Berlin 2018 – wissenschaftliches Programm

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O: Fachverband Oberflächenphysik

O 87: Focus Session: Molecular Nanostructures on surfaces - New Concepts towards Complex Architectures V

O 87.9: Vortrag

Donnerstag, 15. März 2018, 12:45–13:00, MA 004

Two switchable rotaxanes operating in multilayers on solid support investigated by XPS and NEXAFS — •Thomas Heinrich^{1, 2}, Henrik Hupatz², Andreas Lippitz¹, Christoph A. Schalley², and Wolfgang E. S. Unger¹ — ¹Bundesanstalt für Materialforschung und -prüfung (BAM), 6.1 Surface Analysis and Interfacial Chemistry, Unter den Eichen 44-46, 12205 Berlin — ²Institut für Chemie und Biochemie, Freie Universität Berlin, Takustraße 3, 14195 Berlin, Germany

Interfaces provide the structural basis for function as, for example, encountered in nature in the membrane-embedded photosystem or in technology in solar cells. Synthetic functional multilayers of molecules cooperating in a coupled manner can be fabricated on surfaces through layer-by-layer self-assembly. Ordered arrays of stimuli-responsive rotaxanes undergoing well-controlled axle shuttling are excellent candidates for coupled mechanical motion. The present work demonstrates the successful deposition of ordered mono- and multilayers of chemically and photochemically switchable rotaxanes on gold surfaces. Two substrates are investigated - silicon and gold. Of these materials, only gold showed to be suitable for the development of highly preferential oriented rotaxane layers. XPS indicates for both substrates that our layer-by-layer approach worked and a layer growth with every deposition step is present. NEXAFS showed that both stimuli cause an increase of the multilayer's preferential orientation and that the switching is reversible. However, these effects are only observed for the multilayers on gold surfaces.