Author
Alina Schreivogel
Bio: Alina Schreivogel is an academic researcher from University of Stuttgart. The author has contributed to research in topics: Liquid crystal & Discotic liquid crystal. The author has an hindex of 4, co-authored 5 publications receiving 1221 citations.
Papers
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TL;DR: This Review will focus on the major classes of columnar mesogens rather than presenting a library of columner liquid crystals, and emphasis will be given to efficient synthetic procedures, and relevant mesomorphic and physical properties.
Abstract: Most associate liquid crystals with their everyday use in laptop computers, mobile phones, digital cameras, and other electronic devices. However, in contrast to their rodlike (calamitic) counterparts, first described in 1907 by Vorlander, disklike (discotic, columnar) liquid crystals, which were discovered in 1977 by Chandrasekhar et al., offer further applications as a result of their orientation in the columnar mesophase, making them ideal candidates for molecular wires in various optical and electronic devices such as photocopiers, laser printers, photovoltaic cells, light-emitting diodes, field-effect transistors, and holographic data storage. Beginning with an overview of the various mesophases and characterization methods, this Review will focus on the major classes of columnar mesogens rather than presenting a library of columnar liquid crystals. Emphasis will be given to efficient synthetic procedures, and relevant mesomorphic and physical properties. Finally, some applications and perspectives in materials science and molecular electronics will be discussed.
1,056 citations
TL;DR: In this article, an overview of columnar Mesophasentypen and Charakterisierungs methoden columnarer Flussigkristalle folgen ausgewahlte Beispiele aus den Hauptklassen columnerer Mesogene unter besonderer Berucksichtigung effizienter Syntheseverfahren, mesomorpher Eigenschaften and der fur Anwendungen relevanten physikalischen EigENSchaften.
Abstract: Die meisten Menschen verbinden mit dem Begriff Flussigkristalle sofort die Displays von Laptop-Computern, Mobiltelefonen, Digitalkameras und anderen elektronischen Geraten. Im Unterschied zu ihren stabchenformigen (calamitischen) Verwandten, die erstmals 1907 von Vorlander beschrieben wurden, bieten aber die 1977 von Chandrasekhar entdeckten scheibenformigen (diskotischen) Flussigkristalle andere vielversprechende Verwendungsmoglichkeiten. Ihre einzigartige Anordnung in columnaren Mesophasen macht sie zu idealen Kandidaten fur molekulare Drahte in vielen optischen und elektronischen Geraten, beispielsweise in Photokopierern, Laserdruckern, Solarzellen, organischen Leuchtdioden und Feldeffekttransistoren oder zur holographischen Datenspeicherung. Einer Ubersicht uber die verschiedenen Mesophasentypen und Charakterisierungsmethoden columnarer Flussigkristalle folgen ausgewahlte Beispiele aus den Hauptklassen columnarer Mesogene unter besonderer Berucksichtigung effizienter Syntheseverfahren, mesomorpher Eigenschaften und der fur Anwendungen relevanten physikalischen Eigenschaften der Flussigkristalle. Abschliesend werden Anwendungsbeispiele und Perspektiven fur einen Einsatz in den Materialwissenschaften und der molekularen Elektronik vorgestellt.
178 citations
TL;DR: In this paper, a two-electron process was discovered for trifluoroacetamide 1j, 2-methylhexanamide 1k, and 2,4-dimethylbenzamide 1l with less tendency to form 2D hydrogen bonding networks and thus increased solubility as compared to 1h.
48 citations
TL;DR: In this paper, three series of chiral tetraphenylethenes have been prepared: citronellyl-derived ethers 1a, b, lactate derived ethers 2d, g, h, i and lactate-derived esters 3a,c, e-h.
10 citations
TL;DR: In this paper, the synthesis and electrochemical investigations of 9,10-diphenylphenanthrene 2a and its derivatives 2b-2e were reported, and the cyclic voltammetry of derivatives 2a-2c and 2e in different solvent/Bu4NPF6 electrolyte systems revealed that the redox properties are dependent on solvent, temperature, and sweep rate.
Abstract: The synthesis and electrochemical investigations of 9,10-diphenylphenanthrene 2a and its derivatives 2b–2e are reported. The cyclic voltammetry of derivatives 2a–2c and 2e in different solvent/Bu4NPF6 electrolyte systems reveals that the redox properties are dependent on solvent, temperature, and sweep rate. The oxidation of 9,10-diphenylphenanthrene 2a occurred as an irreversible process, while two fully reversible oxidation waves were observed for dimethoxy derivative 2c. The room-temperature oxidation of brominated compound 2b is reversible, whereas AcO-substituted phenanthrene 2e displayed a reversible oxidation peak only at low temperature. Furthermore, the electronic nature of the substituent affects the oxidation potentials. In the CH2Cl2-based electrolyte system, the first oxidation potentials increase in the order 2c<2e<2b.
5 citations
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TL;DR: In this critical review, recent progress in the area ofAIE research is summarized and typical examples of AIE systems are discussed, from which their structure-property relationships are derived.
Abstract: Luminogenic materials with aggregation-induced emission (AIE) attributes have attracted much interest since the debut of the AIE concept in 2001. In this critical review, recent progress in the area of AIE research is summarized. Typical examples of AIE systems are discussed, from which their structure–property relationships are derived. Through mechanistic decipherment of the photophysical processes, structural design strategies for generating new AIE luminogens are developed. Technological, especially optoelectronic and biological, applications of the AIE systems are exemplified to illustrate how the novel AIE effect can be utilized for high-tech innovations (183 references).
4,996 citations
TL;DR: The recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities.
Abstract: In this review, we describe the recent advances in supramolecular helical assemblies formed from chiral and achiral small molecules, oligomers (foldamers), and helical and nonhelical polymers from the viewpoints of their formations with unique chiral phenomena, such as amplification of chirality during the dynamic helically assembled processes, properties, and specific functionalities, some of which have not been observed in or achieved by biological systems. In addition, a brief historical overview of the helical assemblies of small molecules and remarkable progress in the synthesis of single-stranded and multistranded helical foldamers and polymers, their properties, structures, and functions, mainly since 2009, will also be described.
1,235 citations
1,193 citations
TL;DR: The structural origin of chirality in different supramolecular structures through combinations of structural analysis methods has been investigated in this article, where the most ideal building blocks would need to display shape persistence in solution and in the solid state, since only this feature provides access to the use of complementary methods of structural analyses.
Abstract: Dendron-mediated self-assembly, disassembly, and self-organization of complex systems have been investigated. The most ideal building blocks would need to display shape persistence in solution and in the solid state, since only this feature provides access to the use of complementary methods of structural analysis. Most supramolecular dendrimers are chiral even when they are constructed from nonchiral building blocks and are equipped with mechanisms that amplify chirality. This poses additional challenges associated with the understanding of the structural origin of chirality in different supramolecular structures through combinations of structural analysis methods. While many supramolecular structures assembled from dendrimers and dendrons resemble some of the related morphologies generated from block-copolymers, they are much more complex and are not determined by the volume ratio between the dissimilar parts of the molecule.
1,061 citations
TL;DR: Piezochromic luminescent materials - which change the colour of their luminescence in response to mechanical stimuli - are described and have potential for various applications, including sensors, memory and displays.
Abstract: Altering the shape and properties of a material through external factors such as heat, light, pressure, pH, electric or magnetic fields, or the introduction of a guest molecule, is an attractive prospect. In this Perspective, piezochromic luminescent materials - which change the colour of their luminescence in response to mechanical stimuli - are described. Such piezochromism has been observed for a few molecular materials that contain luminescent cores in liquid-crystalline and crystalline solid states, as well as for polymeric materials doped with dyes. These changes in photoluminescent colour can be activated by various types of mechanical pressure such as shearing, grinding or elongation, which can trigger different mechanisms of producing the colour. Such stimuli-responsive materials have potential for various applications, including sensors, memory and displays.
1,032 citations