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Sample records for anhydrous pyridine etude

  1. Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine; Etude de la selectivite de molecules extractantes polyazotees dans la complexation des actinides (III) et des lanthanides (III) en solution dans la pyridine anhydre

    Energy Technology Data Exchange (ETDEWEB)

    Riviere, Ch

    2000-10-05

    The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

  2. Polarographic study of Cd(2), Pb(2), Hg(1) in anhydrous acetic acid; Etude polarographique de Cd(2), Pb(2), Hg(1) dans l'acide acetique anhydre

    Energy Technology Data Exchange (ETDEWEB)

    Conesa-Botta, M C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1966-07-01

    Anhydrous acetic acid is a solvent which can be compared to water as far as its behaviour towards acid-base reactions is concerned. It is in fact, like water both a proton acceptor (basic) - and as such it can provoke the dissociation of acids - and a proton donor (acid). This amphoteric behaviour is characterized by the equilibrium: 2 H O Ac {r_reversible} Ac OH{sub 2}{sup +} + Ac O{sup -} with K{sub i} = |Ac O H{sub 2}|{sup +} |Ac O{sup -}| = 10{sup -14.5} analogue to 2 H{sub 2}O {r_reversible} H{sub 3}O{sup +} + HO{sup -} with K{sub i} = |H{sub 3}O{sup +}| |HO{sup -}| = 10{sup -14} The acid-base reactions can in principle be characterized by a pH scale based on a definition similar to that for the pH scale in aqueous solutions. The essential difference however between aqueous and acetic acid solutions is due to the fact that acetic acid has a low dielectric constant. {epsilon} = 6.1 (at 25 deg. C) The ions therefore remain associated, almost completely, in the form of ion-pairs produced as a result of the strong electrostatic interactions. This phenomenon requires us to modify the reasoning usually applied to aqueous solutions. The new general methods of reasoning have been established and discussed by G. CHARLOT and B. TREMILLON. We will make use of them for the particular case under consideration. In the first part, we have employed the polarographic method for the study of the acetic complexes of two elements: cadmium(II) and lead (II). In the second part we have tried to show that mercurous halides are formed in acetic acid; we have attempted to determine their stability. (author) [French] L'acide acetique anhydre est un solvant qui peut etre rapproche de l'eau par son comportement envers les reactions acides-bases. Il est en effet, comme l'eau, a la fois accepteur de protons (basique) - et comme tel agit sur la dissociation des acides - et donneur de protons (acide). Ce pouvoir amphotere est caracterise par l'equilibre: 2 H O Ac {r_reversible} Ac OH{sub 2

  3. Structural study and crystallography of the major compound of anhydrous cement: tri-calcium silicate; Etude structurale et cristallographie du compose majoritaire du ciment anhydre: le silicate tricalcique

    Energy Technology Data Exchange (ETDEWEB)

    Noirfontaine, M.N. de

    2000-01-01

    Anhydrous (Portland) cement is mainly composed of a synthetic material, the clinker, whose major compound is tri-calcium silicate (Ca{sub 3}SiO{sub 5}), often referred as C{sub 3}S with the compact oxides notations, C = CaO et S = SiO{sub 2}. The polymorphism of C{sub 3}S, still not well known, is the main subject of the thesis. Various crystal structures (rhombohedral R, monoclinic M1, M2, M3 and triclinic T1, T2, T3) can be found, depending on temperature and impurities. The only known structures are T1, M1 and M3, involving large unit cells with an orientational disorder of silicate tetrahedra. The single crystal studies exhibit no clear relation between the various polymorphs. Starting from known results from literature single crystal experiments, we establish the metric and structural relations between the different structures. Averaged structures for the T1, M1 and M3 polymorphs are proposed, together with all the matrices of transformation between the unit cells. We also introduce new 1-D, 2-D, and 3-D structural units, which make easier the understanding of the structures of C{sub 3}S, with the result of a better description of the orientational disorder. The effects of impurities on the structure are discussed. In industrial clinkers, impurities stabilize mainly M1 and M3 monoclinic forms. We propose a space group (Pc) and two structural models (a superstructure and an approximate averaged structure) for the M1 form. All the models are validated on synthetic compounds (M3, M2, M1 et T1) and industrial clinkers analysed by X-Ray powder diffraction with Rietveld analysis. (author)

  4. Molecular dynamics simulations of ter-pyridine and bis-triazinyl-pyridine complexes with lanthanide cations; Etude de dynamique moleculaire de complexes de la bis-triazinyl-pyridine (BTP) et de la terpyridine avec des lanthanides(3)

    Energy Technology Data Exchange (ETDEWEB)

    Guilbaud, Ph. [CEA Valrho, (DCC/DRRV/SEMP), 30 - Marcoule (France)

    2000-07-01

    The search for ligands which specifically separate actinides(III) from lanthanides(III) by liquid-liquid extraction has prompted considerable research in the Process Design and Modeling Department ('Service d'Etude et de Modelisation des Procedes'- SEMP). Ligands with soft donor atoms AS) that are able to perform this separation have already been investigated and research is currently under way to improve their performance for high acidic feeds. Theoretical chemistry research is conducted in the Theoretical and Structural Chemistry Laboratory ('Laboratoire de Chimie Theorique et Structurale') to improve our understanding of the complexation and extraction of these cations with such ligands. Theoretical studies were first carried out for the ter-pyridine (TPY) and bis-triazinyl-pyridine (BTP) ligands that display fairly good ability to separate and extract actinide(III) from lanthanide(III) ions. Molecular dynamics simulations were performed on ter-pyridine and bis-triazinyl-pyridine complexes with three lanthanide cations (La{sup 3+}, Eu{sup 3+} and Lu{sup 3+}) for vacuum and for water solutions. These calculations were carried out without counter-ions, with three nitrate (NO{sub 3}{sup -}) ions, and, in the case of ter-pyridine, with three {alpha}-bromo-caprate anions that are likely to be used experimentally as synergistic agents for the separation and extraction of An(III) from Ln(III). Molecular dynamics simulations were first performed for vacuum to evaluate the distances between nitrogen and lanthanide atoms (Ln{sup 3+},N) and intrinsic interaction energies to poly-nitrogenous ligands with or without NO{sub 3} ions, and for both ligands. The (Ln{sup 3+},N) distances decrease and the cation/ligand interaction energies increase along the La{sup 3+}, Eu{sup 3+}, Lu{sup 3+} series, with decreasing Ln(III) ion radii. The introduction of nitrate counter-ions makes the (Ln{sup 3+},N) distances slightly higher, and the TPY/Ln{sup 3+} and BTP

  5. Study of the selectivity of poly-nitrogenous extracting molecules in the complexation of actinides (III) and lanthanides (III) in solution in anhydrous pyridine

    International Nuclear Information System (INIS)

    Riviere, Ch.

    2000-01-01

    The aim of this work is to better understand the factors which contribute to the separation of lanthanides(III) and actinides(III). Polydentate nitrogenous molecules present an interesting selectivity. A thermodynamic study of the complexation in pyridine of lanthanide and uranium by the bipyridine ligand (bipy) has been carried out. The formation constants and the thermodynamic values of the different complexes have been determined. It has been shown that the bipy complexes formation is controlled by the enthalpy and unfavored by the entropy. The conductometry has revealed too a significant difference in the uranium and lanthanides complexation by the bipyridine ligand. The use of the phenanthroline ligand induces a better complexation of the metallic ions but the selectivity is not improved. On the other hand, the decrease of the basicity and the increase of the ligand denticity (for instance in the case of the use of ter-pyridine) favour the selectivity without improving the complexation. The selectivity difference for the complexation of actinides(III) and lanthanides(III) by the different studied ligands (independent systems) has been confirmed by experiments of inter-metals competition. (O.M.)

  6. Comparison of Intermolecular Forces in Anhydrous Sorbitol and Solvent Cocrystals.

    Science.gov (United States)

    Dierks, Teresa M; Korter, Timothy M

    2017-08-03

    The hygroscopicity of solid sorbitol is important for its utilization as a sweetener in the pharmaceutical and food industries. The molecular foundations of sorbitol hydration characteristics are explored here using two solvated cocrystals, sorbitol-water and sorbitol-pyridine. In this work, solid-state density functional theory and terahertz time-domain spectroscopy were used to evaluate the relative stabilities of these cocrystals as compared to anhydrous sorbitol in terms of conformational and cohesive energies. The modification of the hydrogen-bonding network in crystalline sorbitol by solvent molecules gives new insight into the origins of the notable stability of sorbitol-water as compared to similar solids such as mannitol-water. In particular, the energy analysis reveals that the relative instability of the mannitol hydrate is based primarily in the lack of water-water interactions which provide considerable stabilization in the sorbitol-water crystal.

  7. 21 CFR 168.110 - Dextrose anhydrous.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 2 2010-04-01 2010-04-01 false Dextrose anhydrous. 168.110 Section 168.110 Food... Table Sirups § 168.110 Dextrose anhydrous. (a) Dextrose anhydrous is purified and crystallized D-glucose... solids content is not less than 98.0 percent m/m. (b) The name of the food is “Dextrose anhydrous” or...

  8. Anhydrous ethanol: A renewable source of energy

    Energy Technology Data Exchange (ETDEWEB)

    Kumar, Santosh; Singh, Neetu; Prasad, Ram [Department of Chemical Engineering, H. B. Technological Institute, Kanpur 208002 (India)

    2010-09-15

    Anhydrous ethanol is one of the biofuels produced today and it is a subset of renewable energy. It is considered to be an excellent alternative clean-burning fuel to gasoline. Anhydrous ethanol is commercially produced by either catalytic hydration of ethylene or fermentation of biomass. Any biological material that has sugar, starch or cellulose can be used as biomass for producing anhydrous ethanol. Since ethanol-water solution forms a minimum-boiling azeotrope of composition of 89.4 mol% ethanol and 10.6 mol% water at 78.2 C and standard atmospheric pressure, the dilute ethanol-water solutions produced by fermentation process can be continuously rectified to give at best solutions containing 89.4 mol% ethanol at standard atmospheric pressure. Therefore, special process for removal of the remaining water is required for manufacture of anhydrous ethanol. Various processes for producing anhydrous ethanol have been used/suggested. These include: (i) chemical dehydration process, (ii) dehydration by vacuum distillation process, (iii) azeotropic distillation process, (iv) extractive distillation processes, (v) membrane processes, (vi) adsorption processes and (vii) diffusion distillation process. These processes of manufacturing anhydrous ethanol have been improved continuously due to the increasingly strict requirements for quantity and quality of this product. The literature available on these processes is reviewed. These processes are also compared on the basis of energy requirements. (author)

  9. Transport of anhydrous ammoniac - risk assessment

    International Nuclear Information System (INIS)

    Castellano, S.; Degrange, J.P.; Hubert, P.; Pages, P.; Lamblin, J.

    1989-12-01

    This risk analysis of anhydrous ammonia transport in France was done within a study initiated by the Department of dangerous goods of the Ministry of transport. The study deals with the road and rail transportation of bulk anhydrous ammonia. After analysis of transport system and traffic, the transport accident risks are estimated, as well as their distribution on the French territory. Finally after a synthesis of results, a number of safety measures to be undertaken were identified. This is a joint study of SMC-CEPN, with a specific role of SEMA-METRA-CONSEIL concerning the traffic frequency, and the center for risk evaluation concerning nuclear safety

  10. Pyrimidine-pyridine ring interconversion

    NARCIS (Netherlands)

    Plas, van der H.C.

    2003-01-01

    This chapter discusses the pyrimidine-to-pyridine ring transformation and pyridine-to-pyrimidine ring transformation. In nucleophile-induced pyrimidine-to-pyridine rearrangements, two types of reactions can be distinguished depending on the structure of the nucleophile: (1) reactions in which the

  11. Anhydrous hydrogen fluoride electrolyte battery. [Patent application

    Science.gov (United States)

    Not Available

    1972-06-26

    It is an object of the invention to provide a primary cell or battery using ammonium fluoride--anhydrous hydrogen fluoride electrolyte having improved current and power production capabilities at low temperatures. It is operable at temperatures substantially above the boiling point of hydrogen fluoride. (GRA)

  12. 46 CFR 151.50-32 - Ammonia, anhydrous.

    Science.gov (United States)

    2010-10-01

    ... enclosed anhydrous ammonia tanks complies with the following chemical and physical properties: (1) Boiling... requirements of § 151.50-30 for compressed gases are also applicable to the shipment of anhydrous ammonia...

  13. Folds and Etudes

    Science.gov (United States)

    Bean, Robert

    2007-01-01

    In this article, the author talks about "Folds" and "Etudes" which are images derived from anonymous typing exercises that he found in a used copy of "Touch Typing Made Simple". "Etudes" refers to the musical tradition of studies for a solo instrument, which is a typewriter. Typing exercises are repetitive attempts to type words and phrases…

  14. Protonation of pyridine. Vol. 2

    Energy Technology Data Exchange (ETDEWEB)

    Zahran, N F; Ghoniem, H; Helal, A I [Physics Dept., Nuclear Research Center, AEA., Cairo, (Egypt); Rasheed, N [Nuclear Material Authority, Cairo, (Egypt)

    1996-03-01

    Field ionization mass spectra of pyridine is measured using 10{mu}m activated wire. protonation of pyridine, is observed as an intense peak in the mass spectra. Charge distribution of pyridine molecule is calculated using the modified neglect of diatomic overlap (MNDO) technique, and consequently proton attachment is proposed to be on the nitrogen atom. Temperature dependence of (M+H){sup +} ion is investigated and discussed. MNDO calculations of the protonated species are done, and the proton affinity of pyridine molecule is estimated. Time dependence of the field ionization process of pyridine and protonated ions are observed and discussed. 5 figs.

  15. THz characterization of hydrated and anhydrous materials

    Science.gov (United States)

    Sokolnikov, Andre

    2011-06-01

    The characterization of anhydrous and hydrated forms of materials is of great importance to science and industry. Water content poses difficulties for successful identification of the material structure by THz radiation. However, biological tissues and hydrated forms of nonorganic substances still may be investigated by THz radiation. This paper outlines the range of possibilities of the above characterization, as well as provides analysis of the physical mechanism that allows or prevents penetration of THz waves through the substance. THz-TDS is used to measure the parameters of the characterization of anhydrous and hydrated forms of organic and nonorganic samples. Mathematical methods (such as prediction models of time-series analysis) are used to help identifying the absorption coefficient and other parameters of interest. The discovered dependencies allow designing techniques for material identification/characterization (e.g. of drugs, explosives, etc. that may have water content). The results are provided.

  16. Preparation of pure anhydrous rare earth chlorides

    International Nuclear Information System (INIS)

    Bel'kova, N.L.; Slastenova, N.M.; Batyaev, I.M.; Solov'ev, M.A.

    1979-01-01

    A method has been suggested for obtaining extra-pure anhydrous REE chlorides by chloridizing corresponding oxalates by chlorine in a fluid bed, the chloridizing agents being diluted by an inert gas in a ratio of 2-to-1. The method is applicable to the manufacture of quality chlorides not only of light, but also of heavy REE. Neodymium chloride has an excited life of tau=30 μs, this evidencing the absence of the damping impurities

  17. pyridine-carboxamide complexes

    Indian Academy of Sciences (India)

    (2a and 2b) in appreciable yields (L = L1 = N-(furan-2-ylmethyl)-2-pyridine carboxamide and L = L2 = ... able developments in a variety of catalytic transforma- .... Yield: 70–74%. (0.492 g); C22H20CdN6O8S2: Anal. Found: C, 39.13; H,. 2.91; N, 12.37; Cd, 16.64% Calc.: C, 39.26; H, 3.00; N,. Scheme 1. Reaction scheme.

  18. Electrochemistry of acid-base reactions in anhydrous hydrogen fluoride

    International Nuclear Information System (INIS)

    Masson, J.P.; Devynck, J.; Tremillon, B.

    1975-01-01

    Electrochemical studies were made in following media: water-HF mixtures, anhydrous HF and KF solutions in HF, solutions of the SbF5 type in HF. The acidity level of these solutions was evaluated using the R(H) functions based on the strehlow hypotheses. From the pH measurement in anhydrous HF, it was possible to get acid-base titration curves and pH buffers. The behavior of quinones in anhydrous HF is presented [fr

  19. 3-(Pyridin-2-ylcoumarin

    Directory of Open Access Journals (Sweden)

    Yu-Xia Da

    2010-11-01

    Full Text Available In the title compound, C14H9NO2, the dihedral angle between the pyridine ring and the lactone ring is 10.40 (3°. The coumarin ring system is nearly planar, with a dihedral angle of 1.40 (2° between the lactone and benzene rings. An intramolecular C—H...O hydrogen bond occurs. In the crystal, inversion dimers linked by pairs of C—H...O interactions occur, generating R22(14 loops.

  20. Phosphorus, sulfur and pyridine

    OpenAIRE

    Schönberger, Stefanie

    2013-01-01

    The synthesis of distinct neutral or anionic P,S compounds in solution provides a great challenge for chemists. Due to the similarity in the energies of the P–P, P–S and S–S bonds nearly solely a mixture of compounds with different composition and charge is obtained. Our interest focuses on the system consisting of phosphorus, sulfur and pyridine, with the aim of a greater selectivity of P,S compounds in solution. The combination of these three components offers the opportunity...

  1. 46 CFR 98.25-5 - How anhydrous ammonia may be carried.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false How anhydrous ammonia may be carried. 98.25-5 Section 98... Anhydrous Ammonia in Bulk § 98.25-5 How anhydrous ammonia may be carried. (a) Anhydrous ammonia shall be..., except as otherwise provided in paragraph (b) of this section. (b) When anhydrous ammonia is to be...

  2. Potentiometric titrations in anhydrous acetic acid

    International Nuclear Information System (INIS)

    Le Port, L.

    1966-03-01

    The method used for studying anhydrous acetic acid is potentiometry with a glass electrode. We have in this way studied the titration of common inorganic acids (HClO 4 - HBr - H 2 SO 4 - HCl - HNO 3 - H 3 PO 4 ) and of some metallic salts. Furthermore we have shown that complex acids are formed between HCl and some metallic chlorides. An analysis of the titration curves for the inorganic acids against pyridinium chloride has made it possible to calculate a certain number of values for the dissociation pK of these acids and of the corresponding pyridinium salts. The titration of metallic perchlorates constitutes a method of studying the stability of acetates; we have thus been able to draw up a classification for some of these acetates. The metallic chlorides studied fall into two groups according to their behaviour in weak or strong acids. The differences have been explained on the basis of the role played by solvolysis. In the third part we have studied the acidic properties of mixtures of HCl with certain metallic chlorides. This work has demonstrated the existence, in certain cases, of acid complexes of the type (HCl) m MCl n . (author) [fr

  3. Harvesting Water from Air: Using Anhydrous Salt with Sunlight

    KAUST Repository

    Li, Renyuan; Shi, Yusuf; Shi, Le; Alsaedi, Mossab.; Wang, Peng

    2018-01-01

    Atmospheric water is abundant alternative water resource, equivalent to 6 times of water in all rivers on Earth. This work screens 14 common anhydrous and hydrated salt couples in terms of their physical and chemical stability, water vapor

  4. Research on anhydrous hydrazine synthesis; Recherche sur la synthese de l'hydrazine anhydre

    Energy Technology Data Exchange (ETDEWEB)

    Gaussens, G. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-03-15

    The first part of this work concerns the radiolysis of pure liquid ammonia. The fundamental importance of the dose rate and of the dose on the yield of radiolytic products has been demonstrated. By using a capture solute at concentrations of between 10{sup -3} and 1.2 mole s/litre, it has been possible to determine the yields of radicals and of molecules in the irradiated pure ammonia. During later work, it was possible to determine, by systematically varying the physico-chemical parameters, the most favorable conditions for carrying out the radiosynthesis; the maximum radiochemical yield of the hydrazine obtained has a value: G (N{sub 2}H{sub 4}) = 2.2/100 eV. An analysis of the molecular yields in the presence of deuterated solutes makes it possible to explain partially the role of the capture species. A project is also described for an installation producing hydrazine continuously; it is followed by an economic study of the process. From this work it appears that the yields of hydrazine obtained justify an industrial application, especially if strong radiation sources are available, for example nuclear reactors. (author) [French] La premiere partie de l'etude a porte sur la radiolyse de l'ammoniac liquide pur. Le role fondamental du debit de dose et de la dose sur les rendements des produits de radiolyse a ete mise en evidence. L'emploi de solute capteur dont les concentrations sont comprises entre 10{sup -3} et 1,2 mole/litre, a permis de determiner la valeur des rendements radicalaires et moleculaires dans l'ammoniac pur irradie. Au cours d'une etape ulterieure, une variation systematique des parametres physico-chimiques a permis de determiner les conditions les plus favorables a la radiosynthese le rendement radiochimique maximum de l'hydrazine obtenu a pour valeur: G(N{sub 2}H{sub 4}) 2,2/100 eV. L'analyse des rendements moleculaires en presence de solutes deuteres nous permet de rendre compte partiellement du role des

  5. Research on anhydrous hydrazine synthesis; Recherche sur la synthese de l'hydrazine anhydre

    Energy Technology Data Exchange (ETDEWEB)

    Gaussens, G [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1967-03-15

    The first part of this work concerns the radiolysis of pure liquid ammonia. The fundamental importance of the dose rate and of the dose on the yield of radiolytic products has been demonstrated. By using a capture solute at concentrations of between 10{sup -3} and 1.2 mole s/litre, it has been possible to determine the yields of radicals and of molecules in the irradiated pure ammonia. During later work, it was possible to determine, by systematically varying the physico-chemical parameters, the most favorable conditions for carrying out the radiosynthesis; the maximum radiochemical yield of the hydrazine obtained has a value: G (N{sub 2}H{sub 4}) = 2.2/100 eV. An analysis of the molecular yields in the presence of deuterated solutes makes it possible to explain partially the role of the capture species. A project is also described for an installation producing hydrazine continuously; it is followed by an economic study of the process. From this work it appears that the yields of hydrazine obtained justify an industrial application, especially if strong radiation sources are available, for example nuclear reactors. (author) [French] La premiere partie de l'etude a porte sur la radiolyse de l'ammoniac liquide pur. Le role fondamental du debit de dose et de la dose sur les rendements des produits de radiolyse a ete mise en evidence. L'emploi de solute capteur dont les concentrations sont comprises entre 10{sup -3} et 1,2 mole/litre, a permis de determiner la valeur des rendements radicalaires et moleculaires dans l'ammoniac pur irradie. Au cours d'une etape ulterieure, une variation systematique des parametres physico-chimiques a permis de determiner les conditions les plus favorables a la radiosynthese le rendement radiochimique maximum de l'hydrazine obtenu a pour valeur: G(N{sub 2}H{sub 4}) 2,2/100 eV. L'analyse des rendements moleculaires en presence de solutes deuteres nous permet de rendre compte partiellement du role des capteurs. Un projet d'une installation

  6. Automatic synthesis of [11C]NKY-722 with high specific activity, using anhydrous [11C] methanol as a precursor

    International Nuclear Information System (INIS)

    Suzuki, Kazutoshi; Inoue, Osamu; Itoh, Takashi; Nemoto, Kazuyoshi; Oosumi, Seimei; Miwa, Soichi.

    1992-01-01

    3-(4-allyl-1-piperazinyl)-2,2-dimethylpropyl methyl 1,4-dihydro-2,6-dimethyl- 4-(3-nitrophenyl)-3,5-pyridine dicarboxylate (NKY-722) was labeled with carbon-11 using anhydrous [ 11 C] methanol. Using a computer controlled equipment, a few GBq of [ 11 C] NKY-722 with the specific activity of 120 - 180 GBq/μmol could by synthesized at the radiochemical purity of > 99% in 10 ml of physiological saline containing Polysolvate-80 (1.5 vol%) and ethyl alcohol (0.75 vol%). Preliminary PET experiments using rats and a rhesus monkey have bee done, and very low accumulation of the compound into the brain, however comparatively higher accumulation in the heart were observed. (author)

  7. 27 CFR 21.122 - Pyridine bases.

    Science.gov (United States)

    2010-04-01

    ....122 Pyridine bases. (a) Alkalinity. One ml of pyridine bases dissolved in 10 ml of water is titrated... condenser having a water jacket not less than 400 mm in length. A standardized thermometer is placed in the.... Dissolve 1 ml of pyridine bases in 100 ml of water. (1) Ten ml of this solution are treated with 5 ml of 5...

  8. A fixed cations and low Tg polymer: the poly(4-vinyl-pyridine) quaternized by poly(ethylene oxide) links. Conductivity study; Un electrolyte polymere a cations fixes et bas Tg: les poly(4-vinylpyridine) quaternisees par des chainons de poly(oxyde d`ethylene). Etude de la conductivite

    Energy Technology Data Exchange (ETDEWEB)

    Gramain, Ph. [Ecole Nationale Superieure de Chimie de Montpellier, 34 (France); Frere, Y. [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France). Institut Charles Sadron

    1996-12-31

    The spontaneous ionic polymerization of 4-vinyl-pyridine in presence of mono-tosylated or bromated short chains of poly(ethylene oxide)-(PEO) is used to prepare amorphous comb-like poly-cations with low Tg. The polymer electrolyte properties of these new structures have been studied without any addition of salts. The ionic conductivity of these fixed cation poly-electrolytes depends on the length of the grafted PEO and varies from 10{sup -7} to 10{sup -4} S/cm between 25 and 80 deg. C. It is only weakly dependent on the nature of the cation but it is controlled by the movements of the pyridinium cation which are facilitated by the plastifying effect of the POE chains which do not directly participate to the ionic transport. (J.S.) 17 refs.

  9. A fixed cations and low Tg polymer: the poly(4-vinyl-pyridine) quaternized by poly(ethylene oxide) links. Conductivity study; Un electrolyte polymere a cations fixes et bas Tg: les poly(4-vinylpyridine) quaternisees par des chainons de poly(oxyde d`ethylene). Etude de la conductivite

    Energy Technology Data Exchange (ETDEWEB)

    Gramain, Ph [Ecole Nationale Superieure de Chimie de Montpellier, 34 (France); Frere, Y [Centre National de la Recherche Scientifique (CNRS), 67 - Strasbourg (France). Institut Charles Sadron

    1997-12-31

    The spontaneous ionic polymerization of 4-vinyl-pyridine in presence of mono-tosylated or bromated short chains of poly(ethylene oxide)-(PEO) is used to prepare amorphous comb-like poly-cations with low Tg. The polymer electrolyte properties of these new structures have been studied without any addition of salts. The ionic conductivity of these fixed cation poly-electrolytes depends on the length of the grafted PEO and varies from 10{sup -7} to 10{sup -4} S/cm between 25 and 80 deg. C. It is only weakly dependent on the nature of the cation but it is controlled by the movements of the pyridinium cation which are facilitated by the plastifying effect of the POE chains which do not directly participate to the ionic transport. (J.S.) 17 refs.

  10. The γ-irradiation stability of anhydrous ethylenediamine

    International Nuclear Information System (INIS)

    Zhong Zhijing; Long Suqun; Fu Yibei; Xu Yunshu

    2005-01-01

    Anhydrous Ethylenediamine (AEDA) was irradiated in air or nitrogen at ambient temperatures by 60 Co γ-rays. The radiation degradation products were analyzed by means of GC, GC/MS, MS and FT-IR, etc. Notable gaseous products such as hydrogen, methane, ethylene, ammonia, and some volatile liquid state radiolysis products as well, were examined, and many kinds of polymerized products were detected in the liquid remain sample. It was found that under certain conditions both the hydrogen and methane contents of the products increased with dose. Remarkable effects of radiation degradation and radiation polymerization were observed, and even severe effects were found in nitrogen ambience. Therefore, a worse γ-irradiation stability of anhydrous ethylenediamine was demonstrated. The radiation polymerization of anhydrous ethylenediamine was not reported before. (authors)

  11. Interaction of Ketotifen Fumarate with Anhydrous Theophylline in ...

    African Journals Online (AJOL)

    Purpose: The purpose of the present study was to investigate interaction between ketotifen fumarate and anhydrous theophylline in aqueous media of various pH. Methods: By using Job's continuous-variation analysis and Ardon's spectrophotomeric methods, the values of stability constants of theophylline with ketotifen ...

  12. Effect of anhydrous magnesium sulphate fertilizer and cutting ...

    African Journals Online (AJOL)

    Effect of anhydrous magnesium sulphate fertilizer on Panicum maximum yield and chemical composition of the resultant herbage harvested at 3, 4 and 5 weeks of age was investigated. The treatments were labeled T1 to T6. T1 was fertilized and harvested at 3 weeks cutting interval, T2 was fertilized and harvested at 4 ...

  13. Anhydrous Ammonia Training Module. Trainer's Package. Participant's Package.

    Science.gov (United States)

    Beaudin, Bart; And Others

    This document contains a trainer's and a participant's package for teaching employees on site safe handling procedures for working with anhydrous ammonia, especially on farms. The trainer's package includes the following: a description of the module; a competency; objectives; suggested instructional aids; a training outline (or lesson plan) for…

  14. Process for the production of sodium carbonate anhydrate

    NARCIS (Netherlands)

    Oosterhof, H.; Van Rosmalen, G.M.; Witkamp, G.J.; De Graauw, J.

    2000-01-01

    The invention is directed to a process for the production of sodium carbonate-anhydrate having a bulk density of at least 800 kg/m<3>, said process comprising: providing a suspension of solid sodium carbonate and/or solid sodium bicarbonate and/or solid double salts at least comprising one of sodium

  15. 49 CFR 173.195 - Hydrogen cyanide, anhydrous, stabilized (hydrocyanic acid, aqueous solution).

    Science.gov (United States)

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Hydrogen cyanide, anhydrous, stabilized... Hazardous Materials Other Than Class 1 and Class 7 § 173.195 Hydrogen cyanide, anhydrous, stabilized (hydrocyanic acid, aqueous solution). (a) Hydrogen cyanide, anhydrous, stabilized, must be packed in...

  16. Acid-base strengths in pyridine

    NARCIS (Netherlands)

    Bos, M.; Dahmen, E.A.M.F.

    1971-01-01

    Although pyridine is a solvent with a low dielectric constant, spectrophotometric determinations show simple dissociation without ion pairs as intermediates for some sulfonphthaleins and polynitrophenols in pyridine. The salts of a number of amines and hydrochloric acid, perchloric acid and picric

  17. Glass transition of anhydrous starch by fast scanning calorimetry.

    Science.gov (United States)

    Monnier, Xavier; Maigret, Jean-Eudes; Lourdin, Denis; Saiter, Allisson

    2017-10-01

    By means of fast scanning calorimetry, the glass transition of anhydrous amorphous starch has been measured. With a scanning rate of 2000Ks -1 , thermal degradation of starch prior to the glass transition has been inhibited. To certify the glass transition measurement, structural relaxation of the glassy state has been investigated through physical aging as well as the concept of limiting fictive temperature. In both cases, characteristic enthalpy recovery peaks related to the structural relaxation of the glass have been observed. Thermal lag corrections based on the comparison of glass transition temperatures measured by means of differential and fast scanning calorimetry have been proposed. The complementary investigations give an anhydrous amorphous starch glass transition temperature of 312±7°C. This estimation correlates with previous extrapolation performed on hydrated starches. Copyright © 2017 Elsevier Ltd. All rights reserved.

  18. Harvesting Water from Air: Using Anhydrous Salt with Sunlight

    KAUST Repository

    Li, Renyuan

    2018-04-02

    Atmospheric water is abundant alternative water resource, equivalent to 6 times of water in all rivers on Earth. This work screens 14 common anhydrous and hydrated salt couples in terms of their physical and chemical stability, water vapor harvesting and release capacity under relevant application scenarios. Among the salts screened, copper chloride (CuCl2), copper sulfate (CuSO4) and magnesium sulfate (MgSO4) distinguish themselves and are further made into bi-layer water collection devices, with the top layer being photothermal layer while the bottom layer being salt-loaded fibrous membrane. The water collection devices are capable of capturing water vapor out of the air with low relative humidity (down to 15 %) and releasing water under regular and even weakened sunlight (i.e. 0.7 kW/m2). The work shines light on the potential use of anhydrous salt towards producing drinking water in water scarce regions.

  19. Process for the production of sodium carbonate anhydrate

    OpenAIRE

    Oosterhof, H.; Van Rosmalen, G.M.; Witkamp, G.J.; De Graauw, J.

    2000-01-01

    The invention is directed to a process for the production of sodium carbonate-anhydrate having a bulk density of at least 800 kg/m, said process comprising: providing a suspension of solid sodium carbonate and/or solid sodium bicarbonate and/or solid double salts at least comprising one of sodium carbonate and sodium bicarbonate, in a mixture containing water and an organic, water miscible or partly water miscible solvent, which solvent influences the transition temperature below which sodium...

  20. Dry fumes purifying system using anhydrous baking soda; Procede chimique d`epuration des fumees au bicarbonate de soude anhydre

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1998-04-01

    UNISYSTEMS has developed the industrial implementation of the chemical process using anhydrous backing soda, patented by SOLVAY, for purifying fumes containing inorganic salts and sulphur oxides as polluting agents. The system can be applied to industrial processes releasing this type of polluting agents in the fumes at a temperature over 160 deg C, as it is specially indicated in purifying fumes coming from ceramic firing kilns. (authors)

  1. The Contrasting Alkylations of 4-(Dimethylaminomethyl)pyridine and 4-(Dimethylamino)pyridine: An Organic Chemistry Experiment

    Science.gov (United States)

    Jantzi, Kevin L.; Wiltrakis, Susan; Wolf, Lauren; Weber, Anna; Cardinal, Josh; Krieter, Katie

    2011-01-01

    A critical factor for the increased nucleophilicity of the pyridine nitrogen in 4-(dimethylamino)pyridine (DMAP) is electron donation via resonance from the amino group into the aromatic ring that increases electron density on the pyridine nitrogen. To explore how important this resonance effect is, 4-(dimethylaminomethyl)pyridine (DMAMP) was…

  2. Study of FeC1{sub 2} by neutron diffraction; Etude de Fe C1{sub 2} par diffraction de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Herpin, A; Meriel, P [Commissariat a l' Energie Atomique, Saclay (France)

    1959-07-01

    Magnetic measurements have shown that anhydrous ferrous chloride behaves as a metamagnetic at temperatures below 24 deg. K, in other words as an antiferromagnetic sensitive to the action of an external field of moderate strength. The aim of the neutron diffraction study is to determine precisely the arrangement of the magnetic moments, and to follow its evolution as a function of the applied field. (author) [French] Des mesures magnetiques ont montre que le chlorure ferreux anhydre se comporte comme un metamagnetique a une temperature inferieure a 24 deg. K, c'est a dire comme un antiferromagnetique sensible a l'action d'un champ exterieur modere. L'etude par diffraction de neutrons a pour buts de preciser la disposition des moments magnetiques et de suivre son evolution en fonction du champ applique. (auteur)

  3. Study of FeC1{sub 2} by neutron diffraction; Etude de Fe C1{sub 2} par diffraction de neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Herpin, A.; Meriel, P. [Commissariat a l' Energie Atomique, Saclay (France)

    1959-07-01

    Magnetic measurements have shown that anhydrous ferrous chloride behaves as a metamagnetic at temperatures below 24 deg. K, in other words as an antiferromagnetic sensitive to the action of an external field of moderate strength. The aim of the neutron diffraction study is to determine precisely the arrangement of the magnetic moments, and to follow its evolution as a function of the applied field. (author) [French] Des mesures magnetiques ont montre que le chlorure ferreux anhydre se comporte comme un metamagnetique a une temperature inferieure a 24 deg. K, c'est a dire comme un antiferromagnetique sensible a l'action d'un champ exterieur modere. L'etude par diffraction de neutrons a pour buts de preciser la disposition des moments magnetiques et de suivre son evolution en fonction du champ applique. (auteur)

  4. Thermal decomposition of anhydrous zinc and cadmium salicylates

    International Nuclear Information System (INIS)

    Kharitonov, Yu.Ya.; Tujebakhova, Z.K.

    1984-01-01

    On the basis of studying thermograms, thermogravigrams, IR absorption spectra, X-rayograms of anhydrous znc and cadmium salicylate complexes of the M(HSal) 2 composition, (where M=Zn, Cd; HSal is an anion of once deprotonated salicyclic acid H 2 Sal) and products of their thermal transformations, the processes are characterized of stage-by-stage thermal decomposition of these compounds under continuous heating in the air from room temperature to approximately 1000 deg C. It is shown that the Cd(HSal) 2 pyrolysis proceeds with the formation of CdSal at 170-250 deg C and CdO - at 320-460 deg C

  5. Crystallo-chemistry of boric anhydride and of anhydrous borates

    International Nuclear Information System (INIS)

    Bernardin, Jacques

    1968-01-01

    After an overview of various aspects related to the atomic structure of boron and of its three-bind and four-bind compounds, this report briefly presents the different forms of boric anhydride (in solid, liquid, glassy and gaseous state), presents and comments the structure of these different forms, and addresses the molten boric anhydride which is used as oxide solvent. The next part addresses the structure of anhydrous borates. It presents some generalities on their structure, and describes examples of known structures: dimers, trimers, polymers with a degree higher than three like calcium metaborate, caesium tri-borate, lithium tetraborate, or potassium pentaborate

  6. A New Thickener for CO2 Anhydrous Fracturing Fluid

    Directory of Open Access Journals (Sweden)

    Zhang Jian

    2015-01-01

    Full Text Available CO2 dry fracturing technology is well-known for its advantages. Little water is used in this technology, which is able to ease the pressure of consumption on water resources. Many abroad theoretical researches, laboratory experiments and field tests have been taken to explore the yield mechanism, the adaptability and the technology of pure liquid CO2 fracturing. These achievements have been applied to a variety of reservoirs transformation and improven the effectiveness of stimulation treatment in a degree. The researches and studies in the domestic didn’t get popular until recent years. Thus, this article firstly introduces the main development and application about pure CO2 anhydrous fracturing technology, and sums up the effect and evaluation of its fluid through application examples both in the domestic and abroad. However, although this technology has many excellent qualities, but systematic studies indicate that its proppant-carrying capacity is less competitive because of the low viscosity of pure CO2 liquid and other reasons. In a consequence, it is necessary to develop an appropriate thickener for CO2 anhydrous fracturing fluid to improve its carrying capacity. Then this article describes some studies of previous scholars about CO2 thickener. Then we put forward our own research ideas and transform it into actual experiments. Thanks to the valid performances of these tests, we successfully develop a thickener X and cosolvent B.

  7. Anhydrous crystals of DNA bases are wide gap semiconductors.

    Science.gov (United States)

    Maia, F F; Freire, V N; Caetano, E W S; Azevedo, D L; Sales, F A M; Albuquerque, E L

    2011-05-07

    We present the structural, electronic, and optical properties of anhydrous crystals of DNA nucleobases (guanine, adenine, cytosine, and thymine) found after DFT (Density Functional Theory) calculations within the local density approximation, as well as experimental measurements of optical absorption for powders of these crystals. Guanine and cytosine (adenine and thymine) anhydrous crystals are predicted from the DFT simulations to be direct (indirect) band gap semiconductors, with values 2.68 eV and 3.30 eV (2.83 eV and 3.22 eV), respectively, while the experimentally estimated band gaps we have measured are 3.83 eV and 3.84 eV (3.89 eV and 4.07 eV), in the same order. The electronic effective masses we have obtained at band extremes show that, at low temperatures, these crystals behave like wide gap semiconductors for electrons moving along the nucleobases stacking direction, while the hole transport are somewhat limited. Lastly, the calculated electronic dielectric functions of DNA nucleobases crystals in the parallel and perpendicular directions to the stacking planes exhibit a high degree of anisotropy (except cytosine), in agreement with published experimental results.

  8. Dihydrogen phosphate-water tape and layers vs dihydrogen phosphate layers tuned by hydrophobic isomeric pyridine-diamine functionalized molecules

    Science.gov (United States)

    Huang, Jing; Liu, Tong-Peng; Huo, Li-Hua; Deng, Zhao-Peng; Gao, Shan

    2017-01-01

    Assembly of six isomeric pyridine-diamine-based molecules, N,N‧-bis(pyridin-4-ylmethyl)ethane-1,2-diamine (M1), N,N‧-bis(pyridin-3-ylmethyl)ethane-1,2-diamine (M2), N,N‧-bis(pyridin-2-ylmethyl)ethane-1,2-diamine (M3), N,N‧-bis(pyridin-4-ylmethyl)propane-1,3-diamine (M4), N,N‧-bis(pyridin-3-ylmethyl)propane-1,2-diamine (M5), and N,N‧-bis(pyridin-2-ylmethyl)propane-1,3-diamine (M6), with phosphoric acid (H3PO4) in different ratio (1:2 and 1:4), leads to the formation of nine salts, H2M12+·2H2PO4-·4H2O (1), H2M22+·2H2PO4-·2H2O (2), H2M32+·2H2PO4-·2H2O (3), H4M14+·4H2PO4- (4), H4M24+·4H2PO4- (5), H4M34+·4H2PO4- (6), H2M42+·2H2PO4-·3H2O (7), 2H2M52+·4H2PO4-·2H3PO4 (8), and H2M62+·2H2PO4- (9), which have been characterized by elemental analysis, IR, TG, PL, powder and single-crystal X-ray diffraction. Structural analyses indicate that hydrogen-bonding patterns of H2PO4- anions, conformation of protonated cations can effectively influence the supramolecular architectures through diverse non-covalent interactions. Hydrous salts 1-3 and 7 present 2D and 3D host-guest supramolecular networks, in which the connection of H2PO4- anions and water molecules generates diverse tape and layer motifs. H2PO4- anions in anhydrous salts 4-6 interconnect with each other through hydrogen bonds to form two types of layers, which are joined by discrete H4M4+ cations into 3D inorganic-organic hybrid supramolecular networks. Salts 8-9 also present 2D and 3D host-guest supramolecular networks where the interconnection of H2PO4- anions and its combination with H3PO4 molecules leads to diverse layers. Luminescent analyses indicate that salts 1-9 exhibit violet and blue emission maximum in the range of 390-467 nm at room temperature.

  9. Structural basis for the transformation pathways of the sodium naproxen anhydrate-hydrate system

    DEFF Research Database (Denmark)

    Bond, Andrew; Cornett, Claus; Larsen, Flemming Hofmann

    2014-01-01

    to the monohydrate (MH) and anhydrate (AH) structures, provide a basis to rationalize the observed transformation pathways in the sodium (S)-naproxen anhydrate-hydrate system. All structures contain Na(+)/carboxylate/H2O sections, alternating with sections containing the naproxen molecules. The structure of DH...

  10. Pyridine-induced Dimensionality Change in Hybrid Perovskite Nanocrystals

    KAUST Repository

    Ahmed, Ghada H.; Yin, Jun; Bose, Riya; Sinatra, Lutfan; Alarousu, Erkki; Yengel, Emre; AlYami, Noktan; Saidaminov, Makhsud I.; Zhang, Yuhai; Hedhili, Mohamed N.; Bakr, Osman; Bredas, Jean-Luc; Mohammed, Omar F.

    2017-01-01

    of pyridine during the synthesis of methylammonium lead bromide (MAPbBr) perovskite nanocrystals can transform three-dimensional (3D) cubes into two-dimensional (2D) nanostructures. Density functional theory (DFT) calculations show that pyridine preferentially

  11. Preparation and characterization of ABS/anhydrous cobalt chloride composites

    Science.gov (United States)

    Shao, Chengli; Shang, Peng; Mao, Yapeng; Li, Qiuying; Wu, Chifei

    2018-01-01

    Anhydrous cobalt chloride (CoCl2) particles filled acrylonitrile-butadiene-styrene (ABS) composites were successfully prepared and investigated. A strong interfacial interaction between CoCl2 particles and ABS matrix was generated by heat pressing at 190 °C for 15 min. SEM results demonstrated that the particles were dispersed uniformly in the matrix. Fourier transform infrared, x-ray photoelectron spectroscopy and electron spin resonance were used for the investigation of the coordination reaction. The interfacial interaction resulted from a solid-state coordination reaction between nitrile groups (-CN) and cobalt ions (Co2+), leading to an increase in mechanical properties and glass transition temperature. Moreover, heat deflection temperatures were measured and proved to achieve an improvement of 30.6 °C when the CoCl2 content was 7 wt%.

  12. Anhydrous proton conductor based on composites of PEO and ATMP

    Energy Technology Data Exchange (ETDEWEB)

    Sun Baoying [Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084 (China); Qiu Xinping, E-mail: qiuxp@tsinghua.edu.c [Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084 (China); Zhu Wentao [Key Lab of Organic Optoelectronics and Molecular Engineering, Department of Chemistry, Tsinghua University, Beijing 100084 (China)

    2011-04-15

    A new type anhydrous PEM material based on Poly (ethylene oxide) (PEO)/Amino Trimethylene Phosphonic Acid (ATMP) composite was prepared. In this study, PEO assumed to 'grab' protons via hydrogen bond between PEO and ATMP. Based on this point, the PEO/ATMP composites were prepared firstly as the preliminary study to verify this proton conducting system. Then, PVDF was added to enhance the membrane's stability. The PVDF/PEO/ATMP composite membranes were thermally stable up to 200 {sup o}C in the studied composition ranges. The membrane had relatively compact structure by SEM images. Proton conductivity of 59% PVDF/29% PEO/12% ATMP was up to 6.71 x 10 {sup -3} S cm{sup -1} at 86 {sup o}C after doping with 7.9 wt% phosphoric acid without extra humidification.

  13. Anhydrous proton conductor based on composites of PEO and ATMP

    International Nuclear Information System (INIS)

    Sun Baoying; Qiu Xinping; Zhu Wentao

    2011-01-01

    A new type anhydrous PEM material based on Poly (ethylene oxide) (PEO)/Amino Trimethylene Phosphonic Acid (ATMP) composite was prepared. In this study, PEO assumed to 'grab' protons via hydrogen bond between PEO and ATMP. Based on this point, the PEO/ATMP composites were prepared firstly as the preliminary study to verify this proton conducting system. Then, PVDF was added to enhance the membrane's stability. The PVDF/PEO/ATMP composite membranes were thermally stable up to 200 o C in the studied composition ranges. The membrane had relatively compact structure by SEM images. Proton conductivity of 59% PVDF/29% PEO/12% ATMP was up to 6.71 x 10 -3 S cm -1 at 86 o C after doping with 7.9 wt% phosphoric acid without extra humidification.

  14. Electrocatalytic oxidations of pyridine derivatives using Ru(IV) poly pyridine complex

    International Nuclear Information System (INIS)

    Oliveira, S.M. de.

    1989-01-01

    The oxidation reactions electro catalysed by bi pyridine oxo tri pyridine ruthenium perchlorate metallic complex from selected organic substrates are studied. The obtained results are compared with forecasting results showing the coherence of suggested mechanism. The substrates 2-, 2- and 4- picolines with its respective 1-oxides and 1,2 -; 1,3 - and 1,4 - dimethyl pyridine chloride salts were analysed. The oxidation of toluene as reference substrate was also studied and the mass spectra of oxidation products were interpreted. (M.C.K.)

  15. 2-Aminobenzoic acid–4-(pyridin-4-yldisulfanyl)pyridine (1/1)

    OpenAIRE

    Hadi D. Arman; Trupta Kaulgud; Edward R. T. Tiekink

    2011-01-01

    The title 1:1 co-crystal, C7H7NO2·C10H8N2S2, features a highly twisted 4-(pyridin-4-yldisulfanyl)pyridine molecule [dihedral angle between the pyridine rings = 89.06 (10)°]. A small twist is evident in the 2-aminobenzoic acid molecule, with the C—C—C—O torsion angle being −7.7 (3)°. An N—H...O hydrogen bond occurs in the 2-aminobenzoic acid molecule. In the crystal, molecules are linked by O&#...

  16. Riboflavin Production during Growth of Micrococcus luteus on Pyridine

    OpenAIRE

    Sims, Gerald K.; O'Loughlin, Edward J.

    1992-01-01

    Micrococcus luteus produced 29 μM riboflavin during growth on 6.5 mM pyridine but not during growth on other substrates. On the basis of the results of radiolabelling studies, riboflavin was not directly synthesized from pyridine. Pyridine may interfere with riboflavin biosynthesis or elicit a general stress response in M. luteus.

  17. Automated thin-film analyses of anhydrous interplanetary dust particles in the analytical electron microscope

    Science.gov (United States)

    Bradley, J. P.; Germani, M. S.; Brownlee, D. E.

    1989-01-01

    An AEM apparatus equipped with digital beam control has obtained quantitative point-count analyses of thin sections taken from eight anhydrous chondritic interplanetary dust particles (IDPs); between 200 and 500 X-ray analyses were collected from each thin section and analyzed for Mg, Al, Si, S, Ca, Cr, Mn, Fe, and Ni. Two types of anhydrous chondritic aggregates were observed in the eight IDPs: one highly porous, the other less so. The eight anhydrous IDPs are characterizable as mixtures of fine- and coarse-grained aggregates, large mineral grains, glass, and carbonaceous materials. Their elemental concentrations follow those of solar abundances, suggesting that they are unperturbed by aqueous alteration.

  18. Interaction of alcohols with the anhydrous silico-12-molybdic acid

    International Nuclear Information System (INIS)

    Pinchuk, I.N.; Chuvaev, V.F.; Ovchinnikova, N.S.; Zhuravlev, L.T.; Spitsyn, V.I.

    1984-01-01

    A study was made on interaction of methanol, ethanol and isopropanol with silico-12-molybdic acid (H 4 SiMo 12 O 40 (SMA). It was revealed that anhydrous SMA at room temperature adds a sufficient amount of alcohol from gaseous phase with formation of solvates of the following compositions: H 4 SiMo 12 O 40 x3CH 3 OH, H 4 SiMo 12 O 40 x5C 2 H 5 OH and H 4 SiMo 12 O 40 x3C 3 H 7 OH. Thermal decomposition of SMA solvates was studied and the mechanism of solid-phase heteropolyacid interaction with alcohols was suggested. Temperature ranges of separate catalytic and redox processes were established. Specificity of activity and peculiarities of heteropolyacid transformation in the course of reaction were investigated. It was shown that formation of deprotonated phases of SiMosub(12)Osub(38-y/2) or Csub(n)SiMosub(12)Osub(38-x) type during SMA interaction with alcohol can't be probably reduced to the simple succession of reduction and dehydration reactions

  19. Transport of anhydrous ammoniac - risk assessment; Le transport de l'ammoniac anhydre - analyse et estimation des risques: rapport de synthese

    Energy Technology Data Exchange (ETDEWEB)

    Castellano, S; Degrange, J P; Hubert, P; Pages, P; Lamblin, J

    1989-12-01

    This risk analysis of anhydrous ammonia transport in France was done within a study initiated by the Department of dangerous goods of the Ministry of transport. The study deals with the road and rail transportation of bulk anhydrous ammonia. After analysis of transport system and traffic, the transport accident risks are estimated, as well as their distribution on the French territory. Finally after a synthesis of results, a number of safety measures to be undertaken were identified. This is a joint study of SMC-CEPN, with a specific role of SEMA-METRA-CONSEIL concerning the traffic frequency, and the center for risk evaluation concerning nuclear safety.

  20. Criticality studies; Etudes de criticite

    Energy Technology Data Exchange (ETDEWEB)

    Breton, D; Lecorche, P; Clouet d' Orval, Ch [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1964-07-01

    Criticality studies made at the Commissariat a l'Energie atomique deal on the one hand with experiments on plutonium and uranium solutions, on the other hand with theoretical work on the development and use of computation, methods for the resolution of problems concerning the nuclear safety of chemical and metallurgical plants. I - Since 1958 the experimental studies have dealt with homogeneous media constituted by a fissile salt dissolved in light water. Developed using the reactor Proserpine, the experiments have been carried on at Saclay on the Alecto assemblies where solutions of plutonium or of 90 p.100 - enriched uranium can be made critical. The results already obtained relate to critical masses of cylindrical tanks of diameters from 20 to 50 cm. reflected in several ways (water, concrete, etc. . ) at concentrations up to 100 g/liter. Physical measurements (spectra, reactor noises) and interaction measurements complete the results. Other experiments relating to plutonium solutions were begun in 1963, at the Valduc Center. They deal with the study of critical masses of annular vessels of external diameter 50 cm and internal diameter varying from 10 to 30 cm. These vessels can be water reflected internally, externally, or both. Two of these vessels have been studied in interaction for various geometries. Slabs of various thicknesses were also studied. II - The studies thus undertaken allowed the development of methods of computation which have been tested on several experiments. Particular use has been made of the possibilities of calculations based on transport theory and on Monte Carlo methods. All these theoretical studies are applied to the design and control of industrial plants from the point of view of safety. (authors) [French] Les etudes de criticite effectuees au CEA comportent d'une part des experiences sur des solutions de plutonium et d'uranium enrichi, d'autre part des travaux theoriques portant sur la mise au point et l'exploitation de methodes

  1. Study of alkaline-earth element complexes in anhydrous acetic acid

    International Nuclear Information System (INIS)

    Petit, N.

    1968-10-01

    We have studied the complexes of alkaline-earth elements in anhydrous acetic acid. Using glass-electrode potentiometry we have studied the titration of alkaline earth acetates with perchloric acid which is the strongest acid in anhydrous acetic acid. These titrations have shown that the basic strength of these acetates increases as follows: Mg 4 ); the mixed acetate-acid sulfate complex of barium: Ba (OAc)(HSO 4 ); the mixed acetate-chloride of barium: Ba (OAc)(Cl). (author) [fr

  2. Dehydration Behaviour of Borax Pentahydrate to Anhydrous Borax by Multi-Stage Heating in a Fluidized

    OpenAIRE

    ŞAHİN, Ömer

    2002-01-01

    In order to optimize the anhydrous borax process in a fluidized bed calcinator, it is absolutely necessary to study the dehydration behaviour of borax pentahydrate. It was found that the basic feature of the dehydration of borax pentahydrate to anhydrous borax is concerned with the conditions employed. The bulk density and sodium borate content of the end product were determined to be a function of number of stages of temperature of the dehydration period in the fluidized bed. It...

  3. The Effect of Compaction Force on the Transition to Hydrate of Anhydrous Aripiprazole.

    Science.gov (United States)

    Togo, Taichiro; Taniguchi, Toshiya; Nakata, Yoshitaka

    2018-01-01

    Aripiprazole (APZ) is used to treat schizophrenia and is administered as a tablet containing the anhydrous form of APZ. In this study, the effect of compaction force on the crystal form transition was investigated. The crystalline state was observed by X-ray diffraction (XRD). APZ Anhydrous Form II was compacted into tablets. The XRD intensity of anhydrous APZ became lower with higher compressive force. The degree of crystallinity decreased with the compaction force. The powder and the compacted tablets of anhydrous APZ were stored for one week under 60°C and 75% relative humidity. The powder showed no crystal form transition after storage. For the tablets, however, XRD peaks of APZ hydrate were observed after storage. The tablets compacted with higher force showed the higher XRD diffraction intensity of hydrate form. We concluded that the crystallinity reduction of APZ Anhydrous Form II by compaction caused and accelerated the transition to hydrate under high temperature and humidity conditions. In order to manufacture crystallographically stable tablets containing anhydrous APZ, it is important to prevent this crystallinity reduction during compaction.

  4. Water in Nominally Anhydrous Minerals from Nakhlites and Shergottites

    Science.gov (United States)

    Peslier, Anne H.

    2013-01-01

    Estimating the amount of water in the interior of terrestrial planets has tremendous implications on our understanding of solar nebula evolution, planet formation and geological history, and extraterrestrial volcanism. Mars has been a recent focus of such enquiry with complementary datasets from spacecrafts, rovers and martian meteorite studies. In planetary interiors, water can be dissolved in fluids or melts and hydrous phases, but can also be locked as protons attached to structural oxygen in lattice defects in nominally anhydrous minerals (NAM) such as olivine, pyroxene, or feldspar [1-3]. Measuring water in Martian meteorite NAM is challenging because the minerals are fragile and riddled with fractures from impact processes that makes them break apart during sample processing. Moreover, curing the sample in epoxy causes problems for the two main water analysis techniques, Fourier transform infrared spectrometry (FTIR) and secondary ionization mass spectrometry (SIMS). Measurements to date have resulted in a heated debate on how much water the mantle of Mars contains. SIMS studies of NAM [4], amphiboles [5], and apatites [6-8] from Martian meteorites report finding enough water in these phases to infer that the martian mantle is as hydrous as that of the Earth. On the other hand, a SIMS study of glass in olivine melt inclusions from shergottites concludes that the Martian mantle is much drier [9]. The latter interpretation is also supported by the fact that most martian hydrous minerals generally have the relevant sites filled with Cl and F instead of H [10,11]. As for experimental results, martian basalt compositions can be reproduced using water as well as Cl in the parent melts [12,13]. Here FTIR is used to measure water in martian meteorite minerals in order to constrain the origin of the distribution of water in martian meteorite phases.

  5. Thermometric titration of acids in pyridine.

    Science.gov (United States)

    Vidal, R; Mukherjee, L M

    1974-04-01

    Thermometric titration of HClO(4), HI, HNO(3), HBr, picric acid o-nitrobenzoic acid, 2,4- and 2,5-dinitrophenol, acetic acid and benzoic acid have been attempted in pyridine as solvent, using 1,3-diphenylguanidine as the base. Except in the case of 2,5-dinitrophenol, acetic acid and benzoic acid, the results are, in general, reasonably satisfactory. The approximate molar heats of neutralization have been calculated.

  6. UV-VIS-spectroscopical investigations of the green solutions of nitrogen triiodide-1-pyridine in pyridine

    International Nuclear Information System (INIS)

    Kerbachi, R.; Minkwitz, R.; Engelhardt, U.

    1984-01-01

    Solid, crystalline nitrogen triiodide-1-pyridine has a polymeric structure similar to that of nitrogen triiodide-1-ammonia consisting of NI 4 tetrahedra linked to chains by common vertices. The solubility of both compounds in liquid ammonia is accomplished by a degradation of the chains involving protolysis equilibria with monoiodamine. UV-VIS-spectra of the green solutions of NI 3 pyridine in the aprotic solvent pyridine between -30 and -16 0 C and Raman-spectra of these solutions at -30 0 C or quenched with liquid nitrogen at -196 0 C show, that the chains are retained here at least to some extent. The solutions are instable even at low temperatures and decompose in a first order reaction yielding nitrogen and iodine. The halflife period at -16 0 C is 5 hours, at -30 0 C 20 hours. (author)

  7. Pyridine-Based Conjugated Polymers: Photophysical Properties and Light- Emitting Diodes

    National Research Council Canada - National Science Library

    Epstein, A

    1997-01-01

    We study the photophysical properties of the pyridine-based polymers poly (p-pyridyl vinylene) (PPyV) and poly (p-pyridine) (PPy). The primary photoexcitations in the pyridine-based polymers are singlet excitons...

  8. Synthesis of fertilizers nitrogen and 15N-enriched. Pt. I. Production of enriched 15N-anhydrous ammonia

    International Nuclear Information System (INIS)

    Bendassolli, J.A.; Mortatti, J.; Trivelin, P.C.O.; Victoria, R.L.

    1988-01-01

    The results of 15 N-anhydrous ammonia production through reaction between 15 N-enriched ammonium sulphate and sodium hidroxide are reported. Influence of the reaction temperature, carrier gas flow, reaction time and mass of ammonium sulphate on the production of anhydrous ammonia were studied. Analyses for the cost of production of 5% atoms in 15 N-enriched anhydrous ammonia were made. (M.A.C.) [pt

  9. 2-[(Pyridin-3-ylaminomethyl]phenol

    Directory of Open Access Journals (Sweden)

    Jing Xu

    2011-12-01

    Full Text Available In the title compound, C12H12N2O, the aromatic rings at either ends of the –CH2–NH– link are twisted by 68.79 (7°. In the crystal, the hydroxy substituent is a hydrogen-bond donor to the N atom of the pyridine ring of an adjacent molecule, and the hydrogen bond generates a chain along the b axis; it is also a hydrogen-bond acceptor to the amino group of another adjacent molecule. The two hydrogen bonds lead to the formation of a layer structure.

  10. Microwave Determination of the Structure of Pyridine

    Energy Technology Data Exchange (ETDEWEB)

    Bak, B.; Hansen, L.; Rastrup-Andersen, J. [Chemical Laboratory of the University of Copenhagen, Copenhagen (Denmark)

    1954-12-15

    2‐, 3‐, and 4‐mono‐deutero‐pyridine have been prepared and the microwave spectra recorded. For each of the isotopic species 11—12 transitions (Q‐ and R‐branch lines) were localized, a number of which could be identified by their Stark effect. For all three species rotational constants of high precision were calculated. The material so provided in connection with known rotational constants for ordinary pyridine is insufficient for a complete determination of the ten geometrical parameters of the molecule. Seven models with a choice of C – H distances close to the correct value (1.075‐1.085 A) were considered one of which was shown to be consistent with electron‐diffraction work and current valence theory. In this model d(N – C(2)) = 1.340±0.005; d(C(2) – C(3)) = 1.390±0.005; d(C(3) – C(4)) = 1.400±0.005 A. The valence angles in the aromatic ring (starting with the C(6) – N – C(2) angle) are: 116° 42′; 124° 00′; 118° 36′; 118° 06′.

  11. Preparation of nucleoside-pyridine hybrids and pyridine attached acylureas from an unexpected uracil ring-opening and pyridine ring-forming sequence

    Institute of Scientific and Technical Information of China (English)

    Xue Sen Fan; Xia Wang; Xin Ying Zhang; Dong Feng; Ying Ying Qu

    2009-01-01

    Novel pyrimidine nucleoside-3,5-dicyanopyridine hybrids (4) or pyridine attached acylureas (5) were selectively and efficiently prepared from the reaction of 2'-deoxyuridin-5-yl-methylene malonortitrile (1), malononitrile (2) and thiophenol (3) or from an unexpected uracil ring-opening and pyridine ring-forming sequence via the reaction of 1 and 3. It is the first time such a sequence has ever been reported.

  12. ETUDE - European Trade Union Distance Education.

    Science.gov (United States)

    Creanor, Linda; Walker, Steve

    2000-01-01

    Describes transnational distance learning activities among European trade union educators carried out as part of the European Trade Union Distance Education (ETUDE) project, supported by the European Commission. Highlights include the context of international trade union distance education; tutor training course; tutors' experiences; and…

  13. Cd(II) and Zn(II) Complexes Containing N,N'-Bidentate N-(Pyridin-2-ylmethylene)cyclopentanamine: Synthesis, Characterisation and Methyl Methacrylate Polymerisation

    Energy Technology Data Exchange (ETDEWEB)

    Song, Yu Jin; Lee, Ha Jun; Lee, Hyo Sun [Kyungpook National University, Daeju (Korea, Republic of)

    2014-09-15

    The reaction between [CdBr{sub 2}·4H{sub 2}O] and anhydrous [ZnCl{sub 2}] with N,N'-bidentate N-(pyridin-2-ylmethylene)- cyclopentanamine (impy) in ethanol yields dimeric [(impy)Cd(μ-Br)Br]2 and monomeric [(impy)ZnCl{sub 2}] complexes, respectively. The X-ray crystal structure of Cd(II) and Zn(II) complexes revealed that the cadmium atom in [(impy)Cd(μ-Br)Br]2 and zinc in [(impy)ZnCl{sub 2}] formed a distorted trigonal–bipyramidal and tetrahedral geometry, respectively. Both complexes showed moderate catalytic activity for the polymerisation of methyl methacrylate (MMA) in the presence of modified methylaluminoxane (MMAO), with polymethylmethacrylate (PMMA) syndiotacticity of about 0.70.

  14. Formation of a new crystalline form of anhydrous β-maltose by ethanol-mediated crystal transformation.

    Science.gov (United States)

    Verhoeven, Nicolas; Neoh, Tze Loon; Ohashi, Tetsuya; Furuta, Takeshi; Kurozumi, Sayaka; Yoshii, Hidefumi

    2012-04-01

    β-Maltose monohydrate was transformed into an anhydrous form by ethanol-mediated method under several temperatures with agitation. A new stable anhydrous form of β-maltose (Mβ(s)) was obtained, as substantiated by the X-ray diffraction patterns. Mβ(s) obtained by this method presented a fine porous structure, resulting in greater specific surface area compared to those of β-maltose monohydrate and anhydrous β-maltose obtained by vacuum drying (Mβ(h)). The crystal transformation presumably consisted of two steps: dehydration reaction from the hydrous to amorphous forms and crystal formation from the amorphous forms to the noble anhydrous form. The kinetics of these reactions were determined by thermal analysis using Jander's equation and Arrhenius plots. The overall activation energies of the dehydration reaction and the formation of anhydrous maltose were evaluated to be 100 and 90 kJ/mol, respectively. Copyright © 2012 Elsevier Ltd. All rights reserved.

  15. Outcomes of curettage and anhydrous alcohol adjuvant for low-grade chondrosarcoma of long bone.

    Science.gov (United States)

    Kim, Wanlim; Han, Ilkyu; Kim, Eo Jin; Kang, Seungcheol; Kim, Han-Soo

    2015-06-01

    Low-grade chondrosarcoma of long bones can be treated successfully with extended intralesional curettage using adjuvants. However, there is no study reporting the use of anhydrous alcohol as an adjuvant in the treatment of low-grade chondrosarcoma. We asked (1) whether intralesional curettage and anhydrous alcohol adjuvant for low-grade chondrosarcoma is associated with good oncologic outcomes; and we report (2) the complications of the procedure. Thirty-six patients (13 men, 23 women) with a mean age of 46 years (range, 18-67 years) were treated for low-grade chondrosarcoma and followed up for a median of 62 months (range, 24-169 months). After intralesional curettage, and additional burring, anhydrous alcohol was used as an adjuvant therapy. At the time of last follow-up, there were no local recurrences or distant metastases. Six patients developed complications: 4 postoperative fractures (11%), 1 intra-articular loose body (3%) and 1 postoperative joint stiffness (3%). Anhydrous alcohol is a reasonable adjuvant for the curettage of low-grade chondrosarcoma of long bones. A long-term follow-up study is necessary, considering the slow biological progression of low-grade chondrosarcoma. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. 7 CFR 58.715 - Cream, plastic cream and anhydrous milkfat.

    Science.gov (United States)

    2010-01-01

    ... Service 1 Quality Specifications for Raw Material § 58.715 Cream, plastic cream and anhydrous milkfat. These food products shall be pasteurized, sweet, have a pleasing and desirable flavor and be free from objectionable flavors, and shall be obtained from milk which complies with the quality requirements as specified...

  17. 2-Aminobenzoic acid–4-[2-(pyridin-4-ylethyl]pyridine (2/1

    Directory of Open Access Journals (Sweden)

    Hadi D. Arman

    2013-11-01

    Full Text Available The asymmetric unit of the title co-crystal, C12H12N2·2C7H7NO2, comprises a centrosymmetric 4-[2-(pyridin-4-ylethyl]pyridine molecule and a 2-aminobenzoic acid molecule in a general position. The acid has a small twist between the carboxylic acid residue and the ring [dihedral angle = 7.13 (6°] despite the presence of an intramolecular N—H...O(carbonyl hydrogen bond. Three-molecule aggregates are formed via O—H...N(pyridyl hydrogen bonds, and these are connected into supramolecular layers in the bc plane by N—H...O(carbonyl hydrogen bonds and π–π interactions between pyridine and benzene rings [inter-centroid distance = 3.6332 (9 Å]. Layers are connected along the a axis by weak π–π interactions between benzene rings [3.9577 (10 Å].

  18. Rapid anaerobic mineralization of pyridine in a subsurface sediment inoculated with a pyridine-degrading Alcaligenes sp

    Energy Technology Data Exchange (ETDEWEB)

    Ronen, Z; Bollag, J M [Pennsylvania State Univ., University Park, PA (United States). Lab. of Soil Biochemistry

    1992-05-01

    A denitrifying bacterium capable of pyridine mineralization under anaerobic conditions was isolated from polluted soil. The bacterium, identified as Alcaligenes sp., was used in inoculation experiments. A subsurface sediment from a polluted site was amended with 10 {mu}g/g {sup 14}C-labeled pyridine, and 250 {mu}g/g nitrate, and then inoculated with the bacterium at an inoculum size of 4.5x10{sup 7} cells/g. After 44 h incubation at 28deg C under anaerobic conditions, 67% of the radioactivity was recovered as {sup 14}CO{sub 2}: 2% was extracted with 50% methanol, and 24% was recovered by combustion of the sediment. Analysis of the methanol extract revealed that no pyridine could be detected in the inoculated sediment. In contrast, mineralization of pyridine by the native microflora in the sediment occurred much more slowly: After 7 days of incubation only 10% of the added radioactivity was recovered as {sup 14}CO{sub 2}. At an inoculum size of 2x10{sup 3} cells/g pyridine mineralization was not as effective as at an inoculum size of 2x10{sup 7} cells/g. It is presumed that suppression of the introduced bacteria by the native microflora of the sediment prevents degradation at a low inoculum size. Amending the sediment with nitrate and phosphate improved pyridine mineralization by the introduced bacterium. These findings demonstrate the feasibility of using soil inoculation anaerobically for the bioremediation of pyridine-polluted soils. (orig.).

  19. Lean hydrous and anhydrous bioethanol combustion in spark ignition engine at idle

    International Nuclear Information System (INIS)

    Chuepeng, Sathaporn; Srisuwan, Sudecha; Tongroon, Manida

    2016-01-01

    Highlights: • Anhydrous ethanol burns fastest in uncalibrated engine at equal equivalence ratio. • The leaner hydrous ethanol combustion tends to elevate the COV in imep. • Hydrous ethanol consumption was 10% greater than anhydrous ethanol at ϕ = 0.67 limit. • Optimizing alternative fuel engine at idle for stability and emission is suggested. - Abstract: The applications of anhydrous bioethanol to substitute or replace gasoline fuel have shown to attain benefits in terms of engine thermal efficiency, power output and exhaust emissions from spark ignition engines. A hydrous bioethanol has also been gained more attention due to its energy and cost effectiveness. The main aim of this work is to minimize fuel quantity injected to the intake ports of a four-cylinder engine under idle condition. The engine running with hydrous ethanol undergoes within lean-burn condition as its combustion stability is analyzed using an engine indicating system. Coefficient of variation in indicated mean effective pressure is an indicator for combustion stability with hydrocarbon and carbon monoxide emission monitoring as a supplement. Anhydrous ethanol burns faster than hydrous ethanol and gasoline in the uncalibrated engine at the same fuel-to-air equivalence ratio under idle condition. The leaner hydrous ethanol combustion tends to elevate the coefficient of variation in indicated mean effective pressure. The experimental results have found that the engine consumes greater hydrous ethanol by 10% on mass basis compared with those of anhydrous ethanol at the lean limit of fuel-to-air equivalence ratio of 0.67. The results of exhaust gas analysis were compared with those predicted by chemical equilibrium analysis of the fuel-air combustion; the resemble trends were found. Calibrating the alternative fueled engine for fuel injection quantity should be accomplished at idle with combustion stability and emissions optimization.

  20. Functional conjugated pyridines via main-group element tuning.

    Science.gov (United States)

    Stolar, Monika; Baumgartner, Thomas

    2018-03-29

    Pyridine-based materials have seen widespread attention for the development of n-type organic materials. In recent years, the incorporation of main-group elements has also explored significant advantages for the development and tunability of organic conjugated materials. The unique chemical and electronic structure of main-group elements has led to several enhancements in conventional organic materials. This Feature article highlights recent main-group based pyridine materials by discussing property enhancements and application in organic electronics.

  1. Synthesis of pyridines over zeolites in gas phase

    Czech Academy of Sciences Publication Activity Database

    Slobodník, M.; Hronec, M.; Cvengrošová, Z.; Voláková, Martina; Čejka, Jiří

    2007-01-01

    Roč. 72, 5-6 (2007), s. 618-628 ISSN 0010-0765 Grant - others:VEGA(XE) 1/2459/05 Institutional research plan: CEZ:AV0Z40400503 Source of funding: R - rámcový projekt EK Keywords : pyridine * pyridine bases * ZSM-5 * ethanol Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 0.879, year: 2007

  2. Electroenzymatic Reactions With Oxygen on Laccase-Modified Electrodes in Anhydrous (Pure) Organic Solvent

    DEFF Research Database (Denmark)

    Yarapolov, A.; Shleev, S.; Zaitseva, E.

    2007-01-01

    in two different ways: (i) by studying the electroreduction of oxygen in anhydrous DMSO via a direct electron transfer mechanism without proton donors and (ii) by doing the same experiments in the presence of laccase substrates, which display in pure organic solvents both the properties of electron......The electroenzymatic reactions of Trametes hirsuta laccase in the pure organic solvent dimethyl sulfoxide (DMSO) have been investigated within the framework for potential use as a catalytic reaction scheme for oxygen reduction. The bioelectrochemical characteristics of laccase were investigated...... donors as well as the properties of weak acids. The results obtained with laccase in anhydrous DMSO were compared with those obtained previously in aqueous buffer. It was shown that in the absence of proton donors under oxygenated conditions, formation of superoxide anion radicals is prevented at bare...

  3. Anhydrous proton conducting composite membranes containing Nafion and triazole modified POSS

    International Nuclear Information System (INIS)

    Lei, M.; Wang, Y.G.; Zhang, F.F.; Huang, C.; Xu, X.; Zhang, R.; Fan, D.Y.

    2014-01-01

    Development of membrane electrolytes having reasonable proton conductivity and mechanical strength under anhydrous conditions is of great importance for proton exchange membrane fuel cells operated at elevated temperature. With the introduction of triazole modified polyhedral oligomeric silsesquioxanes (Tz-POSS) into Nafion membrane, the formed composite electrolytes exhibit improved mechanical properties compared to pristine Nafion membrane due to the well distribution of Tz-POSS inside the membrane. The anhydrous proton conductivity of the formed composite membranes increases initially with the increase in temperature, reaching about 0.02 Scm −1 at 140 °C. With further increase in temperature to about 150 °C, the composite membrane reaches its glass transition point above which the proton conductivity decreases dramatically. The performance of assembled single cell from composite membrane is slightly dependent on humidification conditions at 95 °C, reaching 0.45 V at 600 mAcm −2 using hydrogen and oxygen as reaction gases

  4. Method for application of nitrogen-15-labeled anhydrous ammonia to small plots

    International Nuclear Information System (INIS)

    Sanchez, C.A.; Blackmer, A.M.

    1987-01-01

    A method is described that permits precise application of anhydrous ammonia in bands to plots of the size often used in 15 N-tracer studies. This method involves placing a stainless-steel capillary tube in the soil where the ammonia is to be banded, attaching this tube to a cylinder of ammonia, and then pulling the tube through the soil with deposition of ammonia as an even band. The procedure has marked advantages over previously described methods because it can be used with mixtures of anhydrous ammonia and nitrification inhibitors and because the soil environment at the point of application is representative of the soil environment found when a conventional applicator is used

  5. Ab initio and DFT studies of the structure and vibrational spectra of anhydrous caffeine

    Science.gov (United States)

    Srivastava, Santosh K.; Singh, Vipin B.

    2013-11-01

    Vibrational spectra and molecular structure of anhydrous caffeine have been systematically investigated by second order Moller-Plesset (MP2) perturbation theory and density functional theory (DFT) calculations. Vibrational assignments have been made and many previous ambiguous assignments in IR and Raman spectra are amended. The calculated DFT frequencies and intensities at B3LYP/6-311++G(2d,2p) level, were found to be in better agreement with the experimental values. It was found that DFT with B3LYP functional predicts harmonic vibrational wave numbers more close to experimentally observed value when it was performed on MP2 optimized geometry rather than DFT geometry. The calculated TD-DFT vertical excitation electronic energies of the valence excited states of anhydrous caffeine are found to be in consonance to the experimental absorption peaks.

  6. Synthesis of anhydrous K2TiOF4 via a mild hydrothermal method

    Science.gov (United States)

    Felder, Justin B.; Yeon, Jeongho; zur Loye, Hans-Conrad

    2015-10-01

    The synthesis of anhydrous K2TiOF4 has been previously attempted by transforming precursor compounds, such as the peroxide (K2Ti(O2)F4), hydrate (K2TiOF4·H2O) and fluoride (K2TiF6). Due to the large structural differences between these precursors and the anhydrous oxyfluorides, however, these preparations have been unsuccessful. Therefore, a direct method of synthesis has been employed to grow single crystals of K2TiOF4 that were characterized by single crystal x-ray diffraction. K2TiOF4 was found to be isostructural with the previously known K2VOF4.

  7. 78 FR 78393 - Standard on the Storage and Handling of Anhydrous Ammonia; Extension of the Office of Management...

    Science.gov (United States)

    2013-12-26

    ...OSHA solicits public comments concerning its proposal to extend OMB approval of the information collection requirements specified in the Storage and Handling of Anhydrous Ammonia Standard (29 CFR 1910.111). Paragraphs (b)(3) and (b)(4) of the Standard have paperwork requirements that apply to non-refrigerated containers and systems and refrigerated containers, respectively; employers use these containers and systems to store and transfer anhydrous ammonia in the workplace.

  8. Pyridinium bis(pyridine-κNtetrakis(thiocyanato-κNferrate(III

    Directory of Open Access Journals (Sweden)

    Sergii I. Shylin

    2013-06-01

    Full Text Available In the title compound, (C5H6N[Fe(NCS4(C5H5N2], the FeIII ion is coordinated by four thiocyanate N atoms and two pyridine N atoms in a trans arrangement, forming an FeN6 polyhedron with a slightly distorted octahedral geometry. Charge balance is achieved by one pyridinium cation bound to the complex anion via N—H...S hydrogen bonding. The asymmetric unit consists of one FeIII cation, four thiocyanate anions, two coordinated pyridine molecules and one pyridinium cation. The structure exhibits π–π interactions between pyridine rings [centroid–centroid distances = 3.7267 (2, 3.7811 (2 and 3.8924 (2 Å]. The N atom and a neighboring C atom of the pyridinium cation are statistically disordered with an occupancy ratio of 0.58 (2:0.42 (2.

  9. Alkylation of pyridines at their 4-positions with styrenes plus yttrium reagent or benzyl Grignard reagents.

    Science.gov (United States)

    Mizumori, Tomoya; Hata, Takeshi; Urabe, Hirokazu

    2015-01-02

    A new regioselective alkylation of pyridines at their 4-position was achieved with styrenes in the presence of yttrium trichloride, BuLi, and diisobutylaluminium hydride (DIBAL-H) in THF. Alternatively, similar products were more simply prepared from pyridines and benzyl Grignard reagents. These reactions are not only a useful preparation of 4-substituted pyridines but are also complementary to other relevant reactions usually giving 2-substituted pyridines. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Instrumental performance of an etude after three methods of practice.

    Science.gov (United States)

    Vanden Ark, S

    1997-12-01

    For 80 fifth-grade students three practice conditions (mental, mental with physical simulation, and physical with singing) produced significant mean differences in instrumental performance of an etude. No significant differences were found for traditional, physical practice.

  11. 2-Amino­benzoic acid–4-[2-(pyridin-4-yl)eth­yl]pyridine (2/1)

    OpenAIRE

    Arman, Hadi D.; Tiekink, Edward R. T.

    2013-01-01

    The asymmetric unit of the title co-crystal, C12H12N2·2C7H7NO2, comprises a centrosymmetric 4-[2-(pyridin-4-yl)ethyl]pyridine molecule and a 2-aminobenzoic acid molecule in a general position. The acid has a small twist between the carboxylic acid residue and the ring [dihedral angle = 7.13 (6)°] despite the presence of an intramolecular N—H...O(carbonyl) hydrogen bond. Three-molecule aggregates are formed via O—H...N(pyridyl) hydrogen bonds, and these are connecte...

  12. Crystal field influence on vibration spectra: anhydrous uranyl chloride and dihydroxodiuranyl chloride tetrahydrate

    International Nuclear Information System (INIS)

    Perrin, Andre; Caillet, Paul

    1976-01-01

    Vibrational spectra of anhydrous uranyl chloride UO 2 Cl 2 and so called basic uranyl chloride: dihydroxodiuranyl chloride tetrahydrate /UO 2 (OH) 2 UO 2 /Cl 2 (H 2 O) 4 are reported. Factor group method analysis leads for the first time to complete and comprehensive interpretation of their spectra. Two extreme examples of crystal field influence on vibrational spectra are pointed out: for UO 2 Cl 2 , one is unable to explain spectra without taking into account all the elements of primitive crystalline cell, whilst for dihydroxodiuranyl dichloride tetrahydrate the crystal packing has very little effect on vibrational spectra [fr

  13. Using microkinetic analysis to search for novel anhydrous formaldehyde production catalysts

    DEFF Research Database (Denmark)

    Li, Han-Jung; Lausche, Adam C.; Peterson, Andrew A.

    2015-01-01

    Abstract Direct dehydrogenation of methanol to produce anhydrous formaldehyde is investigated using periodic density functional theory (DFT) and combining the microkinetic model to estimate rates and selectivities on stepped (211) surfaces under a desired reaction condition. Binding energies...... that explicitly includes the effects of adsorbate coverage on the rates and selectivities as well as the volcano plots are obtained. Our results show that most of the stepped (211) pure-metallic surfaces such as Au, Pt, Pd, Rh, Ru, Ni, Fe, and Co are located in a region of low activity and selectivity toward CH2O...

  14. Electrolysis of a nitrosyl hexafluoro-molybdate in anhydrous hydrogen fluoride

    International Nuclear Information System (INIS)

    Mougin, Jacques

    1972-01-01

    This thesis addresses the field of irradiated fuel reprocessing, and more particularly the study of the formation of molybdenum hexafluoride (MoF_6) by electrolysis of nitrosyl hexafluoro-molybdate (NOMoF_6) in solution in HF. The author presents the conditions of preparation of an electrolysis in anhydrous HF: solvent purification and control, production of a reference electrode, potential-kinetic study of the behaviour of materials selected for the electrode. The author then addresses the actual hydrolysis of the solution of nitrosyl hexafluoro-molybdate [fr

  15. Relationship between Al content and substitution mechanism of Al-bearing anhydrous bridgmanites

    Science.gov (United States)

    Noda, M.; Inoue, T.; Kakizawa, S.

    2017-12-01

    It is considered that two substitution mechanisms, Tschermak substitution and oxygen vacancy substitution, exist in MgSiO3 bridgmanite for the incorporation of Al in anhydrous condition. Kubo and Akaogi (2000) has conducted the phase equilibrium experiment in the system MgSiO3-Al2O3, and established the phase diagram up to 28 GPa. However the careful observation in the bridgmanite shows that the chemical compositions are slightly deviated from Tschermak substitution join. The same tendency can be also observed in the run products by Irifune et al. (1996). This result indicates that pure Tschermak substitution bridgmanite cannot be stable even in the MgSiO3-Al2O3 join experiment. However, the previous studies used powder samples as the starting materials, so the absorbed water may affect the results. Therefore, we tried to conduct the experiment in the join MgSiO3-Al2O3 in extremely anhydrous condition to clarify whether the pure Tschermak substitution bridgmanite can be stable or not. In addition, we also examined the stability of oxygen vacancy bridgmanite in the extremely anhydrous condition for the comparison. The high pressure synthesis experiments were conducted at 28 GPa and 1600-1700° for 1hour using a Kawai-type multi-anvil apparatus. Four different Al content samples were prepared as the starting materials along the ideal substitution line of Tschermak (Al=0.025, 0.05, 0.1, 0.15 mol) and oxygen-vacancy (Al=0.025, 0.05, 0.075, 0.1 mol) substitutions, respectively (when total cation of 2). The glass rods were used as the starting materials to eliminate the absorbed water on the sample surface. The chemical compositions of the synthesized bridgmanite could not be measured by EPMA because of small grain size less than submicron. Therefore the chemical compositions were estimated from the result of the XRD pattern by subtracting the amount of the other phases. The estimated chemical compositions of Tschermak substitution bridgmanites were consistent with the

  16. Some physical properties of anhydrous and hydrated Brownmillerite doped with NaF

    International Nuclear Information System (INIS)

    Hassaan, M.Y.; El Desoky, M.M.; Salem, S.M.; Yousif, A.A.

    2003-01-01

    Different samples of Brownmillerite (the ferrite phase of cement clinker) doped with 0, 1 or 3 wt.% NaF were prepared. At first, the oxide mixture of Brownmillerite was prepared according to the following composition: 4 mol CaO, 1 mol Al 2 O 3 and 1 mol Fe 2 O 3 in addition to 1 or 3 wt.% NaF. Each mixture was mixed very well, introduced into an electric furnace at 1300 deg. C for 1 h in a platinum crucible, and then quenched in air. The product was divided into four portions mixed with 40 wt.% distilled water to form Brownmillerite paste, except for one portion which was left dry. Each paste was molded into two molds; after 24 h, they were immersed in a distilled water and withdrawn after 1 or 3 days of hydration, respectively. The pastes were ground again. The anhydrous powders of Brownmillerites and the hydrated samples were prepared for a.c. conduction measurements by pressing it to be in pellets form. The two surfaces of each pellet were coated with silver paste. The a.c. conductivity and dielectric constant for different samples were measured using four-probe method. The data was collected from 320 up to 670 K. Moessbauer spectra and X-ray diffraction patterns were measured for each sample (anhydrous and hydrated) to confirm the formation of Brownmillerite, identify the iron states and the magnetic properties. The results showed that NaF addition to Brownmillerite expedites the hydration reaction rate. The superparamagnetic relaxation, which appeared in the anhydrous Brownmillerite spectra due to the small particle size, decreases with increasing the hydration time. Also, the Fe 3+ (Oh) state increases while Fe 3+ (Td) decreases with the time of hydration. The a.c. conductivity value at fixed frequency for anhydrous and hydrated samples was found to increase with NaF addition. The a.c. conductivity and Moessbauer measurements can be used as good tools to verify the purity of Brownmillerite phase and, accordingly, the purity of cement

  17. Synthesis of 1-Substituted-4-(Pyridin-4-yl)

    African Journals Online (AJOL)

    Purpose: To synthesize a new series of 1-substituted-4-(pyridin-4-yl) [1,2,4] triazolo [4,3-a]quinazolin- 5(4H)-ones and evaluate them for H1-antihistaminic activity with negligible side effects in guinea pigs. Methods: The synthesized compounds were characterized by Infrared spectroscopy (IR), proton nuclear magnetic ...

  18. Butane-1,4-diyl bis(pyridine-4-carboxylate

    Directory of Open Access Journals (Sweden)

    J. Muthukumaran

    2011-07-01

    Full Text Available The molecule of the title compound, C16H16N2O4, lies about an inversion centre; the butane chain adopts an extended zigzag conformation. The dihedral angle between the pyridine ring and the adjacent COO group is 3.52 (s14°.

  19. Expanding the chemical diversity of spirooxindoles via alkylative pyridine dearomatization

    Directory of Open Access Journals (Sweden)

    Chunhui Dai

    2012-07-01

    Full Text Available A mild and practical synthesis of spirooxindole [1,3]oxazino derivatives from N-substituted isatins and 1,3-dicarbonyl compounds with pyridine derivatives is reported. The reactions provided good to excellent yields. Further exploration of the molecular diversity of these compounds is demonstrated through Diels–Alder reactions.

  20. Pulse radiolysis of pyridine and methylpyridines in aqueous solutions

    DEFF Research Database (Denmark)

    Solar, S.; Getoff, N.; Sehested, K.

    1993-01-01

    The radicals formed from pyridine, 3-methylpyridine, 3,5-dimethylpyridine, 2,6-dimethylpyridine and 2,4,6-trimethylpyridine by attack of H, e(aq)-, OH and O.- in aqueous solutions were investigated by pulse radiolysis in the pH-range 1-13.8. The UV-vis. absorption spectra as well as the formation...

  1. New pinene-derived pyridines as bidentate chiral ligands

    Czech Academy of Sciences Publication Activity Database

    Malkov, A. V.; Stewart-Liddon, A.; Teplý, Filip; Kobr, L.; Muir, K. W.; Haigh, D.; Kočovský, P.

    2008-01-01

    Roč. 64, č. 18 (2008), s. 4011-4025 ISSN 0040-4020 Institutional research plan: CEZ:AV0Z40550506 Keywords : chiral ligands * transition metal catalysis * asymmetric catalysis * pyridine ligands * oxazoline ligands Subject RIV: CC - Organic Chemistry Impact factor: 2.897, year: 2008

  2. Electrochemistry of ruthenium acetate trigonal cluster with dimethylsulfoxide and pyridine

    International Nuclear Information System (INIS)

    Alexiou, A.D.P.; Toma, H.E.

    1990-01-01

    The electrochemical behaviour of asymetric cluster with two ligands, pyridine and dimethyl-sulfoxide is studied for determining the changes from cluster oxidation influence on DMSO-Ru ligand and for verifying the ligand isomers which were detected in two systems; [Ru(NHsub(3))dmso] sup(3+/2+) [9] and [Ru(edta)dmso] sup(1-/2-)[10]. (author)

  3. An Efficient, Solvent-Free Process for Synthesizing Anhydrous MgCl2

    Energy Technology Data Exchange (ETDEWEB)

    Motkuri, Radha K.; Vemuri, Venkata Rama S.; Barpaga, Dushyant; Schaef, Herbert T.; Loring, John S.; Martin, Paul F.; Lao, David; Nune, Satish K.; McGrail, Bernard P.

    2018-01-02

    A new efficient and solvent-free method for the synthesis of anhydrous MgCl2 from its hexahydrate is proposed. Fluidized dehydration of MgCl2·6H2O feedstock at 200 °C in a porous bed reactor yields MgCl2·nH2O (0 < n < 1), which has a similar diffraction pattern as activated MgCl2. The MgCl2·nH2O is then ammoniated directly using liquefied NH3 in the absence of solvent to form MgCl2·6NH3. Calcination of the hexammoniate complex at 300 °C then yields anhydrous MgCl2. Both dehydration and deammoniation were thoroughly studied using in situ as well as ex situ characterization techniques. Specifically, a detailed understanding of the dehydration process was monitored by in situ PXRD and in situ FTIR techniques where formation of salt with nH2O (n = 4, 2, 1, <1) was characterized. Given the reduction in thermal energy required to produce dehydrated feedstock with this method compared with current strategies, significant cost benefits are expected. Overall, the combined effect of activation, macroporosity, and coordinated water depletion allows the formation of hexammoniate without using solvent, thus minimizing waste formation.

  4. Study of gasoline mixture with 10% of anhydrous ethanol. Physic-chemical properties evaluation

    International Nuclear Information System (INIS)

    Torres, Jaime; Molina, Daniel; Pinto, Carlos; Rueda, Fernando

    2002-01-01

    This study includes the assessment results for blends of premium and regular gasoline produced in Barrancabermeja' s refinery with 10vol% anhydrous ethanol and concentrations within this range (from 5vol% to 15vol%). The results may allow for a more precise definition of the characteristics for the desired blend. The survey basically focused on the Reid vapor pressure (RVP) and the antiknock index (RON+MON/2) properties, in order to determine the variations within these properties when 5vol%, 10vol%, and 15vol% anhydrous ethanol is added to the base fuels. Based on these results, the RVP and antiknock index were determined for the base fuels, blended with 10vol% ethanol, to comply with the quality standards required for Colombian fuels in year 2005. For the adjustment of the base fuel's RVP, light-vapors, nitrogen-dragging stripper was designed and built. As for the adjustment of the base fuel's antiknock index, blends with straight naphtha were made for lower index values, while blends with cracked naphtha and high octane alkylate were made for higher index values. Having determined the specifications for base fuels, as required to blend them with 10vol% ethanol and meet the quality standards for Colombian gasoline in year 2005, water tolerance for the blends was estimated at temperature ranges of 273 k to 313 k

  5. A new anhydrous proton conductor based on polybenzimidazole and tridecyl phosphate

    International Nuclear Information System (INIS)

    Jiang Fengjing; Pu Hongting; Meyer, Wolfgang H.; Guan Yisi; Wan Decheng

    2008-01-01

    Most of the anhydrous proton conducting membranes are based on inorganic or partially inorganic materials, like SrCeO 3 membranes or polybenzimidazole (PBI)/H 3 PO 4 composite membranes. In present work, a new kind of anhydrous proton conducting membrane based on fully organic components of PBI and tridecyl phosphate (TP) was prepared. The interaction between PBI and TP is discussed. The temperature dependence of the proton conductivity of the composite membranes can be modeled by an Arrhenius relation. Thermogravimetric analysis (TGA) illustrates that these composite membranes are chemically stable up to 145 deg. C. The weight loss appearing at 145 deg. C is attributed to the selfcondensation of phosphate, which results in the proton conductivity drop of the membranes occurring at the same temperature. The DC conductivity of the composite membranes can reach ∼10 -4 S/cm for PBI/1.8TP at 140 deg. C and increases with increasing TP content. The proton conductivity of PBI/TP and PBI/H 3 PO 4 composite membranes is compared. The former have higher proton conductivity, however, the proton conductivity of the PBI/H 3 PO 4 membranes increases with temperature more significantly. Compared with PBI/H 3 PO 4 membranes, the migration stability of TP in PBI/TP membranes is improved significantly

  6. Anhydrous proton exchange membrane of sulfonated poly(ether ether ketone) enabled by polydopamine-modified silica nanoparticles

    International Nuclear Information System (INIS)

    Wang, Jingtao; Bai, Huijuan; Zhang, Haoqin; Zhao, Liping; Chen, Huiling; Li, Yifan

    2015-01-01

    Highlights: • The concept of acid/base pairs was employed to design anhydrous PEMs. • Polydopamine-modified silica particles were uniformly dispersed in SPEEK membrane. • The membranes displayed enhancement in both stability and anhydrous proton conductivity. - Abstract: Novel anhydrous proton exchange membrane is (PEM) facilely prepared by embedding dopamine-modified silica nanoparticles (DSiOis 2 ) into sulfonated poly (ether ether ketone) (SPEEK) polymer matrix. DSiO 2 bearing -NH 2 /-NH- groups are synthesized inspired by the bioadhesion principle, which are uniformly dispersed within SPEEK membrane due to the good interfacial compatibility. The interfacial electrostatic attractions render unique rearrangement of the nanophase-separated structure and the chain packing of the resultant hybrid membranes. As a result, the thermal and mechanical stabilities as well as structural stability of the hybrid membranes are enhanced when compared to SPEEK control membrane. On the other hand, induced by the attractions, acid–base pairs are formed at the SPEEK/DSiOarewere 2 interface, where fast proton transfer via Grotthuss mechanism is expected. These features confer much higher proton conductivities on the DSiO 2 -filled membranes under both hydrated and anhydrous conditions, compared to those of the SPEEK control membrane and SiO 2 -filled membranes. Particularly, the hybrid membrane with 15 wt% DSiO 2 achieve the highest conductivities of 4.52achieveachieved × 10 −3 S cm −1 at 120 °C under anhydrous condition, which is much higher than the SPEEK control membrane and the commercial Nafion membrane (0.1iswas × 10 −3 S cm −1 ). The membrane with 9 wt% DSiO 2 show an open cell potential of 0.98showshowed V and an optimum power density of 111.7 mW cm −2 , indicative of its potential application in fuel cell under anhydrous condition

  7. Lithium salt of N,N-dimethylsalicylamide in pyridine and pyridine-water solutions. NMR study on the internal rotation about the C-N bond

    Energy Technology Data Exchange (ETDEWEB)

    Gryff-Keller, A; Szczecinski, P [Politechnika Warszawska (Poland)

    1981-01-01

    NMR spectra of the title compound in pyridine and pyridine-water mixtures have been measured at various temperatures. The dependence of internal rotation rate and of chemical shift difference between N-CH/sub 3/ signals on the solvent composition has been discussed with reference to structure of the solution investigated.

  8. On the one pot syntheses of chromeno[4,3-b]pyridine-3-carboxylate and chromeno[3,4-c]pyridine-3-carboxylate and dihydropyridines

    Energy Technology Data Exchange (ETDEWEB)

    Navarrete-Encina, Patricio A.; Vega-Retter, Christian, E-mail: pnavarre@vtr.ne [Universidad de Chile, Santiago (Chile). Facultad de Ciencias Quimicas y Farmaceuticas. Lab. de Sintesis Organica y Fisicoquimica; Salazar, Ricardo; Perez, Karina; Squella, Juan A.; Nunez-Vergara, Luis J. [Universidad de Chile, Santiago (Chile). Fac. de Ciencias Quimicas y Farmaceuticas. Lab. de Bioelectroquimica

    2010-07-01

    Substituted chromenos, dihydropyridines and pyridines have been important in the syntheses of compounds having interesting pharmacological properties. Therefore, we found of interest to synthesize chromenopyridines and chromeno dihydropyridines (i.e., fused chromeno and dihydropyridine or pyridine rings) to further study their biological activity. Here, we propose one-pot syntheses for substituted ethyl-2,4-dimethyl-5-oxo-5H-chromeno[4,3-b]pyridine-3-carboxylates, ethyl-2,4-dimethyl-5-oxo-5H-chromeno[3,4-c]pyridine-3-carboxylates and their respective 1,4-dihydropyridines based on a modified Hantzsch pyridine synthesis using 2-hydroxyaryl aldehydes, with electron withdrawing and electron donating groups on the phenyl ring, as starting reactants. Sixteen compounds were synthesized by the described method and fully characterized. An average yield of 37% was obtained for the different derivatives. (author)

  9. On the one pot syntheses of chromeno[4,3-b]pyridine-3-carboxylate and chromeno[3,4-c]pyridine-3-carboxylate and dihydropyridines

    International Nuclear Information System (INIS)

    Navarrete-Encina, Patricio A.; Vega-Retter, Christian; Salazar, Ricardo; Perez, Karina; Squella, Juan A.; Nunez-Vergara, Luis J.

    2010-01-01

    Substituted chromenos, dihydropyridines and pyridines have been important in the syntheses of compounds having interesting pharmacological properties. Therefore, we found of interest to synthesize chromenopyridines and chromeno dihydropyridines (i.e., fused chromeno and dihydropyridine or pyridine rings) to further study their biological activity. Here, we propose one-pot syntheses for substituted ethyl-2,4-dimethyl-5-oxo-5H-chromeno[4,3-b]pyridine-3-carboxylates, ethyl-2,4-dimethyl-5-oxo-5H-chromeno[3,4-c]pyridine-3-carboxylates and their respective 1,4-dihydropyridines based on a modified Hantzsch pyridine synthesis using 2-hydroxyaryl aldehydes, with electron withdrawing and electron donating groups on the phenyl ring, as starting reactants. Sixteen compounds were synthesized by the described method and fully characterized. An average yield of 37% was obtained for the different derivatives. (author)

  10. Pyridine-induced Dimensionality Change in Hybrid Perovskite Nanocrystals

    KAUST Repository

    Ahmed, Ghada H.

    2017-05-02

    Engineering the surface energy through careful manipulation of the surface chemistry is a convenient approach to control quantum confinement and structure dimensionality during nanocrystal growth. Here, we demonstrate that the introduction of pyridine during the synthesis of methylammonium lead bromide (MAPbBr) perovskite nanocrystals can transform three-dimensional (3D) cubes into two-dimensional (2D) nanostructures. Density functional theory (DFT) calculations show that pyridine preferentially binds to Pb atoms terminating the surface, driving the selective 2D growth of the nanostructures. These 2D nanostructures exhibit strong quantum confinement effects, high photoluminescence quantum yields in the visible spectral range, and efficient charge transfer to molecular acceptors. These qualities indicate the suitability of the synthesized 2D nanostructures for a wide range of optoelectronic applications.

  11. Pyridine Vapors Detection by an Optical Fibre Sensor

    Directory of Open Access Journals (Sweden)

    Alberto Fernandez-Gutiérrez

    2008-02-01

    Full Text Available An optical fibre sensor has been implemented towards pyridine vapors detection;to achieve this, a novel vapochromic material has been used, which, in solid state, suffers achange in colour from blue to pink-white in presence of pyridine vapours. This complex isadded to a solution of PVC (Poly Vinyl Chloride, TBP (Tributylphosphate andtetrahydrofuran (THF, forming a plasticized matrix; by dip coating technique, the sensingmaterial is fixed onto a cleaved ended optical fibre. The fabrication process was optimizedin terms of number of dips and dipping speed, evaluating the final devices by dynamicrange. Employing a reflection set up, the absorbance spectra and changes in the reflectedoptical power of the sensors were registered to determine their response. A linear relationbetween optical power versus vapor concentration was obtained, with a detection limit of 1ppm (v/v.

  12. Mechanical properties of lunar materials under anhydrous, hard vacuum conditions: applications of lunar glass structural components

    International Nuclear Information System (INIS)

    Blacic, J.D.

    1984-01-01

    Lunar materials and derivatives such as glass may possess very high tensile strengths compared to equivalent materials on earth because of the absence of hydrolytic weakening processes on the moon and in the hard vacuum of free space. Hydrolyzation of Si-O bonds at crack tips or dislocations reduces the strength of silicates by about an order of magnitude in earth environments. However, lunar materials are extremely anhydrous and hydrolytic weakening will be suppressed in free space. Thus, the geomechanical properties of the moon and engineering properties of lunar silicate materials in space environments will be very different than equivalent materials under earth conditions where the action of water cannot be conveniently avoided. Possible substitution of lunar glass for structural metals in a variety of space engineering applications enhances the economic utilization of the moon. 26 references, 3 figures, 2 tables

  13. Controlled synthesis of porous anhydrous cobalt oxalate nanorods with high reversible capacity and excellent cycling stability

    International Nuclear Information System (INIS)

    Xu, Junmin; He, Lei; Liu, Hui; Han, Tao; Wang, Yongjian; Zhang, Changjin; Zhang, Yuheng

    2015-01-01

    Graphical abstract: Display Omitted -- Abstract: One-dimensional porous anhydrous cobalt oxalate nanorods are prepared via a facile water-controlled coprecipitate method followed by thermal annealing treatment under N 2 at 300 °C. The nanorods are characterized by using X-ray diffraction, scanning electron microscopy and transmission electron microscopy. When evaluated as an anode material for lithium ion batteries, the nanorods exhibit high reversible specific capacity and excellent cycling stability (924 mA h g −1 at 50 mA g −1 after 100 cycles and 709 mA h g −1 at 200 mA g −1 after 220 cycles). This remarkable electrochemical performance is attributed to the one-dimensional porous nanostructure that can provide large electrode/electrolyte contact area and short lithium-ion diffusion pathway, meanwhile reduce the volume expansion during the repeated discharge/charge process

  14. Detailed kinetic and heat transport model for the hydrolysis of lignocellulose by anhydrous hydrogen fluoride vapor

    Energy Technology Data Exchange (ETDEWEB)

    Rorrer, G.L.; Mohring, W.R.; Lamport, D.T.A.; Hawley, M.C.

    1988-01-01

    Anhydrous Hydrogen Fluoride (HF) vapor at ambient conditions efficiently and rapidly hydrolyzed lignocellulose to glucose and lignin. The unsteady-state reaction of HF vapor with a single lignocellulose chip was mathematically modeled under conditions where external and internal mass-transfer resistances were minimized. The model incorporated physical adsorption of HF vapor onto the lignocellulosic matrix and solvolysis of cellulose to glucosyl fluoride by adsorbed HF into the differential material and energy balance expressions. Model predictions for the temperature distribution and global glucose yield in the HF-reacting lignocellulose chip as a function of reaction time and HF vapor stream temperature agreed reasonably with the complimentary experimental data. The model correctly predicted that even when mass-transfer resistances for the reaction of HF vapor with a single lignocellulose chip are minimized, external and internal heat-transfer resistances are still significant.

  15. SIMULATION OF THE DISTILLATION BY PRESSURE REDUCTION TO OBTAIN ANHYDROUS ETHANOL

    Directory of Open Access Journals (Sweden)

    Yeney Lauzurique Guerra

    2016-10-01

    Full Text Available In this work the distillation by pressure reduction was evaluated through the HYSYS v3.2 process simulator. Due to the lack of data in the consulted bibliography to perform the simulation, the STATGRAPHICS Centurion XVI software was used to obtain a response surface that would define optimal operating conditions. The property package selected to work was based on the Margules model. An anhydrous ethanol molar composition of 0.9917 was obtained. Temperature profiles were analyzed as well as liquid and vapor molar flows and dehydration column composition profiles. The influence of operating parameters on the efficiency of simulated technology was determined by analyzing one case study. According to economic evaluation, the implementation of this technology is not economically profitable; taking into account current prices and costs mostly due to high energy consumption and construction costs of the tower. This result contributes to the pursuit of other profitable technologies from the economic point of view.

  16. Structural basis for the transformation pathways of the sodium naproxen anhydrate-hydrate system.

    Science.gov (United States)

    Bond, Andrew D; Cornett, Claus; Larsen, Flemming H; Qu, Haiyan; Raijada, Dhara; Rantanen, Jukka

    2014-09-01

    Crystal structures are presented for two dihydrate polymorphs (DH-I and DH-II) of the non-steroidal anti-inflammatory drug sodium (S)-naproxen. The structure of DH-I is determined from twinned single crystals obtained by solution crystallization. DH-II is obtained by solid-state routes, and its structure is derived using powder X-ray diffraction, solid-state (13)C and (23)Na MAS NMR, and molecular modelling. The validity of both structures is supported by dispersion-corrected density functional theory (DFT-D) calculations. The structures of DH-I and DH-II, and in particular their relationships to the monohydrate (MH) and anhydrate (AH) structures, provide a basis to rationalize the observed transformation pathways in the sodium (S)-naproxen anhydrate-hydrate system. All structures contain Na(+)/carboxylate/H2O sections, alternating with sections containing the naproxen molecules. The structure of DH-I is essentially identical to MH in the naproxen region, containing face-to-face arrangements of the naphthalene rings, whereas the structure of DH-II is comparable to AH in the naproxen region, containing edge-to-face arrangements of the naphthalene rings. This structural similarity permits topotactic transformation between AH and DH-II, and between MH and DH-I, but requires re-organization of the naproxen molecules for transformation between any other pair of structures. The topotactic pathways dominate at room temperature or below, while the non-topotactic pathways become active at higher temperatures. Thermochemical data for the dehydration processes are rationalized in the light of this new structural information.

  17. Composite polymer electrolyte containing ionic liquid and functionalized polyhedral oligomeric silsesquioxanes for anhydrous PEM applications.

    Science.gov (United States)

    Subianto, Surya; Mistry, Mayur K; Choudhury, Namita Roy; Dutta, Naba K; Knott, Robert

    2009-06-01

    A new type of supported liquid membrane was made by combining an ionic liquid (IL) with a Nafion membrane reinforced with multifunctional polyhedral oligomeric silsesquioxanes (POSSs) using a layer-by-layer strategy for anhydrous proton-exchange membrane (PEM) application. The POSS was functionalized by direct sulfonation, and the sulfonated POSS (S-POSS) was incorporated into Nafion 117 membranes by the infiltration method. The resultant hybrid membrane shows strong ionic interaction between the Nafion matrix and the multifunctional POSS, resulting in increased glass transition temperature and thermal stability at very low loadings of S-POSS (1%). The presence of S-POSS has also improved the proton conductivity especially at low humidities, where it shows a marked increase due to its confinement in the ionic domains and promotes water uptake by capillary condensation. In order to achieve anhydrous conductivity, the IL 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BMI-BTSI) was incorporated into these membranes to provide proton conduction in the absence of water. Although the incorporation of an IL shows a plasticizing effect on the Nafion membrane, the S-POSS composite membrane with an IL shows a higher modulus at high temperatures compared to Nafion 117 and a Nafion-IL membrane, with significantly higher proton conductivity (5 mS/cm at 150 degrees C with 20% IL). This shows the ability of the multifunctional POSS and IL to work symbiotically to achieve the desirable proton conductivity and mechanical properties of such membranes by enhancing the ionic interaction within the material.

  18. Effects of coffee and caffeine anhydrous on strength and sprint performance.

    Science.gov (United States)

    Trexler, Eric T; Smith-Ryan, Abbie E; Roelofs, Erica J; Hirsch, Katie R; Mock, Meredith G

    2016-09-01

    Caffeine and coffee are widely used among active individuals to enhance performance. The purpose of the current study was to compare the effects of acute coffee (COF) and caffeine anhydrous (CAF) intake on strength and sprint performance. Fifty-four resistance-trained males completed strength testing, consisting of one-rep max (1RM) and repetitions to fatigue (RTF) at 80% of 1RM for leg press (LP) and bench press (BP). Participants then completed five, 10-second cycle ergometer sprints separated by one minute of rest. Peak power (PP) and total work (TW) were recorded for each sprint. At least 48 hours later, participants returned and ingested a beverage containing CAF (300 mg flat dose; yielding 3-5 mg/kg bodyweight), COF (8.9 g; 303 mg caffeine), or placebo (PLA; 3.8 g non-caloric flavouring) 30 minutes before testing. LP 1RM was improved more by COF than CAF (p = .04), but not PLA (p = .99). Significant interactions were not observed for BP 1RM, BP RTF, or LP RTF (p > .05). There were no sprint × treatment interactions for PP or TW (p > .05). 95% confidence intervals revealed a significant improvement in sprint 1 TW for CAF, but not COF or PLA. For PLA, significant reductions were observed in sprint 4 PP, sprint 2 TW, sprint 4 TW, and average TW; significant reductions were not observed with CAF or COF. Neither COF nor CAF improved strength outcomes more than PLA, while both groups attenuated sprint power reductions to a similar degree. Coffee and caffeine anhydrous may be considered suitable pre-exercise caffeine sources for high-intensity exercise.

  19. Crystal structure of aspartame anhydrate from powder diffraction data. Structural aspects of the dehydration process of aspartame

    NARCIS (Netherlands)

    Guguta, C.; Meekes, H.L.M.; Gelder, R. de

    2006-01-01

    Aspartame has three pseudo-polymorphic forms, two hydrates and a hemi-hydrate, for which crystal structures were determined from single-crystal diffraction data. This paper presents the crystal structure of the anhydrate, which was obtained by dehydrating the hemi-hydrate. The crystal structure of

  20. 75 FR 13441 - Hours of Service; Limited 90-Day Waiver for the Distribution of Anhydrous Ammonia in Agricultural...

    Science.gov (United States)

    2010-03-22

    ..., such as grain hauled from an elevator (or sugar beets from a cold storage facility) to a processing... delivering anhydrous ammonia; (2) none of the transportation movements within the distribution chain exceed a... chain exceed a 100 air-mile radius--whether from the retail or wholesale distribution point; and (3) the...

  1. Improved quantification of alite and belite in anhydrous Portland cements by 29Si MAS NMR: Effects of paramagnetic ions

    DEFF Research Database (Denmark)

    Poulsen, Søren Lundsted; Kocaba, Vanessa; Le Saoût, Gwenn

    2009-01-01

    The applicability, reliability, and repeatability of 29Si MAS NMR for determination of the quantities of alite (Ca3SiO5) and belite (Ca2SiO4) in anhydrous Portland cement was investigated in detail for 11 commercial Portland cements and the results compared with phase quantifications based...

  2. Anhydrous ZnCl2: A Highly Efficient Reagent for Facile and Regioselective Conversion of Epoxides to β-Chlorohydrins

    Directory of Open Access Journals (Sweden)

    Ronak Eisavi

    2016-01-01

    Full Text Available Facile conversion of structurally different epoxides to the corresponding β-chlorohydrins was carried out successfully with anhydrous ZnCl2 in CH3CN. The reactions were carried out within 10-50 min to give β-chlorohydrins with perfect regioselectivity and high yields (80-97%.

  3. Theoretical investigations on fluorene-pyridines as electroactive sensor molecules

    International Nuclear Information System (INIS)

    Horner, S.; Romaner, L.; Zojer, E.; Kappaun, S.; Slugovc, C.; Kelterer, A.-M.

    2006-01-01

    Full text: Organic semiconducting oligomers and polymers are promising candidates for chemical sensing applications. In this work, sensor molecules comprising a sequence of para- and meta-linked fluorene- and pyridine- units are studied. Spectroscopic investigations show that upon protonation of the pyridine rings (i.e., when adding acids to the solutions), one observes a distinct red-shift of the absorption and emission maxima by approximately 0.5 eV. The fact that the polymers are highly emissive in both, the non protonated as well as protonated state makes them particularly interesting candidates for ratio metric sensors based on organic semiconductors. To rationalize the observed behaviour, we calculate the geometric and electronic structures of the relevant molecules at various stages of protonation using both semiempirical as well as density functional theory based methods. In general, we obtain good agreement between theory and experiment and excited state localization is found to play a crucial role in the sensing process. In practice, one can expect the interaction between the proton and the nitrogen of the pyridine unit to be modulated by interaction with the counter-ion as well as by screening through solvent molecules. These effects are accounted for in calculations on smaller model systems. (author)

  4. Crystal Structure and Properties of Imidazo-Pyridine Ionic Liquids.

    Science.gov (United States)

    Farren-Dai, Marco; Cameron, Stanley; Johnson, Michel B; Ghandi, Khashayar

    2018-07-05

    Computational studies were performed on novel protic ionic liquids imidazolium-[1,2-a]-pyridine trifluoroacetate [ImPr][TFA] synthesized by the reaction of imidazo-[1,2a]-pyridine (ImPr) with trifluoroacetic acid (TFA), and on fused salt imidazolium-[1,2-a]-pyridine maleamic carbonate [ImPr][Mal] synthesized by reaction of ImPr with maleamic acid (Mal). Synthesis was performed as one-pot reactions, which applies green chemistry tenets. Both these compounds begin to decompose at 180°C. Our computational studies suggest another thermal reaction channel, in which [ImPr][Mal] can also thermally polymerizes to polyacrylamide which then cyclizes. This is thermal product remains stable up to 700 degrees, consistent with our thermogravimetric studies. [ImPr][TFA] exhibited good conductivity and ideal ionic behavior, as evaluated by a Walden plot. X-ray crystallography of [ImPr][TFA] revealed a tightly packed system for the crystals as a result of strong ionic interaction, pi-stacking, and fluorine-CH interactions. Both synthesized compounds exhibited some CO 2 absorptivity, with [ImPr][Mal] outperforming [ImPr][TFA] in this regard. The quantum chemistry based computational methods can shed light on many properties of these ionic liquids, but they are challenged in fully describing their ionic nature. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

  5. 2-Aminobenzoic acid–4-(pyridin-4-yldisulfanylpyridine (1/1

    Directory of Open Access Journals (Sweden)

    Hadi D. Arman

    2011-12-01

    Full Text Available The title 1:1 co-crystal, C7H7NO2·C10H8N2S2, features a highly twisted 4-(pyridin-4-yldisulfanylpyridine molecule [dihedral angle between the pyridine rings = 89.06 (10°]. A small twist is evident in the 2-aminobenzoic acid molecule, with the C—C—C—O torsion angle being −7.7 (3°. An N—H...O hydrogen bond occurs in the 2-aminobenzoic acid molecule. In the crystal, molecules are linked by O—H...N and N—H...N hydrogen bonds into a supramolecular chain along the b axis. These are connected into layers by π–π interactions occurring between pyridine rings [centroid–centroid distance = 3.8489 (15 Å]. The layers are connected along the a axis by C—H...O contacts. The crystal studied was a racemic twin.

  6. Molecular Dynamics and Neutron Scattering Studies of Mixed Solutions of Caffeine and Pyridine in Water.

    Science.gov (United States)

    Tavagnacco, Letizia; Mason, Philip E; Neilson, George W; Saboungi, Marie-Louise; Cesàro, Attilio; Brady, John W

    2018-05-31

    Insight into the molecular interactions of homotactic and heterotactic association of caffeine and pyridine in aqueous solution is given on the basis of both experimental and simulation studies. Caffeine is about 5 times more soluble in a 3 m aqueous pyridine solution than it is in pure water (an increase from ∼0.1 m to 0.5 m). At this elevated concentration the system becomes suitable for neutron scattering study. Caffeine-pyridine interactions were studied by neutron scattering and molecular dynamics simulations, allowing a detailed characterization of the spatial and orientational structure of the solution. It was found that while pyridine-caffeine interactions are not as strong as caffeine-caffeine interactions, the pyridine-caffeine interactions still significantly disrupted caffeine-caffeine stacking. The alteration of the caffeine-caffeine stacking, occasioned by the presence of pyridine molecules in solution and the consequent formation of heterotactic interactions, leads to the experimentally detected increase in caffeine solubility.

  7. 2-[5-(Pyridin-2-yl-1,3,4-thiadiazol-2-yl]pyridin-1-ium perchlorate

    Directory of Open Access Journals (Sweden)

    Abdelhakim Laachir

    2017-03-01

    Full Text Available The cation of the title molecular salt, C12H9N4S+·ClO4−, is approximately planar, with the pyridine and pyridinium rings being inclined to the central thiadiazole ring by 6.51 (9 and 9.13 (9°, respectively. The dihedral angle between the pyridine and pyridinium rings is 12.91 (10°. In the crystal, the cations are linked by N—H...O and C—H...O hydrogen bonds, involving the perchlorate anion, forming chains propagating along the [100] direction. The chains are linked by weak offset π–π interactions [inter-centroid distance = 3.586 (1 Å], forming layers parallel to the ab plane.

  8. Structure of fullerene aggregates in pyridine/water solutions by small-angle neutron scattering

    International Nuclear Information System (INIS)

    Aksenov, V.L.; Belushkin, A.V.; Avdeev, M.V.; Rosta, L.; Mihailovic, D.; Mrzel, A.; Serdyuk, I.N.; Timchenko, A.A.

    2001-01-01

    Results of small-angle neutron scattering experiments on fullerenes (C 60 ) in pyridine/water solutions are reported. They confirm conclusions of the previous studies, in particular, dynamic light scattering experiments. Aggregates with characteristic radius of about 20 nm are formed in the solutions. The contrast variation using different combinations of protonated/deuterated components (water and pyridine) of the solutions points to the small pyridine content inside the aggregates. This fact testifies that the aggregates consist of a massive fullerene core covered by a thin pyridine shell

  9. PENULISAN ETUDE-ETUDE MUSIK TALEMPONG UNGGAN (Sebuah Usaha Pembelajaran Musik Tradisi Berbasis Literatur

    Directory of Open Access Journals (Sweden)

    Asri MK

    2014-12-01

    Full Text Available “Talempong unggan”, a traditional music from Minangkabau community particularly in Unggan, Sumpur Kudus, Sijunjung Regency, West Sumatera Indonesia is classified into genre of “talempong duduak” (rea. Due to its special musical concept and the playing technics, this traditional music is selected as a practising course in the Karawitan Department of Indonesian Institute of Art (ISI Padang Panjang since 1993 till now. In a system of class learning with many students, Talempong Unggan definitely needs supporting methods and learning technics suitable for the course where the students can reach their maximum skills. All the melody of “talempong unggan” that has been made as a material of practice is transcribed to the system of numeric notation and rhythm motive of “gendang” and “aguang” which is written into signs and special notation. All of qualitative data is formulated into finding methods, technics and etude of learning ensamble of Talempong Unggan the traditional music that learned in Karawitan Department of ISI Padang Panjang. Key words: Talempong Unggan, Methods, Technics, Etude

  10. The Role of Hydrogen Bonding on Laminar Burning Velocity of Hydrous and Anhydrous Ethanol Fuel with Small Addition of n-Heptane

    Directory of Open Access Journals (Sweden)

    I Made Suarta

    2016-01-01

    Full Text Available The molecular structure of mixed hydrous and anhydrous ethanol with up to 10% v n-heptane had been studied. The burning velocity was examined in a cylindrical explosion combustion chamber. The result showed that the burning velocity of hydrous ethanol is higher than anhydrous ethanol and n-heptane at stoichiometric, rich, and very rich mixtures. The burning velocity of hydrous ethanol with n-heptane drops drastically compared to the burning velocity of anhydrous ethanol with n-heptane. It is caused by two reasons. Firstly, there was a composition change of azeotropic hydrous ethanol molecules within the mixture of fuel. Secondly, at the same volume the number of ethanol molecules in hydrous ethanol was less than in anhydrous ethanol at the same composition of the n-heptane in the mixture. At the mixture of anhydrous ethanol with n-heptane, the burning velocity decreases proportionally to the addition of the n-heptane composition. The burning velocity is between the velocities of anhydrous ethanol and n-heptane. It shows that the burning velocity of anhydrous ethanol mixed with n-heptane is only influenced by the mixture composition.

  11. Kinetic study of the substitution of pyridine by cyanide in the bis(pyridine)cobalt(III)hematoporphyrin-IX: distinguishing between Isub(d) and D mechanism

    International Nuclear Information System (INIS)

    Birush, M.; Pribanicj, M.

    1977-01-01

    ''Mass-law (rate) retardation'' effect shows that the reaction between the cyanide ion and bis(pyridine)cobalt(III)hematoporphyrin-IX complex to give (CN) 2 cobalt(III)hematoporphyrin-IX occurs by a purely dissociative (D but not Isub(d)) mechanism in chloroform. Limiting rate constant at the excess of cyanide ion concentration at 25 deg C was found to be 2.5x10 -3 S -1 and the competition ratio of pyridine (ksub(-) 1 ) and the cyanide ion (k 2 ) for a five coordinate intermediate (pyridin) cobalt(III)hematoporphyrin-IX complex was obtained as ksub(-) 1 /k 2 =0.35. (author)

  12. (Pyridine-2-aldoximato-κ2N,N′bis[2-(pyridin-2-ylphenyl-κ2C1,N]iridium(III

    Directory of Open Access Journals (Sweden)

    Bimal Chandra Singh

    2013-03-01

    Full Text Available In the title complex, [Ir(C11H8N2(C6H5N2O], the octahedrally coordinated IrIII atom is bonded to two 2-(pyridin-2-ylphenyl ligands, through two phenyl C and two pydidine N atoms, and to one pyridine-2-aldoxime ligand through a pyridine N and an oxime N atom. The oxime O atom of the aldoxime unit forms intermolecular C—H...O hydrogen bonds, which result in a two-dimensional hydrogen-bonded polymeric network parallel to (100. C—H...π interactions are also observed.

  13. Influence of Fe content on the creep properties of olivine under anhydrous and hydrous conditions

    Science.gov (United States)

    Trimmer, M. B.; Zhao, Y.; Zimmerman, M. E.; Kohlstedt, D. L.

    2007-12-01

    High-temperature, high-pressure compressive creep experiments were performed on both wet and dry aggregates of Fa75 in a gas-medium deformation apparatus. The results from these experiments are compared with those for San Carlos olivine, Fa10, and our previous results on Fa30 and Fa50 in order to provide a basis for comparing convection models for the mantle of Earth with those for the more iron-rich mantle of Mars. Samples were fabricated from powders of Fa75 that were synthesized from mixtures of Fe2O3 and SiO2 combined with San Carlos olivine. The Fa75 powders were cold-pressed into Fe capsules and then hot-pressed at 300 MPa, 1473 K for 3 h. The average grain size of the resultant hot-pressed samples was ~40 μm. For experiments under hydrous conditions, three drops of deionized water were added before sealing the sample within telescoping Fe cans for deformation. Water bubbles were present both within olivine grains and along grain boundaries, demonstrating that the samples were water-saturated. Triaxial compressive creep experiments were carried out in a servo-controlled, internally heated gas-medium apparatus at 50 K intervals between 1273 and 1423 K and a confining pressure of 300 MPa with differential stress of 10 to 300 MPa. For each sample, creep tests were performed at several differential stresses at a constant temperature to determine the stress exponent or at several temperatures to determine the activation energy for creep. Under anhydrous conditions the viscosity of samples of Fa75 is more than a factor of 10 lower than the viscosity of Fa50. Previous experiments showed a similar relationship between Fa50 and Fa30 and Fa30 and Fa10. Under hydrous conditions the viscosity of samples of Fa75 are about a factor of 5 lower than the viscosity of Fa50, which is less than that observed between Fa50 and Fa30 or Fa30 and Fa10. The viscosity of a sample of a specific Fe:Mg ratio deformed under hydrous conditions is a factor of 10 lower than its counterpart

  14. Theoretical study of the paramagnetic scattering of neutrons; Etude theorique de la diffusion paramagnetique des neutrons

    Energy Technology Data Exchange (ETDEWEB)

    Saint-James, D [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1962-02-15

    diverses diffusions (elastique et inelastiques) est calculee pour les terres rares soumises a l'action d'un champ cristallin de symetrie cubique, pour les sesquioxydes d'holmium et d'erbium et pour le chlorure ferreux anhydre (Cl{sub 2}Fe). Elle est suffisamment forte pour permettre une detection experimentale, fournissant ainsi une determination directe de la distance des niveaux par mesure de la variation de longueur d'onde du neutron. Il est, de plus, remarquable que, dans le cas du neodyme, de l'holium et de l'erbium, la section efficace totale calculee pour des neutrons de longueur d'onde aux alentours de l'angstrom soit peu sensible aux effets du champ cristallin. On compare les resultats des calculs ci-dessus aux etudes experimentales existantes. On examine egalement l'influence du moment orbital sur la dependance angulaire de la diffusion pour des ions polarises. La loi I = I{sub 0}sin{sup 2}{beta} n'est qu'approchee; on en donne les limites de validite. On envisage enfin l'influence des interactions d'echange entre les ions magnetiques. Les raies de diffusion elastiques et inelastiques sont elargies. Le comportement de la largeur de raie, avec la longueur du vecteur de diffusion k, est different de celui obtenu dans le cas ou le niveau fondamental de l'ion magnetique est defini par un moment cinetique J . La largeur de raie ne tend pas vers zero avec K. (auteur)

  15. Poly[diaqua(μ5-pyridine-3,5-dicarboxylatostrontium

    Directory of Open Access Journals (Sweden)

    Dan Li

    2012-06-01

    Full Text Available In the structure of the title compound, [Sr(C7H3NO4(H2O2]n, the SrII cation is eight-coordinated in form of a distorted dodecahedron by two water O atoms and by five O atoms and one N atom from five pyridine-3,5-dicarboxylate anions. The bridging mode of the anions leads to the formation of a layered network parallel to (100. O—H...O hydrogen bonding between the coordinating water molecules and the carboxylate groups of adjacent layers consolidates the crystal packing. Weak C—H...O interactions are also observed.

  16. Aquabis(methacrylato-κObis(pyridine-κNcopper(II

    Directory of Open Access Journals (Sweden)

    Bin Wu

    2009-05-01

    Full Text Available In the crystal structure of the title complex, [Cu(C4H5O22(C5H5N2(H2O], the CuII cation is located on a twofold rotation axis and coordinated by two methylacrylate anions, two pyridine ligands and one water molecule in a distorted square-pyramidal geometry. The coordinated water molecule is also located on the twofold axis. In the crystal structure O—H...O hydrogen bonds link the molecules, forming chains along the c axis.

  17. (E-2-(4-Chlorophenoxy-N′-(pyridin-4-ylmethylideneacetohydrazide

    Directory of Open Access Journals (Sweden)

    Xiao-jin Rao

    2013-01-01

    Full Text Available In the title compound, C14H12ClN3O2, the acylhydrazone base [C(=O—N—N=C] is essentially planar, with an r.m.s. deviation of 0.0095 Å, and makes a dihedral angle of 12.52 (10°with the pyridine ring. In the crystal, molecules are linked via pairs of N—H...O hydrogen bonds, forming inversion dimers with an R22(8 graph-set motif. The dimers are linked via C—H...π interactions forming chains along [101].

  18. Bis(pyridine-2-carbaldehyde thiosemicarbazonezinc(II dinitrate dihydrate

    Directory of Open Access Journals (Sweden)

    Jian-Quan Wang

    2010-10-01

    Full Text Available The asymmetric unit of the title compound, [Zn(C7H8N4S2](NO32·2H2O, contains two Zn(pht2 cations (pht is pyridine-2-carbaldehyde thiosemicarbazone, four nitrate anions and four water molecules. In the cations, each ZnII ion adopts a distorted octahedral coordination geometry, being chelated by two tridentate pht ligands. In the crystal, the cations, anions and water molecules are connected via O—H...O and N—H...O hydrogen bonds into a three-dimensional network.

  19. Removal of pyridine from liquid and gas phase by copper forms of natural and synthetic zeolites

    International Nuclear Information System (INIS)

    Rehakova, Maria; Fortunova, Lubica; Bastl, Zdenek; Nagyova, Stanislava; Dolinska, Silvia; Jorik, Vladimir; Jona, Eugen

    2011-01-01

    Zeoadsorbents on the basis of copper forms of synthetic zeolite ZSM5 and natural zeolite of the clinoptilolite type (CT) have been studied taking into account their environmental application in removing harmful pyridine (py) from liquid and gas phase. Sorption of pyridine by copper forms of zeolites (Cu-ZSM5 and Cu-CT) has been studied by CHN, X-ray photoelectron spectroscopy, X-ray powder diffractometry, FTIR spectroscopy, thermal analysis (TG, DTA and DTG) and analysis of the surface areas and the pore volumes by low-temperature adsorption of nitrogen. The results of thermal analyses of Cu-ZSM5, Cu-(py) x ZSM5, Cu-CT and Cu-(py) x CT zeolitic products with different composition (x depends on the experimental conditions of sorption of pyridine) clearly confirmed their different thermal properties as well as the sorption of pyridine. In the zeolitic pyridine containing samples the main part of the pyridine release process occurs at considerably higher temperatures than is the boiling point of pyridine, which proves strong bond and irreversibility of py-zeolite interaction. FTIR spectra of Cu-(py) x zeolite samples showed well resolved bands of pyridine. The results of thermal analysis and FTIR spectroscopy are in a good agreement with the results of other used methods.

  20. A new multicomponent reaction for the synthesis of pyridines via cycloaddition of azadienes and ketenimines

    NARCIS (Netherlands)

    Coffinier, D.; El Kaim, L.; Grimaud, L.; Ruijter, E.; Orru, R.V.A.

    2011-01-01

    The ketenimines resulting from a Nef isocyanide/Perkow sequence react with 1-azadienes to form pyridines or pyrimidines depending on their substitution pattern. The reaction is most efficient with ester-substituted ketenimines which leads to pyridines after elimination of the phosphate group. © 2011

  1. Synthesis of a novel class of some biquinoline pyridine hybrids via

    Indian Academy of Sciences (India)

    A small library of novel class of biquinoline containing pyridine moiety were synthesized by a one-pot cyclocondensation of 2-chloro-3-formyl quinoline, active methylene compounds and 3-(pyridine-3- ylamino)cyclohex-2-enone in the presence of catalytic amount of sodium hydroxide. The protocol offers rapid synthesis of ...

  2. Degradation of pyridine and quinoline in aqueous solution by gamma radiation

    Science.gov (United States)

    Chu, Libing; Yu, Shaoqing; Wang, Jianlong

    2018-03-01

    In present work, the degradation of two N-heteroaromatic pollutants, i.e., pyridine and quinoline was investigated by gamma irradiation in the presence of TiO2 nanoparticle. The experimental results showed that quinoline has a higher degradation rate than pyridine. The removal efficiency of the pollutants, TOC and TN reached 93.0%, 11.9% and 12.0% for quinoline, 71.0%, 10.6% and 4.4% for pyridine, respectively at 7.0 kGy and initial concentration of 50 mg/L. Ammonium was detected for both pyridine and quinoline within the absorbed doses, suggesting that the organic nitrogen was transformed into ammonium. The degradation rate constant of pyridine and quinoline was increased by 1.1-1.5 times with addition of TiO2. TiO2 nanoparticles were especially effective to enhance the mineralization. The removal efficiency of TOC and TN was increased by 15-12% for pyridine and 23-25% for quinoline, respectively in the presence of 2.0 g/L TiO2. Following gamma irradiation, 2-hydroxypyridine, 3-hydroxypyridine, oxalic acid and formic acid were identified for pyridine and the hydroxyl quinoline and formic acid were detected for quinoline. Accordingly, the degradation mechanism of pyridine and quinoline by gamma irradiation was tentatively proposed.

  3. Triazole-pyridine ligands: a novel approach to chromophoric iridium arrays

    NARCIS (Netherlands)

    Juríček, M.; Felici, M.; Contreras-Carballada, P.; Lauko, J.; Bou, S.R.; Kouwer, P.H.J.; Brouwer, A.M.; Rowan, A.E.

    2011-01-01

    We describe a novel modular approach to a series of luminescent iridium complexes bearing triazole-pyridine-derived ligands that were conveniently prepared by using "click" chemistry. One, two or three triazole-pyridine units were effectively built into the heteroaromatic macromolecule using

  4. NHC Versus Pyridine: How “Teeth” Change the Redox Behavior of Iron(II) Complexes

    KAUST Repository

    Weiss, Daniel T.; Anneser, Markus R.; Haslinger, Stefan; Pö thig, Alexander; Cokoja, Mirza; Basset, Jean-Marie; Kü hn, Fritz E.

    2015-01-01

    A series of octahedral iron(II) complexes with tetradentate NHC/pyridine hybrid ligands containing up to three pyridyl units was designed to study the influence of NHC and pyridine donors on the electronic structure of the metal center. Structural

  5. Experimental Investigation of Evolution of Pore Structure in Longmaxi Marine Shale Using an Anhydrous Pyrolysis Technique

    Directory of Open Access Journals (Sweden)

    Zhaodong Xi

    2018-05-01

    Full Text Available To better understanding the evolutionary characteristics of pore structure in marine shale with high thermal maturity, a natural Longmaxi marine shale sample from south China with a high equivalent vitrinite reflectance value (Ro = 2.03% was selected to conduct an anhydrous pyrolysis experiment (500–750 °C, and six artificial shale samples (pyrolysis products spanning a maturity range from Ro = 2.47% to 4.87% were obtained. Experimental procedures included mercury intrusion, nitrogen adsorption, and carbon dioxide adsorption, and were used to characterize the pore structure. In addition, fractal theory was applied to analyze the heterogeneous pore structure. The results showed that this sample suite had large differences in macropore, mesopore, and micropore volume (PV, as well as specific surface area (SSA and pore size distributions (PSD, at different temperatures. Micropore, mesopore, and macropore content increased, from being unheated to 600 °C, which caused the pore structure to become more complex. The content of small diameter pores (micropores and fine mesopores, <10 nm decreased and pores with large diameters (large mesopores and macropores, >10 nm slightly increased from 600 to 750 °C. Fractal analysis showed that larger pore sizes had more complicated pore structure in this stage. The variance in pore structure for samples during pyrolysis was related to the further transformation of organic matter and PSD rearrangement. According to the data in this study, two stages were proposed for the pore evolution for marine shale with high thermal maturity.

  6. Preparation and characterization of 1,6 anhydrous Β-D-Glucopyranose from starch

    International Nuclear Information System (INIS)

    Alvarez Lopez, M.S.

    1991-01-01

    In order to prepare 2-deoxi-2-fluoride-D-glucosa (2FDG) in an inert form there are several synthesis methods, but the more interesting one for our study is based in a reaction from the 1,6 anhydrous, Β-D-glucopyranose (1,6AGP), in an attempt to compare the labelling efficiency rate of 2FDG with F-18, which is highly used in nuclear medicine. In the present paper the attainment of starch from white potatoe, infrared analysis of this starch and fusion point are included. Also results are compared with an analytical reactive standard. The process of preparation of 1,6AGP by pyrolysis of starch under reduced pressure, its separation and purification by crystallization and infrared characterization of 1,6AGP, nuclear magnetic resonance and mass spectrometry are also included. 10 kg. of potatoes were used, and 93059 g. ±5.8 of starch with an efficiency rate of 9.32 ±0.631; fusion point was 272 o C and there was a 9.83 ± 1.48 % of humidity. After the pyrolysis, crystallization an purification processes, 1.71 ±0.54 % of 1,6AGP were obtained. Later results of compound characterization, nuclear magnetic resonance, infrared and mass spectrometry were compared with a commercial product and it was proved that it corresponds to such pure compound. (Author)

  7. Anhydrous formic acid and acetic anhydride as solvent or additive in nonaqueous titrations.

    Science.gov (United States)

    Buvári-Barcza, A; Tóth, I; Barcza, L

    2005-09-01

    The use and importance of formic acid and acetic anhydride (Ac2O) is increasing in nonaqueous acid-base titrations, but their interaction with the solutes is poorly understood. This paper attempts to clarify the effect of the solvents; NMR and spectrophotometric investigations were done to reveal the interactions between some bases and the mentioned solvents. Anhydrous formic acid is a typical protogenic solvent but both the relative permittivity and acidity are higher than those of acetic acid (mostly used in assays of bases). These differences originate from the different chemical structures: liquid acetic acid contains basically cyclic dimers while formic acid forms linear associates. Ac2O is obviously not an acidic but an aprotic (very slightly protophilic) solvent, which supposedly dissociates slightly into acetyl (CH3CO+) and acetate (AcO-) ions. In fact, some bases react with Ac2O forming an associate: the Ac+ group is bound to the delta- charged atom of the reactant while AcO- is associated with the delta+ group at appropriate distance.

  8. Investigation of solubility of carbon dioxide in anhydrous milk fat by lab-scale manometric method.

    Science.gov (United States)

    Truong, Tuyen; Palmer, Martin; Bansal, Nidhi; Bhandari, Bhesh

    2017-12-15

    This study aims to examine the solubility of CO 2 in anhydrous milk fat (AMF) as functions of partial pressure, temperature, chemical composition and physical state of AMF. AMF was fractionated at 21°C to obtain stearin and olein fractions. The CO 2 solubility was measured using a home-made experimental apparatus based on changes of CO 2 partial pressures. The apparatus was found to be reliable as the measured and theoretical values based on the ideal gas law were comparable. The dissolved CO 2 concentration in AMF increased with an increase in CO 2 partial pressure (0-101kPa). The apparent CO 2 solubility coefficients (molkg -1 Pa -1 ) in the AMF were 5.75±0.16×10 -7 , 3.9±0.19×10 -7 and 1.19±0.14×10 -7 at 35, 24 and 4°C, respectively. Higher liquid oil proportions resulted in higher CO 2 solubility in the AMF. There was insignificant difference in the dissolved CO 2 concentration among the AMF, stearin and olein fractions in their liquid state at 40°C. Copyright © 2017 Elsevier Ltd. All rights reserved.

  9. Vapor-phase etching of InP using anhydrous HCl and PH/sub 3/ gas

    International Nuclear Information System (INIS)

    Pak, K.; Koide, Y.; Imai, K.; Yoshida, A.; Nakamura, T.; Yasuda, Y.; Nishinaga, T.

    1986-01-01

    In situ etching of the substrate surface for vapor-phase epitaxy is a useful technique for obtaining a smooth and damage-free surface prior to the growth. Previous work showed that the incorporation of in situ etching of InP substrate with anhydrous HCl gas resulted in a significant improvement in the surface morphologies for MOVPE-grown InGaAs/InP and InP epitaxial layers. However, the experiment on the HCl etching of the InP substrate for a wide temperature range has not been performed as yet. In this note, the authors describe the effect of the substrate temperature on the etching morphology of InP substrate by using the anhydrous HCl and PH/sub 3/ gases. In the experiment, they used a standard MOVPE horizontal system. A quartz reactor tube in a 60 mm ID, 60 cm long, was employed

  10. Use of X-ray diffraction to quantify amorphous supplementary cementitious materials in anhydrous and hydrated blended cements

    International Nuclear Information System (INIS)

    Snellings, R.; Salze, A.; Scrivener, K.L.

    2014-01-01

    The content of individual amorphous supplementary cementitious materials (SCMs) in anhydrous and hydrated blended cements was quantified by the PONKCS [1] X-ray diffraction (XRD) method. The analytical precision and accuracy of the method were assessed through comparison to a series of mixes of known phase composition and of increasing complexity. A 2σ precision smaller than 2–3 wt.% and an accuracy better than 2 wt.% were achieved for SCMs in mixes with quartz, anhydrous Portland cement, and hydrated Portland cement. The extent of reaction of SCMs in hydrating binders measured by XRD was 1) internally consistent as confirmed through the standard addition method and 2) showed a linear correlation to the cumulative heat release as measured independently by isothermal conduction calorimetry. The advantages, limitations and applicability of the method are discussed with reference to existing methods that measure the degree of reaction of SCMs in blended cements

  11. Anhydrous polymer-based coating with sustainable controlled release functionality for facile, efficacious impregnation, and delivery of antimicrobial peptides.

    Science.gov (United States)

    Lim, Kaiyang; Saravanan, Rathi; Chong, Kelvin K L; Goh, Sharon H M; Chua, Ray R Y; Tambyah, Paul A; Chang, Matthew W; Kline, Kimberly A; Leong, Susanna S J

    2018-04-17

    Anhydrous polymers are actively explored as alternative materials to overcome limitations of conventional hydrogel-based antibacterial coating. However, the requirement for strong organic solvent in polymerization reactions often necessitates extra protection steps for encapsulation of target biomolecules, lowering encapsulation efficiency, and increasing process complexity. This study reports a novel coating strategy that allows direct solvation and encapsulation of antimicrobial peptides (HHC36) into anhydrous polycaprolactone (PCL) polymer-based dual layer coating. A thin 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphocholine (POPC) film is layered onto the peptide-impregnated PCL as a diffusion barrier, to modulate and enhance release kinetics. The impregnated peptides are eventually released in a controlled fashion. The use of 2,2,2-trifluoroethanol (TFE), as polymerization and solvation medium, induces the impregnated peptides to adopt highly stable turned conformation, conserving peptide integrity, and functionality during both encapsulation and subsequent release processes. The dual layer coating showed sustained antibacterial functionality, lasting for 14 days. In vivo assessment using an experimental mouse wounding model demonstrated good biocompatibility and significant antimicrobial efficacy of the coating under physiological conditions. The coating was translated onto silicone urinary catheters and showed promising antibacterial efficacy, even outperforming commercial silver-based Dover cather. This anhydrous polymer-based platform holds immense potential as an effective antibacterial coating to prevent clinical device-associated infections. The simplicity of the coating process enhances its industrial viability. © 2018 Wiley Periodicals, Inc.

  12. High temperature proton exchange membranes prepared from epoxycyclohexylethyltrimethoxysilane and amino trimethylene phosphonic acid as anhydrous proton conductors

    International Nuclear Information System (INIS)

    Chen, Cheng; Shen, Chunhui; Kong, Gengjin; Gao, Shanjun

    2013-01-01

    High temperature anhydrous proton exchange membranes based on phosphonic acid were prepared from epoxycyclohexylethyltrimethoxysilane (EHTMS) and amino trimethylene phosphonic acid (ATMP) by sol–gel process. The structures and properties of membranes with different phosphonic acid content were extensively characterized by FTIR, TG-DSC and XRD. Their proton conductivity under dry condition was also investigated under different temperature. The results show that the proton conductivity of the prepared membranes strongly depends on temperature, and the proton conductivity ranges from 8.81 × 10 −5 S cm −1 at 20 °C to 4.65 × 10 −2 S cm −1 at 140 °C under anhydrous condition. It indicates that the increasing temperature is favorable for congregating of the grafted–PO 3 H 2 and increasing of the proton mobility. In addition, from the results of AFM images, it was confirmed that the continuous distribution of phosphonic acid groups is favorable for the formation of the proton transport channel, which can significantly enhance the proton conductivity of the membranes. Highlights: ► Hybrid membranes of Epoxycyclohexylethyltrimethoxysilane and Amino trimethylene phosphonic acid. ► The proton conductivity is 4.65 × 10 −2 S cm −1 at 140 °C under anhydrous condition. ► Continuous uniform distributions of phosphonic acid groups can be observed by AFM. ► There could be hydrogen bond network within high temperature membranes

  13. 3-Ethyl-5-(4-methoxyphenoxy-2-(pyridin-4-yl-3H-imidazo[4,5-b]pyridine

    Directory of Open Access Journals (Sweden)

    S. Ranjith

    2011-07-01

    Full Text Available In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5°]. The pyridine ring makes a dihedral angle of 35.5 (5° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking interaction between the phenyl rings of neighbouring molecules [centroid–centroid distance = 3.772 (2 Å, interplanar distance = 3.546 (2 Å and slippage = 1.286 (2 Å].

  14. Anhydrate to hydrate solid-state transformations of carbamazepine and nitrofurantoin in biorelevant media studied in situ using time-resolved synchrotron X-ray diffraction

    DEFF Research Database (Denmark)

    Bøtker, Johan Peter; Rantanen, Jukka; Arnfast, Lærke

    2016-01-01

    with different biorelevant media, simulated fasted and fed state intestinal fluids containing bile salt and dioleoylphosphatidylcholine (DOPC) micelles, DOPC/sodium dodecyl sulfate (SDS) mixture, bile salt solution and water. Two anhydrate compounds (carbamazepine, CBZ and nitrofurantoin, NF) with different...

  15. Implementing Formative Assessment in Engineering Education: The Use of the Online Assessment System Etude

    Science.gov (United States)

    Dopper, Sofia M.; Sjoer, Ellen

    2004-01-01

    This article describes the possibilities offered by the online assessment system Etude to achieve the benefits of formative assessment. In order to find out the way this works in practice, we carried out an experiment with the use of Etude for formative assessment in the course on collaborative report writing. Results show that online formative…

  16. Hexaaquanickel(II tetraaquabis(μ-pyridine-2,6-dicarboxylatobis(pyridine-2,6-dicarboxylatotrinickelate(II octahydrate

    Directory of Open Access Journals (Sweden)

    Javad Safaei-Ghomi

    2010-08-01

    Full Text Available The title compound, [Ni(H2O6][Ni3(C7H3NO44(H2O4]·8H2O, was obtained by the reaction of nickel(II nitrate hexahydrate with pyridine-2,6-dicarboxylic acid (pydcH2 and 1,10-phenanothroline (phen in an aqueous solution. The latter ligand is not involved in formation of the title complex. There are three different NiII atoms in the asymmetric unit, two of which are located on inversion centers, and thus the [Ni(H2O6]2+ cation and the trinuclear {[Ni(pydc2]2-μ-Ni(H2O4}2− anion are centrosymmetric. All NiII atoms exhibit an octahedral coordination geometry. Various interactions, including numerous O—H...O and C—H...O hydrogen bonds and C—O...π stacking of the pyridine and carboxylate groups [3.570 (1, 3.758 (1 and 3.609 (1 Å], are observed in the crystal structure.

  17. Crystal structure of 2-hydroxyimino-2-(pyridin-2-yl-N′-[1-(pyridin-2-ylethylidene]acetohydrazide

    Directory of Open Access Journals (Sweden)

    Maxym O. Plutenko

    2014-12-01

    Full Text Available The molecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å, with the planes of the two pyridine rings inclined to one another by 5.51 (7°. The oxime group is syn to the amide group, probably due to the formation of an intramolecular N—H...N hydrogen bond that forms an S(6 ring motif. In the crystal, molecules are linked by pairs of bifurcated O—H...(O,N hydrogen bonds, forming inversion dimers. The latter are linked via C—H...O and C—H...N hydrogen bonds, forming sheets lying parallel to (502. The sheets are linked via π–π stacking interactions [inter-centroid distance = 3.7588 (9 Å], involving the pyridine rings of inversion-related molecules, forming a three-dimensional structure.

  18. Determination of pyridine in soil and water samples of a polluted area

    International Nuclear Information System (INIS)

    Peters, R.J.B.; Renesse van Duivenbode, J.A.D. van

    1994-01-01

    A method for the analyses of pyridine in environmental samples is described. For soil samples a distillation procedure followed by an extraction, an acidic extraction or a Soxhlet extraction can be used. For water samples a distillation procedure followed by extraction can be employed. Deuterated pyridine is used as an internal standard and the extracts are analyzed by GC-MS. The recoveries of the methods are higher than 80%; the detection limits for pyridine are 0.01 mg/kg for soil samples and 0.2 μg/l for water samples. (orig.)

  19. Surface enhanced raman scattering at Ag-Pyridine interface by use of long range surface plasmon

    International Nuclear Information System (INIS)

    Baik, Moon Gu; Ko, Eu; Kwan, Do Kyeong; Lee, Ja Hyung; Chang, Joon Sung

    1990-01-01

    Surface-enhanced Raman scattering (SERS) experiment of pyridine (C 5 H 5 N) has been performed at silverpyridine interface by use of long range surface plasmon (LRSP) which is generated in the Sarid-type attenuated total reflection (ATR) structure consisting of prism, dielectic, metal and dielectic media. Generation of LRSP has been confirmed by observing the propagation of the LRSP. Raman signal of pyridine adsorbed on the silver surface in the above layered structure has been observed and compared with the bulk Raman signal and SERS signal from the chemically adsorbed pyridine. SERS experiment by use of LRSP has not yet reported to the best of our knowledge. (Author)

  20. SERS spectra of pyridine adsorbed on nickel film prepared by magnetron sputtering

    Science.gov (United States)

    Li, Daoyong; Ouyang, Yu; Chen, Li; Cao, Weiran; Shi, Shaohua

    2011-02-01

    As a repeating well and cheaper enhancement substrate, the nickel film was fabricated with magnetron sputtering coating instrument. Surface enhanced Raman spectra (SERS) of pyridine adsorbed on this nickel film are compared with the experimental values of gaseous pyridine, the theoretical value of pyridine solution listed in other literatures and our method is better than electro-chemical etching electrode method for large scale preparation. The enhancement factor of the nickel film is calculated and the result indicates that magnetron sputtering coating technology is feasible for obtaining good SERS active surface.

  1. 98 Etude Comparative du Systeme Phonematique et Tonal des ...

    African Journals Online (AJOL)

    98. Etude Comparative du Systeme Phonematique et Tonal des. Deux Parlers: Le Yoruba du Nigeria et L'itsa Parle en. Republique du Benin. Ajani Akinwumi Lateef et Ayuba G. Ajibabi http://dx.doi./org/10.4314/ujah.v18i3.5. Résume. En ce début de l'époque ou la mondialisation et la coexistence des peuples dans le ...

  2. Synthesis and characterization of oxovanadium (IV) dithiocarbamates with pyridine

    Energy Technology Data Exchange (ETDEWEB)

    Doadrio, Antonio L.; Sotelo, Jose; Fernandez-Ruano, Ana [Universidad Complutense, Madrid (Spain). Facultad de Farmacia. Dept. de Quimica Inorganica y Bioinorganica]. E-mail: antoniov@farm.ucm.es

    2002-07-01

    We report the synthesis and study of a new series of oxovanadium (IV) dithiocarbamate adducts and derivatives with pyridine and cyclohexyl, di-iso-butyl, di-n-propyl, aniline, morpholine, piperidine and di-iso-propyl amines. The complexes have been characterized by analytical, magneto chemical, IR, visible-UV spectral and thermal studies, and are assigned the formulas [VO(L){sub 2}].py, where L=cyclohexyl, di-iso-butyl, di-n-propyl, aniline dithiocarbamate and [VO(OH)(L)(py){sub 2}] OH.H{sub 2}O (L=morpholine, piperidine and di-iso-propyl dithiocarbamate). The effect of the adduct formation on the p{sub V=0} bound is discussed in terms of the IR (V=O, V-S and V-N stretching frequencies) and electronic spectra (d-d transitions). (author)

  3. Unconventional hydrogen bonding to organic ions in the gas phase: Stepwise association of hydrogen cyanide with the pyridine and pyrimidine radical cations and protonated pyridine

    Energy Technology Data Exchange (ETDEWEB)

    Hamid, Ahmed M.; El-Shall, M. Samy, E-mail: mselshal@vcu.edu [Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284 (United States); Hilal, Rifaat; Elroby, Shaaban; Aziz, Saadullah G. [Department of Chemistry, Faculty of Science, King Abdulaziz University, Jeddah 21589 (Saudi Arabia)

    2014-08-07

    Equilibrium thermochemical measurements using the ion mobility drift cell technique have been utilized to investigate the binding energies and entropy changes for the stepwise association of HCN molecules with the pyridine and pyrimidine radical cations forming the C{sub 5}H{sub 5}N{sup +·}(HCN){sub n} and C{sub 4}H{sub 4}N{sub 2}{sup +·}(HCN){sub n} clusters, respectively, with n = 1–4. For comparison, the binding of 1–4 HCN molecules to the protonated pyridine C{sub 5}H{sub 5}NH{sup +}(HCN){sub n} has also been investigated. The binding energies of HCN to the pyridine and pyrimidine radical cations are nearly equal (11.4 and 12.0 kcal/mol, respectively) but weaker than the HCN binding to the protonated pyridine (14.0 kcal/mol). The pyridine and pyrimidine radical cations form unconventional carbon-based ionic hydrogen bonds with HCN (CH{sup δ+}⋯NCH). Protonated pyridine forms a stronger ionic hydrogen bond with HCN (NH{sup +}⋯NCH) which can be extended to a linear chain with the clustering of additional HCN molecules (NH{sup +}⋯NCH··NCH⋯NCH) leading to a rapid decrease in the bond strength as the length of the chain increases. The lowest energy structures of the pyridine and pyrimidine radical cation clusters containing 3-4 HCN molecules show a strong tendency for the internal solvation of the radical cation by the HCN molecules where bifurcated structures involving multiple hydrogen bonding sites with the ring hydrogen atoms are formed. The unconventional H-bonds (CH{sup δ+}⋯NCH) formed between the pyridine or the pyrimidine radical cations and HCN molecules (11–12 kcal/mol) are stronger than the similar (CH{sup δ+}⋯NCH) bonds formed between the benzene radical cation and HCN molecules (9 kcal/mol) indicating that the CH{sup δ+} centers in the pyridine and pyrimidine radical cations have more effective charges than in the benzene radical cation.

  4. Nuclear study of Melusine; Etude nucleaire de Melusine

    Energy Technology Data Exchange (ETDEWEB)

    Cherot, J [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1959-07-01

    In this report are reviewed - with respect to starting of experiments - the main nuclear characteristics of a 20 per cent enriched uranium lattice, with light water as moderator and reflector. The reactor is to operate at 1 MW. 1) Study of various critical masses. 2) Control. Effectiveness of cadmium. Control rods and of a stainless steel regulating rod. 3) Study of the effect on reactivity of disturbances in the core center. 4) Study of xenon and samarium poisoning. 5) Temperature factor. 6) Heat exchanges in a fuel element. (author) [French] On etudie, dans ce rapport, les principales proprietes nucleaires d'un reseau a uranium enrichi (20 pour cent), dont le moderateur et le reflecteur sont l'eau legere en vue des experiences de demarrage. Ce reacteur devra fonctionner a 1 MW. 1) Etude de diverses masses critiques. 2) Controle. Efficacite des barres de controle en cadmium et d'une barre de reglage en acier inoxydable. 3) Etude de l'effet sur la reactivite de perturbation au centre du coeur. 4) Etude de l'empoisonnement xenon et samarium. 5) Coefficient de temperature. 6) Echanges thermiques dans un element. (auteur)

  5. Constraining the Timescales of Rehydration in Nominally Anhydrous Minerals Using 3D Numerical Diffusion Models

    Science.gov (United States)

    Lynn, K. J.; Warren, J. M.

    2017-12-01

    Nominally anhydrous minerals (NAMs) are important for characterizing deep-Earth water reservoirs, but the water contents of olivine (ol), orthopyroxene (opx), and clinopyroxene (cpx) in peridotites generally do not reflect mantle equilibrium conditions. Ol is typically "dry" and decoupled from H in cpx and opx, which is inconsistent with models of partial melting and/or diffusive loss of H during upwelling beneath mid-ocean ridges. The rehydration of mantle pyroxenes via late-stage re-fertilization has been invoked to explain their relatively high water contents. Here, we use sophisticated 3D diffusion models (after Shea et al., 2015, Am Min) of H in ol, opx, and cpx to investigate the timescales of rehydration across a range of conditions relevant for melt-rock interaction and serpentinization of peridotites. Numerical crystals with 1 mm c-axis lengths and realistic crystal morphologies are modeled using recent H diffusivities that account for compositional variation and diffusion anisotropy. Models were run over timescales of minutes to millions of years and temperatures from 300 to 1200°C. Our 3D models show that, at the high-T end of the range, H concentrations in the cores of NAMs are partially re-equilibrated in as little as a few minutes, and completely re-equilibrated within hours to weeks. At low-T (300°C), serpentinization can induce considerable diffusion in cpx and opx. H contents are 30% re-equilibrated after continuous exposure to hydrothermal fluids for 102 and 105 years, respectively, which is inconsistent with previous interpretations that there is no effect on H in opx under similar conditions. Ol is unaffected after 1 Myr due to the slower diffusivity of the proton-vacancy mechanism at 300°C (2-4 log units lower than for opx). In the middle of the T range (700-1000°C), rehydration of opx and cpx occurs over hours to days, while ol is somewhat slower to respond (days to weeks), potentially allowing the decoupling observed in natural samples to

  6. High temperature proton exchange membranes prepared from epoxycyclohexylethyltrimethoxysilane and amino trimethylene phosphonic acid as anhydrous proton conductors

    Energy Technology Data Exchange (ETDEWEB)

    Chen, Cheng [Department of Polymer Materials and Engineering, School of Material Science and Engineering, Wuhan University of Technology, No. 122 Luoshi Road, Wuhan 430070 (China); Shen, Chunhui, E-mail: shenchunhui@whut.edu.cn [Department of Polymer Materials and Engineering, School of Material Science and Engineering, Wuhan University of Technology, No. 122 Luoshi Road, Wuhan 430070 (China); Kong, Gengjin; Gao, Shanjun [Department of Polymer Materials and Engineering, School of Material Science and Engineering, Wuhan University of Technology, No. 122 Luoshi Road, Wuhan 430070 (China)

    2013-06-15

    High temperature anhydrous proton exchange membranes based on phosphonic acid were prepared from epoxycyclohexylethyltrimethoxysilane (EHTMS) and amino trimethylene phosphonic acid (ATMP) by sol–gel process. The structures and properties of membranes with different phosphonic acid content were extensively characterized by FTIR, TG-DSC and XRD. Their proton conductivity under dry condition was also investigated under different temperature. The results show that the proton conductivity of the prepared membranes strongly depends on temperature, and the proton conductivity ranges from 8.81 × 10{sup −5} S cm{sup −1} at 20 °C to 4.65 × 10{sup −2} S cm{sup −1} at 140 °C under anhydrous condition. It indicates that the increasing temperature is favorable for congregating of the grafted–PO{sub 3}H{sub 2} and increasing of the proton mobility. In addition, from the results of AFM images, it was confirmed that the continuous distribution of phosphonic acid groups is favorable for the formation of the proton transport channel, which can significantly enhance the proton conductivity of the membranes. Highlights: ► Hybrid membranes of Epoxycyclohexylethyltrimethoxysilane and Amino trimethylene phosphonic acid. ► The proton conductivity is 4.65 × 10{sup −2} S cm{sup −1} at 140 °C under anhydrous condition. ► Continuous uniform distributions of phosphonic acid groups can be observed by AFM. ► There could be hydrogen bond network within high temperature membranes.

  7. (Pyridin-2-ylmethyl 6-bromo-2-oxo-1-[(pyridin-2-ylmethyl]-1,2-dihydroquinoline-4-carboxylate

    Directory of Open Access Journals (Sweden)

    Yassir Filali Baba

    2018-02-01

    Full Text Available In the central dihydroquinoline unit of the title compound, C22H16BrN3O3, the dihydropyridinone and benzene rings are inclined to one another by 2.0 (1°, while the outer pyridine rings are almost perpendicular to the plane of the dihydroquinoline ring system. The conformation of the molecule is partially determined by an intramolecular C—H...O hydrogen bond. In the crystal, molecules stack along the b-axis direction through a combination of C—H...N and C—H...O hydrogen bonds and π–π stacking interactions involving the dihydroquinoline units, with a centroid-to-centroid distance of 3.7648 (15 Å.

  8. Anti-Markovnikov hydroimination of terminal alkynes in gold-catalyzed pyridine construction from ammonia.

    Science.gov (United States)

    Wang, Liliang; Kong, Lingbing; Li, Yongxin; Ganguly, Rakesh; Kinjo, Rei

    2015-08-11

    Gold-catalyzed hydroimination of terminal alkynes, giving rise to anti-Markovnikov adducts concomitant with unstable Markovnikov adducts is described. The elementary step can be applied for the construction of pyridine derivatives from ammonia and alkynes.

  9. Ugi-Smiles couplings of 4-substituted pyridine derivatives : a fast access to chloroquine analogues

    NARCIS (Netherlands)

    El Kaïm, Laurent; Grimaud, Laurence; Pravin, Patil; Patil, Pravin

    2012-01-01

    4-Hydroxy and mercapto pyridines were successfully tested in Ugi-Smiles couplings. Such multicomponent reactions applied to quinoline derivatives afford a very convenient and short synthesis of antimalarial analogues.

  10. Ugi-Smiles couplings of 4-substituted pyridine derivatives: a fast access to chloroquine analogues.

    Science.gov (United States)

    El Kaïm, Laurent; Grimaud, Laurence; Pravin, Patil

    2012-01-20

    4-Hydroxy and mercapto pyridines were successfully tested in Ugi-Smiles couplings. Such multicomponent reactions applied to quinoline derivatives afford a very convenient and short synthesis of antimalarial analogues. © 2011 American Chemical Society

  11. Poly[di-μ2-aqua-μ5-(pyridine-2,6-dicarboxylato-μ3-(pyridine-2,6-dicarboxylato-cobalt(IIdisodium

    Directory of Open Access Journals (Sweden)

    Alexander N. Boyko

    2011-12-01

    Full Text Available In the title compound, [CoNa2(C7H3NO42(H2O2]n, the CoII atom is coordinated by two pyridine N atoms and four carboxylate O atoms from two doubly deprotonated pyridine-2,6-dicarboxylate ligands in a distorted octahedral geometry. One Na+ cation is coordinated by three carboxylate O atoms and two water molecules and the other is coordinated by five carboxylate O atoms and two water molecules in an irregular geometry. The bis(pyridine-2,6-dicarboxylatocobalt complex units are connected by Na+ cations and bridging water molecules into a three-dimensional coordination network. O—H...O hydrogen bonds are formed between the water molecules and the carboxylate O atoms.

  12. Binary and ternary cocrystals of sulfa drug acetazolamide with pyridine carboxamides and cyclic amides

    OpenAIRE

    Bolla, Geetha; Nangia, Ashwini

    2016-01-01

    A novel design strategy for cocrystals of a sulfonamide drug with pyridine carboxamides and cyclic amides is developed based on synthon identification as well as size and shape match of coformers. Binary adducts of acetazolamide (ACZ) with lactams (valerolactam and caprolactam, VLM, CPR), cyclic amides (2-pyridone, labeled as 2HP and its derivatives MeHP, OMeHP) and pyridine amides (nicotinamide and picolinamide, NAM, PAM) were obtained by manual grinding, and their single crystals by solutio...

  13. N,N′-(Ethane-1,2-diyldi-o-phenylenebis(pyridine-2-carboxamide

    Directory of Open Access Journals (Sweden)

    Shuranjan Sarkar

    2011-11-01

    Full Text Available The title molecule, C26H22N4O2, is centrosymmetric and adopts an anti conformation. Two intramolecular hydrogen bonds, viz. amide–pyridine N—H...N and phenyl–amide C—H...O, stabilize the trans conformation of the (pyridine-2-carboxamidophenyl group about the amide plane. In the crystal, the presence of weak intermolecular C—H...O hydrogen bonds results in the formation of a three-dimensional network.

  14. Dihydro-β-agarofuran sesquiterpene pyridine alkaloids from the seeds of Euonymus hamiltonianus

    Directory of Open Access Journals (Sweden)

    Mudasir A. Tantry

    2016-09-01

    Full Text Available Plants of the Celastraceae family produce various dihydro-β-agarofuran sesquiterpene pyridine alkaloids. Two dihydro-β-agarofuran sesquitepene pyridine alkaloids (1,2 apart from four known compounds euojaponin C (3, wilforine (4, austronine (5 and O9-benzoyl-O9-deacetylevonine (6, were isolated from the ripe seeds of Euonymus hamiltonianus. Their chemical structures were elucidated mainly by analysis of NMR and MS spectral data. All compounds were evaluated for insecticidal activity.

  15. On the formation of niacin (vitamin B3) and pyridine carboxylic acids in interstellar model ices

    Energy Technology Data Exchange (ETDEWEB)

    McMurtry, Brandon M.; Turner, Andrew M.; Saito, Sean E.J.; Kaiser, Ralf I. [W. M. Keck Research Laboratory in Astrochemistry, University of Hawaii at Manoa, Honolulu, Hawaii, HI 96822 (United States); Department of Chemistry, University of Hawaii at Manoa, Honolulu, Hawaii, HI 96822 (United States)

    2016-06-15

    The formation of pyridine carboxylic acids in interstellar ice grains was simulated by electron exposures of binary pyridine (C{sub 5}H{sub 5}N)-carbon dioxide (CO{sub 2}) ice mixtures at 10 K under contamination-free ultrahigh vacuum conditions. Chemical processing of the pristine ice and subsequent warm-up phase was monitored on line and in situ via Fourier transform infrared spectroscopy to probe for the formation of new radiation induced species. In the infrared spectra of the irradiated ice, bands assigned to nicotinic acid (niacin; vitamin B3; m-C{sub 5}H{sub 4}NCOOH) along with 2,3-, 2,5-, 3,4-, and 3,5-pyridine dicarboxylic acid (C{sub 5}H{sub 3}N(COOH){sub 2}) were unambiguously identified along with the hydroxycarbonyl (HOCO) radical. Our study suggests that the reactive pathway responsible for pyridine carboxylic acids formation involves a HOCO intermediate, which forms through the reaction of suprathermal hydrogen ejected from pyridine with carbon dioxide. The newly formed pyridinyl radical may then undergo radical–radical recombination with a hydroxycarbonyl radical to form a pyridine carboxylic acid.

  16. Pyridine adsorption and diffusion on Pt(111) investigated with density functional theory

    International Nuclear Information System (INIS)

    Kolsbjerg, Esben L.; Groves, Michael N.; Hammer, Bjørk

    2016-01-01

    The adsorption, diffusion, and dissociation of pyridine, C 5 H 5 N, on Pt(111) are investigated with van der Waals-corrected density functional theory. An elaborate search for local minima in the adsorption potential energy landscape reveals that the intact pyridine adsorbs with the aromatic ring parallel to the surface. Piecewise interconnections of the local minima in the energy landscape reveal that the most favourable diffusion path for pyridine has a barrier of 0.53 eV. In the preferred path, the pyridine remains parallel to the surface while performing small single rotational steps with a carbon-carbon double bond hinged above a single Pt atom. The origin of the diffusion pathway is discussed in terms of the C 2 –Pt π-bond being stronger than the corresponding CN–Pt π-bond. The energy barrier and reaction enthalpy for dehydrogenation of adsorbed pyridine into an adsorbed, upright bound α-pyridyl species are calculated to 0.71 eV and 0.18 eV, respectively (both zero-point energy corrected). The calculations are used to rationalize previous experimental observations from the literature for pyridine on Pt(111).

  17. Regulation of Ca2+ release from mitochondria by the oxidation-reduction state of pyridine nucleotides

    Science.gov (United States)

    Lehninger, Albert L.; Vercesi, Anibal; Bababunmi, Enitan A.

    1978-01-01

    Mitochondria from normal rat liver and heart, and also Ehrlich tumor cells, respiring on succinate as energy source in the presence of rotenone (to prevent net electron flow to oxygen from the endogenous pyridine nucleotides), rapidly take up Ca2+ and retain it so long as the pyridine nucleotides are kept in the reduced state. When acetoacetate is added to bring the pyridine nucleotides into a more oxidized state, Ca2+ is released to the medium. A subsequent addition of a reductant of the pyridine nucleotides such as β-hydroxybutyrate, glutamate, or isocitrate causes reuptake of the released Ca2+. Successive cycles of Ca2+ release and uptake can be induced by shifting the redox state of the pyridine nucleotides to more oxidized and more reduced states, respectively. Similar observations were made when succinate oxidation was replaced as energy source by ascorbate oxidation or by the hydrolysis of ATP. These and other observations form the basis of a hypothesis for feedback regulation of Ca2+-dependent substrate- or energy-mobilizing enzymatic reactions by the uptake or release of mitochondrial Ca2+, mediated by the cytosolic phosphate potential and the ATP-dependent reduction of mitochondrial pyridine nucleotides by reversal of electron transport. Images PMID:25436

  18. Investigating the Effect of Pyridine Vapor Treatment on Perovskite Solar Cells - Oral Presentation

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Alison J. [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-25

    Perovskite photovoltaics have recently come to prominence as a viable alternative to crystalline silicon based solar cells. In an effort to create consistent and high-quality films, we studied the effect of various annealing conditions as well as the effect of pyridine vapor treatment on mixed halide methylammonium lead perovskite films. Of six conditions tested, we found that annealing at 100 degree Celsius for 90 minutes followed by 120 degree Celsius for 15 minutes resulted in the purest perovskite. Perovskite films made using that condition were treated with pyridine for various amounts of time, and the effects on perovskite microstructure were studied using x-ray diffraction, UV-Vis spectroscopy, and time-resolved photoluminescence lifetime analysis (TRPL). A previous study found that pyridine vapor caused perovskite films to have higher photoluminescence intensity and become more homogenous. In this study we found that the effects of pyridine are more complex: while films appeared to become more homogenous, a decrease in bulkphotoluminescence lifetime was observed. In addition, the perovskite bandgap appeared to decrease with increased pyridine treatment time. Finally, X-ray diffraction showed that pyridine vapor treatment increased the perovskite (110) peak intensity but also often gave rise to new unidentified peaks, suggesting the formation of a foreign species. It was observed that the intensity of this unknown species had an inverse correlation with the increase in perovskite peak intensity, and also seemed to be correlated with the decrease in TRPL lifetime.

  19. Investigating the Effect of Pyridine Vapor Treatment on Perovskite Solar Cells

    Energy Technology Data Exchange (ETDEWEB)

    Ong, Alison [SLAC National Accelerator Lab., Menlo Park, CA (United States)

    2015-08-20

    Perovskite photovoltaics have recently come to prominence as a viable alternative to crystalline silicon based solar cells. In an effort to create consistent and high-quality films, we studied the effect of various annealing conditions as well as the effect of pyridine vapor treatment on mixed halide methylammonium lead perovskite films. Of six conditions tested, we found that annealing at 100°C for 90 minutes followed by 120°C for 15 minutes resulted in the purest perovskite. Perovskite films made using that condition were treated with pyridine for various amounts of time, and the effects on perovskite microstructure were studied using x-ray diffraction, UV-Vis spectroscopy, and time-resolved photoluminescence lifetime analysis (TRPL). A previous study found that pyridine vapor caused perovskite films to have higher photoluminescence intensity and become more homogenous. In this study we found that the effects of pyridine are more complex: while films appeared to become more homogenous, a decrease in bulk photoluminescence lifetime was observed. In addition, the perovskite bandgap appeared to decrease with increased pyridine treatment time. Finally, X-ray diffraction showed that pyridine vapor treatment increased the perovskite (110) peak intensity but also often gave rise to new unidentified peaks, suggesting the formation of a foreign species. It was observed that the intensity of this unknown species had an inverse correlation with the increase in perovskite peak intensity, and also seemed to be correlated with the decrease in TRPL lifetime.

  20. Preparation and Characterization of High Purity Anhydrous β-Lactose from α-Lactose Monohydrate at Mild Temperature

    Directory of Open Access Journals (Sweden)

    Ana L. López-Pablos

    2018-01-01

    Full Text Available Lactose is a disaccharide of importance in humans dietary, food products, and the pharmaceutical industry. From the existing isomeric forms, β-lactose is rarely found in nature. Thus, in this work, a simple methodology to obtain anhydrous β-lactose (βL from α-lactose monohydrate (αL·H2O is presented. The αL·H2O powder was dispersed into a basic alcoholic solution (72 hours, at controlled conditions of temperature (27, 29, 31, and 32°C, without stirring. The slurry was dried at room temperature and characterized. Fourier transform infrared spectroscopy showed the formation of βL for the samples prepared at 29 and 32°C. Raman spectroscopy confirmed this result and suggested the occurrence of crystalline βL. Rietveld refinement of the X-ray diffraction patterns was employed to identify and quantify the composition of the isomers. The samples prepared at 29 and 31°C showed the formation of pure βL, while those at 27 and 32°C showed the presence of αL·H2O and a mixture of the two isomers, respectively. The morphology of the powders was studied by scanning electron microscopy, observing the formation of irregular shape αL·H2O particles and axe-like βL particles. Clearly, with this methodology, it was possible to obtain pure, crystalline, and anhydrous βL at mild temperature.

  1. Mixed sodium nickel-manganese sulfates: Crystal structure relationships between hydrates and anhydrous salts

    Energy Technology Data Exchange (ETDEWEB)

    Marinova, Delyana M.; Zhecheva, Ekaterina N.; Kukeva, Rositsa R.; Markov, Pavel V. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Nihtianova, Diana D. [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Institute of Mineralogy and Crystallography, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria); Stoyanova, Radostina K., E-mail: radstoy@svr.igic.bas.bg [Institute of General and Inorganic Chemistry, Bulgarian Academy of Sciences, 1113 Sofia (Bulgaria)

    2017-06-15

    The present contribution provides new structural and spectroscopic data on the formation of solid solutions between hydrated and dehydrated sulfate salts of sodium-nickel and sodium-manganese in a whole concentration range: Na{sub 2}Ni{sub 1−x}Mn{sub x}(SO{sub 4}){sub 2}·yH{sub 2}O, 0≤ x≤1.0. Using powder XRD, electron paramagnetic resonance spectroscopy (EPR), IR and Raman spectroscopy it has been found that double sodium-nickel and sodium-manganese salts form solid solutions Na{sub 2}Ni{sub 1−x}Mn{sub x}(SO{sub 4}){sub 2}·4H{sub 2}O with a blödite-type of structure within a broad concentration range of 0≤x≤0.49, while the manganese rich compositions Na{sub 2}Ni{sub 1−x}Mn{sub x}(SO{sub 4}){sub 2}·2H{sub 2}O (0.97≤x≤1.0) crystallize in the kröhnkite-type of structure. The Ni-based blödites Na{sub 2}Ni{sub 1−x}Mn{sub x}(SO{sub 4}){sub 2}·4H{sub 2}O dehydrate between 140 and 260 °C into anhydrous salts Na{sub 2}Ni{sub 1−x}Mn{sub x}(SO{sub 4}){sub 2}, 0≤ x≤0.44, with a structure where Ni{sub 1−x}Mn{sub x}O{sub 6} octahedra are bridged into pairs by edge- and corner sharing SO{sub 4}{sup 2−} groups. Both TEM and EPR methods show that the Ni{sup 2+} and Mn{sup 2+} ions are homogenously distributed over three crystallographic positions of the large monoclinic cell. The dehydration of the kröhnkite phase Na{sub 2}Ni{sub 1−x}Mn{sub x}(SO{sub 4}){sub 2}·2H{sub 2}O yields the alluaudite phase Na{sub 2+δ}Mn{sub 2-δ/2}(SO{sub 4}){sub 3}, where the Na-to-Mn ratio decreases and all Ni{sup 2+} dopants are released from the structure. The process of the dehydration is discussed in terms of structural aspects taking into account the distortion degree of the Ni,MnO{sub 6} and SO{sub 4} polyhedra. - Graphical abstract: Thermal dehydration of the blödite phase Na{sub 2}Ni{sub 1−x}Mn{sub x}(SO{sub 4}){sub 2}·4H{sub 2}O (0≤ x≤0.49) yields nickel-manganese sulfates Na{sub 2}Ni{sub 1−x}Mn{sub x}(SO{sub 4}){sub 2} (0≤ x≤0.44) with

  2. Sulfur Concentration at Sulfide Saturation in Anhydrous Silicate Melts at Crustal Conditions

    Science.gov (United States)

    Liu, Y.; Samaha, N.; Baker, D. R.

    2006-05-01

    The sulfur concentration in silicate melts at sulfide saturation (SCSS) was experimentally investigated in a temperature range from 1250°C to 1450°C and a pressure range from 500 MPa to 1 GPa in a piston-cylinder apparatus. The investigated melt compositions varied from rhyolitic to basaltic. All experiments were saturated with a FeS melt. Temperature was confirmed to have a positive effect on the SCSS and no measurable pressure effect was observed. Oxygen fugacity was controlled to be either near the carbon-carbon monoxide buffer or one log unit above the nickel-nickel oxide buffer, and found to positively affect the SCSS. A series of models were constructed to predict the SCSS as a function of temperature, pressure, melt composition, oxygen fugacity and sulfur fugacity of the system. The coefficients were obtained by the regression of experimental data from this study and from data in the literature. The best model found for the prediction of the SCSS is: ln S (ppm) = 996/T + 9.875 + 0.997 ln MFM + 0.1901 ln fO2 - 0.0722 (P/T) -0.115 ln f S2, where P is in bar, T is in K, and MFM is a compositional parameter describing the melt based upon cation mole fractions: MFM = [Na + K + 2 (Ca + Mg+ Fe2+)]/[Si × (Al + Fe3+)]. This model predicts the SCSS in anhydrous silicate melts from rhyolitic to basaltic compositions at crustal conditions from 1 bar to 1.25 GPa, temperatures from ~1200 to 1400 C, and oxygen fugacities between approximately two log units below the fayalite-quartz-magnetite buffer and one log unit above the nickel-nickel oxide buffer. For cases where the oxygen and sulfur fugacities can not be adequately estimated a simpler model also works acceptably: ln S (ppm) = -5328/T + 8.431 + 1.244 ln MFM - 0.01704(P/T) + ln aFeS, where aFeS is the activity of FeS in the sulfide melt and is well approximated by a value of 1. Additional experiments were performed on other basalts in a temperature range from 1250 C to 1450 C at 1 GPa to test the models. The model

  3. Study by electron paramagnetic resonance of the radiolysis of pyridine N-oxide in a vitreous methanol matrix

    International Nuclear Information System (INIS)

    Quaegebeur, J.P.; Perly, B.

    1977-01-01

    The analysis of esr spectra derived from γ irradiated pyridine N-oxide in a methanolic vitreous matrix at 77 K shows the presence of a mixture of 2- and 4-azacyclohexadienyl N-oxide radicals formed by the addition of the hydroxymethyl primary species to the pyridine ring. The structure of the different radicals was determined by comparison with spectra derived from several substituted pyridine N-oxides

  4. Preparation of novel pyrrolo [2,3-b]pyridine derivatives via a new concise synthetic approach

    Energy Technology Data Exchange (ETDEWEB)

    Guo, Na; Jia, Haiyong; You, Xing; Jiang, Du; Lu, Kui; Yu, Peng [Key Laboratory of Industrial Microbiology, Ministry of Education, College of Biotechnology, Tianjin Key Laboratory of Industry Microbiology, College of Biotechnology, Sino-French Joint Lab of Food Nutrition/Safety and Medicinal Chemistry, Tianjin University of Science and Technology, Tianjin (China)

    2015-04-15

    The pyrrolo[2,3-b]pyridine core structure, a bioisostere of quinolones, is found in several molecules that possess important biological activity. We describe here a new, concise, three-step synthesis of pyrrolo[2,3-b]pyridines starting from L-alanine. A series of 4,7-dihydro-4-oxo-1H-pyrrolo[2,3-b]pyridine-5-carboxylic acid derivatives, which have not been previously reported, were synthesized using this approach.

  5. New pyridine derivatives as inhibitors of acetylcholinesterase and amyloid aggregation.

    Science.gov (United States)

    Pandolfi, Fabiana; De Vita, Daniela; Bortolami, Martina; Coluccia, Antonio; Di Santo, Roberto; Costi, Roberta; Andrisano, Vincenza; Alabiso, Francesco; Bergamini, Christian; Fato, Romana; Bartolini, Manuela; Scipione, Luigi

    2017-12-01

    A new series of pyridine derivatives with carbamic or amidic function has been designed and synthesized to act as cholinesterase inhibitors. The synthesized compounds were tested toward EeAChE and hAChE and toward eqBChE and hBChE. The carbamate 8 was the most potent hAChE inhibitor (IC 50  = 0.153 ± 0.016 μM) while the carbamate 11 was the most potent inhibitor of hBChE (IC 50  = 0.828 ± 0.067 μM). A molecular docking study indicated that the carbamate 8 was able to bind AChE by interacting with both CAS and PAS, in agreement with the mixed inhibition mechanism. Furthermore, the carbamates 8, 9 and 11 were able to inhibit Aβ 42 self-aggregation and possessed quite low toxicity against human astrocytoma T67 and HeLa cell lines, being the carbamate 8 the less toxic compound on both cell lines. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

  6. Characterization of Functionalized Acrylic acid /4- Vinyl Pyridine Graft Copolymers

    International Nuclear Information System (INIS)

    Kamal, H.; Mahmoud, Gh.A.; Hegazy, D.E.

    2009-01-01

    Properties and characterization of the membranes prepared by radiation grafting of acrylic acid (AAc) or/ and 4-vinyl pyridine (4VP) onto low density polyethylene (LDPE) and polypropylene (PP) films were carried out. The FTIR spectra for the grafted membranes were studied to evaluate the structure change as a result of grafting. The swelling behaviour of the graft copolymer in methanol was studied. It was found that the grafting of AAc and/ or 4- VP onto LDPE and PP resulted in introducing good hydrophilic properties to such polymer substrates. The hydrophilic properties were directly proportional to the amount of functional groups. The mechanical properties (Young's modulus, elongation percent and tensile strength) of the grafted membranes also, have been investigated. As the grafting degree increases, the modulus also increases. Increasing the hydrophilicity of the membranes by chemical treatment enhances its mechanical properties. The thermal parameters of the grafted membranes such as δH m1 . δH m2 , and T rc have been also studied by using DSC

  7. Microwave assisted synthesis of bis and tris(ω-bromoacetophenones): versatile precursors for novel bis(imidazo[1,2-a]pyridines), bis(imidazo[1,2-a]pyrimidines) and their tris-analogs

    Science.gov (United States)

    2013-01-01

    Background α-Bromination of the side chain of aromatic ketones using NBS in the presence of p-toluenesulfonic acid (p-TsOH) in acetonitrile is very common. However, regioselective bromination of bis and tris(ω-bromoacetophenones) with NBS in the presence of p-TsOH in acetonitrile under microwave irradiation is quite novel. The bis- and tris(ω-bromoacetophenones) are used in synthesis of bis and tris(heterocycles). bis(heterocycles) have received a great deal of attention, because many biologically active natural and synthetic products have molecular symmetry. The use of the pressurized microwave irradiation is very advantageous to many syntheses and provide a large rate enhancement. Results Bis and tris(ω-bromoacetophenones) were obtained as single monobrominated derivatives in a shorter time than the conventional conditions. The results clearly demonstrate the better reactivity and selectivity of NBS/p-TsOH/CH3CN as a brominating mixture under microwave conditions. The reaction of bis and tris(ω-bromoacetophenone) with 2-aminopyridine and 2-aminopyrimidine proceeded smoothly in a mixture of anhydrous ethanol and DMF under reflux or using 300 W/105°C/ 20 min microwave irradiation conditions to afford the corresponding bis(imidazo[1,2-a]pyridine), bis(imidazo[1,2-a]pyrimidine) and tris(imidazo[1,2-a]pyridine) derivatives in moderate to excellent yields. The carbonyl analogue of the targeted bis(imidazopyridines) could be synthesized by the reaction of N,N-dimethyl-N'-(pyridin-2-yl)formimidamide with bis(ω-bromoacetophenone) in refluxing ethanol. The structures of the newly synthesized compounds were confirmed by their spectral data as well as their elemental analyses. Conclusion In conclusion, selective α-bromination of bis- and tris(acetophenones) has been accomplished efficiently utilizing NBS/p-TsOH/CH3CN under microwave irradiation. In addition, a facile synthesis of novel series of bis- and tris(imidazopyridine) and bis(imidazopyrimidine) derivatives

  8. Radiochemical synthesis of 3-(4-[18F] Fluorophenyl)-8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c] pyridin-5-one: A putative dopamine D$4 receptor PET imaging agent

    International Nuclear Information System (INIS)

    Li, G.C.; Yin, D.Z.; Wang, M.W.; Cheng, D.F.; Wang, Y.X.

    2005-01-01

    Introduction: The dopamine D 4 receptor has lately received increasing interest since it has been hypothesized to be involved in the pathology and pharmacotherapy of schizophrenia. While this receptor is expressed in lower density in various extrastriatal brain regions and its distribution is still unclear due to the lack of suitable imaging agent and its level change in schizophrenia is controversial. Herein, based on the structure-activity analysis of chromeno[3, 4-c]pyridine- 5-ones as potential dopamine D 4 receptor ligands, a putative D 4 subtype positron emission tomography (PET) radioligand, 3-(4-[ 18 F]fluorophenyl)-8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c]pyridin-5-one ([ 18 F]FHTP), was designed and synthesized. Methods: The radiochemical synthesis route was shown in Figure 1. [ 18 F]Fluoride was produced with a Cyclone-30 (IBA, Belgium) by 18 O(p, n) 18 F reaction using enriched 18 O-H 2 O and eluted from a Dowex 1-X8 anion-exchange column with aqueous potassium carbonate (20 mg/mL). 4-[ 18 F]Fluorobenzaldehyde was prepared according to the method reported by Alan A. Wilson and et al.. Then, 8-hydroxy-1, 2, 3, 4-tetrahydrochromeno [3, 4-c]pyridin-5-one, sodium cyanoborohydride, methanol and acetic acid were added to the dry residue, The mixture was then sealed and heated at 120 degree C for 12 min. At the end of the reaction, the mixture was cooled, diluted with ethyl acetate and washed with water. The extracted organic layer was passed through a small anhydrous magnesium sulfate column. After removal of the solvents in the mixture at 50 degree C under a stream of nitrogen, the obtained residue was redissolved in methanol and purified with a semi-preparative HPLC system, then the desired product was collected. Results: The radiochemical synthesis of [ 18 F]FHTP took around 110 min at EOS with an overall radiochemical yield 19% (decay-corrected) and its radiochemical purity was higher than 95%. Conclusion: A presumed dopamine D 4 receptor PET

  9. Resonance Raman detection of iron-ligand vibrations in cyano(pyridine)(octaethylporphinato)iron(III): Effects of pyridine basicity on the Fe-CN bond strength

    International Nuclear Information System (INIS)

    Uno, Tadayuki; Hatano, Keiichiro; Nishimura, Yoshifumi; Arata, Yoji

    1988-01-01

    The influence of axial ligand basicity on the bonding of iron(III) in cyano adducts of octaethylporphyrin has been studied by resonance Raman spectroscopy. In a six-coordinate ferric low-spin complex, cyano(pyridine)(octaethylporphinato)iron(III), Fe(OEP)(CN)(py), Raman lines at 449 and 191 cm -1 were assigned to the ν(Fe-CN) and ν(Fe-py) stretching modes, respectively. When pyridine was displaced with its derivatives, py-X, where X = 4-cyano, 3-acetyl, 3-methyl, 4-methyl, 3,4-dimethyl, and 4-dimethylamino, the ν(Fe-CN) stretching frequency was found to decrease in the complex with a high pyridine basicity. It was concluded that the stronger the trans pyridine basicity, the weaker the iron-carbon (cyanide) bond. A clear frequency shift was observed in the ν 4 model, though most of the porphyrin vibrations were insensitive to the ligand substitution. The frequency of the ν 4 mode, which is the C a -N(pyrrole) breathing vibration of the porphyrin skeleton, was found to increase with an increase in pyridine basicity. This is contrary to what was found in ferrous low-spin hemes as CO complexes. The ν 4 shift in the CN complexes was explained in terms of forward π donation; donation of electrons from the porphyrin π orbital to the d π vacancy of the low-spin iron(III) weakened the C a -N(pyrrole) bonds and hence decreased the ν 4 frequency. 32 references, 8 figures

  10. Pre-treatment of pyridine wastewater by new cathodic-anodic-electrolysis packing.

    Science.gov (United States)

    Jin, Yang; Yue, Qinyan; Yang, Kunlun; Wu, Suqing; Li, Shengjie; Gao, Baoyu; Gao, Yuan

    2018-01-01

    A novel cathodic-anodic-electrolysis packing (CAEP) used in the treatment of pyridine wastewater was researched, which mainly consisted of 4,4'-diamino-2,2'-disulfonic acid (DSD acid) industrial iron sludge. The physical properties and morphology of the packing were studied. The CAEP was used in a column reactor during the pretreatment of pyridine wastewater. The influence of pH, hydraulic retention time (HRT), the air-liquid ratio (A/L) and the initial concentration of pyridine were investigated by measuring the removal of total organic carbon (TOC) and pyridine. The characterization results showed that the bulk density, grain density, water absorption percentage and specific surface area were 921kg/m 3 , 1086kg/m 3 , 25% and 29.89m 2 /g, respectively; the removal of TOC and pyridine could reach 50% and 58% at the optimal experimental conditions (pH=3, HRT=8hr, A/L=2). Notably, the surface of the packing was renewed constantly during the running of the filter, and the handling capacity was stable after running for three months. Copyright © 2017. Published by Elsevier B.V.

  11. (He 1) photoelectron spectra of vinyl- and (1-dimethylaminovinyl)pyridines

    International Nuclear Information System (INIS)

    Baidin, V.N.; Koikov, L.N.; Terent'ev, P.B.; Gloriozov, I.P.

    1985-01-01

    The (He 1) photoelectron spectra of α=, β-, γ-vinyl, α-, β-, and γ-(1-dimethylvinyl)-pyridines, 1-dimethyl- and 1-diethylaminostyrenes were obtained and interpreted within the framework of the molecular orbital perturbation theory. In both pyridine derivative series, there is a regular increase in the ionization energy of the 1α 2 , π/sub C=C/ and n/sub en/ orbitals and decrease in the ionization energy of the 2b 1 orbitals in the order α 2 and 2b 1 is found for γ-vinylpyridine). The splitting of the energy levels of the heterocycle in dimethylaminovinylpyridines is less than in the corresponding vinyl derivatives, which indicates a weakening of the interaction between the aromatic (or heteroaromatic) ring and the enamine fragment extruding from the ring plane. The ionization energy of the unshared electron pair of the nitrogen atom of the pyridine ring for all the compounds except for α- (1-dimethylaminovinyl)pyridine (which displays an ortho effect) is close to that for pyridine. The photoelectron spectral data are compared with the MO energies calculated by the MINDO/3 method

  12. Synthesis of N-methyl and N-11C-methyl spiperone by phase transfer catalysis in anhydrous solvent

    International Nuclear Information System (INIS)

    Omokawa, Hiroyoshi; Tanaka, Akira; Iio, Mayumi; Nishihara, Yoshiaki; Inoue, Osamu; Yamazaki, Toshio.

    1985-01-01

    Spiperone, a butyrophenone neuroleptic drug, has been used in binding studies of dopamine receptors. Langstrom et al. developed N- 11 C-methyl spiperone, and, in cooperate with Wagner et al., made it possible to visualize the distribution of dopamine receptors in the human brain in vivo. In this paper, we independently developed another synthetic method of N- 11 C-methyl spiperone using the phase transfer catalyst in an anhydrous solvent. Separation of the product is feasible only by passing the reactant solution through a Millipore filter and injecting it onto high pressure liquid chromatography (HPLC). The time required for the synthesis and purification of N- 11 C-methyl spiperone from 11 C-methyl iodide and spiperone was 20 min. Radiochemical yield exceeded 35 % against 11 C-methyl iodide without correcting decay of the radioactivity. (author)

  13. Pyridine 2,4-dicarboxylic acid suppresses tomato seedling growth

    Science.gov (United States)

    Fragkostefanakis, Sotirios; Kaloudas, Dimitrios; Kalaitzis, Panagiotis

    2018-01-01

    Pyridine 2,4-dicarboxylic acid is a structural analogue of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μΜ of PDCA decreased hydroxyproline content in roots while only the 250 μΜ treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μΜ PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs) are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μΜ which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analogue. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

  14. Pyridine 2,4-Dicarboxylic Acid Suppresses Tomato Seedling Growth

    Directory of Open Access Journals (Sweden)

    Sotirios Fragkostefanakis

    2018-01-01

    Full Text Available Pyridine 2,4-dicarboxylic acid is a structural analog of 2-oxoglutarate and is known to inhibit 2-oxoglutare-dependent dioxygenases. The effect of this inhibitor in tomato seedlings grown in MS media supplied with various concentrations of PDCA was investigated, resulting in shorter roots and hypocotyls in a dose-dependent manner. The partial inhibition of growth in roots was more drastic compared to hypocotyls and was attributed to a decrease in the elongation of root and hypocotyl cells. Concentrations of 100 and 250 μM of PDCA decreased hydroxyproline content in roots while only the 250 μM treatment reduced the hydroxyproline content in shoots. Seedlings treated with 100 μM PDCA exhibited enhanced growth of hypocotyl and cotyledon cells and higher hydroxyproline content resulting in cotyledons with greater surface area. However, no alterations in hypocotyl length were observed. Prolyl 4 hydroxylases (P4Hs are involved in the O-glycosylation of AGPs and were also highly expressed during seedling growth. Moreover PDCA induced a decrease in the accumulation of HRGPs and particularly in AGPs-bound epitopes in a dose dependent-manner while more drastic reduction were observed in roots compared to shoots. In addition, bulged root epidermal cells were observed at the high concentration of 250 μM which is characteristic of root tissues with glycosylation defects. These results indicate that PDCA induced pleiotropic effects during seedling growth while further studies are required to better investigate the physiological significance of this 2-oxoglutarate analog. This pharmacological approach might be used as a tool to better understand the physiological significance of HRGPs and probably P4Hs in various growth and developmental programs in plants.

  15. Recent Advances in Anhydrous Solvents for CO{sub 2} Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    Energy Technology Data Exchange (ETDEWEB)

    Park, Youngjune [School of Environmental Science and Engineering, Gwangju Institute of Science and Technology (GIST), Gwangju (Korea, Republic of); Lin, Kun-Yi Andrew [Department of Environmental Engineering, National Chung Hsing University, Taichung City (China); Park, Ah-Hyung Alissa, E-mail: ap2622@columbia.edu [Department of Earth and Environmental Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Department of Chemical Engineering, Lenfest Center for Sustainable Energy, Columbia University, New York, NY (United States); Petit, Camille, E-mail: ap2622@columbia.edu [Department of Chemical Engineering, Imperial College London, London (United Kingdom)

    2015-10-01

    CO{sub 2} capture by amine scrubbing, which has a high CO{sub 2} capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO{sub 2} capture from flue gases. The findings from these demonstrations will significantly advance the field of CO{sub 2} capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO{sub 2} capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO{sub 2} capture solvents, which are often anhydrous, have been developed as the third-generation CO{sub 2} capture solvents. These novel classes of liquid materials include ionic liquids, CO{sub 2}-triggered switchable solvents (i.e., CO{sub 2}-binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO{sub 2} capture. Particular attention is given to the mechanisms of CO{sub 2} absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO{sub 2} capture media.

  16. Crystalline anhydrous {alpha},{alpha}-trehalose (polymorph {beta}) and crystalline dihydrate {alpha},{alpha}-trehalose: A calorimetric study

    Energy Technology Data Exchange (ETDEWEB)

    Pinto, Susana S. [Centro de Quimica Estrutural, Complexo Interdisciplinar, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)]. E-mail: susanapinto@ist.utl.pt; Diogo, Herminio P. [Centro de Quimica Estrutural, Complexo Interdisciplinar, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)]. E-mail: hdiogo@ist.utl.pt; Moura-Ramos, Joaquim J. [Centro de Quimica-Fisica Molecular, Complexo Interdisciplinar, Instituto Superior Tecnico, 1049-001 Lisbon (Portugal)]. E-mail: mouraramos@ist.utl.pt

    2006-09-15

    The mean values of the standard massic energy of combustion of crystalline anhydrous {alpha},{alpha}-trehalose (C{sub 12}H{sub 22}O{sub 11}, polymorph {beta}) and crystalline dihydrate {alpha},{alpha}-trehalose (C{sub 12}H{sub 26}O{sub 13}) measured by static-bomb combustion calorimetry in oxygen, at the temperature T=298.15K, are {delta}{sub c}u{sup o}=-(16434.05+/-4.50)J.g{sup -1} and {delta}{sub c}u{sup o}=-(14816.05+/-3.52)J.g{sup -1}, respectively. The standard (p{sup o}=0.1MPa) molar enthalpy of formation of these compounds were derived from the corresponding standard molar enthalpies of combustion, respectively, {delta}{sub f}H{sub m}{sup o} (C{sub 12}H{sub 22}O{sub 11},cr)=-(2240.9+/-3.9)kJ.mol{sup -1}, and {delta}{sub f}H{sub m}{sup o} (C{sub 12}H{sub 26}O{sub 13},cr)=-(2832.6+/-3.6)kJ.mol{sup -1}. The values of the standard enthalpies of formation obtained in this work, together with data on enthalpies of solution at infinite dilution ({delta}{sub sol}H{sup {approx}}) for crystalline dihydrate and amorphous anhydrous trehalose, allow a better insight on the thermodynamic description of the trehalose system which can provide, together with the future research on the subject, a contribution for understanding the metabolism in several organisms, as well as the phase transition between the different polymorphs.

  17. Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    Directory of Open Access Journals (Sweden)

    YOUNGJUNE ePARK

    2015-10-01

    Full Text Available CO2 capture by amine scrubbing, which has a high CO2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO2 capture solvents including high volatility and corrosiveness of the amine solutions, as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO2 capture solvents, which are often anhydrous, have been developed as the third-generation CO2 capture solvents. These novel classes of liquid materials include: Ionic Liquids (ILs, CO2-triggered switchable solvents (i.e., CO2 Binding Organic Liquids (CO2BOLs, Reversible Ionic Liquids (RevILs, and Nanoparticle Organic Hybrid Materials (NOHMs. This paper provides a review of these various anhydrous solvents and their potential for CO2 capture. Particular attention is given to the mechanisms of CO2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO2 capture media.

  18. Structural and energetic characterization of anhydrous and hemihydrated 2-mercaptoimidazole: Calorimetric, X-ray diffraction, and computational studies

    International Nuclear Information System (INIS)

    Silva, Ana L.R.; Morais, Victor M.F.; Ribeiro da Silva, Maria D.M.C.; Simões, Ricardo G.; Bernardes, Carlos E.S.

    2016-01-01

    Highlights: • Rotating-bomb combustion calorimetry was used to obtain the enthalpy of formation of crystalline 2-mercaptoimidazole. • Enthalpy of sublimation of 2-mercaptoimidazole was measured by Calvet microcalorimetry. • Enthalpy of interaction between substituents is calculated using isodesmic reactions. • Crystal X-ray diffraction determinations for anhydrous and hemihydrate 2-mercaptoimidazole forms were carried. • Gas-phase enthalpies of formation of 2-mercaptoimidazole and 1,3-dihydro-2H-imidazole-2-thione estimated by the G3 method. - Abstract: This paper reports an experimental and theoretical study on the structural and energetic characterization of the 2-mercaptoimidazole (2-MI) in the solid and in the gaseous phases. The single crystal X-ray diffraction determinations on the anhydrous and hemihydrate 2-MI forms were carried out at T = (296 ± 2) K and T = (150 ± 2) K, respectively, and suggest that in both forms the 2-MI molecule is closer to the thione conformation, albeit some single bond character is possible. The energy of combustion of the title compound was measured by rotating-bomb combustion calorimetry, being used to derive the corresponding enthalpy of formation in the crystalline-phase. The enthalpy of sublimation of 2-MI, at T = 298.15 K, was obtained from high temperature Calvet microcalorimetry measurements. These two parameters yielded the gas-phase enthalpy of formation, allowing the inherent energetic analysis of the molecule. This result was discussed together with the corresponding predictions for 2-MI and its tautomer, 1,3-dihydro-2H-imidazole-2-thione, by the G3 method. The dehydration reaction of 2-MI · 0.5H_2O(cr) was also investigated and the corresponding enthalpy of dehydration was determined by Calvet microcalorimetry.

  19. Recent Advances in Anhydrous Solvents for CO2 Capture: Ionic Liquids, Switchable Solvents, and Nanoparticle Organic Hybrid Materials

    International Nuclear Information System (INIS)

    Park, Youngjune; Lin, Kun-Yi Andrew; Park, Ah-Hyung Alissa; Petit, Camille

    2015-01-01

    CO 2 capture by amine scrubbing, which has a high CO 2 capture capacity and a rapid reaction rate, is the most employed and investigated approach to date. There are a number of recent large-scale demonstrations including the Boundary Dam Carbon Capture Project by SaskPower in Canada that have reported successful implementations of aqueous amine solvent in CO 2 capture from flue gases. The findings from these demonstrations will significantly advance the field of CO 2 capture in the coming years. While the latest efforts in aqueous amine solvents are exciting and promising, there are still several drawbacks to amine-based CO 2 capture solvents including high volatility and corrosiveness of the amine solutions as well as the high parasitic energy penalty during the solvent regeneration step. Thus, in a parallel effort, alternative CO 2 capture solvents, which are often anhydrous, have been developed as the third-generation CO 2 capture solvents. These novel classes of liquid materials include ionic liquids, CO 2 -triggered switchable solvents (i.e., CO 2 -binding organic liquids, reversible ionic liquids), and nanoparticle organic hybrid materials. This paper provides a review of these various anhydrous solvents and their potential for CO 2 capture. Particular attention is given to the mechanisms of CO 2 absorption in these solvents, their regeneration and their processability – especially taking into account their viscosity. While not intended to provide a complete coverage of the existing literature, this review aims at pointing the major findings reported for these new classes of CO 2 capture media.

  20. Control of powdery mildew on glasshouse-grown roses and tomatoes in the Netherlands using anhydrous milk fat and soybean oil emulsions

    NARCIS (Netherlands)

    Wurms, K.V.; Hofland-Zijlstra, Jantineke

    2015-01-01

    Powdery mildew (PM) is a very serious disease affecting glasshouse-grown roses and tomatoes in the Netherlands. Control is limited because of resistance to existing fungicides. Anhydrous milk fat (AMF) and soybean oil (SBO) emulsions were evaluated for control of PM in roses and tomatoes. Both

  1. Immunogold electron microscopic localization of timothy grass (Phleum pratense) pollen major allergens Phl p I and Phl p V after anhydrous fixation in acrolein vapor

    NARCIS (Netherlands)

    Grote, M.; Dolecek, C.; van Ree, R.; Valenta, R.

    1994-01-01

    We used the vapor phase of acrolein as an anhydrous fixative for timothy grass pollen in an immunogold double-labeling localization study of two different major allergens, Phl p I and Phl p V. More than 48 hr of fixation were needed for the subcellular pollen structures to be satisfactorily

  2. Trace element partitioning between ilmenite, armalcolite and anhydrous silicate melt: Implications for the formation of lunar high-Ti mare basalts

    NARCIS (Netherlands)

    Kan Parker, M. van; Mason, P.R.D.; Westrenen, W. van

    2011-01-01

    We performed a series of experiments at high pressures and temperatures to determine the partitioning of a wide range of trace elements between ilmenite (Ilm), armalcolite (Arm) and anhydrous lunar silicate melt, to constrain geochemical models of the formation of titanium-rich melts in the Moon.

  3. Binary and ternary cocrystals of sulfa drug acetazolamide with pyridine carboxamides and cyclic amides.

    Science.gov (United States)

    Bolla, Geetha; Nangia, Ashwini

    2016-03-01

    A novel design strategy for cocrystals of a sulfonamide drug with pyridine carboxamides and cyclic amides is developed based on synthon identification as well as size and shape match of coformers. Binary adducts of acetazolamide (ACZ) with lactams (valerolactam and caprolactam, VLM, CPR), cyclic amides (2-pyridone, labeled as 2HP and its derivatives MeHP, OMeHP) and pyridine amides (nicotinamide and picolinamide, NAM, PAM) were obtained by manual grinding, and their single crystals by solution crystallization. The heterosynthons in the binary cocrystals of ACZ with these coformers suggested a ternary combination for ACZ with pyridone and nicotinamide. Novel supramolecular synthons of ACZ with lactams and pyridine carboxamides are reported together with binary and ternary cocrystals for a sulfonamide drug. This crystal engineering study resulted in the first ternary cocrystal of acetazolamide with amide coformers, ACZ-NAM-2HP (1:1:1).

  4. Binary and ternary cocrystals of sulfa drug acetazolamide with pyridine carboxamides and cyclic amides

    Directory of Open Access Journals (Sweden)

    Geetha Bolla

    2016-03-01

    Full Text Available A novel design strategy for cocrystals of a sulfonamide drug with pyridine carboxamides and cyclic amides is developed based on synthon identification as well as size and shape match of coformers. Binary adducts of acetazolamide (ACZ with lactams (valerolactam and caprolactam, VLM, CPR, cyclic amides (2-pyridone, labeled as 2HP and its derivatives MeHP, OMeHP and pyridine amides (nicotinamide and picolinamide, NAM, PAM were obtained by manual grinding, and their single crystals by solution crystallization. The heterosynthons in the binary cocrystals of ACZ with these coformers suggested a ternary combination for ACZ with pyridone and nicotinamide. Novel supramolecular synthons of ACZ with lactams and pyridine carboxamides are reported together with binary and ternary cocrystals for a sulfonamide drug. This crystal engineering study resulted in the first ternary cocrystal of acetazolamide with amide coformers, ACZ–NAM–2HP (1:1:1.

  5. Copper-catalyzed aerobic oxidative C-H functionalization of substituted pyridines: synthesis of imidazopyridine derivatives.

    Science.gov (United States)

    Yu, Jipan; Jin, Yunhe; Zhang, Hao; Yang, Xiaobo; Fu, Hua

    2013-12-02

    A novel, efficient, and practical method for the synthesis of imidazopyridine derivatives has been developed through the copper-catalyzed aerobic oxidative C-H functionalization of substituted pyridines with N-(alkylidene)-4H-1,2,4-triazol-4-amines. The procedure occurs by cleavage of the N-N bond in the N-(alkylidene)-4H-1,2,4-triazol-4-amines and activation of an aryl C-H bond in the substituted pyridines. This is the first example of the preparation of imidazopyridine derivatives by using pyridines as the substrates by transition-metal-catalyzed C-H functionalization. This method should provide a novel and efficient strategy for the synthesis of other nitrogen heterocycles. Copyright © 2013 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. pH-responsive fluorescence chemical sensor constituted by conjugated polymers containing pyridine rings.

    Science.gov (United States)

    Adachi, Naoya; Kaneko, Yuki; Sekiguchi, Kazuki; Sugiyama, Hiroki; Sugeno, Masafumi

    2015-12-01

    Poly(p-pyridinium phenylene ethynylene)s (PPyPE) functionalized with alternating donor-acceptor repeat units were synthesized by a Pd-catalyzed Sonogashira coupling reaction between diethynyl monomer and di-iodopyridine for use as a pH-responsive fluorescence chemical sensor. The synthesized PPyPE, containing pyridine units, was characterized by FT-IR, (1)H and (13)C NMR, UV-visible and fluorescence spectroscopies. We investigated the relationship between changes of optical properties and protonation/deprotonation of PPyPE containing pyridine units in solution. Addition of HCl decreased and red-shifted the fluorescence intensity of the conjugated polymers that contained pyridine rings; fluorescence intensity of the polymers increased upon addition of NaOH solution. The synthesized PPyPE was found to be an effective and reusable chemical sensor for pH sensing. Copyright © 2015 John Wiley & Sons, Ltd.

  7. Spin crossover and high spin filtering behavior in Co-Pyridine and Co-Pyrimidine molecules

    Science.gov (United States)

    Wen, Zhongqian; Zhou, Liping; Cheng, Jue-Fei; Li, Shu-Jin; You, Wen-Long; Wang, Xuefeng

    2018-03-01

    We present a theoretical study on a series of cobalt complexes, which are constructed with cobalt atoms and pyridine/pyrimidine rings, using density functional theory. We investigate the structural and electric transport properties of spin crossover (SCO) Co complex with two spin states, namely low-spin configuration [LS] and high-spin configuration [HS]. Energy analyses of the two spin states imply that the SCO Co-Pyridine2 and Co-Pyrimidine2 complexes may display a spin transition process accompanied by a geometric modification driven by external stimuli. A nearly perfect spin filtering effect is observed in the Co-Pyrimidine2 complex with [HS] state. In addition, we also discover the contact-dependent transmission properties of Co-Pyridine2. These findings indicate that SCO Co complexes are promising materials for molecular spintronic devices.

  8. Carbon dioxide is tightly bound in the [Co(Pyridine)(CO2)](-) anionic complex.

    Science.gov (United States)

    Graham, Jacob D; Buytendyk, Allyson M; Zhang, Xinxing; Kim, Seong K; Bowen, Kit H

    2015-11-14

    The [Co(Pyridine)(CO2)](-) anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO2 binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO2)](-) in which a central cobalt atom is bound to pyridine and CO2 moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO2 to be bound within the anionic complex by 1.4 eV.

  9. Carbon dioxide is tightly bound in the [Co(Pyridine)(CO2)]- anionic complex

    Science.gov (United States)

    Graham, Jacob D.; Buytendyk, Allyson M.; Zhang, Xinxing; Kim, Seong K.; Bowen, Kit H.

    2015-11-01

    The [Co(Pyridine)(CO2)]- anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO2 binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO2)]- in which a central cobalt atom is bound to pyridine and CO2 moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO2 to be bound within the anionic complex by 1.4 eV.

  10. SAR studies directed toward the pyridine moiety of the sap-feeding insecticide sulfoxaflor (Isoclast™ active).

    Science.gov (United States)

    Loso, Michael R; Benko, Zoltan; Buysse, Ann; Johnson, Timothy C; Nugent, Benjamin M; Rogers, Richard B; Sparks, Thomas C; Wang, Nick X; Watson, Gerald B; Zhu, Yuanming

    2016-02-01

    Sap-feeding insect pests constitute a major insect pest complex that includes a range of aphids, whiteflies, planthoppers and other insect species. Sulfoxaflor (Isoclast™ active), a new sulfoximine class insecticide, targets sap-feeding insect pests including those resistant to many other classes of insecticides. A structure activity relationship (SAR) investigation of the sulfoximine insecticides revealed the importance of a 3-pyridyl ring and a methyl substituent on the methylene bridge linking the pyridine and the sulfoximine moiety to achieving strong Myzus persicae activity. A more in depth QSAR investigation of pyridine ring substituents revealed a strong correlation with the calculated logoctanol/water partition coefficient (SlogP). Model development resulted in a highly predictive model for a set of 18 sulfoximines including sulfoxaflor. The model is consistent with and helps explain the highly optimized pyridine substitution pattern for sulfoxaflor. Copyright © 2015 Elsevier Ltd. All rights reserved.

  11. A simple and efficient synthesis of imidazolo[1,2-a]pyridines using MgO in aqueous medium

    Directory of Open Access Journals (Sweden)

    S.V. Patil

    2016-11-01

    Full Text Available Various imidazolo[1,2-a]pyridines were synthesized from amino pyridines and aromatic phenacyl bromides by one step process in the presence of MgO in aqueous medium at room temperature. The salient feature of this method includes mild conditions, short reaction time, high yields, easy purification and simple procedure.

  12. Solid-State Examination of Conformationally Diverse Sulfonamide Receptors Based on Bis(2-anilinoethynyl)pyridine, -Bipyridine, and -Thiophene.

    Science.gov (United States)

    Berryman, Orion B; Johnson, Charles A; Vonnegut, Chris L; Fajardo, Kevin A; Zakharov, Lev N; Johnson, Darren W; Haley, Michael M

    2015-03-04

    Utilizing an induced-fit model and taking advantage of rotatable acetylenic C(sp)-C(sp 2 ) bonds, we disclose the synthesis and solid-state structures of a series of conformationally diverse bis-sulfonamide arylethynyl receptors using either pyridine, 2,2'-bipyridine, or thiophene as the core aryl group. Whereas the bipyridine and thiophene structures do not appear to bind guests in the solid state, the pyridine receptors form 2 + 2 dimers with water molecules, two halides, or one of each, depending on the protonation state of the pyridine nitrogen atom. Isolation of a related bis-sulfonimide derivative demonstrates the importance of the sulfonamide N-H hydrogen bonds in dimer formation. The pyridine receptors form monomeric structures with larger guests such as BF 4 - or HSO 4 - , where the sulfonamide arms rotate to the side opposite the pyridine N atom.

  13. Solid-State Examination of Conformationally Diverse Sulfonamide Receptors Based on Bis(2-anilinoethynyl)pyridine, -Bipyridine, and -Thiophene

    Science.gov (United States)

    Berryman, Orion B.; Johnson, Charles A.; Vonnegut, Chris L.; Fajardo, Kevin A.; Zakharov, Lev N.; Johnson, Darren W.; Haley, Michael M.

    2015-01-01

    Utilizing an induced-fit model and taking advantage of rotatable acetylenic C(sp)–C(sp2) bonds, we disclose the synthesis and solid-state structures of a series of conformationally diverse bis-sulfonamide arylethynyl receptors using either pyridine, 2,2′-bipyridine, or thiophene as the core aryl group. Whereas the bipyridine and thiophene structures do not appear to bind guests in the solid state, the pyridine receptors form 2 + 2 dimers with water molecules, two halides, or one of each, depending on the protonation state of the pyridine nitrogen atom. Isolation of a related bis-sulfonimide derivative demonstrates the importance of the sulfonamide N–H hydrogen bonds in dimer formation. The pyridine receptors form monomeric structures with larger guests such as BF4− or HSO4−, where the sulfonamide arms rotate to the side opposite the pyridine N atom. PMID:26405435

  14. Preparation of poly (vinyl alcohol) membranes grafted with n-vinyl pyridine/ acrylic acid binary monomers

    International Nuclear Information System (INIS)

    Ajji, A.; Ali, A.

    2014-03-01

    Poly(vinyl alcohol) films were grafted with two monomers using gamma radiation, acrylic acid and N-vinyl pyridine. The influence of different parameters on the grafting yield was investigated as: the comonomer concentration and composition, and irradiation dose. The suitable conditions of the process had been determined to prepare PVA membranes have both properties of the two monomers, acrylic acid and vinyl pyridine as comonomer concentration and composition, and irradiation dose. Some properties of the membranes had been investigated as maximum swelling and grafting. Also the ability of the grafted films to adsorb some heavy metals and dyes was elaborated and discussed.(author)

  15. One-step synthesis of pyridines and dihydropyridines in a continuous flow microwave reactor

    Directory of Open Access Journals (Sweden)

    Mark C. Bagley

    2013-09-01

    Full Text Available The Bohlmann–Rahtz pyridine synthesis and the Hantzsch dihydropyridine synthesis can be carried out in a microwave flow reactor or using a conductive heating flow platform for the continuous processing of material. In the Bohlmann–Rahtz reaction, the use of a Brønsted acid catalyst allows Michael addition and cyclodehydration to be carried out in a single step without isolation of intermediates to give the corresponding trisubstituted pyridine as a single regioisomer in good yield. Furthermore, 3-substituted propargyl aldehydes undergo Hantzsch dihydropyridine synthesis in preference to Bohlmann–Rahtz reaction in a very high yielding process that is readily transferred to continuous flow processing.

  16. 8-Hydroxy-2-methylquinolinium tetrachlorido(pyridine-2-carboxylato-κ2N,Ostannate(IV

    Directory of Open Access Journals (Sweden)

    Ezzatollah Najafi

    2011-02-01

    Full Text Available In the reaction of pyridine-2-carboxylic acid and stannic chloride in the presence of 2-methyl-8-hydroxyquinoline, the 2-methyl-8-hydroxyquinoline is protonated, yielding the title salt, (C10H10NO[SnCl4(C6H4NO2]. The SnIV atom in the anion is N,O-chelated by a pyridine-2-carboxylate in a cis-SnNOCl4 octahedral geometry. The cation is linked to the anion by an O—H...O hydrogen bond.

  17. trans-Dichlorido­bis(3,4-dimethyl­pyridine)platinum(II)

    Science.gov (United States)

    Chernyshev, Alexander N.; Bokach, Nadezhda A.; Izotova, Youlia A.; Haukka, Matti

    2009-01-01

    In the title compound, trans-[PtCl2(C7H9N)2], the PtII atom is located on an inversion center and is coordinated by two 3,4-dimethyl­pyridine ligands and two chloride ligands, resulting in a typical slightly distorted square-planar geometry. The crystallographic inversion centre forces the value of the C—N—N—C torsion angle to be linear and the 3,4-dimethyl-pyridine ligands to be coplanar. PMID:21581530

  18. Reaction of the diimine pyridine ligand with aluminum alkyls: An unexpectedly complex reaction

    NARCIS (Netherlands)

    Knijnenburg, Q.; Smits, J.M.M.; Budzelaar, P.H.M.

    2006-01-01

    The diimine pyridine ligand 2,6-{2,6-(Pr2C6H3N)-Pr-i=CMe}(2)C5H3N (1) was reacted with a series of aluminum alkyls (Me3Al, Et3Al, (Bu3Al)-Bu-i, (Bu2AlH)-Bu-i, Et2AlCl). Depending on the choice of alkyl, addition to the imine carbon and the pyridine C2 and C4 positions was observed. Addition to C2

  19. Synthesis, antimicrobial and cytotoxic activities of 5-benzylidene-2-[(pyridine-4-ylmethylenehydrazono]-thiazolidin-4-one and 2-[(pyridine-4-ylmethylene hydrazono]-thiazolidin-4-one derivatives

    Directory of Open Access Journals (Sweden)

    Danniel Delmondes Feitoza

    2012-01-01

    Full Text Available A new series of 5-benzylidene-2-[(pyridine-4-ylmethylenehydrazono]-thiazolidin-4-ones 4a-l have been synthesized. These compounds were designed by a molecular hybridization approach. 2-[(Pyridine-4-ylmethylenehydrazono]-thiazolidin-4-ones 3a-d were also obtained and used as intermediates to give the target compounds. The in vitro antimicrobial and cytotoxic activities were evaluated for both series. The intermediate 3b showed considerable antibiotic activity against B. subtilis and C. albicans. In the cytotoxic activity compounds 3b (IC50= 4.25 ± 0.36 µg/mL and 4l (IC50= 1.38 ± 0.04 µg/mL were effective for inhibition of human erythromyeloblastoid leukemia (K-562 and human lung carcinoma (NCI-H292 cell lines, respectively.

  20. Synthesis, antimicrobial and cytotoxic activities of 5-benzylidene-2-[(pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-one and 2-[(pyridine-4-ylmethylene) hydrazono]-thiazolidin-4-one derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Feitoza, Danniel Delmondes; Alves, Antonio Jose; Lima, Jose Gildo de, E-mail: jgildolima@gmail.com [Departamento de Ciencias Farmaceuticas, Universidade Federal de Pernambuco, Recife - PE (Brazil); Araujo, Janete Magali; Aguiar, Jaciana Santos; Rodrigues, Maria do Desterro; Silva, Teresinha Goncalves; Nascimento, Silene Carneiro do; Goes, Alexandre Jose da Silva [Departamento de Antibioticos, Universidade Federal de Pernambuco, Recife - PE (Brazil)

    2012-07-01

    A new series of 5-benzylidene-2-[(pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-ones 4a-l have been synthesized. These compounds were designed by a molecular hybridization approach. 2-[(Pyridine-4-ylmethylene)hydrazono]-thiazolidin-4-ones 3a-d were also obtained and used as intermediates to give the target compounds. The in vitro antimicrobial and cytotoxic activities were evaluated for both series. The intermediate 3b showed considerable antibiotic activity against B. subtilis and C. albicans. In the cytotoxic activity compounds 3b (IC{sub 50} = 4.25 +- 0.36 {mu}g/mL) and 4l (IC{sub 50} = 1.38 +- 0.04 {mu}g/mL) were effective for inhibition of human erythromyeloblastoid leukemia (K-562) and human lung carcinoma (NCI-H292) cell lines, respectively. (author)

  1. Treatment of effluent at the Saclay Centre d'Etudes Nucleaires (1960); Le traitement des effluents du Centre d'Etudes Nucleaires de Saclay (1960)

    Energy Technology Data Exchange (ETDEWEB)

    Wormser, G [Commissariat a l' Energie Atomique, Saclay (France).Centre d' Etudes Nucleaires

    1960-07-01

    The Centre d'Etudes Nucleaires at Saclay possesses several installations from which liquid radioactive effluent is rejected, and it has thus been found necessary to construct a station for the purification of radioactive liquids and to settle various chemical, analytical and technological problems. This report describes, in the following order: - the disposal possibilities at the Centre d'Etudes Nucleaires, Saclay, - the effluents produced at the centre, - the set-up for collecting effluent, - treatment of the effluent, - results of these treatments. (author) [French] La presence, au Centre d'Etudes Nucleaires de Saclay, de plusieurs installations susceptibles de rejeter des effluents liquides radioactifs a necessite la construction d'une station d'epuration d'eaux radioactives et la mise au point de differents problemes chimiques, analytiques et technologiques. Dans ce rapport, nous exposerons successivement: - les possibilites de rejet du Centre d'Etudes Nucleaires de Saclay, - les effluents du centre, - le dispositif de collecte des effluents, - le traitement de ces effluents, - les resultats de ces traitements. (auteur)

  2. Synthesis and evaluation of an 18F-labeled pyrimidine-pyridine amine for targeting CXCR4 receptors in gliomas

    International Nuclear Information System (INIS)

    Demoin, Dustin Wayne; Shindo, Masahiro; Zhang, Hanwen; Edwards, Kimberly J.; Serganova, Inna; Pillarsetty, Naga Vara Kishore; Lewis, Jason S.; Blasberg, Ronald G.

    2016-01-01

    Introduction: Chemokine receptor-4 (CXCR4, fusin, CD184) is expressed on several tissues involved in immune regulation and is upregulated in many diseases including malignant gliomas. A radiolabeled small molecule that readily crosses the blood–brain barrier can aid in identifying CXCR4-expressing gliomas and monitoring CXCR4-targeted therapy. In the current work, we have synthesized and evaluated an [ 18 F]-labeled small molecule based on a pyrimidine–pyridine amine for its ability to target CXCR4. Experimental: The nonradioactive standards and the nitro precursor used in this study were prepared using established methods. An HPLC method was developed to separate the nitro-precursor from the nonradioactive standard and radioactive product. The nitro-precursor was radiolabeled with 18 F under inert, anhydrous conditions using the [ 18 F]-kryptofix 2.2.2 complex to form the desired N-(4-(((6-[ 18 F]fluoropyridin-2-yl)amino)methyl)benzyl)pyrimidin-2-amine ([ 18 F]-3). The purified radiolabeled compound was used in serum stability, partition coefficient, cellular uptake, and in vivo cancer targeting studies. Results: [ 18 F]-3 was synthesized in 4–10% decay-corrected yield (to start of synthesis). [ 18 F]-3 (t R ≈ 27 min) was separated from the precursor (t R ≈ 30 min) using a pentafluorophenyl column with an isocratic solvent system. [ 18 F]-3 displayed acceptable serum stability over 2 h. The amount of [ 18 F]-3 bound to the plasma proteins was determined to be > 97%. The partition coefficient (LogD 7.4 ) is 1.4 ± 0.5. Competitive in vitro inhibition indicated 3 does not inhibit uptake of 67 Ga-pentixafor. Cell culture media incubation and ex vivo urine analysis indicate rapid metabolism of [ 18 F]-3 into hydrophilic metabolites. Thus, in vitro uptake of [ 18 F]-3 in CXCR4 overexpressing U87 cells (U87 CXCR4) and U87 WT indicated no specific binding. In vivo studies in mice bearing U87 CXCR4 and U87 WT tumors on the left and right shoulders were carried

  3. 2-[1-(1-Naphthyl-1H-1,2,3-triazol-4-yl]pyridine

    Directory of Open Access Journals (Sweden)

    Ulrich S. Schubert

    2009-05-01

    Full Text Available In the crystal structure of the title compound, C17H12N4, the angle between the naphthalene and 1H-1,2,3-triazole ring systems is 71.02 (4° and that between the pyridine and triazole rings is 8.30 (9°.

  4. 2-(4-Methylpiperazin-1-yl-4-phenyl-6-(thiophen-2-yl-pyridine-3-carbonitrile

    Directory of Open Access Journals (Sweden)

    Nawal Mishriky

    2013-02-01

    Full Text Available 2-(4-Methylpiperazin-1-yl-4-phenyl-6-(thiophen-2-yl-pyridine-3-carbonitrile (4 was synthesized via nucleophilic substitution reaction of 1-methylpiperazine with 2-bromo analogue 3. The latter was obtained through bromination (Br2/AcOH of 2-[3-oxo-1-phenyl-3-(thiophen-2-ylpropyl]malononitrile (2.

  5. Hydrogen trapping ability of the pyridine-lithium⁺ (1:1) complex.

    Science.gov (United States)

    Chattaraj, Saparya; Srinivasu, K; Mondal, Sukanta; Ghosh, Swapan K

    2015-03-26

    Theoretical studies have been carried out at different levels of theory to verify the hydrogen adsorption characteristics of pyridine-lithium ion (1:1) complexes. The nature of interactions associated with the bonding between pyridine and lithium as well as that between lithium and adsorbed molecular hydrogen is studied through the calculation of electron density and electron-density-based reactivity descriptors. The pyridine-lithium ion complex has been hydrogenated systematically around the lithium site, and each lithium site is found to adsorb a maximum of four hydrogen molecules with an interaction energy of ∼-4.0 kcal/mol per molecule of H2. The fate of the hydrogen adsorbed in a pyridine-lithium ion complex (corresponding to the maximum adsorption) is studied in the course of a 2 ps time evolution through ab initio molecular dynamics simulation at different temperatures. The results reveal that the complex can hold a maximum of four hydrogen molecules at a temperature of 77 K, whereas it can hold only two molecules of hydrogen at 298 K.

  6. Design, synthesis and characterization of 1H-pyridin-4-yl-3,5 ...

    Indian Academy of Sciences (India)

    Keywords. 1H-pyridin-4-yl-3,5-disubstituted indazoles; Suzuki reaction; Akt kinase activity. 1. Introduction. In organic synthesis, Palladium-catalysed new carbon– carbon bond formation from aryl halides with organo boronic acids via Suzuki coupling reaction has been proved to be an important method. The 2010 Nobel.

  7. Lead optimization of a pyridine-carboxamide series as DGAT-1 inhibitors.

    Science.gov (United States)

    Ting, Pauline C; Lee, Joe F; Zorn, Nicolas; Kim, Hyunjin M; Aslanian, Robert G; Lin, Mingxiang; Smith, Michelle; Walker, Scott S; Cook, John; Van Heek, Margaret; Lachowicz, Jean

    2013-02-15

    The structure-activity relationship studies of a novel series of carboxylic acid derivatives of pyridine-carboxamides as DGAT-1 inhibitors is described. The optimization of the initial lead compound 6 based on in vitro and in vivo activity led to the discovery of key compounds 10j and 17h. Copyright © 2013 Elsevier Ltd. All rights reserved.

  8. The synthesis of N-Zn, N-Cu complexes involving 2-amino pyridine ...

    Indian Academy of Sciences (India)

    amino pyridine and ethylenediamine ligands (1a-b and 2a-b) have been described. They were synthesized with a simple, one-pot method, and the crystal structures of 1a, 1b, 2a and 2b were determined by X-ray crystallography. The complexes ...

  9. Unprecedentedly mild direct Pd-catalyzed arylation of oxazolo[4,5-b]pyridine

    DEFF Research Database (Denmark)

    Zhuravlev, Fedor

    2006-01-01

    Pd-catalyzed C-2 arylation of oxazolo[4,5-b]pyridine proceeds efficiently at 30 degrees C and tolerates a variety of aryl halides, including derivatized amino acids for which no racemization was observed during the reaction. Experimental evidence for facile deprotonation of oxazolo[4,5-b...

  10. Multicomponent ternary cocrystals of the sulfonamide group with pyridine-amides and lactams.

    Science.gov (United States)

    Bolla, Geetha; Nangia, Ashwini

    2015-11-04

    SMBA was selected as a bifunctional sulfa drug to design ternary cocrystals with pyridine amides and lactam coformers. Supramolecular assembly of five ternary cocrystals of p-sulfonamide benzoic acid with nicotinamide and 2-pyridone is demonstrated and reproducible heterosynthons are identified for crystal engineering.

  11. Pyridine nucleotides in regulation of cell death and survival by redox and non-redox reactions.

    Science.gov (United States)

    Novak Kujundžić, Renata; Žarković, Neven; Gall Trošelj, Koraljka

    2014-01-01

    Changes of the level and ratios of pyridine nucleotides determine metabolism- dependent cellular redox status and the activity of poly(ADP-ribose) polymerases (PARPs) and sirtuins, thereby influencing several processes closely related to cell survival and death. Pyridine nucleotides participate in numerous metabolic reactions whereby their net cellular level remains constant, but the ratios of NAD+/NADP+ and NADH/NADPH oscillate according to metabolic changes in response to diverse stress signals. In non-redox reactions, NAD+ is degraded and quickly, afterward, resynthesized in the NAD+ salvage pathway, unless overwhelming activation of PARP-1 consumes NAD+ to the point of no return, when the cell can no longer generate enough ATP to accommodate NAD+ resynthesis. The activity of PARP-1 is mandatory for the onset of cytoprotective autophagy on sublethal stress signals. It has become increasingly clear that redox status, largely influenced by the metabolism-dependent composition of the pyridine nucleotides pool, plays an important role in the synthesis of pro-apoptotic and anti-apoptotic sphingolipids. Awareness of the involvement of the prosurvival sphingolipid, sphingosine-1-phosphate, in transition from inflammation to malignant transformation has recently emerged. Here, the participation of pyridine nucleotides in redox and non-redox reactions, sphingolipid metabolism, and their role in cell fate decisions is reviewed.

  12. Hydroxyl pyridine containing polybenzimidazole membranes for proton exchange membrane fuel cells

    DEFF Research Database (Denmark)

    Yang, Jingshuai; Xu, Yixin; Zhou, Lu

    2013-01-01

    A polybenzimidazole variant polymer containing hydroxyl pyridine groups, termed as OHPyPBI, was synthesized from 3,3'-diaminobenzidine tetrahydrochloride and 4-hydroxy-2,6-pyridinedicarboxylic acid. The thermal-oxidative stability of the OHPyPBI polymer was as high as that of poly[2,2'-(m-phenyle...

  13. Enhancement of the stimulated Raman scattering of benzene, acetonitrile and pyridine

    International Nuclear Information System (INIS)

    Munoz, L; Contreras, W A; Cabanzo, R; Aya-RamIrez, O; Mejia-Ospino, E

    2011-01-01

    In this work we used the second harmonic of Nd:YAG laser to observe stimulated Raman scattering (SRS). SRS was observed on benzene, acetonitrile and pyridine using a single shot laser. The SRS radiation is very intense due their laser characteristics, and it is possible to observe several harmonics of different vibrational modes to each molecule studied here.

  14. Bohlmann-Rahtz Cyclodehydration of Aminodienones to Pyridines Using N-Iodosuccinimide

    Directory of Open Access Journals (Sweden)

    Mark C. Bagley

    2010-04-01

    Full Text Available Cyclodehydration of Bohlmann-Rahtz aminodienone intermediates using N-iodosuccinimide as a Lewis acid proceeds at low temperature under very mild conditions to give the corresponding 2,3,6-trisubstituted pyridines in high yield and with total regiocontrol.

  15. Formation of pyridine N-oxides using mesoporous titanium silicalite-1

    DEFF Research Database (Denmark)

    Mielby, Jerrik Jørgen; Abildstrøm, Jacob Oskar; Perez-Ferreras, Susana

    2014-01-01

    Mesoporous titanium silicalite-1 (TS-1) prepared by carbon-templating is significantly more active than conventional TS-1 for the oxidation of pyridine derivatives using aqueous hydrogen peroxide as oxidant. The catalytic activity is increased by the system of mesopores that helps to overcome the...

  16. Suitability of hardwood treated with phenoxy and pyridine herbicides for firewood use

    Science.gov (United States)

    P.B. Bush; D.G. Neary; Charles K. McMahon; J.W. Taylor

    1987-01-01

    Abstract. Potential exposure to pesticide residues resulting from burning wood treated with phenoxyand pyridine herbicides was assessed. Wood samples from trees treated with 2,4-D [2,4-dichlo-rophenoxy acetic acid], dicamba [3,6-dichloro-o-anisic acid], dichlorprop [2-(2,4-dichlorphenoxy) propionic acid], picloram [4-amino-3,5,dtrichloropico-linic...

  17. The synthesis of a pyridine-: N -oxide isophthalamide rotaxane utilizing supplementary amide hydrogen bond interactions

    OpenAIRE

    Evans, Nicholas Henley; Gell, Charlie; Peach, Michael Joseph George

    2016-01-01

    The synthesis of a pyridine-N-oxide containing rotaxane, not requiring an additional ionic template, has been achieved in 32% yield. Successful rotaxane formation is dependent upon the structure of the isophthalamide macrocycle used, an observation which has been rationalised by a combination of NMR spectroscopy, X-ray crystallography and computational modelling.

  18. Reaction of Titanocene Alkyls with Pyridines; A Novel Type of Cyclometallation Reaction

    NARCIS (Netherlands)

    Klei, E.; Teuben, J.H.

    1981-01-01

    Reaction of Cp2TiR (R = alkyl) with 2-substituted-pyridines and with quinolines leads to α-metallation of these ligands with formation of triangular titanocycles containing TiIII. Proof of the metallation at the α-position comes from reactions of the complexes formed with I2 and D2O/DCl which yield

  19. Crystal structure of the pyridine-diiodine (1/1) adduct.

    Science.gov (United States)

    Tuikka, Matti; Haukka, Matti

    2015-07-01

    In the title adduct, C5H5N·I2, the N-I distance [2.424 (8) Å] is remarkably shorter than the sum of the van der Waals radii. The line through the I atoms forms an angle of 78.39 (16)° with the normal to the pyridine ring.

  20. Some thiocyanato complexes of cadmium(II) with substituted pyridines and imidazoles

    Energy Technology Data Exchange (ETDEWEB)

    Mishra, B P; Ramana Rao, D V [Regional Engineering Coll., Rourkela (India). Dept. of Chemistry

    1979-05-01

    The complexes formed by cadmium(II) thiocyanate with 3-acetyl-, 3-bromo-, 3-methyl-, 4-acetyl-, 4-cyano-, 4-benzoyl pyridines, isoquinoline, 3,5-lutidine and imidazole, 2-methyl imidazole, 2-methyl benzimidazoles have been characterised through elemental analysis and molar conductance data. On the basis of infra-red spectroscopic studies, probable structures are discussed.

  1. One-pot, three-component synthesis of highly substituted pyridines ...

    Indian Academy of Sciences (India)

    Administrator

    trile in the presence of nanocrystalline magnesium oxide provides the highly substituted pyridine derivatives in moderate to ..... NAP–MgO (0⋅1 g), ethanol (5 mL) at reflux temperature b ... difference in the electronic and steric properties of.

  2. 1,2-Bis (pyridin-2-ylmethyl)sulfanyl ethane and its dimorphic hydrochloride salt

    DEFF Research Database (Denmark)

    Lennartson, A.; McKenzie, C. J.

    2011-01-01

    and are held together by C-H center dot center dot center dot N and C-H center dot center dot center dot S interactions, resulting in the formation of a three-dimensional network structure. In addition, two polymorphs of the corresponding hydrochloride salt, 2-[(2-[(pyridin-1-ium-2-ylmethyl...

  3. Technetium(I) complexes Tc(CO)3BrL2 (L = phosphine, pyridine, isocyanide)

    International Nuclear Information System (INIS)

    Lorenz, B.; Findeisen, M.; Olk, B.; Schmidt, K.

    1988-01-01

    Technetium pentacarbonyl bromide reacts with π-acceptor ligands L (L = phosphine, pyridine, isocyanide) to form disubstituted compounds of the type Tc(CO) 3 BrL 2 . The stereochemistry of the complexes was established by infrared and 1 H-NMR measurement. Chemical shifts and the half-widths of the 99 Tc-NMR signals are discussed. (author)

  4. Etudes sur le Portugal au Temps de l'Humanisme

    Directory of Open Access Journals (Sweden)

    J. Cruz Costa

    1953-06-01

    Full Text Available BATAILLON (Marcel. — Etudes sur le Portugal au Temps de l'Humanisme.  Acta Universitatis Conimbrigencis, 1952, 309 pp. (Primeiro Parágrafo do Artigo O Prof. Marcel Bataillon, erudito dos mais inteligentes da França atual, autor de uma obra que é hoje impr:scindível para quem pretenda estudar o humanismo renascentista na Espanha ou em Portugal, diríamos melhor, talvez: para quem pretenda estudar o Humanismo e a Renascença, — acaba de publicar, na coleção Acta Universitatis Conimbrigencis, êste volume no qual reune alguns trabalhos da mais alta importância para o conhecimento de muitos aspectos da vida espiritual portuguêsa do século XVI.

  5. Effect of pulverization of the bulk powder on the hydration of creatine anhydrate tablets and their pharmaceutical properties.

    Science.gov (United States)

    Sakata, Yukoh; Shiraishi, Sumihiro; Otsuka, Makoto

    2005-12-10

    The hydration behavior and expansion properties of untreated and pulverized creatine anhydrate (CRA) tablets were studied under 60 and 75%RH at 25 degrees C by using differential scanning calorimetry (DSC), and powder X-ray diffraction (PXRD). The tablet hardness of untreated and pulverized CRA tablets was significantly decreased after hydration. There was a linear relationship between the degree of hydration and the tablet hardness of untreated CRA tablets compressed at 1000 kg/cm2. In contrast, the relationship between the degree of hydration and the tablet hardness of pulverized CRA tablets was nonlinear. These results suggest that the reduction in hardness of pulverized CRA tablets does not depend solely on the hydration level of crystal water. PXRD analysis indicated that the diffraction pattern of the pulverized CRA powder was similar to that of the untreated CRA powder. However, the diffraction intensity of the pulverized CRA powder was slightly lower than that of the untreated CRA powder at high angle. The micropore radius of both untreated and pulverized CRA tablets was significantly increased after hydration, but analysis of the relationship between micropore radius and fractional hydration of crystal water showed that untreated CRA tablets were more affected than pulverized CRA tablets. Therefore, the reduction in tablet hardness depends not only on the hydration behavior but also on the crystal orientation of the CRA powder.

  6. Synthesis and characterizations of two anhydrous metal borophosphates: MIII2BP3O12 (M=Fe, In)

    International Nuclear Information System (INIS)

    Zhang Weilong; Lin Chensheng; Geng Lei; Li Yeyu; Zhang Hao; He Zhangzhen; Cheng Wendan

    2010-01-01

    Two members of M III 2 BP 3 O 12 borophosphates, namely Fe 2 BP 3 O 12 and In 2 BP 3 O 12 , were synthesized by the solid-state method and characterized by the X-ray single crystal diffraction, the powder diffraction and the electron microscopy. They both crystallize in the hexagonal system, space group P6(3)/m (no. 176) and feature 3D architectures, build up of the M 2 O 9 units and B(PO 4 ) 3 groups via sharing the corners; however, they are not isomorphic for the different crystallographically distinct atomic positions. Optical property measurements of both compounds and magnetic susceptibility measurements of Fe 2 BP 3 O 12 also have been performed. Moreover, in order to gain further insights into the relationship between physical properties and band structure of the M III 2 BP 3 O 12 borophosphates, theoretical calculations based on density functional theory (DFT) were performed using the total-energy code CASTEP. - Graphical abstract: Two anhydrous metal borophosphates of M III 2 BP 3 O 12 (M=Fe, In) have been prepared and characterized. They both crystallize in the hexagonal system, space group P6(3)/m (no. 176) and feature 3D architectures build up of the M 2 O 9 units and B(PO 4 ) 3 groups via sharing the corners, but they are not isomorphic for the different crystallographically distinct atomic positions.

  7. High DNA stability in white blood cells and buffy coat lysates stored at ambient temperature under anoxic and anhydrous atmosphere.

    Directory of Open Access Journals (Sweden)

    Anne-Lise Fabre

    Full Text Available Conventional storage of blood-derived fractions relies on cold. However, lately, ambient temperature preservation has been evaluated by several independent institutions that see economic and logistic advantages in getting rid of the cold chain. Here we validated a novel procedure for ambient temperature preservation of DNA in white blood cell and buffy coat lysates based on the confinement of the desiccated biospecimens under anoxic and anhydrous atmosphere in original hermetic minicapsules. For this validation we stored encapsulated samples either at ambient temperature or at several elevated temperatures to accelerate aging. We found that DNA extracted from stored samples was of good quality with a yield of extraction as expected. Degradation rates were estimated from the average fragment size of denatured DNA run on agarose gels and from qPCR reactions. At ambient temperature, these rates were too low to be measured but the degradation rate dependence on temperature followed Arrhenius' law, making it possible to extrapolate degradation rates at 25°C. According to these values, the DNA stored in the encapsulated blood products would remain larger than 20 kb after one century at ambient temperature. At last, qPCR experiments demonstrated the compatibility of extracted DNA with routine DNA downstream analyses. Altogether, these results showed that this novel storage method provides an adequate environment for ambient temperature long term storage of high molecular weight DNA in dehydrated lysates of white blood cells and buffy coats.

  8. High DNA stability in white blood cells and buffy coat lysates stored at ambient temperature under anoxic and anhydrous atmosphere

    Science.gov (United States)

    Luis, Aurélie; Colotte, Marthe; Tuffet, Sophie; Bonnet, Jacques

    2017-01-01

    Conventional storage of blood-derived fractions relies on cold. However, lately, ambient temperature preservation has been evaluated by several independent institutions that see economic and logistic advantages in getting rid of the cold chain. Here we validated a novel procedure for ambient temperature preservation of DNA in white blood cell and buffy coat lysates based on the confinement of the desiccated biospecimens under anoxic and anhydrous atmosphere in original hermetic minicapsules. For this validation we stored encapsulated samples either at ambient temperature or at several elevated temperatures to accelerate aging. We found that DNA extracted from stored samples was of good quality with a yield of extraction as expected. Degradation rates were estimated from the average fragment size of denatured DNA run on agarose gels and from qPCR reactions. At ambient temperature, these rates were too low to be measured but the degradation rate dependence on temperature followed Arrhenius’ law, making it possible to extrapolate degradation rates at 25°C. According to these values, the DNA stored in the encapsulated blood products would remain larger than 20 kb after one century at ambient temperature. At last, qPCR experiments demonstrated the compatibility of extracted DNA with routine DNA downstream analyses. Altogether, these results showed that this novel storage method provides an adequate environment for ambient temperature long term storage of high molecular weight DNA in dehydrated lysates of white blood cells and buffy coats. PMID:29190767

  9. Reactive Precipitation of Anhydrous Alkali Sulfide Nanocrystals with Concomitant Abatement of Hydrogen Sulfide and Cogeneration of Hydrogen.

    Science.gov (United States)

    Li, Xuemin; Zhao, Yangzhi; Brennan, Alice; McCeig, Miranda; Wolden, Colin A; Yang, Yongan

    2017-07-21

    Anhydrous alkali sulfide (M 2 S, M=Li or Na) nanocrystals (NCs) are important materials central to the development of next generation cathodes and solid-state electrolytes for advanced batteries, but not commercially available at present. This work reports an innovative method to directly synthesize M 2 S NCs through alcohol-mediated reactions between alkali metals and hydrogen sulfide (H 2 S). In the first step, the alkali metal is complexed with alcohol in solution, forming metal alkoxide (ROM) and releasing hydrogen (H 2 ). Next, H 2 S is bubbled through the ROM solution, where both chemicals are completely consumed to produce phase-pure M 2 S NC precipitates and regenerate alcohol that can be recycled. The M 2 S NCs morphology may be tuned through the choice of the alcohol and solvent. Both synthetic steps are thermodynamically favorable (ΔG m o <-100 kJ mol -1 ), proceeding rapidly to completion at ambient temperature with almost 100 % atom efficiency. The net result, H 2 S+2 m→M 2 S+H 2 , makes good use of a hazardous chemical (H 2 S) and delivers two value-added products that naturally phase separate for easy recovery. This scalable approach provides an energy-efficient and environmentally benign solution to the production of nanostructured materials required in emerging battery technologies. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  10. Methods for the preparation of ultra-pure anhydrous zirconium tetrafluoride from zirconium tetraborohydride, researches in connection with halide glasses

    International Nuclear Information System (INIS)

    Tortevois, R.

    1990-01-01

    The synthesis of ultrapure zirconium tetrafluoride, the main component of fluorozirconate based optical fibers, was successfully attempted from zirconium tetraborohydride. Of the fluorinating agents used, nitrogen trifluoride doesn't react with zirconium tetraborohydride while xenon difluoride reacts too violently and leads to phases which contain boron. The fluorination in a compatible solvent enabled us to minimize the degradation. The best results were obtained with the fluorination of Zr(BH 4 ) 4 dissolved in CFCl 3 at -40 deg C by anhydrous HF. Using several analytical methods such as graphite furnace atomic absorption and proton activation, we analyzed the purity. The degree of transition element impurities is less than the ppm level for ZrF 4 . The dehydration of ZrF 4 ,H 2 O and ZrF 4 ,3H 2 O at room temperature by CIF 3 in gaseous and liquid state was also investigated. At exceptionally low temperature, this process allows oxide and oxyfluoride components to be reduced

  11. Pectin/anhydrous dibasic calcium phosphate matrix tablets for in vitro controlled release of water-soluble drug.

    Science.gov (United States)

    Mamani, Pseidy Luz; Ruiz-Caro, Roberto; Veiga, María Dolores

    2015-10-15

    Different pectin/anhydrous dibasic calcium phosphate (ADCP) matrix tablets have been developed in order to obtain controlled release of a water-soluble drug (theophylline). Swelling, buoyancy and dissolution studies have been carried out in different aqueous media (demineralized water, progressive pH medium, simulated gastric fluid, simulated intestinal fluid and simulated colonic fluid), to characterize the matrix tablets. When the pectin/ADCP ratio was ≥0.26 (P1, P2, P3 and P4 tablets) a continuous swelling and low theophylline dissolution rate from the matrices were observed. So, pectin gel forming feature predominated over the ADCP properties, yielding pH-independent drug release behavior from these matrices. On the contrary, pectin/ADCP ratios ≤0.11 (P5 and P6 tablets) allowed to achieve drug dissolution pH dependent. Consequently, the suitable selection of the pectin/ADCP ratio will allow to tailor matrix tablets for controlled release of water-soluble drugs in a specific manner in the gastrointestinal tract. Copyright © 2015 Elsevier B.V. All rights reserved.

  12. Kinetics of pyridine degradation along with toluene and methylene chloride with Bacillus sp. in packed bed reactor

    Energy Technology Data Exchange (ETDEWEB)

    Uma, B.; Sandhya, S. [National Environmental Engineering Research Institute, CSIR-Complex, Madras (India)

    1998-04-01

    Bacillus coagulans strain isolated from contaminated soil was immobilised on activated carbon for degradation of pyridine, toluene and methylene chloride containing synthetic wastewaters. Pyridine was supplied as the only source of nitrogen in the wastewaters. Continuous runs in a packed bed laboratory reactor showed that immobilized B. coagulans can degrade pyridine along with other organics rapidly and the effluent ammonia is also controlled in presence of ``organic carbon``. About 644 mg/l of influent TOC was efficiently degraded (82.85%) at 64.05 mg/l/hr loading. (orig.) With 2 figs., 4 tabs., 15 refs.

  13. Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

    KAUST Repository

    Batool, Farhat

    2016-11-18

    Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

  14. Synthesis and Suzuki Cross-Coupling Reactions of 2,6-Bis(trifluoromethyl)pyridine-4-boronic Acid Pinacol Ester

    KAUST Repository

    Batool, Farhat; Emwas, Abdul-Hamid M.; Gao, Xin; Munawar, Munawar A.; Chotana, Ghayoor A.

    2016-01-01

    Iridium-catalyzed aromatic borylation provides quick one-step access to 2,6-bis(trifluoromethyl)pyridine-4-boronic acid pinacol ester. Suzuki couplings of this highly electron-deficient pyridine-4-boronic ester with various (hetero)aryl bromides was successfully carried out and the coupled products were obtained in 46–95% isolated yields. Double and triple Suzuki couplings, with dibromo- and tribromoarenes, respectively, were also achieved. Thus demonstrating that this pyridine-4-boronic ester can be a useful source for the installation of one of the strongest electron-withdrawing aromatic group in organic compounds. Copyright © 2016, Georg Thieme Verlag. All rights reserved.

  15. A study of new anhydrous, conducting membranes based on composites of aprotic ionic liquid and cross-linked SPEEK for fuel cell application

    International Nuclear Information System (INIS)

    Malik, Rajender Singh; Verma, Pawan; Choudhary, Veena

    2015-01-01

    Highlights: • New composite membranes based on SPEEK/EG/IL were fabricated. • Composite membranes exhibit good thermal stability than neat SPEEK and XSPEEK membrane. • Proton conductivity of all composite membranes increased with temperature and amount of ionic liquid. • Proton conductivity was measured under anhydrous condition in the temperature ranging from 30–140 °C. - Abstract: The present study describe the preparation and characterisation of anhydrous proton conducting composite membranes based on sulfonated poly(ether ether ketone) [SPEEK–degree of sulfonation 70–72%]/ethylene glycol [EG]/ionic liquid by solution casting method using water: ethanol (50:50) as solvent. For this purpose several composite membranes were prepared by mixing solution of SPEEK/ethylene glycol (67:33 wt %) in water:ethanol with varying amounts of 1-butyl-3-methyl-imidazolium trifluromethanesulfonate [bmim][OTf] ionic liquid. The cross-linking of SPEEK was carried out by thermal treatment i.e. by heating in vacuum oven at 80 °C (2 h), 100 °C (2 h), 120 °C (2 h) and 135 °C for 16 h. Ethylene glycol was used as a cross-linker for SPEEK to reduce the leaching out of ionic liquid and enhance the mechanical strength of SPEEK membranes. The membranes were characterized for thermal [thermogravimetry analysis], structural [FTIR–ATR], proton conductivity, morphology (XRD, SEM) and leaching out of ionic liquid with water. FTIR studies clearly showed the interactions between SPEEK, EG and ionic liquid. The proton conductivity and dynamic mechanical properties of the composite membranes were investigated at elevated temperature and under anhydrous conditions. Proton conductivity of all the membranes measured in the temperature range of 30–140 °C under anhydrous conditions was in the range of 10 −3 Scm −1 which showed an increase with increase in temperature and amount of ionic liquid

  16. Determining the amount of anhydrous alcohol evaporated in vertical cylindrical tanks; Determinacao da quantidade de alcool etilico anidro evaporado em tanques cilindricos verticais

    Energy Technology Data Exchange (ETDEWEB)

    Oliveira, Elcio Cruz de [TRANSPETRO - PETROBRAS Transporte S.A., Rio de Janeiro, RJ (Brazil)

    2008-07-01

    In order to assess the anhydrous alcohol evaporated amount in vertical cylindrical tanks was developed a calculation methodology based on the rate of mass transfer of the product, the Reynolds number and the mass transfer coefficient. An Excel spreadsheet was prepared with data entry of the tank and physical and chemical properties of the product (temperature and density). For a temperature of 50 deg C, the volume evaporated reaches values of 0.8% by day. (author)

  17. Contribution to the study of several chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses; Contribution a l'etude de quelques nuisances chimiques au centre d'etudes nucleaires de Fontenay-aux-Roses

    Energy Technology Data Exchange (ETDEWEB)

    Megemont, C; Grau, C [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

    1968-10-01

    From the checking of 2750 index cards of hazards, the study relates the distribution of the chemical hazards in the Centre d'Etudes Nucleaires of Fontenay-aux-Roses. Those concerning the greatest number of agents in the Centre are classified according to the categories corresponding to the different conditions of working. Thus, the most important are put forward. Then, the authors rapidly make a review of hazards which may have some special interest because they appear more specific of the nuclear energy or because they are the most frequently noted on the index cards of hazards. The case of the tributylphosphate is studied more precisely. (authors) [French] A partir de l'examen de 2750 fiches de nuisances, l'etude porte sur la repartition des nuisances chimiques au Centre d'Etudes Nucleaires de Fontenay-aux-Roses. Celles qui concernent le plus grand nombre d'agents du Centre sont classees selon les categories correspondant aux differentes conditions de travail. Les plus importantes d'entre elles sont ainsi mises en evidence. | Les auteurs passent ensuite en revue, rapidement, les nuisances qui peuvent presenter un interet particulier soit parce qu'elles semblent plus specifiques de l'Energie Nucleaire, soit parce qu'on les rencontre le plus frequemment sur les fiches de nuisances. Le cas du tributylphosphate est envisage de facon plus detaillee. (auteurs)

  18. Removal of pyridine and quinoline by bio-zeolite composed of mixed degrading bacteria and modified zeolite

    International Nuclear Information System (INIS)

    Bai Yaohui; Sun Qinghua; Xing Rui; Wen Donghui; Tang Xiaoyan

    2010-01-01

    In the process of the biodegradation of pyridine and quinoline, ammonium is often generated because of the transformation of N from pyridine and quinoline. Zeolite has been proven to be an effective sorbent for the removal of the ammonium. The natural zeolite can be modified to be the macroporous carrier in the biological wastewater treatment process. In this study, a specific bio-zeolite composed of mixed bacteria (a pyridine-degrading bacterium and a quinoline-degrading bacterium) and modified zeolite was used for biodegradation and adsorption in two types of wastewater: sterile synthetic and coking wastewater. The experimental results indicated that pyridine and quinoline could be degraded simultaneously by the mixed bacteria. Furthermore, NH 4 + -N transformed from pyridine and quinoline could be removed by the modified zeolite. In addition, the bacterial community structures of the coking wastewater and the bio-zeolite were monitored by the amplicon length heterogeneity polymerase-chain reaction (LH-PCR) technique. Both LH-PCR results and scanning electron microscope (SEM) observations indicated that the microorganisms, including BW001 and BW003, could be easily attached on the surface of the modified zeolite and that the bio-zeolite could be used in the treatment of wastewater containing pyridine and/or quinoline.

  19. Novel semiconducting boron carbide/pyridine polymers for neutron detection at zero bias

    Energy Technology Data Exchange (ETDEWEB)

    Echeverria, Elena; Enders, A.; Dowben, P.A. [University of Nebraska-Lincoln, Department of Physics and Astronomy, Lincoln, NE (United States); James, Robinson; Chiluwal, Umesh; Gapfizi, Richard; Tae, Jae-Do; Driver, M. Sky; Kelber, Jeffry A. [University of North Texas, Department of Chemistry, Denton, TX (United States); Pasquale, Frank L. [University of North Texas, Department of Chemistry, Denton, TX (United States); Lam Research Corporation, PECVD Business Unit, Tualatin, OR (United States); Colon Santana, Juan A. [Center for Energy Sciences Research, Lincoln, NE (United States)

    2014-09-19

    Thin films containing aromatic pyridine moieties bonded to boron, in the partially dehydrogenated boron-rich icosahedra (B{sub 10}C{sub 2}H{sub X}), prove to be an effective material for neutron detection applications when deposited on n-doped (100) silicon substrates. The characteristic I-V curves for the heterojunction diodes exhibit strong rectification and largely unperturbed normalized reverse bias leakage currents with increasing pyridine content. The neutron capture generated pulses from these heterojunction diodes were obtained at zero bias voltage although without the signatures of complete electron-hole collection. These results suggest that modifications to boron carbide may result in better neutron voltaic materials. (orig.)

  20. Adsorption behaviors of trivalent actinides and lanthanides on pyridine resin in lithium chloride aqueous solution

    International Nuclear Information System (INIS)

    Tatsuya Suzuki

    2013-01-01

    The adsorption behaviors of trivalent actinides and lanthanides on pyridine resin in lithium chloride aqueous solution were investigated. The adsorbed amounts of lanthanides and the degree of mutual separation of lanthanides increased with an increase in the concentration of lithium chloride in aqueous solution. The group separation of the trivalent actinides and lanthanides was observed. This separation phenomenon is similar in a hydrochloric acid solution. However, the adsorption behavior of lanthanides in lithium chloride is different from their behavior in a hydrochloric acid solution. This fact shows that the adsorption mechanisms of lanthanides in a lithium chloride aqueous solution and in a hydrochloric acid solution are different; the adsorption mechanisms are attributed to the ion exchange in a hydrochloric acid solution, and to the complex formation with pyridine group in a lithium chloride solution. (author)

  1. Measurement and correlation of vapour pressures of pyridine and thiophene with [EMIM][SCN] ionic liquid

    International Nuclear Information System (INIS)

    Khelassi-Sefaoui, Asma; Mutelet, Fabrice; Mokbel, Ilham; Jose, Jacques; Negadi, Latifa

    2014-01-01

    Highlights: • VLE of (pyridine + [EMIM][SCN]), or (thiophene + [EMIM][SCN]) binary mixtures were measured. • The investigated temperatures are 273 K to 363 K. • The PC-SAFT equation of state has been used to correlate the vapour pressures of the binary systems. - Abstract: In this work (vapour + liquid) equilibrium (VLE) measurements were performed on binary systems of the ionic liquid 1-ethyl-3-methylimidazolium thiocynate [EMIM][SCN] with thiophene or pyridine at pressures close to the atmospheric pressure using a static device at temperatures between 273 K and 363 K. Experimental data were correlated by the PC-SAFT EoS. The binary interaction parameters k ij were optimised on experimental VLE data. The results obtained for the two binary mixtures studied in this paper indicate that the PC-SAFT EoS can be used to represent systems containing ionic liquids

  2. Discovery of pyridine-based agrochemicals by using Intermediate Derivatization Methods.

    Science.gov (United States)

    Guan, Ai-Ying; Liu, Chang-Ling; Sun, Xu-Feng; Xie, Yong; Wang, Ming-An

    2016-02-01

    Pyridine-based compounds have been playing a crucial role as agrochemicals or pesticides including fungicides, insecticides/acaricides and herbicides, etc. Since most of the agrochemicals listed in the Pesticide Manual were discovered through screening programs that relied on trial-and-error testing and new agrochemical discovery is not benefiting as much from the in silico new chemical compound identification/discovery techniques used in pharmaceutical research, it has become more important to find new methods to enhance the efficiency of discovering novel lead compounds in the agrochemical field to shorten the time of research phases in order to meet changing market requirements. In this review, we selected 18 representative known agrochemicals containing a pyridine moiety and extrapolate their discovery from the perspective of Intermediate Derivatization Methods in the hope that this approach will have greater appeal to researchers engaged in the discovery of agrochemicals and/or pharmaceuticals. Copyright © 2015 Elsevier Ltd. All rights reserved.

  3. 2,3-Diamino-pyridinium 6-carb-oxy-pyridine-2-carboxyl-ate.

    Science.gov (United States)

    Foroughian, Mahsa; Foroumadi, Alireza; Notash, Behrouz; Bruno, Giuseppe; Amiri Rudbari, Hadi; Aghabozorg, Hossein

    2011-12-01

    The asymmetric unit of the title proton-transfer compound, C(5)H(8)N(3) (+)·C(7)H(4)NO(4) (-), consists of one mono-deprotonated pyridine-2,6-dicarb-oxy-lic acid as anion and one protonated 2,3-diamino-pyridine as cation. The crystal packing shows extensive O-H⋯O, N-H⋯O and N-H⋯N hydrogen bonds. Thre are also several π-π inter-actions between the anions and also between the cations [centriod-centroid distances = 3.6634 (7), 3.7269 (7), 3.6705 (7) and 3.4164 (7) Å].

  4. SYNTHESIS AND BIOLOGIC PROPERTIES OF SOME 1-(ALCHYLPHENYL-3-(4-(3-(PYRIDIN-2-ILACRYLOYLPHENYLTHIOUREA

    Directory of Open Access Journals (Sweden)

    A. Popusoi

    2013-06-01

    Full Text Available This paper describe the synthesis of some 1-(alchylaril-3-(4-(3-pyridin-2-il acryloylphenylthiourea obtained by condensation of 2-pyridincarboxaldehide with some derivatives of 4-acetylphenilthioureas in basic medium or by addition of aliphatic and aromatic amines to the correspondingisothiocyanatopropenones. 12 new compounds were obtained and their biological properties were analysed. The substituted thioureas by pyridine radicals, morpholine and phenol show a maximum bacteriostatic activity for Gram positive microorganisms like: Staphylococcus Aureus and Enterococcus Faecalis at the minimum inhibitory concentration 9.37-37.5 μM. Antifungal activity for Candida Albicans, Aspergillus Niger, AspergillusFumigatus, Penicillium is weak, in minimum inhibitory concentration 600->600 μM. The leukemia activity like inhibitor (HL-60, is 84-96.9% at the concentration 10-5mol/l and 15- 20% and at the concentrations 10-6, 10-7mol/l.

  5. NHC Versus Pyridine: How “Teeth” Change the Redox Behavior of Iron(II) Complexes

    KAUST Repository

    Weiss, Daniel T.

    2015-10-06

    A series of octahedral iron(II) complexes with tetradentate NHC/pyridine hybrid ligands containing up to three pyridyl units was designed to study the influence of NHC and pyridine donors on the electronic structure of the metal center. Structural analysis of the iron complexes by NMR spectroscopy and single-crystal X-ray diffraction reveals different coordination modes of the ligand depending on the linkage of the different donor moieties. The oxidation potentials of all complexes correlate linearly with the number of NHC moieties coordinated to iron, as shown by cyclic voltammetry. The influence, although minor, of structural properties on the oxidation potential and (in one case) the influence of the oxidation state of the coordination geometry of the hybrid ligand are also demonstrated.

  6. Synthesis, reactions, and antiarrhythmic activities of some novel pyrimidines and pyridines fused with thiophene moiety

    OpenAIRE

    AMR, Abdel-Galil El-Sayed; ABDEL-HAFEZ, Naglaa Abdel-Samei

    2009-01-01

    We report herein the synthesis and antiarrhythmic activities of some newly synthesized heterocyclic theino[2,3-c]pyrimidine and theino[2,3-c]pyridine derivatives fused with thiophene moiety. Initially the acute toxicity of the compounds was assayed via the determination of their LD50. The antiarrhythmic activities for the compounds were determined and all the tested compounds were found more potent than Procaine amide\\textregistered and Lidocaine\\textregistered as positive antiarrhyth...

  7. Synthesis, reactions, and antiarrhythmic activities of some novel pyrimidines and pyridines fused with thiophene moiety

    OpenAIRE

    AMR, Abdel-Galil El-Sayed; ABDEL-HAFEZ, Naglaa Abdel-Samei; MOHAMED, Salwa Fahem; ABDALLA, Mohamed Mostafa

    2014-01-01

    We report herein the synthesis and antiarrhythmic activities of some newly synthesized heterocyclic theino[2,3-c]pyrimidine and theino[2,3-c]pyridine derivatives fused with thiophene moiety. Initially the acute toxicity of the compounds was assayed via the determination of their LD50. The antiarrhythmic activities for the compounds were determined and all the tested compounds were found more potent than Procaine amide\\textregistered and Lidocaine\\textregistered as positive antiarrhyth...

  8. Palladium(II) complexes supported by a bidentate bis(secondary)phosphine linked by pyridine

    KAUST Repository

    Winston, Matthew S.; Bercaw, John E.

    2014-01-01

    A series of complexes of the type (PNP-H2)PdX2 (X=Cl, Br, I) have been synthesized, where PNP-H2 is a bis(secondary)phosphine ligand linked by a pyridine, 2,6-(2'-(Ph(H)P)(C6H4))2(C5H3N). Due to chirality at phosphorus, the parent ligand exists as a

  9. N,N-Diethyl-4-[(E-(pyridin-3-yldiazenyl]aniline

    Directory of Open Access Journals (Sweden)

    Tatiana V. Timofeeva

    2013-08-01

    Full Text Available The molecule of the title compound, C15H18N4, adopts a trans conformation with respect to the diazo N=N bond. The dihedral angle between the benzene and pyridine rings in the molecule is 8.03 (5°. In the crystal, a weak C—H...π interaction arranges the molecules into a corrugated ribbon, with an antiparallel orientation of neighboring molecules propagating in the [100] direction.

  10. (E-4-Methoxy-3,5-dimethyl-2-[(3-nitrophenylethenyl]pyridine

    Directory of Open Access Journals (Sweden)

    Youness El Bakri

    2016-12-01

    Full Text Available In the crystal of the title compound, C16H16N2O3, weak C—H...O hydrogen bonds involving the nitro group as acceptor form chains extending in the b-axis direction. The chains are arranged into layers by π–π stacking interactions along the c-axis direction between the substituted pyridine rings, separated by 3.624 (1 Å.

  11. Preparation and characterization of some pyridine-2,6-dicarboxylato thorium(IV) complexes

    Energy Technology Data Exchange (ETDEWEB)

    Degetto, S; Baracco, L [Consiglio Nazionale delle Ricerche, Padua (Italy). Lab. di Chimica e Tecnologia dei Radioelementi; Graziani, R [Padua Univ. (Italy). Istituto di Chimica Generale ed Inorganica; Celon, E [Padua Univ. (Italy). Istituto di Chimica Organica

    1978-12-01

    The preparation of complexes of pyridine-2,6-dicarboxylic acid (H/sub 2/PDC) with thorium(IV) is reported and discussed. The reactivity of Th(PDC)/sub 2/(H/sub 2/O)/sub 4/ was tested by preparing adducts with some neutral ligands. The complexes were characterized by i.r. spectroscopy, elemental analysis and thermal behaviour. Preliminary information on the structure obtained by x-ray analysis is also reported.

  12. Thermodynamic study of complexation of thorium with pyridine monocarboxylates by calorimetry and DFT calculations

    International Nuclear Information System (INIS)

    Rama Mohana Rao, D.; Rawat, Neetika; Sawant, R.M.; Tomar, B.S.; Manna, D.; Ghanty, T.K.

    2013-01-01

    Stability constants of Th(IV) complexes with pyridine mono-carboxylates, namely, picolinate, nicotinate and isonicotinate have been determined following potentiometric titration of the metal ion and ligand mixtures with NaOH solution of known concentration. These data were used during the analysis of the calorimetric titration data to obtain the enthalpy of complexation reactions. The experimental data have been compared with that obtained from the DFT based theoretical calculations. (author)

  13. Effective transport properties for the pyridine-granular activated carbon adsorption system

    OpenAIRE

    Baz-Rodríguez, S. A.; Ocampo-Pérez, R.; Ruelas-Leyva, J. P.; Aguilar-Madera, C. G.

    2012-01-01

    In this work, the kinetics of pyridine adsorption onto granular activated carbon was studied from the point of view of an up-scaling process by using the method of volume averaging. The pore and surface effective diffusivities were estimated by supposing simple microscale geometries (ordered media of cylinders and spheres) and those of images processed from SEM (Scanning Electron Microscopy) micrographs. In addition, as a rough estimate, the point surface diffusivity is reported. The results ...

  14. Synthesis, Reactivity and Stability of Aryl Halide Protecting Groups towards Di-Substituted Pyridines

    Directory of Open Access Journals (Sweden)

    Ptoton Mnangat Brian

    2016-03-01

    Full Text Available This paper reports the synthesis and reactivity of different Benzyl derivative protecting groups. The synthesis and stability of Benzyl halides, 4-methoxybenzyl halides, 3,5-dimethoxybenzyl halides, 3,4-dimethoxybenzyl halides, 3,4,5-trimethoxybenzyl halide protecting groups and their reactivity towards nitrogen atom of a di-substituted pyridine ring in formation of pyridinium salts is also reported.

  15. Pharmacological Potential and Synthetic Approaches of Imidazo[4,5-b]pyridine and Imidazo[4,5-c]pyridine Derivatives

    Directory of Open Access Journals (Sweden)

    Malwina Krause

    2017-03-01

    Full Text Available The structural resemblance between the fused imidazopyridine heterocyclic ring system and purines has prompted biological investigations to assess their potential therapeutic significance. They are known to play a crucial role in numerous disease conditions. The discovery of their first bioactivity as GABAA receptor positive allosteric modulators divulged their medicinal potential. Proton pump inhibitors, aromatase inhibitors, and NSAIDs were also found in this chemical group. Imidazopyridines have the ability to influence many cellular pathways necessary for the proper functioning of cancerous cells, pathogens, components of the immune system, enzymes involved in carbohydrate metabolism, etc. The collective results of biochemical and biophysical properties foregrounded their medicinal significance in central nervous system, digestive system, cancer, inflammation, etc. In recent years, new preparative methods for the synthesis of imidazopyridines using various catalysts have been described. The present manuscript to the best of our knowledge is the complete compilation on the synthesis and medicinal aspects of imidazo[4,5-b]pyridines and imidazo[4,5-c]pyridines reported from the year 2000 to date, including structure–activity relationships.

  16. Aqua{2-(pyridin-2-yl-N-[(pyridin-2-ylmethylidene]ethanamine-κ3N,N′,N′′}(sulfato-κ2O,O′copper(II tetrahydrate

    Directory of Open Access Journals (Sweden)

    Daniel Tinguiano

    2013-01-01

    Full Text Available The title complex, [Cu(SO4(C13H13N3(H2O]·4H2O, was obtained by mixing copper sulfate pentahydrate and 2-(pyridin-2-yl-N-(pyridin-2-ylmethylideneethanamine in ethanol under reflux conditions. The CuII ion shows a Jahn–Teller-distorted octahedral geometry, with equatorial positions occupied by three N atoms from the tridentate ligand (average Cu—N = 2.004 Å and one O atom from a bidentate sulfate anion [Cu—O = 1.963 (2 Å]. The axial positions are occupied by one O atom from a coordinating water molecule [Cu—O = 2.230 (3 Å] and one weakly bonded O atom [Cu—O = 2.750 (2 Å] from the bidentate sulfate ion. The complex molecules are connected through O—H...O hydrogen bonds between the coordinating water molecules and sulfate ions from neighboring complexes, forming a double chain parallel to the c axis. The chains are stabilized through additional hydrogen bonds by one of the non-coordinating water molecules bridging between neighboring strands of the double chains. The remaining three water molecules fill the interstitial space between the double chains and are involved in an intricate hydrogen-bonding network that consolidates the structure.

  17. Crystal structure of 2-hy-droxy-imino-2-(pyridin-2-yl)-N'-[1-(pyridin-2-yl)ethyl-idene]acetohydrazide.

    Science.gov (United States)

    Plutenko, Maxym O; Lampeka, Rostislav D; Haukka, Matti; Nordlander, Ebbe

    2014-12-01

    The mol-ecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å), with the planes of the two pyridine rings inclined to one another by 5.51 (7)°. The oxime group is syn to the amide group, probably due to the formation of an intra-molecular N-H⋯N hydrogen bond that forms an S(6) ring motif. In the crystal, mol-ecules are linked by pairs of bifurcated O-H⋯(O,N) hydrogen bonds, forming inversion dimers. The latter are linked via C-H⋯O and C-H⋯N hydrogen bonds, forming sheets lying parallel to (502). The sheets are linked via π-π stacking inter-actions [inter-centroid distance = 3.7588 (9) Å], involving the pyridine rings of inversion-related mol-ecules, forming a three-dimensional structure.

  18. Crystal structure of 2-hy­droxy­imino-2-(pyridin-2-yl)-N′-[1-(pyridin-2-yl)ethyl­idene]acetohydrazide

    Science.gov (United States)

    Plutenko, Maxym O.; Lampeka, Rostislav D.; Haukka, Matti; Nordlander, Ebbe

    2014-01-01

    The mol­ecule of the title compound, C14H13N5O2, is approximately planar (r.m.s deviation for all non-H atoms = 0.093 Å), with the planes of the two pyridine rings inclined to one another by 5.51 (7)°. The oxime group is syn to the amide group, probably due to the formation of an intra­molecular N—H⋯N hydrogen bond that forms an S(6) ring motif. In the crystal, mol­ecules are linked by pairs of bifurcated O—H⋯(O,N) hydrogen bonds, forming inversion dimers. The latter are linked via C—H⋯O and C—H⋯N hydrogen bonds, forming sheets lying parallel to (502). The sheets are linked via π–π stacking inter­actions [inter-centroid distance = 3.7588 (9) Å], involving the pyridine rings of inversion-related mol­ecules, forming a three-dimensional structure. PMID:25552998

  19. Pharmacological Potential and Synthetic Approaches of Imidazo[4,5-b]pyridine and Imidazo[4,5-c]pyridine Derivatives.

    Science.gov (United States)

    Krause, Malwina; Foks, Henryk; Gobis, Katarzyna

    2017-03-04

    The structural resemblance between the fused imidazopyridine heterocyclic ring system and purines has prompted biological investigations to assess their potential therapeutic significance. They are known to play a crucial role in numerous disease conditions. The discovery of their first bioactivity as GABA A receptor positive allosteric modulators divulged their medicinal potential. Proton pump inhibitors, aromatase inhibitors, and NSAIDs were also found in this chemical group. Imidazopyridines have the ability to influence many cellular pathways necessary for the proper functioning of cancerous cells, pathogens, components of the immune system, enzymes involved in carbohydrate metabolism, etc. The collective results of biochemical and biophysical properties foregrounded their medicinal significance in central nervous system, digestive system, cancer, inflammation, etc. In recent years, new preparative methods for the synthesis of imidazopyridines using various catalysts have been described. The present manuscript to the best of our knowledge is the complete compilation on the synthesis and medicinal aspects of imidazo[4,5- b ]pyridines and imidazo[4,5- c ]pyridines reported from the year 2000 to date, including structure-activity relationships.

  20. Structural and physicochemical characterization of pyridine derivative salts of anti-inflammatory drugs

    Science.gov (United States)

    Nechipadappu, Sunil Kumar; Trivedi, Darshak R.

    2017-08-01

    Salts of common anti-inflammatory drugs mefenamic acid (MFA), tolfenamic acid (TFA) and naproxen (NPX) with various pyridine derivatives (4-amino pyridine (4AP), 4-dimethylaminopyridine (DMAP) and 2-amino pyridine (2AP)) were synthesized by crystal engineering approach based on the pKa values of API's and the salt former. All the salts were characterized systematically by various spectroscopic methods including FT-IR and 1H NMR and the crystal structure was determined by single-crystal X-ray diffraction techniques (SCXRD). DMAP salt of NPX and 2AP salts of MFA and TFA were not obtained in the salt screening experiments. All the molecular salts exhibited 1:1 molecular stoichiometry in the asymmetric unit and except NPX-2AP salt, all the molecular salts included a water molecule in the crystal lattice. Physicochemical and structural properties between drug-drug molecular salts of MFA-4AP, TFA-4AP and NPX-4AP have been evaluated and it was found that these molecular salts were found to be stable for a time period of six months at ambient condition and further hydration of molecular salts were not observed even at accelerated humid conditions (∼75% RH). It was found that 4AP salts of MFA and TFA and DMAP salts of MFA and TFA are isostructural.

  1. Fluorescent property of 3-hydroxymethyl imidazo[1,2-a]pyridine and pyrimidine derivatives

    Directory of Open Access Journals (Sweden)

    Velázquez-Olvera Stephania

    2012-08-01

    Full Text Available Abstract Background Imidazo[1,2-a]pyridines and pyrimidines are important organic fluorophores which have been investigated as biomarkers and photochemical sensors. The effect on the luminescent property by substituents in the heterocycle and phenyl rings, have been studied as well. In this investigation, series of 3-hydroxymethyl imidazo[1,2-a]pyridines and pyrimidines were synthesized and evaluated in relation to fluorescence emission, based upon the hypothesis that the hydroxymethyl group may act as an enhancer of fluorescence intensity. Results Compounds of both series emitted light in organic solvents dilutions as well as in acidic and alkaline media. Quantitative fluorescence spectroscopy determined that both fused heterocycles fluoresced more intensely than the parent unsubstituted imidazo[1,2-a]azine fluorophore. In particular, 3-hydroxymethyl imidazo[1,2-a]pyridines fluoresced more intensely than 3-hydroxymethyl imidazo[1,2-a]pyrimidines, the latter emitting blue light at longer wavelengths, whereas the former emitted purple light. Conclusion It was concluded that in most cases the hydroxymethyl moiety did act as an enhancer of the fluorescence intensity, however, a comparison made with the fluorescence emitted by 2-aryl imidazo[1,2-a]azines revealed that in some cases the hydroxymethyl substituent decreased the fluorescence intensity.

  2. Enhanced Charge Separation Efficiency in Pyridine-Anchored Phthalocyanine-Sensitized Solar Cells by Linker Elongation.

    Science.gov (United States)

    Ikeuchi, Takuro; Agrawal, Saurabh; Ezoe, Masayuki; Mori, Shogo; Kimura, Mutsumi

    2015-11-01

    A series of zinc phthalocyanine sensitizers (PcS22-24) having a pyridine anchoring group are designed and synthesized to investigate the structural dependence on performance in dye-sensitized solar cells. The pyridine-anchor zinc phthalocyanine sensitizer PcS23 shows 79 % incident-photon to current-conversion efficiency (IPCE) and 6.1 % energy conversion efficiency, which are comparable with similar phthalocyanine dyes having a carboxylic acid anchoring group. Based on DFT calculations, the high IPCE is attributed with the mixture of an excited-state molecular orbital of the sensitizer and the orbitals of TiO2 . Between pyridine and carboxylic acid anchor dyes, opposite trends are observed in the linker-length dependence of the IPCE. The red-absorbing PcS23 is applied for co-sensitization with a carboxyl-anchor organic dye D131 that has a complementary spectral response. The site-selective adsorption of PcS23 and D131 on the TiO2 surface results in a panchromatic photocurrent response for the whole visible-light region of sun light. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Synthesis of pyridine and isoquinoline labelled with 14C on the nitrogen heterocycle

    International Nuclear Information System (INIS)

    Robveille, Jacques

    1985-01-01

    This research thesis addresses the synthesis of derivatives of pyridine and isoquinoline labelled with carbon 14 ( 14 C) in the nitrogenated heterocycle as these compounds are of biological and pharmacological interest. The author aimed at developing rather general synthesis schemes which could be easily applied to the synthesis of radioactive compounds, and could produce, through a given synthesis way, the largest as possible family of differently substituted compounds. Different sources for labelled pyridine and isoquinoline have been used: dioxo-1,5 or their corresponding dioxins, substituted pentadienoic acids, derivatives of acrylic acid, and derivatives of cinnamic acid. Thus, three different synthesis processes have been developed to obtain 14 C labelled pyridine, and one of them is applied to the preparation of 14 C labelled isoquinoline. These synthesis processes can have a very general application, and allow different 14 C labelling positions to be envisaged. The possibility to obtain the same compounds but labelled with tritium can also be envisaged to obtain much higher specific activities [fr

  4. Dihydropyridine-fused and pyridine-fused coumarins: Reduction on a glassy carbon electrode in dimethylformamide

    International Nuclear Information System (INIS)

    Nuñez-Vergara, Luis J.; Pardo-Jiménez, V.; Barrientos, C.; Olea-Azar, C.A.; Navarrete-Encina, P.A.; Squella, J.A.

    2012-01-01

    In this study, two series of dihydropyridine-fused and pyridine-fused coumarins were synthesised and electrochemically characterised in aprotic medium. In both series, the most easily reducible groups were the endocyclic carbonyl groups. The electrochemical mechanism for both types of compounds is strongly dependent on the experimental time-scale. Cyclic voltammetric (CV) reduction on a glassy carbon electrode (GCE) of the endocyclic carbonyl group of dihydropyridine-fused coumarins involves an ECEC mechanism with two electron transfer steps that are coupled with chemical reactions to produce the corresponding hemiacetal derivative. In the case of pyridine-fused coumarins, CV reduction of the endocyclic carbonyl group involves an EEC mechanism. ESR studies revealed the presence of a stabilised intermediate only for the pyridine-fused derivatives. Our theoretical study showed a spin density map of radical species delocalised mainly within the coumarin ring, indicating the reduction of the endocyclic carbonyl group. In the case of the dihydropyridine-fused derivatives, the mildly acid hydrogen of the dihydropyridine ring destabilises the radical via a father–son type reaction.

  5. Etude de la qualité physico-chimique et biologique des eaux du ...

    African Journals Online (AJOL)

    Etude de la qualité physico-chimique et biologique des eaux du fleuve Niger à Niamey. ... le récepteur principal des rejets d'eaux usées de la ville de Niamey, capital du ... La description de ces taxons montre une variation de la structure des ...

  6. English Department Reforms at the Hautes Etudes Commerciales: Entering the Nineties.

    Science.gov (United States)

    Shanahan, Daniel

    1993-01-01

    Discusses the reforms made in the fall of 1990 in the English department at the Ecole Hautes Etudes Commerciales (Paris, France), which were based on the basis of a combination of literature-culture and second- and foreign-language acquisition pedagogical biases. (four references) (VWL)

  7. Contribution a l'etude des plantes alimentaires mineures dans la ...

    African Journals Online (AJOL)

    Contribution a l'etude des plantes alimentaires mineures dans la prefecture de Dankpen (Togo). AB Kebenzikato, S Akpavi, K Batawila, K Wala, M Dourma, K Kossi-Titrikou, KS Amouzou, I Butare, H Dantsey-Barry, K Akpagana ...

  8. 152 Etude de cas sur l'impact des amendements organiques vis-à ...

    African Journals Online (AJOL)

    john mukalay

    Etude de cas sur l'impact des amendements organiques vis-à-vis de la salinité en culture de bananier. Michel Mazinga KWEY1, Séverin Kalala BANZE2 et John Banza MUKALAY2*. 1Laboratoire des cultures in vitro, Département de phytotechnie, Faculté des sciences agronomiques,. Université de Lubumbashi, BP 1825, ...

  9. 186 Etude théorique du transport électronique par la simulation ...

    African Journals Online (AJOL)

    youness

    Choukria SAYAH et al. 186. Etude théorique du ... For that we carried out the microscopic simulations, based on the Monte. Carlo method. ... intervalles, piezoelectric as well as the interactions of alloy and on ionized impurities. ..... SAYA et al. 198. [5] - R. W. Hockney, J. W. Eastwood, "Computer simulation using particles",.

  10. Etude comparative de la flore aux abords des cours d'eau dans les ...

    African Journals Online (AJOL)

    Etude comparative de la flore aux abords des cours d'eau dans les zones hypo et hyper endémiques d'ulcère de Buruli en Côte d'Ivoire. C. Cisse Boni, E. Ehouman, D. Soro, M.W. Kone, A. Bakayoko, F. Dembele, K. Bauthire, M Dosso ...

  11. Alecto 2 - interaction studies; Alecto 2 - etudes d'interaction

    Energy Technology Data Exchange (ETDEWEB)

    Brunet, J P; Clouet d' Orval, Ch; Mougniot, J C; Penet, F [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1965-07-01

    Weak interactions were experimentally studies with the tank of the critical assembly Alecto II and one, two or three bottles containing solutions of various concentrations. In particular, was studied the validity of certain classical assumptions, shielding effects, screening and semi-reflexion effects, importance of thermal coupling. The method of the 'k{sub eff}, solid angle' is shown to apply to such a system. The determination by divergence and pulsed neutron technique of the reactivity related to a millimeter of solution level affords the obtention of critical heights in terms of reactivity. (authors) [French] Une etude experimentale d'interactions faibles a ete faite entre la cuve de l'experience critique ALECTO II et une, deux ou trois bouteilles contenant des concentrations variees. On etudie, en particulier, la validite de certaines hypotheses classiques, effets d'ombre, d'ecrans, de semi-reflexion, importance du couplage thermique. On montre d'autre part que la methode du 'K{sub eff}, angle solide' peut s'appliquer a un tel systeme. La determination par divergence et neutrons pulses de la reactivite liee au millimetre de solution permet de traduire les hauteurs critiques obtenues, en terme de reactivite. (auteurs)

  12. Baby fission chambers; Etude de chambres a fission miniatures

    Energy Technology Data Exchange (ETDEWEB)

    Guery, U; Tachon, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The present report is intended, on the one band, as a study of the main types of fission chambers produced to date, and on the other, to deal more generally with this type of detector. Originally, it was with a view to the charting of neutron scatter in 'Proserpine' that the authors undertook the study of these chambers. During the course of the task, it was considered worth tbe trouble of developing its scope to include a more general application: neutron scatter measurement of various energy neutrons within a reduced volume with slight local disturbance. (author) [French] Le present rapport se propose, d'une part, d'exposer les principales realisations de chambres a fission, d'autre part de faire une mise au point a caractere plus general sur ces detecteurs. Au depart, c'est surtout en vue des mesures de densite neutronique dans 'Proserpine' que les auteurs ont etudie ces chambres; au cours de la mise au point, il a paru interessant de developper leur etude pour des applications plus generales: mesures de densites de neutrons de differentes energies dans un element de volume tres reduit et avec faible perturbation locale. (auteur)

  13. SEPA (Service d'etudes, de Procedes et Analyses)

    International Nuclear Information System (INIS)

    2017-01-01

    The SEPA (Service d'etudes, de Procedes et Analyses), is an engineering department specializing in the analysis and processing of uranium ore. It comes from a long tradition of mining in France that began sixty-five years ago with the French Atomic Energy Commission (CEA) and that has been carried on by COGEMA and then Areva. SEPA brings a combination of experience and excellence to its activities thanks to its multidisciplinary staff (mineralogists, chemists, mechanical engineers, instrumentation specialists...), who come from diverse cultural backgrounds. Today, the SEPA draws on its wealth of know-how and expertise to devise and develop new methods for processing and valorizing ores everywhere in the world. Its mission is to: - Develop and conduct laboratory tests on methods for processing uranium and other valuable elements such as molybdenum, vanadium, rare earths, niobium, tantalum and thorium; - Analyze ores obtained during prospecting at locations all over the world; -Serve as an advisor in the commissioning of Areva industrial units and ore processing plants; -Perform environmental analyses during the full period of mining operations; -Conduct audits and provide advice on processes and analysis methods; -Carry out research and development in all aspects of minerals treatment (including the filing of patents). The SEPA combines experience, skills and a global approach to technologies used in ore processing. Its role is to continually improve the processes for extracting, processing and valorizing ores while protecting the environment

  14. Baby fission chambers; Etude de chambres a fission miniatures

    Energy Technology Data Exchange (ETDEWEB)

    Guery, U.; Tachon, J. [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1957-07-01

    The present report is intended, on the one band, as a study of the main types of fission chambers produced to date, and on the other, to deal more generally with this type of detector. Originally, it was with a view to the charting of neutron scatter in 'Proserpine' that the authors undertook the study of these chambers. During the course of the task, it was considered worth tbe trouble of developing its scope to include a more general application: neutron scatter measurement of various energy neutrons within a reduced volume with slight local disturbance. (author) [French] Le present rapport se propose, d'une part, d'exposer les principales realisations de chambres a fission, d'autre part de faire une mise au point a caractere plus general sur ces detecteurs. Au depart, c'est surtout en vue des mesures de densite neutronique dans 'Proserpine' que les auteurs ont etudie ces chambres; au cours de la mise au point, il a paru interessant de developper leur etude pour des applications plus generales: mesures de densites de neutrons de differentes energies dans un element de volume tres reduit et avec faible perturbation locale. (auteur)

  15. Raman spectra from very concentrated aqueous NaOH and from wet and dry, solid, and anhydrous molten, LiOH, NaOH, and KOH.

    Science.gov (United States)

    Walrafen, George E; Douglas, Rudolph T W

    2006-03-21

    High-temperature, high-pressure Raman spectra were obtained from aqueous NaOH solutions up to 2NaOHH2O, with X(NaOH)=0.667 at 480 K. The spectra corresponding to the highest compositions, X(NaOH)> or =0.5, are dominated by H3O2-. An IR xi-function dispersion curve for aqueous NaOH, at 473 K and 1 kbar, calculated from the data of Franck and Charuel indicates that the OH- ion forms H3O2- by preferential H bonding with nonhydrogen-bonded OH groups. Raman spectra from wet to anhydrous, solid LiOH, NaOH, and KOH yield sharp, symmetric OH- stretching peaks at 3664, 3633, and 3596 cm(-1), respectively, plus water-related, i.e., H3O2-, peaks near LiOH, 3562 cm(-1), NaOH, 3596 cm(-1), and, KOH, 3500 cm(-1). Absence of H3O2- peaks from the solid assures that the corresponding melt is anhydrous. Raman spectra from the anhydrous melts yield OH- stretching peak frequencies: LiOH, 3614+/-4 cm(-1), 873 K; NaOH, 3610+/-2 cm(-1), 975 K; and, KOH, 3607+/-2 cm(-1), 773 K, but low-frequency asymmetry due to ion-pair interactions is present which is centered near 3550 cm(-1). The ion-pair-related asymmetry corresponds to the sole IR maximum near 3550 cm(-1) from anhydrous molten NaOH, at 623 K. Bose-Einstein correction of published low-frequency Raman data from molten LiOH revealed an acoustic phonon, near 205 cm(-1), related to restricted translation of OH- versus Li+, and an optical phonon, at 625 cm(-1) and tau approximately 0.05 ps, due to protonic precession and/or pendular motion. Strong H bonding between water and the O atom of OH- forms H3O2-, but the proton of OH- does not bond with H significantly. Large Raman bandwidths (aqueous solutions) are explained in terms of inhomogeneous broadening due to proton transfer in a double well. Vibrational assignments are presented for H3O2-.

  16. Rhodium(III)-Catalyzed ortho-Alkylation of Phenoxy Substrates with Diazo Compounds via C-H Activation: A Case of Decarboxylative Pyrimidine/Pyridine Migratory Cyclization Rather than Removal of Pyrimidine/Pyridine Directing Group.

    Science.gov (United States)

    Ravi, Manjula; Allu, Srinivasarao; Swamy, K C Kumara

    2017-03-03

    An efficient Rh(III)-catalyzed ortho-alkylation of phenoxy substrates with diazo compounds has been achieved for the first time using pyrimidine or pyridine as the directing group. Furthermore, bis-alkylation has also been achieved using para-substituted phenoxypyrimidine and 3 mol equiv of the diazo ester. The ortho-alkylated derivatives of phenoxy products possessing the ester functionality undergo decarboxylative pyrimidine/pyridine migratory cyclization (rather than deprotection of pyrimidine/pyridine group) using 20% NaOEt in EtOH affording a novel class of 3-(pyrimidin-2(1H)-ylidene)benzofuran-2(3H)-ones and 6-methyl-3-(pyridin-2(1H)-ylidene)benzofuran-2(3H)-one. The ortho-alkylated phenoxypyridine possessing ester functionality also undergoes decarboxylative pyridine migratory cyclization using MeOTf/NaOMe in toluene providing 6-methyl-3-(1-methylpyridin-2(1H)-ylidene)benzofuran-2(3H)-one.

  17. 3-Ethyl-5-(4-meth­oxy­phen­oxy)-2-(pyridin-4-yl)-3H-imidazo[4,5-b]pyridine

    Science.gov (United States)

    Ranjith, S.; SubbiahPandi, A.; Suresh, A. D.; Pitchumani, K.

    2011-01-01

    In the title compound, C20H18N4O2, the imidazopyridine fused ring system is almost perpendicular to the benzene ring [dihedral angle = 87.6 (5)°]. The pyridine ring makes a dihedral angle of 35.5 (5)° with the mean plane of the imidazopyridine fragment. The crystal structure is stabilized by an aromatic π–π stacking inter­action between the phenyl rings of neighbouring mol­ecules [centroid–centroid distance = 3.772 (2) Å, inter­planar distance = 3.546 (2) Å and slippage = 1.286 (2) Å]. PMID:21837144

  18. Etude aerodynamique d'un jet turbulent impactant une paroi concave

    Science.gov (United States)

    LeBlanc, Benoit

    Etant donne la demande croissante de temperatures elevees dans des chambres de combustion de systemes de propulsions en aerospatiale (turbomoteurs, moteur a reaction, etc.), l'interet dans le refroidissement par jets impactant s'est vu croitre. Le refroidissement des aubes de turbine permet une augmentation de temperature de combustion, ce qui se traduit en une augmentation de l'efficacite de combustion et donc une meilleure economie de carburant. Le transfert de chaleur dans les au bages est influence par les aspects aerodynamiques du refroidissement a jet, particulierement dans le cas d'ecoulements turbulents. Un manque de comprehension de l'aerodynamique a l'interieur de ces espaces confinees peut mener a des changements de transfert thermique qui sont inattendus, ce qui augmente le risque de fluage. Il est donc d'interet pour l'industrie aerospatiale et l'academie de poursuivre la recherche dans l'aerodynamique des jets turbulents impactant les parois courbes. Les jets impactant les surfaces courbes ont deja fait l'objet de nombreuses etudes. Par contre des conditions oscillatoires observees en laboratoire se sont averees difficiles a reproduire en numerique, puisque les structures d'ecoulements impactants des parois concaves sont fortement dependantes de la turbulence et des effets instationnaires. Une etude experimentale fut realisee a l'institut PPRIME a l'Universite de Poitiers afin d'observer le phenomene d'oscillation dans le jet. Une serie d'essais ont verifie les conditions d'ecoulement laminaires et turbulentes, toutefois le cout des essais experimentaux a seulement permis d'avoir un apercu du phenomene global. Une deuxieme serie d'essais fut realisee numeriquement a l'Universite de Moncton avec l'outil OpenFOAM pour des conditions d'ecoulement laminaire et bidimensionnel. Cette etude a donc comme but de poursuivre l'enquete de l'aerodynamique oscillatoire des jets impactant des parois courbes, mais pour un regime d'ecoulement transitoire, turbulent

  19. Ringwoodite growth rates from olivine with ~75 ppmw H2O: Metastable olivine must be nearly anhydrous to exist in the mantle transition zone

    Energy Technology Data Exchange (ETDEWEB)

    Du Frane, Wyatt L. [Arizona State Univ., Tempe, AZ (United States). School of Earth and Space Exploration; Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States). Atmospheric, Earth and Energy Division; Sharp, Thomas G. [Arizona State Univ., Tempe, AZ (United States). School of Earth and Space Exploration; Mosenfelder, Jed L. [California Inst. of Technology (CalTech), Pasadena, CA (United States). Division of Geological and Planetary Sciences; Leinenweber, Kurt [Arizona State Univ., Tempe, AZ (United States). School of Earth and Space Exploration

    2013-04-15

    It has been previously demonstrated that as little as 300 ppmw H2O increases wadsleyite and ringwoodite growth rates to magnitudes that are inconsistent with the metastable olivine hypothesis. To further test this hypothesis, we present new ringwoodite growth rate measurements from olivine with ~75 ppmw H2O at 18 GPa and 700, 900, and 1100 °C. These growth rates are nearly identical to those from olivine with ~300 ppmw H2O, and significantly higher than those from nominally anhydrous olivine. We infer that transformation of olivine with 75-300 ppmw H2O is primarily enhanced by hydrolytic weakening of reaction rims, which reduces the elastic strain-energy barrier to growth. We present a new method for fitting nonlinear nominally anhydrous data, to demonstrate that reduction of growth rates by elastic strain energy is an additional requirement for metastable olivine. In conclusion, based on previous thermokinetic modeling, these enhanced growth rates are inconsistent with the persistence of metastable olivine wedges into the mantle transition zone. Metastable persistence of olivine into the mantle transition-zone would therefore require < 75 ppmw H2O.

  20. A structural phase transition coupled to the Fe{sup 3+} spin-state crossover in anhydrous RbMn[Fe(CN){sub 6}

    Energy Technology Data Exchange (ETDEWEB)

    Rykov, A. I., E-mail: rykov3@yahoo.com; Wang, J., E-mail: wangjh@dicp.ac.cn; Zhang, T. [Chinese Academy of Sciences, Moessbauer Effect Data Center, Dalian Institute of Chemical Physics (China); Nomura, K. [University of Tokyo, Graduate School of Engineering (Japan)

    2013-04-15

    Linkage isomerism is the coexistence of iso-compositional molecules or solids differing by connectivity of the metal to a ligand. In a crystalline solid state, the rotation is possible for asymmetric ligands, e.g., for cyanide ligand. Here we report on our observation of a phase transition in anhydrous RbMn[Fe(CN){sub 6}] (nearly stoichiometric) and on the effect of linkage isomerism ensuing our interpretation of the results of Moessbauer study in which we observe the iron spin state crossover among two phases involved into this transition. The anhydrous RbMn[Fe(CN){sub 6}] can be prepared via prolonged thermal treatment (1 week at at 80 Degree-Sign C) of the as-synthesized hydrated RbMn[Fe(CN){sub 6}]{center_dot}H{sub 2}O. The latter compound famous for its charge-transfer phase transition is a precursor in our case. As the temperature is raising above 80 Degree-Sign C (remaining below 100 Degree-Sign C) we observe RbMn[Fe(CN){sub 6}] that inherited its F-43 m symmetry from RbMn[Fe(CN){sub 6}]{center_dot}H{sub 2}O transforming to a phase of the Fm-3 m symmetry. In the latter, more than half of Fe{sup 3 + } ions are in high-spin state. We suggest a plausible way to explain the spin-crossover that is to allow the linkage isomerism by rotation of the cyanide ligands.

  1. Synthesis of a Bis(thiophenolate)pyridine Ligand and Its Titanium, Zirconium, and Tantalum Complexes

    KAUST Repository

    Lenton, Taylor N.

    2012-11-12

    A precursor to a new tridentate LX 2 type ligand, bis(thiophenol)pyridine ((SNS)H 2 = (2-C 6H 4SH) 2-2,6-C 5H 3N), was prepared. Bis(thiophenolate)pyridine complexes of Ti, Zr, and Ta having dialkylamido coligands were synthesized and structurally characterized. The zirconium complex (SNS)Zr(NMe 2) 2 (4) displays C 2 symmetry in the solid state, unlike a related bis(phenolate)pyridine compound, C s-symmetric (ONO)Ti(NMe 2) 2. This change is likely the result of strain about the sulfur atom in the six-membered chelate with longer metal-sulfur and carbon-sulfur bonds. Solid-state structures of tantalum complexes (SNS)Ta(NMe 2) 3 (5) and (SNS)TaCl(NEt 2) 2 (6) also display pronounced C 2 twisting of the SNS ligand. 1D and 2D NMR experiments show that 5 is fluxional, with rotation about the Ta-N(amide) bonds occurring on the NMR time scale that interchange the equatorial amide methyl groups (ΔG ‡ 393 = 25.0(3) kcal/mol). The fluxional behavior of 6 in solution was also studied by variable-temperature 1H NMR. Observation of separate signals for the diastereotopic protons of the methylene unit of the diethylamide indicates that the complex remains locked on the NMR time scale in one diastereomeric conformation at temperatures below -50 °C, fast rotation about the equatorial amide Ta-N bonds occurs at higher temperature (ΔG ‡ 393 = 13.4(3) kcal/mol), and exchange of diastereomeric methylene protons occurs via inversion at Ta that interconverts antipodes (ΔG ‡ 393 ≈ 14(1) kcal/mol). © 2012 American Chemical Society.

  2. Reaction of pyridine-N-oxides with halogens; Vzaimodejstvie piridin-N-oksidov s galogenami

    Energy Technology Data Exchange (ETDEWEB)

    Kanibolotskij, A L; Mikhzajlov, V A; Savelova, V A [AN Ukrainskoj SSR, Donetsk (Ukraine). Inst. Fiziko-Organicheskoj Khimii i Uglekhimii

    1994-12-31

    By the methods of conductometry, NMR and IR spectroscopy it has been ascertained that interaction of pyridine-N-oxides with bromine, iodine and interhalides (ICl and IBr) gives rise to the formation of crystal complexes of 1:1 composition. The complexes mentioned are of presumably ionic structure: [RC{sub 5}H{sub 4}N-O...X...O-NC{sub 5}H{sub 4}R]{sup +}[Y-X-Y]{sup -},where X,Y = Cl,Br,I.

  3. A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex

    International Nuclear Information System (INIS)

    Arya, S. P.; Mahajan, M.

    1998-01-01

    A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 μg ml -1 . Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C [it

  4. Determination of low concentrations of pyridine in piperidine by gas chromatography and infrared spectroscopy

    International Nuclear Information System (INIS)

    Perez Garcia, M. M.; Parellada Bellod, R.

    1979-01-01

    This paper describes the determination of low amounts of piperidine in pyridine in the concentration range of 0-5%. After an exhausting review of the bibliography on the column selection, the chromatographic separation and determination are made on the following column: 27% Pennwalt- 223; 4% KOH on Gas-Chrom R; 80-100 mesh with flame ionization detector. The retention indexes of both compounds and tho Rohrschneider constants of the phase used are calculated. The minimum detection limit achieved for piperidine is 0,25%. (Author) 25 refs

  5. 5-Bromo-N3-[(E-(6-bromopyridin-2-ylmethylidene]pyridine-3,4-diamine

    Directory of Open Access Journals (Sweden)

    Mingjian Cai

    2011-12-01

    Full Text Available The title compound, C11H8Br2N4, is a Schiff base obtained from 6-bromopicolinaldehyde and 5-bromopyridine-3,4-diamine. The molecule has an E configuration about the C=N bond and the dihedral angle between the two pyridine rings is 14.02 (1°. The observed conformation is stabilised by an intramolecular N—H...N hydrogen bond. In the crystal, molecules are stacked along the b axis and are linked through N—H...N hydrogen bonds into chains along the c axis.

  6. (E-3-[5-(Diphenylaminothiophen-2-yl]-1-(pyridin-3-ylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Rui Li

    2013-09-01

    Full Text Available In the title compound, C24H18N2OS, the pyridine and the two phenyl rings are oriented at dihedral angles of 10.1 (5, 71.7 (6 and 68.7 (5°, respectively, to the central thiophene ring. In the crystal, pairs of weak C—H...O hydrogen bonds link inversion-related molecules, forming dimers. The dimers are linked by further weak C—H...O hydrogen bonds, forming chains running along the a-axis direction.

  7. Synthesis, spectroscopic and thermochemical studies of some novel carbazole-pyridine co-polymers (abstract)

    International Nuclear Information System (INIS)

    Saeed, A.; Irfan, M.

    2011-01-01

    Two series of a novel class of carbazole-4-phenylpyridine co-polymers has been synthesized by a modified Chichibabin reaction. The synthesis was carried out by a simple and cheaper method compared to the lengthy methods usually adopted for the preparation of carbazole-pyridine copolymers which involve costly catalysts. All the polymers were characterized by IR, /sup 1/H and /sup 13/C NMR, UV-vis spectroscopy, fluorimetry, TGA and DSC. The weight average molecular masses (M/sub w/) of the polymers were estimated by Laser Light Scattering (LLS) technique. (author)

  8. Ternary systems, consist of erbium nitrates, water and nitrates of pyridines, quinolines

    International Nuclear Information System (INIS)

    Starikova, L.I.; Zhuravlev, E.F.; Khalfina, L.R.

    1979-01-01

    At 25 and 50 deg C investigated is solubility of solid phases in ternary water salt systems: erbium nitrate-pyridine nitrate-water; erbium nitrate-quinoline nitrate-water. Formation of congruently soluble compounds of the Er(NO 3 ) 3 x2C 5 H 5 NxHNO 3 , Er(NO 3 ) 3 x2C 9 H 7 NxHNO 3 x4H 2 O composition is established. X-ray phase and thermogravimetric analyses have been carried out

  9. Oxidation reactivity channels for 2-(pyridin-2-yl)-N,N-diphenylacetamides

    Energy Technology Data Exchange (ETDEWEB)

    Pailloux, Sylvie; Binyamin, Iris; Deck, Lorraine M.; Rapko, Brian M.; Hay, Benjamin P.; Duesler, Eileen N.; Paine, Robert T.

    2007-11-01

    Synthetic routes to 2-(pyridin-2-yl)-N,N-diphenylacetamide and 2-(6-methylpyridin-2-yl)-N,N-diphenylacetamide are described along with results from the chemical oxidation of these compounds with peracetic acid, m-chloroperbenzoic acid, and OXONE. In each case, oxidations generate four products in varying amounts depending on the oxidant and reaction conditions. Each product has been characterized by spectroscopic methods and the molecular structures of several of the new compounds have been confirmed by X-ray crystallography.

  10. Oxidation Reactivity Channels for 2-(Pyridin-2-yl)-N,N-diphenyl-acetamides

    Energy Technology Data Exchange (ETDEWEB)

    Pailloux, Sylvie [University of New Mexico, Albuquerque; Binyamin, Iris [University of New Mexico, Albuquerque; Kim, Sung-jun [University of New Mexico, Albuquerque; Deck, Lorraine M. [University of New Mexico, Albuquerque; Rapko, Brian M. [Pacific Northwest National Laboratory (PNNL); Hay, Benjamin [ORNL; Duesler, Eileen N. [University of New Mexico, Albuquerque; Paine, Robert T. [University of New Mexico, Albuquerque

    2007-11-01

    Synthetic routes to 2-(pyridin-2-yl)-N,N-diphenylacetamide and 2-(6-methylpyridin-2-yl)-N,N-diphenyl-acetamide are described along with results from the chemical oxidation of these compounds with peracetic acid, m-chloroperbenzoic acid, and OXONE. In each case, oxidations generate four products in varying amounts depending on the oxidant and reaction conditions. Each product has been characterized by spectroscopic methods and the molecular structures of several of the new compounds have been confirmed by X-ray crystallography.

  11. 2,3-Diamino?pyridinium 6-carb?oxy?pyridine-2-carboxyl?ate

    OpenAIRE

    Foroughian, Mahsa; Foroumadi, Alireza; Notash, Behrouz; Bruno, Giuseppe; Amiri Rudbari, Hadi; Aghabozorg, Hossein

    2011-01-01

    The asymmetric unit of the title proton-transfer compound, C5H8N3+·C7H4NO4−, consists of one mono-deprotonated pyridine-2,6-dicarboxylic acid as anion and one protonated 2,3-diaminopyridine as cation. The crystal packing shows extensive O—H...O, N—H...O and N—H...N hydrogen bonds. Thre are also several π–π interactions between the anions and also between the cations [centriod–centroid distances = 3.6634&...

  12. Butylbis(diphenylglyoximato(pyridine-κNcobalt(IIIThis article is dedicated to late Professor B. D. Gupta.

    Directory of Open Access Journals (Sweden)

    Sarvendra Kumar

    2012-02-01

    Full Text Available In the title compound, [Co(C4H9(C14H11N2O22(C5H5N], the CoIII atom is coordinated by a butyl group, a nitrogen-bonded pyridine and two N,N′-bidentate diphenylglyoximate ligands in a distorted octahedral geometry. The crystal structure features two short O—H...O bridges between the two chelating anions, with O...O distances less than 2.5 Å.

  13. Synthesis of 2,4,6-Trisubstituted Pyridines by Oxidative Eosin Y Photoredox Catalysis.

    Science.gov (United States)

    Rohokale, Rajendra S; Koenig, Burkhard; Dhavale, Dilip D

    2016-08-19

    Eosin Y, an organic dye, was activated as a photoredox catalyst in the presence of molecular oxygen using visible light and, when it was used in the reaction of aryl ketones and benzyl amines, afforded good yields (52-87%) of 2,4,6-triarylpyridines (21 examples) at ambient temperature. The aryl groups at the 2- and 6-positions are derived from ketones, while benzyl amine plays the dual role of providing an aryl functionality at the 4-position of pyridine as well as being a nitrogen donor.

  14. Synthesis of modified pyridine and bipyridine substituted coumarins as potent antimicrobial agents

    Directory of Open Access Journals (Sweden)

    Lad Hemali B.

    2015-01-01

    Full Text Available In search for new antimicrobial agents a series of new modified pyridine and bipyridine substituted coumarins 5a-y was designed and synthesized by adopting molecular hybridization strategy. All the synthesized compounds were evaluated for their in vitro antimicrobial activity using broth dilution method against selected bacterial (Gram-positive and Gram-negative and fungal strains. Compounds 5a, 5f, 5g, 5n, 5r, 5t, 5w, 5x and 5y demonstrated promising antibacterial activity while other derivatives showed comparable activity to standard drugs used as reference.

  15. Complexation of thorium with pyridine monocarboxylates: A thermodynamic study by experiment and theory

    International Nuclear Information System (INIS)

    Rama Mohana Rao, D.; Rawat, Neetika; Manna, D.; Sawant, R.M.; Ghanty, T.K.; Tomar, B.S.

    2013-01-01

    Highlights: ► The thermodynamic parameters have been determined for the first time. ► The Th-picolinate complexation was exothermic in nature. ► The complexation of Th(IV) with the other two isomers was endothermic process. ► Isonicotinate forms stronger complexes than nicotinate with Th(IV). ► The theoretically calculated values are in line with the experimental results. -- Abstract: Complexation of thorium with pyridine monocarboxylates namely picolinic acid (pyridine-2-carboxylic acid), nicotinic acid (pyridine-3-carboxylic acid) and isonicotinic acid (pyridine-4-carboxylic acid) has been studied by potentiometry and calorimetry to determine the thermodynamic parameters (log K, ΔG, ΔH and ΔS) of complexation. All the studies were carried out at 1.0 M ionic strength adjusted by NaClO 4 and at a temperature of 298 K. The detailed analysis of potentiometric data by Hyperquad confirmed the formation of four complexes, ML i (i = 1–4) in case of picolinate but only one complex (ML) in case of nicotinate and isonicotinate. The stepwise formation constant for ML complex (log K ML ) of thorium-picolinate is higher than those of thorium-nicotinate and thorium-isonicotinate complexes. Further the changes in enthalpy during formation of thorium-picolinate complexes are negative whereas the same for the complexes of thorium with the other two isomers was positive. This difference in the complexation process is attributed to chelate formation in case of thorium-picolinate complexes in which the thorium ion is bound to the picolinate through both the nitrogen in the pyridyl ring and one of the carboxylate oxygen atoms. The complexation process of thorium-nicotinate and thorium-isonicotinate are found to be endothermic in nature and are entropy driven confirming the similar binding nature as in simple carboxylate complexes of thorium. The complexation energies, bond lengths and charges on each atom in the complexes of various possible geometries were calculated

  16. Systems of pyridine, piperidine, piperazine, morpholine hydrochlorides-terbium (dysprosium) chloride-water

    International Nuclear Information System (INIS)

    Gajfutdinova, R.K.; Sharafutdinova, A.A.; Murinov, Yu.I.

    1988-01-01

    The isothermal cross section method at 25 and 50 deg C is applied to study pyridine hydrochloride-terbium chloride-water (1) piperidine hydrochloride-dysprosium chloride-water (2), piperazine dihydrochloride-dysprosium chloride-water (3) and morpholine hydrochloride-terbium chloride (4) systems. Solubility isotherma prove the formation of incongruently soluble compound of the TbCl 3 x6C 5 H 5 NxHCl composition systems (1). The individuality of the new solid phase is proved by the chemical and DTA methods. Systems (2-4) are of a simple eutonic type

  17. Oppositines A and B, Sesquiterpene Pyridine Alkaloids from a Sri Lankan Pleurostylia opposita

    Science.gov (United States)

    Whitson, Emily L.; Mala, S.M.V. Damayanthi; Veltri, Charles. A.; Bugni, Tim S.; de Silva, E. Dilip; Ireland, Chris M.

    2008-01-01

    Two new sesquiterpene pyridine alkaloids, oppositines A (1) and B (2), have been isolated from the plant, Pleurostylia opposita (Celastraceae), collected in Sri Lanka. The compounds were isolated and purified by solvent/solvent partitioning, column chromatography and HPLC. Their structures were assigned on the basis of extensive 1D and 2D NMR studies as well as analysis by HRESIMS. Oppositines A (1) and B (2) showed moderate cytotoxicity against HCT116 cell lines with EC50 values of 27 ± 2 and 26 ± 3 μM, respectively. PMID:17190474

  18. Bis(2-hydroxy-N′-isopropylidenebenzohydrazidato-κ2N′,Obis(pyridine-κNcobalt(II

    Directory of Open Access Journals (Sweden)

    Xiaojuan Zhao

    2009-04-01

    Full Text Available In the title complex, [Co(C10H11N2O22(C5H5N2], the CoII atom lies on a centre of symmetry and adopts a distorted cis-CoO2N4 octahedral geometry. The two acetone salicyloylhydrazone ligands are deprotonated and act as N,O-bidentate monoanionic ligands, forming the equatorial plane, while the axial positions are occupied by two N atoms of two pyridine molecules. The complex presents O—H...N and C—H...N intramolecular hydrogen bonds. Intermolecular C—H...N and C—H...O interactions are also present in the crystal.

  19. fac-Tris(pyridine-2-carboxylato-κ2N,Ocobalt(III

    Directory of Open Access Journals (Sweden)

    Irina A. Golenia

    2011-11-01

    Full Text Available In the title compound, [Co(C6H4NO23], the CoIII ion lies on a threefold rotation axis and is in a distorted octahedral environment defined by three N and three O donor atoms from three fac-disposed pyridine-2-carboxylate ligands. The ligands are coordinated in a chelate fashion, forming three five-membered rings. In the crystal, translationally related complex molecules are organized into columns along [001] via C—H...O hydrogen bonds.

  20. fac-Tris(pyridine-2-carboxyl­ato-κ2 N,O)cobalt(III)

    Science.gov (United States)

    Golenia, Irina A.; Boyko, Alexander N.; Kotova, Natalia V.; Haukka, Matti; Kalibabchuk, Valentina A.

    2011-01-01

    In the title compound, [Co(C6H4NO2)3], the CoIII ion lies on a threefold rotation axis and is in a distorted octa­hedral environment defined by three N and three O donor atoms from three fac-disposed pyridine-2-carboxyl­ate ligands. The ligands are coordinated in a chelate fashion, forming three five-membered rings. In the crystal, translationally related complex molecules are organized into columns along [001] via C—H⋯O hydrogen bonds. PMID:22219826

  1. Synthesis of new pyrrole–pyridine-based ligands using an in situ Suzuki coupling method

    Directory of Open Access Journals (Sweden)

    Matthias Böttger

    2012-07-01

    Full Text Available The compounds 6-(pyrrol-2-yl-2,2‘-bipyridine, 2-(pyrrol-2-yl-1,10-phenanthroline and 2-(2-(N-methylbenz[d,e]imidazole-6-(pyrrol-2-yl-pyridine were synthesized by using an in situ generated boronic acid for the Suzuki coupling. Crystals of the products could be grown and exhibited interesting structures by X-ray analysis, one of them showing a chain-like network with the adjacent molecules linked to each other via intermolecular N–H…N hydrogen bonds.

  2. Computational, electrochemical, and spectroscopic studies of two mononuclear cobaloximes: the influence of an axial pyridine and solvent on the redox behaviour and evidence for pyridine coordination to cobalt(I) and cobalt(II) metal centres†

    Science.gov (United States)

    Lawrence, Mark A. W.; Celestine, Michael J.; Artis, Edward T.; Joseph, Lorne S.; Esquivel, Deisy L.; Ledbetter, Abram J.; Cropek, Donald M.; Jarrett, William L.; Bayse, Craig A.; Brewer, Matthew I.; Holder, Alvin A.

    2018-01-01

    [Co(dmgBF2)2(H2O)2] 1 (where dmgBF2 = difluoroboryldimethylglyoximato) was used to synthesize [Co(dmgBF2)2(H2O)(py)]·0.5(CH3)2CO 2 (where py = pyridine) in acetone. The formulation of complex 2 was confirmed by elemental analysis, high resolution MS, and various spectroscopic techniques. The complex [Co(dmgBF2)2(solv)(py)] (where solv = solvent) was readily formed in situ upon the addition of pyridine to complex 1. A spectrophotometric titration involving complex 1 and pyridine proved the formation of such a species, with formation constants, log K = 5.5, 5.1, 5.0, 4.4, and 3.1 in 2-butanone, dichloromethane, acetone, 1,2-difluorobenzene/acetone (4 : 1, v/v), and acetonitrile, respectively, at 20 °C. In strongly coordinating solvents, such as acetonitrile, the lower magnitude of K along with cyclic voltammetry, NMR, and UV-visible spectroscopic measurements indicated extensive dissociation of the axial pyridine. In strongly coordinating solvents, [Co(dmgBF2)2(solv)(py)] can only be distinguished from [Co(dmgBF2)2(solv)2] upon addition of an excess of pyridine, however, in weakly coordinating solvents the distinctions were apparent without the need for excess pyridine. The coordination of pyridine to the cobalt(II) centre diminished the peak current at the Epc value of the CoI/0 redox couple, which was indicative of the relative position of the reaction equilibrium. Herein we report the first experimental and theoretical 59Co NMR spectroscopic data for the formation of Co(I) species of reduced cobaloximes in the presence and absence of py (and its derivatives) in CD3CN. From spectroelectrochemical studies, it was found that pyridine coordination to a cobalt(I) metal centre is more favourable than coordination to a cobalt(II) metal centre as evident by the larger formation constant, log K = 4.6 versus 3.1, respectively, in acetonitrile at 20 °C. The electrosynthesis of hydrogen by complexes 1 and 2 in various solvents demonstrated the dramatic effects of the axial

  3. Reactivity of N-heterocyclic carbene-pyridine palladacyclopentadiene complexes toward halogen addition. The unpredictable course of the reaction.

    Science.gov (United States)

    Visentin, Fabiano; Santo, Claudio; Scattolin, Thomas; Demitri, Nicola; Canovese, Luciano

    2017-08-08

    As an extension of a previously published work we have reacted some palladacyclopentadiene complexes stabilized by bidentate N-heterocyclic carbene-pyridine or monodentate N-heterocyclic carbene-pyridine and isocyanide ligands with the halogens I 2 and Br 2 . All the bidentate and monodentate complexes react with halogens to give at first the expected σ-coordinated butadienyl fragment. However, two of the less hindered NHC carbene-pyridine bidentate butadienyl iodo derivatives undergo a further rearrangement and novel Pd(ii) complexes characterized by a ten term coordinative ring were isolated and characterized. In the most favorable case we were able to carry out the kinetics of rearrangement and measure its reaction rate. Moreover, we have surmised a plausible mechanism on the basis of a dedicated computational approach and in one case the surprising structure characterized by the ten term coordinative ring was resolved by X-ray diffraction.

  4. catena-Poly[[bromidocopper(I)]-?-?2,?1-3-(2-allyl-2H-tetra?zol-5-yl)pyridine

    OpenAIRE

    Wang, Wei

    2008-01-01

    The title compound, [CuBr(C9H9N5)] n , has been prepared by the solvothermal treatment of CuBr with 3-(2-allyl-2H-tetra?zol-5-yl)pyridine. It is a new homometallic CuI olefin coord?ination polymer in which the CuI atoms are linked by the 3-(2-allyl-2H-tetra?zol-5-yl)pyridine ligands and bonded to one terminal Br atom each. The organic ligand acts as a bidentate ligand connecting two neighboring Cu centers through the N atom of the pyridine ring and the double bond of the allyl group. A three-...

  5. Carbon dioxide is tightly bound in the [Co(Pyridine)(CO{sub 2})]{sup −} anionic complex

    Energy Technology Data Exchange (ETDEWEB)

    Graham, Jacob D.; Buytendyk, Allyson M.; Zhang, Xinxing; Bowen, Kit H., E-mail: kbowen@jhu.edu [Department of Chemistry, Johns Hopkins University, Baltimore, Maryland 21218 (United States); Kim, Seong K. [Department of Chemistry, Seoul National University, Seoul 151-747 (Korea, Republic of)

    2015-11-14

    The [Co(Pyridine)(CO{sub 2})]{sup −} anionic complex was studied through the combination of photoelectron spectroscopy and density functional theory calculations. This complex was envisioned as a primitive model system for studying CO{sub 2} binding to negatively charged sites in metal organic frameworks. The vertical detachment energy (VDE) measured via the photoelectron spectrum is 2.7 eV. Our calculations imply a structure for [Co(Pyridine)(CO{sub 2})]{sup −} in which a central cobalt atom is bound to pyridine and CO{sub 2} moieties on either sides. This structure was validated by acceptable agreement between the calculated and measured VDE values. Based on our calculations, we found CO{sub 2} to be bound within the anionic complex by 1.4 eV.

  6. Analysis of denitrifier community in a bioaugmented sequencing batch reactor for the treatment of coking wastewater containing pyridine and quinoline

    Energy Technology Data Exchange (ETDEWEB)

    Bai, Yaohui; Xing, Rui; Wen, Donghui; Tang, Xiaoyan [Peking Univ., Beijing (CN). Key Lab. of Water and Sediment Sciences (Ministry of Education); Sun, Qinghua [Peking Univ., Beijing (CN). Key Lab. of Water and Sediment Sciences (Ministry of Education); Chinese Center for Disease Control and Prevention, Beijing (China). Inst. of Environmental Health and Related Product Safety

    2011-05-15

    The denitrifier community and associated nitrate and nitrite reduction in the bioaugmented and general sequencing batch reactors (SBRs) during the treatment of coking wastewater containing pyridine and quinoline were investigated. The efficiency and stability of nitrate and nitrite reduction in SBR was considerably improved after inoculation with four pyridine- or quinoline-degrading bacterial strains (including three denitrifying strains). Terminal restriction fragment length polymorphism (T-RFLP) based on the nosZ gene revealed that the structures of the denitrifier communities in bioaugmented and non-bioaugmented reactors were distinct and varied during the course of the experiment. Bioaugmentation protected indigenous denitrifiers from disruptions caused by pyridine and quinoline. Clone library analysis showed that one of the added denitrifiers comprised approximately 6% of the denitrifier population in the bioaugmented sludge. (orig.)

  7. The study of interaction of lanthanum-, cerium- and neodymium chlorides with sodium borohydride in pyridine- and tetrahydrofuran medium

    International Nuclear Information System (INIS)

    Mirsaidov, U.; Rotenberg, T.G.; Dymova, T.N.

    1976-01-01

    Bis-tetrahydrofurans of lanthanum and neodymium borohydrides and bis-pyridinates of lanthanum, cerium and neodymium borohydrides were obtained by interacting sodium borohydride with lanthanum-, cerium and neodymium chlorides in pyridine and tetrahydrofuran media. All operations involving reagent combination, sampling and phase separation are performed in inert atmosphere using argonvacuum equipment. The reaction in pyridine was virtually instantaneous and accompanied by flocculanet precipitation. The interaction of lanthanum chloride and neodymium chloride with sodium borohydride in tetrahydrofuran (THF) was a slow (23-30 hr) heterophase process. The interaction rate was affected by size reduction of the intial substances, temperature, reagent proportion and mixing rate. The reaction time was twice reduced with boiling tetrahydrofuran

  8. Interaction between poly(vinyl pyridine) and poly(2,6-dimethyl-1,4-phenylene oxide) : A copolymer blend miscibility study

    NARCIS (Netherlands)

    de Wit, Joost; van Ekenstein, Gert Alberda; ten Brinke, Gerrit

    2007-01-01

    The phase behavior of blends of poly(2,6-dimethyl-1,4-phenylene oxide) (PPO) with random copolymers of styrene and 2-vinyl pyridine, Poly(S-co-2VP), as well as with random copolymers of styrene and 4-vinyl pyridine, Poly(S-co-4VP), has been investigated in order to estimate the values of the

  9. Diphenyl (4′-(Aryldiazenylbiphenyl-4-ylamino(pyridin-3-ylmethylphosphonates as Azo Disperse Dyes for Dyeing Polyester Fabrics

    Directory of Open Access Journals (Sweden)

    Mohamed F. Abdel-Megeed

    2013-01-01

    Full Text Available Diphenyl (4′-aminobiphenyl-4-ylamino(pyridin-3-ylmethylphosphonate (1 was synthesized in 88% yield from reaction of pyridine-3-carboxaldehyde with benzidine and triphenylphosphite in the presence of titanium tetrachloride as a catalyst. Diazotization of 1 gave the corresponding diazonium salt 2 which was coupled with several hydroxyl or amino compounds to give the corresponding azo dyes 3–8 in 82–88% yields after crystallization. The dyes produced were applied to polyesters as disperse dyes and their fastness properties were elevated.

  10. Crystal structure of [tris(pyridin-2-ylmethyl)amine-κ4N]copper(II) bromide

    OpenAIRE

    Emma C. Bridgman; Megan M. Doherty; Kaleigh A. Ellis; Elizabeth A. Homer; Taylor N. Lashbrook; Margaret E. Mraz; Gina C. Pernesky; Emma M. Vreeke; Kayode D. Oshin; Allen G. Oliver

    2016-01-01

    In the asymmetric unit of the title compound, [CuBr(C18H18N4)]Br, there are three crystallographically independent cations. One of the cations exhibits positional disorder of the pyridin-2-yl?methyl groups over two sets of sites with refined occupancies of 0.672?(8) and 0.328?(8). The outer-sphere bromine counter-ion is severely disordered over multiple sites. In each cation, the CuII ion is coordinated by the four N atoms of the tris?(pyridin-2-ylmeth?yl)amine ligand and one bromine and adop...

  11. FT-IR Spectroscopic study on the 4-(3-Cyclohexen-1-yl)pyridine metal (II) tetracyanonickelate complex

    International Nuclear Information System (INIS)

    Parlak, C.

    2005-01-01

    New Hofmann type complex in the form of M(4-Chpy) 2 Ni(CN) 4 (where 4-Chpy=4-(3- Cyclohexen-1-yl)pyridine and M = Ni) was prepared in powder form and its infrared spectra is reported in the range of 4000-400 cm - 1. The spectral findings suggest that this compound is similar in structure to the Hofmann type complexes and its structure consists of polymeric layers | M-Ni(CN) 4 |∞ with the 4-(3-Cyclohexen-1-yl)pyridine molecule bound to the metal atom (M)

  12. SYNTHESIS AND CHARACTERIZATION OF NEW THERMALLY STABLE POLYAMIDES BASED ON 2,5-PYRIDINE DICARBOXYLIC ACID AND AROMATIC DIAMINES

    OpenAIRE

    FAGHIHI, KHALIL

    2009-01-01

    Six new thermally stable polyamides 3a-f were synthesized through the polycondensation reaction of 2,5-pyridine dicarboxylic acid 1 with six different derivatives of aromatic diamines 2a-f in amedium consisting of N-methyl-2-pyrrolidone, triphenyl phosphite, calcium chloride and pyridine. The polycondensation reaction produced a series of novel polyamides containing pyridyl moieties in the main chain in high yield with inherent viscosities between 0.50-0.82 dL/g. The resulting polymers were f...

  13. Molecular dynamics simulations of ter-pyridine, BTP, and their complexes with La3+, Eu3+ and Lu3+

    International Nuclear Information System (INIS)

    Guilbaud, P.; Dognon, J.P.

    2000-01-01

    This poster presents molecular dynamics simulations performed to study ter-pyridine and bis-triazinyl-pyridine with lanthanide cations for the gas phase and for water solution. Different counter-ions have been tested in order to assess their influence on complexes structures and stabilities in both phases. For stable complexes, Gibbs free energy calculations have been achieved to estimate the selectivity of these complexes towards the lanthanide cations. Finally, some tests have been done adding a polarization term in the potential energy in order to have a more precise description of interaction energies. (authors)

  14. FTIR investigation of the reaction between pyridine and iodine in a polyethylene host. Formation of N-iodopyridinium polyiodide

    DEFF Research Database (Denmark)

    Karlsen, Eva; Spanget-Larsen, Jens

    2009-01-01

    The reaction between pyridine and I2 in a low-density polyethylene (LDPE) host is investigated by FTIR vibrational spectroscopy in the mid- and far-IR regions. The investigation is supported by linear dichroism measurements on stretched LDPE samples, and by the results of quantum chemical density...... functional theoretical (DFT) calculations. Unlike the situation in liquid alkane solutions, pyridine and I2 dissolved in LDPE react to form N-iodopyridinium polyiodide. The ionic reaction is particularly efficient in stretched LDPE, suggesting that the reaction cavities in the stretched polymer catalyze...

  15. Synthesis of polysubstituted 4,5,6,7-tetrahydrofuro[2,3-c]pyridines by a novel multicomponent reaction.

    Science.gov (United States)

    Fayol, Aude; Zhu, Jieping

    2004-01-08

    [reaction: see text] A novel three-component synthesis of tetrahydrofuro[2,3-c]pyridines from readily accessible starting materials is described. Simply heating a toluene solution of an aminopentynoate, an aldehyde, and an alpha-isocyanoacetamide in the presence of ammonium chloride provided the 4,5,6,7-tetrahydrofuro[2,3-c]pyridines in good to excellent yield. The fused ring system is produced in this one-pot process by the concomitant formation of five chemical bonds.

  16. Pyridine substituted spirofluorene derivative as an electron transport material for high efficiency in blue organic light-emitting diodes

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Soon Ok; Yook, Kyoung Soo; Lee, Jun Yeob, E-mail: leej17@dankook.ac.k

    2010-11-01

    The quantum efficiency of blue fluorescent organic light-emitting diodes was enhanced by 20% using a pyridine substituted spirofluorene-benzofluorene derivative as an electron transport material. 2',7'-Di(pyridin-3-yl)spiro[benzofluorene-7,9'-fluorene] (SPBP) was synthesized and it was used as the electron transport material to block the hole leakage from the emitting layer. The improvement of the quantum efficiency and power efficiency of the blue fluorescent organic light-emitting diodes using the SPBP was investigated.

  17. Magnetic resonance studies of solid polymers; Etude des polymeres solides par resonance magnetique

    Energy Technology Data Exchange (ETDEWEB)

    Lenk, R [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    This paper is a review of the application of nuclear magnetic resonance (NMR) to solid polymers. In the first, theoretical part, the elements of the theory of NMR, which are necessary for the study of the properties of solid polymers are discussed: the moments method, nuclear relaxation and the distribution of correlation times. In the second part the experimental results are presented. (author) [French] Cette etude est une recherche bibliographique sur l'application de la resonance magnetique nucleaire (RMN) aux polymeres solides. Dans la premiere partie theorique on discute les elements de la theorie de RMN, necessaires pour l'etude des proprietes des polymeres solides: la methode des moments, la relaxation nucleaire et la distribution des temps de correlation. La deuxieme partie presente les resultats des experiences. (auteur)

  18. Coordination chemistry of gadolinium complexes having pyridine carboxylate units in relation with the medical imagery

    International Nuclear Information System (INIS)

    Gateau, C.; Chatterton, N.; Nonat, A.; Mazzanti, M.; Pecaut, J.; Borel, A.; Merbach, A.; Heim, L.

    2005-01-01

    In order to study the influence of the coordination sphere on the properties which govern the relaxivity, ligands containing pyridine carboxylates units have been particularly studied. It has been shown that the tripodal ligand tpaa forms with gadolinium (III) a neutral complex having a relaxivity (r1p=13.3 mM -1 at 298 K and 60 MHz) which is three times superior to the contrast agents currently used in NMR Imaging. To explain this remarkably relaxivity, two new ligands analogous to the tpaa: the tpatcn and the bpeda containing pyridine carboxylate units bound to one or several aliphatic nitrogen have been studied in modulating the number of coordination sites and the symmetry degree. The study of the relaxivity of the corresponding gadolinium (III) complexes gives precious data on the understanding of the results in the case of the complex [Gd(tpaa)]. The synthesis and the properties of these gadolinium (III) complexes will be presented during this conference. (O.M.)

  19. Biotransformation of fluorophenyl pyridine carboxylic acids by the model fungus Cunninghamella elegans.

    Science.gov (United States)

    Palmer-Brown, William; Dunne, Brian; Ortin, Yannick; Fox, Mark A; Sandford, Graham; Murphy, Cormac D

    2017-09-01

    1. Fluorine plays a key role in the design of new drugs and recent FDA approvals included two fluorinated drugs, tedizolid phosphate and vorapaxar, both of which contain the fluorophenyl pyridyl moiety. 2. To investigate the likely phase-I (oxidative) metabolic fate of this group, various fluorinated phenyl pyridine carboxylic acids were incubated with the fungus Cunninghamella elegans, which is an established model of mammalian drug metabolism. 3.  19 F NMR spectroscopy established the degree of biotransformation, which varied depending on the position of fluorine substitution, and gas chromatography-mass spectrometry (GC-MS) identified alcohols and hydroxylated carboxylic acids as metabolites. The hydroxylated metabolites were further structurally characterised by nuclear magnetic resonance spectroscopy (NMR), which demonstrated that hydroxylation occurred on the 4' position; fluorine in that position blocked the hydroxylation. 4. The fluorophenyl pyridine carboxylic acids were not biotransformed by rat liver microsomes and this was a consequence of inhibitory action, and thus, the fungal model was crucial in obtaining metabolites to establish the mechanism of catabolism.

  20. Changes in pyridine metabolism profile during growth of trigonelline-forming Lotus japonicus cell cultures.

    Science.gov (United States)

    Yin, Yuling; Matsui, Ayu; Sakuta, Masaaki; Ashihara, Hiroshi

    2008-12-01

    Changes in the profile of pyridine metabolism during growth of cells were investigated using trigonelline-forming suspension-cultured cells of Lotus japonicus. Activity of the de novo and salvage pathways of NAD biosynthesis was estimated from the in situ metabolism of [(3)H] quinolinic acid and [(14)C] nicotinamide. Maximum activity of the de novo pathway for NAD synthesis was found in the exponential growth phase, whereas activity of the salvage pathway was increased in the lag phase of cell growth. Expression profiles of some genes related to pyridine metabolism were examined using the expression sequence tags obtained from the L. japonicus database. Transcript levels of NaPRT and NIC, encoding salvage enzymes, were enhanced in the lag phase of cell growth, whereas the maximum expression of NADS was found in the exponential growth phase. Correspondingly, the activities of the salvage enzymes, nicotinate phosphoribosyltransferase (EC 2.4.2.11) and nicotinamidase (EC 3.5.1.19), increased one day after transfer of the stationary phase cells to the fresh medium. The greatest in situ trigonelline synthesis, both from [(3)H] quinolinic acid and [(14)C] nicotinamide, was found in the stationary phase of cell growth. The role of trigonelline in leguminous plants is discussed.

  1. Fluorescent chemosensor for pyridine based on N-doped carbon dots.

    Science.gov (United States)

    Campos, B B; Abellán, C; Zougagh, M; Jimenez-Jimenez, J; Rodríguez-Castellón, E; Esteves da Silva, J C G; Ríos, A; Algarra, M

    2015-11-15

    Fluorescent carbon dots (CDs) and its nitrogen doped (N-CDs) nanoparticles have been synthesized from lactose as precursor using a bottom-up hydrothermal methodology. The synthesized nanoparticles have been characterized by elemental analysis, FTIR, Raman, TEM, DLS, XPS, and steady-state and life-time fluorescence. The synthesized carbon nanoparticles, CDs and N-CDs, have a size at about 7.7±2.4 and 50±15nm, respectively, and quantum yields of 8% (CDs) and 11% (N-CDs). These techniques demonstrated the effectiveness of the synthesis procedure and the functionalization of the CDs surface with amine and amide groups in the presence of NH3 in aqueous media. The effect of excitation wavelength and pH on the luminescent properties was studied. Under the optimal conditions, the nitrogen doped nanoparticles can be used as pyridine sensor in aqueous media because they show an enhancement of its fluorescence with a good linear relationship. The analytical method is simple, reproducible and very sensitive for pyridine determination. Copyright © 2015 Elsevier Inc. All rights reserved.

  2. Synthesis of schiff bases of pyridine-4-carbaldehyde and their antioxidant and DNA binding studies

    International Nuclear Information System (INIS)

    Shamim, S.; Murtaza, S.; Nazar, M.F.

    2016-01-01

    A series of Schiff bases of pyridine-4-carbaldehyde with 3-aminobenzoic acid, 2-aminobenzoic acid, 4-aminobenzoic acid, 1,3-phenylenediamine, 1,2-phenylenediamine, 2-aminothiophenol, 4-aminoantipyrene, 2-aminophenol and naphthalene-1-amine was synthesized and compounds were characterized by FTIR, NMR and mass spectrometry. The synthesized compounds were evaluated for their antioxidant and DNA binding interaction studies. DPPH scavenging method was used to evaluate the antioxidant activities of synthesized Schiff bases at six gradually increasing concentrations of 0.5-5mg/ml. 2-((pyridin-4-ylmethylidene)amino)phenol came out to be the most efficient antioxidant at a concentration of 4mg/ml with 74% inhibition of free radicals generated by DPPH. The DNA binding interaction of the synthesized Schiff bases was determined using UV-Vis absorption titration method. Both the hypochromic and hyperchromic effects were observed along the series. The values for the binding constant (K) and free energy change (G) were calculated and most of the Schiff bases have high positive K values which indicate the efficient binding of Schiff bases with DNA. Molecular docking studies as carried out using PatchDock molecular algorithm software also indicated the high values for geometrical shape complementarity score suggesting the stabilities of Schiff bases/DNA complex. Docking studies also suggested the minor groove binding of the Schiff bases with DNA. Drug-likeness of the synthesized compounds was also tested in silico and the results are accordingly discussed. (author)

  3. Sulfonated poly(ether sulfone)s containing pyridine moiety for PEMFC.

    Science.gov (United States)

    Jang, Hohyoun; Islam, Md Monirul; Lim, Youngdon; Hossain, Md Awlad; Cho, Younggil; Joo, Hyunho; Kim, Whangi; Jeon, Heung-Seok

    2014-10-01

    Sulfonated poly(ether sulfone)s with varied degree of sulfonation (DS) were prepared via post-sulfonation of synthesized pyridine based poly(ether sulfone) (PPES) using concentrated sulfuric acid as sulfonating agent. The DS was varied with different mole ratio of 4,4'-(2,2-diphenylethenylidene)diphenol, DHTPE in the polymer unit. PPES copolymers were synthesized by direct polycondensation of pyridine unit with bis-(4-fluorophenyl)-sulfone, 4, 4'-sulfonyldiphenol and DHTPE. The structure of the resulting PPES copolymer membranes with different sulfonated units were studied by 1H NMR spectroscopy and thermogravimetric analysis (TGA). Sorption experiments were conducted to observe the interaction of sulfonated polymer with water. The ion exchange capacity (IEC) and proton conductivity were evaluated according to the increase of DS. The water uptake (WU) of the resulting membranes was in the range of 17-58%, compared to that of Nafion 211 28%. The membranes provided proton conductivities of 65-95 mS/cm in contrast to 103 mS/cm of Nafion 211.

  4. Pyridine-2,6-diyl dinitroxides as room-temperature triplet ligands

    Energy Technology Data Exchange (ETDEWEB)

    Kawakami, Hinako; Tonegawa, Asato; Ishida, Takayuki, E-mail: takayuki.ishida@uec.ac.jp [Department of Engineering Science, The University of Electro-Communications, Tokyo (Japan)

    2016-02-01

    We have proposed tert-butyl 2-pyridyl nitroxide radicals as a promising paramagnetic chelating ligand, where the direct radical-metal bond leads to strong magnetic interaction. We successfully synthesized and isolated PyBN derivatives (pyridine-2,6-diyl bis(tert-butyl nitroxides)). The molecular and crystal structures of the target biradicals, MesPyBN, AntPyBN and tBuOPyBN were determined from the X-ray crystal structure analysis, which possess mesityl, 9-anthryl and tert-butoxy groups at the 5-position of the pyridine ring, respectively. The ground triplet state was characterized by means of SQUID susceptometry for each compound. On heating, the χ{sub m}T values of all the PyBN derivatives increased and reached a plateau at ca. 1.0 cm{sup 3} K mol{sup −1} at 300 K. It implies that biradicals behaved as triplet molecules even at room temperature, or 2J/k{sub B} >> 300 K. From the decay monitored in solution electron-spin resonance spectroscopy, MesPyBN was the most persistent, while tBuOPyBN was the most reactive, of the three.

  5. Pyridine-type alkaloid composition affects bacterial community composition of floral nectar.

    Science.gov (United States)

    Aizenberg-Gershtein, Yana; Izhaki, Ido; Santhanam, Rakesh; Kumar, Pavan; Baldwin, Ian T; Halpern, Malka

    2015-06-30

    Pyridine-type alkaloids are most common in Nicotiana species. To study the effect of alkaloid composition on bacterial community composition in floral nectar, we compared the nicotine-rich wild type (WT) N. attenuata, the nicotine biosynthesis-silenced N. attenuata that was rich in anatabine and the anabasine-rich WT N. glauca plants. We found that the composition of these secondary metabolites in the floral nectar drastically affected the bacterial community richness, diversity and composition. Significant differences were found between the bacterial community compositions in the nectar of the three plants with a much greater species richness and diversity in the nectar from the transgenic plant. The highest community composition similarity index was detected between the two wild type plants. The different microbiome composition and diversity, caused by the different pyridine-type alkaloid composition, could modify the nutritional content of the nectar and consequently, may contribute to the change in the nectar consumption and visitation. These may indirectly have an effect on plant fitness.

  6. Dithiafulvene-based organic sensitizers using pyridine as the acceptor for dye-sensitized solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Cheng, Jun; Cao, Yaxiong; Liang, Xiaozhong; Zheng, Jingxia; Zhang, Fang [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Wei, Shuxian; Lu, Xiaoqing [College of Science, China University of Petroleum, Qingdao, Shandong 266555 (China); Guo, Kunpeng, E-mail: guokunpeng@tyut.edu.cn [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Yang, Shihe, E-mail: chsyang@ust.hk [Ministry of Education Key Laboratory of Interface Science and Engineering in Advanced Materials, Research Center of Advanced Materials Science and Technology, Taiyuan University of Technology, Taiyuan 030024 (China); Department of Chemistry, The Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong (China)

    2017-05-01

    Three dithiafulvene-based metal-free organic sensitizers all using pyridine as the acceptor but with different π-bridges of phenyl (DTF-Py1), thienyl (DTF-Py2) and phenyl-thienyl (DTF-Py3) have been designed, synthesized and used as photosensitizers for dye-sensitized solar cells (DSCs). Introducing thienyl unit into the π-bridge, as well as extension of the π-bridge can dramatically improve their light harvesting ability and suppress the electron recombination, thus uplifting the performance of DSCs. The overall power conversion efficiency of DSC based on DTF-Py3 shows the highest efficiency of 2.61% with a short-circuit photocurrent density of 7.99 mA cm{sup -2}, an open-circuit photovoltage of 630 mV, and a fill factor of 0.52, under standard global AM 1.5 solar light condition. More importantly, the long-term stability of the DTF-Py3 based DSCs under 500 h light-soaking has been demonstrated. - Highlights: • Dithiafulvene sensitizers using pyridine ring as the acceptor were synthesized for the first time. • The power conversion efficiency of 2.61% was obtained for DTF-Py3 sensitized cell. • DTF-Py3 loaded TiO{sub 2} film shows improved light harvesting ability and suppressed electron recombination.

  7. Aerobic granulation strategy for bioaugmentation of a sequencing batch reactor (SBR) treating high strength pyridine wastewater

    Energy Technology Data Exchange (ETDEWEB)

    Liu, Xiaodong; Chen, Yan [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Zhang, Xin [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Suzhou Institute of Architectural Design Co., Ltd, Suzhou 215021, Jiangsu Province (China); Jiang, Xinbai; Wu, Shijing [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Shen, Jinyou, E-mail: shenjinyou@mail.njust.edu.cn [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Sun, Xiuyun; Li, Jiansheng; Lu, Lude [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China); Wang, Lianjun, E-mail: wanglj@mail.njust.edu.cn [Jiangsu Key Laboratory for Chemical Pollution Control and Resources Reuse, School of Environmental and Biological Engineering, Nanjing University of Science and Technology, Nanjing 210094, Jiangsu Province (China)

    2015-09-15

    Abstract: Aerobic granules were successfully cultivated in a sequencing batch reactor (SBR), using a single bacterial strain Rhizobium sp. NJUST18 as the inoculum. NJUST18 presented as both a good pyridine degrader and an efficient autoaggregator. Stable granules with diameter of 0.5–1 mm, sludge volume index of 25.6 ± 3.6 mL g{sup −1} and settling velocity of 37.2 ± 2.7 m h{sup −1}, were formed in SBR following 120-day cultivation. These granules exhibited excellent pyridine degradation performance, with maximum volumetric degradation rate (V{sub max}) varied between 1164.5 mg L{sup −1} h{sup −1} and 1867.4 mg L{sup −1} h{sup −1}. High-throughput sequencing analysis exhibited a large shift in microbial community structure, since the SBR was operated under open condition. Paracoccus and Comamonas were found to be the most predominant species in the aerobic granule system after the system had stabilized. The initially inoculated Rhizobium sp. lost its dominance during aerobic granulation. However, the inoculation of Rhizobium sp. played a key role in the start-up process of this bioaugmentation system. This study demonstrated that, in addition to the hydraulic selection pressure during settling and effluent discharge, the selection of aggregating bacterial inocula is equally important for the formation of the aerobic granule.

  8. Aerobic granulation strategy for bioaugmentation of a sequencing batch reactor (SBR) treating high strength pyridine wastewater

    International Nuclear Information System (INIS)

    Liu, Xiaodong; Chen, Yan; Zhang, Xin; Jiang, Xinbai; Wu, Shijing; Shen, Jinyou; Sun, Xiuyun; Li, Jiansheng; Lu, Lude; Wang, Lianjun

    2015-01-01

    Abstract: Aerobic granules were successfully cultivated in a sequencing batch reactor (SBR), using a single bacterial strain Rhizobium sp. NJUST18 as the inoculum. NJUST18 presented as both a good pyridine degrader and an efficient autoaggregator. Stable granules with diameter of 0.5–1 mm, sludge volume index of 25.6 ± 3.6 mL g −1 and settling velocity of 37.2 ± 2.7 m h −1 , were formed in SBR following 120-day cultivation. These granules exhibited excellent pyridine degradation performance, with maximum volumetric degradation rate (V max ) varied between 1164.5 mg L −1 h −1 and 1867.4 mg L −1 h −1 . High-throughput sequencing analysis exhibited a large shift in microbial community structure, since the SBR was operated under open condition. Paracoccus and Comamonas were found to be the most predominant species in the aerobic granule system after the system had stabilized. The initially inoculated Rhizobium sp. lost its dominance during aerobic granulation. However, the inoculation of Rhizobium sp. played a key role in the start-up process of this bioaugmentation system. This study demonstrated that, in addition to the hydraulic selection pressure during settling and effluent discharge, the selection of aggregating bacterial inocula is equally important for the formation of the aerobic granule

  9. Singing as a Therapeutic Agent, inThe Etude, 1891-1949.

    Science.gov (United States)

    Hunter

    1999-01-01

    The Etude music magazine, founded by Theodore Presser, was one of a number of popular music magazines published in the years prior to the establishment of the music therapy profession in 1950. During its publication run from 1883 to 1957, over 100 music therapy related articles appeared, including 13 on the health benefits of singing published between 1891 and 1949. Written by authors with diverse backgrounds, such as the famous Battle Creek, Michigan physician John Harvey Kellogg and Boston music critic Louis C. Elson, the articles contained consistent and adamant support regarding the health benefits of singing. The advantages described were both physical and psychological, and were recommended prophylactically for well persons and therapeutically for ill persons. Although the articles varied in perspective, from philosophical to theoretical to pedagogical, there is a consistent holistic medicine theme that appeared almost ahead of its time and no doubt linked to the push for vocal music education in that era. The importance of The Etude in promulgating ideas that helped shape the early practice of music therapy should not be underestimated. For much of its publication run The Etude was the largest music periodical in print, reaching its peak circulation of 250,000 copies per month in 1924.

  10. Pseudocapacitive properties of nano-structured anhydrous ruthenium oxide thin film prepared by electrostatic spray deposition and electrochemical lithiation/delithiation

    Energy Technology Data Exchange (ETDEWEB)

    Park, S.H.; Kim, J.Y.; Kim, K.B. [Division of Materials Science and Engineering, Yonsei University, Seoul (Korea, Republic of)

    2010-10-15

    Nano-structured anhydrous ruthenium oxide (RuO{sub 2}) thin films were prepared using an electrostatic spray deposition (ESD) technique followed by electrochemical lithiation and delithiation. During the electrochemical lithiation process, RuO{sub 2} decomposed to nano-structured metallic ruthenium Ru with the concomitant formation of Li{sub 2}O. Nano-structured RuO{sub 2} was formed upon subsequent electrochemical extraction of Li from the Ru/Li{sub 2}O nanocomposite. Electrochemical lithiation/deliathiation at different charge/discharge rates (C-rate) was used to control the nano-structure of the anhydrous RuO{sub 2}. Electrochemical lithiation/delithiation of the RuO{sub 2} thin film electrode at different C-rates was closely related to the specific capacitance and high rate capability of the nano-structured anhydrous RuO{sub 2} thin film. Nano-structured RuO{sub 2} thin films prepared by electrochemical lithiation and delithiation at 2C rate showed the highest specific capacitance of 653 F g{sup -1} at 20 mV s{sup -1}, which is more than two times higher than the specific capacitance of 269 F g{sup -1} for the as-prepared RuO{sub 2}. In addition, it showed 14% loss in specific capacitance from 653 F g{sup -1} at 20 mV s{sup -1} to 559 F g{sup -1} at 200 mV s{sup -1}, indicating significant improvement in the high rate capability compared to the 26% loss of specific capacitance of the as-prepared RuO{sub 2} electrode from 269 F g{sup -1} at 20 mV s{sup -1} to 198 F g{sup -1} at 200 mV s{sup -1} for the same change in scan rate. (Abstract Copyright [2010], Wiley Periodicals, Inc.)

  11. Changes in the solid state of anhydrous and hydrated forms of sodium naproxen under different grinding and environmental conditions: Evidence of the formation of new hydrated forms.

    Science.gov (United States)

    Censi, Roberta; Rascioni, Riccardo; Di Martino, Piera

    2015-05-01

    The aim of the present work was to investigate the solid state change of the anhydrous and hydrate solid forms of sodium naproxen under different grinding and environmental conditions. Grinding was carried out manually in a mortar under the following conditions: at room temperature under air atmosphere (Method A), in the presence of liquid nitrogen under air atmosphere (Method B), at room temperature under nitrogen atmosphere (Method C), and in the presence of liquid nitrogen under nitrogen atmosphere (Method D). Among the hydrates, the following forms were used: a dihydrate form (DSN) obtained by exposing the anhydrous form at 55% RH; a dihydrate form (CSN) obtained by crystallizing sodium naproxen from water; the tetrahydrate form (TSN) obtained by exposing the anhydrous form at 75% RH. The metastable monohydrate form (MSN), previously described in the literature, was not used because of its high physical instability. The chemical stability during grinding was firstly assessed and proven by HPLC. Modification of the particle size and shape, and changes in the solid state under different grinding methods were evaluated by scanning electron microscopy, and X-ray powder diffractometry and thermogravimetry, respectively. The study demonstrated the strong influence of starting form, grinding and environmental conditions on particle size, shape and solid state of recovered sodium naproxen forms. In particular, it was demonstrated that in the absence of liquid nitrogen (Methods A and C), either at air or at nitrogen atmosphere, the monohydrate form (MSN) was obtained from any hydrates, meaning that these grinding conditions favored the dehydration of superior hydrates. The grinding process carried out in the presence of liquid nitrogen (Method B) led to further hydration of the starting materials: new hydrate forms were identified as one pentahydrate form and one hexahydrate form. The hydration was caused by the condensation of the atmospheric water on sodium naproxen

  12. Crystal structures of nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper and chloro-(2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) copper

    Energy Technology Data Exchange (ETDEWEB)

    Chumakov, Yu. M. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Paholnitcaia, A. Yu. [State University of Moldova (Moldova, Republic of); Petrenko, P. A. [Academy of Sciences of Moldova, Institute of Applied Physics (Moldova, Republic of); Tsapkov, V. I., E-mail: vtsapkov@gmail.com [State University of Moldova (Moldova, Republic of); Poirier, D. [Centre Hospitalier Universitaire de Quebec (Canada); Gulea, A. P. [State University of Moldova (Moldova, Republic of)

    2015-01-15

    Two crystal modifications of nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper (I and II) and two modifications of chloro-(2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) copper (III and IV) have been synthesized and studied by X-ray diffraction. In structures I and II, the copper atoms coordinate a monodeprotonated molecule of the organic ligand, nitrate ions, and a water molecule. In crystals of I, the complexes are monomeric, whereas complexes II are linked via nitrate ions to form polymeric chains. In both structures the coordination polyhedron of the copper atom can be described as a distorted tetragonal bipyramid—(4 + 1 + 1) in I and (4 + 2) in II. These coordination polyherdra have different compositions. In structures III and IV, the metal atoms coordinate a monodeprotonated (2-[2-phenyl(pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazole molecule and chloride ions. In III the complex-forming ion has square-planar coordination geometry, whereas structure IV consists of centrosymmetric dimers with two bridging chlorine atoms. It was found that nitrato-(2-[2-(1-pyridine-2-ylethylidene)hydrazine]-1,3-benzothiazolo) aquacopper possesses antitumor activity.

  13. Crystal structure of bis-[N-(2-hy-droxy-eth-yl)-N-methyl-dithio-carbamato-κ2S,S'](pyridine)-zinc(II) pyridine monosolvate and its N-ethyl analogue.

    Science.gov (United States)

    Poplaukhin, Pavel; Tiekink, Edward R T

    2017-07-01

    The common structural feature of the title compounds, [Zn(C 4 H 8 NOS 2 ) 2 (C 5 H 5 N)]·C 5 H 5 N (I) and [Zn(C 5 H 10 NOS 2 ) 2 (C 5 H 5 N)]·C 5 H 5 N (II), which differ by having di-thio-carbamate N-bound methyl (I) and ethyl (II) groups, is the coordination of each Zn II atom by two non-symmetrically chelating di-thio-carbamate ligands and by a pyridine ligand; in each case, the non-coordinating pyridine mol-ecule is connected to the Zn-containing mol-ecule via a (hy-droxy)O-H⋯N(pyridine) hydrogen bond. The resulting NS 4 coordination geometry is closer to a square-pyramid than a trigonal bipyramid in the case of (I), but almost inter-mediate between the two extremes in (II). The mol-ecular packing features (hy-droxy)O-H⋯O(hy-droxy) hydrogen bonds, leading to supra-molecular chains with a zigzag arrangement along [10-1] (I) or a helical arrangement along [010] (II). In (I), π-π [inter-centroid distances = 3.4738 (10) and 3.4848 (10) Å] between coordinating and non-coordinating pyridine mol-ecules lead to stacks comprising alternating rings along the a axis. In (II), weaker π-π contacts occur between centrosymmetrically related pairs of coordinating pyridine mol-ecules [inter-centroid separation = 3.9815 (14) Å]. Further inter-actions, including C-H⋯π(chelate) inter-actions in (I), lead to a three-dimensional architecture in each case.

  14. Selective recovery of a pyridine derivative from an aqueous waste stream containing acetic acid and succinonitrile with solvent impregnated resins

    NARCIS (Netherlands)

    Bokhove, J.; Visser, T.J.; Schuur, Boelo; de Haan, A.B.

    2015-01-01

    Solvent impregnated resins (SIRs) were evaluated for the recovery of pyridine derivatives from an aqueous waste-stream containing also acetic acid and succinonitrile. For this purpose, a new solvent was developed, synthesized and impregnated in Amberlite XAD4. Sorption studies were used to determine

  15. Post-synthetic modification of MIL-101(Cr) with pyridine for high-performance liquid chromatographic separation of tocopherols.

    Science.gov (United States)

    Yang, Fang; Yang, Cheng-Xiong; Yan, Xiu-Ping

    2015-05-01

    Effective separation of tocopherols is challenging and significant due to their structural similarity and important biological role. Here we report the post-synthetic modification of metal-organic framework (MOF) MIL-101(Cr) with pyridine for high-performance liquid chromatographic (HPLC) separation of tocopherols. Baseline separation of four tocopherols was achieved on a pyridine-grafted MIL-101(Cr) packed column within 10 min using hexane/isopropanol (96:4, v/v) as the mobile phase at a flow rate of 0.5 mL min(-1). The pyridine-grafted MIL-101(Cr) packed column gave high column efficiency (85,000 plates m(-1) for δ-tocopherol) and good precision (0.2-0.3% for retention time, 1.8-3.4% for peak area, 2.6-2.7% for peak height), and also offered much better performance than unmodified MIL-101(Cr) and commercial amino-bonded silica packed column for HPLC separation of tocopherols. The results not only show the promising application of pyridine-grafted MIL-101(Cr) as a novel stationary phase for HPLC separation of tocopherols, but also reveal a facile post-modification of MOFs to expand the application of MOFs in separation sciences. Copyright © 2015 Elsevier B.V. All rights reserved.

  16. Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF5-substituted phenylboronic esters and iodobenzenes

    Directory of Open Access Journals (Sweden)

    George Iakobson

    2015-08-01

    Full Text Available Pyridine promotes dediazoniation of aryldiazonium tetrafluoroborates. The formed aryl radicals were trapped with B2pin2, iodine, or tetrahydrofuran to afford boronic esters, iodobenzenes and benzenes, respectively. The application to the synthesis of (pentafluorosulfanylphenylboronic esters, iodo(pentafluorosulfanylbenzenes and (pentafluorosulfanylbenzene is shown.

  17. Poly[propane-1,3-diammonium [cuprate(II-bis(μ2-pyridine-2,3-dicarboxylato] trihydrate

    Directory of Open Access Journals (Sweden)

    Shabnam Hooshmand

    2008-02-01

    Full Text Available The title polymeric compound {(C3H12N2[Cu(C7H3NO42]·3H2O}n or {(pnH2[Cu(py-2,3-dc2]·3H2O}n (pn is propane-1,3-diamine and py-2,3-dcH2 is pyridine-2,3-dicarboxylic acid, was synthesized by reaction of copper(II chloride dihydrate with a proton-transfer compound, propane-1,3-diammonium pyridine-2,3-dicarboxylate or (pnH2(py-2,3-dc, in aqueous solution. The anion is a six-coordinate complex (site symmetry overline{1}, with a distorted octahedral geometry around CuII, consisting of two bidentate pyridine-2,3-dicarboxylate groups and two O atoms of bridging ligands from (py-2,3-dc2− fragments, which are located in trans positions. The (pnH22+ cation is disordered over two sites by the center of inversion. Intermolecular hydrogen bonds, π–π [centroid–centroid distances of 3.539 (3 Å] and C—O...π stacking interactions [O...Cg = 3.240 (5 Å; Cg is the center of the pyridine ring], connect the various components into a supramolecular structure.

  18. Formation of mono- and multilayers of metal complexes of 4-(((10,12-pentacosadiynoyl)oxy)methyl)pyridine

    NARCIS (Netherlands)

    Werkman, P J; Wilms, H; Wieringa, R H; Schouten, A J

    1998-01-01

    The monolayer properties of the amphiphile, 4-(((10,12-pentacosadiynoyl)oxy)methyl)pyridine have been studied by measuring the surface pressure-area isotherms. The amphiphile forms stable monolayers at the air-water interface and protonation of the monolayers occurs at pH values of 3.00 or lower.

  19. Rotational barriers of 1,3-substitute pyridines and benzenes as models for the NAD+/NADH coenzyme

    NARCIS (Netherlands)

    Vanhommerig, S.A.M.; Meier, R.J.; Sluyterman, L.A.A.E.; Meijer, E.M.

    1994-01-01

    The NAD+/NADH coenzyme is involved in many enzyme-catalysed oxidation-reduction reactions. In order to obtain better insight in the catalytic mechanism of NAD+/NADH dependent dehydrogenases, conformational studies of 1,3-substituted pyridines and benzenes were carried out, using ab initio,

  20. Mechanistic Dichotomy in the Asymmetric Allylation of Aldehydes with Allyltrichlorosilanes Catalyzed by Chiral Pyridine N-Oxides

    Czech Academy of Sciences Publication Activity Database

    Malkov, A. V.; Stončius, S.; Bell, M.; Castelluzzo, F.; Ramírez-López, P.; Biedermannová, Lada; Langer, V.; Rulíšek, Lubomír; Kočovský, P.

    2013-01-01

    Roč. 19, č. 28 (2013), s. 9167-9185 ISSN 0947-6539 R&D Projects: GA MŠk LC512 Institutional support: RVO:61388963 ; RVO:86652036 Keywords : allylation * allylsilanes * calculations * organocatalysis * pyridine N-oxides Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 5.696, year: 2013

  1. Synthesis and Characterization of 2-Phenylimidazo[1,2-a]pyridine: A Privileged Structure for Medicinal Chemistry

    Science.gov (United States)

    Santaniello, Brandi S.; Price, Matthew J.; Murray, James K., Jr.

    2017-01-01

    A straightforward synthesis of 2-phenylimidazo[1,2-a]pyridine is described. The reaction is designed to demonstrate to students the preparation of a bridged N-heterocycle, in which the heteroatom occupies a bridgehead position. The product is obtained in moderate to high yield and is highly crystalline. The compound can be purified either by…

  2. Synthesis and luminescence properties of europium and terbium complexes with pyridine- or bipyridine-linked oligothiophene ligand

    International Nuclear Information System (INIS)

    Liu Ping; Huang Mingsheng; Pan Wanzhang; Zhang Yamin; Hu Jianhua; Deng Wenji

    2006-01-01

    With an aim to develop novel luminescence materials, europium and terbium complexes of 2,5-(2-thiophene)-pyridine (TPY) and 5,5'-bis(5-(2,2'-bithiophene))-2,2'-bipyridine (B2TBPY) were synthesized, and their luminescence properties studied. The complexes exhibit ligand-sensitized emission, which is typical of Eu(III) and Tb(III) ions

  3. Study of New Thiazole Based Pyridine Derivatives as Potential Corrosion Inhibitors for Mild Steel: Theoretical and Experimental Approach

    Directory of Open Access Journals (Sweden)

    T. K. Chaitra

    2016-01-01

    Full Text Available Three new thiazole based pyridine derivatives 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-2-ylmethylene-hydrazide (2-MTPH, 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-3-ylmethylene-hydrazide (3-MTPH, and 5-(4-methoxy-phenyl-thiazole-2-carboxylic acid pyridin-4-ylmethylene-hydrazide (4-MTPH were synthesized and characterized. Corrosion inhibition performance of the prepared compounds on mild steel in 0.5 M HCl was studied using gravimetric, potentiodynamic polarisation, and electrochemical impedance techniques. Inhibition efficiency has direct relation with concentration and inverse relation with temperature. Thermodynamic parameters for dissolution and adsorption process were evaluated. Polarisation study reveals that compounds act as both anodic and cathodic inhibitors with emphasis on the former. Impedance study shows that decrease in charge transfer resistance is responsible for effective protection of steel surface by inhibitors. The film formed on the mild steel was investigated using FTIR, SEM, and EDX spectroscopy. Quantum chemical parameters like EHOMO, ELUMO, ΔE, hardness, softness, and ionisation potential were calculated. Higher value of EHOMO and lower value of ΔE indicate the better inhibition efficiency of the compounds. Lower ionisation potential of inhibitors indicates higher reactivity and lower chemical stability.

  4. Formation of Bonded Exciplex in the Excited States of Dicyanoanthracene-Pyridine System : Time Dependent Density Functional Theory Study

    NARCIS (Netherlands)

    Setiawan, D.; Sethio, D.; Martoprawiro, M.A.; Filatov, M.; Gaol, FL; Nguyen, QV

    2012-01-01

    Strong quenching of fluorescence was recently observed in pyridine solutions of 9,10-dicyanoanthracene chromophore. It was hypothesized that quenching may be attributed to the formation of bound charge transfer complexes in the excited states of the molecules. In this work, using time-dependent

  5. Activation and desensitization of peripheral muscle and neuronal nicotinic acetylcholine receptors by selected, naturally-occurring pyridine alkaloids

    Science.gov (United States)

    Teratogenic alkaloids can cause developmental defects due to inhibition of fetal movement that results from desensitization of fetal muscletype nicotinic acetylcholine receptors (nAChRs). We investigated the ability of two known teratogens, the piperidinyl-pyridine anabasine and its 1,2-dehydropiper...

  6. Synthesis and characterization of two novel pyridine-containing framework gallium ethylenediphosphonates

    International Nuclear Information System (INIS)

    Yuan Zhanhui; Clegg, William; Attfield, Martin P.

    2006-01-01

    Two novel gallium diphosphonates, (C 5 H 5 N)Ga 3 F(O 3 PC 2 H 4 PO 3 ) 2 (I) (triclinic, P-1, a=8.2880(12) A, b=11.7197(16) A, c=11.7601(17) A, α=71.589(3) o , β=70.577(3) o , γ=77.313(3) o , V=1013.7(2) A 3 , Z=2, R 1 =0.0352, wR 2 =0.0980) and (C 5 H 5 NH) 2 [Ga 4 F 2 (O 3 PC 2 H 4 PO 3 ) 3 ] (II) (triclinic, P-1, a=8.670(4) A, b=9.742(3) A, c=10.406(2) A, α=81.44(3) o , β=65.83(5) o , γ=67.16(3) o , V=739.0(4) A 3 , Z=2, R 1 =0.0600, wR 2 =0.1495) have been synthesised by solvothermal methods in the presence of pyridine and their structures determined using single-crystal X-ray diffraction data. Both compounds I and II are composed of various Ga-centered polyhedra and ethylenediphosphonate groups that link together to form framework materials with one- and two-dimensional channel systems, respectively. The two structures are formed in the presence of structure-directing pyridine molecules that are directly bound to some of the Ga atoms in I, and are protonated as pyridinium cations in II. Compounds I has a charge-neutral framework, while compound II has an anionic framework. Both materials provide rare examples of organically structure-directed framework metal diphosphonate materials. - Graphical abstract: (C 5 H 5 N)Ga 3 F(O 3 PC 2 H 4 PO 3 ) 2 (I) and (C 5 H 5 NH) 2 [Ga 4 F 2 (O 3 PC 2 H 4 PO 3 ) 3 ] (II) are novel gallium diphosphonate materials composed of Ga-centered polyhedra and ethylenediphosphonate groups that link together to form framework materials with one- and two-dimensional channel systems, respectively. The two structures are formed in the presence of structure-directing pyridine molecules or pyridinium cations and are examples of organically structure-directed framework metal diphosphonates

  7. One-photon mass-analyzed threshold ionization (MATI) spectroscopy of pyridine: Determination of accurate ionization energy and cationic structure

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yu Ran; Kang, Do Won; Kim, Hong Lae, E-mail: chkwon@kangwon.ac.kr, E-mail: hlkim@kangwon.ac.kr; Kwon, Chan Ho, E-mail: chkwon@kangwon.ac.kr, E-mail: hlkim@kangwon.ac.kr [Department of Chemistry and Institute for Molecular Science and Fusion Technology, College of Natural Sciences, Kangwon National University, Chuncheon 200-701 (Korea, Republic of)

    2014-11-07

    Ionization energies and cationic structures of pyridine were intensively investigated utilizing one-photon mass-analyzed threshold ionization (MATI) spectroscopy with vacuum ultraviolet radiation generated by four-wave difference frequency mixing in Kr. The present one-photon high-resolution MATI spectrum of pyridine demonstrated a much finer and richer vibrational structure than that of the previously reported two-photon MATI spectrum. From the MATI spectrum and photoionization efficiency curve, the accurate ionization energy of the ionic ground state of pyridine was confidently determined to be 73 570 ± 6 cm{sup −1} (9.1215 ± 0.0007 eV). The observed spectrum was almost completely assigned by utilizing Franck-Condon factors and vibrational frequencies calculated through adjustments of the geometrical parameters of cationic pyridine at the B3LYP/cc-pVTZ level. A unique feature unveiled through rigorous analysis was the prominent progression of the 10 vibrational mode, which corresponds to in-plane ring bending, and the combination of other totally symmetric fundamentals with the ring bending overtones, which contribute to the geometrical change upon ionization. Notably, the remaining peaks originate from the upper electronic state ({sup 2}A{sub 2}), as predicted by high-resolution photoelectron spectroscopy studies and symmetry-adapted cluster configuration interaction calculations. Based on the quantitatively good agreement between the experimental and calculated results, it was concluded that upon ionization the pyridine cation in the ground electronic state should have a planar structure of C{sub 2v} symmetry through the C-N axis.

  8. N-acetyltransferase-dependent activation of 2-hydroxyamino-1-methyl-6-phenylimidazo[4,5-b]pyridine: formation of 2-amino-1-methyl-6-(5-hydroxy)phenylimidazo [4,5-b]pyridine, a possible biomarker for the reactive dose of 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine

    DEFF Research Database (Denmark)

    Frandsen, Henrik Lauritz; Alexander, J.

    2000-01-01

    2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) is a mutagenic and carcinogenic heterocyclic amine formed during ordinary cooking. PhIP is metabolically activated to the ultimate mutagenic metabolite by CYP P450-mediated N-hydroxylation followed by phase II esterification, Incubation of N...

  9. Poly[μ2-aqua-aqua-μ4-pyridine-2,4-dicarboxylato-strontium

    Directory of Open Access Journals (Sweden)

    Zohreh Derikvand

    2009-08-01

    Full Text Available In the title polymeric complex, [Sr(C7H3NO4(H2O2]n, the SrII atom is eight-coordinated by four O atoms and one N atom of four pyridine-2,4-dicarboxylate (py-2,4-dc ligands and three O atoms of three coordinated water molecules in a dodecahedral geometry. These units are connected via the carboxylate O atoms and water molecules, building polymeric layers parallel to (100. In the crystal structure, non-covalent interactions consisting of O—H...O hydrogen bonds and π–π stacking interactions [centroid–centroid distances = 3.862 (17 and 3.749 (17 Å] connect the various components, forming a three-dimensional structure.

  10. Palladium(II) complexes supported by a bidentate bis(secondary)phosphine linked by pyridine

    KAUST Repository

    Winston, Matthew S.

    2014-10-01

    A series of complexes of the type (PNP-H2)PdX2 (X=Cl, Br, I) have been synthesized, where PNP-H2 is a bis(secondary)phosphine ligand linked by a pyridine, 2,6-(2\\'-(Ph(H)P)(C6H4))2(C5H3N). Due to chirality at phosphorus, the parent ligand exists as a mixture of nearly equivalent rac and meso diastereomers non-interconverting at room temperature. When ligated to Pd(II) halides, however, the diastereomeric ratio is dependent upon the halide. The chloro, bromo, and iodo complexes have been characterized crystallographically. Conformationally similar meso diastereomers of each dihalide are roughly C s symmetric in the solid state, while the rac diastereomers (identified only for X=Br, I) show substantially different solid-state conformations. © 2014 Elsevier B.V.

  11. Bis[(E-N-(pyridin-3-ylmethylidenehydroxylamine-κN1]silver(I perchlorate

    Directory of Open Access Journals (Sweden)

    Jing Xu

    2012-06-01

    Full Text Available Each of the ions in the title salt, [Ag(C6H6N2O2]ClO4, is completed by the application of crystallographic twofold symmetry. The AgI atom is coordinated by two pyridine N atoms in an almost linear fashion [N—Ag—N = 170.0 (2°], with the T-shaped coordination geometry being completed by a weakly associated perchlorate-O atom. Supramolecular zigzag chains along [100] mediated by O—H...N hydrogen bonds [as parts of R22(6 loops] feature in the crystal packing. The perchlorate O atoms are disordered over two sets of sites in a statistical ratio.

  12. Pyrrole-Pyridine and Pyrrole-Naphthyridine Hosts for Anion Recognition

    Directory of Open Access Journals (Sweden)

    M. Angeles García

    2015-05-01

    Full Text Available The association constants of the complexes formed by two hosts containing pyrrole, amide and azine (pyridine and 1,8-naphthyridine groups and six guests, all monoanions (Cl−, CH3CO2−, NO3−, H2PO4−, BF4−, PF6−, have been determined using NMR titrations. The X-ray crystal structure of the host N2,N5-bis(6-methylpyridin-2-yl-3,4-diphenyl-1H-pyrrole- 2,5-dicarboxamide (1 has been solved (P21/c monoclinic space group. B3LYP/6-31G(d,p and calculations were carried out in an attempt to rationalize the trends observed in the experimental association constants.

  13. catena-Poly[[[aquapyridinezinc(II]-μ2-3,3′-(p-phenylenediacrylato] pyridine solvate

    Directory of Open Access Journals (Sweden)

    Dongpo Su

    2010-09-01

    Full Text Available The title compound, {[Zn(C12H8O4(C5H5N(H2O]·C5H5N}n, has been prepared by hydrothermal reaction. The ZnII atom is six-coordinated by four carboxylate O atoms of two p-phenylenediacrylate (ppda2− ligands, one N atom of a pyridine molecule and one O atom of a water molecule in a distorted octahedral environment. The carboxylate groups of the ppda2− anions are in a bridging–chelating mode, in which two O atoms chelate one Zn2+ ion. These connections result in an extended chain structure. Parallel packing of the chains forms a two-dimensional network with intermolecular edge-to-face interactions. Further linkages between the layers through O—H...O hydrogen-bonding interactions result in a three-dimensional supramolecular architecture with one-dimensional rectanglar channels.

  14. Aquabis(4-methylbenzoato-κO;κ2O,O′-bis(pyridine-κNnickel(II

    Directory of Open Access Journals (Sweden)

    Li-Li Ji

    2008-04-01

    Full Text Available In the title mononuclear complex, [Ni(C8H7O22(C5H5N2(H2O], the NiII atom is in a distorted octahedral arrangement, coordinated by three carboxylate O atoms from one bidentate 4-methylbenzoate ligand and one monodentate 4-methylbenzoate ligand, two N atoms from pyridine ligands, axially positioned, and a water molecule. The equatorially positioned water molecule and uncoordinated carboxylate O atom form an intramolecular hydrogen bond. An intermolecular O—H...O hydrogen bond between the coordinated water molecule and carboxylate O atom of the 4-methylbenzoate ligand forms infinite chains along the b axis. These chains are connected by C—H...π interactions.

  15. Ruthenium complexes containing 2-(2-nitrosoaryl)pyridine: structural, spectroscopic, and theoretical studies.

    Science.gov (United States)

    Chan, Siu-Chung; Cheung, Ho-Yuen; Wong, Chun-Yuen

    2011-11-21

    Ruthenium complexes containing 2-(2-nitrosoaryl)pyridine (ON(^)N) and tetradentate thioether 1,4,8,11-tetrathiacyclotetradecane ([14]aneS4), [Ru(ON(^)N)([14]aneS4)](2+) [ON(^)N = 2-(2-nitrosophenyl)pyridine (2a), 10-nitrosobenzo[h]quinoline (2b), 2-(2-nitroso-4-methylphenyl)pyridine, (2c), 2-(2-nitrosophenyl)-5-(trifluoromethyl)pyridine (2d)] and analogues with the 1,4,7-trithiacyclononane ([9]aneS3)/tert-butylisocyanide ligand set, [Ru(ON(^)N)([9]aneS3)(C≡N(t)Bu)](2+) (4a and 4b), have been prepared by insertion of a nitrosonium ion (NO(+)) into the Ru-aryl bond of cyclometalated ruthenium(II) complexes. The molecular structures of the ON(^)N-ligated complexes 2a and 2b reveal that (i) the ON(^)N ligands behave as bidentate chelates via the two N atoms and the bite angles are 86.84(18)-87.83(16)° and (ii) the Ru-N(NO) and N-O distances are 1.942(5)-1.948(4) and 1.235(6)-1.244(5) Å, respectively. The Ru-N(NO) and N-O distances, together with ν(N═O), suggest that the coordinated ON(^)N ligands in this work are neutral moiety (ArNO)(0) rather than monoanionic radical (ArNO)(•-) or dianion (ArNO)(2-) species. The nitrosated complexes 2a-2d show moderately intense absorptions centered at 463-484 nm [ε(max) = (5-6) × 10(3) dm(3) mol(-1) cm(-1)] and a clearly discriminable absorption shoulder around 620 nm (ε(max) = (6-9) × 10(2) dm(3) mol(-1) cm(-1)), which tails up to 800 nm. These visible absorptions are assigned as a mixing of d(Ru) → ON(^)N metal-to-ligand charge-transfer and ON(^)N intraligand transitions on the basis of time-dependent density functional theory (TD-DFT) calculations. The first reduction couples of the nitrosated complexes range from -0.53 to -0.62 V vs Cp(2)Fe(+/0), which are 1.1-1.2 V less negative than that for [Ru(bpy)([14]aneS4)](2+) (bpy = 2,2'-bipyridine). Both electrochemical data and DFT calculations suggest that the lowest unoccupied molecular orbitals of the nitrosated complexes are ON(^)N-centered. Natural population

  16. Amplification of light emission of chiral pyridine Eu(III) complex by copper nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Reisfeld, Renata; Levchenko, Viktoria [Institute of Chemistry, The Hebrew University of Jerusalem, Givat Ram, Jerusalem 91904 (Israel); Piccinelli, Fabio; Bettinelli, Marco [Laboratorio Materiali Luminescenti, DB, Universita di Verona and INSTM, UdR Verona, Strada Le Grazie 15, 37134 Verona (Italy)

    2016-02-15

    We outline the applications of lanthanides luminescence in a number of modern fields. The intensity of the luminescence of the expensive lanthanides can be increased by their interaction with nanoparticles of inexpensive copper. As a typical example the chiral pyridine-based Eu{sup 3+} complex was incorporated into amorphous films of polyvinyl alcohol with hydroxyethyl cellulose. The luminescence intensity of the complex is increased by three hundred percent by its interaction with copper nanoparticles. The synthesis and steady state spectroscopy of the materials are presented. - Highlights: • Nanoparticles of copper were for the first time synthesized at 80 °C. • Copper NPs were incorporated with a luminescent Eu{sup 3+} complex in a polymeric matrix. • The films produced were characterized by photoluminescence spectroscopy. • The luminescence of Eu{sup 3+} complex with Cu NPs is 3 times higher than the original one.

  17. N-(3-{[(Z-(3-Hydroxy-4-methylphenylimino]methyl}pyridin-2-ylpivalamide

    Directory of Open Access Journals (Sweden)

    Şehriman Atalay

    2016-03-01

    Full Text Available The molecular structure of the title compound, C18H21N3O2, contains pivalamide, pyridin and hydroxy-methylphenyl moieties. The whole molecule is not planar, the dihedral angle between the benzene rings being 34.84 (7°. The molecular conformation is stabilized by an intramolecular N—H...N hydrogen bond. In the crystal, molecules are linked by O—H...O, O—H...N and C—H...O hydrogen bonds. The C and H atoms of the tert-butyl group disordered over two sets of sites with an occupancy ratio of 0.692 (5:0.308 (5.

  18. Effective transport properties for the pyridine-granular activated carbon adsorption system

    Directory of Open Access Journals (Sweden)

    S. A. Baz-Rodríguez

    2012-09-01

    Full Text Available In this work, the kinetics of pyridine adsorption onto granular activated carbon was studied from the point of view of an up-scaling process by using the method of volume averaging. The pore and surface effective diffusivities were estimated by supposing simple microscale geometries (ordered media of cylinders and spheres and those of images processed from SEM (Scanning Electron Microscopy micrographs. In addition, as a rough estimate, the point surface diffusivity is reported. The results revealed that the up-scaled diffusional model satisfactorily interpreted the concentration decay curves and the effective diffusivity was found to be an increasing function of the concentration, mainly due to the contribution of surface diffusion. In general, the diffusivity coefficients involved in the adsorption system are related through the expression molecular diffusivity = 22 ï‚' point surface diffusivity = 5/2 x‚' pore effective diffusivity = 1/12 x ‚' surface effective diffusivity.

  19. Investigations of the reactivity of pyridine carboxylic acids with diazodiphenylmethane in protic and aprotic solvents.

    Directory of Open Access Journals (Sweden)

    ALEKSANDAR D. MARINKOVIC

    2005-04-01

    Full Text Available Rate constants for the reaction of diazodiphenylmethane with isomeric pyridine carboxylic acids were determined in chosen protic and aprotic solvents at 30 °C, using the well known UV spectrophotometric method. The values of the rate constants of the investigated acids in protic solvents were higher than those in aprotic solvents. The second order rate constants were correlated with solvent parameters using the Kamlet-Taft solvatochromic equation in the form: log k = log k0 + sp* + aa + bb . The correlation of the obtained kinetic data were performed by means of multiple linear regression analysis taking appropriate solvent parameters. The signs of the equation coefficients were in agreement with the postulated reaction mechanism. The mode of the influence of the solvent on the reaction rate in all the investigated acids are discussed on the basis of the correlation results.

  20. 1,3-Dicyclohexyl-3-[(pyridin-2-ylcarbonyl]urea monohydrate from synchrotron radiation

    Directory of Open Access Journals (Sweden)

    Solange M. S. V. Wardell

    2011-10-01

    Full Text Available The title urea derivative crystallizes as a monohydrate, C19H27N3O2·H2O. The central C3N grouping is almost planar (r.m.s. deviation = 0.0092 Å, and the amide and pyridine groups are substantially twisted out this plane [dihedral angles = 62.80 (12 and 34.98 (10°, respectively]. Supramolecular double chains propagating along the b-axis direction feature in the crystal packing whereby linear chains sustained by N—H...O hydrogen bonds formed between the amide groups are linked by helical chains of water molecules (linked by O—H...O hydrogen bonds. The H atom that participates in these water chains is disordered over two positions of equal occupancy. The double chains are connected into a two-dimensional array by C—H...O contacts and the layers stack along the a axis.

  1. Identification of combustion intermediates in low-pressure premixed pyridine/oxygen/argon flames.

    Science.gov (United States)

    Tian, Zhenyu; Li, Yuyang; Zhang, Taichang; Zhu, Aiguo; Qi, Fei

    2008-12-25

    Combustion intermediates of two low-pressure premixed pyridine/oxygen flames with respective equivalence ratios of 0.56 (C/O/N = 1:4.83:0.20) and 2.10 (C/O/N = 1:1.29:0.20) have been identified with tunable synchrotron vacuum ultraviolet (VUV) photoionization and molecular-beam mass spectrometry techniques. About 80 intermediates in the rich flame and 60 intermediates in the lean flame, including nitrogenous, oxygenated, and hydrocarbon intermediates, have been identified by measurements of photoionization mass spectra and photoionization efficiency spectra. Some radicals and new nitrogenous intermediates are identified in the present work. The experimental results are useful for studying the conversion of volatile nitrogen compounds and understanding the formation mechanism of NO(x) in flames of nitrogenous fuels.

  2. The simple production of nonsymmetric quaterpyridines through Kröhnke pyridine synthesis

    Directory of Open Access Journals (Sweden)

    Isabelle Sasaki

    2015-09-01

    Full Text Available Quaterpyridines have been demonstrated to be useful building blocks in metallo-supramolecular chemistry; however, their synthesis requires the preparation of sensitive building blocks. We present here three examples of nonsymmetric quaterpyridines that were easily obtained in yields of 70–85% by condensation of commercially available enones with 6-acetyl-2,2’:6’,2’’-terpyridine through a Kröhnke pyridine synthesis. Easy access to 6-acetyl-2,2’:6’,2’’-terpyridine starting from 2,6-diacetylpyridine and 2-acetylpyridine is described. The X-ray analysis of a chiral quaterpyridine and its Pt(II complex is presented.

  3. Distinct sesquiterpene pyridine alkaloids from in Salvadoran and Peruvian Celastraceae species.

    Science.gov (United States)

    Callies, Oliver; Núñez, Marvin J; Perestelo, Nayra R; Reyes, Carolina P; Torres-Romero, David; Jiménez, Ignacio A; Bazzocchi, Isabel L

    2017-10-01

    As part of a bioprospecting program aimed at the discovery of undescribed natural products from Salvadoran and Peruvian flora, the phytochemical investigations of four Celastraceae species, Celastrus vulcanicola, Maytenus segoviarum, Maytenus jeslkii, and Maytenus cuzcoina, were performed. The current study reports the isolation and structural characterization of five previously undescribed macrolide sesquiterpene pyridine alkaloids, named vulcanicoline-A, cuzcoinine, vulcanicoline-B, jelskiine, and vulcanicoline-C, along with sixteen known alkaloids. The structures of the alkaloids were established by spectrometric and extensive 1D and 2D NMR spectroscopic analysis, including COSY, HSQC, HMBC, and ROESY experiments. The absolute configurations of alkaloids were proposed based on optical rotation sign, and biogenetic considerations. This study represents the first phytochemical analysis of Maytenus segoviarum. Copyright © 2017 Elsevier Ltd. All rights reserved.

  4. Diaquabis(pyridine-2-carboxylato-κ2N,Omanganese(II dimethylformamide hemisolvate

    Directory of Open Access Journals (Sweden)

    Irina A. Golenya

    2011-11-01

    Full Text Available There are two crystallographically independent complex molecules with very similar geometries in the unit cell of the title compound, [Mn(C6H4NO22(H2O2]·0.5C3H7NO. The central ion is situated in a distorted octahedral environment of two N- and four O-donor atoms from two pyridine-2-carboxylate ligands and two cis-disposed water molecules. The carboxylate ligands are coordinated in a chelate fashion with the formation of two five-membered rings. In the crystal, the complex molecules are connected by O—H...O hydrogen bonds between the coordinated water molecules and the uncoordinated carboxylate O atoms, thus forming hydrogen-bonded walls disposed perpendicularly to the bc plane.

  5. Tetrakis[bis(pyridin-2-ylamine-κN2](nitrato-κOsilver(I

    Directory of Open Access Journals (Sweden)

    Yuliia Parashchenko

    2014-02-01

    Full Text Available In the title complex, [Ag(NO3(C10H9N34], the nitrate ligand is found to be disordered over two sets of positions, with occupancy factors of 0.473 (5 and 0.527 (5. The AgI ion is located in a square-pyramidal coordination environment formed by four N atoms from four bis(pyridin-2-ylamine ligands and one O atom from a nitrate ligand. Weak interactions between the AgI ions and the nitrate anions acting in a monodentate mode [Ag...O = 2.791 (13 and 2.816 (9 Å for the major component of the nitrate ligand, and 2.865 (8 and 2.837 (8 Å for the minor component] link the complex molecules into a chain along [001]. N—H...O hydrogen bonds are observed.

  6. Syntheses and a Solid State Structure of a Dinuclear Molybdenum(V Complex with Pyridine

    Directory of Open Access Journals (Sweden)

    Jon Zubieta

    2010-01-01

    Full Text Available A mononuclear complex [MoOCl4(H2O]− readily forms a metal−metal bonded {Mo2O4}2+ core. A high content of pyridine in the reaction mixture prevents further aggregation of dinuclear cores into larger clusters and a neutral, dinuclear complex with the [Mo2O4Cl2(Py4] composition is isolated as a product. Solid state structures of two compounds containing this complex, [Mo2O4Cl2(Py4]·2.25Py (1 and [Mo2O4Cl2(Py4]·1.5PyHCl (2, were investigated by X-ray crystallography.

  7. Polymer Concentration-Controlled Substrate Specificity in Solvolysis of p-Nitrophenyl Alkanoates Catalyzed by 4-(Dialkylamino)pyridine- Functionalized Polymer in Aqueous Methanol Solution

    National Research Council Canada - National Science Library

    Wang, Guang-Jia

    1996-01-01

    The substrate specificity in solvolysis reactions of p-nitrophenyl alkanoates 2 (n=2-18) catalyzed by 4-(dialkylamino)pyridine-functionalized polymer 1 can be controlled by the concentration of 1 in 1...

  8. Synthesis and biological evaluation of certain 2-H-Pyran-2-Ones and some derived 1-H-Pyridin-2-One analogs as antimicrobial agents

    International Nuclear Information System (INIS)

    Faidallah, Hassan M.; Al-Saadi, Mohammad S.; Rostom, Sherif A. F.

    2008-01-01

    Pyran-2-one and pyridine-2-one analogs are known to be biological versatile compounds possessing variety of pharmacological activities. Some 4-(4-nitrophenyl)-5, 6-diphenyl-pyran-2-ones and their 1H-pyridin-2-oneanalogs were synthesized and evaluated for their in vitro intermediates and target compounds were discussed. The results evaluated that some compounds exhibited promising antibacterial and antifungal activities. Compound 8; 1-hydroxy-4-(4-nitrophenyl)-5, 6-diphenyl-1H-pyridin-2-one; showed the most potent broad spectrum antimicrobial activity. 1-Methyl-4-(4-nitrophenyl)-5, 6-diphenyl-1H-pyridin-2-thione 12; was able to exert weak growth inhibitory effect against the Mycobacterium tuberculosis. (author)

  9. Etude de l'impact de la variation de la température sur les activités ...

    African Journals Online (AJOL)

    Etude de l'impact de la variation de la température sur les activités microbiennes : application à une population de Listeria monocytogenes CIP 7831, Listeria monocytogenes Scott A CIP 103575 et Escherichia coli ATCC 25922.

  10. New 1-hydroxy-1,1-bisphosphonates derived from 1H-pyrazolo[3,4-b]pyridine: synthesis and characterization

    Energy Technology Data Exchange (ETDEWEB)

    Teixeira, Fatima C.; Lucas, Carla; Curto, M. Joao M., E-mail: fatima.teixeira@lneg.pt [Laboratorio Nacional de Energia e Geologia, Lisboa (Portugal); Neves, M. [Instituto Superior Tecnico, Instituto Tecnologico e Nuclear (IST/ITN), Campus Tecnologico e Nuclear, Universidade Tecnica de Lisboa, Sacavem (Portugal); Duarte, M. Teresa; Andre, Vania; Teixeira, Antonio P.S. [Centro de Quimica Estrutural, Instituto Superior Tecnico, Universidade Tecnica de Lisboa (Portugal)

    2013-07-15

    A number of 1H-pyrazolo[3,4-b]pyridine derivatives, starting from 2-chloro-3-formyl pyridine, was synthesized to obtain new 1-hydroxybisphosphonates, a class of compounds with potential biological interest. Spectroscopic data were used to characterize all compounds and to identify N-1 and N-2 regioisomers, and mono- and bisphosphonates derivatives. X-ray diffractometry studies of compound 7a confirmed the proposed structure. (author)

  11. Synthesis of a novel series of 4-arylpiperazinyl derivatives linked to a 2-(pyridin-3-yl)-1H-benzimidazole as new Delavirdine analogues

    International Nuclear Information System (INIS)

    Pessoa-Mahana, David; Nunez, Andres; Espinosa, Christian; Mella-Raipn, Jaime; Pessoa-Mahana, Hernan

    2010-01-01

    The synthesis of a series of substituted arylpiperazines linked to a 2-(pyridin-3-yl)-1H-benzo[d]imidazole scaffold through an alkylic linker is reported. The novel 1-(2-(4-arylpiperazin-1-yl)alkyl)-2-(pyridin-3-yl)-1H-benzimidazole derivatives are structurally related to the anti-HIV-1 drug Delavirdine and belong to the bis(heteroaryl)piperazines family (BHAPs), a well known HIV-1 reverse transcriptase inhibitors group. (author)

  12. Bio-metric study of pig karyotype; Etude biometrique du caryotype du porc

    Energy Technology Data Exchange (ETDEWEB)

    Haag, J; Lacourly, N; Nizza, P [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1969-07-01

    This study has a twofold purpose, the former is to determine the swine karyotype as accurately as possible, the latter is to try and develop a method of automatic classification and to show its possibilities and limits. (authors) [French] Cette etude a un double objet: d'une part, de definir de la facon aussi precise que possible le caryotype du porc et d'autre part, de tenter une methode de classification automatique et d'en montrer les possibilites ainsi que les limites. (auteurs)

  13. Poly[diaquadi-μ-hydroxido-κ4O:O-dinitrato-κ4O:O′-bis[3-(pyridin-4-yl-κN-5-(pyridin-3-yl-1,2,4-oxadiazole]dicopper(II

    Directory of Open Access Journals (Sweden)

    Longfei Wu

    2012-04-01

    Full Text Available The title compound, [Cu2(NO32(OH2(C12H8N4O2(H2O2]n, consists of a neutral polymeric CuII complex in which each CuII atom has a distorted octahedral geometry defined by a pyridyl N atom from a 3-(pyridin-3-yl-5-(pyridin-4-yl-1,2,4-oxadiazole ligand and five O atoms from a water molecule, two nitrates and two hydroxides. Two CuII ions are bridged by two hydroxide anions resulting in a Cu2O2 loop, located across an inversion center and connected by the nitrate anions into a broad two-dimensional polymeric structure parallel to (100. In the crystal, there are O—H...O hydrogen bonds between the coodinated water molecule and the nitrate and hydroxide, and between the hydroxide and the nitrate. Intermolecular π–π interactions are present between pyridine rings in adjacent two-dimensional structures, with a centroid–centroid distance of 3.582 (2 Å.

  14. Synthesis and crystal structures of 2-methyl-4-aryl-5-oxo-5H-indeno [1,2-b] pyridine carboxylate derivatives

    DEFF Research Database (Denmark)

    Pandian, Ramesh; Naushad, Edayadulla; Vijayakumar, Vinodhkumar

    2014-01-01

    pyridine derivatives through oxidation. Consequently, the interest in this aromatization reaction, investigation of a wide range of 1, 4-DHPs continues to attract the attention of researchers. Herein, we report the preparation of pyridine derivatives and the crystal structures determined by X......-ray crystallographic methods.Results: The crystal structures and conformational studies of two organic compounds, namely ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (I) and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate (II) are reported. The terminal ethyl......) dimer running along 011 direction.Conclusion: The crystal structures ethyl 2-methyl-4-phenyl-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate and ethyl 2-methyl-4-(4 chlorophenyl)-5-oxo-5H-indeno [1,2-b] pyridine-3-carboxylate have been investigated in detail. The terminal ethyl group of compound I...

  15. Extraction of bivalent vanadium as its pyridine thiocyanate complex and separation from uranium, titanium, chromium and aluminium

    International Nuclear Information System (INIS)

    Yatirajam, V.; Arya, S.P.

    1975-01-01

    A simple method is described for the extraction of V(II) as its pyridine thiocyanate complex. Vanadate is reduced to V(II) in 1 to 2 N sulphuric acid by zinc amalgam. Thiocyanate and pyridine are added, the solution is adjusted to pH 5.2 to 5.5 and the complex extracted with chloroform. The vanadium is back-extracted with peroxide solution. Zinc from the reductant accompanies the vanadium but alkali and alkaline earth metal ions, titanium, uranium, chromium and aluminium are separated, besides those ions reduced to the elements by zinc amalgam. The method takes about 20 min and is applicable to microgram as well as milligram amounts of vanadium. (author)

  16. Antiinflammatory and neurological activity of pyrithione and related sulfur-containing pyridine N-oxides from Persian shallot (Allium stipitatum)

    DEFF Research Database (Denmark)

    Krejčová, Petra; Kučerová, Petra; Stafford, Gary Ivan

    2014-01-01

    ETHNOPHARMACOLOGICAL RELEVANCE: Persian shallot (Allium stipitatum) is a bulbous plant native to Turkey, Iran and Central Asia. It is frequently used in folk medicine for the treatment of a variety of disorders, including inflammation and stress. Antiinflammatory and neurological activities...... of pyrithione and four related sulfur-containing pyridine N-oxides which are prominent constituents of Allium stipitatum were tested. METHODS: The antiinflammatory activity was tested by the ability of the compounds to inhibit cyclooxygenase (COX-1 and COX-2), whereas the neurological activities were evaluated...... by assessing the compounds ability to inhibit monoamine oxidase-A (MAO-A) and acetylcholinesterase (AChE). The compounds׳ affinity for the serotonin transport protein (SERT) and the GABAA-benzodiazepine receptor were also investigated. RESULTS: 2-[(Methylthio)methyldithio]pyridine N-oxide showed very high...

  17. Direct Alkynylation of 3H-Imidazo[4,5-b]pyridines Using gem-Dibromoalkenes as Alkynes Source.

    Science.gov (United States)

    Aziz, Jessy; Baladi, Tom; Piguel, Sandrine

    2016-05-20

    C2 direct alkynylation of 3H-imidazo[4,5-b]pyridine derivatives is explored for the first time. Stable and readily available 1,1-dibromo-1-alkenes, electrophilic alkyne precursors, are used as coupling partners. The simple reaction conditions include an inexpensive copper catalyst (CuBr·SMe2 or Cu(OAc)2), a phosphine ligand (DPEphos) and a base (LiOtBu) in 1,4-dioxane at 120 °C. This C-H alkynylation method revealed to be compatible with a variety of substitutions on both coupling partners: heteroarenes and gem-dibromoalkenes. This protocol allows the straightforward synthesis of various 2-alkynyl-3H-imidazo[4,5-b]pyridines, a valuable scaffold in drug design.

  18. 2,3-Diamino­pyridinium 6-carb­oxy­pyridine-2-carboxyl­ate

    Science.gov (United States)

    Foroughian, Mahsa; Foroumadi, Alireza; Notash, Behrouz; Bruno, Giuseppe; Amiri Rudbari, Hadi; Aghabozorg, Hossein

    2011-01-01

    The asymmetric unit of the title proton-transfer compound, C5H8N3 +·C7H4NO4 −, consists of one mono-deprotonated pyridine-2,6-dicarb­oxy­lic acid as anion and one protonated 2,3-diamino­pyridine as cation. The crystal packing shows extensive O—H⋯O, N—H⋯O and N—H⋯N hydrogen bonds. Thre are also several π–π inter­actions between the anions and also between the cations [centriod–centroid distances = 3.6634 (7), 3.7269 (7), 3.6705 (7) and 3.4164 (7) Å]. PMID:22199823

  19. 4-Benzyl-6-bromo-2-(4-methoxyphenyl-4H-imidazo[4,5-b]pyridine monohydrate

    Directory of Open Access Journals (Sweden)

    Y. Ouzidan

    2010-04-01

    Full Text Available The imidazopyridine fused ring in the title compound, C20H16BrN3O·H2O, is coplanar with the aromatic ring at the 2-position [dihedral angle = 5.2 (1°]. In the five-membered imidazo portion, the C—N bond whose C atom is also connected to the pyridine N atom has predominantly double-bond character [1.334 (2 Å] whereas the C—N bond whose atom is connected to the pyridine C atom has predominantly single-bond character [1.371 (2 Å]. The water molecule engages in hydrogen bonding with the latter N atom; it is also connected to a symmetry-related water molecule, generating a linear chain structure.

  20. Synthesis of trifluoromethyl-substituted pyrazolo[4,3-c]pyridines – sequential versus multicomponent reaction approach

    Directory of Open Access Journals (Sweden)

    Barbara Palka

    2014-07-01

    Full Text Available A straightforward synthesis of 6-substituted 1-phenyl-3-trifluoromethyl-1H-pyrazolo[4,3-c]pyridines and the corresponding 5-oxides is presented. Hence, microwave-assisted treatment of 5-chloro-1-phenyl-3-trifluoromethylpyrazole-4-carbaldehyde with various terminal alkynes in the presence of tert-butylamine under Sonogashira-type cross-coupling conditions affords the former title compounds in a one-pot multicomponent procedure. Oximes derived from (intermediate 5-alkynyl-1-phenyl-3-trifluoromethyl-1H-pyrazole-4-carbaldehydes were transformed into the corresponding 1H-pyrazolo[4,3-c]pyridine 5-oxides by silver triflate-catalyzed cyclization. Detailed NMR spectroscopic investigations (1H, 13C, 15N and 19F were undertaken with all obtained products.

  1. Dynamic changes in nicotinamide pyridine dinucleotide content in normal human epidermal keratinocytes and their effect on retinoic acid biosynthesis

    International Nuclear Information System (INIS)

    Pinkas-Sarafova, Adriana; Markova, N.G.; Simon, M.

    2005-01-01

    The function of many enzymes that regulate metabolism and transcription depends critically on the nicotinamide pyridine dinucleotides. To understand the role of NAD(P)(H) in physiology and pathophysiology, it is imperative to estimate both their amount and ratios in a given cell type. In human epidermis and in cultured epidermal keratinocytes, we found that the total dinucleotide content is in the low millimolar range. The dinucleotide pattern changes during proliferation and maturation of keratinocytes in culture. Differences in the concentrations of NAD(P)(H) of 1.5- to 12-fold were observed. This resulted in alteration of the NAD(P)H/NAD(P) ratio, which could impact the differential regulation of both transcriptional and metabolic processes. In support of this notion, we provide evidence that the two-step oxidation of retinol to retinoic acid, a nuclear hormone critical for epidermal homeostasis, can be regulated by the relative physiological amounts of the pyridine dinucleotides

  2. Di-μ-iodido-bis(iodido{methyl 4-[(pyridin-2-ylmethylideneamino]benzoate-κ2N,N′}cadmium

    Directory of Open Access Journals (Sweden)

    Tushar S. Basu Baul

    2013-11-01

    Full Text Available The complete binuclear molecule of the title compound, [Cd2I4(C14H12N2O22], is generated by the application of a centre of inversion. The Cd—I bond lengths of the central core are close and uniformly longer than the exocyclic Cd—I bond. The coordination sphere of the CdII atom is completed by two N atoms of a chelating methyl 4-[(pyridin-2-ylmethylideneamino]benzoate ligand, and is based on a square pyramid with the terminal I atom in the apical position. The three-dimensional crystal packing is stabilized by C—H...O and C—H...π interactions, each involving the pyridine ring.

  3. N-[5-Methyl-2-(2-nitrophenyl-4-oxo-1,3-thiazolidin-3-yl]pyridine-3-carboxamide monohydrate

    Directory of Open Access Journals (Sweden)

    Mehmet Akkurt

    2011-02-01

    Full Text Available In the title compound, C16H14N4O4S·H2O, the benzene and pyridine rings make a dihedral angle of 85.8 (1°. Both enantiomers of the chiral title compound are statistically disordered over the same position in the unit cell. The methyl and carbonyl group attached to the stereogenic center (C5 of the thiazolidine ring were therefore refined with common site-occupation factors of 0.531 (9 and 0.469 (9, respectively, for each stereoisomer. In the crystal, intermolecular N—H...O, O—H...O and O—H...N hydrogen bonds link the molecules, forming a three-dimensional supramolecular network. The crystal structure further shows π–π stacking interactions [centroid–centroid distance = 3.5063 (13 Å] between the pyridine rings.

  4. Pyridine-promoted dediazoniation of aryldiazonium tetrafluoroborates: Application to the synthesis of SF5-substituted phenylboronic esters and iodobenzenes

    Czech Academy of Sciences Publication Activity Database

    Iakobson, George; Du, J.; Slawin, A. M. Z.; Beier, Petr

    2015-01-01

    Roč. 11, Aug 26 (2015), s. 1494-1502 ISSN 1860-5397 R&D Projects: GA ČR GAP207/12/0072 Institutional support: RVO:61388963 Keywords : borylation * diazonium salts * iodination * pyridine * sulfur pentafluorides Subject RIV: CC - Organic Chemistry Impact factor: 2.697, year: 2015 http://www.beilstein-journals.org/bjoc/single/articleFullText.htm?publicId=1860-5397-11-162

  5. Ultrasound-Promoted One-Pot, Four-Component Synthesis of Pyridin-2(1H-One Derivatives

    Directory of Open Access Journals (Sweden)

    Jinming Yang

    2013-11-01

    Full Text Available An efficient one-pot synthesis of 1,6-diamino-2-oxo-1,2,3,4-tetrahydro- pyridine-3,5-dicarbonitrile derivatives by four-component piperidine-catalyzed reactions of a ketone, malononitrile, ethyl cyanoacetate and hydrazine hydrate under ultrasound irradiation is described. This method provides several advantages such as shorter reaction times, excellent yields, and a simple workup procedure.

  6. (E-5,6-Dimethoxy-2-(pyridin-4-ylmethylidene-2,3-dihydro-1H-inden-1-one

    Directory of Open Access Journals (Sweden)

    Mohamed Ashraf Ali

    2010-11-01

    Full Text Available The molecule of the title compound, C17H15NO3, is slightly twisted, with a dihedral angle of 12.12 (3° between the dihydroindenone group and the pyridine ring. In the crystal, molecules are connected into layers parallel to the ab plane via intermolecular C—H...O hydrogen bonds. Weak π–π [centroid–centroid distance = 3.5680 (6 Å] interactions are also observed.

  7. Determination of submicromolar amounts of uranium(VI) by compleximetric titration with pyridine-2,6-dicarboxylic acid

    International Nuclear Information System (INIS)

    Marsh, S.F.; Betts, M.R.; Rein, J.E.

    1980-01-01

    Uranium(VI) is selectively determined by a compleximetric titration with pyridine-2,6-dicarboxylic acid, using arsenazo-I indicator and hexamethylenetetramine buffer at pH 4.9. Cyclohexanediaminetetraacetic acid and diethylenetriaminepentaacetic acid provide masking of interfering metal ions. A probe colorimeter apparatus is recommended for end-point detection. The relative standard deviation is 0.6% for 0.17-0.76 μmol of uranium. (Auth.)

  8. Determination of submicromolar amounts of uranium(VI) by compleximetric titration with pyridine-2,6-dicarboxylic acid

    Energy Technology Data Exchange (ETDEWEB)

    Marsh, S F; Betts, M R; Rein, J E [Los Alamos Scientific Lab., NM (USA)

    1980-10-01

    Uranium(VI) is selectively determined by a compleximetric titration with pyridine-2,6-dicarboxylic acid, using arsenazo-I indicator and hexamethylenetetramine buffer at pH 4.9. Cyclohexanediaminetetraacetic acid and diethylenetriaminepentaacetic acid provide masking of interfering metal ions. A probe colorimeter apparatus is recommended for end-point detection. The relative standard deviation is 0.6% for 0.17-0.76 ..mu..mol of uranium.

  9. Synthesis and physicochemical properties of 7,8-dicarba-nido-undecarborane(11) adducts with pyridine bases

    International Nuclear Information System (INIS)

    Volkov, O.V.; Il'inchik, E.A.; Volkov, V.V.; Voronina, G.S.; Yur'eva, O.P.; Polyanskaya, T.M.

    1993-01-01

    Synthesis of some 7,8-C 2 B 9 H 11 adducts in conducted via 7.8-C 2 B 9 H 12 ion interaction with iron (3) chloride at presence of pyridine derivatives and their study is carried out using IR, NMR 12 B, PMR, X-ray phase, UV spectroscopy techniques. Character of bond between heterocycle and carborane holyhedron is discussed. Luminescent properties of the prepared compounds under UV radiation are detected

  10. Quantum-chemical ab initio and B3LYP study of donor-acceptor complexes of gallium halides with pyridine

    International Nuclear Information System (INIS)

    Timoshkin, A.Yu.; Suvorov, A.V.; Shefer, G.F.

    1999-01-01

    By the ab initio and density functional methods the structural characteristics and vibrational spectra of gallium iodide donor-acceptor complexes with pyridine have been calculated. The standard thermodynamic characteristics of GaI 3 Py complex dissociation in gaseous phase have been calculated, as well. Short I-H intramolecular distances suggest that hydrogen iodide elimination with Ga-N chemical bond retention is the first stage of the complex pyrolysis [ru

  11. Methyl 2-({6-[(1-methoxy-2-methyl-1-oxopropan-2-ylcarbamoyl]pyridin-2-yl}formamido-2-methylpropanoate

    Directory of Open Access Journals (Sweden)

    Abdel-Galil E. Amr

    2012-05-01

    Full Text Available In the title compound, C17H23N3O6, the two methoxycarbonyl C—O—C=O planes are inclined at dihedral angles of 5.3 (4 and 83.9 (4° with respect to the central pyridine ring. An intramolecular N—H...O hydrogen bond generates an S(5 ring motif. In the crystal, molecules are linked into a chain along the c axis via C—H...O hydrogen bonds.

  12. Direct detection of pyridine formation by the reaction of CH (CD) with pyrrole: a ring expansion reaction

    Energy Technology Data Exchange (ETDEWEB)

    Soorkia, Satchin; Taatjes, Craig A.; Osborn, David L.; Selby, Talitha M.; Trevitt, Adam J.; Wilson, Kevin R.; Leone, Stephen R.

    2010-03-16

    The reaction of the ground state methylidyne radical CH (X2Pi) with pyrrole (C4H5N) has been studied in a slow flow tube reactor using Multiplexed Photoionization Mass Spectrometry coupled to quasi-continuous tunable VUV synchrotron radiation at room temperature (295 K) and 90 oC (363 K), at 4 Torr (533 Pa). Laser photolysis of bromoform (CHBr3) at 248 nm (KrF excimer laser) is used to produce CH radicals that are free to react with pyrrole molecules in the gaseous mixture. A signal at m/z = 79 (C5H5N) is identified as the product of the reaction and resolved from 79Br atoms, and the result is consistent with CH addition to pyrrole followed by Helimination. The Photoionization Efficiency curve unambiguously identifies m/z = 79 as pyridine. With deuterated methylidyne radicals (CD), the product mass peak is shifted by +1 mass unit, consistent with the formation of C5H4DN and identified as deuterated pyridine (dpyridine). Within detection limits, there is no evidence that the addition intermediate complex undergoes hydrogen scrambling. The results are consistent with a reaction mechanism that proceeds via the direct CH (CD) cycloaddition or insertion into the five-member pyrrole ring, giving rise to ring expansion, followed by H atom elimination from the nitrogen atom in the intermediate to form the resonance stabilized pyridine (d-pyridine) molecule. Implications to interstellar chemistry and planetary atmospheres, in particular Titan, as well as in gas-phase combustion processes, are discussed.

  13. Spectrophotometric determination of palladium (II) with rubeanic acid (RA) in presence of pyridine, piperidine and 3-picoline

    International Nuclear Information System (INIS)

    Hassiruzzaman, M.; Hossain, M.A.; Rahman, G.M.M.; Kamal, A.S.M.; Kabir, M.H.; Mustafa, A.I.

    1999-01-01

    Unpretentious and exclusive methods for the spectrophotometric determination of trace amount of divalent palladium (II) have been developed with rubeanic acid (dithio-oxamide) in presence of secondary ligands like pyridine, piperidine and 3-picoline. Both direct and extraction spectrophotometry showed that coloured rubeanates are only stable in acidic medium. The violent yellow coloured products are formed below ph 5.0 with an absorption maxima at 416.0 and 422.0 (pyridine), 405.0 and 416.5 (piperidine) and 418.0 and 422.0 (3-picoline) both in direct and isoamyl alcohol (IAA) extracted system, respectively. Results indicate that the highest sensitivity and molar absorptivity of Pd-RA pyridine system in direct spectrophotometry were 0.01497 mu g Pd(II) cm/sup -2/ and 7107.89 L mol sup -1/ cm/sup -1/ respectively. IAA extracted Pd-RA-piperidine system was found to give a sensitivity of 0.01087 mu g(Pd(II) cm /sup -2/ and molar absorptivity of 9788.80 L mol /sup -1/ cm/sup -1/ which were the highest of all the system. The effects due to variation of pH, reagent concentrations, order of addition of reagents, time, temperature and solvent media on the absorption spectra have been investigated and the optimum conditions determined. The effects of diverse ions and their tolerance limit have also been studies. (author)

  14. Synthesis and structure of pyridine-functionalized mesoporous SBA-15 organosilicas and their application for sorption of diclofenac

    Science.gov (United States)

    Barczak, Mariusz

    2018-02-01

    A series of pyridine-functionalized mesoporous silicas have been prepared for the first time via direct co-condensation of tetraethoxysilane (TEOS) and 2-(2-pyridyl)ethyltrimethoxysilane (PETS) using the block copolymer Pluronic P123 as a structure-directing agent. The obtained materials were fully characterized by a wide range of instrumental techniques and employed as adsorbents for the removal of a diclofenac which is considered a priority hazardous drug. The synthesized materials exhibit a high adsorption capacities and rapid adsorption rates. The structural and adsorption properties depend largely on the relative amount of PETS/TEOS ratio: the gradual degradation of ordered structure and porosity was observed with the increasing amount of PETS. However due to the highest loading of pyridine units the most structurally degraded material had the highest adsorption uptake (631 mg g-1) indicating that the surface chemistry plays - along with porosity - an important role in governing the adsorption process. The experimental adsorption data were modelled using the Langmuir, Freundlich and Langmuir-Freundlich isotherms - among them the Langmuir-Freundlich model turned out to be the most suitable for describing adsorption behaviour of diclofenac onto the materials. The collected data show that the pyridine-functionalized mesoporous silicas can be a promising absorbent of pharmaceuticals.

  15. Zirconium and Titanium Propylene Polymerization Precatalysts Supported by a Fluxional C 2 -Symmetric Bis(anilide)pyridine Ligand

    KAUST Repository

    Tonks, Ian A.

    2012-03-12

    Titanium and zirconium complexes supported by a bis(anilide)pyridine ligand (NNN = pyridine-2,6-bis(N-mesitylanilide)) have been synthesized and crystallographically characterized. C 2-symmetric bis(dimethylamide) complexes were generated from aminolysis of M(NMe 2) 4 with the neutral, diprotonated NNN ligand or by salt metathesis of the dipotassium salt of NNN with M(NMe 2) 2Cl 2. In contrast to the case for previously reported pyridine bis(phenoxide) complexes, the ligand geometry of these complexes appears to be dictated by chelate ring strain rather than metal-ligand π bonding. The crystal structures of the five-coordinate dihalide complexes (NNN)MCl 2 (M = Ti, Zr) display a C 1-symmetric geometry with a stabilizing ipso interaction between the metal and the anilido ligand. Coordination of THF to (NNN)ZrCl 2 generates a six-coordinate C 2-symmetric complex. Facile antipode interconversion of the C 2 complexes, possibly via flat C 2v intermediates, has been investigated by variable-temperature 1H NMR spectroscopy for (NNN)MX 2(THF) n (M = Ti, Zr; X = NMe 2, Cl) and (NNN)Zr(CH 2Ph) 2. These complexes were tested as propylene polymerization precatalysts, with most complexes giving low to moderate activities (10 2-10 4 g/(mol h)) for the formation of stereoirregular polypropylene. © 2012 American Chemical Society.

  16. Crystal structures of three co-crystals of 1,2-bis-(pyridin-4-yl)ethane with 4-alk-oxy-benzoic acids: 4-eth-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1), 4-n-propoxybenzoic acid-1,2-bis(pyridin-4-yl)ethane (2/1) and 4-n-but-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1).

    Science.gov (United States)

    Tabuchi, Yohei; Gotoh, Kazuma; Ishida, Hiroyuki

    2015-11-01

    The crystal structures of three hydrogen-bonded co-crystals of 4-alk-oxy-benzoic acid-1,2-bis-(pyridin-4-yl)ethane (2/1), namely, 2C9H10O3·C12H12N2, (I), 2C10H12O3·C12H12N2, (II), and 2C11H14O3·C12H12N2, (III), have been determined at 93, 290 and 93 K, respectively. In (I), the asymmetric unit consists of one 4-eth-oxy-benzoic acid mol-ecule and one half-mol-ecule of 1,2-bis-(pyridin-4-yl)ethane, which lies on an inversion centre. In (II) and (III), the asymmetric units each comprise two crystallographically independent 4-alk-oxy-benzoic acid mol-ecules and one 1,2-bis-(pyridin-4-yl)ethane mol-ecule. In each crystal, the two components are linked by O-H⋯N hydrogen bonds, forming a linear hydrogen-bonded 2:1unit of the acid and the base. Similar to the structure of 2:1 unit of (I), the units of (II) and (III) adopt nearly pseudo-inversion symmetry. The 2:1 units of (I), (II) and (III) are linked via C-H⋯O hydrogen bonds, forming tape structures.

  17. Controlled interactions between anhydrous keggin-type heteropolyacids and silica support: Preparation and characterization of well-defined silica-supported polyoxometalate species

    KAUST Repository

    Grinenval, Eva

    2010-11-11

    Anhydrous Keggin-type phosphorus heteropolyacids were deposited on partially dehydroxylated silica by using the surface organometallic chemistry (SOMC) strategy. The resulting solids were characterized by a combination of physicochemical methods including IR, Raman, 1D and 2D 1H, and 31P MAS NMR, electron microscopy experiments and density functional theory (DFT) calculations. It is shown that the main surface species is [ - Si(OH...H+)]2[H+]1[PM 12O403-] where the polyoxometalate is linked to the support by proton interaction with two silanols. Two other minor species (10% each) are formed by coordination of the polyoxometalate to the surface via the interaction between all three protons with three silanol groups or via three covalent bonds formed by dehydroxylation of the above species. Comparison of the reactivity of these solids and of compounds prepared by a classical way shows that the samples prepared by the SOMC approach contain ca. 7 times more acid sites. © 2010 American Chemical Society.

  18. Roll Compaction/Dry Granulation of Dibasic Calcium Phosphate Anhydrous-Does the Morphology of the Raw Material Influence the Tabletability of Dry Granules?

    Science.gov (United States)

    Grote, Simon; Kleinebudde, Peter

    2018-04-01

    The influence of raw material particle morphology on the tabletabilty of dry granules was investigated. Therefore, dibasic calcium phosphate anhydrous was used as a model material. One milled grade, 2 agglomerated grades with different porosities, and a functionalized structure, that is, an agglomerate formed by very small primary particles, were included. Particle size, density, and specific surface area of raw materials were measured. The starting materials and 2 fractions of dry granules were compressed to tablets. The tabletability of granules was compared to that of the powders and the influence of specific compaction force, granule size, and lubrication on tablet tensile strength was evaluated. All materials showed a loss in tabletability induced by a previous compaction step but to a varying extent. Only in case of the functionalized calcium phosphate morphology, this effect depended on the specific compaction force. In contrast to the other materials, the tabletability of functionalized calcium phosphate was influenced by the granule size. This effect was not related to an overlubrication as internal and external lubrication resulted in similar tensile strengths. A clear influence of the particle morphology on tablet strength was demonstrated by the study. The functionalized structure showed aspects of a more plastic deformation behavior. The functionalized dibasic calcium phosphate and the more porous agglomerate performed as potential filler/binder in the field of roll compaction/dry granulation. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

  19. Predictive evaluation of pharmaceutical properties of direct compression tablets containing theophylline anhydrate during storage at high humidity by near-infrared spectroscopy.

    Science.gov (United States)

    Otsuka, Yuta; Yamamoto, Masahiro; Tanaka, Hideji; Otsuka, Makoto

    2015-01-01

    Theophylline anhydrate (TA) in tablet formulation is transformed into monohydrate (TH) at high humidity and the phase transformation affected dissolution behavior. Near-infrared spectroscopic (NIR) method is applied to predict the change of pharmaceutical properties of TA tablets during storage at high humidity. The tablet formulation containing TA, lactose, crystalline cellulose and magnesium stearate was compressed at 4.8 kN. Pharmaceutical properties of TA tables were measured by NIR, X-ray diffraction analysis, dissolution test and tablet hardness. TA tablet was almost 100% transformed into TH after 24 hours at RH 96%. The pharmaceutical properties of TA tablets, such as tablet hardness, 20 min dissolution amount (D20) and increase of tablet weight (TW), changed with the degree of hydration. Calibration models for TW, tablet hardness and D20 to predict the pharmaceutical properties at high-humidity conditions were developed on the basis of the NIR spectra by partial least squares regression analysis. The relationships between predicted and actual measured values for TW, tablet hardness and D20 had straight lines, respectively. From the results of NIR-chemometrics, it was confirmed that these predicted models had high accuracy to monitor the tablet properties during storage at high humidity.

  20. Anhydrous thallium hydrogen L-glutamate: polymer networks formed by sandwich layers of oxygen-coordinated thallium ions cores shielded by hydrogen L-glutamate counterions.

    Science.gov (United States)

    Bodner, Thomas; Wirnsberger, Bianca; Albering, Jörg; Wiesbrock, Frank

    2011-11-07

    Anhydrous thallium hydrogen L-glutamate [Tl(L-GluH)] crystallizes from water (space group P2(1)) with a layer structure in which the thallium ions are penta- and hexacoordinated exclusively by the oxygen atoms of the γ-carboxylate group of the hydrogen L-glutamate anions to form a two-dimensional coordination polymer. The thallium-oxygen layer is composed of Tl(2)O(2) and TlCO(2) quadrangles and is only 3 Å high. Only one hemisphere of the thallium ions participates in coordination, indicative of the presence of the 6s(2) lone pair of electrons. The thallium-oxygen assemblies are shielded by the hydrogen l-glutamate anions. Only the carbon atom of the α-carboxylate group deviates from the plane spanned by the thallium ions, the γ-carboxylate groups and the proton bearing carbon atoms, which are in trans conformation. Given the abundance of L-glutamic and L-aspartic acid in biological systems on the one hand and the high toxicity of thallium on the other hand, it is worth mentioning that the dominant structural motifs in the crystal structure of [Tl(L-GluH)] strongly resemble their corresponding analogues in the crystalline phase of [K(L-AspH)(H(2)O)(2)].

  1. Proposed replacement and operation of the anhydrous hydrogen fluoride supply and fluidized-bed chemical processing systems at Building 9212, Y-12 Plant, Oak Ridge, Tennessee

    International Nuclear Information System (INIS)

    1995-09-01

    The US Department of Energy (DOE) proposes to replace the existing anhydrous hydrogen fluoride (AHF) supply and fluidized-bed reactor systems for the Weapons Grade Highly Enriched Uranium Chemical Recovery and Recycle Facility, Building 9212, which is located within the Y-12 Plant on DOE's Oak Ridge Reservation in Oak Ridge, Tennessee. The proposed replacement system would be based upon modern design criteria and safety analyses. The replacement AHF supply and distribution system equipment would be located on the existing Dock 8/8A at Building 9212. Utilities would be extended to the dock to service the process equipment. The following process equipment modules would be prefabricated for installation at the modified dock: an AHF cylinder enclosure, an AHF supply manifold and vaporizer module, an AHF sump tank and transfer skid, and an AHF supply off-gas scrubber assembly module. The fluidized-bed reactor system would be constructed in an area adjacent to the existing system in Building 9212. The replacement equipment would consist of a new reduction fluidized-bed reactor, a hydrofluorination fluidized-bed reactor, and associated air emission control equipment. The no-action alternative, which is the continued operation of the existing AHF supply and fluidized-bed reactor systems, was also evaluated

  2. Utilization of diesel fuel, anhydrous ethanol and additives blend of a stationary diesel engine with rotatory pump; Utilizacao de mistura ternaria alcool, diesel e aditivo em motores do ciclo diesel com bomba de injecao rotativa

    Energy Technology Data Exchange (ETDEWEB)

    Reyes Cruz, Yordanka; Cavado Osorio, Alberto [Centro de Pesquisas de Petroleo (CEINPET), Havana (Cuba); Belchior, Carlos Rodrigues Pereira; Pereira, Pedro P.; Pinto, Nauberto Rodrigues [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Centro de Tecnologia. Dept. de Engenharia Naval e Mecanica; Aranda, Donato A. Gomes [Universidade Federal do Rio de Janeiro (UFRJ), RJ (Brazil). Escola de Quimica

    2008-07-01

    In this paper is analyzed the performance and fuel consumption of a stationary Diesel engine, with rotary diesel fuel injection pump, using (diesel fuel + anhydrous ethanol + 0.5% additive) blend. The engine performance parameters and fuel consumption tests were performed at the Termic Machine Laboratory, located in Federal University of Rio de Janeiro, and evaluated using a MWM Series 10 model 4.10 TCA. Two test cycles were used for this test program: the tests were carried out starting from the base diesel S-500, used as a reference; the engine operated with (diesel fuel S-500 - 8% anhydrous ethanol - DIOLEFECT additive (0,5% SPAN80 + 0,1% Biomix-D)) blend. The results indicate that: the reduction levels in power and torque of engine are approximately the same which is (2,55{+-}2%), the brake specific fuel consumption increased in 1,8%. (author)

  3. The formation of scientists and technicians at the 'Centre d'Etudes Nucleaires' at Saclay

    International Nuclear Information System (INIS)

    Debiesse, J.

    1958-01-01

    The considerable needs in research workers and scientists which are asked by the nuclear energy obliged the Commissariat a l'Energie atomique to deal with a particular effort to increase the quantitative and qualitative formation of scientists. Most various ways have been used. 1- A National Institute of Nuclear Sciences and Nuclear Techniques was created, by a joint decree of the Prime Minister and the Minister for National Education (june 18, 1957). This Institute of Higher Teaching (250 students) indulges in the following matters: atomic engineering, quantum mechanics, theory and technic of particle accelerators, special metallurgy, radiobiology, thermic and mechanics of fluids. 2- An associated centre of the 'Conservatoire National des Arts et Metiers' was created (200 students) for technical assistants, drawers, etc. 3- In contribution with both electronic industry and Ministry of Work, the Centre d'Etudes Nucleaires contributes to an accelerated formation of technical assistants into Professional Centres. Conclusion: Training of scientists and research workers is one of the most important activities of the Centre d'Etudes Nucleaires de Saclay. Without losing its technical efficiency, it has supplied and varied means adapted to the various purposes that we shall reach. (author) [fr

  4. Synthesis and properties of di- and trinitrobenzyl substituted pyridine derivates. The paper is supposed to be published in the special issue of the ESOR XII 2009 meeting in Haifa. Editor of the issue is Amnon Stanger

    OpenAIRE

    2010-01-01

    Abstract A new method to obtain di- and trinitrobenzyl substituted pyridines is presented. By systematic variation of reaction parameters the reaction conditions were optimized. The novel synthesis circumvents the commonly used nitration of benzyl pyridines, and thus avoids the nitration of the heterocycle which is a common side reaction. Furthermore, the starting materials for the synthesis of a variety of photochromic nitrobenzyl pyridines are easily accessible. The half-lifes of...

  5. High conductive, long-term durable, anhydrous proton conductive solid-state electrolyte based on a metal-organic framework impregnated with binary ionic liquids: Synthesis, characteristic and effect of anion

    Science.gov (United States)

    Chen, Hui; Han, Shu-Yan; Liu, Rui-Heng; Chen, Teng-Fei; Bi, Kai-Lun; Liang, Jian-Bo; Deng, Yu-Heng; Wan, Chong-Qing

    2018-02-01

    Incorporating ionic liquids (abbreviated as ILs) into porous metal-organic framework (MOF) to obtain ILs@MOF nanocomposites is documented as a feasible method to achieve new type of anhydrous proton conductor with high performance. We newly synthesized a series of ILs with different acid counter anions (R-SO3-) and their ILs@MOF hybrid materials, i.e. SA-EIMS@MIL-101, MSA-EIMS@MIL-101 and PTSA-EIMS@MIL-101 (SA = sulfate acid, MSA = methanesulfonate acid, PTSA = p-toluenesulfonate acid, EIMS = 1-(1-ethyl-3-imidazolium)propane-3-sulfonate). Such hybrid materials displayed as anhydrous proton conduction with long-term durability even heated at 150 °C open to air. σ value of SA-EIMS@MIL-101 is up to 1.89 × 10-3 S cm-1, being in the range of the most conductive MOF-based materials. MOF support exhibited favorable proton transport and long-term retention for ILs. Anion volumes of R-SO3- displayed significant effects on the proton conductivity of such hybrid ILs@MOF materials. The smaller the van der Waals volume of R-SO3- is, the higher the conductivity of ILs@MOF is. This work suggests that the combination of a variety of the incorporated ILs and a MOF framework would afford high proton transport and gives an idea to explore the safe, anhydrous, solid-state electrolyte for high temperature proton exchange membrane fuel cell.

  6. Poly[tetraaqua-μ3-pyridine-3,5-dicarboxylato-strontium(II

    Directory of Open Access Journals (Sweden)

    Shirin Daneshvar

    2008-02-01

    Full Text Available The reaction of strontium(II nitrate with the proton-transfer compound (pdaH2(py-3,5-dc·H2O (where pda = propane-1,3-diamine and py-3,5-dcH2 = pyridine-3,5-dicarboxylic acid leads to the formation of the title polymeric compound, [Sr(C7H3NO4(H2O4]n. The propane-1,3-diaminium cation is not incorporated in this crystal structure. The SrII atom lies on an inversion centre and is eight-coordinated by four O atoms from three py-3,5-dc ligands and four O atoms from four coordinated water molecules. The coordination polyhedron of the SrII atom is a distorted dodecahedron. These binuclear units are connected via the carboxylate O atoms to build a one-dimensional polymeric chain. In the crystal structure, non-covalant interactions consisting of hydrogen bonds (X—H...O, with X = O and C and π–π stacking interactions [3.4604 (19 Å] connect the various components to form a supramolecular structure.

  7. Aluminium effects on pyridine nucleotide redox state in roots of Scots pine

    Directory of Open Access Journals (Sweden)

    Gabriela Lorenc-Plucińska

    2014-01-01

    Full Text Available After prolonged (3-9 weeks hydroponic treatment of Scots pine seedlings with different concentrations (0.5-4.0 mM of Al (AI(N033, the levels of pyridine nucleotides were determined in root homogenates. After 3 weeks of Al stress, a significant decrease of the anabolic reduction charge (ARC: NADPH/(NADP+ + NADPH and an increase of the redox status (NAD(PH/NAD(P+, catabolic reduction charge (CRC: NADH/(NAD+ + NADH and phosphorylation capacity expressed as NADP+/NAD+ ratio was found in the 4.0 mM Al treatment. After 6 weeks, Al at concentrations of 0.5 and 1.0 mM induced an enhancement of the NADH level and a reduction of NADPH level, but the redox ratios were not changed significantly. After 9 weeks treatment with Al concentrations ranging from 0.5 to 4.0 mM, decreases of the relative level of NADP+, NADPH and NADH and increases of NAD+ were found. Consequently, the CRC, NAD(PH/NAD(P+ and NADP+/NAD+ ratios reached a minimum and ARC a maximum as compared to previous measurements.

  8. A method for the determination of ascorbic acid using the iron(II)-pyridine-dimethylglyoxime complex

    Energy Technology Data Exchange (ETDEWEB)

    Arya, S. P.; Mahajan, M. [Haryana, Kurukshetra Univ. (India). Dept. of Chemistry

    1998-05-01

    A simple and rapid spectrophotometric method for the determination of ascorbic acid is proposed. Ascorbic acid reduces iron (III) to iron (II) which forms a red colored complex with dimethylglyoxime in the presence of pyridine. The absorbance of the resulting solution is measured at 514 nm and a linear relationship between absorbance and concentration of ascorbic acid is observed up to 14 {mu}g ml{sup -1}. Studies on the interference of substances usually associated with ascorbic acid have been carried out and the applicability of the method has been tested by analysing pharmaceutical preparations of vitamin C. [Italiano] Si propone un rapido e semplice metodo spettrofotometrico per la determinazione dell`acido ascorbico. L`acido ascorbico riduce il ferro(III) a ferro(II) che forma con la dimetilgliossima, in presenza di piridina, un complesso colorato in rosso. L`assorbanza della soluzione risultante e` misurata a 514 nm e si ottiene una relazione lineare tra assorbanza e concentrazione dell`acido ascorbico fino a 14 {mu}g ml{sup -1}. Si sono condotti studi sugli interferenti usualmente associati all`acido ascorbico ed e` stata valutata l`applicabilita` del metodo all`analisi di preparati farmaceutici di vitamina C.

  9. Bis{2-[(diisopropylphosphanylamino]pyridine-κ2N1,P}copper(I hexafluoridophosphate

    Directory of Open Access Journals (Sweden)

    Özgür Öztopcu

    2010-07-01

    Full Text Available The crystal structure of the title compound, [Cu(C11H19N2P2]PF6, is composed of discrete [Cu(PN-iPr2]+ cations [PN-iPr is 2-(diisopropylphosphanylaminopyridine] and PF6− anions. The Cu(I atom is bis-chelated by two independent PN-iPr ligands. It has a distorted tetrahedral coordination by two P atoms [Cu—P = 2.2277 (4 and 2.2257 (4 Å] and two pyridine N atoms [Cu—N = 2.0763 (11 and 2.0845 (12 Å]. Bond angles about Cu vary from 85.11 (3 (P—Cu—N to 130.37 (2° (P—Cu—P. In the crystal, N—H...F hydrogen bonds link the Cu complexes and the PF6− anions into continuous chains, which show a cross-bedded spatial arrangement. In addition, several weaker C—H...F interactions contribute to the coherence of the structure.

  10. Pyridine-substituted thiazolylphenol derivatives: Synthesis, modeling studies, aromatase inhibition, and antiproliferative activity evaluation.

    Science.gov (United States)

    Ertas, Merve; Sahin, Zafer; Berk, Barkin; Yurttas, Leyla; Biltekin, Sevde N; Demirayak, Seref

    2018-04-01

    Drugs used in breast cancer treatments target the suppression of estrogen biosynthesis. During this suppression, the main goal is to inhibit the aromatase enzyme that is responsible for the cyclization and structuring of estrogens either with steroid or non-steroidal-type inhibitors. Non-steroidal derivatives generally have a planar aromatic structure attached to the triazole ring system in their structures, which inhibits hydroxylation reactions during aromatization by coordinating the heme group. Bioisosteric replacement of the triazole ring system and development of aromatic/cyclic structures of the side chain can increase the selectivity for aromatase enzyme inhibition. In this study, pyridine-substituted thiazolylphenol derivatives, which are non-steroidal triazole bioisosteres, were synthesized using the Hantzsch method, and physical analysis and structural determination studies were performed. The IC 50 values of the compounds were determined by a fluorescence-based aromatase inhibition assay. Then, their antiproliferative activities on the MCF7 and HEK 293 cell lines were evaluated with the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. Furthermore, the crystal structure of human placental aromatase was subjected to a series of docking experiments to identify the possible interactions between the most active structure and the active site. Lastly, an in silico technique was performed to analyze and predict the drug-likeness, molecular and ADME properties of the synthesized molecules. © 2018 Deutsche Pharmazeutische Gesellschaft.

  11. Theoretical study on the molecular tautomerism of the 3-hydroxy-pyridin-4-one system

    Science.gov (United States)

    Zborowski, Krzysztof K.; Mohammadpour, Mehrdad; Sadeghi, Amir; Proniewicz, Leonard M.

    2013-04-01

    3-hydroxy-pyridin-4-one is a parent molecule for the family of hydroxypyridinones that are known in coordination chemistry as efficient metal ions chelators. In this work, relative stabilities of some possible tautomers were investigated using several quantum chemical methods: CBS (complete basis set methods), Gn, DFT (density functional theory), Hartree-Fock and MP2. Performed calculations show that the system under consideration exists as a mixture of two tautomers with comparable energies. Among them, the hydroxypyridinone structure of the studied molecular system seems to be a bit more stable than the o-dihydroxypyridine one, by a few kJ/mol only. Aromaticity and intra-molecular hydrogen bonding are the main effects influencing the stability of the studied tautomeric structures. Consequently, aromatic effects were calculated using several indices of aromaticity: HOMA (harmonic oscillator model of aromaticity), NICS (nucleus independent chemical shift), H, PDI (para delocalisation index), MCI (multi-centre index) and ASE (aromatic stabilisation energy). The strength of possible intra-molecular hydrogen bonds (H-bonds) was determined by means of the AIM (atoms-in-molecules) method and by calculating enthalpies for theoretical reactions that do or do not involve H-bonds. The AIM method was employed to understand how variations in atomic energies influence the stability of different tautomeric structures.

  12. Combined MCD/DFT/TDDFT Study of the Electronic Structure of Axially Pyridine Coordinated Metallocorroles.

    Science.gov (United States)

    Rhoda, Hannah M; Crandall, Laura A; Geier, G Richard; Ziegler, Christopher J; Nemykin, Victor N

    2015-05-18

    A series of metallocorroles were investigated by UV-vis and magnetic circular dichroism spectroscopies. The diamagnetic distorted square-pyramidal main-group corrole Ga(tpfc)py (2), the diamagnetic distorted octahedral transition-metal adduct Co(tpfc)(py)2 (3), and paramagnetic distorted octahedral transition-metal complex Fe(tpfc)(py)2 (4) [H3tpfc = tris(perfluorophenyl)corrole] were studied to investigate similarities and differences in the electronic structure and spectroscopy of the closed- and open-shell metallocorroles. Similar to the free-base H3tpfc (1), inspection of the MCD Faraday B-terms for all of the macrocycles presented in this report revealed that a ΔHOMO MCD spectra. In addition, the MCD spectra of the cobalt and the iron complexes were also complicated by a number of charge-transfer states in the visible region. Iron complex 4 also exhibits a low-energy absorption in the NIR region (1023 nm). DFT and TDDFT calculations were used to elaborate the electronic structures and provide band assignments in UV-vis and MCD spectra of the metallocorroles. DFT and TDDFT calculations predict that the orientation of the axial pyridine ligand(s) has a very minor influence on the calculated electronic structures and absorption spectra in the target systems.

  13. 3-(Aminocarbonylpyridinium diaqua-bis(pyridine-2,6-dicarboxylatobismuthate(III monohydrate

    Directory of Open Access Journals (Sweden)

    Janet Soleimannejad

    2012-07-01

    Full Text Available The asymmetric unit of the ionic title compound, (C6H7N2O[Bi(C7H3NO42(H2O2]·H2O or (acpyH[Bi(pydc2(H2O2]·H2O, contains an [Bi(pydc2(H2O2]− anion (where pydcH2 is pyridine-2,6-dicarboxylic acid, a protonated 3-(aminocarbonylpyridine as counter-ion, (acpyH+, and one uncoordinated water molecule. The anion is an eight-coordinate complex with a square-antiprismatic geometry around the BiIII atom. In the crystal, extensive O—H...O and N—H...O hydrogen bonds, as well as ion pairing, C=O...π interactions [O...centroid distance = 3.583 (5 Å], π–π stacking [centroid–centroid distance = 3.864 (3 Å], and C—H...π and C—H...O interactions, play an important role in the formation and stabilization of the three-dimensional supramolecular structure.

  14. Design, synthesis, and herbicidal activity of novel substituted 3-(pyridin-2-yl)benzenesulfonamide derivatives.

    Science.gov (United States)

    Xie, Yong; Chi, Hui-Wei; Guan, Ai-Ying; Liu, Chang-Ling; Ma, Hong-Juan; Cui, Dong-Liang

    2014-12-31

    A series of novel substituted 3-(pyridin-2-yl)benzenesulfonamide derivatives were designed and synthesized using 2-phenylpridines as the lead compound by intermediate derivatization methods in an attempt to obtain novel compound candidates for weed control. The herbicidal activity assay in glasshouse tests showed several compounds (II6, II7, II8, II9, II10, II11, III2, III3, III4, and III5) could efficiently control velvet leaf, youth-and-old age, barnyard grass, and foxtail at the 37.5 g/ha active substance. Especially, the activities of II6, II7, III2, and III4 were proved roughly equivalent to the saflufenacil and better than 95% sulcotrione at the same concentration. The result of the herbicidal activity assay in field tests demonstrated that II7 at 60 g/ha active substance could give the same effect as bentazon at 1440 g/ha active substance to control dayflower and nightshade, meanwhile II7 showed better activity than oxyfluorfen to control arrowhead and security to rice. The present work indicates that II7 may be a novel compound candidate for potential herbicide.

  15. Synthesis of some pyridine and pyrimidine derivatives via Michael-Addition

    International Nuclear Information System (INIS)

    El-Baih, Fatma E.M.; Al-Rasheed, Hessa H.; Al-Hazimi, Hassan M.

    2006-01-01

    Synthesis of pyridine and pyrimidine analogues 4 and 6-9 were achieved by Michael-addition of compounds containing either active methylene groups like, malononitrile , ethyl cyanoacetate and 1-tetralone or compounds containing active hydrogen atoms like, guanidine in the presence of an oxidizing agent and thiourea to 2-arylmethylidine-1-tetralone and 2-arylmethylidine-6-methoxy-1-tetralone (2) (enones). Addition of malononitrile in piperidine at room temperature to 2-amino-3-cyno-naphtho [1, 2-malonoitrile in sodium alkoxide or sodium hydroxide to 2 gave 4. Cyclization of 3a with acetic anhydride in the presence of conc. H2sO4 gave the naphtha-pyrano[2, 3-d]pyrimidin-8-one (5). Condensation of the pyrimidine thione derivatives 9 with chloroacetic acid gave the 3-oxobenzo[h]thiazoladino[2, 3-b]quinazoline derivatives (10), which were reacted through their active methylene groups with aromatic aldehydes to give the arylidine derivatives 11. These compounds were also prepared in one step by reacting 9 with chloroacetic acid and aromatic aldehydes. Condensation of 9 with 3-bromopropanoic acid gave 4-oxo-benzo[h]1, 3-thiazino[2, 3-b]quinazoline derivatives (12). The structures of the prepared compounds were mainly confirmed on the basis of spectroscopic methods. (author)

  16. Late Neoproterozoic to Carboniferous genesis of A-type magmas in Avalonia of northern Nova Scotia: repeated partial melting of anhydrous lower crust in contrasting tectonic environments

    Science.gov (United States)

    Murphy, J. Brendan; Shellnutt, J. Gregory; Collins, William J.

    2018-03-01

    Avalonian rocks in northern mainland Nova Scotia are characterized by voluminous 640-600 Ma calc-alkalic to tholeiitic mafic to felsic magmas produced in a volcanic arc. However, after the cessation of arc activity, repeated episodes of felsic magmatism between ca. 580 Ma and 350 Ma are dominated by A-type geochemical characteristics. Sm-Nd isotopic data, combined with zircon saturation temperature estimates, indicate that these magmas were formed by high temperature (800-1050 °C) melting of the same anhydrous crustal source. Regional tectonic considerations indicate that A-type felsic magmatism was produced (1) at 580 Ma in a San Andreas-type strike slip setting, (2) at 495 Ma as Avalonia rifted off Gondwana, (3) at 465 and 455 in an ensialic island arc environment and (4) at 360-350 Ma during post-collisional, intra-continental strike-slip activity as Avalonia was translated dextrally along the Laurentian margin. These results attest to the importance of crustal source, rather than tectonic setting, in the generation of these A-type magmas and are an example of how additional insights are provided by comparing the geochemical and isotopic characteristics of igneous suites of different ages within the same terrane. They also suggest that the shallow crustal rocks in northern mainland Nova Scotia were not significantly detached from their lower crustal source between ca. 620 Ma and 350 Ma, a time interval that includes the separation of Avalonia from Gondwana, its drift and accretion to Laurentia as well as post-accretionary strike-slip displacement.

  17. Calorimetric investigations of hydrogen bonding in binary mixtures containing pyridine and its methyl-substituted derivatives. II. The dilute solutions of methanol and 2-methyl-2-propanol

    International Nuclear Information System (INIS)

    Marczak, Wojciech; Heintz, Andreas; Bucek, Monika

    2004-01-01

    Enthalpies of solution of methanol and 2-methyl-2-propanol (tert-butanol) in pyridine and its methyl derivatives were investigated in the range of mole fractions of alcohol x≤0.02 at temperature 298.15 K by a titration calorimeter. Dissolution of methanol is an exothermic process, with heat effects very close to those for water reported in part I of this study. The negative enthalpy of solution increases in the following order: pyridine < 3-methylpyridine < 4-methylpyridine < 2-methylpyridine < 2,6-dimethylpyridine < 2,4,6-trimethylpyridine. Positive enthalpies of solution of 2-methyl-2-propanol increase as follows: 2-methylpyridine < 2,4,6-trimethylpyridine < 4-methylpyridine < 2,6-dimethylpyridine < 3-methylpyridine < pyridine. The propensity of pyridine derivatives to hydrogen bonding is enhanced by the ortho effect. Methyl groups are probably too small to prevent the nitrogen atom in the pyridine ring from hydrogen bonding. However, spacious hydrocarbon group in 2-methyl-2-propanol molecule makes the bonding difficult for 2,6-dimethylpyridine and 2,4,6-trimethylpyridine, thus the number of O-H···N bonds is smaller than that in the solutions of methanol or water. The two latter seem to be very close to each other

  18. A combined experimental and computational study of 3-bromo-5-(2,5-difluorophenyl) pyridine and 3,5-bis(naphthalen-1-yl)pyridine: Insight into the synthesis, spectroscopic, single crystal XRD, electronic, nonlinear optical and biological properties

    Science.gov (United States)

    Ghiasuddin; Akram, Muhammad; Adeel, Muhammad; Khalid, Muhammad; Tahir, Muhammad Nawaz; Khan, Muhammad Usman; Asghar, Muhammad Adnan; Ullah, Malik Aman; Iqbal, Muhammad

    2018-05-01

    Carbon-carbon coupling play a vital role in the synthetic field of organic chemistry. Two novel pyridine derivatives: 3-bromo-5-(2,5-difluorophenyl)pyridine (1) and 3,5-bis(naphthalen-1-yl)pyridine (2) were synthesized via carbon-carbon coupling, characterized by XRD, spectroscopic techniques and also investigated by using density functional theory (DFT). XRD data and optimized DFT studies are found to be in good correspondence with each other. The UV-Vis analysis of compounds under study i.e. (1) and (2) was obtained by using "TD-DFT/B3LYP/6-311 + G(d,p)" level of theory to explain the vertical transitions. Calculated FT-IR and UV-Vis results are found to be in good agreement with experimental FT-IR and UV-Vis findings. Natural bond orbital (NBO) study was performed using B3LYP/6-311 + G(d,p) level to find the most stable molecular structure of the compounds. Frontier molecular orbital (FMO) analysis were performed at B3LYP/6-311 + G(d,p) level of theory, which indicates that the molecules might be bioactive. Moreover, the bioactivity of compounds (1) and (2) have been confirmed by the experimental activity in terms of zones of inhibition against bacteria and fungus. Chemical reactivity of compounds (1) and (2) was indicated by mapping molecular electrostatic potential (MEP) over the entire stabilized geometries of the compounds under study. The nonlinear optical properties were computed with B3LYP/6-311 + G(d,p) level of theory which are found greater than the value of urea due to conjugation effect. Two state model has been further employed to explain the nonlinear optical properties of compounds under investigation.

  19. {1-[1-(2-Hydroxyphenylethylidene]-2-(pyridin-2-yl-κNhydrazine-κ2N′,O}{1-[1-(2-oxidophenylethylidene]-2-(pyridin-2-yl-κNhydrazine-κ2N′,O}nickelate(II nitrate hemihydrate

    Directory of Open Access Journals (Sweden)

    Sarr Mamour

    2018-05-01

    Full Text Available The 2-hydrazinopyridine precursor has been widely used to prepare ligands of various kinds by condensation with carbonyl compounds. These types of ligands are suitable for synthesizing novel transition metal (II complexes with interesting magnetic properties. In this context we have synthesized the ligand 1-(2-hydroxyphenyl-2-ethylidene-2-(pyridin-2-ylhydrazine (HL which was used in the preparation of the mononuclear title complex, [Ni(C13H12N3O(C13H13N3O]NO3·0.5H2O. As a result of the presence of HL and L in the [{Ni(HL(L}]+ unit, the complex appears to be a supramolecular dimer composed of the Δ(− and Λ(− optical isomers, which are linked by strong hydrogen-bonds. As well as the dimer generated by two mononuclear [{Ni(HL(L}]+ cations, the asymmetric unit also contains two nitrate anions and one water molecule. Each Ni atom is coordinated to two ligand molecules by a nitrogen atom of the pyridine ring, an imine nitrogen atom and a phenolic oxygen atom of one of the ligand molecules and a phenolate oxygen atom of the other organic molecules. The environment around the cation is a distorted octahedron. The basal planes are defined by the two nitrogen atoms of the pyridine rings and the two phenolic oxygen atoms of the ligand, the apical positions being occupied by the azomethine atoms. The O atoms of one of the nitrate ions are disordered over two sets of sites in a 0.745 (9:0.255 (9 ratio. In the crystal, the dimers are linked by numerous hydrogen bonds, forming a three-dimensional framework.

  20. Pyridine induction of cytochrome P450IIE1: Evidence for enhanced protein synthesis

    International Nuclear Information System (INIS)

    Kim, S.G.; Novak, R.F.

    1990-01-01

    The dose-, and time-dependent induction of P450IIE1 in the rat by pyridine (PY) has been characterized. A single injection of PY (100 mg/kg, i.p.) increased as the levels of IIE1 2-, 3- and 4-fold at 6, 10 and 24 hr, respectively, relative to controls based on p-nitrophenol hydroxylase activity and Western blot analysis. Induction of IIE1 was dose-dependent over the range 10 to 200 mg/kg. Cycloheximide administration completely prevented the induction of IIE1 by PY, while actinomycin D failed to affect PY induction of IIE1. The rate of IIE1 synthesis was examined by labelling of proteins with [ 14 C] leucine in vivo, followed by SDS-PAGE and autoradiographic analysis of isolated microsomes. Enhanced intensity of the IIE1 band was observed in microsomes isolated from rats treated with either PY or acetone relative to untreated rats. Slot and Northern blot analyses were employed to assess IIE1 mRNA levels in total RNA and poly(A + ) mRNA isolated from livers of rats at 1, 5 and 12 hr following a single dose of PY. No increase in IIE1 mRNA in total RNA was monitored. A time-dependent decrease in IIE1 poly(A + ) mRNA however, was observed with the maximal decrease occurring at ∼12 hr. These results suggest that induction of IIE1 by PY does not involve transcriptional activation but occurs by protein synthesis possibly through increased translational efficiency

  1. Intermolecular interactions between σ- and π-holes of bromopentafluorobenzene and pyridine: computational and experimental investigations.

    Science.gov (United States)

    Yang, Fang-Ling; Yang, Xing; Wu, Rui-Zhi; Yan, Chao-Xian; Yang, Fan; Ye, Weichun; Zhang, Liang-Wei; Zhou, Pan-Pan

    2018-04-25

    The characters of σ- and π-holes of bromopentafluorobenzene (C6F5Br) enable it to interact with an electron-rich atom or group like pyridine which possesses an electron lone-pair N atom and a π ring. Theoretical studies of intermolecular interactions between C6F5Br and C5H5N have been carried out at the M06-2X/aug-cc-pVDZ level without and with the counterpoise method, together with single point calculations at M06-2X/TZVP, wB97-XD/aug-cc-pVDZ and CCSD(T)/aug-cc-pVDZ levels. The σ- and π-holes of C6F5Br exhibiting positive electrostatic potentials make these sites favorably interact with the N atom and the π ring of C5H5N with negative electrostatic potentials, leading to five different dimers connected by a σ-holen bond, a σ-holeπ bond or a π-holeπ bond. Their geometrical structures, characteristics, nature and spectroscopy behaviors were systematically investigated. EDA analyses reveal that the driving forces in these dimers are different. NCI, QTAIM and NBO analyses confirm the existence of intermolecular interactions formed via σ- and π-holes of C6F5Br and the N atom and the π ring of C5H5N. The experimental IR and Raman spectra gave us important information about the formation of molecular complexes between C6F5Br and C5H5N. We expect that the results could provide valuable insights into the investigation of intermolecular interactions involving σ- and π-holes.

  2. Butane-1,4-diammonium bis(pyridine-2,6-dicarboxylatocuprate(II trihydrate

    Directory of Open Access Journals (Sweden)

    Mohammad Ghadermazi

    2008-05-01

    Full Text Available In the title compound, (C4H14N2[Cu(C7H3NO42]·3H2O or (bdaH2[Cu(pydc2]·3H2O (where bda is butane-1,4-diamine and pydcH2 is pyridine-2,6-dicarboxylic acid, the CuII atom is coordinated by four O atoms [Cu—O = 2.0557 (16–2.3194 (16 Å] and two N atoms [Cu—N = 1.9185 (18 and 1.9638 (18 Å] from two chelating rings of the pydc2− anions, which act as tridentate ligands. The geometry of the resulting CuN2O4 coordination can be described as distorted octahedral. The the two pydc2− fragments are almost perpendicular to one another [77.51 (11°]. To balance the charges, two centrosymmetric protonated butane-1,4-diammonium, (bdaH22+ cations are present. In the crystal structure, extensive O—H...O, N—H...O and C—H...O hydrogen bonds [D...A = 2.720 (2–3.446 (3 Å], ion pairing, C—O...π [O...π = 3.099 (2 Å] and π–π stacking interactions between the pydc2− rings [centroid–centroid distance = 3.5334 (15 Å] contribute to the formation of a three-dimensional supramolecular structure.

  3. Copolymers based on N-acryloyl-L-leucine and urea methacrylate with pyridine moieties

    Directory of Open Access Journals (Sweden)

    Buruiana Emil C.

    2016-01-01

    Full Text Available By using free radical polymerization of (N-methacryloyloxyethyl-N′-4-picolyl-urea (MAcPU and N-acryloyl-L-leucine (AcLeu, an optically active copolymer, poly[(N-methacryloyloxyethyl-N′-4-picolyl-urea-co-N-acryloyl-L-leucine], MAcPU-co-AcLeu (1.86:1 molar ratio was prepared and subsequently functionalized at the pyridine-N with (1R/S-(−/+-10-camphorsulfonic acid (R/S-CSA and at carboxyl group with (R-(+-α-ethylbenzylamine (R-EBA or trans-4-stilbene methanol (t-StM. The structures, chemical composition and chiroptical activity of the monomers and the copolymers were characterized by spectral analysis (FTIR, 1H (13C-NMR, 1H,1H-COSY, UV/vis, thermal methods (TGA, DSC, fluorescence spectroscopy, gel permeation chromatography and specific rotation measurements. Influence of the optical activity of monomer and modifier on modified copolymers suggested a good correlation between the experimental data obtained (23[α]589=+12.5° for AcLeu and MAcPU-co-AcLeu, 23[α]589=0°+27.5° for (MAcPU-co-AcLeu-R/S-CSA, 23[α]589=+25° for (MAcPU-co-AcLeu-R-EBA, and 23[α]589 = 0° for (MAcPU-co-AcLeu-St. In addition, the photobehavior of the stilbene copolymer (MAcPU-co-AcLeu-St in film was investigated by UV-vis spectroscopy. The fluorescence quenching of the stilbene species in the presence of aliphatic/aromatic amine in DMF solution was evaluated, more efficiently being 4,4′−dipyridyl (detection limit: 7.2 x 10-6 mol/L.

  4. Novel quinolines carrying pyridine, thienopyridine, isoquinoline, thiazolidine, thiazole and thiophene moieties as potential anticancer agents

    Directory of Open Access Journals (Sweden)

    Ghorab Mostafa M.

    2016-06-01

    Full Text Available As a part of ongoing studies in developing new anticancer agents, novel 1,2-dihydropyridine 4, thienopyridine 5, isoquinolines 6–20, acrylamide 21, thiazolidine 22, thiazoles 23–29 and thiophenes 33–35 bearing a biologically active quinoline nucleus were synthesized. The structure of newly synthesized compounds was confirmed on the basis of elemental analyses and spectral data. All the newly synthesized compounds were evaluated for their cytotoxic activity against the breast cancer cell line MCF7. 2,3-Dihydrothiazole-5-carboxamides 27, 25, 4,5,6,7-tetrahydrobenzo[b]thiophene-3-carboxamide (34, 1,2-dihydroisoquinoline-7-carbonitrile (7, 5,6,7,8-tetrahydro-4H-cyclohepta[b]thiophene-3-carboxamide (35, 1,2-dihydroisoquinoline-7-carbonitrile (6, 2-cyano-3-(dimethylamino-N-(quinolin-3-ylacrylamide (21, 1,2-dihydroisoquinoline-7-carbonitriles (11 and (8 exhibited higher activity (IC50 values of 27–45 μmol L–1 compared to doxorubicin (IC50 47.9 μmol L–1. LQ quinolin-3-yl-1,2-dihydroisoquinoline-7-carbonitrile (12, 2-thioxo-2,3-dihydrothiazole-5-carboxamide (28 and quinolin-3-yl-1,2-dihydroisoquinoline-7-carbonitrile (15 show activity comparable to doxorubicin, while (quinolin-3-yl-1,2-dihydroisoquinoline-7-carbonitrile (9, 2,3-dihydrothiazole-5-carboxamide (24, thieno [3,4-c] pyridine-4(5H-one (5, cyclopenta[b]thiophene-3-carboxamide (33 and (quinolin-3-yl-6-stryl-1,2-dihydroisoquinoline-7-carbonitrile (10 exhibited moderate activity, lower than doxorubicin.

  5. On the interactions of nitriles and fluoro-substituted pyridines with silicon tetrafluoride: Computations and thin film IR spectroscopy

    Science.gov (United States)

    Hora, Nicholas J.; Wahl, Benjamin M.; Soares, Camilla; Lara, Skylee A.; Lanska, John R.; Phillips, James A.

    2018-04-01

    The nature of the interactions between silicon tetrafluoride and series of nitrogen bases, including nitriles (RCN, with R > CH3), pyridine, and various fluoro-substituted pyridines, has been investigated via quantum-chemical computations, low-temperature IR spectroscopy, and bulk reactivity experiments. Using (primarily) M06 with the 6-311+G(2df,2pd) basis set, we obtained equilibrium structures, binding energies, harmonic frequencies, and N-Si potentials in the gas-phase and in bulk dielectric media for an extensive series of 1:1 molecular complexes, including: C6H5CH2CN-SiF4, CH3CH2CN-SiF4, (CH3)3CCN-SiF4, C5H5N-SiF4, 4-FC5H4N-SiF4, 3,5-C5F2H3N-SiF4, 2,6-C5F2H3N-SiF4 and 3,4,5-C5F3H2N-SiF4. In addition, for the analogous 2:1 complexes of pyridine and 3,5-difluororpyridine, we obtained equilibrium structures, binding energies, and harmonic frequencies. The N-Si distances in the 1:1 nitrile complexes are fairly long, ranging from 2.84 Å to 2.88 Å, and the binding energies range from 4.0 to 4.2 kcal/mol (16.7-17.6 kJ/mol). Also, computations predict extremely anharmonic N-Si potentials, for which the inner portions of the curve are preferentially stabilized in dielectric media, which predict an enhancement of these interactions in condensed-phases. However, we see no evidence of bulk reactivity between C6H5CH2CN, CH3CH2CN, or (CH3)3CCN and SiF4, nor any significant interaction between (CH3)3CCN and SiF4 in low temperature IR spectra of solid, (CH3)3CCN/SiF4 thin films. Conversely, the interactions in four of the five 1:1, pyridine-SiF4 complexes are generally stronger; binding energies range from 5.7 to 9.6 kcal/mol (23.8-40.2 kJ/mol), and correspondingly the N-Si distances are relatively short (2.12-2.25 Å). The exception is 2,6-C5F2H3N-SiF4, for which the binding energy is only 3.6 kcal/mol (15.1 kJ/mol), and the N-Si distance is quite long (3.12 Å). In addition, both pyridine and 3,5-difluororpyridine were found to form stable reaction products with SiF4

  6. Bactericidal activity of an imidazo[1, 2-a]pyridine using a mouse M. tuberculosis infection model.

    Directory of Open Access Journals (Sweden)

    Yong Cheng

    Full Text Available Tuberculosis remains a global threat due in part to the long treatment regimen and the increased prevalence of drug resistant M. tuberculosis strains. Therefore, new drug regimens are urgently required to combat this deadly disease. We previously synthesized and evaluated a series of new anti-tuberculosis compounds which belong to the family of imidazo[1,2-a]pyridines. This family of compounds showed low nM MIC (minimal inhibitory concentration values against M. tuberculosis in vitro. In this study, a derivative of imidazo[1,2-a]pyridines, (N-(4-(4-chlorophenoxybenzyl-2,7-dimethylimidazo[1,2-a]pyridine-3-carboxamide (ND-09759, was selected as a promising lead compound to determine its protective efficacy using a mouse infection model. Pharmacokinetic analysis of ND-09759 determined that at a dosage of 30 mg/kg mouse body weight (PO gave a maximum serum drug concentration (Cmax of 2.9 µg/ml and a half-life of 20.1 h. M. tuberculosis burden in the lungs and spleens was significantly decreased in mice treated once daily 6 days per week for 4-weeks with ND-09759 compared to untreated mice and this antibiotic activity was equivalent to isoniazid (INH and rifampicin (RMP, two first-line anti-TB drugs. We observed slightly higher efficacy when using a combination of ND-09759 with either INH or RMP. Finally, the histopathological analysis revealed that infected mice treated with ND-09759 had significantly reduced inflammation relative to untreated mice. In conclusion, our findings indicate ND-09759 might be a potent candidate for the treatment of active TB in combination with current standard anti-TB drugs.

  7. Syntheses and structures of three heterometallic coordination polymers derived from 4-pyridin-3-yl-benzoic acid

    International Nuclear Information System (INIS)

    Fang, Wei-Hui; Yang, Guo-Yu

    2014-01-01

    Three lanthanide–transition-metal coordination polymers, namely, [Er 2 L 6 (H 2 O)][Cu 2 I 2 ] (1), [ErL 3 ][CuI] (2), and [Dy 2 L 6 (BPDC) 0.5 (H 2 O) 4 ][Cu 3 I 2 ] (3) (HL=4-pyridin-3-yl-benzoic acid, H 2 BPDC=4,4′-biphenyldicarboxylic acid) have been made by reacting Ln 2 O 3 and CuI with HL at different temperatures under hydrothermal conditions. All the complexes are characterized by elemental analysis, IR spectroscopy, thermogravimetric analysis, powder X-ray diffraction, and single-crystal X-ray diffraction, respectively. 1–3 all construct from dimeric (Ln 2 ) and (Cu 2 ) units and exhibit two types of the structural features: 1 is a two-dimensional layer, 2–3 are three-dimensional frameworks. Interestingly, the in situ formation of the BPDC ligand is found in the structure of 3. The distinct architectures of these complexes indicated that the reaction temperature plays an important role in the formation of higher dimensional coordination polymers. - Graphical abstract: By hydrothermal reaction of lanthanide oxide, copper halide, and 4-pyridin-3-yl-benzoic ligand at different temperatures, a series of 1-D to 3-D 3d–4f coordination polymers, namely [ErL 3 (H 2 O) 2 ][CuI], [Er 2 L 6 (H 2 O)][Cu 2 I 2 ], [ErL 3 ][CuI], and [Dy 2 L 6 (BPDC) 0.5 (H 2 O) 4 ][Cu 3 I 2 ], have been made, respectively. - Highlights: • Three novel heterometallic coordination polymers derived from 4-pyridin-3-yl-benzoic acid have been hydrothermally synthesized. • Mixed dinuclear motifs of (Ln 2 ) and (Cu 2 ) serve as secondary building units to generate 2-D layer and 3-D frameworks. • It is proved that higher temperature is apt to permit construction of high dimensional architectures

  8. Optoelectronic and Photovoltaic Performances of Pyridine Based Monomer and Polymer Capped ZnO Dye-Sensitized Solar Cells.

    Science.gov (United States)

    Singh, Satbir; Raj, Tilak; Singh, Amarpal; Kaur, Navneet

    2016-06-01

    The present research work describes the comparative analysis and performance characteristics of 4-pyridine based monomer and polymer capped ZnO dye-sensitized solar cells. The N, N-dimethyl-N4-((pyridine-4yl)methylene) propaneamine (4,monomer) and polyamine-4-pyridyl Schiff base (5, polymer) dyes were synthesized through one step condensation reaction between 4-pyridinecarboxaldehyde 1 and N, N-dimethylpropylamine 2/polyamine 3. Products obtained N, N-dimethyl-N4-((pyridine-4yl)methylene)propaneamine (4) and polyamine-4-pyridyl Schiff base (5) were purified and characterized using 1H, 13C NMR, mass, IR and CHN spectroscopy. Both the dyes 4 and 5 were further coated over ZnO nanoparticles and characterized using SEM, DLS and XRD analysis. Absorption profile and emission profile was monitored using fluorescence and UV-Vis absorption spectroscopy. A thick layer of these inbuilt dye linked ZnO nanoparticles of dyes (4) and (5) was pasted on one of the conductive side of ITO glass followed with a liquid electrolyte and counter electrode of the same conductive glass. Polyamine-4-pyridyl Schiff base polymer (5) decorated dye sensitized solar cell has shown better exciting photovoltaic properties in the form of short circuit current density (J(sc) = 6.3 mA/cm2), open circuit photo voltage (V(oc) = 0.7 V), fill factor (FF = 0.736) than monomer decorated dye sensitized solar cell. Polymer dye (5) based ZnO solar cell has shown a maximum solar power to electrical conversion efficiency of 3.25%, which is enhanced by 2.16% in case of monomer dye based ZnO solar cell under AM 1.5 sun illuminations.

  9. Generalities on the dynamic behaviour of rapid reactors. Preliminary studies on Rapsodie; Generalites sur le comportement dynamique des piles rapides. Etudes preliminaires de rapsodie

    Energy Technology Data Exchange (ETDEWEB)

    Campan, J L; Chaumont, J P; Clauzon, P P; Ghesquiere, G; Leduc, J; Schmitt, A P; Zaleski, C P [Commissariat a l' Energie Atomique, Cadarache (France). Centre d' Etudes Nucleaires

    1963-07-01

    The study of the dynamic behaviour of fast reactors may be divided into three section: 1. Stability studies around equilibrium power only the linear case was examining. S. Transient studies in the case of usual reactor operation (shut down, scram, etc.) with thermal shocks evaluation, for instance. 3. Explosion studies, for the maximum credible accidents. This report presents the status of the studies performed at the 'Physics Research Department' at Cadarache. Methods used are detailed and illustrated with the results obtained on a preliminary metallic core of the Rapsodie Reactor. (authors) [French] Le comportement dynamique des piles rapides, se presente tout naturellement sous trois aspects: 1. Etude de stabilite autour d'un regime d'equilibre (nous nous sommes bornes ici au cas lineaire). 2. Etude de regimes transitoires lors des operations normales de pile (arret, arret d'urgence, etc.) avec evaluation des chocs thermiques par exemple. 3. Etude des regimes transitoires de caractere explosif lors des accidents les plus graves possibles. Ce rapport presente l'etat des etudes a la date du 20 decembre 1961 a la Section d'Etudes de Piles Rapides a CADARACHE. Les methodes employees ont ete detaillees et illustrees a partir des resultats obtenus sur une premiere version 'combustible metallique' de Rapsodie. (auteurs)

  10. Etude cinétique de la dégradation de l'Endosufane en solution ...

    African Journals Online (AJOL)

    Etude cinétique de la dégradation de l'Endosufane en solution. S Traore, K Mamadou, A Dembele, V Yao, Y Bekro, P Mazellier, B Legube, P Houenou. Abstract. Les pesticides sont fréquemment utilisés en Côte d'Ivoire. Leur détection dans les eaux de forage témoigne de leur mauvais usage et d'un grave problème ...

  11. Quantum chemical analysis of the electronic structure and Moessbauer spectra parameters for low spin cyanide- and pyridine-hemichromes

    International Nuclear Information System (INIS)

    Khleskov, V.I.; Kolpakov, E.V.; Smirnov, A.B.

    1992-01-01

    The work contains results of quantum-chemical calculations of electronic structure and Moessbauer spectra parameters for low spin S=1/2 hexa-coordinated ferri-porphyrin complexes with cyanide (CN) and pyridine (Py) as axial ligands. Theoretical results made it possible to explain experimentally observed regularity of anomalous quadrupole splitting decrease after substitution of Py-ligands by CN. Comparison of theoretical and experimental data indicated that 2 E g must be the ground state of investigated hemichromes. In this state unpaired electron symmetrically occupies d π -orbitals of Fe-ion. (orig.)

  12. The Guareschi Pyridine Scaffold as a Valuable Platform for the Identification of Selective PI3K Inhibitors.

    Science.gov (United States)

    Galli, Ubaldina; Ciraolo, Elisa; Massarotti, Alberto; Margaria, Jean Piero; Sorba, Giovanni; Hirsch, Emilio; Tron, Gian Cesare

    2015-09-18

    A novel series of 4-aryl-3-cyano-2-(3-hydroxyphenyl)-6-morpholino-pyridines have been designed as potential phosphatidylinositol-3-kinase (PI3K) inhibitors. The compounds have been synthesized using the Guareschi reaction to prepare the key 4-aryl-3-cyano-2,6-dihydroxypyridine intermediate. A different selectivity according to the nature of the aryl group has been observed. Compound 9b is a selective inhibitor against the PI3Kα isoform, maintaining a good inhibitory activity. Docking studies were also performed in order to rationalize its profile of selectivity.

  13. Transformation of Zwitterionic Pyridine Derivatives to a Spiro-Fused Ring System: Azoniabenzo[de]fluorine. Synthesis and Mechanistic Rationalization.

    Science.gov (United States)

    Palkó, Roberta; Egyed, Orsolya; Rokob, Tibor András; Bombicz, Petra; Riedl, Zsuzsanna; Hajós, György

    2015-01-02

    Reaction of aryl- and benzylsulfanopyridinium amidates bearing a methyl group in position 6 with 2 equiv of diphenylketene afforded a spiro-fused ring system: azoniabenzo[de]fluorine. By use of an excess amount of ketene, a distinct reaction was observed via which a 1H-pyrrolo[3,2-b]pyridin-2(3H)-one derivative was furnished. The structure of the tetracyclic spiro-fused ring system was unambiguously confirmed by X-ray diffraction, and its formation was rationalized by DFT calculations.

  14. Reduction from copper(II) to copper(I) upon collisional activation of (pyridine)2CuCl+

    Czech Academy of Sciences Publication Activity Database

    Révész, Agnes; Milko, Petr; Žabka, Ján; Schröder, Detlef; Roithová, J.

    2010-01-01

    Roč. 45, č. 11 (2010), s. 1246-1252 ISSN 1076-5174 R&D Projects: GA AV ČR KJB400550704; GA ČR GA203/08/1487 Grant - others:European Research Council(XE) AdG HORIZOMS Institutional research plan: CEZ:AV0Z40550506; CEZ:AV0Z40400503 Keywords : copper chloride * electrospray ionization * mass spectrometry * pyridine * redox reactions Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 3.289, year: 2010

  15. The Guareschi Pyridine Scaffold as a Valuable Platform for the Identification of Selective PI3K Inhibitors

    Directory of Open Access Journals (Sweden)

    Ubaldina Galli

    2015-09-01

    Full Text Available A novel series of 4-aryl-3-cyano-2-(3-hydroxyphenyl-6-morpholino-pyridines have been designed as potential phosphatidylinositol-3-kinase (PI3K inhibitors. The compounds have been synthesized using the Guareschi reaction to prepare the key 4-aryl-3-cyano-2,6-dihydroxypyridine intermediate. A different selectivity according to the nature of the aryl group has been observed. Compound 9b is a selective inhibitor against the PI3Kα isoform, maintaining a good inhibitory activity. Docking studies were also performed in order to rationalize its profile of selectivity.

  16. Synthesis, characterization, and photophysical properties of a thiophene-functionalized bis(pyrazolyl) pyridine (BPP) tricarbonyl rhenium(I) complex.

    Science.gov (United States)

    Lytwak, Lauren A; Stanley, Julie M; Mejía, Michelle L; Holliday, Bradley J

    2010-09-07

    A bromo tricarbonyl rhenium(I) complex with a thiophene-functionalized bis(pyrazolyl) pyridine ligand (L), ReBr(L)(CO)(3) (1), has been synthesized and characterized by variable temperature and COSY 2-D (1)H NMR spectroscopy, single-crystal X-ray diffraction, and photophysical methods. Complex 1 is highly luminescent in both solution and solid-state, consistent with phosphorescence from an emissive (3)MLCT excited state with an additional contribution from a LC (3)(pi-->pi*) transition. The single-crystal X-ray diffraction structure of the title ligand is also reported.

  17. Characterization of Plasma-Polymerized 4-vinyl pyridine on Poly(Ethylene Terephthalate) film for anti-microbial properties

    DEFF Research Database (Denmark)

    Jiang, Juan; Winther-Jensen, Bjørn; Kjær, Erik Michael

    2005-01-01

    As an efficient way to create an anti-bacterial function on polymer surfaces, we have used plasma polymerisation to create a poly-4-vinyl-pyridine coating on the surface of a common polymer, PET, a polymerisation process that we have shown also works well on several other polymers. We have found....... The mechanical strength of the bond between the substrate and the surface layer has been tested by several methods, and the antibacterial effect of the surface layer with and without silver nano particles has been estimated by measuring electrical resistance as a function of time. The bacteria investigated were...

  18. Determination of reaction rate constants for alkylation of 4-(p-nitrobenzyl) pyridine by different alkylating agents.

    Science.gov (United States)

    Walles, S A

    1980-02-01

    The rate constants have been determined for the reaction between some different alkylating agents and 4-(p-nitrobenzyl) pyridine (NBP) in methanol. These constants have been compared with those for alkylation of aniline in water. All the constants were lower in methanol than in water but in different degrees. The rate constants of the different alkylating agents have been calculated at a nucleophilic strength n=2. The genetic risk defined as the degree of alkylation of a nucleophile (n=2) is equivalent to the rate constant kn=2 and the target dose. The dependence of the genetic risk on the rate constant (kn=2) is discussed.

  19. Helical self-organization and hierarchical self-assembly of an oligoheterocyclic pyridine-pyridazine strand into extended supramolecular fibers.

    Science.gov (United States)

    Cuccia, Louis A; Ruiz, Eliseo; Lehn, Jean-Marie; Homo, Jean-Claude; Schmutz, Marc

    2002-08-02

    The synthesis and characterization of an alternating pyridine-pyridazine strand comprising thirteen heterocycles are described. Spontaneous folding into a helical secondary structure is based on a general molecular self-organization process enforced by the conformational information encoded within the primary structure of the molecular strand itself. Conformational control based on heterocyclic "helicity codons" illustrates a strategy for designing folding properties into synthetic oligomers (foldamers). Strong intermolecular interactions of the highly ordered lock-washer subunits of compound 3 results in hierarchical supramolecular self-assembly into protofibrils and fibrils. Compound 3 also forms mechanically stable two-dimensional Langmuir-Blodgett and cast thin films.

  20. Ruthenium(II) chloro-bis(bipyridyl) complexes with substituted pyridine ligands: interpretation of their electronic absorption spectra

    International Nuclear Information System (INIS)

    Sizova, O.V.; Ershov, A.Yu.; Ivanova, N.V.; Shashko, A.D.; Kutejkina-Teplyakova, A.V.

    2003-01-01

    A number of complexes cis-[Ru(Bipy) 2 (L)(Cl)](BF 4 ), where Bipy-2,2'-bipyridine, L-pyridine, 4-aminopyridine, 4-picoline, nicotinamide, isonicotinamide, 3- and 4-cyanopyridine, 4,4'-bipyridine, trans-1,2-bis(4-pyridyl)ethylene, 4,4'-azopyridine, pyrazine, imidazole and NH 3 , were prepared. Using the CINDO-CI semiempirical method the energies and intensities of transition in electronic absorption spectra (EAS) of the complexes were calculated. It is shown that major differences in EAS of the compounds stem from position of transitions with charge transfer d π (Ru)→π*(L) [ru

  1. Gold(III) complexes with 2-substituted pyridines as experimental anticancer agents: solution behavior, reactions with model proteins, antiproliferative properties.

    Science.gov (United States)

    Maiore, Laura; Cinellu, Maria Agostina; Nobili, Stefania; Landini, Ida; Mini, Enrico; Gabbiani, Chiara; Messori, Luigi

    2012-03-01

    Gold(III) compounds form a family of promising cytotoxic and potentially anticancer agents that are currently undergoing intense preclinical investigations. Four recently synthesized and characterized gold(III) derivatives of 2-substituted pyridines are evaluated here for their biological and pharmacological behavior. These include two cationic adducts with 2-pyridinyl-oxazolines, [Au(pyox(R))Cl(2)][PF(6)], [pyox(R)=(S)-4-benzyl-2-(pyridin-2-yl)-4,5-dihydrooxazole, I; (S)-4-iso-propyl-2-(pyridin-2-yl)-4,5-dihydrooxazole, II] and two neutral complexes [Au(N,N'OH)Cl(2)], III, and [Au(N,N',O)Cl], IV, containing the deprotonated ligand N-(1-hydroxy-3-iso-propyl-2-yl)pyridine-2-carboxamide, N,N'H,OH, resulting from ring opening of bound pyox(R) ligand of complex II by hydroxide ions. The solution behavior of these compounds was analyzed. These behave as classical prodrugs: activation of the metal center typically takes place through release of the labile chloride ligands while the rest of the molecule is not altered; alternatively, activation may occur through gold(III) reduction. All compounds react eagerly with the model protein cyt c leading to extensive protein metalation. ESI MS experiments revealed details of gold-cyt c interactions and allowed us to establish the nature of protein bound metal containing fragments. The different behavior displayed by I and II compared to III and IV is highlighted. Remarkable cytotoxic properties, against the reference human ovarian carcinoma cell lines A2780/S and A2780/R were disclosed for all tested compounds with IC(50) values ranging from 1.43 to 6.18 μM in the sensitive cell line and from 1.59 to 10.86 μM in the resistant one. The common ability of these compounds to overcome cisplatin resistance is highlighted. The obtained results are thoroughly discussed in the frame of current knowledge on cytotoxic gold compounds. Copyright © 2011 Elsevier Inc. All rights reserved.

  2. Cyanoacetanilides intermediates in heterocyclic synthesis. Part 6: Preparation of some hitherto unknown 2-oxopyridine, bipyridine, isoquinoline and chromeno[3,4-c]pyridine containing sulfonamide moiety

    Directory of Open Access Journals (Sweden)

    Yousry A. Ammar

    2014-11-01

    Full Text Available Treatment of cyanoacetanilide derivative 1 with tetracyanoethylene (2 in dioxane/triethylamine furnished 2-pyridone derivative 6. Aminopyridine 9 was obtained by cyclization of compound 1 with ketene dithioacetal 7/EtONa. Cyclocondensation of 1 with malononitrile and/or acetylacetone (1:1 M ratio gave pyridine derivatives 11 and 13. Ternary condensation of compound 1, aliphatic aldehydes and malononitrile (1:1:1 M ratio yielded the 2-pyridones 20a and b. Bipyridines 22a–c were prepared by refluxing of compound 21 with active methylene reagents. Cyclization of chromene derivatives 24 and 28 with malononitrile produced the novel chromeno[3,4-c]pyridine 26 and pyrano[3′,2′:6,7]chromeno[3,4-c]pyridine 29.

  3. Structure of pyridine and quinoline vinyl ethers according to data from 1H and 13C NMR spectra and quantum-chemical calculations

    International Nuclear Information System (INIS)

    Afonin, A.V.; Voronov, V.K.; Andriankov, M.A.; Danovich, D.K.

    1987-01-01

    A systematic investigation of the structure of the vinyl ethers of heterocyclic compounds has not been undertaken. The present work was devoted to investigation of the stereochemical and electronic structure of the vinyl ethers of pyridine and quinoline. The PMR spectra of the samples were recorded for 5% solutions in deuterochloroform on a Tesla BS-497 spectrometer at 100 MHz. The 13 C NMR spectra were recorded on a Tesla BS-567A spectrometer at 25.1 MHz in deuterochloroform with the samples at concentrations of 30%. The internal standard was HMDS. The vinyl ethers of pyridine and quinoline exist preferentially in the nonplanar S-trans conformation. In the vinyl esters of pyridine and quinoline the p-π conjugation is concurrent in nature and depends on the position of the vinyloxy group in the heterocycle

  4. Study of the tributyl phosphate - 30% dodecane solvent; Etude du solvant phosphate tributylique - 30 % dodecane

    Energy Technology Data Exchange (ETDEWEB)

    Leroy, P [Commissariat a l' Energie Atomique, Fontenay-aux-Roses. Centre d' Etudes Nucleaires, 92 (France)

    1967-07-01

    This study, originating mainly from a literature survey, gives the principal chemical and physical features of the tributyl-phosphate (TBP) agent diluted at 30 volumes per cent in dodecane. The mixture is a very commonly used extractant in nuclear fuel processing. In this paper, the main following points are reported: -) the components (TBP and diluents) -) the TBP-diluents systems (non-loaded), -) the TBP-diluents-water systems, -) TBP-diluents-water-nitric acid systems, and -) industrial solvents. (author) [French] Cette etude, d'origine bibliographique, regroupe les caracteristiques physico-chimiques essentielles du phosphate tributylique (TBP) dilue a 30% en volume dans du dodecane. Ce melange constitue un agent d'extraction tres utilise dans le traitement des combustibles nucleaires. Les principaux points traites sont les suivants: -) les constituants (TBP et diluants), -) les systemes TBP-diluants non charges, -) les systemes TBP-diluants-eau, -) les systemes TBP-diluants-eau-acide nitrique, et -) les solvants industriels. (auteur)

  5. An economic study of the site of Marcoule; Etude economique du site de Marcoule

    Energy Technology Data Exchange (ETDEWEB)

    Duprat, H [Commissariat a l' Energie Atomique, Marcoule (France). Centre d' Etudes Nucleaires

    1964-07-01

    The study of this site of the Marcoule Center shows that its regional economical influence is limited to the buying power distributed among its personnel. This entails distortions between first this supplementary buying power and the overall markets within the possible Marcoule influence zone, and secondly the concentration on Bagnols-sur-Ceze and this town's normal extension possibilities. (author) [French] L'etude du site de Marcoule demontre que son influence economique se limite, pour la region, au pouvoir d'achat distribue a son personnel. Ceci entraine une disproportion d'une part entre ce pouvoir d'achat supplementaire et l'ensemble des marches contenus dans l'aire d'influence possible de Marcoule, d'autre part entre la concentration realisee a Bagnole-sur-Ceze et la capacite d'extension normale de cette agglomeration. (auteur)

  6. Neutronic study of the two french heavy water reactors; Etude neutronique des deux piles francaises a eau lourde

    Energy Technology Data Exchange (ETDEWEB)

    Horowitz, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

    1955-07-01

    The two french reactors - the reactor of Chatillon, named Zoe, and the reactor of Saclay - P2 - were the object of detailed neutronic studies which the main ideas are exposed in this report. These studies were mostly done by the Department of the Reactor Studies (D.E.P.). We have thus studied the distribution of neutronic fluxes; the factors influencing reactivity; the link between reactivity and divergence with the formula of Nordheim; the mean time life of neutrons; neutron spectra s of P2; the xenon effect; or the effect of the different adjustments of the plates and controls bar. (M.B.) [French] Les deux reacteurs francais - la pile de Chatillon, appelee ZOE, et la pile de Saclay, designee dans la suite par P2 - ont fait l'objet d'etudes neutroniques detaillees dont les principales sont exposees dans ce rapport. Ces etudes ont ete pour la plupart effectuees dans le cadre du Departement des Etudes de Piles (D.E.P.). Nous avons ainsi entre autre etudie la distribution du flux neutronique; les facteurs influencants la reactivite; le lien entre reactivite et divergence par la formule de Nordheim; le temps de vie moyen des neutrons; les spectres de neutrons de P2; l'effet xenon; ou encore l'effet des differents reglages des plaques et barres de controles. (M.B.)

  7. The performance of the anthraquinone/p-Si and the pyridine/p-Si rectifying device under X-ray irradiation

    International Nuclear Information System (INIS)

    Şahin, Yılmaz; Aydoğan, Şakir; Ekinci, Duygu; Turut, Abdulmecit

    2016-01-01

    Some X-ray irradiation-induced electrical characteristics of the Au/anthraquinone/p-Si and the Au/pyridine/p-Si junction devices have been investigated. The experimental ideality factors increased for both devices with increasing irradiation dose from 25 Gy to 150 Gy. These values ranged from 1.10 to 1.52 for Au/anthraquinone/p-Si and from 1.46 to 1.77 for Au/pyridine/p-Si, respectively. Furthermore, the barrier height of Au/anthraquinone/p-Si increased with increasing irradiation dose from 0.75 to 0.91 eV, whereas it displayed about a constant value for Au/pyridine/p-Si. In addition, the series resistance of both devices increased with x-ray dose too. The increase in the series resistance with x-ray irradiation has been attributed to the decrease in the active dopant densities. It was seen that the ionization damage is effective on most of the junction characteristics. The leakage current of the Au/anthraquinone/p-Si device decreased with x-ray irradiation since the irradiation induced the formation of electron-hole pairs and hydroquinone structure, and thus some of them are trapped by the interface states. The degradation of the I-V curves of Au/pyridine/p-Si/Al device is attributed to the variation of the surface or interface states distribution for the devices. The reverse and forward bias currents relatively increased after x-ray irradiation because of the decrease in bulk lifetime. In addition, ATR-FTIR spectra of anthraquinone and pyridine films showed that pyridine is more stable than anthraquinone under x-ray irradiation. - Highlights: • Two junction devices based on organic materials were fabricated. • The effect of the x-ray irradiation on devices were examined. • Both devices showed x-irradiation-dependence.

  8. The performance of the anthraquinone/p-Si and the pyridine/p-Si rectifying device under X-ray irradiation

    Energy Technology Data Exchange (ETDEWEB)

    Şahin, Yılmaz [Department of Physics, Faculty of Sciences, University of Atatürk, 25240 Erzurum (Turkey); Aydoğan, Şakir, E-mail: saydogan@atauni.edu.tr [Department of Physics, Faculty of Sciences, University of Atatürk, 25240 Erzurum (Turkey); Ekinci, Duygu [Department of Chemistry, Faculty of Sciences, University of Atatürk, 25240 Erzurum (Turkey); Turut, Abdulmecit [Department of Engineering Physics, Faculty of Sciences, Istanbul Medeniyet University (Turkey)

    2016-11-01

    Some X-ray irradiation-induced electrical characteristics of the Au/anthraquinone/p-Si and the Au/pyridine/p-Si junction devices have been investigated. The experimental ideality factors increased for both devices with increasing irradiation dose from 25 Gy to 150 Gy. These values ranged from 1.10 to 1.52 for Au/anthraquinone/p-Si and from 1.46 to 1.77 for Au/pyridine/p-Si, respectively. Furthermore, the barrier height of Au/anthraquinone/p-Si increased with increasing irradiation dose from 0.75 to 0.91 eV, whereas it displayed about a constant value for Au/pyridine/p-Si. In addition, the series resistance of both devices increased with x-ray dose too. The increase in the series resistance with x-ray irradiation has been attributed to the decrease in the active dopant densities. It was seen that the ionization damage is effective on most of the junction characteristics. The leakage current of the Au/anthraquinone/p-Si device decreased with x-ray irradiation since the irradiation induced the formation of electron-hole pairs and hydroquinone structure, and thus some of them are trapped by the interface states. The degradation of the I-V curves of Au/pyridine/p-Si/Al device is attributed to the variation of the surface or interface states distribution for the devices. The reverse and forward bias currents relatively increased after x-ray irradiation because of the decrease in bulk lifetime. In addition, ATR-FTIR spectra of anthraquinone and pyridine films showed that pyridine is more stable than anthraquinone under x-ray irradiation. - Highlights: • Two junction devices based on organic materials were fabricated. • The effect of the x-ray irradiation on devices were examined. • Both devices showed x-irradiation-dependence.

  9. SO 2 Phototriggered Crystalline Nanomechanical Transduction of Aromatic Rotors in Tosylates: Rationalization via Photocrystallography of [Ru(NH 3 ) 4 SO 2 X]tosylate 2 (X = pyridine, 3-Cl-pyridine, 4-Cl-pyridine)

    Energy Technology Data Exchange (ETDEWEB)

    Sylvester, Sven O.; Cole, Jacqueline M.; Waddell, Paul G.; Nowell, Harriott; Wilson, Claire

    2014-07-24

    Thermally-reversible solid-state linkage SO2 photoisomers of three complexes in the [Ru(NH3)4SO2X]tosylate2 family are captured in their metastable states using photocrystallography, where X = pyridine (1), 3-Cl-pyridine (2) and 4-Cl-pyridine (3). This photoisomerism only exists in the single-crystal form; accordingly, the nature of the crystalline environment surrounding the photo-active species controls its properties. In particular, the structural role of the tosylate anion needs to be understood against possible chemical influences due to varying the trans ligand, X. The photo-excited geometries, photoconversion levels and thermal stabilities of the photoisomers that form in 1-3 are therefore studied. 1 and 2 yield two photo-isomers at 100 K: the O-bound end-on n1-SO2 Page 1 of 32 ACS Paragon Plus Environment The Journal of Physical Chemistry (MS1) configuration and the side-bound n2-SO2 (MS2), while 3 only exhibits the more thermally stable MS2 geometry. The decay kinetics of the MS2 geometry for 1-3 demonstrate that the greater the free volume of the GS SO2 ligand for a given counterion, the greater the MS2 thermal stability. Furthermore, a rationalization is sought for the SO2 phototriggered molecular rotation of the phenyl ring in the tosylate anion; this is selectively observed in 2, manifesting as nanomechanical molecular transduction. This molecular transduction was not observed in 1, despite the presence of the MS1 geometry due to the close intermolecular interactions between the MS1 SO2 and the neighbouring tosylate ion. The decay of this anionic molecular rotor in 2, however, follows a non-traditional decay pathway, as determined by time-resolved crystallographic analysis; this contrasts with the well-behaved first-order kinetic decay of its MS1 SO2 phototrigger.

  10. Research on anhydrous hydrazine synthesis

    International Nuclear Information System (INIS)

    Gaussens, G.

    1967-03-01

    The first part of this work concerns the radiolysis of pure liquid ammonia. The fundamental importance of the dose rate and of the dose on the yield of radiolytic products has been demonstrated. By using a capture solute at concentrations of between 10 -3 and 1.2 mole s/litre, it has been possible to determine the yields of radicals and of molecules in the irradiated pure ammonia. During later work, it was possible to determine, by systematically varying the physico-chemical parameters, the most favorable conditions for carrying out the radiosynthesis; the maximum radiochemical yield of the hydrazine obtained has a value: G (N 2 H 4 ) = 2.2/100 eV. An analysis of the molecular yields in the presence of deuterated solutes makes it possible to explain partially the role of the capture species. A project is also described for an installation producing hydrazine continuously; it is followed by an economic study of the process. From this work it appears that the yields of hydrazine obtained justify an industrial application, especially if strong radiation sources are available, for example nuclear reactors. (author) [fr

  11. catena-Poly[[[diaquabis(selenocyanato-κNiron(II]-μ-1,2-bis(pyridin-4-ylethane-κ2N:N′] 1,2-bis(pyridin-4-ylethane disolvate dihydrate

    Directory of Open Access Journals (Sweden)

    Susanne Wöhlert

    2013-06-01

    Full Text Available The title compound, {[Fe(NCSe2(C12H12N2(H2O2]·2C12H12N2·2H2O}n, was obtained by the reaction of iron(II sulfate heptahydrate and potassium selenocyanate with 1,2-bis(pyridin-4-ylethane (bpa in water. The FeII cation is coordinated by two N-bonded selenocyanate anions, two water molecules and two 1,2-bis(pyridin-4-ylethane (bpa ligands in a slightly distorted octahedral geometry. In addition, two non-coordinating bpa molecules and two water molecules are present. The FeII cation is located on a center of inversion while the coordinating bpa ligand is located on a twofold rotation axis. The FeII cations are linked by the bpa ligands into chains along the b-axis direction, which are further connected into layers perpedicular to the c axis by O—H...N and O—H...O hydrogen bonds to the non-coordinating bpa and the water molecules. The crystal studied was twinned by pseudo-merohedry (180° rotation along c*; contribution of the minor twin component 3.7%.

  12. Effect of alkali metal ions on the pyrrole and pyridine π-electron systems in pyrrole-2-carboxylate and pyridine-2-carboxylate molecules: FT-IR, FT-Raman, NMR and theoretical studies

    Science.gov (United States)

    Świderski, G.; Wojtulewski, S.; Kalinowska, M.; Świsłocka, R.; Lewandowski, W.

    2011-05-01

    The FT-IR, FT-Raman and 1H and 13C NMR spectra of pyrrole-2-carboxylic acid (PCA) and lithium, sodium, potassium, rubidium and caesium pyrrole-2-carboxylates were recorded, assigned and compared in the Li → Na → K → Rb → Cs salt series. The effect of alkali metal ions on the electronic system of ligands was discussed. The obtained results were compared with previously reported ones for pyridine-2-carboxylic acid and alkali metal pyridine-2-carboxylates. Calculations for pyrrole-2-carboxylic acid and Li, Na, K pyrrole-2-carboxylates in B3LYP/6-311++G ** level and Møller-Plesset method in MP2/6-311++G ** level were made. Bond lengths, angles and dipole moments as well as aromaticity indices (HOMA, EN, GEO, I 6) for the optimized structures of pyrrole-2-carboxylic acid (PCA) and lithium, sodium, potassium pyrrole-2-carboxylates were also calculated. The degree of perturbation of the aromatic system of ligand under the influence of metals in the Li → Cs series was investigated with the use of statistical methods (linear correlation), calculated aromaticity indices and Mulliken, NBO and ChelpG population analysis method. Additionally, the Bader theory (AIM) was applied to setting the characteristic of the bond critical points what confirmed the influence of alkali metals on the pyrrole ring.

  13. Poly[bis[μ-4-(4-carboxyphenoxybenzoato](μ-4,4′-oxydibenzoatobis[μ-3-(pyridin-4-yl-5-(pyridin-3-yl-1H-1,2,4-triazole]dicadmium(II

    Directory of Open Access Journals (Sweden)

    Xiao-Jin Qi

    2016-07-01

    Full Text Available Three kinds of bridging ligands, 4,4′-oxydibenzoate, 4-(4-carboxyphenoxybenzoate and 3-(pyridin-4-yl-5-(pyridin-3-yl-1H-1,2,4-triazole, link the CdII cations to form the title polymeric complex, [Cd2(C14H8O5(C14H9O52(C12H9N52]n, in which each CdII cation is in a distorted N2O5 pentagonal–bipyramidal coordination geometry. The 4,4′-oxydibenzoate dianion exhibits point group symmetry 2, with the central O atom located on a twofold rotation axis. Classical N—H...O, O—H...N hydrogen bonds and weak C—H...O hydrogen bonds link the complex molecules into a three-dimensional supramolecular architecture. A solvent-accessible void of 53 (2 Å3 is observed, but no solvent molecule could reasonably located there.

  14. Pyridinium bis­(pyridine-κN)tetra­kis­(thio­cyanato-κN)ferrate(III)–pyrazine-2-carbo­nitrile–pyridine (1/4/1)

    Science.gov (United States)

    Shylin, Sergii I.; Gural’skiy, Il’ya A.; Haukka, Matti; Golenya, Irina A.

    2013-01-01

    In the title compound, (C5H6N)[Fe(NCS)4(C5H5N)2]·4C5H3N3·C5H5N, the FeIII ion is located on an inversion centre and is six-coordinated by four N atoms of the thio­cyanate ligands and two pyridine N atoms in a trans arrangement, forming a slightly distorted octa­hedral geometry. A half-occupied H atom attached to a pyridinium cation forms an N—H⋯N hydrogen bond with a centrosymmetrically-related pyridine unit. Four pyrazine-2-carbo­nitrile mol­ecules crystallize per complex anion. In the crystal, π–π stacking inter­actions are present [centroid–centroid distances = 3.6220 (9), 3.6930 (9), 3.5532 (9), 3.5803 (9) and 3.5458 (8) Å]. PMID:23723782

  15. Thermodynamics of mixtures containing amines. IX. Application of the concentration-concentration structure factor to the study of binary mixtures containing pyridines

    Energy Technology Data Exchange (ETDEWEB)

    Gonzalez, Juan Antonio, E-mail: jagl@termo.uva.es [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain); Cobos, Jose Carlos; Garcia de la Fuente, Isaias; Mozo, Ismael [G.E.T.E.F. Dpto Termodinamica y Fisica Aplicada, Facultad de Ciencias, Universidad de Valladolid, Valladolid 47071 (Spain)

    2009-10-10

    Binary mixtures formed by a pyridine base and an alkane, or an aromatic hydrocarbon, or a 1-alkanol have been studied in the framework of the concentration-concentration structure factor, S{sub CC}(0), formalism. Deviations between experimental data and those provided by the DISQUAC model are discussed. Systems containing alkanes are characterized by homocoordination. In pyridine + alkane mixtures, S{sub CC}(0) decreases with the chain length of the longer alkanes, due to size effects. For a given alkane, S{sub CC}(0) also decreases with the number of CH{sub 3}- groups in the pyridine base. This has been interpreted assuming that the number of amine-amine interactions available to be broken upon mixing also decreases similarly, probably as steric hindrances exerted by the methyl groups of the aromatic amine increase with the number of these groups. Homocoordination is higher in mixtures with 3,5-dimethylpyridine than in those with 2,6-dimethylpyridine. That is, steric effects exerted by methyl groups in positions 3 and 5 are stronger than when they are in positions 2 and 6. Similarly, from the application of the DISQUAC (dispersive-quasichemical) model, it is possible to conclude that homocoordination is higher in systems with 3- or 4-methylpyridine than in those involving 2-methylpyridine. Systems including aromatic hydrocarbons are nearly ideal, which seems to indicate that there is no specific interaction in such solutions. Mixtures with 1-alkanols show heterocoordination. This reveals the existence of interactions between unlike molecules, characteristic of alkanol + amine mixtures. Methanol systems show the lowest S{sub CC}(0) values due, partially, to size effects. This explains the observed decrease of homocoordination in such solutions in the order: pyridine > 2-methylpyridine > 2,6-dimethylpyridine. Moreover, as the energies of the OH-N hydrogen bonds are practically independent of the pyridine base considered when mixed with methanol, it suggests that

  16. Characterization of plasma-polymerized 4-vinyl pyridine with silver nanoparticies on poly(ethylene terephthalate) film for anti-microbial properties

    DEFF Research Database (Denmark)

    Jiang, J.; Winther-Jensen, Bjørn; Kjær, Erik Michael

    2006-01-01

    scanning electron microscopy (FE-SEM), atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Different thicknesses Of poly(4-vinyl pyridine) coating under different plasma polymerization conditions were studied. Silver nanoparticles with diameter around 50nm deposit were precipitated...... on the poly(4-vinyl pyridine) coating by UV irradiation in Silver nitride water solution, in order to enhance the anti-microbial properties. Different kinds of modified PET films were tested for anti-microbial properties against yeast (Debaryomyces hansenii) by using microbiological analyser mu-4200...

  17. Synthesis, spectroscopic and electrochemical properties of mononuclear and dinuclear bis(bipy)ruthenium(II) complexes containing dimethoxyphenyl(pyridin-2-yl)-1,2,4-triazole ligands

    NARCIS (Netherlands)

    Passaniti, Paolo; Browne, Wesley R.; Lynch, Fiona C.; Hughes, Donal; Nieuwenhuyzen, Mark; James, Paraic; Maestri, Mauro; Vos, Johannes G.

    2002-01-01

    The ligands HL1 and H(2)L2 and the complexes [Ru(bipy)(2)L1]PF6.2H(2)O 1, [(Ru(bipy)(2))(2)L2](PF6)(2).7H(2)O 2, {where HL1 = 3-(2', 5'-dimethoxyphenyl)-5-(pyridin-2"-yl)- 1H-1,2,4-triazole, H(2)L2 = 1,4- bis(5'-(pyridin-2"-yl)- 1'H- 1', 2', 4'-triazol-3'-yl)- 2,5-dimethoxybenzene and bipy =

  18. (Pyridine)(tetrahydroborato)zinc complex, (Zn(BH4)2(py)), as a new stable, efficient and chemoselective reducing agent for reduction of carbonyl compounds

    International Nuclear Information System (INIS)

    Zeynizadeh, Behzad; Faraji, Fariba

    2003-01-01

    (Pyridine)(tetrahydroborato)zinc complex, (Zn(BH 4 ) 2 (py)), as a stable white solid, was prepared quantitatively by complexation of an equimolar amount of zinc tetrahydroborate and pyridine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins, α-diketones and α,β-unsaturated carbonyl compounds to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in ether or THF at room temperature or under reflux conditions. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing agent

  19. (Pyridine)(tetrahydroborato)zinc complex, (Zn(BH{sub 4}){sub 2}(py)), as a new stable, efficient and chemoselective reducing agent for reduction of carbonyl compounds

    Energy Technology Data Exchange (ETDEWEB)

    Zeynizadeh, Behzad; Faraji, Fariba [Urima Univ., Urima (Iran, Islamic Republic of)

    2003-04-01

    (Pyridine)(tetrahydroborato)zinc complex, (Zn(BH{sub 4}){sub 2}(py)), as a stable white solid, was prepared quantitatively by complexation of an equimolar amount of zinc tetrahydroborate and pyridine at room temperature. This reagent can easily reduce variety of carbonyl compounds such as aldehydes, ketones, acyloins, {alpha}-diketones and {alpha},{beta}-unsaturated carbonyl compounds to their corresponding alcohols in good to excellent yields. Reduction reactions were performed in ether or THF at room temperature or under reflux conditions. In addition, the chemoselective reduction of aldehydes over ketones was accomplished successfully with this reducing agent.

  20. Enhancement of catalytic activity of enzymes by heating in anhydrous organic solvents: 3D structure of a modified serine proteinase at high resolution.

    Science.gov (United States)

    Sharma, S; Tyagi, R; Gupta, M N; Singh, T P

    2001-01-01

    For the first time, it is demonstrated that exposure of an enzyme to anhydrous organic solvents at optimized high temperature enhances its catalytic power through local changes at the binding region. Six enzymes, namely, proteinase K, wheat germ acid phosphatase, alpha-amylase, beta-glucosidase, chymotrypsin and trypsin were exposed to acetonitrile at 70 degrees C for three hr. The activities of these enzymes were found to be considerably enhanced. In order to understand the basis of this change in the activity of these enzymes, proteinase K was analyzed in detail using X-ray diffraction method. The overall structure of the enzyme was found to be similar to the native structure in aqueous environment. The hydrogen bonding system of the catalytic triad remained intact after the treatment. However, the water structure in the substrate binding site underwent some rearrangement as some of the water molecules were either displaced or completely absent. The most striking observation concerning the water structure was the complete deletion of the water molecule which occupied the position at the so-called oxyanion hole in the active site of the native enzyme. Three acetonitrile molecules were found in the present structure. All the acetonitrile molecules were located in the recognition site. Interlinked through water molecules, the sites occupied by acetonitrile molecules were independent of water molecules. The acetonitrile molecules are involved in extensive interactions with the protein atoms. The methyl group of one of the acetonitrile molecules (CCN1) interacts simultaneously with the hydrophobic side chains of Leu 96, Ile 107 and Leu 133. The development of such a hydrophobic environment at the recognition site introduced a striking conformation change in Ile 107 by rotating its side chain about C alpha-C beta bond by 180 degrees to bring about the delta-methyl group within the range of attractive van der Waals interactions with the methyl group of CCN1. A similar

  1. Synthesis and antitumor activity of some novel thiophene, pyrimidine, coumarin, pyrazole and pyridine derivatives

    Directory of Open Access Journals (Sweden)

    Albratty Mohammed

    2017-03-01

    Full Text Available 2-Cyano-N-(thiazol-2-yl acetamide (2a and 2-cyano-N-(oxazol- 2-yl acetamide (2b were obtained via the reaction of ethyl cyanoacetate with either 2-aminothiazole (1a or 2-aminooxazole (1b. The formed products were directed toward the reaction with cyclopentanone and elemental sulfur in the presence of triethylamine to give cyclopenta[b]thiophene derivatives (3a,b. The latter products were reacted with either ethyl cyanoacetate or malononitrile to form compounds 4a,b and 5a,b, respectively. Compounds 4a,b were aimed at synthesizing some heterocyclic compounds; thus internal cyclization reactions were introduced to form compounds 6a,b. Also, compounds 4a,b reacted with salicylaldehyde, hydrazine derivatives and either urea or thiourea to produce coumarin derivatives (7a,b, pyrazole derivatives (8a-d and pyrimidine derivatives (9a-d, respectively. Reaction of either benzaldehyde or benzene diazonium chloride (11 with compounds 4a,b afforded compounds 10a,b and 12a,b, respectively. On the other hand, compounds 5a,b underwent internal cyclization to form pyrimidine derivatives 13a,b. Also, when compounds 5a,b reacted with either ethyl cyanoacetate or malononitrile, they gave pyridine derivatives (15a-d through the formation of intermediates (14a-d. Finally, formation of fused pyrimidine derivatives (17a,b was achieved through the reaction of compounds 5a,b and salicylaldehyde applying two different pathways. The first pathway used a catalytic amount of piperidine to form compounds 16a,b; the latter products underwent cyclization to give compounds 17a,b. The second pathway, using a catalytic amount of sodium ethoxide solution directly in one step, afforded compounds 17a,b. Structures of the newly synthesized compounds were established using IR, 1H NMR, 13C NMR and mass spectrometry and their antitumor activity was investigated. Some of these compounds showed promising inhibitory effects on three different cell lines. However, fused pyrimidine

  2. Xafs studies on actinide-pyridine-diamide complexes for development of an innovative separation process

    International Nuclear Information System (INIS)

    Hideaki, Shiwaku; Tsuyoshi, Yaita; Tohru, Kobayashi; Masahiko, Numakura; Tsuyoshi, Yaita; Shinichi, Suzuki; Yoshihiro, Okamoto

    2007-01-01

    We have been studying the bond properties and the structures of actinide (An) and lanthanide (Ln) complexes in detail using several kinds of X-ray analyses by synchrotron radiation in order to elucidate the ionic recognition mechanism of organic ligands. Generally, an oxygen donor type ligand separates both An and Ln from solutions of spent fuel or high level radioactive waste. Separation ability of this type of ligand for An and Ln follows the order of the surface charge density of an ion, i.e., An 4+ > AnO 2 2+ > An 3+ = Ln 3+ > AnO 2+ and/or a few structural factors. Therefore, this type of ligand is ineffective for the separation of An 3+ and Ln 3+ due to their similar chemical properties. Recently, new extractants like aromatic N-donor ligands have been developed using the preference of soft-donors to achieve the An 3+ /Ln 3+ separation. However, aromatic N-donor ligands often show a few problems such as protonation. In this developing process, we synthesized a new type of ligand, N,N'-dimethyl-N,N'-diphenyl-pyridine-2,6-carboxy-amide (DMDPh-PDA). The PDA is hybrid type ligand having oxygen and nitrogen as donor atoms and follows a unique separation order, i.e., An 4+ > An 3+ > AnO 2 2+ > Ln 3+ > AnO 2 + , probably arising from the combined effects of covalent bonding and steric hindrance. Hence, clarification of any ionic recognition mechanism of the PDA is very interesting from the view point of structural analysis. In this presentation, we will show XAFS results of An and Ln complexes with PDA in solution and discuss separation mechanism of An and Ln by PDA. Various kinds of complexes between Ln/An and PDA were prepared for XAFS analysis. The Ln complexes were measured in transmission mode at the K absorption edge on the BL11XU at SPring-8. On the other hand, the U complexes were measured in fluorescence mode at the L III absorption edge on the BL-27B at Photon Factory, High-energy Accelerator Research Organization (KEK). (authors)

  3. Theoretical Investigation on Single-Wall Carbon Nanotubes Doped with Nitrogen, Pyridine-Like Nitrogen Defects, and Transition Metal Atoms

    Directory of Open Access Journals (Sweden)

    Michael Mananghaya

    2012-01-01

    Full Text Available This study addresses the inherent difficulty in synthesizing single-walled carbon nanotubes (SWCNTs with uniform chirality and well-defined electronic properties through the introduction of dopants, topological defects, and intercalation of metals. Depending on the desired application, one can modify the electronic and magnetic properties of SWCNTs through an appropriate introduction of imperfections. This scheme broadens the application areas of SWCNTs. Under this motivation, we present our ongoing investigations of the following models: (i (10, 0 and (5, 5 SWCNT doped with nitrogen (CNxNT, (ii (10, 0 and (5, 5 SWCNT with pyridine-like defects (3NV-CNxNT, (iii (10, 0 SWCNT with porphyrine-like defects (4ND-CNxNT. Models (ii and (iii were chemically functionalized with 14 transition metals (TMs: Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Pd, Ag, Pt and Au. Using the spin-unrestricted density functional theory (DFT, stable configurations, deformations, formation and binding energies, the effects of the doping concentration of nitrogen, pyridine-like and porphyrine-like defects on the electronic properties were all examined. Results reveal that the electronic properties of SWCNTs show strong dependence on the concentration and configuration of nitrogen impurities, its defects, and the TMs adsorbed.

  4. Crucial role of molecular planarity on the second order nonlinear optical property of pyridine based chalcone single crystals

    Science.gov (United States)

    Menezes, Anthoni Praveen; Jayarama, A.; Ng, Seik Weng

    2015-05-01

    An efficient nonlinear optical material 2E-3-(4-bromophenyl)-1-(pyridin-3-yl) prop-2-en-1-one (BPP) was synthesized and single crystals were grown using slow evaporation solution growth technique at room temperature. Grown crystal had prismatic morphology and its structure was confirmed by various spectroscopic studies, elemental analysis, and single crystal X-ray diffraction (XRD) technique. The single crystal XRD of the crystal showed that BPP crystallizes in monoclinic system with noncentrosymmetric space group P21 and the cell parameters are a = 5.6428(7) Å, b = 3.8637(6) Å, c = 26.411(2) Å, β = 97.568(11) deg and v = 575.82(12) Å3. The UV-Visible spectrum reveals that the crystal is optically transparent and has high optical energy band gap of 3.1 eV. The powder second harmonic generation efficiency (SHG) of BPP is 6.8 times that of KDP. From thermal analysis it is found that the crystal melts at 139 °C and decomposes at 264 °C. High optical transparency down to blue region, higher powder SHG efficiency and better thermal stability than that of urea makes this chalcone derivative a promising candidate for SHG applications. Furthermore, effect of molecular planarity on SHG efficiency and role of pyridine ring adjacent to carbonyl group in forming noncentrosymmetric crystal systems of chalcone family is also discussed.

  5. Proof of concept for molecular velcro based on the attractive interaction between porphyrin and pyridine containing copolymers

    Directory of Open Access Journals (Sweden)

    M. Sievers

    2018-06-01

    Full Text Available In this short communication, we investigated the synthesis and mixing of porphyrin and pyridine functionalized copolymers as a proof of concept for a velcro-like interaction. A functionalized porphyrin monomer with one polymerizable side chain was synthesized following a rational synthetic pathway. Subsequent copolymerization and careful removal of residual free porphyrin led to poly(n-butyl acrylate-co-5,10,15-triphenyl-20-(3-vinylphenylporphyrin. The immobilized porphyrin was transformed into the corresponding zinc(II complex, which is capable of the coordinative binding of one pyridine moiety. Complete metallation was proven by absorption spectroscopy. 4-Vinylpyridine was immobilized by copolymerization with n-butyl acrylate, too. Via controlled radical polymerization conditions, the molecular weight of poly(n-butyl acrylate-co-4-vinylpyridine was limited to one tenth of the molecular weight of the porphyrin containing copolymer. This large difference in the molecular weight easily allowed identifying the polymers in the mixture of both. With the help of diffusion ordered nuclear magnetic resonance spectroscopy, the complete and temperature-stable precipitation of the porphyrin containing copolymer was observed, proving the expected attractive interaction and supramolecular network formation.

  6. Low-energy electron-induced dissociation in gas-phase nicotine, pyridine, and methyl-pyrrolidine

    Science.gov (United States)

    Ryszka, Michal; Alizadeh, Elahe; Li, Zhou; Ptasińska, Sylwia

    2017-09-01

    Dissociative electron attachment to nicotine, pyridine, and N-methyl-pyrrolidine was studied in the gas phase in order to assess their stability with respect to low-energy electron interactions. Anion yield curves for different products at electron energies ranging from zero to 15 eV were measured, and the molecular fragmentation pathways were proposed. Nicotine does not form a stable parent anion or a dehydrogenated anion, contrary to other biological systems. However, we have observed complex dissociation pathways involving fragmentation at the pyrrolidine side accompanied by isomerization mechanisms. Combining structure optimization and enthalpy calculations, performed with the Gaussian09 package, with the comparison with a deuterium-labeled N-methyl-d3-pyrrolidine allowed for the determination of the fragmentation pathways. In contrast to nicotine and N-methylpyrrolidine, the dominant pathway in dissociative electron attachment to pyridine is the loss of hydrogen, leading to the formation of an [M—H]- anion. The presented results provide important new information about the stability of nicotine and its constituent parts and contribute to a better understanding of the fragmentation mechanisms and their effects on the biological environment.

  7. Multi-signalling cation sensing behaviour of a bis(pyridin-2-yl methyl)aniline based hetarylazo dye

    International Nuclear Information System (INIS)

    Kaur, Paramjit; Sareen, Divya; Kaur, Mandeep; Singh, Kamaljit

    2013-01-01

    Graphical abstract: The chromogenic and electrochemical behaviour of bis(pyridine-2-yl methyl)aniline based hetarylazo dye gets perturbed in the presence of cations, most effective being Cu 2+ . The conversion of ICT to ICT/MLCT is witnessed by TD-DFT calculations. -- Highlights: •Cation sensing of hetarylazo dye based upon visual, absorption and electrochemical changes is described. •Sensing mechanism is based upon perturbation in intramolecular charge-transfer upon interaction with cations. •Sensing protocol is supported by 1 H NMR studies as well as theoretical calculations. •Hetarylazo dye acts as a multichannel sensor. •Response of the dye towards various cations has also been explored in acidic pH window. -- Abstract: We investigated the cation sensing behaviour of a bis(pyridin-2-yl methyl)aniline appended hetarylazo dye via chromogenic and electrochemical transduction channels. The binding pocket constituting both the pyridyl as well as aniline nitrogen atoms acts as recognition site for the cations and consequent perturbation in the intramolecular charge-transfer prevailing in the dye results in the chromogenic response manifested in the form of hypsochromic shift in the intramolecular charge-transfer band and the attendant naked-eye color changes. The dye exhibits significant changes in its electrochemical behaviour in the presence of cations. The experimental results are also rationalized by time-dependent density functional theory (TD-DFT) calculations

  8. Synthesis and characterisation of 5-acyl-6,7-dihydrothieno[3,2-c]pyridine inhibitors of Hedgehog acyltransferase

    Directory of Open Access Journals (Sweden)

    Thomas Lanyon-Hogg

    2016-06-01

    Full Text Available In this data article we describe synthetic and characterisation data for four members of the 5-acyl-6,7-dihydrothieno[3,2-c]pyridine (termed “RU-SKI” class of inhibitors of Hedgehog acyltransferase, including associated NMR spectra for final compounds. RU-SKI compounds were selected for synthesis based on their published high potencies against the enzyme target. RU-SKI 41 (9a, RU-SKI 43 (9b, RU-SKI 101 (9c, and RU-SKI 201 (9d were profiled for activity in the related article “Click chemistry armed enzyme linked immunosorbent assay to measure palmitoylation by Hedgehog acyltransferase” (Lanyon-Hogg et al., 2015 [1]. 1H NMR spectral data indicate different amide conformational ratios between the RU-SKI inhibitors, as has been observed in other 5-acyl-6,7-dihydrothieno[3,2-c]pyridines. The synthetic and characterisation data supplied in the current article provide validated access to the class of RU-SKI inhibitors.

  9. Am and Eu extraction from acidic media by synergistic mixtures of substituted bis-tetrazolyl pyridines with chlorinated cobalt dicarbollide

    International Nuclear Information System (INIS)

    Smirnov, I.V.; Chirkov, A.V.; Babain, V.A.; Pokrovskaya, E.Yu.; Artamonova, T.A.

    2009-01-01

    Americium (Am) and europium (Eu) extraction from HNO 3 and HClO 4 media by a synergistic mixture of 2.6-bis(1-aryl-1H-tetrazol-5-yl)pyridines (ATP) with chlorinated cobalt dicarbollide (CCD) was studied by using m-nitrobenzotrifluoride, phenyltrifluoromethyl sulfone, and 1,2-dichloroethane as diluents. We examined the effects of diluents, of the aqueous phase composition and the nature of substituents in the ATP aryl ring on Am/Eu extraction efficiency and selectivity. The Am/Eu separation factor was found to be close to 100 at the optimal ratio of ATPs: CCD ∝ 1:1. We also studied the extraction of 85 Sr, 137 Cs and 133 Ba; a PhATP-CCD mixture provided the separation of the Sr/Ba pair with a factor of 35. A high resistance of 2,6-bis-aryltetrazolyl pyridines to 6 M nitric and perchloric acids at 95 C was demonstrated. (orig.)

  10. A density functional study of inhibition of the HDS hydrogenation pathway by pyridine, benzene, and H2S on MoS2-based catalysts

    DEFF Research Database (Denmark)

    Logadottir, A.; Moses, Poul Georg; Hinnemann, Berit

    2006-01-01

    hydrogen from neighboring SH group can he transferred to the pyridine molecule resulting in the creation of more strongly held pyridinium ions. At the so-called S edge, hydrogen is tightly bound and this transfer is not favored. The present results, therefore, also stress the importance of the hydrogen...... binding properties of HDS catalysts. (c) 2005 Elsevier B.V. All rights reserved....

  11. Reactions of zinc hydride and magnesium hydride with pyridine; synthesis and characterization of 1,4-dihydro-1-pyridylzinc and -magnesium complexes

    NARCIS (Netherlands)

    Koning, A.J. de; Boersma, J.; Kerk, G.J.M. van der

    1980-01-01

    The synthesis and characterization of 1,4-dihydro-1-pyridylzinc and -magnesium complexes are described. Zinc hydride and magnesium hydride dissolve in and react with pyridine, and the reaction has been studied in detail in the case of zinc hydride. Evaporation of the solvent after 1–2 hours at 0°C

  12. Syntheses of two potential dopamine D{sub 4} receptor radioligands: {sup 18}F labelled chromeno[3,4-c]pyridin-5-ones

    Energy Technology Data Exchange (ETDEWEB)

    Gu-Cai Li; Duan-Zhi Yin; Ming-Wei Wang; Deng-Feng Cheng; Yong-Xian Wang [Research Center of Radiopharmaceuticals, Shanghai Inst. of Applied Physics, Chinese Academy of Sciences, Shanghai, SH (China)

    2006-07-01

    The dopamine D{sub 4} receptor is hypothesized to relate with the pathophysiology and pharmacotherapy of schizophrenia while its level in brain regions is much lower and to date no suitable tracer is available for the study of D{sub 4} receptor in vivo. Therefore, selective imaging agents for the D{sub 4} subtype are badly needed. Based on the structure-activity analysis of chromeno[3,4-c]pyridin-5-ones as dopamine D{sub 4} receptor ligands, two fluorine-18 labelled chromeno[3,4-c] pyridin-5-one derivatives, 3-(4-[{sup 18}F]fluorobenzyl)-8-hydroxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one and 3-(4-[{sup 18}F]fluorobenzyl)-8,9-dimethoxy-1,2,3,4-tetrahydrochromeno[3,4-c]pyridin-5-one were synthesized through a two-step one-pot method. Their radiochemical yields were around 19.7% (decay-corrected) and radiochemical purities were higher than 95% with specific activities of about 120 GBq/{mu}mol. (orig.)

  13. Synthesis of substituted [{sup 123}I]imidazo[1,2-a]pyridines as potential probes for the study of the peripheral benzodiazepine receptors using SPECT

    Energy Technology Data Exchange (ETDEWEB)

    Katsifis, A.; Mattner, F.; Dikic, B.; Papazian, V. [Radiopharmaceuticals Div. R and D, ANSTO, Menai, NSW (Australia)

    2000-07-01

    The imidazo[1,2-a]pyridines N,N'-dimethyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 1. N,N'-diethyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 2, and N-methyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 3, are high affinity and selective ligands for the peripheral benzodiazepineodiazepine receptors (PBR). The [{sup 123}I]1-3 labelled analogues of these compounds were subsequently synthesised for the potential study of the PBR in vivo using SPECT. Radioiodination was achieved by iododestannylation reactions of the corresponding tributyl tin precursors with Na[{sup 123}I] in the presence of peracetic acid, chloramine-T or Iodogen. Purification of the crude product was achieved by semipreparative C-18 RP HPLC to give the products in radiochemical yields of 40-85%. The products were obtained in >97% chemical and radiochemical purity and with specific activities >80 GBq/{mu}mol. (orig.)

  14. Synthesis of substituted [123I]imidazo[1,2-a]pyridines as potential probes for the study of the peripheral benzodiazepine receptors using SPECT

    International Nuclear Information System (INIS)

    Katsifis, A.; Mattner, F.; Dikic, B.; Papazian, V.

    2000-01-01

    The imidazo[1,2-a]pyridines N,N'-dimethyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 1. N,N'-diethyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 2, and N-methyl-6-chloro-(4'-iodophenyl)imidazo[1,2-a]pyridine-3-acetamide 3, are high affinity and selective ligands for the peripheral benzodiazepineodiazepine receptors (PBR). The [ 123 I]1-3 labelled analogues of these compounds were subsequently synthesised for the potential study of the PBR in vivo using SPECT. Radioiodination was achieved by iododestannylation reactions of the corresponding tributyl tin precursors with Na[ 123 I] in the presence of peracetic acid, chloramine-T or Iodogen. Purification of the crude product was achieved by semipreparative C-18 RP HPLC to give the products in radiochemical yields of 40-85%. The products were obtained in >97% chemical and radiochemical purity and with specific activities >80 GBq/μmol. (orig.)

  15. Facilitating Students' Review of the Chemistry of Nitrogen-Containing Heterocyclic Compounds and Their Characterization through Multistep Synthesis of Thieno[2,3-"b"]Pyridine Derivatives

    Science.gov (United States)

    Liu, Hanlin; Zaplishnyy, Vladimir; Mikhaylichenko, Lana

    2016-01-01

    A multistep synthesis of thieno[2,3-"b"]pyridine derivatives is described that is suitable for the upper-level undergraduate organic laboratory. This experiment exposes students to various hands-on experimental techniques as well as methods of product characterization such as IR and [superscript 1]H NMR spectroscopy, and…

  16. Morphological changes of monolayers of two polymerizable pyridine amphiphiles upon complexation with Cu(II) ions at the air-water interface

    NARCIS (Netherlands)

    Werkman, P.J.; Schouten, A.J.; Noordegraaf, M.A.; Kimkes, P.; Sudhölter, E.J.R.

    1998-01-01

    The monolayer behavior of two amphiphilic, diacetylenic units containing pyridine Ligands at the air-water interface is studied by measuring the surface pressure-area isotherms and by Brewster angle microscopy(BAM). Both amphiphiles form stable monolayers at the air-water interface. The amphiphile

  17. Synthesis and muscarinic receptor pharmacology of a series of 4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridine bioisosteres of arecoline

    DEFF Research Database (Denmark)

    Pedersen, H; Bräuner-Osborne, H; Ball, R G

    1999-01-01

    A series of O- and ring-alkylated derivatives of 4,5,6,7-tetrahydroisothiazolo[4,5-c]pyridin-3-ol was synthesized via treatment of appropriately substituted 4-benzylamino-1,2,5,6-tetrahydropyridine-3-carboxamides with hydrogen sulfide and subsequent ring closure by oxidation with bromine. The mus...

  18. Pyridine synthesis by reactions of allyl amines and alkynes proceeding through a Cu(OAc)2 oxidation and Rh(III)-catalyzed N-annulation sequence.

    Science.gov (United States)

    Kim, Dong-Su; Park, Jung-Woo; Jun, Chul-Ho

    2012-11-28

    A new methodology has been developed for the synthesis of pyridines from allyl amines and alkynes, which involves sequential Cu(II)-promoted dehydrogenation of the allylamine and Rh(III)-catalyzed N-annulation of the resulting α,β-unsaturated imine and alkyne.

  19. Pure white OLED based on an organic small molecule: 2,6-Di(1H-benzo[d]imidazol-2-yl)pyridine

    Science.gov (United States)

    Liu, Jian

    2015-10-01

    2,6-Di(1H-benzo[d]imidazol-2-yl)pyridine (DBIP) was synthesized. The single-crystal structure of DBIP was resolved. DBIP-based OLED was fabricated. The electroluminescence for the device corresponds to a pure white emission. In addition, thermal stability, UV-vis, photoluminescence and electrochemical behaviors of DBIP were investigated as well.

  20. A potential method using Ge{iPrNC[N(SiMe_3)_2]NiPr}{sub 2}, (Et{sub 3}Si){sub 2}Te and anhydrous hydrazine for germanium tellurides

    Energy Technology Data Exchange (ETDEWEB)

    Du, Liyong; Du, Shulei; Ding, Yuqiang [School of Chemical and Material Engineering, Jiangnan University, Wuxi (China)

    2017-12-29

    A germanium(II)-guanidine derivative of formula Ge{iPrNC[N(SiMe_3)_2]NiPr}{sub 2} (1) was synthesized and characterized by {sup 1}H NMR, {sup 13}C NMR, elemental analysis, and X-ray diffraction method. Thermal property was also studied to identify its thermal stability and volatility. More importantly, compound 1 was synthesized to develop a new method for germanium tellurides, where anhydrous hydrazine was introduced to prompt the activity of germanium(II) guanidines (or derivatives) towards (Et{sub 3}Si){sub 2}Te. Solution reaction of compound 1, (Et{sub 3}Si){sub 2}Te, and anhydrous hydrazine was investigated to pre-identify the feasibility of this combination for ALD process. The EDS data of the black precipitate from this reaction verified the potential of this method to manufacture germanium tellurides. (copyright 2017 WILEY-VCH Verlag GmbH and Co. KGaA, Weinheim)