Dresden 2009 – wissenschaftliches Programm
Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe
O: Fachverband Oberflächenphysik
O 42: Poster Session II (Nanostructures at surfaces: arrays; Nanostructures at surfaces: Dots, particles, clusters; Nanostructures at surfaces: Other; Nanostructures at surfaces: Wires, tubes; Metal substrates: Adsorption of O and/or H; Metal substrates: Clean surfaces; Metal substrates: Adsorption of organic/bio moledules; Metal substrates: Solid-liquid interfaces; Metal substrates: Adsorption of inorganic molecules; Metal substrates: Epitaxy and growth; Heterogeneous catalysis; Surface chemical reactions; Ab-initio approaches to excitations in condensed matter; Organic, polymeric, biomolecular films– also with adsorbates; Particles and clusters)
O 42.53: Poster
Mittwoch, 25. März 2009, 17:45–20:30, P2
Self-assembly of amino acids on noble metal surfaces: universality of the amino acid bonding scheme — •Joachim Reichert1, Agustin Schiffrin1,2, Yan Pennec2, Willi Auwärter1, Alexander Weber-Bargioni2, Matthias Marschall1, Dean Cvetko3, Albano Cossaro3, Alberto Morgante3, and Johannes V. Barth1 — 1Physik Department, TU München, Germany — 2Chemistry Department, University of British Columbia, Vancouver, Canada — 3INFM/TASC, Trieste, Italy
We investigated the molecular self-assemblies of L-methionine on Cu(111) and L-tyrosine on Ag(111) by means of STM, HAS, XPS and NEXAFS in UHV. The self-assembly of L-methionine on Cu(111) is strongly influenced by the substrate reactivity and reveals a temperature dependent structural transformation involving a chiral orientational switch and the emergence of an ordered 1D high temperature phase. XPS data show that this transformation is triggered by a thermally activated deprotonation of the NH3+ group. The ordered phase shows noncovalent molecular dimerization and alignment into chains which are commensurate with the underlying substrate. L-tyrosine on Ag(111) self-assembles into linear nanoribbons primarily following the substrate crystalline symmetry. A zwitterionic noncovalent molecular dimerization is observed, and NEXAFS data provide evidence of a non-flat adsorption of the phenol ring. This dimerization scheme is reminiscent of methionine on Cu(111) and Ag(111), and supports a universal self-assembling trend for amino acids on close-packed noble metal surfaces.