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)

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 Synthesis, Mesomorphism and the Optical Properties of Alkyl-deuterated Nematogenic 4-[(2,6-difluorophenyl)ethynyl]biphenyls

Materials ◽  
2021 ◽  
Vol 14 (16) ◽  
pp. 4653
Author(s):  
Jakub Herman ◽  
Piotr Harmata ◽  
Michał Czerwiński ◽  
Olga Strzeżysz ◽  
Marta Pytlarczyk ◽  
...  
Keyword(s):  
Molecular Structure ◽  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Optical Properties ◽  
Liquid Crystalline ◽  
Near Infrared ◽  
Synthesis And Characterization ◽  
Molecular Approach ◽  
Scanning Calorimetry

The synthesis and characterization of new deuterated liquid crystal (LC) compounds based on phenyl tolane core is described in this paper. The work presents an alternative molecular approach to the conventional LC design. Correlations between molecular structure and mesomorphic and optical properties for compounds which are alkyl-hydrogen terminated and alkyl-deuterium, have been drawn. The compounds are characterized by mass spectrometry (electron ionization) analysis and infrared spectroscopy. They show enantiotropic nematic behavior in a broad temperature range, confirmed by a polarizing thermomicroscopy and differential scanning calorimetry. Detailed synthetic procedures are attached. Synthesized compounds show a significantly reduced absorption in the near-infrared (NIR) and medium-wavelength infrared (MWIR) radiation range, and stand as promising components of medium to highly birefringent liquid crystalline mixtures.

scholarly journals Synthesis and characterization of solid 2-methoxycinnamylidenepyruvic acid

2008 ◽  
Vol 33 (4) ◽  
pp. 61-68 ◽  
Author(s):  
C. T. de Carvalho ◽  
A. B. Siqueira ◽  
E. Y. Ionashiro ◽  
M. Pivatto ◽  
M. Ionashiro
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Magnetic Resonance ◽  
Differential Scanning Calorimetry ◽  
Infrared Spectroscopy ◽  
Magnetic Resonance ◽  
Molecular Geometry ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Purity Determination

The 2-methoxycinnamylidenepyruvic acid (2-MeO-HCP) was synthesized and characterized for nuclear magnetic resonance (¹H and 13C NMR), mass spectrometry (MS), Infrared spectroscopy (FTIR) and differential scanning calorimetry (DSC). The application of DSC for purity determination is well documented in literature and is used in the analysis of pure organic compounds. The molecular geometry and vibrational frequencies of 2-MeO-HCP have been calculated.

Synthesis and Characterization of Stilbene Derivatives for Possible Incorporation as Smart Additives in Polymers Used as Packaging Films.

1997 ◽  
Vol 50 (4) ◽  
pp. 425 ◽  
Author(s):  
Gary M. Day ◽  
Owen T. Howell ◽  
Michael R. Metzler ◽  
Paul D. Woodgate
Keyword(s):  
Differential Scanning Calorimetry ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Packaging Films ◽  
Multiple Phase ◽  
Liquid Crystalline Phases ◽  
Crystal Properties ◽  
Stilbene Derivatives

Several series of stilbene derivatives for possible use as smart additives in polymers used as packaging films have been prepared and characterized. Differential scanning calorimetry was performed on some of the stilbenes in order to determine any liquid crystal properties. Those compounds which had multiple phase transitions were also shown to have two liquid crystalline phases according to optical microscopy.

scholarly journals Organic Salts of Pharmaceutical Impurity p-Aminophenol

Molecules ◽  
2020 ◽  
Vol 25 (8) ◽  
pp. 1910
Author(s):  
U. B. Rao Khandavilli ◽  
Leila Keshavarz ◽  
Eliška Skořepová ◽  
René R. E. Steendam ◽  
Patrick J. Frawley
Keyword(s):  
Differential Scanning Calorimetry ◽  
Salicylic Acid ◽  
Infrared Spectroscopy ◽  
Efficacy And Safety ◽  
Salt Formation ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Organic Salts ◽  
X Ray ◽  
Dark Color

The presence of impurities can drastically affect the efficacy and safety of pharmaceutical entities. p-Aminophenol (PAP) is one of the main impurities of paracetamol (PA) that can potentially show toxic effects such as maternal toxicity and nephrotoxicity. The removal of PAP from PA is challenging and difficult to achieve through regular crystallization approaches. In this regard, we report four new salts of PAP with salicylic acid (SA), oxalic acid (OX), l-tartaric acid (TA), and (1S)-(+)-10-camphorsulfonic acid (CSA). All the PAP salts were analyzed using single-crystal X-ray diffraction, powder X-ray diffraction, infrared spectroscopy, differential scanning calorimetry, and thermogravimetric analysis. The presence of minute amounts of PAP in paracetamol solids gives a dark color to the product that was difficult to remove through crystallization. In our study, we found that the addition of small quantities of the aforementioned acids helps to remove PAP from PA during the filtration and washings. This shows that salt formation could be used to efficiently remove challenging impurities.

Synthesis and Characterization of Smectic Polymorphism in Higher Homologues of N-(p-n-Alkoxybenzylidene)-p-n-(Alkylanilines)

2003 ◽  
Vol 58 (2-3) ◽  
pp. 103-108 ◽  
Author(s):  
Venkata G. K. M. Pisipati ◽  
A. K. George ◽  
Ch. Srinivasu ◽  
P. N. Murty
Keyword(s):  
Differential Scanning Calorimetry ◽  
Alkyl Chain ◽  
Synthesis And Characterization ◽  
Transition Temperatures ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Phase Variants ◽  
Miscibility Studies

Higher homologues of N-(p-n-alkoxybenzylidene)-p-n-alkylanilines (nO.m) compounds with n = 15 and 18 and m = 4 to 10, 12, 14, and 16 have been synthesized and the smectic polymesomorphism is studied. The transition temperatures were obtained both from thermal polarizing microscopy and differential scanning calorimetry. The compounds exhibit a smectic-F phase from the isotropic melt, their amount increasing with the number of the alkoxy chain. This implies that with the alkoxy chain number the manifestation of smectic-F occurs with shorter alkyl chain. The phase variants were confirmed with miscibility studies

Synthesis and characterization of novel tetrakis (3-hydroxypropylmercapto)-substituted phthalocyanines

2013 ◽  
Vol 17 (06n07) ◽  
pp. 573-586 ◽  
Author(s):  
Çiğdem Yağcı ◽  
Ahmet Bilgin
Keyword(s):  
Differential Scanning Calorimetry ◽  
Thermal Properties ◽  
Synthesis And Characterization ◽  
The Novel ◽  
Scanning Calorimetry ◽  
Metal Free ◽  
Visible Spectra ◽  
Ft Ir ◽  
Aromatic Nitro

A phthalonitrile precursor 4-(3-hydroxypropylmercapto)phthalonitrile (3) was synthesized via a base-catalyzed nucleophilic aromatic nitro displacement of 4-nitrophthalonitrile with the 3-mercapto-1-propanol. A novel tetrasubstituted metal-free phthalocyanine (4) ( M = 2 H ) and its metal complexes (5–8) ( M = Zn , Ni , Cu and Co ) bearing 3-hydroxypropylmercapto moieties were prepared by the cyclotetramerization reaction of (3) with the appropriate materials. The visible spectra of the zinc(II) phthalocyanine (5) was recorded with different concentrations and different ions as Ag +, Hg 2+ and Pb 2+ in DMF and also with different solvents as dimethylformamide and pyridine. Fluorescence spectrum of the compound (5) was also studied. Temperature and frequency dependence of AC conductivity for (4–8) was investigated in air and under vacuum and were found to be ~10-8–10-5 S.m-1. Thermal properties of the phthalocyanines were examined by differential scanning calorimetry. All the novel compounds have been characterized by elemental analysis, UV-vis, FT-IR, NMR and MS spectral data and DSC techniques.

Synthesis and Characterization of Segmented Copolymers of a Methylated Polyamide and a Thermotropic Liquid Crystalline Polyester

1989 ◽  
Vol 171 ◽  
Author(s):  
Gregory T. Pawlikowski ◽  
R. A. Weiss ◽  
S. J. Huang
Keyword(s):  
Differential Scanning Calorimetry ◽  
Composite Material ◽  
Block Copolymer ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Segmented Copolymers ◽  
Liquid Crystalline Polyester ◽  
Solution Polycondensation

ABSTRACTA block copolymer consisting of liquid crystalline polyester segments and methylated polyamide segments has been synthesized. Solution polycondensation of acid chloride end-capped poly(terephthaloyl phenylhydroquinone) (LCP portion) with an amine terminated poly(N,N'-dimethylethylene sebacamide) was utilized to prepare the block copolymer. Characterization by differential scanning calorimetry, infrared spectroscopy, thermogravimetric analysis, optical microscopy and elemental analysis has been performed to verify the existence of the block copolymer that may have potential as a molecular composite material or self-reinforcing thermoplastic.

scholarly journals Organic Salts of p-Coumaric Acid and Trans-Ferulic Acid with Aminopicolines

Molecules ◽  
2020 ◽  
Vol 25 (3) ◽  
pp. 751
Author(s):  
Sosthene Nyomba Kamanda ◽  
Ayesha Jacobs
Keyword(s):  
Crystal Structure ◽  
Thermal Stability ◽  
Differential Scanning Calorimetry ◽  
Fourier Transform ◽  
Ferulic Acid ◽  
Hirshfeld Surface ◽  
Coumaric Acid ◽  
Scanning Calorimetry ◽  
Organic Salts ◽  
Thermal Stability Of

p-Coumaric acid (pCA) and trans-ferulic acid (TFA) were co-crystallised with 2-amino-4-picoline (2A4MP) and 2-amino-6-picoline (2A6MP) producing organic salts of (pCA−)(2A4MP+) (1), (pCA̶ )(2A6MP+) (2) and (TFA̶ )(2A4MP+)·( 3 2 H2O) (3). For salt 3, water was included in the crystal structure fulfilling a bridging role. pCA formed a 1:1 salt with 2A4MP (Z’ = 1) and a 4:4 salt with 2A6MP (Z’ = 4). The thermal stability of the salts was determined using differential scanning calorimetry (DSC). Salt 2 had the highest thermal stability followed by salt 1 and salt 3. The salts were also characterised using Fourier transform infrared (FTIR) spectroscopy. Hirshfeld surface analysis was used to study the different intermolecular interactions in the three salts. Solvent-assisted grinding was also investigated in attempts to reproduce the salts.

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