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

The Influence of the Position of Oxygen on the Phase Behaviour of Benzylidene Anilines

2003 ◽  
Vol 58 (12) ◽  
pp. 735-737 ◽  
Author(s):  
N. Ajeetha ◽  
V. G. K. M. Pisipati
Keyword(s):  
Differential Scanning Calorimetry ◽  
Phase Behaviour ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Rigid Core ◽  
Thermal Microscopy ◽  
Phase Variants

Synthesis and Characterization of N (p-n-alkyl benzylidene)-p-n-alkoxy anilines (n.Om), N (p-nalkoxy benzylidene)-p-n-alkoxy anilines (nO.Om) and N (p-n-alkyl benzylidene)-p-n-alkyl anilines (n.m), where n = m = either 4 or 5, has been carried out using thermal microscopy (TM) and differential scanning calorimetry (DSC). The results are discussed in the light of other experimental observations on N (p-n-alkoxy benzylidene)-p-n alkyl anilines (nO.m). It has been observed that the position of oxygen on either side of the rigid core of the benzylidene moiety plays an important role in the manifestation of different phase variants.

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.

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 Liquid Crystalline Compounds in the Thiophene Series, Part 6+ Synthesis and Characterization of Azomethines and Vinylenes with Two Mesogenic Groups and Different Alkylene Spacer Lengths

1993 ◽  
Vol 48 (6) ◽  
pp. 826-843 ◽  
Author(s):  
Gerhard Koßmehl ◽  
Frank Dirk Hoppe ◽  
Barbara Hirsch
Keyword(s):  
Aromatic Amines ◽  
Liquid Crystalline ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
Polarizing Microscopy ◽  
Alkyl Chains ◽  
Liquid Crystalline Phases ◽  
Smectic Mesophase ◽  
Methylene Groups

Compounds which have two mesogenic groups with and without terminal alkyl chains containing thiophene systems, were prepared from α.ω-bis(5-formyl-2-thienyl)alkanes (3a-3n) and various aromatic amines or 2-fluorenyl-Wittig-salt (10). The liquid crystalline properties of these compounds were characterized by differential scanning calorimetry (DSC) and polarizing microscopy. Only the series of α.ω-bis{5-[N-(4′-butyloxybiphenyl-4-yl)imino]formyl-2-thienyl}alkanes (7a-71) showed enantiotropic smectic and nematic mesophases. The series of E,E-α.ω-bis[5-(2-fluorenylvinyl)-2-thienyl]alkanes (8a-81) showed enantiotropic nematic mesophases for the compounds with 4 and 6 methylene groups, monotropic nematic mesophases for the compounds with 7—12 methylene groups and no liquid crystalline phases for compounds with 3, 5, 16 methylene groups in the connecting alkylene chain. In contrast to the compounds 8a-81, E-l-(5-butyl-2-thienyl)-2-(2-fluorenyl)ethylene has a smectic mesophase.

Synthesis and Characterization of Triethanolamine Borate

2013 ◽  
Vol 709 ◽  
pp. 28-31
Author(s):  
Cheng Xue Wang ◽  
Tian Tian Liang ◽  
Chun Qiao Wei
Keyword(s):  
Mass Spectrometry ◽  
Differential Scanning Calorimetry ◽  
Synthesis And Characterization ◽  
Spectroscopy Analysis ◽  
Scanning Calorimetry ◽  
Reaction Conditions ◽  
Different Types ◽  
Ft Ir ◽  
Ft Ir Spectroscopy

Starting with boric acid and triethanolamine , the effect of the different types of the water-carrying agent on the yield was invested, and influences of dosage of water-carrying agent ,the mole ratio of reactants, reaction time on yield were discussed, the optimized reaction conditions were confirmed. The structure of the product was described by Fourier transform-infrared (FT-IR) spectroscopy, NMR Spectroscopy analysis, mass spectrometry (MS) and thermodynamic properties was analyzed by differential scanning calorimetry (DSC) and thermogravimetry (TG).

Characterization, liquid crystallinity and spin-coated films of some metalated 1,4,8,11,15,18,22,25-octaalkyl tetrabenzo [b,g,l,q][5,10,15]triazaporphyrin derivatives

2011 ◽  
Vol 15 (09n10) ◽  
pp. 890-897 ◽  
Author(s):  
Andrew N. Cammidge ◽  
Isabelle Chambrier ◽  
Michael J. Cook ◽  
Ernie H.G. Langner ◽  
Muhibur Rahman ◽  
...  
Keyword(s):  
Differential Scanning Calorimetry ◽  
Optical Microscopy ◽  
Alkyl Chain ◽  
Bulk Material ◽  
Polarized Light ◽  
Scanning Calorimetry ◽  
Liquid Crystallinity ◽  
Derivatives Of ◽  
Deposited Films

The preparation and characterization of a number of metalated derivatives of 1,4,8,11,15,18,22,25-octahexyl and 1,4,8,11,15,18,22,25-octadecyl tetrabenzotriazaporphyrins (TBTAPs) are reported. The mesophase behavior of the compounds has been characterized by differential scanning calorimetry (DSC) and by polarized light optical microscopy. Mesophase behavior is compared with data for the corresponding phthalocyanine derivatives reported earlier. The temperature range of the mesophase(s) exhibited by the title compounds is generally broader than those of their phthalocyanine analogs. UV-vis data for examples of the TBTAP compounds as spin-coated films reveal differences in the type of molecular packing in the as-deposited films that is largely dependent upon the length of the alkyl chain substituents. On heating, the films undergo molecular reorganizations at temperatures corresponding to the mesophase transitions of bulk material observed by DSC.

Synthesis and characterization of 4-chloromethylstyrene polymers containing bulky organosilicon groups

e-Polymers ◽  
2004 ◽  
Vol 4 (1) ◽  
Author(s):  
Kazem Dindar Safa ◽  
Mirzaagha Babazadeh
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Gel Permeation Chromatography ◽  
Synthesis And Characterization ◽  
Scanning Calorimetry ◽  
H Nmr ◽  
Gel Permeation ◽  
Covalently Linked ◽  
C Nmr

Abstract The homopolymer of 4-chloromethylstyrene and its copolymers with styrene (in 1:3 and 1:1 mole ratio) were synthesized by bulk and solution freeradical polymerisations, respectively, at 70±1°C using α,α'-azoisobutyronitrile as an initiator. Highly sterically hindered tris(trimethylsilyl)methyl (Tsi) substituents were then covalently linked to the obtained homopolymer and copolymers. The polymers were characterized by IR, 1H NMR and 13C NMR, differential scanning calorimetry (DSC) and gel permeation chromatography. DSC showed that incorporation of Tsi substituents in the side chains of homopolymer and copolymers increases the rigidity of the polymers and, subsequently, their glass transition temperature.

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