title: Substrate Effects in the Supramolecular Assembly of 1,3,5-Benzene Tricarboxylic Acid on Graphite and Graphene.
abstract: The behavior of small molecules on a surface depends critically on both molecule-substrate and intermolecular interactions. We present here a detailed comparative investigation of 1,3,5-benzene tricarboxylic acid (trimesic acid, TMA) on two different surfaces: highly oriented pyrolytic graphite (HOPG) and single-layer graphene (SLG) grown on a polycrystalline Cu foil. On the basis of high-resolution scanning tunnelling microscopy (STM) images, we show that the epitaxy matrix for the hexagonal TMA chicken wire phase is identical on these two surfaces, and, using density functional theory (DFT) with a non-local van der Waals correlation contribution, we identify the most energetically favorable adsorption geometries. Simulated STM images based on these calculations suggest that the TMA lattice can stably adsorb on sites other than those identified to maximize binding interactions with the substrate. This is consistent with our net energy calculations that suggest that intermolecular interactions (TMA-TMA dimer bonding) are dominant over TMA-substrate interactions in stabilizing the system. STM images demonstrate the robustness of the TMA films on SLG, where the molecular network extends across the variable topography of the SLG substrates and remains intact after rinsing and drying the films. These results help to elucidate molecular behavior on SLG and suggest significant similarities between adsorption on HOPG and SLG.
authors.affiliation: †INRS Énergie, Matériaux et Télécommunications, Université du Québec, 1650 Boul. Lionel-Boulet, Varennes, QC J3X 1S2, Canada.
authors.forename: J M
authors.initials: JM
authors.lastname: MacLeod
authors.affiliation: †INRS Énergie, Matériaux et Télécommunications, Université du Québec, 1650 Boul. Lionel-Boulet, Varennes, QC J3X 1S2, Canada.
authors.forename: J A
authors.initials: JA
authors.lastname: Lipton-Duffin
authors.affiliation: †INRS Énergie, Matériaux et Télécommunications, Université du Québec, 1650 Boul. Lionel-Boulet, Varennes, QC J3X 1S2, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Cui
authors.affiliation: ‡Department of Chemistry, Division of Molecular Imaging and Photonics, KU Leuven-University of Leuven, Celestijnenlaan 200F, B-3001 Leuven, Belgium.
authors.forename: S
authors.initials: S
authors.lastname: De Feyter
authors.affiliation: †INRS Énergie, Matériaux et Télécommunications, Université du Québec, 1650 Boul. Lionel-Boulet, Varennes, QC J3X 1S2, Canada.|§Center for Self-Assembled Chemical Structures, McGill University, 801 Sherbrooke Street West, Montreal, QC H3A 0B8, Canada.
authors.forename: F
authors.initials: F
authors.lastname: Rosei