The synthesis of two series of N-annulated perylene bisimides (PBIs), compounds 1 and 2 , is reported, and their self-assembling features are thoroughly investigated by a complete set of spectroscopic measurements and theoretical calculations. The study corroborates the enormous influence that the distance between the PBI core and the peripheral groups exerts on the chiroptical properties and the supramolecular polymerization mechanism. Compounds 1 , with the peripheral groups separated from the central PBI core by two methylenes and an ester group, form J-type supramolecular polymers in a cooperative manner but exhibit negligible chiroptical properties. The lack of clear helicity, due to the staircase arrangement of the self-assembling units in the aggregate, justifies these features. In contrast, attaching the peripheral groups directly to the N-annulated PBI core drastically changes the self-assembling properties of compounds 2 , which form H-type aggregates following an isodesmic mechanism. These H-type aggregates show a strong aggregation-caused quenching (ACQ) effect that leads to nonemissive aggregates. Chiral ( S ) -2 and ( R )-2 experience an efficient transfer of asymmetry to afford P - and M-type aggregates, respectively, although no amplification of asymmetry is achieved in majority rules or “sergeants-and-soldiers” experiments. A solvent-controlled stereomutation is observed for chiral ( S )- 2 and ( R )- 2 , which form helical supramolecular polymers of different handedness depending on the solvent (methylcyclohexane or toluene). The stereomutation is accounted for by considering the two possible conformations of the terminal phenyl groups, eclipsed or staggered, which lead to linear or helical self-assemblies, respectively, with different relative stabilities depending on the solvent.

We present the pressure area isotherms for Langmuir films made of calix[8]arene, the calix[8]arene/C60 complex, and the calix[8]arene/C70 complex, all of them measured at 306.1 K. A Brewster angle microscope was used to observe the phases shown by the π−A isotherms. In these three cases, we found a solid phase and its solid−gas coexistence but no expanded liquid phases. The Langmuir films made of calix[8]arene and the calix[8]arene/C60 complex are very similar. The experimental information is consistent with the assumption that C60 is situated inside the cavity of calix[8]arene. The Langmuir films of calix[8]arene and the calix[8]arene/C70 complex are not very similar; we present a discussion to explain the origin of this difference.

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Carbon nanotubes are very promising candidates for molecular wires, and as such it is important to understand their electrical and mechanical properties. Here single‐walled carbon nanotubes (SWNTs) are investigated using non‐contact dynamic scanning force microscopy (SFM). The nanotubes are locally probed using metallized cantilever tips to correlate the mechanical and electrical properties, and the simultaneously obtained force vs. distance and current vs. distance curves are compared. The measurements reveal that electrical contact occurs for very small load forces.

A completely soluble optically active polyaniline-multiwalled carbon nanotube composite was investigated by spectroscopic and microscopic techniques. It was found that the polymer's optical activity was retained in the presence of carbon nanotubes. Solutions were found to be easily processable into thin films, which exhibited dendritic structures only in the presence of nanotubes.

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We report the covalent functionalization of single-walled carbon nanotubes (SWNTs) with biotin. The synthesized functionalized SWNT materials were fully characterized by FTIR and thermogravimetric analysis. These characterization techniques provided valuable information concerning the nature of the obtained SWNT materials as well as the efficiency of the employed synthetic route towards SWNT covalent functionalization with biotin.

In this letter, a method is presented to qualitatively investigate the electrical connection between single-walled carbon nanotubes and gold electrodes. By applying a time independent bias voltage to the scanning force microscope tip, there is a clear apparent growth effect in the topography of the electrically connected carbon nanotubes. This effect is induced by the electrostatic interaction of the tip with the free charges located at the conducting areas of the surface. This is a general method that could be applied to any molecular conducting nanowire.