Hierarchically structured microfibers of "single stack" perylene bisimide and quaterthiophene nanowires.
Organic nanowires and microfibers are excellent model systems for charge transport in organic semiconductors under nanoscopic confinement and may be relevant for future nanoelectronic devices. For this purpose, however, the preparation of well-ordered organic nanowires with uniform lateral dimensions remains a challenge to achieve. Here, we used the self-assembly of oligopeptide-substituted perylene bisimides and quaterthiophenes to obtain well-ordered nanofibrils. The individual nanofibrils were investigated by spectroscopic and imaging methods, and the preparation of hierarchically structured microfibers of aligned nanofibrils allowed for a comprehensive structural characterization on all length scales with molecular level precision. Thus, we showed that the molecular chirality resulted in supramolecular helicity, which supposedly serves to suppress lateral aggregation. We also proved that, as a result, the individual nanofibrils comprised a single stack of the π-conjugated molecules at their core. Moreover, the conformational flexibility between the hydrogen-bonded oligopeptides and the π-π stacked chromophores gave rise to synergistically enhanced strong π-π interactions and hydrogen-bonding. The result is a remarkably tight π-π stacking inside the nanofibrils, irrespective of the electronic nature of the employed chromophores, which may render them suitable nanowire models to investigate one-dimensional charge transport along defined π-π stacks of p-type or n-type semiconductors.
Institute of Materials, Laboratory of Macromolecular and Organic Materials, Ecole Polytechnique Fédérale de Lausanne (EPFL) , EPFL - STI - IMX - LMOM, MXG 037, Station 12, 1015 Lausanne, Switzerland.
Roman
R
Marty
Ruth
R
Szilluweit
Antoni
A
Sánchez-Ferrer
Sreenath
S
Bolisetty
Jozef
J
Adamcik
Raffaele
R
Mezzenga
Eike-Christian
EC
Spitzner
Martin
M
Feifer
Stephan N
SN
Steinmann
Clémence
C
Corminboeuf
Holger
H
Frauenrath