Journal ArticleDOI
X-ray studies on the columnar structures of discotic liquid crystals
TLDR
The columnar mesophase as mentioned in this paper is characterized by a structure in which the disc shaped molecules are stacked one on top of the other to form columns, the different columns constituting a two-dimensional lattice.Abstract:
Since the discovery of discotic liquid crystals in 1977 [1] the field has grown rapidly with an estimated 3000 compounds belonging to this category. Generally these compounds have flat or nearly flat cores and surrounded by four to eight long chain substituents. A vast majority of these compounds exhibit the columnar mesophase. This phase is characterized by a structure in which thedisc shaped molecules are stacked one on top of the other to form columns, the different columns constituting a two-dimensional lattice. Several variants of the columnar structure have been identified-upright columns, tilted columns, hexagonal lattice, rectangular lattice, etc. The stacking of the discs within the column could be on the one extreme, liquid-like or on the other have a true long range order. Although X-ray measurements on quite a few compounds exhibiting these different structures have been reported, the temperature dependence of the various structural parameters does not seem to have received much attention. We ...read more
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Journal ArticleDOI
Novel discotic liquid crystal oligomers: 1,3,5-triazine-based triphenylene dimer and trimer with wide mesophase
TL;DR: A series of novel 1,3,5-triazine-based triphenylene oligomers 7, 10 and 12 with large bridging polyaromatic core were designed and synthesized by simple procedures in high yields as mentioned in this paper.
Journal ArticleDOI
Hexathioalkyl sumanenes: an electron-donating buckybowl as a building block for supramolecular materials
Yoshiaki Shoji,Takashi Kajitani,Fumitaka Ishiwari,Qiang Ding,Hiroyasu Sato,Hayato Anetai,Tomoyuki Akutagawa,Hidehiro Sakurai,Takanori Fukushima +8 more
TL;DR: The first successful synthesis of liquid-crystalline (LC) sumanenes, which was brought about by the incorporation of six thioalkyl groups (R = SC6H13 or SC12H25) into the aromatic part of sumanene, was reported in this paper.
Journal ArticleDOI
Columnar Mesophases Controlled by Counterions in Potassium Complexes of Dibenzo[18]crown‐6 Derivatives
Martin Kaller,Stefan Tussetschläger,Peter Fischer,Christopher Deck,Angelika Baro,Frank Giesselmann,Sabine Laschat +6 more
TL;DR: Dibenzo[18]crown-6 derivatives 1 with two lateral tetraalkyloxy o-terphenyl units were prepared and converted to the corresponding complexes KX1 (X = halide, BF(4), PF(6), SCN) and NH(4)PF(6)1, which improve the mesomorphic properties yielding mesophases with up to 70 degrees C phase widths.
Journal ArticleDOI
Effect of dispersion of gold nanoparticles on the optical and electrical properties of discotic liquid crystal
TL;DR: In this article, gold nanoparticles (GNPs) were embedded in a mononitro-substituted triphenylene-based discotic liquid crystal (DLC), which shows columnar plastic phase and columnar hexagonal phase at room temperature.
Journal ArticleDOI
Substituted crown ethers as central units in discotic liquid crystals: effects of crown size and cation uptake
TL;DR: In this paper, a series of crown ether-based liquid crystals was synthesized and the effect of different crown ether ring sizes, terminal groups and complexed salts on the mesomorphic properties was investigated.
References
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MonographDOI
Handbook of liquid crystals
John W. Goodby,Peter J. Collings,Takashi Kato,Carsten Tschierske,Helen F. Gleeson,Peter Raynes +5 more
TL;DR: In this article, the basic principles of both low and high-molecular weight materials, as well as the synthesis, characterization, modification, and applications of all types of liquid crystals are discussed.
Journal ArticleDOI
The Crystalline State
TL;DR: The first results of the X-ray method dealt with the stereochemistry of the solid state, which always had been nearly impossible to attack with previous methods as discussed by the authors, and this side of the development is by no means neglected in the first volume of the work before us; the title seems adequate because of the preponderant role the crystalline state has played in the great majority of investigations.