Contact
    Start Publications Arylic versus Alkylic-Hydrophobic Linkers Determine the ...
    ←  Publication Finder
    KSV NIMA

    Arylic versus Alkylic-Hydrophobic Linkers Determine the Supramolecular Structure and Optoelectronic Properties of Tripodal Amphiphilic Push-Pull Thiazoles

    Year: 2019

    Journal: Langmuir, Volume 35, 1-Feb, page 2561–2570

    Authors: Hupfer, M. L.; Kaufmann, M.; Roussille, L.; Preiss, J.; Weiss, D.; Hinrichs, K.; Deckert, V.; Dietzek, B.; Beckert, R.; Presselt, M.

    Organizations: Bundesministerium fur Bildung und Forschung (BMBF)Federal Ministry of Education & Research (BMBF) [FKZ 03EK3507]; Deutsche Forschungsgemeinschaft (DFG)German Research Foundation (DFG) [PR 1415/21]; Nagelschneider Stiftung; German Science Foundation (DFG)German Research Foundation (DFG) [TRR 166, TRR 234]; Ministerium fur Innovation, Wissenschaft und Forschung des Landes Nordrhein-Westfalen; Regierende Burgermeister von Berlin-Senatskanzlei Wissenschaft und Forschung; European UnionEuropean Union (EU) [EFRE 1.8/13]

    The supramolecular structures and their constituents essentially determine the optoelectronic properties of thin films. The introduction of amphiphilicity to the constituents and interface assembly is one established technique to control supramolecular structures and resulting material properties. To yield amphiphilicity, rather hydrophobic chromophores are linked to hydrophilic head groups via flexible alkyl chains. In the present work, we investigate whether replacement of the alkyl linkers by a phenylene linker, that is, replacing an electrically isolating moiety with a potentially semiconducting one, increases the conductivity through the resulting layers. After investigating the influence of the linker on molecular properties of the 2-(4-N,N-dimethylaminophenyl)-4-hydroxy-5-nitrophenyl-1,3 thiazoles exemplarily used in this work, we produce supramolecular structures by means of the Langmuir-Blodgett (LB) technique. Atomic force microscopy (AFM) and UV-vis absorption spectroscopy reveal that thin films made from the more rigid thiazole bearing the arylic linker feature a more homogeneous and stable supramolecular structure as compared to those made from the thiazole dye containing the flexible alkylic linker. Finally, conductive AFM (cAFM) results disclose that the LB films made from the thiazole bearing the pi-conjugated arylic linker are less conductive than their counterparts based on the alkylic linkers. In the latter layers, the alkylic linkers provide sufficient motional degrees of freedom to allow for supramolecular rearrangement upon electrical operation during cAFM measurements, hence yielding supramolecular structures featuring increased conductivity with successive cAFM measurements. This work highlights the importance of supramolecular structures for optoelectronic properties by presenting a case where supramolecular effects excel the property changes introduced by molecular modifications.
    View publication