Discovery of Structural Complexity through Self‐Assembly of Molecules Containing Rodlike Components

Abstract

Hierarchicals tructures are important for transferring and amplifying molecular functions to macroscopic properties of materials. In this regard,r odlikem olecules have emerged as one of the most promising molecular building blockst oc onstruct functional materials. Although the self-assembly of conventional molecules containing rodlike components generally results in nematic or layered smectic phases, due to the preferred parallel arrangements of rodlikec omponents, extensive efforts have revealed that rational molecular design provides aversatile platform to en-gineer richs elf-assembled structures. Herein, first successes achieved in polyphilic liquid crystals and rod-coil block systems are summarized.S pecial attention is paidt or ecent progress in the conjugation of rodlikeb uilding blocks with other molecular building blocks through the molecular Lego approach. Rod-based giant surfactants, sphere-rod conjugates, and dendritic rodlike molecules are covered. Future perspectives of the self-assembly of molecules containing rodlike components are also provided.[a] Dr.Figure 7. Perforated lamellar phase observedi nrod-coil diblock oligomers. a) TEM image of as olution-cast thin film stained with RuO 4 .b)Aselectedarea electron diffraction pattern of an unstained film. c)SAXS pattern. d) Schematic representation of perforated lamellar phasesf ormed by rodcoil diblocko ligomers. The rod segmentsa re alignedaxially perpendicular to the layer plane with ah erringbone arrangement. Reprinted with permission from ref. [35].

Functional Hybrid Molecules for the Visualization of Cancer: PESIN‐Homodimers Combined with Multimodal Molecular Imaging Probes for Positron Emission Tomography and Optical Imaging: Suited for Tracking of GRPR‐Positive Malignant Tissue**

“…As mentioned before,t he convergents ynthesis strategyt o synthesize an appropriately functionalized biomolecule (in our case, the maleimide-modified PESIN-dimer 5)a sw ell as the functionalizedM IUs (6a-13 a)a part from each other enables on the one hand the efficient formation of the complexf inal multimodali maging agents 6-13 which is not possible by fol-lowing ad ivergents ynthesis strategy.I na ddition, this modulars trategy, based on the "molecular Lego concept", [24] exhibits some further advantages. In our study,e ach MIU could be investigated regarding its chemical, radiochemical and photophysical properties, enabling to determinet he influence of the individuald ye on the mentioned properties of the re-spectiveMIU 6a-13 a.The same holds true forthe respectiveb ioconjugates 6-13.O nly by this, we were able to identify structure-activity-relationships (SARs) for the different multimodali maging agents and to determine the influenceo fe ach molecular building block on the globalp roperties of the compounds.…”

Supramolecular meso-Trick: Ambidextrous Mirror Symmetry Breaking in a Liquid Crystalline Network with Tetragonal Symmetry

“…Complex nanostructured supermolecular systems build the basis of biological evolution as well as new materials . Therefore, the fundamental understanding of the formation of such systems by simple molecules, especially the development of structural complexity − and emergence of chirality, − is of importance. Emergence of chirality and amplification of asymmetry by spontaneous helix formation were well investigated in the crystalline and solution aggregated states of chiral and achiral C 3 symmetric benzene-1,3,5-tricarboxamides − and related compounds. − ,− However, for achiral molecules, at the transition to the liquid crystalline (LC) state, supermolecular chirality is typically lost in the one-dimensional (1D) columnar assemblies due to emerging helix inversion defects. − Network formation by three-dimensional branching of the columns can remove these defects and synchronize the chirality in these network phases with cubic symmetry (bicontinuous cubic phases, Cub bi ) and even, in some cases, in the isotropic liquid mesophases occurring adjacent to them. − The Cub bi phases have also attracted significant attention due to their structural complexity and importance in biological structures, − as well as for various applications, including ion transportation, catalysis, drug delivery, organic electronic devices, and energy conversion. ,− The double network Cub bi phase with an Ia 3̅ d space group, known as the double gyroid, and a second one with an I 23 space group and triple network structure (Figures and S1) are often observed for achiral rodlike π-conjugated molecules with at least two or more terminally attached flexible chains (polycatenar molecules). − …”

C(1)‐Phenethyl Derivatives of [closo‐1‐CB11H12]− and [closo‐1‐CB9H10]− Anions: Difunctional Building Blocks for Molecular Materials

“…[35] Alternatively, the PhI + can be converted into an iodo substituent and used in Pd-catalyzed C-B cross-couplingr eactions. Thus, the two synthetic intermediates A-1 b and B-1 b can potentially lead to av ariety of functionalm aterials [36] that incorporate the 10 long phenethyl-carbaborate fragment through standard chemical transformations (Figure 11). As ad emonstration,w eh ave prepared two ionic liquid crystals A-9 c[Pyr] and B-9 c[Pyr].…”