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Article Citation - WoS: 2Citation - Scopus: 3Selective Adsorption of a Supramolecular Structure on Flat and Stepped Gold Surfaces(Elsevier, 2018) Pekoz, Rengin; Donadio, DavideHalogenated aromatic molecules assemble on surfaces forming both hydrogen and halogen bonds. Even though these systems have been intensively studied on flat metal surfaces, high-index vicinal surfaces remain challenging, as they may induce complex adsorbate structures. The adsorption of 2,6-dibromoanthraquinone (2,6-DBAQ) on flat and stepped gold surfaces is studied by means of van der Waals corrected density functional theory. Equilibrium geometries and corresponding adsorption energies are systematically investigated for various different adsorption configurations. It is shown that bridge sites and step edges are the preferred adsorption sites for single molecules on flat and stepped surfaces, respectively. The role of van der Waals interactions, halogen bonds and hydrogen bonds are explored for a monolayer coverage of 2,6-DBAQ molecules, revealing that molecular flexibility and intermolecular interactions stabilize two-dimensional networks on both flat and stepped surfaces. Our results provide a rationale for experimental observation of molecular carpeting on high-index vicinal surfaces of transition metals. (C) 2017 Elsevier B.V. All rights reserved.Article Citation - WoS: 32Citation - Scopus: 33The Interaction of Halogen Atoms and Molecules With Borophene(Royal Soc Chemistry, 2017) Khanifaev, Jamoliddin; Pekoz, Rengin; Konuk, Mine; Durgun, EnginThe realization of buckled monolayer sheets of boron (i.e., borophene) and its other polymorphs has attracted significant interest in the field of two-dimensional systems. Motivated by borophene's tendency to donate electrons, we analyzed the interaction of single halogen atoms (F, Cl, Br, I) with borophene. The possible adsorption sites are tested and the top of the boron atom is found as the ground state configuration. The nature of bonding and strong chemical interaction is revealed by using projected density of states and charge difference analysis. The migration of single halogen atoms on the surface of borophene is analyzed and high diffusion barriers that decrease with atomic size are obtained. The metallicity of borophene is preserved upon adsorption but anisotropy in electrical conductivity is altered. The variation of adsorption and formation energy, interatomic distance, charge transfer, diffusion barriers, and bonding character with the type of halogen atom are explored and trends are revealed. Lastly, the adsorption of halogen molecules (F-2, Cl-2, Br-2, I-2), including the possibility of dissociation, is studied. The obtained results are not only substantial for fundamental understanding of halogenated derivatives of borophene, but also are useful for near future technological applications.
