Ultrathin Films

Linear oligomers on thiophene basis with aliphatic end groups of varying branching topology show strongly expressed self-assembly in organic solvents with the formation of cylindrical nanoobjects. The driving force originates from phase separation of the stiff linear cores and the flexible bulky end groups as known from coil-rod-coil block copolymers and it is the delicate balance between core length and branching topology of the end groups which is decisive for the formation of superstructures. The self-assembly plays also a crucial role in solid state by forming liquid crystalline phases and ultra-thin films, from which monolayer field effect transistors can be constructed. A new synthetic strategy for the plane oligothiophenes was developed based on metal-catalysed coupling chemistry and ring-closure reactions.

 

  • Ellinger, S.; Kreyes, A.; Ziener, U.; Hoffmann-Richter, C.; Landfester, K.; Möller, M. Aggregation Phenomena of Long alpha- and alpha,omega-Substituted Oligothiophenes – the Effect of Branched vs. Linear End Groups. Eur. J. Org. Chem. 2007, (34), 5686.
  • Ellinger, S.; Ziener, U.; Thewalt, U.; Landfester, K.; Möller, M. The Synthesis and Self-Organization of alpha,omega-Substituted Oligothiophenes With Long Branched Alkyl Substituents. Chem. Mater. 2007, 19 (5), 1070.
  • Kreyes, A.; Amirkhani, M.; Lieberwirth, I.; Mauer, R.; Laquai, F.; Landfester, K.; Ziener, U. The Longest β-Unsubstituted Oligothiophenes and Their Self-Assembly in Solution. Chem. Mater. 2010, 22 (23), 6453.
  • Kreyes, A.; Ellinger, S.; Landfester, K.; Defaux, M.; Ivanov, D. A.; Elschner, A.; Meyer-Friedrichsen, T.; Ziener, U. Fine Tuning of Solid-State Properties of Septithiophenes by Tailoring the Substituents. Chem. Mater. 2010, 22 (6), 2079.
  • Defaux, M.; Gholamrezaie, F.; Wang, J.; Kreyes, A.; Ziener, U.; Anokhin, D. V.; Ivanov, D. A.; Moser, A.; Neuhold, A.; Salzmann, I.et al. Solution-Processable Septithiophene Monolayer Transistor. Adv. Mater. 2012, 24 (7), 973.
  • Kreyes, A.; Mourran, A.; Hong, Z.; Wang, J.; Möller, M.; Gholamrezaie, F.; Roelofs, W. S. C.; de Leeuw, D. M.; Ziener, U. Predictability of Thermal and Electrical Properties of Endcapped Oligothiophenes by a Simple Bulkiness Parameter. Chem. Mater. 2013, 25 (10), 2128.
  • Wang, J.; de Jeu, W. H.; Speiser, M.; Kreyes, A.; Ziener, U.; Magerl, D.; Philipp, M.; Müller-Buschbaum, P.; Möller, M.; Mourran, A. Biaxial alignment of block copolymer-complex lamellae. Soft Matter 2013, 9 (4), 1337.
  • de Jeu, W. H.; Rahimi, K.; Ziener, U.; Vill, R.; Herzig, E. M.; Muller-Buschbaum, P.; Moller, M.; Mourran, A. Substituted Septithiophenes with End Groups of Different Size: Packing and Frustration in Bulk and Thin Films. Langmuir 2016, 32 (6), 1533.
Polarisationsmikroskopisches Bild eines niedermolekularen Flüssigkristalls