scholarly journals NEW MACROMOLECULAR STRUCTURES SYNTHESIS AND CHARACTERIZATION

2020 ◽  
Vol 17 (35) ◽  
pp. 109-119
Author(s):  
Adel Ismael JABBAR ◽  
Rehab Ayal RAWI ◽  
Jasim Mohammed ABDULHAMEED
Keyword(s):  
Liquid Crystal ◽  
Central Core ◽  
Organic Salt ◽  
Spectroscopic Techniques ◽  
Sonogashira Coupling ◽  
Scanning Calorimetry ◽  
Organic Salts ◽  
Crystal Property ◽  
Liquid Crystal Property ◽  
Temperature Maps

Liquid crystals are unique in their properties and use and has an essential role in the area of technological applications such as electrical, optical, displayers, temperature maps, and switching materials. This study aimed to synthesize hexaethynylbenzene derivatives starting from 1,3,5-trichlorobenzene benzene as a central core substituted with three aromatic ring and three armed of 2-chloro-4,6-bis((3,7-dimethyloct-6-en-1-yl) oxy)-1,3,5-triazine. These molecules are formed by the covalent linking of three arms symmetrically to a central core which may be attached to the central core through flexible, semi-flexible or rigid linkers. The substitution occured at the acetylenic periphery on the central benzene ring and was achieved efficiently by Sonogashira coupling. The six-armed compounds based on the benzene core was mixed with the complementary 4-dodecyloxybenzoic acid 1:1 ratio, which already possessed liquid crystal property to increase the formation of these resulting in an organic salt. The obtained organic salts were investigated for their liquid crystal behaviour by polarizing optical microscopy (POM) and differential scanning calorimetry (DSC). All the intermediate and final compounds were confirmed by spectroscopic techniques (1H NMR, 13C NMR, and mass spectrometry).

scholarly journals Six-armed Structures Based on Benzene Ring, Synthesis and Characterization Via Sonogashira Coupling

2020 ◽  
Vol 20 (3) ◽  
pp. 705
Author(s):  
Mohammed Hadi Ali Al-Jumaili ◽  
Ahmed Solaiman Hamed ◽  
Nihat Akkurt ◽  
Lokman Torun
Keyword(s):  
Differential Scanning Calorimetry ◽  
Benzene Ring ◽  
Organic Salt ◽  
Synthesis And Characterization ◽  
Spectroscopic Methods ◽  
Sonogashira Coupling ◽  
Scanning Calorimetry ◽  
Organic Salts ◽  
Crystal Property ◽  
Liquid Crystal Property

A new six-armed compounds consist of benzene ring as a central core substituted with aromatic ring and three rod-like armed of 2-chloro-4,6-bis(dodecyloxy)-1,3,5-triazine as the peripheral arms unit which obtained by sequential nucleophilic substitution of chlorine atoms in cyanuric chloride. The substitution took place at the acetylenic periphery on the central benzene ring by Sonogashira coupling. Equimolar mixtures of the six-armed compounds based on the benzene core with the complementary 4-dodecyloxybenzoic acid, which already possessed liquid crystal property, resulted in an organic salt. The organic salts and structures were investigated by differential scanning calorimetry (DSC), and confirmed by spectroscopic methods (1H-NMR, 13C-NMR and Mass spectroscopy)

Synthesis and Liquid Crystal Property of New Fluoro Coumarin Carboxylates

2013 ◽  
Vol 570 (1) ◽  
pp. 20-35 ◽  
Author(s):  
Kittappa M. Mahadevan ◽  
Hosanagara N. Harishkumar ◽  
Jagadeesh N. Masagalli ◽  
Hosapalya T. Srinivasa
Keyword(s):  
Liquid Crystal ◽  
Crystal Property ◽  
Liquid Crystal Property

Experimental and DFT Studies on Well-Defined Odd-Even Effect in Organic Liquid Crystal Tetramers Incorporating Two Chiral Centers

2021 ◽  
Vol 14 ◽  
Author(s):  
Mursyida Abdul Rahim ◽  
Guan-Yeow Yeap ◽  
Wai Kit Tang ◽  
Chi-Kit Siu
Keyword(s):  
Phase Transition ◽  
Liquid Crystal ◽  
Computational Study ◽  
Organic Liquid ◽  
Spectroscopic Techniques ◽  
Texture Characteristic ◽  
Scanning Calorimetry ◽  
Spacer Length ◽  
Chiral Nematic ◽  
Phase Transition Temperatures

: A new series of organic liquid crystal tetramers containing two symmetrical mesogenic units of 4-(4’-phenoxylimino)methyl)phenol joined by methylene –(CH2)m- spacer wherein m varied from 5 to 10 has been synthesized. The length for each of the mesogenic units was extended further via connection with two chiral entities of (S)-2- methylbutyl-4-(4’-bromobutyloxyphenyl)benzoate situated at both terminal ends. The structures of these tetramers were elucidated using elemental analysis and spectroscopic techniques (FT-IR and 1H-NMR) while the texture and the phase transition temperatures were studied using polarizing optical microscopy (POM) along with differential scanning calorimetry (DSC). All the homologues in this series are enantiotropic mesogens exhibiting oily streak texture or fan shaped texture characteristic of chiral nematic phase. The odd-even effect can be observed upon increasing the methylene spacer length. The structure-properties connectivity has demonstrated that the phase transition temperature for tetramers with even- numbered methylene units in the spacer is relatively higher in comparison with the odd- numbered members. The computational study via constraint molecular dynamics performed at the DFTB level of theory has further supported that more energy is required for the even- numbered tetramer than the odd-numbered member to undergo the structural transition from folded to extended geometries.

Self-suspended polypyrrole with liquid crystal property

2018 ◽  
Vol 25 (2) ◽  
Author(s):  
Jiahui He ◽  
Haian Xie ◽  
Jie Hong ◽  
Zhaodongfang Gao ◽  
Zhikang Liu ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Crystal Property ◽  
Liquid Crystal Property

A low-dimensional molecular spin system with two steps of magnetic transitions and liquid crystal property

2011 ◽  
Vol 40 (14) ◽  
pp. 3622 ◽  
Author(s):  
Hai-Bao Duan ◽  
Xiao-Ming Ren ◽  
Lin-Jiang Shen ◽  
Wan-Qin Jin ◽  
Qing-Jin Meng ◽  
...  
Keyword(s):  
Liquid Crystal ◽  
Spin System ◽  
Magnetic Transitions ◽  
Crystal Property ◽  
Liquid Crystal Property ◽  
Molecular Spin ◽  
Low Dimensional

Ethylene Oxide Functionalized Imidazolium Salts: Liquid Crystal Property, Ion Conductivity and Antibacterial Activity

2013 ◽  
Vol 5 (3) ◽  
pp. 216-226 ◽  
Author(s):  
Rondla Rohini ◽  
Yi Ting Chen ◽  
Roy T. W. Huang ◽  
Guang Huey Lin ◽  
Ivan J. B. Lin
Keyword(s):  
Antibacterial Activity ◽  
Liquid Crystal ◽  
Ethylene Oxide ◽  
Ion Conductivity ◽  
Imidazolium Salts ◽  
Crystal Property ◽  
Liquid Crystal Property

scholarly journals Synthesis and Characterization of Lateral Fluoro-substituents Liquid Crystals

2021 ◽  
Vol 11 (5) ◽  
pp. 12495-12505
Keyword(s):  
Molecular Structure ◽  
Differential Scanning Calorimetry ◽  
Liquid Crystal ◽  
Linkage Group ◽  
Optical Microscope ◽  
Synthesis And Characterization ◽  
Spectroscopic Techniques ◽  
Dielectric Measurements ◽  
Scanning Calorimetry

Lateral difluoro substituent liquid crystal based on a three-aromatic core has been synthesized. It has been designed to correlate the molecular structure and mesomorphism with reference to the difluoro substituent and -COO- linkage group. This compound was characterized by elementary analyses and spectroscopic techniques such as FTIR and 1H-NMR. The synthesis compound's mesomorphic behavior was studied by polarizing optical microscope, differential scanning calorimetry, and dielectric measurements. The recent investigation reveals only SmB phase.

scholarly journals Systematic synthesis of a 6-component organic-salt alloy of naftopidil, and pentanary, quaternary and ternary multicomponent crystals

IUCrJ ◽  
2018 ◽  
Vol 5 (6) ◽  
pp. 816-822 ◽  
Author(s):  
Rambabu Dandela ◽  
Srinu Tothadi ◽  
Udaya Kiran Marelli ◽  
Ashwini Nangia
Keyword(s):  
Single Crystal ◽  
Carboxylic Acids ◽  
Active Pharmaceutical Ingredient ◽  
Organic Salt ◽  
X Ray Diffraction ◽  
Dihydroxybenzoic Acid ◽  
Scanning Calorimetry ◽  
Organic Salts ◽  
X Ray ◽  
Substituted Benzoic Acids

The single-crystal X-ray structure of a 6-component organic-salt alloy (hexanary) of naftopidil (1) (an active pharmaceutical ingredient) with benzoic acid (2) and four different hydroxy-substituted benzoic acids, i.e. salicylic acid (3), 2,3-dihydroxybenzoic acid (4), 2,4-dihydroxybenzoic acid (5) and 2,6-dihydroxybenzoic acid (6), is reported. The hexanary assembly originates from the observation that the binary salts of naftopidil with the above acids are isostructural. In addition to the 6-component solid, we also describe five 5-component, ten 4-component, and ten 3-component organic-salt alloys of naftopidil (1) with carboxylic acids (2)–(6). These alloys were obtained from different combinations of the acids with the drug. The synthetic design of the multicomponent organic alloys is based on the rationale of geometrical factors (shape and size) and chemical interactions (hydrogen bonds). The common supramolecular synthon in all these crystal structures was the cyclic N+—H...O− and O—H...O hydrogen-bonded motif of R_2^2(9) graph set between the 2-hydroxyammonium group of naftopidil and the carboxylate anion. This ionic synthon is strong and robust, directing the isostructural assembly of naftopidil with up to five different carboxylic acids in the crystal structure together with the lower-level multicomponent adducts. Solution crystallization by slow evaporation provided the multicomponent organic salts and alloys which were characterized by a combination of single-crystal X-ray diffraction, powder X-ray diffraction, NMR and differential scanning calorimetry techniques.

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