Johannes Barth

Affiliation: TUM School of Natural Sciences

Research Interests: Molecular Nanoscience & Chemical Physics of Interfaces

Title: Surface-confined metalated graphdiyne sheet

Abstract: Extended organometallic honeycomb alkynyl−silver networks representing metalated graphdiyne sheets have been synthesized on a noble metal surface under ultrahigh vacuum conditions via a gas- mediated surface reaction protocol. Specifically, the controlled exposure to molecular oxygen efficiently deprotonates terminal alkyne moieties of 1,3,5-tris(4-ethynylphenyl)benzene (Ext-TEB) precursors adsorbed on Ag(111), whereby long-range ordered alkynyl−silver networks incorporating substrate atoms are fabricated, featuring Ag-bis-acetylide motifs, high structural quality and a regular arrangement of nanopores with a van der Waals cavity of ≈8.3 nm2 [1]. The electronic features of the adsorbed layer are revealed by complementary scanning tunnelling and angle-resolved photoemission spectroscopies, demonstrating electronic bandstructure formation with an appreciable gap [2]. Extensive density functional theory calculations substantiate the experimental findings in line with recent theoretical insights on the proper combination of frontier molecular orbital and lattice symmetries to generate unconventional band structures. Finally, the transmetalation of the alkynyl-Ag-alkynyl linkages with copper atoms is recognized and implemented as a means to obtain a more robust Ag-GDY sheet with modified electronic properties [3].