Room-temperature discotic liquid crystals based on oligothiophenes—attached and fused triazatruxenes

2009 ◽  
Vol 19 (44) ◽  
pp. 8327 ◽  
Author(s):  
Jing Luo ◽  
Baomin Zhao ◽  
Jinjun Shao ◽  
Kheng Aik Lim ◽  
Hardy Sze On Chan ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Room Temperature ◽  
Discotic Liquid Crystals

Discotic liquid crystals of transition metal complexes, part 36: syntheses and mesomorphic properties of very large discotic liquid crystals based on triphenylenocyanine and 1,4-diazatriphenylenocyanine

2006 ◽  
Vol 10 (09) ◽  
pp. 1145-1155 ◽  
Author(s):  
Masahiro Ichihara ◽  
Masakazu Miida ◽  
Bernhard Mohr ◽  
Kazuchika Ohta
Keyword(s):  
Liquid Crystals ◽  
Room Temperature ◽  
Optical Microscope ◽  
Decomposition Temperature ◽  
Discotic Liquid Crystals ◽  
Large Area ◽  
Scanning Calorimetry ◽  
Nitrogen Gas ◽  
Homeotropic Alignment ◽  
Mesomorphic Properties

Two series of very large discotic complexes of tetrakis (2,3,6,7-tetraalkoxy)triphenylenocyaninato copper(II) (abbreviated as ( C n O )16 TcCu ; n = 8, 10, 12 and 14) and tetrakis(2,3,6,7-tetraalkoxy)-1,4-diazatriphenylenocyaninato copper(II) (abbreviated as ( C n O )16 TzCu ; n = 8, 10, 12 and 14), were synthesized to investigate their mesomorphic properties by differential scanning calorimetry, thermogravimetry analysis, polarizing optical microscope observation and temperature-dependent X-ray studies. The results show that each of the ( C n O )16 TcCu derivatives exhibits two or three disordered rectangular columnar ( Col rd ) mesophases from room temperature to the decomposition temperature at ca. 330-340°C under nitrogen gas. However, each of the ( C n O )16 TzCu complexes exhibits only one ordered tetragonal columnar ( Col tet.o ) mesophase in an extremely wide temperature region from room temperature to the decomposition temperature at ca 300°C and ca. 340-350°C under the atmosphere and nitrogen gas, respectively. It is very interesting that the Col tet.o mesophase of ( C n O )16 TzCu for n = 10, 12 and 14 shows remarkable spontaneous homeotropic alignment in a large area, without disclinations and polydomains, in the temperature range from room temperature to the decomposition temperature. As far as we know, these discotic liquid crystals are the first examples to show homeotropic alignment at room temperature. Furthermore, the difference between the mesomorphic properties of ( C n O )16 TcCu and ( C n O )16 TzCu originated only from the additional eight nitrogen atoms in the central core in ( C n O )16 TzCu .

Synthesis, characterization and nonlinear optical studies of novel blue-light emitting room temperature truxene discotic liquid crystals

RSC Advances ◽  
2015 ◽  
Vol 5 (34) ◽  
pp. 26596-26603 ◽  
Author(s):  
D. R. Vinayakumara ◽  
Manish Kumar ◽  
P. Sreekanth ◽  
Reji Philip ◽  
Sandeep Kumar
Keyword(s):  
Liquid Crystals ◽  
Nonlinear Optical ◽  
Room Temperature ◽  
Discotic Liquid Crystals ◽  
Structure Property ◽  
Optical Studies ◽  
Light Emitting ◽  
Self Assembling ◽  
Structure Property Relationship ◽  
Linear And Nonlinear

A new series of discotic liquid crystals based on a truxene core has been synthesized to study the structure–property relationship in view of the self-assembling property and their linear and nonlinear optical properties.

Uber die drei discotischen Mesophasen der scyllo-Inosithexaester / On the Three Discotic Mesophases of scyllo-Inositol Hexaesters

1986 ◽  
Vol 41 (8) ◽  
pp. 1036-1044 ◽  
Author(s):  
Bernd Kohne ◽  
Klaus Praefcke ◽  
Jan Billard
Keyword(s):  
Liquid Crystals ◽  
Homologous Series ◽  
Room Temperature ◽  
Mutual Orientation ◽  
Discotic Liquid Crystals ◽  
Aromatic Character ◽  
Naturally Occurring ◽  
Stable Temperature ◽  
Temperature Ranges ◽  
Increasing Temperature

AbstractThe mesophases of eleven homologous hexaesters ( 1b -1) of the naturally occurring scylloinositol (1a ) representing the first series of alicyclic saturated discogens are studied by calorimetry and optical microscopy. The three derivatives 1 b -d of this hexahydroxy cyclohexane with each six acetyl, propionyl or butyroyl side chains, respectively, exhibit a very organized discophase D1. The hexa-0-acetyl-scyllo-inositol (1b , range of mesophase: Δt = 4.8 °C!) is the discogen having the shortest identical ester groups as lateral functions so far reported for discotic liquid crystals. The pentanoyloxy com pound (1e) exhibits a monotopic D0 mesophase and an enantiotropic optically isotropic and, probably, cubic mesophase D0 different from the smectic D mesophase. Versus increasing temperature the phase sequences are D1 → DE and D1 → D0. Examples of mutual orientation of D1 and DE discophases and binary mixtures exhibiting stable DE discophase at room temperature are also reported. The mesophases of seven more compounds (1f-1) of the homologous series having lateral functions larger than pentanoyloxy are identified by total miscibility as discophase DE. Their stable temperature ranges are very wide e.g. hexa-0-heptanoyl-scyllo- inositol (1g , Δt = 132 °C) which are exceeded only by those discogens having much larger “cores” (up to now of aromatic character only).

Optoelectronic exploration of novel non-symmetrical star-shaped discotic liquid crystals based on cyanopyridine

2018 ◽  
Vol 42 (20) ◽  
pp. 16999-17008 ◽  
Author(s):  
D. R. Vinayakumara ◽  
K. Swamynathan ◽  
Sandeep Kumar ◽  
Airody Vasudeva Adhikari
Keyword(s):  
Liquid Crystals ◽  
Charge Transport ◽  
Transport Properties ◽  
Blue Light ◽  
Room Temperature ◽  
Light Emission ◽  
Discotic Liquid Crystals ◽  
Blue Light Emission ◽  
Hexagonal Columnar

Novel unsymmetrical star-shaped cyanopyridines were shown to possess an ordered hexagonal columnar assembly at room temperature. Their inherent intramolecular charge transport properties cause a technologically important intense blue light emission in the aggregated state.

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