Catalytic effects of iron adatoms in poly(-phenylene) synthesis on rutile TiO(110).

-Armchair graphene nanoribbons (nAGNRs) are promising components for next-generation nanoelectronics due to their controllable band gap, which depends on their width and edge structure. Using non-metal surfaces for fabricating nAGNRs gives access to reliable information on their electronic properties. We investigated the influence of light and iron adatoms on the debromination of 4,4''-dibromo--terphenyl precursors affording poly(-phenylene) (PPP as the narrowest GNR) wires through the Ullmann coupling reaction on a rutile TiO(110) surface, which we studied by scanning tunneling microscopy and X-ray photoemission spectroscopy.

Octaethyl vs Tetrabenzo Functionalized Ru Porphyrins on Ag(111): Molecular Conformation, Self-Assembly and Electronic Structure.

Metalloporphyrins on interfaces offer a rich playground for functional materials and hence have been subjected to intense scrutiny over the past decades. As the same porphyrin macrocycle on the same surface may exhibit vastly different physicochemical properties depending on the metal center and its substituents, it is vital to have a thorough structural and chemical characterization of such systems. Here, we explore the distinctions arising from coverage and macrocycle substituents on the closely related ruthenium octaethyl porphyrin and ruthenium tetrabenzo porphyrin on Ag(111).

Transmetalation in Surface-Confined Single-Layer Organometallic Networks with Alkynyl-Metal-Alkynyl Linkages.

Transmetalation represents an appealing strategy toward fabricating and tuning functional metal-organic polymers and frameworks for diverse applications. In particular, building two-dimensional metal-organic and organometallic networks affords versatile nanoarchitectures of potential interest for nanodevices and quantum technology. The controlled replacement of embedded metal centers holds promise for exploring versatile material varieties by serial modification and different functionalization.

Attosecond chronoscopy of the photoemission near a bandgap of a single-element layered dielectric.

We report on the energy dependence of the photoemission time delay from the single-element layered dielectric HOPG (highly oriented pyrolytic graphite). This system offers the unique opportunity to directly observe the Eisenbud-Wigner-Smith (EWS) time delays related to the bulk electronic band structure without being strongly perturbed by ubiquitous effects of transport, screening, and multiple scattering. We find the experimental streaking time shifts to be sensitive to the modulation of the density of states in the high-energy region ( ≈ 100 eV) of the band structure.

Unconventional Band Structure via Combined Molecular Orbital and Lattice Symmetries in a Surface-Confined Metallated Graphdiyne Sheet.

Graphyne (GY) and graphdiyne (GDY)-based monolayers represent the next generation 2D carbon-rich materials with tunable structures and properties surpassing those of graphene. However, the detection of band formation in atomically thin GY/GDY analogues has been challenging, as both long-range order and atomic precision have to be fulfilled in the system. The present work reports direct evidence of band formation in on-surface synthesized metallated Ag-GDY sheets with mesoscopic (≈1 µm) regularity.