scholarly journals Synthesis and Study of Chemical, Thermal, Mesomorphic, and Optical Properties of Terphenyls Modified with Nitrile Groups

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
M. L. Mota González ◽  
A. Carrillo Castillo ◽  
R. C. Ambrosio Lázaro ◽  
J. Flores Méndez ◽  
Mario Moreno ◽  
...  
Keyword(s):  
Optical Properties ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Photoluminescence Properties ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
X Ray ◽  
H Nmr ◽  
Cross Coupling Reaction ◽  
Vis Spectroscopy

We report the synthesis, characterization, and the thermotropic and photoluminescence properties of dialkoxyterphenyls with (T12-CN and T12-2CN) and without (T12) nitrile groups. These terphenyls were prepared through the Suzuki-Miyaura cross-coupling reaction using a palladium-based catalyst. The products obtained were analyzed as powders or after being drop-casted or spin-coated on glass. Nuclear Magnetic Resonance (1H NMR) and Fourier Transform Infrared (FTIR) spectroscopy techniques confirmed the structure and purity of the synthesized terphenyls. The mesomorphic behavior was studied by differential scanning calorimetry (DSC), polarizing optical microscopy (POM), and X-ray diffraction (XRD). T12 developed various mesophases, whereas T12-CN and T12-2CN displayed one single mesophase of low order over a wide temperature range. The films topology was studied by AFM and the optical properties were determined by ultraviolet-visible (UV-Vis) spectroscopy and spectrofluorometry. Higher roughness was found for the films prepared with the asymmetric terphenyl (T12-CN). The photoluminescence (PL) spectrum obtained for the asymmetric terphenyl (T12-CN) exhibited the expected characteristics with an emission band centered at 381 nm and an overtone around 760 nm.

scholarly journals Synthesis and Structure of (Nitronyl Nitroxide-2-ido)(tert-butyldiphenylphosphine)gold(I) and -(Di(tert-butyl)phenylphosphine)gold(I) Derivatives; Their Comparative Study in the Cross-Coupling Reaction

Crystals ◽  
2020 ◽  
Vol 10 (9) ◽  
pp. 770
Author(s):  
Igor Zayakin ◽  
Irina Bagryanskaya ◽  
Dmitri Stass ◽  
Maxim Kazantsev ◽  
Evgeny Tretyakov
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Oxidation Potential ◽  
Nitronyl Nitroxide ◽  
X Ray ◽  
Tert Butyl ◽  
Cross Coupling Reaction ◽  
Vis Spectroscopy ◽  
The Cross ◽  
Derivatives Of

We synthesized two new organogold derivatives of a nitronyl nitroxide (NN) with phosphine ligands, namely NN-Au-PtBuPh2 and NN-Au-PtBu2Ph. They were characterized by X-ray diffraction analysis, cyclic voltammetry, and ESR, IR, and UV/Vis spectroscopy. The X-ray structural analysis revealed a tendency of the NN moiety to form a large number of short intermolecular contacts. This phenomenon is related to the anionic nature of the paramagnetic group NN, as evidenced by a significantly lower oxidation potential in comparison with purely organic derivatives of NN radicals. The cross-coupling reaction of NN-Au-PPh3, NN-Au-PtBuPh2, or NN-Au-PtBu2Ph with an activated bromoarene, namely, p-BrC6H4NO2, was investigated. It was shown that regardless of the presence of the bulky tert-butyl substituent, all gold derivatives have similar activities in the cross-coupling reaction and give a cross-coupling product, NN-C6H4NO2, with comparable yields.

scholarly journals Some mechanistic aspects regarding the Suzuki–Miyaura reaction between selected ortho-substituted phenylboronic acids and 3,4,5-tribromo-2,6-dimethylpyridine

2018 ◽  
Vol 14 ◽  
pp. 2384-2393
Author(s):  
Piotr Pomarański ◽  
Piotr Roszkowski ◽  
Jan K Maurin ◽  
Armand Budzianowski ◽  
Zbigniew Czarnocki
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
X Ray ◽  
H Nmr ◽  
Important Group ◽  
Cross Coupling Reaction ◽  
Efficient Access ◽  
Phenylboronic Acids ◽  
Derivatives Of ◽  
Single Bonds

Background: Atropisomers are very interesting stereoisomers having axial chirality resulting from restricted rotation around single bonds and are found in various classes of compounds. ortho-Substituted arylpyridines are an important group of them. A regio- and atropselective Suzuki–Miyaura cross-coupling reaction on 3,4,5-tribromo-2,6-dimethylpyridine was studied. Results: Reactions with various amounts of ortho-substituted phenylboronic acids with 3,4,5-tribromo-2,6-dimethylpyridine gave a series of mono- di- and triarylpyridine derivatives which allowed to draw conclusions about the order of substitution. Also, the observed selectivity in the case of ortho-methoxyphenylboronic acid suggested an additional metal O-chelation effect in the transition state, apparently not present in the ortho-chloro analogues. The rotational barrier in selected atropisomers was determined on the basis of HT NMR and thermal epimerisation experiments. The structure of most presented atropisomeric derivatives of 2,6-dimethylpyridine was confirmed by single-crystal X-ray analysis. Racemic chiral, differently substituted atropisomers were also examined by 1H NMR spectroscopy in the presence of a chiral solvating agent. Conclusion: This regio- and atropselectivity may be generally applicable to other arylpyridine systems. A regio- and atropselective Suzuki–Miyaura cross-coupling process has been observed, giving an efficient access to a class of atropisomeric compounds. An opposite selectivity using a differently ortho-substituted phenylbornic acid was observed.

scholarly journals Synthesis and characterization of the cyanobenzene-ethylenedithio-TTF donor

2015 ◽  
Vol 11 ◽  
pp. 951-956 ◽  
Author(s):  
Sandrina Oliveira ◽  
Dulce Belo ◽  
Isabel Cordeiro Santos ◽  
Sandra Rabaça ◽  
Manuel Almeida
Keyword(s):  
Coupling Reaction ◽  
Cross Coupling ◽  
Triethyl Phosphite ◽  
High Yield ◽  
Synthesis And Characterization ◽  
X Ray Diffraction ◽  
X Ray ◽  
Cross Coupling Reaction ◽  
Uv Visible

A dissymmetric TTF-type electron donor, cyanobenzene-ethylenedithio-tetrathiafulvalene (CNB-EDT-TTF), was obtained in high yield, by a cross-coupling reaction with triethyl phosphite between 2-thioxobenzo[d][1,3]dithiole-5-carbonitrile and 5,6-dihydro-[1,3]dithiolo[4,5-b][1,4]dithiin-2-one. This new donor was characterized namely by single crystal X-ray diffraction, cyclic voltammetry, NMR, UV-visible and IR spectroscopy.

One-Pot Synthesis of a Cyclic Pyrene Octamer from Two Bifunctionalized Pyrene Monomers

Synthesis ◽  
2020 ◽  
Vol 53 (02) ◽  
pp. 344-347
Author(s):  
Hiroko Yamada ◽  
Naoki Aratani ◽  
Peifeng Mei ◽  
Ryo Kurosaki ◽  
Akinobu Matsumoto
Keyword(s):  
Molecular Structure ◽  
Single Crystal ◽  
Diffraction Analysis ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
X Ray Diffraction ◽  
One Pot ◽  
X Ray ◽  
One Pot Synthesis ◽  
Cross Coupling Reaction

AbstractA 2,2′-tert-butyl-5,9-6′,8′-cyclooctameric pyrenylene ([8]CP) was synthesized by a one-pot Suzuki–Miyaura cross-coupling reaction from two kinds of bifunctionalized monomers, as a rare example of a cyclic octamer. The octameric molecular structure of [8]CP was revealed by single-crystal X-ray diffraction analysis.

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.

Salts of purine alkaloids caffeine and theobromine with 2,6-dihydroxybenzoic acid as coformer: structural, theoretical, thermal and spectroscopic studies

2021 ◽  
Vol 77 (11) ◽  
Author(s):  
Mateusz Gołdyn ◽  
Anna Komasa ◽  
Mateusz Pawlaczyk ◽  
Aneta Lewandowska ◽  
Elżbieta Bartoszak-Adamska
Keyword(s):  
Hydrogen Bonds ◽  
Water Solubility ◽  
Theoretical Calculations ◽  
Spectroscopic Studies ◽  
X Ray Diffraction ◽  
Dihydroxybenzoic Acid ◽  
Scanning Calorimetry ◽  
X Ray ◽  
Purine Alkaloids ◽  
Vis Spectroscopy

The study of various forms of pharmaceutical substances with specific physicochemical properties suitable for putting them on the market is one of the elements of research in the pharmaceutical industry. A large proportion of active pharmaceutical ingredients (APIs) occur in the salt form. The use of an acidic coformer with a given structure and a suitable pK a value towards purine alkaloids containing a basic imidazole N atom can lead to salt formation. In this work, 2,6-dihydroxybenzoic acid (26DHBA) was used for cocrystallization of theobromine (TBR) and caffeine (CAF). Two novel salts, namely, theobrominium 2,6-dihydroxybenzoate, C7H9N4O2 +·C7H5O4 − (I), and caffeinium 2,6-dihydroxybenzoate, C8H11N4O2 +·C7H5O4 − (II), were synthesized. Both salts were obtained independently by slow evaporation from solution, by neat grinding and also by microwave-assisted slurry cocrystallization. Powder X-ray diffraction measurements proved the formation of the new substances. Single-crystal X-ray diffraction studies confirmed proton transfer between the given alkaloid and 26DHBA, and the formation of N—H...O hydrogen bonds in both I and II. Unlike the caffeine cations in II, the theobromine cations in I are paired by noncovalent N—H...O=C interactions and a cyclic array is observed. As expected, the two hydroxy groups in the 26DHBA anion in both salts are involved in two intramolecular O—H...O hydrogen bonds. C—H...O and π–π interactions further stabilize the crystal structures of both compounds. Steady-state UV–Vis spectroscopy showed changes in the water solubility of xanthines after ionizable complex formation. The obtained salts I and II were also characterized by theoretical calculations, Fourier-transform IR spectroscopy (FT–IR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC) and elemental analysis.

scholarly journals Fe2O3 Modified Physical, Structural and Optical Properties of Bismuth Silicate Glasses

2013 ◽  
Vol 2013 ◽  
pp. 1-5 ◽  
Author(s):  
Rajesh Parmar ◽  
R. S. Kundu ◽  
R. Punia ◽  
N. Kishore ◽  
P. Aghamkar
Keyword(s):  
Optical Properties ◽  
Silicate Glasses ◽  
Bandgap Energy ◽  
X Ray Diffraction ◽  
Structural And Optical Properties ◽  
Scanning Calorimetry ◽  
Bismuth Silicate ◽  
Vis Spectroscopy ◽  
Amorphous Nature ◽  
Optical Bandgap Energy

Iron-containing bismuth silicate glasses with compositions 60SiO2·(100−x)Bi2O3·xFe2O3 have been prepared by conventional melt-quenching technique. The amorphous nature of the glass samples has been ascertained by the X-ray diffraction. The density (d) has been measured using Archimedes principle, molar volume (Vm) has also been estimated, and both are observed to decrease with the increase in iron content. The glass transition temperature (Tg) of these iron bismuth silicate glasses has been determined using differential scanning calorimetry (DSC) technique, and it increases with the increase in Fe2O3 content. The IR spectra of these glasses consist mainly of [BiO6], [BiO3], and [SiO4] structural units. The optical properties are measured using UV-VIS spectroscopy. The optical bandgap energy (Eop) is observed to decrease with the increase in Fe2O3 content, whereas reverse trend is observed for refractive index.

TOWARD EFFICIENT ELECTRON-TRANSPORTING AND BLUE-EMITTING MATERIALS FOR ORGANIC LIGHT-EMITTING DIODES: STRUCTURE AND PHOTOLUMINESCENT PROPERTIES OF SILOLE DERIVATIVES

2005 ◽  
Vol 14 (04) ◽  
pp. 487-495 ◽  
Author(s):  
YOUNGJIN KANG ◽  
JUNGCHEOL PARK ◽  
JUN HEO ◽  
KI-MIN PARK ◽  
JUN-HWAN AHN ◽  
...  
Keyword(s):  
Reduction Potential ◽  
Energy Levels ◽  
Coupling Reaction ◽  
Organic Light Emitting Diodes ◽  
X Ray Diffraction ◽  
Light Emitting ◽  
X Ray ◽  
Cyclic Voltametry ◽  
Organic Light ◽  
Cross Coupling Reaction

The potential blue-emitting as well as electron-transporting materials, 2,5-bis(3,5-trifluoromethylphenyl)-1,1-dimethyl-3,4-diphenylsilole (silole = silacyclopentadiene) (1) and 2,5-bis(3,5-trifluoromethylphenyl)-1,1-diphenyl-3,4-diphenylsilole (2), were synthesized by the Pd-mediated cross coupling reaction of corresponding bis(pheny-lethynyl)silanes with 1-bromo-3,5-trifluoromethylbenzene via intramolecular reductive cyclization. The structure of 2 was established by single-crystal X-ray diffraction analysis. In crystal structure, the dihedral angle between the functionalized phenyl groups containing CF3 at 2,5-position and central silole ring is about 48.70(6)°, showing the diminution of effective conjugation. These compounds exhibited high thermal stability without degradation up to 200°C. The absorption and photoluminescent properties, and cyclic voltametry have been evaluated. Compounds 1 and 2 in thin films showed intense blue emissions at 464–473 nm, respectively, in photoluminescence (PL). In electrochemistry, the reduction potential of 1 and 2 were at -1.92 and -1.81 V, respectively. The presence of substituents at 2,5′ — and/or 1,1′ — positions of siloe ring affected the LUMO energy levels through σ*–π* conjugation.

A Novel Reductive Cross-coupling Reaction of 2-nitrobenzoic Hydrazides and Aldehydes or Ketones Promoted by the Low-valence Titanium Reagent: An Access to 2,3,4,5-tetrahydro-1H-1,3,4-benzotriazepine-5-one Derivatives

2005 ◽  
Vol 2005 (9) ◽  
pp. 553-555 ◽  
Author(s):  
Daqing Shi ◽  
Chunling Shi ◽  
Liangce Rong ◽  
Juxian Wang ◽  
Qiya Zhuang ◽  
...  
Keyword(s):  
Elemental Analysis ◽  
Nmr Spectra ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Reductive Coupling ◽  
Facile Synthesis ◽  
H Nmr ◽  
Cross Coupling Reaction

A short and facile synthesis of a series of 2,3,4,5-tetrahydro-1H-1,3,4-benzotriazepine-5-one derivatives was accomplished in good yields via the intermolecular reductive coupling reaction of 2-nitrobenzoic hydrazides and aldehydes or ketones promoted by the low-valence titanium reagent (TiCl4/Zn system). Structures were established on the basis of elemental analysis, IR and 1H NMR spectra.

scholarly journals Highly Luminescent 4H-1,2,4-Triazole Derivatives: Synthesis, Molecular Structure and Photophysical Properties

Materials ◽  
2020 ◽  
Vol 13 (24) ◽  
pp. 5627
Author(s):  
Monika Olesiejuk ◽  
Agnieszka Kudelko ◽  
Marcin Świątkowski
Keyword(s):  
Photophysical Properties ◽  
Coupling Reaction ◽  
Cross Coupling ◽  
Luminescent Properties ◽  
Boronic Acids ◽  
Molecular Structures ◽  
X Ray ◽  
Cross Coupling Reaction ◽  
Alternative Approach ◽  
Large Quantum

An alternative approach to the Suzuki cross-coupling reaction is used to synthesize a series of new luminophores based on 4-alkyl-4H-1,2,4-triazole cores conjugated via 1,4-phenylene linker to fused-bicyclic and tricyclic aromatic, or heteroaromatic arrangements. The described methodology allows one to conduct the coupling reaction with the use of commercially available boronic acids in the presence of conventional solvents or ionic liquids and produced excellent yields. It was found that the use of ultrasounds or microwaves significantly accelerates the reaction. The obtained compounds exhibited high luminescent properties and a large quantum yield of emitted photons. The X-ray molecular structures of three highly conjugated 4H-1,2,4-triazole representatives are also presented.

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