Two‐step alkylations of benzimidazole, 2‐methylbenzimidazole, and imidazole at their nitrogen atoms with various bifunctional alkylating agents have afforded a series of 16‐membered quaternary azacyclophanes. Of these macrocycles, those bearing methyl or methoxy groups on the azole or at the aromatic bridges have been found to exist as mixtures of conformers. In some cases, the structures of the conformers have been determined by NMR methods and X‐ray crystallography, and have been correlated with the results of a computer‐aided conformational search.

The excited state processes in N-propyl-4-piperidinyl-1,8-naphthalimide have been studied by measuring its fluorescence spectra and decay curves in solvents of different polarity and viscosity and also in a frozen solvent glass. The results unanimously proved the formation of a dark twisted intramolecular charge transfer (TICT) state from the emissive charge transfer (CT) species, the direct product of excitation. The rate coefficients of the TICT process and the deactivations of the CT and TICT species were determined, using a reversible two-state kinetic model. The temperature dependence of the kinetic data was consistent with a kinetic barrier consisting of three terms, the inherent barrier of the reaction, and the contributions of the solute-solvent interactions related to the solvent viscosity and polarity. The potential energy surfaces were calculated in the S0 and the S1 states along the coordinate of turning motion which was conclusive concerning the direction of the twisting and indicated a possible conformational change of the piperidinyl unit. The theoretical calculations confirmed that the TICT species is dark and has a stronger charge transfer character compared to the CT state.

A novel functionality was introduced in the pillararene family by the Claisen rearrangement of monoallyl pillar[5]arene. This new key derivative can lead to the formation of a 10 + 1 functionalized derivative, a useful scaffold for further derivatization. Except for the previously known monodeprotection reaction, all steps proceed efficiently with high yields and easy separation. In addition, a solvent-responsive pseudo[1]rotaxane was synthesized based on this novel functionality.

Äußerst wählerisch: Die Selektivitätsfilter biologischer Ionenkanäle dienen als Vorlage für die Entwicklung von ionophormodifizierten Festkörpernanoporen mit außergewöhnlicher Ionenselektivität (siehe Bild). Die potentiometrische Transduktion wird als eine Methode eingeführt, um die Ionensensorwirkung solcher Nanoporen zu demonstrieren.

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