Self-assembly in situ, where synthetic molecules are programmed to organize in a specific and complex environment i.e., within living cells, can be a unique strategy to influence cellular functions. Here we present a small series of rationally designed oligothiophene analogues that specifically target, locate and dynamically self-report their supramolecular behavior within the confinement of a cell. Through the recognition of the terminal alkyl substituent and the amphiphilic pyridine motif, we show that the cell provides different complementary pathways for self-assembly that can be traced easily with fluorescence microscopy as their molecular organization emits in distinct fluorescent bands. Importantly, the control and induction of both forms are achieved by time, temperature and the use of the intracellular transport inhibitor, bafilomycin A1. We showcase the importance of both intrinsic (cell) and extrinsic (stimulus) factors for self-organization and the potential of such a platform toward developing synthetic functional components within living cells.

We report on three different liquid crystalline compounds with a central septithiophene core and alkylated end groups of strongly increasing bulkiness. In principle, the thiophene cores prefer to pack parallel to optimize their π-π interactions, which becomes sterically impossible for the bulkier end groups. Using X-ray diffraction, we find that the way out of this packing dilemma is toward liquid-crystal phases of higher dimensionality in the order smectic → columnar ↔ bicontinuous cubic. For the smectic phase, packing in a monolayer is no problem; for the other ones packing considerations become more stringent in films due to the boundaries. Surface X-ray techniques and atomic force microscopy indicate an appreciable difference between monolayer and three-layer films, in which the monolayers appear to escape from packing frustration by generating superstructures. We propose a basic structure of columns parallel to the substrate that provides a compromise between preserving some π-π interactions and packing the bulky alkyl groups.

Caution must be exercised when evaluating data of supramolecular polymerization at high concentrations and various methods should be employed.

A systematic series of septi‐, noni‐ and undecithiophenes and the corresponding pre‐oligomers with five different dendrimer‐like branched end‐groups have been synthesized and their thermal solid‐state properties investigated. The substituents vary in terms of the lengths of the linkers between the silicon branching points. Comparison of the compounds in the series reveals that the linker connecting the oligomeric core with the first branching point has the strongest effect on the thermal properties. Furthermore, the relatively large volume of the substituents causes surprisingly low overall transition enthalpies and entropies for the oligomers of 10–20 kJ mol–1 and 15–40 J mol–1 K–1, respectively, whereas the pre‐oligomers with interrupted conjugation display values in the range of 15–40 kJ mol–1 and 40–100 J mol–1 K–1, respectively. Polarizing optical microscopy (POM) revealed textures pointing to smectic and columnar liquid‐crystalline phases but X‐ray and AFM data of a representative example are typical of cubic phases.

No abstract