Papers by Keyword: Pyridine

Abstract: The hybrid perovskites of amino(methyl) pyridines (AMP) and lead (II) bromide (PbBr₂) were synthesised using a reflux method in 40% hydrobromic acid medium in a closed-nitrogen condition. The structural, chemical and optical properties of the as-synthesised compounds were analysed analytically using XRD, FT-IR and UV-Vis. Based on the XRD analysis, all compounds have distinct and evenly spaced diffraction peaks, indicating that they are strongly oriented and well-crystallised. The presence of aromatics and primary amines in mono-substituted pyridinium cation variations was confirmed by the FT-IR analysis. All compounds absorbed strongly in visible spectra at 430 nm, 427 nm and 355 nm, respectively. This study demonstrates that organic-tailoring effects in the shifting of aminomethyl position in the pyridine chain contribute to different dimensionalities of hybrid perovskite frameworks, even when synthesised under the same conditions. The as-synthesised low-dimensional hybrid perovskite can be further utilised as a light-harvester material in Perovskite Solar Cells (PSCs).

Abstract: Breast cancer is a major health problem with an increasing number of cases over the years. Few classes of anticancer agents have been developed, but they established toxic effects on normal cells. In this study, a new hybrid anthracene-thiophene chalcone 1 has been synthesized via a Claisen-Schmidt condensation of substituted anthracene aldehyde and a thiophene ketone. The cyclo-condensation reaction of chalcone 1 formed a new anthracene-thiophene pyridine 2. The synthesized compounds were structurally characterized by Fourier Transform Infrared (FT-IR) and Nuclear Magnetic Resonance (NMR) spectroscopy. The molecular docking activities using AutoDock 4.2 software were performed to study the intermolecular interactions between these compounds with breast cancer protein, 3ERT as the estrogen receptor-α. Chalcone 1 showed free binding energy of -9.81 kcal/mol, while pyridine 2 exhibited better free binding energy of -10.45 kcal/mol against 3ERT protein. The interactions in pyridine 2 include one hydrogen bonding with MET343 amino acid and several hydrophobic interactions such as π-σ interaction with LEU384, π-anion interaction with ASP351, π-alkyl interactions with ALA350, LEU346, LEU391, LEU525, and MET388 and also a π-sulfur interaction with MET343. Chalcone 1 has only noncovalent interactions such as π-σ interaction with THR347 and π-alkyl interactions with ALA350, LEU346, LEU349, LEU387, LEU391, LEU525, and MET388. The molecular docking study of these compounds indicated that chalcone 1 and pyridine 2 showed a promising anticancer effect.

Abstract: In the present work, the extraction of Mongolian Baganuur coal in solvents as pyridine and ionic liquid with 1-butyl-3-methyl-imidazolium chloride ([Bmim]Cl) anion was first applied. The as recieved coal, its extracts and insoluble residues were then characterized using the Fourier transform infrared (FTIR) spectroscopy. The obtained FTIR spectra have revealed many new features in the field of coal study. An appearance or sharpening of the particular bands after the chemical treatment allow a determination of inactive or weak fundamental vibrations precisely. Some emphasis are as follows, substantial quantitative change, the integrated area decrease of water molecule band at 3260 cm−1 comparing to as received sample and ionic liquid treated extract, can be seen for the extract spectrum in the pyridine treatment. Pyridine react to coal structure particularly in long-wave frequency zone means very susceptible to the oxygen containing functional group. Upon interaction between acidic group of the coal and the basic solvent as pyridine, the inter-fragment hydrogen and ester bonding in the coal structure is breaking, thus increasing the solubility of the individual fragments via producing new components. Towards forming H bond in the short wave zone Cl− anion shows a strong effect on the coal molec-ular structure. A stabilization of hydrogen bonds show well fluidization and a strong intermolecular interaction of the process via its powerful spectral intensity that is followed many new bands and con-siderable strengthening of band spectral integral area in this frequency region. In long-wave vibrational region there are appearances of many new bands, shift in frequency and depletion of the as recieved coal bands. [Bmim]Cl treatment exhibits the highest effect of the disruption on the carboxylic acids dimer.

Abstract: The crystal structures of two fused pyridine derivatives viz Ethyl 3-amino-6-phenyl-4-tolylfuro[2,3-b]pyridine-2-carboxylate (I) and Ethyl 3-amino-6-phenyl-4-tolylthieno[2,3-b] pyridine-2-carboxylate (II) were optimized by semi-empirical methods using MOPAC2009 program. The geometries optimized for both the structures from Austin Model 1 (AM1) and Parametrization Model 6 (PM6) describe the conformational discrepancy and crystal packing effects. The parametric molecular electrostatic potential (PMEP) calculated by AM1 semi-empirical method describe the involvement of nitrogen and oxygen atoms in the crystal packing interactions in both the structures. The frontier molecular orbitals highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO) indicate the intramolecular charge transfer interactions. The HOMED indices computed for the phenyl rings in the structures describe the p-electron delocalization. The linear regression analysis shows good correlation between experimental and theoretical structures.

Abstract: Containing pyrimidine and pyridine monomers were incorporated respectively into the main chain of a sulfonated polyimide in order to investigate the effect of nitrogen-containing heterocycles on membrane properties such as water uptake and proton conductivity. With increasing content of the nitrogen-containing heterocycles, water uptake of membranes and dimensional changes remarkable decrease. The copolymer showed higher thermal stability (desulfonation temperature up to 330 °C) and reasonable good mechanical properties. These membranes also showed higher proton conductivity, which was comparable or even higher than Nafion 117.

Abstract: Al and S co-doped TiO2 (S-Al-TiO2) mesoporous materials as a kind of visible light photo- catalysts are prepared using pyridine as a template through a solid state reaction route. The materials features are characterized by the advanced instruments. The photodegradation kinetic of paclobutra- zol is investigated. It is shown that the doping of S and Al could effectively inhibit the growth of anatase TiO2, both S and Al have entered into the lattice of TiO2. Surface area of 81.3m2/g and narrow pore size distribution (~2.1nm) are presented, it not only enables the visible-light absorption but also promotes photocatalytic property of paclobutrazol. Moreover, within 150 min of visible-light irradiation, the photocatalytic degradation of paclobutrazol approximately follows an order kinetics, and the photodegradation rate in 46.7% and reaction rate constant of 0.00414 min-1 are obtained.

Abstract: With tetrabutyl orthotitanate, hydrazine hydrate and aluminum chloride hexahydrate as original materials and pyridine as a template reagent, N/Al doped TiO2 (N-TiO2, Al-TiO2, Al-N-TiO2) mesoporous nanomaterials were successfully synthesized through a simple and environmentally friendly solid state reaction route. The textural properties of the samples were characterized by X-ray diffraction (XRD), high resolution transmission electron microscope (HRTEM), ultraviolet visible light spectroscopy (UV-Vis), X-ray photoelectron spectroscopy (XPS), Raman spectroscope and N2 adsorption-desorption at 77K. Moreover, the formation mechanism of the N/Al-doped TiO2 mesoporous material was proposed in presence of pyridine. It clearly shows that the microscopic structure of Al-N-TiO2 nanomaterial with crystal anatase phase is an irregular shape nanoparticle with size of 5~20 nm. N atoms as N3- states have been incorporated into the lattice of TiO2 or have been entered into the interstice of TiO2 lattice. Al ions occupy the sites of Ti in crystal lattices by isomorphous replacement. Either the doping of N or Al, or the co-doping of N and Al, it can effectively embarrass the crystal growth of TiO2. The specific surface area and the average pore diameter are the 138.4 m2/g and 1.9 nm, respectively. Interestingly, the UV-vis spectra display that the adsorption intensity of N-Al-TiO2 nanomaterial decreases in the order of N-Al-TiO2＞N-TiO2＞Al-TiO2.

Abstract: The high temperature proton exchange membrane fuel cell (HT-PEMFC) is widely paid attention to due to the characteristics of simple water management, high intolerance of CO and high utilization of heat. In order to discover the effects of different operating factors on the performance of HT-PEMFC, several sets of experiments based on pyridine polymer were carried out in the testing system testing VI curves. The experimental results show that the fuel cell temperature affects enormously on the performance of the HT-PEMFC; humidification of reactant on the performance is almost negligible, which contribute to the understanding the working mechanism of HT-PEMFC.

Abstract: Continuous synthesis of pyridine with (MoO₃-NiO) / Al₂O₃ has been developed. The doped NiO improved the dispersion of the MoO₃ particles and forms the new phase NiMoO₄ so that the Mo⁺⁶ particles were retained as the active sites. NiO also was found to have a great effect on the catalyst acidity. The reaction parameters were optimized and pyridine was obtained in a yield of 86.19%.

Abstract: This article used thiosemicarbazide and para-pyridinecarboxylic acid to carry out reaction and synthesized 5-(4-pyridyl)-2-amino-1,3,4-thiadiazole, and then reacted with benzoyl isocyanate to synthesize a new type of urea biological active meterial. The structure of the target compound was confirmed by IR, 1H NMR and elemental analysis. The preliminarily biological activity tests show that the target compound has an activity as plant growth regulator, it’s activity as auxin is 19.3% and it’s activity as cytokinin is 27.4%.