on different molecules that form more complex structures. AbstractLateral heterostructures consisting of 2D transition metal dichalcogenides (TMDCs) directly interfaced with molecular networks or nanowires can be used to construct new hybrid materials with interesting electronic and spintronic properties. However, chemical methods for selective and controllable bond formation between 2D materials and organic molecular networks need to be developed. As a demonstration of a self ‐assembled organic nanowire‐TMDC system, a method to link and interconnect epitaxial single‐layer MoS2 flakes with organic molecules is demonstrated. Whereas pristine epitaxial single ‐layer MoS2 has no affinity for molecular attachment, it is found that single ‐layer MoS2 will selectively bind the organic molecule 2,8 ‐dibromodibenzothiophene (DBDBT) in a surface‐assisted Ullmann coupling reaction when the MoS2 has been activated by pre ‐exposing it to hydrogen. Atom‐resolved scanning tunneling microscopy (STM) imaging is used to analyze the bonding of the nanowires, and thereby it is revealed that selective bonding takes place on a specific S ...
Source: Small - Category: Nanotechnology Authors: Tags: Full Paper Source Type: research