Berlin 2015 – wissenschaftliches Programm
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DS: Fachverband Dünne Schichten
DS 3: Organic Thin Films
DS 3.14: Vortrag
Montag, 16. März 2015, 19:00–19:15, H 2032
Molecular Orientations in Photochromic Layers on Silicon(111) Investigated by X-ray Absorption Spectroscopy — •Daniel Przyrembel1, Michael Åxman Petersen2,3, Andreas Hebert2, Karola Rück-Braun2, Cornelius Gahl1, and Martin Weinelt1 — 1Department of Physics, Freie Universität Berlin, Arnimallee 14, 14195 Berlin, Germany — 2Department of Organic Chemistry, Technische Universität Berlin, Straße des 17. Juni 135, 10623 Berlin, Germany — 3Department of Chemistry, Danmarks Tekniske Universitet, Anker Engelunds Vej 1, 2800 Kongens Lyngby, Denmark
Fulgimides are a class of photochromic molecular switches that undergo ring closing and opening upon illumination with UV and visible light, respectively.[1] When coupled to self-assembled monolayers (SAMs) of suitable anchoring molecules they retain the ability to reversibly isomerize and show photostationary states dominated by either a ring-opened E/Z mixture or the ring-closed form.[2] We have investigated individual preparation steps towards as well as the resulting densely packed SAMs of a fulgimide on Si(111) single crystal surfaces by X-ray absorption spectroscopy. From the polarization-dependent contrast of the near edge X-ray absorption fine structure (NEXAFS) we deduced mean molecular orientations with respect to the sample surface and we evaluated the changes induced by UV illumination.
[1] Y. Yokoyama Chem. Rev. 2000, 100, 1717-1739.
[2] K. Rück-Braun, M. Å. Petersen, F. Michalik et al. Langmuir 2013, 29, 11758-11769.