Discotic liquid crystals stabilized by interionic interactions: imidazolium ion-anchored paraffinic triphenylene

Motoyanagi, Jin; Fukushima, Takanori; Aida, Takuzo

doi:10.1039/b414649b

Cited by 81 publications

(55 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[254] oder ein (167 b) oder sechs Imidazoliumionen (168) angeknüpft werden. [255,256] Diese Triphenylensalze waren mesomorph und zeigten columnare Mesophasen (Schema 70).…”

Section: Columnare Mesophasen Auf Basis Von Wasserstoffbrückenunclassified

Diskotische Flüssigkristalle: Von der maßgeschneiderten Synthese zur Kunststoffelektronik

et al. 2007

View full text Add to dashboard Cite

Die meisten Menschen verbinden mit dem Begriff Flüssigkristalle sofort die Displays von Laptop‐Computern, Mobiltelefonen, Digitalkameras und anderen elektronischen Geräten. Im Unterschied zu ihren stäbchenförmigen (calamitischen) Verwandten, die erstmals 1907 von Vorländer beschrieben wurden, bieten aber die 1977 von Chandrasekhar entdeckten scheibenförmigen (diskotischen) Flüssigkristalle andere vielversprechende Verwendungsmöglichkeiten. Ihre einzigartige Anordnung in columnaren Mesophasen macht sie zu idealen Kandidaten für molekulare Drähte in vielen optischen und elektronischen Geräten, beispielsweise in Photokopierern, Laserdruckern, Solarzellen, organischen Leuchtdioden und Feldeffekttransistoren oder zur holographischen Datenspeicherung. Einer Übersicht über die verschiedenen Mesophasentypen und Charakterisierungsmethoden columnarer Flüssigkristalle folgen ausgewählte Beispiele aus den Hauptklassen columnarer Mesogene unter besonderer Berücksichtigung effizienter Syntheseverfahren, mesomorpher Eigenschaften und der für Anwendungen relevanten physikalischen Eigenschaften der Flüssigkristalle. Abschließend werden Anwendungsbeispiele und Perspektiven für einen Einsatz in den Materialwissenschaften und der molekularen Elektronik vorgestellt.

show abstract

“…[254] oder ein (167 b) oder sechs Imidazoliumionen (168) angeknüpft werden. [255,256] Diese Triphenylensalze waren mesomorph und zeigten columnare Mesophasen (Schema 70).…”

Section: Columnare Mesophasen Auf Basis Von Wasserstoffbrückenunclassified

Diskotische Flüssigkristalle: Von der maßgeschneiderten Synthese zur Kunststoffelektronik

et al. 2007

View full text Add to dashboard Cite

show abstract

“…In 2005, we reported that 1 10 forms an LC assembly with a Col h geometry. 6 The phase sequence upon cooling displayed, after the Col h mesophase (111-47°C), an optically isotropic phase, which however was unidentifiable due to no clear diffractions with our conventional diffractometer for X-ray analysis (XRD). Quite recently, we reinvestigated the phase diagram of 1 10 using a synchrotron radiation beam and found that the optically isotropic phase is not amorphous but an LC mesophase with a Cub bi geometry ( Figure 1b).…”

mentioning

confidence: 99%

“Bicontinuous Cubic” Liquid Crystalline Materials from Discotic Molecules: A Special Effect of Paraffinic Side Chains with Ionic Liquid Pendants

et al. 2009

Self Cite

View full text Add to dashboard Cite

Triphenylene (TP) derivatives bearing appropriate paraffinic side chains with imidazolium ion-based ionic liquid (IL) pendants were unveiled to display a phase diagram with liquid crystalline (LC) mesophases of bicontinuous cubic (Cub(bi)) and hexagonal columnar (Col(h)) geometries. While their phase transition behaviors are highly dependent on the length of the side chains and the size of the ionic liquid pendants, TPs with hexadecyl side chains exclusively form a Cub(bi) LC assembly over an extremely wide temperature range of approximately 200 degrees C from room temperature when the anions of the IL pendants are relatively small. Wide-angle X-ray diffraction analysis suggested that the Cub(bi) LC mesophase contains pi-stacked columnar TP arrays with a plane-to-plane separation of approximately 3.5 A. Consistently, upon laser flash photolysis, it showed a transient microwave conductivity comparable to that of a Col(h) LC reference.

show abstract

“…66 observation is outstanding because paraffinic TP 6 ( Figure 18) without imidazolium ion functionalities has been reported to form a columnar mesophase only in a much narrower temperature range (58-69 C). 67 Interestingly, upon mixing with an equimolar amount of 1-hexyl-3-methylimidazolium tetrafluoroborate (HMIBF 4 , Figure 2), the temperature range of the columnar LC phase is significantly expanded from 47-111 to 4-117 C (Figures 19b and 20b).…”

Section: Stabilization Of One-dimensional Columnar Assembly By Interimentioning

confidence: 96%

π-Electronic Soft Materials Based on Graphitic Nanostructures

Fukushima

2006

Polym J

Self Cite

View full text Add to dashboard Cite

ABSTRACT:This review focuses on our recent studies on the development of soft materials consisting of graphitic nanostructures. We found that single-walled carbon nanotubes, when suspended in imidazolium ion-based ionic liquids and ground in an agate mortar, form physical gels (bucky gels), where entangled nanotube bundles are exfoliated to give highly dispersed, much finer bundles. The use of polymerizable ionic liquids as the gelling media leads to the formation of highly electroconductive polymer/nanotube composites, which show a dramatic enhancement in mechanical properties. Bucky gels allow the fabrication of the first printable actuator that operates for a long time in air at low applied voltages. We also succeeded in the development of a new family of nanotubular graphite through self-assembly of amphiphilic hexabenzocoronene derivatives. The nanotube consists of a graphitic wall formed from a great number of -stacked hexabenzocoronene units, which provide a charge carrier transport pathway. Suitable chemical modifications of the amphiphile resulted in the formation of nanotubes with various interesting properties. Details of the design, properties, and scope of such -electronic soft nanomaterials are described herein. [doi:10.1295/polymj.PJ2006042] KEY WORDS Nanotube / Nanomaterial / Soft Material / Graphene / Self-Assembly / -Electronic System / Ionic Liquid / A two-dimensional (2D) honeycomb network of sp 2 -hybridized carbon is known as graphene, which stacks in a three-dimensional regular order to form graphite, a traditional carbon material. While the isolation and electronic properties of a single-layered graphene was reported quite recently, 1-3 the 2D carbon layer has drawn considerable attention in relation to carbon nanotubes. Carbon nanotubes are cylindrical carbon nanoclusters with an extremely high aspect ratio, which are formed by rolling-up of a graphene sheet (Figure 1). 4 Since their discovery, 5,6 not only such an interesting structural aspect but also the extraordinary electronic and mechanical properties of carbon nanotubes have fascinated researchers in many fields, thereby leading to remarkable advances in nanoscience and nanotechnology over the last decade.On the other hand, graphene can be regarded as one of the ultimate structural aspects of -conjugated system. Although any methodologies in organic synthesis are currently inaccessible to the infinite 2D carbon layer, organic chemists can design its molecular fragments, i.e., polycyclic aromatic hydrocarbon (PAHs), bearing desired functions. As graphene stacks to form graphite, PAHs possess strong tendency to form one-dimensional columnar structures via -stacking interactions. Since such unidirectionally aligned assemblies of PAHs can provide anisotropic charge carrier and energy transport pathways, PAHs have been considered as promising components for molecular electronic and optoelectronic devices. [7][8][9][10] We were motivated to explore novel materials based on graphitic nanostructures, in particular, focusing on one-dimensi...

show abstract

Discotic liquid crystals stabilized by interionic interactions: imidazolium ion-anchored paraffinic triphenylene

Cited by 81 publications

References 15 publications

Diskotische Flüssigkristalle: Von der maßgeschneiderten Synthese zur Kunststoffelektronik

Diskotische Flüssigkristalle: Von der maßgeschneiderten Synthese zur Kunststoffelektronik

“Bicontinuous Cubic” Liquid Crystalline Materials from Discotic Molecules: A Special Effect of Paraffinic Side Chains with Ionic Liquid Pendants

π-Electronic Soft Materials Based on Graphitic Nanostructures

Contact Info

Product

Resources

About