Highly conductive coaxial supramolecular wires are prepared by using a new family of dendrimers that combines two rigid aromatic parts and two flexible aliphatic parts. The two external regions consist of a promesogenic block based on a third generation Percec-type dendron with four terminal dodecyloxy alkyl chains, whereas the two internal regions are formed by one, two, or three carbazole units bearing flexible spacers. These functional dendrimers self-organize in columnar liquid crystal phases with a strong coaxial segregation within each column. Interestingly, the charge mobility studies revealed that these dendrimers display semiconductor properties with hole mobility values up to 0.5 cm V s, depending on the packing within the columns which can be tuned by the number of carbazole functional units. The high hole mobility values measured in these materials are among the highest values reported for columnar liquid crystals.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1021/acsmacrolett.8b00505 | DOI Listing |
Beilstein J Org Chem
December 2024
Institut de Physique et Chimie des Matériaux de Strasbourg (IPCMS), CNRS-Université de Strasbourg (UMR 7504), F-67034 Strasbourg, France.
The high potential of non-covalent arene-fluoroarene intermolecular interactions in the design of liquid crystals lies in their ability to strongly promote self-assembly, improve the order and stability of the supramolecular mesophases, and enable tuneability of the optical and electronic properties, which can potentially be exploited for advanced applications in display technologies, photonic devices, sensors, and organic electronics. We recently successfully reported the straightforward synthesis of several mesogens containing four lateral aliphatic chains and derived from the classical triphenylene core self-assembling in columnar mesophases based on this paradigm. These mesogenic compounds were simply obtained in good yields by the nucleophilic substitution (SFAr) of various types of commercially available fluoroarenes with the electrophilic organolithium derivatives 2,2'-dilithio-4,4',5,5'-tetraalkoxy-1,1'-biphenyl (2Li- ).
View Article and Find Full Text PDFSmall
December 2024
Department of Engineering Science, Graduate School of Informatics and Engineering, The University of Electro-Communications, 1-5-1 Chofugaoka, Chofu, Tokyo, 182-8585, Japan.
This paper discusses the controlled morphology of hierarchical liquid crystalline DNA assemblies. Through a process of heating and slow cooling, double-stranded DNAs (dsDNAs) having 23 complementary bases and two base overhangs (a pair of 25mer oligonucleotides) spontaneously assemble into micro-sized hexagonal platelets in a solution containing poly(ethylene glycol) (PEG) and salt. Remarkably, the addition of a shorter dsDNA with AA/TT overhangs (a pair of 18mer oligonucleotides) to a PEG-salt solution of 25mer DNA with AA/TT overhangs results in the formation of molecular tubes, each with a central blockage.
View Article and Find Full Text PDFCommun Chem
December 2024
Department of Chemistry, Universitat de les Illes Balears, Palma de Mallorca, Spain.
Supramolecular self-assembly is an advanced approach for constructing ordered nanoscale architectures with broad applications. While the principles of supramolecular polymerization have been thoroughly explored in artificial small molecules, polymer transformations remain barely explored, likely due to the lack of suitable reference models presenting well-defined and reversible transitions between aggregates. In this study, we introduce a series of bisdendronized squaramides (SQs) 1-3, showcasing complex self-assembly behaviours involving four distinct aggregates, three different interaction patterns, and various thermodynamically controlled polymorph transformations.
View Article and Find Full Text PDFMolecules
December 2024
Suzhou Key Laboratory of Macromolecular Design and Precision Synthesis, Jiangsu Key Laboratory of Advanced Functional Polymer Design and Application, State and Local Joint Engineering Laboratory for Novel Functional Polymeric Materials, College of Chemistry, Chemical Engineering and Materials Science, Soochow University, Suzhou 215123, China.
Cyanostilbene (CS)-related conjugated groups can be considered as dual functional groups of AIEgen and mesogen to construct photoluminescent liquid crystals, and it is essential to study the relationship between their molecular structures and compound properties systematically. In this paper, we designed and synthesized linear and bent-shaped CS derivatives containing ester- and amide-connecting groups and different substituted numbers of alkoxy tails. Their phase behaviors and photophysical properties were investigated in depth.
View Article and Find Full Text PDFMolecules
November 2024
Department of Chemistry, University of Calgary, 2500 University Drive NW, Calgary, AB T2N 1N4, Canada.
This study explores the liquid crystalline properties of novel amphiphilic β-cyclodextrin derivatives functionalized with seven oligoethylene glycol chains at the primary face, terminated with either an O-methyl or an O-cyanoethyl group, and fourteen hydrophobic aliphatic chains (elaidic or oleic acids) at the secondary face. These derivatives were designed to study the impact of chain conformation and terminal group polarity on their mesomorphic behavior. Thermal, microscopic, and X-ray diffraction studies revealed that the elaidic derivatives form columnar hexagonal mesophases, with the O-cyanoethyl derivative undergoing a slow, temperature-dependent transition to a bicontinuous cubic phase.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!