Supramolecular Assembly of Self‐Labeled Amphicalixarenes

Abstract

The synthesis and precise supramolecular organization of new amphicalixarene 4 bearing four rodlike aligned fluorescent terephthalic benzamide moieties in the upper rim is reported. The aggregation of 4 was monitored by a combination of fluorescence, conductometry, and cryo-TEM measurements at different pH values and revealed significant structural differences. Most interestingly, we found that exactly 12 molecules of 4 assemble to form a spherical and structurally persistent micelle at pH 7, which coexists with rodlike micelles. In contrast to other examples of structurally defined micelles reported previously, this new type of self-labeled amphiphile serves as a fluorescence reporter with the terephthalic units additionally providing an extended cavity structure in the hydrophilic part, which facilitates the inclusion of guest molecules. In addition to the observed formation of well-defined micelles, the other highly important finding from this study is the fact that guest molecules directly influence the micellar organization because they can interact with both the free amphiphiles below the critical micelle concentration (cmc) or the micellar aggregate itself. These two types of interactions are especially pronounced in the case of the cationic pyrene derivative 10, which binds electrostatically with the amphiphile 4. In addition, a very unique membrane structure exhibiting a regular hexagonal pattern of 5 nm pores is formed by 4 at pH 4.

Virus‐Sized DNA Nanoparticles for Gene Delivery Based on Micelles of Cationic Calixarenes

“…Thus, this work presents a two-step hierarchical assembly of small DNA nanoparticles for gene delivery based on amphiphilic cone-shaped cationic calixarenes. Keywords: calixarenes · DNA · gene delivery · micelles · self-assembly due to their pre-organized conical shape, they are prospective ion sensors, [20] nanocapsules, [21] and building blocks for assembly of micelles [22,23] and vesicles. [24] The highly diverse biomedical applications of these molecules now include antibacterial, anticancer, antiviral, antithrombotic, and membranotropic activities, ion sensors, selective enzyme blocking and mimicking, as well as protein complexation and gene delivery.…”

Sodium Effect on Self‐Organization of Amphiphilic Carboxylates: Formation of Structured Micelles and Superlattices

“…K + , in contrast, stays away from the major intracellular anions, increasing the net charge and thus solubility of molecules containing these anionic groups and also leaving these anionic groups available to act as binding determinants. [1][2][3]18] Amphiphilic perylenes such as 2 [19,20] show a very pronounced and selective exfoliation efficiency for the dissolution, individualization, and doping of carbon nanotubes [21][22][23] and graphene. [14,15] The importance of the nature of the counterion for the aggregation of amphiphiles has been overlooked so far.…”

Towards engineering of self-assembled nanostructures using non-ionic dendritic amphiphiles

“…[7][8][9][10] In recent times much attention has been focused on a new category of amphiphilic systems, dendritic amphiphiles, for use as functional supramolecular materials. 11,12 Dendritic amphiphiles with well-defined structures lie at the interface of classical surfactants and amphiphilic polymers in terms of their structure, and their self-assembly result in well-defined and persistent [13][14][15] nanostructures. 16 Multiple functional groups at the hydrophilic end of dendritic amphiphiles make them unique building blocks for the construction of functional materials compared to linear amphiphiles.…”