STM study on the self-assembly of oligothiophene-based organic semiconductors

• Elena Mena-Osteritz,
• Marta Urdanpilleta,
• Erwaa El-Hosseiny,
• Berndt Koslowski,
• Paul Ziemann and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 802–808, doi:10.3762/bjnano.2.88

• oligo- and polythiophenes and can be explained by van der Waals interaction driven full interdigitation of the alkyl chains of two opposite molecules in their all-trans conformation in different rows [9][10][11][12][18]. Theoretical calculations on a group of four molecules, excluding the substrate

• columns amounts to 1.3 nm and the space is filled by interdigitating alkyl chains (Figure 4 and Figure 5, right). The 2-D crystal of the longest oligomer, H12TCOOH, is shown in Figure 6, left. A densely packed monolayer can be seen. One can easily recognize the molecules, which are arranged in columns and

Optical properties of fully conjugated cyclo[n]thiophenes – An experimental and theoretical approach

• Elena Mena-Osteritz,
• Fan Zhang,
• Günther Götz,
• Peter Reineker and
• Peter Bäuerle

Beilstein J. Nanotechnol. 2011, 2, 720–726, doi:10.3762/bjnano.2.78

• absorption band in series I indicates slightly lower π-conjugation due to bigger distorsions of the thiophenes induced by steric interactions of the increased number of alkyl chains (8 versus 6 for C16T and C15T, respectively). A closer look at the smallest macrocycles (C8T and C10T) reveals a weak, but

STM visualisation of counterions and the effect of charges on self-assembled monolayers of macrocycles

• Tibor Kudernac,
• Natalia Shabelina,
• Wael Mamdouh,
• Sigurd Höger and
• Steven De Feyter

Beilstein J. Nanotechnol. 2011, 2, 674–680, doi:10.3762/bjnano.2.72

• (Figure 2b) reveal that individual macrocycles are tilted either clockwise or counter-clockwise with respect to the direction of the alignment of molecular rows. Measurements of the area available for adsorption of alkyl side chains, together with the number of visualised alkyl chains (Figure 2b), suggest

• is attributed to variations in the geometry (sharpness) of the STM tips used. Based on the high resolution images (Figure 3b) and the average area occupied by molecules, a tentative molecular packing model is proposed (Figure 3c). Molecules have eight alkyl chains adsorbed. The pmm symmetry

• the corresponding unit cell. Based on the STM contrast, on measurements of the area available for adsorption of alkyl chains, and on the ideal periodicity for physisorbed alkanes on graphite [18][19], it can be concluded that only eight out of twelve alkyl chains are adsorbed on graphite. STM images

Self-organizing bioinspired oligothiophene–oligopeptide hybrids

• Alexey K. Shaytan,
• Eva-Kathrin Schillinger,
• Elena Mena-Osteritz,
• Sylvia Schmid,
• Pavel G. Khalatur,
• Peter Bäuerle and
• Alexei R. Khokhlov

Beilstein J. Nanotechnol. 2011, 2, 525–544, doi:10.3762/bjnano.2.57

• than for hybrid 1' (20 ± 2 nm versus 11 ± 2 nm). Thus, more dimers of 6' interact laterally in the superstructure, possibly due to favorable van der Waals interactions of the alkyl chains, leading to a greater width of the fiber. The height of the fiber was experimentally determined to be 3.5 ± 0.4 nm

• -azidophenyl-alanine side chain and alkyl chains, is considered to be in a planar, extended conformation corresponding to the local energy minimum. In order to construct a proper periodic arrangement that could be used as an elementary structure to construct long fibrils, a corresponding periodic unit cell

• three Cartesian directions; c) proposed ensemble of four molecules of 6'. Theoretical analysis workflow (see text). Constructed periodic crystalline cells for (a) antiparallel and (b) parallel arrangement of peptide strands in single-layer fibrils. Alkyl chains are not shown. Dashed lines represent the