Deep-Blue Photoluminescent Properties of a Liquid Crystal TB10A

2011 ◽  
Vol 181-182 ◽  
pp. 33-38 ◽  
Author(s):  
Qing Lan Ma ◽  
Rui Xiong ◽  
Yuan Ming Huang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Electronic Structures ◽  
Room Temperature ◽  
Tight Binding ◽  
Electronic Structure Calculations ◽  
Scanning Calorimetry ◽  
Deep Blue ◽  
Tight Binding Method ◽  
Structure Calculations

A typical liquid crystal (LC) N,N-(terephthalylidene) bis (4-decylbenzenamine) (TB10A) was firstly synthesized at room temperature. The synthesized LC TB10A were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), ultraviolet-visible (UV-vis) spectrophotometry, photoluminecence (PL) spectroscopy and electronic structure calculations. Upon the 325 nm excitation, the dilute tetrahydrofuran solutions of TB10A could give off blue PL. With Hückel tight-binding method, the electronic structures of the TB10A were calculated. Our results demonstrated that the deep-blue PL observed at about 489 nm (2.54 eV) can be assigned to theπ* →ntransition for the TB10A.

Optical Properties and Electronic Structures of a Liquid Crystal TBO10A

2011 ◽  
Vol 181-182 ◽  
pp. 110-114
Author(s):  
Yuan Ming Huang ◽  
Qing Lan Ma ◽  
Bao Gai Zhai
Keyword(s):  
Liquid Crystal ◽  
Electronic Structures ◽  
Room Temperature ◽  
Tight Binding ◽  
Electronic Structure Calculations ◽  
Scanning Calorimetry ◽  
Absorption Bands ◽  
Rigid Core ◽  
Tight Binding Method ◽  
Structure Calculations

A liquid crystal (LC) N,N-(terephthalylidene) bis (4-octyloxyaniline) (TBO10A) was synthesized at room temperature. The LC TBO10A were investigated by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), ultraviolet-visible spectrophotometry, photoluminecence (PL) spectroscopy and electronic structure calculations. In tetrahydrofuran solutions, two optical absorption bands were recorded for TBO10A at about 298 and 379 nm, respectively. Under the 325 nm excitation, dilute tetrahydrofuran solutions of the TBO10A can give off weak blue PL. With Hückel tight-binding method, the electronic structures of the TBO10A were calculated. Our results demonstrated that two absorptions can be attributed to theπ→π* andn→π* transitions in the rigid core of the TBO10A while the PL observed at about 481 nm (2.58 eV) can be assigned to theπ* →ntransition.

Evidence for room temperature mesomorphism in a mixed-valent diruthenium(II,III) quintapalmitoleate polymer

1998 ◽  
Vol 76 (11) ◽  
pp. 1520-1523
Author(s):  
Jennifer F Caplan ◽  
Christopher A Murphy ◽  
Susan Swansburg ◽  
Robert P Lemieux ◽  
T Stanley Cameron ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Powder Diffraction ◽  
Strong Evidence ◽  
Room Temperature ◽  
Variable Temperature ◽  
Mixed Valence ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Crystal Transition

The synthesis of Ru2(μ-O2CR)4(μ´-O2CR) (1), R = -CH2(CH2)6CH=CH(CH2)5CH3, has been achieved and characterization using elemental analysis and FTIR and UV-Vis spectroscopies undertaken. Strong evidence for a hexagonal discotic mesophase has been found using differential scanning calorimetry, variable-temperature polarizing optical microscopy, and X-ray powder diffraction. A solid to liquid crystal transition was found upon heating at 128°C and the mesophase is found to persist to room temperature upon cooling from 150°C. This is the first report of room temperature mesomorphism in a mixed-valent metallomesogen. Key words: ruthenium carboxylate, liquid crystal, metallomesogen, mixed valence, polymer.

Mesophase Studies and Charge Transportation Properties of 3,6-dicarbethoxy-2,7,10,11-tetra-pentyloxytriphenylene

2011 ◽  
Vol 181-182 ◽  
pp. 193-196
Author(s):  
Chun Xiu Zhang ◽  
Jia Ling Pu ◽  
Hao Wu ◽  
Ao Zhang ◽  
Ming Xia Zhang ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Optical Microscopy ◽  
Chemical Structure ◽  
Room Temperature ◽  
Time Of Flight ◽  
Scanning Calorimetry ◽  
Columnar Phase ◽  
Discotic Liquid Crystal ◽  
Time Of Flight Method

In this study, a triphenylene-based discotic liquid crystal 3,6-dicarbethoxy-2,7,10,11-tetra-pentyloxytriphenylene was synthesized. The chemical structure was characterized by FTIR, 1HNMR.The mesophases of the material synthesized here was characterized by using polarizing optical microscopy (POM), differential scanning calorimetry (DSC). It was found that the compound displayed columnar phase during cooling at 164.7 °C and the columnar phase can be preserved even at room temperature. The charge transportation properties of the compound were measured by using time-of-flight method.

ELECTRONIC STRUCTURE CALCULATIONS ON MoTe2 WITH ROTATED PLANES

2005 ◽  
Vol 19 (26) ◽  
pp. 3933-3943
Author(s):  
A. TLAHUICE ◽  
E. FLORES ◽  
D. H. GALVÁN
Keyword(s):  
Electronic Structure ◽  
Diffraction Pattern ◽  
Tight Binding ◽  
Electronic Structure Calculations ◽  
Experimental Measurements ◽  
Metallic Behavior ◽  
Tight Binding Method ◽  
Total Energies ◽  
Structure Calculations ◽  
Good Agreement

Electronic structure calculations have been carried out using Extended Hückel tight-binding method for 2 H — MoTe 2 for the cases both unrotated and with rotated planes. It has been found that relative rotations of the tellurium layers ranging from 5 to 16 degrees have the same total energies and total energies/atom as the unrotated structure. Moreover, an increased in metallic behavior has been observed, as long as the degrees of rotated planes are increased. Finally, good agreement has been found among previous experimental measurements in the diffraction pattern of irradiated MoTe 2 and our calculated 5, 6 and 7 degrees of rotations.

One-Step Synthesis of a Liquid Crystal TB4A at Room Temperature

2011 ◽  
Vol 181-182 ◽  
pp. 168-172
Author(s):  
Qing Lan Ma ◽  
Bao Gai Zhai ◽  
Yuan Ming Huang
Keyword(s):  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Liquid Crystal ◽  
Room Temperature ◽  
Scanning Calorimetry ◽  
Smectic A ◽  
Smectic C ◽  
Infrared Spectrometer ◽  
One Step

A rod-like liquid crystal (LC) N,N-(terephthalylidene) bis (4-n-butylaniline) (TB4A) was synthesized by one step at room temperature. The synthesized TB4A were investigated with nuclear magnetic resonance, fourier transform infrared spectrometer and ultraviolet-visible spectrophotometry, differential scanning calorimetry and polarizing optical microscopy. Our results demonstrated that the TB4A can form nematic, smectic A, smectic C, smectic F and smectic G LC phases.

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