Semirigid Homo- and Copoly(Imide-Carbonate)s Based on 3,4,3″,4″ -p-Terphenyltetracarboxdiimide

1998 ◽  
Vol 10 (1) ◽  
pp. 155-162 ◽  
Author(s):  
Moriyuki Sato ◽  
Seiji Ujiie ◽  
Yuji Tada ◽  
Takashi Kato
Keyword(s):  
Nematic Phase ◽  
Liquid Crystalline ◽  
Molar Ratio ◽  
Temperature Dependent ◽  
X Ray ◽  
Melt Polycondensation ◽  
Elemental Analyses ◽  
Temperature Ranges ◽  
Ft Ir ◽  
C Nmr

Novel thermotropic liquid crystalline (LC) semirigid homo- and copoly(imidecarbonate)s composed of a 3, 4, 3″, 4″- p-terphenyltetracarboxdiimide ring and aliphatic chains were prepared by melt polycondensation of a dihexanol derivative of 3, 4, 3″, 4″- p-terphenyltetracarboxdiimide and/or a dioxydihexanol of biphenyl taken in a definite molar ratio with hexamethylene diphenyl dicarbonate in the presence of zinc acetate, and their thermal and mesogenic properties were evaluated. The assigned structures of polymers were characterized by FT-IR and 13C NMR spectroscopy, and elemental analyses. DSC and TG-DTA measurements, polarizing microscope observations of textures and temperature-dependent x-ray analyses demonstrated that the polymers have wider LC temperature ranges (nematic phase) than analogous semirigid poly(ester-imide)s and are thermally stable up to 300 °C in air.

Synthesis and Properties of Thermotropic Liquid Crystalline Polyesters with Flexible Polymethylene Spacer

2010 ◽  
Vol 428-429 ◽  
pp. 126-131
Author(s):  
Wei Zhong Lu ◽  
Chun Wei ◽  
Qui Shan Gao
Keyword(s):  
Optical Microscopy ◽  
Liquid Crystalline ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Structure Morphology ◽  
Temperature Ranges ◽  
Ft Ir ◽  
Diffraction Peaks ◽  
Ubbelohde Viscometer

Polymethylene bis(p-hydroxybenzoates) were prepared from methyl p-hydroxybenzoate and different diols by melted transesterification reaction. Three liquid crystalline polyesters were synthesized from terephthaloyl dichloride and polymethylene bis(p-hydroxybenzoates). Its structure, morphology and properties were characterized by Ubbelohde viscometer, Fourier transform infrared spectroscopy (FT-IR), Differential scanning calorimetry (DSC), polarized optical microscopy (POM) with a hot stage, and wide-angle X-ray diffraction (WAXD). Results indicated that the intrinsic viscosities were between 0.088 and 0.210 dL/g. Optical microscopy showed that the TLCP has a highly threaded liquid crystalline texture and a high birefringent schlieren texture character of nematic phase and has wider mesophase temperature ranges for all polyesters. DSC analysis were found that the melting point (Tm), isotropic temperature (Ti) of TLCPs decreased and the temperature range of the liquid crystalline phase became wider with increased number of methylene spacers in the polyester. The WAXD results showed that TLCPs owned two strong diffraction peaks at 2θ near 19° and 23°.

Darstellung und Kristallstrukturbestimmung von 1,2-Di-t-butyl-1,2-diiodo- diarsan (t-C4H9AsI)2 und Synthese von 1,2,3,4-Tetrakis(t-butyl)tetraarsetan (t-C4H9As)4 über selektive Reduktion von t-Butylarsendiiodid t-C4H9AsI2 Synthesis and Crystal Structure of 1,2-Di-t-butyl-1,2-diiododiarsane (t-C4H9AsI)2 and Synthesis of 1,2,3,4-Tetrakis(t-butyl)tetraarsetane (t-C4H9As)4 via Selective Reduction of t-Butylarsenic Diiodide t-C4H9AsI2

1997 ◽  
Vol 52 (7) ◽  
pp. 790-794 ◽  
Author(s):  
Klaus Megges ◽  
Evgeni V. Avtomonov ◽  
Jörg Lorberth
Keyword(s):  
Crystal Structure ◽  
Low Temperatures ◽  
Selective Reduction ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Synthesis And Crystal Structure ◽  
X Ray ◽  
Elemental Analyses ◽  
High Yields ◽  
C Nmr

Abstract 1,2,3,4-Tetrakis(t-butyl)tetraarsetane (t-C4H9As)4(4) has been synthesized by reduction of t-butylarsenic (III) diiodide (1) with equivalent quantities of either Mg, Ca, Zn, Li, or CoCp2 in THF at low temperatures in high yields. Treatment of 1 with CoCp2 in a molar ratio 1:1 in n-pentane at -78 °C leads to the formation of 1,2-di-t-butyl-1,2-diiododiarsine (2) (t-C4H9AsI)2 in 69 % yield. The products have been characterized by spectroscopic methods (H, 13C-NMR, EI-MS) and elemental analyses. The crystal structure of 2 has been determined by X-ray diffraction methods.

Thermal Properties of a Liquid-Crystalline Polyurethanes Containing Biphenyl Mesogen

2006 ◽  
Vol 321-323 ◽  
pp. 1385-1388
Author(s):  
Jong Baek Lee ◽  
Kwang Hyun Lee ◽  
Byung Chul Kang ◽  
Byung Won Kang ◽  
Sang Ll Lee ◽  
...  
Keyword(s):  
Nematic Phase ◽  
Liquid Crystalline ◽  
Main Chain ◽  
Spectroscopic Methods ◽  
Liquid Crystallinity ◽  
Cooling Stage ◽  
Temperature Ranges ◽  
New Type ◽  
Ft Ir ◽  
Tolylene Diisocyanate

A new type of thermotropic main-chain liquid crystalline polyurethanes containing biphenyl units was synthesized by polyaddition reaction of diisocyanates such as 2,6-tolylene diisocyanate, 2,5-tolylene diisocyanate, 2,4-tolylene diisocyanate, and 1,4-phenylene diisocyanate, with 4,4′-Bis(11-hydroxyundeyloxy)biphenyl (BP11). The structure of the monomer and the corresponding polymers were confirmed FT-IR and 1H NMR spectroscopic methods. BP11 exhibited a smectic type mesophase, however, nematic phase was found for all synthesized liquid crystalline polyurethanes except for 1,4-phenylene diisocyanate/BP11 based polyurethane. For example, polyurethane 2,5-TDI/BP11 exhibited monotropic liquid crystallinity in the temperature ranges from 173 to 156 °C on the cooling stage.

scholarly journals Crystal structure of (E)-4-hydroxy-6-methyl-3-{1-[2-(4-nitrophenyl)hydrazinylidene]ethyl}-2H-pyran-2-one

2017 ◽  
Vol 73 (2) ◽  
pp. 223-226 ◽  
Author(s):  
Kirandeep ◽  
Ahmad Husain ◽  
Pooja Negi ◽  
Girijesh Kumar ◽  
Ramesh Kataria
Keyword(s):  
Single Crystal ◽  
Crystal Packing ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
X Ray ◽  
H Nmr ◽  
Dehydroacetic Acid ◽  
Compound C ◽  
Ft Ir ◽  
C Nmr

The title compound, C14H13N3O5(HMNP), was synthesized by the simple condensation ofp-nitrophenylhydrazine with dehydroacetic acid (DHA) in a 1:1 molar ratio in ethanol. HMNP has been characterized by using FT–IR,1H and13C NMR and UV–Vis spectroscopic and single-crystal X-ray diffraction techniques. The crystal packing reveals strong hydrogen bonds between the NH group and the carbonyl O atom of dihydropyranone moiety, forming chains along [101]. The thermal stability of the synthesized compound was confirmed by thermogravimetric analysis and it was found to be stable up to 513 K. The UV–Vis spectrum shows the presence of a strong band at λmax394 nm.1H NMR and single-crystal X-ray analyses confirmed the presence of theenolform of the ligand and dominance over theketoform. The crystal studied was a non-merohedral twin with the refined ratio of the twin components being 0.3720 (19):0.6280 (19).

Liquid crystalline polyureas with oligo(ethylene glycol) sequences

e-Polymers ◽  
2010 ◽  
Vol 10 (1) ◽  
Author(s):  
Shahram Mehdipour-Ataei ◽  
Leila Akbarian-Feizi
Keyword(s):  
Liquid Crystalline ◽  
Spectroscopic Method ◽  
Polymerization Reaction ◽  
X Ray Diffraction ◽  
Subsequent Reaction ◽  
Scanning Calorimetry ◽  
Polar Solvents ◽  
X Ray ◽  
H Nmr ◽  
Ft Ir

AbstractA diamine monomer containing ester, amide and ether functional groups was prepared and its polymerization reaction with different diisocyanates to give main chain poly(ester amide ether urea)s was investigated. The monomer was synthesized via reaction of terephthaloyl chloride with 4-hydroxybenzoic acid and subsequent reaction of the resulted diacid with 1,8-diamino-3,6-dioxaoctane. The polymers were characterized by FT-IR and 1H-NMR spectroscopic method and elemental analysis. The resulting polymers exhibited excellent solubility in polar solvents. Crystallinity of the resulted polymers was evaluated by wide-angle X-ray diffraction (WXRD) method, and they exhibited semi-crystalline patterns. The glass transition temperatures (Tg) of the polymers determined by differential scanning calorimetry (DSC) and dynamic mechanical thermal analysis (DMTA) were in the range of 88-112 °C. The temperatures for 10% weight loss (T10) from their thermogravimetric analysis (TGA) curves were found to be in the range of 297-312 °C in air. Also the prepared polyureas showed liquid crystalline character.

Thermotropic behavior of sodium cholesteryl carbonate

2009 ◽  
Vol 24 (1) ◽  
pp. 156-163 ◽  
Author(s):  
Rabkwan Chuealee ◽  
Timothy S. Wiedmann ◽  
Teerapol Srichana
Keyword(s):  
Phase Behavior ◽  
Chemical Structure ◽  
Liquid Crystalline ◽  
Polarized Light ◽  
Wave Number ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
X Ray Scattering ◽  
C Nmr

Sodium cholesteryl carbonate ester (SCC) was synthesized, and its phase behavior was studied. The chemical structure was assessed by solid-state infrared spectroscopy based on vibration analysis. The wave number at 1705 and 1276 cm−1 corresponds to a carbonyl carbonate and O–C–O stretching of SCC, respectively. Molecular structure of SCC was further investigated with 1H and 13C NMR spectroscopy. The chemical shift, for the carbonyl carbonate resonance appeared at 155.5 ppm. A molecular mass of SCC was at m/z of 452. Differential scanning calorimetry (DSC), video-enhanced microscopy (VEM) together with polarized light microscopy, and small-angle x-ray scattering (SAXS) were used to characterize the phase behavior as a function of temperature of SCC. Liquid crystalline phase was formed with SCC. Based on the thermal properties and x-ray diffraction, it appears that SCC forms a structure analogous to the type II monolayer structure observed with cholesterol esters.

scholarly journals Simple Methylcadmium Alkoxides

2007 ◽  
Vol 62 (10) ◽  
pp. 1339-1342 ◽  
Author(s):  
Surajit Jana ◽  
Tania Pape ◽  
Norbert W. Mitzel
Keyword(s):  
Mass Spectrometry ◽  
Solid State ◽  
Molecular Formula ◽  
Equimolar Ratio ◽  
X Ray ◽  
X Ray Crystallography ◽  
Elemental Analyses ◽  
Solid State Structures ◽  
Structural Aspects ◽  
C Nmr

The reaction of dimethylcadmium with alcohols R-OH in equimolar ratio leads to the formation of tetrameric methylcadmium alkoxides with molecular formula [(MeCd)4 (OR)4] [R = Me (1), Et (2) and iPr (3)]. These compounds have been characterised by 1H, 13C NMR and IR spectroscopy, by mass spectrometry, elemental analyses and by X-ray crystallography (for 2 and 3). The solid state structures show distorted cubane-type aggregates with Cd4O4 cores. The structural aspects and the spectroscopic characterisations of these compounds are discussed.

Synthesis, characterization and fluorescence properties of mixed-ligand cobalt(II), copper(II), zinc(II) and cadmium(II) coordination polymer complexes involving 4,4’-bipyridine and 2,5-pyridinedicarboxylic acid

2021 ◽  
Vol 25 (7) ◽  
pp. 147-156
Author(s):  
Ajeet Kumar Maurya ◽  
Ashish Kumar Srivastava ◽  
Krishna Srivastava ◽  
Jagdish Prasad
Keyword(s):  
Coordination Polymer ◽  
Thermal Analyses ◽  
Mixed Ligand ◽  
Molar Ratio ◽  
X Ray Diffraction ◽  
Polymer Complexes ◽  
Pyridinedicarboxylic Acid ◽  
Elemental Analyses ◽  
Ligand Coordination ◽  
Ft Ir

Four mixed-ligand coordination polymer complexes of cobalt(II), copper(II), zinc(II), and cadmium(II) were synthesized by solvothermal method in 1:1:1 metal: 4,4’-bipy: 2,5-pdc molar ratio using 2,5-pyridinedicarboxylic acid (2,5-pdc) and 4,4’-bipyridine (4,4’-bipy). These complexes are viz; 1. [Co2(4,4'-bipy)(2,5-pdc)2(H2O)4]n 2. [Cu2(4,4'-bipy) (2,5-pdc)2]n 3. [Zn2(4,4'-bipy)(2,5-pdc)2(H2O)4]n and 4. [Cd3(4,4'-bipy)(2,5-pdc)2(OOCCH3)2(H2O)4]n.. All these complexes (1-4) have been characterized by elemental analyses (C,H,N), FT-IR-spectra, thermal analyses (TGA/DTA/DTG), fluorescence spectra and powder X-ray diffraction (PXRD) analyses to arrive at conclusion regarding their geometrical structure.

A Density Functional Theory Study of 3,5-dichlorosalicyliden-p-iminoacetophenone oxime Complexes with Co, Ni, Cu and Zn Metals

2019 ◽  
Vol 41 (5) ◽  
pp. 770-770
Author(s):  
Ali apan Ali apan ◽  
Erdal Canpolat Erdal Canpolat ◽  
Henar Sleman and Niyazi Bulut Henar Sleman and Niyazi Bulut
Keyword(s):  
Metal Complexes ◽  
Density Functional ◽  
Azomethine Nitrogen ◽  
Carboxyl Oxygen Atom ◽  
Tetrahedral Geometry ◽  
Functional Theory ◽  
X Ray ◽  
Mechanical Methods ◽  
Elemental Analyses ◽  
Ft Ir

In this work, new Schiff baz ligand was synthesized by reaction of p-iminoacetophenone oxime with 3,5-dichlorosalicylaldehyde. Metal complexes of Co+2, Ni+2, Cu+2 and Zn+2 acetate metal salts were synthesized with this ligand. The ligand and complexes are characterized in experimental by their elemental analyses, X-ray, 1H-NMR, 13C-NMR, UV-Vis, FT-IR, magnetic susceptibility and thermogravimetric analyses (TGA) and also have been investigated by using quantum mechanical methods. The transition metals are coordinated to the schiff base through the azomethine nitrogen and the carboxyl oxygen atom. Obtained metal complexes were studied the magnetic properties and their geometries were determined. Co+2, Ni+2 and Zn+2 complexes have been found tetrahedral geometry and Cu+2 complex has been found four coordinated geometry.

scholarly journals Synthesis, Structural, and Antimicrobial Studies of Some New Coordination Compounds of Palladium(II) with Azomethines Derived from Amino Acids

2013 ◽  
Vol 2013 ◽  
pp. 1-8 ◽  
Author(s):  
Monika Gupta ◽  
Sangeeta Sihag ◽  
A. K. Varshney ◽  
S. Varshney
Keyword(s):  
Amino Acids ◽  
Coordination Compounds ◽  
Reaction Medium ◽  
Molar Ratio ◽  
Spectral Studies ◽  
Antimicrobial Studies ◽  
Elemental Analyses ◽  
C Nmr ◽  
Insecticidal Activities

Some new coordination compounds of palladium(II) have been synthesized by the reaction of palladium(II) acetate with azomethines in a 1 : 2 molar ratio using acetonitrile as a reaction medium. Azomethines used in these studies have been prepared by the condensation of 2-acetyl fluorene and 4-acetyl biphenyl with glycine, alanine, valine, and leucine in methanol. An attempt has been made to probe their bonding and structures on the basis of elemental analyses and IR,1H, and13C NMR spectral studies. Pd(II) compounds have been found to be more active than their uncomplexed ligands as both of them were screened for antibacterial, antifungal, and insecticidal activities.

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