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Sample records for pyridines

  1. 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 ni

  2. Parallel interactions at large horizontal displacement in pyridine-pyridine and benzene-pyridine dimers.

    Science.gov (United States)

    Ninković, Dragan B; Andrić, Jelena M; Zarić, Snežana D

    2013-01-14

    A study of crystal structures from the Cambridge Structural Database (CSD) and DFT calculations reveals that parallel pyridine-pyridine and benzene-pyridine interactions at large horizontal displacements (offsets) can be important, similar to parallel benzene-benzene interactions. In the crystal structures from the CSD preferred parallel pyridine-pyridine interactions were observed at a large horizontal displacement (4.0-6.0 Å) and not at an offset of 1.5 Å with the lowest calculated energy. The calculated interaction energies for pyridine-pyridine and benzene-pyridine dimers at a large offset (4.5 Å) are about 2.2 and 2.1 kcal mol(-1), respectively. Substantial attraction at large offset values is a consequence of the balance between repulsion and dispersion. That is, dispersion at large offsets is reduced, however, repulsion is also reduced at large offsets, resulting in attractive interactions.

  3. Polyvinyl pyridine microspheres

    Science.gov (United States)

    Rembaum, Alan (Inventor); Gupta, Amitava (Inventor); Volksen, Willi (Inventor)

    1980-01-01

    Microspheres are produced by cobalt gamma radiation initiated polymerization of a dilute aqueous vinyl pyridine solution. Addition of cross-linking agent provides higher surface area beads. Addition of monomers such as hydroxyethylmethacrylate acrylamide or methacrylamide increases hydrophilic properties and surface area of the beads. High surface area catalytic supports are formed in the presence of controlled pore glass substrate.

  4. 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.

  5. 27 CFR 21.122 - Pyridine bases.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Pyridine bases. 21.122....122 Pyridine bases. (a) Alkalinity. One ml of pyridine bases dissolved in 10 ml of water is titrated.... Dissolve 1 ml of pyridine bases in 100 ml of water. (1) Ten ml of this solution are treated with 5 ml of...

  6. Pyridine Aggregation in Helium Nanodroplets

    Science.gov (United States)

    Nieto, Pablo; Poerschke, Torsten; Habig, Daniel; Schwaab, Gerhard; Havenith, Martina

    2012-06-01

    Pyridine crystals show the unusual property of isotopic polymorphism. Experimentally it has been observed that deuterated pyridine crystals exist in two phases while non-deuterated pyridine does not show a phase transition. Therefore, although isotopic substitution is the smallest possible modification of a molecule it greatly affects the stability of pyridine crystals. A possible experimental approach in order to understand this striking effect might be the study of pyridine aggregation for small clusters. By embedding the clusters in helium nanodroplets the aggregates can be stabilized and studied by means of Infrared Depletion Spectroscopy. Pyridine oligomers were investigated in the C-H asymmetric vibration region (2980-3100 cm-1) using this experimental technique. The number of molecules for the clusters responsibles for each band were determined by means of pick-up curves as well as mass sensitive depletion spectra. Furthermore, the intensity dependence of the different bands on applying a dc electric field was studied. The assignment of the different structures for pyridine clusters on the basis of these measurements were also carried out. S. Crawford et al., Angew. Chem. Int. Ed., 48, 755 (2009).

  7. Basicity of pyridine and some substituted pyridines in ionic liquids.

    Science.gov (United States)

    Angelini, Guido; De Maria, Paolo; Chiappe, Cinzia; Fontana, Antonella; Pierini, Marco; Siani, Gabriella

    2010-06-04

    The equilibrium constants for ion pair formation of some pyridines have been evaluated by spectrophotometric titration with trifluoroacetic acid in different ionic liquids. The basicity order is the same in ionic liquids and in water. The substituent effect on the equilibrium constant has been discussed in terms of the Hammett equation. Pyridine basicity appears to be less sensitive to the substituent effect in ionic liquids than in water.

  8. Molecular dynamics simulation of pyridine

    Science.gov (United States)

    Trumpakaj, Zygmunt; Linde, Bogumił

    2015-04-01

    Molecular Dynamics (MD) simulations are used for the investigation of molecular motions in pyridine in the temperature range 20-480 K under normal pressure. The results obtained are analyzed within the frame of the Mori Zwanzig memory function formalism. An analytical approximation of the first memory function K(t) is applied to predict some dependences on temperature. Experimental results of the Rayleigh scattering of depolarized light from liquid pyridine are used as the main base for the comparison.

  9. [Zn(sulfasalazine)2(pyridine)

    Institute of Scientific and Technical Information of China (English)

    王锡森; 宋玉梅; 熊仁根

    2005-01-01

    In compound [Zn(sulfasalazine)2(pyridine)] (1), each zinc atom not only coordinates to nitrogen atom of pyridine, but also is connected with four oxygen atoms from carboxylic acid groups of four sulfasalazine ligands,to result in the formation of a distorted tetragonal pyramid. In addition, each sulfasalazine ligand coordinates to two zinc atoms through its two oxygen atoms of carboxylic acid group to afford a 1D chain. CCDC: 274842.

  10. 40 CFR 721.8775 - Substituted pyridines.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted pyridines. 721.8775... Substances § 721.8775 Substituted pyridines. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as substituted pyridine (PMN P-84-1219)...

  11. 40 CFR 721.8675 - Halogenated pyridines.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated pyridines. 721.8675... Substances § 721.8675 Halogenated pyridines. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated pyridine (PMN P-83-1163)...

  12. UV photolysis for accelerating pyridine biodegradation.

    Science.gov (United States)

    Zhang, Yongming; Chang, Ling; Yan, Ning; Tang, Yingxia; Liu, Rui; Rittmann, Bruce E

    2014-01-01

    Pyridine, a nitrogen-containing heterocyclic compound, is slowly biodegradable, and coupling biodegradation with UV photolysis is a potential means to accelerate its biotransformation and mineralization. The initial steps of pyridine biodegradation involve mono-oxygenation reactions that have molecular oxygen and an intracellular electron carrier as cosubstrates. We employed an internal circulation baffled biofilm reactor for pyridine biodegradation following three protocols: direct biodegradation (B), biodegradation after photolysis (P+B), and biodegradation with succinic acid added (B+S). Succinic acid was the main UV-photolysis product from pyridine, and its catabolic oxidation generates internal electron carriers that may accelerate the initial steps of pyridine biodegradation. Compared with direct biodegradation of pyridine (B), the removal rate for the same concentration of photolyzed pyridine (P+B) was higher by 15 to 43%, depending on the initial pyridine concentrations (increasing through the range of 130 to 310 mg/L). Adding succinic acid alone (B+S) gave results similar to P+B, which supports that succinic acid was the main agent for accelerating the pyridine biodegradation rate. In addition, protocols P+B and B+S were similar in terms of increasing pyridine mineralization over 10 h: 84% and 87%, respectively, which were higher than with protocol B (72%). The positive impact of succinic acid-whether added directly or produced via UV photolysis-confirms that its catabolism, which produced intracellular electron carriers, accelerated the initial steps of pyridine biotransformation.

  13. Highly Regioselective Halogenation of Pyridine N-Oxide: Practical Access to 2-Halo-Substituted Pyridines.

    Science.gov (United States)

    Chen, Ying; Huang, Jinkun; Hwang, Tsang-Lin; Chen, Maosheng J; Tedrow, Jason S; Farrell, Robert P; Bio, Matthew M; Cui, Sheng

    2015-06-19

    A highly efficient and regioselective halogenation reaction of unsymmetrical pyridine N-oxide under mild conditions is described. The methodology provides a practical access to various 2-halo-substituted pyridines, which are pharmaceutically important intermediates.

  14. [Biodegradation of pyridine under UV irradiation].

    Science.gov (United States)

    Fang, Miao-Miao; Yan, Ning; Zhang, Yong-Ming

    2012-02-01

    Pyridine, a complex nitrogen-containing heterocyclic compounds, is usually difficult to degrade by means of single biological method. The internal loop photobiodegradation reactor (ILPBR) was used for degradation of pyridine in batch and continuous experiments following three protocols: photolysis alone (P), biodegradation alone (B), and intimately coupled photolysis and biodegradation (P&B) to investigate the regularity of pyridine degradation. The experimental results indicated that pyridine removal rate by P&B was fastest among three protocols in batch experiment, in which protocol B was faster than P. For initial pyridine concentration of 100 mg L(-1), the pyridine removal rates were respectively 4.95, 10.2 and 14.58 mg (L x h)(-1) corresponding to protocol P, B and P&B. Pyridine degradation kinetic equations were established based on Monod model, and the saturation constants decreased from 1920.4 mg x L(-1) for protocol B to 1094.1 mg x L(-1) for protocol P&B. Protocols P, B and P&B were also used for pyridine degradation in continuous flow and influent pyridine concentration increased from 50 to 300 mg x L(-1), and their average removal rates were respectively 15.8 mg (L x h)(-1) for protocol P, 23.1 mg x (L x h)(-1) for protocol B and 24.9 mg x (L x h)(-1) for protocol P&B, in which the removal rates were higher than that in batch. Experiments suggested that the inhibition of pyridine to biofilm could be relieved due to UV irradiation in process of intimately coupled UV photolysis and biodegradation, and biofilm had kept its bioactivity degrading pyridine and enhanced pyridine removal rates.

  15. Bacterial pyridine hydroxylation is ubiquitous in environment.

    Science.gov (United States)

    Sun, Ji-Quan; Xu, Lian; Tang, Yue-Qin; Chen, Fu-Ming; Zhao, Jing-Jing; Wu, Xiao-Lei

    2014-01-01

    Ten phenol-degrading bacterial strains were isolated from three geographically distant environments. Five of them, identified as Diaphorobacter, Acidovorax, Acinetobacter (two strains), and Corynebacterium, could additionally transform pyridine, through the transcription of phenol hydroxylase genes induced both by phenol and pyridine. HPLC-UV and LC-MS analyses indicated that one metabolite (m/e = 96.07) with the same molecular weight as monohydroxylated pyridine was produced from the five phenol-degrading strains, when pyridine was the sole carbon source. Phenol (50 mg l(-1)) could initially inhibit and later stimulate the pyridine transformation. In addition, heterologous expression of the phenol hydroxylase gene (pheKLMNOP) resulted in the detection of monohydroxylated pyridine, which confirmed the phenol hydroxylase could catalyze pyridine hydroxylation. Phylogeny of the phenol hydroxylase genes revealed that the genes from the five pyridine-hydroxylating strains form a clade with each other and with those catalyzing the hydroxylation of phenol, BTEX (acronym of benzene, toluene, ethylbenzene, and xylene), and trichloroethylene. These results suggest that pyridine transformation via hydroxylation by phenol hydroxylase may be prevalent in environments than expected.

  16. Vibrational studies of benzene, pyridine, pyridine-N-oxide and their cations.

    Science.gov (United States)

    Kumar, M; Srivastava, Mayuri; Yadav, R A

    2013-07-01

    IR and Raman spectra of pyridine and pyridine-N-oxide have been recorded and analyzed. The optimized molecular geometries, APT charges and vibrational characteristics for benzene, pyridine, pyridine-N-oxide and their cations have been computed using DFT method. Due to attachment of O atom at N site or removal of electron all the modes are affected in magnitudes. However, significant changes are noticed in their IR intensities, Raman activities and depolarization ratios of the Raman bands in going from pyridine to its N-oxide or in going from neutrals to their cations. It is interesting to note that in going from benzene to benzene cation charge redistribution takes place to reduce the symmetry from D6h to D2h. The calculated frequencies have been correlated with the experimental frequencies for the pyridine and pyridine-N-oxide molecules.

  17. 5-(Pyridin-4-ylisophthalic acid

    Directory of Open Access Journals (Sweden)

    Yong-Fang Zhang

    2010-11-01

    Full Text Available In the title compound, C13H9NO4, the two carboxylic groups and the benzene ring are approximately co-planar with a maximum atomic deviation 0.175 (4 Å, while the pyridine ring is oriented at a dihedral angle of 31.07 (18° with respect to the benzene ring. In the crystal, molecules are linked by O—H...O, O—H...N and weak C—H...O hydrogen bonds, forming a three-dimensional supramolecular framework.

  18. 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

  19. Riboflavin production during growth of Micrococcus luteus on pyridine

    Energy Technology Data Exchange (ETDEWEB)

    Sims, G.K. (Environmental Chemistry Lab., Dow Elanco, Midland, MI (United States)); O' Loughlin, E.J. (Ohio State Univ., Columbus (United States))

    1992-10-01

    Micrococcus luteus produced 29 {mu}M riboflavin during growth on 6.5 mM pyridine but not during growth on other substrates. On the basic 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. The optimum concentration of pyridine for both growth of the organism and pyridine degradation was 13 mM. Above 25 mM, pyridine temporarily inhibited growth, pyridine degradation, oxygen uptake, and pigment production.

  20. 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…

  1. A FOURIER TRANSFORM INFRARED SPECTROSCOPIC STUDY OF THE REACTION BETWEEN POLY (VINYL PYRIDINE)S AND EPOXY COMPOUNDS

    Institute of Scientific and Technical Information of China (English)

    XUE Gi; JIANG Shankeng

    1987-01-01

    Chemical reactions between poly (vinyl pyridine)s and 1,4-butanediol diglycidyl ether and other epoxy compounds were studied by Fouriertransform infrared spectroscopy and other techniques. The epoxy group was found to react with the pyridine side group of poly (4-vinyl pyridine), forming crosslinked networks which contain cyclic amide structures. The reaction was also observed in the interfacial region of poly(vinyl pyridine) and γ-glycidoxy propyl trimethoxysilane hydrolyzate (γ-GPS) coatings on PET fiber substrates.Poly(2-vinyl pyridine) does not show the same reaction.

  2. The Curious Case of Pyridine - Water

    Science.gov (United States)

    Mackenzie, Becca; Dewberry, Chris; Smith, CJ; Cornelius, Ryan D.; Leopold, Ken

    2016-06-01

    The rotational spectrum of the pyridine\\cdotswater complex has been observed in the 2-18 GHz region using chirped-pulse and cavity Fourier transform microwave spectroscopy. The water is hydrogen bonded to the nitrogen, as expected, but the hydrogen bond is bent, with the oxygen tilted toward either of the ortho hydrogens of the pyridine. This gives rise to a pair of equivalent configurations and the possibility of a tunneling motion involving an in-plane rocking of the water. DFT calculations support this view. Experimentally, a pair of states with severely perturbed rotational structure has been identified and the spectra assigned. Analysis of the perturbations in the a-type (pure rotation) spectra has enabled an accurate determination of the tunneling splitting, which has been confirmed by direct observation of b-type (rotation-tunneling) transitions. A simultaneous fit of the a- and b- type transitions gives the most accurate value of the tunneling splitting. Results for the H2O, D2O, and D-bound HOD complexes will be presented. The tunneling splittings are as follows: H2O-pyridine (10402.9 MHz), HOD-pyridine (12513.4 MHz, determined only from perturbation analysis), and D2O-pyridine (13582.3 MHz). Curiously, the tunneling splitting increases with increased deuteration. Additional small splittings have been observed in some transitions, indicating the possibility of further internal dynamics. This system offers an interesting test case for theoretical treatments of large amplitude motion.

  3. In vitro genotoxicity of pyridine in human lymphocytes.

    Science.gov (United States)

    Emelnsia, Aida D; Rather, Irfan A

    2016-05-01

    This work was carried out to study the genotoxicity of pyridine in vitro on human leucocyte culture. Cyclophosphamide, a well-known carcinogen was used as positive control. The four different concentrations of pyridine and cyclophosphamide showed breaks and pulverization of chromosomes in dose dependent manner. Higher number of pulverization was observed with higher concentration of pyridine (3.25μg/mL). Based on this data, our results confirm that both pyridine and its precursor showed genotoxicity against human lymphocytes.

  4. 40 CFR 721.8750 - Halogenated substituted pyridine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated substituted pyridine. 721... Substances § 721.8750 Halogenated substituted pyridine. (a) Chemical substances and significant new uses... pyridine (PMN P-86-838) is subject to reporting under this section for the significant new uses...

  5. 40 CFR 721.8780 - Substituted pyridine azo substituted phenyl.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted pyridine azo substituted... Specific Chemical Substances § 721.8780 Substituted pyridine azo substituted phenyl. (a) Chemical substance... substituted pyridine azo substituted phenyl (PMNs P-96-767 and P-96-773) are subject to reporting under...

  6. 40 CFR 721.8700 - Halogenated alkyl pyridine.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Halogenated alkyl pyridine. 721.8700... Substances § 721.8700 Halogenated alkyl pyridine. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as halogenated alkyl pyridine (PMN P-83-237)...

  7. Tetraaquabis(pyridine-κNnickel(II dinitrate

    Directory of Open Access Journals (Sweden)

    Mario Wriedt

    2010-07-01

    Full Text Available In the title compound, [Ni(C5H5N2(H2O4](NO32, the NiII ion is coordinated by two N-bonded pyridine ligands and four water molecules in an octahedral coordination mode. The asymmetric unit consists of one NiII ion located on an inversion center, as well as one pyridine ligand, one nitrate anion and two water molecules in general positions. In the crystal structure, the discrete complex cations and nitrate anions are connected by O—H...O and C—H...O hydrogen bonds.

  8. Synthesis of 2-substituted pyridines via a regiospecific alkylation, alkynylation, and arylation of pyridine N-oxides.

    Science.gov (United States)

    Andersson, Hans; Almqvist, Fredrik; Olsson, Roger

    2007-03-29

    [structure: see text]. Sequential addition of Grignard reagents to pyridine N-oxides in THF at room temperature followed by treatment with acetic anhydride at 120 degrees C afforded 2-substituted pyridines in good to high yields. Furthermore, by exchanging acetic anhydride for DMF in the second step, 2-substituted pyridine N-oxides were obtained, as intermediates suitable for addition of a second Grignard reagent for the synthesis of 2,6-disubstituted pyridines.

  9. Electrochemical properties of pyridine and dihydropyridine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Abou-Elenien, G.; Rieser, J.; Ismail, N.; Wallenfels, K.

    1981-03-01

    The electrochemical oxidation and reduction properties of different dihydropyridines and pyridines have been investigated in non aqueous solvent as benzonitrile and acetonitrile with tetra-n-butylammonium perchlorate as supporting electrolyte at platinum electrodes using DC-voltametry, cycl. voltametry and coulometry. Possible redox-mechanisms are discussed.

  10. Benzene and Pyridine on Silicon (001)

    DEFF Research Database (Denmark)

    Warschkow, Oliver; Bennett, J.M.; Miwa, J. A.

    2017-01-01

    The adsorption chemistry of benzene and pyridine on the silicon (001) surface is characterized by two prominent adsorbate configurations: a precursor structure bonded to a single Si Si dimer and a "tight-bridge" configuration that connects two adjacent dimers. We examine here the performance of 2...

  11. Analytical reagents based on pyridine aldehydes

    Energy Technology Data Exchange (ETDEWEB)

    Lejtis, L.Ya.; Skolmejstere, R.A.; Rubina, K.I.; Yansone, D.P.; Shimanskaya, N.V. (AN Latvijskoj SSR, Riga. Inst. Organicheskogo Sinteza)

    1985-03-01

    The papers published in 1950 through 1983 on the use of pyriodine aldehydes and their derivatives as analytical reagents for determining inorganic and organic substances are considered. To determining cations of transition metals, pyridine aldehydes, such as oximethanephosphonic acid, oximes azomethines, hydrazones, semicarbazones, are also applied. The complexing reactions of transition metal ions with pyrimine aldehydes and the structure of complexes obtained are considered. Spectrophotometric characteristics of complexes of Cd, V, Rv and other metals with pyridine aldehydes are given. Optimum conditions are shown for the formation of complexes as well as their stability, concentration ranges in which the beer law is observed, sensitivity and errors of spectrophotometric determination of the ions are in question.

  12. SYNTHESIS AND CHARACTERIZATION OF HETEROAROMATIC POLYMERS CONTAINING PYRIDINE MOIETIES

    Institute of Scientific and Technical Information of China (English)

    LI Yanfeng; WANG Xiaolong; ZHANG Shujiang

    2006-01-01

    The progress on the molecular design, synthesis and characterizations of some kinds of pyridine-containing heteroaromatic polymers in main chain were reviewed in this paper, they would include polyimides (PIs), polypyrrolones (PPYs), poly(pyrrolone-imide)s (PPIs), and poly(pyrrolone-benzimidazone)s (PPBs) containing pyrldine moieties. The pyridine-containing polymers reported all exhibit good processability, excellent thermal properties and mechanical properties. However, the contribution of pyridine ring to polymers properties is still need to research further, the heteroarornatic polymers containing pyridine moieties have focused by more and more researchers.

  13. 40 CFR 721.10034 - Substituted pyridine coupled with diazotized substituted nitrobenzonitrile, diazotized...

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Substituted pyridine coupled with... Specific Chemical Substances § 721.10034 Substituted pyridine coupled with diazotized substituted... as substituted pyridine coupled with diazotized substituted nitrobenzonitrile, diazotized...

  14. Self-Assembled Pyridine-Dipyrrolate Cages.

    Science.gov (United States)

    Zhang, Huacheng; Lee, Juhoon; Lammer, Aaron D; Chi, Xiaodong; Brewster, James T; Lynch, Vincent M; Li, Hao; Zhang, Zhan; Sessler, Jonathan L

    2016-04-06

    An inherently nonlinear pyridine dipyrrolate ligand, namely 2,6-bis(3,4-diethyl-5-carboxy-1H-pyrrol-2yl)pyridine (compound 1), is able to distinguish between different zinc(II) cation sources, namely Zn(acac)2 and Zn(OAc)2, respectively. This differentiation is manifest both in terms of the observed fluorescent behavior in mixed organic media and the reaction chemistry. Treatment of 1 with Zn(acac)2 gives rise to a cage dimer, cage-1, wherein two molecules of compound 1 act as double bridging units to connect two individual cage subunits. As inferred from X-ray crystallographic studies, this cage system consists of discrete zinc dimers with hydroxide bridges that, with the assistance of bound DMF solvent molecules, serve to fix the geometry and orientation of the pyridine dipyrrolate building blocks. When a different zinc source, Zn(OAc)2, is used to carry out an ostensibly similar complexation reaction with compound 1, an acetate-bridged 1D abacus-like cage polymer is obtained as inferred from X-ray diffraction analysis. This extended solid state structure, cage-2, contains individual zinc dimer cage submits and appears stabilized by solvent molecules (DMF) and the counteranion (acetate). Rod-like assemblies are also observed by DLS and SEM. This construct, in contrast to cage-1, proved fluorescent in mixed organic media. The structure of the ligand itself (i.e., in the absence of Zn(II)) was confirmed by X-ray crystallographic analysis and was found to assemble into a supramolecular polymer. Conversion to a dimer form was seen upon the addition of TBAOAc. On the basis of the metric parameters, the structures seen in the solid state are stabilized via hydrogen bonding interactions involving solvent molecules.

  15. 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.

  16. 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.

  17. Synthesis of Chiral Macrocyclic or Linear Pyridine Carboxamides from Pyridine-2,6-dicarbonyl Dichloride as Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Abd El-Galil E Amr

    2010-09-01

    Full Text Available A series of chiral linear and macrocyclic bridged pyridines has been prepared starting from pyridine-2,6-dicarbonyl dichloride (2. The coupling of 1 with D-alanyl methyl ester gave 2,6-bis-D-alanyl pyridine methyl ester (3. Hydrazinolysis of 3 with hydrazine hydrate afforded bis-hydrazide 4. The latter was reacted with thiophene-2-carbaldehyde, phthalic anhydride or cyclohexanone to afford bis-carboxamide pyridine derivatives 5-7, respectively. Compound 4 was coupled with p-methoxy- or p-nitroaceto-phenone to yield compounds 8 and 9. In addition, 4 was reacted with 1,2,4,5-benzenetetra-carboxylic acid dianhydride or 1,4,5,8-naphthalenetetracarboxylic acid dianhydride to afford the macrocyclic octacarboxaamide pyridines 10 and 11. The detailed synthesis, spectroscopic data and antimicrobial screening for the synthesized compounds are reported.

  18. Van der Waals Interactions in Pyridine and Pyridine-like Molecular Crystals: An ab initio Molecular Dynamics Study

    Science.gov (United States)

    Ko, Hsin-Yu; Distasio, Robert A., Jr.; Santra, Biswajit; Car, Roberto

    2014-03-01

    Pyridine has recently been investigated as a potentially effective material for use in artificial light harvesting.In this work, we propose the use of ab initio molecular dynamics (AIMD) to gain valuable physical insight into the artificial photosynthetic processes occurring in condensed-phase pyridine, the study of which has been limited to semi-empirical force fields to date.For this purpose, we introduce an accurate and efficient AIMD method, based on density functional theory (DFT) and a self-consistent pairwise description of van der Waals (vdW) interactions, for use in finite temperature and pressure (NPT) simulations on pyridine and several pyridine-like molecular crystals (PLMCs). Utilizing this approach, we demonstrate that vdW forces play a crucial role in the theoretical prediction of the structure and density of pyridine and PLMCs, and therefore must be accounted for in studies of these potential alternative energy materials. DOE: DE-SC0008626, NSF: DMS-1065894.

  19. Pyridine-grafted chitosan derivative as an antifungal agent.

    Science.gov (United States)

    Jia, Ruixiu; Duan, Yunfei; Fang, Qiang; Wang, Xiangyang; Huang, Jianying

    2016-04-01

    Pyridine moieties were introduced into chitosan by nucleophilic substitution to afford N-(1-carboxybutyl-4-pyridinium) chitosan chloride (pyridine chitosan). The resulting chitosan derivative was well characterized, and its antifungal activity was examined, based on the inhibition of mycelial growth and spore germination. The results indicated that pyridine chitosan exhibited enhanced antifungal activity by comparison with pristine chitosan. The values of the minimum inhibitory concentration and the minimal fungicidal concentration of pyridine chitosan against Fulvia fulva were 0.13 mg/ml and 1 mg/ml, respectively, while the corresponding values against Botrytis cinerea were 0.13 mg/ml and 4 mg/ml, respectively. Severe morphological changes of pyridine chitosan-treated B. cinerea were observed, indicative that pyridine chitosan could damage and deform the structure of fungal hyphae and subsequently inhibit strain growth. Non-toxicity of pyridine chitosan was demonstrated by an acute toxicity study. These results are beneficial for assessing the potential utilization of this chitosan derivative and for exploring new functional antifungal agents with chitosan in the food industry.

  20. Synthesis and Structure of Bis-(o-vanillin)di-pyridine Nickel(Ⅱ)-pyridine Dihydrate

    Institute of Scientific and Technical Information of China (English)

    孙命; 王瑾玲; 段月琴; 缪方明; 翁林红; 冷雪冰

    2001-01-01

    The structure of the complex bis-(o-vanillin)di-pyridine nickel(Ⅱ)([ Ni X-ray analysis.The crystal data are as follows: Monoclinic,P21/n,a=12.273(1),b=17.4700.674mm-1,F(000)=1328,final R=0.0428,Rw=0.1228 for 4528 observable reflections with I≥2σ(Ⅰ).The Nickel(Ⅱ)atom in the complex has a slightly distorted octahedral coordination geometr y and is six-coordinated by four O atoms from two O-Vanillin ligands and two N atoms from two pyridines.In the crystal,the Ni(Ⅱ)-complex and water molecules are linked through a network of hydrogen bonds.

  1. The mechanism of pyridine hydrogenolysis on molybdenum-containing catalysts : II. Hydrogenation of pyridine to piperidine

    NARCIS (Netherlands)

    Sonnemans, J.; Berg, van den G.H.; Mars, P.

    1973-01-01

    The kinetics of pyridine hydrogenation was studied at high hydrogen pressures on a Mo-Al oxide and a Co-Mo-Al oxide catalyst. The rate equation was found to be r = kPpyrPH2n/Ppyro, in which n is 1.5 at 300 and 375 °C and 1.0 at 250 °C. This rate equation can be derived assuming strong adsorption of

  2. PYRIDINATION OF POLY(VINYL CHLORIDE) via A HOMOLYTIC PATHWAY

    Institute of Scientific and Technical Information of China (English)

    Sa(a)d Moulay; Zakia Zeffouni

    2007-01-01

    PVC was subjected to a chemical modification aiming at replacing the chlorine atoms by pyridine groups via a homolytic route. Pyridine groups were peculiarly affixed to the PVC matrix via a carbon-carbon bond rather than a carbonnitrogen one. PVC was first iodinated using the Conant-Finkelstein reaction, followed by the application of the homolytic conditions of Minisci to generate pyridinated PVC with a varying degree of substitution. The extent of substitution was not high; the reaction on 30% iodinated PVC afforded a degree of modification no greater than 3%.

  3. Homocoupling of Aryl Bromides Catalyzed by Nickel Chloride in Pyridine

    Institute of Scientific and Technical Information of China (English)

    TAO, Xiao-Chun; ZHOU, Wei; ZHANG, Yue-Ping; DAI, Chun-ya; SHEN, Dong; HUANG, Mei

    2006-01-01

    Pyridine was used as a solvent for homocoupling of aryl bromides catalyzed by nickel chloride/triarylphosphine in the presence of zinc and recycled easily. Triphenylphosphine was the best ligand for nickel in this coupling reaction.

  4. Microbial degradation of pyridine using Pseudomonas sp. and isolation of plasmid responsible for degradation.

    Science.gov (United States)

    Mohan, S Venkata; Sistla, Srinivas; Guru, R Kumar; Prasad, K Krishna; Kumar, C Suresh; Ramakrishna, S V; Sarma, P N

    2003-01-01

    Pseudomonas (PI2) capable of degrading pyridine was isolated from the mixed population of the activated sludge unit which was being used for treating complex effluents, the strain was characterized. Aerobic degradation of pyridine was studied with the isolated strain and the growth parameters were evaluated. Pyridine degradation was further conformed by chromatography (HPLC) analysis. The process parameters like biomass growth and dissolved oxygen consumption were monitored during pyridine degradation. In order to conform with the plasmid capability to degrade pyridine, the requisite plasmid was isolated and transferred to DH 5alpha Escherichia coli. The subsequent biodegradation studies revealed the ability of the transformed plasmid capability to degrade the pyridine.

  5. Lewis acid activation of pyridines for nucleophilic aromatic substitution and conjugate addition.

    Science.gov (United States)

    Abou-Shehada, Sarah; Teasdale, Matthew C; Bull, Steven D; Wade, Charles E; Williams, Jonathan M J

    2015-03-01

    A clean, mild and sustainable method for the functionalization of pyridines and their analogues is reported. A zinc-based Lewis acid is used to activate pyridine and its analogues towards nucleophilic aromatic substitution, conjugate addition, and cyclization reactions by binding to the nitrogen on the pyridine ring and activating the pyridine ring core towards further functionalization. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Synthesis and Catalytic Asymmetric Reaction of Chiral Pyridine Prolinol Derivatives

    Institute of Scientific and Technical Information of China (English)

    CHEN Xiao; ZHANG Yong-Xin; DU Da-Ming; HUA Wen-Ting

    2003-01-01

    @@ The enantioselective reduction of prochiral ketones with borane in the presence of a chiral ligand leading to enantiomerically pure secondary alcohols has received considerable attention in recent years. [1] Enantiomerically pure secondary alcohols are important intermediates for the synthesis of various other organic compounds such as halides, esters, ethers, ketones and amines. To the best of our knowledge, the use of pyridine prolinol derivatives in the reduction of ketones has not been reported so far. Thus, it should be of interest to investigate the catalytic a bility of such ligands. We have an ongoing project in the synthesis and application of chiral pyridine derivatives in chiral molecular recognition[2] and we want to evaluate the effect resulting from the introduction of a pyridinyl moiety onto the catalysts. We expect that the cooperation of pyridine unit and chiral prolinol unit in new ligands may result in unique properties for catalytic reaction.

  7. SULFONATED POLYIMIDES CONTAINING PYRIDINE GROUPS AS PROTON EXCHANGE MEMBRANE MATERIALS

    Institute of Scientific and Technical Information of China (English)

    Rui Lei; Chuan-qing Kang; Yun-jie Huang; Xue-peng Qiu; Xiang-ling Ji; Wei Xing; Lian-xun Gao

    2011-01-01

    A series of sulfonated polyimides (SPIs) containing pyridine groups were prepared by direct polycondensation from 1,4,5,8-naphthalenetetracarboxylic dianhydride (NTDA),4,4′-diaminodiphenyl ether-2,2′-disulfonic acid (ODADS) and 4-(4-methoxy)phenyl-2,6-bis(4-aminophenyl)pyridine (DAM).The resulting copolymers displayed good solubility in common organic solvents.Flexible,transparent,tough membranes were obtained via solution casting.All the films showed high thermal stability with desulfonation temperature over 300℃.They exhibited prominent mechanical properties with Young's modulus around 2.0 GPa.High proton conductivity (0.23 S/em at 100% RH) was also observed.More importantly,the new materials exhibited low water uptake (30 wt%-75 wt% at 80℃) and improved water stability,which were attributed to the acid-base interaction between sulfonic acid and pyridine functional groups.

  8. The regioselective iodination of quinolines, quinolones, pyridones, pyridines and uracil.

    Science.gov (United States)

    Dutta, Uttam; Deb, Arghya; Lupton, David W; Maiti, Debabrata

    2015-12-28

    A radical based direct C-H iodination protocol for quinolines, quinolones, pyridones, pyridines, and uracil has been developed. The iodination occurs in a C3 selective manner for quinolines and quinolones. Pyridones and pyridines undergo C3 and C5 iodination, while dimethyl uracil undergoes C5 iodination. Scope of the method was demonstrated through the rapid synthesis of both electron rich as well as electron poor heteroaromatic iodides. The protocol was found to be scalable and general, while a mechanism has been proposed.

  9. Nuclear alkylated pyridine aldehyde polymers and conductive compositions thereof

    Science.gov (United States)

    Rembaum, A.; Singer, S. (Inventor)

    1970-01-01

    A thermally stable, relatively conductive polymer was disclosed. The polymer was synthesized by condensing in the presence of catalyst a 2, 4, or 6 nuclear alklylated 2, 3, or 4 pyridine aldehyde or quaternary derivatives thereof to form a polymer. The pyridine groups were liked by olefinic groups between 2-4, 2-6, 2-3, 3-4, 3-6 or 4-6 positions. Conductive compositions were prepared by dissolving the quaternary polymer and an organic charge transfer complexing agent such as TCNQ in a mutual solvent such as methanol.

  10. 2-(Pyridin-2-yl-1,3-oxathiane

    Directory of Open Access Journals (Sweden)

    David Turner

    2012-06-01

    Full Text Available The title compound, C9H11NOS, exhibits a unique structural motif, with free rotation of the aliphatic oxathiane ring about the C—C bond connecting this moiety to the aromatic pyridine ring. The structure elucidation was undertaken due to its potential as a bidentate ligand for organometallic complexes. The oxathiane ring adopts the expected chair conformation, with the S atom in proximity to the N atom on the pyridine ring. The corresponding S—C—C—N torsion angle is 69.07 (14°. In the crystal, molecules aggregate as centrosymmetric pairs connected by pairs of C—H...N hydrogen bonds.

  11. Synthesis of some new Thieno[2,3-b]pyridines, Pyrimidino[4',5':4,5]thieno[2,3-b]pyridine and Pyridines Incorporating 5-Bromobenzofuran-2-yl Moiety.

    Science.gov (United States)

    Abdelriheem, Nadia Abdelhamed; Ahmad, Sayed Abdel-Kader; Abdelhamid, Abdou Osman

    2015-01-07

    2-Sulfanyl-6-(2-thienyl)pyridine-3-carbonitrile, 1-Amino-6-(5-bromo-benzofuran-2-yl)-2-oxo-1,2-dihydro-pyridine-3-carbonitrile, thieno[2,3-b]pyridins, pyrimidino[4',5':4,5] thieno[2,3-b]pyridine, quinazoline and carbamate derivatives were synthesized from sodium 3-(5-bromobenzofuran-2-yl)-3-oxoprop-1-en-1-olate with. The newly synthesized compounds were elucidated by elemental analysis, spectral data, and alternative synthesis whenever possible and chemical transportation.

  12. 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...

  13. A Concise Synthesis of Monoterpene Pyridine Alkaloid Aucubinine B

    Institute of Scientific and Technical Information of China (English)

    杨晓霞; 赵景瑞; 贾学顺; 杨力维; 翟宏斌

    2003-01-01

    Aucubinine B (4), a monoterpene alkaloid obtained from the metabolites of aucubin in the presence of human intestinal bacteria, has been synthesized from 3-bromo-4-pyridinecarboxaldehyde (5) in four steps with 39% overall yield. The construction of the cyclopenta[c]pyridine intermediate (7) was realized by an intramolecular Heck reaction.

  14. Facile and Rapid Access to Poly Functionalized Pyridine Derivatives

    Institute of Scientific and Technical Information of China (English)

    Shinde Pravin V; Shingate Bapurao B; Shingare Murlidhar S

    2011-01-01

    An efficient and greener protocol for the synthesis of poly functionalized pyridines using tetra-n-butyl ammo-nium fluoride (TBAF) in water is established. Remarkable advantages of the present synthetic strategy over the others are shorter reaction times, higher isolated yields, reuse of catalytic system, simple work-up procedure and more especially its applicability to heteryl and aliphatic aldehydes.

  15. Investigations into the mechanisms of pyridine ring cleavage in vismodegib.

    Science.gov (United States)

    Khojasteh, S Cyrus; Yue, Qin; Ma, Shuguang; Castanedo, Georgette; Chen, Jacob Z; Lyssikatos, Joseph; Mulder, Teresa; Takahashi, Ryan; Ly, Justin; Messick, Kirsten; Jia, Wei; Liu, Lichuan; Hop, Cornelis E C A; Wong, Harvey

    2014-03-01

    Vismodegib (Erivedge, GDC-0449) is a first-in-class, orally administered small-molecule Hedgehog pathway inhibitor that is approved for the treatment of advanced basal cell carcinoma. Previously, we reported results from preclinical and clinical radiolabeled mass balance studies in which we determined that metabolism is the main route of vismodegib elimination. The metabolites of vismodegib are primarily the result of oxidation followed by glucuronidation. The focus of the current work is to probe the mechanisms of formation of three pyridine ring-cleaved metabolites of vismodegib, mainly M9, M13, and M18, using in vitro, ex vivo liver perfusion and in vivo rat studies. The use of stable-labeled ((13)C2,(15)N)vismodegib on the pyridine ring exhibited that the loss of carbon observed in both M9 and M13 was from the C-6 position of pyridine. Interestingly, the source of the nitrogen atom in the amide of M9 was from the pyridine. Evidence for the formation of aldehyde intermediates was observed using trapping agents as well as (18)O-water. Finally, we conclude that cytochrome P450 is involved in the formation of M9, M13, and M18 and that M3 (the major mono-oxidative metabolite) is not the precursor for the formation of these cleaved products; rather, M18 is the primary cleaved metabolite.

  16. Directed solid-phase synthesis of trisubstituted imidazo[4,5-c]pyridines and imidazo[4,5-b]pyridines.

    Science.gov (United States)

    Lemrová, Barbora; Smyslová, Petra; Popa, Igor; Oždian, Tomáš; Zajdel, Pawel; Soural, Miroslav

    2014-10-13

    An efficient method is described for the solid-supported synthesis of imidazo[4,5-b]pyridines and imidazo[4,5-c]pyridines from 2,4-dichloro-3-nitropyridine. The key pyridine building block was reacted with polymer-supported amines, followed by replacement of the second chlorine with amines, nitro group reduction, and imidazole ring closure with aldehydes. Depending on the combination of polymer-supported and solution-phase reagents, the strategy allowed for the simple preparation of the target trisubstituted derivatives with variable positioning of the pyridine nitrogen atom. Additionally, after a slight modification of the method, the preparation of strictly isomeric imidazopyridines was possible.

  17. Determination of impurities in raw light pyridine bases

    Energy Technology Data Exchange (ETDEWEB)

    Novikov, E.G.; Dybkin. L.A.; Galleway, B.J.; Lisina, L.A.; Tsaur, A.G.

    1981-01-01

    An estimate has been made of the annual average content of phenols, cyanides, rhodanides and chlorides in the raw light pyridine bases of the works in the East of the USSR. The mean values of the content of every component in the tests are given, and the amount of water in them is indicated. The bases with the highest content of phenols were those of the Cherepovets Metallurgical Works and the Gubakhin Coke and Chemical Works, and some specimens of the Karagandinsk Metallurgical Works. For most enterprises, the concentration of phenols depended on the time of the year: the phenol content in the specimens was mostly higher in the summer than in the winter. For the works in the East of USSR, the mean annual content of cyanides was 1.5 g/lit. Some enterprises supplied light pyridine bases whose cyanide content was almost ten times less. The pyridine bases of the Karagandinsk Metallurgical Works, especially those with phenolates, have an especially high content of cyanides. For instance, the cyanide content in one test was 8.9 g/lit. The mean annual content of rhodanides in the tested bases was 3.5-4.0 g/lit. The raw light pyridine bases of the Karagandinsk Metallurgical Works, from which a large amount of crystalline salt mixtures precipitates during storage when they contain phenolates, have the highest rhodamine content. The bases of the Chelyabin Metallurgical Works and the Gubakhin Coke and Chemical Works contain the least amount of salts. The mean annual content of phenols in the tests of the works in the East of the USSR is 5%. This is probably less than in the specimens of the works in the Sought of the USSR. It has been established that, besides the above-mentioned impurities, raw light pyridine bases have components which form a dark flake-like precipitate of an unknown composition during storage.

  18. Cross-linked polyvinyl pyridine coated glass particle catalyst support and aqueous composition or polyvinyl pyridine adducted microspheres

    Science.gov (United States)

    Rembaum, Alan (Inventor); Gupta, Amitava (Inventor); Volksen, Willi (Inventor)

    1981-01-01

    Microspheres are produced by cobalt gamma radiation initiated polymerization of a dilute aqueous vinyl pyridine solution. Addition of cross-linking agent provides higher surface area beads. Addition of monomers such as hydroxyethylmethacrylate acrylamide or methacrylamide increases hydrophilic properties and surface area of the beads. High surface area catalytic supports are formed in the presence of controlled pore glass substrate.

  19. Pyridine N-Oxide vs Pyridine Substrates for Rh(III)-Catalyzed Oxidative C-H Bond Functionalization.

    Science.gov (United States)

    Neufeldt, Sharon R; Jiménez-Osés, Gonzalo; Huckins, John R; Thiel, Oliver R; Houk, K N

    2015-08-12

    The origin of the high reactivity and site selectivity of pyridine N-oxide substrates in O-pivaloyl hydroxamic acid-directed Rh(III)-catalyzed (4+2) annulation reactions with alkynes was investigated computationally. The reactions of the analogous pyridine derivatives were previously reported to be slower and to display poor site selectivity for functionalization of the C(2)-H vs the C(4)-H bonds of the pyridine ring. The N-oxide substrates are found to be more reactive overall because the directing group interacts more strongly with Rh. For N-oxide substrates, alkyne insertion is rate-limiting and selectivity-determining in the reaction with a dialkyl alkyne, but C-H activation can be selectivity-determining with other coupling partners such as terminal alkynes. The rates of reaction with a dialkyl alkyne at the two sites of a pyridine substrate are limited by two different steps: C-H activation is limiting for C(2)-functionalization, while alkyne insertion is limiting for C(4)-functionalization. Consistent with the observed poor site selectivity in the reaction of a pyridine substrate, the overall energy barriers for functionalization of the two positions are nearly identical. High C(2)-selectivity in the C-H activation step of the reaction of the N-oxide is due to a cooperative effect of the C-H Brønsted acidity, the strength of the forming C-Rh bond, and intramolecular electrostatic interactions between the [Rh]Cp* and the heteroaryl moieties. On the other hand, some of these forces are in opposition in the case of the pyridine substrate, and C(4)-H activation is moderately favored overall. The alkyne insertion step is favored at C(2) over C(4) for both substrates, and this preference is largely influenced by electrostatic interactions between the alkyne and the heteroarene. Experimental results that support these calculations, including kinetic isotope effect studies, H/D exchange studies, and results using a substituted pyridine, are also described.

  20. 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)

  1. 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.

  2. 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.

  3. 2-Nitro-N′-[1-(pyridin-2-ylethylidene]benzohydrazide

    Directory of Open Access Journals (Sweden)

    Xiaofeng Li

    2011-12-01

    Full Text Available In the title compound, C14H12N4O3, the dihedral angle between the benzene ring and the pyridine ring is 60.9 (2°. The major twist in the molecule occurs about the (NH—(CO—Car—Car (ar = aromatic bond, the relevant torsion angle being 63.97 (12°. In the crystal, inversion dimers linked by pairs of N—H...O hydrogen bonds generate R22(8 loops.

  4. Adsorption of Pyridine at the Au(110) - Solution Interface

    Science.gov (United States)

    1990-05-28

    Electroanalytical Chemistry Guelph-Waterloo Center for Graduate Work in Chemistry Waterloo, Campus Department of Chemistry University of Waterloo...Year, Month, Day) S PAGE COUNT Technical FROM 05/ 8 9 TO 05/89 1990-05-28 37 16. SUPPLEMENTARY NOTATION Submitted to Journal of Electroanalytical ... Chemistry 17 COSATI CODES 18 SUBJECT TERMS (Continue on riverse if necessary and identify by block number) FIELD GROUP SUB-GROUP Pyridine adsorption

  5. Adsorption of Pyridine at the Au(311) - Solution Interface

    Science.gov (United States)

    1991-02-15

    Solution Interface by L. Stolberg, J. Lipkowski, and D.E. Irish Prepared for Publication in Journal of Electroanalytical Chemistry Guelph-Waterloo...REPORT (Year, Month,ODay) iSPAGE COUNTITechnical T1FRO 89 T0729071 1990-02-5I 3 16. SUPPLEMENTARY NOTATION Submitted to Journal of Electroanalytical ... Chemistry 17 COSATI CODES 1S SUBjECT TERMIS (Continue on reverse of necessary and identify by block number) FIELD GROUP SUB-GROUP Pyridine adsorption on Au

  6. 1-[Phenyl(pyridin-2-ylaminomethyl]-2-naphthol

    Directory of Open Access Journals (Sweden)

    Jie Xiao

    2010-11-01

    Full Text Available The title compound, C22H18N2O, was synthesized from naphthalen-2-ol, benzaldehyde and pyridin-2-amine. In the crystal, molecules are linked into centrosymmetric R22(16 dimers by pairs of O—H...N hydrogen bonds. The molecular conformation is stabilized by an N—H...O hydrogen bond. The dihedral angle between the naphthylene ring system and the phenyl ring is 72.86 (12°.

  7. Pyridine metabolism in tea plants: salvage, conjugate formation and catabolism.

    Science.gov (United States)

    Ashihara, Hiroshi; Deng, Wei-Wei

    2012-11-01

    Pyridine compounds, including nicotinic acid and nicotinamide, are key metabolites of both the salvage pathway for NAD and the biosynthesis of related secondary compounds. We examined the in situ metabolic fate of [carbonyl-(14)C]nicotinamide, [2-(14)C]nicotinic acid and [carboxyl-(14)C]nicotinic acid riboside in tissue segments of tea (Camellia sinensis) plants, and determined the activity of enzymes involved in pyridine metabolism in protein extracts from young tea leaves. Exogenously supplied (14)C-labelled nicotinamide was readily converted to nicotinic acid, and some nicotinic acid was salvaged to nicotinic acid mononucleotide and then utilized for the synthesis of NAD and NADP. The nicotinic acid riboside salvage pathway discovered recently in mungbean cotyledons is also operative in tea leaves. Nicotinic acid was converted to nicotinic acid N-glucoside, but not to trigonelline (N-methylnicotinic acid), in any part of tea seedlings. Active catabolism of nicotinic acid was observed in tea leaves. The fate of [2-(14)C]nicotinic acid indicates that glutaric acid is a major catabolite of nicotinic acid; it was further metabolised, and carbon atoms were finally released as CO(2). The catabolic pathway observed in tea leaves appears to start with the nicotinic acid N-glucoside formation; this pathway differs from catabolic pathways observed in microorganisms. Profiles of pyridine metabolism in tea plants are discussed.

  8. Anticancer efficacy of unique pyridine-based tetraindoles.

    Science.gov (United States)

    Fu, Chih-Wei; Hsieh, Yun-Jung; Chang, Tzu Ting; Chen, Chia-Ling; Yang, Cheng-Yu; Liao, Anne; Hsiao, Pei-Wen; Li, Wen-Shan

    2015-11-02

    Results of previous studies demonstrated that the tetraindole, SK228, which has a high lipid but low water solubility, displayed moderate anticancer efficacy in a xenograft model of breast cancer. This finding led to the proposal that new, pyridine based tetraindole (PBT) analogs of SK228, containing tetraindole moieties distributed about central protonated pyridine cores, would have enhanced bioavailabilities and anticancer efficacies. Among the PBTs prepared and subjected to biological studies, 3f (FCW81) was observed to display the highest antiproliferative activity against the two triple negative breast cancer (TNBCs) cell lines, MDA-MB-231 and BT549. In addition, its mode of action was shown to involve G2/M arrest of the cell cycle along with the promotion of increased levels of cyclin B1 and p-chk2 and a decreased level of p-cdc2. DNA damage and induction of apoptosis caused by FCW81 was found to be associated with a decrease in DNA repair. Significantly, FCW81 displays therapeutic efficacy in a xenograft model of human breast cancer by not only serving to inhibit markedly the growth of cancer cells but also to block effectively cancer cell metastasis. Collectively, the results of these studies have led to the identification of novel pyridine-tetraindole based anticancer agents with potential use in TNBC therapy.

  9. The role of electron donors generated from UV photolysis for accelerating pyridine biodegradation.

    Science.gov (United States)

    Tang, Yingxia; Zhang, Yongming; Yan, Ning; Liu, Rui; Rittmann, Bruce E

    2015-09-01

    Employing an internal circulation baffled biofilm reactor (ICBBR), we evaluated the mechanisms by which photolysis accelerated the biodegradation and mineralization of pyridine (C5 H5 N), a nitrogen-containing heterocyclic compound. We tested the hypothesis that pyridine oxidation is accelerated because a key photolysis intermediate, succinate, is as electron donor that promotes the initial mono-oxygenation of pyridine. Experimentally, longer photolysis time generated more electron-donor products (succinate), which stimulated faster pyridine biodegradation. This pattern was confirmed by directly adding succinate, and the stimulation effect occurred similarly with addition of the same equivalents of acetate and formate. Succinate, whether generated by UV photolysis or added directly, also accelerated mono-oxygenation of the first biodegradation intermediate, 2-hydroxyl pyridine (2HP). 2HP and pyridine were mutually inhibitory in that their mono-oxygenations competed for internal electron donor; thus, the addition of any readily biodegradable donor accelerated both mono-oxygenation steps, as well as mineralization.

  10. A novel porphyrin-containing polyimide nanofibrous membrane for colorimetric and fluorometric detection of pyridine vapor.

    Science.gov (United States)

    Lv, Yuanyuan; Zhang, Yani; Du, Yanglong; Xu, Jiayao; Wang, Junbo

    2013-11-19

    A novel zinc porphyrin-containing polyimide (ZPCPI) nanofibrous membrane for rapid and reversible detection of trace amounts of pyridine vapor is described. The membrane displays a distinct color change, as well as dramatic variations in absorption and fluorescent emission spectra, upon exposure to pyridine vapor. This condition allows the detection of the analyte at concentrations as low as 0.041 ppm. The vapochromic and spectrophotometric responses of the membrane are attributed to the formation of the ZPCPI-pyridine complex upon axial coordination. From surface plasmon resonance analysis, the affinity constant of ZPCPI-pyridine complex was calculated to be (3.98 ± 0.25) × 104 L · mol(-1). The ZPCPI nanofibrous membrane also showed excellent selectivity for pyridine vapor over other common amines, confirming its applicability in the manufacture of pyridine-sensitive gas sensors.

  11. Correlation between the Standard Formation Enth alpy and the Path Index of Pyridine-Derivatives

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    A formulated as △ H (PDDs ,g)=a+ ∑ biPi+ ∑ cifi is put forward for estimating standard formation enthalpies of pyridine-derivatives (PDDs),in which ,Pi is path index and cifi is an amended term of interaction between substituent and N atom on pyridine ring. The Calculations based on the model were carried out for some pyridine-derivatives. The values of standard formation enthalpy calculated are consistent with those in literature

  12. Synthesis of a New Aromatic Dianhydride Containing Pyridine Ring and Related Polyimide

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    A new aromatic dianhydride monomer containing pyridine moiety, 2,6-bis[4'-(3",4"dicarboxyphenoxy)benzoyl]-pyridine dianhydride (Md), was synthesized in four steps, starting from 2,6-pyridinedicarboxyl chloride. A novel pyridine-containing polyimide was prepared via polycondensation of Md with ODA by two-step method. The resulting polyimide exhibits excellent solubility, film-forming capability and high thermal resistance.

  13. Highly stable supramolecular hydrogels formed from 1,3,5-benzenetricarboxylic acid and hydroxyl pyridines

    Institute of Scientific and Technical Information of China (English)

    Li Ming Tang; Yu Jiang Wang

    2009-01-01

    New supramolecular hydrogels with the maximal sol-gel transition temperature (T_(gel)) of 95 ℃ were obtained by using gelators formed from 1,3,5-benzenetricarboxylic acid (BTA) and para-hydroxyl pyridine (PHP) or meta-hydroxyl pyridine (MHP). The single crystal structure of the complex formed from BTA and ortho-hydroxyl pyridine (OHP) indicated that the molecules assembled into superstructure via both hydrogen bonds and π-π stacking interaction.

  14. Synthesis of a new pyridine-containing diamine and related polyimide

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    A new kind of aromatic diamine monomer containing pyridine unit,2,6-bis[4-(4-aminophenoxy)phenoxy]pyridine(BAPP),was synthesized in three steps,using hydroquinone as starting material.A novel pyridine-containing polyimide was prepared from the resulting diamine BAPP with 4,4'-oxydiphthalic anhydride(ODPA) via a conventional two-step thermal imidization method.The resulting polyimide exhibits excellent solubility,film-forming capability and high thermal resistance.

  15. Structural rearrangements and magic numbers in reactions between pyridine-containing water clusters and ammonia.

    Science.gov (United States)

    Ryding, Mauritz J; Ruusuvuori, Kai; Andersson, Patrik U; Zatula, Alexey S; McGrath, Matthew J; Kurtén, Theo; Ortega, Ismael K; Vehkamäki, Hanna; Uggerud, Einar

    2012-05-24

    Molecular cluster ions H(+)(H(2)O)(n), H(+)(pyridine)(H(2)O)(n), H(+)(pyridine)(2)(H(2)O)(n), and H(+)(NH(3))(pyridine)(H(2)O)(n) (n = 16-27) and their reactions with ammonia have been studied experimentally using a quadrupole-time-of-flight mass spectrometer. Abundance spectra, evaporation spectra, and reaction branching ratios display magic numbers for H(+)(NH(3))(pyridine)(H(2)O)(n) and H(+)(NH(3))(pyridine)(2)(H(2)O)(n) at n = 18, 20, and 27. The reactions between H(+)(pyridine)(m)(H(2)O)(n) and ammonia all seem to involve intracluster proton transfer to ammonia, thus giving clusters of high stability as evident from the loss of several water molecules from the reacting cluster. The pattern of the observed magic numbers suggest that H(+)(NH(3))(pyridine)(H(2)O)(n) have structures consisting of a NH(4)(+)(H(2)O)(n) core with the pyridine molecule hydrogen-bonded to the surface of the core. This is consistent with the results of high-level ab initio calculations of small protonated pyridine/ammonia/water clusters.

  16. Influence of supramolecular structures in crystals on parallel stacking interactions between pyridine molecules.

    Science.gov (United States)

    Janjić, Goran V; Ninković, Dragan B; Zarić, Snezana D

    2013-08-01

    Parallel stacking interactions between pyridines in crystal structures and the influence of hydrogen bonding and supramolecular structures in crystals on the geometries of interactions were studied by analyzing data from the Cambridge Structural Database (CSD). In the CSD 66 contacts of pyridines have a parallel orientation of molecules and most of these pyridines simultaneously form hydrogen bonds (44 contacts). The geometries of stacked pyridines observed in crystal structures were compared with the geometries obtained by calculations and explained by supramolecular structures in crystals. The results show that the mean perpendicular distance (R) between pyridine rings with (3.48 Å) and without hydrogen bonds (3.62 Å) is larger than that calculated, because of the influence of supramolecular structures in crystals. The pyridines with hydrogen bonds show a pronounced preference for offsets of 1.25-1.75 Å, close to the position of the calculated minimum (1.80 Å). However, stacking interactions of pyridines without hydrogen bonds do not adopt values at or close to that of the calculated offset. This is because stacking interactions of pyridines without hydrogen bonds are less strong, and they are more susceptible to the influence of supramolecular structures in crystals. These results show that hydrogen bonding and supramolecular structures have an important influence on the geometries of stacked pyridines in crystals.

  17. Oxyfunctionalization of pyridine derivatives using whole cells of Burkholderia sp. MAK1

    Science.gov (United States)

    Stankevičiūtė, Jonita; Vaitekūnas, Justas; Petkevičius, Vytautas; Gasparavičiūtė, Renata; Tauraitė, Daiva; Meškys, Rolandas

    2016-01-01

    Pyridinols and pyridinamines are important intermediates with many applications in chemical industry. The pyridine derivatives are in great demand as synthons for pharmaceutical products. Moreover, pyridines are used either as biologically active substances or as building blocks for polymers with unique physical properties. Application of enzymes or whole cells is an attractive strategy for preparation of hydroxylated pyridines since the methods for chemical synthesis of pyridinols, particularly aminopyridinols, are usually limited or inefficient. Burkholderia sp. MAK1 (DSM102049), capable of using pyridin-2-ol as the sole carbon and energy source, was isolated from soil. Whole cells of Burkholderia sp. MAK1 were confirmed to possess a good ability to convert different pyridin-2-amines and pyridin-2-ones into their 5-hydroxy derivatives. Moreover, several methylpyridines as well as methylated pyrazines were converted to appropriate N-oxides. In conclusion, regioselective oxyfunctionalization of pyridine derivatives using whole cells of Burkholderia sp. MAK1 is a promising method for the preparation of various pyridin-5-ols and pyridin-N-oxides. PMID:27982075

  18. Structure of Fullerene Aggregates in Pyridine/Water Solutions by Small-Angle Neutron Scattering

    CERN Document Server

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

    2001-01-01

    Results of small-angle neutron scattering experiments on fullerenes (Co_{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.

  19. Exo conformers of N-(pyridin-2-yl)- and N-(pyridin-3-yl)norbornene-5,6-dicarboximide crystals.

    Science.gov (United States)

    Vazquez-Vuelvas, Oscar F; Hernández-Madrigal, Julia V; Pineda-Contreras, Armando; Hernández-Ortega, Simón; Reyes-Martínez, Reyna; Morales-Morales, David

    2015-03-01

    Two isomeric pyridine-substituted norbornenedicarboximide derivatives, namely N-(pyridin-2-yl)-exo-norbornene-5,6-dicarboximide, (I), and N-(pyridin-3-yl)-exo-norbornene-5,6-dicarboximide, (II), both C(14)H(12)N(2)O(4), have been crystallized and their structures unequivocally determined by single-crystal X-ray diffraction. The molecules consist of norbornene moieties fused to a dicarboximide ring substituted at the N atom by either pyridin-2-yl or pyridin-3-yl in an anti configuration with respect to the double bond, thus affording exo isomers. In both compounds, the asymmetric unit consists of two independent molecules (Z' = 2). In compound (I), the pyridine rings of the two independent molecules adopt different conformations, i.e. syn and anti, with respect to the methylene bridge. The intermolecular contacts of (I) are dominated by C-H...O interactions. In contrast, in compound (II), the pyridine rings of both molecules have an anti conformation and the two independent molecules are linked by carbonyl-carbonyl interactions, as well as by C-H...O and C-H...N contacts.

  20. In search of oligo(2-thienyl)-substituted pyridine derivatives: a modular approach to di-, tri- and tetra(2-thienyl)pyridines.

    Science.gov (United States)

    Bera, Mrinal K; Hommes, Paul; Reissig, Hans-Ulrich

    2011-10-10

    Herein, we describe our attempts to systematically prepare a series of oligo(2-thienyl)-substituted pyridine derivatives. The crucial starting material, a β-alkoxy-β-ketoenamide, is easily available on a large scale by the reaction of lithiated methoxyallene with thiophene-2-carbonitrile and thiophene-2-carboxylic acid. This three-component reaction is followed by intramolecular cyclization to yield the suitably functionalized 2,6-di(2-thienyl)-substituted pyridine derivates. The two oxygen atoms allow the programmed activation of positions C-3, C-4, or C-5 of the pyridine ring to perform palladium-catalyzed coupling reactions with thiophene-2-boronic acid or 2-(tributylstannyl)thiophene, and alternatively, reductive removal of groups. With this concept, we were able to prepare five pyridine derivatives with 2-thienyl substituents in the 2,6-, 2,3,6-, 2,4,6-, 2,3,4,6-, and 2,3,5,6-positions. 2,3,4,5,6-Penta(2-thienyl)pyridine was not available with our methods. The UV/Vis and fluorescence spectra of all pyridines were recorded and showed a dependence on the substitution pattern and protonation state. For the protonated 2,3,5,6-tetra(2-thienyl)-substituted pyridine, a Stokes shift of about 180 nm with an emission at 515 nm was observed.

  1. 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.

    Science.gov (United States)

    Hamid, Ahmed M; El-Shall, M Samy; Hilal, Rifaat; Elroby, Shaaban; Aziz, Saadullah G

    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 C5H5N(+·)(HCN)n and C4H4N2 (+·)(HCN)n clusters, respectively, with n = 1-4. For comparison, the binding of 1-4 HCN molecules to the protonated pyridine C5H5NH(+)(HCN)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(δ+)⋯NCH). Protonated pyridine forms a stronger ionic hydrogen bond with HCN (NH(+)⋯NCH) which can be extended to a linear chain with the clustering of additional HCN molecules (NH(+)⋯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(δ+)⋯NCH) formed between the pyridine or the pyrimidine radical cations and HCN molecules (11-12 kcal/mol) are stronger than the similar (CH(δ+)⋯NCH) bonds formed between the benzene radical cation and HCN molecules (9 kcal/mol) indicating that the CH(δ+) centers in the pyridine and pyrimidine radical cations have more effective charges than in the benzene radical cation.

  2. Pyridine alkaloids from Senna multijuga as acetylcholinesterase inhibitors.

    Science.gov (United States)

    Francisco, Welington; Pivatto, Marcos; Danuello, Amanda; Regasini, Luis O; Baccini, Luciene R; Young, Maria C M; Lopes, Norberto P; Lopes, João L C; Bolzani, Vanderlan S

    2012-03-23

    As part of an ongoing research project on Senna and Cassia species, five new pyridine alkaloids, namely, 12'-hydroxy-7'-multijuguinol (1), 12'-hydroxy-8'-multijuguinol (2), methyl multijuguinate (3), 7'-multijuguinol (4), and 8'-multijuguinol (5), were isolated from the leaves of Senna multijuga (syn. Cassiamultijuga). Their structures were elucidated on the basis of spectroscopic data analysis. Mass spectrometry was used for confirmation of the positions of the hydroxy groups in the side-chains of 1, 2, 4, and 5. All compounds exhibited weak in vitro acetylcholinesterase inhibitory activity as compared with the standard compound physostigmine.

  3. 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.

  4. HALOMETHYLATION OF POLYSTYRENE AND SUBSEQUENT PYRIDINATION VIA A HOMOLYTIC PATHWAY

    Institute of Scientific and Technical Information of China (English)

    Sa(a)d Moulay; Nadia Mehdi

    2006-01-01

    Chloromethylation of polystyrene (PS) with two different chloromethylating systems methylal/thionyl chloride and paraformaldehyde/trimethylchlorosilane was studied. Soluble chloromethylated polystyrene with a degree of substitution of 89% was obtained. The Conant-Finkelstein reaction on the chloromethylated PS afforded soluble iodomethylated polystyrene with a degree of substitution as high as 96%. The reaction conditions of Minisci were employed to radically pyridinate PS via its iodomethylated derivative. Polyelectrolytes were formed which could be converted to normal polymers by treatment with a 20% aqueous solution of NaOH.

  5. Pyridine-2,6-dicarboxaldehyde bis[(diphenylmethylidenehydrazone

    Directory of Open Access Journals (Sweden)

    Florina Dumitru

    2011-05-01

    Full Text Available The title compound, C33H25N5, belongs to the family of pyridine-2,6-dicarboxaldehyde Schiff bases which possess a terdentate coordinating site (–N=C–C=N–C–C=N– similar to terpyridine derivatives. The dihedral angles between pairs of terminal rings are 69.67 (9 and 66.23 (9°. The shortest distance between the centroids of aromatic rings in neighbouring molecules is 3.8080 (14 Å.

  6. 3-(Pyridin-4-ylthiopentane-2,4-dione

    Directory of Open Access Journals (Sweden)

    Qing-Fu Zhang

    2011-04-01

    Full Text Available In the title compound, C10H11NO2S, the acetylacetone group crystallizes in the keto form with all the non-hydrogen atoms in the acetylacetone group approximately co-planar with a maximum atomic deviation 0.055 (2 Å; the dihedral angle between the acetylacetone group and the pyridine ring is 85.90 (6°. An intramolecular O—H...O hydrogen bond involving the acetylacetone group forms a six-membered ring.

  7. Separation of rare earth elements by tertiary pyridine type resin

    Energy Technology Data Exchange (ETDEWEB)

    Suzuki, Tatsuya [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)]. E-mail: tasuzuki@nr.titech.ac.jp; Itoh, Keisuke [Graduate School of Material Science and Engineering, Shibaura Institute of Technology, Shibaura, Minato-ku, Tokyo 108-8584 (Japan); Ikeda, Atsushi [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Aida, Masao [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Ozawa, Masaki [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Oarai Engineering Center, Japan Nuclear Cycle Development Institute, Narita-machi, Oarai-machi, Higashiibaraki-gun, Ibaraki 311-1393 (Japan); Fujii, Yasuhiko [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

    2006-02-09

    The novel separation method of rare earth elements by using the tertiary pyridine type resin with methanol and nitric acid mixed solution was developed. The separating operation in this method is very simple and easy, and the waste generation in this method is expected to be low. The adsorption and separation behaviors of rare earth elements were investigated with changing the nitric acid concentration, the methanol concentration, and the alcoholic species. It was confirmed that the rare earth elements can be well separated mutually.

  8. 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.

  9. Pyridine radical cation and its fluorine substituted derivatives

    Science.gov (United States)

    Bondybey, V.E.; English, J.H.; Shiley, R.H.

    1982-01-01

    The spectra and relaxation of the pyridine cation and of several of its fluorinated derivatives are studied in low temperature Ne matrices. The ions are generated by direct photoionization of the parent compounds. Of the compounds studied, laser induced → and → fluorescence is observed only for the 2, 6‐difluoropyridine cation. The analysis of the spectrum indicates that the ion is planar both in the and states. The large variety in the spectroscopic and relaxation behavior of fluoropyridine radical cations is explained in terms of their electronic structure and of the differential shifts of the individual electronic states caused by the fluorine substitution.

  10. (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].

  11. Methods for the synthesis of deuterated vinyl pyridine monomers

    Science.gov (United States)

    Hong, Kunlun; Yang, Jun; Bonnesen, Peter V

    2014-02-25

    Methods for synthesizing deuterated vinylpyridine compounds of the Formula (1), wherein the method includes: (i) deuterating an acyl pyridine of the Formula (2) in the presence of a metal catalyst and D.sub.2O, wherein the metal catalyst is active for hydrogen exchange in water, to produce a deuterated acyl compound of Formula (3); (ii) reducing the compound of Formula (3) with a deuterated reducing agent to convert the acyl group to an alcohol group, and (iii) dehydrating the compound produced in step (ii) with a dehydrating agent to afford the vinylpyridine compound of Formula (1). The resulting deuterated vinylpyridine compounds are also described.

  12. Research on the degradation mechanism of pyridine in drinking water by dielectric barrier discharge.

    Science.gov (United States)

    Li, Yang; Yi, Rongjie; Yi, Chengwu; Zhou, Biyun; Wang, Huijuan

    2017-03-01

    Pyridine, an important chemical raw material, is widely used in industry, for example in textiles, leather, printing, dyeing, etc. In this research, a dielectric barrier discharge (DBD) system was developed to remove pyridine, as a representative type of nitrogen heterocyclic compound in drinking water. First, the influence of the active species inhibitors tertiary butanol alcohol (TBA), HCO3(-), and CO3(2-) on the degradation rate of pyridine was investigated to verify the existence of active species produced by the strong ionization discharge in the system. The intermediate and final products generated in the degradation process of pyridine were confirmed and analyzed through a series of analytical techniques, including liquid chromatography-mass spectrometry (LC-MS), high performance liquid chromatography (HPLC), ion chromatography (IC), total organic carbon (TOC) analysis, ultraviolet (UV) spectroscopy, etc. The results showed that the degradation of pyridine was mainly due to the strong oxidizing power of ozone and hydroxyl radical produced by the DBD system. Several intermediate products including 3-hydroxyl pyridine, fumaric acid, 2, 3-dihydroxypyridine, and oxalic acid were detected. Nitrogen was removed from the pyridine molecule to form nitrate. Through analysis of the degradation mechanism of pyridine, the oxidation pathway was deduced. The study provided a theoretical and experimental basis for the application of DBD strong ionization discharge in treatment of nitrogen heterocyclic compounds in drinking water. Copyright © 2016. Published by Elsevier B.V.

  13. 4-[3-(Pyridin-3-ylprop-2-enoyl]phenyl 4-dodecyloxybenzoate

    Directory of Open Access Journals (Sweden)

    Sie-Tiong Ha

    2015-12-01

    Full Text Available Steglich esterification between 1-(4-hydroxyphenyl-3-(pyridin-3-ylprop-2-en-1-one and 4-dodecyloxybenzoic acid has produced a new compound, 4-[3-(pyridin-3-yl prop-2-enoyl]phenyl 4-dodecyloxybenzoate. The title compound was characterized by IR and NMR analysis.

  14. Novel Amino-Pyridine Functionalized Chitosan Quaternary Ammonium Derivatives: Design, Synthesis, and Antioxidant Activity.

    Science.gov (United States)

    Li, Qing; Zhang, Caili; Tan, Wenqiang; Gu, Guodong; Guo, Zhanyong

    2017-01-18

    Chemical modification of chitosan is increasingly studied for its potential of providing new applications of chitosan. Here, a group of novel chitosan quaternary ammonium derivatives containing pyridine or amino-pyridine were designed and successfully synthesized through chemical modification of chitosan. Pyridine and amino-pyridine were used as functional groups to improve the antifungal activity of chitosan derivatives. The chitosan derivatives' antioxidant activity against hydroxyl-radical and 1,1-Diphenyl-2-picrylhydrazyl (DPPH)-radical was tested in vitro. The results showed that chitosan derivatives had better water solubility and stronger antioxidant activity compared with chitosan in all assays. Especially, compounds 3C and 3E (with 3-amino pyridine and 2,3-diamino pyridine as substitute respectively) exhibited stronger hydroxyl-radical and DPPH-radical scavenging ability than other synthesized compounds. These data demonstrated that the synergistic effect of the amino group and pyridine would improve the antioxidant activity of chitosan derivatives, and the position of the amino group on pyridine could influence the antioxidant property of chitosan derivatives.

  15. Novel Amino-Pyridine Functionalized Chitosan Quaternary Ammonium Derivatives: Design, Synthesis, and Antioxidant Activity

    Directory of Open Access Journals (Sweden)

    Qing Li

    2017-01-01

    Full Text Available Chemical modification of chitosan is increasingly studied for its potential of providing new applications of chitosan. Here, a group of novel chitosan quaternary ammonium derivatives containing pyridine or amino-pyridine were designed and successfully synthesized through chemical modification of chitosan. Pyridine and amino-pyridine were used as functional groups to improve the antifungal activity of chitosan derivatives. The chitosan derivatives’ antioxidant activity against hydroxyl-radical and 1,1-Diphenyl-2-picrylhydrazyl (DPPH-radical was tested in vitro. The results showed that chitosan derivatives had better water solubility and stronger antioxidant activity compared with chitosan in all assays. Especially, compounds 3C and 3E (with 3-amino pyridine and 2,3-diamino pyridine as substitute respectively exhibited stronger hydroxyl-radical and DPPH-radical scavenging ability than other synthesized compounds. These data demonstrated that the synergistic effect of the amino group and pyridine would improve the antioxidant activity of chitosan derivatives, and the position of the amino group on pyridine could influence the antioxidant property of chitosan derivatives.

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

    Energy Technology Data Exchange (ETDEWEB)

    Rehakova, Maria, E-mail: maria.rehakova@upjs.sk [Institute of Chemistry, Faculty of Science, P.J. Safarik University, 041 54 Kosice (Slovakia); Fortunova, Lubica [Institute of Chemistry, Faculty of Science, P.J. Safarik University, 041 54 Kosice (Slovakia); Bastl, Zdenek [J. Heyrovsky Institute of Physical Chemistry, ASCR, v.v.i., 18223 Prague 8 (Czech Republic); Nagyova, Stanislava [Department of Physics, Electrotechnical Faculty, Technical University, 042 00 Kosice (Slovakia); Dolinska, Silvia [Institute of Geotechnics, Slovak Academy of Sciences, 043 53 Kosice (Slovakia); Jorik, Vladimir [Department of Inorganic Chemistry, Faculty of Chemical and Food Technology, Slovak University of Technology, 81237 Bratislava (Slovakia); Jona, Eugen [Department of Chemistry and Technology of Inorganic Materials, Faculty of Industrial Technologies, Trencin University of Alexander Dubcek, 02032 Puchov (Slovakia)

    2011-02-15

    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){sub x}ZSM5, Cu-CT and Cu-(py){sub 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){sub 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.

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

    Science.gov (United States)

    Reháková, Mária; Fortunová, Lubica; Bastl, Zdeněk; Nagyová, Stanislava; Dolinská, Silvia; Jorík, Vladimír; Jóna, Eugen

    2011-02-15

    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.

  18. Ab initio calculations on the structure of pyridine in its lowest triplet state

    NARCIS (Netherlands)

    Buma, W.J.; Groenen, E.J.J.; Schmidt, J.

    1990-01-01

    Recently we have experimentally shown that pyridine-d5, as a guest in a single crystal of benzene-d6, adopts a boatlike structure upon excitation into the lowest triplet state T0. Here MRDCI ab initio calculations are presented that reveal that the observed nonplanarity of the molecule is not caused

  19. Metal controlled regioselectivity in the cyclometallation of 2-(1-naphthyl)-pyridine.

    Science.gov (United States)

    Kondrashov, Mikhail; Raman, Sudarkodi; Wendt, Ola F

    2015-01-18

    Cyclometallation of 2-(1-naphthyl)-pyridine is described. While cyclopalladation results in a five-membered metallacycle, cycloauration displays a completely orthogonal regioselectivity, resulting in the six-membered ring analogue. Bromination of the gold metallacycle results in the new C-H functionalisation product 2-(8-bromonaphth-1-yl)pyridine.

  20. 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]pyridine...

  1. Liquid Crystalline Thiadiazole Derivatives: Thiadiazole Derivatives Containing Pyridine Ring as Terminal Group

    Institute of Scientific and Technical Information of China (English)

    XU,Yah(徐艳); XU,Yan; ZHU,Zhi-Guo(朱志国)XU; ZHU,Zhi-Guo; XU,Zheng(徐正); XU,Zheng

    2001-01-01

    The synthesis and mesomorphic behavior of a new series of liquid crystals coutaining 1,3,4-thiadiazole and pyridine rings with-CH = N-central group are reported. All compounds ex hibit enantiotropic snectic A mesophase, but the Schiff' s base analogues hnve no mesomorphic behavior. The innuence of the pyridine ing and thiadiazole ring is discussed.

  2. New Chiral Pyridine Prolinol Derivatives and Preliminary Study on Asymmetric Catalytic Reaction

    Institute of Scientific and Technical Information of China (English)

    Xiao CHEN; Yong Xin ZHANG; Da Ming DU; Wen Ting HUA

    2004-01-01

    Two new chiral pyridine prolinol derivatives have been synthesized from N-alkylation of (S)-α,α-diphenyl-2-pyrrolidinemethanol with 2-bromomethylpyridine and 2, 6-dibromo-methyl-pyridine. The catalytic asymmetric borane reduction of prochiral ketones and the asymmetric addition of diethylzinc to benzaldehyde were investigated.

  3. DFT analysis of the nucleophilicity of substituted pyridines and prediction of new molecules having nucleophilic character stronger than 4-pyrrolidino pyridine

    Indian Academy of Sciences (India)

    Kaustavmoni Deka; Prodeep Phukan

    2016-04-01

    Some commonly used 3-substituted, 4-substituted and 3,4,5-substituted pyridines were examined using DFT to predict the nucleophilicity behavior based on four different methods known in the literature. HOMO-LUMO energy calculations were done using DFT/B3LYP/6-311G+(d,p) level of theory. To establish the most suitable nucleophilicity scale for all the ranges of pyridines covered herein, either Hammett substituent constant () or experimental nucleophilicity values were computed. On the basis of this study, some new 4-substituted pyridines with enhanced nucleophilicity have been proposed. Nucleophilic behaviour of a few predicted molecules was found to be better than that of 4-pyrrolidino pyridine.

  4. Charting the Chemical Reactivity Space of 2,3-Substituted Furo[2,3-b]pyridines Synthesized via the Heterocyclization of Pyridine-N-oxide Derivatives.

    Science.gov (United States)

    Fumagalli, Fernando; da Silva Emery, Flavio

    2016-11-04

    A concise strategy for the synthesis of 2,3-substituted furo[2,3-b]pyridines is described. Mild, metal-free conditions were successfully applied to produce a range of 2-(alkyl or aryl)-3-ethylcarboxylate-furo[2,3-b]pyridines in yields of 50-91%. Then, the chemical reactivity of this heterocyclic framework was explored to develop straightforward methods for its functionalization. The pyridine moiety reactivity was successfully explored by C-H amination and borylation reactions, although C-H fluorination and radical C-H arylation processes were not as efficient. In addition, while the furopyridine core proved stable under basic conditions, the ring-opening reaction of the furan moiety with hydrazine generated a valuable new pyridine-dihydropyrazolone scaffold.

  5. 2,3,5-Trisubstituted pyridines as selective AKT inhibitors-Part I: Substitution at 2-position of the core pyridine for ROCK1 selectivity.

    Science.gov (United States)

    Lin, Hong; Yamashita, Dennis S; Zeng, Jin; Xie, Ren; Wang, Wenyong; Nidarmarthy, Sirishkumar; Luengo, Juan I; Rhodes, Nelson; Knick, Victoria B; Choudhry, Anthony E; Lai, Zhihong; Minthorn, Elisabeth A; Strum, Susan L; Wood, Edgar R; Elkins, Patricia A; Concha, Nestor O; Heerding, Dirk A

    2010-01-15

    2,3,5-Trisubstituted pyridines have been designed as potent AKT inhibitors that are selective against ROCK1 based on the comparison between AKT and ROCK1 structures. Substitution at the 2-position of the core pyridine is the key element to provide selectivity against ROCK1. An X-ray co-crystal structure of 9p in PKA supports the proposed rationale of ROCK1 selectivity.

  6. Orientations of axially coordinated imidazoles and pyridines in crystal structures of model systems of cytochromes.

    Science.gov (United States)

    Rakić, Aleksandra A; Medaković, Vesna B; Zarić, Snezana D

    2006-01-01

    Many properties of cytochromes and model systems depend on orientations of axial ligands. In this work, we elucidated the role of porphyrin substituents on orientation of axial ligands in model systems of cytochromes. The orientations of axially coordinated imidazoles and pyridines in crystal structures of model systems of cytochromes were analyzed and data were compared with previous quantum-chemical calculations. The results show that eight ethyl groups on porphyrin ring strongly favor parallel orientation, hence, in all these complexes axial ligands, pyridines or imidazoles, are mutually parallel. Four phenyl or mesityl groups at meso-carbons also favor parallel orientation but less strongly. Hence, in most of the bis-imidazole complexes the orientation is parallel, while in bis-pyridine complexes the orientation of pyridines depends on oxidation state of Fe. In bis-pyridine Fe(II) complexes orientation is parallel, in Fe(III) it is orthogonal. This analysis is in agreement with previous quantum-chemical calculations.

  7. Application of Ultraviolet and Ultrasound Irradiation for the Degradation of Pyridine in Wastewater: A Comparative Study

    Directory of Open Access Journals (Sweden)

    Mohamed Elsayed

    2015-01-01

    Full Text Available The photochemical and sonochemical degradation of aqueous solutions of pyridine, a common refractory pollutant in wastewater effluents, have been investigated by means of ultraviolet (UV, ultrasound (US, UV/H2O2, and US/H2O2 irradiation processes. The pure photochemical process were demonstrated to be efficient for degradation of low initial concentrations of pyridine (10 ppm. Sonochemical degradation proceeded very slowly, leading to less than 53% of pyridine removal after 200 min. The degradation efficiency was increased with increasing H2O2 concentration; however, the marginal benefit became decreasing with further increasing of H2O2 due to the scavenging effect of excess H2O2. The kinetics of photochemical and sonochemical degradation of pyridine were found to follow a first-order rate law. A possible degradation pathway for pyridine was also proposed.

  8. Co-conformational Exchange Triggered by Molecular Recognition in a Di(acylamino)pyridine-Based Molecular Shuttle Containing Two Pyridine Rings at the Macrocycle.

    Science.gov (United States)

    Martinez-Cuezva, Alberto; Carro-Guillen, Fernando; Pastor, Aurelia; Marin-Luna, Marta; Orenes, Raul-Angel; Alajarin, Mateo; Berna, Jose

    2016-06-17

    We describe the incorporation of endo-pyridine units into the tetralactam ring of di(acylamino)pyridine-based rotaxanes. This macrocycle strongly associates with the linear interlocked component as confirmed by X-ray diffraction studies of rotaxane 2 b. Dynamic NMR studies of 2 b in solution revealed a rotational energy barrier that was higher than that of the related rotaxane 2 a, which lacks of pyridine rings in the macrocycle. The macrocycle distribution of the molecular shuttle 4 b, containing two endo-pyridine rings, shows that the major co-conformer is that with the cyclic component sitting over the di(acylamino)pyridine station. DFT calculations also support the marked preference of the ring for occupying the heterocyclic binding site. The association of N-hexylthymine with the di(acylamino)pyridine binding site of 4 b led to the formation of a rare 'S'-shaped co-conformer in which the tetralactam ring interacts simultaneously with both stations of the thread.

  9. Raman vapor spectrum and vibrational assignment for pyridine

    Science.gov (United States)

    Klots, T. D.

    1998-09-01

    Assignment modifications for the pyridine fundamentals are proposed, based on first time Raman vapor measurements, and a more complete set of infrared and Raman spectra for the gas and liquid. Raman polarization measurements are newly given for some 70 lines between 1600 and 3000 cm -1. The Kakiuti et al. (Kakiuti et al., J. Mol. Spectrosc. 61 (1976) 164) assignment for the nonplanar modes in CS 2 solution is shown to be the only previous correct assignment. Planar assignment modifications, though generally small, are warranted because of the benchmark nature of pyridine. A previous set of vibrational frequencies, derived from a scaled 4-21G force field calculation (Pongor et al., J. Am. Chem. Soc. 106 (1984) 2765; Pongor et al., J. Mol. Spectrosc. 114 (1985) 445), is in excellent agreement with the observed fundamentals, and in fact, tips the balance in favor of assigning ν22 to 1053 cm -1. Ideal-gas entropies derived from spectroscopic constants are also seen to be in excellent agreement with those from calorimetry (Chirico et al., J. Chem. Thermodyn. 28 (1996) 797; Chirico and Steele, J. Chem. Thermodyn. 28 (1996) 819).

  10. Determination of impurities in crude light pyridine bases

    Energy Technology Data Exchange (ETDEWEB)

    Novikov, E.G.; Tsaur, A.G.; Lisina, L.A.; Dybkin, P.A.

    1981-01-01

    Hydrogen cyanide, hydrogen sulfide, ammonia and phenols are always products of coal pyrolysis. In addition the coke oven gas contains carbon disulfide. The simultaneous presence of ammonia and carbon disulfide leads inevitably to the formation of thiocyanates in the entire recovery system before the saturator, and particularly in the ammonia liquor. All these compounds may be expected to be present in the crude light pyridine bases (CLPB). This causes corrosion of the equipment and reduces the photostability of the final process products. The ability of the phenols to form high boiling point azeotropes with the bases reduces the ..beta..-picoline fraction yield. For these reasons the presence of the stated impurities in the CLPB is undesirable. In the present work an estimate has been made of the average annual concentration of phenols, cyanides, thiocyanates and chlorides in the crude light pyridine bases of all the plants supplying this material in the Eastern USSR. The table shows only the mean values of the concentrations for each component in the samples of the individual plants, and also those for water.

  11. Pyridine analogues of spirocyclic σ₁ receptor ligands.

    Science.gov (United States)

    Miyata, Kengo; Möller, Guido; Schepmann, Dirk; Wünsch, Bernhard

    2014-08-01

    Spirocyclic benzopyrans 2 interact with high affinity and selectivity with σ₁ receptors. Bioisosteric replacement of the benzene ring of the benzopyran substructure with the electron rich thiophene ring (3) led to increased σ₁ affinity. Herein the synthesis and pharmacological evaluation of electron deficient pyridine bioisosteres 4 are reported. Homologation of the aldehyde 6 to afford the pyridylacetaldehyde derivative 8 was performed by a Wittig reaction. Bromine lithium exchange of the bromopyridine 8, addition to 1-benzylpiperidin-4-one and cyclization led to the spirocyclic pyrranopyridine 10. Hydrogenolytic removal of the N-benzyl moiety of 10 provided the secondary amine 11, which allowed the introduction of various N-substituents (12a-d). Cyclization of the hydroxy acetal 9 with HCl led to various modifications of the substituent in 3'-position. Generally the σ₁ affinity of the pyridine derivatives is reduced compared with those of the benzene and thiophene derivatives 2 and 3. However, the relationships between the structure and the σ₁ affinity follow the same rules as for the benzene and thiophene derivatives. The most promising σ₁ ligand within this class of compounds is the pyranopyridine 15 with a double bond in the pyran ring revealing a Ki-value of 4.6 nM and a very high selectivity (>217-fold) over the σ₂ subtype.

  12. Synthesis and cytotoxicity of thieno[2,3-b]pyridine and furo[2,3-b]pyridine derivatives.

    Science.gov (United States)

    Hung, Joy M; Arabshahi, Homayon J; Leung, Euphemia; Reynisson, Jóhannes; Barker, David

    2014-10-30

    Forty seven thieno[2,3-b]pyridines-2-carboxamides, furo[2,3-b]pyridines-2-carboxamides and tetrahydrothieno[2,3-b]quinolones-2-carboxamides derivatives were synthesized and tested for their antiproliferative activity against the NCI-60 cell lines. The 5-keto-tetrahydrothieno[2,3-b]quinolones-2-carboxamides (series 17) were found to have the greatest activity, with the compound containing a 3-methoxyphenylcarboxamide (compound 17d) being the most active, with GI50 values in the low nanomolar range against a range of cell lines, in particular the melanoma cell line MDA-MD-435 (GI50 - 23 nM) and the breast cancer cell line MDA-MB-468 (GI50 - 46 nM). Molecular modelling of series 17 against phosphoinositide specific-phospholipase C reveals that the side chains of the amino acids His356, Glu341, Arg549 and Lys438 are involved in hydrogen bonding with the ligands as well as a lipophilic pocket is occupied by the phenyl carboxamide moiety.

  13. 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.

  14. Structures of two co-crystals of pyridine betaine with L(+)-tartaric acid

    Science.gov (United States)

    Dega-Szafran, Z.; Dutkiewicz, G.; Kosturkiewicz, Z.

    2010-07-01

    Crystal structure of pyridine betaine with L(+)-tartaric acid, crystallized from methanol, is determined by X-ray diffraction methods. The crystal 1, at the 2:1 ratio of pyridine betaine and tartaric acid, is orthorhombic, space group P2 12 12 and contains disordered methanol guest molecules. Tartaric acid is bonded to two pyridine betaine molecules by the COOH···OOC hydrogen bonds of 2.443(2) Å. Complex 1 is situated at the special position, on twofold axis. After recrystallization of 1 from butanol crystal 2 is formed at the 3:1 ratio of pyridine betaine and semi-tartrate anion, without solvent molecules. Crystal 2 is monoclinic, space group P2 1 and shows an ionic character. Semi-tartrate anions form infinite chains and each anion is joined to one pyridine betaine molecule by the O-H···OOC hydrogen bonds, formed between two hydroxyl groups of semi-tartrate anion and the carboxylate oxygen atoms of pyridine betaine, of 2.772(2) and 2.738(2) Å. The counter-ion appears as a homoconjugated cation of two pyridine betaine molecules linked by the O·H·O hydrogen bond of 2.481(2) Å, using the proton transferred form tartaric acid. The FTIR and NMR spectra of 1 and 2 complexes are different. The 1H NMR spectrum in D 2O confirms the presence of methanol in 1.

  15. Semiconducting boron carbides with better charge extraction through the addition of pyridine moieties

    Science.gov (United States)

    Echeverria, Elena; Dong, Bin; Peterson, George; Silva, Joseph P.; Wilson, Ethiyal R.; Sky Driver, M.; Jun, Young-Si; Stucky, Galen D.; Knight, Sean; Hofmann, Tino; Han, Zhong-Kang; Shao, Nan; Gao, Yi; Mei, Wai-Ning; Nastasi, Michael; Dowben, Peter A.; Kelber, Jeffry A.

    2016-09-01

    The plasma-enhanced chemical vapor (PECVD) co-deposition of pyridine and 1,2 dicarbadodecaborane, 1,2-B10C2H12 (orthocarborane) results in semiconducting boron carbide composite films with a significantly better charge extraction than plasma-enhanced chemical vapor deposited semiconducting boron carbide synthesized from orthocarborane alone. The PECVD pyridine/orthocarborane based semiconducting boron carbide composites, with pyridine/orthocarborane ratios ~3:1 or 9:1 exhibit indirect band gaps of 1.8 eV or 1.6 eV, respectively. These energies are less than the corresponding exciton energies of 2.0 eV-2.1 eV. The capacitance/voltage and current/voltage measurements indicate the hole carrier lifetimes for PECVD pyridine/orthocarborane based semiconducting boron carbide composites (3:1) films of ~350 µs compared to values of  ⩽35 µs for the PECVD semiconducting boron carbide films fabricated without pyridine. The hole carrier lifetime values are significantly longer than the initial exciton decay times in the region of ~0.05 ns and 0.27 ns for PECVD semiconducting boron carbide films with and without pyridine, respectively, as suggested by the time-resolved photoluminescence. These data indicate enhanced electron-hole separation and charge carrier lifetimes in PECVD pyridine/orthocarborane based semiconducting boron carbide and are consistent with the results of zero bias neutron voltaic measurements indicating significantly enhanced charge collection efficiency.

  16. 3-{[Bis(pyridin-2-ylmethylamino]methyl}-2-hydroxy-5-methylbenzaldehyde

    Directory of Open Access Journals (Sweden)

    Ruo-Xu Wang

    2012-06-01

    Full Text Available In the title compound, C21H21N3O2, the pyridine rings and the benzene ring lie in a propeller arrangement around the central tertiary amine N atom. The dihedral angles formed by the benzene ring with the pyridine rings are 61.0 (3 and 49.6 (3°, while the dihedral angle between the pyridine rings is 69.7 (3°. The molecular conformation is stabilized by intramolecular bifurcated O—H...N hydrogen bonds. In the crystal, inversion dimers are formed via pairs of C—H...N hydrogen bonds.

  17. Photo-physical studies of pyridine capped ZnO nanostructures

    Science.gov (United States)

    Bhatti, H. S.; Singh, Karamjit; Kavita; Kumar, Sunil; Choubey, R. K.

    2014-07-01

    Pyridine capped ZnO nanocrystals with different sizes were synthesized at room temperature by wet chemical synthesis. Pyridine provides the control over the morphology of final product. X-ray study confirms the crystalline hexagonal structure of the capped and uncapped ZnO nanocrystals. The particle size was found to decrease with increase in capping concentration. Electron microscopy investigation reveals the uniform morphology of the product. Optical absorption studies indicate the blue shift effect for pyridine capped ZnO as compare to uncapped ZnO.

  18. Synthesis and Characterization of Novel Polyimides Based on Pyridine-containing Diamine

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    A new aromatic diamine monomer containing pyridine unit, 2,6-bis (4-aminophenoxy4′-benzoyl)pyridine(BABP), was synthesized in three steps, starting from 2,6-pyridinedicarboxyl chloride. A series of novel pyridine-containing polyimides were prepared via the polycondensation of BABP with various aromatic dianhydrides through poly(amic acid) precursors, and thermal or chemical imidization of the precursors. The polyimides exhibit desirable properties,e.g., good solubility in N-methyl-2-pyrrolidone and m-cresol, excellent thermal stability and ftlm-forming capability, as well as high inherent viscosity, indicating high molecular weight.

  19. Influence of deuteration and fluorination on the supramolecular architecture of pyridine N-oxide crystals.

    Science.gov (United States)

    Shishkin, Oleg V; Shishkina, Svitlana V; Maleev, Andrey V; Zubatyuk, Roman I; Vasylyeva, Vera; Merz, Klaus

    2013-03-18

    To understand how deuterium and fluorine substituents influence the supramolecular architecture of pyridine N-oxide crystals, the crystal structure of 3-fluoropyridine N-oxide (PNO-3F) was determined and the crystal packing motives of non-deuterated pyridine-N-oxide (PNO), partial-deuterated pyridine-N-oxide (PNO-D) and PNO-3F were analyzed based on ab initio quantum-chemical calculations of the intermolecular interaction energy, using the MP2/6-311G(d,p) method. The appearance of the weak-directing substituents deuterium and fluorine leads to significant changes in the crystal organization of the isotropic packing of PNO molecules.

  20. 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)

  1. Organic Electrofluorescent Materials Using Pyridine-Containing Macrocyclic Compounds

    Institute of Scientific and Technical Information of China (English)

    Tingxi LI; Long FU; Wenwen YU; Renhe HUANG

    2008-01-01

    Novel pyridine-containing macrocyclic compounds, such as 6,12,19,25-tetramethyl-7,11,20,24-dinitrilo-dibenzo[b,m]l,4,12,15-tetra-azacyclodoc osine (TMCD), were synthesized and used as electron transport layer in organic electroluminescent devices. Devices with a structure of glass/indium-tin oxide/arylamine derivative/tris(quinolinolato)aluminum(Ⅲ) (AIq)/TMCD/LiF/AI exhibited green emission from the Alq layer with external quantum efficiency of 0.84% and luminous efficiency of 1.3 lm/W. The derivatives of TMCD were synthesized and characterized as well. These compounds were also found to be useful as the electron-transporting materials in organic electroluminescent devices.

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

    Directory of Open Access Journals (Sweden)

    Antonio L. Doadrio

    2002-07-01

    Full Text Available 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, anilin, morpholin, piperidin and di-iso-propyl amines. The complexes have been characterized by analytical, magnetochemical, IR, visible-UV spectral and thermal studies, and are assigned the formulas [VO(L2].py, where L=cyclohexyl, di-iso-butyl, di-n-propyl, anilin dithiocarbamate and [VO(OH(L(py2]OH.H2O (L=morpholin, piperidin and di-iso-propyl dithiocarbamate. The effect of the adduct formation on the pV=0 bound is discussed in terms of the IR (V=O, V-S and V-N stretching frequencies and electronic spectra (d-d transitions.

  3. Identification of pyridine analogues as new predator-derived kairomones

    Directory of Open Access Journals (Sweden)

    Julien eBrechbühl

    2015-07-01

    Full Text Available In the wild, animals have developed survival strategies relying on their senses. The individual ability to identify threatening situations is crucial and leads to increase in the overall fitness of the species. Rodents, for example have developed in their nasal cavities specialized olfactory neurons implicated in the detection of volatile cues encoding for impending danger such as predator scents or alarm pheromones. In particular, the neurons of the Grueneberg ganglion (GG, an olfactory subsystem, are implicated in the detection of danger cues sharing a similar chemical signature, a heterocyclic sulfur- or nitrogen-containing motif. Here we used a from the wild to the lab approach to identify new molecules that are involuntarily emitted by predators and that initiate fear-related responses in the recipient animal, the putative prey. We collected urines from carnivores as sources of predator scents and first verified their impact on the blood pressure of the mice. With this approach, the urine of the mountain lion emerged as the most potent source of chemical stress. We then identified in this biological fluid, new volatile cues with characteristic GG-related fingerprints, in particular the methylated pyridine structures, 2,4-lutidine and its analogues. We finally verified their encoded danger quality and demonstrated their ability to mimic the effects of the predator urine on GG neurons, on mice blood pressure and in behavioral experiments. In summary, we were able to identify here, with the use of an integrative approach, new relevant molecules, the pyridine analogues, implicated in interspecies danger communication.

  4. (2Z-3-Hydroxy-1-(pyridin-2-yl-3-(pyridin-3-ylprop-2-en-1-one: crystal structure and Hirshfeld surface analysis

    Directory of Open Access Journals (Sweden)

    Sze-Ling Lee

    2016-06-01

    Full Text Available The title compound, C13H10N2O2 [also called 1-(pyridin-2-yl-3-(pyridin-3-ylpropane-1,3-dione], features an almost planar (r.m.s. deviation = 0.0095 Å central C3O2 core consolidated by an intramolecular hydroxy-O—H...O(carbonyl hydrogen bond. Twists are evident in the molecule, as seen in the dihedral angles between the central core and the 2- and pyridin-3-yl rings of 8.91 (7 and 15.88 (6°, respectively. The conformation about the C=C bond [1.3931 (17 Å] is Z, and the N atoms lie to the same side of the molecule. In the molecular packing, supramolecular chains along the a axis are mediated by π(pyridin-2-yl–π(pyridin-3-yl interactions [inter-centroid distance = 3.7662 (9 Å]. The observation that chains pack with no directional interactions between them is consistent with the calculated electrostatic potential, which indicates that repulsive interactions dominate.

  5. Poly[[tetraaquatetrakis[μ3-5-(pyridine-4-carboxamidoisophthalato]cobalt(IIdiholmium(III] tetrahydrate

    Directory of Open Access Journals (Sweden)

    Yi-Fang Deng

    2011-11-01

    Full Text Available In the centrosymmetric polymeric title compound, {[CoHo2(C14H8N2O54(H2O4]·4H2O}n, the HoIII ion is coordinated by one water molecule and four 5-(pyridine-4-carboxamidoisophthalate (L ligands in a distorted square-antiprismatic arrangement. The CoII ion, located on an inversion center, is coordinated by two pyridine N atoms, two carboxylate O atoms and two water molecules in a distorted octahedral geometry. One L ligand bridges two Ho ions and one Co ion through two carboxylate groups and one pyridine N atom. The other L ligand bridges two Ho ions and one Co ion through two carboxylate groups, while the uncoordinated pyridine N atom accepts a hydrogen bond from an adjacent coordinated water molecule. Extensive O—H...O, N—H...O and O—H...N hydrogen bonding is present in the crystal.

  6. Determination of Pyridine in Modified JP-4 VIA High Performance Liquid Chromatography (HPLC).

    Science.gov (United States)

    1981-04-01

    data collection and calculations automatically, with the results printed on a teletype. Least square curve fitting accentuated the reliability for determining pyridine in the 0.5 to 5.0 weight percent concentration range. (Author)

  7. Crystal structure of N,N′-bis[(pyridin-4-ylmethyl]naphthalene diimide

    Directory of Open Access Journals (Sweden)

    Mariana Nicolas-Gomez

    2014-09-01

    Full Text Available In the centrosymmetric title compound, C26H16N4O4 {systematic name: 6,13-bis[(pyridin-4-ylmethyl]-6,13-diazatetracyclo[6.6.2.04,16011,15]hexadeca-1,3,8,10,15-pantaene-5,7,12,14-tetrone}, the central ring system is essentially planar [maximum deviation = 0.0234 (8 Å] and approximately perpendicular to the terminal pyridine ring [dihedral angle = 84.38 (3°]. The molecules displays a trans conformation with the (pyridin-4-ylmethyl groups on both sides of the central naphthalene diimide plane. In the crystal, molecules are linked by π–π stacking between parallel pyridine rings [centroid–centroid distances = 3.7014 (8 and 3.8553 (8 Å] and weak C—H...O hydrogen bonds, forming a three-dimensional supramolecular architecture.

  8. Antimicrobial evaluation of new synthesized pyridine nucleosides under solvent-free conditions.

    Science.gov (United States)

    Rateb, Nora M; El-Deab, Hany A; Abdou, Ibrahim M

    2013-01-01

    Two series of novel 3-cyano-2-(2,3,4,6-tetra-O-acetyl-β-D-glucopyranosyloxo) pyridines and 3-cyano-2-(2,3,5-tri-O-acetyl-β-D-ribofuranosyloxy)-4-trifluromethyl-6-phenyl pyridine were synthesized using efficient microwave methods. The targeted compounds were obtained in high yields by reacting 2-(1H)-pyridone or its salt with activated sugars using SiO₂ under solvent-free conditions. Ammonolysis of the resulted acetylated nucleosides produced 3-cyano-2-(β-D-glucopyranosyloxo)-pyridines and 3-cyano-2-(β-D-ribofuranosyloxy)-4-trifluoromethyl-6-phenyl pyridine. These new products were fully characterized using 1D and 2D NMR. These compounds were screened for their antibacterial activities against G(+) and G(-) bacteria and some found to exhibit better antibacterial activities than the control drug.

  9. Elimination and migration of hydrogen in the vacuum-ultraviolet photodissociation of pyridine molecules

    Science.gov (United States)

    Wasowicz, Tomasz J.; Dąbkowska, Iwona; Kivimäki, Antti; Coreno, Marcello; Zubek, Mariusz

    2017-01-01

    Elimination of the excited hydrogen atoms H(n), n = 4-7, and hydrogen migration in formation of the excited NH(A 3Π) free radicals in the photodissociation of pyridine, C5H5N, molecules have been studied over the 17.5-70 eV photon energy range. In the measurements the photon-induced fluorescence spectroscopy technique has been applied. Both fragments are produced through excitation of pyridine molecules into higher-lying superexcited Rydberg or doubly excited states. The mechanisms for fragmentation of pyridine into H(n) and NH(A 3Π) are discussed. Ab initio quantum chemical calculations have been performed to elucidate the hydrogen migration mechanism in the NH formation, which is not a self-contained unit in the structure of pyridine.

  10. Atmospheric degradation of pyridine: UV absorption spectrum and reaction with OH radicals and O3

    Science.gov (United States)

    Errami, M.; El Dib, G.; Cazaunau, M.; Roth, E.; Salghi, R.; Mellouki, A.; Chakir, A.

    2016-10-01

    The UV absorption spectrum of pyridine and its gas phase reactions with OH radicals and O3 were investigated. UV absorption cross-sections were determined by using a D2-lamp system in the range 200-350 nm. The kinetic studies were carried out at room temperature and atmospheric pressure of purified air. The rate coefficient for the reaction of pyridine with OH was determined relative to that with acetone while that with O3 was measured under pseudo first order conditions. The rate coefficients obtained are (in cm3 molecule-1 s-1): k(OH + pyridine) = (5.40 ± 0.80) × 10-13 and k(O3 + pyridine) = (3.28 ± 1.70) × 10-20.

  11. The structure of 3-(diethylborylethynyl)pyridine: a nonplanarly arranged cyclic trimer.

    Science.gov (United States)

    Wakabayashi, Shigeharu; Kuse, Mitsumi; Kida, Aimi; Komeda, Seiji; Tatsumi, Kazuyuki; Sugihara, Yoshikazu

    2014-08-07

    3-(Diethylborylethynyl)pyridines 2 assemble into a cyclic trimer stabilized via intermolecular boron–nitrogen coordination bonds both in solution and in the crystalline state. The outstanding structural features of the methoxy derivative 2b in the crystalline state are that (1) two pyridine rings (P1 and P2) of the cyclic trimer of 2b are almost coplanar, and the third pyridine ring (P3) is largely bent away from P1 and P2, and (2) P3 of the cyclic trimer stacks in a face-to-face fashion with one of the pyridine rings (P3’) of an adjacent cyclic trimer. The crystallographic study revealed that the conformation of the cyclic trimer is flexible enough to be affected by the crystal packing.

  12. Pyridine derivatives as insecticides. Part 1: synthesis and toxicity of some pyridine derivatives against cowpea aphid, Aphis craccivora Koch (Homoptera: Aphididae).

    Science.gov (United States)

    Bakhite, Etify A; Abd-Ella, Aly A; El-Sayed, Mohamed E A; Abdel-Raheem, Shaban A A

    2014-10-15

    Five pyridine derivatives, namely, N-morpholinium 7,7-dimethyl-3-cyano-4-(4'-nitrophenyl)-5-oxo-1,4,5,6,7,8-hexahydroquinoline-2-thiolate (1), sodium 5-acetyl-3-amino-4-(4'-methoxyphenyl)-6-methylthieno[2,3-b] pyridine-2-carboxylate (2), piperidinium 3,5-dicyano-2-oxo-4-spirocyclopentane-1,2,3,4-tetrahydropyridine-6-thiolate (3), piperidinium 5-acetyl-3-cyano-4-(4'-methoxyphenyl)-6-methylpyridine-2-thiolate (4), and piperidinium 5-acetyl-4-(4'-chlorophenyl)-3-cyano-6-methyl-pyridine-2-thiolate (5) were prepared in pure state and subjected to the title study. The bioassay results indicated that the insecticidal activity of compound 1 is about 4-fold that of acetamiprid insecticide. The rest of the tested compounds possess moderate to strong aphidicidal activities.

  13. Dibromidobis(pyridine-3-carbonitrile-κN1mercury(II

    Directory of Open Access Journals (Sweden)

    Reza Ghiasi

    2011-05-01

    Full Text Available In the crystal structure of the title compound, [HgBr2(C6H4N22], the Hg atom is four coordinated by two pyridine N atoms and two Br− anions in a considerably distorted tetrahedral environment. π–π interactions between adjacent pyridine rings [centroid–centroid distance of 3.648 (3 Å] stabilize the crystal structure.

  14. Synthesis and evaluation of antitumor activity ofsome thiazolo[4,5-b]pyridines

    Directory of Open Access Journals (Sweden)

    Ogurtsov V. V.

    2012-09-01

    Full Text Available Aim. To synthesize a series of novel 3H-thiazolo[4,5-b]pyridine-2-ones by structural modification of the core heterocycle in its N3- and N6-positions and to evaluate their anticancer activity in vitro on several tumor cell lines. Methods. Organic synthesis, 1H-NMR spectroscopy, trypan blue cell viability assay. Results. A new convenient synthetic approach was developed and optimized conditions were studied for the reaction of preparation of 3H- thiazolo[4,5-b]pyridin-2-one derivatives. 5,7-Dimethyl-3H-thiazolo[4,5-b]pyridin-2-one and 6-phenylazo-5,7- dimethyl-3H-thiazolo[4,5-b]pyridin-2-one were obtained by [3 + 3]cyclocondensation of 4-iminothiazolidone- 2 with acetylacetone and phenylazoacetylacetone in methanol medium in the presence of sodium methylate. They were used as starting compounds for further structural modification of the core thiazolo[4,5-b]pyridine heterocycle in its 3- and 6-positions. On the basis of in vitro cytotoxicity studies of synthesized compounds several structure-functional relationships underlying anticancer potential of 5,7-dimethyl-3H-thiazolo[4,5-b]pyridin- 2-one derivatives were identified. Conclusions. 3H-thiazolo[4,5-b]pyridin-2-one can be considered as a promising molecular scaffold for rational design of potential anticancer drug candidates. Introduction of phenylazo substitute at C6-position of 3H-thiazolo[4,5-b]pyridin-2-one proved to be the most efficient, as it led to 3-fold increase of its anticancer potential.

  15. Synthesis of 2, 6-(substituded) pyridine Derivatives Using Amide and Imine Groups

    Institute of Scientific and Technical Information of China (English)

    2003-01-01

    A new ‘two-armed' acyclic diamide Ⅰa 2, 6-bis(1-ethanecarbozamido-2-amino)pyridine,and a new series of aromatic aldehyde schiff bases containing pyridine ring and amide bridge, Ⅱa-f,were prepared. The compounds were characterized by elemental analysis, IR, 1HNMR and MS.The bioactivity half inhibitory concentration C1/2 is given.

  16. 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.

  17. 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.

  18. 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.

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

    Science.gov (United States)

    McMurtry, Brandon M.; Turner, Andrew M.; Saito, Sean E. J.; Kaiser, Ralf I.

    2016-06-01

    The formation of pyridine carboxylic acids in interstellar ice grains was simulated by electron exposures of binary pyridine (C5H5N)-carbon dioxide (CO2) 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-C5H4NCOOH) along with 2,3-, 2,5-, 3,4-, and 3,5-pyridine dicarboxylic acid (C5H3N(COOH)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.

  20. Investigation of Pyridine Carboxylic Acids in CM2 Carbonaceous Chondrites: Potential Precursor Molecules for Ancient Coenzymes

    Science.gov (United States)

    Smith, Karen E.; Callahan, Michael P.; Gerakines, Perry A.; Dworkin, Jason P.; House, Christopher H.

    2014-01-01

    The distribution and abundances of pyridine carboxylic acids (including nicotinic acid) in eight CM2 carbonaceous chondrites (ALH 85013, DOM 03183, DOM 08003, EET 96016, LAP 02333, LAP 02336, LEW 85311, and WIS 91600) were investigated by liquid chromatography coupled to UV detection and high resolution Orbitrap mass spectrometry. We find that pyridine monocarboxylic acids are prevalent in CM2-type chondrites and their abundance negatively correlates with the degree of pre-terrestrial aqueous alteration that the meteorite parent body experienced. We also report the first detection of pyridine dicarboxylic acids in carbonaceous chondrites. Additionally, we carried out laboratory studies of proton-irradiated pyridine in carbon dioxide-rich ices (a 1:1 mixture) to serve as a model of the interstellar ice chemistry that may have led to the synthesis of pyridine carboxylic acids. Analysis of the irradiated ice residue shows that a comparable suite of pyridine mono- and dicarboxylic acids was produced, although aqueous alteration may still play a role in the synthesis (and ultimate yield) of these compounds in carbonaceous meteorites. Nicotinic acid is a precursor to nicotinamide adenine dinucleotide, a likely ancient molecule used in cellular metabolism in all of life, and its common occurrence in CM2 chondrites may indicate that meteorites may have been a source of molecules for the emergence of more complex coenzymes on the early Earth.

  1. 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.

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

    Science.gov (United States)

    Lehninger, A L; Vercesi, A; Bababunmi, E A

    1978-04-01

    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 Ca(2+) 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, Ca(2+) is released to the medium. A subsequent addition of a reductant of the pyridine nucleotides such as beta-hydroxybutyrate, glutamate, or isocitrate causes reuptake of the released Ca(2+). Successive cycles of Ca(2+) 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 Ca(2+)-dependent substrate- or energy-mobilizing enzymatic reactions by the uptake or release of mitochondrial Ca(2+), mediated by the cytosolic phosphate potential and the ATP-dependent reduction of mitochondrial pyridine nucleotides by reversal of electron transport.

  3. Electrochemical degradation of pyridine by Ti/SnO2-Sb tubular porous electrode.

    Science.gov (United States)

    Li, Duo; Tang, Jingyan; Zhou, Xiezhen; Li, Jiansheng; Sun, Xiuyun; Shen, Jinyou; Wang, Lianjun; Han, Weiqing

    2016-04-01

    Diffusion in electrochemistry is a critical issue for water purification. Electrocatalytic reactor system in improving water quality is a useful way to induce convection to enhance diffusion. This study focuses on the preparation and the characterization of Ti/SnO2-Sb tubular porous electrode for degrading pyridine wastewater. The electrode as an anode in reactor system is prepared by coating SnO2-Sb as an electro-catalyst via Pechini method on the tubular porous Ti. Scanning Electron Microscopy, Energy Dispersive Spectrum, X-ray Diffraction and Pore Distribution are employed to evaluate the structure and morphology of the electrodes coatings, and Linear Sweep Voltammetry and Cyclic Voltammetry are used to illustrate the electrochemical properties of the electrodes coatings. Furthermore, the electrochemical oxidation performance of Ti/SnO2-Sb tubular porous electrode is characterized by degrading pyridine wastewater. The effects of flow and static pattern, initial pyridine concentration, supporting electrolyte concentration, current density and pH on the performance of the reactor were investigated in the electrocatalytic reactor system. The results indicated that the removal ratio of pyridine reaches maximum which is 98% under the optimal operation conditions, that are 100 mg L(-1) initial pyridine concentration, 10 g L(-1) supporting electrolyte concentration, 30 mA cm(-2) current density and pH 3. Transition state calculation based on the density function theory was combined with High Performance Liquid Chromatography, Gas Chromatography and Ionic Chromatography results to describe the pathway of pyridine degradation.

  4. Promotive effect of pyridine on indole degradation by activated sludge under anoxic conditions

    Institute of Scientific and Technical Information of China (English)

    LI Yongmei; LI Wenshu; GU Guowei

    2007-01-01

    Batch experiments were carried out to investigate the promotive effect ofpyridine on indole degradation under denitrifying conditions.The seed sludge was obtained from a local coal-coking wastewater treatment facility and was acclimated in the laboratory.Indole and pyridine were supplemented to the synthetic wastewater at different ratios.The optimum ratio of chemical oxygen demand (COD) to nitrate (C/N) was 8.4-8.9 for both denitrification and indole and pyridine degradation.At a temperature of 28℃ and pH of 7.0-7.5,the nitrate reductase activity (NRA) was in the best state.The addition of pyridine could promote NRA and the degradation of indole.When the initial concentration of indole was 150 mg/L,the concentration ratio of indole to pyridine was in the range of 1-10.Under optimum C/N conditions,the degradation of indole could be described with pseudo-zero-order kinetics.There was no accumulation of nitrite during the reaction.When the concentration ratio of pyridine to indole was less than 0.25 with an increase in the pyridine proportion,there were more significant augment rates for NRA and the degradation of indole than the situation when the concentration ratio was more than 0.25.

  5. Novel S1P1 receptor agonists - Part 5: From amino-to alkoxy-pyridines.

    Science.gov (United States)

    Bolli, Martin H; Lescop, Cyrille; Birker, Magdalena; de Kanter, Ruben; Hess, Patrick; Kohl, Christopher; Nayler, Oliver; Rey, Markus; Sieber, Patrick; Velker, Jörg; Weller, Thomas; Steiner, Beat

    2016-06-10

    In a previous communication we reported on the discovery of aminopyridine 1 as a potent, selective and orally active S1P1 receptor agonist. More detailed studies revealed that this compound is phototoxic in vitro. As a result of efforts aiming at eliminating this undesired property, a series of alkoxy substituted pyridine derivatives was discovered. The photo irritancy factor (PIF) of these alkoxy pyridines was significantly lower than the one of aminopyridine 1 and most compounds were not phototoxic. Focused SAR studies showed, that 2-, 3-, and 4-pyridine derivatives delivered highly potent S1P1 receptor agonists. While the 2-pyridines were clearly more selective against S1PR3, the corresponding 3- or 4-pyridine analogues showed significantly longer oral half-lives and as a consequence longer pharmacological duration of action after oral administration. One of the best compounds, cyclopentoxy-pyridine 45b lacked phototoxicity, showed EC50 values of 0.7 and 140 nM on S1PR1 and S1PR3, respectively, and maximally reduced the blood lymphocyte count for at least 24 h after oral administration of 10 mg/kg to Wistar rats.

  6. New approach toward the synthesis of deuterated pyrazolo[1,5-a]pyridines and 1,2,4-triazolo[1,5-a]pyridines

    Directory of Open Access Journals (Sweden)

    Aleksey Yu. Vorob’ev

    2017-05-01

    Full Text Available An efficient and operationally simple synthesis of 7-deuteropyrazolo[1,5-a]pyridine and 7-deutero-1,2,4-triazolo[1,5-a]pyridine derivatives using α-H/D exchange of 1-aminopyridinium cations in basic D2O followed by a 1,3-cycloaddition of acetylenes and nitriles is presented. A high regioselectivity and a high degree of deuterium incorporation were achieved. The procedure was applied for several 4-R-1-aminopyridinium cations (R = H, Me, OMe.

  7. Ionization of pyridine: Interplay of orbital relaxation and electron correlation

    Science.gov (United States)

    Trofimov, A. B.; Holland, D. M. P.; Powis, I.; Menzies, R. C.; Potts, A. W.; Karlsson, L.; Gromov, E. V.; Badsyuk, I. L.; Schirmer, J.

    2017-06-01

    The valence shell ionization spectrum of pyridine was studied using the third-order algebraic-diagrammatic construction approximation scheme for the one-particle Green's function and the outer-valence Green's function method. The results were used to interpret angle resolved photoelectron spectra recorded with synchrotron radiation in the photon energy range of 17-120 eV. The lowest four states of the pyridine radical cation, namely, 2A2(1 a2 -1), 2A1(7 a1 -1), 2B1(2 b1 -1), and 2B2(5 b2 -1), were studied in detail using various high-level electronic structure calculation methods. The vertical ionization energies were established using the equation-of-motion coupled-cluster approach with single, double, and triple excitations (EOM-IP-CCSDT) and the complete basis set extrapolation technique. Further interpretation of the electronic structure results was accomplished using Dyson orbitals, electron density difference plots, and a second-order perturbation theory treatment for the relaxation energy. Strong orbital relaxation and electron correlation effects were shown to accompany ionization of the 7a1 orbital, which formally represents the nonbonding σ-type nitrogen lone-pair (nσ) orbital. The theoretical work establishes the important roles of the π-system (π-π* excitations) in the screening of the nσ-hole and of the relaxation of the molecular orbitals in the formation of the 7a1(nσ)-1 state. Equilibrium geometric parameters were computed using the MP2 (second-order Møller-Plesset perturbation theory) and CCSD methods, and the harmonic vibrational frequencies were obtained at the MP2 level of theory for the lowest three cation states. The results were used to estimate the adiabatic 0-0 ionization energies, which were then compared to the available experimental and theoretical data. Photoelectron anisotropy parameters and photoionization partial cross sections, derived from the experimental spectra, were compared to predictions obtained with the continuum

  8. Stepwise modification of titanium alkoxy chloride compounds by pyridine carbinol.

    Science.gov (United States)

    Boyle, Timothy J; Ottley, Leigh Anna M; Rodriguez, Mark A; Sewell, Robin M; Alam, Todd M; McIntyre, Sarah K

    2008-11-17

    The stepwise modifications of stoichiometric mixtures of titanium chloride (TiCl 4) and titanium iso-propoxide (Ti(OPr (i)) 4) by 2-pyridine methanol (H-OPy) led to the isolation of a systematically varied, novel family of compounds. The 3:1 reaction mixture of Ti(OPr (i)) 4:TiCl 4 yielded [Cl(OPr (i)) 2Ti(mu-OPr (i))] 2 ( 1). Modification of 1 with 1 and 2 equiv of H-OPy produced [Cl(OPr (i)) 2Ti(mu c-OPy)] 2 ( 2, where mu c = chelating bridge) and "(OPy) 2TiCl(OPr (i))" ( 3, not crystallographically characterized), respectively. Altering the Ti(OPr (i)) 4 to TiCl 4 stoichiometry to 1:1 led to isolation and identification of another dimeric species [Cl 2(OPr (i))Ti(mu-OPr (i))] 2 ( 4). Upon modification with 1 equiv of H-OPy, [Cl 2(OPr (i))Ti(mu c-OPy)] 2 ( 5) was isolated from toluene and (OPy)TiCl 2(OPr (i))(py) ( 6) from py. An additional equivalent of H-OPy led to the monomeric species (OPy) 2TiCl 2 ( 7). Because of the low solubility and similarity in constructs of these compounds, additional analytical data, such as the beryllium dome or BeD-XRD powder analyses, were used to verify the bulk samples, which were found to be in agreement with the single crystal structures.

  9. Deglycosylation of chondroitin sulfate proteoglycan by hydrogen fluoride in pyridine.

    Science.gov (United States)

    Olson, C A; Krueger, R; Schwartz, N B

    1985-04-01

    The original deglycosylation procedure using HF/pyridine has been modified for maximal removal of carbohydrate from chondroitin sulfate proteoglycan, with minimal alteration of the core protein. Gas-liquid chromatography analysis after treatment for various times showed that 95% of xylose and mannose and 70-85% of other sugars were removed within 30 min, indicating that almost all chondroitin sulfate chains and about 80% of N- and O-linked oligosaccharides were removed. In contrast to the loss of carbohydrate, no change in amino acid composition or loss of immunoreactivity occurred. Longer treatment of up to 16 h resulted in little additional removal of carbohydrate, but did cause a significant decrease in solubility and recovery of the deglycosylated product. Optimal removal of xylose residues after about 1 h was also shown by maximal acceptor activity of the product in a xylosyltransferase assay. Rapid removal of the HF reagent by vacuum evacuation and ion-exchange chromatography, coupled with the reduced time of treatment allowed recovery of an intact, homogenous protein core that is amenable to structural and sequence studies.

  10. Synthesis and Microbial Studies of New Pyridine Derivatives-Ⅲ

    Institute of Scientific and Technical Information of China (English)

    PATEL,N.B.; AGRAVAT,S. N.

    2007-01-01

    2-Amino substituted benzothiazole 4a-41 and p-acetamidobenzenesulfonyl chloride 2 were used to prepare 2-(p-aminophenylsulfonamido) substituted benzothiazole 6a-61 using mixture of pyridine and acetic anhydride which formed an electrophilic complex (N-acetyl pyridinium) to facilitate condensation to give desired product by removal of HCl. 2-{p-[(3-Carboxypyrid-2-yl)amino]phenylsulfonamido}benzothiazoles 8a-81 were synthesized from 2-chloropyridine-3-carboxylic acid 7 and 6a-61 in 2-ethoxy ethanol using Cu-powder and K2CO3. Acid chlorides 9a-91 were condensed with 2-hydroxyethyl piperazine 10 and 2,3-dichloropiperazine 11 for amide derivatives 2-(p-((3-(4-(2-hydroxyethyl)piperazin-1-ylcarbonyl)pyrid-2-yl)amino)phenylsulfonamido)benzothiazoles 12a -121 and 2-{p-[3-(2,3-dichloropiperazin-1-ylcarbonyl)pyrid-2-ylamino]phenylsulfonamido}benzothiazoles 13a-131 respectively. The structures of the new compounds have been established on the basis of their chemical analysis and spectral data (IR, 1H NMR and mass). All the compounds have been screened for their antibacterial and antifungal activities.

  11. Kinetics study of pyridine biodegradation by a novel bacterial strain, Rhizobium sp. NJUST18.

    Science.gov (United States)

    Shen, Jinyou; Zhang, Xin; Chen, Dan; Liu, Xiaodong; Zhang, Libin; Sun, Xiuyun; Li, Jiansheng; Bi, Huiping; Wang, Lianjun

    2014-06-01

    Biodegradation of pyridine by a novel bacterial strain, Rhizobium sp. NJUST18, was studied in batch experiments over a wide concentration range (from 100 to 1,000 mg l(-1)). Pyridine inhibited both growth of Rhizobium sp. NJUST18 and biodegradation of pyridine. The Haldane model could be fitted to the growth kinetics data well with the kinetic constants μ* = 0.1473 h(-1), K s = 793.97 mg l(-1), K i = 268.60 mg l(-1) and S m = 461.80 mg l(-1). The true μ max, calculated from μ*, was found to be 0.0332 h(-1). Yield coefficient Y X/S depended on S i and reached a maximum of 0.51 g g(-1) at S i of 600 mg l(-1). V max was calculated by fitting the pyridine consumption data with the Gompertz model. V max increased with initial pyridine concentration up to 14.809 mg l(-1) h(-1). The q S values, calculated from [Formula: see text], were fitted with the Haldane equation, yielding q Smax = 0.1212 g g(-1) h(-1) and q* = 0.3874 g g(-1) h(-1) at S m' = 507.83 mg l(-1), K s' = 558.03 mg l(-1), and K i' = 462.15 mg l(-1). Inhibition constants for growth and degradation rate value were in the same range. Compared with other pyridine degraders, μ max and S m obtained for Rhizobium sp. NJUST18 were relatively high. High K i and K i' values and extremely high K s and K s' values indicated that NJUST18 was able to grow on pyridine within a wide concentration range, especially at relatively high concentrations.

  12. Synthesis and antibacterial activity against ralstonia solanacearum for novel hydrazone derivatives containing a pyridine moiety

    Directory of Open Access Journals (Sweden)

    Wu Jian

    2012-04-01

    Full Text Available Abstract Background Ralstonia solanacearum, one of the most important bacterial diseases on plants, is a devastating, soil-borne plant pathogen with a global distribution and an unusually wide host range. In order to discover new bioactive molecules and pesticides acting on tobacco bacterial wilt, we sought to combine the active structure of hydrazone and pyridine together to design and synthesize a series of novel hydrazone derivatives containing a pyridine moiety. Results A series of hydrazone derivatives containing a pyridine moiety were synthesized. Their structures were characterized by 1 H-NMR, 13 C-NMR, IR, and elemental analysis. The preliminary biological activity tests showed that compound 3e and 3g exhibited more than 80% activity against Ralstonia solanacearum at 500 mg/L, especially compound 3g displayed relatively good activity to reach 57.0% at 200 mg/L. Conclusion A practical synthetic route to hydrazone derivatives containing a pyridine moiety by the reaction of intermediates 2 with different aldehydes in ethanol at room temperature using 2-chloronicotinic acid and 2-amino-5-chloro-3-methylbenzoic acid as start materials is presented. This study suggests that the hydrazone derivatives containing a substituted pyridine ring could inhibit the growth of Ralstonia solanacearum.

  13. Formation of BH3 Adducts with Pyridine-2-Methylaminophosphine ligands: An experimental and computational study

    Indian Academy of Sciences (India)

    Harinath Adimulam; Dwijendra P Kukri; Bhabani S Mallik; Tarun K Panda

    2016-01-01

    The reaction of pyridine-2-methylaminophosphine [C5H4N-CH2NHPPh2] (1) and pyridine-2-methylphosphinoselenoic amide [C5H4N-CH2NHP(Se)Ph2] (2) with BH3·SMe2 yields the corresponding adducts [C5H4N(BH3)-CH2NHP(BH3)Ph2] (1a), and [C5H4N(BH3)-CH2NHP(Se)Ph2] (2a), respectively. The solid state structures of both the compounds were established by single crystal X-ray diffraction analysis. The phosphorus and the pyridine nitrogen atoms are coordinated to the boron atom in the case of 1a whereas only pyridine nitrogen atom is attached to the BH3 group in the case of 2a. To understand the nature of P-B/ N-B bonds and to compare the basicities of pyridine nitrogen, amino nitrogen and phosphorus atoms, density functional theoretical (DFT) calculations were performed on the BH3 adducts 1a and 2a. The results are consistent with the experimental results.

  14. Pyridine coordination chemistry for molecular assemblies on surfaces.

    Science.gov (United States)

    de Ruiter, Graham; Lahav, Michal; van der Boom, Milko E

    2014-12-16

    CONSPECTUS: Since the first description of coordination complexes, many types of metal-ligand interactions have creatively been used in the chemical sciences. The rich coordination chemistry of pyridine-type ligands has contributed significantly to the incorporation of diverse metal ions into functional materials. Here we discuss molecular assemblies (MAs) formed with a variety of pyridine-type compounds and a metal containing cross-linker (e.g., PdCl2(PhCN2)). These MAs are formed using Layer-by-Layer (LbL) deposition from solution that allows for precise fitting of the assembly properties through molecular programming. The position of each component can be controlled by altering the assembly sequence, while the degree of intermolecular interactions can be varied by the level of π-conjugation and the availability of metal coordination sites. By setting the structural parameters (e.g., bond angles, number of coordination sites, geometry) of the ligand, control over MA structure was achieved, resulting in surface-confined metal-organic networks and oligomers. Unlike MAs that are constructed with organic ligands, MAs with polypyridyl complexes of ruthenium, osmium, and cobalt are active participants in their own formation and amplify the growth of the incoming molecular layer. Such a self-propagating behavior for molecular systems is rare, and the mechanism of their formation will be discussed. These exponentially growing MAs are capable of storing metal salts that can be used during the buildup of additional molecular layers. Various parameters influencing the film growth mechanism will be presented, including (i) the number of binding sites and geometry of the organic ligands, (ii) the metal and the structure of the polypyridyl complexes, (iii) the influence of the metal cross-linker (e.g., second or third row transition metals), and (iv) the deposition conditions. By systematic variation of these parameters, switching between linear and exponential growth could

  15. The mechanism of unexpected reduction of dimethyl pyridine-2,3-dicarboxylate to 1,2,3,4-tetrahydrofuro[3,4-b]-pyridin-5(7H)-one with sodium borohydride

    Institute of Scientific and Technical Information of China (English)

    Yan Bo Tang; Qing Jian Zhang; De Quan Yu

    2012-01-01

    An unexpected reduction of dimethyl pyridine-2,3-dicarboxylate to 1,2,3,4-tetrahydrofuro[3,4-b]pyridin-5(7H)-one with sodium borohydride in ethanol and tetrahydrofuran,respectively,is described,a hypothetic mechanism for the unusual reductive product is proposed.

  16. C-H activation of ethers by pyridine tethered PCsp3P-type iridium complexes.

    Science.gov (United States)

    Cui, Peng; Babbini, Dominic C; Iluc, Vlad M

    2016-06-14

    Iridium PCsp3P complexes featuring a novel bis(2-diphenylphosphinophenyl)-2-pyridylmethane ligand (PC(Py)HP) are reported. C-H activation reactions between the dihydride complex [(PC(Py)P)Ir(H)2] and tetrahydrofuran or methyl tert-butyl ether in the presence of a hydrogen acceptor, norbornene (NBE), at ambient temperature led exclusively to the hydrido oxyalkyl complexes, [(PC(Py)P)IrH(C4H7O)] and [(PC(Py)P)IrH(CH2O(t)Bu)], respectively. The internal pyridine donor is important and stabilizes these species by coordination to the iridium center. The coordination of pyridine to the iridium center is labile, however, and its dissociation occurs in the presence of a suitable substrate, as demonstrated by the intramolecular nucleophilic attack of pyridine on a vinylidene intermediate generated from PhC[triple bond, length as m-dash]CH.

  17. 3,5-Bis[(pyridin-4-ylmethoxy]benzoic acid

    Directory of Open Access Journals (Sweden)

    Hong Lin

    2013-01-01

    Full Text Available Single crystals of the title compound, C19H16N2O4, were obtained under hydrothermal conditions by an unintended recrystallization of the employed microcrystalline starting material. The [(pyridin-4-ylmethoxy]benzoic acid unit is nearly planar, with a maximum deviation from the least-squares plane of 0.194 (2 Å. This plane is inclined by 35.82 (6° to that defined by the second (pyridin-4-ylmethoxy group [in which the largest deviation from the least-squares plane is 0.013 (2 Å]. In the crystal, molecules are linked by O—H...N hydrogen bonds involving the acid hydroxy group and a pyridine N atom into chains parallel to [-201].

  18. Dibromidobis{1-[4-(pyridin-4-ylphenyl]ethanone-κN}mercury(II

    Directory of Open Access Journals (Sweden)

    Wen-Shen Zhang

    2011-12-01

    Full Text Available In the title compound, [HgBr2(C13H11NO2], the HgII atom adopts a four-coordinated HgN2Br2 geometry, formed by two pyridine N atoms from two ligands and two bromide anions. The complex is located on a twofold axis. The coordination geometry is close to forming a see-saw (SS-4 polyhedron, the symmetry-related organic ligands being almost perpendicular; the dihedral angles between the two pyridine rings and between the two benzene rings are 85.5 (4 and 87.7 (4°, respectively. Within the organic ligand, the pyridine ring is nearly coplanar with the benzene ring [dihedral angle = 13.1 (8°]. In the crystal, the molecular complexes are connected through weak intermolecular C—H...Br contacts.

  19. Synthesis and antituberculosis activity of indole-pyridine derived hydrazides, hydrazide-hydrazones, and thiosemicarbazones.

    Science.gov (United States)

    Velezheva, Valeriya; Brennan, Patrick; Ivanov, Pavel; Kornienko, Albert; Lyubimov, Sergey; Kazarian, Konstantin; Nikonenko, Boris; Majorov, Konstantin; Apt, Alexander

    2016-02-01

    We describe the design, synthesis, and in vitro antimycobacterial activity of a series of novel simple hybrid hydrazides and hydrazide-hydrazones combining indole and pyridine nuclei. The compounds are derivatives of 1-acetylindoxyl or substituted indole-3-carboxaldehydes tethered via a hydrazine group by simple C-N or double C=N bonds with 3- and 4-pyridines, 1-oxide 3- and 4-pyridine carbohydrazides. The most active of 15 compounds showed MICs values against an INH-sensitive strain of Mycobacterium tuberculosis H37Rv equal to that of INH (0.05-2 μg/mL). Five compounds demonstrated appreciable activity against the INH-resistant M. tuberculosis CN-40 clinical isolate (MICs: 2-5 μg/mL), providing justification for further in vivo studies.

  20. Quantitative structure activity relationships of some pyridine derivatives as corrosion inhibitors of steel in acidic medium.

    Science.gov (United States)

    El Ashry, El Sayed H; El Nemr, Ahmed; Ragab, Safaa

    2012-03-01

    Quantum chemical calculations using the density functional theory (B3LYP/6-31G DFT) and semi-empirical AM1 methods were performed on ten pyridine derivatives used as corrosion inhibitors for mild steel in acidic medium to determine the relationship between molecular structure and their inhibition efficiencies. Quantum chemical parameters such as total negative charge (TNC) on the molecule, energy of highest occupied molecular orbital (E (HOMO)), energy of lowest unoccupied molecular orbital (E (LUMO)) and dipole moment (μ) as well as linear solvation energy terms, molecular volume (Vi) and dipolar-polarization (π) were correlated to corrosion inhibition efficiency of ten pyridine derivatives. A possible correlation between corrosion inhibition efficiencies and structural properties was searched to reduce the number of compounds to be selected for testing from a library of compounds. It was found that theoretical data support the experimental results. The results were used to predict the corrosion inhibition of 24 related pyridine derivatives.

  1. Nickel(2) complexes of cyclen- and cyclam-pyridine: topological reorganizations induced by electron transfer

    Energy Technology Data Exchange (ETDEWEB)

    Sanae, El Ghachtouli; Cadiou, C.; Dechamps-Olivier, I.; Chuburu, F.; Aplincourt, M. [Reims Champagne-Ardenne Univ., GRECI, 51 (France); Patinec, V.; Le Baccon, M.; Handel, H. [Universite de Bretagne Occidentale, Chimie, Electrochimie moleculaires et chimie analytique, UMR CNRS 6521, CS 93837, 29 - Brest (France); Roisnel, Th. [Institut de Chimie de Rennes, UMR CNRS 6511, CS 74205, 35 - Rennes (France)

    2006-03-15

    The Ni(II) complexes of cyclen- and cyclam-pyridine (respectively 1-pyridine-2-ylmethyl-1,4,7,10-tetra-aza-cyclo-dodecane and 1-pyridine-2-ylmethyl-1,4,8,11-tetra-aza-cyclo-tetra-decane denoted [Ni(II)L(1)]{sup 2+} and [Ni(II)L(2)]{sup 2+}) have been isolated and characterised by X-ray diffraction, UV-visible spectroscopy and electrochemical studies for the [Ni(II)L(2)]{sup 2+} complex. In particular, the [Ni(II)L(2)]{sup 2+} complex adopts two distinct and stable geometries (type I and V), which mainly differ by the macrocycle configuration. In solution, the isomerization process between these two configurations is driven by the nickel-centered electron transfer. (authors)

  2. Hydrogen bonded complexes of cyanuric acid with pyridine and guanidinium carbonate

    Indian Academy of Sciences (India)

    K Sivashankar

    2000-12-01

    Hydrogen bonded complexes of cyanuric acid (CA) with pyridine, [C3N3H3O3:C5H5N], 1, and guanidinium carbonate [C3H2N3][C(NH2)3], 2, have been prepared at room temperature and characterized by single-crystal X-ray diffraction. Structure of 1 shows pyridine molecules substituting the inter-tape hydrogen bond in CA by N-H…N and C-H…O hydrogen bonds. The structure reveals CA-pyridine hydrogen-bonded single helices held together by dimeric N-H…O hydrogen bonding between CA molecules. In 2, the CA tapes, resembling a sine wave interact with the guanidinium cations through N-H…O and N-H…N hydrogen bonds forming guanidinium cyanurate sheets.

  3. Thieno[2,3-b]pyridines--a new class of multidrug resistance (MDR) modulators.

    Science.gov (United States)

    Krauze, Aivars; Grinberga, Signe; Krasnova, Laura; Adlere, Ilze; Sokolova, Elina; Domracheva, Ilona; Shestakova, Irina; Andzans, Zigmars; Duburs, Gunars

    2014-11-01

    To identify new potent multidrug resistance modulators, we have synthesized a series of novel thieno[2,3-b]pyridines and furo[2,3-b]pyridines, and examined their structure-activity relationships. All synthesized compounds were tested to determine BCRP1, P-gp, and MRP1 inhibitor activity, and most potent MDR modulators were also screened for their toxicity, cytotoxicity and Ca(2+) channel antagonist activity. Among these compounds, thieno[2,3-b]pyridine (6r) was found to exhibit a potent P-gp inhibitory action with EC50 = 0.3 ± 0.2 μM, MRP1 inhibitory action with EC50 = 1.1 ± 0.1 μM and BCRP1 inhibitory action with EC50 = 0.2 ± 0.05 μM and may represent suitable candidate for further pharmacological studies.

  4. 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.

  5. Can A Denaturant Stabilize DNA? Pyridine Reverses DNA Denaturation in Acidic pH.

    Science.gov (United States)

    Portella, Guillem; Terrazas, Montserrat; Villegas, Núria; González, Carlos; Orozco, Modesto

    2015-09-01

    The stability of DNA is highly dependent on the properties of the surrounding solvent, such as ionic strength, pH, and the presence of denaturants and osmolytes. Addition of pyridine is known to unfold DNA by replacing π-π stacking interactions between bases, stabilizing conformations in which the nucleotides are solvent exposed. We show here experimental and theoretical evidences that pyridine can change its role and in fact stabilize the DNA under acidic conditions. NMR spectroscopy and MD simulations demonstrate that the reversal in the denaturing role of pyridine is specific, and is related to its character as pseudo groove binder. The present study sheds light on the nature of DNA stability and on the relationship between DNA and solvent, with clear biotechnological implications.

  6. 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.

  7. Large-Scale Solvent-Free Chlorination of Hydroxy-Pyrimidines, -Pyridines, -Pyrazines and -Amides Using Equimolar POCl3

    Directory of Open Access Journals (Sweden)

    Zhihua Sun

    2012-04-01

    Full Text Available Chlorination with equimolar POCl3 can be efficiently achieved not only for hydroxypyrimidines, but also for many other substrates such as 2-hydroxy-pyridines, -quinoxalines, or even -amides. The procedure is solvent-free and involves heating in a sealed reactor at high temperatures using one equivalent of pyridine as base. It is suitable for large scale (multigram batch preparations.

  8. Structure-Activity Relationships for the 9-(Pyridin-2’-yl- aminoacridines

    Directory of Open Access Journals (Sweden)

    Katherine S. Frost

    2004-02-01

    Full Text Available A series of 9-(pyridin-2’-yl-aminoacridines was prepared and analyzed for their ability to change the thermal denaturation temperature of genomic calf thymus DNA. Development of a QSAR equation indicated that electron withdrawing groups on the pyridine ring promoted the interaction with double stranded DNA.

  9. Biosynthesis inspired Diels-Alder route to pyridines: synthesis of the 2,3-dithiazolylpyridine core of the thiopeptide antibiotics.

    Science.gov (United States)

    Moody, Christopher J; Hughes, Rachael A; Thompson, Stewart P; Alcaraz, Lilian

    2002-08-21

    Reaction of serine derived 1-alkoxy-2-azadienes with dehydroalanine derived dienophiles results in Diels-Alder reaction and aromatisation to give 2,3,6-trisubstituted pyridines, thereby establishing the viability of the proposed biosynthetic route to the pyridine ring of the thiopeptide antibiotics originally proposed by Bycroft and Gowland.

  10. Profiles of the biosynthesis and metabolism of pyridine nucleotides in potatoes (Solanum tuberosum L.).

    Science.gov (United States)

    Katahira, Riko; Ashihara, Hiroshi

    2009-12-01

    As part of a research program on nucleotide metabolism in potato tubers (Solanum tuberosum L.), profiles of pyridine (nicotinamide) metabolism were examined based on the in situ metabolic fate of radio-labelled precursors and the in vitro activities of enzymes. In potato tubers, [(3)H]quinolinic acid, which is an intermediate of de novo pyridine nucleotide synthesis, and [(14)C]nicotinamide, a catabolite of NAD, were utilised for pyridine nucleotide synthesis. The in situ tracer experiments and in vitro enzyme assays suggest the operation of multiple pyridine nucleotide cycles. In addition to the previously proposed cycle consisting of seven metabolites, we found a new cycle that includes newly discovered nicotinamide riboside deaminase which is also functional in potato tubers. This cycle bypasses nicotinamide and nicotinic acid; it is NAD --> nicotinamide mononucleotide --> nicotinamide riboside --> nicotinic acid riboside --> nicotinic acid mononucleotide --> nicotinic acid adenine dinucleotide --> NAD. Degradation of the pyridine ring was extremely low in potato tubers. Nicotinic acid glucoside is formed from nicotinic acid in potato tubers. Comparative studies of [carboxyl-(14)C]nicotinic acid metabolism indicate that nicotinic acid is converted to nicotinic acid glucoside in all organs of potato plants. Trigonelline synthesis from [carboxyl-(14)C]nicotinic acid was also found. Conversion was greater in green parts of plants, such as leaves and stem, than in underground parts of potato plants. Nicotinic acid utilised for the biosynthesis of these conjugates seems to be derived not only from the pyridine nucleotide cycle, but also from the de novo synthesis of nicotinic acid mononucleotide.

  11. Vibrational dephasing and frequency shifts of hydrogen-bonded pyridine-water complexes

    Science.gov (United States)

    Kalampounias, A. G.; Tsilomelekis, G.; Boghosian, S.

    2015-01-01

    In this paper we present the picosecond vibrational dynamics and Raman shifts of hydrogen-bonded pyridine-water complexes present in aqueous solutions in a wide concentration range from dense to extreme dilute solutions. We studied the vibrational dephasing and vibrational frequency modulation by calculating time correlation functions of vibrational relaxation by fits in the frequency domain. The concentration induced variations in bandwidths, band frequencies and characteristic dephasing times have been estimated and interpreted as effects due to solute-solvent interactions. The time-correlation functions of vibrational dephasing were obtained for the ring breathing mode of both "free" and hydrogen-bonded pyridine molecules and it was found that sufficiently deviate from the Kubo model. There is a general agreement in the whole concentration range with the modeling proposed by the Rothschild approach, which applies to complex liquids. The results have shown that the reorientation of pyridine aqueous solutions is very slow and hence in both scattering geometries only vibrational dephasing is probed. It is proposed that the spectral changes depend on the perturbations induced by the dynamics of the water molecules in the first hydration cell and water in bulk, while at extreme dilution conditions, the number of bulk water molecules increases and the interchange between molecules belonging to the first hydration cell may not be the predominant modulation mechanism. The evolution of several parameters, such as the characteristic times, the percentage of Gaussian character in the peak shape and the a parameter are indicative of drastic variations at extreme dilution revealing changes in the vibrational relaxation of the pyridine complexes in the aqueous environment. The higher dilution is correlated to diffusion of water molecules into the reference pyridine system in agreement with the jump diffusion model, while at extreme dilutions, almost all pyridine molecules are

  12. Sulfur Dioxide-Pyridine Dimer. FTIR and Theoretical Evidence for a Low-Symmetry Structure.

    Science.gov (United States)

    Keller, John W

    2015-10-15

    Sulfur dioxide-pyridine complex formation was reinvestigated using Fourier transform infrared (FTIR) spectroscopy and computational methods. The SO2-pyridine dimer has been proposed to have a v-shaped, Cs-symmetric structure based on the microwave spectrum; however, recent research showing the occurrence of X···H-C hydrogen bonds in noncovalent complexes suggested that the structure of the complex should be re-examined. The FTIR spectrum of the dimer was obtained by numerical analysis of the spectra of pyridine-SO2 mixtures in CCl4. The spectrum showed ortho C-H stretching modes consistent with a C1-symmetric structure containing a S-O bond oriented approximately coplanar with the pyridine ring and adjacent to an ortho C-H moiety. The C1 structure, which was identified as the global minimum by various density functional theory and correlated ab initio calculations, is also consistent with the out-of-plane second moment (Pbb) value previously determined by microwave spectroscopy. The complex is converted to its mirror image via three possible Cs-symmetric transition states: v-shaped, bisected, and flat. At the M06-2X/6-311++G(2d,p) level of theory, the rotational barriers (ΔG(o‡)) are 1.40, 1.87, and 3.63 kcal mol(-1), respectively. Natural bond order analysis indicated the asymmetric complex is stabilized both by N→S donation and back-donation from O to antibonding orbitals on pyridine. Atoms in molecules calculations identified a bond critical point within the O···H-C gap consistent with a normal, albeit weak, hydrogen bond. Theoretical studies also identified a high-energy sandwich-type dimer with Cs symmetry, and a C2-symmetric SO2-pyridine2 trimer.

  13. Vibrational dephasing and frequency shifts of hydrogen-bonded pyridine-water complexes.

    Science.gov (United States)

    Kalampounias, A G; Tsilomelekis, G; Boghosian, S

    2015-01-25

    In this paper we present the picosecond vibrational dynamics and Raman shifts of hydrogen-bonded pyridine-water complexes present in aqueous solutions in a wide concentration range from dense to extreme dilute solutions. We studied the vibrational dephasing and vibrational frequency modulation by calculating time correlation functions of vibrational relaxation by fits in the frequency domain. The concentration induced variations in bandwidths, band frequencies and characteristic dephasing times have been estimated and interpreted as effects due to solute-solvent interactions. The time-correlation functions of vibrational dephasing were obtained for the ring breathing mode of both "free" and hydrogen-bonded pyridine molecules and it was found that sufficiently deviate from the Kubo model. There is a general agreement in the whole concentration range with the modeling proposed by the Rothschild approach, which applies to complex liquids. The results have shown that the reorientation of pyridine aqueous solutions is very slow and hence in both scattering geometries only vibrational dephasing is probed. It is proposed that the spectral changes depend on the perturbations induced by the dynamics of the water molecules in the first hydration cell and water in bulk, while at extreme dilution conditions, the number of bulk water molecules increases and the interchange between molecules belonging to the first hydration cell may not be the predominant modulation mechanism. The evolution of several parameters, such as the characteristic times, the percentage of Gaussian character in the peak shape and the a parameter are indicative of drastic variations at extreme dilution revealing changes in the vibrational relaxation of the pyridine complexes in the aqueous environment. The higher dilution is correlated to diffusion of water molecules into the reference pyridine system in agreement with the jump diffusion model, while at extreme dilutions, almost all pyridine molecules are

  14. Enhancement of 4-electron O2 reduction by a Cu(ii)-pyridylamine complex via protonation of a pendant pyridine in the second coordination sphere in water.

    Science.gov (United States)

    Kotani, Hiroaki; Yagi, Tomomi; Ishizuka, Tomoya; Kojima, Takahiko

    2015-09-07

    We have synthesised a novel copper(ii) complex with a pyridine pendant as a proton relay port for electrocatalytic 4e(-) reduction of O2 in water. The enhancement of the electrocatalytic O2 reduction via protonation of the pyridine pendant is demonstrated in comparison with a copper(ii) complex without the pyridine pendant.

  15. Facile Diversity-Oriented Synthesis of Polycyclic Pyridines and Their Cytotoxicity Effects in Human Cancer Cell Lines.

    Science.gov (United States)

    Goswami, Limi; Gogoi, Shyamalee; Gogoi, Junali; Boruah, Rajani K; Boruah, Romesh C; Gogoi, Pranjal

    2016-05-09

    A three-component cascade method has been developed for the direct synthesis of polysubstituted pyridines. This strategy provides a very convenient route to pyridines using a variety of β-bromo-α,β-unsaturated aldehydes, 1,3-diketones, and ammonium acetate without any additional catalyst or metal salt under mild conditions. A variety of β-ketoesters and 4-hydroxycoumarin were also used instead of 1,3-diketones for the diverse synthesis of polycyclic pyridines. One of the synthesized pyridines has been unambiguously established by a single crystal XRD study. All of the synthesized pyridine derivatives were evaluated for their antiproliferative properties in vitro against the human cancer cell lines HeLa, Me180, and ZR751. Compounds 4{4,1} and 4{2,4} showed significant cytotoxicity in the human breast cancer cell line ZR751 and cervical cancer cell line Me180, respectively, and a few other compounds were found to have moderate activities.

  16. Solvatochromic study of highly fluorescent alkylated isocyanonaphthalenes, their π-stacking, hydrogen-bonding complexation, and quenching with pyridine.

    Science.gov (United States)

    Nagy, Miklós; Rácz, Dávid; Lázár, László; Purgel, Mihály; Ditrói, Tamás; Zsuga, Miklós; Kéki, Sándor

    2014-11-10

    Mono- and dialkylated derivatives of 1-amino-5-isocyanonaphthalene (ICAN) were studied as new members of a multifunctional, easy-to-prepare fluorophore family, which showed excellent solvatochromic properties. The monoallyl derivative and the starting ICAN exhibited strong fluorescence quenching in the presence of small amounts of pyridine. The formation of a hydrogen-bonded ground-state pyridine complex was detected; however, analysis of quantum chemical calculations suggested the presence of an additional π-stacked pyridine complex. The Stern-Volmer plot of the quenching process exhibited a downward curvature and after reaching a minimum the fluorescence intensity increased back to a significant level at high pyridine concentrations. Significant fluorescence was observed even in pure pyridine. A new mechanism and a simple mathematical equation were derived to explain the downward curvature and the remaining fluorescence by the formation of a fluorescent π-stacked complex.

  17. Tetraaquabis(pyridine-κNcobalt(II bis[4-amino-N-(6-chloropyridazin-3-ylbenzenesulfonamidate

    Directory of Open Access Journals (Sweden)

    Zhen-Feng Chen

    2009-12-01

    Full Text Available The structure of the title compound, [Co(C5H5N2(H2O4](C10H8ClN4O2S2, consists of a discrete tetraaquabis(pyridine-κNcobalt(II cation and two 4-amino-N-(6-chloropyridazin-3-ylbenzenesulfonamidate anions. In the cation, the CoII ion sits on an inversion centre and is octahedrally coordinated by two pyridine N atoms and four O atoms. A two-dimensional network parallel to (010 is formed via intermolecular O—H...O, O—H...N, N—H...N and N—H...O hydrogen bonds.

  18. 2-Methoxycarbonylpyridinium 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 methanol, one equivalent of the carboxylic acid is protonated at the amino site and is also esterified, yielding the title salt, (C7H8NO2[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 N—H...O hydrogen bond.

  19. Fine-tuning of atomic point charges: Classical simulations of pyridine in different environments

    Science.gov (United States)

    Macchiagodena, Marina; Mancini, Giordano; Pagliai, Marco; Del Frate, Gianluca; Barone, Vincenzo

    2017-06-01

    A correct description of electrostatic contributions in force fields for classical simulations is mandatory for an accurate modeling of molecular interactions in pure liquids or solutions. Here, we propose a new protocol for point charge fitting, aimed to take into the proper account different polarization effects due to the environment employing virtual sites and tuning the point charge within the polarizable continuum model framework. The protocol has been validated by means of molecular dynamics simulations on pure pyridine liquid and on pyridine aqueous solution, reproducing a series of experimental observables and providing the information for their correct interpretation at atomic level.

  20. Isomerisation of aldoses in pyridine in the presence of aluminium oxide.

    Science.gov (United States)

    Ekeberg, Dag; Morgenlie, Svein; Stenstrøm, Yngve

    2005-02-28

    Addition of aluminium oxide to boiling pyridine solutions of D-xylose, L-arabinose, D-mannose and D-glucose strongly increased the reaction rate of the aldose-ketose transformation. The maximum content of 2-ketose was reached after less than 2h for the aldopentoses and 3h for the aldohexoses. D-Threo-2-pentulose (xylulose) was prepared from D-xylose, and isolated as its O-isopropylidene derivative, the yield was nearly twice that compared to that usually obtained in the classical Lobry de Bruyn-Alberda van Ekenstein transformation in pyridine.

  1. 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.

  2. MICROWAVE PROMOTED SUZUKI COUPLINGS OF 2,6-DIBROMO PYRIDINE WITH ARYL BORONIC ACIDS : SYNTHESIS OF MONO AND DIARYL PYRIDINES MICROWAVE PROMOTED Suzuki-Kupplungen von 2,6-DIBROMO PYRIDINE Mit Arylboronsäuren: Synthese von Mono-und Diaryl PYRIDINE

    Directory of Open Access Journals (Sweden)

    Hemasri Y, Mallikarjun,Jayaprakash Rao Y

    2013-01-01

    Full Text Available A simple and general method for the synthesis of symmetrical and unsymmetrical aryl pyridines developed under Microwave irradiation by adopting Suzuki-Miyaura cross couplings. A variety of boronic acids are coupled with 2, 6-dibromo pyridines (1a – h using Pd[dppf]Cl2 under conventional and Microwave irradiation. Microwave irradiation facilitated reaction course and afforded mono(2a – h and double coupled(3a – h products in moderate to high yields in just 15 mins

  3. Photodissociation of Isoxazole and Pyridine Studied Using Chirped Pulse Microwave Spectroscopy in Pulsed Uniform Supersonic Flows

    Science.gov (United States)

    Ariyasingha, Nuwandi M.; Joalland, Baptiste; Mebel, Alexander M.; Suits, Arthur

    2016-06-01

    Chirped - Pulse Fourier-transform microwave spectroscopy in uniform supersonic flows (Chirped- Pulse/Uniform Flow: CPUF) has been applied to study the photodissociation of two atmospherically relevant N containing heterocyclic compounds; pyridine and isoxazole. Products were detected using rotational spectroscopy. HC3N, HCN were observed for pyridine and CH3CN, HCO and HCN were observed for isoxazole and we report the first detection of HNC for both of the systems. Key points in potential energy surface were explored and compared with the experimental observations. Branching ratios were calculated for all the possible channels and will be presented.

  4. Access to pyrrolo-pyridines by gold-catalyzed hydroarylation of pyrroles tethered to terminal alkynes

    Directory of Open Access Journals (Sweden)

    Elena Borsini

    2011-10-01

    Full Text Available In a simple procedure, the intramolecular hydroarylation of N-propargyl-pyrrole-2-carboxamides was accomplished with the aid of gold(III catalysis. The reaction led to differently substituted pyrrolo[2,3-c]pyridine and pyrrolo[3,2-c]pyridine derivatives arising either from direct cyclization or from a formal rearrangement of the carboxamide group. Terminal alkynes are essential to achieve bicyclic pyrrolo-fused pyridinones by a 6-exo-dig process, while the presence of a phenyl group at the C–C triple bond promotes the 7-endo-dig cyclization giving pyrrolo-azepines.

  5. 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.

  6. {2,6-Bis[(pyridin-2-ylsulfanylmethyl]pyridine-κ2N,N′}(η3-prop-2-enylpalladium(II hexafluorophosphate

    Directory of Open Access Journals (Sweden)

    Giuseppe Bruno

    2014-04-01

    Full Text Available The title compound, [Pd(C3H5(C17H15N3S2]PF6, is built up by a [(η3-allylPd]2+ fragment coordinated by a 2,6-bis[(pyridin-2-ylsulfanylmethyl]pyridine ligand coordinated through the N atoms. One of the S atoms is at a close distance to the metal centeratom [3.2930 (8 Å]. The PdII atom is tetracoordinated in a strongly distorted square-planar environment mainly determined by the η3-allyl anion in which the central C atom is disordered over two equally occupied positions. The crystal packing is very compact and is characterized by a three-dimensional network of C—H...F interactions between the F atoms of each anion and several H atoms of the surrounding cationic complexes.

  7. 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)

  8. Novel pyridine containing ligands as models for the copper centres in nitrite reductase

    CERN Document Server

    Arnold, P J

    2001-01-01

    This thesis is concerned with the synthesis of a series of novel pyridine containing ligands and their copper co-ordination chemistry. The aim was to design ligands which would produce copper complexes which model the active sites within certain copper-containing Nitrite Reductase enzymes. The first chapter reviews previous work in this area and details the promising nature of pyridine-containing ligands. The remainder of this thesis is concerned with the synthesis and characterisation of some novel pyridine-containing ligands and their copper chemistry. The synthetic routes developed during this work enabled tris(pyrid-2-yl)methylamine ligands to be produced and studied which were tripodal in form but which had a primary amine group at the cap which could be further elaborated. Additional substituents were also placed on the pyridine rings to investigate their impact on the chemistry of their copper complexes. These ligands showed a variety, counter ion dependent chemistry. The structures of number of the co...

  9. (Z-3-Amino-5-(pyridin-2-ylmethylidene-2-thioxo-1,3-thiazolidin-4-one

    Directory of Open Access Journals (Sweden)

    Petra Hirsova

    2015-11-01

    Full Text Available 3-Aminorhodanine reacts with aldehydes to form either 5-[(arylalkylidene]-substituted products or Schiff bases or derivatives substituted at both the 3-amino group and the 5-methylene group, depending on the reaction conditions. In this note, synthesis and characterization of 3-amino-5-(pyridin-2-ylmethylidene-2-thioxo-1,3-thiazolidin-4-one is reported.

  10. Preparation and Luminescence Thermochromism of Tetranuclear Copper(I)-Pyridine-Iodide Clusters

    Science.gov (United States)

    Parmeggiani, Fabio; Sacchetti, Alessandro

    2012-01-01

    A simple and straightforward synthesis of a tetranuclear copper(I)-pyridine-iodide cluster is described as a laboratory experiment for advanced inorganic chemistry undergraduate students. The product is used to demonstrate the fascinating and visually impressive phenomenon of luminescence thermochromism: exposed to long-wave UV light, the…

  11. 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...

  12. Utility of Sulphones in Heterocyclic Synthesis: Synthesis of Some Pyridine, Chromene and Thiophene Derivatives

    Directory of Open Access Journals (Sweden)

    M. E. A. Zaki

    2000-05-01

    Full Text Available Phenylsulfonylacetonitrile (1 when reacted with α,β-unsaturated nitriles (2a,b and/or 2-hydroxynaphthaldehyde yields pyridine derivatives (3a,b and / or the iminochromene derivative (4 respectively. The behavior of (1 towards some a-halogenated compounds has been investigated.

  13. Preparation and Luminescence Thermochromism of Tetranuclear Copper(I)-Pyridine-Iodide Clusters

    Science.gov (United States)

    Parmeggiani, Fabio; Sacchetti, Alessandro

    2012-01-01

    A simple and straightforward synthesis of a tetranuclear copper(I)-pyridine-iodide cluster is described as a laboratory experiment for advanced inorganic chemistry undergraduate students. The product is used to demonstrate the fascinating and visually impressive phenomenon of luminescence thermochromism: exposed to long-wave UV light, the…

  14. (2E-3-(4-Methylphenyl-1-(pyridin-3-ylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Mauricio de Sousa Oliveiria

    2012-08-01

    Full Text Available The title compound, C15H13NO, has two crystallographically independent molecules in the asymmetric unit which differ principally in the periplanar angle formed by the benzene and pyridine rings [41.41 (3 and 17.92 (5°]. The molecules exhibit an E conformation between the keto group with respect to the olefin double bond.

  15. Chemical and electronic non-innocence of the bis(imine) pyridine ligand

    NARCIS (Netherlands)

    Knijnenburg, Q.

    2006-01-01

    Bis(imine) pyridine ligands combine two striking characteristics. On the one hand, they are extremely non-innocent in the sense that they interfere in the chemistry of their complexes, both chemically and electronically. On the other hand, their Fe and Co complexes form one of the known two late tra

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

    Science.gov (United States)

    Evans, Nicholas H; Gell, Charles E; Peach, Michael J G

    2016-08-16

    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.

  17. 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...

  18. Synthesis and Antimicrobial Activity of Some New Chalcones of 2-Acetyl Pyridine

    Directory of Open Access Journals (Sweden)

    Y. Rajendra Prasad

    2008-01-01

    Full Text Available Six new chalcones were synthesised by condensing 2-acetyl pyridine with aldehyde derivatives in dilute ethanolic potassium hydroxide solution at room temperature according to Claisen-Schmidt condensation. All these compounds were characterised by means of their IR, 1H NMR spectroscopic data and microanalyses. The antimicrobial activity of these compounds was evaluated by the cup plate method.

  19. Synthesis and Antimicrobial Activity of Some New Chalcones of 2-Acetyl Pyridine

    OpenAIRE

    2008-01-01

    Six new chalcones were synthesised by condensing 2-acetyl pyridine with aldehyde derivatives in dilute ethanolic potassium hydroxide solution at room temperature according to Claisen-Schmidt condensation. All these compounds were characterised by means of their IR, 1H NMR spectroscopic data and microanalyses. The antimicrobial activity of these compounds was evaluated by the cup plate method.

  20. Bis{2-[(4-bromophenyliminomethyl]pyridine-κ2N,N′}copper(I tetraphenylborate

    Directory of Open Access Journals (Sweden)

    Maryam Hajikazemi

    2008-08-01

    Full Text Available In the crystal structure of the title compound, [Cu(C12H9BrN22](C24H20B, the copper(I cation is coordinated by four N atoms of two crystallographically independent 2-[(4-bromophenyliminomethyl]pyridine ligands within a distorted tetrahedron.

  1. Re-mediated C-C coupling of pyridines and imidazoles.

    Science.gov (United States)

    Espinal Viguri, Maialen; Huertos, Miguel A; Pérez, Julio; Riera, Lucía; Ara, Irene

    2012-12-19

    Rhenium tricarbonyl complexes with three N-heterocyclic ligands (N-alkylimidazoles or pyridines) undergo deprotonation with KN(SiMe(3))(2) and then oxidation with AgOTf to afford complexes with pyridylimidazole or bipyridine bidentate ligands resulting from deprotonation, C-C coupling and rearomatization.

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

    NARCIS (Netherlands)

    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 py

  3. SYNTHESIS AND ANTIBACTERIAL ACTIVITY OF NEW SULFONAMIDE ISOXAZOLO[5,4-b]PYRIDINE DERIVATIVES.

    Science.gov (United States)

    Poręba, Krystyna; Pawlik, Krzysztof; Rembacz, Krzysztof P; Kurowska, Ewa; Matuszyk, Janusz; Długosz, Anna

    2015-01-01

    A series of novel sulfonamide isoxazolo[5,4-b]pyridines were synthesized. The substrates for their synthesis were 3-aminoisoxazolo[5,4-b]pyridine and selected aryl sulfonic chlorides, chlorosulfonic acid and selected amines. Reactions were carried out using the classical and microwave methods. Selected compounds were tested towards antibacterial and antiproliferative activity. The structure of the obtained new derivatives was determined by elemental analysis and acquired IR and 1H NMR spectra. Among the tested compounds: N- isoxazolo[5,4-b]pyridine-3-yl-benzenesulfonamide (2) and N-isoxazolo[5,4-b]pyridine-3-yl-4-methylbenzene-sulfonamide (5) showed antimicrobial activity towards Pseudomonas aeruginosa (ATCC 27853) and Escherichia coli (ATCC 25922) at doses: 125, 250 and 500 µg. Both compounds showed a 50% inhibition of proliferation of breast carcinoma cell line MCF7 at concentrations of 152.56 µg/mL and 160 161.08 µg/mL, respectively.

  4. Monasnicotinates A–D, Four New Pyridine Alkaloids from the Fungal Strain Monascus pilosus BCRC 38093

    Directory of Open Access Journals (Sweden)

    Gwo-Fang Yuan

    2011-06-01

    Full Text Available Four new pyridine derivatives, monasnicotinates A–D (1–4 were isolated from the red yeast rice of Monascus pilosus BCRC 38093. Their structures were elucidated on the basis of physicochemical evidence, in-depth NMR spectroscopic analysis, and high-resolution mass spectrometry. Their inhibitory effects on NO production was also evaluated.

  5. 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.

  6. Influence of surfactant concentration on counter-ion induced solubility of poly(pyridine-2,5-diyl)

    Institute of Scientific and Technical Information of China (English)

    IMIT Mokhtar; YAMAMOTO Takakazu; IMIN Patigul

    2005-01-01

    Protonating the pyridine rings of poly(pyridine-2,5-diyl) with dodecybenzenesulfonic acid and camphorsulphonic acid produces polymer materials which can be dissolved in chloroform (in contrast to the unprotonated polymer, which can only be dissolved in strong acids such as formic acid) and allows mixing the protonated polymers with other chloroform soluble conjugated polymers for use in electronic devices. The protonating behavior of poly(pyridine-2,5-diyl) with two kinds of surfactants is different in some levels. Dodecybenzenesulfonic acid has higher protonating ability than camphorsulphonic acid.

  7. Synthesis and Spectral Studies of Copper (II and Manganese (II Complexes Using 2-Hydroxybenzyl-(pyridine-2-carboIminohydrazone and 2-Furyl(pyridine-2-carboIminohydrazone: Evaluation of Their Magnetic, and Antimicrobial Properties

    Directory of Open Access Journals (Sweden)

    Jagvir Singh

    2013-01-01

    Full Text Available Three new coordination complexes [Cu(HPBH2]Cl2 (1, [Cu(FPFH2]Cl2 (2, and [Mn(HPBH2] Cl2 (3 (where HPBH=2-Hydroxybenzyl(pyridine-2-carboiminohydrazone, and FPFH=2-furyl(pyridine-2-carboiminohydrazone have been synthesized using two different tridentate hydrazones ligand. The ligands were prepared by condensation of Pyridine-2-acetylchloride, 2-Hydroxybenzaldehyde and Furan-2-carbaldehyde with hydrazine, respectively, in spite of varying the carbonyl functionality attached to the pyridine moiety present in the hydrazones ligand. In both the Schiff bases, we obtained three mononuclear complexes 1, 2, and 3 which were clearly characterized from physicochemical studies. Spectroscopic investigations like 1H and 13C NMR, mass spectrometric, FTIR, and UV/Vis have been carried out for new compounds. For complexes 2 cyclic voltammetry, magnetic and EPR properties have also been recorded. Antimicrobial studies have also been performed for these compounds with different antimicrobial species.

  8. Synthesis of meta-substituted [(18)F]3-fluoro-4-aminopyridine via direct radiofluorination of pyridine N-oxides.

    Science.gov (United States)

    Brugarolas, P; Freifelder, R; Cheng, S-H; DeJesus, O

    2016-06-04

    Due to their electron-rich aromatic structure, nucleophilic (radio)fluorination of pyridines is challenging, especially at the meta position. In this paper, we describe the first example of direct fluorination of a pyridine N-oxide to produce a meta fluorinated pyridine. Specifically, fluorination of 3-bromo-4-nitropyridine N-oxide produced in several minutes 3-fluoro-4-nitropyridine N-oxide in moderate yield at room temperature. This intermediate compound was later converted to 3-fluoro-4-aminopyridine easily by catalytic hydrogenation. Furthermore, this approach was successfully applied for labeling with fluorine-18. The use of pyridine N-oxides for the preparation of fluoropyridines is unprecedented in the chemical literature and has the potential to offer a new way for the synthesis of these important structures in pharmaceuticals and radiopharmaceuticals.

  9. Solubilization of silica: Synthesis, characterization and study of penta-coordinated pyridine N-oxide silicon complexes

    Indian Academy of Sciences (India)

    Subramania Ranganathan; Ch Chandrashekhar Rao; Suvarchala Devi Vudayagiri; Y B R D Rajesh; B Jagadeesh

    2004-03-01

    In an effort to design agents that could solubilize silica in water, under ambient conditions and pH, as takes place in nature, novel zwitterionic, penta-oxo-coordinated silicon compounds with siliconate cores have been prepared from 4-substituted pyridine N-oxides (H, OMe, morpholino, NO2) as donor ligands, their structures established by 1H, 13C and MS, and the coordination number of silicon, by 29Si NMR. The formation of complexes from pyridine N-oxides is noteworthy since they arise from interaction with a weakly nucleophilic oxygen centre. The ability of the pyridine N-oxides to enhance the solubilization of silica in water has been experimentally demonstrated. Possible rationalization of this observation on the basis of O→Si coordination via the oxygen atom of pyridine N-oxide is suggested.

  10. Influence of Boron Substitution on Conductance of Pyridine- and Pentane-Based Molecular Single Electron Transistors: First-Principles Analysis

    Science.gov (United States)

    Srivastava, Anurag; Santhibhushan, B.; Sharma, Vikash; Kaur, Kamalpreet; Shahzad Khan, Md.; Marathe, Madura; De Sarkar, Abir; Shahid Khan, Mohd.

    2016-04-01

    We have investigated the modeling of boron-substituted molecular single-electron transistor (SET), under the influence of a weak coupling regime of Coulomb blockade between source and drain metal electrodes. The SET consists of a single organic molecule (pyridine/pentane/1,2-azaborine/butylborane) placed over the dielectric, with boron (B) as a substituent. The impact of B-substitution on pyridine and pentane molecules in isolated, as well as SET, environments has been analyzed by using density functional theory-based ab initio packages Atomistix toolkit-Virtual NanoLab and Gaussian03. The performance of proposed SETs was analyzed through charging energies, total energy as a function of gate potential and charge stability diagrams. The analysis confirms that the B-substituted pentane (butylborane) and the boron-substituted pyridine (1,2-azaborine) show remarkably improved conductance in SET environment in comparison to simple pyridine and pentane molecules.

  11. An unexpected reaction of cyanothioacetamide: Novel preparation of pyrazolo[3,4-b]-pyridine derivatives under MWI

    Institute of Scientific and Technical Information of China (English)

    Xue Sen Fan; Xia Wang; Xiao Yan Li

    2008-01-01

    An unexpected multi-component reaction of cyanothioacetamide with aldehyde and aminopyrazole under MWI was reported. Through this reaction, a series of pyrazolo[3,4-b]-pyridine derivatives was prepared in high yields via simple operational procedure.

  12. The catalytic performance of Ru–NHC alkylidene complexes: PCy3 versus pyridine as the dissociating ligand

    Directory of Open Access Journals (Sweden)

    Stefan Krehl

    2010-12-01

    Full Text Available The catalytic performance of NHC-ligated Ru-indenylidene or benzylidene complexes bearing a tricyclohexylphosphine or a pyridine ligand in ring closing metathesis (RCM, cross metathesis, and ring closing enyne metathesis (RCEYM reactions is compared. While the PCy3 complexes perform significantly better in RCM and RCEYM reactions than the pyridine complex, all catalysts show similar activity in cross metathesis reactions.

  13. Design, synthesis and characterization of 1-pyridin-4-yl-3,5-disubstituted indazoles and their AKT inhibition activity

    Indian Academy of Sciences (India)

    Surendrareddy Gogireddy; Arunasree M Kalle; P K Dubey; Arava Veera Reddy

    2014-07-01

    A new series of 1-pyridin-4-yl-3,5-disubstituted indazoles and their derivatives were synthesized by the reaction of 5-Bromo-1-(2-cyano-pyridin-4-yl)-1-indazole-3-carboxylic acid diethylamide with aryl boronic acids by Suzuki coupling reaction in the presence of Pd(OAc)2 and CsF. All the new compounds have been characterized by spectral data. The title compounds were subsequently evaluated for their Akt kinase activity.

  14. Microwave-prompted rapid and efficient synthesis of 3-alkyl substituted imidazo[1,5-a] pyridines

    Institute of Scientific and Technical Information of China (English)

    Lai Bao Wang; Jia Pan; Can Ling Tang; Xiu Ren Bu; Jie Wang

    2007-01-01

    Under regular heating and microwave irradiation, 3-alkyl substituted imidazo[1,5-a] pyridines were synthesized from 2,2′-pyridil, di-2-pyridyl ketone and aliphatic aldehydes in the presence of ammonium acetate and acetic acid. Compared to the traditional heating condition, the reaction time under microwave irradiation was shorter and 3-alkyl imidazo[1,5-a]pyridines were given in higher yield.

  15. Synthesis, antimicrobial and antimycobacterial evaluation of [2-(substituted phenyl)-imidazol-1-yl]-pyridin-3-yl-methanones.

    Science.gov (United States)

    Narasimhan, Balasubramanian; Sharma, Deepika; Kumar, Pradeep; Yogeeswari, Perumal; Sriram, Dharmarajan

    2011-10-01

    A series of [2-(substituted phenyl)-imidazol-1-yl]-pyridin-3-yl-methanones (1-11) were synthesized and screened for their antimicrobial and antimycobacterial activities. Further, a series of [2-(substituted phenyl)-benzimidazol-1-yl]-pyridin-3-yl-methanones (12-20) reported in our earlier study was also screened for their antimycobacterial activity. The antimycobacterial activity results indicated that [2-(4-Nitro-phenyl)-imidazol-1-yl]-pyridin-3-yl-methanone (8, minimum inhibitory concentration [MIC] = 3.13 µg) was equipotent as standard drug ciprofloxacin and [2-(4-Nitro-phenyl)-benzimidazol-1-yl]-pyridin-3-yl-methanone (16, MIC = 1.56 µg) was equipotent as standard drug ethambutol. The results of antimicrobial screening demonstrated that 2-[1-(Pyridine-3-carbonyl)-1H-imidazol-2-yl]-benzoic acid (compound 11, MIC = 0.002 µg) was two times more effective than standard drug ciprofloxacin (MIC = 0.004 µg) against tested bacterial strains and [2-(2,5-Dimethyl-phenyl)-imidazol-1-yl]-pyridin-3-yl-methanone (compound 3, MIC = 0.005 µg) was equipotent to the reference compound, fluconazole against tested fungal strains.

  16. 4-(Naphthalene-2-carboxamidopyridin-1-ium thiocyanate–N-(pyridin-4-ylnaphthalene-2-carboxamide (1/1

    Directory of Open Access Journals (Sweden)

    Sohail Saeed

    2012-10-01

    Full Text Available The asymmetric unit of the title compound, C16H13N2O+·NCS−·C16H12N2O, contains two N-(pyridin-4-ylnaphthalene-2-carboxamide molecules, both are partially protonated in the pyridine moiety, i.e. the H atom attached to the pyridine N atom is partially occupied with an occupancy factor of 0.61 (3 and 0.39 (3, respectively. In the crystal, protonated and neutral N-(pyridin-4-ylnaphthalene-2-carboxamide molecules are linked by N—H...N hydrogen bonding; the thiocyanate counter-ion links with both protonated and neutral N-(pyridin-4-ylnaphthalene-2-carboxamide molecules via N—H...S and N—H...N hydrogen bonding. The dihedral angles between the pyridine ring and naphthalene ring systems are 11.33 (6 and 9.51 (6°, respectively. π–π stacking is observed in the crystal structure, the shortest centroid–centroid distance being 3.5929 (8 Å. The crystal structure was determined from a nonmerohedral twin {ratio of the twin components = 0.357 (1:0.643 (1 and twin law [-100 0-10 -101]}.

  17. 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.)

  18. Synthesis of Novel 1-(4-Substituted pyridine-3-sulfonyl-3-phenylureas with Potential Anticancer Activity

    Directory of Open Access Journals (Sweden)

    Krzysztof Szafrański

    2015-07-01

    Full Text Available A series of novel 4-substituted-N-(phenylcarbamoyl-3-pyridinesulfonamides 11–27 have been synthesized by the reaction of 4-substituted pyridine-3-sulfonamides 2–10 with the appropriate aryl isocyanates in presence of potassium carbonate. The in vitro anticancer activity of compounds 11, 12, 14–21 and 24–26 was evaluated at the U.S. National Cancer Institute and in light of the results, some structure-activity relationships were discussed. The most prominent compound, N-[(4-chlorophenylcarbamoyl]-4-[4-(3,4-dichlorophenylpiperazin-1-yl]pyridine-3-sulfonamide (21 has exhibited a good activity profile and selectivity toward the subpanels of leukemia, colon cancer and melanoma, with average GI50 values ranging from 13.6 to 14.9 µM.

  19. Stabilizing G-quadruplex DNA by methylazacalix[n]pyridine through shape-complementary interaction.

    Science.gov (United States)

    Guan, Ai-Jiao; Shen, Meng-Jie; Zhang, En-Xuan; Li, Qian; Wang, Li-Xia; Xu, Li-Jin; Xiang, Jun-Feng; Tang, Ya-Lin

    2016-01-15

    It is found that G-quadruplexes have important functions in biological systems, such as gene expression. Molecules which can stabilize the G-quadruplex structure may have potential application in regulating the expression of gene. A series of methylazacalix[n]pyridine (n=4, 6, 7, 8, 9) has been tested to stabilize the intermolecular human telomeric G-quadruplex (T12 and H12), intramolecular TBA, c-kit and bcl-2 G-quadruplex by CD denaturation experiments. The results showed that only methylazacalix[6]pyridine (MACP6) can stabilize the intermolecular G-quadruplex formed from the 12bp human telomere. Further studies evidenced that the shape-complementary binding mode was what contributed to the interaction between MACP6 and T12 G-quadruplex.

  20. 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.

  1. Ethyl 2-(pyridine-4-carboxamido-4,5,6,7-tetrahydro-1-benzothiophene-3-carboxylate

    Directory of Open Access Journals (Sweden)

    Asma Mukhtar

    2012-07-01

    Full Text Available In the title compound, C17H18N2O3S, the dihedral angles between the thiophene ring and the ethyl ester group and the pyridine-4-carboxamide unit are 7.1 (2 and 9.47 (11°, respectively. An intramolecular N—H...O hydrogen bond generates an S(6 ring. In the crystal, inversion dimers linked by pairs of C—H...O hydrogen bonds between the tetrahydro-1-benzothiophene and the pyridine-4-carboxamide residues generate R22(16 loops. There exists positional disorder in three methelene groups of the cyclohexane ring and the terminal C atom of the ethyl ester side chain in a 0.691 (14:0.309 (14 occupancy ratio.

  2. 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.

  3. Bis{2,6-bis[(2-hydroxy-5-methylphenyliminomethyl]pyridine} monohydrate

    Directory of Open Access Journals (Sweden)

    Muhammet Kose

    2011-12-01

    Full Text Available The title compound, 2C21H19N3O2·H2O, was synthesized by a Schiff base condensation of 2,6-diformylpyridine with 2-amino-4-methylphenol in ethanol. In the crystal, two molecules of 2,6-bis[(2-hydroxy-5-methylphenyliminomethyl]pyridine dimerize via hydrogen bonding to a water molecule, which lies on a twofold axis. There are also intramolecular phenol–imine hydrogen bonds. The dimers are further linked via π–π (phenyl–pyridine [centroid–centroid distance = 3.707 (2 Å] and π–π edge-to-edge [3.392 (2 Å] interactions. The dihedral angles between the central ring and the two pendant rings are 11.46 (8 and 2.06 (8° while the pendant rings make a dihedral angle of 10.14 (8°.

  4. Spectral studies of copper(II) complexes of 6-(3-thienyl) pyridine-2-thiosemicarbazone

    Energy Technology Data Exchange (ETDEWEB)

    Mahjoub, Omima Abdalla; Farina, Yang [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor (Malaysia)

    2014-09-03

    Two novel copper(II) complexes [Cu(HL)Cl]Cl.H{sub 2}O (1) and [Cu(L)NO{sub 3}]Ðœ‡H{sub 2}O (2) of the three NNS donor thiosemicarbazone ligand 6-(3-thienyl) pyridine-2-thiosemicarbazone have been synthesized. The ligand and its copper(II) complexes were characterized by elemental analysis (C, H, N, and S), FT-IR, UV-visible, magnetic susceptibility and molar conductance. The thiosemicarbazone is present either as the thione form in complex 1 or as thiol form in complex 2 and is coordinated to copper(II) atom via the pyridine nitrogen atom, the azomethine nitrogen atom and the sulfur atom. The physicochemical and spectral data suggest square planar geometry for copper(II) atoms.

  5. Aldose-ketose interconversion in pyridine in the presence of aluminium oxide.

    Science.gov (United States)

    Ekeberg, Dag; Morgenlie, Svein; Stenstrøm, Yngve

    2007-10-15

    The reaction rate of the Lobry de Bruyn-Alberda van Ekenstein transformation of aldoses to ketoses in boiling pyridine was strongly increased by the addition of aluminium oxide. In addition to aldose-ketose transformation, 2-epimers of the starting aldoses and 3-epimers of the primarily produced ketoses were formed to some extent, as reported also when these reactions are carried out without aluminium oxide. The relative amounts of the primary ketose and the starting aldose in the reaction mixtures may be explained on the basis of their stability, predicted from reported free energy calculations. Isomerisation of ketoses to aldoses was much slower than the reverse reaction. The relative free energies are also in these cases important, the very stable xylo-2-hexulose gave only 7% and 6% of the aldoses gulose and idose, respectively, after boiling for 7h in pyridine in the presence of aluminium oxide.

  6. Electron energy-loss spectroscopy of excited states of the pyridine molecules

    Science.gov (United States)

    Linert, Ireneusz; Zubek, Mariusz

    2016-04-01

    Electron energy-loss spectra of the pyridine, C5H5N, molecules in the gas phase have been measured to investigate electronic excitation in the energy range 3.5-10 eV. The applied wide range of residual electron energy and the scattering angle range from 10° to 180° enabled to differentiate between optically-allowed and -forbidden transitions. These measurements have allowed vertical excitation energies of the triplet excited states of pyridine to be determined and tentative assignments of these states to be proposed. Some of these states have not been identified in the previous works. Contribution to the Topical Issue "Advances in Positron and Electron Scattering", edited by Paulo Limao-Vieira, Gustavo Garcia, E. Krishnakumar, James Sullivan, Hajime Tanuma and Zoran Petrovic.

  7. Structural analysis of pyridine-imino boronic esters involving secondary interactions on solid state

    Science.gov (United States)

    Sánchez-Portillo, Paola; Arenaza-Corona, Antonino; Hernández-Ahuactzi, Irán F.; Barba, Victor

    2017-04-01

    Twelve boronic esters (1a-1l) synthesized from 4-halo- substituted arylboronic acids (halo = F, Cl, Br, I and CF3) with 2-amino-2- alkyl (H, Me) -1,3-propanediol in presence of (3- or 4)-pyridine carboxaldehyde are described. A solvent mixture toluene/methanol 1:4 ratio was used. All compounds include both donor/acceptor functional groups, which are the necessary elements to self-assembly of the molecular species. Several secondary interactions as I⋯N, Br⋯Br, Br⋯B, F⋯B, Csbnd H⋯N, Csbnd H⋯O, Br⋯π and Csbnd H⋯π support the 1D and 2D polymeric frameworks in solid state. The coordination of the nitrogen atom from the pyridine moiety with the boron atom was not observed in either solution or solid state.

  8. 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.

  9. HEAT-RESISTANT PYRIDINE-BASED POLY(ETHER-ESTER)S: SYNTHESIS,CHARACTERIZATION AND PROPERTIES

    Institute of Scientific and Technical Information of China (English)

    Shahram Mehdipour-Ataei; Ali Mahmoodi

    2013-01-01

    A pyridine-based diacid was synthesized via nucleophilic substitution reaction of 4-hydroxy benzoic acid with 2,6-dichloropyridine in the presence of potassium carbonate.The diacid was characterized using FT-IR and 1H-NMR spectroscopic methods and also with elemental analysis.Polycondensation reaction of the diacid with different diols including 1,4-dihydroxy benzene,1,5-dihydroxy naphthalene,bis-phenol A and bis-phenol-P resulted in preparation of pyridine-based poly(ether-ester)s.The polymers were characterized and their physical and thermal properties including inherent viscosity,molecular weight,solubility,thermal stability,thermal behavior and crystallinity were studied.They revealed high heat-resistance and improved solubility in polar solvents.Structure-property relations for the prepared polyester were also studied.

  10. Novel hydrazone derivatives containing pyridine amide moiety: Design, synthesis, and insecticidal activity.

    Science.gov (United States)

    Yang, Zai-Bo; Hu, De-Yu; Zeng, Song; Song, Bao-An

    2016-02-15

    A series of novel hydrazone derivatives containing pyridine amide moiety were designed, synthesized, and evaluated for their insecticidal activity. Bioassays indicated that some of the target compounds exhibited good insecticidal activities against Nilaparvata lugens (N. lugens), Plutella xylostella (P. xylostella), Mythimna separata (M. separata), Helicoverpa armigera (H. armigera), Pyrausta nubilalis (P. nubilalis), and Culex pipiens pallens (C. pipiens pallens). In particular, compound 5j revealed excellent insecticidal activity against C. pipiens pallens, with the 50% lethal concentration (LC50) and the 95% lethal concentration (LC95) values of 2.44 and 5.76 mg/L, respectively, which were similar to those of chlorpyrifos (3.26 and 6.98 mg/L, respectively), tebufenozide (1.22 and 2.49 mg/L, respectively), and RH-5849 (2.61 and 6.37 mg/L, respectively). These results indicated that hydrazone derivatives containing pyridine amide moiety could be developed as novel and promising insecticides.

  11. Catalyst: and solvent-free synthesis of imidazo[1,2-a]pyridines

    OpenAIRE

    Zhu,Dong-Jian; Chen,Jiu-Xi; Liu,Miao-Chang; Ding,Jin-Chang; Wu,Hua-Yue

    2009-01-01

    A highly efficient and facile method has been described for the synthesis of imidazo[1,2-a]pyridines in good to excellent yields by condensation of the α-haloketones (ArCOCHXR², Ar = C6H5, 4-MeOC6H4, 4-ClC6H4, 2,4-Cl2C6H3; X = Br, Cl; R² = H, CH3) with 2-aminopyridines without the use of any additional catalyst and solvent.

  12. Bis(imidazo[1,2-a]pyridin-1-ium tetrachloridocuprate(II dihydrate

    Directory of Open Access Journals (Sweden)

    Sonia Mokaddem

    2017-02-01

    Full Text Available In the title salt, (C7H7N22[CuCl4]·2H2O, the Cu2+ cation is coordinated by four Cl atoms and adopts a distorted tetrahedral geometry. Two molecules of imidazo[1,2-a]pyridine are protonated ensuring electrical neutrality. O—H...Cl and N—H...O hydrogen bonds link the organic and the inorganic moieties, leading to a self-organized hydrated hybrid structure.

  13. Dichloridobis[2-methyl-sulfanyl-4-(pyridin-2-yl)pyrimidine-κN,N]cobalt(II).

    Science.gov (United States)

    Yang, Wen-Na

    2011-09-01

    The asymmetric unit of the title compound, [CoCl(2)(C(10)H(9)N(3)S)(2)], contains one half-mol-ecule with the Co(II) atom situtated on a twofold rotational axis. The Co(II) atom, in an octa-hedral enviroment, is coordinated by four N atoms from two 2-methyl-sulfanyl-4-(pyridin-2-yl)pyrimidine ligands and two Cl atoms.

  14. Catalyst: and solvent-free synthesis of imidazo[1,2-a]pyridines

    OpenAIRE

    Zhu,Dong-Jian; Chen,Jiu-Xi; Liu,Miao-Chang; Ding,Jin-Chang; Wu,Hua-Yue

    2009-01-01

    A highly efficient and facile method has been described for the synthesis of imidazo[1,2-a]pyridines in good to excellent yields by condensation of the α-haloketones (ArCOCHXR², Ar = C6H5, 4-MeOC6H4, 4-ClC6H4, 2,4-Cl2C6H3; X = Br, Cl; R² = H, CH3) with 2-aminopyridines without the use of any additional catalyst and solvent.

  15. {2,2′-[Pyridine-3,4-diylbis(nitrilomethylidyne]diphenolato}zinc(II

    Directory of Open Access Journals (Sweden)

    Ning Sheng

    2009-11-01

    Full Text Available The title compound, [Zn(C19H13N3O2], has been synthesized by the reaction of Zn(ClO42·6H2O and the tetradentate Schiff base ligand 2,2′-[pyridine-3,4-diylbis(nitrilomethylidyne]diphenol (L. The coordination geometry of the ZnII ion is slightly distorted square-planar, formed by two N atoms and two O atoms from the L ligand.

  16. 2-[1-(9-Anthrylmethyl-1H-pyrazol-3-yl]pyridine

    Directory of Open Access Journals (Sweden)

    Shi-Lu Zhang

    2009-11-01

    Full Text Available The title compound, C23H17N3, can be used in coordination chemistry. The anthracene ring makes dihedral angles of 86.08 (5 and 76.63 (6°, respectively, with the pyridine and pyrazole rings. The dihedral angle between the pyrazole and pyrimidine rings is 11.79 (7°. In the structure, weak intermolecular C—H...N hydrogen bonds are observed.

  17. 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.

  18. Catalytic wet peroxidation of pyridine bearing wastewater by cerium supported SBA-15

    Energy Technology Data Exchange (ETDEWEB)

    Subbaramaiah, V. [Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand (India); Srivastava, Vimal Chandra, E-mail: vimalcsr@yahoo.co.in [Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand (India); Mall, Indra Deo [Department of Chemical Engineering, Indian Institute of Technology Roorkee, Roorkee 247667 Uttarakhand (India)

    2013-03-15

    Highlights: ► Cerium supported SBA-15 (Ce/SBA-15) synthesized by two-step synthesis. ► Characterization of Ce/SBA-15 by FTIR, XRD and BET surface area. ► Catalytic peroxidation of pyridine by Ce/SBA-15. ► Optimization of parameters like catalyst dose, H{sub 2}O{sub 2} dose, initial concentration and temperature. ► Catalyst reusability and leaching study performed. -- Abstract: Cerium supported SBA-15 (Ce/SBA-15) was synthesized by two-step synthesis method in acidic medium. It was further characterized by various characterization techniques such as X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy and N{sub 2} adsorption–desorption pore size distribution analysis. The Ce/SBA-15 showed highly ordered meso-structure with pore diameter ≈ 70–100 A and pore volume ≈ 0.025 cm{sup 3}/g. Ce/SBA-15 was further evaluated as a catalyst for the oxidation of highly toxic and non-biodegradable material, pyridine, by catalytic wet-peroxidation method. The effects of various operating parameters such as catalyst dose (0.5–6 g/l), stoichiometric ratio of H{sub 2}O{sub 2}/pyridine (1–6), initial pyridine concentration (50–800 mg/l) and temperature (313–358 K) have been evaluated and optimized. Ce/SBA-15 showed stable performance during reuse for six cycles with negligible cerium leaching. Kinetic and thermodynamic parameters and operation cost have also been determined.

  19. Mixed Pyridine-phenol Boron Complex Encapsulated in Polymer/Silica Hybrid Sol-gel Matrix

    Institute of Scientific and Technical Information of China (English)

    DONG Wei; TANG Jun; WANG Yue

    2008-01-01

    A novel pyridine-phenol boron complex[(dppy)BF]was encapsulated into polymer/silica composite matrix by sol-gel process.UV-Vis absorption spectra show that this process can control the aggregation structure of complex(dppy)BF.The results of photoluminescence of(dppy)BF in sol-gel composite film indicate that both fluorescence intensity and photostability are markedly increased using this method compared with other methods,which increases the practical significance of such composite film.

  20. Crystal structures of the solvates of diethylaminogossypol with ethyl acetate and pyridine

    Science.gov (United States)

    The crystal structures of diethylaminogossypol with ethyl acetate (DEAG-EA) and pyridine (DEAG-P) were studied by room-temperature X-ray diffraction. The host-to-guest molecule ratio in these complexes is 2:1 for DEAG-EA and 2:5 for DEAG-P. The crystal and cell parameters for DEAG-EA are C34H40N2O6...

  1. Palladium-Catalyzed Suzuki-Miyaura Type Coupling Reaction of Aryl Halides with Triphenylborane-Pyridine

    Institute of Scientific and Technical Information of China (English)

    杨明华; 顾勇冰; 王艳; 赵玺玉; 严国兵

    2012-01-01

    The Suzuki-Miyaura type coupling reaction of aryl halides with triphenylborane-pyridine was described. The reaction can be catalyzed by Pd(OAc)2 (5 mol%) in presence of Cs2CO3 at 50 ℃ or 80 ℃, and functionalized biaryls were obtained in good to excellent yields. This protocol is general and can tolerate a wide range of func- tional groups.

  2. The Effect of Xe Underlayers on the Surface Enhanced Raman Scattering of Pyridine on Cold Silver.

    Science.gov (United States)

    1984-11-01

    enhancement effect on deposited pyridine can be dramatically reduced. ~Present address: INIFTA, Division Fisicoquimica de Superficies, CC 16, * Suc...is increased beyond 70K we see dramatic increases in peaks for all four - quadrant. See Figure 3. Certain structural changes begin to take place at...this stage. One such changes is the beginning of appreciable sublimation of the physisorbed Xe, even out of the pores. 18 Another change might involve

  3. Pyridine ring opening at room temperature at a rhenium tricarbonyl bipyridine complex.

    Science.gov (United States)

    Huertos, Miguel A; Pérez, Julio; Riera, Lucía

    2008-04-30

    Pyridine ring opening occurs in the reaction of [Re(CO)3(MeIm)(bipy)]OTf with KN(SiMe3)2 followed by double methylation with methyl trifluoromethanesulfonate. Analogues of the neutral product of the initial deprotonation and of the product of the first methylation were isolated by using mesitylimidazole (MesIm) in place of methylimidazole (MeIm) and/or 1,10-phenanthroline (phen) instead of 2,2'-bipyridine (bipy).

  4. (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.

  5. (E-Benzaldehyde O-{[3-(pyridin-3-ylisoxazol-5-yl]methyl}oxime

    Directory of Open Access Journals (Sweden)

    Rodolfo Moreno-Fuquen

    2012-04-01

    Full Text Available The asymmetric unit of the title compound, C16H13N3O2, contains two independent molecules in which the pyridine and benzene rings form dihedral angles of 81.7 (2 and 79.8 (2°, indicating the twist in the molecules. In the crystal, weak C—H...N interactions link molecules into chains along [100].

  6. Ab initio MO study on equilibrium bond distance between Fe and pyridine in bis(pyridine)(porphinato) iron for various electronic states

    Science.gov (United States)

    Saito, Minoru; Kashiwagi, Hiroshi

    1985-04-01

    For bis(pyridine)(porphinato) iron [FeP(py)2], a correlation between the iron electronic state and the equilibrium Fe-Npy distance was investigated. Potential energy curves as a function of the Fe-Npy distance were calculated for low-spin, intermediate-spin, and high-spin states of the ferric and ferrous ions by the ab initio SCF MO method. The equilibrium Fe-Npy distances were obtained from the potential curves. The values obtained for the ferric low-spin and high-spin states were in good agreement with the experimental values for Fe(III)(OEP)(3-Clpy)2 within the differences, ±0.05 Å. The following significant features were found. The equilibrium distance is elongated by the occupation of the 3dz2 orbital and is shortened by the oxidation of the iron atom. The distance and the force constant for the symmetrical py-Fe-py stretching are strongly correlated with the overlap population between the 3dz2 orbital and pyridine-nitrogen orbitals.

  7. catena-Poly[[[iodidocopper(I]-{μ-N-[(pyridin-2-yl-κNmethylidene]pyridin-3-amine-κ2N3:N1}] acetonitrile hemisolvate

    Directory of Open Access Journals (Sweden)

    Ali Mahmoudi

    2012-10-01

    Full Text Available In the asymmetric unit of the title polymeric complex, {[CuI(C11H9N3]·0.5CH3CN}n, there are two CuI atoms, two N-[(pyridin-2-yl-κNmethylidene]pyridin-3-amine (PyPy ligands and two I atoms. Both CuI atoms have a distorted tetrahedral geometry, each being coordinated by one I atom, two N atoms of one PyPy ligand and one N atom from an adjacent PyPy ligand. In the crystal, infinite helical chains of [Cu2(PyPy2]n are formed propagating along the b axis. These chains are linked via weak C—H...I hydrogen bonds and π–π stacking interactions [shortest centroid–centroid distance = 3.2727 (14 Å]. During the refinement, electron-density peaks were located that were believed to be highly disordered solvent molecules (possibly acetonitrile. The SQUEEZE option in PLATON [Spek (2009. Acta Cryst. D65, 148–155] indicated there were solvent cavities with a total volume of 196 Å3 containing approximately 60 electrons per unit cell, which equated to one molecule of acetonitrile per asymmetric unit.

  8. Poly[[tetraaquatetrakis[μ3-5-(pyridine-4-carboxamidoisophthalato]cobalt(IIdigadolinium(III] tetrahydrate

    Directory of Open Access Journals (Sweden)

    Dai-Zhi Kuang

    2011-10-01

    Full Text Available In the centrosymmetric polymeric title compound, {[CoGd2(C14H8N2O54(H2O4]·4H2O}n, the GdIII cation is coordinated by one water molecule and four pyridine-4-carboxamidoisophthalate (L anions in a distorted square-antiprismatic arrangement, while the CoII cation, located on an inversion center, is coordinated by two pyridyl-N atoms, two carboxylate-O atoms and two water molecules in a distorted octahedral geometry. The asymmetric unit contains two anionic L ligands: one bridges two Gd cations and one Co cation through two carboxyl groups and one pyridine-N atom; the other bridges two Gd cations and one Co cation through two carboxyl groups and the uncoordinated pyridine-N atom is hydrogen-bonded to the adjacent coordinated water molecule. Extensive O—H...O and N—H...O hydrogen bonds are present in the crystal structure.

  9. Study on the structure and morphology of supramolecular shape memory polyurethane containing pyridine moieties

    Science.gov (United States)

    Chen, S. J.; Hu, J. L.; Chen, S. G.; Zhang, C. L.

    2011-06-01

    Fabricating smart materials has been an attractive research topic in recent years. In this study, a series of pyridine-containing shape memory polyurethanes (Py-SMPUs) with different pyridine contents were synthesized. Based on the theoretical analysis, the structure and morphology of Py-SMPUs were studied systematically with FT-IR, DSC, WAXD, DMA, AFM, etc. Results show that a hydrogen-bonded supramolecular structure is formed in the Py-SMPUs. Hydrogen bonds present in the urethane group and pyridine ring are the most favorable hydrogen bonds which play an important role in the movement of the polymer chain. Microphase separation consisting of a soft phase and hard phase occurs in the Py-SMPUs. The soft phase is influenced greatly by the N, N-bis(2-hydroxyl ethyl) isonicotinamide (BINA) unit and the hard phase is mainly a result of the hexamethylene diisocyanate and 1,4-butanediol (HDI-BDO) units. As the BINA content decreases, the soft phase tends to change gradually from a continuous amorphous phase to a droplet-like dispersion phase, whereas the hard phase develops from a droplet-like dispersion amorphous phase to a continuous crystalline phase.

  10. POLYAMIDES WITH PENDANT 1,3,4-OXADIAZOLE AND PYRIDINE MOIETIES

    Institute of Scientific and Technical Information of China (English)

    Yagoub Mansoori; Behzad Koohi-Zargar; Hemayat Shekaari; Mohammad Reza Zamanloo; Gholam Hassan Imanzadeh

    2012-01-01

    A novel aromatic diamine,2-(5-(3,5-diaminophenyl)-1,3,4-oxadiazole-2-yl)pyridine (POBD),containing a pyridine ring and a 1,3,4-oxadiazole moiety,was synthcsized.It was used in a polycondensation with various aromatic and aliphatic diacid chlorides to generate a series of new aromatic polyamides with pendant 1,3,4-oxadiazole groups.The prepared polyamides were characterized by IR,elemental analysis and through the synthesis of model compounds.Thermophysical properties of the synthesized polyamides have been studied by DSC,TGA and inherent viscosity measurements.Relatively high inherent viscosity values (0.76-1.62 dL/g,in 0.125% H2SO4 at 25℃) were observed for these compounds.Number average molecular weight (Mn) of the polymers was measured by vapor phase osmometry (VPO).The introduction of bulky side chains in the structure of aromatic polyamides led to increased solubility of these polymers in common polar and aprotic solvents,such as DMF,DMSO,NMP and DMAc,which allowed thin films to be cast from polymer solutions.The highest molecular weight (Mn =51190) was observed for polymer (Ⅸ),which was prepared from pyridine-2,6-dichlorocarbonyl.

  11. Role of vanadium and pyridine in heteropolycompounds for selective oxidation of alcohols with hydrogen peroxide

    Indian Academy of Sciences (India)

    Valeria Palermo; Paula I Villabrille; Patricia G Vázquez; Carmen V Cáceres; Pietro Tundo; Gustavo P Romanelli

    2013-11-01

    This study describes the application of heteropolyacids H3PMo12O40,H4SiMo12O40, H4PMo11VO40, H5PMo10V2O40, H9PMo6V6O40, and a hybrid pyridine-modified heteropolyacid with Keggin structure for selective oxidation of alcohols to ketones or aldehydes using aqueous hydrogen peroxide and acetonitrile as solvent. Performance of these different catalysts in 1-phenylethanol oxidation was studied. Influence of reaction temperature, amount of catalyst and hydrogen peroxide and reaction time on the yield of acetophenone was investigated to obtain optimal reaction conditions. Oxidation ability of the catalyst depended on the number of vanadium atoms present in the Keggin ion and to a lesser extent on pyridine substitution in the Keggin secondary structure. In order to explore the applicability of the method for selective oxidation of alcohols to ketones or aldehydes, various alcohols were investigated according to the general procedure using hybrid pyridine-modified heteropolyacid.

  12. 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.

  13. Benzene-pyridine interactions predicted by the effective fragment potential method.

    Science.gov (United States)

    Smith, Quentin A; Gordon, Mark S; Slipchenko, Lyudmila V

    2011-05-12

    The accurate representation of nitrogen-containing heterocycles is essential for modeling biological systems. In this study, the general effective fragment potential (EFP2) method is used to model dimers of benzene and pyridine, complexes for which high-level theoretical data -including large basis spin-component-scaled second-order perturbation theory (SCS-MP2), symmetry-adapted perturbation theory (SAPT), and coupled cluster with singles, doubles, and perturbative triples (CCSD(T))-are available. An extensive comparison of potential energy curves and components of the interaction energy is presented for sandwich, T-shaped, parallel displaced, and hydrogen-bonded structures of these dimers. EFP2 and CCSD(T) potential energy curves for the sandwich, T-shaped, and hydrogen-bonded dimers have an average root-mean-square deviation (RMSD) of 0.49 kcal/mol; EFP2 and SCS-MP2 curves for the parallel displaced dimers have an average RMSD of 0.52 kcal/mol. Additionally, results are presented from an EFP2 Monte Carlo/simulated annealing (MC/SA) computation to sample the potential energy surface of the benzene-pyridine and pyridine dimers.

  14. Redetermination of pyridine-4-carbonitrile–chloranilic acid (1/1 at 180 K

    Directory of Open Access Journals (Sweden)

    Hiroyuki Ishida

    2008-07-01

    Full Text Available In the crystal structure of the title compound, C6H4N2·C6H2Cl2O4, two chloranilic acid (systematic name: 2,5-dichloro-3,6-dihydroxy-1,4-benzoquinone molecules are connected by O—H...O hydrogen bonds to form a dimeric unit. The pyridine-4-carbonitrile molecules are linked on both sides of the dimer via N...H...O hydrogen bonds to give a centrosymmetric 2:2 complex of pyridine-4-carbonitrile and chloranilic acid. The H atom in the N...H...O hydrogen bond is disordered over two positions with approximately equal occupancies. The pyridine ring makes a dihedral angle of 61.54 (14° with the chloranilic acid plane. The 2:2 units are further linked by intermolecular C—H...O and C—H...Cl hydrogen bonds. This determination presents a siginficantly higher precision crystal structure than the previously published structure [Tomura & Yamasshita (2008. X-ray Struct. Anal. Online, 24, x31–x32].

  15. A Pyridine-copper Inclusion Complex of a New Tripodal Ligand

    Institute of Scientific and Technical Information of China (English)

    范承; 马成丙; 陈昌源; 陈锋; 刘秋田

    2003-01-01

    A pyridine-copper inclusion complex with [Cu(py)4Cl]+ core was prepared in the presence of tripodal ligand tbst {tbst = 1,3,5-tris(2-benzimidazol)sulfanylmethyl-2,4,6-trimethyl- benzene}, and its structure has been determined. It crystallizes in triclinic, space group Pī with a = 9.0822(2), b = 17.6026(4), c = 18.7156(4)(A°),α= 93.40,β= 91.2980(1),γ= 91.5560(1)°, V = 2984.81(1)(A°)3, C58H63Cl2CuN11O4S3, Mr = 1208.81, Z = 2, F(000) = 1262, Dc = 1.345 g/cm3,β= 0.615 mm-1, R = 0.0713 and wR = 0.1307 for 7798 observed reflections (I > 2σ(1)). X-ray analysis reveals that the uncoordinated tbst and pyridine as guest molecules are included in the complex with formula {[Cu(py)4Cl]Cl}@(tbst)@(py)@4H2O. The tbst, pyridine, aqua and Cl- anion in the com- plex form extensive hydrogen-bonding interactions, building up a quasi-dinuclear structure.

  16. Catalytic wet peroxidation of pyridine bearing wastewater by cerium supported SBA-15.

    Science.gov (United States)

    Subbaramaiah, V; Srivastava, Vimal Chandra; Mall, Indra Deo

    2013-03-15

    Cerium supported SBA-15 (Ce/SBA-15) was synthesized by two-step synthesis method in acidic medium. It was further characterized by various characterization techniques such as X-ray diffraction, field-emission scanning electron microscopy, Fourier transform infrared spectroscopy and N2 adsorption-desorption pore size distribution analysis. The Ce/SBA-15 showed highly ordered meso-structure with pore diameter≈70-100Ǻ and pore volume≈0.025cm(3)/g. Ce/SBA-15 was further evaluated as a catalyst for the oxidation of highly toxic and non-biodegradable material, pyridine, by catalytic wet-peroxidation method. The effects of various operating parameters such as catalyst dose (0.5-6g/l), stoichiometric ratio of H2O2/pyridine (1-6), initial pyridine concentration (50-800mg/l) and temperature (313-358K) have been evaluated and optimized. Ce/SBA-15 showed stable performance during reuse for six cycles with negligible cerium leaching. Kinetic and thermodynamic parameters and operation cost have also been determined.

  17. Highly efficient non-doped blue organic light emitting devices based on anthracene–pyridine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Haykir, Gulcin; Tekin, Emine; Atalar, Taner; Türksoy, Figen

    2013-12-02

    Four different 2-(10-aryl)anthracen-9-yl)pyridine derivatives 5a–d were synthesized via the Suzuki cross-coupling reaction. Photo-physical characteristics of these materials having strong electron donating or electron withdrawing groups were explored. Multilayer small molecule organic light emitting diodes without any dopant were fabricated in the following sequence: Indium tin oxide/4,4′-bis(N-(1-naphthyl)-N-phenylamino)biphenyl (50 nm)/5a–d (30 nm)/4,7-diphenyl-1,10-phenanthroline (30 nm)/LiF/Al. The electroluminescent property of the device fabricated with 5d as an emitter exhibited a high external quantum efficiency of 3.80% (at around 1 mA/cm{sup 2}) with Commission Internationale De L'Eclairage coordinates of (0.14, 0.25). - Highlights: • Synthesis and characterization of 2-(10-aryl)anthracen-9-yl)pyridine derivatives • Thermal, photophysical and electrochemical properties of anthracene derivatives • Emitters from blue to greenish blue for organic light emitting device applications • Organic light emitting device fabrication and characterization of 2-(10-aryl)anthracen-9-yl)pyridine derivatives.

  18. Synthesis and Characterization of Polyamide-Containing 2, 6-(Substituded) pyridine Derivatives

    Institute of Scientific and Technical Information of China (English)

    XU Kuoxi; HU Peizhi; CAI Lihua

    2006-01-01

    A new series of acyclic aromatic polyamide pyridine derivatives a-h and a new macrocyclic polyamide containing pyri dine ring I were synthesized by the reaction of N2 , N6-bis (2-aminoethyl) pyridine-2,6-dicarboxamide or N2 , N6-bis ( 3-aminopropyl) pyridine-2,6-dicarboxamide with various acyl chloride.The compounds were characterized by MS, 1H NMR,IR and elemental analysis. The single-crystal structure of g confirmed that the crystal is of triclinic, space group P-1 with Mr =487.55, a=9.303 1(19), b=12.167(2) , c=126.50(3) nm,a=108.91(3)°, β=97.57(3)°, γ=102.07(3)°, V=1 293.5nm, Z=2, D() =1. 252 kg/m3,μ=0.086 mm-1 , F(000) =516. X-ray analysis reveals that there exist hydrogen bonding and network structure in the crystal.

  19. Research Progress on the Synthesis of Energetic Pyridines%吡啶类含能化合物的合成研究进展

    Institute of Scientific and Technical Information of China (English)

    马丛明; 刘祖亮; 许晓娟; 姚其正

    2014-01-01

    吡啶类化合物在含能材料领域中的研究和应用较为广泛。从分子结构出发,按照硝基吡啶、吡啶类含能离子盐和吡啶类含能配合物分类,综述了多种吡啶硝基衍生物的合成,并简单介绍了一些重要的硝基吡啶类含能化合物的特性及主要应用。%Pyridines are widely used in energetic materials. Based on molecular structure, and classified themselves by nitro-pyridines, pyridine-based energetic salts, pyridine-based energetic complexes, a large number of energetic pyridines are sum-marized. The characteristics and main applications of some important energetic pyridines are also introduced briefly.

  20. Photochemical activation of ruthenium(II)-pyridylamine complexes having a pyridine-N-oxide pendant toward oxygenation of organic substrates.

    Science.gov (United States)

    Kojima, Takahiko; Nakayama, Kazuya; Sakaguchi, Miyuki; Ogura, Takashi; Ohkubo, Kei; Fukuzumi, Shunichi

    2011-11-09

    Ruthenium(II)-acetonitrile complexes having η(3)-tris(2-pyridylmethyl)amine (TPA) with an uncoordinated pyridine ring and diimine such as 2,2'-bipyridine (bpy) and 2,2'-bipyrimidine (bpm), [Ru(II)(η(3)-TPA)(diimine)(CH(3)CN)](2+), reacted with m-chloroperbenzoic acid to afford corresponding Ru(II)-acetonitrile complexes having an uncoordinated pyridine-N-oxide arm, [Ru(II)(η(3)-TPA-O)(diimine)(CH(3)CN)](2+), with retention of the coordination environment. Photoirradiation of the acetonitrile complexes having diimine and the η(3)-TPA with the uncoordinated pyridine-N-oxide arm afforded a mixture of [Ru(II)(TPA)(diimine)](2+), intermediate-spin (S = 1) Ru(IV)-oxo complex with uncoordinated pyridine arm, and intermediate-spin Ru(IV)-oxo complex with uncoordinated pyridine-N-oxide arm. A Ru(II) complex bearing an oxygen-bound pyridine-N-oxide as a ligand and bpm as a diimine ligand was also obtained, and its crystal structure was determined by X-ray crystallography. Femtosecond laser flash photolysis of the isolated O-coordinated Ru(II)-pyridine-N-oxide complex has been investigated to reveal the photodynamics. The Ru(IV)-oxo complex with an uncoordinated pyridine moiety was alternatively prepared by reaction of the corresponding acetonitrile complex with 2,6-dichloropyridine-N-oxide (Cl(2)py-O) to identify the Ru(IV)-oxo species. The formation of Ru(IV)-oxo complexes was concluded to proceed via intermolecular oxygen atom transfer from the uncoordinated pyridine-N-oxide to a Ru(II) center on the basis of the results of the reaction with Cl(2)py-O and the concentration dependence of the consumption of the starting Ru(II) complexes having the uncoordinated pyridine-N-oxide moiety. Oxygenation reactions of organic substrates by [Ru(II)(η(3)-TPA-O)(diimine)(CH(3)CN)](2+) were examined under irradiation (at 420 ± 5 nm) and showed selective allylic oxygenation of cyclohexene to give cyclohexen-1-ol and cyclohexen-1-one and cumene oxygenation to afford cumyl alcohol

  1. Phosphine-Free Palladium-Catalyzed Direct C-3 Arylation of 2-Phenylimidazo[1,2-a]pyridine Using Silver(I Carboxylate

    Directory of Open Access Journals (Sweden)

    Sridevi Kona

    2013-01-01

    Full Text Available Phosphine-free palladium-catalyzed direct arylation of 2-phenyl-imidazo[1,2-a]pyridine has been developed with the concept of using silver(I carboxylate. This protocol efficiently catalyzes the C-H arylation of 2-phenyl-imidazo[1,2-a]pyridine with aryl iodides to afford the corresponding 2-phenyl-3-aryl-imidazo[1,2-a]pyridines in moderate to-good yields.

  2. The effect of an anti-hydrogen bond on Fermi resonance:A Raman spectroscopic study of the Fermi doublet v1-v12 of liquid pyridine

    Institute of Scientific and Technical Information of China (English)

    Li Dong-Fei; Gao Shu-Qin; Sun Cheng-Lin; Li Zuo-Wei

    2012-01-01

    The effects of an anti-hydrogen bond on the v1-v12 Fermi resonance (FR) of pyridine are experimentally investigated by using Raman scattering spectroscopy.Three systems,pyridine/water,pyridine/formamide,and pyridine/carbon tetrachloride,provide varying degrees of strength for the diluent-pyridine anti-hydrogen bond complex.Water forms a stronger anti-hydrogen bond with pyridine than with formamide,and in the case of adding non-polar solvent carbon tetrachloride,which is neither a hydrogen bond donor nor an acceptor and incapable of forming a hydrogen bond with pyridine,the intermolecular distance of pyridine will increase and the interaction of pyridine molecules will reduce.The dilution studies are performed on the three systems.Comparing with the values of the Fermi coupling coefficient W of the ring breathing mode v1 and triangle mode v12 of pyridine at different volume concentrations,which are calculated according to the Bertran equations,in three systems,we find that the solution with the strongest anti-hydrogen bond,water,shows the fastest change in thev1-v12 Fermi coupling coefficient W with the volume concentration varying,followed by the formamide and carbon tetrachloride solutions.These results suggest that the stronger anti-hydrogen bond-forming effect will cause a greater reduction in the strength of the v1-v12 FR of pyridine.According to the mechanism of the formation of an anti-hydrogen bond in the complexes and the FR theory,a qualitative explanation for the anti-hydrogen bond effect in reducing the strength of the v1 - v12 FR of pyridine is given.

  3. X-ray Structures of Precursors of Styrylpyridine-Derivatives Used to Obtain 4-((E)-2-(Pyridin-2-yl)vinyl)benzamido-TEMPO: Synthesis and Characterization

    OpenAIRE

    Guillermo Soriano-Moro; María Judith Percino; Ana Laura Sánchez; Víctor Manuel Chapela; Margarita Cerón; María Eugenia Castro

    2015-01-01

    The synthesis and characterization of the precursor isomers trans-4-(2-(pyridin-2-yl)vinylbenzaldehyde (I), trans-4-(2-(pyridin-4-yl)vinylbenzaldehyde (II), trans-4-(2-(pyridin-2-yl)vinylbenzoic acid (III) and (E)-4-(2-(pydridin-4-yl)vinylbenzoic acid (IV) are reported. These compounds were prepared in order to obtain trans-4-((E)-2-(pyridin-2-yl)vinyl)benzamide-TEMPO (V). Compounds I and II were obtained by using a Knoevenagel reaction in the absence of a condensing agent and solvent. Oxidat...

  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. Synthesis of Diethyl Pyridin-2-ylphosphonates and Quinolin-2-ylphosphonates by Deoxygenative Phosphorylation of the Corresponding N-Oxides

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sangjin; Kim, Hyunsoo; Yang, Haewon; Yoo, Byungwoo; Yoon, Cheol Min [Korea Univ., Seoul (Korea, Republic of)

    2014-07-15

    The reaction of pyridine N-oxide and quinoline N-oxide activated by ethyl chloroformate with triethyl phosphites at rt gave the corresponding diethyl pyridin-2-ylphosphonate and diethyl quinolin-2-ylphosphonate regio-selectively in good to excellent yield through oxygenative phosphorylation. The reaction condition is mild and efficient compared to the reported methods. All chemicals including commercially available pyridine N-oxides were purchased from specialized suppliers with analytical purity and used without further purification. Non commercially available pyridine N-oxide for the reaction were prepared by known method. IR spectra of products were recorded on a Perkin-Elmer FT-IR 240-c spectrometer using KBr disks. {sup 1}H NMR (300 MHz) and {sup 13}C NMR (75 MHz) spectra were recorded on a Bruker 300 spectrometer in CDCl{sub 3}. High-resolution ESI-MS spectra were obtained on an IT-TOF (Shimadzu, Japan) at Korea Basic Science Institute (KBSI). Column chromatography was performed using Merck silica gel (230-400 mesh). Some known products have physical, spectroscopic, and analytic data identical to those (shown as a CAS registry number) given in the literature. Dialkyl pyridin-2-ylphosphonates widely used as corrosion inhibitors, dispersing and emulsifying agents, antistatics and lubricant additives in various technological fields are known as potent insecticides, fungicides and herbicides. Pyridin-2-ylphosphonates have also been reported to have a promising cytokinin activity, anti-proliferating and antiplatelet activating factor (anti-PAF) activities, and to be used as a chelate ligand to prepare various metal-organic frameworks, such as polymeric material with Zn, Cd and Ag showing luminescence properties, iron complex as a catalyst and copper complex with weak ferromagnetism. Because biological properties of dialkyl pyridin-2-ylphosphonates and physical properties of their complexes depend both on the phosphorus-containing ligand, simple and efficient

  6. Crystal structure of [2,6-di­fluoro-3-(pyridin-2-yl-κN)pyridin-4-yl-κC 4](pentane-2,4-dionato-κ2 O,O′)platinum(II)

    Science.gov (United States)

    Park, Ki-Min; Lee, Jieun; Kang, Youngjin

    2015-01-01

    The asymmetric unit of the title compound, [Pt(C10H5F2N2)(C5H7O2)], comprises one PtII atom, one 2,6-di­fluoro-2,3-bi­pyridine ligand and one acetyl­acetonate anion. The PtII atom adopts a distorted square-planar coordination geometry, being C,N-chelated by the 2,6-di­fluoro-3-(pyridin-2-yl)pyridin-4-yl ligand and O,O′-chelated by the pentane-2,4-dionate ligand. The two pyridine rings of the bi­pyridine ligand are approximately coplanar, making a dihedral angle of 1.2 (2)°. A variety of intra- and inter­molecular C—H⋯O and C—H⋯F hydrogen bonds, as well as π–π inter­actions [centroid–centroid distances = 4.337 (3) and 3.774 (3) Å] contribute to the stabilization of the mol­ecular and crystal structures, and result in the formation of a three-dimensional supra­molecular framework. PMID:26029388

  7. Crystal structure of [2,6-di-fluoro-3-(pyridin-2-yl-κN)pyridin-4-yl-κC (4)](pentane-2,4-dionato-κ(2) O,O')platinum(II).

    Science.gov (United States)

    Park, Ki-Min; Lee, Jieun; Kang, Youngjin

    2015-04-01

    The asymmetric unit of the title compound, [Pt(C10H5F2N2)(C5H7O2)], comprises one Pt(II) atom, one 2,6-di-fluoro-2,3-bi-pyridine ligand and one acetyl-acetonate anion. The Pt(II) atom adopts a distorted square-planar coordination geometry, being C,N-chelated by the 2,6-di-fluoro-3-(pyridin-2-yl)pyridin-4-yl ligand and O,O'-chelated by the pentane-2,4-dionate ligand. The two pyridine rings of the bi-pyridine ligand are approximately coplanar, making a dihedral angle of 1.2 (2)°. A variety of intra- and inter-molecular C-H⋯O and C-H⋯F hydrogen bonds, as well as π-π inter-actions [centroid-centroid distances = 4.337 (3) and 3.774 (3) Å] contribute to the stabilization of the mol-ecular and crystal structures, and result in the formation of a three-dimensional supra-molecular framework.

  8. Two isostructural carbamates: the o-tolyl N-(pyridin-3-yl)carbamate and 2-bromo-phenyl N-(pyridin-3-yl)carbamate monohydrates.

    Science.gov (United States)

    Mocilac, Pavle; Gallagher, John F

    2015-11-01

    The title carbamate monohydrates, C13H12N2O2·H2O and C12H9BrN2O2·H2O, form isomorphous crystals that are isostructural in their primary hydrogen-bonding modes. In both carbamates, the primary hydrogen bonding and aggregation involves cyclic amide-water-pyridine moieties as (N-H⋯O-H⋯N)2 dimers about inversion centres [as R 4 (4)(14) rings], where the participation of strong hydrogen-bonding donors and acceptors is maximized. The remaining water-carbonyl O-H⋯O=C inter-action extends the aggregation into two-dimensional planar sheets that stack parallel to the (100) plane. The Br derivative does not participate in halogen bonding. A weak intra-molecular C-H⋯O hydrogen bond is observed in each compound.

  9. Synthesis of Eu(Ⅲ) and Tb(Ⅲ) complexes with novel pyridine dicarboxylic acid derivatives and their fluorescence properties

    Institute of Scientific and Technical Information of China (English)

    Tang Ruiren; Yan Zi'er; Guo Cancheng; Luo Yiming

    2006-01-01

    Starting from pyridine-2,6-dicarboxylic acid (DPA),a series of novel pyridine-2,6-dicarboxylic acid derivatives were synthesized.In these compounds,4-(hydroxymethyl)pyridine-2,6-dicarboxylate (4-HMDPA) and 4-[(bis-carboxymethyl-amino)-methyl] -pyridine-2,6-dicarboxylic acid (4-BMDPA) were used as multifunctional ligands to coordinate with Tb(Ⅲ) and Eu(Ⅲ) and the complexes were prepared.The fluorescence properties of the solid complexes and their solutions were investigated in detail.The results indicated that the weak election-withdrawing group 4-hydroxymethyl in 4-position of pyridine in 4-HMDPA could weaken the fluorescence intensity of the lanthanide complexes.The contradistinctive experimental results showed that the fluorescence intensities of these complexes are related to pH values of the aqueous solutions and the dipole moments of solvent molecules:in the neutral aqueous solutions,the fluorescence intensities of these complexes were strongest,while the dipole moments were lower when the fluorescence intensifies were stronger.4-BMDPA is the better sensitizer and may be used as time-resolved fluoroimmunoassay.

  10. Association of symmetrical alkane diols with pyridine: DFT/GIAO calculation of (1) H NMR chemical shifts.

    Science.gov (United States)

    Lomas, John S; Joubert, Laurent; Maurel, François

    2016-05-31

    Proton nuclear magnetic resonance (NMR) shifts of the free diol and of its 1 : 1 and 1 : 2 hydrogen-bonded complexes with pyridine have been computed for five symmetrical alkane diols on the basis of density functional theory, by applying the gauge-including atomic orbital method to geometry-optimized conformers. For certain conformers, intramolecular OH···OH interactions, evidenced by high NMR OH proton shifts, are further enhanced on going from the free diol to the corresponding 1 : 1 diol/pyridine complex. This is confirmed by atoms-in-molecules and non-covalent interaction plots. The computed OH and CH proton shifts for the diol and the two complexes correlate well with values obtained by analysing data from the NMR titration of the diols in benzene against pyridine. Shift values for the diols in neat pyridine are calculated by weighting the shifts of the various protons in the three forms (free diol, 1 : 1 and 1 : 2 diol/pyridine complexes) according to the experimentally determined association constants. The results are in good agreement with those observed, and after empirical scaling, the root mean square difference is 0.18 ppm. Copyright © 2016 John Wiley & Sons, Ltd. Copyright © 2016 John Wiley & Sons, Ltd.

  11. Catalytic Hydrogenation Activity and Electronic Structure Determination of Bis(arylimidazol-2-ylidene)pyridine Cobalt Alkyl and Hydride Complexes

    Science.gov (United States)

    Yu, Renyuan Pony; Darmon, Jonathan M.; Milsmann, Carsten; Margulieux, Grant W.; E. Stieber, S. Chantal; DeBeer, Serena

    2013-01-01

    The bis(arylimidazol-2-ylidene)pyridine cobalt methyl complex, (iPrCNC)CoCH3, was evaluated for the catalytic hydrogenation of alkenes. At 22 °C and 4 atm of H2 pressure, (iPrCNC)CoCH3 is an effective pre-catalyst for the hydrogenation of sterically hindered, unactivated alkenes such as trans-methylstilbene, 1-methyl-1-cyclohexene and 2,3-dimethyl-2-butene, representing one of the most active cobalt hydrogenation catalysts reported to date. Preparation of the cobalt hydride complex, (iPrCNC)CoH was accomplished by hydrogenation of (iPrCNC)CoCH3. Over the course of 3 hours at 22 °C, migration of the metal-hydride to the 4-position of the pyridine ring yielded (4-H2-iPrCNC)CoN2. Similar alkyl migration was observed upon treatment of (iPrCNC)CoH with 1,1-diphenylethylene. This reactivity raised the question as to whether this class of chelate is redoxactive, engaging in radical chemistry with the cobalt center. A combination of structural, spectroscopic and computational studies was conducted and provided definitive evidence for bis(arylimidazol-2-ylidene)pyridine radicals in reduced cobalt chemistry. Spin density calculations established that the radicals were localized on the pyridine ring, accounting for the observed reactivity and suggest a wide family of pyridine-based pincers may also be redox active. PMID:23968297

  12. Bis(pyridine-κN{N2,N2′-[1,1′-(pyridine-2,6-diyldiethylidyne]benzenesulfonohydrazonato-κ5O,N,N′,N′′,O′}nickel(II

    Directory of Open Access Journals (Sweden)

    Juahir Yusnita

    2010-02-01

    Full Text Available In the crystal structure of the title compound, [Ni(C21H19N5O4S2(C5H5N2], the metal center is seven-coordinate, with an approximate pentagonal-bipyramidal configuration. The Ni atom is chelated by a dianionic pentadentate Schiff base via the pyridine N atom, the two azomethine N atoms and the two sulfonyl O atoms. The latter coordinate to Ni at different distances, viz. 2.3337 (12 and 2.7988 (12 Å. Two apically coordinated pyridine molecules complete the seven-coordinate geometry. The dihedral angle between the two pyridine ring planes is 68.25 (6°.

  13. 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.

  14. Synthesis and Crystal Structure of [Copper(1,10-phenanthroline)2(pyridine)]perchlorates

    Institute of Scientific and Technical Information of China (English)

    牛德仲; 路再生; 马恒俊; 孙柏旺

    2001-01-01

    The complex [Cu(phen)2py](ClO4)2 was obtained by the reaction of 1,10-phenanthroline with Cu(C1O4)2·6H2O in water and by recrystallization from pyridine. A single-crystal X-ray study shows that the complex is a square pyramidal arrangement of five nitrogen atoms from the two 1,10-phenanthroline ligands and one pyridine ligand, respectively.The compound is orthorhombic, C29H21N5C12O8Cu, Mr = 701.958, with space group Pbcn,α = 29.9593(3), b = 16.1240(3), c = 11.9183(6)A, V= 5757.3(3)A3, Z = 8, Dc= 1.409g/cm3,μ =1.121 mm-1, F(000) = 2465, R = 0.0539, Rw = 0.1380 for 4293 reflections with I>2 σ(I). The bond lengths of Cu(1)-N(1), Cu(1)-N(2), Cu(1)-N(3) and Cu(1)-N(4) are 2.223(3),2.017(3), 2.013(3) and 2.038(3) A, respectively. The distance from copper to pyridine N(5) is 2.012(3) A. The angles N(2)-Cu(1)-N(3) and N(4)-Cu(1)-N(5) are 176.1(1)°and 160.9(1)°,respectively. The angles between axial position nitrogen atom N(1) and four square position nitrogen atoms N(2), N(3), N(4), N(5) are 79.3(1), 98.3(1), (1),108.4(1)°,respectively.

  15. Lignocellulosic-derived modified agricultural waste: development, characterisation and implementation in sequestering pyridine from aqueous solutions.

    Science.gov (United States)

    Ahmed, Md Juned K; Ahmaruzzaman, M; Reza, Ruhul A

    2014-08-15

    The development and characterisation of modified agricultural waste (MAW) by H3PO4 activation is addressed in this study for sequestering pyridine from aqueous solutions. The adsorbent is characterised by carbon, hydrogen and nitrogen content of 55.53%, 3.28% and 0.98% respectively. The adsorbent also shows acidic (carboxylic, lactonic, phenolic groups) and basic carbon surface functionalities, functional groups viz. hydroxyl, carboxylic acid and bounded water molecules, BET surface area of 1254.67 m(2) g(-1), heterogeneous surface morphology and graphite like XRD patterns. Adsorption of pyridine is executed to evaluate the adsorptive uptake in batch (q(e)=107.18 mg g(-1)) as well as in column system (q(e)=140.94 mg g(-1)). The adsorption process followed the pseudo-second-order kinetics with the Langmuir isotherm best representing the equilibrium adsorption data. The thermodynamic parameters (ΔH(o)=9.39 kJ mol(-1), ΔG(o)=-5.99 kJ mol(-1), ΔS(o)=50.76 J K(-1) mol(-1)) confirm the endothermic and spontaneous nature of the adsorption process with increase in randomness at solid/solution interface. The adsorption mechanism is governed by electrostatic and π-π dispersive interactions as well as by a two stage diffusion phenomena. Thermally regenerated spent MAW exhibited better adsorption efficiency for five adsorption-desorption cycles than chemically regenerated. The low-cost of MAW (USD 10.714 per kg) and favourable adsorption parameters justifies its use in the adsorptive removal of pyridine.

  16. 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.

  17. 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.

  18. 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.

  19. Tetra-μ-acetato-bis[(pyridine N-oxidecopper(II](Cu—Cu

    Directory of Open Access Journals (Sweden)

    Ya-Bo Xie

    2009-08-01

    Full Text Available The molecule of the title binuclear copper(II complex, [Cu2(CH3COO4(C5H5NO2], occupies a special position on a crystallographic inversion centre; the coordination environment of the CuII atom is slightly distorted square-pyramidal and is made up of four O atoms belonging to four acetate groups in the basal plane with the O atom of pyridine N-oxide ligand in the apical position. The Cu—Cu distance is 2.6376 (6 Å.

  20. Synthesis, antibacterial, and antiviral evaluation of new heterocycles containing the pyridine moiety.

    Science.gov (United States)

    Salem, Marwa S; Sakr, Sameh I; El-Senousy, Waled M; Madkour, Hassan M F

    2013-10-01

    A facile one-pot four-component reaction was utilized to construct 2-oxo-1,2-dihydropyridine-3-carbonitrile as a scaffold for the synthesis of many fused heterocyclic systems, namely, furopyridine, pyridothiadiazepinthione, and pyridotriazine, as well as non-fused heterocyclic systems such as phthalazin-2(1H)-ylnicotinonitrile, pyridin-2-yl-1H-pyrazole, and pyrazol-1-ylnicotino-nitrile,1-(3-cyanopyridin-2-yl)-1H-pyrazole. The new compounds were evaluated as antimicrobial and antiviral agents.

  1. 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.

  2. 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.

  3. 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.

  4. catena-Poly[[bis(pyridine-3-carboxylic acid-κNmercury(II]-di-μ-chlorido

    Directory of Open Access Journals (Sweden)

    Sadif A. Shirvan

    2012-04-01

    Full Text Available In the title compound, [HgCl2(C6H5NO22]n, the HgII cation is located on an inversion center and is six-coordinated in a distorted octahedral geometry by two N atoms from two pyridine-3-carboxylic acid molecules and four bridging Cl− anions. The bridging function of the Cl− anions leads to polymeric chains running along the a axis. One Hg—Cl bond is much longer than the other. In the crystal, O—H...O and weak C—H...Cl hydrogen bonds are observed.

  5. 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.

  6. Bis[μ-3,5-bis(pyridin-2-ylpyrazolato]bis[(hexafluorophosphatocopper(II

    Directory of Open Access Journals (Sweden)

    Satoshi Kawata

    2013-08-01

    Full Text Available The title dinuclear complex molecule, [Cu2(C13H9N42(PF62], lies about an inversion center. The CuII atom shows a square-pyramidal coordination geometry with the basal plane formed by four N atoms of the two bis-chelating 3,5-bis(pyridin-2-ylpyrazolate ions and with one F atom of the hexafluorophosphate ion in the apical position. Molecules are stacked in a column along the a axis through C—H...F hydrogen bonds. The columns are further linked by other C—H...F hydrogen bonds, forming a three-dimensional network.

  7. A pyridine-functionalized pyrazolinofullerene used as a buffer layer in polymer solar cells.

    Science.gov (United States)

    Yang, Pingao; Chen, Shan; Liu, Yu; Xiao, Zuo; Ding, Liming

    2013-10-28

    A pyridine-functionalized pyrazolinofullerene (1) was synthesized in 42% yield via an improved one-pot reaction of C60, 3,6-di(2-pyridyl)-1,2,4,5-tetrazine, and water. The structure of 1 was unambiguously determined by X-ray diffraction of its single crystal. Due to the coordination capability of the functional groups on fullerene, compound 1 was used as a buffer layer to modify ZnO in inverted polymer solar cells. The power conversion efficiency was improved from 3.65% to 4.18% for inverted P3HT:PC61BM solar cells.

  8. Bis(N-benzyl-N-methyldithiocarbamato-κ2S,S′(pyridine-κNcadmium(II

    Directory of Open Access Journals (Sweden)

    Muhammad Ali Ehsan

    2016-01-01

    Full Text Available The title compound, [Cd(C9H10NS22(C5H5N], features a five-coordinate CdII atom, being coordinated by two nearly symmetrically chelating dithiocarbamate ligands and a pyridine N atom. The resulting NS4 donor set defines a distorted coordination geometry tending toward square pyramidal. In the molecular packing, centrosymmetric ten-membered {...HCNCS}2 synthons arise as a result of methylene-C—H...S interactions. These are connected into layers parallel to (10-2 via weak methyl-C—H...π(phenyl interactions.

  9. (E-N′-[3-(4-Chlorobenzoyloxybenzylidene]pyridine-4-carbohydrazide acetic acid monosolvate monohydrate

    Directory of Open Access Journals (Sweden)

    Zhi Fan

    2012-05-01

    Full Text Available In the Schiff base molecule of the title compound, C20H14ClN3O3·CH3COOH·H2O, the central benzene ring makes dihedral angles of 36.26 (7 and 27.59 (8°, respectively, with the terminal chlorophenyl and pyridine rings. In the crystal, the three components are linked by O—H...O, N—H...O, O—H...N and C—H...O hydrogen bonds into a double-tape structure along the a axis.

  10. Synthesis, Characterization, and Antimicrobial Activity Studies of Ni(II Complex with Pyridine as a Ligand

    Directory of Open Access Journals (Sweden)

    Faridul Islam

    2015-01-01

    Full Text Available We represent a metal complex which has been synthesized by the simple reaction with Ni(II chloride and pyridine (as a lignd affording a complex having the molecular formula [NiC5H5N2Cl2], characterized on the basis of elemental analyses, electronic, infrared, 1H NMR, 13C NMR spectra, magnetic susceptibility, and also aid of molar conductivity measurement. Conductivity measurement reveals nonelectrolytic nature of the complex. IR and 13C NMR spectra reveal the presence of cis- and trans-structure. On the basis of above analyses the square planar cis- and trans-structures are proposed for the prepared complex.

  11. 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.

  12. Colorimetric and electrochemical Pb2+ detection by imine-bridged tetrathiafulvalene-pyridine derivatives

    Institute of Scientific and Technical Information of China (English)

    TUNG; ChenHo

    2009-01-01

    Imine-bridged TTF-π-pyridine derivatives, 2NTTF, 3NTTF and 4NTTF, were synthesized and the cation-binding study was performed. It is noted that with the addition of the micromolar concentration of Pb2+ to the solution, these compounds display remarkable changes in solution color, 1H NMR spectra and electrochemical properties. The nitrogen atom of the imine-bridge in 2NTTF not only serves as a π-conjugated spacer but also participates in the sensing and coordinating properties.

  13. PROPERTIES OF DILUTE SOLUTIONS OF HYDROPHOBICALLY MODIFIED POLY(4-VINYL PYRIDINE) (POLYSOAPS)

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Hydrophobically modified poly(4-vinyl pyridines) by alkyl bromides are kinds of polysoap similar to the surfactant. Properties of dilute solutions were studied through the viscosity measurements in pure water and NaCl solutions. In aqueous solutions of polysoaps hydrophobic interaction can be attributed to aggregation of hydrophobic groups of the polysoap main chains. The hydrophobic groups of polysoap can aggregate to form hydrophobic microdomains (micelles) in aqueous solution. This is a compact conformation. The formation of such microdomains is a process of dynamic equilibrium.

  14. Structure, luminescence and antimicrobial properties of mononuclear silver(I) complexes of pyridine 2-carboxamide

    Indian Academy of Sciences (India)

    Sutapa Joardar; Shounak Roy; Suvendu Samanta; Amit Kumar Dutta

    2015-10-01

    Two Ag(I) complexes, [Ag(HL)2]ClO4 (1) and [Ag(HL)2]NO3·H2O (2), where HL is pyridine 2– carboxamide, have been synthesized and characterized by various spectroscopic techniques. The X-ray crystal structural analyses indicate that both the complexes consist of slightly distorted square planar silver(I) ions and ligand-supported weak Ag⋯Ag metallophilic interactions. Both the complexes show photoluminescence in solid state and acetonitrile solution at room temperature. Antimicrobial studies have been performed with these silver(I) complexes against various gram +ve, gram −ve bacterial and fungal species.

  15. (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.

  16. Pyridine hydroxamic acids are specific anti-HCV agents affecting HDAC6.

    Science.gov (United States)

    Kozlov, Maxim V; Kleymenova, Alla A; Romanova, Lyudmila I; Konduktorov, Konstantin A; Kamarova, Kamila A; Smirnova, Olga A; Prassolov, Vladimir S; Kochetkov, Sergey N

    2015-06-01

    Recently we reported benzohydroxamic acids (BHAs) as potent and selective inhibitors of hepatitis C virus (HCV) replicon propagation. In this work 12 pyridine hydroxamic acids (PHAs) were synthesized and tested in full-genome replicon assay. It was found that PHAs possessed very similar anti-HCV properties compared to BHAs. Both classes of hydroxamic acids caused hyperacetylation of α-tubulin pointing to inhibition of histone deacetylase 6 (HDAC6) as part of their antiviral activity. The tested compounds did not inhibit the growth of poliovirus, displaying high selectivity against HCV.

  17. Bis[μ-N-(pyridin-2-ylmethylpyridin-2-amine-κ2N:N′]disilver(I bis(trifluoromethanesulfonate

    Directory of Open Access Journals (Sweden)

    Suk-Hee Moon

    2011-12-01

    Full Text Available In the binuclear title compound, [Ag2(C11H11N32](CF3O3S2, the complex cation is centrosymmetric, with the unique Ag+ cation coordinated by two pyridine N atoms from two symmetry-related N-(pyridin-2-ylmethylpyridin-2-amine ligands in a geometry slightly distorted from linear [N—Ag—N 161.02 (7°]. This set-up leads to the formation of a 14-membered cyclic dimer. The two pyridine rings coordinated to the Ag+ cation are tilted by 80.19 (7° with respect to each other. Intermolecular N—H...O hydrogen-bonding interactions between the cyclic dimer and the anion exist. A two-dimensional network parallel to the ac plane is constructed by three weak Ag...(O,N interactions as well as an F...F contact of 2.890 (4 Å.

  18. 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.)

  19. Synthesis of Some New Pyridine-2,6-carboxamide-derived Schiff Bases as Potential Antimicrobial Agents

    Directory of Open Access Journals (Sweden)

    Abd El-Galil E. Amr

    2010-07-01

    Full Text Available A series of pyridine-bridged 2,6-bis-carboxamide Schiff's bases has been prepared starting from 2,6-pyridinedicarbonyl dichloride (1 and L-alanine or 2-methyl-alanine methyl ester.The coupling of acid chloride 1 with L-alanine methyl ester hydrochloride -or 2-methylalanine methyl ester hydrochloride gave the corresponding 2,6-bis-carboxamide pyridine methyl esters 2a,b.Hydrazonolysis of 2 with hydrazine hydrate afforded the corresponding bis-hydrazides 3a,b. Treatment of 3a,b with appropriate aromatic or heterocyclic aldehydes afforded the corresponding pyridine- bridged 2,6-bis-carboxamide Schiff's bases 4a-f and 5a-f, respectively. The newly synthesized compounds 2-5 were screened for their bactericidal and fungicidal activities. Many of the obtained compounds exhibited significant antimicrobial activity, comparable to streptomycin and fusidic acid, which were used as reference antibiotic drugs.

  20. Bis[μ-N,N'-bis(quinolin-8-yl)pyridine-2,6-dicarboxamido]dizinc(II) dichloromethane disolvate.

    Science.gov (United States)

    Xu, Hui-Hua; Tao, Xian; Li, Yue-Qin; Shen, Ying-Zhong; Wei, Yan-Hong

    2011-04-01

    The title compound, [Zn(2)(C(25)H(15)N(5)O(2))(2)]·2CH(2)Cl(2), is a dinuclear double-helical complex which lies on a crystallographic twofold axis. In the complex, both ligands are partitioned into two tridentate domains which allow each ligand to bridge both metal centres. Each Zn(II) atom is six-coordinated in a distorted octahedral environment formed by two amide N atoms, two quinoline N atoms and two pyridine N atoms from two different ligand molecules, with the central pyridine ring, unusually, bridging two Zn(II) atoms. The deprotonated ligand is not planar, the amide side chains being considerably twisted out from the plane of the central pyridine ring.

  1. 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.

  2. One-pot synthesis of 2-phenylimidazo[1,2-α]pyridines from acetophenone, [Bmim]Br(3) and 2-aminopyridine under solvent-free conditions.

    Science.gov (United States)

    Le, Zhang-Gao; Xie, Zong-Bo; Xu, Jian-Ping

    2012-11-09

    One-pot synthesis of 2-phenylimidazo[1,2-α]pyridines from acetophenone, [Bmim]Br(3) and 2-aminopyridine under solvent-free conditions in the presence of Na(2)CO(3), gave the corresponding 2-phenylimidazo[1,2-α]pyridines in excellent yields ranging from 72% to 89%.

  3. Carbon-Oxygen Bond Cleavage by Bis(imino)pyridine Iron Compounds : Catalyst Deactivation Pathways and Observation of Acyl C-O Bond Cleavage in Esters

    NARCIS (Netherlands)

    Trovitch, Ryan J.; Lobkovsky, Emil; Bouwkamp, Marco W.; Chirik, Paul J.

    2008-01-01

    Investigations into the substrate scope of bis(imino)pyridine iron-catalyzed hydrogenation and [2 pi + 2 pi]. diene cyclization reactions identified C-O bond cleavage as a principal deactivation pathway. Addition of diallyl or allyl ethyl ether to the bis(imino)pyridine iron dinitrogen complex, ((iP

  4. How to minimize toxic exposure to pyridine during continuous infusion of ceftazidime in patients with cystic fibrosis?

    Science.gov (United States)

    Bourget, P; Amin, A; Dupont, C; Abely, M; Desmazes-Dufeu, N; Dubus, J C; Jouani, B-L; Merlette, C; Nové-Josserand, R; Pages, J; Panzo, R; Vidal, F; Voge, F; Hubert, D

    2014-05-01

    Ceftazidime is particularly efficient against Pseudomonas aeruginosa in cystic fibrosis patients. Thus, the spontaneous production of pyridine, which is a toxic product, raises some concern. Our aim was to examine the kinetics of degradation of ceftazidime in portable infusion pumps either at 4°C, 22°C, or 33°C and to propose some recommendations in order to reduce the pyridine exposure. Two administration models were studied in vitro. In model 1, we administered 12 g of ceftazidime infused over 23 h (once-daily infusion) compared to 6 g infused over 11.5 h in model 2 (twice-daily regimen). Samples were collected at 0 h and then every 4 and 2 h after the shaping of portable infusion pumps in models 1 and 2, respectively. Both ceftazidime and pyridine were analyzed using an ultraviolet high-performance liquid chromatograph. Production of pyridine is highly depending on the temperature. The in situ production of pyridine per day of treatment decreases at a ratio close to 1/6 and 1/3 between 33°C and 4°C in models 1 and 2, respectively. Regardless of the conditions, the production of pyridine is significantly lower in model 2, whereas the total delivery amount of ceftazidime is significantly higher at 4°C and 33°C compared to that in model 1. According to a the precautionary principle, these findings lead to three major recommendations: (i) exposing a solution of ceftazidime to over 22°C should be strictly avoided, (ii) a divided dose of 6 g over 11.5 h instead of a once-daily administration is preferred, and (iii) infusion should be administered immediately after reconstitution.

  5. Mechanism of the 6-hydroxy-3-succinoyl-pyridine 3-monooxygenase flavoprotein from Pseudomonas putida S16.

    Science.gov (United States)

    Yu, Hao; Hausinger, Robert P; Tang, Hong-Zhi; Xu, Ping

    2014-10-17

    6-Hydroxy-3-succinoyl-pyridine (HSP) 3-monooxygenase (HspB), a flavoprotein essential to the pyrrolidine pathway of nicotine degradation, catalyzes pyridine-ring β-hydroxylation, resulting in carbon-carbon cleavage and production of 2,5-dihydroxypyridine. Here, we generated His6-tagged HspB in Escherichia coli, characterized the properties of the recombinant enzyme, and investigated its mechanism of catalysis. In contrast to conclusions reported previously, the second product of the HspB reaction was shown to be succinate, with isotope labeling experiments providing direct evidence that the newly introduced oxygen atom of succinate is derived from H2O. Phylogenetic analysis reveals that HspB is the most closely related to two p-nitrophenol 4-monooxygenases, and the experimental results exhibit that p-nitrophenol is a substrate of HspB. The reduction of HspB (with maxima at 375 and 460 nm, and a shoulder at 485 nm) by NADH was followed by stopped-flow spectroscopy, and the rate constant for reduction was shown to be stimulated by HSP. Reduced HspB reacts with oxygen to form a C(4a)-(hydro)peroxyflavin intermediate with an absorbance maximum at ∼400 nm within the first few milliseconds before converting to the oxidized flavoenzyme species. The formed C(4a)-hydroperoxyflavin intermediate reacts with HSP to form an intermediate that hydrolyzes to the products 2,5-dihydroxypyridine and succinate. The investigation on the catalytic mechanism of a flavoprotein pyridine-ring β-position hydroxylase provides useful information for the biosynthesis of pyridine derivatives.

  6. Chemical Coupling SERS Properties of Pyridine on Silver-Caged Metal Clusters M@Ag12 (M = V-, Nb-, Ta-, Cr, Mo, W, Mn+, Tc+, Re+)

    Science.gov (United States)

    Chen, Lei; Wang, Zhigang; Li, Zhengqiang; Zhang, Rui-Qin

    2017-07-01

    Using density functional theory, this work presents a comprehensive analysis of nonresonant surface-enhanced Raman scattering enhancement of pyridine on M@Ag12 (M = V-, Nb-, Ta-, Cr, Mo, W, Mn+, Tc+, Re+). Computational results indicate that the chemical enhancement of pyridine on M@Ag12 is closely associated with the charge properties of silver-caged clusters. Pyridine on negative clusters exhibits the strongest chemical enhancement with a factor of about 103, while the chemical enhancement is only about 102 for pyridine on neutral clusters and 10 for pyridine on positive clusters. The polarizability analyses elucidate the nature of the chemical enhancement that delocalized electrons of negative adsorption systems occupy higher molecular orbitals than those of neutral and positive adsorption systems, which can lead to stronger nonresonant chemical enhancement.

  7. Synthesis and cytotoxicity of thieno[2,3-b]quinoline-2-carboxamide and cycloalkyl[b]thieno[3,2-e]pyridine-2-carboxamide derivatives.

    Science.gov (United States)

    Leung, Euphemia; Pilkington, Lisa I; van Rensburg, Michelle; Jeon, Chae Yeon; Song, Mirae; Arabshahi, Homayon J; De Zoysa, Gayan Heruka; Sarojini, Vijayalekshmi; Denny, William A; Reynisson, Jóhannes; Barker, David

    2016-03-01

    Seventy nine derivatives of thieno[2,3-b]quinolines, tetrahydrothieno[2,3-b]quinoline, dihydrocyclopenta[b]thieno[3,2-e]pyridine, cyclohepta[b]thieno[3,2-e]pyridine and hexahydrocycloocta[b]thieno[3,2-e]pyridine were either synthesized or obtained commercially and tested for their antiproliferative activity against HCT116, MDA-MB-468 and MDA-MB-231 human cancer cell lines. The most potent eight compounds were active against all cell lines with IC50 values in the 80-250nM range. In general hexahydrocycloocta[b]thieno[3,2-e]pyridines were most active with increasing activity observed as larger cycloalkyl rings were fused to the pyridine ring.

  8. Chemical Coupling SERS Properties of Pyridine on Silver-Caged Metal Clusters M@Ag12 (M = V-, Nb-, Ta-, Cr, Mo, W, Mn+, Tc+, Re+)

    Science.gov (United States)

    Chen, Lei; Wang, Zhigang; Li, Zhengqiang; Zhang, Rui-Qin

    2016-10-01

    Using density functional theory, this work presents a comprehensive analysis of nonresonant surface-enhanced Raman scattering enhancement of pyridine on M@Ag12 (M = V-, Nb-, Ta-, Cr, Mo, W, Mn+, Tc+, Re+). Computational results indicate that the chemical enhancement of pyridine on M@Ag12 is closely associated with the charge properties of silver-caged clusters. Pyridine on negative clusters exhibits the strongest chemical enhancement with a factor of about 103, while the chemical enhancement is only about 102 for pyridine on neutral clusters and 10 for pyridine on positive clusters. The polarizability analyses elucidate the nature of the chemical enhancement that delocalized electrons of negative adsorption systems occupy higher molecular orbitals than those of neutral and positive adsorption systems, which can lead to stronger nonresonant chemical enhancement.

  9. One-pot synthesis of tetracyclic fused imidazo[1,2-a]pyridines via a three-component reaction

    Science.gov (United States)

    Yang, Bo; Tao, Chuanye; Shao, Taofeng

    2016-01-01

    Summary A novel three-component reaction has been developed to assemble biologically and pharmaceutically important tetracyclic fused imidazo[1,2-a]pyridines in a one-pot fashion utilizing readily available 2-aminopyridines, isatins and isocyanides. The three-component coupling proceeds through the Groebke–Blackburn–Bienaymé reaction followed by a retro-aza-ene reaction and subsequent nucleophilic reaction of the in-situ generated imidazo[1,2-a]pyridines bearing an isocyanate functional group. PMID:27559401

  10. cis-Bis(4-methylpiperazine-1-carbodithioato-κ2S,S′bis(pyridine-κNcadmium

    Directory of Open Access Journals (Sweden)

    P. Valarmathi

    2012-01-01

    Full Text Available In the title complex, [Cd(C6H11N2S22(C5H5N2], the CdII ion is hexacoordinated by two N atoms from two pyridine ligands and by four S atoms from two dithiocarbamate ligands in a distorted octahedral geometry. The CdII ion lies on a twofold axis. The piperazine ring is in chair conformation and its least-squares plane makes a dihedral angle of 81.4 (1° with that of the pyridine ring.

  11. Identification of Intermediates in Pyridine Pyrolysis with Molecular-beam Mass Spectrometry and Tunable Synchrotron VUV Photoionization

    Institute of Scientific and Technical Information of China (English)

    Xin Hong; Taichang Zhang; Lidong Zhang; Fei Qi

    2009-01-01

    The pyrolysis of pyridine (5.26% pyridine in argon) was performed with tunable synchrotron vacuum ultraviolet photoionization and molecular-beam mass spectrometry technique at the temperature range of 1255-1765 K at 267 Pa. About 20 products and intermediates, containing major species H2, HCN, C2H2, C5H3N, C4H2, and C3H3N, were identified by near-threshold measurements of photoionization mass spectra and their mole fractions vs.temperatures were estimated. The major reaction pathways are analyzed based on the experimental observations.

  12. Proton-coupled electron transfer in [pyridine·(H2O)n]-, n = 3, 4, clusters

    Science.gov (United States)

    Archer, Kaye A.; Jordan, Kenneth D.

    2016-09-01

    The equation-of-motion method is used to map out one-dimensional potentials for proton-coupled electron transfer in the [pyridine·(H2O)n]-, n = 3, 4, clusters. In both cases there is an avoided crossing between valence-type pyridinyl·(OH-) (H2O)n-1 and dipole-bound pyridine·(H2O)n- anion species. For the n = 3 cluster, the mixing is sufficiently strong that both limiting structures are predicted to be sampled in the vibrational zero-point level.

  13. Dimethyl and diethyl esters of 5,6-bis-(pyridin-2-yl)pyrazine-2,3-di-carb-oxy-lic acid: a comparison.

    Science.gov (United States)

    Alfonso, Montserrat; Stoeckli-Evans, Helen

    2016-02-01

    In dimethyl 5,6-bis-(pyridin-2-yl)pyrazine-2,3-di-carboxyl-ate, C18H14N4O4, (I), and diethyl 5,6-bis-(pyridin-2-yl)pyrazine-2,3-di-carboxyl-ate, C20H18N4O4, (II), the dimethyl and diethyl esters of 5,6-bis-(pyridin-2-yl)pyrazine-2,3-di-carb-oxy-lic acid, the orientation of the two pyridine rings differ. In (I), pyridine ring B is inclined to pyrazine ring A by 44.8 (2)° and the pyridine and pyrazine N atoms are trans to one another, while pyridine ring C is inclined to the pyrazine ring by 50.3 (2)°, with the pyridine and pyrazine N atoms cis to one another. In compound (II), the diethyl ester, which possesses twofold rotation symmetry, the pyridine ring is inclined to the pyrazine ring by 40.7 (1)°, with the pyridine and pyrazine N atoms trans to one another. In the crystal of (I), mol-ecules are linked by C-H⋯N hydrogen bonds, forming chains along [001]. The chains are linked by C-H⋯π inter-actions, forming a three-dimensional structure. In the crystal of (II), mol-ecules are linked via C-H⋯O hydrogen bonds, forming a three-dimensional framework. There are C-H⋯π inter-actions present within the framework.

  14. Structure and Luminescence Property of a Hexanuclear Silver(I) Cluster Containing Pyridine-3-carboxaldehyde Thiosemicarbazone

    Institute of Scientific and Technical Information of China (English)

    SUN Qiao-Zhen; CHAI Li-Yuan

    2012-01-01

    A new hexanuclear silver(I) compound containing thiosemicarbazone with group of 3-pyridine was synthesized and structurally characterized by single-crystal X-ray diffraction,elemental analysis and fluorescence spectrum.The title compound 3 crystallizes in monoclinic,space group C2/m with a = 18.6523(9),b = 24.7519(11),c = 22.4542(15) ,β = 93.4960(10)°,V = 10347.4(10)3,C68H104Ag6N30O8S6,Mr = 2309.39,Dc = 1.482g/cm3,μ(MoKα) = 1.293 mm-1,F(000) = 4656,Z = 4,the final R = 0.0544 and wR = 0.1580 for 6733 observed reflections(I 〉 2σ(I)).In the structure,two Ag6L36(L3 = pyridine-3-carboxaldehyde thiosemicarbazone) clusters are contained.In each cluster,the S atom of ligand L3 served as a triply bridged chelator to connect the six silver atoms into a Ag6L36 cluster.Luminescence investigation revealed that the band at 630 nm was attributed to cluster-centered(CC) electron transfer,and those at 493 and 530 nm to the LMCT and CC transitions,respectively.

  15. 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.

  16. Gold-catalyzed Synthesis of Pyridine Containing Macrocycles, Related to Porphyrin

    Institute of Scientific and Technical Information of China (English)

    DYKER,Gerald; LIU,Jian-Hui; MERZ,Klaus

    2004-01-01

    @@ Porphyrins are very important substances used in a wide range of model systems in many areas, such as biomimic chemistry and material science. This kind of macrocycle generally consists of 5-membered ring to form a cyclic extended aromatic network. Recently much work have been done concerning the modification of porphyrins core structures, and many kinds of analogues have been recorded. One of the important aspects was the research of the porphyrinogen ligand.These macrocycles bear functional resemblance to certain kind of polydentate ligand, and provide a variety of tri-dimensional binding cavities for metal ions. In addition, some other kinds of analogues have been recorded, involving the introduction of a CH unit to replace one of the nitrogen atoms. We also notice the fact that pyridine is a very effective ligand, and it can coordinate with many kinds of metals. Based on these observations, we would like to design and synthesize a new porphyrinogen (5) analogue containing a NNNN core, two of the N atoms from pyrrole and the other two N from pyridine. Such core modifications may alter the electronic structure of the ring and provide variable cavity for metal coordination.

  17. 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.

  18. N,N′-Bis(pyridin-2-ylbenzene-1,4-diamine–quinoxaline (2/1

    Directory of Open Access Journals (Sweden)

    Barbara Wicher

    2011-12-01

    Full Text Available The asymmetric unit of the title compound, 2C16H14N4·C8H6N2, consits of one molecule of N,N′-bis(pyridin-2-ylbenzene-1,4-diamine (PDAB and one half-molecule of quinoxaline (QX that is located around an inversion centre and disordered over two overlapping positions. The PDAB molecule adopts a non-planar conformation with an E configuration at the two partially double exo C...;N bonds of the 2-pyridylamine units. In the crystal, these self-complementary units are N—H...N hydrogen bonded via a cyclic R22(8 motif, creating tapes of PDAB molecules extending along [010]. Inversion-related tapes are arranged into pairs through π–π stacking interactions between the benzene rings [centroid–centroid distance = 3.818 (1 Å] and the two symmetry-independent pyridine groups [centroid–centroid distance = 3.760 (1 Å]. The QX molecules are enclosed in a cavity formed between six PDAB tapes.

  19. CONDUCTING BLENDS OF POLY(2-VINYL PYRIDINE) AND POLYETHYLENE OXIDE WITH HIGH MOLECULAR WEIGHT

    Institute of Scientific and Technical Information of China (English)

    CUI Minhui; GUO Junshi; XIE Hongquan; CHENG Donghua

    1997-01-01

    Ionic, electronic and mixed (ionic-electronic) conductivities of blends of poly(2-vinyl pyridine) (P2VP) and poly(ethylene oxide) (PEO) with high molecular weight after doped with LiClO4, TCNQ or LiClO4 and TCNQ were investigated. Effects of LiClO4 and TCNQ concentrations on the conductivity of PEO/P2VP/LiClO4 or TCNQ blend were studied.The ionic conductivity of PEO/P2VP/LiClO4 blend increases with increasing PEO content.At a Li/ethylene oxide molar ratio of 0.10 and a TCNQ/2-vinyl pyridine molar ratio of 0.5,the mixed conductivity of PEO/P2VP/LiClO4/TCNQ is higher than the total of ionic conductivity of PEO/P2VP/LiClO4 and electronic conductivity of PEO/P2VP/TCNQ when the weight ratio of PEO and P2VP is 6/4 or 5/5. Scanning electron microscopy (SEM) on the broken cross-section of the PEO/P2VP/LiClO4 blend and differential scanning calorimetry (DSC) results show that LiClO4 could act as a compatibilizer in the blend.

  20. Role of Pyridinic-N for Nitrogen-doped graphene quantum dots in oxygen reaction reduction.

    Science.gov (United States)

    Sun, Lang; Luo, Yi; Li, Ming; Hu, Guanghui; Xu, Yongjie; Tang, Tao; Wen, Jianfeng; Li, Xinyu; Wang, Liang

    2017-12-15

    Nitrogen-doped graphene quantum dots (N-GQDs) exhibit exciting properties in the oxygen reduction reaction (ORR) for ample electrocatalytic edging and N-doped active sites. However, low yield and high dispersity of N-GQDs prohibit their direct application as the electrocatalyst. In this paper, two facile hydrothermal progress were developed to synthesize the high-yield N-GQDs with the diameter of ca. 2-6nm and the hybrid of N-GQDs/Reduced Graphene Oxide (N-GQDs/r-GO). The results demonstrated that the N-GQDs/r-GO display remarkable electrocatalytic activity. Moreover, it can be found that the pyridinic-N plays a major role in ORR. Both the average electron transfer number and the onset potential depend on the content of pyridinic-N. The proposed synthesis strategy is facile and low-cost, serving as a feasible method for the development of highly efficient electrocatalysts. Copyright © 2017 Elsevier Inc. All rights reserved.

  1. The co-occurrence of two pyridine alkaloids, mimosine and trigonelline, in Leucaena leucocephala.

    Science.gov (United States)

    Ogita, Shinjiro; Kato, Misako; Watanabe, Shin; Ashihara, Hiroshi

    2014-01-01

    Leucaena leucocephala is a nitrogen-fixing tropical leguminous tree that produces two pyridine alkaloids, i. e. mimosine [beta-(3-hydroxy-4-pyridon-1-yl)-L-alanine] and trigonelline (1-methylpyridinium-3-carboxylate). Mimosine has been detected in leaves, flowers, pods, seeds, and roots, and it is one of the principal non-protein amino acids that occurs in all organs. Asparagine was the most abundant amino acid in flowers. The mimosine content varied from 3.3 micromol/g fresh weight (FW) in developing flowers to 171 micromol/g FW in mature seeds. Trigonelline was also detected in leaves, flowers, pods, and seeds, but not roots. The trigonelline content was lower than that of mimosine in all organs. It varied from 0.12 micromol/g FW in developing seeds to 2.6 micromol/g FW in mature seeds. [2-14C]Nicotinic acid supplied to the developing seeds was incorporated into trigonelline but not mimosine. This indicates that the pyridine and dihydroxypyridine structures of these two alkaloids are derived from distinct precursors. The physiological functions of mimosine and trigonelline are discussed briefly.

  2. Organometallic mediated radical polymerization of vinyl acetate using bis(imino)pyridine vanadium trichloride complexes.

    Science.gov (United States)

    Perry, Mitchell R; Allan, Laura E N; Decken, Andreas; Shaver, Michael P

    2013-07-07

    The synthesis and characterization of one novel proligand and six novel vanadium(III) trichloride complexes is described. The controlled radical polymerization activity towards vinyl acetate of these, and eight other bis(imino)pyridine vanadium trichloride complexes previously reported, is investigated. Those complexes possessing variation at the N-aryl para-position with no steric protection offered by ortho-substituents (4 examples) result in poor control over poly(vinyl acetate) polymerization. Control is improved with increasing steric bulk at the ortho-position of the N-aryl substituent (4 examples) although attempts to increase steric bulk past isopropyl were unsuccessful. Synthesizing bis(imino)pyridine vanadium trichloride complexes with substituted imine backbones restores polymerization control when aliphatic substituents are used (4 examples) but ceases to make any drastic improvements on catalyst lifetime. Modification of the polymerization conditions is also investigated, in an attempt to improve the catalyst lifetime. Expansion of the monomer scope to include other vinyl esters, particularly those derived from renewable resources, shows promising results.

  3. Proton Migration in Clusters Consisting of Protonated Pyridine Solvated by Water Molecules.

    Science.gov (United States)

    Berthias, Francis; Feketeová, Linda; Chermette, Henry; Forquet, Valérian; Morell, Christophe; Abdoul-Carime, Hassan; Farizon, Bernadette; Farizon, Michel; Märk, Tilmann D

    2015-10-26

    Proton transfer (PT) from protonated pyridine to water molecules is observed after excitation of microhydrated protonated pyridine (Py) clusters PyH(+) (H2 O)n (n=0-5) is induced by a single collision with an Ar atom at high incident velocity (95×10(3)  m s(-1) ). Besides the fragmentation channel associated with the evaporation of water molecules, the charged-fragment mass spectrum shows competition between the production of the PyH(+) ion (or its corresponding charged fragments) and the production of H(+) (H2 O) or H(+) (H2 O)2 ions. The increase in the production of protonated water fragments as a function of the number of H2 O molecules in the parent cluster ion as well sd the observation of a stable H(+) (H2 O)2 fragment, even in the case of the dissociation of PyH(+) (H2 O)2 , are evidence of the crucial role of PT in the relaxation process, even for a small number of solvating water molecules.

  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. Synthesis, characterization, and antioxidant properties of novel inulin derivatives with amino-pyridine group.

    Science.gov (United States)

    Hu, Yunxia; Zhang, Jun; Yu, Chunwei; Li, Qing; Dong, Fang; Wang, Gang; Guo, Zhanyong

    2014-09-01

    A series of novel inulin derivatives were synthesized via reaction of chloracetyl inulin (CAIL) with amino-pyridines, including 2-(2-amino-pyridyl)acetyl inulin chloride (2APAIL), 2-(3-amino-pyridyl)acetyl inulin chloride (3APAIL), 2-(4-amino-pyridyl)acetyl inulin chloride (4APAIL), 2-(2,3-diamino-pyridyl)acetyl inulin chloride (2,3DAPAIL), and 2-(3,4-diamino-pyridyl)acetyl inulin (3,4DAPAIL). The antioxidant property of the products and 2-pyridylacetyl inulin chloride (PAIL) against hydroxyl radicals (·OH), superoxide radicals (O2·), and DPPH radicals (DPPH·) were evaluated in vitro, respectively. Results showed that 4APAIL and 3,4DAPAIL exhibited remarkable improvement on scavenging ·OH and DPPH·, which can scavenge the radical of OH completely at 0.4 mg/mL. Besides, the scavenging activity of 2,3DAPAIL to O2· was excellent among all of the tested samples, reaching 85% at 1.6 mg/mL. These data indicate that all of the inulin derivatives have better antioxidant activities than inulin, and the scavenging effect indices are affected by the number and position of the amino group on pyridine grafted to the inulin derivatives.

  6. Solution-state 2D NMR of ball-milled plant cell wall gels in DMSO-d6/pyridine-d5†

    Science.gov (United States)

    Ralph, John

    2014-01-01

    NMR fingerprinting of the components of finely divided plant cell walls swelled in DMSO has been recently described. Cell wall gels, produced directly in the NMR tube with perdeutero-dimethylsulfoxide, allowed the acquisition of well resolved/dispersed 2D 13C–1H correlated solution-state NMR spectra of the entire array of wall polymers, without the need for component fractionation. That is, without actual solubilization, and without apparent structural modification beyond that inflicted by the ball milling and ultrasonication steps, satisfactorily interpretable spectra can be acquired that reveal compositional and structural details regarding the polysaccharide and lignin components in the wall. Here, the profiling method has been improved by using a mixture of perdeuterated DMSO and pyridine (4:1, v/v). Adding pyridine provided not only easier sample handling because of the better mobility compared to the DMSO-d6-only system but also considerably elevated intensities and improved resolution of the NMR spectra due to the enhanced swelling of the cell walls. This modification therefore provides a more rapid method for comparative structural evaluation of plant cell walls than is currently available. We examined loblolly pine (Pinus taeda, a gymnosperm), aspen (Populus tremuloides, an angiosperm), kenaf (Hibiscus cannabinus, an herbaceous plant), and corn (Zea mays L., a grass, i.e., from the Poaceae family). In principle, lignin composition (notably, the syringyl : guaiacyl : p-hydroxyphenyl ratio) can be quantified without the need for lignin isolation. Correlations for p-coumarate units in the corn sample are readily seen, and a variety of the ferulate correlations are also well resolved; ferulates are important components responsible for cell wall cross-linking in grasses. Polysaccharide anomeric correlations were tentatively assigned for each plant sample based on standard samples and various literature data. With the new potential for chemometric analysis

  7. 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.

  8. Crystal structure of poly[[μ-4-(hy-droxy-meth-yl)pyridine-κ(2) N:O][4-(hy-droxy-meth-yl)pyridine-κN](μ-thio-cyanato-κ(2) N:S)(thio-cyanato-κN)cadmium].

    Science.gov (United States)

    Werner, Julia; Jess, Inke; Näther, Christian

    2015-06-01

    The crystal structure of the title compound, [Cd(NCS)2(C6H7NO)2] n is made up of Cd(2+) cations that are coordinated by three thio-cyanate ligands and three 4-(hy-droxy-meth-yl)pyridine ligands within distorted N4OS octa-hedra. The asymmetric unit consists of one Cd(2+) cation, two thio-cyanate anions and two 4-(hy-droxy-meth-yl)pyridine ligands in general positions. Two Cd(2+) cations are linked by two μ-1,3 N- and S-bonding thio-ycanate anions into dimers which are further linked into branched chains along [100] by two μ-1,6 N- and O-bonding 4-(hy-droxy-meth-yl)pyridine ligands. One additional N-bonded 4-(hy-droxy-meth-yl)pyridine ligand and one additional N-bonded thio-cyanate anion are only terminally bonded to the metal cation. Inter-chain O-H⋯S hydrogen bonds between the hy-droxy H atoms and one of the thio-cyanate S atoms connect the chains into a three-dimensional network.

  9. Crystal structure of bis-(2,2'-bi-pyridine-κ(2) N,N')bis-(thio-cyanato-κN)mang-anese(II) 2,2'-bi-pyridine monosolvate.

    Science.gov (United States)

    Suckert, Stefan; Jess, Inke; Näther, Christian

    2015-01-01

    In the crystal structure of the mononuclear title compound, [Mn(NCS)2(C10H8N2)2]·C10H8N2, the Mn(II) cation is coordin-ated in an all-cis configuration by two N-bound thio-cyanate anions and two 2,2'-bi-pyridine ligands within a slightly distorted octa-hedral environment. The asymmetric unit consists of one Mn(II) cation, two thio-cyanate anions and two 2,2'-bi-pyridine ligands, as well as two non-coordinating 2,2'-bi-pyridine ligands that are each located on centres of inversion. In the crystal structure, the discrete [Mn(NCS)2(C10H8N2)2] complex mol-ecules are arranged in such a way that cavities are formed, in which the solvent 2,2'-bi-pyridine mol-ecules are located. Apart from van der Waals forces, there are no remarkable inter-molecular inter-actions present in the crystal structure.

  10. Crystal structure of bis-(2,2'-bi-pyridine)[N'-(quino-lin-2-ylmethylidene)pyridine-2-carbohydrazide]ruthenium(II) bis(tetra-fluorido-borate) di-chloro-methane tris-olvate.

    Science.gov (United States)

    Mori, Asami; Suzuki, Takayoshi; Nakajima, Kiyohiko

    2015-02-01

    The title compound, [Ru(C10H8N2)2(C16H12N4O)](BF4)2·3CH2Cl2, crystallizes with one complex dication, two BF4 (-) counter-anions and three di-chloro-methane solvent mol-ecules in the asymmetric unit. The central Ru(II) atom adopts a distorted octa-hedral coordination sphere with two 2,2'-bi-pyridine (bpy) and one quinoline-2-carbaldehyde (pyridine-2-carbon-yl)hydrazone (HL) ligand. The hydrazone ligand has a Z form and coordinates to the Ru(II) atom via the amide-O and imine-N atoms, affording a planar five-membered chelate ring, while its pyridine-N and quinoline-N donor atoms in the substituents are non-coordinating. The hydrazone N-H group forms an intra-molecular hydrogen bond with the quinoline-N atom. In the crystal, the quinoline moiety of HL shows the shortest π-π stacking inter-action with the pyridine substituent of HL in a neighbouring complex, the centroid-to-centroid distance being 3.793 (3) Å.

  11. 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

    Science.gov (United States)

    Chumakov, Yu. M.; Paholnitcaia, A. Yu.; Petrenko, P. A.; Tsapkov, V. I.; Poirier, D.; Gulea, A. P.

    2015-01-01

    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.

  12. Differentiation of the pyridine radical cation from its distonic isomers by ion-molecule reactions with dioxygen

    Science.gov (United States)

    Jobst, Karl J.; de Winter, Julien; Flammang, Robert; Terlouw, Johan K.; Gerbaux, Pascal

    2009-09-01

    In a previous study on the pyridine ion (1) and the pyridine-2-ylid isomer (2), we reported that ions 2 readily react with H2O to produce 2-pyridone ions at m/z 95, by O-atom abstraction. The mechanism for this intriguing reaction, however, was not established. This prompted us to use model chemistry calculations (CBS-QB3) to probe various mechanistic scenarios and to perform complementary experiments with the new, more versatile, ion-molecule reaction chamber of the Mons Autospec 6F mass spectrometer. It appears that H2O is not reacting neutral that produces the 2-pyridone ion of the above reaction, but rather O2 from air co-introduced with the water vapour. Theory and experiment agree that the exothermic reaction of O2 with the pyridine-2-ylid ion leads to loss of 3O from a stable peroxide-type adduct ion at m/z 111. Similarly, pyridine-3-ylid ions (3) generate 3-pyridone ions, but the reaction in this case is thermoneutral. The m/z 111:95 peak intensity ratios in the spectra of the ion-molecule products from ions 2 and 3 may serve to differentiate the isomers.

  13. Synthesis of Imidazo pyridines and Pyridopyrimidines in Water and their S{sub N}Ar Cyclizations

    Energy Technology Data Exchange (ETDEWEB)

    Chanu, Langpoklakpam Gellina; Singh, Thokchom Prasanta; Singh, Okram Mukherjee [Manipur Univ., Manipur (India); Jang, Yong Ju; Yoon, Yongjin; Singh, Okram Mukherjee; Lee, Sanggyeong [Gyeongsang National Univ., Jinju (Korea, Republic of)

    2014-04-15

    Synthesis of tetrahydroimidazo pyridines and tetrahydropyrido pyrimidines by a one-pot and three component reaction of α-oxoketenedithioacetals, diamines and DMAD in water has been described. Different routes for accessing the desired compounds were examined and a few specially designed-substrates have been utilized further to afford the new imidazo and pyrido fused naphthyridine tetracyclic compound by SNAr intramolecular cyclization.

  14. Synthesis of Pyridinic-Rich N, S Co-doped Carbon Quantum Dots as Effective Enzyme Mimics

    Science.gov (United States)

    Liu, Teng; Cui, Zhi-wei; Zhou, Jun; Wang, Ying; Zou, Zhi-gang

    2017-05-01

    N and S co-doped carbon quantum dots (N, S-CQDs) with high N- and S-doping level were synthesized by microwave solid-phase pyrolysis within 50 s. Owing to the dominant pyridinic N injection into the conjugated framework, both high enzyme mimics catalytic activity and photoluminescence quantum yield are achieved simultaneously.

  15. ADDP and PS-PPh3: an efficient Mitsunobu protocol for the preparation of pyridine ether PPAR agonists

    Directory of Open Access Journals (Sweden)

    Wilhite David M

    2006-10-01

    Full Text Available Abstract A series of pyridine ether PPAR agonists were synthesized through an ADDP and PS-PPh3 modified Mitsunobu protocol, which eliminated significant by-product formation. This method proved to be versatile, efficient and amenable to parallel synthesis.

  16. Nanostructured polystyrene-block-poly(4-vinyl pyridine)(pentadecylphenol) thin films as templates for polypyrrole synthesis

    NARCIS (Netherlands)

    Zoelen, Wendy van; Bondzic, Sasa; Fernández Landaluce, Tatiana; Brondijk, Johan; Loos, Katja; Schouten, Arend-Jan; Rudolf, Petra; Brinke, Gerrit ten

    2009-01-01

    Polypyrrole has been chemically synthesized on thin film nanostructures obtained from comb-shaped supramolecules of polystyrene-block-poly(4-vinyl pyridine) (PS-b-P4VP) hydrogen bonded with pentadecylphenol (PDP). PDP was washed from thin films of cylindrical and lamellar self-assembled

  17. Efficient Synthesis of the Functionalized Spiro[indoline-3,4'-pyridine] via Four-component Reaction

    Institute of Scientific and Technical Information of China (English)

    孙晶; 吴群; 张藜娟; 颜朝国

    2012-01-01

    An efficient synthetic procedure for the functionalized spiro[indoline-3,4'-pyridine] was developed via the four-component reactions of arylamines, acetylenedicarboxylates, isatins and malononitrile with triethylamine as the base catalyst. The advantages of this reaction are using common starting material, mild reaction conditions, broad scope of reactants and operational simplicity.

  18. L-proline-catalysed synthesis of functionalized unsymmetrical dihydro-1H-indeno[1,2-b]pyridines

    Indian Academy of Sciences (India)

    Farahnaz Kargar Behbahani; Hourieh Sadat Alaei

    2013-05-01

    Aromatic aldehydes have been employed in a one-pot four-component reaction with ethyl acetoacetate, 1,3-indandione and ammonium acetate in the presence of L-proline in water and under reflux condition to afford the corresponding dihydro-1H-indeno[1,2-b]pyridines in very good yields.

  19. Langmuir-Blodgett films of metal complexes of 4-(10,12-pentacosadiynamidomethyl)pyridine : A structural investigation

    NARCIS (Netherlands)

    Werkman, PJ; Wieringa, RH; Vorenkamp, EJ; Schouten, AJ

    1998-01-01

    Complex formation between 4-(10,12-pentacosadiynamidomethyl)pyridine and metal ions in the subphase results in stable Langmuir monolayers up to surface pressures of 35 mN m(-1). Electron microscopy pictures show a flat monomer monolayer before polymerization and a polymer monolayer exhibiting a more

  20. Fe(111)-Mediated Electrooxidation of Pyridine and Several Derivatives to Produce a Novel n-Dopable Conducting Polymer

    Science.gov (United States)

    1998-06-29

    Prepared for publication in Journal of Electroanalytical Chemistry 12a. DISTRIBUTION /AVAILABILITY STATEMENT This document has been prepared for public...Conducting Polymer E. Shouji and D. A. Buttry Prepared for publication in Journal of Electroanalytical Chemistry Department of Chemistry...Submitted to: Journal of Electroanalytical Chemistry 12. Unlimited distribution 13. Abstract: Pyridine and lutidine can be oxidatively

  1. 1-Phenylpyrazolo[4',3':5,6]pyrano[3,2-c]pyridine-4(1H-thione

    Directory of Open Access Journals (Sweden)

    Wolfgang Holzer

    2010-04-01

    Full Text Available The title compound is prepared by treatment of 1-phenylpyrazolo[4',3':5,6]pyrano[3,2-c]pyridin-4(1H-one with Lawesson’s reagent in refluxing toluene. Detailed spectroscopic data (1H NMR, 13C NMR, 15N NMR, MS are presented.

  2. 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...

  3. A study on the anti-inflammatory effects of new derivatives of 3-hydroxy pyridine-4-one

    Directory of Open Access Journals (Sweden)

    Valiollah Hajhashemi

    2014-01-01

    Conclusions: Because cyclooxygenase and lipoxygenase as key enzymes of the inflammation pathway are heme-dependent, it seems that the anti-inflammatory effect of derivatives of pyridine-4-one may be related to their iron chelating properties. However, more investigations are needed to find out their exact mechanism of actions.

  4. [Raman spectra and structure analysis of 2,6-pyridine dicarboxylic acid in different states and single Bacillus spore].

    Science.gov (United States)

    Huang, Rong-shao; Huang, Xi; Xu, Lan-lan; Li, Yong-qing; Huang, Shu-shi

    2011-03-01

    The Raman spectra of 2,6-pyridine dicarboxylic acid (DPA) and their calcium salts(Ca-DPA) in different states and the Ca-DPA in a single bacterial spore have been recorded by laser tweezers Raman system (LTRS) and the spectra have been assigned. Raman spectra of different states of DPA and Ca-DPA are different evidently. Analysis leading to differences in the structure of spectrum may be due to that the Raman spectra of DPA crystalline reflected more precise characteristics information compared to DPA powder, in which the laser can penetrate through DPA crystalline and the Raman scatter from the crystalline interior is greater than that from DPA powder. The second reason is that DPA powder and Ca-DPA crystalline contain water molecules, and the intermolecular hydrogen bonding in the crystals of these molecules is extensive. The presence of calcium ions would affect the pyridine ring so that both sides of the carboxyl pyridine ring have a certain geometric deformation and the hydroxy carboxylic was damaged. The DPA2-anion is principal in Ca-DPA and the DPA solution. The calcium ion affects the stability of the pyridine ring structure in the Ca-DPA solution. The result from the spectra also showed that the DPA in single spores present Ca-DPA crystal state.

  5. Improved performance of graphene doped with pyridinic N for Li-ion battery: a density functional theory model.

    Science.gov (United States)

    Kong, Xiang-kai; Chen, Qian-wang

    2013-08-21

    The performance of N-doped graphene on Li-ion battery has been investigated systematically by means of a density functional theory method. Pyridinic N doping, graphitic N atoms and 5-8-5 double vacancies have been selected as the functional defects to study their influence on Li storage compared to the pristine graphene. It has been confirmed that introducing pyridinic N atoms with p-type doping is a suitable method, especially for graphene doped with 4 pyridinic N atoms, whose structural distortion induced by Li intercalation is small and supplies strong force for Li adsorption. The diffusion barrier for this model is lower than for pristine graphene, both for the side and center diffusion routes, contributing to the high mobility. In addition, we point out that the strong catch force for Li will cause more Li to stay on the pyridinic N-doped graphene during the charge-discharge cycles, leading to a faster decrease of capacity compared to pristine graphene.

  6. Atomic-scale insight into the origin of pyridine inhibition of MoS2-based hydrotreating catalysts

    DEFF Research Database (Denmark)

    Temel, Burcin; Tuxen, Anders K.; Kibsgaard, Jakob

    2010-01-01

    Basic nitrogen-containing compounds such as pyridine are well known to be inhibitors of the hydrodesulfurization (HDS) reaction for the MoS2-based catalysts. From an interplay of scanning tunneling microscopy (STM) experiments and density functional theory (DFT) calculations, atomic-scale insight...

  7. 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.

  8. Synthesis and fluorescence properties of Tb(Ⅲ) complexes with pyridine-2,6-dicarboxylic acid derivatives

    Institute of Scientific and Technical Information of China (English)

    TANG Rui-ren; ZHENG You-hu; GU Guo-liang

    2008-01-01

    Two novel ligands named 4-styrylpyridine-2,6-dicarboxylic acid (4-SPDA) and 4-(4-(2-(2, 6-dicarboxypyridin-4-yl)-vinyl)styryl)pyridine-2,6-dicarboxylic acid(DSPDA) and their complexes with Tb(Ⅲ) were synthesized and characterized by infrared spectrometry, 1H nuclear magnetic resonance, elemental analysis and gas chromatograph-mass spectrometry. The ligand synthetic route was optimized. The fluorescence properties of the complex in solid state, in different kind of solvents and in solutions with different pH values were investigated in detail. The results show that the yields of DSPDA and 4-SPDA reach over 78% by Wittig-Horner reaction and other eight pyridine-2, 6-dicarboxylic acid derivatives with different substituents on pyridine ring, and their complexes with Tb(Ⅲ) are also obtained. The fluorescence intensities of the complexes with electron-donating groups are more intense than those of the complexes with electron-withdrawing groups on pyridine ring; fluorescence intensities of the complexes are the strongest in neutral solution (pH=7), and the less the dipole moment of solvent molecule is, the stronger the fluorescence intensity is. It is found that the two ligands (4-APDA and DSPDA) are the good sensitizers for Tb(Ⅲ) ion.

  9. Large work function reduction by adsorption of a molecule with a negative electron affinity: pyridine on ZnO(1010).

    Science.gov (United States)

    Hofmann, Oliver T; Deinert, Jan-Christoph; Xu, Yong; Rinke, Patrick; Stähler, Julia; Wolf, Martin; Scheffler, Matthias

    2013-11-07

    Using thermal desorption and photoelectron spectroscopy to study the adsorption of pyridine on ZnO(1010), we find that the work function is significantly reduced from 4.5 eV for the bare ZnO surface to 1.6 eV for one monolayer of adsorbed pyridine. Further insight into the interface morphology and binding mechanism is obtained using density functional theory. Although semilocal density functional theory provides unsatisfactory total work functions, excellent agreement of the work function changes is achieved for all coverages. In a closed monolayer, pyridine is found to bind to every second surface Zn atom. The strong polarity of the Zn-pyridine bond and the molecular dipole moment act cooperatively, leading to the observed strong work function reduction. Based on simple alignment considerations, we illustrate that even larger work function modifications should be achievable using molecules with negative electron affinity. We expect the application of such molecules to significantly reduce the electron injection barriers at ZnO/organic heterostructures.

  10. Abnormal Nucleophilic Reaction of Ethyl Crotonate: An Easy Way to Form Novel Imidazo[1,5-a] pyridine derivatives

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    An abnormal intramolecular nucleophilic reaction of α-carbon of α,β-unsaturated ester was discovered and the reaction makes it very easy to form imidazo[1,5-a]pyridine derivatives. The mechanism of the reaction was discussed.

  11. Imidazo[1,2-a]pyridin-3-amines as potential HIV-1 non-nucleoside reverse transcriptase inhibitors

    CSIR Research Space (South Africa)

    Bode, ML

    2011-06-01

    Full Text Available the best anti-HIV-1 IIIB whole cell activity (MAGI IC50 = 0.18 µM, IC90 = 1.06 µM), along with a good selectivity index (>800), was 2-(2-chlorophenyl)-3-(cyclohexylamino)imidazo[1,2-a]pyridine-5-carbonitrile 38....

  12. Resin screening for the removal of pyridine-derivatives from waste-water by solvent impregnated resin technology

    NARCIS (Netherlands)

    Bokhove, J.; Schuur, B.; Haan, de A.B.

    2013-01-01

    The selective removal of pyridine derivatives by solvent impregnated resins has been studied. A solvent impregnated resin consists of a macro-porous particle that is impregnated with a solvent. This technology allows the use liquid–liquid extraction in fixed-bed operation, and prevents problems like

  13. 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…

  14. Solid State Oxidative Aromatization of Hantzsch 1,4-Dihydropyridines to Pyridines Using Iodobenzene Diacetate or Hydroxy(tosyloxy)iodobenzene

    Institute of Scientific and Technical Information of China (English)

    KUMAR Parvin

    2009-01-01

    An easy,safe,solvent-free and effective method for oxidative aromatization of Hantzsch 1,4-dihydropyridines catalyzed by hypervalent iodine (IBD and HTIB) to corresponding pyridine derivatives in high yields within short span of time.All reactions were carried out just by grinding the two reactants.

  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.

  16. Chemical and cellular investigations of trans-ammine-pyridine-dichlorido-platinum(II), the likely metabolite of the antitumor active cis-diammine-pyridine-chorido-platinum(II).

    Science.gov (United States)

    Xu, Dechen; Min, Yuanzeng; Cheng, Qinqin; Shi, Hongdong; Wei, Kaiju; Arnesano, Fabio; Natile, Giovanni; Liu, Yangzhong

    2013-12-01

    It has been proposed that the well-studied monofunctional platinum complex cis-[PtCl(NH3)2(py)](+) (cDPCP) forms DNA adducts similar to those of the trans platinum complex trans-[PtCl2(NH3)(py)] (ampyplatin, py=pyridine). Thus this latter could be the active form of cDPCP. Detailed studies on the mechanism of ampyplatin action were performed in this work. Results indicate that ampyplatin has significantly higher antiproliferative activity than cDPCP and is comparable to cisplatin. Cellular uptake experiments indicate that ampyplatin can be efficiently accumulated in A549 cancer cells. Binding of ampyplatin to DNA mainly produces monofunctional adducts; remarkably, these adducts can be recognized by the HMGB1 protein. Kinetic studies on the reaction with GMP indicate that the reactivity of ampyplatin is much lower than that of transplatin and is more similar to that of trans-[PtCl2{E-HN=C(Me)OMe}2] (trans-EE), a widely investigated antitumor active trans-oriented platinum complex. In addition, the hydrolysis of ampyplatin is significantly suppressed, whereas the hydrolysis of the mono-GMP adduct is highly enhanced. These results indicate that the mechanism of ampyplatin differs not only from that of antitumor inactive transplatin but also from that of antitumor active trans-EE and this could account for the remarkable activity of parent cDPCP.

  17. 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.

  18. A resonance Raman enhancement mechanism for axial vibrational modes in the pyridine adduct of myoglobin proximal cavity mutant (H93G).

    Science.gov (United States)

    Franzen, Stefan; Brown, Derek; Gaff, John; Delley, B

    2012-09-06

    The proximal cavity mutant of myoglobin consists of a mutation of the proximal histidine to glycine (H93G), which permits exogenous ligands to bind to the heme iron. A non-native pyridine ligand can ligate to the heme to yield a five-coordinate adduct, H93G(Pyr), that cannot be formed freely in solution since the six-coordinate bis-pyridine adduct is more stable than the five-coordinate adduct. We have used resonance Raman spectroscopy in the Soret band region of the heme to study the enhancement of axial vibrations of bound pyridine in the H93G(Pyr) adduct. The observation that the pyridine ring breathing mode (ν(1)) and the symmetric ring stretching (ν(3)) modes are enhanced under these conditions is explained by a computational approach that shows that coupling of the π-system of the heme with the p-orbitals of the pyridine is analogous to π-backbonding in diatomic ligand adducts of heme proteins. The result has the broader significance that it suggests that the resonance enhancement of pyridine modes could be an important aspect of Raman scattering of pyridine on conducting surfaces such as those studied in surface enhanced Raman scattering experiments.

  19. 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

    compounds. In order to understand the observed inhibitor trends. DFT studies oil (lie adsorption of benzene which is a weaker poison than pyridine, and H2S, which has no or only a very minor influence on the HYD pathway. have also been made, We find that the adsorption of pyridine is quite strong....... Furthermore, H2S is observed not to interact strongly with these sites. The present results have also provided insight into the nitrogen compound inhibition of the direct desulturization DDS pathway. The difference in the poisoning by benzene and pyridine is observed to be related to the ease with which...

  20. 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.

  1. Synthesis of Dihydropyridines and Pyridines from Imines and Alkynes via C-H Activation

    Energy Technology Data Exchange (ETDEWEB)

    Ellman, Jonathan A.; Colby, Denise; Bergman, Robert

    2007-11-20

    A convenient one-pot C-H alkenylation/electrocyclization/aromatization sequence has been developed for the synthesis of highly substituted pyridine derivatives from alkynes and {alpha},{beta}-unsaturated N-benzyl aldimines and ketimines that proceeds through dihydropyridine intermediates. A new class of ligands for C-H activation was developed, providing broader scope for the alkenylation step than could be achieved with previously reported ligands. Substantial information was obtained about the mechanism of the reaction. This included the isolation of a C-H activated complex and its structure determination by X-ray analysis; in addition, kinetic simulations using the Copasi software were employed to determine rate constants for this transformation, implicating facile C-H oxidative addition and slow reductive elimination steps.

  2. Electrocatalytically switchable CO2 capture: first principle computational exploration of carbon nanotubes with pyridinic nitrogen.

    Science.gov (United States)

    Jiao, Yan; Zheng, Yao; Smith, Sean C; Du, Aijun; Zhu, Zhonghua

    2014-02-01

    Carbon nanotubes with specific nitrogen doping are proposed for controllable, highly selective, and reversible CO2 capture. Using density functional theory incorporating long-range dispersion corrections, we investigated the adsorption behavior of CO2 on (7,7) single-walled carbon nanotubes (CNTs) with several nitrogen doping configurations and varying charge states. Pyridinic-nitrogen incorporation in CNTs is found to induce an increasing CO2 adsorption strength with electron injecting, leading to a highly selective CO2 adsorption in comparison with N2 . This functionality could induce intrinsically reversible CO2 adsorption as capture/release can be controlled by switching the charge carrying state of the system on/off. This phenomenon is verified for a number of different models and theoretical methods, with clear ramifications for the possibility of implementation with a broader class of graphene-based materials. A scheme for the implementation of this remarkable reversible electrocatalytic CO2 -capture phenomenon is considered.

  3. Ab initio atom-atom potentials using CamCASP: Application to pyridine

    CERN Document Server

    Misquitta, Alston J

    2015-01-01

    In Part I of this two-part investigation we described a methodology for the development of robust, analytic, many-body atom-atom potentials for small organic molecules from first principles. Here we demonstrate how these theoretical ideas, which are implemented in the CamCASP suite of programs, can be used to develop a series of many-body potentials for the pyridine system. Even the simplest of these potentials exhibit r.m.s. errors of only about 0.5kJ mol$^{-1}$, significantly surpassing the best empirical potentials. Further, the functional form can be made systematically more elaborate so as to improve the accuracy without a significant increase in the human-time spent in their generation. We investigate the effects of anisotropy, rank of multipoles, and choice of polarizability and dispersion models.

  4. Calorimetric evidence for a mobile surface layer in ultrathin polymeric films: poly(2-vinyl pyridine).

    Science.gov (United States)

    Madkour, Sherif; Yin, Huajie; Füllbrandt, Marieke; Schönhals, Andreas

    2015-10-28

    Specific heat spectroscopy was used to study the dynamic glass transition of ultrathin poly(2-vinyl pyridine) films (thicknesses: 405-10 nm). The amplitude and the phase angle of the differential voltage were obtained as a measure of the complex heat capacity. In a traditional data analysis, the dynamic glass transition temperature Tg is estimated from the phase angle. These data showed no thickness dependency on Tg down to 22 nm (error of the measurement of ±3 K). A derivative-based method was established, evidencing a decrease in Tg with decreasing thickness up to 7 K, which can be explained by a surface layer. For ultrathin films, data showed broadening at the lower temperature side of the spectra, supporting the existence of a surface layer. Finally, temperature dependence of the heat capacity in the glassy and liquid states changes with film thickness, which can be considered as a confinement effect.

  5. 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.

  6. Crystal structure of fac-trichlorido[tris(pyridin-2-yl-Namine]chromium(III

    Directory of Open Access Journals (Sweden)

    Yukiko Yamaguchi-Terasaki

    2015-01-01

    Full Text Available In the neutral complex molecule of the title compound, fac-[CrCl3(tpa] [tpa is tris(pyridin-2-ylamine; C15H12N4], the CrIII ion is bonded to three N atoms that are constrained to a facial arrangement by the tpa ligand and by three chloride ligands, leading to a distorted octahedral coordination sphere. The average Cr—N and Cr—Cl bond lengths are 2.086 (5 and 2.296 (4 Å, respectively. The complex molecule is located on a mirror plane. In the crystal, a combination of C—H...N and C—H...Cl hydrogen-bonding interactions connect the molecules into a three-dimensional network.

  7. 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.

  8. Synthesis and antioxidant and antitumor activity of novel pyridine, chromene, thiophene and thiazole derivatives.

    Science.gov (United States)

    Fadda, Ahmed A; Berghot, Moged A; Amer, Fathy A; Badawy, Doria S; Bayoumy, Nesma M

    2012-05-01

    2-Tosylacetonitrile (1) when reacted with α,β-unsaturated nitriles 2a-c or a mixture of formaldehyde and 3-amino-2-substituted-pent-2-endinitriles 6a,b yielded pyridine derivatives 3a-c and 9a,b, respectively, while when subjected to react with salicylaldehyde yielded chromene derivatives 4 and 5, subsequently. The behavior of thiocarbamoyl derivative 10 derived from 1 towards some α-halogenated compounds have been investigated as well as its behavior towards elemental sulfur and phenyl isothiocyanate. Newly synthesized compounds were screened for their antioxidant activity, erythrocytes haemolysis and bleomycin-independent DNA damage. Some of the tested compounds exhibited promising activities. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  9. Recognition of amino acids and anions by a Zn(Ⅱ)-methylazacalix[4]pyridine complex

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    As a powerful macrocyclic host molecule with unique conformation and cavity structure that are fine-tuned by the bridging nitrogen atoms, methylazacalix[4]pyridine (MACP-4) has been shown to selectively recognize Zn2+ and form stable Zn(Ⅱ)-MACP-4 complexes both in solid state and solution with an association constant up to 5.97 (logKs). The molecular recognition of Zn(Ⅱ)-MACP-4 complexes towards various amino acids and anions with different geometry was investigated by using the spectral titration methods and X-ray analysis. The Zn(Ⅱ)-MACP-4 complex was found to recognize the 17 amino acids tested with the association constant up to 3.97 (logKs). On the other hand, the Zn(Ⅱ)-MACP-4 complex selectively interacted with anions and the maximum association constant of 3.9 (logKs) was obtained.

  10. Bis[μ-N-(tert-butyldimethylsilyl-N-(pyridin-2-ylmethylamido]bis[methylcobalt(II

    Directory of Open Access Journals (Sweden)

    Astrid Malassa

    2012-09-01

    Full Text Available The green title complex, [Co2(CH32(C12H21N2Si2], was obtained from bis{[μ-N-tert-butyldimethylsilyl-N-(pyridin-2-ylmethylamido]chloridocobalt(II} and methyllithium in diethyl ether at 195 K via a metathesis reaction. The dimeric cobalt(II complex exhibits a crystallographic center of inversion in the middle of the Co2N2 ring (average Co—N = 2.050 Å. The CoII atom shows a distorted tetrahedral coordination sphere. The exocyclic Co—N bond length to the pyridyl group shows a similar value of 2.045 (4 Å. The exocyclic methyl group has a rather long Co—C bond length of 2.019 (5 Å.

  11. 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.

  12. Bis(acetato-κObis(pyridine-2-aldoxime-κ2N,N′nickel(II

    Directory of Open Access Journals (Sweden)

    Youtao Si

    2012-05-01

    Full Text Available In the mononuclear title compound, [Ni(CH3COO2(C6H6N2O2], the NiII atom is coordinated by two pyridine-2-aldoxime (PaoH ligands and two acetate groups, with cis coordination for the pairs of identical ligands. While each acetate group binds to the NiII atom by one O atom, each PaoH chelates the NiII atom through two N atoms. The O atom on PaoH is not deprotonated and does not participate in bonding to the NiII atom. Thus, the NiII atom exhibits an octahedral environment. Intramolecular O—H...O hydrogen-bonding interactions and intermolecular C—H...O hydrogen-bonding interactions are present in the structure. Adjacent molecules pack along [100] through van der Waals forces.

  13. 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.

  14. (E-4-(Benzo[d]thiazol-2-yl-N-(pyridin-3-ylmethylideneaniline hemihydrate

    Directory of Open Access Journals (Sweden)

    Li Hong

    2016-10-01

    Full Text Available The title compound, C19H13N3S·0.5H2O, is a benzothiazole derivative that crystallized as a hemihydrate, the water O atom being situated on a twofold rotation axis. The dihedral angles between the central benzene ring and the benzothiazole (r.m.s. deviation = 0.012 Å and pyridine rings are 3.57 (6 and 10.12 (8°, respectively, indicating that the molecule is nearly planar. The conformation about the N=C bond is E. In the crystal, molecules are linked by Owater—H...Npyridine hydrogen bonds, forming dimers, which in turn are linked by C—H...O hydrogen bonds into layers parallel to the ab plane. The layers are linked by offset π–π interactions, forming a three-dimensional network [shortest intercentroid distance = 3.721 (2 Å].

  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 configurational diffusion limitations within the microporous catalyst. The use of a carbon-template for generation of secondary porosity is more effective than desilication. The desilicated catalyst is slightly more active than conventional TS-1, probably due to a decrease of the mean diffusion path length....... In contrast, carbon-templated mesopores provides an efficient transport throughout the zeolite, thus preventing deactivation due to product confinement. All catalysts were characterised by X-ray powder diffraction, scanning electron microscopy, UV-Vis spectroscopy and nitrogen physisorption. The results...

  16. Pyrrolo[2,3-b]pyridine derivatives as potent Bruton's tyrosine kinase inhibitors.

    Science.gov (United States)

    Zhao, Xinge; Huang, Wei; Wang, Yazhou; Xin, Minhang; Jin, Qiu; Cai, Jianfeng; Tang, Feng; Zhao, Yong; Xiang, Hua

    2015-08-01

    A series of pyrrolo[2,3-b]pyridine-based derivatives were designed as potent Bruton's tyrosine kinase (BTK) inhibitors by using a scaffold-hopping strategy. Structure-activity relationship studies identified five compounds (3n, 3p, 3q, 3r, and 3s) with IC50 of less than 10nM in BTK enzyme assay and five compounds (3m, 3n, 3o, 3p, and 3t) with IC50 of less than 20 nM in Ramos cell assay. As one of the most potent inhibitors, compound 3p exhibited superior activity to that of compound 1 (RN486) and pyrrolo[2,3-d]pyrimidine derivative 2 in both BTK enzymatic (IC50=6.0 nM) and cellular inhibition (IC50=14 nM) assays. In addition, 3p displayed favorable overall pharmacokinetic profiles compared with 1 and 2.

  17. POLYMERIZATION OF ETHYLENE WITH UNSYMMETRIC 2,6-BIS(IMINO)PYRIDINE IRON(Ⅱ) COMPLEX

    Institute of Scientific and Technical Information of China (English)

    Zhi Ma; Wen-hua Sun; Zi-long Li; Chang-xing Shao; You-liang Hu

    2002-01-01

    An unsymmetric 2,6-bis(imino)pyridine iron(Ⅱ) complex 1' was synthesized. The relationship between catalyst structure and its activity in ethylene polymerization is discussed. The kinetic behavior of ethylene polymerization and the effects of polymerization conditions such as temperature, aluminum/iron molar ratio on the activity of catalyst and the characteristics of polyethylene were reported. The unsymmetric catalyst 1' has a good catalytic performance of 3.47 ×106 gPE @ mol-1 @ Fe @ h-1 at 40℃ with aluminum/iron molar ratio = 2500. A dependence of catalyst activity on the methylaluminoxane (MAO) concentration and reaction temperature was found. The molecular weight (MW) of polyethylene with broad dispersity is about 104-105 g/mol. The melting temperature and branching of polyethylenes vary with changing reaction temperature and aluminum/iron molar ratio.

  18. 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.

  19. Growth aspects, structural, optical, thermal and mechanical properties of benzotriazole pyridine-2-carboxylic acid single crystal

    Science.gov (United States)

    Thirunavukkarsu, A.; Sujatha, T.; Umarani, P. R.; Nizam Mohideen, M.; Silambarasan, A.; Kumar, R. Mohan

    2017-02-01

    Benzotriazole pyridine-2-carboxylic acid single crystal (BTPCA) was grown by slow evaporation solution growth technique. The cell parameters and crystallinity of BTPCA crystal were found by single crystal and powder X-ray diffraction studies. The presence of functional groups was studied by FT-IR analysis. UV-vis-NIR transmission studies reveal that the BTPCA crystal is transparent in the entire visible region with lower optical cut-off wavelength of 306 nm. The thermal stability, melting point and decomposition stages of BTPCA were analysed from the thermogravimetric and differential thermal analyses. The second harmonic output power of BTPCA was measured to be 2.5 times that of KDP reference crystal. Hardness studies reveal that grown crystal shows the reverse indentation size effect and breakeven point due to release of internal fatigue generated during indentation.

  20. Pyridine salvage and nicotinic acid conjugate synthesis in leaves of mangrove species.

    Science.gov (United States)

    Ashihara, Hiroshi; Yin, Yuling; Deng, Wei-Wei; Watanabe, Shin

    2010-01-01

    The metabolic fate of [carbonyl-14C]nicotinamide was surveyed in leaf disks of seven mangrove species, Bruguiera gymnorrhiza, Rhizophora stylosa, Kandeliaobovata, Sonneratia alba, Pemphis acidula, Lumnitzera racemosa and Avicennia marina, with and without 250 mM NaCl. Uptake of [14C]nicotinamide by leaf disks was stimulated by 250 mM NaCl in K. candel, R. stylosa, A. marina and L. racemosa. [Carbonyl-14C]nicotinamide was converted to nicotinic acid and was utilised for the synthesis of nucleotides and nicotinic acid conjugates. Formation of nicotinic acid by the deaminase reaction was rapid; there was little accumulation of nicotinamide in the disks 3h after administration. Radioactivity from [carbonyl-14C]nicotinamide was incorporated into pyridine nucleotides (mainly NAD and NADP) in all mangrove leaves, and the rates varied from 2% (in L. racemosa) to 15% (S. alba) of the total radioactivity taken up. NaCl generally reduced nicotinic acid salvage for NAD and NADP. In all mangrove leaf disks, the most heavily labelled compounds (up to 70% of total radioactivity) were trigonelline (N-methylnicotinic acid) and/or nicotinic acid N-glucoside. Trigonelline was formed in all mangrove plants, but N-glucoside synthesis was found only in leaves of A. marina and K. obovata. In A. marina, incorporation of radioactivity into N-glucoside (51%) was much greater than incorporation into trigonelline (2%). In general, NaCl stimulates the synthesis of these pyridine conjugates. The rate of decarboxylation of nicotinic acid in roots of A. marina seedlings was much greater than for the corresponding reaction observed in leaves.

  1. Docking studies and effects of syn-anti isomery of oximes derived from pyridine imidazol bicycled systems as potential human acetylcholinesterase reactivators

    National Research Council Canada - National Science Library

    Guimarães, Ana Paula; França, Tanos Celmar Costa; Ramalho, Teodorico Castro; Rennó, Magdalena Nascimento; da Cunha, Elaine Fontes Ferreira; Matos, Karina Silvia; Mancini, Daiana Teixeira; Kuča, Kamil

    2011-01-01

    In order to contribute to a better understanding of the mechanism of action of oximes, we evaluated the affinities of 10 new oximes, derived from pyridine-imidazol bicycled systems, for human acetylcholinesterase (HssAChE...

  2. Synthesis, structural, spectroscopic and docking studies of new 5C-substituted 2,4-diamino-5H-chromeno[2,3-b]pyridine-3-carbonitriles

    Science.gov (United States)

    Vereshchagin, Anatoly N.; Elinson, Michail N.; Anisina, Yuliya E.; Ryzhkov, Fedor V.; Goloveshkin, Alexander S.; Novikov, Roman A.; Egorov, Mikhail P.

    2017-10-01

    Multicomponent synthesis of 5-C substituted 2,4-diamino-5H-chromeno[2,3-b]pyridine-3-carbonitriles from salicylaldehydes 2-aminoprop-1-ene-1,1,3-tricarbonitrile and 1,3-cyclohexanediones was carried out in 59-88% yields. The structures of compounds obtained were characterized by several techniques, including elemental analysis, IR, XRD, mass, 1H, 13C and NOESY spectral studies. The chromeno[2,3-b]pyridines obtained are enols in solid phase. Keto-enol equilibrium is observed in DMSO solutions. Molecular docking studies of the synthesized chromeno[2,3-b]pyridine-3-carbonitriles were also carried out to elucidate their relationship with the binding pockets of the mitogen activated protein kinase (MK). It have been found that chlorine-containing chromeno[2,3-b]pyridines have best binding energy both MK-1 and MK-2.

  3. Design, synthesis and biological evaluation of 1H-pyrrolo[2,3-b]pyridine and 1H-pyrazolo[3,4-b]pyridine derivatives as c-Met inhibitors.

    Science.gov (United States)

    Liu, Na; Wang, Yanfen; Huang, Gongchao; Ji, Conghui; Fan, Wei; Li, Haitao; Cheng, Ying; Tian, Hongqi

    2016-04-01

    Five novel 1H-pyrrolo[2,3-b]pyridine or 1H-pyrazolo[3,4-b]pyridine derivatives, with a methylene, sulfur, sulfoxide or cyclopropyl group as a linker, were designed, synthesized and biologically evaluated against c-Met and ALK. The development of these methods of compound synthesis may provide an important reference for the construction of novel 7-azaindole and 7-azaindazole derivatives with a single atom linker. The enzyme assay and cell assay in vitro showed that compound 9 displayed strong c-Met kinase inhibition with IC50 of 22.8nM, moderate ALK kinase inhibition, and strong cell inhibition with MKN-45 IC50 of 329nM and EBC-1 IC50 of 479nM. In order to find the better candidate compounds, compounds 8, 9 and 10 have been selected as tool compounds for further optimization.

  4. Formation and Molecular Structure of an Ion Pair Iron(Ⅱ)Compound Derived from 2,6-Bis-[ 1-(2,6-dibromophenylimino)-ethyl ] pyridine and 2-Acetyl-6-[ 1-( 2, 6-dibromophenylimino )-ethyl ] pyridine

    Institute of Scientific and Technical Information of China (English)

    CHEN,Rui-Fang(陈瑞芳); CHEN,Rui-Fang; QIAN,Chang -Tao(钱长涛); QIAN,Chang-Tao; SUN,Jie(孙杰); SUN,Jie

    2001-01-01

    Two novel tridentate ligands of 2,6-bis-[ 1-( 2,6-dibromophenylimino)ethyl]pyridine (L1)andd 2-aeetyl-6-[1-(2,6-dibromophenylimino) ethyl ] pyridine ( I2 ) have been synthesized. The iron(Ⅱ) complex of L1 and L2 has been characterized with the crystal structure of [Fe(L1)(L2)]2+ [FeCl4]2·CH2 [monoclinic, P21/m ( # 11), a = 1.0562(4), b =2.0928(4), c = 1.2914(2) nm, β= 100.12°, V= 2.810(1)nm3, Dc= 1.879 g/cm3 and Z=2].

  5. CuI-pyridine-β-CD包合物的合成、表征及应用%Synthesis, characteristic and application of inclusion complex of CuI-pyridine-β-CD

    Institute of Scientific and Technical Information of China (English)

    董瑞风; 乔洁; 唐胜男; 李笃信; 双少敏; 董川

    2010-01-01

    为了改善CuI-pyridine配合物的物理性质,采用溶液搅拌法合成了CuI-pyridine配合物与β-CD的包合物,用IR、1H NMR、荧光光谱等分析方法对其进行了表征,并用电分析方法初步研究了各种气体对包合物修饰膜电极的响应.结果表明,CuI-pyridine-β-CD包合物为水溶性的荧光化合物(固体状态时EMmax=563 nm),荧光发射稳定;随着甲烷气体不断通入,包合物荧光强度逐渐降低,且甲烷气体对CuI-pyridine-β-CD包合物膜有显著的响应.

  6. Pesticides of Trifluoro-pyridine Derivatives%三氟甲基吡啶衍生物类农药综述

    Institute of Scientific and Technical Information of China (English)

    邓红霞

    2011-01-01

    介绍了三氟甲基吡啶衍生物类农药的结构,并对它们的用途、特点及部分中间体进行了探讨。%Trifluoro-pyridine derivatives are a family of very important compounds due to their anti- inflammatory. The structures of Trifluoro-pyridine Derivatives, their purposes, characteristics and some intermediates were discussed.

  7. 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)

  8. Thieno[2,3-b]pyridines as negative allosteric modulators of metabotropic GluR5 receptors: hit-to-lead optimization.

    Science.gov (United States)

    Nógrádi, Katalin; Wágner, Gábor; Domány, György; Bobok, Amrita; Magdó, Ildikó; Kiss, Béla; Kolok, Sándor; Fónagy, Katalin; Gyertyán, István; Háda, Viktor; Kóti, János; Gál, Krisztina; Farkas, Sándor; Keserű, György M; Greiner, István; Szombathelyi, Zsolt

    2014-08-15

    An HTS campaign of our corporate compound library resulted in thieno[2,3-b]pyridines derivative hits with mGluR5 negative allosteric modulator effects. During the hit-to-lead development our objective was to improve affinity, and to keep the ligand efficiency values at an acceptable level. After different modifications of the linker resulted in a 2-sulfonyl-thieno[2,3-b]pyridines derivative, which fulfilled the lead criteria.

  9. Synthesis of a novel series of 4-arylpiperazinyl derivatives linked to a 2-(pyridin-3-yl)-1H-benzimidazole as new Delavirdine analogues

    Energy Technology Data Exchange (ETDEWEB)

    Pessoa-Mahana, David; Nunez, Andres; Espinosa, Christian; Mella-Raipn, Jaime [Pontificia Universidad Catolica de Chile, Santiago (Chile). Facultad de Quimica. Dept. de Farmacia; Pessoa-Mahana, Hernan [Universidad de Chile, Santiago (Chile). Facultad de Ciencias Quimicas. Dept. de Quimica Organica y Fisico-Quimica

    2010-07-01

    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)

  10. Formation of a dinuclear copper(II) complex through the cleavage of CN bond of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole

    Science.gov (United States)

    Shardin, Rosidah; Pui, Law Kung; Yamin, Bohari M.; Kassim, Mohammad B.

    2014-09-01

    A simple mononuclear octahedral copper(II) complex was attempted from the reaction of three moles of 1-benzoyl-3-(pyridin-2-yl)-1H-pyrazole and one mole of copper(II) perchlorate hexahydrate in methanol. However, the product of the reaction was confirmed to be a dinuclear copper(II) complex with μ-{3-(pyridin-2-yl)-pyrazolato} and 3-(pyridin-2-yl)-1H-pyrazole ligands attached to each of the Cu(II) centre atom. The copper(II) ion assisted the cleavage of the CbenzoylN bond afforded a 3-(pyridin-2-yl)-1H-pyrazole molecule. Deprotonation of the 3-(pyridin-2-yl)-1H-pyrazole gave a 3-(pyridin-2-yl)-pyrazolato, which subsequently reacted with the Cu(II) ion to give the {3-(pyridin-2-yl)-pyrazolato}{3-(pyridin-2-yl)-1H-pyrazole}Cu(II) product moiety. The structure of the dinuclear complex was confirmed by x-ray crystallography. The complex crystallized in a monoclinic crystal system with P2(1)/n space group and cell dimensions of a = 12.2029(8) Å, b = 11.4010(7) Å, c = 14.4052(9) Å and β = 102.414(2)°. The compound was further characterized by mass spectrometry, CHN elemental analysis, infrared and UV-visible spectroscopy and the results concurred with the x-ray structure. The presence of d-d transition at 671 nm (ɛ = 116 dm3 mol-1 cm-1) supports the presence of Cu(II) centres.

  11. 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...

  12. Excited states of selected hydrazo-compounds on the example of 5-nitro-2-(2-phenylhydrazinyl)pyridine and its 3-, 4- or 6-methyl isomers

    Science.gov (United States)

    Michalski, J.; Kucharska, E.; Sąsiadek, W.; Lorenc, J.; Hanuza, J.

    2016-11-01

    Syntheses of 5-nitro-2-(2-phenylhydrazinyl)pyridine (5-nitro-2-phenylhydrazopyridine), 3-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (3-methyl-5-nitro-2-phenylhydrazopyridine), 4-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (4-methyl-5-nitro-2-phenylhydrazopyridine) and 6-methyl-5-nitro-2-(2-phenylhydrazinyl)pyridine (6-methyl-5-nitro-2-phenylhydrazo-pyridine) have been described. Electronic absorption and emission spectra of the compounds in the solid state and in various solvents have been measured at room temperature and discussed in terms of DFT quantum chemical calculations. The molecular structures and energy sequences of the singlet and triplet states have been determined in the B3LYP/6-311G(2d,2p) approximations. The Mulliken analysis and non-bonding orbital approach have been used in characterization of the studied compounds. It has been shown that the HOMO-LUMO transition of the studied compounds is observed in the range 23,900 ÷ 29,300 cm-1 and in this excitation the π-electrons of phenyl ring are transferred to nitro group of pyridine ring. In such a transition the hydrazo-bridge should take part as a mediator. The luminescence of the studied hydrazo-compounds is weak, not measureable in the solid state but measureable in solution.

  13. Crystal structure of bis-[2-tert-but-oxy-6-fluoro-3-(pyridin-2-yl-κN)pyridin-4-yl-κC (4)](pentane-2,4-dionato-κ(2) O,O')iridium(III).

    Science.gov (United States)

    Park, Ki-Min; Kang, Youngjin

    2014-11-01

    The title mol-ecule, [Ir(C14H14FN2O)2(C5H7O2)], is located on a twofold rotation axis, which passes through the Ir(III) atom and the central C atom of the pentane-2,4-dionate anion. The Ir(III) atom adopts a distorted octa-hedral coordination geometry, being C,N-chelated by two 2-tert-but-oxy-6-fluoro-3-(pyridin-2-yl)pyridin-4-yl ligands and O,O'-chelated by the pentane-2,4-dionato ligand. The bipyridinate ligands, which are perpendicular to each other [dihedral angle between the two least-squares planes = 89.95 (5)°], are arranged in a cis-C,C' and trans-N,N' fashion relative to the central metal cation. Intra-molecular C-H⋯O and C-H⋯N hydrogen bonds and inter-molecular C-H⋯F hydrogen bonds as well as π-π inter-actions between neighbouring pyridine rings [centroid-centroid distance 3.680 (1) Å] contribute to the stabilization of the mol-ecular and crystal structure, respectively.

  14. 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.

  15. Synthesis and crystal structure of complex of Ce(NO3)3 with N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl- pyridin-2-yl) hydrazone

    Institute of Scientific and Technical Information of China (English)

    JIANG; Yinzhi; HU; Weixiao

    2004-01-01

    The reaction of 3,6-di-(3-methyl-pyridin-2-yl)-s-tetrazine (DMPTZ, II) with CeIII salt [Ce(NO3)3·6H2O] generates a new ligand, N-(3-methyl-pyridin-2-yl)-formimidoyl-(3-methyl- pyridin-2-yl) hydrazone (L), and forms a new complex: a mononuclear complex [Ce(L)(NO3)2 (H2O)3]·NO3 (III). Crystal data for III: space group P-1, with a = 0.7133(4) nm, b = 1.1139(2) nm, c = 1.4572(3) nm, β= 102.13(2)°, β= 99.81(3)°, γ= 91.10(3)°, Z = 2, V = 1113.6(7) nm3, μ = 2.123 mm-1 and F(000) = 630. L acts as a tri-dentate chelating ligand in III. There are 10 coordination sites around Ce3+ of III, which are respectively occupied by seven oxygen atoms (four from two nitrate anions and three from three H2O molecules) and three nitrogen atoms (all from L). The cerium atom and three chelating nitrogen atoms are coplanar. The mechanism of the metal assisted decomposition is discussed briefly.

  16. 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.

  17. Structure-Dependent 4-Tert-Butyl Pyridine-Induced Band Bending at TiO2 Surfaces

    Directory of Open Access Journals (Sweden)

    Mats Göthelid

    2011-01-01

    Full Text Available The role of 4-tert butyl pyridine (4TBP adsorption on TiO2 surface band bending has been studied using photoelectron spectroscopy. Surface oxygen vacancies pin the Fermi level near the conduction band edge on rutile (110. 4TBP preferentially adsorbs in those vacancies and shift the Fermi level to lower binding energy in the band gap. This is done by transferring vacancy excess charge into the empty π∗ orbital in the pyridine ring. The anatase (100 surface contains much less oxygen vacancies although the surface is much rougher than the rutile (110. 4TBP adsorption does not have any significant effect on the surface band bending. Thus the positive role associated with 4TBP addition to solar cell electrolytes is suggested to protection against adsorption of other electrolyte components such as Li and I.

  18. N-[2-(4-Bromophenyl-5-methyl-4-oxo-1,3-thiazolidin-3-yl]pyridine-3-carboxamide

    Directory of Open Access Journals (Sweden)

    Mehmet Akkurt

    2011-04-01

    Full Text Available In the title compound, C16H14BrN3O2S, the atoms of the 1,3-thiazolidine group, except for the N and the C atoms attached to the bromobenzene ring, are disordered over two sets of sites with occupancies of 0.605 (13 and 0.395 (13. The benzene and pyridine rings make a dihedral angle of 86.2 (2°. In the crystal, molecules are linked by intermolecular N—H...N and C—H...O hydrogen bonds, forming a three-dimensional network. Furthermore, there is a π–π stacking interaction [centroid–centroid distance = 3.758 (2 Å] between the pyridine and benzene rings.

  19. Pyrrolo[3',2':6,7]cyclohepta[1,2-b]pyridines with potent photo-antiproliferative activity.

    Science.gov (United States)

    Spanò, Virginia; Giallombardo, Daniele; Cilibrasi, Vincenzo; Parrino, Barbara; Carbone, Anna; Montalbano, Alessandra; Frasson, Ilaria; Salvador, Alessia; Richter, Sara N; Doria, Filippo; Freccero, Mauro; Cascioferro, Stella; Diana, Patrizia; Cirrincione, Girolamo; Barraja, Paola

    2017-03-10

    Pyrrolo[3',2':6,7]cyclohepta[1,2-b]pyridines were synthesized as a new class of tricyclic system in which the pyridine ring is annelated to a cycloheptapyrrole scaffold, with the aim of obtaining new photosensitizing agents with improved antiproliferative activity and lower undesired toxic effects. A versatile synthetic pathway was approached, which allowed the isolation of derivatives of the title ring system with a good substitution pattern on the pyrrole moiety. Photobiological studies revealed that the majority of the new compounds showed a potent cytotoxic effect upon photoactivation with light of the proper wavelength, especially when decorated with a 2-ethoxycabonyl group and a N-benzyl substituted moiety, with EC50 values reaching the submicromolar level. The mechanism of action was evaluated.

  20. Synthesis, antimicrobial and anticancer activities of a novel series of diphenyl 1-(pyridin-3-yl)ethylphosphonates.

    Science.gov (United States)

    Abdel-Megeed, Mohamed F; Badr, Badr E; Azaam, Mohamed M; El-Hiti, Gamal A

    2012-04-01

    A novel series of diphenyl 1-(arylamino)-1-(pyridin-3-yl)ethylphosphonates 1-5 was obtained in high yields from reactions of 3-acetyl pyridine with aromatic amines and triphenylphosphite in the presence of lithium perchlorate as a catalyst. The structures of the synthesized compounds were confirmed by IR, (1)H NMR spectral data and microanalyses. Compounds 1-5 showed high antimicrobial activities against Escherichia coli (NCIM2065) as a Gram-negative bacterium, Bacillus subtilis (PC1219) and Staphylococcus aureus (ATCC25292) as Gram-positive bacteria and Candidaalbicans and Saccharomyces cerevisiae as fungi, at low concentrations (10-100 μg/mL). Also, the synthesized compounds showed significant cytotoxicity anticancer activities against liver carcinoma cell line (HepG2) and human breast adenocarcinoma cell line (MCF7). The lethal dose of the synthesized compounds was also determined and indicated that most compounds are safe to use.

  1. 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

    a linear relation between the polymerisation time and the thickness of the surface layer. To further strengthen the antibacterial function the poly-4-vinyl-pyridine surface layer can act as the base for including nano particles of silver precipitated from a salt solution due to ultraviolet radiation....... 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......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...

  2. The Study Of Charge Carrier Transport On The Calamitic Liquid Crystals `` 5, 5'-Di-(Alkyl-Pyridin-Yl) - 2' Bithiophenes''

    Science.gov (United States)

    Shakya, Naresh; Pokhrel, Chandra; Ellman, Brett; Getmanenko, Yulia; Twieg, Robert

    2010-03-01

    The hole and electron mobilities in both types of calamitic liquid crystals C9 [5,5'-Di-(5-n-nonyl-pyridin-2-yl)-2,2'-bithiophenes] and C10 [5,5'-Di-(5-n-decyl-pyridin-2-yl)-2,2'-bithiophenes] were studied. The charge carrier mobilities were strongly electric field dependent. The mobilities decreased continuously with increase in the electric field up to a certain value, after which it became constant. Both types of charge carrier mobilities are independent of the temperature over our temperature range. The qualitative feature of our results could be tentatively explained by the Monte--Carlo modeling proposed by H Bassler. However, the results require further study for better understanding.

  3. Design, Synthesis and Antimycobacterial Activity of Novel Imidazo[1,2-a]pyridine Amide-Cinnamamide Hybrids.

    Science.gov (United States)

    Li, Linhu; Li, Zhuorong; Liu, Mingliang; Shen, Weiyi; Wang, Bin; Guo, Huiyuan; Lu, Yu

    2015-12-30

    We report herein the design and synthesis of a series of novel imidazo[1,2-a]pyridine amide-cinnamamide hybrids linked via an alkyl carbon chain. All 38 new hybrids were evaluated for their antimycobacterial activity against M. tuberculosis (MTB) H37Rv ATCC 27294 using the microplate Alamar Blue assay (MABA). Although the hybrids are less active than the two reference compounds, the promising activity (MICs: 4 μg/mL) of 2,6-dimethylimidazo[1,2-a]pyridine amide-cinnamamide hybrids 11e and 11k could be a good starting point to further find new lead compounds against multi-drug-resistant tuberculosis.

  4. trans-Chlorido(dimethyl sulfoxide-κS(pyridine-2-carboxylato-κ2N,Oplatinum(II

    Directory of Open Access Journals (Sweden)

    Kwang Ha

    2010-03-01

    Full Text Available In the title complex, [Pt(C6H4NO2Cl(C2H6OS], the PtII ion is in a distorted square-planar environment defined by the N and O atoms from the chelating pyridine-2-carboxylate (pic anionic ligand, one S atom of the dimethyl sulfoxide molecule and one Cl ion. The complex is disposed about a crystallographic mirror plane parallel to the ac plane passing through all the atoms of the complex except the methyl atoms of the dimethyl sulfoxide. The molecules are stacked in columns along the b axis with a Pt...Pt distance of 4.9508 (5 Å. Within the column, intermolecular C—H...O hydrogen bonds and weak π–π interactions between adjacent pyridine rings are present, the shortest centroid–centroid distance being 5.153 (4 Å.

  5. 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.

  6. 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...... the formation of extended polyiodide chain structures. The spectroscopic analysis indicates that the ionic product is present in the form of a well-defined complex....

  7. Photolysis and thermolysis of bis(imino)pyridine cobalt azides: C-H activation from putative cobalt nitrido complexes.

    Science.gov (United States)

    Hojilla Atienza, Crisita Carmen; Bowman, Amanda C; Lobkovsky, Emil; Chirik, Paul J

    2010-11-24

    A series of planar aryl-substituted bis(imino)pyridine cobalt azide complexes were prepared and evaluated as synthetic precursors for the corresponding cobalt nitrido compounds. Thermolysis or photolysis of two examples resulted in intramolecular C-H activation of the benzylic positions of the aryl substituents. For the mesityl-substituted compound, C-H activation by the putative nitride resulted in formation of a neutral imine ligand and modification of the chelate by hydrogen transfer to the imine carbon.

  8. 3-[(8-Butoxyquinolin-2-ylmethyl]-1-(pyridin-2-ylmethyl-1H-imidazol-3-ium hexafluoridophosphate

    Directory of Open Access Journals (Sweden)

    Jing Jing

    2012-05-01

    Full Text Available In the cation of the title compound, C23H25N4O+·PF6−, the imidazolium ring make dihedral angles of 87.20 (6 and 79.89 (5° with the pyridine ring and the quinoline system, respectively. In the crystal, C—H...F and C—H...N hydrogen bonds are observed.

  9. 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.

  10. Dichloridobis[2-methylsulfanyl-4-(pyridin-2-ylpyrimidine-κ2N3,N4]cobalt(II

    Directory of Open Access Journals (Sweden)

    Wen-Na Yang

    2011-09-01

    Full Text Available The asymmetric unit of the title compound, [CoCl2(C10H9N3S2], contains one half-molecule with the CoII atom situtated on a twofold rotational axis. The CoII atom, in an octahedral enviroment, is coordinated by four N atoms from two 2-methylsulfanyl-4-(pyridin-2-ylpyrimidine ligands and two Cl atoms.

  11. Ozonation of pyridine and other N-heterocyclic aromatic compounds: Kinetics, stoichiometry, identification of products and elucidation of pathways.

    Science.gov (United States)

    Tekle-Röttering, Agnes; Reisz, Erika; Jewell, Kevin S; Lutze, Holger V; Ternes, Thomas A; Schmidt, Winfried; Schmidt, Torsten C

    2016-10-01

    Pyridine, pyridazine, pyrimidine and pyrazine were investigated in their reaction with ozone. These compounds are archetypes for heterocyclic aromatic amines, a structural unit that is often present in pharmaceuticals, pesticides and dyestuffs (e.g., enoxacin, pyrazineamide or pyrimethamine). The investigated target compounds react with ozone with rate constants ranging from 0.37 to 57 M(-1) s(-1), hampering their degradation during ozonation. In OH radical scavenged systems the reaction of ozone with pyridine and pyridazine is characterized by high transformation (per ozone consumed) of 55 and 54%, respectively. In non scavenged system the transformation drops to 52 and 12%, respectively. However, in the reaction of pyrimidine and pyrazine with ozone this is reversed. Here, in an OH radical scavenged system the compound transformation is much lower (2.1 and 14%, respectively) than in non scavenged one (22 and 25%, respectively). This is confirmed by corresponding high N-oxide formation in the ozonation of pyridine and pyridazine, but probably low formation in the reaction of pyrimidine and pyrazine with ozone. With respect to reaction mechanisms, it is suggested that ozone adduct formation at nitrogen is the primary step in the ozonation of pyridine and pyridazine. On the contrary, ozone adduct formation to the aromatic ring seems to occur especially in the ozonation of pyrimidine as inferred from hydrogen peroxide yield. However, also OH radical reactions are supposed processes in the case of pyrimidine and in particular for pyrazine, albeit negligible OH radical yields are obtained. The low compound transformation in OH radical scavenged system can prove this. As a result of negligible OH radical yields in all cases (less than 6%) electron transfer as primary reaction pathway plays a subordinate role.

  12. Synthesis of 6-Nitroderivatives of Oxazolo[3,2-a]-pyridines and Their Reactions with Nucleophiles

    Directory of Open Access Journals (Sweden)

    Eugene V. Babaev

    2003-06-01

    Full Text Available 5-Nitro-2-pyridone can be selectively N-phenacylated, and the resulting phenacylpyridones I undergo cyclization to 6-nitrooxazolo[3,2-a]pyridinium salts II. These salts II readily react with ammonia and aliphatic amines leading to the products of pyridine ring opening - previously unknown 1-amino-2-nitro-4-(oxazole-2-ylbutadienes-1,3. Reaction of salts II with water lead to hydrolytic cleavage of the oxazole fragment.

  13. Thermal conversion of glycerol to value-added chemicals: pyridine derivatives by one-pot microwave-assisted synthesis

    OpenAIRE

    BAYRAMOĞLU, Duygu; GÜREL, Gökay; SINAĞ, Ali; GÜLLÜ, Mustafa

    2014-01-01

    One-pot syntheses of the value-added heterocyclic compounds 3-methylpyridine and pyridine using a renewable chemical, glycerol, were achieved in acidic medium by thermal conversion reactions. Condensation/cyclization reactions of the thermal degradation products of glycerol were investigated in situ using different ammonia and acidic moiety producing inorganic ammonium salts under pyrolysis or microwave heating conditions. The reaction parameters were studied in detail and satisfying product ...

  14. Thermal conversion of glycerol to value-added chemicals: pyridine derivatives by one-pot microwave-assisted synthesis

    OpenAIRE

    BAYRAMOĞLU, Duygu; GÜREL, Gökay; SINAĞ, Ali; GÜLLÜ, Mustafa

    2015-01-01

    One-pot syntheses of the value-added heterocyclic compounds 3-methylpyridine and pyridine using a renewable chemical, glycerol, were achieved in acidic medium by thermal conversion reactions. Condensation/cyclization reactions of the thermal degradation products of glycerol were investigated in situ using different ammonia and acidic moiety producing inorganic ammonium salts under pyrolysis or microwave heating conditions. The reaction parameters were studied in detail and satisfying product ...

  15. COMPATIBILITY OF POLY (STYRENE-B-2-VINYL PYRIDINE)/IONOMER BLENDS BASED ON ION-LIGAND INTERACTION

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    In this work, DSC and SEM studies indicate that ion-ligand interaction can be utilized toenhance the interaction of poly (styrene-block-2-vinyl pyridine)[P (S-b-2VP)] and polyethylenebased ionomer (Surlyn). The compatibility for this blending system can be improved by this specialinteraction and 20/80 wt is the optimum blending composition with good compatibility. FTIR resultsfurther certify that strong interactions exist in the blending system.

  16. (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.

  17. Synthesis of 3-amino-6-methyl-5-ethoxycarbonyl-4,7-dihydrothieno(2,3-b)pyridine derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Krauze, A.A.; Liepin' sh, E.E.; Pelcher, Yu.E.; Dubur, G.Ya.

    1987-07-01

    The alkylation of piperidinium salts of substituted 1,4-dihydropyridine-2-thiols with chloroacetonitrile or iodoacetamide gave 2-cyanomethylthio- and 2-carbamoylmethylthio-substituted 6-methyl-4-acryl(pyridyl)-5-ethoxycarbonyl-3-cyano-1,4-dihydropyridines, which undergo intramolecular cyclization in basic media to give 3-amino-6-methyl-4-aryl(pyridyl)-5-ethoxycarbonyl-2-cyano(carbamoyl)-4,7-dihydrothieno(2,3-b)pyridines.

  18. 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.

  19. Modification of pineapple peel fiber as metal ion adsorbent through reaction with succinic anhydride in pyridine and dimethyl sulfoxide solvents.

    Science.gov (United States)

    Hu, Xiuyi; Zhao, Mouming; Huang, Huihua

    2010-08-01

    Reactions between saponified pineapple peel fiber (SPPF) and succinic anhydride were performed in refluxed pyridine and dimethyl sulfoxide to obtain modified pineapple peel fiber in pyridine (MPPF-PY) and modified pineapple peel fiber in dimethyl sulfoxide at room temperature (MPPF-DMRT) and at 70 degrees C (MPPF-DM70) as novel metal ionic adsorbents. The modified pineapple peel fibers were characterized by Fourier transform infrared (FTIR) and X-ray diffraction (XRD). The MPPF-PY, MPPF-DMRT, and MPPF-DM70 showed higher Cu2+, Cd2+, and Pb2+ adsorption capacity than raw pineapple peel fiber (RPPF) and SPPF. Dimethyl sulfoxide favored introduction of a carboxylic function group into pineapple peel fiber compared with pyridine. The elevated reaction temperature of dimethyl sulfoxide could increase the adsorption capacity of the modified pineapple fiber. Optimum pH values for Cu2+, Cd2+, and Pb2+ removal by MPPF-DM70 were pH 5.5, 7.5, and 5.5, respectively. The Cu2+, Cd2+, and Pb2+ adsorptions by MPPF-DM70 followed the pseudo second-order kinetics model and Langmuir model.

  20. p-Bromophenacyl bromide prevents cumene hydroperoxide-induced mitochondrial permeability transition by inhibiting pyridine nucleotide oxidation.

    Science.gov (United States)

    Zhukova, A; Gogvadze, G; Gogvadze, V

    2004-01-01

    Mitochondrial permeability transition is commonly characterized as a Ca2+ -dependent non-specific increase in inner membrane permeability that results in swelling of mitochondria and their de-energization. In the present study, the effect of different inhibitors of phospholipase A2--p-bromophenacyl bromide, dibucaine, and aristolochic acid--on hydroperoxide-induced permeability transitions in rat liver mitochondria was tested. p-Bromophenacyl bromide completely prevented the hydroperoxide-induced mitochondrial permeability transition while the effects of dibucaine or aristolochic acid were negligible. Organic hydroperoxides added to mitochondria undergo reduction to corresponding alcohols by mitochondrial glutathione peroxidase. This reduction occurs at the expense of GSH which, in turn, can be reduced by glutathione reductase via oxidation of mitochondrial pyridine nucleotides. The latter is considered a prerequisite step for mitochondrial permeability transition. Among all the inhibitors tested, only p-bromophenacyl bromide completely prevented hydroperoxide-induced oxidation of mitochondrial pyridine nucleotides. Interestingly, p-bromophenacyl bromide had no affect on mitochondrial glutathione peroxidase, but reacted with mitochondrial glutathione that prevented pyridine nucleotides from being oxidized. Our data suggest that p-bromophenacyl bromide prevents hydroperoxide-induced deterioration of mitochondria via interaction with glutathione rather than through inhibition of phospholipase A2.

  1. catena-Poly[[diaquabis{μ2-3,5-bis[(pyridin-4-ylmethylamino]benzoato}nickel] monohydrate

    Directory of Open Access Journals (Sweden)

    Xiao-Chun Cheng

    2011-10-01

    Full Text Available In the title coordination polymer, {[Ni(C19H17N4O22(H2O2]·H2O}n, the Ni2+ cation is located on an inversion center and coordinated by two carboxylate O atoms from two different 3,5-bis(pyridin-4-ylmethylaminobenzoate anions, two O atoms from two coordinated water molecules and two N atoms from two different 3,5-bis(pyridin-4-ylmethylaminobenzoate anions, displaying a slightly distorted NiN2O4 octahedral geometry. Each 3,5-bis(pyridin-4-ylmethylaminobenzoate anion acts as a μ2-bridge, linking different nickel ions into a chain along [010]. In the crystal, adjacent chains are further linked through N—H...O, O—H...O, O—H...N and C—H...O hydrogen bonds into a three-dimensional network. The coordinated water molecules and a disordered water molecule of hydration with 0.50 site occupancy play an important role in the formation of these hydrogen-bonding interactions.

  2. 2,3-Pyridine dicarboxylic acid functionalized gold nanoparticles: Insight into experimental conditions for Cr3 + sensing

    Science.gov (United States)

    Shaikh, Ruqaya; Memon, Najma; Solangi, Amber R.; Shaikh, Huma I.; Agheem, Muhammad Hassan; Ali, Syed Abid; Shah, Muhammad Raza; Kandhro, Aftab

    2017-02-01

    Selectivity of gold nanoparticles (AuNPs) depends upon surface functionality; small changes in structure or concentration bring significant changes in the behavior of AuNPs. In this study, citrate-capped AuNPs were functionalized with ortho-dicarboxylate substituted pyridine (2,3-PDCA) and detailed studies on experimental conditions were carried out to check the stability of AuNPs and response for Cr3 +. Stability of PDCA-AuNPs was found sensitive to the pH, ionic strength of buffer and its type. Capping behavior of PDCA on C-AuNPs was examined by FTIR spectroscopy. Surface morphology and size of synthesized AuNPs were confirmed by AFM, XRD, and DLS techniques where particles were found 11 nm in size, monodisperse and spherical in shape. Interaction of stabilized AuNPs was tested with various metal ions; where Cr3 + induced the changes in localized surface plasmon band (LSPR) of PDCA-AuNPs which leads to a color change from wine red to violet blue. The phenomenon is explained as cooperative effect of citrate and pyridine nitrogen on surface of AuNPs in contrary to meta-dicarboxylate substituted pyridine derivatives. Further, under optimized and controlled conditions Cr3 + shows linear response with decrease in absorbance at LSPR intensity of AuNPs (518 nm). Moreover, to demonstrate the applicability of method, Cr3 + was determined in the presence of Cr (VI) which shows 96% recovery.

  3. 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.

  4. Three novel dipicolinate complexes with the pyridine-2,6-dimethanol - A combined structural, spectroscopic, antimicrobial and computational study

    Science.gov (United States)

    Uçar, İbrahim; Tamer, Ömer; Sarıboğa, Bahtiyar; Büyükgüngör, Orhan

    2013-01-01

    Three new dipicolinate complexes, [M(dmp)(dpc)]·H2O [M = Co(II) (1); Zn(II) (2); Ni(II) (3); dmp: pyridine-2,6-dimethanol; dpc: dipicolinate or pyridine-2,6-dicarboxylate], were synthesized and combined with experimental and theoretical study on molecular, vibrational and electronical properties. The central M(II) ion in all complexes is bonded to dpc and dmp ligands through pyridine nitrogen atom together with two oxygen atom, forming the distorted octahedral geometry. The complex molecules, connected via O-H⋯O hydrogen bonds, form a supramolecular structure. The complexes were also screened for antimicrobial activity against human pathogenic Gram-positive, Gram-negative bacteria and fungi. Among the tested microorganisms, Streptococcus pneumoniae was the most sensitive strain, especially to H2dpc and its complexes. The EPR spectra of Cu2+ doped polycrystalline complexes indicate that the paramagnetic center has a rhombic symmetry. Although the supramolecular interactions have some influences on the molecular geometry in solid state phase, calculated data show that the predicted geometries can reproduce the structural parameters. The electronic station in the frontier orbitals of the dipicolinate complexes calculated from the experimental data is compared to the results of time-depended DFT calculations with the polarizable continuum model and UV-Vis spectrum of the complexes has been discussed on this basis. Calculated vibrational frequencies using the DFT and HF method are consistent with the experimental IR data.

  5. Self-assembly and supramolecular liquid crystals based on organic cation encapsulated polyoxometalate hybrid reverse micelles and pyridine derivatives.

    Science.gov (United States)

    Yin, Shengyan; Sun, Hang; Yan, Yi; Zhang, Hui; Li, Wen; Wu, Lixin

    2011-09-15

    The controlled self-assembly of multi-components in one system represents the capability integrating intermolecular interactions and functions of components and is believed the key procedure leading to multifunctional materials finally. In pursuing this goal, we used a double-chain cationic surfactant with a benzoic acid group at the end of one tail to encapsulate Keggin-type polyanion clusters via electrostatic interaction, obtaining uniform supramolecular hybrid reverse micelles, which served as hydrogen-bonding donors. Five pyridine derivatives containing conjugated and non-conjugated groups were chosen as hydrogen-bonding acceptors to bind with reverse micelles. Through mixing with these components according to chemical stoichiometry, the hybrid reverse micelle changed to a new self-assembly precursor through intermolecular hydrogen bonding. The as-prepared reverse micelles bearing conjugated pyridine groups exhibit supramolecular liquid crystal properties, which were characterized by differential scanning calorimetry, polarizing optical microscopy, and X-ray diffraction. The length and number of the alky chain in the pyridine derivatives, as well as the charges of polyoxometalates were also studied with regard to the liquid crystal structure. The synergistic effect of among three components was analyzed, and the liquid crystal properties could be conveniently adjusted through the modification of the hydrogen-bonding acceptor components.

  6. Gas-phase lithium cation basicity of histamine and its agonist 2-([beta]-aminoethyl)-pyridine

    Science.gov (United States)

    Hallmann, M.; Raczynska, E. D.; Gal, J. F.; Maria, P. C.

    2007-11-01

    The gas-phase lithium cation basicities (LCBs) were obtained for histamine (HA) and its agonist 2-([beta]-aminoethyl)-pyridine (AEP) from collision-induced dissociation of lithium adducts using Fourier-transform ion cyclotron resonance mass spectrometry (FT-ICR-MS). For measurements, MeO(CH2)2OMe, Et3PO and (Me2N)3PO (HMPA) were used as the reference compounds. The experimental LCB of AEP was located between those of Et3PO and (Me2N)3PO. The experimental LCB of HA was found to be higher than those of AEP and HMPA by more than 2 kcal mol-1 clearly indicating that the LCB of HA is higher than any LCB for a neutral base yet measured (crown-ethers excepted). The experimental LCBs of the parent bases (pyridine and imidazole) are lower by more than 10 kcal mol-1. In parallel, DFT calculations {B3LYP/6-31G*//B3LYP/6-31G* and B3LYP/6-311+G**//B3LYP/6-31G*} were performed for HA, AEP and their lithium adducts. Among the 22 reasonable conformations of the HA-Li+ adduct, only one appears to be significantly more stable than the others. This is also the case for one structure among seven conformations of the AEP-Li+ adduct. These two stable structures have the [`]scorpion' conformation, in which the Li+ cation is almost equally chelated by two basic nitrogen atoms, the ring N-aza and the chain N-amino. Other HA-Li+ and AEP-Li+ conformations have noticeably higher energies than the [`]scorpion' structures. The difference between the DFT calculated LCBs of HA and AEP (about 4 kcal mol-1) is in agreement with that experimentally obtained (>2 kcal mol-1). The high experimental and theoretical values of LCB for HA and AEP militate in favor of a strong chelation of Li+ by both ligands in the gas-phase. This chelation effect was also evidenced previously for the proton gas-phase basicity.

  7. Synthesis and Crystal Structure of 2-Benzoyl Pyridine Thiosemicarbazato Palladium(Ⅱ)Chloride

    Institute of Scientific and Technical Information of China (English)

    刘泽华; 王守兴; 段春迎; 游效曾

    2001-01-01

    The title complex,2-benzoyl pyridine thiosemicarbazato palladium(Ⅱ)chloride [C13H11N4SPdCl,Mr=379.17],crystallizes in monoclinic,space group C2/c with a=12.1061(5),b=21.877(3),c=11.4832(6)A,β=108.29(9)°,V=2887.7(4)A3,Z=8,Dc=1.827g/cm3; μ=1.608cm-1 and F(000)=1568.R=0.0281 and wR=0.0684 for 1446 reflections with I > 2σ(Ⅰ).X-ray crystal structure analysis revealed that the coordination geometry of Pd atom is a distorted square plane with two Pd- N bonds,one Pd - S bond and one Pd - Cl bond.The Schiff-base ligand loses a proton from its tautomeric thiol form and coordinates to the Pd atom via the mercapto sulfur and theβ-nitrogen atoms.

  8. Electron transport properties of bis[2-(2-hydroxyphenyl)-pyridine]beryllium investigated by impedance spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Yanping; Chen, Jiangshan; Huang, Jinying; Ma, Dongge, E-mail: mdg1014@ciac.jl.cn, E-mail: dongls@ciac.jl.cn [State Key Laboratory of Polymer Physics and Chemistry, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Changchun 130022 (China); Dong, Lisong, E-mail: mdg1014@ciac.jl.cn, E-mail: dongls@ciac.jl.cn [Key Laboratory of Polymer Ecomaterials, Changchun Institute of Applied Chemistry, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Changchun 130022 (China); Chen, Hui [Department of Science, Shenyang University of Chemical Technology, Shenyang 110142 (China)

    2014-06-14

    The electron transport properties of bis[2-(2-hydroxyphenyl)-pyridine] beryllium (Bepp{sub 2}) are investigated by impedance spectroscopy over a frequency range of 10 Hz to 13 MHz. The Cole-Cole plots demonstrate that the Bepp{sub 2}-based device can be represented by a single parallel resistance R{sub p} and capacitance C{sub p} network with a series resistance R{sub s}. The current-voltage characteristics and the variation of R{sub p} with applied bias voltage indicate the electron conduction of space-charge-limited current with exponential trap distributions in Bepp{sub 2}. It can be seen that the electron mobility exhibits strong field-dependence in low electric field region and almost saturate in high electric field region. It is experimentally found that Bepp{sub 2} shows dispersion transport and becomes weak as the electric field increases. The activation energy is determined to be 0.043 eV by temperature-dependent conductivity, which is consistent with the result obtained from the temperature-dependent current density characteristics. The electron mobility reaches the orders of 10{sup −6}–10{sup −5} cm{sup 2} V{sup −1} s{sup −1}, depending on the electric field.

  9. Hybrid imidazole (benzimidazole)/pyridine (quinoline) derivatives and evaluation of their anticancer and antimycobacterial activity.

    Science.gov (United States)

    Mantu, Dorina; Antoci, Vasilichia; Moldoveanu, Costel; Zbancioc, Gheorghita; Mangalagiu, Ionel I

    2016-01-01

    The design, synthesis, structure, and in vitro anticancer and antimycobacterial activity of new hybrid imidazole (benzimidazole)/pyridine (quinoline) derivatives are described. The strategy adopted for synthesis is straight and efficient, involving a three-step setup procedure: N-acylation, N-alkylation, and quaternization of nitrogen heterocycle. The solubility in microbiological medium and anticancer and antimycobacterial activity of a selection of new synthesized compounds were evaluated. The hybrid derivatives have an excellent solubility in microbiological medium, which make them promising from the pharmacological properties point of view. One of the hybrid compounds, 9 (with a benzimidazole and 8-aminoquinoline skeleton), exhibits a very good and selective antitumor activity against Renal Cancer A498 and Breast Cancer MDA-MB-468. Moreover, the anticancer assay suggests that the hybrid Imz (Bimz)/2-AP (8-AQ) compounds present a specific affinity to Renal Cancer A498. Concerning the antimycobacterial activity, only the hybrid compound, 9, has a significant activity. SAR correlations have been performed.

  10. Dichloridobis(pyridine-2-thiolato-κ2N,Stin(IV: a new polymorph

    Directory of Open Access Journals (Sweden)

    Sheyda R. Ismaylova

    2012-07-01

    Full Text Available The title compound, [SnCl2(C5H4NS2], is the product of reaction of 2,2′-dipyridyl disulfide with tin tetrachloride. The SnIV atom adopts a distorted octahedral geometry, with the two bidentate pyridine-2-thiolate ligands forming two planar four-membered chelate rings. The two Sn—Cl, two Sn—N and two Sn—S bonds are in cis, cis and trans configurations, respectively. The crystal grown from acetonitrile represents a new monoclinic polymorph in space group C2/c with the molecule having twofold rotational symmetry, the SnIV atom lying on the twofold axis. The molecular structure of the monoclinic polymorph is very close to that of the triclinic polymorph studied previously in space group P-1, the molecule occupying a general position [Masaki & Matsunami (1976. Bull. Chem. Soc. Jpn, 49, 3274–3279; Masaki et al. (1978. Bull. Chem. Soc. Jpn, 51, 3298–3301]. Apparently, the formation of the two polymorphs is determined by the different systems of intermolecular interactions. In the crystal of the monoclinic polymorph, molecules are bound into ribbons along the c axis by C—H...Cl hydrogen bonds, whereas in the crystal of the triclinic polymorph, molecules form chains along the a axis by attractive S...S interactions. The crystal studied was a pseudo-merohedral twin; the refined BASF value is 0.221 (1.

  11. 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 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.

  12. Microcalorimetric Study on the Inhibition of Escherichia coil by Some Novel Pyridine Amide Schiff Base Derivatives

    Institute of Scientific and Technical Information of China (English)

    LI Chao-Hong; ZHANG Li-Xia; CAI Li-Hua; LIU Yi; HU Pei-Zhi

    2008-01-01

    The antibacterial effect of a series of novel pyridine amide Schiff base compounds on Escherichia coli was investigated by a microcalorimetric method at 37℃.The metabolic power-time curves of the bacteria treated by the compounds were obtained,and the thermokinetic parameters were analyzed,from which the antibacterial activities of these compounds were evaluated.The results show that two compounds F and G have good activity on aerobic multiplying metabolism of E.coli,with the value of IC50 106 and 113 mg/L respectively,but have no effective action on the fermentation metabolism of E.coli.The action of the compounds on the non-multiplying metabolism was investigated by taking the heat output of E.coli in the stationary phase as the guideline of the activity.The experimental results revealed that the hydrophilicity of these Schiff bases had a great influence on their antibacterial activity,which results from the bacterial cell wall structure.The antibacterial structure-activity relationship of these Schiff base derivatives was also briefly discussed.The antibacterial activity of the compounds against E.coli was as follows:compound F>G>C>D>E>B>A.

  13. Blue-violet photoluminescence of 4-isopropyl-pyridine hydroxide crystals.

    Science.gov (United States)

    Vaganova, Evgenia; Wachtel, Ellen; Leitus, Gregory; Danovich, David; Popov, Inna; Dubnikova, Faina; Yitzchaik, Shlomo

    2014-05-01

    There is continuing interest in determining essential structural features of polymer gels, which display photoelectric and/or thermoelectric behavior. One such gel is the blend, poly(4-vinylpyridine-co-butyl methacrylate)/poly(4-vinylpyridine), dissolved in liquid pyridine. Following extended aeration of a three-component mixture, which serves as a model for the gel side chain interactions, crystallization of a new molecule, 4-isopropylpyridine hydroxide (IPPOH), occurs. X-ray diffraction, DFT modeling, and spectroscopy were used to determine the structural, electronic, and luminescent properties of the crystal. The crystal structure reveals molecules forming head-to-tail, hydrogen-bonded chains without base stacking or marked interchain interaction. The molecular chains are characterized by moderately long-lived, blue-violet luminescence excited in the near-UV. Because these photoluminescent properties resemble those of the gel from which the crystals are derived, we may posit similar structural features in the gel for which direct structural analysis is not available.

  14. Binding of Ru(terpyridine)(pyridine)dipyridophenazine to DNA studied with polarized spectroscopy and calorimetry.

    Science.gov (United States)

    Mårtensson, Anna K F; Lincoln, Per

    2015-02-28

    Linear and circular dichroism (LD and CD) spectroscopy as well as isothermal titration calorimetry (ITC) have been used to investigate the interaction of Ru(tpy)(py)dppz(2+) (tpy = 2,2':6',2''-terpyridyl; py = pyridine; dppz = dipyrido[3,2-a:2'3'-c]phenazine) with DNA, providing detailed information about the DNA binding thermodynamics and binding geometry of the metal complex. Flow LD, CD and isotropic absorption indicate that Ru(tpy)(py)dppz(2+) bind to DNA from the minor groove with the dppz ligand intercalated between base pairs, very similar to its chiral structural isomers Δ- and Λ-Ru(bpy)2dppz(2+) (bpy = 2,2'-bipyridine). A simple cooperative binding model with one binding geometry provide an excellent fit for calorimetric and absorption titration data. The values of the neighbor interaction thermodynamic parameters for Ru(tpy)(py)dppz(2+) suggest that complexes bound contiguously prefer to have their tpy ligands oriented towards the same strand.

  15. THE EXTRACTION OF GOLD FROM CYANIDE SOLUTION BY α—ALKYL SUBSTITUTED PYRIDINE RESIN

    Institute of Scientific and Technical Information of China (English)

    GANWeitang; LIUYouying; 等

    1992-01-01

    In this paper,we have studied the adsorption properties of gold by α-alkyl substituted pyridine resin( BPR) in alkaline solution.The single and dual component kinetic mass transfer process of Au(I),Ag(I) and other metal cyanide ions were also investigated.The results obtained show that the mass transfer rates of the cyanide ions in the resin phase are closely related to the molar ratio and the configuration of metal cyanide ions. The elution kinetics of Au(I) and other cyanide ions by NH4SCN has been investigated systematically.The intraparticle diffusion coefficient and activation energy of Au(I),Ag(I),Ni(I) Fe(Ⅲ) cyanide anions were determined in CI,NO3,OH-type BPR resin at different temperatures.It is found from the experimental results that the mechanism for extracting Au(I),Ag(I) and other metal cyanide anions by BPR resin belongs to ion exchange process.The difference of activation entropy of some metal cyanide anions(ΔS-ΔS-) was evaluated.

  16. Thermal and magnetic properties and vibrational analysis of 4-(dimethylamino) pyridine: a quantum chemical approach.

    Science.gov (United States)

    Balachandran, V; Rajeswari, S; Lalitha, S

    2014-04-24

    The FT-IR and FT-Raman spectra of 4-(dimethylamino) pyridine (4DMAP) have been recorded in the region 4000-500 cm(-1)and 3500-100 cm(-1). Quantum chemical calculations of energy, geometry and vibrational wavenumbers of 4DMAP were carried out by using ab initio HF and density functional theory (DFT/B3LYP) with complete relaxation in the potential energy surface using 6-311++G(d,p) basis set. The harmonic vibrational wavenumbers were calculated and the scaled wavenumbers have been compared with the experimental FT-IR and FT-Raman spectra. The quantum chemical parameters have been computed from the HOMO-LUMO energy values. Temperature dependence thermodynamic parameters and magnetic properties of the title compound have been analyzed. Using NBO analysis the stability of the molecule arising from hyper-conjugative interactions, charge delocalization has been analyzed. The first-order hyper-polarizability (β) values of the title molecule were computed by B3LYP method. Finally the theoretically spectrograms for FT-IR and FT-Raman spectra of the title molecule have been constructed which show good agreement with recorded spectra.

  17. 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.

  18. 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.

  19. Protonation effects on the photophysical properties of poly(2,5-pyridine diyl)

    Science.gov (United States)

    Monkman, A. P.; Halim, M.; Samuel, I. D. W.; Horsburgh, L. E.

    1998-12-01

    We have recently shown that poly(2,5-pyridine diyl) (PPY) can be synthesized to yield a polymer with high photoluminescence quantum yield (PLQY) in the solid state, and that it is an excellent electron transport material. To explore the photophysical properties of PPY further, we have used a range of acidic "dopants" to protonate the nitrogen sites on each ring and made observations on how this affects the optical properties of the resultant protonated PPY films. In general, we find that sulphonic acids have the greatest effect, causing perturbations to both the ground-state and excited-state properties of the PPY. These changes occur with only moderate reduction of the PLQY, whereas nonsulphonic acids cause a larger reduction in PLQY without significantly affecting the ground- or excited-state energy levels. These aspects of the photophysics of PPY can be described using a simple ring torsion argument. This model can also account for the observed shifts between solution state and solid-state emission wavelengths.

  20. Three new bismuth(III) pyridine-2,6-dicarboxylate compounds: Synthesis, characterization and crystal structures

    Science.gov (United States)

    Hakimi, Mohammad; Motieiyan, Elham; Bertolotti, Federica; Marabello, Domenica; Nunes Rodrigues, Vitor Hugo

    2015-11-01

    Three new metal-organic compounds containing bismuth and pyridine-2,6-dicarboxylate (pydc) formulated as (2-apyH)2[Bi(pydc)2(pydcH)]·2H2O, 1, (4-apyH)[Bi(pydc) (pydcH)2].4H2O, 2 and (pipzeaH)[Bi2(pydc)3(pydcH) (H2O)2]·5H2O, 3, (2-apy = 2-aminopyridine, 4-apy = 4-aminopyridine, pipzea = 2-piperazin-1-ylethanamine), have been synthesized in deionized water and characterized by elemental analysis (C, H and N), spectral (UV-Vis, IR), 1H NMR spectroscopy, TGA and single crystal X-ray diffraction. These compounds were obtained via proton transfer methodology. Compounds 1 and 2 have similar monomeric bismuth coordination units, whereas compound 3 has a dimeric bismuth coordination unit. The compounds are anionic in 1 and 2 and they are connected non-covalently to 2-apyH and 4-apyH, respectively. In 3, two molecules are present, one neutral and one anionic, and both are connected non-covalently to pipzeaH cations. Five different coordination modes of Bi-pydc exist in 1, 2 and 3. These compounds are stabilized in the solid state by a complex network of hydrogen bonds between crystallization water molecules, anionic, cationic and neutral fragments, forming 3D-supramolecular arrays.

  1. Characteristic electron transport on pyridine-linked molecular devices with graphene nanoribbons electrodes and gold electrodes

    Science.gov (United States)

    Li, Jie; Zhou, Yi; Zhang, Leining; Li, Hui

    2016-09-01

    The electrodes in the molecular devices play a crucial role in creating functional organic electronic devices. We employed the first-principles calculations to investigate the conjugated pyridine-terminated molecule-4, 4‧-vinylenedipyridine attached to monolayer zigzag graphene nanoribbons (ZGNRs) and Au electrodes. Results show that the ZGNRs-based device exhibits excellent electrical properties. It has larger equilibrium conductance or stronger transmission capacity due to higher strength of individual channel and stronger delocalization of electronic states at the Fermi level. The transmission of two devices near the Fermi level is influenced by resonant electron transport through the discrete energy and the edge states. Comparatively, different from the rising trend of gold-based device with the increasing voltage, the current of the device with ZGNRs electrodes changes in a completely different way with the augment of the applied voltage, exhibiting a negative differential resistance effect unexpectedly. The changing trends of the current through two devices are elucidated by the evolution of the transmission peak nearest to the Fermi level.

  2. 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.

  3. Synthesis and Application of 1-(Pyridin-2-yl)-2-azabuta-1,3-dienes%1-(2-吡啶基)-2-氮杂-1,3-丁二烯的合成与应用

    Institute of Scientific and Technical Information of China (English)

    杨维芳; 徐晓丽; 张站斌

    2014-01-01

    1-(Pyridin-2-yl)-2-azabuta-1,3-dienes (2) prepared from pyridine-2-carboxaldehyde underwent Diels-Alder reac-tion with electron-poor dienophiles such as alkenes and alkynes to give 6-(pyridin-2-yl)piperidin-2-ones and dihydro-6-(pyri-din-2-yl)pyridin-2-ones. Dihydro-6-(pyridin-2-yl)pyridin-2-one was oxidized with 2,3-dichloro-5,6-dicyano-1,4-benzoquinone (DDQ) to afford 6-(pyridin-2-yl) pyridin-2-one. Treatment of 6-(pyridin-2-yl)pyridin-2-one with phosphorus oxychloride gave bipyridine derivative.%以2-吡啶甲醛为起始原料制备1-(2-吡啶基)-2-氮杂-1,3-丁二烯(2),然后与烯烃、炔烃发生Diels-Alder反应分别得到6-(2-吡啶基)-2-哌啶酮和6-(2-吡啶基)-二氢-2-吡啶酮。用2,3-二氯-5,6-二氰基-1,4-苯醌(DDQ)氧化6-(2-吡啶基)-二氢-2-吡啶酮得到6-(2-吡啶基)-2-吡啶酮,最后用三氯氧磷处理得到联吡啶类化合物。

  4. Nitrogen-doped graphene films from chemical vapor deposition of pyridine: influence of process parameters on the electrical and optical properties

    Directory of Open Access Journals (Sweden)

    Andrea Capasso

    2015-10-01

    Full Text Available Graphene films were produced by chemical vapor deposition (CVD of pyridine on copper substrates. Pyridine-CVD is expected to lead to doped graphene by the insertion of nitrogen atoms in the growing sp2 carbon lattice, possibly improving the properties of graphene as a transparent conductive film. We here report on the influence that the CVD parameters (i.e., temperature and gas flow have on the morphology, transmittance, and electrical conductivity of the graphene films grown with pyridine. A temperature range between 930 and 1070 °C was explored and the results were compared to those of pristine graphene grown by ethanol-CVD under the same process conditions. The films were characterized by atomic force microscopy, Raman and X-ray photoemission spectroscopy. The optical transmittance and electrical conductivity of the films were measured to evaluate their performance as transparent conductive electrodes. Graphene films grown by pyridine reached an electrical conductivity of 14.3 × 105 S/m. Such a high conductivity seems to be associated with the electronic doping induced by substitutional nitrogen atoms. In particular, at 930 °C the nitrogen/carbon ratio of pyridine-grown graphene reaches 3%, and its electrical conductivity is 40% higher than that of pristine graphene grown from ethanol-CVD.

  5. New fluorescent heterocyclic systems from imidazo[1,2-a]pyridine: Design, synthesis, spectral studies and quantum-chemical investigations

    Science.gov (United States)

    Pordel, Mehdi; Chegini, Hamed; Ramezani, Shirin; Daee, Mohammadreza

    2017-02-01

    Two new fluorescent heterocyclic systems dipyrido[1‧,2‧:1,2]imidazo[4,5-b:4,5-e]pyridine-13-carbonitrile and pyrido[1‧,2‧:1,2]imidazo[4,5-b]pyrido[2‧,1‧:2,3]imidazo[4,5-e]pyridine-13-carbonitrile were synthesized by one-pot reaction of imidazo[1,2-a]pyridine with 2-(imidazo[1,2-a]pyridin-3-yl)acetonitrile and 2-(imidazo[1,2-a]pyridin-2-yl)acetonitrile, respectively, in MeOH/KOH solution via the nucleophilic substitution of hydrogen in high yields. Spectral and analytical data have confirmed the structures of the synthesized dyes. The optical and solvatochromic properties of the compounds were investigated and the results showed that they exhibited interesting photophysical properties. Density functional theory (DFT) calculations of fluorescent dyes were performed to provide the optimized geometries and relevant frontier orbitals by using the B3LYP hybrid functional and the 6-311 ++ G(d,p) basis set. Calculated electronic absorption spectra were also obtained by time-dependent density functional theory (TD-DFT) method. In addition, electron density iso-surface map, intra- and intermolecular interactions of these fluorescent heterocyclic systems were evaluated by AIM (Atoms in Molecules) analysis.

  6. Self-assembly of Bis[2-(2-hydroxyphenyl)-pyridine]Copper(Ⅱ) Induced by C-H…π and π…π Stacking Interaction

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@ Introduction The control of molecular assembly in the solid state is an important theme of modern chemistry.It is in this regard that there is an activity in the area of supramolecular structures at present.The self-assembly of molecules can form well-defined supramolecular structures under the influence of drive forces such as hydrogen bonds[1-3],metal-ligand coordination bonds[4-6] and π…π stacking interactions[7-10].Word et al.have described the co-ordination chemistry of polydentate chelating ligands which contain mixed pyridine-phenol donor sets[11].Some unusual structures of transition metal pyridine-phenol complexes have been established in which non-covalent interactions such as hydrogen bonding and π…π stacking appear to play a dominant part.These observations suggest that it might be possible to construct supramolecular structures with a metal pyridine-phenol system.To explore this idea we have begun to investigate the self-assembly properties of metal pyridine-phenol complexes.Herein we present the self-assembly properties of Cu(pp)2[pp=2-(2-hydroxyphenol)-pyridine] under different conditions.

  7. 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.

  8. 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.

  9. Hg(II Coordination Polymers Based on N,N’-bis(pyridine-4-ylformamidine

    Directory of Open Access Journals (Sweden)

    Wayne Hsu

    2016-04-01

    Full Text Available Reactions of N,N’-bis(pyridine-4-ylformamidine (4-Hpyf with HgX2 (X = Cl, Br, and I afforded the formamidinate complex {[Hg(4-pyf2]·(THF}n, 1, and the formamidine complexes {[HgX2(4-Hpyf]·(MeCN}n (X = Br, 2; I, 3, which have been structurally characterized by X-ray crystallography. Complex 1 is a 2D layer with the {44·62}-sql topology and complexes 2 and 3 are helical chains. While the helical chains of 2 are linked through N–H···Br hydrogen bonds, those of 3 are linked through self-complementary double N–H···N hydrogen bonds, resulting in 2D supramolecular structures. The 4-pyf- ligands of 1 coordinate to the Hg(II ions through one pyridyl and one adjacent amine nitrogen atoms and the 4-Hpyf ligands of 2 and 3 coordinate to the Hg(II ions through two pyridyl nitrogen atoms, resulting in new bidentate binding modes. Complexes 1–3 provide a unique opportunity to envisage the effect of the halide anions of the starting Hg(II salts on folding and unfolding the Hg(II coordination polymers. Density function theory (DFT calculation indicates that the emission of 1 is due to intraligand π→π * charge transfer between two different 4-pyf- ligands, whereas those of 2 and 3 can be ascribed to the charge transfer from non-bonding p-type orbitals of the halide anions to π * orbitals of the 4-pyf- ligands (n→π *. The gas sorption properties of the desolvated product of 1 are compared with the Cu analogues to show that the nature of the counteranion and the solvent-accessible volume are important in determining their adsorption capability.

  10. Synthesis, Structure and Antimicrobial Properties of Novel Benzalkonium Chloride Analogues with Pyridine Rings.

    Science.gov (United States)

    Brycki, Bogumił; Małecka, Izabela; Koziróg, Anna; Otlewska, Anna

    2017-01-13

    Quaternary ammonium compounds (QACs) are a group of compounds of great economic significance. They are widely used as emulsifiers, detergents, solubilizers and corrosion inhibitors in household and industrial products. Due to their excellent antimicrobial activity QACs have also gained a special meaning as antimicrobials in hospitals, agriculture and the food industry. The main representatives of the microbiocidal QACs are the benzalkonium chlorides (BACs), which exhibit biocidal activity against most bacteria, fungi, algae and some viruses. However, the misuses of QACs, mainly at sublethal concentrations, can lead to an increasing resistance of microorganisms. One of the ways to avoid this serious problem is the introduction and use of new biocides with modified structures instead of the biocides applied so far. Therefore new BAC analogues P13-P18 with pyridine rings were synthesized. The new compounds were characterized by NMR, FT-IR and ESI-MS methods. PM3 semiempirical calculations of molecular structures and the heats of formation of compounds P13-P18 were also performed. Critical micellization concentrations (CMCs) were determined to characterize the aggregation behavior of the new BAC analogues. The antimicrobial properties of novel QACs were examined by determining their minimal inhibitory concentration (MIC) values against the fungi Aspergillus niger, Candida albicans, Penicillium chrysogenum and bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The MIC values of N,N-dimethyl-N-(4-methylpyridyl)-N-alkylammonium chlorides for fungi range from 0.1 to 12 mM and for bacteria, they range from 0.02 to 6 mM.

  11. Synthesis, Structure and Antimicrobial Properties of Novel Benzalkonium Chloride Analogues with Pyridine Rings

    Directory of Open Access Journals (Sweden)

    Bogumił Brycki

    2017-01-01

    Full Text Available Quaternary ammonium compounds (QACs are a group of compounds of great economic significance. They are widely used as emulsifiers, detergents, solubilizers and corrosion inhibitors in household and industrial products. Due to their excellent antimicrobial activity QACs have also gained a special meaning as antimicrobials in hospitals, agriculture and the food industry. The main representatives of the microbiocidal QACs are the benzalkonium chlorides (BACs, which exhibit biocidal activity against most bacteria, fungi, algae and some viruses. However, the misuses of QACs, mainly at sublethal concentrations, can lead to an increasing resistance of microorganisms. One of the ways to avoid this serious problem is the introduction and use of new biocides with modified structures instead of the biocides applied so far. Therefore new BAC analogues P13–P18 with pyridine rings were synthesized. The new compounds were characterized by NMR, FT-IR and ESI-MS methods. PM3 semiempirical calculations of molecular structures and the heats of formation of compounds P13–P18 were also performed. Critical micellization concentrations (CMCs were determined to characterize the aggregation behavior of the new BAC analogues. The antimicrobial properties of novel QACs were examined by determining their minimal inhibitory concentration (MIC values against the fungi Aspergillus niger, Candida albicans, Penicillium chrysogenum and bacteria Staphylococcus aureus, Bacillus subtilis, Escherichia coli and Pseudomonas aeruginosa. The MIC values of N,N-dimethyl-N-(4-methylpyridyl-N-alkylammonium chlorides for fungi range from 0.1 to 12 mM and for bacteria, they range from 0.02 to 6 mM.

  12. New 3-Cyano-2-Substituted Pyridines Induce Apoptosis in MCF 7 Breast Cancer Cells

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    Ahmed Malki

    2016-02-01

    Full Text Available The synthesis of new 3-cyano-2-substituted pyridines bearing various pharmacophores and functionalities at position 2 is described. The synthesized compounds were evaluated for their in vitro anti-cancer activities on five cancer cell lines using 5-FU as reference compound. The results revealed that the benzohydrazide derivative 9a induced growth inhibition in human breast cancer cell line MCF-7 with an IC50 value of 2 μM and it showed lower cytotoxicity on MCF-12a normal breast epithelial cells. Additionally, 9a induced apoptotic morphological changes and induced apoptosis in MCF-7 in a dose and time-dependent manner according to an enzyme linked immunosorbent apoptosis assay which is further confirmed by a TUNEL assay. Flow cytometric analysis indicated that 9a arrested MCF-7 cells in the G1 phase, which was further confirmed by increased expression of p21 and p27 and reduced expression of CDK2 and CDK4. Western blot data revealed significant upregulation of the expression of p53, Bax, caspase-3 and down-regulation of Bcl-2, Mdm-2 and Akt. Additionally, 9a increased the release of cytochrome c from mitochondria to cytoplasm which provokes the mitochondrial apoptotic pathway while it showed no significant change on the expression of the death receptor proteins procaspase-8, caspase-8 and FAS. Furthermore, 9a reduced the expression of phospho AKT and β-catenin in dose dependent manner while inhibiting the expression of migration-related genes such as matrix metalloproteinase (MMP-9 and vascular endothelial growth factor (VEGF. Our findings suggest that compound 9a could be considered as a lead structure for further development of more potent apoptosis inducing agents with anti-metastatic activities.

  13. 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.

  14. Structures and Magnetic Properties of Monomeric Copper(II) Bromide Complexes with a Pyridine-Containing Tridentate Schiff Base

    Energy Technology Data Exchange (ETDEWEB)

    Kang, Sung Kwon [Chungnam National Univ., Daejeon (Korea, Republic of); Yong, Soon Jung; Song, Young Kwang; Kim, Young Inn [Pusan National Univ., Busan (Korea, Republic of)

    2013-12-15

    Two novel copper(II) bromide complexes with pyridine containing Schiff base ligands, Cu(pmed)Br{sub 2} and Cu(dpmed)Br{sub 2} where pmed = N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (pmed) and dpmed = N,N-diethyl-N'-((pyridin-2-yl)methylene)ethane-1,2-diamine (dpmed) were synthesized and characterized using Xray single crystal structure analysis, optical and magnetic susceptibility measurements. Crystal structural analysis of Cu(pmed)Br{sub 2} showed that the copper(II) ion has a distorted square-pyramidal geometry with the trigonality index of τ = 0.35 and two intermolecular hydrogen bonds, which result in the formation of two dimensional networks in the ab plane. On the other hand, Cu(dpmed)Br{sub 2} displayed a near square-pyramidal geometry with the value of τ = 0.06. In both compounds, the NNN Schiff base and one Br atom occupy the basal plane, whereas the fifth apical position is occupied by the other Br atom at a greater Cu-Br apical distance. The reported complexes show g{sub Π} > g{sub Τ} > 2.0023 with a d{sub x2-y2} ground state and a penta-coordinated square pyramidal geometry. Variable temperature magnetic susceptibility measurements showed that the developed copper(II) complexes follow the Curie-Weiss law, that is there are no magnetic interactions between the copper(II) ions since the Cu--Cu distance is too far for magnetic contact.

  15. 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.

  16. Synthesis and Crystal Structure of 2,5-Di- (pyridin-3-yl)-1,3,4-oxadiazolendium Nitrate

    Institute of Scientific and Technical Information of China (English)

    JIANG Yin-Zhi; ZHANG Lian-Qun; ZHAO Jian-Min; QIN Men-Yun

    2007-01-01

    In order to continue our studies on the synthesis, properties and coordination of s-tetrazine, 3,6-di-(pyridin-3-yl)-s-tetrazine (Ⅱ, 3-dptz) was synthesized and characterized by 1HNMR, MS and IR spectra. And the coordination reaction of 3-dptz with nitrate of Cu(Ⅱ) was studied. 3-dptz reacting with CuⅡ salt [Cu(NO3)2·2H2O] generates a new salt, nitrate of 2,5-di-(pyridin-3- yl)-1,3,4-oxadiazolene (Ⅲ). Ⅲ was determined by IR spectra and single-crystal X-ray diffraction to give the following crystal data: space group P21/c, a = 4.9112(1), b = 8.4101(3), c = 29.499(1)(A), β = 93.266(2)°, V = 1216.44(7) nm3, Mr = 287.24, Z = 4, Dc = 1.568 g/cm3,μ= 0.122 mm-1, F(000) = 592, R = 0.0430 and wR = 0.1240. The results show that Ⅲ is composed of one cation and one nitrate anion. The cation consists of one H+ and one 2,5-di-(pyridin-3-yl)-1,3,4-oxadiazol molecule, with the former being attached to the latter via electrovalent bond with N3 atom. And the O(42) atom in the nitrate anion is disordered. Intra- and intermolecular H-bonds are observed in the crystal of the title compound. The mechanism of metal-assisted decomposition was also discussed briefly.

  17. Biomonitoring the Cooked Meat Carcinogen 2-Amino-1-methy-6-phenylimidazo[4,5-b]pyridine in Canine Fur

    OpenAIRE

    Gu, Dan; Neuman, Zachary L.; Modiano, Jaime F.; Turesky, Robert J.

    2012-01-01

    2-Amino-1-methyl-6-phenylimidazo[4, 5-b]pyridine (PhIP) is a heterocyclic aromatic amine (HAA) that is formed during the cooking of meat, poultry, and fish. PhIP is a rodent carcinogen and thought to contribute to several diet-related cancers in humans. PhIP is present in the hair of human omnivores but not in the hair of vegetarians. We have now identified PhIP in the fur of fourteen out of sixteen healthy dogs consuming different brands of commercial pet food. The levels of PhIP in canine f...

  18. Synthesis, and antimicrobial evaluation of new pyridine imidazo [2,1b]-1,3,4-thiadiazole derivatives

    Directory of Open Access Journals (Sweden)

    Varun Bhardwaj

    2016-09-01

    Full Text Available With the aim of producing new biologically active compounds, a series of New Pyridine Imidazo [2,1b]-1,3,4-thiadiazole derivatives 4(a–k were synthesized. All the compounds were characterized via IR, 1H-NMR and Mass spectral studies. The antimicrobial activity of newly synthesized compounds against various bacteria; Bacillus pumillus, Staphylococcus aureus, Vibrio cholera, Escherichia coli, Proteus mirabilis, Pseudomonas aeruginosa, and fungi; Candida albicans were evaluated. Among the compounds tested, 4(a, 4(b, 4(f, 4(h and 4(k exhibited good antimicrobial activity while others responded moderately with reference to standard drugs ampicillin and amphotericin B.

  19. Discovery of 7-aminofuro[2,3-c]pyridine inhibitors of TAK1: optimization of kinase selectivity and pharmacokinetics.

    Science.gov (United States)

    Hornberger, Keith R; Chen, Xin; Crew, Andrew P; Kleinberg, Andrew; Ma, Lifu; Mulvihill, Mark J; Wang, Jing; Wilde, Victoria L; Albertella, Mark; Bittner, Mark; Cooke, Andrew; Kadhim, Salam; Kahler, Jennifer; Maresca, Paul; May, Earl; Meyn, Peter; Romashko, Darlene; Tokar, Brianna; Turton, Roy

    2013-08-15

    The kinase selectivity and pharmacokinetic optimization of a series of 7-aminofuro[2,3-c]pyridine inhibitors of TAK1 is described. The intersection of insights from molecular modeling, computational prediction of metabolic sites, and in vitro metabolite identification studies resulted in a simple and unique solution to both of these problems. These efforts culminated in the discovery of compound 13a, a potent, relatively selective inhibitor of TAK1 with good pharmacokinetic properties in mice, which was active in an in vivo model of ovarian cancer.

  20. Synthesis and characterization of novel star-shaped pyridine cored compounds with alternating carbazole and triphenylamine moieties

    Institute of Scientific and Technical Information of China (English)

    Ji Bing Yuan; Zhi Guo Zhang; Louis Man Leung; Ke Li Zhang

    2008-01-01

    Amorphous 2,4,6-trissubstituted pyridines containing three peripheral carbazole or two triphenylamine and one carbazole moieties, respectively, have been synthesized and characterized. The properties of the compounds are investigated by UV-visabsorption, photoluminescence spectroscopy, thermal analysis as well as cyclic voltammetry. The results show that the compounds have high thermal stability, emit blue light. Also, the compounds possess the HOMO and LUMO energy levels comparable to those of NPB. The effects of different substituents on the electronic properties of the materials have been discussed.

  1. Thieno[2,3-b]pyridines as negative allosteric modulators of metabotropic GluR5 receptors: Lead optimization.

    Science.gov (United States)

    Nógrádi, Katalin; Wágner, Gábor; Domány, György; Bobok, Amrita; Magdó, Ildikó; Kolok, Sándor; Mikó-Bakk, Mónika L; Vastag, Mónika; Sághy, Katalin; Gyertyán, István; Kóti, János; Gál, Krisztina; Farkas, Sándor; Keserű, György M; Greiner, István; Szombathelyi, Zsolt

    2015-04-15

    An HTS campaign of our corporate compound library, and hit-to lead development resulted in thieno[2,3-b]pyridine derivative leads with mGluR5 negative allosteric modulator effects. During the lead optimization process, our objective was to improve affinity and metabolic stability. Modification of the first two targeted regions resulted in compounds with nanomolar affinity, then optimal substitution of the third region improved metabolic stability. One of the most promising compounds showed excellent in vivo efficacy and is a potential development candidate.

  2. A scanning electron microscopy study of the macro-crystalline structure of 2-(2,4-dinitrobenzyl) pyridine

    Science.gov (United States)

    Ware, Jacqueline; Hammond, Ernest C., Jr.

    1989-01-01

    The compound, 2-(2,4-dinitrobenzyl) pyridine, was synthesized in the laboratory; an introductory level electron microscopy study of the macro-crystalline structure was conducted using the scanning electron microscope (SEM). The structure of these crystals was compared with the macrostructure of the crystal of 2-(2,4-dinitrobenzyl) pyridinium bromide, the hydrobromic salt of the compound which was also synthesized in the laboratory. A scanning electron microscopy crystal study was combined with a study of the principle of the electron microscope.

  3. (2SR,3RS-Methyl 2-(adamantan-1-yl-3-phenylsulfonyl-3-(pyridin-2-ylsulfanylpropanoate dichloromethane hemisolvate

    Directory of Open Access Journals (Sweden)

    Rosa-Luisa Meza-León

    2011-04-01

    Full Text Available The title compound, C25H29NO4S2 0.5CH2Cl2, was obtained as a racemate. The pyridine and phenyl rings are arranged face-to-face, giving a weak intramolecular π–π interaction [centroid–centroid separation = 3.759 (3 Å]. These interactions are extended intermolecularly, forming chains of stacked rings along [001] with separations of 3.859 (3 and 3.916 (3 Å. The solvent used for crystallization, CH2Cl2, is located in voids between the chains of molecules, with a site occupancy of 0.5.

  4. Syntheses, Structures, and Blue Luminescent Properties of 2,6-Bis (benzimidazolyl) Pyridine and Its Mercury Complex

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    A novel blue luminescent mercury ( Ⅱ ) complex of 2,6-bis ( benzimidazolyl ) pyridine (L) was synthesized. In solid state, this complex has the formula [ Hg(L) Cl2 ] · 2DMF( 1 ). The molecular structures of both the ligand and the complex were determined by using single-crystal X-ray diffraction. Crystallographic studies of the mercury ( Ⅱ ) complex reveal that the complex possesses a five-coordinated geometry that can be best described as a distorted trigonal-bipyramidal. The luminescent properties of ligand L and complex 1 both in solution and in solid state were also studied.

  5. 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.

  6. Synthesis of 2-pyrazolines from pyridine based chalcone by conventional and microwave techniques: Their comparison and antimicrobial studies

    Directory of Open Access Journals (Sweden)

    Navin B. Patel

    2016-09-01

    Full Text Available 2-Pyrazolines from pyridine based chalcones by conventional and microwave techniques have been synthesized and their antimicrobial activity as well as a comparison study between conventional and microwave techniques has been done. Antimicrobial activity was carried out according to the broth micro dilution method and it was observed that compound 2d was found to be most active against gram negative bacteria and fungus Candida albicans. Microwave technique has been found superior over the conventional method in view of reaction time and energy requirement. Compounds have been characterized by 1H NMR, 13C NMR, IR and Mass spectral analyses.

  7. Novel amide-type ligand bearing bis-pyridine cores: Synthesis, spectral characterizations and X-ray structure analyses

    Science.gov (United States)

    Ke, Shaoyong

    2016-08-01

    The novel salicylamide-type ligand containing bis-pyridine moieties, i.e. 2-((6-chloropyridin-3-yl)methoxy)-N-(2-((6-chloropyridin-3-yl)methylthio)phenyl)benzamide, which has been successfully synthesized and characterized by typical spectroscopic techniques mainly including IR, 1H NMR and ESI-MS. The structure of target compound was further determined by single crystal X-ray diffraction method and which crystallized in the monoclinic system with space group P2(1)/c.

  8. Tautomerism of 2-(pyridine-2-yl)-1,3-diazaspiro[4.4]non-1-en-4-one

    Science.gov (United States)

    Šimůnek, Petr; Panov, Illia; Růžičková, Zdeňka; Sedlák, Miloš

    2017-01-01

    The work deals with both solution state (using 1H, 13C and 15N NMR) and solid state (using X-ray) structure of 2-(pyridine-2-yl)-1,3-diazaspiro[4.4]non-1-en-4-one. The compound exists in the solution predominantly as 5-oxo tautomer where the amount of 4-oxo form depends on the solvent used. Mutual interconversion between the tautomers is slow on the NMR time scale and is studied by means of both EXSY and variable temperature NMR. In the solid state, the compound is solely as 5-oxo tautomer.

  9. Chlorido(dimethyl sulfoxide(pyridine-2-thiolato N-oxide-κ2S,Oplatinum(II

    Directory of Open Access Journals (Sweden)

    Dieter Schollmeyer

    2008-07-01

    Full Text Available The asymmetric unit of the title compound, [Pt(C5H4NOSCl(C2H6OS], contains two independent complex molecules having similar geometries. Each PtII atom is four-coordinated in a distorted square-planar geometry by S and O atoms of one pyridine N-oxide ligand, the S atom of one dimethyl sulfoxide molecule and one terminal Cl− ion. The molecules are linked into a three-dimensional framework by C—H...O and C—H...Cl hydrogen bonds.

  10. 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

    4-vinyl pyridine was polymerized on poly(ethylene terephthalate) (PET) film by using lower energy pulsed AC plasma under low pressure in Ar atmosphere. The plasma polymerized coating was characterized by ATR Fourier transform infrared (FT-IR), scanning electron microscopy (SEM), field emission...... 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...

  11. Pyridine on flat Pt(111) and stepped Pt(355)—An in situ HRXPS investigation of adsorption and thermal evolution

    Energy Technology Data Exchange (ETDEWEB)

    Wöckel, Claudia; Eilert, Andrè; Welke, Martin; Schöppke, Matthias; Denecke, Reinhard, E-mail: denecke@uni-leipzig.de [Wilhelm-Ostwald-Institut für Physikalische und Theoretische Chemie, Universität Leipzig, Linnéstraße 2, 04103 Leipzig (Germany); Steinrück, Hans-Peter [Lehrstuhl für Physikalische Chemie II, Friedrich-Alexander-Universität Erlangen-Nürnberg, Egerlandstraße 3, 91058 Erlangen (Germany)

    2016-01-07

    We investigated the adsorption and reaction of pyridine on flat Pt(111) and stepped Pt(355) surfaces via high-resolution in situ x-ray photoelectron spectroscopy. The surfaces were exposed to pyridine at temperatures between 112 and 300 K while simultaneously recording XP spectra. Subsequently, the crystals were annealed and the temperature dependencies of the N 1s and C 1s core levels were studied again in a continuous and quantitative way. Various surface species were found, namely, physisorbed, flat-lying and end-on pyridine, α-pyridyl species on the terraces and on the steps and several unidentified high temperature species. We were able to show an influence of the steps of Pt(355) by pre-adsorbing silver next to the step, which selectively suppresses the step adsorption.

  12. Another challenge to paramagnetic relaxation theory: a study of paramagnetic proton NMR relaxation in closely related series of pyridine-derivatised dysprosium complexes.

    Science.gov (United States)

    Rogers, Nicola J; Finney, Katie-Louise N A; Senanayake, P Kanthi; Parker, David

    2016-02-14

    Measurements of the relaxation rate behaviour of two series of dysprosium complexes have been performed in solution, over the field range 1.0 to 16.5 Tesla. The field dependence has been modelled using Bloch-Redfield-Wangsness theory, allowing estimates of the electronic relaxation time, T1e, and the size of the magnetic susceptibility, μeff, to be made. Changes in relaxation rate of the order of 50% at higher fields were measured, following variation of the para-substituent in the single pyridine donor. The magnetic susceptibilities deviated unexpectedly from the free-ion values for certain derivatives in each series examined, in a manner that was independent of the electron-releasing/withdrawing ability of the pyridine substituent, suggesting that the polarisability of just one pyridine donor in octadenate ligands can play a significant role in defining the magnetic susceptibility anisotropy.

  13. 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.

  14. Oxidative cross-coupling of pyridine N-oxides and ethers between C(sp(2))-H/C(sp(3))-H bonds under transition-metal-free conditions.

    Science.gov (United States)

    Sun, Wei; Xie, Zuguang; Liu, Jie; Wang, Lei

    2015-04-21

    A novel and efficient method based on the cross-coupling reactions of pyridine N-oxides with ethers between C(sp(2))-H/C(sp(3))-H bonds in the presence of TBHP was developed. The strategy provides an alternative approach to the pyridine moiety under transition-metal-free conditions.

  15. Structure-dependent effects of pyridine derivatives on mechanisms of intestinal fatty acid uptake: regulation of nicotinic acid receptor and fatty acid transporter expression.

    Science.gov (United States)

    Riedel, Annett; Lang, Roman; Rohm, Barbara; Rubach, Malte; Hofmann, Thomas; Somoza, Veronika

    2014-07-01

    Pyridines are widely distributed in foods. Nicotinic acid (NA), a carboxylated pyridine derivative, inhibits lipolysis in adipocytes by activation of the orphan NA receptor (HM74A) and is applied to treat hyperlipidemia. However, knowledge on the impact of pyridine derivatives on intestinal lipid metabolism is scarce. This study was performed to identify the structural determinants of pyridines for their effects on fatty acid uptake in enterocyte-like Caco-2 cells and to elucidate the mechanisms of action. The impact of 17 pyridine derivatives on fatty acid uptake was tested. Multiple regression analysis revealed the presence of a methyl group to be the structural determinant at 0.1 mM, whereas at 1 mM, the presence of a carboxylic group and the N-methylation presented further structural characteristics to affect the fatty acid uptake. NA, showing a stimulating effect on FA uptake, and N-methyl-4-phenylpyridinium (MPP), inhibiting FA uptake, were selected for mechanistic studies. Gene expression of the fatty acid transporters CD36, FATP2 and FATP4, and the lipid metabolism regulating transcription factors peroxisome proliferator-activated receptor (PPAR) α and PPARγ was up-regulated upon NA treatment. Caco-2 cells were demonstrated to express the low-affinity NA receptor HM74 of which the gene expression was up-regulated upon NA treatment. We hypothesize that the NA-induced fatty acid uptake might result from NA receptor activation and related intracellular signaling cascades. In contrast, MPP increased transepithelial electrical resistance. We therefore conclude that NA and MPP, both sharing the pyridine motif core, exhibit their contrary effects on intestinal FA uptake by activation of different mechanisms.

  16. 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.

  17. 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%.

  18. Thermodynamics of the equilibrium of the reaction between (5,10,15,20-tetra(2-methoxyphenyl)porphinato)chloroindium(III) and pyridine

    Science.gov (United States)

    Bichan, N. G.; Ovchenkova, E. N.; Mozhzhukhina, E. G.; Lomova, T. N.

    2017-07-01

    The results from thermodynamic and quantum-chemical studies of the reversible reaction between (5,10,15,20-tetra(2-methoxyphenyl)porphinato)chloroindium(III) and pyridine are reported. The main physicochemical parameters of properties of its supramolecular products are obtained and analyzed. The addition of pyridine molecules to metalloporphyrin proceeds in one step to attain an equilibrium state with the formation of supramolecules with a stoichiometry of 2: 1; spectral characteristics and parameters of the stability of the latter are identified. The possibility of using substituted indium(III)porphyrin for further research in the field of hybrid solar cells is discussed.

  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. Bis[3-(pyrazin-2-yl-5-(pyridin-2-yl-κN-1,2,4-triazol-1-ido-κN1]copper(II

    Directory of Open Access Journals (Sweden)

    Zhi-Liang Liu

    2012-05-01

    Full Text Available In the mononuclear title complex, [Cu(C11H7N62], the CuII atom lies on a crystallographic inversion centre and is coordinated by four N atoms from two bidentate chelate monoanionic 3-(pyrazin-2-yl-5-(pyridin-2-yl-1,2,4-triazol-1-ido ligands, two from the triazolide rings [Cu—N = 1.969 (2 Å] and two from the pyridine rings [Cu—N = 2.027 (2 Å], giving a slightly distorted square-planar geometry.

  1. Investigations and design of pyridine-2-carboxylic acid thiazol-2-ylamide analogs as methionine aminopeptidase inhibitors using 3D-QSAR and molecular docking

    DEFF Research Database (Denmark)

    Hauser, Alexander Sebastian

    2014-01-01

    -dimensional quantitative structure–activity relationship (3D-QSAR) studies were carried out on a series of pyridine-2-carboxylic acid thiazol-2-ylamide-based MetAP inhibitors using comparative molecular field analysis (CoMFA) and comparative molecular similarity indices analysis (CoMSIA) techniques. The models were...... complexes, four new pyridine-2-carboxylic acid thiazol-2-ylamide analogs were designed. These analogs exhibit significantly better predicted activity than the reported molecules. The present work has implications for the development of novel antibiotics as potent MetAP inhibitors....

  2. Molecular structure effect of pyridine-based surface ligand on the performance of P3HT:TiO₂ hybrid solar cell.

    Science.gov (United States)

    Lin, Jhih-Fong; Tu, Guang-Yao; Ho, Chun-Chih; Chang, Chun-Yu; Yen, Wei-Che; Hsu, Sheng-Hao; Chen, Yang-Fang; Su, Wei-Fang

    2013-02-01

    Colloid TiO(2) nanorods are used for solution-processable poly(3-hexyl thiophene): TiO(2) hybrid solar cell. The nanorods were covered by insulating ligand of oleic acid (OA) after sol-gel synthesis. Three more conducting pyridine type ligands: pyridine, 2,6-lutidine (Lut) and 4-tert-butylpyridine (tBP) were investigated respectively to replace OA. The power conversion efficiency (PCE) of the solar cell was increased because the electronic mobility of pyridine-type ligand-modified TiO(2) is higher than that of TiO(2)-OA. The enhancement of PCE is in the descending order of Lut > pyridine > tBP because of the effective replacement of OA by Lut. The PCE of solar cell can be further enhanced by ligand exchange of pyridine type ligand with conjugating molecule of 2-cyano-3-(5-(7-(thiophen-2-yl)-benzothiadiazol-4-yl) thiophen-2-yl) acrylic acid (W4) on TiO(2) nanorods because W4 has aligned bandgap with P3HT and TiO(2) to facilitate charge separation and transport. The electronic mobility of two-stage ligand exchanged TiO(2) is improved furthermore except Lut, because it adheres well and difficult to be replaced by W4. The amount of W4 on TiO(2)-tBP is 3 times more than that of TiO(2)-Lut (0.20 mol % vs. 0.06 mol %). Thus, the increased extent of PCE of solar cell is in the decreasing order of tBP > pyridine > Lut. The TiO(2)-tBP-W4 device has the best performance with 1.4 and 2.6 times more than TiO(2)-pyridine-W4 and TiO(2)-Lut-W4 devices, respectively. The pKa of the pyridine derivatives plays the major role to determine the ease of ligand exchange on TiO(2) which is the key factor mandating the PCE of P3HT:TiO(2) hybrid solar cell. The results of this study provide new insights of the significance of acid-base reaction on the TiO(2) surface for TiO(2)-based solar cells. The obtained knowledge can be extended to other hybrid solar cell systems.

  3. 1-[3-(Anthracen-9-yl-5-(pyridin-2-yl-4,5-dihydro-1H-pyrazol-1-yl]ethanone

    Directory of Open Access Journals (Sweden)

    Kun Huang

    2012-05-01

    Full Text Available In the title compound, C24H19N3O, the pyrazoline ring adopts an envelope conformation with the C atom linking to the pyridine ring as the flap. The mean plane of the pyrazoline ring makes dihedral angles of 85.54 (4 and 81.66 (3° with the pyridine ring and the anthracene ring system, respectively. In the crystal, molecules are linked by C—H...O hydrogen bonds. In addition, weak π–π interactions [centroid–centroid distances = 3.695 (3–3.850 (7 Å] are observed.

  4. 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 = 2,2'-bi

  5. Structural Studies of Divalent Transition Metal Cobalt With Bis-(2,6-Diacetyl Pyridine Monoxime 1,2-Di-Iminobenzene.

    Directory of Open Access Journals (Sweden)

    Shamshad Ahmad Khan

    2015-12-01

    Full Text Available The complexes of divalent Cobalt with bis(2,6-diacetyl pyridine monoxime1,2-di-iminobenzene have been prepared separately in presence of respective salts. The general molecular formula of the complexes have been found to be [Co(L]X2 where L=Bis(2,6-diacetyl pyridine monoxime1,2-di-iminobenzene, X=chloride, bromide, sulphate, perchlorate, nitrate, acetate ions, On the characterisation of the complexes by usual physico-chemical method, all the complexes have been found to be monomeric and octahedral in geometry.

  6. [5-(Pyridin-2-yl-1H-tetrazole-κ2N4,N5]bis(triphenylphosphane-κPcopper(I tetrafluoridoborate

    Directory of Open Access Journals (Sweden)

    Lei Lu

    2012-12-01

    Full Text Available In the title CuI compound, [Cu(C6H5N5(C18H15P2]BF4, the CuI cation is N,N′-chelated by a 5-(pyridin-2-yl-1H-tetrazole ligand and coordinated by two triphenylphosphane ligands in a distorted tetrahedral geometry. The tetrazole and pyridine rings are essentially coplanar [dihedral angle = 4.1 (3°]. The tetrafluoridoborate anion links to the complex cation via an N—H...F hydrogen bond.

  7. Synthesis and antiproliferative activity of benzophenone tagged pyridine analogues towards activation of caspase activated DNase mediated nuclear fragmentation in Dalton's lymphoma.

    Science.gov (United States)

    Al-Ghorbani, Mohammed; Thirusangu, Prabhu; Gurupadaswamy, H D; Girish, V; Shamanth Neralagundi, H G; Prabhakar, B T; Khanum, Shaukath Ara

    2016-04-01

    A series of benzophenones possessing pyridine nucleus 8a-l were synthesized by multistep reaction sequence and evaluated for antiproliferative activity against DLA cells by in vitro and in vivo studies. The results suggested that, compounds 8b with fluoro group and 8e with chloro substituent at the benzoyl ring of benzophenone scaffold as well as pyridine ring with hydroxy group exhibited significant activity. Further investigation in mouse model suggests that compounds 8b and 8e have the potency to activate caspase activated DNase (endonuclease) which is responsible for DNA fragmentation, a primary hallmark of apoptosis and thereby inhibits the Dalton's lymphoma ascites tumour growth.

  8. Synthesis of novel 1,2,3-triazole tagged pyrazolo[3,4-b]pyridine derivatives and their cytotoxic activity.

    Science.gov (United States)

    Kurumurthy, Chavva; Veeraswamy, Banda; Sambasiva Rao, Pillalamarri; Santhosh Kumar, Gautham; Shanthan Rao, Pamulaparthy; Loka Reddy, Velaturu; Venkateswara Rao, Janapala; Narsaiah, Banda

    2014-02-01

    A series of novel 1,2,3-triazole tagged pyrazolo[3,4-b]pyridine derivatives 3 and 4 were prepared respectively starting from 6-phenyl-4-(trifluoromethyl)-1H-pyrazolo[3,4-b]pyridin-3-amine 1 via selective N-propargylation, followed by reaction with diverse substituted alkyl/perfluoroalkyl/aryl/aryl amide azides under Sharpless conditions. All the synthesized compounds 3 and 4 were screened for cytotoxic activity against four human cancer cell lines such as U937, THP-1, HL60 and B16-F10. Compounds 3e, 4g, 4i and 4j which showed promising activity have been identified.

  9. 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......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...

  10. 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

  11. One-pot three-component synthesis of pyrano [3,2-b]pyrazolo[4,3-e]pyridin-8(1H)-ones.

    Science.gov (United States)

    Safaei, Shirin; Mohammadpoor-Baltork, Iraj; Khosropour, Ahmad Reza; Moghadam, Majid; Tangestaninejad, Shahram; Mirkhani, Valiollah; Khavasi, Hamid Reza

    2013-03-11

    An efficient one-pot synthesis of novel pyrano[3,2-b]pyrazolo[4,3-e]pyridin-8(1H)-ones via three-component condensation of kojic acid, 1-H-pyrazol-5-amines and aldehydes in the presence of a catalytic amount of Zn(OTf)(2) followed by H(2)O(2)-mediated oxidation is reported. Furthermore, the synthesis of 1'H-spiro[indoline-3,4'-pyrano[2,3-b]pyrazolo[3,4-e]pyridine]-2,8'(9'H)-diones were chosen for the library validation.

  12. 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.

  13. Synthesis, characterization, crystal structure and DNA-binding study of four cadmium(II) pyridine-carboxamide complexes

    Indian Academy of Sciences (India)

    BIPLAB MONDAL; BUDDHADEB SEN; SANDIPAN SARKAR; ENNIO ZANGRANDO; PABITRA CHATTOPADHYAY

    2017-01-01

    Treatment of perchlorate or nitrate salt of cadmium(II) with carboxamide derivatives (L) generated four novel mononuclear metal complexes, represented as [Cd(L)₄](ClO₄)₂ (1a and 1b) and [Cd(L)₂(ONO₂)₂] (2a and 2b) in appreciable yields (L = L¹ = N-(furan-2-ylmethyl)-2-pyridine carboxamide and L = L² = N-(thiophen-2-ylmethyl)-2-pyridine carboxamide). The complexes have been characterized by FT-IR, UVVisible, elemental analysis and single crystal X-ray crystallographic analysis which revealed eight coordinated cadmium ions, but in different coordination environments, depending on the counter anion used. In addition,electronic absorption, fluorescence spectroscopy and viscosity measurements revealed a significant interaction of the four complexes with CT-DNA via intercalative/groove binding mode. The intrinsic binding constant Kbobtained varies from 0.4 × 10⁴ to 1.11 × 10⁵ M⁻¹. The results suggest that neutral complexes 2a and 2b bind to DNA in an intercalative mode. On the other hand, cationic complexes 1a and 1b bind with DNA via weak electrostatic/covalent interaction.

  14. Role of Pyridine as a Biomimetic Organo-Hydride for Homogeneous Reduction of CO2 to Methanol

    CERN Document Server

    Lim, Chern-Hooi; Hynes, James T; Musgrave, Charles B

    2014-01-01

    We use quantum chemical calculations to elucidate a viable homogeneous mechanism for pyridine-catalyzed reduction of CO2 to methanol. In the first component of the catalytic cycle, pyridine (Py) undergoes a H+ transfer (PT) to form pyridinium (PyH+) followed by an e- transfer (ET) to produce pyridinium radical (PyH0). Examples of systems to effect this ET to populate the LUMO of PyH+(E0calc ~ -1.3V vs. SCE) to form the solution phase PyH0 via highly reducing electrons include the photo-electrochemical p-GaP system (ECBM ~ -1.5V vs. SCE at pH= 5) and the photochemical [Ru(phen)3]2+/ascorbate system. We predict that PyH0 undergoes further PT-ET steps to form the key closed-shell, dearomatized 1,2-dihydropyridine (PyH2) species. Our proposed sequential PT-ET-PT-ET mechanism transforming Py into PyH2 is consistent with the mechanism described in the formation of related dihydropyridines. Because it is driven by its proclivity to regain aromaticity, PyH2 is a potent recyclable organo-hydride donor that mimics the ...

  15. 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.

  16. Experimental and theoretical investigation of a pyridine containing Schiff base: Hirshfeld analysis of crystal structure, interaction with biomolecules and cytotoxicity

    Science.gov (United States)

    Chithiraikumar, S.; Neelakantan, M. A.

    2016-03-01

    A pyridine containing Schiff base (E)-2-methoxy-6-(((pyridin-2-ylmethyl)imino)methyl) phenol (L) was isolated in single crystals. The molecular structure of L was studied by FT-IR, NMR, UV-Vis techniques, single crystal XRD analysis and computationally by DFT method. L prefers enol form in the solid state. Electronic spectrum of L was recorded in different organic solvents to investigate the dependence of tautomerism on solvent types. The polar solvents facilitate the proton transfer by decreasing the activation energy needed for transition state. Potential energy curve for the intramolecular proton transfer in the ground state is generated in gas and solution phases. The 3D Hirshfeld surfaces and the associated 2D fingerprint plots were investigated. The percentages of various interactions were analyzed by fingerprint plots of Hirshfeld surface. The interaction of L with CT DNA was investigated under physiological conditions using UV-Vis spectroscopy, fluorescence quenching and molecular docking methods. Molecular docking studies reveal that binding of L to the groove of B-DNA is through hydrogen bonding and hydrophobic interactions. The in vitro cytotoxicity of L was carried out in two different human tumor cell lines, MCF 7 and MIA-Pa-Ca-2 exhibits moderate activity.

  17. Kinetics and equilibria for the axial ligation of bromomethyl (aqua)cobaloxime with pyridines - Isolation characterization and DNA binding

    Indian Academy of Sciences (India)

    Kotha Laxma Reddy; K Ashwini Kumar; N Ravi Kumar Reddy; Penumaka Nagababu; A Panasa Reddy; S Satyanarayana

    2009-11-01

    The kinetics and equilibria for the axial ligation of pyridine and substituted pyridines to bromomethyl(aqua)cobaloxime have been measured spectrophotometrically in aqueous solutions of ionic strength 1.0 M (KC1) at 25°C as a function of H. The binding constants and rate of formation increase in the order 4-NH2Py 4-EtPy > 4-MePy > Py > 2-NH2Py > 2-EtPy. The data have been interpreted based on the basicity of the ligand, -back bonding from Co(III) → L and hard and soft interactions. The rate of substitution of H2O varies with the pKa of the incoming ligand, thus establishing the existence of nucleophilic participation of the ligand in the transition state. We have investigated the DNA binding of bromomethyl(aqua)cobaloxime with DNA. Bromomethyl(ligand)cobaloximes were isolated and characterized by elemental analysis, IR and NMR (1H, 13C) spectra.

  18. Ruthenium(III)/phosphine/pyridine complexes applied in the hydrogenation reactions of polar and apolar double bonds

    Science.gov (United States)

    Rodrigues, Claudia; Delolo, Fábio G.; Ferreira, Lucas M.; da S. Maia, Pedro I.; Deflon, Victor M.; Rabeah, Jabor; Brückner, Angelika; Norinder, Jakob; Börner, Armin; Bogado, André L.; Batista, Alzir A.

    2016-05-01

    In this work, five ruthenium(III) complexes containing phosphine and pyridine based ligands with general formula mer-[RuCl3(dppb)(N)] [where dppb = 1,4-bis(diphenylphosphino)butane and N = pyridine (py), 4-methylpyridine (4-Mepy), 4-vinylpyridine (4-Vpy), 4-tert-butylpyridine (4-tBupy) and 4-phenylpyridine (4-Phpy)] were synthesized and characterized using spectroscopic and electrochemical techniques, as well as magnetic susceptibility to check the paramagnetism of these compounds. These complexes were tested as catalytic precursors in hydrogenation reactions with cyclohexene, undecanal and cyclohexanecarboxaldehyde, as compounds bearing Cdbnd C and Cdbnd O groups. Broad screening was carried out in order to find the optimal reaction conditions with the highest conversion. It was found that by using a ratio of Ru-catalyst/substrate = 1:530 at 80 °C and 15 bar of H2 for 24 h, cyclohexene can be reduced. Hydrogenation of undecanal was possible using a Ru-catalyst/substrate ratio of 1:100 at 160 °C and 100 bar for 24 h, and for the reduction of cyclohexanecarboxaldehyde the reaction conditions were Ru-catalyst/substrate ratio of 1:100 at 160 °C and 50 bar for 24 h.

  19. Hydrothermal Synthesis, Crystal Structure and Thermal Analysis of a Dinuclear Complex Cd2(3,5-Dinitrobenzoate)4(pyridine)4

    Institute of Scientific and Technical Information of China (English)

    GUO Jin-Yu; ZHANG Tong-Lai; ZHANG Jian-Guo; LIU Yan-Hong; QIAO Xiao-Jing; YANG Li

    2006-01-01

    A dinuclear complex Cd2(dnba)4(pyridine)4 (dnba = 3,5-dinitrobenzoate) has been synthesized by hydrothermal method and characterized by X-ray single-crystal diffraction, elemen- tal analysis, FT-IR spectroscopy, DSC and TG-DTG techniques. The complex with empirical formula C48H32Cd2N12O24 (Mr = 692.83) crystallizes in monoclinic, space group P21/n with a = 12.0344(14), b = 10.5752(13), c = 21.578(3) (A), β = 104.150(2)o, V = 2662.8(6) (A)3, Z = 2, Dc = 1.728 g/cm3, μ(MoKα) = 0.897 mm-1, F(000) = 1384, S = 1.016 and (Δ/σ)max = 0.001. R = 0.0638 and wR = 0.0737 for all data; the final R = 0.0337 and wR = 0.0644. In this complex, four carboxylates are bidentate- or chelate-coordinated with the Cd(Ⅱ) centers to give the dinuclear structure. The other coordination positions of Cd(Ⅱ) are occupied by the lone pair electrons from N of four pyridines. Thermal analyses DSC and TG-DTG have been used to determine the thermal decomposition mechanism of the title complex.

  20. Syntheses, characterization, and anti-cancer activities of pyridine-amide based compounds containing appended phenol or catechol groups

    Indian Academy of Sciences (India)

    Afsar Ali; Deepak Bansal; Nagendra K Kaushik; Neha Kaushik; Neha Kaushik; Eun Ha Choi; Rajeev Gupta

    2014-07-01

    Several pyridine-amide compounds appended with phenol/catechol groups are synthesized. These compounds consist of protected or deprotected phenol/catechol groups and offer pyridine, amide, and phenol/catechol functional groups. All compounds have been well-characterized by various spectroscopic methods, elemental analysis, thermal studies, and crystallography. The biological activities of all compounds were investigated while a few compounds significantly decreased the metabolic viability, growth and clonogenicity of T98G cells in dose dependent manner. Accumulation of ROS was observed in T98G cells, which displayed a compromised redox status as evident from increased cellular Caspase 3/7 activity and formation of micronuclei. The in silico pharmacokinetic studies suggest that all compounds have good bioavailability, water solubility and other drug-like parameters. A few compounds were identified as the lead molecules for future investigation due to their: (a) high activity against T98G brain, H-460 lung, and SNU-80 thyroid cancer cells; (b) low cytotoxicity in non-malignant HEK and MRC-5 cells; (c) low toxic risks based on in silico evaluation; (d) good theoretical oral bioavailability according to Lipinski ‘rule of five’ pharmacokinetic parameters; and (e) better drug-likeness and drug-score values.