Homeotropic Alignment and Director Structures in Thin Films of Triphenylamine-Based Discotic Liquid Crystals Controlled by Supporting Nanostructured Substrates and Surface Confinement

2011 ◽  
Vol 115 (4) ◽  
pp. 609-617 ◽  
Author(s):  
Trirup Dutta Choudhury ◽  
Nandiraju V. S. Rao ◽  
Robert Tenent ◽  
Jeffrey Blackburn ◽  
Brian Gregg ◽  
...  
Keyword(s):  
Thin Films ◽  
Liquid Crystals ◽  
Discotic Liquid Crystals ◽  
Homeotropic Alignment ◽  
Surface Confinement ◽  
Nanostructured Substrates

scholarly journals Discotic liquid crystals of transition metal complexes 50: spiranthes-like supramolecular structure of phthalocyanine-fullerene dyads

2014 ◽  
Vol 18 (05) ◽  
pp. 366-379 ◽  
Author(s):  
Aya Ishikawa ◽  
Kenta Ono ◽  
Kazuchika Ohta ◽  
Mikio Yasutake ◽  
Musubu Ichikawa ◽  
...  
Keyword(s):  
Liquid Crystals ◽  
Transition Metal Complexes ◽  
Supramolecular Structure ◽  
Liquid Crystalline ◽  
Molecular Design ◽  
Glass Plate ◽  
Helical Structure ◽  
Discotic Liquid Crystals ◽  
One Dimensional ◽  
Homeotropic Alignment

We have synthesized novel liquid crystalline Pc - C 60 dyads (CnS)6PcCu-C60 (n = 14, 16, 18: 1a–1c) by using our developed synthetic method in order to investigate the mesomorphism and alignment behavior. Each of the (CnS)6PcCu-C60 dyads shows perfect homeotropic alignment in the Colho mesophase between two glass plates for n = 14, 16, 18 and also on a glass plate for n = 14, although none of the parent Pc compounds (CnS)8PcCu and the Pc precursors (CnS)6PcCu-OH and (CnS)6PcCu-OFBA shows homeotropic alignment. It may be attributed to the strong affinity between fullerene and glass surface. Although the reason is not so clear at the present time, this is very useful guideline for the molecular design to prepare homeotropic alignment-showing discotic liquid crystals. Very interestingly, the spherical C 60 parts form a helical structure around the column formed by the disk-like Pc parts This supramolecular structure very resembles spiranthes. The spiranthes-like supramolecular structure is compatible with one-dimensional nano-array expecting the high conversion efficiency of solar cells.

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 .

Synchronized optical and electrical characterization of discotic liquid crystals thin films

2010 ◽  
Vol 81 (3) ◽  
pp. 033907 ◽  
Author(s):  
Annalisa Calò ◽  
Pablo Stoliar ◽  
Massimiliano Cavallini ◽  
Yves H. Geerts ◽  
Fabio Biscarini
Keyword(s):  
Thin Films ◽  
Liquid Crystals ◽  
Electrical Characterization ◽  
Discotic Liquid Crystals

Photogeneration and transport in thin films of p- and n-type discotic liquid crystals

2003 ◽  
Vol 137 (1-3) ◽  
pp. 905-906 ◽  
Author(s):  
P. Miskiewicz ◽  
A. Rybak ◽  
J. Jung ◽  
I. Glowacki ◽  
J. Ulanski ◽  
...  
Keyword(s):  
Thin Films ◽  
Liquid Crystals ◽  
Discotic Liquid Crystals

Thin films of discotic liquid crystals and their applications

2016 ◽  
Vol 43 (13-15) ◽  
pp. 2079-2091 ◽  
Author(s):  
R. K. Gupta ◽  
V. Manjuladevi ◽  
C. Karthik ◽  
Keerti Choudhary
Keyword(s):  
Thin Films ◽  
Liquid Crystals ◽  
Discotic Liquid Crystals

Discotic liquid crystals of transition metal complexes 44: synthesis of hexaphenoxy-substituted phthalocyanine derivatives showing spontaneous perfect homeotropic alignment

2012 ◽  
Vol 16 (10) ◽  
pp. 1114-1123 ◽  
Author(s):  
Masaaki Ariyoshi ◽  
Makiko Sugibayashi-Kajita ◽  
Ayumi Suzuki-Ichihara ◽  
Takayuki Kato ◽  
Tenpei Kamei ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystals ◽  
Transition Metal ◽  
Transition Metal Complexes ◽  
Discotic Liquid Crystals ◽  
X Ray Diffraction ◽  
Temperature Dependent ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Homeotropic Alignment

We have synthesized novel hexaphenoxy-substituted phthalocyanine derivatives, 2-(12-hydroxydodecyloxy)-3-methoxy-9,10,16,17,23,24-hexakis(3,4-di-n-alkoxyphenoxy)phthalocyaninato copper(II) (abbreviated as Cn(OC12OH)PcCu : n = 10, 12, 14), and investigated their columnar mesomorphism and homeotropic alignment property. These hexaphenoxy-substituted Pc derivatives could be successfully isolated and purified from the mixture products by polarity difference. It was revealed by using polarizing optical microscopic observations, differential scanning calorimetry and temperature-dependent X-ray diffraction studies that each of the hexaphenoxy-substituted Pc derivatives has plural mesophases, and that the tetragonal columnar (Coltet) mesophase shows spontaneous perfect homeotropic alignment between two non-surface-treated glass plates without any defects and polydomain boundaries.

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