On‐surface assembly of hydrogen‐ and halogen‐bonded supramolecular graphyne‐like networks

The on-surface assembly of graphyne-related two directive for the long-awaited reliable synthesis of the carbon allotrope graphyne. Some of the challenges in the graphyne synthesis is the control of the alkyne coupling reaction on metal surfaces and the fabrication of single-layered materials in solution-based methods. Here, we demonstrate a supramolecular approach to fabricate highly ordered monolayered hydrogen- and halogen-bonded graphyne-like 2D materials from triethynyltriazine derivatives on Au(111) and Ag(111). The 2D networks are stabilized by N...H-C( sp )-bonds and N...Br-C( sp )-bonds to the triazine core, respectively. The structural properties and the binding energies of the supramolecular graphynes have been investigated by scanning tunneling microscopy in combination with density-functional theory calculations. It is revealed that the N...Br-C( sp ) -bonds lead to significantly stronger bonded networks compared to the hydrogen-bonded networks. A systematic analysis of the binding energies of triethynyltriazine and triethynylbenzene derivatives further demonstrates that the X 3 -synthon, which is commonly observed for bromobenzene derivatives, is weaker than the X 6 -synthon for our bromotriethynyl derivatives.