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Sample records for 1-furfuryl pyrrole characterization

  1. Electrochemical synthesis and surface characterization of (pyrrole+2-methylfuran) copolymer

    Science.gov (United States)

    Djaouane, Linda; Nessark, Belkacem; Sibous, Lakhdar

    2017-02-01

    Electrochemical copolymerization of pyrrole (Py) and 2-methylfuran (2 MF) was performed on platinum and ITO substrates in acetonitrile/lithium perchlorate solution, using cyclic voltammetry method. The electrochemical behavior of the modified electrode surface by polypyrrole, poly(2-methylfuran) homopolymers and (pyrrole+2-methylfuran) copolymer was characterized by cyclic voltammetry, electrochemical impedance spectroscopy (EIS), UV-visible spectroscopy, atomic force microscopy (AFM) and scanning electron microscopy (SEM). The cyclic voltammetry shows anodic and cathodic peaks which are characteristic of the oxidation and the reduction of the formed films. The electrochemical impedance spectroscopy confirmed the results obtained by cyclic voltammetry. AFM and SEM analyses proved as well that the morphology and the electrochemical properties of the polypyrrole film are modified in the presence of 2-methylfuran.

  2. Preparation and characterization of new poly-pyrrole having side chain liquid crystalline moieties

    Energy Technology Data Exchange (ETDEWEB)

    Hosseini, S. Hossein, E-mail: hosseini_sh44@yahoo.com [Department of Chemistry, Faculty of Science and Engineering, Imam Hossein University, Babaee Express Way, Tehran (Iran, Islamic Republic of); Mohammadi, M. [Department of Chemistry, Faculty of Science and Engineering, Imam Hossein University, Babaee Express Way, Tehran (Iran, Islamic Republic of)

    2009-06-01

    We have synthesized a novel liquid-crystalline (LC)-conducting polymer by introducing LC group into pyrrole monomer and polymerizing it with FeCl{sub 3}. The N-substituted pyrrole with LC group (Py-RedII) was prepared by direct reaction of potassium pyrrole salt with 2-[N-ethyl-N-[4-[(4-nitrophenyl)azo]-phenyl]amino]ethyl-3-chloropropionate (RedII). The polymerization of this monomer was successful, giving a conjugated polymer system with liquid crystalline moieties in moderate yield. The polymer obtained was soluble in organic solvents and had a thermotropic liquid crystallinity with mosaic texture characterized by polarizing optical microscopy. Phase transitions, thermal analysis and rheological studies were also evaluated by means of differential scanning calorimetry (DSC), thermogravimetry analysis (TGA) and scanning electron microscopy (SEM), respectively. Spectral properties of poly (2-[N-ethyl-N-[4-[(nitrophenyl)azo]phenyl]amino]ethyl-N-pyrrolyl propionate) (PPy-RedII) were characterized by UV, IR, {sup 1}H NMR, and {sup 13}C NMR spectroscopies. The photoluminescence spectrum of the film showed that maximum photoluminescence peak emission is located at 437 nm, corresponding to the photon energy of 2.5 eV. Electrical conductivity of PPy-RedII was studied by the four-probe method and produced a conductivity of 7.5 x 10{sup -4} S cm{sup -1}.

  3. -pyrrole substituted porphyrin-pyrene dyads using vinylene spacer: Synthesis, characterization and photophysical properties

    Indian Academy of Sciences (India)

    P Silviya Reeta; Ravi Kumar Kanaparthi; L Giribabu

    2013-03-01

    We have designed and synthesized donor-acceptor conjugates having donor pyrene at the pyrrole- position of either free-base porphyrin or Zn(II) porphyrin using vinylene spacer. Both the dyads have been completely characterized by elemental analysis,MALDI-MS, UV-Vis., and fluorescence (steady state and timeresolved) spectroscopies as well as cyclic voltammetry. The absorption maxima of both dyads are red-shifted by 8-12 nm. The ground state properties showed that there exist minimum - interaction between the aromatic subunits of these D-A systems. Quenched emission was observed in both the dyads when excited at 290 nm. The quenched emission explained in terms of intramolecular excitation energy transfer competes with the photo-induced electron transfer reaction in these D-A system.

  4. Synthesis and spectroscopic characterization of pyrrole-2,3-diones and their following reactions with 1,2-aromatic diamines

    Directory of Open Access Journals (Sweden)

    İrfan Koca

    2012-01-01

    Full Text Available 4-aroyl-5-aryl-2,3-furandiones and N,N-dialkyl urea combine with loss of water yielding the pyrrole-2,3-dione derivatives in moderate yields (47-68%. Then, these compounds were converted into 2(1H-quinoxalinones with various 1,2-phenylenediamines. The structures and characterizations of the synthesized compounds were established by the 1H- and 13C-NMR, IR and elemental analysis.

  5. Characterization of electrogenerated polypyrrole-benzophenone films coated on poly(pyrrole-methyl metacrylate) optic-conductive fibers.

    Science.gov (United States)

    Abu-Rabeah, Khalil; Atias, Danit; Herrmann, Sebastien; Frenkel, Julia; Tavor, Dorith; Cosnier, Serge; Marks, Robert S

    2009-09-01

    A conductive surface was created for the development of a biosensing platform via chemical polymerization of pyrrole onto the surface of poly(methyl methacrylate) (PMMA) fibers, with a subsequent electrogeneration of a photoactive linker pyrrole-benzophenone (PyBz) monomer on the fiber surface. Irradiation of the benzophenone groups embedded in the polypyrrole (Ppy) films by UV (350 nm) formed active radicals, allowing covalent attachment of the desired biomaterials. Characterization and optimization of this platform were carried out, with the platform showing conductive, stable, thin, controllable, and light-transmissible film features. Various parameters such as time deposition, process temperature, and activator plus pyrrole monomer concentrations were examined in the study. The morphology and permeability of the optic-fiber PMMA fibers were investigated to examine mass transfer ability. Cyclic voltammetry and amperometry techniques were applied to characterize the electrical features of the surface and charge transfer. The platform potential was then demonstrated by the construction of both amperometric and optical biosensors.

  6. Conjugated polymers with pyrrole as the conjugated bridge: synthesis, characterization, and two-photon absorption properties.

    Science.gov (United States)

    Li, Qianqian; Zhong, Cheng; Huang, Jing; Huang, Zhenli; Pei, Zhiguo; Liu, Jun; Qin, Jingui; Li, Zhen

    2011-07-14

    The synthesis, one- and two-photon absorption (2PA) and emission properties of two novel pyrrole-based conjugated polymers (P1 and P2) are reported. They emitted strong yellow-green and orange fluorescence with fluorescent quantum yields (Φ) of 46 and 33%, respectively. Their maximal 2PA cross sections (δ) measured by the two-photon-induced fluorescence method using femtosecond laser pulses in THF were 2392 and 1938 GM per repeating unit, respectively, indicating that the 2PA chromophores consisting of the triphenylamine with nonplanar structure as the donor and electron-rich pyrrole as the conjugated bridge could be the effective repeating units to enhance the δ values.

  7. Characterization of poly pyrrole/montmorillonite electro polymerised onto Pt; Caracterizacao de filmes PPy/montmorilonita eletropolimerizados sobre Pt

    Energy Technology Data Exchange (ETDEWEB)

    Castagno, K.R.L., E-mail: katiarlc@pelotas.ifsul.edu.b [Instituto Federal Sul-rio-grandense (IFSul), RS (Brazil). Dept. de Quimica; Azambuja, D.S.; Dalmoro, V.; Mauller, R.S. [Universidade Federal do Rio Grande do Sul (UFRGS), Pelotas, RS (Brazil). Inst. de Quimica

    2010-07-01

    In this study films of polypyrrole/montmorillonite (PPy/MT) were electropolymerized on platinum in order to evaluate the performance of this technique in the preparation of nanocomposite materials and to determine the thermal properties and conductivity of the composites. The films were synthesized from a solution containing pyrrole, dodecylbenzene sulfonate, acid and two types of clays: montmorillonite-Na + (MT-Na) and montmorillonite-30B (MT-M). The characterization of the films we have used FT-IR, TEM, XRD, TGA, DSC and resistivity measurement by the four-point van der Pauw method. The study showed that the adopted method of exfoliation and the electropolymerization method used, allows obtaining nanocomposite materials. Analyses of FT-IR, TEM and XRD show that the clays are exfoliated in the polymer matrix. Thermal analysis of the films indicates that the addition of clay reflects an enhancement in the thermal properties of the matrix of PPy, but decreases the conductivity of the same. (author)

  8. Electrochemical synthesis of Poly[3, 4-Propylenedioxythiophene-co-N-Phenylsulfonyl Pyrrole]: Morphological, electrochemical and spectroscopic characterization

    Directory of Open Access Journals (Sweden)

    2011-06-01

    Full Text Available Electroactive random copolymers of 3,4-Propylenedioxythiophene (ProDOT and N-Phenylsulfonyl Pyrrole (PSP were electrochemically synthesized on single carbon fiber microelectrode (SCFME by cyclic voltammetry (CV. Fourier Transform Infrared-Attenuated Total Reflectance (FTIR-ATR measurements indicate the inclusion of PSP into the copolymer structure. The influence of feed ratios on the copolymers was studied by CV and electrochemical impedance spectroscopy (EIS and equivalent circuit modelling (ECM. The morphologies and film thicknesses of copolymers were characterized by scanning electron microscopy (SEM and atomic force microscopy (AFM. The results have shown that the principal changes in morphology, conductivity, porous nature and thickness of Poly(ProDOT-co-PSP film depend on the concentration of PSP. The strong electron-withdrawing sulfonyl group substitution on PSP significantly inhibited electrochemical copolymerization. Semicircular characteristics at Nyquist plots reflected an increasing trend with the increase of PSP concentration in the feed at high frequency. The semicircular characteristic of the copolymer film is useful for the bioelectrochemical sensor applications.

  9. Synthesis, characterization and anticancer studies of new steroidal oxadiazole, pyrrole and pyrazole derivatives

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    Shamsuzzaman

    2015-07-01

    Full Text Available In the present study steroidal derivatives, 3β-[5′-mercapto-1′,3′,4′-oxadiazole-2-yl]methoxy cholest-5-ene 2, 3β-[2′,5′-dimethylpyrrole-1-yl]aminocarbonylmethoxycholest-5-ene 3 and 3β-[3′,5′-dimethyl pyrazole-1-yl]carbonylmethoxycholest-5-ene 4 have been synthesized from cholest-5-en-3β-O-acetyl hydrazide 1 using CS2/KOH, acetonyl acetone and acetyl acetone, respectively as reagents and are characterized by IR, 1H NMR,13C NMR, MS and elemental analysis. Compounds 2–4 were also evaluated for anticancer activity against human leukemia cell line (HL-60 by MTT assay and compound 4 displayed the promising behavior by showing better anticancer activity.

  10. Flexible supercapacitor based on electrochemically synthesized pyrrole formyl pyrrole copolymer coated on carbon microfibers

    Science.gov (United States)

    Gholami, Mehrdad; Moozarm Nia, Pooria; Narimani, Leila; Sokhakian, Mehran; Alias, Yatimah

    2016-08-01

    The main objective of this work is to prepare a flexible supercapacitor using electrochemically synthesized pyrrole formyl pyrrole copolymer P(Py-co-FPy) coated on the carbon microfibers. Due to difficulties of working with carbon microfibers, glassy carbon was used to find out optimized conditions by varying mole ratio of pyrrole and formyl pyrrole monomers on the capacitance value. The prepared electrodes were characterized using Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FESEM), Brunauer-Emmett-Teller (BET) analysis, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Then the X-ray photoelectron spectroscopy (XPS) was used to characterize the optimized electrode. The specific capacitance is calculated using cyclic voltammetry, charge/discharge method, and impedance spectroscopy. The charge/discharge study reveals that the best specific capacitance is estimated to be 220.3 mF cm-2 for equal mole fraction of pyrrole and formyl pyrrole Py (0.1)-FP (0.1) at discharge current of 3 × 10-4 A. This optimized electrode keeps about 92% of its capacitance value in high current of discharging. The specific capacitances calculated by all the mentioned methods are in agreement with each other. Finally, the found optimized conditions were successfully applied to produce a flexible supercapacitor on the surface of carbon microfibers.

  11. The Chemical and Physical Properties of Pyrrole-Based Conducting Polymers: The Characterization of As-Grown Films by X-Ray Photoemission Spectroscopy.

    Science.gov (United States)

    1983-04-07

    by identifying the existence of both, pyrrole rinp and perchlorate anions. It should be mentioned, however, that no significant density of states can...XPS indicates one tetrafluoroborate anion for 4 pyrrole rinp in PP+BF . More precisely, 0.26 boron atoms were found on an average over 4 samples

  12. Synthesis and characterization of reduced graphene oxide supported gold nanoparticles-poly(pyrrole-co-pyrrolepropylic acid) nanocomposite-based electrochemical biosensor.

    Science.gov (United States)

    Puri, Nidhi; Niazi, Asad; Srivastava, Avanish K; Rajesh

    2014-10-01

    A conducting poly(pyrrole-co-pyrrolepropylic acid) copolymer nanocomposite film (AuNP-PPy-PPa) incorporating gold nanoparticles (AuNP) was electrochemically grown using a single step procedure over electrochemically reduced graphene oxide (RGO) flakes deposited on a silane-modified indium-tin-oxide (ITO) glass plate. The RGO support base provided excellent mechanical and chemical stability to the polymer nanocomposite matrix. The porous nanostructure of AuNP-PPy-PPa/RGO provided a huge accessible area to disperse AuNP, and it avoided metallic agglomeration within the polymer matrix. The AuNP-PPy-PPa/RGO was characterized by high-resolution transmission electron microscopy (HRTEM), contact angle measurements, Fourier transform infrared spectroscopy (FTIR), and electrochemical techniques. The pendant carboxyl group of AuNP-PPy-PPa/RGO was covalently bonded with myoglobin protein antibody, Ab-Mb, for the construction of a bioelectrode. Electrochemical impedance spectroscopy technique was used for the characterization of the bioelectrode and as an impedimetric biosensor for the detection of human cardiac biomarker, Ag-cMb. The bioelectrode exhibited a linear impedimetric response to Ag-cMb in the range of 10 ng mL(-1) to 1 μg mL(-1), in phosphate-buffered solution (PBS) (pH 7.4, 0.1 M KCl) with a sensitivity of 92.13 Ω cm(2) per decade.

  13. Flexible supercapacitor based on electrochemically synthesized pyrrole formyl pyrrole copolymer coated on carbon microfibers

    Energy Technology Data Exchange (ETDEWEB)

    Gholami, Mehrdad, E-mail: mehrdad897@um.edu.my [University of Malaya center for ionic liquids, Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Chemistry, Marvdasht Branch, Islamic Azad University, P.O. Box 465, Marvdasht (Iran, Islamic Republic of); Moozarm Nia, Pooria, E-mail: pooriamn@yahoo.com [University of Malaya center for ionic liquids, Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Narimani, Leila, E-mail: Narimani.leila@gmail.com [University of Malaya center for ionic liquids, Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Sokhakian, Mehran, E-mail: m.sokhakian@gmail.com [University of Malaya center for ionic liquids, Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Alias, Yatimah, E-mail: yatimah70@um.edu.my [University of Malaya center for ionic liquids, Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia); Department of Chemistry, Faculty of Science, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2016-08-15

    Highlights: • A Flexible supercapacitor prepared by carbon microfibers coated with P(Py-co-FPy). • The variation of capacitance with different mole ratio of monomers is investigated. • The capacitance measured by different electrochemical methods. • This flexible supercapacitor can be discharged in higher currents for longer time. - Abstract: The main objective of this work is to prepare a flexible supercapacitor using electrochemically synthesized pyrrole formyl pyrrole copolymer P(Py-co-FPy) coated on the carbon microfibers. Due to difficulties of working with carbon microfibers, glassy carbon was used to find out optimized conditions by varying mole ratio of pyrrole and formyl pyrrole monomers on the capacitance value. The prepared electrodes were characterized using Fourier transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FESEM), Brunauer–Emmett–Teller (BET) analysis, cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). Then the X-ray photoelectron spectroscopy (XPS) was used to characterize the optimized electrode. The specific capacitance is calculated using cyclic voltammetry, charge/discharge method, and impedance spectroscopy. The charge/discharge study reveals that the best specific capacitance is estimated to be 220.3 mF cm{sup −2} for equal mole fraction of pyrrole and formyl pyrrole Py (0.1)-FP (0.1) at discharge current of 3 × 10{sup −4} A. This optimized electrode keeps about 92% of its capacitance value in high current of discharging. The specific capacitances calculated by all the mentioned methods are in agreement with each other. Finally, the found optimized conditions were successfully applied to produce a flexible supercapacitor on the surface of carbon microfibers.

  14. Thermodynamic characterization of halide-π interactions in solution using "two-wall" aryl extended calix[4]pyrroles as model system.

    Science.gov (United States)

    Adriaenssens, Louis; Gil-Ramírez, Guzmán; Frontera, Antonio; Quiñonero, David; Escudero-Adán, Eduardo C; Ballester, Pablo

    2014-02-26

    Herein, we report our latest experimental investigations of halide-π interactions in solution. We base this research on the thermodynamic characterization of a series of 1:1 complexes formed between halides (Cl(-), Br(-), and I(-)) and several α,α-isomers of "two-wall" calix[4]pyrrole receptors bearing two six-membered aromatic rings in opposed meso positions. The installed aromatic systems feature a broad range of electron density as indicated by the calculated values for their electrostatic surface potentials at the center of the rings. We show that a correlation exists between the electronic nature of the aromatic walls and the thermodynamic stability of the X(-)⊂receptor complexes. We give evidence for the existence of both repulsive and attractive interactions between π systems and halide anions in solution (between 1 and -1 kcal/mol). We dissect the measured free energies of binding for chloride and bromide with the receptor series into their enthalpic and entropic thermodynamic quantities. In acetonitrile solution, the binding enthalpy values remain almost constant throughout the receptor series, and the differences in free energies are provoked exclusively by changes in the entropic term of the binding processes. Most likely, this unexpected behavior is owed to strong solvation effects that make up important components of the measured magnitudes for the enthalpies and entropies of binding. The use of chloroform, a much less polar solvent, limits the impact of solvation effects revealing the expected existence of a parallel trend between free energies and enthalpies of binding. This result indicates that halide-π interactions in organic solvents are mainly driven by enthalpy. However, the typical paradigm of enthalpy-entropy compensation is still not observed in this less polar solvent.

  15. Morphology and electrical properties of electrochemically synthesized pyrrole-formyl pyrrole copolymer

    Science.gov (United States)

    Gholami, Mehrdad; Nia, Pooria Moozarm; Alias, Yatimah

    2015-12-01

    A direct electrochemical copolymerization of pyrrole-formyl pyrrole (Py-co-FPy) was carried out by oxidative copolymerization of formyl pyrrole and pyrrole in LiClO4 aqueous solution through galvanostatic method. The (Py-co-FPy) copolymer was characterized using Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FESEM), energy-filtering transmission electron microscope (EFTEM), thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The FESEM images showed that the synthesized copolymer had a hollow whelk-like helixes structure, which justifies the enhancement of charge transportation through the copolymer film. Cyclic voltammetry studies revealed that the electrocatalytic activity of synthesized copolymer has improved and the surface coverage in copolymer enhanced 1.6 times compared to polypyrrole alone. Besides, (Py-co-FPy) copolymer showed 2.5 times lower electrochemical charge transfer resistance (Rct) value in impedance spectroscopy. Therefore, this copolymer has a strong potential to be used in several applications such as sensor applications.

  16. Polycondensation of pyrrole and benzaldehyde catalyzed by Maghnite–H+

    Directory of Open Access Journals (Sweden)

    2007-07-01

    Full Text Available Rapid synthesis of poly[(pyrrole-2,5-diyl-co-(benzylidene] was achieved under microwave irradiation via the condensation of pyrrole and benzaldehyde in 1,2-dichloroethane using acid exchanged montmorillonite clay called Maghnite–H+ (Mag–H+ as an efficient catalyst. The effect of the amount of catalyst and of time on the polymerization yield and on the viscosity of the polymers was studied. Compared with conventional static interfacial polymerization, the microwave-radiation polymerization reaction proceeded rapidly and was completed within 35 s. The conjugated polymer was characterized by means of 1H-NMR, X-ray diffraction, FT-IR spectroscopy and AFM. The X-ray data showed the presence of a backbone form of the [(pyrrole-2,5-diyl-co-(benzylidene] formed.

  17. Synthesis and characterization of new electron-withdrawing moiety thieno[2,3-c]pyrrole-4,6-dione-based molecules for small molecule solar cells

    DEFF Research Database (Denmark)

    Fu, Lei; Pan, Hongbin; Larsen-Olsen, Thue Trofod

    2013-01-01

    efficient performance with an obviously high open-circuit voltage (VOC) of 0.97 V and a power conversion efficiency of 1.20% after annealing and using MoO3 as electron-blocking layer. The solar cells based on DTS(BTTPD)2 and PC61BM blend also exhibited a high VOC of 0.97 V under optimized conditions.......–π–donor–π–acceptor type end-capped with thieno[2,3-c]pyrrole-4,6-dione (TPD) units for small molecule solar cells have been prepared through coupling of dithienosilole and TPD units bridged with thienylene and bithienylene. They are soluble in common organic solvents and show an interesting absorption. These small...... molecules have very similar optical band gaps (1.87 eV and 1.92 eV) and fairly close highest occupied molecular orbital energy levels (−5.52 to −5.55 eV). The best solar cells using DTS(TTPD)2 as an electron donor and [6,6]-phenyl-C61-butyric acid methyl ester (PC61BM) as an electron acceptor demonstrated...

  18. Synthesis and spectroscopic characterization on 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid: A DFT approach.

    Science.gov (United States)

    Kurt, M; Sas, E Babur; Can, M; Okur, S; Icli, S; Demic, S; Karabacak, M; Jayavarthanan, T; Sundaraganesan, N

    2016-01-05

    A complete structural and vibrational analysis of the 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid (TPBA), was carried out by ab initio calculations, at the density functional theory (DFT) method. Molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO) (13)C NMR and (1)H NMR chemical shift values of (TPBA), in the ground state have been calculated by using ab initio density functional theory (DFT/B3LYP) method with 6-311G(d,p) as basis set for the first time. Comparison of the observed fundamental vibrational modes of (TPBA) and calculated results by DFT/B3LYP method indicates that B3LYP level of theory giving yield good results for quantum chemical studies. Vibrational wavenumbers obtained by the DFT/B3LYP method are in good agreement with the experimental data. The study was complemented with a natural bond orbital (NBO) analysis, to evaluate the significance of hyperconjugative interactions and electrostatic effects on such molecular structure. By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals analysis and thermodynamic properties of TPBA were investigated using theoretical calculations.

  19. Synthesis and spectroscopic characterization on 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid: A DFT approach

    Science.gov (United States)

    Kurt, M.; Sas, E. Babur; Can, M.; Okur, S.; Icli, S.; Demic, S.; Karabacak, M.; Jayavarthanan, T.; Sundaraganesan, N.

    2016-01-01

    A complete structural and vibrational analysis of the 4-(2,5-di-2-thienyl-1H-pyrrol-1-yl) benzoic acid (TPBA), was carried out by ab initio calculations, at the density functional theory (DFT) method. Molecular geometry, vibrational wavenumbers and gauge including atomic orbital (GIAO) 13C NMR and 1H NMR chemical shift values of (TPBA), in the ground state have been calculated by using ab initio density functional theory (DFT/B3LYP) method with 6-311G(d,p) as basis set for the first time. Comparison of the observed fundamental vibrational modes of (TPBA) and calculated results by DFT/B3LYP method indicates that B3LYP level of theory giving yield good results for quantum chemical studies. Vibrational wavenumbers obtained by the DFT/B3LYP method are in good agreement with the experimental data. The study was complemented with a natural bond orbital (NBO) analysis, to evaluate the significance of hyperconjugative interactions and electrostatic effects on such molecular structure. By using TD-DFT method, electronic absorption spectra of the title compound have been predicted and a good agreement with the TD-DFT method and the experimental one is determined. In addition, the molecular electrostatic potential (MEP), frontier molecular orbitals analysis and thermodynamic properties of TPBA were investigated using theoretical calculations.

  20. Synthesis of poly[(pyrrole-2,5-diyl)-co-(4-hydroxylbenzylidene)] catalysed by Maghnite– H+

    OpenAIRE

    Bouhadjar Larbi; Aïcha Hachemaoui; Yahiaoui Ahmed; Bouchama Abdelghani; Chikh Karime; Belbachir Mohamed

    2014-01-01

    Rapid synthesis of poly[(pyrrole-2,5-diyl)-co-(4-hydroxylbenzylidene)] was achieve via the condensation of pyrrole and 4-hydroxylbenzylidene in dichloromethane using acid exchanged montmorillonite clay called Maghnite– H+ (Mag–H+) as an efficient catalyst The conjugated polymer was characterized by means of 1H-NMR, UV-visible, FT-IR spectroscopy and TGA.

  1. Synthesis of new pyrrole-containing biomolecules as building blocks for functionalized polypyrroles in nanobiotechnology

    Energy Technology Data Exchange (ETDEWEB)

    Karsten, S; Liebscher, J [Department of Chemistry, Humboldt-Universitaet zu Berlin, Brook-Taylor-Str. 2, 12489 Berlin (Germany); Nan, A; Turcu, R, E-mail: sebastian.karsten@chemie.hu-berlin.d, E-mail: liebscher@chemie.hu-berlin.d [National Instiute of Research and Development for Isotopic and Molecular Technologies, Donath 65-103, RO-400293 Cluj-Napoca (Romania)

    2009-08-01

    New pyrroles were synthesized wherein biomolecules such as {alpha}-amino acids, peptides or carbohydrates are attached to position 1 or 3 via suitable linkers. These conjugates were copolymerized with pyrrole by chemical polymerisation alone giving corresponding copolymers or in the presence of magnetic iron oxid nanoparticles resulting in functionalized core-shell-nanoparticles. Such products are interesting for biosensing, imaging or separation of biomaterials. They were characterized by several methods such as TEM, HRTEM, FTIR and measuring of magnetization.

  2. Testing the Limits of the BOPHY Platform: Preparation, Characterization, and Theoretical Modeling of BOPHYs and Organometallic BOPHYs with Electron-Withdrawing Groups at β-Pyrrolic and Bridging Positions.

    Science.gov (United States)

    Zatsikha, Yuriy V; Nemez, Dion B; Davis, Rebecca L; Singh, Simarpreet; Herbert, David E; King, Alex J; Ziegler, Christopher J; Nemykin, Victor N

    2017-07-19

    Several BOPHY derivatives with and without ferrocene fragments, and with electron-withdrawing ester groups appended to the β-pyrrolic positions have been prepared and characterized by NMR, UV/Vis near-infrared (NIR), high-resolution mass spectrometry, and fluorescence spectroscopy, as well as X-ray crystallography. The redox properties of new BOPHYs were probed by electrochemical (cyclic and differential pulse voltammetry) and spectroelectrochemical methods. In an attempt to prepare BOPHY derivatives with a cyano group at the bridging position using a similar approach for BODIPY cyanation, adducts from the nucleophilic attack of the cyanide anion on the bridging position in BOPHY have been isolated and characterized by spectroscopic methods. Oxidation of such adducts, however, resulted in formation of either the starting BOPHYs, or partial extrusion of the BF2 fragment from the BOPHY core, which was confirmed by spectroscopy and X-ray crystallography. DFT and TDDFT calculations on all target materials correlate well with the experimental data, and suggest the dramatic reduction of the nitrogen atom basicity at the hydrazine bridge of the BOPHY upon introduction of the cyano group at the bridging-carbon atom. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  3. Poly [(pyrrole-2, 5-diyl) co(4-Nitro benzylidene)]: A new synthetic approach and electronic properties

    Science.gov (United States)

    Gherras, H.; Hachemaoui, A.; Yahiaoui, A.; Belbachir, M.; Belfedal, A.

    2012-02-01

    A new poly (heteroarylene methylene) containing one to four α-pyrrole rings alternating with an sp3-carbon atom in the main chain were synthesized and characterized. The synthesized poly [(pyrrole-2, 5-diyl)-co-(4-nitrobenzylidene)] was found to be highly dehydrogenated, thus resulting in black materials with conjugated segments larger than a single pyrrole ring. The conjugated polymers containing alternating aromatic and quinoid heteroarylene moieties in the main chain were prepared by polycondensation of 4-nitrobenzaldehyde and pyrrole catalysed by Maghnite-H+. The new polymer is useful precursors to small-bandgap polymers based on poly (heteroarylene methines) and is also useful model system for the investigation of the effects of π-conjugation length on the electronic and optical properties of conjugated polymers.

  4. Synthesis, vapor growth, polymerization, and characterization of thin films of novel diacetylene derivatives of pyrrole. The use of computer modeling to predict chemical and optical properties of these diacetylenes and poly(diacetylenes)

    Science.gov (United States)

    Paley, M. S.; Frazier, D. O.; Abeledeyem, H.; Mcmanus, S. P.; Zutaut, S. E.

    1992-01-01

    In the present work two diacetylene derivatives of pyrrole which are predicted by semiempirical AM1 calculations to have very different properties, are synthesized; the polymerizability of these diacetylenes in the solid state is determined, and the results are compared to the computer predictions. Diacetylene 1 is novel in that the monomer is a liquid at room temperature; this may allow for the possibility of polymerization in the liquid state as well as the solid state. Thin poly(diacetylene) films are obtained from compound 1 by growing films of the monomer using vapor deposition and polymerizing with UV light; these films are then characterized. Interestingly, while the poly(diacetylene) from 1 does not possess good nonlinear optical properties, the monomer exhibits very good third-order effects (phase conjugation) in solution. Dilute acetone solutions of the monomer 1 give intensity-dependent refractive indices on the order of 10 exp -6 esu; these are 10 exp 6 times better than for CS2.

  5. Electropolymerization of pyrrole on silanized polycrystalline titanium substrates

    Energy Technology Data Exchange (ETDEWEB)

    Mekhalif, Z. [Laboratory of Chemistry and Electrochemistry of Surfaces, University of Namur (FUNDP), Rue de Bruxelles, 61, B-5000 Namur (Belgium)], E-mail: zineb.mekhalif@fundp.ac.be; Cossement, D.; Hevesi, L.; Delhalle, J. [Laboratory of Chemistry and Electrochemistry of Surfaces, University of Namur (FUNDP), Rue de Bruxelles, 61, B-5000 Namur (Belgium)

    2008-04-30

    In this work is reported the silanization of titanium substrates and subsequent polymerization of pyrrole on the resulting substrates. First, titanium substrates were modified by n-hexyltrichlorosilane (HTCS) and 6-(1'-pyrrolyl)-n-hexyltrichlorosilane (PyHTCS). The corresponding self-assembled monolayers were characterized by X-ray photoelectron spectroscopy and contact angle measurements. They were found to be densely packed. Second, pyrrole was electrochemically polymerized on silanized titanium substrates. Chronoamperometry was used to study the growth of polypyrrole films. The polymer films were characterized by qualitative peel tests, cyclic voltametry and scanning electron spectroscopy. Polypyrrole grown from PyHTCS was found to adherent as compared to HTCS modified and bare substrates. Cyclic voltametry indicated that polymer films formed from PyHTCS have an oxidation peak potential located at higher values than HTCS-modified and bare substrates. Moreover, the films grown on the three types of substrates were found to be equally uniform. Finally, we improved the electrochemical properties of the polypyrrole films using a two-step process, electroreticulation of the PyHTCS monolayers followed by a pyrrole polymerization.

  6. Cyclo[n]pyrroles and methods thereto

    Energy Technology Data Exchange (ETDEWEB)

    Sessler, Jonathan L.; Seidel, Daniel; Bolze, Frederic R.; Koehler, Thomas

    2006-01-10

    The present invention provides an oxidative coupling procedure that allows efficient synthesis of novel cyclo[n]pyrrole macrocycles. Therefore, the present invention provides cyclo[n]pyrroles where n is 6, 7, 8, 9, 10, 11, or 12, and derivatives, multimers, isomers, and ion and neutral molecule complexes thereof as new compositions of matter. A protonated form of cyclo[n]pyrrole displays a gap of up to 700 nm between strong Soret and Q-like absorption bands in the electronic spectrum, demonstrating no significant ground state absorption in the visible portion of the electronic spectrum. Uses of cyclo[n]pyrroles as separation media, nonlinear optical materials, information storage media and infrared filters are provided.

  7. Synthesis of poly[(pyrrole-2,5-diyl-co-(4-hydroxylbenzylidene] catalysed by Maghnite– H+

    Directory of Open Access Journals (Sweden)

    Bouhadjar Larbi

    2014-01-01

    Full Text Available Rapid synthesis of poly[(pyrrole-2,5-diyl-co-(4-hydroxylbenzylidene] was achieve via the condensation of pyrrole and 4-hydroxylbenzylidene in dichloromethane using acid exchanged montmorillonite clay called Maghnite– H+ (Mag–H+ as an efficient catalyst The conjugated polymer was characterized by means of 1H-NMR, UV-visible, FT-IR spectroscopy and TGA.

  8. A new pyrrole alkaloid from seeds of Castanea sativa.

    Science.gov (United States)

    Hiermann, Alois; Kedwani, Samir; Schramm, Hans Wolfgang; Seger, Christoph

    2002-02-01

    A new pyrrole alkaloid, methyl-(5-formyl-1H-pyrrole-2-yl)-4-hydroxybutyrate (1), was isolated from sweet chestnut seeds and its structure elucidated on the basis of data from NMR spectroscopy and by comparison with synthetic analogues.

  9. Synthesis of star-shaped pyrrole and thiophene functionalized monomers and optoelectrochemical properties of corresponding copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Ak, Metin [Middle East Technical University, Department of Chemistry, 06531 Ankara (Turkey); Pamukkale University, Department of Chemistry, 20020 Denizli (Turkey); Toppare, Levent [Middle East Technical University, Department of Chemistry, 06531 Ankara (Turkey)], E-mail: toppare@metu.edu.tr

    2009-04-15

    Star-shaped thiophene and pyrrole functionalized monomers namely 2,4,6-tris(4-(1H-pyrrol-1-yl)phenoxy)-1,3,5-triazine (TriaPy) and 2,4,6-tris(4-(1H-pyrrol-1-yl)phenoxy)-1,3,5-triazine (TriaTh) were synthesized from 2,4,6-trichloro-1,3,5-triazine, thiophen-3-ylmethanol and 4-(1H-pyrrol-1-yl)phenol. Electrochemical copolymerization of monomers with thiophene and pyrrole was achieved in tetrabutylammonium tetrafluoroborate/acetonitrile (TBAFB/AN). Resulting copolymers were characterized by Fourier transform infrared (FTIR) spectrometer, cyclic voltammetry (CV) and conductivity measurements. Spectroelectrochemical analysis reflected that copolymer films have low {lambda}{sub max} for {pi}-{pi}* electronic transitions accompanied with a rather high band gap compared to polythiophene and polypyrrole. Switching abilities of copolymer films were evaluated by a kinetic study via measuring the transmittance (%T) at the maximum contrast.

  10. Electrophilic surface sites as precondition for the chemisorption of pyrrole on GaAs(001) surfaces

    Energy Technology Data Exchange (ETDEWEB)

    Bruhn, Thomas [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr.36, D-10623 Berlin (Germany); Leibniz-Institut für Analytische Wissenschaften - ISAS - e.V., Albert-Einstein-Str.9, 12489 Berlin (Germany); Fimland, Bjørn-Ove [Department of Electronics and Telecommunications, Norwegian University of Science and Technology, NO-7491 Trondheim (Norway); Vogt, Patrick, E-mail: patrick.vogt@tu-berlin.de [Institut für Festkörperphysik, Technische Universität Berlin, Hardenbergstr.36, D-10623 Berlin (Germany)

    2015-03-14

    We report how the presence of electrophilic surface sites influences the adsorption mechanism of pyrrole on GaAs(001) surfaces. For this purpose, we have investigated the adsorption behavior of pyrrole on different GaAs(001) reconstructions with different stoichiometries and thus different surface chemistries. The interfaces were characterized by x-ray photoelectron spectroscopy, scanning tunneling microscopy, and by reflectance anisotropy spectroscopy in a spectral range between 1.5 and 5 eV. On the As-rich c(4 × 4) reconstruction that exhibits only nucleophilic surface sites, pyrrole was found to physisorb on the surface without any significant modification of the structural and electronic properties of the surface. On the Ga-rich GaAs(001)-(4 × 2)/(6 × 6) reconstructions which exhibit nucleophilic as well as electrophilic surface sites, pyrrole was found to form stable covalent bonds mainly to the electrophilic (charge deficient) Ga atoms of the surface. These results clearly demonstrate that the existence of electrophilic surface sites is a crucial precondition for the chemisorption of pyrrole on GaAs(001) surfaces.

  11. Synthesis and recognition properties of higher order tetrathiafulvalene (TTF) calix n pyrroles (n=4-6)

    DEFF Research Database (Denmark)

    Park, J. S.; Bejger, C.; Larsen, K. R.

    2012-01-01

    of the condensation reaction, the expanded calix[n]pyrroles (n = 5 and 6) are characterized by a larger cavity size and a higher number of TTF units (albeit the same empirical formula). Analysis of the binding isotherms obtained from UV-Vis spectroscopic titrations carried out in CHCl3 in the presence of both anionic...

  12. BRIEF COMMUNICATIONS: Picosecond spectroscopy of pyrrol pigments

    Science.gov (United States)

    Lippitsch, M. E.; Leitner, A.; Riegler, M.; Aussenegg, F. R.

    1982-05-01

    Picosecond fluorescence and absorption spectroscopy methods were used to study pyrromethenone, pyrromethene, and biliverdin. These methods made it possible to determine some details of the kinetics of various relaxation mechanisms. The results obtained provided a better understanding of the biological action of pyrrol pigments.

  13. Tris[2-(pyrrol-2-ylmethyleneaminoethyl]amine

    Directory of Open Access Journals (Sweden)

    Hongbing Fu

    2008-03-01

    Full Text Available The title compound, C21H27N7, was synthesized by reaction of tris(2-aminoethylamine and pyrrole-2-carbaldehyde in ethanol at room temperature. The structure is stabilized by intra- and intermolecular C—H...N and N—H...N hydrogen-bonding interactions.

  14. Electrochemical polypyrrole formation from pyrrole 'adlayer'.

    Science.gov (United States)

    Plausinaitis, Deivis; Sinkevicius, Linas; Mikoliunaite, Lina; Plausinaitiene, Valentina; Ramanaviciene, Almira; Ramanavicius, Arunas

    2017-01-04

    In this research study, we investigated the morphology of polypyrrole nanostructures, which were formed during the electrochemical deposition of conducting polymer. An electrochemical quartz crystal microbalance (EQCM) cell equipped with a flow-through system was employed to exchange solutions of different compositions within the EQCM cell. When bare PBS buffer in the EQCM cell was exchanged with PBS buffer with pyrrole we observed a distinct increase in the resonance frequency Δf. This change in the resonance frequency and electrical capacitance, which was calculated from electrochemical impedance spectroscopy (EIS) data, illustrate that pyrrole on the surface of the gold electrode formed an adsorbed layer (adlayer). The formation of a pyrrole adlayer before the potential pulse that induced polymerization was investigated by QCM-based measurements. The electrochemical polymerization of this adlayer was induced by a single potential pulse and a nanostructured layer, which consisted of adsorbed polypyrrole (Ppy) nanoparticles with a diameter of 50 nm, was formed. QCM and EIS data revealed that by the next cycle of the electrochemical formation of Ppy, which was investigated after flow-through-based exchange of solutions, the initially formed Ppy surface was covered by the adlayer of pyrrole. This adlayer was desorbed when pyrrole was removed from the solution. When electrochemical polymerization was performed using 50 potential pulses, a Ppy layer, which had more complex morphology, was formed on the EQCM crystal. Scanning electron microscopy showed that the conductivity of this layer was unequally distributed. We observed that the polypyrrole layer formed by electrochemical deposition, which was performed using potential pulses, was formed out of aggregated spherical Ppy particles with a diameter of 50 nm.

  15. Vibrational Overtone Spectroscopy of Pyrrole and Pyrrolidine

    Science.gov (United States)

    1991-05-23

    general pattern is a strong peak accompanied by two or three weaker peaks to lower energy. For instance, the 13,305 cm-I band in pyrrole has three weaker...Orza, J.M. Anales de Quimica 1984, 80, 59. 29. Navarro, R.; Orza, J.M. Anales de Quimica 1982, 79, 557. 30. Xie, Y; Fan, K.; Boggs,J., Molec. Phys

  16. Probing the hydrolytic reactivity of 2-difluoromethyl pyrroles.

    Science.gov (United States)

    Melanson, Jennifer A; Figliola, Carlotta; Smithen, Deborah A; Kajetanowicz, Aleksandra K; Thompson, Alison

    2016-12-20

    α-Difluoromethyl pyrroles were found to be stable while N-protected with an electron-withdrawing group. Due to the propensity of pyrroles to access azafulvenium-like intermediates, the C-F bonds of an α-difluoromethyl substituent are labile under hydrolytic conditions. The presence of certain electron-withdrawing substituents about the pyrrolic ring can accelerate this process, as determined through a kinetic comparison of the deprotection and subsequent hydrolysis reactions of N-protected β-aryl α-difluoromethyl pyrroles.

  17. TTF derivative of 2,5-aromatic disubstituted pyrrole, synthesis and electronic study

    Science.gov (United States)

    Fomina, Lioudmila; León, Chistopher; Bizarro, Monserrat; Baeza, Alejandro; Gómez-Vidales, Virginia; Sansores, L. Enrique; Salcedo, Roberto

    2016-03-01

    TTF derivative of substituted pyrrole was obtained by means electrochemical synthesis, the resultant colored mix was characterized by Mass spectrometry, NMR and EPR studies, its intrinsic electronic behavior was measured by a four point probe method, besides theoretical calculations were carried out on the possible structures of the resultant molecular adduct. All the results show that there is a net transfer of an electron between both organic moieties in solution giving place to a semiconductor species.

  18. Experimental and theoretical study of 4-formyl pyrrole derived aroylhydrazones

    Science.gov (United States)

    Rawat, Poonam; Singh, R. N.

    2015-03-01

    Two new 4-formyl pyrrole derived aroylhydrazones (3a, b) from ethyl 4-formyl-3,5-dimetyl-1H-pyrrole-2-carboxylate and aroylhydrazides (3,5-dinitrobenzohydrazide/2-hydrazinocarbonyl-N-phenyl-acetamide) have been synthesized and characterized by various spectroscopic techniques 1H NMR, Mass, UV-Visible and FT-IR. The calculated thermodynamic parameters show that the formation of 3a as spontaneous, whereas 3b as non-spontaneous. TD-DFT has been used to calculate the absorption wavelengths, oscillator strength (f) and the nature of electronic excitations. Natural bond orbital (NBO) analysis has been carried out to explore the various conjugative and hyperconjugative interactions and their second order stabilization energy (E(2)) within monomer and its dimer. The dimer formation of 3a, 3b due to result of intermolecular hydrogen bonding N1sbnd H30⋯O84, N1sbnd H28⋯O60 is obvious in 1H NMR, NBO and FT-IR as down field chemical shifts, n(O84) → σ∗(N1sbnd H30), n(O60) → σ∗(N1sbnd H28) interactions, vibrational red shifts, respectively. To determine the strength and nature of hydrogen bonding, topological parameters at bond critical points (BCP) have been analyzed by 'Quantum theory of Atoms in molecules' (QTAIM) in detail. The global electrophilicity index (ω) has been calculated to determine the relative electrophilic strength of molecules. The local reactivity descriptors analyses such as Fukui functions (fk+, fk-), local softnesses (sk+, sk-) and electrophilicity indices (ωk+, ωk-) have been performed to determine the reactive sites within molecules. The first hyperpolarizabilities (β0) of 3a, b have been computed to evaluate the non-linear optical (NLO) response of the investigated molecules.

  19. Revisiting the relaxation dynamics of isolated pyrrole

    Energy Technology Data Exchange (ETDEWEB)

    Montero, Raúl; Ovejas, Virginia; Fernández-Fernández, Marta; Longarte, Asier, E-mail: asier.longarte@ehu.es [Departamento de Química Física, Universidad del País Vasco (UPV/EHU), Apart. 644, 48080 Bilbao (Spain); Peralta Conde, Álvaro [Centro de Láseres Pulsados (CLPU), Edificio M3, Parque Científico, 37185 Villamayor (Spain)

    2014-07-07

    Herein, the interpretation of the femtosecond-scale temporal evolution of the pyrrole ion signal, after excitation in the 267–217 nm interval, recently published by our group [R. Montero, A. Peralta Conde, V. Ovejas, M. Fernández-Fernández, F. Castaño, J. R. Vázquez de Aldana, and A. Longarte, J. Chem. Phys.137, 064317 (2012)] is re-visited. The observation of a shift in the pyrrole{sup +} transient respect to zero delay reference, initially attributed to ultrafast dynamics on the πσ{sup *} type state (3s a{sub 1} ← π 1a{sub 2}), is demonstrated to be caused by the existence of pump + probe populated states, along the ionization process. The influence of these resonances in pump-prone ionization experiments, when multi-photon probes are used, and the significance of a proper zero-time reference, is discussed. The possibility of preparing the πσ{sup *} state by direct excitation is investigated by collecting 1 + 1 photoelectron spectra, at excitation wavelengths ranging from 255 to 219 nm. No conclusive evidences of ionization through this state are found.

  20. Effect of Pyrrole and N-Methylpyrrole Coatings on Corrosion Resistance of Mild Steel

    Institute of Scientific and Technical Information of China (English)

    AliAshrafi; M.A.Golozarl; S.Mallakpour; AliGhasemi

    2004-01-01

    Electrochemical polymerizations of various ratios of pyrrole and methylpyrrole monomers were performed in aqueous toluene-4-sulfinic acid sodium salt (T4SNa) electrolyte, using galvanostatic method, pH of electrolyte was adjusted by p-toluene sulfonic acid (PTSA). In order to prevent corrosion of mild steel substrates during coating deposition, specimens were pretreated in 0.5M oxalic acid solution, employing galvanostatic method. This would passivate the steel substrate and facilitate the coating process as well. Corrosion resistance of coated substrates was investigated in 1M NaCl solution using Tafel polarization technique. In addition, using scanning electron microscopy (SEM), morphological characterization of coatings produced, was investigated. Regarding the corrosion characteristics, results obtained revealed that the ratio of 1 to 1(Pyrrole/Methylpyrrole) could play an important role.

  1. Effect of Pyrrole and N-Methylpyrrole Coatings on Corrosion Resistance of Mild Steel

    Institute of Scientific and Technical Information of China (English)

    Ali Ashrafi; M.A.Golozar; S.Mailakpour; Ali Ghasemi

    2004-01-01

    Electrochemical polymerizations of various ratios of pyrrole and methylpyrrole monomers were performed in aqueous toluene-4-sulfinic acid sodium salt (T4SNa) electrolyte, using galvanostatic method. pH of electrolyte was adjusted by p-toluene sulfonic acid (PTSA). In order to prevent corrosion of mild steel substrates during coating deposition,specimens were pretreated in 0.5M oxalic acid solution, employing galvanostatic method. This would passivate the steel substrate and facilitate the coating process as well. Corrosion resistance of coated substrates was investigated in 1M NaCl solution using Tafel polarization technique. In addition, using scanning electron microscopy (SEM), morphological characterization of coatings produced, was investigated. Regarding the corrosion characteristics, results obtained revealed that the ratio of 1 to 1 (Pyrrole/Methylpyrrole) could play an important role.

  2. 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.

  3. On the fluorescence of pyrrole derivative oligomer

    Energy Technology Data Exchange (ETDEWEB)

    Guimaraes, Jeconias Rocha; Amazonas, Jarlesson Gama; Alberto Brito Silva Junior, Carlos [Pos-Graduacao em Fisica, Universidade Federal do Para, 66075-110 Belem, Para (Brazil); Melo, Celso P. de [Departamento de Fisica, Universidade Federal de Pernambuco, 50670-020 Recife, Pernambuco (Brazil); Laks, Bernardo [Instituto de Fisica, UNICAMP, 13083-970 Campinas, Sao Paulo (Brazil); Nero, Jordan del [Departamento de Fisica, Universidade Federal do Para, 66075-110 Belem, Para (Brazil)], E-mail: jordan@ufpa.br

    2008-08-01

    In this work we have investigated the ground state and others eletronic properties of the biosensor 3-methyl pyrrole-4-carboxilic acid (MPC) oligomers and related compounds. We considered the systems described by a DFT/B3LYP/6-31G* type Hamiltonian and explored the effects due to the presence of conformational defects. Furthermore the excited states have been determined by a post Hartree-Fock CI methodology. The results revealed the existence of different electronic patterns for the MPC if compared to the ones existing for the oligopyrrole derivative systems. The response of one of investigated polymers (MPC) was found to be critically dependent on the radicals linked to the studied oligomer chain structure so that the electronic structure analyses should be easily improved by choosing a proper set of preparation parameters to design conducting polymers with desirable properties.

  4. Hydroquinone–pyrrole dyads with varied linkers

    Directory of Open Access Journals (Sweden)

    Hao Huang

    2016-01-01

    Full Text Available A series of pyrroles functionalized in the 3-position with p-dimethoxybenzene via various linkers (CH2, CH2CH2, CH=CH, C≡C has been synthesized. Their electronic properties have been deduced from 1H NMR, 13C NMR, and UV–vis spectra to detect possible interactions between the two aromatic subunits. The extent of conjugation between the subunits is largely controlled by the nature of the linker, with the largest conjugation found with the trans-ethene linker and the weakest with the aliphatic linkers. DFT calculations revealed substantial changes in the HOMO–LUMO gap that correlated with the extent of conjugation found experimentally. The results of this work are expected to open up for use of the investigated compounds as components of redox-active materials in sustainable, organic electrical energy storage devices.

  5. STUDY OF ELECTROPOLIMERIZATION PROCESSES OF PYRROLE BY CYCLIC VOLTAMMETRIC TECHNIQUE

    Directory of Open Access Journals (Sweden)

    Adhitasari Suratman

    2010-06-01

    Full Text Available Electropolymerization processes and electrochemical properties of polypyrrole as electroactive polymer have been studied by cyclic voltammetric technique. Pyrrole was electropolymerized to form polypyrrole in water-based solvent containing sodium perchlorate as supporting electrolyte in several pH values. The pH of the solutions were varied by using Britton Robinson buffer. The results showed that oxidation potential limit of electropolymerization processes of pyrrole was 1220 mV vs Ag/AgCl reference electrode. It can be seen that cyclic voltammetric respon of polypyrrole membrane that was prepared by electropolymerization processes of pyrrole at the scanning rate of 100 mV/s was stable. While the processes of pyrrole electropolymerization carried out at the variation of pH showed that the best condition was at the pH range of 2 - 6.   Keywords: polypyrolle, electropolymer, voltammetric technique

  6. Morphology and electrical properties of electrochemically synthesized pyrrole–formyl pyrrole copolymer

    Energy Technology Data Exchange (ETDEWEB)

    Gholami, Mehrdad, E-mail: mehrdad897@um.edu.my [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Chemistry, Marvdasht Branch, Islamic Azad University, P.O. Box 465, Marvdasht (Iran, Islamic Republic of); Nia, Pooria Moozarm, E-mail: pooriamn@yahoo.com [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Alias, Yatimah, E-mail: yatimah70@um.edu.my [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2015-12-01

    Graphical abstract: - Highlights: • The (Py–co-FPy) copolymer was synthesized electrochemically. • This copolymer has 1.6 times higher surface coverage compared to polypyrrole. • This copolymer showed 2.5 times lower resistance compared to polypyrrole. • The conjugated structure between Py and FPy causes enhancement of conductivity. • This conducting copolymer has a strong potential to be used in various applications. - Abstract: A direct electrochemical copolymerization of pyrrole–formyl pyrrole (Py–co-FPy) was carried out by oxidative copolymerization of formyl pyrrole and pyrrole in LiClO{sub 4} aqueous solution through galvanostatic method. The (Py–co-FPy) copolymer was characterized using Fourier-transform infrared spectroscopy (FT-IR), field emission scanning electron microscope (FESEM), energy-filtering transmission electron microscope (EFTEM), thermal gravimetric analysis (TGA), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The FESEM images showed that the synthesized copolymer had a hollow whelk-like helixes structure, which justifies the enhancement of charge transportation through the copolymer film. Cyclic voltammetry studies revealed that the electrocatalytic activity of synthesized copolymer has improved and the surface coverage in copolymer enhanced 1.6 times compared to polypyrrole alone. Besides, (Py–co-FPy) copolymer showed 2.5 times lower electrochemical charge transfer resistance (R{sub ct}) value in impedance spectroscopy. Therefore, this copolymer has a strong potential to be used in several applications such as sensor applications.

  7. Electrochemical synthesis of poly(pyrrole-co-o-anisidine)/chitosan composite films

    Science.gov (United States)

    Yalçınkaya, Süleyman; Çakmak, Didem

    2017-05-01

    In this study, poly(pyrrole-co-o-anisidine)/chitosan composite films were electrochemically synthesized in various monomers feed ratio (pyrrole: o-anisidine; 9:1, 7:3, 1:1, 3:7 and 1:9) of pyrrole and o-anisidine on the platinum electrode. Electrochemical synthesis of the composite films was carried out via cyclic voltammetry technique. They were characterized by FT-IR, cyclic voltammetry, SEM micrographs, digital images, TGA and DSC techniques. The SEM results indicated that the particle size of the composite decreased with increasing o-anisidine ratio and the films became more likely to be smooth morphology. The TGA results proved that the film of the composite with 1:1 ratio showed highest final degradation temperature and lowest weight loss (83%) compared to copolymer and 9:1 1:9 composite films. The 1:1 composite film had higher thermal stability than copolymer and the other composite films (9:1 1:9). Meanwhile, electrochemical studies exhibited that the 1/9 composite film had good electrochemical stability as well.

  8. Electrochemical impedance of poly(9-tosyl-9H-carbazole-co-pyrrole) electrocoated carbon fiber

    Energy Technology Data Exchange (ETDEWEB)

    Ates, Murat; Uludag, Nesimi [Department of Chemistry, Faculty of Arts and Sciences, Namik Kemal University, Degirmenalti Campus, 59030, Tekirdag (Turkey); Sarac, A. Sezai, E-mail: sarac@itu.edu.tr [Department of Chemistry, Polymer Science and Technology, Istanbul Technical University, Maslak, 34469, Istanbul (Turkey)

    2011-05-16

    Research highlights: {yields} Impedance study of poly(9-tosyl-9H-carbazole-co-pyrrole) electrocoated carbon fiber. {yields} Copolymer of 9-tosyl-9H-carbazole and pyrrole were electrocoated on carbon fiber. {yields} Impedance spectroscopy and circuit models of poly(9-tosyl-9H-carbazole-co-pyrrole). - Abstract: In this paper, copolymer of 9-tosyl-9H-carbazole (TCz) and pyrrole (Py) comonomers were electrochemically deposited onto carbon fiber micro electrode (CFME) as an active electrode material. An electrochemical impedance study on the prepared electrodes is reported. Poly(TCz-co-Py)/CFME is characterized by cyclic voltammetry (CV), Fourier transform infrared reflectance-attenuated total reflection spectroscopy (FTIR-ATR), scanning electron microscopy-energy dispersive X-ray analysis (SEM-EDX), and electrochemical impedance spectroscopy (EIS). Capacitive behaviors of modified CFMEs were defined via Nyquist, Bode-magnitude and Bode-phase plots. An examination is made of which equivalent circuits of R(C(R(Q(RW)))) and R(C(R(Q(RW))))(CR) used for modeling the system. The effect of monomer ratio (mole fraction, X{sub TCz} = n{sub TCz}/n{sub TCz} + n{sub Py}) on the formation of copolymer is reported in 0.1 M sodium perchlorate (NaClO{sub 4})/acetonitrile (ACN) solution. The inclusion of TCz in the copolymer structure was also confirmed by FTIR-ATR, SEM, and CV measurements. The highest low frequency capacitance (C{sub LF} = 22.7 for R(C(R(Q(RW)))) and C{sub LF} = 22.6 mF cm{sup -2} for R(C(R(Q(RW))))(CR)) were obtained for X{sub TCz} = 0.91.

  9. Polymerization of Pyrrole and Thiophene on Polyethylene Adipate Electrodes

    OpenAIRE

    Erturan, Seyfettin; TORAMAN, Burcu YALVAÇ and Sena

    1998-01-01

    Polymerizations of pyrrole and thiophene on a platinum foil coated by polyethylene adipate (PEA) were carried out in acetonitrile by electrochemical methods. Different compositions of semi-conducting composite films of PEA/Polypyrrole(PPy), PEA/Polythiophene(PT) were prepared by the electrochemical polymerization of pyrrole and thiophene on PEA electrode. The polymerization was possible only for a certain thickness of the polyethylene adipate(PEA) on the platinum. Conductivities of PEA/PPy, P...

  10. An Electrochemical Investigation into a Series of Tricyanovinylated Pyrrole Moieties

    NARCIS (Netherlands)

    McCormac, Timothy; Farrell, David; Browne, Wesley; Vos, Johannes G.

    2004-01-01

    The electrochemical behavior of three tri-cyanovinylated pyrrole species namely, 2-tricyanovinyl-pyrrole (C4H4N-C5N3), 2-tricyanovinyl-N-methylpyrrole (C5H6N-C5N3) and 2-tricyanovinyl-N-phenylpyrrole (C10H8N-C5N3), has been studied. All compounds were found to exhibit both an irreversible oxidation

  11. Simple two-step synthesis of 2,4-disubstituted pyrroles and 3,5-disubstituted pyrrole-2-carbonitriles from enones

    Directory of Open Access Journals (Sweden)

    Murat Kucukdisli

    2014-02-01

    Full Text Available The cyclocondensation of enones with aminoacetonitrile furnishes 3,4-dihydro-2H-pyrrole-2-carbonitriles which can be readily converted to 2,4-disubstituted pyrroles by microwave-induced dehydrocyanation. Alternatively, oxidation of the intermediates produces 3,5-disubstituted pyrrole-2-carbonitriles.

  12. The harmonic force field and vibrational spectra of pyrrole

    Science.gov (United States)

    Xie, Yaoming; Fan, Kangnian; Boggs, James E.

    The complete harmonic vibrational force field of pyrrole has been calculated by the ab initio gradient method at the Hartree-Fock level using the 4-21 basis set. The force field was then scaled with a set of six factors transferred from benzene, and the vibrational spectrum of pyrrole was calculated. This a priori prediction, made with no reference to observations on pyrrole, agreed with the known experimental fundamental frequencies with a mean deviation of 12 cm-1 for in-plane modes and 20 cm-1 for out-of-plane modes except for the NH wagging and NH stretch. A new set of ten scale factors was next obtained by direct fitting of the computed force field to the observed pyrrole spectrum, producing the best force field obtainable by combined use of the theoretical and experimental information. This force field reproduced the entire pyrrole spectrum with mean deviations of 4·2 cm-1 (in-plane) and 5·9 cm-1 (out-of-plane). The spectra of three deuterated forms of pyrrole were also computed. Infrared absorption intensities were calculated and proved very useful in examining assignments of the two ring torsional modes and the CH stretching modes.

  13. Assessment of conformational, spectral, antimicrobial activity, chemical reactivity and NLO application of Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone)

    Science.gov (United States)

    Rawat, Poonam; Singh, R. N.

    2015-04-01

    An orange colored pyrrole dihydrazone: Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone) (PDBO) has been synthesized by reaction of oxalic acid dihydrazide with 2,5 diformyl-1H-pyrrole and has been characterized by spectroscopic analysis (1H, 13C NMR, UV-visible, FT-IR and DART Mass). The properties of the compound has been evaluated using B3LYP functional and 6-31G(d,p)/6-311+G(d,p) basis set. The symmetric (3319, 3320 cm-1) and asymmetric (3389, 3382 cm-1) stretching wave number confirm free NH2 groups in PDBO. NBO analysis shows, inter/intra molecular interactions within the molecule. Topological parameters have been analyzed by QTAIM theory and provide the existence of intramolecular hydrogen bonding (N-H⋯O). The local reactivity descriptors analyses determine the reactive sites within molecule. The calculated first hyperpolarizability value (β0 = 23.83 × 10-30 esu) of pyrrole dihydrazone shows its suitability for non-linear optical (NLO) response. The preliminary bioassay suggested that the PDBO exhibits relatively good antibacterial and fungicidal activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, Aspergillus niger. The local reactivity descriptors - Fukui functions (fk+, fk-), local softnesses (sk+, sk-) and electrophilicity indices (ωk+, ωk-) analyses have been used to determine the reactive sites within molecule.

  14. Assessment of conformational, spectral, antimicrobial activity, chemical reactivity and NLO application of Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone).

    Science.gov (United States)

    Rawat, Poonam; Singh, R N

    2015-04-05

    An orange colored pyrrole dihydrazone: Pyrrole-2,5-dicarboxaldehyde bis(oxaloyldihydrazone) (PDBO) has been synthesized by reaction of oxalic acid dihydrazide with 2,5 diformyl-1H-pyrrole and has been characterized by spectroscopic analysis (1H, 13C NMR, UV-visible, FT-IR and DART Mass). The properties of the compound has been evaluated using B3LYP functional and 6-31G(d,p)/6-311+G(d,p) basis set. The symmetric (3319, 3320 cm(-1)) and asymmetric (3389, 3382 cm(-1)) stretching wave number confirm free NH2 groups in PDBO. NBO analysis shows, inter/intra molecular interactions within the molecule. Topological parameters have been analyzed by QTAIM theory and provide the existence of intramolecular hydrogen bonding (N-H⋯O). The local reactivity descriptors analyses determine the reactive sites within molecule. The calculated first hyperpolarizability value (β0=23.83×10(-30) esu) of pyrrole dihydrazone shows its suitability for non-linear optical (NLO) response. The preliminary bioassay suggested that the PDBO exhibits relatively good antibacterial and fungicidal activity against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Streptococcus pyogenes, Candida albicans, Aspergillus niger. The local reactivity descriptors--Fukui functions (fk+, fk-), local softnesses (sk+, sk-) and electrophilicity indices (ωk+, ωk-) analyses have been used to determine the reactive sites within molecule. Copyright © 2014 Elsevier B.V. All rights reserved.

  15. Synthesis, autoxidation and photooxidation of hindered pyrrole derivatives. Hindered pyrrolic nitroxide radicals; Synthese, autoxydation et photoxidation de pyrroles encombres radicaux nitroxydes pyrroliques encombres

    Energy Technology Data Exchange (ETDEWEB)

    Ramasseul, R. [Commissariat a l' Energie Atomique, Grenoble (France). Centre d' Etudes Nucleaires

    1969-07-01

    2,5-di-t-butyl and 2,3,5-tri-t-butyl pyrrole are prepared from pinacoline and their structure is confirmed by comparison with 2,5-di-t-butyl furan and thiophene (I.R., U.V. and N.M.R. {sup 13}C satellites observation giving J{sub 13{sub C-H}} and J{sub H{sub 3}-H{sub 4}}). The sensitized photooxidation of these hindered pyrroles gives corresponding hydroperoxides which most likely structure is determined using physical and chemical methods. Oxidation of 2,5-di-t-butyl and 2,3,5-tri-t-butyl pyrrole by hydrogen peroxide in presence of inorganic per-acid of by p-nitro-perbenzoic acid does not give the pyrrolic nitroxides in contrast with secondary amines. Some N-hydroxypyrroles are then prepared from pinacoline and ethyl pivaloyl-acetate. Their oxidation by lead dioxide gives the corresponding pyrrolic nitroxides. 2,5-di-t-butyl 3,4-di-ethoxycarbonyl pyrryl 1-oxy is isolated and studied spectroscopically (visible and U.V., E.P.R.). In marked contrast with ordinary nitroxides it does not show solvent effect. It can be compared with 2,4-di-t-butyl cyclopentadienone, a carbon analog. For both, the long wave length transition does not show the usual n - {pi}* behaviour; that is confirmed by E.P.R. Using Huckel method for pyrrolic nitroxide skeleton, it is possible to have a good interpretation of experimental data. (author) [French] Les di-t-butyl 2,5 et tri-t-butyl-2,3,5 pyrrole sont synthetises a partir de la pinacoline et leur structure confirmee par comparaison avec les di-t-butyl-2,5 furanne et thiophene (I.R., U.V. et R.M.N.: observation des satellites {sup 13}C conduisant a la mesure des J{sub 13{sub C-H}} et J{sub H{sub 3}{sub -H{sub 4}}). La photoxydation sensibilisee de ces pyrroles encombres conduit aux hydroperoxydes correspondants dont la structure la plus probable est determinee par les methodes physicochimiques. L'oxydation des di-t-butyl-2,5 et tri-t-butyl-2,3,5 pyrrole par l'eau oxygenee en presence de peracide mineral ou par l'acide p

  16. Elastic electron collisions with the aza-derivatives of furan, pyrrole and thiophene

    Energy Technology Data Exchange (ETDEWEB)

    Kossoski, Fabris; Freitas, Thiago Correa de; Bettega, Marcio Henrique Franco [Universidade Federal do Parana (UFPR), Curitiba, PR (Brazil)

    2011-07-01

    Full text. Experimental studies of electron collisions with furan, pyrrole, thiophene and their corresponding aza-derivatives show the occurrence of several resonant states at low impact energies (0-10 eV), for all the structures. These resonances are associated with the occupation of an unoccupied molecular orbital by the incident electron, and the consequent formation of a temporary anionic state, or resonance. Theoretical studies of elastic electron collisions with furan and pyrrole also show the presence of shape resonances in good agreement with the experimental positions of the resonance peaks. In this work we present integral cross sections for elastic scattering of low-energy electrons by the aza-derivatives of furan, pyrrole and thiophene, namely, oxazole, isoxazole, imidazole, pyrazole, thiazole and isothiazole. Our studied structures differ from furan, pyrrole and thiophene by the substitution of a C-H by an N atom, in different positions of the ring. The ground state geometry was optimized using second order perturbation theory with the TZV++(2d,1p) basis set. The molecular ground state was described in the Hartree-Fock approximation, and the virtual molecular orbitals obtained were used to represent the scattering orbitals. In order to compute the elastic cross sections we employed the Schwinger multichannel method implemented with pseudopotentials of Bachelet, Hamann and Schlueter, in the static-exchange approximation. The six molecules present shape resonances at low energies, in both A' and A{sup '}' symmetries. Electronic structure calculations were performed in order to characterize the resonant orbitals. Each of the three pairs of isomers presented very similar integral cross sections at high energies. At low energies, on the other hand, the cross sections become more distinct, specially due to the different positions of the resonances. We also discuss the effects on the cross sections caused by aza-substitution, when compared to

  17. Electrogenerated poly(pyrrole-lactosyl and poly(pyrrole-3’-sialyllactosyl interfaces: towards the impedimetric detection of lectins

    Directory of Open Access Journals (Sweden)

    Chantal eGondran

    2013-07-01

    Full Text Available This paper reports on the impedimetric transduction of binding reaction between polymerized saccharides and target lectins. The controlled potential electro-oxidation of pyrrole-lactosyl and pyrrole-3’-sialyllactosyl at 0.95 V vs Ag/AgCl, provides thin and reproducible poly(pyrrole-saccharide films. The affinity binding of two lectins: Arachis hypogaea, (PNA and Maackia amurensis (MAA onto poly(pyrrole-lactosyl and poly(pyrrole-3’-sialyllactosyl electrodes, was demonstrated by cyclic voltammetry in presence of ruthenium hexamine and hydroquinone. In addition, rotating disk experiments were carried out to determine the permeability of both polypyrrole films and its evolution after incubating with lectin target. Finally, the possibility of using the poly(pyrrole-lactosyl or poly(pyrrole-3’-siallyllactosyl films for the impedimetric transduction of the lectin binding reaction, was investigated with hydroquinone (2×10-3 mol L-1 as a redox probe in phosphate buffer. The resuting impedance spectra were interpreted and modeled as an equivalent circuit indicating that charge transfer resistance (Rct and relaxation frequency (f° parameters are sensitive to the lectin binding. Rct increases from 77 to 97 Ω cm2 for PNA binding and from 93 to 131 Ω cm2 for MAA binding. In parallel, f° decreases from 276 to 222 Hz for PNA binding and from 223 to 131 Hz for MAA binding. This evolution of both parameters reflects the steric hindrances generated by the immobilised lectins towards the permeation of the redox probe.

  18. 3-Phenyl-1-(pyrrol-2-ylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Zhen-Qi Gong

    2008-01-01

    Full Text Available The title molecule, C13H11NO, is almost flat, the angle between the pyrrole and the phenyl rings being 10.9 (1°. The atoms of the central C3O unit are coplanar, with a mean deviation from the plane of 0.001 (1 Å. The angles between this plane and the pyrrole and phenyl rings are 3.3 (1 and 8.0 (1°, respectively. The molecules form centrosymmetric dimers through a pair of N—H...O hydrogen bonds with an R22(10 motif.

  19. A colorimetric tetrathiafulvalene-calix 4 pyrrole anion sensor

    DEFF Research Database (Denmark)

    Nielsen, K. A.

    2012-01-01

    The interaction and colorimetric sensing properties of a tetrathiafulvalene substituted calix[4]pyrrole sensor with anions were investigated using H-1 NMR and absorption spectroscopic techniques. Visual color changes were observed upon addition of different anions (Cl-, Br-, CN-, and AcO-) to a s......The interaction and colorimetric sensing properties of a tetrathiafulvalene substituted calix[4]pyrrole sensor with anions were investigated using H-1 NMR and absorption spectroscopic techniques. Visual color changes were observed upon addition of different anions (Cl-, Br-, CN-, and Ac......O-) to a solution of the sensor. (C) 2012 Elsevier Ltd. All rights reserved....

  20. Versatile functionalization of nanoelectrodes by oligonucleotides via pyrrole electrochemistry.

    Science.gov (United States)

    Descamps, Emeline; Nguyen, Khoa; Bouchain-Gautier, Christelle; Filoramo, Arianna; Goux-Capes, Laurence; Goffman, Marcello; Bourgoin, Jean-Philippe; Mailley, Pascal; Livache, Thierry

    2010-11-15

    Surface modification at the nanometer scale is a challenge for the future of molecular electronics. In particular, the precise anchoring and electrical addressing of biological scaffolds such as complex DNA nanonetworks is of importance for generating bio-directed assemblies of nano-objects for nanocircuit purposes. Herein, we consider the individual modification of nanoelectrodes with different oligonucleotide sequences by an electrochemically driven co-polymerization process of pyrrole and modified oligonucleotide sequences bearing pyrrole monomers. We demonstrate that this one-step technique presents the advantages of simplicity, localization of surface modification, mechanical, biological and chemical stability of the coatings, and high lateral resolution.

  1. An ab-initio study of pyrrole and imidazole arylamides

    Directory of Open Access Journals (Sweden)

    Abramyan Ara M.

    2013-01-01

    Full Text Available Arylamide foldamers have been shown to have a number of biological and medicinal applications. For example, a class of pyrrole-imidazole polyamide foldamers is capable of binding specific DNA sequences and preventing development of various gene disorders, most importantly cancer. Molecular dynamics (MD simulations can provide crucial details in understanding the atomic level events related to foldamer/DNA binding. An important first step in the accurate simulation of these foldamer/DNA systems is the reparametrization of force field parameters for torsion around the aryl-amide bonds. Here we highlight our Density Functional Theory (DFT potential energy profiles and derived force field parameters for four aryl-amide bond types for the pyrrole and imidazole building blocks extensively used in foldamer design for the DNA-binding polyamides. These results contribute to developing of computational tools for an appropriate molecular modeling of pyrrole-imidazole polyamide/DNA binding, and provide an insight into the chemical factors that influence the flexibility of the pyrrole-imidazole polyamides, and their binding to DNA.

  2. Preparation and enhanced electrochemical properties of nano-sulfur/poly(pyrrole-co-aniline) cathode material for lithium/sulfur batteries

    Energy Technology Data Exchange (ETDEWEB)

    Qiu Linlin [School of Materials Science and Engineering, Beihang University, Xueyuan Road, Haidian District, Beijing 100083 (China); Zhang Shichao, E-mail: csc@buaa.edu.c [School of Materials Science and Engineering, Beihang University, Xueyuan Road, Haidian District, Beijing 100083 (China); Zhang Lan; Sun, Mingming [School of Materials Science and Engineering, Beihang University, Xueyuan Road, Haidian District, Beijing 100083 (China); Wang Weikun [Military Power Sources Research and Development Center, Chemical Defense Institute, Beijing 100083 (China)

    2010-06-01

    Poly(pyrrole-co-aniline) (PPyA) copolymer nanofibers were prepared by chemical oxidation method with cetyltrimethyl ammonium chloride (CTAC) as template, and the nano-sulfur/poly(pyrrole-co-aniline) (S/PPyA) composite material in lithium batteries was achieved via co-heating the mixture of PPyA and sublimed sulfur at 160 deg. C for 24 h. The component and structure of the materials were characterized by FTIR, Raman, XRD, and SEM. PPyA with nanofiber network structure was employed as a conductive matrix, adsorbing agent and firm reaction chamber for the sulfur cathode materials. The nano-dispersed composite exhibited a specific capacity up to 1285 mAh g{sup -1} in the initial cycle and remained 866 mAh g{sup -1} after 40 cycles.

  3. Bandgap Engineering in π-Extended Pyrroles. A Modular Approach to Electron-Deficient Chromophores with Multi-Redox Activity.

    Science.gov (United States)

    Zhylitskaya, Halina; Cybińska, Joanna; Chmielewski, Piotr; Lis, Tadeusz; Stępień, Marcin

    2016-09-07

    A family of bandgap-tunable pyrroles structurally related to rylene dyes was computationally designed and prepared using robust, easily scalable chemistry. These pyrroles show highly variable fluorescence properties and can be used as building blocks for the synthesis of electron-deficient oligopyrroles. The latter application is demonstrated through the development of π-extended porphyrins containing naphthalenediamide or naphthalenediimide units. These new macrocycles exhibit simultaneously tunable visible and near-IR absorptions, an ability to accept up to 8 electrons via electrochemical reduction, and high internal molecular free volumes. When chemically reduced under inert conditions, the most electron-deficient of these macrocycles revealed reversible formation of eight charged states, characterized by remarkably red-shifted optical absorptions, extending beyond 2200 nm. Such features make these oligopyrroles of interest as functional chromophores, charge-storage materials, and tectons for crystal engineering.

  4. SPECTROSCOPIC STUDY OF EFFECTS OF TETRAALKYLAMMONIUM CATIONS ON F--SENSING PROPERTIES OF CALIX[4]PYRROLE BORADIAZAINDACENE DYE

    Directory of Open Access Journals (Sweden)

    Yongjun Lv

    Full Text Available A novel meso-tetracyclohexylcalix[4]pyrrole-based boradiazaindacene dye 3 was synthesized and characterized. F--binding properties of the dye in the presence of tetrabutylammonium (TBA+, tetraethylammonium (TEA+, and tetramethylammonium (TMA+ counter ions were investigated by UV-Vis, fluorescence, and NMR spectroscopies. Dye 3 displayed various degrees of absorption red shift, fluorescence quenching, and downfield shifts of NH signals for the three fluoride salts. The association constants of these salts mainly depend on cation size effects and ion-pairing effects and were in the order KTMA+ > KTEA+ > KTBA+. Thus, we speculate that both F- and tetraalkylammonium cations are concomitantly located above and below a bowl-shaped calix[4]pyrrole cup in an ion-paired complex, respectively.

  5. Synthesis, insecticidal, and acaricidal activities of novel 2-aryl-pyrrole derivatives containing ester groups.

    Science.gov (United States)

    Zhao, Yu; Li, Yongqiang; Ou, Xiaoming; Zhang, Pengxiang; Huang, Zhiqiang; Bi, Fuchun; Huang, Runqiu; Wang, Qingmin

    2008-11-12

    A series of novel 2-aryl-pyrrole derivatives containing ester groups were synthesized, and their structures were characterized by (1)H NMR spectroscopy and elemental analysis. The insecticidal activities against oriental armyworm, mosquito, diamondback moth, green rice leafhopper, and bean aphids and acaricidal activities against spider mite of these new compounds were evaluated. The results of bioassays indicated that some of these title compounds exhibited excellent insecticidal and acaricidal activities. The insecticidal activities against oriental armyworm of compounds IVa, IVd, IVe, IVf, IVg, IVi, IVk, and IVp were equal to commercialized Chlorfenapyr, and the insecticidal activities of most of compounds IVb, IVc, IVd, IVf, IVg, IVj, IVk, IVl, IVs, IVt, IVu, IVw, IVx, IVz, and Chlorfenapyr against mosquito at 0.10 mg kg (-1) were 100%, and the acaricidal activities of compounds IVd, IVe, IVf, IVg, IVh, IVi, and IVk were equal or superior to Chlorfenapyr. Especially, the results indicated that the acaricidal activity of [4-bromo-2-(4-chlorophenyl)-3-cyano-5-(trifluoromethyl)pyrrol-1-yl]methyl 3-methylbutanoate ( IVg) against spider mite was 2.65-fold as high as that of Chlorfenapyr from the value of LC 50.

  6. Synthetic, structural and biological studies of organosilicon(IV complexes of Schiff bases derived from pyrrole-2-carboxaldehyde

    Directory of Open Access Journals (Sweden)

    KIRAN SING

    2010-07-01

    Full Text Available Selected new organosilicon(IV complexes having the general formula R2SiCl[L] and R2Si[L] 2 were synthesized by the reactions of Me2SiCl2 with Schiff bases (5-mercapto-4-[(1H-pyrrol-2ylmethyleneamino]-s-triazole, 5-mercapto-3-methyl-4-[(1H-pyrrol-2ylmethyleneamino]-s-triazole and 3-ethyl-5-mercapto-4-[(1H-pyrrol-2ylmethyleneamino]-s-triazole in 1:1 and 1:2 molar ratios. All of the compounds were characterized by elemental analysis, molar conductance, and IR, UV, 1H-, 13C- and 29Si-NMR spectral studies. All the spectral data suggest an involvement with an azomethine nitrogen in coordination to the central silicon atom. With the help of above-mentioned spectral studies, penta and hexacoordinated environments around the central silicon atoms in the 1:1 and 1:2 complexes, respectively, are proposed. Finally, the free ligands and their metal complexes were tested in vitro against some pathogenic bacteria and fungi to assess their antimicrobial properties.

  7. Calix[4]pyrrole derivative: recognition of fluoride and mercury ions and extracting properties of the receptor-based new material.

    Science.gov (United States)

    de Namor, Angela F Danil; Khalife, Rasha

    2008-12-11

    A calix[4]pyrrole derivative, namely, meso-tetramethyl tetrakis (4-phenoxy methyl ketone) calix[4]pyrrole, 1, was synthesized and structurally (1H NMR) and thermodynamically characterized. The complexing properties of this receptor with a wide variety of anions and cations in dipolar aprotic media (acetonitrile, propylene carbonate, and dimethyl sulfoxide) were investigated through 1H NMR and conductance studies. The former technique was used to assess whether or not complexation occurs and if so to identify the active sites of interaction of 1 with ions. The composition of the complexes was established by conductance measurements. It was found that in dipolar aprotic solvents, 1 interacts only with two polluting ions (fluoride and mercury). The complexation thermodynamics of 1 and these ions in these solvents is reported. The medium effect on the binding process involving the fluoride ion is discussed taking into account the solvation properties of reactants and the product. Complexes of moderate stability are found. Given that this is an important factor to consider for the recycling of the loaded material in extraction processes, 1 was treated with formaldehyde in basic medium leading to the production of a calix[4]pyrrole based material able to extract fluoride and mercury (II) ions from water. Thus the optimum conditions for the extraction of these ions from aqueous solutions were established. The material is easily recyclable using an organic acid. Final conclusions are given.

  8. Evaluation of molecular assembly, spectroscopic interpretation, intra-/inter molecular hydrogen bonding and chemical reactivity of two pyrrole precursors

    Science.gov (United States)

    Rawat, Poonam; Singh, R. N.

    2014-10-01

    This paper describes the evaluation of conformational, spectroscopic, hydrogen bonding and chemical reactivity of pyrrole precursor: ethyl 3,5 dimethyl-1H-pyrrole-2-carboxylate (EDPC) and ethyl 3,4-dimethyl-4-acetyl-1H-pyrrole-2-carboxylate (EDAPC) for the convenient characterization, synthetic usefulness and comparative evaluations. All experimental spectral values of 1H NMR, UV-Vis and FT-IR spectra coincide well with calculated values by DFT. The orbital interactions in EDPC and EDAPC are found to lengthen their Nsbnd H and Cdbnd O bonds and lowers their vibrational frequencies (red shift) resulting to dimer formation. The QTAIM and NBO analyses provide the strength of interactions and charge transfer in the hydrogen bonding unit and stability of dimers. The binding energy of EDPC and EDPAC dimer are found to be 9.92, 10.22 kcal/mol, respectively. In EDPAC and EDPC dimer, hyperconjugative interactions between monomer units is due to n1(O) → σ*(Nsbnd H) that stabilize the molecule up to 9.7 and 9.3 kcal/mol, respectively. On evaluation of molecular electrostatic potential (MEP) and electronic descriptors for EDPC it has been found that it is a good precursor for synthesis of formyl and acetyl derivatives whereas EDAPC has been found to be a good precursor for synthesis of schiff base, hydrazones, hydrazide-hydrazones and chalcones.

  9. Multiphoton ionization of pyrrole-water mixed clusters

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Multiphoton ionization of the hydrogen-bonded pyrrole-water clusters ( C4H5 N)n H2O)m is studied with a reflectron—time of flight mass spectrometer at 355 nm. With increasing partial concentration of pyrrole in a gas mixture source, a series of poly-pyrrole-water binary-mixed cluster ions can be observed, including unprotonated cluster ions [(C4H5N)x (H2O)y]* , protonated cluster ions [(C4H5N)x (H2O)yH]* and dehydrogenated cluster ions [ ( C4 H4 N) ( C4 H5 N) x ( H2O) y ] + . Ab initio calculations of their structures, bond strengths, charge distributions and re action energies are carried out. Stable structures of these clusters are obtained from the calculations. A probable forma tion mechanism of the cluster ions [(C4H5N)x(H2O)y] + , [(C4H5N)x (H2O)y]H+ and [(C4H4N) (C4H5N)x (H2O)y]-is supposed to be the ionization of clusters followed by dissociation.

  10. Substituent effect in the photochromism of two isomeric asymmetric diarylethenes having pyrrole and thiophene units

    Science.gov (United States)

    Wang, Renjie; Zhang, Xiaoxia; Pu, Shouzhi; Liu, Gang; Dai, Yanfeng

    2017-02-01

    Two new asymmetric isomeric diarylethenes having pyrrole and thiophene units have been synthesized by one-pot reaction and characterized by single crystal X-ray diffraction analysis. The two prepared diarylethenes had disparate crystal structures, and they exhibited distinctly different photochromic behavior, both in solution and in the solid state. Their photochromism, fatigue resistance, and fluorescence were investigated systematically. The methyl group at the reactive carbon atom could significantly enhance the quantum yield of cyclization step and decrease the quantum yield of cycloreversion step, whereas a cyano group at the same position could notably suppress the photocyclization reaction and promote the photocycloreversion reaction. The results indicated that the substituent at the reactive carbon atom could readily modulate the optoelectronic and physical properties for these diarylethenes.

  11. A novel quinoxaline bearing electroactive monomer: Pyrrole as the donor moiety

    Energy Technology Data Exchange (ETDEWEB)

    Taskin, Asli Tuba; Balan, Abidin; Epik, Bugra; Yildiz, Ersin [Middle East Technical University, Department of Chemistry, 06531, Ankara (Turkey); Udum, Yasemin Arslan [Gazi University, Institute of Science and Technology, Department of Advanced Technologies, 06570, Ankara (Turkey); Toppare, Levent [Middle East Technical University, Department of Chemistry, 06531, Ankara (Turkey)], E-mail: toppare@metu.edu.tr

    2009-09-30

    A novel electroactive monomer 5,8-di(1H-pyrrol-2-yl)-2,3-di(thiophen-2-yl)quinoxaline (PTQ) was successfully synthesized and its electrochromic properties were reported. Nuclear magnetic resonance ({sup 1}H NMR-{sup 13}C NMR) and mass spectroscopy were used to characterize the monomer. The monomer was electrochemically polymerized in the presence of tetrabutylammonium perchlorate (TBAP) as supporting electrolyte in dichloromethane. Monomer reveals relatively low oxidation potential at +0.70 V. Spectroelectrochemical behaviors and switching ability of homopolymer were investigated by UV-vis spectroscopy and cyclic voltammetry. Two {pi}-{pi}* transitions were observed at 400 and 815 nm with a low band gap, 1.0 eV. Polymer possesses 66% optical contrast in the Near IR region, which may be promising in NIR electrochromic device applications.

  12. One-pot Green Synthesis of Pyrrole Derivatives Catalyzed by Nano Sulfated Zirconia as a Solid Acid Catalyst%One-pot Green Synthesis of Pyrrole Derivatives Catalyzed by Nano Sulfated Zirconia as a Solid Acid Catalyst

    Institute of Scientific and Technical Information of China (English)

    Teimouri, Abbas; Chermahini, Alireza Najafi

    2012-01-01

    A new and efficient method for the preparation of N-substituted pyrroles from one-pot Paal-Knorr condensation has been accomplished using nano-crystalline sulfated zirconia (SZ) as the catalyst in ethanol at moderate temperature. This new protocol has the advantages of easy availability, stability, reusability and eco-friendliness of the catalyst, high to excellent yields, simple experimental and work-up procedure. The synthesized compounds were confirmed through spectral characterization using IR, 1H NMR, 13C NMR and mass spectra.

  13. Novel and efficient supramolecular synthesis of pyrroles in the presence of β-cyclodextrin in water

    Institute of Scientific and Technical Information of China (English)

    K. Ramesh; K. Karnakar; G. Satish; Y.V.D. Nageswar

    2012-01-01

    A simple and efficient synthesis of highly substituted pyrroles was achieved in water medium via multi-component strategy,using amine,DMAD/DEAD as well as phenacyl bromide catalyzed by β-CD.Utilizing this protocol various pyrrole derivatives were synthesized in good to excellent yields.

  14. Microfabrication of proangiogenic cell-laden alginate-g-pyrrole hydrogels.

    Science.gov (United States)

    DeVolder, Ross J; Zill, Andrew T; Jeong, Jae H; Kong, Hyunjoon

    2012-11-01

    Cells have been extensively studied for their uses in various therapies because of their capacities to produce therapeutic proteins and recreate new tissues. It has often been suggested that the efficacy of cell therapies can greatly be improved through the ability to localize and regulate cellular activities at a transplantation site; however, the technologies for this control are lacking. Therefore, this study reports a cell-Laden hydrogel patch engineered to support the proliferation and angiogenic growth factor expression of cells adhered to their surfaces, and to further promote neovascularization. Hydrogels consisting of alginate chemically linked with pyrrole units, termed alginate-g-pyrrole, were prepared through an oxidative cross-linking reaction between pyrrole units. Fibroblasts adhered to the alginate-g-pyrrole hydrogels, and exhibited increased proliferation and overall vascular endothelial growth factor (VEGF) expression, compared to those on pyrrole-free hydrogels. Furthermore, the alginate-g-pyrrole hydrogel surfaces were modified to present microposts, subsequently increasing the amount of pyrrole units on their surfaces. Cells adhered to the microfabricated gel surfaces exhibited increased proliferation and overall VEGF expression proportional to the density of the microposts. The resulting micropatterned alginate-g-pyrrole hydrogels exhibited increases in the size and density of mature blood vessels when implanted on chick chorioallantoic membranes (CAMs). The hydrogel system developed in this study will be broadly useful for improving the efficacy of a wide array of cell-based wound healing and tissue regenerative therapies.

  15. Interesting reactivity of diketones with pyrrole under acidic condition

    Indian Academy of Sciences (India)

    Sanjeev Pran Mahanta; Pradeepta Kumar Panda

    2011-09-01

    The acid catalysed condensation of diketones with pyrrole did not result in the formation of expected divergent bisdipyrromethane always; instead the product depends on the chain length of the diketones, in particular the distance between the two carbonyl functional groups.When the two carbonyl groups are linked via one or two methylene groups, unusual ring annulation occurs resulting in the formation of various bridged bipyrroles. However, on further increase in the length of the spacer, between the two carbonyl groups, synthesis of the expected bisdipyrromethanes could be achieved.

  16. Pyrrolic Amide: A New Hydrogen Bond Building Block for Self-assembly

    Institute of Scientific and Technical Information of China (English)

    YIN Zhen-Ming; LI Jian-Feng; HE Jia-Qi; ZHU Xiao-Qing; CHENG Jin-Pei

    2003-01-01

    @@ Molecular self-assembly has emerged as a powerful technology for the synthesis of nanostructured materials. In design of various molecular assemblies, hydrogen bonding is a preferably selected intra- or inter-molecular weak interaction in recent research by virtue of the directionality and specificity. The research for novel hydrogen bond building blocks that self-assembly into well defined structures is great important not only for gaining an understanding of the concepts of self-assembly but also for the design of new molecular materials. Pyrrolic amide moiety has one hydrogen bond acceptor (C =O) and two hydrogen bond donors (pyrrole NH and amide NH). By deliberately design, pyrrolic amide compounds would be new kinds hydrogen bond building blocks. So, pyrrolic amide compounds 1 ~ 6, which bear one, two or three pyrrolic amide moieties respectively, were designed and synthesized.

  17. Eco-friendly synthesis, spectral and computational study of pyrrole-2-carboxaldehyde salicylhydrazone (PCSH) for its application

    Science.gov (United States)

    Rawat, Poonam; Singh, R. N.

    2015-11-01

    In this paper we present eco-friendly synthesis of Pyrrole-2-carboxaldehyde salicylhydrazone (PCSH) and its molecular structural elucidation, spectral analysis and reactivity evaluation. Pyrrole-2-carboxaldehyde and salicyl hydrazide in water undergo condensation reaction to produce PCSH in good yield (88%). All results of quantum chemical calculation corroborate well with the experimental findings. The PCSH has been characterized by elemental analysis, FT-IR, 1H NMR, UV-Visible, and ESI-Mass spectroscopy. Density functional theory (DFT) calculations have been carried out for PCSH by performing B3LYP functional using the standard basis set 6-31 + g (d, p), and additional basis sets 6D and 10F. Two most stable conformers for PCSH have been observed around the dihedral angle N1C5C6N7. The red shift observed in O-H stretching vibration in the FT-IR spectrum indicates the presence of intramolecular hydrogen bonding. The rotational barrier between syn-syn (closed) syn-syn (open) found to be 2966.9 kcal/mol. The presence of hydroxyl proton at 10.45 ppm downfield in experimental 1H NMR spectrum confirms the existence of intramolecular hydrogen bonding in PCSH. Further, topological parameters analysis at the bond critical points using 'Atoms in molecules' theory reveals intramolecular hydrogen bonding. The energy of homonuclear intramolecular hydrogen bond (O17-H28⋯O10) is calculated to be 14.03 kcal/mol. The ellipticity results confirm the resonance assisted nature of this intramolecular hydrogen bond. In addition to this work, the reactive sites in PCSH have been explored using DFT descriptors, predicting nucleophilic reactions at carbonyl carbon and electrophilic reactions are possible at pyrrolic NH, amidic NH and double bond Cdbnd N leading to several heterocyclic products and metal complexes.

  18. Transition metal doped poly(aniline-co-pyrrole)/multi-walled carbon nanotubes nanocomposite for high performance supercapacitor electrode materials

    Energy Technology Data Exchange (ETDEWEB)

    Dhibar, Saptarshi; Bhattacharya, Pallab; Hatui, Goutam; Das, C.K., E-mail: chapal12@yahoo.co.in

    2015-03-15

    Highlights: • The CuCl{sub 2} doped copolymer (PANI and PPy)/MWCNTs nanocomposite was prepared. • The nanocomposite achieved highest specific capacitance of 383 F/g at a 0.5 A/g. • Nanocomposite exhibits better energy density as well as power density. • The nanocomposite also showed better electrical conductivity at room temperature. • The nanocomposite can be used as promising electrode materials for supercapacitor. - Abstract: In this present communication, copolymer of polyaniline (PANI) and polypyrrole (PPy) that is poly(aniline-co-pyrrole) [poly(An-co-Py)], copper chloride (CuCl{sub 2}) doped poly(aniline-co-pyrrole) [poly(An-co-Py) Cu], and CuCl{sub 2} doped poly(aniline-co-pyrrole)/multi walled carbon nanotubes (MWCNTs) [poly(An-co-Py) Cu CNT] nanocomposite have been prepared by a simple and inexpensive in-situ chemical oxidative polymerization method, using ammonium persulfate (APS) as oxidant and hydrochloric acid (HCl) as dopant and investigated as high performance supercapacitor electrode materials. The possible interaction between CuCl{sub 2} with copolymers and MWCNTs was investigated by Fourier transform infrared spectroscopy (FTIR) and UV–visible spectroscopy analysis. The morphological characteristic of all the electrode materials were analyzed by Field emission scanning electron microscopy (FESEM) and Transmission electron microscopy (TEM) study. The electrochemical characterizations of all the electrode materials were carried out by three electrode probe method where, standard calomel electrode and platinum were used as reference and counter electrodes, respectively. Among all the electrode materials, poly(An-co-Py) Cu CNT nanocomposite achieved highest specific capacitance value of 383 F/g at 0.5 A/g scan rate. The nanocomposite showed better electrical conductivity at room temperature and also attained nonlinear current–voltage characteristic. Based on the superior electrochemical as well as other properties the as prepared

  19. 2-Ethyl 4-methyl 5-ethyl-3-methyl-1H-pyrrole-2,4-dicarboxylate

    Directory of Open Access Journals (Sweden)

    Gui-Fen Lu

    2012-02-01

    Full Text Available The title pyrrole derivative compound, C12H17NO4, was synthesized from methyl 3-oxopentanoate by a Knorr-type reaction and contains a pyrrole ring to which two diagonal alkoxycarbonyl groups and two diagonal alkyl substituents are attached. The methylcarbonyl and ethylcarbonyl substituents are approximately co-planar with the pyrrole ring, making dihedral angles of 5.64 (2 and 3.44 (1°, respectively. In the crystal, adjacent molecules are assembled by pairs of N—H...O hydrogen bonds into dimers in a head-to-head mode.

  20. 2-Pyrrole Carboxylic Acid Nitro-Phenylamide: New Colorimetric Sensor for Anion

    Institute of Scientific and Technical Information of China (English)

    YIN Zhen-Ming; YANG Wen-Zhi; HE Jia-Qi; ZHU Xiao-Qing; CHENG Jin-Pei

    2003-01-01

    @@ Due to the role played by anions in the field of biology and environmental chemistry, the development of selec tive and sensitive chemosensor for anion sensing is a topic of current attention. Colorimetric anion sensor, which does not require the use of a potentiostate or spectrometer to detect redox or optical perturbation, can give immediate qualitative anion sensing information by visual detection and therefore has advantages over other molecular sensors.According the anion binding ability of some pyrrolic amides reported by Schmuck and Gale, we linked the color reporter group of nitroanile to pyrrole moiety and synthesized two 2-pyrrole carboxylic acid nitro-phenylamides (1 and 2).

  1. A Submarine Journey: The Pyrrole-Imidazole Alkaloids

    Directory of Open Access Journals (Sweden)

    Alessandra Scolaro

    2009-11-01

    Full Text Available In his most celebrated tale “The Picture of Dorian Gray”, Oscar Wilde stated that “those who go beneath the surface do so at their peril”. This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity − from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products.

  2. A submarine journey: the pyrrole-imidazole alkaloids.

    Science.gov (United States)

    Forte, Barbara; Malgesini, Beatrice; Piutti, Claudia; Quartieri, Francesca; Scolaro, Alessandra; Papeo, Gianluca

    2009-11-27

    In his most celebrated tale "The Picture of Dorian Gray", Oscar Wilde stated that "those who go beneath the surface do so at their peril". This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity--from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products.

  3. A Submarine Journey: The Pyrrole-Imidazole Alkaloids †

    Science.gov (United States)

    Forte, Barbara; Malgesini, Beatrice; Piutti, Claudia; Quartieri, Francesca; Scolaro, Alessandra; Papeo, Gianluca

    2009-01-01

    In his most celebrated tale “The Picture of Dorian Gray”, Oscar Wilde stated that “those who go beneath the surface do so at their peril”. This sentence could be a prophetical warning for the practitioner who voluntarily challenges himself with trying to synthesize marine sponge-deriving pyrrole-imidazole alkaloids. This now nearly triple-digit membered community has been growing exponentially in the last 20 years, both in terms of new representatives and topological complexity – from simple, achiral oroidin to the breathtaking 12-ring stylissadines A and B, each possessing 16 stereocenters. While the biosynthesis and the role in the sponge economy of most of these alkaloids still lies in the realm of speculations, significant biological activities for some of them have clearly emerged. This review will account for the progress in achieving the total synthesis of the more biologically enticing members of this class of natural products. PMID:20098608

  4. (4-Butoxyphenyl(1H-pyrrol-2-ylmethanone

    Directory of Open Access Journals (Sweden)

    Rajni Kant

    2012-05-01

    Full Text Available The asymmetric unit of the title compound, C15H17NO2, contains two independent molecules in which the dihedral angles between the pyrrole and benzene rings are 42.43 (9 and 45.70 (9°. In both molecules, the butoxy chains are disordered over two sets of sites, with occupancy ratios of 0.701 (7:0.299 (7 and 0.869 (4:0.131 (4. Each molecule forms a dimer with an inversion-related molecule, through a pair of N—H...O hydrogen bonds. Weak C—H...O interactions link these dimers in the crystal structure.

  5. A role of nanotube dangling pyrrole and oxygen functions in the electrochemical synthesis of polypyrrole/MWCNTs hybrid materials

    Energy Technology Data Exchange (ETDEWEB)

    Krukiewicz, Katarzyna, E-mail: katarzyna.krukiewicz@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Herman, Artur P., E-mail: artur.herman@polsl.pl [Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, Krzywoustego 4, Gliwice 44-100 (Poland); Turczyn, Roman, E-mail: roman.turczyn@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland); Szymańska, Katarzyna, E-mail: katarzyna.szymanska@polsl.pl [Department of Chemical and Process Engineering, Silesian University of Technology, Strzody 7, 44-100 Gliwice (Poland); Koziol, Krzysztof K.K., E-mail: kk292@cam.ac.uk [Department of Materials Science and Metallurgy, University of Cambridge, 27 Charles Babbage Road, Cambridge CB3 0FS (United Kingdom); Boncel, Sławomir, E-mail: slawomir.boncel@polsl.pl [Department of Organic Chemistry, Bioorganic Chemistry and Biotechnology, Silesian University of Technology, Krzywoustego 4, Gliwice 44-100 (Poland); Zak, Jerzy K., E-mail: jerzy.zak@polsl.pl [Department of Physical Chemistry and Technology of Polymers, Silesian University of Technology, Strzody 9, 44-100 Gliwice (Poland)

    2014-10-30

    Highlights: • The effect of MWCNT functionalization on properties of PPy composites was explained. • The behavior of pristine, pyrrole-modified and oxidized MWCNT was explained. • Functionalization of MWCNT improved their dispersibility and processability. • Different mechanisms of (f-)MWCNT incorporation into PPy composites were explained. • Orientation of growing PPy chains was tailored through the addition of (f-)MWCNT. - Abstract: The effect of the functionalization of multi-walled carbon nanotubes (MWCNTs) on the process of electrochemical co-deposition of MWCNTs and polypyrrole (PPy), as well as the morphology of obtained composites have been demonstrated. As the nanotube components of the hybrids, three types of MWCNT were used, namely c-CVD derived (pristine) MWCNTs, their oxidized counterparts MWCNT-Ox and pyrrole-modified MWCNT-Py. The stability of pristine and functionalized MWCNTs (f-MWCNT) dispersions in tetrahydrofuran and water was studied together with the description of the process of formation PPy/(f-)MWCNT hybrid materials via electrochemical co-deposition. The structural and morphological properties of the hybrids were characterized by Raman spectroscopy, scanning electron microscopy and atomic force microscopy revealing substantial differences among hybrid materials in their surface morphology and the influence of MWCNT functionalization on the orientation of growing PPy chains.

  6. One-Pot Conversion of Carbohydrates into Pyrrole-2-carbaldehydes as Sustainable Platform Chemicals.

    Science.gov (United States)

    Adhikary, Nirmal Das; Kwon, Sunjeong; Chung, Wook-Jin; Koo, Sangho

    2015-08-07

    A practical conversion method of carbohydrates into N-substituted 5-(hydroxymethyl)pyrrole-2-carbaldehydes (pyrralines) was developed by the reaction with primary amines and oxalic acid in DMSO at 90 °C. Further cyclization of the highly functionalized pyrralines afforded the pyrrole-fused poly-heterocyclic compounds as potential intermediates for drugs, food flavors, and functional materials. The mild Maillard variant of carbohydrates and amino esters in heated DMSO with oxalic acid expeditiously produced the pyrrole-2-carbaldehyde skeleton, which can be concisely transformed into the pyrrole alkaloid natural products, 2-benzyl- and 2-methylpyrrolo[1,4]oxazin-3-ones 8 and 9, lobechine 10, and (-)-hanishin 11 in 23-32% overall yields from each carbohydrate.

  7. Auto-oligomerization and hydration of pyrrole revealed by x-ray absorption spectroscopy

    Energy Technology Data Exchange (ETDEWEB)

    Advanced Light Source; Schwartz, Craig P.; Uejio, Janel S.; Duffin, Andrew M.; England, Alice H.; Prendergast, David; Saykally, Richard J

    2009-05-29

    Near edge x-ray absorption fine structure (NEXAFS) spectra have been measured at the carbon and nitrogen K-edges of the prototypical aromatic molecule, pyrrole, both in the gas phase and when solvated in water, and compared with spectra simulated using a combination of classical molecular dynamics and first principles density functional theory in the excited state core hole approximation. The excellent agreement enabled detailed assignments. Pyrrole is highly reactive, particularly in water, and reaction products formed by the auto-oligomerization of pyrrole are identified. The solvated spectra have been measured at two different temperatures, indicating that the final states remain largely unaffected by both hydration and temperature. This is somewhat unexpected, since the nitrogen in pyrrole can donate a hydrogen bond to water.

  8. Biosynthesis, asymmetric synthesis, and pharmacology, including cellular targets, of the pyrrole-2-aminoimidazole marine alkaloids

    Digital Repository Service at National Institute of Oceanography (India)

    Al-Mourabit, A.; Zancanella, M.A.; Tilvi, S.; Romo, D.

    The pyrrole-2-aminoimidazole (P-2-AI) alkaloids are a growing family of marine alkaloids, now numbering well over 150 members, with high topographical and biological information content. Their intriguing structural complexity, rich and compact...

  9. Synthesis and biological activity of pyrrole analogues of combretastatin A-4.

    Science.gov (United States)

    Jung, Eun-Kyung; Leung, Euphemia; Barker, David

    2016-07-01

    A series of pyrrole analogues of combretastatin (CA-4) were synthesized and tested for their anti-proliferative activity. The highly diastereoselective acyl-Claisen rearrangement was used to provide 2,3-syn disubstituted morpholine amides which were used as precursors for the various analogues. This synthesis allows for the preparation of 1,2- and 2,3-diaryl-1H-pyrroles which are both geometrically similar to CA-4. These pyrrolic analogues were tested for their anti-proliferative activity against two human cell lines, K562 and MDA-MB-231 with 2,3-diaryl-1H-pyrrole 35 exhibiting the most potent activity with IC50 value of 0.07μM against MDA-MB-231 cell line.

  10. Synthesis of highly functionalized pyrroles from primary amines and activated acetylenes in water

    Institute of Scientific and Technical Information of China (English)

    S.Zahra Sayyed-Alangi; Zinatossadat Hossaini; Faramarz Rostami-Charati

    2012-01-01

    Stable derivatives of pyrroles were prepared using multicomponent reactions of dialkyl acetylenedicarboxylate,primary amine and propiolate in the presence of N-methylimidazole in water at room temperature in good yields.

  11. Pyrrole as a promising electrolyte additive to trap polysulfides for lithium-sulfur batteries

    Science.gov (United States)

    Yang, Wu; Yang, Wang; Song, Ailing; Gao, Lijun; Sun, Gang; Shao, Guangjie

    2017-04-01

    Lithium-sulfur batteries are a promising energy storage devices beyond conventional lithium ion batteries. However, the ;shuttle effect; of soluble polysulfides is a major barrier between electrodes, resulting in rapid capacity fading. To address above issue, pyrrole has been investigated as an electrolyte additive to trap polysulfides. When pyrrole is added into electrolyte, a surface protective layer of polypyrrole can be formed on the sulfur cathode, which not only acts as a conductive agent to provide an effective electron conduction path but also acts as an absorbing agent and barrier layer suppressing the diffusion of polysulfide intermediates. The results demonstrate that an appropriate amount of pyrrole added into the electrolyte leads to excellent cycling stability and rate capability. Apparently, pyrrole is an effective additive for the entrapment of polysulfides of lithium-sulfur batteries.

  12. A mixed experimental and DFT study on ethyl 4-[3-(4-dimethylamino-phenyl)-acryloyl]-3,5-dimethyl-1H-pyrrole-2-carboxylate

    Science.gov (United States)

    Singh, R. N.; Rawat, Poonam; Sahu, Sangeeta

    2014-05-01

    A new pyrrole containing chalcone, ethyl 4-[3-(4-dimethylamino-phenyl)-acryloyl]-3,5-dimethyl-1H-pyrrole-2-carboxylate (EDPADPC) derived from ethyl 4-acetyl-3,5-dimethyl-1H-pyrrole-2-carboxylate and 4-dimethylamino-benzaldehyde has been characterized by spectroscopic techniques (1H NMR, UV-Visible, FT-IR) and results have been compared by means of theoretical findings. A combined experimental and theoretical vibrational analysis identified red shifts in vNH and vCO indicating the formation of dimer in the solid state. The binding energy of dimer has been evaluated as 9.89 kcal/mol and the strength and nature of hydrogen bonding have also been analyzed in detail. The DFT derived reactivity descriptors indicate that EDPADPC is suitable for the formation of new heterocyclic compounds. The first hyperpolarizability (β0) of EDPADPC has been computed and found to be 62.0226 × 10-30 indicating its use as non-linear optical (NLO) material.

  13. A convenient synthesis of pyrroles catalyzed by acidic resin under solvent-free condition

    Institute of Scientific and Technical Information of China (English)

    Shi

    2010-01-01

    A convenient and effective Paal-Knorr condensations of 2,5-hexanedione with most amines have been carried out at room temperature under solvent-free condition. Macroporous strongly acidic styrol resin (D001) as a novel, efficient, cost-effective, and reusable solid acid catalyst for the synthesis of pyrroles under the same conditions. The pyrroles were obtained in high yields in short reaction times.

  14. (E-2,4,6-Trimethyl-N-[(1H-pyrrol-2-ylmethylidene]aniline

    Directory of Open Access Journals (Sweden)

    Wolfgang Imhof

    2013-01-01

    Full Text Available The title compound, C14H16N2, is a pyrrole-2-carbaldimine ligand that shows an E conformation at the imine double bond. The dihedral angle between the rings is 78.3 (1°. In the crystal, pairs of molecules form centrosymmetric dimers [graph-set descriptor is presumably R22(10] via N—H...N hydrogen bonds between the pyrrole N—H group and the imine N atom of a neighbouring molecule.

  15. An Efficient and Short Route for the Synthesis of Reverse Pyrrole Ribonucleosides

    Directory of Open Access Journals (Sweden)

    Pereira Letícia O. R.

    2002-01-01

    Full Text Available The synthesis of reverse pyrrole ribonucleosides methyl 5-C-(4-acetyl-5-methyl-pyrrol-1-yl-2,3-O-isopropylidene-5-deoxy- beta-D-ribofuranoside (10, methyl 5-C-(4-ethoxycarbonyl-5-methyl-pyrrol-1-yl-2,3-O-isopropylidene-5-deoxy- beta-D-ribofuranoside (11, methyl 5-C-(4-acetyl-5-methyl-pyrrol-1-yl-5-deoxy-beta-D-ribofuranoside (12, methyl 5-C-(4-ethoxycarbonyl-5-methyl-pyrrol-1-yl-5-deoxy- beta-D-ribofuranoside (13, methyl 5-deoxy-5-C-(3'-formyl-4'-hydroxypropyl-pyrrol-1'-yl-2,3-O-isopropylidene- beta-D-ribofuranoside (16 and methyl 5-deoxy-5-C-(3'-formyl-pyrrol-1'-yl-2,3-O-isopropylidene- beta-D-ribofuranoside (18 are described starting from readily available methyl 5-amino-5-deoxy-2,3-O-isopropylidene-beta-D-ribofuranoside (9. The synthetic strategy for the construction of the heterocyclic ring was based on the nucleophilic attack of (9 to 4-acetyl-2-n-butoxy-5-methyl-4,5-dihydrofuran (4, 4-carbetoxy-2-n-butoxy-5-methyl-4,5-dihydrofuran (5, 4-formyl-2-n-butoxy-4,5-dihydrofuran (6 and 4-formyl-1-methyl dioxabyciclo[3.3.0]oct-3-en (8, in situ. The later compounds were obtained from reaction between 3-diazo-2,4-pentadione (1, ethyl 2-diazoacetoacetate (2 or diazomalonaldehyde (3 and enol ethers using dirhodium tetraacetate as a catalyst.

  16. Synthesis and Crystal Structure of 1-H-Pyrrole-2-carboxylic Acid [2-(Naphthalen-1-ylamino)-ethyl]-amide

    Institute of Scientific and Technical Information of China (English)

    YIN Zhen-Ming; WANG Jian-Ying

    2006-01-01

    1-H-Pyrrole-2-carboxylic acid [2-(naphthalen-1-ylamino)-ethyl]-amide has been synthesized and characterized. Its crystal is of monoclinic, space group P21/n with a = 5.930(6), b =12.144(13), c = 20.10(2) (A),β = 95.709(17)°, V= 1441(3) (A), Z= 4, C17H17N3O, Mr= 279.34, Dc=1.288 g/cm3, F(000) = 592, μ(MoKα) = 0.083 mm-1, S = 1.019, R = 0.0473 and wR = 0.1181 for 1713 observed reflections with 1 > 2σ(Ⅰ). X-ray diffraction reveals that two molecules of the title compound form a dimer through a pair of N-H…O hydrogen bonds.

  17. Organic-inorganic interactions in the system of pyrrole-hematite-water at elevated temperatures and pressures

    Science.gov (United States)

    Ding, Kangle

    2015-11-01

    The distribution and abundance of pyrrolic compounds in sediments and crude oils are most likely influenced by inorganic sedimentary components. In this paper, thermal simulation experiments on the system pyrrole-hematite-water were carried out at elevated temperatures and pressures in order to investigate the effect of organic-inorganic interactions on the preservation of pyrrolic compounds. Compositions of the reaction products were analyzed with GC-MS and GC-FID methods. In the closed system pyrrole-hematite-water, the nitrogen-oxygen exchange obviously occurred at temperatures above 350ºC in accordance with the thermochemical calculation. Large amounts of furan and ammonia were generated after simulation experiments, indicating that the conversion of pyrrole into furan was the dominant reaction. Thermochemical exchange effect between organic nitrogen and inorganic oxygen was obviously facilitated by elevated temperatures and found to be catalyzed by hematite, but inhibited by the increasing volume of water. Thermodynamically water spontaneously reacts with pyrrole above 300ºC. The reaction of pyrrole-hematite-water is an exothermic process in which the reaction heat positively correlates with temperature. The heat released was estimated as 9.0 KJ/(mol) pyrrole - 15.0 KJ/(mol) pyrrole in typical oil reservoirs (100ºC-150ºC) and 15.0-23.0 KJ/(mol) pyrrole in typical gas reservoirs (150ºC-200ºC). The calculated activation energy of the nitrogen-oxygen atom exchange is about 129.59 kJ/mol. According to the experimental results, a small amount of water may effectively initiate the nitrogen-oxygen exchange. The study would improve our evaluating of the preservation and fate of pyrrolic compounds in deeply buried geologic settings and further understanding of thermochemical processes behind the degradation of petroleum.

  18. Protonation sites in gaseous pyrrole and imidazole: a neutralization-reionization and ab initio study.

    Science.gov (United States)

    Nguyen, V Q; Turecek, F

    1996-10-01

    Mild gas-phase acids C4H9+ and NH4+ protonate pyrrole at C-2 and C-3 but not at the nitrogen atom, as determined by deuterium labeling and neutralization-reionization mass spectrometry. Proton affinities in pyrrole are calculated by MP2/6-311G(2d,p) as 866, 845 and 786 kJ mol-1 for protonation at C-2, C-3 and N, respectively. Vertical neutralization of protonated pyrrole generates bound radicals that in part dissociate by loss of hydrogen atoms. Unimolecular loss of hydrogen atom from C-2- and C-3-protonated pyrrole cations is preceded by proton migration in the ring. Protonation of gaseous imidazole is predicted to occur exclusively at the N-3 imine nitrogen to yield a stable aromatic cation. Proton affinities in imidazole are calculated as 941, 804, 791, 791 and 724 for the N-3, C-4, C-2, C-5 and N-1 positions, respectively. Radicals derived from protonated imidazole are only weakly bound. Vertical neutralization of N-3-protonated imidazole is accompanied by large Franck-Condon effects which deposit on average 183 kJ mol-1 vibrational energy in the radicals formed. The radicals dissociate unimolecularly by loss of hydrogen atom, which involves both direct N-H bond cleavage and isomerization to the more stable C-2 H-isomer. Potential energy barriers to isomerizations and dissociations in protonated pyrrole and imidazole isomers and their radicals were investigated by ab initio calculations.

  19. Synthesis and Reactions of Furo[2,3-b]pyrroles

    Directory of Open Access Journals (Sweden)

    A. Lycka

    1997-04-01

    Full Text Available Methyl 6H-furo[2,3-b]pyrrole-5-carboxylate (2a was prepared by thermolysis of the corresponding methyl 2-azido-3-(3-furylpropenoate (1. 6-Methyl (2b and 6-benzyl (2c derivatives were obtained using phase-transfer catalysis conditions (PTC. The formylation of 2a-2c gave 2-formylated compounds (3a-3c. Compounds 4b, 4c were prepared by reactions of corresponding esters 2b, 2c with hydrazine in refluxing ethanol. By reaction of 3a-3c with hydroxylammonium chloride in acetic anhydride in the presence of pyridine, methyl 2-cyano-6-R1-furo[2,3-b]pyrrole-5-carboxylates (5a-5c were obtained. The reaction of these compounds with sodium azide and ammonium chloride in dimethylformamide led to methyl 2-(5'-tetrazolyl-6-R1-furo[2,3-b]pyrrole-5-carboxylates (6a-6c. A series of 5-methoxycarbonyl-6-R1-furo[2,3-b]pyrrole-2-carbaldehyde N,N-dimethylhydrazones (7a-7c was prepared from methyl 2-formyl-6-R1-furo[2,3-b]pyrrole-5-carboxylates (3a-3c and unsym-dimethylhydrazine. The correlation of the 13C and 15N chemical shifts with the data of the calculated (AM1 net atomic charges is discussed.

  20. A novel and facile approach for synthesis of 5-amino-7-aryl-6-cyano-4-pyrano[3,2-]pyrroles

    Indian Academy of Sciences (India)

    Reza Sandaroos; Saman Damavandi

    2012-07-01

    An efficient and iron-catalysed synthesis of 4-pyrano[3,2-]pyrrole is reported. The reactions proceed through a one-pot, three component cyclocondensation of 3-hydroxypyrrole, malononitrile and various aldehydes to afford 4-pyrano[3,2-]pyrrole derivatives in moderate to good yield using ferric hydrogensulphate, Fe(HSO4)3, as the catalyst.

  1. Separation of Phenolic Compounds and Organic Anions Using ODS Column Coated with Meso-octamethylcalix[4]pyrrole and Water as Eluent

    Institute of Scientific and Technical Information of China (English)

    Li Jun HE; Shi Jun SHAO; Yong GUO; Hua Jiao MA; Xia LIU; Sheng Xiang JIANG

    2003-01-01

    Octadecylsilanized silica (ODS) was coated with meso-octamethylcalix[4]pyrrole toobtain a novel calix[4]pyrrole containing stationary phase for HPLC. Compared to ODS, the newstationary phase showed a relatively large retention and an improved separation for phenoliccompounds and organic anions, using pure water as mobile phase. The results can be ascribed tothe interaction between analytes and calix[4]pyrrole.

  2. Self-Assembly of Dimeric Tetrathiafulvalene-Calix 4 pyrrole: Receptor for 1,375-Trinitrobenzene

    DEFF Research Database (Denmark)

    Nielsen, K. A.; Stein, P. C.

    2011-01-01

    The synthesis and binding properties of a tetrathiafulvalene (TTF)-calix[4]pyrrole receptor 2 appended with one 3,5-dinitrobenzoate guest moiety are reported. The preliminary studies revealed that the receptor is self-compiexing into a dimer receptor 2 center dot 2. The self-complexation of the r......The synthesis and binding properties of a tetrathiafulvalene (TTF)-calix[4]pyrrole receptor 2 appended with one 3,5-dinitrobenzoate guest moiety are reported. The preliminary studies revealed that the receptor is self-compiexing into a dimer receptor 2 center dot 2. The self...

  3. Porphodilactones as synthetic chlorophylls: relative orientation of β-substituents on a pyrrolic ring tunes NIR absorption.

    Science.gov (United States)

    Ke, Xian-Sheng; Chang, Yi; Chen, Jia-Zhen; Tian, Jiangwei; Mack, John; Cheng, Xin; Shen, Zhen; Zhang, Jun-Long

    2014-07-09

    Porphodilactones represent the porphyrin analogues, in which the peripheral bonds of two pyrrole rings are replaced by lactone moieties. They provide an opportunity to investigate how β-substituent orientation of porphyrinoids modulates the electronic structures and optical properties, in a manner similar to what is observed with naturally occurring chlorophylls. In this work, a comprehensive description of the synthesis, characterization, and optical properties of meso-tetrakispentafluorophenylporphodilactone isomers is first reported. The β-dilactone moieties are found to lie at opposite pyrrole positions (trans- and cis-configurations are defined by the relative orientations of the carbonyl group when one lactone moiety is fixed), in accordance with earlier computational predictions (Gouterman, M. J. Am. Chem. Soc. 1989, 111, 3702). The relative orientation of the β-dilactone moieties has a significant influence on the electronic structures and photophysical properties. For example, the Qy band of trans-porphodilactone is red-shifted by 19 nm relative to that of the cis-isomer, and there is a 2-fold increase in the absorption intensity, which resembles the similar trends that have been reported for natural chlorophyll f and d. An in depth analysis of magnetic circular dichroism spectral data and TD-DFT calculations at the B3LYP/6-31G(d) level of theory demonstrates that the trans- and cis-orientations of the dilactone moieties have a significant effect on the relative energies of the frontier π-molecular orbitals. Importantly, the biological behaviors of the isomers reveal their different photocytotoxicity in NIR region (>650 nm). The influence of the relative orientation of the β-substituents on the optical properties in this context provides new insights into the electronic structures of porphyrinoids which could prove useful during the development of near-infrared absorbing photosensitizers.

  4. Hydrolytic study of the copolymer Poly pyrrole/ Polyethyleneglycol and Poly pyrrole synthesized by plasma; Estudio hidrolitico del copolimero polipirrol/polietilenglicol y polipirrol sintetizado por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Colin, E.; Enriquez, M.A.; Olayo, M.G.; Cruz, G.J.; Carapia, L.; Romero, M. [ININ, 52045 Ocoyoacac, Estado de Mexico (Mexico); Morales, J.; Olayo, R. [UAM-I, A.P. 55-534 Iztapalapa, Mexico D.F. (Mexico)

    2006-07-01

    In this work the study about the hydrolytic compatibility of semiconductor polymers, copolymer Poly pyrrole/ Polyethyleneglycol (PPy/PEG) and Poly pyrrole (PPy) for their possible use as biomaterials. The polymers were synthesized by plasma between 10 and 100 W, with discharges of splendor RF to 13.5 MHz with resistive coupling. The hydrolytic affinity was evaluated calculating the contact angle with solutions of NaCl, NaCl-MgSO{sub 4} and Krebs-Ringer. The results show a hydrophilicity increment due to the increase of the surface ruggedness with the synthesis energy. On the contrary, the crystallinity diminishes when increasing the power in PPy and it stays approximately constant in PPy/PEG. The electric conductivity presents a growth from 2 to 4 magnitude orders in function of the water content in the polymers. (Author)

  5. Intramolecular redox reaction for the synthesis of N-aryl pyrroles catalyzed by Lewis acids.

    Science.gov (United States)

    Du, Hong-Jin; Zhen, Le; Wen, Xiaoan; Xu, Qing-Long; Sun, Hongbin

    2014-12-21

    An efficient approach to synthesize N-aryl pyrroles via Lewis acid-mediated 1,5-hydride shift and isomerization of 2-(3-pyrroline-1-yl)arylaldehydes has been achieved in up to 89% yield. This methodology is applicable to the synthesis of fluorazene derivatives as electron donor (D)/acceptor (A) molecules.

  6. Identification of a new electron-transfer relaxation pathway in photoexcited pyrrole dimers.

    Science.gov (United States)

    Neville, Simon P; Kirkby, Oliver M; Kaltsoyannis, Nikolas; Worth, Graham A; Fielding, Helen H

    2016-04-21

    Photoinduced electron transfer is central to many biological processes and technological applications, such as the harvesting of solar energy and molecular electronics. The electron donor and acceptor units involved in electron transfer are often held in place by covalent bonds, π-π interactions or hydrogen bonds. Here, using time-resolved photoelectron spectroscopy and ab initio calculations, we reveal the existence of a new, low-energy, photoinduced electron-transfer mechanism in molecules held together by an NH⋯π bond. Specifically, we capture the electron-transfer process in a pyrrole dimer, from the excited π-system of the donor pyrrole to a Rydberg orbital localized on the N-atom of the acceptor pyrrole, mediated by an N-H stretch on the acceptor molecule. The resulting charge-transfer state is surprisingly long lived and leads to efficient electronic relaxation. We propose that this relaxation pathway plays an important role in biological and technological systems containing the pyrrole building block.

  7. Identification of a new electron-transfer relaxation pathway in photoexcited pyrrole dimers

    Science.gov (United States)

    Neville, Simon P.; Kirkby, Oliver M.; Kaltsoyannis, Nikolas; Worth, Graham A.; Fielding, Helen H.

    2016-04-01

    Photoinduced electron transfer is central to many biological processes and technological applications, such as the harvesting of solar energy and molecular electronics. The electron donor and acceptor units involved in electron transfer are often held in place by covalent bonds, π-π interactions or hydrogen bonds. Here, using time-resolved photoelectron spectroscopy and ab initio calculations, we reveal the existence of a new, low-energy, photoinduced electron-transfer mechanism in molecules held together by an NH⋯π bond. Specifically, we capture the electron-transfer process in a pyrrole dimer, from the excited π-system of the donor pyrrole to a Rydberg orbital localized on the N-atom of the acceptor pyrrole, mediated by an N-H stretch on the acceptor molecule. The resulting charge-transfer state is surprisingly long lived and leads to efficient electronic relaxation. We propose that this relaxation pathway plays an important role in biological and technological systems containing the pyrrole building block.

  8. Cellular fibronectin and von Willebrand factor concentrations in plasma of rats treated with monocrotaline pyrrole

    NARCIS (Netherlands)

    Schultze, A.E.; Emeis, J.J.; Roth, R.A.

    1996-01-01

    The monocrotaline pyrrole (MCTP)-treated rat is a useful model for the study of certain chronic pulmonary vascular diseases. A single, i.v. administration of a low dose of MCTP causes pneumotoxicity, pulmonary vascular remodeling, sustained increases in pulmonary arterial pressure, and right ventric

  9. Synthesis of Iso-condensed Heteroaromatic Pyrroles and Their Application in the Preparation of Conducting Polymers

    Institute of Scientific and Technical Information of China (English)

    Chin-Kang Sha; Su-Ya Cheng; Yuan-Liang Kuo; Liu Chia-Lin; V. Raghukumar

    2004-01-01

    Iso-condensed heteroaromatic pyrroles 1 are 10 -electron aromatic compounds. They are of interest from both theoretical and synthetic points of view. They are the cyclic analogues of heteroaromatic ortho-quinodimethanes 2, and can react with dienophiles in a Diels-Alder reaction to give the synthetically useful cycloadducts 3. Many of them are also of potential pharmaceutical importance because they are isosteric with indoles. Iso-condensed heteroaromatic pyrroles 1 can be used also as the monomers for the synthesis of new conducting polymers 5 with special properties and characteristics. However, the methods for the efficient preparation of the iso-condensed heteroaromatic pyrroles are quite limited. Iso-condensed heteroaromatic pyrroles are generally unstable in acidic conditions and are easily oxidized by air. In our laboratories, we developed three methods for the preparation of this labile heterocyclic ring system under acidic, neutral, and basic conditions.1 Synthesis of the conjugated systems such as 6 for OLED applications will also be discussed.

  10. Nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole derivatives: Synthesis of pyrrolopyrazinone, pyrrolotriazinone, and pyrrolooxazinone moieties

    Directory of Open Access Journals (Sweden)

    Işıl Yenice

    2017-05-01

    Full Text Available Intramolecular nucleophilic and electrophilic cyclization of N-alkyne-substituted pyrrole esters is described. Efficient routes towards the synthesis of pyrrolopyrazinone, pyrrolotriazinone and pyrrolooxazinone have been developed. First, N-alkyne-substituted pyrrole ester derivatives were synthesized. Introduction of various substituents into the alkyne functionality was accomplished by a copper-catalyzed cross-coupling reaction. Nucleophilic cyclization of N-alkyne-substituted methyl 1H-pyrrole-2-carboxylates with hydrazine afforded the 6-exo-dig/6-endo-dig cyclization products depending on the electronic nature of the substituents attached to the alkyne. On the other hand, cyclization of N-alkyne-substituted methyl 1H-pyrrole-2-carboxylates with iodine only resulted in the formation of the 6-endo-dig cyclization product regardless of the substitution of the alkyne functionality.

  11. Use of Graphite Oxide and Graphene Oxide as Catalysts in the Synthesis of Dipyrromethane and Calix[4]pyrrole

    Directory of Open Access Journals (Sweden)

    Sweta Mishra

    2011-08-01

    Full Text Available Graphite oxide and graphene oxides have been used as solid catalysts for the synthesis of 5,5-dialkyldipyrromethanes and calix[4]pyrroles in organic and aqueous solutions at room temperature.

  12. DABCO-promoted facile and convenient synthesis of novel isoxazolyl-1H-2,3-pyrrole dicarboxylates

    Institute of Scientific and Technical Information of China (English)

    Rajanarendar Eligeti; Kishore Baireddy; Ramakrishna Saini

    2013-01-01

    Synthesis of isoxazolyl-1H-2,3-pyrrole dicarboxylate (4) was simply achieved by one-pot three component reaction of isoxazole amine (1) with diethyl acetylenedicarboxylate (DEAD) (2),and glyoxal (3),in acetonitrile catalyzed by diazabicyclo octane (DABCO).

  13. Biofabrication Using Pyrrole Electropolymerization for the Immobilization of Glucose Oxidase and Lactate Oxidase on Implanted Microfabricated Biotransducers

    Directory of Open Access Journals (Sweden)

    Christian N. Kotanen

    2014-03-01

    Full Text Available The dual responsive Electrochemical Cell-on-a-Chip Microdisc Electrode Array (ECC MDEA 5037 is a recently developed electrochemical transducer for use in a wireless, implantable biosensor system for the continuous measurement of interstitial glucose and lactate. Fabrication of the biorecognition membrane via pyrrole electropolymerization and both in vitro and in vivo characterization of the resulting biotransducer is described. The influence of EDC-NHS covalent conjugation of glucose oxidase with 4-(3-pyrrolyl butyric acid (monomerization and with 4-sulfobenzoic acid (sulfonization on biosensor performance was examined. As the extent of enzyme conjugation was increased sensitivity decreased for monomerized enzymes but increased for sulfonized enzymes. Implanted biotransducers were examined in a Sprague-Dawley rat hemorrhage model. Resection after 4 h and subsequent in vitro re-characterization showed a decreased sensitivity from 0.68 (±0.40 to 0.22 (±0.17 µA·cm−2·mM−1, an increase in the limit of detection from 0.05 (±0.03 to 0.27 (±0.27 mM and a six-fold increase in the response time from 41 (±18 to 244 (±193 s. This evidence reconfirms the importance of biofouling at the bio-abio interface and the need for mitigation strategies to address the foreign body response.

  14. Developing novel C-4 analogues of pyrrole-based antitubulin agents: weak but critical hydrogen bonding in the colchicine site.

    Science.gov (United States)

    Da, Chenxiao; Telang, Nakul; Hall, Kayleigh; Kluball, Emily; Barelli, Peter; Finzel, Kara; Jia, Xin; Gupton, John T; Mooberry, Susan L; Kellogg, Glen E

    2013-01-01

    The synthesis, biological evaluation and molecular modeling of a series of pyrrole compounds related to 3,5-dibromo-4-(3,4-dimethoxyphenyl)-1H-pyrrole-2-carboxylic acid that evaluates and optimizes C-4 substituents are reported. The key factor for microtubule depolymerization activity appears to be the presence of an appropriately positioned acceptor for Cys241β in the otherwise hydrophobic subpocket A.

  15. Convenient synthesis of substituted pyrroles via a cerium (IV ammonium nitrate (CAN-catalyzed Paal–Knorr reaction

    Directory of Open Access Journals (Sweden)

    Ahmed Kamal

    2016-07-01

    Full Text Available A screening of various cerium salts for promoting the Paal–Knorr pyrrole synthesis revealed the superiority of cerium (IV ammonium nitrate (CAN as a catalyst. Excellent yields of substituted pyrroles were obtained in CAN-catalyzed Paal–Knorr reactions of 1,4-diketones with various amines. The protocol is noteworthy for the mild reaction condition, short reaction times, scalability and easy isolation of products and high yields of the products.

  16. Ab initio multiple cloning simulations of pyrrole photodissociation: TKER spectra and velocity map imaging.

    Science.gov (United States)

    Makhov, Dmitry V; Saita, Kenichiro; Martinez, Todd J; Shalashilin, Dmitrii V

    2015-02-07

    We report a detailed computational simulation of the photodissociation of pyrrole using the ab initio Multiple Cloning (AIMC) method implemented within MOLPRO. The efficiency of the AIMC implementation, employing train basis sets, linear approximation for matrix elements, and Ehrenfest configuration cloning, allows us to accumulate significant statistics. We calculate and analyze the total kinetic energy release (TKER) spectrum and Velocity Map Imaging (VMI) of pyrrole and compare the results directly with experimental measurements. Both the TKER spectrum and the structure of the velocity map image (VMI) are well reproduced. Previously, it has been assumed that the isotropic component of the VMI arises from long time statistical dissociation. Instead, our simulations suggest that ultrafast dynamics contributes significantly to both low and high energy portions of the TKER spectrum.

  17. 3-/3,5-Pyrrole-substituted BODIPY derivatives and their photophysical and electrochemical studies

    Indian Academy of Sciences (India)

    KARTHIKA J KADASSERY; AKANKSHA NIMESH; SANOJ RAJ; NEERAJ AGARWAL

    2016-09-01

    Nucleophilic substitution on 3-bromo/3,5-dibromo-4,4'-difluoro-8-(aryl)-4-bora-3a,4a-diaza-sindacene (BODIPY), substituted with anisyl or thienyl at meso positions, with neat pyrrole afforded the mono and di-pyrrole substituted BODIPYs 1–4 in good yields. Large bathochromic shifts, upto ∼180 nm in absorption maxima (581–682 nm), and fluorescence maxima (606–695 nm) were observed for these BODIPYs. Absorption and fluorescence properties were studied in different solvents to compare the effect of mono and di substitution on BODIPY. The Lippert-Mataga equations were used which predict strong polarization of monosubstituted BODIPYs. Electrochemical studies were carried out to find the oxidation potential and HOMO energy levels were calculated. Theoretical studies of 1–4 provide the insight on the electron density distribution in 1–4. Theoretical and experimental photo-physical studies in different solvents were correlated to findthe substituent effects on BODIPY.

  18. Dichloridobis(4-pyridylmethyl 1H-pyrrole-2-carboxylate-κNzinc

    Directory of Open Access Journals (Sweden)

    Guilong Zhang

    2012-03-01

    Full Text Available In the title molecule, [ZnCl2(C11H10N2O22], the ZnII ion, situated on a twofold axis, is in a distorted tetrahedral coordination environment formed by two chloride anions and two pyridine N atoms of the two organic ligands. In the pyrrole-2-carboxylate unit, the pyrrole N—H group and the carbonyl group point approximately in the same direction. The dihedral angle between the two pyridine rings is 54.8 (3°. The complex molecules are connected into chains extending along [101] by N—H...Cl hydrogen bonds. The chains are further assembled into (-101 layers by C—H...O and C—H...Cl interactions.

  19. Poly(pyrrole) microwires fabrication process on flexible thermoplastics polymers: application as a biosensing material

    OpenAIRE

    Garcia-Cruz, Alvaro; Lee, Michael; Zine, Nadia; Sigaud, Monique; Bausells, Joan; Errachid, Abdelhamid

    2015-01-01

    The authors would like to thank to Carole FARRE (Institute of Analytical Sciences, Univ. Lyon I) for the optical microscopy guidance; International audience; We present a new low-cost technology to fabricate poly(pyrrole) microwires (PPy-mu Ws)by micro contact printing (mu CP) and controlled chemical polymerization (mu CP-CCP) using three different techniques ("grafting printing", "addressed printing", and "direct printing". These developed techniques provide a platform to regulate PPy wire s...

  20. Determination of solvation and binding site profile within electropolymerised poly(pyrrole-N-propionic acid)

    DEFF Research Database (Denmark)

    Glidle, A.; Swann, M.J.; Gadegaard, Nikolaj

    2000-01-01

    Specular neutron reflectivity measurements were performed on electropolymerised films of poly(pyrrole-N-propionic acid) to determine the degree to which the solvents are capable of supporting biological macromolecules can penetrate the polymer film. The permeation profile of Ni2+ ions which chela...... to the polymer's carboxylic acid moieties for subsequent modified protein binding was also determined. (C) 2000 Elsevier Science B.V. All rights reserved....

  1. Selective Colorimetric Fluoride Sensor: A Heteroditopic Re-ceptor Combining Pyrrolic Amide with Urea

    Institute of Scientific and Technical Information of China (English)

    YIN Zhenming; LIU Shangyuan

    2009-01-01

    A heteroditopic anion receptor, beating one pyrrolic amide site and a urea site, has been synthesized. UV-Vis spectrum studies in CH3CN solution revealed that the receptor had higher anion binding ability than the homoditopic one. A naked-eye detectable color change, from colorless to yellow, of the receptor solution took place when fluoride was added, which indicates that the receptor has potential application to selective colorimetric fluo-ride sensing.

  2. tert-Butyl 2-borono-1H-pyrrole-1-carboxylate

    Directory of Open Access Journals (Sweden)

    Zheng Zhong

    2009-04-01

    Full Text Available In the crystal structure of the title compound, C9H14BNO4, the boronic acid group and carbamate groups are nearly co-planar with the pyrrole ring, making dihedral angles of 0.1 (2 and 2.2 (2°, respectively. Intramolecular and intermolecular O—H...O hydrogen bonds help to stabilize the structure, the latter interaction leading to inversion dimers..

  3. Absolute intensities of NH-stretching transitions in dimethylamine and pyrrole.

    Science.gov (United States)

    Miller, Benjamin J; Du, Lin; Steel, Thomas J; Paul, Allanah J; Södergren, A Helena; Lane, Joseph R; Henry, Bryan R; Kjaergaard, Henrik G

    2012-01-12

    Vibrational spectra of vapor-phase dimethylamine (DMA) and pyrrole have been recorded in the 1000 to 13000 cm(-1) region using long path conventional spectroscopy techniques. We have focused on the absolute intensities of the NH-stretching fundamental and overtone transitions; Δν(NH) = 1-4 regions for DMA and the Δν(NH) = 1-3 regions for pyrrole. In the Δν(NH) = 1-3 regions for DMA, evidence of tunneling splitting associated with the NH-wagging mode is observed. For DMA, the fundamental NH-stretching transition intensity is weaker than the first NH-stretching overtone. Also, the fundamental NH-stretching transition in DMA is much weaker than the fundamental transition in pyrrole. We have used an anharmonic oscillator local mode model with ab initio calculated local mode parameters and dipole moment functions at the CCSD(T)/aug-cc-pVTZ level to calculate the NH-stretching intensities and explain this intensity anomaly in DMA.

  4. Novel pyrrole derivatives bearing sulfonamide groups: Synthesis in vitro cytotoxicity evaluation, molecular docking and DFT study

    Science.gov (United States)

    Bavadi, Masoumeh; Niknam, Khodabakhsh; Shahraki, Omolbanin

    2017-10-01

    The synthesis of new derivatives of pyrrole substituted sulfonamide groups is described. The in vitro anticancer activity of these pyrroles was evaluated against MCF7, MOLT-4 and HL-60 cells using MTT assay. The target compounds showed inhibitory activity against tested cell lines. Among the compounds, compound 1a exhibited good cytotoxic activity. The potential of this analog to induce apoptosis was confirmed in a nuclear morphological assay by Hoechst 33258 staining in the PC-12 cells. Finally, molecular docking was performed to determine the probable binding mode of the designed pyrrole derivatives into the active site of FGFR1 protein. DFT calculations were carried out at the B3LYP levels of theory with 6-31+G (d,p) basis set for compound 1a. The point group (C1) of it was obtained based on the optimized structures; the calculation of the FT-IR vibrational frequencies, 1H NMR and 13C NMR chemical shifts of the compound were carried out and compared with those obtained experimentally.

  5. Evaluation on the inhibition of pyrrol-2-yl ethanone derivatives to lactate dehydrogenase and anticancer activities

    Science.gov (United States)

    Lu, Na-Na; Weng, Zhao-Yue; Chen, Qiu-Yun; Boison, Daniel; Xiao, Xin-Xin; Gao, Jing

    2016-08-01

    Lactate dehydrogenase A (LDH-A) is a potentially important metabolic target for the inhibition of the highly activated glycolysis pathway in cancer cells. In order to develop bifunctional compounds as inhibitor of LDH-A and anticancer agents, two pyrrol-2-yl methanone (or ethanone) derivatives (PM1 and PM2) were synthesized and evaluated as inhibitors of LDH-A based on the enzyme assay and cell assay by spectroscopy analysis. Fluorescence and CD spectra results demonstrated that both the change of second structure of LDH-A and the affinity interaction for compounds to LDH-A gave great effect on the activity of LDH-A. In particular, low concentration of compounds (1 μμ-25 μμ) could change the level of pyruvate in cancer cells. Moreover, the in vitro assay results demonstrated that pyrrol-2-yl ethanone derivatives can inhibit the proliferation of cancer cells. Therefore, pyrrol-2-yl ethanone derivatives (PM2) can be both LDH-A inhibitor and anticancer agents.

  6. Interaction of derived polymers from pyrrole with biocompatible solutions; Interaccion de polimeros derivados de pirrol con soluciones biocompatibles

    Energy Technology Data Exchange (ETDEWEB)

    Lopez G, O. G.

    2010-07-01

    This work presents a study about the synthesis by plasma, the electric properties and superficial interaction of polymers derived from pyrrole doped with Iodine with potential use as bio material. Poly-pyrrole is a semiconductor and biocompatible polymer with potential application in the development of artificial muscles and implants where the electric interaction between cells and material is an important variable. The syntheses were made at 13.5 MHz in a glass tubular reactor of 1500 cm{sup 3} with electrodes of 6.5 cm diameter and stainless steel flanges. An electrode was connected to the RF terminal of the power supply that is combined with a matching coupling resistance. The monomer and dopant used in this work were pyrrole and Iodine respectively, in closed containers. They were vaporized and injected separately into the reactor at room temperature and 0.1 mbar. The vapors of the reagents mixed freely in the reactor. The synthesis time was 240 min at 40, 60, 80 and 100 W. The polymers were obtained as thin films adhered to the reactor walls. The films were washed and swollen with distilled water and removed from the reactor walls with a small spatula. The polymers were irradiated with gamma rays at 18 and 22 KGy. Due to the fact that the doses are cumulative, the final dose applied was 40 KGy. The polymers characterization was carried out by Fourier Transform Infrared Spectroscopy, thermogravimetric analysis (TGA), scanning electron microscopy, contact angle, electrical conductivity and X-ray diffraction. The analyses indicates that the polymers have very similar structure in almost the entire power range, showing C-O, C=C, C-H, O-H, N-H bonds with a predominantly amorphous structure. The TGA analyses showed that the material has 4 or 5 loses of material. The first one starts after that 115 C except for the material irradiated at 40 KGy, this one begins in 87 C, the second one is in the interval of 196 and 295 C, the third one between 311 and 500 C, and the

  7. Electrodeposition of (pyrrole-co-phenol) on steel surfaces in mixed electrolytes of oxalic acid and DBSA

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudian, M.R., E-mail: M_R_mahmoudian@yahoo.com [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Alias, Y.; Basirun, W.J. [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2010-12-01

    Poly (pyrrole-co-phenol) (co-PyPh) was synthesised using cyclic voltammetry in the mixture of dodecyl benzene sulphonic acid (DBSA) with oxalic acid solution on steel electrodes. The morphology and compositions were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR) techniques and Energy-dispersive X-ray spectroscopy (EDX). Electrode/co-PyPh/electrolyte system was studied in 0.1 M NaCl solutions by Electrochemical Impedance Spectroscopy (EIS). The Warburg impedance observed in mid frequency region is an evidence of the effective barrier behaviour of coating. The results of EDX indicate that the content of doped sulphur can influence the morphology of co-PyPh. Three dissimilar morphologies of co-PyPh and different amount of doped sulphur in co-PyPh are observed. The existence of phenol monomer leads to a decrease in the amount of doped sulphur in co-PyPh compared with synthesised polypyrrole (PPy) in the same environment.

  8. Electrochemical characteristics of coated steel with poly(N-methyl pyrrole) synthesized in presence of ZnO nanoparticles

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudian, M.R., E-mail: M_R_mahmoudian@yahoo.com [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Chemistry, Masjed-Soleiman Branch, Islamic Azad University, Masjed-Soleiman (Iran, Islamic Republic of); Basirun, W.J.; Alias, Y. [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Khorsand Zak, A. [Low Dimensional Materials Research Center, Department of Physics, University of Malaya, 50603 Kuala Lumpur (Malaysia)

    2011-10-31

    Poly(N-methyl pyrrole) (PMPy) coating was electrodeposited on steel substrates in mixed electrolytes of dodecyl benzene sulphonic acid with oxalic acid in the absence and the presence of ZnO nanoparticles (NPs). The morphology and compositions were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy and Energy-dispersive X-ray spectroscopy. Electrode/coating/electrolyte system was studied by Electrochemical Impedance Spectroscopy. The comparison between the pore resistance (R{sub po}) of synthesized PMPy in the absence and presence of ZnO NPs indicated that the existence of ZnO increased the R{sub po} of the coating. The FESEM micrographs indicated that the size of micro-spherical grains in the morphology of PMPy is significantly reduced and the surface area of PMPy is increased with the presence of ZnO NPs. The increase of the ability to interact with the ions liberated during the corrosion reaction of steel and the increase of the rate probability for the occurrence of cathodic reduction of oxygen on the PMPy with the increase of the surface area can be considered as reasons for improvement of protective properties of synthesized PMPy in the presence of ZnO NPs.

  9. Biological activity of two new pyrrole derivatives against stored-product species: influence of temperature and relative humidity.

    Science.gov (United States)

    Boukouvala, M C; Kavallieratos, N G; Athanassiou, C G; Hadjiarapoglou, L P

    2016-08-01

    Members of the pyrrole group are likely to have interesting properties that merit additional investigation as insecticides at the post-harvest stages of agricultural commodities. In the present work, the insecticidal effect of two new pyrrole derivatives, ethyl 3-(benzylthio)-4,6-dioxo-5-phenyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrrole-carboxylate (3i) and isopropyl 3-(benzylthio)-4,6-dioxo-5-phenyl-2,4,5,6-tetrahydropyrrolo[3,4-c]pyrrole-carboxylate (3k) were studied as stored-wheat protectants against two major stored-product insect species, the confused flour beetle, Tribolium confusum Jaquelin du Val adults and larvae and the Mediterranean flour moth, Ephestia kuehniella Zeller larvae at different doses (0.1, 1 and 10 ppm), exposure intervals (7, 14 and 21 days), temperatures (20, 25 and 30°C) and relative humidity (55 and 75%) levels. For T. confusum adults, in the case of the pyrrole derivative 3i, mortality was low and it did not exceed 32.2% in wheat treated with 10 ppm 3i at 30°C and 55% relative humidity. Progeny production was very low (confusum larvae, in the case of the pyrrole derivative 3i, at the highest dose, mortality was 82.2% at 25°C and 55% relative humidity whereas in the case of 3k it reached 77.8% at the same combination. In contrast, mortality at 75% relative humidity remained very low and did not exceed 13.3%. For E. kuehniella larvae, the highest mortalities, 44.4 and 63.3%, were observed in 10 ppm at 25°C and 55% relative humidity for both pyrrole derivatives. The compounds tested here have a certain insecticidal effect, but this effect is moderated by the exposure, the target species, the temperature and the relative humidity.

  10. Role of the ribose-specific marker furfuryl-amine in the formation of aroma active 1-(furan-2-ylmethyl)-1H-pyrrole (or furfuryl-pyrrole) derivatives.

    Science.gov (United States)

    Nikolov, Plamen Y; Yaylayan, Varoujan A

    2012-10-10

    Furfuryl-pyrroles possess a diverse range of organoleptic properties described as roasted, chocolaty, green, horseradish-like, and mushroom-like and are detected in various foods such as coffee, chocolate, popcorn, and roasted chicken. Although their origin in food was attributed to furfuryl-amine, the latter has not been detected so far in Maillard model systems or in foods. In this study, furfuryl-amine was shown to be formed specifically from ribose through nitrogen atom transfer from the α-amino group of any amino acid. Such a transfer can be achieved through decarboxylation of the Schiff base adduct and isomerization followed by hydrolysis. Through the use of (15)Nα-lysine it was revealed that only the (15)Nα nitrogen atom was incorporated into its structure, indicating a specific role for the carboxylate moiety in the mechanism of its formation. Furthermore, isotope labeling studies have indicated that furfuryl-pyrrole derivatives can be formed by the interaction of 2 mol of furfuryl-amine with 3-deoxyribosone followed by dehydration and cyclization to form 1-(furan-2-yl)-N-{[1-(furan-2-ylmethyl)-1H-pyrrol-2-yl]methylidene}methanamine. After hydrolysis, this intermediate can generate furfuryl-formyl-pyrrole, furfuryl-pyrrole carboxylic acid, and furfuryl-pyrrole. In this study, the furfuryl-amine derivatives were also detected in different coffee beans after pyrolysis and analysis by GC-MS. The potential of these compounds to form in aqueous model systems at a temperature of 120 °C was also demonstrated.

  11. Pyrrole Derivatives and Diterpene Alkaloids from the South China Sea Sponge Agelas nakamurai.

    Science.gov (United States)

    Chu, Mei-Jun; Tang, Xu-Li; Qin, Guo-Fei; Sun, Yan-Ting; Li, Lei; de Voogd, Nicole J; Li, Ping-Lin; Li, Guo-Qiang

    2017-07-01

    Two pairs of new non-brominated racematic pyrrole derivatives, (±)-nakamurine D (1) and (±)-nakamurine E (2), two new diterpene alkaloids, isoagelasine C (16) and isoagelasidine B (21), together with 13 known pyrrole derivatives ((±)-3 - 15), five known diterpene alkaloids (17 - 20, 22) were isolated from the South China Sea sponge Agelas nakamurai. The racemic mixtures, compounds 1 - 4, were resolved into four pairs of enantiomers, (+)-1 and (-)-1, (+)-2 and (-)-2, (+)-3 and (-)-3, and (+)-4 and (-)-4, by chiral HPLC. The structures and absolute configurations were elucidated on the basis of comprehensive spectroscopic analyses, quantum chemical calculations, quantitative measurements of molar rotations, application of van't Hoff's principle of optical superposition, and comparison with the literature data. The NMR and MS data of compound 3 are reported for the first time, as the structure was listed in SciFinder Scholar with no associated reference. These non-brominated pyrrole derivatives were found in this species for the first time. Compound 18 showed valuable cytotoxicities against HL-60, K562, and HCT-116 cell lines with IC50 values of 12.4, 16.0, and 19.8 μm, respectively. Compounds 16 - 19, 21, and 22 showed potent antifungal activities against Candida albicans with MIC values ranging from 0.59 to 4.69 μg/ml. Compounds 16 - 19 exhibited moderate antibacterial activities against Proteusbacillus vulgaris (MIC values ranging from 9.38 to 18.75 μg/ml). © 2017 Wiley-VHCA AG, Zurich, Switzerland.

  12. Copper-catalyzed C(sp(3))-H functionalization of ketones with vinyl azides: synthesis of substituted-1H-pyrroles.

    Science.gov (United States)

    Donthiri, Ramachandra Reddy; Samanta, Supravat; Adimurthy, Subbarayappa

    2015-10-28

    Copper-catalyzed C(sp(3))-H functionalization of ketones with vinyl azides for the synthesis of substituted pyrroles has been developed. The method is a straightforward and efficient way to access a series of 2,3,5-trisubstituted-1H-pyrroles in modest to excellent yields with broad functional group tolerance under mild conditions.

  13. Sustainable Pathways to Pyrroles through Iron-Catalyzed N-Heterocyclization from Unsaturated Diols and Primary Amines.

    Science.gov (United States)

    Yan, Tao; Barta, Katalin

    2016-09-01

    Pyrroles are prominent scaffolds in pharmaceutically active compounds and play an important role in medicinal chemistry. Therefore, the development of new, atom-economic, and sustainable catalytic strategies to obtain these moieties is highly desired. Direct catalytic pathways that utilize readily available alcohol substrates have been recently established; however, these approaches rely on the use of noble metals such as ruthenium or iridium. Here, we report on the direct synthesis of pyrroles using a catalyst based on the earth-abundant and inexpensive iron. The method uses 2-butyne-1,4-diol or 2-butene-1,4-diol that can be directly coupled with anilines, benzyl amines, and aliphatic amines to obtain a variety of N-substituted pyrroles in moderate-to-excellent isolated yields.

  14. A Bis-Calix[4]pyrrole Enzyme Mimic that Constrains Two Oxoanions in Close Proximity

    DEFF Research Database (Denmark)

    He, Qing; Kelliher, Michael; Bähring, Steffen

    2017-01-01

    Herein we describe a large capsule-like bis-calix[4]pyrrole 1 , that is able to host concurrently two dihydrogen phosphate anions within a relatively large internal cavity. Evidence for the concurrent, dual recognition of the encapsulated anions came from 1H NMR and UV-vis spectroscopies and ITC...... by spectroscopic analyses. Finally, receptor 1 was found capable of accommodating two trianionic pyrophosphate anions in the cavity. The present experimental findings are supported by DFT calculations along with 1H NMR and UV-vis spectroscopies, ITC studies, and single crystal X-ray diffraction analyses....

  15. Indium(III)-catalyzed synthesis of N-substituted pyrroles under solvent-free conditions

    OpenAIRE

    Chen,Jiu-Xi; Liu,Miao-Chang; Yang,Xiao-Liang; Ding,Jin-Chang; Wu,Hua-Yue

    2008-01-01

    A variety of N-substituted pyrroles have been synthesized by reacting γ-diketones (R¹C(O)CH2CH2C(O)R²: R¹, R² = Me, Ph) with amines (RNH2: R=Alkyl, Aryl, TsNH) or diamines (1,6-diaminohexane and 1,2-diaminoethane) in the presence of indium tribromide, indium trichloride or indium trifluoromethanesulfonate at room temperature under solvent-free conditions. The experiment protocol features simple operations, and the products are isolated in high to excellent yields (81-98%).

  16. N-Benzyl-2,5-bis(2-thienyl)pyrrole.

    Science.gov (United States)

    Palenzuela Conde, Jesús; Elsegood, Mark R J; Ryder, Karl S

    2004-03-01

    The solid-state structure of the title compound, C19H15NS2, is unusual among substituted thiophene/pyrrole derivatives in that the molecular packing is dominated by pi-pi interactions between the benzyl substituents. This may be due to the large torsion angles observed between adjacent heterocycles. Torsion angles between adjacent rings in polypyrrole and polythiophene conducting polymers are related to conjugation length and the conductivity properties of the polymer materials. The title compound crystallizes in space group P21/c with two molecules in the asymmetric unit, both of which exhibit disorder in one of their thiophene rings.

  17. Copper-diamine-catalyzed N-arylation of pyrroles, pyrazoles, indazoles, imidazoles, and triazoles.

    Science.gov (United States)

    Antilla, Jon C; Baskin, Jeremy M; Barder, Timothy E; Buchwald, Stephen L

    2004-08-20

    This paper details the copper-catalyzed N-arylation of pi-excessive nitrogen heterocycles. The coupling of either aryl iodides or aryl bromides with common nitrogen heterocycles (pyrroles, pyrazoles, indazoles, imidazoles, and triazoles) was successfully performed in good yield with catalysts derived from diamine ligands and CuI. General conditions were found that tolerate functional groups such as aldehydes, ketones, alcohols, primary amines, and nitriles on the aryl halide or heterocycle. Hindered aryl halides or heterocycles were also found to be suitable substrates using the conditions reported herein. Copyright 2004 American Chemical Society

  18. Indium(III)-catalyzed synthesis of N-substituted pyrroles under solvent-free conditions

    OpenAIRE

    Chen,Jiu-Xi; Liu,Miao-Chang; Yang, Xiao-Liang; Ding,Jin-Chang; Wu,Hua-Yue

    2008-01-01

    A variety of N-substituted pyrroles have been synthesized by reacting γ-diketones (R¹C(O)CH2CH2C(O)R²: R¹, R² = Me, Ph) with amines (RNH2: R=Alkyl, Aryl, TsNH) or diamines (1,6-diaminohexane and 1,2-diaminoethane) in the presence of indium tribromide, indium trichloride or indium trifluoromethanesulfonate at room temperature under solvent-free conditions. The experiment protocol features simple operations, and the products are isolated in high to excellent yields (81-98%).

  19. Low frequency ac conduction and dielectric relaxation in poly(N-methyl pyrrole)

    Indian Academy of Sciences (India)

    Amarjeet K Narula; Ramadhar Singh; Subhas Chandra

    2000-06-01

    The ac conductivity and dielectric constant of poly(N-methyl pyrrole) thin films have been investigated in the temperature range 77–350 K and in the frequency range 102–106 Hz. The well defined loss peaks have been observed in the temperature region where measured ac conductivity approaches dc conductivity. These loss peaks are associated with the hopping of the charge carriers. The frequency and temperature dependence of ac conductivity have been qualitatively explained by considering the contribution from two mechanisms; one giving a linear dependence of conductivity on frequency and other having distribution of relaxation times giving rise to broad dielectric loss peak.

  20. 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.

  1. (E)-2,4,6-Trimethyl-N-[(1H-pyrrol-2-yl)methyl-idene]aniline.

    Science.gov (United States)

    Imhof, Wolfgang

    2013-01-01

    The title compound, C14H16N2, is a pyrrole-2-carbaldimine ligand that shows an E conformation at the imine double bond. The dihedral angle between the rings is 78.3 (1)°. In the crystal, pairs of mol-ecules form centrosymmetric dimers [graph-set descriptor is presumably R(2)2(10)] via N-H⋯N hydrogen bonds between the pyrrole N-H group and the imine N atom of a neighbouring mol-ecule.

  2. Synthesis and Cytotoxic Evaluation of Pyrrole Hetarylazoles Containing Benzimidazole/Pyrazolone/1,3,4-Oxadiazole Motifs.

    Science.gov (United States)

    Mochona, Bereket; Jackson, Timothy; McCauley, DeCoria; Mazzio, Elizabeth; Redda, Kinfe K

    2016-11-01

    Azomethine linked pyrrole bishetarylazoles containing benzimidazole/pyrazolone/1,3,4-oxadiazole were synthesized in satisfactory yields. Their structures were confirmed by IR, (1)H-NMR, (13)C-NMR and elemental analysis. Evaluation for the cytotoxic activities In vitro against a panel of breast cancer cell lines (MDA-AB-231, BT-474 and Ishikawa cells) revealed that the pyrrole-benzimidazole hybrids are more potent than the pyrazolone and 1,3,4-oxadiazole hybrids in all cell lines. Compound (9) displayed promising cytotoxicity against BT-474 cell line with IC50 values, 7.7 µM.

  3. Pyrrole Alkaloids with Potential Cancer Chemopreventive Activity Isolated from a Goji Berry-Contaminated Commercial Sample of African Mango

    OpenAIRE

    Li, Jie; Pan, Li; Naman, C. Benjamin; Deng, Ye; Chai, Heebyung; Keller, William J.; Kinghorn, A. Douglas

    2014-01-01

    Bioassay-guided fractionation of a commercial sample of African mango (Irvingia gabonensis) that was later shown to be contaminated with goji berry (Lycium sp.) led to the isolation of a new pyrrole alkaloid, methyl 2-[2-formyl-5-(hydroxymethyl)-1H-pyrrol-1-yl]propanoate, 1, along with seven known compounds, 2?8. The structures of the isolated compounds were established by analysis of their spectroscopic data. The new compound 1g showed hydroxyl radical-scavenging activity with an ED50 value ...

  4. Bis(pyrrole-benzimidazole) conjugates as novel colorimetric sensor for anions

    Indian Academy of Sciences (India)

    SANJEEV PRAN MAHANTA; PRADEEPTA KUMAR PANDA

    2017-05-01

    Novel bis(pyrrole-benzimidazole) (PYBI) conjugates were investigated as colorimetric anion recognition motif by employing multiple donor sites. In this regard, PYBI derivatives where pyrrole unit is connected to the C2 position of benzimidazole via its α-position were synthesized and their anion recognitionbehavior were evaluated by UV-Vis, fluorescence and 1H NMR spectroscopy. PYBI selectively interacts with fluoride ion, whereas introduction of nitro group on the benzimidazole moiety enhances the binding affinity by at least one order, albeit at the expense of the selectivity. Bridging of two PYBIs led to interesting cooperative effect between the two subunits, which gets enhanced upon changing the spacer between the two from nonconjugatingtype (sp3-C) to conjugating one (quinoxaline). This also affects the way they interact with anions, with the latter moiety displaying very interesting stepwise double deprotonation of benzimidazole protons upon addition of fluoride ions with strong colorimetric as well as fluorometric response. Further, acidity of the H-bond donor sites was found to play pivotal role in the anion complexation mechanism and selectivity.

  5. Synthesis of Conductive PPy/SiO2 Aerogels Nanocomposites by In Situ Polymerization of Pyrrole

    Directory of Open Access Journals (Sweden)

    Daliana Muller

    2015-01-01

    Full Text Available Electrical conductive nanocomposite aerogels were synthesized through in situ oxidative polymerization of pyrrole (Py using ammonium persulfate (APS as an oxidizing agent in SiO2 gels. The effect of Py concentration on the electrical conductivity and physical and morphological properties of aerogels SiO2/PPy was evaluated. B.E.T. analysis indicated that the surface area of the composite SiO2/PPy decreases with increasing concentration of Py. CHN analysis showed an increase in the amount of PPy, from 13 wt.% to 23 wt.%, with increasing concentration of pyrrole synthesis. FTIR-ATR analysis of the composites revealed bands in the region of 1500–1400 cm−1, indicating the presence of the conductive polymer in the silica aerogel as well as the characteristic bands of Si-O-Si and Si-OH covalent bonds. TEM micrographs revealed the presence of particles of PPy with the increased size of the nanoparticles. The composites were successfully applied as passive components, in RC circuits, for low-pass frequency filters. The filters exhibited a cutoff frequency at approximately 435 Hz. The aerogels obtained in this work exhibited suitable electrical conductivity for use in various other applications in electronics.

  6. Electrochemical Detection of Clenbuterol in Pig Liver at Pyrrole-DNA Modified Boron-doped Diamond Electrode

    Institute of Scientific and Technical Information of China (English)

    WU Jing; LI Xiao-li; WU Xu-mei; HUAN Shuang-yan; SHEN Guo-li; YU Ru-qin

    2005-01-01

    The direct detection of clenbuterol(CL) in pig liver without any extraction separation at a pyrrole-DNA modified boron-doped diamond(BDD) electrode is reported. The pyrrole-DNA modified BDD electrode has a strong electrocatalytic effect on the redox reaction of CL. One oxidization and two reduction peaks of CL appear at 340.2, 299.8 and 166.6 mV(versus SCE), respectively. The pyrrole polymer alone cannot electrocatalyze the above reaction at a BDD electrode; the electrocatalytic effect of a BDD electrode modified with DNA membrane is unsufficient for the analytical detection of CL; the replacement of boron-doped diamond by glass carbon makes the electrocatalytic reaction impossible; the redox process is pH dependent. The influences of various experimental parameters on the pyrrole-DNA modified BDD electrode were investigated. A sensitive cyclic voltammetric response for CL was obtained in a linear range from 3.4×10-6 to 5×10-4 mol/L with a detection limit of 8.5×10-7 mol/L. A mean recovery of 102.7% of CL in the pig liver sample solution and a reproducibility of 3.2% were obtained.

  7. Chemistry of sulfonylmethyl isocyanides. 45. A direct synthesis of 2-(trimethylstannyl)pyrroles from Michael acceptors and stannylated tosylmethyl isocyanide

    NARCIS (Netherlands)

    Dijkstra, HP; ten Have, Ronald; van Leusen, A.M.

    1998-01-01

    A series of 2-(trimethylstannyl)pyrroles 3, with substituents at the 3- and 4-positions, is synthesized efficiently by a base-induced reaction of stannylated TosMIC with Michael accepters. Stills cross-couplings with bromobenzene and double cross-couplings with 1,4-dibromobenzene have been achieved

  8. Sustainable Pathways to Pyrroles through Iron-Catalyzed N-Heterocyclization from Unsaturated Diols and Primary Amines

    NARCIS (Netherlands)

    Yan, Tao; Barta, Katalin

    2016-01-01

    Pyrroles are prominent scaffolds in pharmaceutically active compounds and play an important role in medicinal chemistry. Therefore, the development of new, atom-economic, and sustainable catalytic strategies to obtain these moieties is highly desired. Direct catalytic pathways that utilize readily a

  9. (E-3-(1-Methyl-1H-pyrrol-2-yl-1-phenylprop-2-en-1-one

    Directory of Open Access Journals (Sweden)

    Li Liu

    2011-04-01

    Full Text Available The crystal structure of the title compound, C14H13NO, exhibits an E configuration. The conjugated compound is slightly twisted with a dihedral angle of 29.3° between the benzene and pyrrole rings. Two intermolecular C—H...O interactions lead to a dimer. In the crystal, intermolecular C—H...O interactions generate an inversion dimer.

  10. Pseudocapacitive Electrodes Produced by Oxidant-Free Polymerization of Pyrrole between the Layers of 2D Titanium Carbide (MXene).

    Science.gov (United States)

    Boota, Muhammad; Anasori, Babak; Voigt, Cooper; Zhao, Meng-Qiang; Barsoum, Michel W; Gogotsi, Yury

    2016-02-17

    Heterocyclic pyrrole molecules are in situ aligned and polymerized in the -absence of an oxidant between layers of the 2D Ti3C2Tx (MXene), resulting in high volumetric and gravimetric capacitances with capacitance retention of 92% after 25,000 cycles at a 100 mV s(-1) scan rate.

  11. Photodissociation dynamics of pyrrole: evidence for mode specific dynamics from conical intersections.

    Science.gov (United States)

    Wei, J; Riedel, J; Kuczmann, A; Renth, F; Temps, F

    2004-01-01

    The H and D atom elimination mechanisms in the photodissociation of jet cooled pyrrole and pyrrole-d1 have been studied by photofragment velocity map imaging. The molecules were excited to the 1 1A2 (pi sigma*) state at lambda = 243 nm and to the 1 1B2 (pi pi*) state at lambda = 217 nm. H/D atoms were detected by (2 + 1) resonance enhanced multiphoton ionization (REMPI) at lambda = 243 nm. The analysis of the images and the resulting translational energy distributions from the 1 1A2 state demonstrates the existence of two decay pathways, fast mode-specific cleavage of the NH bond in the excited state (channel A) and internal conversion (IC) to the electronic ground state (S0) followed by unimolecular decomposition of the vibrationally hot S0 molecules (channel B). The angular distributions of the H/D atoms from the direct dissociation in the excited state are strongly anisotropic, whereas the decay of the S0 molecules leads to spatially isotropic distributions. The results at lambda = 217 nm indicate that the 1 1B2 state undergoes an ultrafast radiationless transition to 1 1A2 followed by the abovementioned direct mode-specific NH bond fission on the 1 1A2 potential energy surface (channel A') or conversion to S0 and subsequent unimolecular decomposition (channel B'). The latter pathway may also be initiated by a direct relaxation from 1 1B2 to S0. The anisotropy parameter of beta approximately -1 for the direct NH bond fission at lambda = 217 nm is in accordance with the expectations for a perpendicular electronic excitation and a dissociation lifetime that is short compared to the rotational period of the molecules. The fast decay dynamics of both excited electronic states can be rationalized with reference to the theoretically predicted conical intersections between the pi pi*, pi sigma*, and S0 potential energy surfaces and the antibonding nature of the pi sigma* potential energy surface with respect to the NH bond [A. L. Sobolewski, W. Domcke. C. Dedonder

  12. Bis{2-[(2,4,6-trimethylphenyliminomethyl]pyrrol-1-ido}palladium(II

    Directory of Open Access Journals (Sweden)

    Wolfgang Imhof

    2013-02-01

    Full Text Available The title compound, [Pd(C14H15N22], is a square-planar palladium complex composed of two deprotonated pyrrole-2-carbaldimine ligands coordinating a central PdII atom. In the crystal, three crystallographically independent complex molecules are observed, one of which is located in a general position, whereas the PdII atoms of the other molecules are situated on crystallographic inversion centers. The aromatic substituents at the imine N atoms in the three molecules show dihedral angles of 87.6 (7/83.64 (7, 74.3 (7 and 88.3 (7° with respect to the corresponding PdN4 plane.

  13. A poly(pyrrole-Cobalt(IIdeuteroporphyrin electrode for the potentiometric determination of nitrite

    Directory of Open Access Journals (Sweden)

    Michael Wedel

    2003-07-01

    Full Text Available The electrochemical properties of a new Co(II deuteroporphyrin substituted by two electropolymerizable pyrrole groups has been investigated in organic solvent. This functionalization has allowed the preparation of the first example of a cobalt deuteroporphyrin film by oxidative electropolymerization. The resulting conducting polypyrrole film exhibits the regular electroactivity of cobalt deuteroporphyrin. Compared to conventional cobalt porphyrin electrochemistry, the replacement of porphyrin macrocycle by deuteroporphyrin ring results in markedly more negative potential values for the metalcentered oxidation and reduction processes. The influence of NO2- as axial ligand on the reductive behavior of the electropolymerized cobalt (II deuteroporphyrin is examined. The recognition properties of the film illustrated by the potentiometric shift of the Co(II/(I reduction were exploited for the determination of NO2- in the concentration range 2 10-6- 2.5 10-4 M.

  14. Outer-Sphere Mechanism in the Oxidation of Pyrrole-2- Carboxaldehyde by Hexacyanoferrate (III Complex.

    Directory of Open Access Journals (Sweden)

    Abd-Alhakeem H. Abu-Nawwas

    2014-01-01

    Full Text Available The kinetics and mechanism of base-catalyzed oxidation of pyrrole-2-carboxaldehyde with hexacyanoferrate (III is reported. The reaction showed first order with respect to aldahyde , alkali and hexaeyanoferrate(III. The kinetic data suggest that the oxidation involves the formation of an anion of the substrate undergoes oxidation with hexaeyanoferrate(III via outer sphere mechanism process. The free radical thus produced is further oxidized to form the final products. A suitable mechanism was proposed and rate law was derived as − d[Fe CN 6 ] 3− = 2k1k2 RC(OH2 [Fe CN 6 ] 3−[OH−] k−1 H2O

  15. ELECTRICALLY CONDUCTIVE COMPOSITE PREPARED BY ELECTROCHEMICAL POLYMERIZATION OF PYRROLE IN POLY- (p- PHENYLENE TEREPHTHALAMIDE ) MATRIX

    Institute of Scientific and Technical Information of China (English)

    BI Xiantong; PEI Qibing; HAN Baozhen; BAO Jingshen

    1991-01-01

    The preparation of PPy/PPTA conductive composite films by electrochemical method is presented.The first step is to cast a thin layer of poly (p-phenylene-terephthalamide)(PPTA)on a slice of Pt working electrode. The second step is to electrochemically polymerize pyrrole on the PPTA/Pt working electrode. Both of the electrical conductivity and the mechanical properties of the PPy/PPTA composite film are better than those of the pure PPy film, and the film has excellent flexibility at low temperature, even in liquid nitrogen.The SEM picture of the cross-section of PPy/PPTA composite film showed that the two components were well mixed.Cyclic voltammograms of PPy/PPTA film in aqueous solution showed that the conductive films could be reduced and reoxidized.

  16. Colorimetric chemosensor for multi-signaling detection of metal ions using pyrrole based Schiff bases.

    Science.gov (United States)

    Udhayakumari, Duraisamy; Velmathi, Sivan

    2014-03-25

    Pyrrole based Schiff bases act as a highly sensitive probe for metal ions in aqueous medium. Both receptors R1 and R2 are sensitive towards Fe(3+), Cu(2+), Hg(2+) and Cr(3+) among the other metal ions. The sensing ability of the receptors are investigated via colorimetric, optical and emission spectroscopic studies. The binding stoichiometries of R1 and R2 with metal ions have been determined as 2:1 by using Job's plot. The colorimetric receptors exhibited high sensitivity with a low detection limit of μM levels. In the presence of metal ions both receptors shows fluorescence quenching. This might be due to the photo induced electron transfer mechanism. The quenching constant was further determined using Stern-Volmer plot.

  17. State-specific tunneling lifetimes from classical trajectories: H-atom dissociation in electronically excited pyrrole

    Science.gov (United States)

    Xie, Weiwei; Domcke, Wolfgang; Farantos, Stavros C.; Grebenshchikov, Sergy Yu.

    2016-03-01

    A trajectory method of calculating tunneling probabilities from phase integrals along straight line tunneling paths, originally suggested by Makri and Miller [J. Chem. Phys. 91, 4026 (1989)] and recently implemented by Truhlar and co-workers [Chem. Sci. 5, 2091 (2014)], is tested for one- and two-dimensional ab initio based potentials describing hydrogen dissociation in the 1B1 excited electronic state of pyrrole. The primary observables are the tunneling rates in a progression of bending vibrational states lying below the dissociation barrier and their isotope dependences. Several initial ensembles of classical trajectories have been considered, corresponding to the quasiclassical and the quantum mechanical samplings of the initial conditions. It is found that the sampling based on the fixed energy Wigner density gives the best agreement with the quantum mechanical dissociation rates.

  18. Caveats in the interpretation of time-resolved photoionization measurements: A photoelectron imaging study of pyrrole

    Science.gov (United States)

    Crane, Stuart W.; Zawadzki, Magdalena M.; Thompson, James O. F.; Kotsina, Nikoleta; Ghafur, Omair; Townsend, Dave

    2016-12-01

    We report time-resolved photoelectron imaging studies of gas-phase pyrrole over the 267-240 nm excitation region, recorded in conjunction with a 300 nm probe. Of specific interest is the lowest-lying (3 s /π σ* ) state, which exhibits very weak oscillator strength but is thought to be excited directly at wavelengths ≤254 nm. We conclude, however, that the only significant contribution to our photoelectron data at all wavelengths investigated is from non-resonant ionization. Our findings do not rule out (3 s /π σ* ) state excitation (as appears to be confirmed by supporting time-resolved ion-yield measurements) but do potentially highlight important caveats regarding the use and interpretation of photoreactant ionization measurements to interrogate dynamical processes in systems exhibiting significant topological differences between the potential energy surfaces of the neutral and cation states.

  19. Theoretical Study on Measure of Hydrogen Bonding Strength: R-C≡N…pyrrole Complexes

    Institute of Scientific and Technical Information of China (English)

    史福强; 安静仪; 俞稼镛

    2005-01-01

    The R-C≡N…pyrrole (R=H, CH3, CH2F, CHF2, CF3, NH2, BH2, OH, F, CH2Cl, CHCl2, CCl3, Li, Na) complexes were considered as the simple sample for measure of hydrogen bonding strength. Density functional theory B3LYP/6-311 + + G** level was applied to the optimization of geometries of complexes and monomers. Measure of hydrogen bonding strength based on geometrical and topological parameters, which were derived from the AIM theory, was analyzed. Additionally, natural bond orbital (NBO) analysis and frequency calculations were performed.From the computation results it was found that the electronic density at N-H bond critical points was also strictly correlated with the hydrogen bonding strength.

  20. Zn(OTf)2 promoted rearrangement of 1,2-cyclopropanated sugars with amines: a convenient method for the synthesis of 3-polyhydroxyalkyl-substituted pyrrole derivatives.

    Science.gov (United States)

    Shen, Xudong; Xia, Jianhui; Liang, Peng; Ma, Xiaofeng; Jiao, Wei; Shao, Huawu

    2015-11-28

    A rearrangement reaction of 1,2-cyclopropanated sugars with alkylamines or arylamines promoted by Zn(OTf)2 is described. The method offers a series of 3-polyhydroxyalkyl-substituted pyrrole derivatives with multiple chiral centers in moderate to excellent yields. The epimerization is achieved by inverting the stereochemistry at the free hydroxyl group of the resulting pyrrole, which would give access to many more possible stereoisomers.

  1. Vinyl azides derived from allenes: thermolysis leading to multisubstituted 1,4-pyrazines and Mn(III)-catalyzed photochemical reaction leading to pyrroles.

    Science.gov (United States)

    Sajna, K V; Kumara Swamy, K C

    2012-10-05

    Thermolysis of phosphorus-based vinyl azides under solvent- and catalyst-free conditions furnished a new route for 1,4-pyrazines. A simple one-pot, Mn(III)-catalyzed photochemical route has been developed for multisubstituted pyrroles starting from allenes and 1,3-dicarbonyls via in situ-generated vinyl azides. The utility of new phosphorus-based pyrroles is also demonstrated in the Horner reaction. The structures of key products are unequivocally confirmed by X-ray crystallography.

  2. Synthesis and characterization of polypyrrole grafted chitin

    Science.gov (United States)

    Ramaprasad, A. T.; Latha, D.; Rao, Vijayalakshmi

    2017-05-01

    Synthesis and characterization of chitin grafted with polypyrrole (PPy) is reported in this paper. Chitin is soaked in pyrrole solution of various concentrations for different time intervals and polymerized using ammonium peroxy disulphate (APS) as an initiator. Grafting percentage of polypyrrole onto chitin is calculated from weight of chitin before and after grafting. Grafting of polymer is further verified by dissolution studies. The grafted polymer samples are characterized by FTIR, UV-Vis absorption spectrum, XRD, DSC, TGA, AFM, SEM and conductivity studies.

  3. Comparative Analysis of the Antineoplastic Activity of C60 Fullerene with 5-Fluorouracil and Pyrrole Derivative In Vivo

    Science.gov (United States)

    Lynchak, O. V.; Prylutskyy, Yu I.; Rybalchenko, V. K.; Kyzyma, O. A.; Soloviov, D.; Kostjukov, V. V.; Evstigneev, M. P.; Ritter, U.; Scharff, P.

    2017-01-01

    The antitumor activity of pristine C60 fullerene aqueous solution (C60FAS) compared to 5-fluorouracil (5-FU) and pyrrole derivative 1-(4-Cl-benzyl)-3-Cl-4-(CF3-fenylamino)-1H-pyrrol-2.5-dione (MI-1) cytostatic drugs was investigated and analyzed in detail using the model of colorectal cancer induced by 1.2-dimethylhydrazine (DMH) in rats. The number, size, and location of the tumors were measured, and the pathology was examined. It was found that the number of tumors and total lesion area decreased significantly under the action of C60FAS and MI-1. Because these drugs have different mechanisms of action, their simultaneous administration can potentially increase the effectiveness and significantly reduce the side effects of antitumor therapy.

  4. Ethyl 5-cyano-4-[2-(2,4-dichlorophenoxyacetamido]-1-phenyl-1H-pyrrole-3-carboxylate

    Directory of Open Access Journals (Sweden)

    Jing Xu

    2009-08-01

    Full Text Available In the title compound, C22H17Cl2N3O4, the pyrrole ring and the 2,4-dichlorophenyl group form a dihedral angle of 8.14 (13°; the phenyl ring is twisted with respect to the pyrrole ring, forming a dihedral angle of 60.77 (14°. The C=O bond length is 1.213 (3 Å, indicating that the molecule is in the keto form, associated with a –CONH– group, and the amide group adopts the usual trans conformation. The molecule is stabilized by an intramolecular N—H...O hydrogen-bonding interaction. In the crystal, the stacked molecules exhibit intermolecular C—H...O and C—H...N hydrogen-bonding interactions.

  5. CHANGES OF STRUCTURE AND PROPERTIES OF POLY (ETHYLENE TEREPHTHALATE)CAUSED BY IN-SITU POLYMERIZATION OF PYRROLE

    Institute of Scientific and Technical Information of China (English)

    HE Jiasong; FENG Zhihai

    1991-01-01

    Conductive polymer composites based on crystalline polymer matrix have been prepared by using an in-situ polymerization process of pyrrole in amorphous poly (ethylene terephthalate) (PET) film.The DSC and WAXD measurement and SEM observation show that liquid-induced crystallization of PET matrix has occurred during the preparation of composite films. Depending upon the equilibrium degree of swelling and crystallinity, the limited depth of penetration of pyrrole molecules results in a skin-core structure of the composite film. The skin layer containing charge transfer intercalated polypyrrole has a surface resistance of 3.5 × 104 Ω. Rigid and heat-resistant polypyrrole molecules formed in PET film increase the tensile modulus and, especially, the rigidity of PET at elevated temperatures. However, they decrease the tensile strength and elongation at break, and impair the thermal ductility of PET.

  6. Green Synthesis of Ag and Pd Nanospheres, Nanowires, and Nanorods Using Vitamin B2: Catalytic Polymerisation of Aniline and Pyrrole

    Directory of Open Access Journals (Sweden)

    Mallikarjuna N. Nadagouda

    2008-01-01

    Full Text Available For the first time, we report green chemistry approach using vitamin B2 in the synthesis of silver (Ag and palladium (Pd, nanospheres, nanowires, and nanorods at room temperature without using any harmful reducing agents, such as sodium borohydride (NaBH4 or hydroxylamine hydrochloride and any special capping or dispersing agent. Vitamin B2 was used as reducing agent as well as capping agent due to its high-water solubility, biodegradability, and low-toxicity compared with other reducing agents. The average particle size of nanoprticle was found to be Ag (average size 6.1±0.1 nm and Pd (average size 4.1±0.1 nm nanoparticles in ethylene glycol and Ag (average size 5.9±0.1 nm, and average size 6.1±0.1 nanoparticles in acetic acid and NMP, respectively. The formation of noble multiple shape nanostructures and their self assembly were dependent on the solvent employed for the preparation. When water was used as solvent media, Ag and Pd nanoparticles started to self-assemble into rod-like structures and in isopropanol Ag and Pd nanoparticles yielded wire-like structures with a thickness in the range of 10 to 20 nm and several hundred microns in length. In acetone and acetonitrile medium, the Ag and Pd nanoparticles are self-assembled into a regular pattern making nanorod structures with thicknesses ranging from 100 to 200 nm and lengths of a few microns. The so-synthesized nanostructures were characterized using scanning electron microscopy (SEM, transmission electron microscopy (TEM, energy dispersive X-ray (EDX analysis, and UV spectroscopy. The ensuing Ag and Pd nanoparticles catalyzed the reactions of aniline and pyrrole to generate polyaniline and polypyrrole nanofibers and may find various technological and biological applications. This single-step greener approach is general and can be extended to other noble metals and transition metal oxides.

  7. 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.

  8. Cation-π interaction of the univalent silver cation with meso-octamethylcalix[4]pyrrole: Experimental and theoretical study

    Science.gov (United States)

    Polášek, Miroslav; Kvíčala, Jaroslav; Makrlík, Emanuel; Křížová, Věra; Vaňura, Petr

    2017-02-01

    By using electrospray ionization mass spectrometry (ESI-MS), it was proven experimentally that the univalent silver cation Ag+ forms with meso-octamethylcalix[4]pyrrole (abbrev. 1) the cationic complex species 1·Ag+. Further, applying quantum chemical DFT calculations, four different conformations of the resulting complex 1·Ag+ were derived. It means that under the present experimental conditions, this ligand 1 can be considered as a macrocyclic receptor for the silver cation.

  9. Tetraaryl-, Pentaaryl-, and Hexaaryl-1,4-dihydropyrrolo 3,2-b pyrroles: Synthesis and Optical Properties

    DEFF Research Database (Denmark)

    Krzeszewski, M.; Thorsted, B.; Brewer, J.

    2014-01-01

    examination of various reaction parameters (solvent, acid, temperature) p-toluenesulfonic acid was identified as the crucial catalyst. As a result, 1,4-dihydropyrrolo[3,2-b]pyrroles were obtained in the highest yields reported to date. The scope and limitation studies showed that this new method...... in the near-IR region were surprisingly high (hundreds of GM), given the limited conjugation in these propeller-shaped dyes....

  10. Visible-light-induced formal [3+2] cycloaddition for pyrrole synthesis under metal-free conditions.

    Science.gov (United States)

    Xuan, Jun; Xia, Xu-Dong; Zeng, Ting-Ting; Feng, Zhu-Jia; Chen, Jia-Rong; Lu, Liang-Qiu; Xiao, Wen-Jing

    2014-05-26

    A photocatalytic formal [3+2] cycloaddition of 2H-azirines with alkynes has been achieved under irradiation by visible light in the presence of organic dye photocatalysts. This transformation provides efficient access to highly functionalized pyrroles in good yields and has been applied to the synthesis of drug analogues. A primary trial of photocascade catalysis merging energy transfer and redox neutral reactions was shown to be successful. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Pyrrole PMOs, incorporating new N-heterocyclic compounds on an ethene-PMO through Diels–Alder reactions

    Energy Technology Data Exchange (ETDEWEB)

    Esquivel, Dolores; De Canck, Els [Center for Ordered Materials, Organometallics and Catalysis, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent (Belgium); Jiménez-Sanchidrián, César [Department of Organic Chemistry, Nanochemistry and Fine Chemistry Research Institute (IUIQFN), Faculty of Sciences, University of Córdoba, Campus de Rabanales, Marie Curie Building, Ctra. Nnal. IV, km 396, 14071 Córdoba (Spain); Romero-Salguero, Francisco J., E-mail: qo2rosaf@uco.es [Department of Organic Chemistry, Nanochemistry and Fine Chemistry Research Institute (IUIQFN), Faculty of Sciences, University of Córdoba, Campus de Rabanales, Marie Curie Building, Ctra. Nnal. IV, km 396, 14071 Córdoba (Spain); Van Der Voort, Pascal, E-mail: pascal.vandervoort@ugent.be [Center for Ordered Materials, Organometallics and Catalysis, Department of Inorganic and Physical Chemistry, Ghent University, Krijgslaan 281-S3, 9000 Ghent (Belgium)

    2014-11-14

    The ethenylene bridges on the walls of an ethenylene-bridged periodic mesoporous organosilica were successfully modified with a variety of pyrrole derivatives – pyrrole, methylpyrrole, dimethylpyrrole, trimethylpyrrole and 1-phenylpyrrole – through Diels–Alder reactions. X-ray diffraction measurements and N{sub 2} adsorption–desorption analysis confirmed the preservation of the ordering and mesoporosity of the parent material as well as the decoration of the pores with the surface Diels–Alder adducts. Moreover, other techniques such as DRIFT, {sup 13}C and {sup 29}Si nuclear magnetic resonances revealed the formation of the surface N-heterocyclic compounds at the parent ethenylene sites. - Highlights: • Chemical modification of the double bonds on an ethene-PMO through the Diels–Alder reaction. • A family of pyrrole derivatives act as dienes in the Diels–Alder reaction. • Well-ordering and mesoporosity are retained after the post-functionalization. • N-containing compounds on the surface of ethene-PMO are present after the Diels–Alder reaction.

  12. Synthesis and Crystal Structure of 3-(Pyrrole-2'-carboxamido)propanoic Acid·(1/2)H2O

    Institute of Scientific and Technical Information of China (English)

    ZENG Xiang-Chao; XU Shi-Hai; GU Jian; LIU Po-Run

    2005-01-01

    3-(Pyrrole-2'-carboxamido)propanoic acid I has been synthesized from the reaction of β-alanine methyl ester with 2-trichloroacetylpyrrole followed by saponifying and acidating in 85.4% yield, and the crystal structure of 3-(pyrrole-2'-carboxamido)propanoic acid· (1/2)H2O (C8H11N2O3.5, Mr = 191.19) was obtained and determined by X-ray diffraction method. The crystal is of monoclinic, space group C2/c with a = 19.010(4), b = 8.3515(17), c = 13.788(3) (A), β = 125.88(3)°, V = 1773.6(6) (A)3, Z = 8, Dc = 1.432 g/cm3, λ = 0.71073 (A), μ-MoKα) = 0.114 mm-1 and F(000) = 768. The structure was refined to R = 0.0354 and wR = 0.0942 for 1642 observed reflections with I > 2σ(I). It is revealed that the title compound has one pyrrole ring and one propionic acid subchain linked by an amido bond at C(4), and there are 8 molecules of com- pound I and 4 crystal water molecules in each unit cell. The supramolecular layers are stabilized by the hydrogen bonds of N(2) H…O(2), N(1) H…O(4), O(4) H(1W)…O(2) and O(3) H…O(1).

  13. Aggregation behavior and electrical properties of amphiphilic pyrrole-tailed ionic liquids in water, from the viewpoint of dielectric relaxation spectroscopy.

    Science.gov (United States)

    Fan, Xiaoqing; Zhao, Kongshuang

    2014-05-14

    The self-aggregation behavior of amphiphilic pyrrole-tailed imidazolium ionic liquids (Py(CH₂)₁₂mim⁺Br⁻: Py = pyrrole, mim = methylimidazolium) in water is investigated by dielectric spectroscopy from 40 Hz to 110 MHz. Dielectric determination shows that the critical micelle concentration (CMC) is 8.5 mM, which is lower than that for traditional ionic surfactants. The thermodynamic parameter of the micellization, the Gibbs free energy ΔG, was calculated for Py(CH₂)₁₂mim⁺Br⁻ and compared to those of the corresponding C(n)mim⁺Br⁻ (n = 12, 14). It was found that the main driven forces of the Py(CH₂)₁₂mim⁺Br⁻ aggregation were hydrophobic interaction and π-π interactions among the adjacent Py groups. Further, the structure of aggregation was speculated theoretically that Py groups partially insert into the alkyl chains and the staggered arrangement in micelles is formed. When the concentration of Py(CH₂)₁₂mim⁺Br⁻ is higher than CMC, two remarkable relaxations which originated from diffusion of counterions and interfacial polarization between the micelles and solution, were observed at about 1.3 MHz and 55 MHz. The relaxation parameters representing the real properties of the whole system were obtained by fitting the experimental data with Cole-Cole equation. A dielectric model characterizing the structure and electrical properties of spherical micelles was proposed by which the conductivity, permittivity and the volume fraction of micelles as well as electrical properties of solution were calculated from the relaxation parameters. An intriguingly high permittivity of about 150 for the micelle was found to be a direct consequence of the strong orientational order of water molecules inside the core of micelle, and essentially is attributed to the special structure of the micelle. Furthermore, the calculation of the interfacial electrokinetic parameters of the micelles, i.e., the surface conductivity, surface charge density

  14. Spiroheterocyclization of Methyl 1-Aryl-3-cinnamoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates by the Action of 3-(Arylamino-1H-inden-1-ones

    Directory of Open Access Journals (Sweden)

    Аndrey N. Maslivets

    2012-11-01

    Full Text Available Methyl 1-aryl-3-cinnamoyl-4,5-dioxo-4,5-dihydro-1H-pyrrole-2-carboxylates interact with 3-(arylamino-1H-inden-1-ones to give the corresponding 1,1'-diaryl-3'-cinnamoyl-4'-hydroxy-1H-spiro[indeno[1,2-b]pyrrole-3,2'-pyrrole]-2,4,5'(1'H-triones in good yields.

  15. Synthesis, cytotoxic activity, and tubulin polymerization inhibitory activity of new pyrrol-2(3H)-ones and pyridazin-3(2H)-ones.

    Science.gov (United States)

    Abbas, Samar Hafez; Abuo-Rahma, Gamal El-Din A A; Abdel-Aziz, Mohamed; Aly, Omar M; Beshr, Eman A; Gamal-Eldeen, Amira M

    2016-06-01

    A series of new pyrrol-2(3H)-ones 4a-f and pyridazin-3(2H)-ones 7a-f were synthesized and characterized using different spectroscopic tools. Some of the tested compounds revealed moderate activity against 60 cell lines. The E form of the pyrrolones 4 showed good cytotoxic activity than both the Z form and the corresponding open amide form. Furthermore, the in vitro cytotoxic activity against HepG2 and MCF-7 cell lines revealed that compounds (E)4b, 6f and 7f showed good cytotoxic activity against HepG2 with IC50 values of 11.47, 7.11 and 14.80μM, respectively. Compounds (E)4b, 6f, 7d and 7f showed a pronounced inhibitory effect against cellular localization of tubulin. Flow cytometric analysis indicated that HepG2 cells treated with (E)4b showed a predominated growth arrest at the S-phase compared to that of G2/M-phase. Molecular modeling study using MOE® program indicated that most of the target compounds showed good binding of β-subunit of tubulin with the binding free energy (dG) values about -10kcal/mole.

  16. Palladium complexes of pyrrole-2-aldehyde thiosemicarbazone: Synthesis, structure and spectral properties

    Indian Academy of Sciences (India)

    Piyali Paul; Samaresh Bhattacharya

    2014-09-01

    Reaction of pyrrole-2-aldehyde thiosemicarbazone (abbreviated as H2L, where H2 stands for the two potentially dissociable protons) with [Pd(PPh3)2Cl2] in ethanol in the presence of NEt3 afforded two complexes, [Pd(PPh3)(HLNS)Cl] and [Pd(PPh3)(LNNS)], where the thiosemicarbazone ligand is coordinated to the metal centre respectively as monoanionic N,S-donor (depicted by HLNS) and dianionic N,N,S-donor (depicted by LNNS). Similar reaction with Na2[PdCl4] afforded a bis-complex, [Pd(HLNS)2]. Crystal structures of all the three complexes have been determined.With reference to the structure of the uncoordinated thiosemicarbazone (H2L), the N,S-coordinationmode observed in [Pd(PPh3)(HLNS)Cl] and [Pd(HLNS)2] is associated with a geometrical change around the imine bond.While the N,N,S-mode of binding observed in [Pd(PPh3)(LNNS)] takes place without any such geometrical change. All three complexes display intense absorptions in the visible and ultraviolet regions, which have been analyzed by TDDFT method.

  17. Efficient Synthesis of Peptide and Protein Functionalized Pyrrole-Imidazole Polyamides Using Native Chemical Ligation

    Directory of Open Access Journals (Sweden)

    Brian M. G. Janssen

    2015-06-01

    Full Text Available The advancement of DNA-based bionanotechnology requires efficient strategies to functionalize DNA nanostructures in a specific manner with other biomolecules, most importantly peptides and proteins. Common DNA-functionalization methods rely on laborious and covalent conjugation between DNA and proteins or peptides. Pyrrole-imidazole (Py–Im polyamides, based on natural minor groove DNA-binding small molecules, can bind to DNA in a sequence specific fashion. In this study, we explore the use of Py–Im polyamides for addressing proteins and peptides to DNA in a sequence specific and non-covalent manner. A generic synthetic approach based on native chemical ligation was established that allows efficient conjugation of both peptides and recombinant proteins to Py–Im polyamides. The effect of Py–Im polyamide conjugation on DNA binding was investigated by Surface Plasmon Resonance (SPR. Although the synthesis of different protein-Py–Im-polyamide conjugates was successful, attenuation of DNA affinity was observed, in particular for the protein-Py–Im-polyamide conjugates. The practical use of protein-Py–Im-polyamide conjugates for addressing DNA structures in an orthogonal but non-covalent manner, therefore, remains to be established.

  18. Crystal structures of unsymmetrically mixed β-pyrrole substituted nickel(II)-meso-tetraphenylporphyrins

    Indian Academy of Sciences (India)

    BHYRAPPA PUTTAIAH; VELKANNAN VEERAPANDIAN; SARANGI UJWAL KUMAR

    2016-07-01

    Crystal structures of solvated unsymmetrically substituted meso-tetraphenylporphyrins, 2,3,12,13, 17-pentachloro-5,7,8,10,15,18,20-hepta-phenylporphyrin, H₂TPP(Ph)₃(Cl)₅, 1 and its nickel(II), NiTPP(Ph)₃(Cl)₅, 2 were determined by single crystal XRD analysis. In addition, a new unsymmetricallysubstituted porphyrin, 2,3,12,13,17-pentacyano-5,7,8,10,15,18,20-heptaphenyl-porphinato nickel(II) complex, NiTPP(Ph)₃(CN)₅, 3 complex was synthesized and its solvated structure was examined by crystallography. These porphyrins exhibited dramatic nonplanar conformation of the macrocycle as evidenced from the averagedisplacement of the β-pyrrole carbon (±ΔCβ ) from the mean plane of the porphyrin ring and the trend in nonplanarity varies in the order: 2 (1.189(5) Å) > 1 (1.036(6) Å) > 3 (0.895(6) Å). The normal-coordinate structural decomposition analysis of these structures revealed mainly saddle distortion of the macrocycle combined with small degree of ruffled or domed distortions. The Hirshfeld surface analysis of structures 1-3 revealed solvate dependent intermolecular contacts with varying degree of H. . .H (43–49%), C. . .H (17–19%), H. . .Cl (25–30%) and N. . .H (~19%) contact contributions.

  19. Evaluation of the pyrrole insecticide chlorfenapyr against pyrethroid resistant and susceptible Anopheles funestus (Diptera: Culicidae).

    Science.gov (United States)

    Oliver, S V; Kaiser, M L; Wood, O R; Coetzee, M; Rowland, M; Brooke, B D

    2010-01-01

    To evaluate the pyrrole insecticide chlorfenapyr, which has a novel non-neurotoxic mode of action and is a promising alternative to conventional adulticides, against Anopheles funestus. The toxicity of a range of concentrations of chlorfenapyr against pyrethroid resistant and susceptible laboratory reared southern African An. funestus was assessed using standard WHO protocols and analysed using probit analysis. The pyrethroid resistant strain showed consistently higher LD50 and LD95 values compared to the susceptible strain, but these differences were not statistically significant and the magnitude was twofold at most. The LD50 values recorded for An. funestus are approximately three-fold higher than those reported elsewhere for other species of anopheline. Monooxygenase based pyrethroid resistance in An. funestus does not influence the toxic effect of chlorfenapyr. It is unlikely that such a small decrease in susceptibility of An. funestus to chlorfenapyr relative to other anophelines would have any operational implications. Chlorfenapyr is an important addition to insecticides available for malaria vector control, and could be used as a resistance management tool to either circumvent or slow the development of resistance.

  20. Efficient Synthesis of Peptide and Protein Functionalized Pyrrole-Imidazole Polyamides Using Native Chemical Ligation.

    Science.gov (United States)

    Janssen, Brian M G; van Ommeren, Sven P F I; Merkx, Maarten

    2015-06-04

    The advancement of DNA-based bionanotechnology requires efficient strategies to functionalize DNA nanostructures in a specific manner with other biomolecules, most importantly peptides and proteins. Common DNA-functionalization methods rely on laborious and covalent conjugation between DNA and proteins or peptides. Pyrrole-imidazole (Py-Im) polyamides, based on natural minor groove DNA-binding small molecules, can bind to DNA in a sequence specific fashion. In this study, we explore the use of Py-Im polyamides for addressing proteins and peptides to DNA in a sequence specific and non-covalent manner. A generic synthetic approach based on native chemical ligation was established that allows efficient conjugation of both peptides and recombinant proteins to Py-Im polyamides. The effect of Py-Im polyamide conjugation on DNA binding was investigated by Surface Plasmon Resonance (SPR). Although the synthesis of different protein-Py-Im-polyamide conjugates was successful, attenuation of DNA affinity was observed, in particular for the protein-Py-Im-polyamide conjugates. The practical use of protein-Py-Im-polyamide conjugates for addressing DNA structures in an orthogonal but non-covalent manner, therefore, remains to be established.

  1. Flexible electrochemical capacitors based on polypyrrole/carbon fibers via chemical polymerization of pyrrole vapor

    Science.gov (United States)

    Yuan, Wei; Han, Gaoyi; Xiao, Yaoming; Chang, Yunzhen; Liu, Cuixian; Li, Miaoyu; Li, Yanping; Zhang, Ying

    2016-07-01

    Polypyrrole (PPy) has been deposited on the carbon fibers (CFs) via chemical oxidation of monomer vapor strategy, during which FeCl3·6H2O in acetonitrile adsorbed on CFs acts as oxidant to polymerize the pyrrole vapor. The morphologies and capacitive properties of the PPy deposited on CFs (PPy/CFs) are strongly influenced by the concentration of oxidant used in the process. The assembled flexible capacitors by using PPy/CFs as electrodes and LiCl/polyvinyl alcohol as gel electrolyte have been evaluated by cyclic voltammetry, galvanostatic charge/discharge and electrochemical impedance spectroscopy. The results show that the composites of PPy/CFs prepared by using 350 mg mL-1 FeCl3·6H2O as oxidant (PPy/CFs-350) exhibit relatively higher specific capacitance and good rate capability. Compared with PPy/CFs prepared by electrochemical deposition (retaining 5% of the initial capacitance), the PPy/CFs prepared by chemically polymerizing monomer vapor shows excellent stability (retaining 85% of initial capacitance after 5000 cycles). Furthermore, cells fabricated by PPy/CFs show a fairly good performance under various bending states, three cells of PPy/CFs-350 connected in series can light up a light emitting diode with a voltage threshold of about 2.5 V for approximate 10 min after being charged for about 3 min, revealing the potential of the cells' practical applications.

  2. Molecular design and performance prediction of poly-dinitroamino pyrrole compounds as energetic materials

    Indian Academy of Sciences (India)

    MEI LI; FENG-MIN WU; HANG XU

    2017-01-01

    To identify superior and safe energetic materials, eighteen poly-dinitroamino pyrrole derivatives were studied at the B3LYP/6-311G** level of density functional theory (DFT). The isodesmic reactions were employed to calculate the heats of formation (HOFs) for these compounds. The detonation velocity (D) and pressure (P) were evaluated using the Kamlet-Jacobs equations. Results indicate that –N(NO₂)₂ group is an effective substituent for enhancing the detonation performance since most of the molecules have larger energy density than RDX (1,3,5-trinitro-1,3,5-triazinane), and a few molecules, C1(N-R) - D3(N-R), with D ranging from 8.55 to 9.04 km s−1 and P ranging from 35.53 to 40.36 GPa outperform RDX (D = 8.75 km s⁻¹ and P = 34.00 GPa). The calculated bond dissociation energy (BDE) revealed that the new compounds exhibit good thermal stability and meet the requirements of energetic materials. Besides, the N-NO₂ bond on the side chain was found to be the trigger bond during decomposition. The characteristic height (h₅₀) of the compound was calculated, and thirteen compounds exhibited lower sensitivity than CL-20 (2,4,6,8,10,12-hexanitro-2,4,6,8,10,12-hexaazaisowurtzitane).

  3. Zn(II), Cd(II) and Cu(II) complexes of 2,5-bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrole: synthesis, structures and their high catalytic activity for efficient cyclic carbonate synthesis.

    Science.gov (United States)

    Vignesh Babu, Heeralal; Muralidharan, Krishnamurthi

    2013-01-28

    The syntheses of Zn(II), Cd(II) and Cu(II) complexes of 2,5-bis{N-(2,6-diisopropylphenyl)iminomethyl}pyrrole (DIP(2)pyr)H 1 and their catalytic activities in CO(2) fixation are reported. The structures of these complexes were characterized by IR, (1)H, (13)C NMR and single crystal X-ray diffraction techniques. The catalytic activities of these complexes for the cycloaddition of CO(2) to an epoxide under one atmosphere of pressure and mild temperature conditions to yield cyclic carbonate have been studied. Among the four complexes synthesized, the Zn(II) and Cu(II) complexes were found to be versatile whereas the Cu(II) complex was more selective in the conversion. They were highly effective for the conversion of monosubstituted terminal epoxides, disubstituted terminal and internal epoxides to their corresponding cyclic carbonates with good to high yields.

  4. Evaluation of the pyrrole insecticide chlorfenapyr for the control of Culex quinquefasciatus Say.

    Science.gov (United States)

    Raghavendra, K; Barik, T K; Bhatt, R M; Srivastava, H C; Sreehari, U; Dash, A P

    2011-04-01

    Culex quinquefasciatus Say (Diptera: Culicidae) is a widely distributed mosquito vector species in India and also in other tropical regions of the world. This species is implicated in the transmission of lymphatic filariasis in many countries. This species is reported to be widely resistant to insecticides of different classes in current use. In the present study, bio-efficacy of chlorfenapyr, an insecticide of pyrrole class with a novel mode of action was tested for the control of Cx. quinquefasciatus. Studies were performed to determine the diagnostic dosage; residual efficacy on different artificially fabricated substrates, namely wood, mud, mud+lime, cement and cement+distemper; to assess cross-resistance with different insecticides; and synergism/antagonism using piperonyl butoxide (PBO). A dosage of 5.0% chlorfenapyr was determined as diagnostic dosage with 2 h exposure and 48 h holding period for assessing the susceptibility of mosquitoes. The residual efficacy was observed up to 34 weeks on wood and mud+lime substrates while on other substrates, it was about 15 weeks at a dosage of 400mg a.i./m(2). Laboratory-reared strains of Cx. quinquefasciatus showed cross-resistance, whereas field-collected mosquitoes showed absence of cross-resistance to chlorfenapyr. Potentiation bioassays showed antagonistic effect of PBO to chlorfenapyr toxicity owing to the involvement of oxidases in the initial step of a conversion of pro-insecticide chlorfenapyr to toxic form CL 303268. The present study results have shown that chlorfenapyr can be a potential insecticide for the control of multiple insecticide resistant strains of Cx. quinquefasciatus. However, in countries where indoor residual spray (IRS) is not targeted for the control of this species, like in India, chlorfenapyr used in IRS for the control of malaria vectors in rural and peri-urban areas can additionally provide control of Cx. quinquefasciatus also. Copyright © 2011 Elsevier B.V. All rights reserved.

  5. 2-(ω-Carboxyethyl)pyrrole Antibody as a New Inhibitor of Tumor Angiogenesis and Growth.

    Science.gov (United States)

    Wu, Chunying; Wang, Xizhen; Tomko, Nicholas; Zhu, Junqing; Wang, William R; Zhu, Jinle; Wang, Yanming; Salomon, Robert G

    2016-09-22

    Angiogenesis is a fundamental process in the progression, invasion, and metastasis of tumors. Therapeutic drugs such as bevacizumab and ranibuzumab have thus been developed to inhibit vascular endothelial growth factor (VEFG)-promoted angiogenesis. While these anti-angiogenic drugs have been commonly used in the treatment of cancer, patients often develop significant resistance that limits the efficacy of anti-VEGF therapies to a short period of time. This is in part due to the fact that an independent pathway of angiogenesis exists, which is mediated by 2-(ω-carboxyethyl)pyrrole (CEP) in a TLR2 receptor-dependent manner that can compensate for inhibition of the VEGF-mediated pathway. In this work, we evaluated a CEP antibody as a new tumor growth inhibitor that blocks CEP-induced angiogenesis. We first evaluated the effectiveness of a CEP antibody as a monotherapy to impede tumor growth in two human tumor xenograft models. We then determined the synergistic effects of bevacizumab and CEP antibody in a combination therapy, which demonstrated that blocking of the CEP-mediated pathway significantly enhanced the anti-angiogenic efficacy of bevacizumab in tumor growth inhibition indicating that CEP antibody is a promising chemotherapeutic drug. To facilitate potential translational studies of CEP-antibody, we also conducted longitudinal imaging studies and identified that FMISO-PET is a non-invasive imaging tool that can be used to quantitatively monitor the anti-angiogenic effects of CEP-antibody in the clinical setting. That treatment with CEP antibody induces hypoxia in tumor tissue was indicated by 43% higher uptake of [18F]FMISO in CEP antibody-treated tumor xenografs than in the control PBS-treated littermates.

  6. 7-glutathione pyrrole adduct: a potential DNA reactive metabolite of pyrrolizidine alkaloids.

    Science.gov (United States)

    Xia, Qingsu; Ma, Liang; He, Xiaobo; Cai, Lining; Fu, Peter P

    2015-04-20

    Pyrrolizidine alkaloid (PA)-containing plants are the most common poisonous plants affecting livestock, wildlife, and humans. PAs require metabolic activation to form pyrrolic metabolites to exert cytotoxicity and tumorigenicity. We previously determined that metabolism of tumorigenic PAs produced four DNA adducts, designated as DHP-dG-3, DHP-dG-4, DHP-dA-3, and DHP-dA-4, that are responsible for liver tumor initiation. 7-Glutathione-(±)-6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine (7-GS-DHP), formed in vivo and in vitro, and 7,9-di-GS-DHP, formed in vitro, are both considered detoxified metabolites. However, in this study we determined that incubation of 7-GS-DHP with 2'-deoxyguanosine (dG) and 2'-deoxyadenosine (dA) yields DHP-dG-3, DHP-dG-4, DHP-dA-3, and DHP-dA-4 adducts as well as the reactive metabolite DHP. Furthermore, reaction of 7-GS-DHP with calf thymus DNA in aqueous solution at 37 °C for 4, 8, 16, 24, 48, or 72 h, followed by enzymatic hydrolysis yielded DHP-dG-3, DHP-dG-4, DHP-dA-3, and DHP-dA-4 adducts. Under our current experimental conditions, DHP-dA-3 and DHP-dA-4 adducts were formed in a trace amount from the reaction of 7,9-di-GS-DHP with dA. No DHP-dG-3 or DHP-dG-4 adducts were detected from the reaction of 7,9-di-GS-DHP with dG. This study represents the first report that the 7-GS-DHP adduct can be a potential reactive metabolite of PAs leading to DNA adduct formation.

  7. Morphological and physicochemical properties of dip-coated poly {(2,5-diyl pyrrole) [4-nitrobenzylidène]} (PPNB) thin films: towards photovoltaic applications

    Science.gov (United States)

    Mouchaal, Younes; Gherrass, Hamou; Bendoukha Reguig, Abdelkarim; Hachemaoui, Aïcha; Yahiaoui, Ahmed; Makha, Mohamed; Khelil, Abdelbacet; Bernede, Jean-Christian

    2015-02-01

    A new material: conjugated poly {(2,5-diyl pyrrole) [4-nitrobenzylidène]}, that we called (PPNB), has been synthesized and characterized. The cyclic voltammetry has been used in order to estimate first oxidation (Ep) and reduction (En) potentials of our polymer. These values have been assigned, respectively, to the position of the highest occupied molecular orbital (HOMO) and the lowest unoccupied molecular orbital (LUMO) and determination of the energy band gap which have been estimated to be 6.16, 3.89 and 2.27 eV respectively. Energy levels values of the HOMO and LUMO of the PPNB polymeric donor material were evaluated and the results are compatible with an electron transfer to C60 within an eventual junction, such values show that PPNB could be probed for applications in organic solar cells as donor material. PPNB Thin films have been deposited by dip-coating technique from Dichloromethane solvent with different polymer concentrations, and a dipping speed of 3.0 cm/min. For morphological characterization of the films scanning electron microscopy (SEM) was carried out. The samples, when observed by SEM, reveals that the films deposited are less dense, uniform. Cross-sectional SEM micrographs PPNB films show that thickness of the layers is homogeneous and has value of 35-40 nm. Optical characteristics of the polymer thin films were studied using UV-vis spectroscopy; absorption of wide range of wavelengths from 350 to 700 nm was observed. The optical band gap energy ranges between 1.9 eV and 1.94 eV. Based on these analyzes we realized heterojunction organic solar cells with the structure: ITO/Au/PPNB/C60/BCP/Al, the cells had a photovoltaique effect after J-V measuring, however the efficiency of photo generation under AM1.5 illumination was weak (about 0.02%) and needs to be improved.

  8. Synthesis and characterization of acetic acid and ethanoic acid (based)-maleimide

    Science.gov (United States)

    Poad, Siti Nashwa Mohd; Hassan, Nurul Izzaty; Hassan, Nur Hasyareeda

    2016-11-01

    A new route to the synthesis of maleimide is described. 2-(2,5-dioxo-2,5-dihydro-1H-pyrrol-1-yl)acetic acid maleimide (1) and 2-(4-(2,5-Dioxo-2,5-dihydro- 1H-pyrrol-1-yl)phenyl)ethanoic acid maleimide (2) have been synthesized by the reaction of maleic anhydride with glycine and 4-aminophenyl acetic aicd. Maleimide (1) was synthesized by conventional technique while maleimide (2) was synthesized by microwave method. The compounds were characterized using FT-Infrared (FT-IR), 1H and 13C Nuclear Magnetic Resonance (NMR) spectroscopies and Mass Spectrometry.

  9. Synthesis and antiproliferative activity of 2,5-bis(3'-indolyl)pyrroles, analogues of the marine alkaloid nortopsentin.

    Science.gov (United States)

    Carbone, Anna; Parrino, Barbara; Barraja, Paola; Spanò, Virginia; Cirrincione, Girolamo; Diana, Patrizia; Maier, Armin; Kelter, Gerhard; Fiebig, Heinz-Herbert

    2013-03-01

    2,5-bis(3'-Indolyl)pyrroles, analogues of the marine alkaloid nortopsentin, were conveniently prepared through a three step procedure in good overall yields. Derivatives 1a and 1b exhibited concentration-dependent antitumor activity towards a panel of 42 human tumor cell lines with mean IC50 values of 1.54 μM and 0.67 μM, respectively. Investigating human tumor xenografts in an ex-vivo clonogenic assay revealed selective antitumor activity, whereas sensitive tumor models were scattered among various tumor histotypes.

  10. Synthesis and Antiproliferative Activity of 2,5-bis(3′-Indolyl)pyrroles, Analogues of the Marine Alkaloid Nortopsentin

    Science.gov (United States)

    Carbone, Anna; Parrino, Barbara; Barraja, Paola; Spanò, Virginia; Cirrincione, Girolamo; Diana, Patrizia; Maier, Armin; Kelter, Gerhard; Fiebig, Heinz-Herbert

    2013-01-01

    2,5-bis(3′-Indolyl)pyrroles, analogues of the marine alkaloid nortopsentin, were conveniently prepared through a three step procedure in good overall yields. Derivatives 1a and 1b exhibited concentration-dependent antitumor activity towards a panel of 42 human tumor cell lines with mean IC50 values of 1.54 μM and 0.67 μM, respectively. Investigating human tumor xenografts in an ex-vivo clonogenic assay revealed selective antitumor activity, whereas sensitive tumor models were scattered among various tumor histotypes. PMID:23455514

  11. A Hydrogen Peroxide Sensor Prepared by Electropolymerization of Pyrrole Based on Screen-Printed Carbon Paste Electrodes

    OpenAIRE

    Hui Xu; You Wang; Guang Li

    2007-01-01

    A disposable amperometric biosensor for commercial use to detect hydrogen peroxide has been developed. The sensor is based on screen-printed carbon paste electrodes modified by electropolymerization of pyrrole with horseradish peroxidase (HRP) entrapped. The facture techniques of fabricating the enzyme electrodes are suitable for mass production and quality control. The biosensor shows a linear amperometric response to H2O2 from 0.1 to 2.0 mM, with a sensitivity of 33.24 µA mM-1 cm-2. Differe...

  12. A Hydrogen Peroxide Sensor Prepared by Electropolymerization of Pyrrole Based on Screen-Printed Carbon Paste Electrodes

    Directory of Open Access Journals (Sweden)

    Hui Xu

    2007-03-01

    Full Text Available A disposable amperometric biosensor for commercial use to detect hydrogenperoxide has been developed. The sensor is based on screen-printed carbon paste electrodesmodified by electropolymerization of pyrrole with horseradish peroxidase (HRP entrapped.The facture techniques of fabricating the enzyme electrodes are suitable for mass productionand quality control. The biosensor shows a linear amperometric response to H2O2 from 0.1to 2.0 mM, with a sensitivity of 33.24 μA mM-1 cm-2. Different operational parameters ofelectropolymerization are evaluated and optimized.

  13. Electropolymerization of pyrrole: effects of pH and anions on the conductivity and growth kinetics of polypyrrole

    Energy Technology Data Exchange (ETDEWEB)

    Kupila, E.L. (Dept. of Chemistry, Univ. of Turku (Finland)); Kankare, J. (Dept. of Chemistry, Univ. of Turku (Finland))

    1993-03-22

    Polypyrrole is one of the most studied conducting polymers. In situ AC conductimetry during electropolymerization is a method which allows the specific conductivity to be estimated for the polymer in statu nascendi. We have applied this method to the electropolymerization of pyrrole in aqueous solutions at various conditions. Polymers synthesized at lower pH range are of better quality than those synthesized at higher pH values. The use of small anions in the supporting electrolyte results in a layer of low conductivity at pH 7. The use of long-chain organic anions like sodium dodecylsulfate gives a high quality polymer even in neutral unbuffered solutions. (orig.)

  14. Theoretical Study on Structure and Electronic Properties of 2, 5-Bis [4-N, N-Diethylaminostyryl] Thiophene and Its Furan and Pyrrole Derivatives Using Density Functional Theory (Dft

    Directory of Open Access Journals (Sweden)

    *B. Semire

    2012-12-01

    Full Text Available Theoretical calculations using Density Functional Theory (DFT were performed on 2,5-bis[4-N,N-diethylaminostyryl]thiophene and its furan and pyrrole derivatives The energy band gaps calculated at B3LYP/6-31G(d level for thiophene derivatives are lower than that of furan and pyrrole analogues. The absorption λmax calculated using DFT was shifted to longer wavelength by replacement of R = CH3 by C2H5 for all studied molecules. The geometries and electronic properties of the compounds were also studied.

  15. 2-(5-Bromo-1H-indol-3-yl-4-(4-bromophenyl-5-(4-chlorobenzoyl-1H-pyrrole-3-carbonitrile dimethyl sulfoxide monosolvate

    Directory of Open Access Journals (Sweden)

    Y. AaminaNaaz

    2016-07-01

    Full Text Available In the title solvated compound, C26H14Br2ClN3O·C2H6OS, the indole ring is inclined to the central pyrrole ring by 25.7 (2°. The chlorobenzene ring and the bromobenzene rings subtend dihedral angles of 56.5 (2 and 53.4 (2°, respectively, with the central pyrrole ring. In the crystal, molecules are bridged by N—H...O hydrogen bonds, involving the dimethyl sulfoxide solvent molecule, forming chains along [010]. There are no other significant intermolecular interactions present.

  16. Rhodium and iridium complexes of N-(2'-hydroxyphenyl)pyrrole-2-aldimine: Synthesis, structure, and spectral and electrochemical properties

    Indian Academy of Sciences (India)

    Semanti Basu; Indrani Pal; Ray J Butcher; Georgina Rosair; Samaresh Bhattacharya

    2005-03-01

    Reaction of N-(2'-hydroxyphenyl)pyrrole-2-aldimine (H2L) with [M(PPh3)3Cl] (M = Rh, Ir) affords complexes of type [M(PPh3)2(L)Cl]. Structures of both complexes have been determined by X-ray crystallography. In both complexes, the N-(2'-hydroxyphenyl)pyrrole-2-aldimine ligand is coordinated to the metal centre, via dissociation of the acidic protons, as a dianionic tridentate N,N,O-donor. The M(L)Cl fragment constitutes an equatorial plane with the metal at the centre and the two PPh3 ligands occupying axial positions. The complexes are diamagnetic (low-spin 6, = 0) and show intense MLCT transitions in the visible region. Cyclic voltammetry of the [M(PPh3)2(L)Cl] complexes shows reversible M(III)-M(IV) oxidation near 0.5 V vs SCE and quasi-reversible ligand-centred oxidative response near 1.0 V vs SCE.

  17. Photodissociation of pyrrole-ammonia clusters by velocity map imaging: mechanism for the H-atom transfer reaction.

    Science.gov (United States)

    Rubio-Lago, L; Amaral, G A; Oldani, A N; Rodríguez, J D; González, M G; Pino, G A; Bañares, L

    2011-01-21

    The photodissociation dynamics of pyrrole-ammonia clusters (PyH·(NH(3))(n), n = 2-6) has been studied using a combination of velocity map imaging and non-resonant detection of the NH(4)(NH(3))(n-1) products. The excited state hydrogen-atom transfer mechanism (ESHT) is evidenced through delayed ionization and presents a threshold around 236.6 nm, in agreement with previous reports. A high resolution determination of the kinetic energy distributions (KEDs) of the products reveals slow (∼0.15 eV) and structured distributions for all the ammonia cluster masses studied. The low values of the measured kinetic energy rule out the existence of a long-lived intermediate state, as it has been proposed previously. Instead, a direct N-H bond rupture, in the fashion of the photodissociation of bare pyrrole, is proposed. This assumption is supported by a careful analysis of the structure of the measured KEDs in terms of a discrete vibrational activity of the pyrrolyl co-fragment.

  18. Synthesis and characterization of active ester-functionalized polypyrrole-silica nanoparticles: application to the covalent attachment of proteins.

    Science.gov (United States)

    Azioune, Ammar; Slimane, Amel Ben; Hamou, Lobnat Ait; Pleuvy, Anne; Chehimi, Mohamed M; Perruchot, Christian; Armes, Steven P

    2004-04-13

    Novel ester-functionalized polypyrrole-silica nanocomposite particles were prepared by oxidative copolymerization of pyrrole and N-succinimidyl ester pyrrole (50/50% initial concentrations), using FeCl3 in the presence of ultrafine silica nanoparticles (20 nm diameter). The N-succinimidyl ester pyrrole monomer was prepared in aqueous solution using 1-(2-carboxyethylpyrrole) and N-hydroxysuccinimide in the presence of 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide. The resulting nanocomposites (N-succinimidyl ester polypyrrole-silica) are raspberry-shaped agglomerates of silica sol particles "glued" together by the insoluble poly(pyrrole-co-N-succinimidyl pyrrole). The N-succinimidyl ester polypyrrole-silica particles were characterized in terms of their size, density, copolymer content, and polydispersity. Scanning electron microscopy and disk centrifuge sedimentometry confirmed that the nanocomposite particles had narrow size distributions. X-ray photoelectron spectroscopy analysis indicated a silica-rich surface and a high surface concentration of N-succinimidyl ester groups. These nanoparticles exhibited good long-term dispersion stability. The chemical stability of the ester functions in aqueous media after several weeks of storage was monitored by FTIR spectroscopy. The functionalized nanocomposites were tested as bioadsorbents of human serum albumin (HSA). The very high amount of immobilized HSA determined by UV-visible spectroscopy is believed to be due to covalent binding. Incubation of the HSA-grafted nanocomposite with anti-HSA resulted in immediate flocculation, an indication that they are alternative candidates for visual diagnostic assays.

  19. Radiosynthesis and in vivo evaluation of [{sup 11}C]-labelled pyrrole-2-carboxamide derivates as novel radioligands for PET imaging of monoamine oxidase A

    Energy Technology Data Exchange (ETDEWEB)

    De Bruyne, Sylvie [Laboratory for Radiopharmacy, Ghent University, 9000 Ghent (Belgium); La Regina, Giuseppe [Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Universita di Roma, I-00185 Rome (Italy); Staelens, Steven [IBITECH-Medisip, Ghent University-IBBT, 9000 Ghent (Belgium); Wyffels, Leonie [Laboratory for Radiopharmacy, Ghent University, 9000 Ghent (Belgium); Deleye, Steven [IBITECH-Medisip, Ghent University-IBBT, 9000 Ghent (Belgium); Silvestri, Romano [Istituto Pasteur, Fondazione Cenci Bolognetti, Dipartimento di Chimica e Tecnologie del Farmaco, Sapienza Universita di Roma, I-00185 Rome (Italy); De Vos, Filip [Laboratory for Radiopharmacy, Ghent University, 9000 Ghent (Belgium)], E-mail: filipx.devos@ugent.be

    2010-05-15

    Introduction: Since MAO-A is an enzyme involved in the metabolism of neurotransmitters, fluctuations in MAO-A functionality are associated with psychiatric and neurological disorders as well as with tobacco addiction and behaviour. This study reports the radiolabelling of two [{sup 11}C]-labelled pyrrole-2-carboxamide derivates, RS 2315 and RS 2360, along with the characterization of their in vivo properties. Methods: The radiolabelling of [{sup 11}C]-RS 2315 and [{sup 11}C]-RS 2360 was accomplished by alkylation of their amide precursors with [{sup 11}C]CH{sub 3}I. Biodistribution, blocking and metabolite studies of both tracers were performed in NMRI mice. Finally, a PET study in Sprague-Dawley rats was performed for [{sup 11}C]-RS 2360. Results: Both tracers were obtained in a radiochemical yield of approximately 30% with radiochemical purity of >98%. Biodistribution studies showed high brain uptake followed by rapid brain clearance for both radiotracers. In the brain, [{sup 11}C]-RS 2360 was more stable than [{sup 11}C]-RS 2315. Blocking studies in mice could not demonstrate specificity of [{sup 11}C]-RS 2315 towards MAO-A or MAO-B. The blocking and imaging study with [{sup 11}C]-RS 2360 on the other hand indicated specific binding in MAO-A at the earliest time points. Conclusions: [{sup 11}C]-RS 2315 displayed a high nonspecific binding and is therefore not suitable for visualization of MAO-A in vivo. [{sup 11}C]-RS 2360 on the other hand has potential for mapping MAO-A since specific binding is demonstrated.

  20. Flow synthesis using gaseous ammonia in a Teflon AF-2400 tube-in-tube reactor: Paal-Knorr pyrrole formation and gas concentration measurement by inline flow titration.

    Science.gov (United States)

    Cranwell, Philippa B; O'Brien, Matthew; Browne, Duncan L; Koos, Peter; Polyzos, Anastasios; Peña-López, Miguel; Ley, Steven V

    2012-08-14

    Using a simple and accessible Teflon AF-2400 based tube-in-tube reactor, a series of pyrroles were synthesised in flow using the Paal-Knorr reaction of 1,4-diketones with gaseous ammonia. An inline flow titration technique allowed measurement of the ammonia concentration and its relationship to residence time and temperature.

  1. The Synthesis of Novel 3-Substituted Poly(pyrroles) Bearing Crown-ether Moieties and a Study of their Electrochemical Properties

    DEFF Research Database (Denmark)

    Guernion, Nicolas J.L.; Blencowe, A.; Hayes, Wayne;

    2006-01-01

    A series of fourteen novel pyrrole monomers substituted at the 3-position with aliphatic and aromatic crown-ether moieties have been synthesised in good yield and characterised extensively. Several of those compounds were electropolymerised successfully in acetonitrile, using both potentiostatic ...

  2. Thieno[3,4-c]pyrrole-4,6-dione-3,4-difluorothiophene Polymer Acceptors for Efficient All-Polymer Bulk Heterojunction Solar Cells

    KAUST Repository

    Liu, Shengjian

    2016-09-16

    Branched-alkyl-substituted poly(thieno[3,4-c]pyrrole-4,6-dione-alt-3,4-difluorothiophene) (PTPD[2F]T) can be used as a polymer acceptor in bulk heterojunction (BHJ) solar cells with a low-band-gap polymer donor (PCE10) commonly used with fullerenes. The

  3. Reconciling Experiment and Theory in the Use of Aryl-Extended Calix[4]pyrrole Receptors for the Experimental Quantification of Chloride–π Interactions in Solution

    Directory of Open Access Journals (Sweden)

    Antonio Bauzá

    2015-04-01

    Full Text Available In this manuscript we consider from a theoretical point of view the recently reported experimental quantification of anion–π interactions (the attractive force between electron deficient aromatic rings and anions in solution using aryl extended calix[4]pyrrole receptors as model systems. Experimentally, two series of calix[4]pyrrole receptors functionalized, respectively, with two and four aryl rings at the meso positions, were used to assess the strength of chloride–π interactions in acetonitrile solution. As a result of these studies the contribution of each individual chloride–π interaction was quantified to be very small (<1 kcal/mol. This result is in contrast with the values derived from most theoretical calculations. Herein we report a theoretical study using high-level density functional theory (DFT calculations that provides a plausible explanation for the observed disagreement between theory and experiment. The study reveals the existence of molecular interactions between solvent molecules and the aromatic walls of the receptors that strongly modulate the chloride–π interaction. In addition, the obtained theoretical results also suggest that the chloride-calix[4]pyrrole complex used as reference to dissect experimentally the contribution of the chloride–π interactions to the total binding energy for both the two and four-wall aryl-extended calix[4]pyrrole model systems is probably not ideal.

  4. Bis{2-[(2,4,6-trimethyl-phen-yl)imino-methyl]pyrrol-1-ido}palladium(II).

    Science.gov (United States)

    Imhof, Wolfgang

    2013-02-01

    The title compound, [Pd(C(14)H(15)N(2))(2)], is a square-planar palladium complex composed of two deprotonated pyrrole-2-carbaldimine ligands coordinating a central Pd(II) atom. In the crystal, three crystallographically independent complex mol-ecules are observed, one of which is located in a general position, whereas the Pd(II) atoms of the other mol-ecules are situated on crystallographic inversion centers. The aromatic substituents at the imine N atoms in the three mol-ecules show dihedral angles of 87.6 (7)/83.64 (7), 74.3 (7) and 88.3 (7)° with respect to the corresponding PdN(4) plane.

  5. Acylguanidine inhibitors of beta-secretase: optimization of the pyrrole ring substituents extending into the S1' substrate binding pocket.

    Science.gov (United States)

    Jennings, Lee D; Cole, Derek C; Stock, Joseph R; Sukhdeo, Mohani N; Ellingboe, John W; Cowling, Rebecca; Jin, Guixian; Manas, Eric S; Fan, Kristi Y; Malamas, Michael S; Harrison, Boyd L; Jacobsen, Steve; Chopra, Rajiv; Lohse, Peter A; Moore, William J; O'Donnell, Mary-Margaret; Hu, Yun; Robichaud, Albert J; Turner, M James; Wagner, Erik; Bard, Jonathan

    2008-01-15

    The proteolytic enzyme beta-secretase (BACE-1) produces amyloid beta (Abeta) peptide, the primary constituent of neurofibrillary plaques, implicated in Alzheimer's disease, by cleavage of the amyloid precursor protein. A small molecule inhibitor of BACE-1, (diaminomethylene)-2,5-diphenyl-1H-pyrrole-1-acetamide (1, BACE-1 IC(50)=3.7 microM), was recently described, representing a new small molecule lead. Initial SAR investigation demonstrated the potential of accessing the nearby S(3) and S(1)(') substrate binding pockets of the BACE-1 enzyme by building substituents off one of the phenyl substituents and guanidinyl functional group. We report here the optimization of guanidinyl functional group substituents on 1, leading to potent submicromolar BACE-1 inhibitors.

  6. Non-radiative relaxation dynamics of pyrrole following excitation in the range 249.5-200 nm

    Science.gov (United States)

    Kirkby, Oliver M.; Parkes, Michael A.; Neville, Simon P.; Worth, Graham A.; Fielding, Helen H.

    2017-09-01

    The non-radiative relaxation dynamics of pyrrole have been investigated using time-resolved photoelectron spectroscopy and quantum dynamics simulations. Following excitation of the A2 (11 πσ∗) state, we observe population flow out of the Franck-Condon region on a ≲ 50 fs timescale. Following excitation of the B2 (21 ππ∗) state, we observe population being transferred to the A2 (11 πσ∗) state on a <50 fs timescale and subsequently out of the Franck-Condon region, also on a <50 fs timescale. Quantum dynamics calculations suggest that population is transferred from the B2 (21 ππ∗) state through the A2 (1 π 3pz) state to the B1 (21 πσ∗) state before being transferred to the A2 (11 πσ∗) state.

  7. Large area in situ fabrication of poly(pyrrole)-nanowires on flexible thermoplastic films using nanocontact printing

    Science.gov (United States)

    Garcia-Cruz, Alvaro; Lee, Michael; Marote, Pedro; Zine, Nadia; Sigaud, Monique; Bonhomme, Anne; Pruna, Raquel; Lopez, Manuel; Bausells, Joan; Jaffrezic, Nicole; Errachid, Abdelhamid

    2016-08-01

    Highly efficient nano-engineering tools will certainly revolutionize the biomedical and sensing devices research and development in the years to come. Here, we present a novel high performance conducting poly(pyrrole) nanowires (PPy-NW) patterning technology on thermoplastic surfaces (poly(ethylene terephthalate (PETE), poly(ethylene 2,6-naphthalate (PEN), polyimide (PI), and cyclic olefin copolymer) using nanocontact printing and controlled chemical polymerization (nCP-CCP) technique. The technique uses a commercial compact disk as a template to produce nanopatterned polydimethylsiloxane (PDMS) stamps. The PDMS nanopatterned stamp was applied to print the PPy-NWs and the developed technology of nCP-CCP produced 3D conducting nanostructures. This new and very promising nanopatterning technology was achieved in a single step and with a low cost of fabrication over large areas.

  8. Multichromic conducting copolymer of 1-benzyl-2,5-di(thiophen-2-yl)-1H-pyrrole with EDOT

    Energy Technology Data Exchange (ETDEWEB)

    Camurlu, Pinar [Department of Chemistry, Akdeniz University, 07058 Antalya (Turkey); Tarkuc, Simge; Akhmedov, idris Mecidoglu; Tanyeli, Cihangir; Toppare, Levent [Department of Chemistry, Middle East Technical University, 06531 Ankara (Turkey); Sahmetlioglu, Ertugrul [Department of Chemistry, Nigde University, 51100 Nigde (Turkey)

    2008-02-15

    Despite the significant progress made in the field of electrochromic polymers, the multichromic facility of current knowledge is restricted. Therefore, as previously proven, electrochemical copolymerization of 1-benzyl-2,5-di(thiophen-2-yl)-1H-pyrrole (SNBS) and 3,4-ethylenedioxythiophene (EDOT) was used as a strategy to achieve desired multichromic properties, where the resultant copolymer displayed distinct color changes between claret red, yellow, green, and blue colors with short switching times and high optical contrast. As an application, absorption/transmission type electrochromic device with indium tin oxide (ITO)/copolymer/gel electrolyte PEDOT/ITO configuration was constructed, where copolymer and PEDOT functioned as the anodically and the cathodically coloring layers, respectively. Results implied the successive use of this copolymer in electrochromic device applications, since the device exhibited short switching times with a wide color variation upon applied potential. (author)

  9. From indole to pyrrole, furan, thiophene and pyridine: Search for novel small molecule inhibitors of bacterial transcription initiation complex formation.

    Science.gov (United States)

    Thach, Oscar; Mielczarek, Marcin; Ma, Cong; Kutty, Samuel K; Yang, Xiao; Black, David StC; Griffith, Renate; Lewis, Peter J; Kumar, Naresh

    2016-03-15

    The search for small molecules capable of inhibiting transcription initiation in bacteria has resulted in the synthesis of N,N'-disubstituted hydrazines and imine-carbohydrazides comprised of indole, pyridine, pyrrole, furan and thiophene using the respective trichloroacetyl derivatives, carbohydrazides and aldehydes. Replacement of the indole moiety by smaller heterocycles linked by CONHNC linkers afforded a broad variety of compounds efficiently targeting the RNA polymerase-σ(70)/σ(A) interaction as determined by ELISA and exhibiting increased inhibition of the growth of Escherichia coli compared to Bacillus subtilis in culture. The structural features of the synthesized transcription initiation inhibitors needed for antibacterial activity were identified employing molecular modelling and structure-activity relationship (SAR) studies.

  10. Excited state non-adiabatic dynamics of pyrrole: A time-resolved photoelectron spectroscopy and quantum dynamics study

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Guorong [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); State Key Laboratory of Molecular Reaction Dynamics, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Dalian, Liaoning 116023 (China); Synergetic Innovation Center of Quantum Information and Quantum Physics, University of Science and Technology of China, Hefei, Anhui 230026 (China); Neville, Simon P.; Worth, Graham A., E-mail: g.a.worth@bham.ac.uk [School of Chemistry, University of Birmingham, Edgbaston, Birmingham B15 2TT (United Kingdom); Schalk, Oliver [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Department of Physics, AlbaNova University Center, Stockholm University, Roslagstullsbacken 21, 109 61 Stockholm (Sweden); Sekikawa, Taro [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Department of Applied Physics, Hokkaido University, Kita-13 Nishi-8, Kita-ku, Sapporo 060-8628 (Japan); Ashfold, Michael N. R. [School of Chemistry, University of Bristol, Bristol BS8 1TS (United Kingdom); Stolow, Albert, E-mail: astolow@uottawa.ca [National Research Council of Canada, 100 Sussex Drive, Ottawa, Ontario K1A 0R6 (Canada); Departments of Chemistry and Physics, University of Ottawa, 10 Marie Curie, Ottawa, Ontario K1N 6N5 (Canada)

    2015-02-21

    The dynamics of pyrrole excited at wavelengths in the range 242-217 nm are studied using a combination of time-resolved photoelectron spectroscopy and wavepacket propagations performed using the multi-configurational time-dependent Hartree method. Excitation close to the origin of pyrrole’s electronic spectrum, at 242 and 236 nm, is found to result in an ultrafast decay of the system from the ionization window on a single timescale of less than 20 fs. This behaviour is explained fully by assuming the system to be excited to the A{sub 2}(πσ{sup ∗}) state, in accord with previous experimental and theoretical studies. Excitation at shorter wavelengths has previously been assumed to result predominantly in population of the bright A{sub 1}(ππ{sup ∗}) and B{sub 2}(ππ{sup ∗}) states. We here present time-resolved photoelectron spectra at a pump wavelength of 217 nm alongside detailed quantum dynamics calculations that, together with a recent reinterpretation of pyrrole’s electronic spectrum [S. P. Neville and G. A. Worth, J. Chem. Phys. 140, 034317 (2014)], suggest that population of the B{sub 1}(πσ{sup ∗}) state (hitherto assumed to be optically dark) may occur directly when pyrrole is excited at energies in the near UV part of its electronic spectrum. The B{sub 1}(πσ{sup ∗}) state is found to decay on a timescale of less than 20 fs by both N-H dissociation and internal conversion to the A{sub 2}(πσ{sup ∗}) state.

  11. Post Hartree–Fock and DFT Studies on Pyrrole···Nitrogen and Pyrrole···Carbon Monoxide Molecules

    Directory of Open Access Journals (Sweden)

    P. Kolandaivel

    2002-07-01

    Full Text Available Abstract: The hydrogen bonded and van der Waals isomers of pyrrole···nitrogen and pyrrole···carbon monoxide have been studied using ab initio and density functional theory methods. Complex geometries and total energies of the isomers have been determined at HF, MP2, B3LYP and B3PW91 levels of theory employing 6-31G* basis set. For pyrrole···nitrogen complex, only two isomers have stable structure and the more stable one is found to be the hydrogen bonded isomer. Among the five isomers of pyrrole···carbon monoxide complex, the hydrogen bonded isomer is found to be the most stable form. The interaction energy for all these isomers have been calculated after eliminating the basis set superposition errors by using the full counterpoise correction method. Chemical hardness, chemical potential have been calculated and are used to study the stability of the molecules.

  12. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2015. Scientific Opinion on Flavouring Group Evaluation 77, Revision 2 (FGE.77Rev2): Consideration of Pyridine, Pyrrole and Quinoline Derivatives evaluated by JECFA (63rd meeting) structurally related, to Pyridine, Pyrrole, Indole and Quinoline Derivatives evaluated by EFSA in FGE.24Rev2 (2013)

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Nørby, Karin Kristiane

    evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The present consideration concerns a group of 22 pyridine, pyrrole and quinoline derivatives evaluated by JECFA (63rd meeting). The revision of this consideration is made since additional toxicity data have become available...

  13. Deproto-metallation of N-arylated pyrroles and indoles using a mixed lithium–zinc base and regioselectivity-computed CH acidity relationship

    Directory of Open Access Journals (Sweden)

    Mohamed Yacine Ameur Messaoud

    2015-08-01

    Full Text Available The synthesis of N-arylated pyrroles and indoles is documented, as well as their functionalization by deprotonative metallation using the base in situ prepared from LiTMP and ZnCl2·TMEDA (1/3 equiv. With N-phenylpyrrole and -indole, the reactions were carried out in hexane containing TMEDA which regioselectively afforded the 2-iodo derivatives after subsequent iodolysis. With pyrroles and indoles bearing N-substituents such as 2-thienyl, 3-pyridyl, 4-methoxyphenyl and 4-bromophenyl, the reactions all took place on the substituent, at the position either adjacent to the heteroatom (S, N or ortho to the heteroatom-containing substituent (OMe, Br. The CH acidities of the substrates were determined in THF solution using the DFT B3LYP method in order to rationalize the experimental results.

  14. Silica sulfuric acid: a reusable solid catalyst for one pot synthesis of densely substituted pyrrole-fused isocoumarins under solvent-free conditions

    Directory of Open Access Journals (Sweden)

    Sudipta Pathak

    2013-11-01

    Full Text Available A convenient and efficient methodology for the synthesis of densely substituted pyrrole-fused isocoumarins, which employs solid-supported silica sulfuric acid (SSA as catalyst, has been developed. When the mixture of ninhydrin adducts of acetylacetone/ethyl acetoacetate and primary amines was heated on the solid surface of SSA under solvent-free conditions, the pyrrole-fused isocoumarins were formed in good yields. This synthetic method has several advantages such as the employment of solvent-free reaction conditions without the use of any toxic reagents and metal catalysts, the ease of product isolation, the use of a recyclable catalyst, the low cost, the easy availability of the starting materials, and the excellent yields of products.

  15. Electrochemical dechlorination of chloroform in neutral aqueous solution on palladium/foam-nickel and palladium/polymeric pyrrole film/foam-nickel electrodes

    Institute of Scientific and Technical Information of China (English)

    SUN Zhirong; LI Baohua; HU Xiang; SHI Min; HOU Qingnan; PENG Yongzhen

    2008-01-01

    Electrochemical dechlonnafion of chloroform in neutral aqueous solution was investigated using palladium-loaded electrodes at ambient temperature.Palladium/foam-nickel (Pd/foam-Ni) and palladium/polymeric pyrrole film/foam-nickel (Pd/PPy/foam-Ni)composite electrodes which provided catalytic surface for reductive dechiorination of chloroform in aqueous solution were prepared using an electrodepositing method.Scanning electron microscope (SEM) micrographs showed that polymeric pyrrole film modified the electrode-surface characteristics and resulted in the uniform dispersion of needle-shaped palladium particles on foam-Ni supporting electrode.The experimental results of dechlorination indicated that the removal efficiency of chloroform and current efficiency in neutral aqueous solution on Pd/PPy/foam-Ni electrode could be up to 36.8% and 33.0% at dechlorination current of 0.1 mA and dechlorination time of 180 rain,which is much higher than that of Pd/foam-Ni electrode.

  16. Synthesis and phototoxicity of isomeric 7,9-diglutathione pyrrole adducts: Formation of reactive oxygen species and induction of lipid peroxidation

    Directory of Open Access Journals (Sweden)

    Liang Ma

    2015-09-01

    Full Text Available Pyrrolizidine alkaloids (PAs are hepatotoxic, genotoxic, and carcinogenic in experimental animals. Because of their widespread distribution in the world, PA-containing plants are probably the most common poisonous plants affecting livestock, wildlife, and humans. Upon metabolism, PAs generate reactive dehydro-PAs and other pyrrolic metabolites that lead to toxicity. Dehydro-PAs are known to react with glutathione (GSH to form 7-GSH-(+/−-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (7-GS-DHP in vivo and in vitro and 7,9-diGS-DHP in vitro. To date, the phototoxicity of GS-DHP adducts has not been well studied. In this study, we synthesized 7-GS-DHP, a tentatively assigned 9-GS-DHP, and two enantiomeric 7,9-diGS-DHP adducts by reaction of dehydromonocrotaline with GSH. The two 7,9-diGS-DHPs were separated by high performance liquid chromatography (HPLC and their structures were characterized by 1H nuclear magnetic resonance (NMR and 1H–1H correlation spectroscopy (COSY NMR spectral analysis. Photoirradiation of 7-GS-DHP, 9-GS-DHP, and the two 7,9-diGS-DHPs as well as dehydromonocrotaline, dehydroheliotrine, and the 7-R enantiomer of DHP (DHR, by UVA light at 0 J/cm2, 14 J/cm2, and 35 J/cm2 in the presence of a lipid, methyl linoleate, all resulted in lipid peroxidation in a light dose-responsive manner. The levels of lipid peroxidation induced by the two isomeric 7,9-diGS-DHPs were significantly higher than that by 7-GS-DHP and 9-GS-DHP. When 7,9-diGS-DHP was irradiated in the presence of sodium azide (NaN3, the level of lipid peroxidation decreased; lipid peroxidation was enhanced when methanol was replaced by deuterated methanol. These results suggest that singlet oxygen is a product induced by the irradiation of 7,9-diGS-DHP. When irradiated in the presence of superoxide dismutase (SOD, the level of lipid peroxidation decreased, indicating that lipid peroxidation is also mediated by superoxide. These results indicate that lipid

  17. Complete dechlorination of 2,4-dichlorophenol in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel composite electrode

    Energy Technology Data Exchange (ETDEWEB)

    Sun, Zhirong, E-mail: zrsun@bjut.edu.cn [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Wei, Xuefeng; Han, Yanbo; Tong, Shan [College of Environmental and Energy Engineering, Beijing University of Technology, Beijing 100124 (China); Hu, Xiang, E-mail: huxiang99@163.com [College of Chemical Engineering, Beijing University of Chemical Technology, Beijing 100029 (China)

    2013-01-15

    Highlights: ► Pd/PPy-CTAB/foam-Ni electrode with high surface area and low Pd content was prepared. ► The composite electrode was applied to dechlorination of 2,4-DCP in aqueous solution. ► Complete dechlorination of 2,4-DCP was achieved with higher current efficiency. ► Removal efficiency kept 100% after 10 times dechlorination on the stable electrode. ► The electrochemically reductive activation energy was 25.8 kJ mol{sup −1} in this system. -- Abstract: The electrochemically reductive dechlorination of 2,4-dichlorophenol (2,4-DCP) in aqueous solution on palladium/polymeric pyrrole-cetyl trimethyl ammonium bromide/foam-nickel electrode (Pd/PPy-CTAB/foam-Ni electrode) was investigated in this paper. Pd/PPy-CTAB/foam-Ni electrode was prepared and characterized by cyclic voltammetry (CV), scanning electron microscope (SEM), X-ray diffraction (XRD), Brunauer–Emmett–Teller (BET) adsorption and inductively coupled plasma-atomic emission spectroscopy (ICP-AES). The influences of some experimental factors such as the dechlorination current, dechlorination time and the initial pH on the removal efficiency and the current efficiency of 2,4-DCP dechlorination on Pd/PPy-CTAB/foam-Ni electrode were studied. Complete removal of 2,4-DCP was achieved and the current efficiency of 47.4% could be obtained under the conditions of the initial pH of 2.2, the dechlorination current of 5 mA and the dechlorination time of 50 min when the initial 2,4-DCP concentration was 100 mg L{sup −1}. The analysis of high performance liquid chromatography (HPLC) identified that the intermediate products were 2-chlorophenol (2-CP) and 4-chlorophenol (4-CP). The final products were mainly phenol. Its further reduction product cyclohexanone was also detected. The electrocatalytic dechlorination pathways of 2,4-DCP on Pd/PPy-CTAB/foam-Ni electrode were discussed. The stability of the electrode was favorable that it could keep dechlorination efficiency at 100% after having been reused

  18. Trimethoxybenzene- and trimethylbenzene-based compounds bearing imidazole, indole and pyrrole groups as recognition units: synthesis and evaluation of the binding properties towards carbohydrates.

    Science.gov (United States)

    Rosien, Jan-Ruven; Seichter, Wilhelm; Mazik, Monika

    2013-10-14

    The aim of the study was to evaluate the potential of trimethoxybenzene- and trimethylbenzene-based compounds bearing imidazole or indole groups as recognition sites in the complexation of carbohydrates. Representatives of these compounds were prepared and their binding properties toward selected carbohydrates evaluated. The results of the binding studies were compared with those obtained for the prepared pyrrole bearing analogues and for the previously described triethylbenzene-based receptors.

  19. The activity of the pyrrole insecticide chlorfenapyr in mosquito bioassay: towards a more rational testing and screening of non-neurotoxic insecticides for malaria vector control

    OpenAIRE

    Oxborough, RM; N'Guessan, R.; Jones, R.; Kitau, J; Ngufor, C; Malone, D; Mosha, FW; Rowland, MW

    2015-01-01

    Background\\ud The rapid selection of pyrethroid resistance throughout sub-Saharan Africa is a serious threat to malaria vector control. Chlorfenapyr is a pyrrole insecticide which shows no cross resistance to insecticide classes normally used for vector control and is effective on mosquito nets under experimental hut conditions. Unlike neurotoxic insecticides, chlorfenapyr owes its toxicity to disruption of metabolic pathways in mitochondria that enable cellular respiration. A series of exper...

  20. A Convenient Method for the Preparation of 1,5-Diaryl-3-(arylamino)-I H-pyrrol-2(5 H)-ones

    Institute of Scientific and Technical Information of China (English)

    Ghashang, Majid; Shaterian, Hamid Reza~

    2011-01-01

    A simple and eco-friendly method for the preparation of 1,5-diaryl-3-(arylamino)-lH-pyrrol-2(5H)-ones via the cyclo-condensation reaction of aldehydes, amines and ethyl pyruvate in the presence of silica supported ferric chlo- ride (SiO2-FeCl3) as reusable heterogeneous catalyst is described. The present methodology offers several advantages such as excellent yields, simple procedure and short reaction times.

  1. Synthesis and Charge Transport Properties of Polymers Derived from Oxidation of 1-H-1’(6-pyrrol-1-yl)-hexyl-4,4’-bipyridinium

    Science.gov (United States)

    1988-08-15

    platinized poly(3- methylthiophene),7b a viologen /quinone polymer, 9 ferrocyanide-loaded protonated poly(4-vinylpyridine),l 0 and electroactive metal oxides...article describes the synthesis and electrochemical properties of redox polymers, having a poly- pyrrole backbone and viologen subunits, derived from...study aspects of the charge transport behavior of the viologen redox system. Poly(P-V-Me2 ) and poly(P-V-H2+ ) have been used to investigate the

  2. Synthese des ABCD-Ringsystems und absolute Stereochemie des Pyrrol-Imidazol-Alkaloids Palau'amin aus dem Meeresschwamm Stylotella aurantium

    OpenAIRE

    Jacquot, Delphine

    2003-01-01

    Die Pyrrol-Imidazol-Alkaloide bilden eine Familie von etwa 90 Naturstoffen, die ausschliesslich aus Meeresschwämmen isoliert worden sind. Eine wichtige Untergruppe bilden die cyclischen Monomeren des Oroidins (14). Zu diesen gehört das in Phakellia mauritiana gefundene, cytotoxische Dibromphakellstatin (20), welches eine grosse Herausforderung an den Synthetiker repräsentiert. Die Struktur weist ein gespanntes tetracyclisches System mit benachbarten tertiären und quaternären stereogenen Zentr...

  3. 2,2′,5,5′-Tetramethyl-1,1′-(hexane-1,6-diyldi-1H-pyrrole

    Directory of Open Access Journals (Sweden)

    Ana C. Santos

    2009-07-01

    Full Text Available The molecule of the title compound, C18H28N2, composed of two 2,5-dimethylpyrrole groups linked by a hexane chain, lies across a crystallographic inversion centre. The mean plane of the pyrrole ring is almost perpendicular to the mean plane of the central chain, making a dihedral angle of 89.09 (8°. The crystal structure is stabilized by intermolecular C—H...π interactions.

  4. Antitumor Activity of a 5-Hydroxy-1H-Pyrrol-2-(5H-One-Based Synthetic Small Molecule In Vitro and In Vivo.

    Directory of Open Access Journals (Sweden)

    Yunyun Geng

    Full Text Available Alternative chemo-reagents are in great demand because chemotherapy resistance is one of the major challenges in current cancer treatment. 5-hydoxy-1H-pyrrol-2-(5H-one is an important N-heterocyclic scaffold that is present in natural products and medicinal chemistry. However, its antitumor activity has not been systematically explored. In this study, we screened a panel of 5-hydoxy-1H-pyrrol-2-(5H-one derivatives and identified compound 1d as possessing strong anti-proliferative activity in multiple cancer cell lines. Cell cycle analysis revealed that 1d can induce S-phase cell cycle arrest and that HCT116 was sensitive to 1d-induced apoptosis. Further analysis indicated that 1d preferentially induced DNA damage and p53 activation in HCT116 cells and that 1d-induced apoptosis is partly dependent on p53. Furthermore, we showed that 1d significantly suppressed tumor growth in xenograft tumor models in vivo. Taken together, our results suggest that 5-hydoxy-1H-pyrrol-2-(5H-one derivatives bear potential antitumor activity and that 1d is an effective agent for cancer treatment.

  5. Synthesis and antitumor activity of duocarmycin derivatives: modification at C-8 position of A-ring pyrrole compounds bearing the simplified DNA-binding groups.

    Science.gov (United States)

    Amishiro, N; Nagamura, S; Murakata, C; Okamoto, A; Kobayashi, E; Asada, M; Gomi, K; Tamaoki, T; Okabe, M; Yamaguchi, N; Yamaguchi, K; Saito, H

    2000-02-01

    A series of the 8-O-substituted A-ring pyrrole derivatives of duocarmycin bearing the simplified DNA-binding moieties such as cinnamoyl or heteroarylacryloyl groups were synthesized, and evaluated for in vitro anticellular activity against HeLa S3 cells and in vivo antitumor activity against murine sarcoma 180 in mice. In addition, the stability of the 8-O-substituted analogues in aqueous solution and the conversion to their active form (cyclopropane compound) from the 8-O-substituted analogues in mice or human serum were examined. The 8-O-substituted A-ring pyrrole derivatives bearing the simplified DNA-binding moieties showed remarkably potent in vivo antitumor activity and low peripheral blood toxicity compared with the 8-O-substituted A-ring pyrrole derivatives having the trimethoxyindole skeleton in segment-B (Seg-B), which were equal to 8-O-[(N-methylpiperazinyl)carbonyl] derivatives of 4'-methoxycinnamates and 4'-methoxy-beta-heteroarylacrylates. Moreover, among 8-O-substituted analogues, several compounds can be chemically or enzymatically converted to their active form in human serum. This result indicated that new 8-O-substituted derivatives were different prodrugs from KW-2189 and 8-O-substituted analogues being the same type of prodrug as KW-2189.

  6. 5-Benzoyl-2-(5-bromo-1H-indol-3-yl-4-(4-methoxyphenyl-1H-pyrrole-3-carbonitrile

    Directory of Open Access Journals (Sweden)

    G. Vimala

    2016-05-01

    Full Text Available In the title compound, C27H18BrN3O, the indole and central pyrrole ring systems are inclined to one another by 13.15 (15°. The carbonitrile group is almost coplanar with its attached pyrrole ring, the C[triple-bond]N bond making a dihedral angle of 1.9 (2° with the ring plane. The 4-methoxybenzene ring and the benzoyl ring are inclined to the central pyrrole ring by 55.1 (2 and 51.5 (2°, respectively. The dihedral angle between these two benzene rings is 37.68 (17°. In the crystal, molecules are linked by pairs of N—H...N hydrogen bonds, forming inversion dimers with an R22(16 ring motif. The dimers are linked by offset π–π interactions [intercentroid distance = 3.614 (2 Å], which leads to the formation of chains propagating in the [010] direction.

  7. Antimycobacterial, antimicrobial activity, experimental (FT-IR, FT-Raman, NMR, UV-Vis, DSC) and DFT (transition state, chemical reactivity, NBO, NLO) studies on pyrrole-isonicotinyl hydrazine.

    Science.gov (United States)

    Rawat, Poonam; Singh, R N; Ranjan, Alok; Ahmad, Sartaj; Saxena, Rajat

    2017-05-15

    As part of a study of pyrrole hydrazone, we have investigated quantum chemical calculations, molecular geometry, relative energy, vibrational properties and antimycobacterial/antimicrobial activity of pyrrole-2-carboxaldehyde isonicotinyl hydrazone (PCINH), by applying the density functional theory (DFT) and Hartree Fock (HF). Good reproduction of experimental values is obtained and with small percentage error in majority of the cases in comparison to theoretical result (DFT). The experimental FT-IR and Raman wavenumbers were compared with the respective theoretical values obtained from DFT calculations and found to agree well. In crystal structure studies the hydrated PCINH (syn-syn conformer) shows different conformation than from anhydrous form (syn-anti conformer). The rotational barrier between syn-syn and syn-anti conformers of PCINH is 12.7kcal/mol in the gas phase. In this work, use of FT-IR, FT-Raman, (1)H NMR, (13)C NMR and UV-Vis spectroscopies has been made for full characterization of PCINH. A detailed interpretation of the vibrational spectrum was carried out with the aid of normal coordinate analysis using single scaling factor. Our results support the hydrogen bonding pattern proposed by reported crystalline structure. The calculated nature of electronic transitions within molecule found to be π→π*. The electronic descriptors study indicates that PCINH can be used as robust synthon for synthesis of new heterocyclic compounds. The first static hyperpolarizability (β0) of PCINH is calculated as 33.89×10(-30)esu, (gas phase); 68.79×10(-30) (CHCl3), esu; 76.76×10(-30)esu (CH2Cl2), 85.16×10(-30)esu (DMSO). The solvent induced effects on the first static hyperpolarizability were studied and found to increase as dielectric constants of the solvents increases. Investigated molecule shows better NLO value than Para nitroaniline (PNA). The compound PCINH shows good antifungal and antibacterial activity against Aspergillus niger and gram

  8. Preparation of thin {alpha}-particle sources using poly-pyrrole films functionalized by a chelating agent; Preparation de sources minces d'emetteurs alpha a l'aide de films de polypyrrole fonctionnalises par un ligand chelatant

    Energy Technology Data Exchange (ETDEWEB)

    Mariet, C. [CEA Saclay, INSTN, Institut National des Sciences et Techniques Nucleaires, 91 - Gif-sur-Yvette (France); Universite Pierre et Marie Curie, 75 - Paris (France)

    2000-07-01

    This work takes place in the scope of analysis of the {alpha}-particle emitting elements U, Pu and Am present in compound environmental matrix like sols and sediments. The samples diversity and above all the {alpha}-ray characteristics require the analyst to implement a sequence of chemical steps in which the more restricting is the actinides concentration in a uniform and thin layer en allowing an accurately measure of alpha activity. On this account, we studied a new technique for radioactive sources preparation based on tow steps: preparation of a thin film as source support; incorporation of radioactive elements by a chelating extraction mechanism. The thin films were obtained through electro-polymerization of pyrrole monomer functionalized by an chelating ligand able to extract actinides from concentrated acidic solutions. Polymerization conditions of this monomer were perfected, then obtained films were characterized from a physico-chemical point of view. We point out their extracting properties were comparable to (retention capacity, distribution coefficient) to those of usual ion-exchange resins. The underscore of uranyl and americium nitrate complexes formed in the thin layer allowed to calculate the extraction constants in case acid extraction is negligible. Thanks to this results, the values of the coefficients distribution D{sub U} and D{sub Am} could be provided for all nitric solutions in which acid extraction is negligible. Optimal actinides retention conditions in the polymer were defined and used to settle a protocol for plutonium analysis in environmental samples. (author)

  9. Quantitation of Pyrrole-Imidazole Polyamide in Rat Plasma by High-Performance Liquid Chromatography Coupled with UV Detection

    Directory of Open Access Journals (Sweden)

    Tomonori Kamei

    2012-01-01

    Full Text Available A simple and robust method using high-performance liquid chromatography with UV detection was developed and validated for the determination of six pyrrole-imidazole (PI polyamides (HN.49, TGF-β1f, TGF-β1t, HN.50f, HN.50t, and LOX-1 in rat plasma. After the plasma proteins were precipitated with methanol containing phenacetin as an internal standard, the analytes were separated on a Luna C18 (2 (5 μm, 4.6×150 mm. Calibration curves were linear over the range of 0.5 to 200 μg/mL for HN.49, 0.25 to 200 μg/mL for TGF-β1f, TGF-β1t, HN.50t, and LOX-1, 1 to 200 μg/mL for HN.50f in rat plasma. The inter- and intraday precision were below 15%, and the accuracy was within 15% at the quality controls. The validated method was successfully applied to sample analysis for the pharmacokinetic study.

  10. Effect of non-electroactive additives on the early stage pyrrole electropolymerization on indium tin oxide electrodes

    Energy Technology Data Exchange (ETDEWEB)

    Castro-Beltran, A. [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Ave. Pedro de Alba s/n, Ciudad Universitaria, C.P. 66451 San Nicolás de los Garza, N.L. (Mexico); Centro de Innovación Investigación y Desarrollo en Ingeniería y Tecnología (CIIDIT), Universidad Autónoma de Nuevo León, PIIT-Monterrey C.P. 66600 Apodaca, N.L. (Mexico); Dominguez, C.; Bahena-Uribe, D. [Centro Investigación en Ingeniería y Ciencias Aplicadas (CIICAp), Universidad Autónoma del Estado de Morelos, Av. Universidad 1001, Col. Chamilpa, C.P. 62209 Cuernavaca, Mor. (Mexico); Sepulveda-Guzman, S., E-mail: selene.sepulvedagz@uanl.edu.mx [Facultad de Ingeniería Mecánica y Eléctrica, Universidad Autónoma de Nuevo León, Ave. Pedro de Alba s/n, Ciudad Universitaria, C.P. 66451 San Nicolás de los Garza, N.L. (Mexico); Centro de Innovación Investigación y Desarrollo en Ingeniería y Tecnología (CIIDIT), Universidad Autónoma de Nuevo León, PIIT-Monterrey C.P. 66600 Apodaca, N.L. (Mexico); Cruz-Silva, R. [Research Center for Exotic NanoCarbon, Shinshu University, 4-17-1 Wakasato, Nagano 380-8553 (Japan)

    2014-09-01

    The use of non-electroactive additives during electrodeposition of conducting polymers has long been used to modify the properties of deposited films. These additives can improve the adhesion, and not only change the morphology and deposition rate but also modify the chemical composition of the electrodeposited polymer. Several compounds have been used to modify deposition of polypyrrole; however, there is no systematic study of these compounds. In this work, we comparatively studied several water soluble chemical compounds, a cationic polymer, an anionic polymer, a cationic surfactant, and an anionic surfactant during potentiostatic electrodeposition of polypyrrole. In order to study the effect of these compounds on the interface, where the electrochemical polymerization takes place, we used electrochemical impedance spectroscopy. The morphology during the initial stage of growth was studied by atomic force microscopy, whereas the resulting polypyrrole films were observed by scanning electron microscopy. - Highlights: • Early-stage polymerization polypyrrole particles on indium tin oxide (ITO). • Anionic additives promote pyrrole oxidation and polypyrrole film growth on ITO. • Cationic polyelectrolyte promotes adhesion between ITO and polypyrrole film. • Non-electroactive additives strongly influence polypyrrole nucleation on ITO.

  11. Electropolymerization of pyrrole and immobilization of glucose oxidase in a flow system: influence of the operating conditions on analytical performance.

    Science.gov (United States)

    Vidal, J C; Garcia, E; Castillo, J R

    1998-03-01

    The in situ potentiostatic electropolymerization of pyrrole (Py) on a Pt electrode in a thin-layer amperometric cell and the entrapment of the enzyme glucose oxidase (GOx) for the determination of glucose are reported. Polypyrrole (PPy) is directly formed by continuous passage of a buffered solution of the monomer (0.4 M) and enzyme (250 U mL-1) at pH 7 at a flow rate of 0.05-0.1 mL min-1 under a constant applied potential of +0.85 V vs Ag/AgCl decreases. The electrosynthesis of PPy by injection of 500 microL of a Py + GOx solution in a carrier electrolyte consisting of 0.05 M phosphate buffer and 0.1 M KCl at pH 7.0 was also assayed. The influence of the electropolymerization conditions on the analytical response of the sensor to glucose was investigated. The analytical performance of the PPy/GOx sensor was also studied in terms of durability and storage life, as well as selectivity against electroactive species such as ascorbic acid and uric acid as a function of the thickness of the polymer film formed.

  12. Sub-10 nm Platinum Nanocrystals with Size and Shape Control: Catalytic Study for Ethylene and Pyrrole Hydrogenation

    Energy Technology Data Exchange (ETDEWEB)

    Tsung, Chia-Kuang; Kuhn, John N.; Huang, Wenyu; Aliaga, Cesar; Hung, Ling-I; Somorjai, Gabor A.; Yang, Peidong

    2009-03-02

    Platinum nanocubes and nanopolyhedra with tunable size from 5 to 9 nm were synthesized by controlling the reducing rate of metal precursor ions in a one-pot polyol synthesis. A two-stage process is proposed for the simultaneous control of size and shape. In the first stage, the oxidation state of the metal ion precursors determined the nucleation rate and consequently the number of nuclei. The reaction temperature controlled the shape in the second stage by regulation of the growth kinetics. These well-defined nanocrystals were loaded into MCF-17 mesoporous silica for examination of catalytic properties. Pt loadings and dispersions of the supported catalysts were determined by elemental analysis (ICP-MS) and H2 chemisorption isotherms, respectively. Ethylene hydrogenation rates over the Pt nanocrystals were independent of both size and shape and comparable to Pt single crystals. For pyrrole hydrogenation, the nanocubes enhanced ring-opening ability and thus showed a higher selectivity to n-butylamine as compared to nanopolyhedra.

  13. Maleimides (1 H-pyrrole-2,5-diones) as molecular indicators of anoxygenic photosynthesis in ancient water columns

    Science.gov (United States)

    Grice, Kliti; Gibbison, Robert; Atkinson, Jane E.; Schwark, Lorenz; Eckardt, Christian B.; Maxwell, James R.

    1996-10-01

    Maleimides (1 H-pyrrole-2,5-diones), degradation products of photosynthetic tetrapyrrole pigments, have been found for the first time in the polar fraction of the solvent extracts of two marine sediments deposited in restricted basins: Kupferschiefer (Permian) and Serpiano shale (Mid-Triassic). GC and GC—MS analyses of the TBDMS ( tertiary-butyldimethylsilyl) derivatives show a simple component distribution, dominated by Me Et maleimide, mainly of planktonic origin; Me n-Pr and Me i-Bu maleimides, present in low abundance, are thought on structural grounds to be derived from the bacteriochlorophylls c, d, or e of Chlorobiaceae (anoxygenic green sulfur bacteria). This is confirmed for Kupferschiefer by isotope ratio monitoring (irm) GCMS which shows them to be enriched in 13C as a result of their photosynthetic carbon assimilation, which takes place by the reversed tricarboxylic acid (TCA) cycle. The structurally more specific Me i-Bu maleimide is, however, slightly more enriched in 13C than Me n-Pr maleimide, suggesting that the latter is derived in part from reduction of the C 3-acid substituent at C-17 of phytoplanktonic chlorophyll. These results provide evidence for the existence in both depositional settings of microbial communities containing Chlorobiaceae. In turn, this indicates that there must have been periods when the water column was highly stratified and anoxia extended into the zone of light penetration.

  14. Synthesis of 1-((4-methoxyphenyl-3-alkynes-1H-pyrrole-2,5-diones and functionalization to tria

    Directory of Open Access Journals (Sweden)

    Bakhat Ali

    2017-05-01

    Full Text Available A series of alkynyl maleimides were prepared via one-step cross-coupling reaction using bromomaleimide and acetylenes under the Sonogashira conditions, affording 1-((4-methoxyphenyl-3-alkynes-1H-pyrrole-2,5-diones in good to high yields. These products were subsequently converted in the corresponding 1,2,3-triazole using conventional click chemistry approach. The alkynyl maleimide compound (8g crystallized in the triclinic space group P1 with unit cell parameters a = 5.3692(6, b = 9.2513(10, c = 10.3070(11 Å, α = 85.349(4, β = 86.892(4, γ = 86.892(4°, V = 507.31(10 Å3, and Z = 1. In the crystal the molecules are stacked parallel to the c axis and held together through a C–H⋯π and a C–H⋯O interaction.

  15. Study of the Pyrrol/Diphenylamine Copolymer by FT-IR spectroscopy and conductivity

    Directory of Open Access Journals (Sweden)

    Carlos Alberto Perez

    2004-01-01

    Full Text Available The main goal of this study was to analyze the physical properties of the copolymer formed by the electrochemical deposition of the polydiphenylamine (PDPA on polypyrrole (Ppy and Ppy on PDPA, in different conditions, through the characterization of the materials formed by the resonant Raman, FT-IR and conductivity techniques. The interactions among the species which are present in the new copolymer structure and the changes in electronic conductivity, were verified. The copolymer was also synthesized electrochemically in the presence of iodide species and the material was characterized by FT-IR spectroscopy and conductivity. The role of the dopant was studied in the process of charge transfer between the copolymer-dopant, acting in the stabilization of the species in the polymer backbone and the increase of the electronic conductivity.

  16. Pyrrole Hydrogenation over Rh(111) and Pt(111) Single-Crystal Surfaces and Hydrogenation Promotion Mediated by 1-Methylpyrrole: A Kinetic and Sum-Frequency Generation Vibrational Spectroscopy Study

    Energy Technology Data Exchange (ETDEWEB)

    Kliewer, Christopher J.; Bieri, Marco; Somorjai, Gabor A.

    2008-03-04

    Sum-frequency generation (SFG) surface vibrational spectroscopy and kinetic measurements using gas chromatography have been used to study the adsorption and hydrogenation of pyrrole over both Pt(111) and Rh(111) single-crystal surfaces at Torr pressures (3 Torr pyrrole, 30 Torr H{sub 2}) to form pyrrolidine and the minor product butylamine. Over Pt(111) at 298 K it was found that pyrrole adsorbs in an upright geometry cleaving the N-H bond to bind through the nitrogen evidenced by SFG data. Over Rh(111) at 298 K pyrrole adsorbs in a tilted geometry relative to the surface through the p-aromatic system. A pyrroline surface reaction intermediate, which was not detected in the gas phase, was seen by SFG during the hydrogenation over both surfaces. Significant enhancement of the reaction rate was achieved over both metal surfaces by adsorbing 1-methylpyrrole before reaction. SFG vibrational spectroscopic results indicate that reaction promotion is achieved by weakening the bonding between the N-containing products and the metal surface because of lateral interactions on the surface between 1-methylpyrrole and the reaction species, reducing the desorption energy of the products. It was found that the ring-opening product butylamine was a reaction poison over both surfaces, but this effect can be minimized by treating the catalyst surfaces with 1-methylpyrrole before reaction. The reaction rate was not enhanced with elevated temperatures, and SFG suggests desorption of pyrrole at elevated temperatures.

  17. Research on interfacial polymerization of pyrrole assist with Span80 system

    Science.gov (United States)

    Yang, Q. H.; Tu, Z. Y.; Zhao, N. Y.

    2016-07-01

    With assistance of surfactants, self-assembled Polypyrrole (PPy) film was prepared via oil / water interfacial polymerization. The chemical structure and morphologies of the obtained samples have been characterized by Fourier transform infrared (FT-IR) and Scanning Electron Microscope (SEM), respectively. The electrochemical performance recorded on an electrochemical workstation, mainly includes cyclic voltammetry (CV) tests. The prepared PPy film has its own extremely vesicular structures from results and indicates by using different concentration surfactant Span80. The PPy film prepared 25 °C with 3.32 g/L Span80 (surpass its critical micelle concentration) as a surfactant possess a supernal specific capacitance of 368.18 F/g at a scan rate 50 mV/s in 1 M NaNO3 aqueous solution at.

  18. Chlorfenapyr: a pyrrole insecticide for the control of pyrethroid or DDT resistant Anopheles gambiae (Diptera: Culicidae) mosquitoes.

    Science.gov (United States)

    N'Guessan, R; Boko, P; Odjo, A; Akogbéto, M; Yates, A; Rowland, M

    2007-04-01

    Owing to the development and spread of pyrethroid resistance in Anopheles gambiae in Africa there is an urgent need to develop alternative insecticides to supplement the pyrethroids. Chlorfenapyr is a pyrrole insecticide first commercialized for the control of agricultural pests and termites. Performance against An. gambiae bearing kdr (pyrethroid and DDT resistance) or Ace-1(R) insensitive acetylcholinesterase (organophosphate and carbamate resistance) mechanisms was studied using a variety of adult bioassay tests including a simulated-experimental hut system (tunnel tests) that allows uninhibited mosquito behaviour/insecticide interactions. Strains resistant to pyrethroids and organophosphates showed no cross resistance to chlorfenapyr. In cone bioassays on treated netting the mortality of adult mosquitoes showed an unexpected curvilinear response, with highest mortality occurring at intermediate dosages. Adults expressed irritability to chlorfenapyr at higher dosages, which might explain the dosage-mortality trend. Toxic activity of chlorfenapyr was slow compared to conventional neurotoxic insecticides and additional mortality occurred between 24h and 72 h. In tunnel tests, the dosage-mortality trend showed a more typical sigmoid response and most mortality occurred during the first 24h. Mosquito penetration through the holed, treated netting showed only limited inhibition and blood-feeding was not inhibited. Mortality rates in the kdr strain exposed to chlorfenapyr treated netting in tunnel tests were much higher than with permethrin treated netting over the same 100-500 mg/m(2) dosage range. Chlorfenapyr has potential for malaria control in treated-net or residual spraying applications in areas where mosquitoes are pyrethroid resistant. For treated-net applications chlorfenapyr might be combined with pyrethroid as a mixture to provide personal protection as well as to give control of resistant mosquitoes.

  19. PTCA (1H-pyrrole-2,3,5-tricarboxylic acid) as a marker for oxidative hair treatment.

    Science.gov (United States)

    Petzel-Witt, Silvana; Meier, Sylvia I; Schubert-Zsilavecz, Manfred; Toennes, Stefan W

    2017-09-20

    Hair analysis for the assessment of alcohol or drug abstinence became a routine procedure in forensic toxicology. Hair coloration leading to loss of incorporated xenobiotics and to false negative results turned out to be a major problem. Currently only colored extracts provide hints of manipulations but not bleaching. A liquid chromatographic-mass spectrometric (LC-MSMS) method was developed and validated to determine 1H-pyrrole-2,3,5-tricarboxylic acid (PTCA), a major oxidation product of melanin. PTCA was determined in natural hair samples (n=21) after treatment with 3% hydrogen peroxide (H2 O2 ) for 30 or 40 min with concentrations up to 12% for 40 min. In another series, 12 natural hair samples were submitted to different coloration procedures (henna, tinting, semi-permanent and permanent dyeing, bleaching) and the changes in PTCA content were determined. A significant increase in the PTCA content was found for both incubation times and increasing H2 O2 concentrations. Coloration with henna or tinting had no influence on PTCA levels detected, but a significant increase was observed after semi-permanent and permanent dyeing and bleaching. As PTCA concentrations in natural hair were found to be in a range of hair. In case of naturally low melanin content (lightblond or white hair), no marked increase in PTCA may occur. The present study demonstrated that PTCA is formed during oxidative treatment of melanin in hair, which can be used to detect previous hair coloration including oxidation. This article is protected by copyright. All rights reserved.

  20. Single-step substitution of all the α, β-positions in pyrrole: choice of binuclear versus multinuclear complex of the novel polydentate ligand.

    Science.gov (United States)

    Ghorai, Debasish; Mani, Ganesan

    2014-04-21

    The α and β-positions of pyrrole were substituted with 3,5-dimethylpyrazolylmethyl groups in a single step that involved the reaction between 2,5-dimethylaminomethylpyrrole and 3,5-dimethylpyrazole-1-carbinol, affording 2,3,4,5-tetrakis(3,5-dimethylpyrazol-1-ylmethyl)pyrrole LH in 40% yield. The coordination chemistry of this new polydentate ligand LH was explored by synthesizing several Pd(II), Cu(I), and Ag(I) complexes. When LH was used as a neutral ligand with [Pd(COD)Cl2], AgBF4, and CuX (X = Cl and I), compartmental type binuclear Pd(II) and Ag(I) complexes such as [Pd2Cl4(μ-C4HN-2,3,4,5-(CH2Me2pz)4-N,N,N,N)] and [Ag2(μ-C4HN-2,3,4,5-(CH2Me2pz)4-N,N,N,N)(CH3CN)2](2+)[BF4(-)]2 and cage-like copper(I) complexes [Cu2(μ-X)(μ-C4HN-2,3,4,5-(CH2Me2pz)4-N,N,N,N)](+)[CuX2](-) (X = Cl and I) containing a halide ion bridging in a bent fashion were obtained, respectively. Conversely, when the same metal precursors were treated with LH in the presence of n-BuLi, the multinuclear complexes [Pd2Cl3(μ-C4N-2,3,4,5-(CH2Me2pz)4-N,N,N,N,N)], [(Cu2(μ-I){μ-C4N-2,3,4,5-(CH2Me2pz)4-N,N,N,N,N})2Cu](+)I(-), and [Ag4(μ-C4N-2,3,4,5-(CH2Me2pz)4-N,N,N,N)2](2+)[BF4(-)]2 were obtained. In addition, the treatment of LH with [Pd(OAc)2] gave the mononuclear complex, [Pd(OAc)(C4N-2,3,4,5-(CH2Me2pz)4-N,N,N)]. The chloride analogue of this complex was obtained by the reaction of LH with [Pd(COD)Cl2] in the presence of triethylamine. The structures of all complexes were determined by single-crystal X-ray diffraction analyses, which revealed interesting structural features, including pyrazole arms adopting different conformations with respect to the pyrrole ring plane and linear two- and three-coordinated copper(I) and silver(I) atoms exhibiting weak interactions between the metal and the pyrrolic carbon atoms and Ag(I)···Ag(I) interactions. The observed shorter metal pyrrolide nitrogen (M-N) bond distances and the elongation of the C-C double and single bond distances of the pyrrole

  1. Synthesis and characterization of dicyanovinyl-substituted thienylpyrroles as new nonlinear optical chromophores.

    Science.gov (United States)

    Raposo, M Manuela M; Sousa, Ana M R C; Kirsch, G; Cardoso, P; Belsley, M; de Matos Gomes, E; Fonseca, A Maurício C

    2006-08-17

    [structure: see text] New dicyanovinyl-substituted 1-(alkyl)aryl-2-(2'-thienyl)pyrroles 2 were synthesized and characterized. The solvatochromic behavior of the synthesized compounds was investigated. All the derivatives showed reversible oxidation and reduction on the CV time scale. The hyperpolarizabilities (beta) of compounds 2 were measured using hyper-Rayleigh scattering. The results are among the highest beta values reported for donor-acceptor-substituted thienylpyrroles.

  2. Structure and spectroscopic properties of N,S-coordinating 2-methylsulfanyl-N-[(1H-pyrrol-2-ylmethylidene]aniline methanol monosolvate

    Directory of Open Access Journals (Sweden)

    D. Douglas Richards

    2015-10-01

    Full Text Available The reaction of pyrrole-2-carboxaldehyde and 2-(methylsulfanylaniline in refluxing methanol gave an olive-green residue in which yellow crystals of the title compound, C12H12N2S·CH3OH, were grown from slow evaporation of methanol at 263 K. In the crystal, hydrogen-bonding interactions link the aniline molecule and a nearby methanol solvent molecule. These units are linked by a pair of weak C—H...Omethanol interactions, forming inversion dimers consisting of two main molecules and two solvent molecules.

  3. 1,2,4-Triazolyl octahydropyrrolo[2,3-b]pyrroles: A new series of potent and selective dopamine D3 receptor antagonists.

    Science.gov (United States)

    Micheli, Fabrizio; Bernardelli, Andrea; Bianchi, Federica; Braggio, Simone; Castelletti, Laura; Cavallini, Palmina; Cavanni, Paolo; Cremonesi, Susanna; Dal Cin, Michele; Feriani, Aldo; Oliosi, Beatrice; Semeraro, Teresa; Tarsi, Luca; Tomelleri, Silvia; Wong, Andrea; Visentini, Filippo; Zonzini, Laura; Heidbreder, Christian

    2016-04-15

    A novel series of 1,2,4-triazolyl octahydropyrrolo[2,3-b]pyrroles showing high affinity and selectivity at the DA D3 receptor is reported here. Compounds endowed with high selectivity over the hERG channel were identified and their pharmacokinetic properties thoroughly analyzed. A few derivatives with appropriate developability characteristics were selected for further studies and progression along the screening cascade. In particular, derivative 60a, (DA D3 pKi=8.4, DA D2 pKi=6.0 and hERG fpKi=5.2) showed a balanced profile and further refinements are in progress around this molecule.

  4. 1,4,10,13-Tetra-oxa-7,16-diazo-nia-cyclo-octa-decane bis-(1H-pyrrole-2-carboxyl-ate).

    Science.gov (United States)

    Zeng, Fanglei; Yin, Zhenming

    2013-01-01

    In the title salt, C12H28N2O4 (2+)·2C5H4NO2 (-), the 1,4,10,13-tetra-oxa-7,16-di-aza-cyclo-octa-decane dication possesses inversion symmetry. In the crystal, the pyrrole-carboxyl-ate anions are linked via pairs of N-H⋯O hydrogen bonds, forming inversion dimers. These dimers are linked by the dications, via N-H⋯O hydrogen bonds, forming chains propagating along [110].

  5. Cobalt(II) Porphyrin-Catalyzed Intramolecular Cyclopropanation of N-Alkyl Indoles/Pyrroles with Alkylcarbene: Efficient Synthesis of Polycyclic N-Heterocycles.

    Science.gov (United States)

    Reddy, Annapureddy Rajasekar; Hao, Fei; Wu, Kai; Zhou, Cong-Ying; Che, Chi-Ming

    2016-01-26

    A protocol on chemoselective cobalt(II) porphyrin-catalyzed intramolecular cyclopropanation of N-alkyl indoles/pyrroles with alkylcarbenes has been developed. The reaction enables the rapid construction of a range of nitrogen-containing polycyclic compounds in moderate to high yields from readily accessible materials. These N-containing polycyclic compounds can be converted into a variety of N-heterocycles with potential synthetic and biological interest. Compared to their N-tosylhydrazone counterparts, the use of bulky N-2,4,6-triisopropylbenzenesulfonyl hydrazones as carbene precursors allows cyclopropanation to occur under milder reaction conditions.

  6. A DFT Study of Pyrrole-Isoxazole Derivatives as Chemosensors for Fluoride Anion

    Directory of Open Access Journals (Sweden)

    Shanshan Tang

    2012-09-01

    Full Text Available The interactions between chemosensors, 3-amino-5-(4,5,6,7-tetrahydro-1H-indol-2-ylisoxazole-4-carboxamide (AIC derivatives, and different anions (F Cl, Br, AcO, and H2PO4 have been theoretically investigated using DFT approaches. It turned out that the unique selectivity of AIC derivatives for F is ascribed to their ability of deprotonating the host sensors. Frontier molecular orbital (FMO analyses have shown that the vertical electronic transitions of absorption and emission for the sensing signals are characterized as intramolecular charge transfer (ICT. The study of substituent effects suggests that all the substituted derivatives are expected to be promising candidates for fluoride chemosensors both in UV-vis and fluorescence spectra except for derivative with benzo[d]thieno[3,2-b]thiophene fragment that can serve as ratiometric fluorescent fluoride chemosensor only.

  7. Initial state-specific photodissociation dynamics of pyrrole via 1 π σ ∗/ S 0 conical intersection initiated with optimally controlled UV-laser pulses

    Science.gov (United States)

    Nandipati, K. R.; Kanakati, Arun Kumar; Singh, H.; Lan, Z.; Mahapatra, S.

    2017-09-01

    Optimal initiation of quantum dynamics of N-H photodissociation of pyrrole on the S 0-1 π σ ∗(1 A 2) coupled electronic states by UV-laser pulses in an effort to guide the subsequent dynamics to dissociation limits is studied theoretically. Specifically, the task of designing optimal laser pulses that act on initial vibrational states of the system for an effective UV-photodissociation is considered by employing optimal control theory. The associated control mechanism(s) for the initial state dependent photodissociation dynamics of pyrrole in the presence of control pulses is examined and discussed in detail. The initial conditions determine implicitly the variation in the dissociation probabilities for the two channels, upon interaction with the field. The optimal pulse corresponds to the objective fixed as maximization of overall reactive flux subject to constraints of reasonable fluence and quantum dynamics. The simple optimal pulses obtained by the use of genetic algorithm based optimization are worth an experimental implementation given the experimental relevance of π σ ∗-photochemistry in recent times.

  8. The partial reduction of electron-deficient pyrroles: procedures describing both Birch (Li/NH3) and ammonia-free (Li/DBB) conditions.

    Science.gov (United States)

    Donohoe, Timothy J; Thomas, Rhian E

    2007-01-01

    The partial reduction of electron-deficient pyrroles using either Birch (Li/NH(3)) or ammonia-free (Li/di-tert-butyl biphenyl) conditions allows formation of pyrroline compounds in good yield and, when combined with a reductive alkylation or similar approach, leads to highly functionalized, synthetically useful compounds. This methodology has been proven in the syntheses of several complex natural products, all of which show interesting biological activity. This protocol describes in detail the following stages of the partial reduction procedure: formation of the reducing solution, partial reduction of the pyrrole compound and finally quench of the resulting anion/dianion using either protonating agents or an aldehyde. The ammonia-free conditions described herein are particularly useful for reactions requiring the use of reactive electrophiles, such as acid chlorides or enolizable aldehydes, which are incompatible with the standard Birch reduction conditions. The reaction procedure for the ammonia Birch reduction (procedure A) takes about 9.5 h to complete. Those described for the ammonia-free reductions, procedure B and procedure C, can be expected to take approximately 33 and 8 h, respectively.

  9. Crystal structure of 4-(2-azidophenyl-5-benzoyl-2-(1H-indol-3-yl-1H-pyrrole-3-carbonitrile

    Directory of Open Access Journals (Sweden)

    G. Vimala

    2015-05-01

    Full Text Available In the title compound, C26H16N6O, the dihedral angles between the central pyrrole ring and the pendant indole ring system (r.m.s. deviation = 0.027 Å and the azide-bearing benzene ring are 37.56 (8 and 51.62 (11°, respectively. The azide group is almost coplanar with its attached benzene ring [C—C—N—N = 3.8 (3°]. The benzoyl benzene ring is disordered over two orientations twisted with respect to each other by 9.29 (8° in a 0.514 (2:0.486 (2 ratio. In the crystal, inversion dimers linked by pairs of Np—H...O (p = pyrrole hydrogen bonds generate R22(10 loops. A second inversion dimer arises from a pair of Ni—H...Nc (i = indole and c = cyanide hydrogen bonds, which generates an R22(16 loop. Together, the hydrogen bonds lead to [011] chains in the crystal.

  10. Sulfur-containing constituents and one 1H-pyrrole-2-carboxylic acid derivative from pineapple [Ananas comosus (L.) Merr.] fruit.

    Science.gov (United States)

    Zheng, Zong-Ping; Ma, Jinyu; Cheng, Ka-Wing; Chao, Jianfei; Zhu, Qin; Chang, Raymond Chuen-Chung; Zhao, Ming; Lin, Zhi-Xiu; Wang, Mingfu

    2010-12-01

    Two sulfur-containing compounds, (S)-2-amino-5-((R)-1-carboxy-2-((E)-3-(4-hydroxy-3-methoxyphenyl)allylthio)ethyl-amino)-5-oxopentanoic acid (1) and (S)-2-amino-5-((R)-1-(carboxymethylamino)-3-((E)-3-(4-hydroxyphenyl)allylthio)-1-oxopropan-2-ylamino)-5-oxopentanoic acid (2), and one 1H-pyrrole-2-carboxylic acid derivative, 6-(3-(1H-pyrrole-2-carbonyloxy)-2-hydroxypropoxy)-3,4,5-trihydroxy-tetrahydro-2H-pyran-2-carboxylic acid (3), together with eighteen known phenolic compounds, were isolated from the fruits of pineapple. Their structures were elucidated by a combination of spectroscopic analyses. Some of these compounds showed inhibitory activities against tyrosinase. The half maximal inhibitory concentration values of compounds 1, 4, 5, 6, 7 are lower than 1 mM. These compounds may contribute to the well-known anti-browning effect of pineapple juice and be potential skin whitening agents in cosmetic applications.

  11. Density Functional Study on A-Units Based on Thieno[3,4- c]pyrrole-4,6-dione for Organic Solar Cells

    Science.gov (United States)

    Tang, Xiaoqin; Shen, Wei; Fu, Zhiyong; Liu, Xiaorui; Li, Ming

    2017-08-01

    The use of polymer donor materials has allowed great progress in organic solar cells. To search for potential donor materials, we have designed a series of donor-acceptor (D-A)-type alternating polymers composed of dithieno[3,2- b:2',3'- d]pyrrole (DTP) electron-rich units and thieno[3,4- c]pyrrole-4,6-dione (TPD) electron-deficient units. Their electronic and optical properties have been investigated using density functional theory and Marcus theory. The calculation results demonstrate that introduction of cyclic compounds (furyl, thienyl, and phenyl) into electron-deficient units of the molecules can result in lower highest occupied molecular orbital (HOMO) levels and reorganization energies compared with the experimental molecule ( X 0 ). To investigate the effects of electron-withdrawing units, three electron-withdrawing substituents (-OCH3, -F, and -CN) were introduced into the thienyl. The results indicated that the polymer X 2-3 will show the best performance among the designed polymers, offering low-lying HOMO energy level (-5.47 eV), narrow energy gap (1.97 eV), and high hole mobility (7.45 × 10-2 cm2 V-1 s-1). This work may provide a guideline for the design of efficient D-A polymers for organic solar cells with enhanced performance.

  12. ITN mixtures of chlorfenapyr (Pyrrole) and alphacypermethrin (Pyrethroid) for control of pyrethroid resistant Anopheles arabiensis and Culex quinquefasciatus.

    Science.gov (United States)

    Oxborough, Richard M; Kitau, Jovin; Matowo, Johnson; Feston, Emmanuel; Mndeme, Rajab; Mosha, Franklin W; Rowland, Mark W

    2013-01-01

    Pyrethroid resistant Anopheles gambiae malaria vectors are widespread throughout sub-Saharan Africa and continued efficacy of pyrethroid ITNs is under threat. Chlorfenapyr is a promising pyrrole insecticide with a unique mechanism of action conferring no cross-resistance to existing public health insecticides. Mixtures of chlorfenapyr (CFP) and alphacypermethrin (alpha) may provide additional benefits over chlorfenapyr or alphacypermethrin used alone. An ITN mixture of CFP 100 mg/m(2)+alpha 25 mg/m(2) was compared with CFP 100 mg/m(2) and alpha 25 mg/m(2) in a small-scale experimental hut trial in an area of wild An. arabiensis. The same treatments were evaluated in tunnel tests against insectary-reared pyrethroid susceptible and resistant Culex quinquefasciatus. Performance was measured in terms of insecticide-induced mortality, and blood-feeding inhibition. Tunnel tests showed that mixtures of CFP 100+ alpha 25 were 1.2 and 1.5 times more effective at killing susceptible Cx. quinquefasciatus than either Alpha 25 (P = 0.001) or CFP 100 (P = 0.001) ITNs. Mixtures of CFP100+ alpha 25 were 2.2 and 1.2 times more effective against resistant Cx. quinquefasciatus than either alpha 25 (P = 0.001) or CFP100 (P = 0.003) ITNs. CFP 100+ alpha 25 produced higher levels of blood-feeding inhibition than CFP alone for susceptible (94 vs 46%, P = 0.001) and resistant (84 vs 53%, P = 0.001) strains. In experimental huts the mixture of CFP 100+ Alpha 25 killed 58% of An. arabiensis, compared with 50% for alpha and 49% for CFP, though the differences were not significant. Blood-feeding inhibition was highest in the mixture with a 76% reduction compared to the untreated net (P = 0.001). ITN mixtures of chlorfenapyr and alphacypermethrin should restore effective control of resistant populations of An. gambiae malaria vectors, provide protection from blood-feeding, and may have benefits for resistance management, particularly in areas with low or moderate

  13. ITN mixtures of chlorfenapyr (Pyrrole and alphacypermethrin (Pyrethroid for control of pyrethroid resistant Anopheles arabiensis and Culex quinquefasciatus.

    Directory of Open Access Journals (Sweden)

    Richard M Oxborough

    Full Text Available Pyrethroid resistant Anopheles gambiae malaria vectors are widespread throughout sub-Saharan Africa and continued efficacy of pyrethroid ITNs is under threat. Chlorfenapyr is a promising pyrrole insecticide with a unique mechanism of action conferring no cross-resistance to existing public health insecticides. Mixtures of chlorfenapyr (CFP and alphacypermethrin (alpha may provide additional benefits over chlorfenapyr or alphacypermethrin used alone. An ITN mixture of CFP 100 mg/m(2+alpha 25 mg/m(2 was compared with CFP 100 mg/m(2 and alpha 25 mg/m(2 in a small-scale experimental hut trial in an area of wild An. arabiensis. The same treatments were evaluated in tunnel tests against insectary-reared pyrethroid susceptible and resistant Culex quinquefasciatus. Performance was measured in terms of insecticide-induced mortality, and blood-feeding inhibition. Tunnel tests showed that mixtures of CFP 100+ alpha 25 were 1.2 and 1.5 times more effective at killing susceptible Cx. quinquefasciatus than either Alpha 25 (P = 0.001 or CFP 100 (P = 0.001 ITNs. Mixtures of CFP100+ alpha 25 were 2.2 and 1.2 times more effective against resistant Cx. quinquefasciatus than either alpha 25 (P = 0.001 or CFP100 (P = 0.003 ITNs. CFP 100+ alpha 25 produced higher levels of blood-feeding inhibition than CFP alone for susceptible (94 vs 46%, P = 0.001 and resistant (84 vs 53%, P = 0.001 strains. In experimental huts the mixture of CFP 100+ Alpha 25 killed 58% of An. arabiensis, compared with 50% for alpha and 49% for CFP, though the differences were not significant. Blood-feeding inhibition was highest in the mixture with a 76% reduction compared to the untreated net (P = 0.001. ITN mixtures of chlorfenapyr and alphacypermethrin should restore effective control of resistant populations of An. gambiae malaria vectors, provide protection from blood-feeding, and may have benefits for resistance management, particularly in areas with low or

  14. Facile fabrication of Zn/Zn 5(OH) 8Cl 2·H 2O flower-like nanostructure on the surface of Zn coated with poly ( N-methyl pyrrole)

    Science.gov (United States)

    Mahmoudian, M. R.; Basirun, W. J.; Alias, Y.; Ebadi, M.

    2011-10-01

    Zn/Zn 5(OH) 8Cl 2·H 2O flower-like nanostructures was electrodeposited on the coated Zn with poly ( N-methyl pyrrole) in 0.1 M Zn (NO 3) 2 and 0.1 M KCl solution. The morphology and the structure of the Zn/Zn 5(OH) 8Cl 2·H 2O were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction analysis (XRD). The FT-IR results showed special peaks at 908 and 728 cm -1 related to Zn 5(OH) 8Cl 2·H 2O. The FESEM results indicated that Zn/Zn 5(OH) 8Cl 2·H 2O consists of a flower-like nanostructure and these flower-shaped structures contain many shaped nanopetals with the thickness of 27.8 nm. The XRD result confirmed that the major phase of electrodeposited product in 0.1 M KCl as supporting electrolyte was Zn 5(OH) 8Cl 2·H 2O. The ability of PMPy to create a thin film and the existence of several pores in its matrix act as a mold for the growth of Zn/Zn 5(OH) 8Cl 2·H 2O flower-like nanostructure. The trapping of Cl - and OH - within pores can be considered as the reason for the formation of flowerlike Zn/Zn 5(OH) 8Cl 2·H 2O nanostructures in 0.1 M KCl.

  15. Facile fabrication of Zn/Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O flower-like nanostructure on the surface of Zn coated with poly (N-methyl pyrrole)

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudian, M.R., E-mail: M_R_mahmoudian@yahoo.com [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Department of Chemistry, Masjed-Soleiman Branch, Islamic Azad University, Masjed-Soleiman (Iran, Islamic Republic of); Basirun, W.J.; Alias, Y.; Ebadi, M. [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2011-10-01

    Zn/Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O flower-like nanostructures was electrodeposited on the coated Zn with poly (N-methyl pyrrole) in 0.1 M Zn (NO{sub 3}){sub 2} and 0.1 M KCl solution. The morphology and the structure of the Zn/Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier transform infrared (FT-IR) spectroscopy and X-ray diffraction analysis (XRD). The FT-IR results showed special peaks at 908 and 728 cm{sup -1} related to Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O. The FESEM results indicated that Zn/Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O consists of a flower-like nanostructure and these flower-shaped structures contain many shaped nanopetals with the thickness of 27.8 nm. The XRD result confirmed that the major phase of electrodeposited product in 0.1 M KCl as supporting electrolyte was Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O. The ability of PMPy to create a thin film and the existence of several pores in its matrix act as a mold for the growth of Zn/Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O flower-like nanostructure. The trapping of Cl{sup -} and OH{sup -} within pores can be considered as the reason for the formation of flowerlike Zn/Zn{sub 5}(OH){sub 8}Cl{sub 2}.H{sub 2}O nanostructures in 0.1 M KCl.

  16. Catalytic mechanisms of direct pyrrole synthesis via dehydrogenative coupling mediated by PNP-Ir or PNN-Ru pincer complexes: Crucial role of proton-transfer shuttles in the PNP-Ir system

    KAUST Repository

    Qu, Shuanglin

    2014-04-02

    Kempe et al. and Milstein et al. have recently advanced the dehydrogenative coupling methodology to synthesize pyrroles from secondary alcohols (e.g., 3) and β-amino alcohols (e.g., 4), using PNP-Ir (1) and PNN-Ru (2) pincer complexes, respectively. We herein present a DFT study to characterize the catalytic mechanism of these reactions. After precatalyst activation to give active 1A/2A, the transformation proceeds via four stages: 1A/2A-catalyzed alcohol (3) dehydrogenation to give ketone (11), base-facilitated C-N coupling of 11 and 4 to form an imine-alcohol intermediate (18), base-promoted cyclization of 18, and catalyst regeneration via H2 release from 1R/2R. For alcohol dehydrogenations, the bifunctional double hydrogen-transfer pathway is more favorable than that via β-hydride elimination. Generally, proton-transfer (H-transfer) shuttles facilitate various H-transfer processes in both systems. Notwithstanding, H-transfer shuttles play a much more crucial role in the PNP-Ir system than in the PNN-Ru system. Without H-transfer shuttles, the key barriers up to 45.9 kcal/mol in PNP-Ir system are too high to be accessible, while the corresponding barriers (<32.0 kcal/mol) in PNN-Ru system are not unreachable. Another significant difference between the two systems is that the addition of alcohol to 1A giving an alkoxo complex is endergonic by 8.1 kcal/mol, whereas the addition to 2A is exergonic by 8.9 kcal/mol. The thermodynamic difference could be the main reason for PNP-Ir system requiring lower catalyst loading than the PNN-Ru system. We discuss how the differences are resulted in terms of electronic and geometric structures of the catalysts and how to use the features in catalyst development. © 2014 American Chemical Society.

  17. Synthesis, characterization and conductivity studies of polypyrrole–fly ash composites

    Indian Academy of Sciences (India)

    M V Murugendrappa; Syed Khasim; M V N Ambika Prasad

    2005-10-01

    in situ polymerization of pyrrole was carried out in the presence of fly ash (FA) to synthesize polypyrrole–fly ash composites (PPy/FA) by chemical oxidation method. The PPy/FA composites have been synthesized with various compositions (10, 20, 30, 40 and 50 wt%) of fly ash in pyrrole. The surface morphology of these composites was studied with scanning electron micrograph (SEM). The polypyrrole–fly ash composites were also characterized by employing X-ray diffractometry (XRD) and infrared spectroscopy (IR). The a.c. conductivity behaviour has been investigated in the frequency range 102–106 Hz. The d.c. conductivity was studied in the temperature range from 40–200°C. The dimensions of fly ash in the matrix have a greater influence on the observed conductivity values. The results obtained for these composites are of greater scientific and technological interest.

  18. [{sup 18}F]fluoromethylated phenyl-pyrroles and 7-azaindole analog as potential dopamine D{sub 4} receptor imaging agents

    Energy Technology Data Exchange (ETDEWEB)

    Ji, D. Y. [Inha Univ., Inchon (Korea, Republic of); Oh, S. Z.; Choi, Y. S.; Lee, K. C.; Kim, S. E.; Choi, Y.; Lee, K. H.; Kim, B. T. [Samsung Biomedical Research Insititute, Seoul (Korea, Republic of)

    1997-07-01

    An association between the dopamine D{sub 4} receptor and schizophrenia was recently suggested and the D{sub 4} receptor antagonists may thus have potential in elucidating the role of the receptor in schizophrenic patients. The purpose of this study was to develop some of these antagonists as potential dopamine D{sub 4} receptor imaging agents for PET. We have prepared 1-(3-[{sup 18}F]fluoromethylphenyl)-3-([4-(pyridin-2-yl)piperazin-1-yl)methyl) pyrrole (1), 1-(3-[{sup 18}F]fluoromethylphenyl)-3-([4-(pyridin-2-yl)piperazin-1-yl)methyl) pyrrole (2), and 3-([4-(4-[{sup 18}F]fluoro methylbenzyl)piperazin-1-yl)methyl)-1H-pyrrolo(2,3,-b)pyridine (3) as potential imaging agents for the dopamine D{sub 4} receptor for PET. The compounds [{sup 18}F]1 and [{sup 18}F]2 were prepared by coupling of (3-[{sup 18}F]fluoromethylphenyl)-pyrrol-1- yl-3-aldehyde and the piperazine moiety in the presence of NaBH{sub 3}CN. The [{sup 18}F]fluorinated aldehyde was obtained in 60-85% yield by the displacement of the corresponding mesylate with F-18-(THF, 90 .deg. C, 5 min). HPLC purification (Alltech Econosil C-18 columm, 250 x 10 mm, 35: 65 = 0.1M NH{sub 4}CI{sub 2}H : CH{sub 3}OH, 4 ml/min, t{sub R}=26.6 min) gave the [{sup 18}F]1 and [{sup 18}F]2 in 7-12% yield. In the case of azaindole 3, a methlene link was inserted between the piperazinyl and a fluoromethyl phenyl group. Radiochemical synthesis of the [{sup 18}F]3 was carried out by coupling of the piperazne moiety and [{sup 18}F]fluoromethylbenzyl mesylate in the presence of NEt{sub 3}(3:1-CH{sub 3}CN: DMF, 120 .deg. C, 30 min). Purification was carried out by HPLC using a C-18 column (Alltech Econosil, 50 x 10 mm, 100% 0.1M NH{sub 4}CO{sub 2}H for 5 min followed by 40:60=0.1 M NH{sub 4}CO{sub 2}H : MeOH, 4 ml/min t{sub R}=28.7 min). The time of synthesis including HPLC purification was 100 min. The overall yield of [{sup 18}F]3 was 10-15% with a radiochemical purity better than 97% and a specific activity greater than 1000 ci/mmol.

  19. Blood pyrrole-protein adducts as a diagnostic and prognostic index in pyrrolizidine alkaloid-hepatic sinusoidal obstruction syndrome

    Directory of Open Access Journals (Sweden)

    Gao H

    2015-08-01

    Full Text Available Hong Gao,1,* Jianqing Q Ruan,2,* Jie Chen,1 Na Li,2 Changqiang Q Ke,3 Yang Ye,3–5 Ge Lin,2,4,5 Jiyao Y Wang1,61Department of Gastroenterology, Zhongshan Hospital, Fudan University, Shanghai, People’s Republic of China; 2School of Biomedical Sciences, Chinese University of Hong Kong, Hong Kong; 3Shanghai Institute of Materia Medica, Shanghai, People’s Republic of China; 4Joint Research Laboratory for Promoting Globalization of Traditional Chinese Medicines, Shanghai Institute of Materia Medica, 5Chinese University of Hong Kong, Hong Kong; 6Center of Evidence-Based Medicine Fudan University, Shanghai, People’s Republic of China*These authors contributed equally to this work and share first authorship Background: The diagnosis of hepatic sinusoidal obstruction syndrome (HSOS induced by pyrrolizidine alkaloids is mainly based on clinical investigation. There is currently no prognostic index. This study evaluated the quantitative measurement of blood pyrrole-protein adducts (PPAs as a diagnostic and prognostic index for pyrrolizidine alkaloid-induced HSOS.Methods: Suspected drug-induced liver injury patients were prospectively recruited. Blood PPAs were quantitatively measured using ultra-performance liquid chromatography-tandem mass spectrometry. Patients’ age, sex, biochemistry test results, and a detailed drug history were recorded. The patients were divided into two groups, ie, those with HSOS induced by pyrrolizidine alkaloid-containing drugs and those with liver injury induced by drugs without pyrrolizidine alkaloids. The relationship between herb administration, clinical outcomes, blood sampling time, and blood PPA concentration in pyrrolizidine alkaloid-associated HSOS patients was analyzed using multiple linear regression analysis.Results: Forty patients met the entry criteria, among whom 23 had pyrrolizidine alkaloid-associated HSOS and 17 had liver injury caused by drugs without pyrrolizidine alkaloids. Among the 23

  20. Schiff base functionalized Organopropylsilatranes: Synthesis and structural characterization

    Indian Academy of Sciences (India)

    Gurjaspreet Singh; Promila; Amandeep Saroa; Jandeep Singh; Raj Pal Sharm; V Ferretti

    2016-02-01

    Synthesis of Schiff bases linked to organopropylsilatranes were performed by condensation reaction of post-functionalized silatranes such as aminopropylsilatrane (4), aminopropyl-3,7,10-trimethylsilatrane (5) and N-substituted aminopropylsilatrane (10) with two different aldehydes viz. pyrrole-2-carboxaldehyde and 2-hydroxy-1-napthaldehyde. The resulting Schiff base substituted silatranes were well characterized by elemental analysis, spectroscopic studies [IR, (1H, 13C) NMR, and MS]. The structures of two silatranes were confirmed by single crystal X-ray diffraction analysis.

  1. Discovery of 2-azetidinone and 1H-pyrrole-2,5-dione derivatives containing sulfonamide group at the side chain as potential cholesterol absorption inhibitors.

    Science.gov (United States)

    Yuan, Xinrui; Lu, Peng; Xue, Xiaojian; Qin, Hui; Fan, Chen; Wang, Yubin; Zhang, Qi

    2016-02-01

    Cholesterol absorption inhibitor (CAI) targeting Niemann-Pick C1-like1 protein was developed for the treatment of hyperlipidaemia and only ezetimibe was approved so far. For developing novel CAIs, we synthesized sixteen 2-azetidinone derivatives and thirteen 1H-pyrrole-2,5-dione derivatives containing sulfonamide group at the side chain, and their inhibitory activity of cholesterol absorption was evaluated in Caco-2 cell line in vitro. Furthermore, top six compounds were measured by cytotoxicity and partition coefficient, and 2-azetidinone analogue 9e was selected for in vivo study. Finally, 9e considerably reduced total cholesterol, LDL-C, FFA and triglyceride in the serum and increased the rate of HDL-C to total cholesterol, suggesting it could regulate the lipid metabolism and act as a potent CAI.

  2. Acylguanidine inhibitors of beta-secretase: optimization of the pyrrole ring substituents extending into the S1 and S3 substrate binding pockets.

    Science.gov (United States)

    Cole, Derek C; Stock, Joseph R; Chopra, Rajiv; Cowling, Rebecca; Ellingboe, John W; Fan, Kristi Y; Harrison, Boyd L; Hu, Yun; Jacobsen, Steve; Jennings, Lee D; Jin, Guixian; Lohse, Peter A; Malamas, Michael S; Manas, Eric S; Moore, William J; O'Donnell, Mary-Margaret; Olland, Andrea M; Robichaud, Albert J; Svenson, Kristine; Wu, JunJun; Wagner, Eric; Bard, Jonathan

    2008-02-01

    Proteolytic cleavage of amyloid precursor protein by beta-secretase (BACE-1) and gamma-secretase leads to formation of beta-amyloid (A beta) a key component of amyloid plaques, which are considered the hallmark of Alzheimer's disease. Small molecule inhibitors of BACE-1 may reduce levels of A beta and thus have therapeutic potential for treating Alzheimer's disease. We recently reported the identification of a novel small molecule BACE-1 inhibitor N-[2-(2,5-diphenyl-pyrrol-1-yl)-acetyl]guanidine (3.a.1). We report here the initial hit-to-lead optimization of this hit and the SAR around the aryl groups occupying the S(1) and S(2') pockets leading to submicromolar BACE-1 inhibitors.

  3. Emission and absorption of light in poly pyrrole synthesized by plasma; Emision y absorcion de luz en polipirrol sintetizado por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Enriquez, M.A.; Colin, E.; Olayo, M.G.; Cruz, G.J.; Ordonez, E. [ININ, A.P. 18-1027, 11801 Mexico D.F. (Mexico); Benavides, R. [Departamento de Procesos de Transformacion, CIQA, Blvd. Enrique Reyna 140, Saltillo, Coahuila (Mexico); Morales, J.; Olayo, R. [UAM-I, Apdo. Postal 55-534, Iztapalapa, D.F. (Mexico)]. e-mail: gcc@nuclear.inin.mx

    2007-07-01

    The poly pyrrole structure (PPy) consists of heterocyclic rings with conjugation that it depends on the intensity of the electric field applied during the synthesis, and its luminescence is related with the {pi}-{pi}{sup *} transitions of that conjugation. To irradiate with light of different wavelengths, the results indicate that the polymer absorbs in the interval from 290 to 700 nm and it emits between 450 and 470 nm. The basal conductivity of the polymers, without electromagnetic excitation, it was measured in 10{sup -15} S/cm, however, to interact with visible light it is increased approximately 10 times and when excite with UV light it is increased up to 3 magnitude orders. (Author)

  4. Synthesis and photovoltaic properties of organic sensitizers incorporating a thieno[3,4-c]pyrrole-4,6-dione moiety.

    Science.gov (United States)

    Feng, Quanyou; Lu, Xuefeng; Zhou, Gang; Wang, Zhong-Sheng

    2012-06-14

    Novel organic sensitizers containing a thieno[3,4-c]pyrrole-4,6-dione (TPD) moiety with triphenylamine or julolidine as the electron donor have been designed and synthesized for quasi-solid-state dye-sensitized solar cells (DSSCs). For comparison, two organic dyes based on a terthiophene spacer have also been synthesized. The absorption, electrochemical and photovoltaic properties of all sensitizers have been systematically investigated. We found that the incorporation of TPD is highly beneficial to broaden the absorption spectra of the organic sensitizers and prevent the intermolecular interaction. Therefore, the charge recombination possibility is reduced, which is revealed by the controlled intensity modulated photovoltage spectroscopy. A quasi-solid-state DSSC based on sensitizer FNE38 with TPD and triphenylamine moieties demonstrates a solar energy conversion efficiency of 4.71% under standard AM 1.5G sunlight without the use of coadsorbant agents.

  5. (1R*,2S*-N,N′-Bis[(E-1H-pyrrol-2-ylmethylidene]cyclohexane-1,2-diamine monohydrate

    Directory of Open Access Journals (Sweden)

    Kate J. Akerman

    2012-12-01

    Full Text Available The title compound, C16H20N4·H2O, was synthesized from cis-1,2-diaminocyclohexane (a racemic mixture of the (1R,2S and (1S,2R enantiomers. The compound crystallized with two molecules (A and B in the asymmetric unit with a single water solvent molecule per Schiff base molecule. Molecules A and B have similar conformations as illustrated by the least-squares-fit with an r.m.s. deviation of 0.242 Å. The molecules within the asymmetric unit are bridged by hydrogen bonds to the two water molecules, resulting in a heterotetramer. The water molecule acts as both a hydrogen-bond donor and acceptor. The pyrrole-imine units are not co-planar, making an angle of 73.9 (3° and 76.9 (3° in molecules A and B, respectively.

  6. Effects of Molecular Structure on Intramolecular Charge Carrier Transport in Dithieno [3,2-b: 2,3-d] Pyrrole-Based Conjugated Copolymers

    Directory of Open Access Journals (Sweden)

    Yoshihito Honsho

    2012-01-01

    Full Text Available Intramolecular mobility of positive charge carriers in conjugated polymer films based on dithieno [2,3-b: 2,3-d] pyrrole (DTP is studied by time-resolved microwave conductivity (TRMC. A series of DTP homopolymer and copolymers combined with phenyl, 2,2-biphenyl, thiophene, 2,2-bithiophene, and 9,9-dioctylfluorene were synthesized by Suzuki-Miyaura and Yamamoto coupling reactions. Polymers containing DTP unit are reported to show high value of hole mobility measured by FET method, and this type of polymers is expected to have stable HOMO orbitals which are important for hole transportation. Among these copolymers, DTP coupled with 9,9-dioctylfluorene copolymer showed the highest charge carrier mobility as high as 1.7 cm2/Vs, demonstrating an excellent electrical property on rigid copolymer backbones.

  7. A Readily Accessible Chiral NNN Pincer Ligand with a Pyrrole Backbone and Its Ni(II) Chemistry: Syntheses, Structural Chemistry, and Bond Activations.

    Science.gov (United States)

    Wenz, Jan; Kochan, Alexander; Wadepohl, Hubert; Gade, Lutz H

    2017-03-20

    A new class of chiral C2-symmetric N-donor pincer ligands, 2,5-bis(2-oxazolinyldimethylmethyl)pyrroles (PdmBox)H, was synthesized starting from the readily available ethyl 2,2-dimethyl-3-oxobutanoate (1). The synthesis of the ligand backbone was achieved by oxidative enole coupling with CuC12 followed by Paal-Knorr-type pyrrole synthesis. The corresponding protioligands ((R)PdmBox)H (R = iPr: 5a; Ph: 5b) were obtained by condensation with amino alcohols and subsequent zinc-catalyzed cyclization. Reaction of the lithiated ligands with [NiCl2(dme)] yielded the corresponding square-planar nickel(II) complexes [((R)PdmBox)NiCl] (6a/b). Salt metathesis of 6a with the corresponding alkali or cesium salts in acetone led to the formation of air- and moisture-stable [((iPr)PdmBox)NiX] (X = F (7), X = Br (8), X = I (9), X = N3 (10), X = OAc (11). Furthermore, the conversion of [((iPr)PdmBox)NiF] (7) with hydride transfer reagents such as PhSiH3 led to the stable hydrido species [((iPr)PdmBox)NiH] (27), the stoichiometric transformations of which were studied. Treatment of 6a with organometallic reagents such as ZnEt2, PhLi, PhC≡CLi, NsLi, or ((4F)Bn)2Mg(THF)2 gave the corresponding alkyl, alkynyl, or aryl complexes. The availability of the new nonisomerizable PdmBox pincer ligands allowed the comparative study of their ligation to square-planar complexes as helically twisted spectator ligands as opposed to the enforced planar rigidity of their iso-PmBox analogues and the way this influences the reactivity of the Ni complexes.

  8. Gamma irradiation effect on polymers derived of pyrrole synthesized by plasma; Efecto de irradiacion gamma en polimeros derivados de pirrol sintetizados por plasma

    Energy Technology Data Exchange (ETDEWEB)

    Lopez G, O. G.

    2013-07-01

    This work studies the effect of gamma irradiation at doses of 50, 100, 200, 400 and 800 kGy on polymers obtained from pyrrole synthesized by plasma. The evolution of the structure was studied by Fourier transform infrared spectroscopy (Ftir) and X-ray photoelectron spectroscopy (XPS). The Ftir spectra show that poly pyrroles have N-H, C-H, C=O, triple and consecutive double bonds in their structure. The irradiated polymers show the same chemical groups in their structure without significant changes. Nevertheless, a more detailed analysis by XPS allows the identification of superficial chemical states, such as: C=CH-C, C=CC-C, C-NH-C, C-NC-C, etc., and shows that most of these states are present in all polymers but with different participation. One possible mechanism indicates that as the irradiation dose increases, dehydrogenation processes are performed increasing fragmentation, crosslinking and formation of multiple bonds. The fragmentation and thermal degradation were studied by thermogravimetric analysis, indicating that the loss of moisture and light compounds formed during gamma irradiation occurs in the firsts 100 grades C. The main degradation of all polymers occurs from 150 to 700 grades C, suggesting that the thermal stability is independent of the irradiation dose in the interval studied. Morphology was studied using scanning electron microscopy techniques. Before irradiation, the polymer presented a uniform and practically smooth surface, however, after gamma irradiation, the applied energy increased roughness and macro fragmentation. The roughness and functional groups on the surface reduced the contact angle with water as the irradiation dose increased. However, the polymers are hydrophilic, because for all doses that contact angle is smaller than 90 grades C. Electrical conductivity was calculated respect to temperature in the interval from 25 to 100 grades C. Conductivity increases with temperature and is slightly greater in the irradiated polymers

  9. Metal organic frameworks (MOFs) for magnetic solid-phase extraction of pyrazole/pyrrole pesticides in environmental water samples followed by HPLC-DAD determination.

    Science.gov (United States)

    Ma, Jiping; Yao, Zhidan; Hou, Liwei; Lu, Wenhui; Yang, Qipeng; Li, Jinhua; Chen, Lingxin

    2016-12-01

    Magnetic metal-organic frameworks (MOFs, [MIL-101]) were prepared and used as magnetic solid-phase extraction (MSPE) adsorbents for preconcentration of four kinds of pyrazole/pyrrole pesticides (flusilazole, fipronil, chlorfenapyr, and fenpyroximate) in environmental water samples, followed by high-performance liquid chromatography-diode-array detector (HPLC-DAD) determination. Several variables affecting MSPE efficiency were systematically investigated, including amount of MIL-101, extraction time, sample pH, salt concentration, type of desorption solvent and desorption number of times. Under optimized conditions, excellent linearity was achieved in the range of 5.0-200.0μg/L for flusilazole and fipronil, and 2.0-200.0μg/L for chlorfenapyr and fenpyroximate, with correlation coefficients r>0.9911. Limits of detection and quantification were 0.3-1.5μg/L and 1.0-5.0μg/L, respectively. The intra-day and inter-day precision (relative standard deviation, n=6, %) at three spiked levels were 1.1-5.4% and 3.9-7.8% in terms of peak area, respectively. The method recoveries at three fortified concentration levels ranged from 81.8% to 107.5% for reservoir water samples, 81.0-99.5% for river water samples, and 80.2-106.5% for seawater samples. The developed MOFs based MSPE coupled with HPLC method proved to be a convenient, rapid and eco-friendly alternative to the sensitive determination of pyrazole/pyrrole pesticides with high repeatability and excellent practical applicability.

  10. Anticancer potential of pyrrole (1, 2, a) pyrazine 1, 4, dione, hexahydro 3-(2-methyl propyl) (PPDHMP) extracted from a new marine bacterium, Staphylococcus sp. strain MB30.

    Science.gov (United States)

    Lalitha, P; Veena, V; Vidhyapriya, P; Lakshmi, Pragna; Krishna, R; Sakthivel, N

    2016-05-01

    Marine bacterium, strain MB30 isolated from the deep sea sediment of Bay of Bengal, India, exhibited antimicrobial activity against human pathogenic bacteria. Based on the 16S rRNA sequence homology and subsequent phylogenetic tree analysis, the strain MB30 was identified as Staphylococcus sp. The bioactive metabolite produced by the strain MB30 was purified through silica gel column chromatography and preparative HPLC. Purified metabolite was further characterized by FT-IR, LC-MS and NMR analyses. On the basis of spectroscopic data, the metabolite was identified as pyrrole (1, 2, a) pyrazine 1, 4, dione, hexahydro 3-(2-methyl propyl) (PPDHMP). The PPDHMP exhibited in vitro anticancer potential against lung (A549) and cervical (HeLa) cancer cells in a dose-dependent manner with the IC50 concentration of 19.94 ± 1.23 and 16.73 ± 1.78 μg ml(-1) respectively. The acridine orange (AO)/ethidium bromide (EB) and 4,6-diamidino-2-phenylindole dihydrochloride (DAPI) staining of the IC50 concentration of PPDHMP-treated cancer cells exhibited an array of morphological changes such as nuclear condensation, cell shrinkage and formation of apoptotic bodies. The PPDHMP-treated cancer cells induced the progressive accumulation of fragmented DNA in a time-dependent manner. Based on the flow cytometric analysis, it has become evident that the compound was also effective in arresting the cell cycle at G1 phase. Further, the Western blotting analysis confirmed the down-regulation of cyclin-D1, cyclin dependent kinase (CDK-2), anti-apoptotic Bcl-2 family proteins (Bcl-2 and Bcl-xL), activation of caspase-9 and 3 with the cleavage of PARP. The PPDHMP-treated cancer cells also showed the inhibition of migration and invasive capacity of cancer cells. In the present investigation, for the first time, we have reported the extraction, purification and characterization of an anticancer metabolite, PPDHMP from a new marine bacterium, Staphylococcus sp. strain MB30.

  11. Thieno[3,2-b]- and thieno[2,3-b]pyrrole bioisosteric analogues of the hallucinogen and serotonin agonist N,N-dimethyltryptamine.

    Science.gov (United States)

    Blair, J B; Marona-Lewicka, D; Kanthasamy, A; Lucaites, V L; Nelson, D L; Nichols, D E

    1999-03-25

    The synthesis and biological activity of 6-[2-(N, N-dimethylamino)ethyl]-4H-thieno[3,2-b]pyrrole (3a) and 4-[2-(N, N-dimethylamino)ethyl]-6H-thieno[2,3-b]pyrrole (3b), thienopyrroles as potential bioisosteres of N,N-dimethyltryptamine (1a), are reported. Hallucinogen-like activity was evaluated in the two-lever drug discrimination paradigm using LSD- and DOI-trained rats. Neither 3a nor 3b substituted for LSD or DOI up to doses of 50 micromol/kg. By comparison, 1a fully substituted in LSD-trained rats. However, 3a and 3b fully substituted for the 5-HT1A agonist LY293284 ((-)-(4R)-6-acetyl-4-(di-n-propylamino)-1,3,4, 5-tetrahydrobenz[c,d]indole). Both 3a and 3b induced a brief "serotonin syndrome" and salivation, an indication of 5-HT1A receptor activation. At the cloned human 5-HT2A receptor 3b had about twice the affinity of 3a. At the cloned human 5-HT2B and 5-HT2C receptors, however, 3a had about twice the affinity of 3b. Therefore, thiophene lacks equivalence as a replacement for the phenyl ring in the indole nucleus of tryptamines that bind to 5-HT2 receptor subtypes and possess LSD-like behavioral effects. Whereas both of the thienopyrroles had lower affinity than the corresponding 1a at 5-HT2 receptors, 3a and 3b had significantly greater affinity than 1a at the 5-HT1A receptor. Thus, thienopyrrole does appear to serve as a potent bioisostere for the indole nucleus in compounds that bind to the serotonin 5-HT1A receptor. These differences in biological activity suggest that serotonin receptor isoforms are very sensitive to subtle changes in the electronic character of the aromatic systems of indole compounds.

  12. The effect of β-saturated pyrrolic rings on the electronic structures and aromaticity of magnesium porphyrin derivatives: a density functional study.

    Science.gov (United States)

    Wan, Liang; Qi, Dongdong; Zhang, Yuexing

    2011-09-01

    Density functional theory (DFT) calculation on the molecular structures, molecular orbitals, electronic absorption spectra, and magnetic properties of magnesium porphyrin (MgPor) and a series of five hydrogenated magnesium porphyrin complexes with different number of β-saturated pyrrolic rings, namely MgPor-β-1Hy, MgPor-β-opp-2Hy, MgPor-β-adj-2Hy, MgPor-β-3Hy, and MgPor-β-4Hy, clarifies the red-shift of the lowest energy absorption band from chlorophyll a to bacteriochlorophyll and reveals the strong chemical stability for both of them. The energy levels of highest occupied molecular orbitals (HOMO) and HOMO-1 for MgPor are reversed upon hydrogenation at β-positions (2 and 3, 7 and 8, 12 and 13, and 17 and 18) of porphyrin ring. Along with the increase of β-saturated pyrrolic rings from 1, 2, 3, to 4, the HOMO energy increases from -4.78 eV to -3.10 eV in a regular manner. In contrast, the lowest unoccupied molecular orbitals (LUMO) energy levels of MgPor, MgPor-β-1Hy, and MgPor-β-opp-2Hy are very similar with each other. As a result, the lowest energy absorption band involving main transition from HOMO to LUMO is red-shifted from MgPor-β-1Hy to MgPor-β-opp-2Hy which is representative of chlorophyll a and bacteriochlorophyll, respectively. Natural hydroporphyrins represented by MgPor, MgPor-β-1Hy, and MgPor-β-opp-2Hy have turned out to be aromatic and stable enough, in good accordance with the ubiquity of their derivatives in the nature. In contrast, MgPor-β-adj-2Hy, MgPor-β-3Hy, and MgPor-β-4Hy with relatively weak aromaticity seem to be unstable and therefore were not found in nature.

  13. Characterization of thin poly(pyrrole-benzophenone) film morphologies electropolymerized on indium tin oxide coated optic fibers for electrochemical and optical biosensing

    Energy Technology Data Exchange (ETDEWEB)

    Konry, T.; Heyman, Y. [Department of Biotechnology Engineering, Faculty of Engineering Science, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel); Cosnier, S.; Gorgy, K. [Departement de Chimie Moleculaire, UMR-5250, ICMG FR-2607, CNRS, Universite Joseph Fourier BP 53, 38041 Grenoble Cedex 9 (France); Marks, R.S. [Department of Biotechnology Engineering, Faculty of Engineering Science, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel); National Institute for Biotechnology in the Negev, Ben Gurion University of the Negev, P.O. Box 653, Beer Sheva 84105 (Israel)

    2008-06-30

    We report that electropolymerization parameters (duration and voltage) modulate the properties and morphological structures of photoactive polymers which influence both the efficiency of bioreceptor attachment to the polymer surface, and the resulting biosensor assay performance. We have compared two biosensor technologies, optical and electrochemical, for the detection of anti-cholera toxin antibodies using our singular conductive optic fibers, albeit at this stage in separate experiments. Both biosensor systems were more sensitive than conventional detection and pave the way for the possibility to one day make simultaneous optical and electrochemical sensing using the same biosensor. (author)

  14. The influence of concentration of pyrrole on the wave absorption performance of the polypyrrole coated cotton composites%吡咯浓度对聚吡咯涂层棉复合材料吸波性能的影响

    Institute of Scientific and Technical Information of China (English)

    刘元军; 赵晓明

    2016-01-01

    随着手机、电脑、电视等广泛应用于生活和工作中,电磁辐射日益严重,而电磁辐射危害人体健康且影响精密电子设备的运行.为了解决上述问题,以棉机织物为基布,以吡咯为单体,采用原位聚合法制备具有良好吸波性能的柔性聚吡咯涂层棉复合材料,探讨了吡咯浓度对复合材料介电常数实部、虚部、损耗角正切、表面电阻的影响,并对其外观形貌进行了研究.研究表明:吡咯浓度对聚吡咯涂层棉复合材料介电常数实部、虚部、损耗角正切、表面电阻影响较大;吡咯浓度为0.6 mol/L时,聚吡咯涂层棉复合材料的介电常数实部和虚部均最大,吡咯浓度为0.4 mol/L时,聚吡咯涂层棉复合材料损耗角正切值最大.%With the wide application of mobile phone, computer, TV and so on in life and work, electromagnetic radiation is increasingly serious. Electromagnetic radiation causes serious damage to human health and affects the operation of sophisticated electronic equipment. The polypyrrole coated cotton composites with good wave absorption performance were produced using pyrrole as monomer by in-situ polymerization on cotton fabric. Firstly, the influence of concentration of pyrrole on the dielectric constant, dielectric loss, and surface resistance of composites were discussed. Secondly, exterior morphology was analyzed. The results showed that the concentration of pyrrole have great influence on the dielectric constant, dielectric loss, and surface resistance of the composite material. When pyrrole concentration was 0.6 mol/L, the dielectric constant real part and imaginary part of the polypyrrole coated cotton composites was the maximum. When pyrrole concentration was 0.4 mol/L, the loss tangent value of the polypyrrole coated cotton composites was the maximum.

  15. Pyrrole and 2,5-heptanedione in the urine of rats and 2,5-heptanedione in the urine of man: analytical determination of excretion upon exposure to n-heptane; Pyrrole und 2,5-Heptandion im Urin der Ratte und 2,5-Heptandion im Urin des Menschen: Analytische Bestimmung der Ausscheidung nach Exposition gegn n-Heptan

    Energy Technology Data Exchange (ETDEWEB)

    Stoermer, A.G.C.

    1997-09-01

    A method for quantifying levels of the neurotoxic metabolite 2,5-heptanedione in rats and man after experimental exposure to n-heptane was developed. It consisted in determining the quantity of 2,5-heptanedione excreted in urine and the relevant excretion kinetics. Moreover, the excretion of pyrrole in the urine of rats was measured. In the urine of non-exposed rats and man, a basic excretion of 2,5-heptanedione was measured, with the rates of excretion being 0.11 and 4.5 nmol per hour, respectively. This basic excretion of 2,5-heptanedione is assumed to have an endogenous cause. The quantitive investigation of the dose dependence of the excretion of 2,5-heptanedione and pyrrole in the urine of rats and of 2,5-heptanedione in the urine of man is a prerequisite for assessing the risk posed by n-heptane with a view to peripheral neuropathies. (orig./MG) [Deutsch] Ziel dieser Arbeit war die Entwicklung einer Methode zur Quantifizierung der Belastung von Ratte und Mensch mit dem neurotoxischen Metaboliten 2,5-Heptandion nach experimentellen Expositionen gegen n-Heptan. Dazu sollte jeweils die ausgeschiedene Menge und die zugehoerige Ausscheidungskinetik von 2,5-Heptandion im Urin bestimmt werden. Darueber hinaus sollte die Ausscheidung von Pyrrolen im Urin von Ratten gemessen werden. Im Urin von nicht exponierten Ratten und Menschen wurde eine Grundausscheidung von 2,5-Heptandion gefunden, wobei die Ausscheidungsraten jeweils 0,11 bzw. 4,5 nmol/h betrugen. Fuer die Grundausscheidung von 2,5-Heptandion wird ein endogener Ursprung angenommen. Die quantitativen Untersuchungen zur Dosisabhaengigkeit der Ausscheidung im Urin von 2,5-Heptandion und Pyrrolen bei der Ratte und von 2,5-Heptandion beim Menschen sind eine Grundvoraussetzung fuer eine Abschaetzung des Risikos von n-Heptan fuer periphere Neuropathien. (orig./MG)

  16. Synthesis, characterisation and electrical properties of supramolecular DNA-templated polymer nanowires of 2,5-(bis-2-thienyl)-pyrrole.

    Science.gov (United States)

    Watson, Scott M D; Hedley, Joseph H; Galindo, Miguel A; Al-Said, Said A F; Wright, Nick G; Connolly, Bernard A; Horrocks, Benjamin R; Houlton, Andrew

    2012-09-17

    Supramolecular polymer nanowires have been prepared by using DNA-templating of 2,5-(bis-2-thienyl)-pyrrole (TPT) by oxidation with FeCl(3) in a mixed aqueous/organic solvent system. Despite the reduced capacity for strong hydrogen bonding in polyTPT compared to other systems, such as polypyrrole, the templating proceeds well. FTIR spectroscopic studies confirm that the resulting material is not a simple mixture and that the two types of polymer interact. This is indicated by shifts in bands associated with both the phosphodiester backbone and the nucleobases. XPS studies further confirm the presence of DNA and TPT, as well as dopant Cl(-) ions. Molecular dynamics simulations on a [{dA(24):dT(24)}/{TPT}(4)] model support these findings and indicate a non-coplanar conformation for oligoTPT over much of the trajectory. AFM studies show that the resulting nanowires typically lie in the 7-8 nm diameter range and exhibit a smooth, continuous, morphology. Studies on the electrical properties of the prepared nanowires by using a combination of scanned conductance microscopy, conductive AFM and variable temperature two-terminal I-V measurements show, that in contrast to similar DNA/polymer systems, the conductivity is markedly reduced compared to bulk material. The temperature dependence of the conductivity shows a simple Arrhenius behaviour consistent with the hopping models developed for redox polymers.

  17. 4-Acyl Pyrrole Derivatives Yield Novel Vectors for Designing Inhibitors of the Acetyl-Lysine Recognition Site of BRD4(1).

    Science.gov (United States)

    Hügle, Martin; Lucas, Xavier; Weitzel, Gerhard; Ostrovskyi, Dmytro; Breit, Bernhard; Gerhardt, Stefan; Einsle, Oliver; Günther, Stefan; Wohlwend, Daniel

    2016-02-25

    Several human diseases, including cancer, show altered signaling pathways resulting from changes in the activity levels of epigenetic modulators. In the past few years, small-molecule inhibitors against specific modulators, including the bromodomain and extra-terminal (BET) bromodomain family of acetylation readers, have shown early promise in the treatment of the genetically defined midline carcinoma and hematopoietic malignancies. We have recently developed a novel potent inhibitor of BET proteins, 1 (XD14[ Angew. Chem., Int. Ed. 2013, 52, 14055]), which exerts a strong inhibitory potential on the proliferation of specific leukemia cell lines. In the study presented here, we designed analogues of 1 to study the potential of substitutions on the 4-acyl pyrrole backbone to occupy additional sites within the substrate recognition site of BRD4(1). The compounds were profiled using ITC, DSF, and X-ray crystallography. We could introduce several substitutions that address previously untargeted areas of the substrate recognition site. This work may substantially contribute to the development of therapeutics with increased target specificity against BRD4-related malignancies.

  18. Determination of silver(I) by electrothermal-AAS in a microdroplet formed from a homogeneous liquid-liquid extraction system using tetraspirocyclohexylcalix[4]pyrroles.

    Science.gov (United States)

    Ghiasvand, Ali Reza; Moradi, Farzaneh; Sharghi, Hashem; Hasaninejad, Ali Reza

    2005-04-01

    A simple and efficient method for the selective separation and preconcentration of Ag+ using homogeneous liquid-liquid extraction was developed. Tetraspirocyclohexylcalix[4]pyrrole (TSCC4P) was synthesized and investigated as a suitable selective complexing ligand for Ag+. Zonyl FSA (FSA) was applied as a phase-separator agent under mild pH conditions. Under the optimal conditions ([TSCC4P] = 3.4 x 10(-4) M, [THF] = 25.0% v/v, [FSA] = 1.25% w/v, and pH = 4.5), 5 microg of Ag+ in 6.0 ml aqueous phase could be extracted quantitatively into 20 microl of the sedimented phase. The maximum concentration factor was 300-fold. The limit of detection of the proposed method was 0.005 ng/ml. The reproducibility of the proposed method was at most 3.5%. The influence of the pH, type and volume of the water-miscible organic solvent, concentration of FSA, concentration of the complexing ligand and the effect of different diverse ions on the extraction and determination of Ag+ were investigated. The proposed method was applied to the extraction and determination of Ag+ in different water samples.

  19. Sequence-specific DNA alkylation and transcriptional inhibition by long-chain hairpin pyrrole-imidazole polyamide-chlorambucil conjugates targeting CAG/CTG trinucleotide repeats.

    Science.gov (United States)

    Asamitsu, Sefan; Kawamoto, Yusuke; Hashiya, Fumitaka; Hashiya, Kaori; Yamamoto, Makoto; Kizaki, Seiichiro; Bando, Toshikazu; Sugiyama, Hiroshi

    2014-09-01

    Introducing novel building blocks to solid-phase peptide synthesis, we readily synthesized long-chain hairpin pyrrole-imidazole (PI) polyamide-chlorambucil conjugates 3 and 4 via the introduction of an amino group into a GABA (γ-turn) contained in 3, to target CAG/CTG repeat sequences, which are associated with various hereditary disorders. A high-resolution denaturing polyacrylamide sequencing gel revealed sequence-specific alkylation both strands at the N3 of adenines or guanines in CAG/CTG repeats by conjugates 3 and 4, with 11bp recognition. In vitro transcription assays using conjugate 4 revealed that specific alkylation inhibited the progression of RNA polymerase at the alkylating sites. Chiral substitution of the γ-turn with an amino group resulted in higher binding affinity observed in SPR assays. These assays suggest that conjugates 4 with 11bp recognition has the potential to cause specific DNA damage and transcriptional inhibition at the alkylating sites. Copyright © 2014 Elsevier Ltd. All rights reserved.

  20. Dendrimer Templated Synthesis of One Nanometer Rh and Pt Particles Supported on Mesoporous Silica: Catalytic Activity for Ethylene and Pyrrole Hydrogenation.

    Energy Technology Data Exchange (ETDEWEB)

    Huang, Wenyu; Kuhn, John N.; Tsung, Chia-Kuang; Zhang, Yawen; Habas, Susan E.; Yang, Peidong; Somorjai, Gabor A.

    2008-05-09

    Monodisperse rhodium (Rh) and platinum (Pt) nanoparticles as small as {approx}1 nm were synthesized within a fourth generation polyaminoamide (PAMAM) dendrimer, a hyperbranched polymer, in aqueous solution and immobilized by depositing onto a high-surface-area SBA-15 mesoporous support. X-ray photoelectron spectroscopy indicated that the as-synthesized Rh and Pt nanoparticles were mostly oxidized. Catalytic activity of the SBA-15 supported Rh and Pt nanoparticles was studied with ethylene hydrogenation at 273 and 293 K in 10 torr of ethylene and 100 torr of H{sub 2} after reduction (76 torr of H{sub 2} mixed with 690 torr of He) at different temperatures. Catalysts were active without removing the dendrimer capping but reached their highest activity after hydrogen reduction at a moderate temperature (423 K). When treated at a higher temperature (473, 573, and 673 K) in hydrogen, catalytic activity decreased. By using the same treatment that led to maximum ethylene hydrogenation activity, catalytic activity was also evaluated for pyrrole hydrogenation.

  1. Self-doped anthranilic acid-pyrrole copolymer/gold electrodes for selective preconcentration and determination of Cu(I) by differential pulse anodic stripping voltammetry.

    Science.gov (United States)

    Nateghi, M R; Fallahian, M H

    2007-05-01

    Electropolymerization of anthranilic acid/pyrrole (AA/PY) at solid substrate electrodes (platinum, gold, and glassy carbon) gave stable and water-insoluble films under a wide range of pH. Combining high conductivity of the polypyrrole (PPY) and pH independence of the electrochemical activity of the self-doped carboxylic acid-substituted polyaniline allows us to prepare an improved functionalized PPY-modified electrode to collect and measure Cu(I) species. The differential pulse stripping analysis of the copper ions using a polyanthranilic acid-co-polypyrrole (PAA/PPY)-modified electrode consisted of three steps: accumulation, electrochemical reduction to the elemental copper and stripping step. Factors affecting these steps, including electropolymerization conditions, accumulation and stripping medium, reduction potential, reduction time and accumulation time, were systematically investigated. A detection limit of 5.3 x 10(-9) M Cu(I) was achieved for a 7.0 min accumulation. For 12 determinations of Cu(I) at concentrations of 1.0 x 10(-8) M, an RSD of 3.5% was obtained. The log I(p) was found to vary linearly with log[Cu(I)] in the concentration range from 7.0 x 10(-9) to 1.0 x 10(-5) M.

  2. 1,4-Dihydropyrrolo[3,2-b]pyrroles as a Single Component Photoactive Layer: A New Paradigm for Broadband Detection.

    Science.gov (United States)

    Canjeevaram Balasubramanyam, Ram Kumar; Kandjani, Ahmad E; Harrison, Christopher J; Abdul Haroon Rashid, Syed Sulthan Alaudeen; Sabri, Ylias M; Bhargava, Suresh K; Narayan, Ramanuj; Basak, Pratyay; Ippolito, Samuel J

    2017-08-23

    Single component organic photodetectors capable of broadband light sensing represent a paradigm shift for designing flexible and inexpensive optoelectronic devices. The present study demonstrates the application of a new quadrupolar 1,4-dihydropyrrolo[3,2-b]pyrrole derivative with spectral sensitivity across 350-830 nm as a potential broadband organic photodetector (OPD) material. The amphoteric redox characteristics evinced from the electrochemical studies are exploited to conceptualize a single component OPD with ITO and Al as active electrodes. The photodiode showed impressive broadband photoresponse to monochromatic light sources of 365, 470, 525, 589, 623, and 830 nm. Current density-voltage (J-V) and transient photoresponse studies showed stable and reproducible performance under continuous on/off modulations. The devices operating in reverse bias at 6 V displayed broad spectral responsivity (R) and very good detectivity (D*) peaking a maximum 0.9 mA W(-1) and 1.9 × 10(10) Jones (at 623 nm and 500 μW cm(-2)) with a fast rise and decay times of 75 and 140 ms, respectively. Low dark current densities ranging from 1.8 × 10(-10) Acm(-2) at 1 V to 7.2 × 10(-9) A cm(-2) at 6 V renders an operating range to amplify the photocurrent signal, spectral responsivity, and detectivity. Interestingly, the fabricated OPDs display a self-operational mode which is rarely reported for single component organic systems.

  3. Bis{2-[(4-chlorophenyliminomethyl]pyrrol-1-ido-κ2N,N′}bis(dimethylamido-κNtitanium(IV toluene monosolvate

    Directory of Open Access Journals (Sweden)

    Yahong Li

    2012-05-01

    Full Text Available The mononuclear title compound, [Ti(C11H8ClN22(C2H6N2]·C7H8, was synthesized by the reaction of N-(4-chlorophenyl-2-pyrrolylcarbaldimine with Ti(C2H6N4. The TiIV ion is situated on a twofold rotation axis and displays a distorted octahedral geometry defined by four N atoms from two 2-[(4-chlorophenyliminomethyl]pyrrol-1-ide ligands and two N atoms from two dimethylamine ligands. The Ti—Npyrrole bond length [2.1041 (19 Å] is longer than the Ti—Ndimethylamine bond length [1.9013 (19 Å]; the imine N atom exhibits the longest Ti—N bond [2.3152 (17 Å]. The toluene solvent molecule is located on a twofold rotation axis running through the C atom of the methyl group. Consequently, the H atoms of the latter are rotationally disordered. The compound contains no markable hydrogen-bonding interactions.

  4. Photocatalytic Degradation of Eosin Yellow Using Poly(pyrrole-co-aniline-Coated TiO2/Nanocellulose Composite under Solar Light Irradiation

    Directory of Open Access Journals (Sweden)

    T. S. Anirudhan

    2015-01-01

    Full Text Available The present study describes the feasibility of a novel adsorbent cum photocatalyst, poly(pyrrole-co-aniline-coated TiO2/nanocellulose composite (P(Py-co-An-TiO2/NCC, to remove eosin yellow (EY from aqueous solutions. The removal of EY was investigated by batch adsorption followed by photocatalysis. The effect of various adsorption parameters like adsorbent dose, pH, contact time, initial concentration, and ionic strength has been optimized for treating effluents from the dye industry. Adsorption of EY reached maximum at pH 4.5 and complete removal of dye was achieved using 3.5 g/L of P(Py-co-An-TiO2/NCC. Adsorption equilibrium data were fitted with Langmuir and Fritz-Schlunder isotherm models and the kinetics of adsorption follows a second-order mechanism. The adsorption capacity of P(Py-co-An-TiO2/NCC was found to be 3.39 × 10−5 mol/g and reached equilibrium within 90 min. The photocatalytic degradation of adsorbed dye under sunlight was possible and about 92.3% of dye was degraded within 90 min. The reusability of P(Py-co-An-TiO2/NCC was also investigated. The results indicate that P(Py-co-An-TiO2/NCC is the best material for the wiping out of EY from aqueous solutions.

  5. Performance limitations in thieno[3,4-c]pyrrole-4,6-dione-based polymer:ITIC solar cells

    KAUST Repository

    Yang, Fan

    2017-08-15

    We report a systematic study of the efficiency limitations of non-fullerene organic solar cells that exhibit a small energy loss (Eloss) between the polymer donor and the non-fullerene acceptor. To clarify the impact of Eloss on the performance of the solar cells, three thieno[3,4-c]pyrrole-4,6-dione-based conjugated polymers (PTPD3T, PTPD2T, and PTPDBDT) are employed as the electron donor, which all have complementary absorption spectra compared with the ITIC acceptor. The corresponding photovoltaic devices show that low Eloss (0.54 eV) in PTPDBDT:ITIC leads to a high open-circuit voltage (Voc) of 1.05 V, but also to a small quantum efficiency, and in turn photocurrent. The high Voc or small energy loss in the PTPDBDT-based solar cells is a consequence of less non-radiative recombination, whereas the low quantum efficiency is attributed to the unfavorable micro-phase separation, as confirmed by the steady-state and time-resolved photoluminescence experiments, grazing-incidence wide-angle X-ray scattering, and resonant soft X-ray scattering (R-SoXS) measurements. We conclude that to achieve high performance non-fullerene solar cells, it is essential to realize a large Voc with small Eloss while simultaneously maintaining a high quantum efficiency by manipulating the molecular interaction in the bulk-heterojunction.

  6. ToF-SIMS characterization of silk fibroin and polypyrrole composite actuators

    Energy Technology Data Exchange (ETDEWEB)

    Bradshaw, Nathan P.; Severt, Sean Y.; Wang, Zhaoying; Fengel, Carly V.; Larson, Jesse D.; Zhu, Zihua; Murphy, Amanda R.; Leger., Janelle M.

    2015-11-01

    Biocompatible materials capable of controlled actuation under biologically relevant conditions are in high demand for use in a number of biomedical applications. Recently, we demonstrated that a composite material composed of silk biopolymer and the conducting polymer poly(pyrrole) can bend under an applied voltage using a simple bilayer device. Here we present further characterization of these bilayer actuators using time of flight secondary ion mass spectrometry, and provide clarification on the mechanism of actuation and factors affecting device performance and stability. We will discuss the results of this study in the context of strategies for optimization of device performance.

  7. Synthesis, characterization and prospective applications of nitrogen-doped graphene: A short review

    Directory of Open Access Journals (Sweden)

    Roshni Yadav

    2017-06-01

    Full Text Available Graphene is a high crystalline material possessing the high electronic qualities. Doping of nitrogen in graphene is to tailor/control the electronic, chemical and structural properties of graphene by manipulating it through the means of doping such as its surface area and functional sites. Different configurations i.e. Pyridinic N, Pyrrolic N, Graphitic N are obtained while doping nitrogen into graphene. This review paper focusses on various synthesis and characterization techniques for the analysis of structural configurations of the nitrogen-doped graphene and its potential applications in various fields such as nanoelectronics, energy storage and electrochemical biosensing.

  8. Submicron magnetic core conducting polypyrrole polymer shell: Preparation and characterization.

    Science.gov (United States)

    Tenório-Neto, Ernandes Taveira; Baraket, Abdoullatif; Kabbaj, Dounia; Zine, Nadia; Errachid, Abdelhamid; Fessi, Hatem; Kunita, Marcos Hiroiuqui; Elaissari, Abdelhamid

    2016-04-01

    Magnetic particles are of great interest in various biomedical applications, such as, sample preparation, in vitro biomedical diagnosis, and both in vivo diagnosis and therapy. For in vitro applications and especially in labs-on-a-chip, microfluidics, microsystems, or biosensors, the needed magnetic dispersion should answer various criteria, for instance, submicron size in order to avoid a rapid sedimentation rate, fast separations under an applied magnetic field, and appreciable colloidal stability (stable dispersion under shearing process). Then, the aim of this work was to prepare highly magnetic particles with a magnetic core and conducting polymer shell particles in order to be used not only as a carrier, but also for the in vitro detection step. The prepared magnetic seed dispersions were functionalized using pyrrole and pyrrole-2-carboxylic acid. The obtained core-shell particles were characterized in terms of particle size, size distribution, magnetization properties, FTIR analysis, surface morphology, chemical composition, and finally, the conducting property of those particles were evaluated by cyclic voltammetry. The obtained functional submicron highly magnetic particles are found to be conducting material bearing function carboxylic group on the surface. These promising conducting magnetic particles can be used for both transport and lab-on-a-chip detection.

  9. Evaluation of indoor residual spraying with the pyrrole insecticide chlorfenapyr against pyrethroid-susceptible Anopheles arabiensis and pyrethroid-resistant Culex quinquefasciatus mosquitoes.

    Science.gov (United States)

    Oxborough, R M; Kitau, J; Matowo, J; Mndeme, R; Feston, E; Boko, P; Odjo, A; Metonnou, C G; Irish, S; N'guessan, R; Mosha, F W; Rowland, M W

    2010-10-01

    Chlorfenapyr is a pyrrole insecticide with a unique non-neurological mode of action. Laboratory bioassays of chlorfenapyr comparing the mortality of pyrethroid-susceptible and -resistant Anopheles gambiae s.s. and Culex quinquefasciatus mosquitoes indicated that operational cross-resistance is unlikely to occur (resistance ratio ranged between 0 and 2.1). Three trials of chlorfenapyr indoor residual spraying were undertaken in experimental huts in an area of rice irrigation in northern Tanzania that supports breeding of A. arabiensis. Daily mosquito collections were undertaken to assess product performance primarily in terms of mortality. In the second trial, 250mg/m(2) and 500mg/m(2) chlorfenapyr were tested for residual efficacy over 6 months. Both dosages killed 54% of C. quinquefasciatus, whilst for A. arabiensis 250mg/m(2) killed 48% compared with 41% for 500mg/m(2); mortality was as high at the end of the trial as at the beginning. In the third trial, 250mg/m(2) chlorfenapyr was compared with the pyrethroid alpha-cypermethrin dosed at 30mg/m(2). Chlorfenapyr performance was equivalent to the pyrethroid against A. arabiensis, with both insecticides killing 50% of mosquitoes. Chlorfenapyr killed a significantly higher proportion of pyrethroid-resistant C. quinquefasciatus (56%) compared with alpha-cypermethrin (17%). Chlorfenapyr has the potential to be an important addition to the limited arsenal of public health insecticides for indoor residual control of A. arabiensis and pyrethroid-resistant species of mosquito. Copyright © 2010 Royal Society of Tropical Medicine and Hygiene.

  10. Marked Consequences of Systematic Oligothiophene Catenation in Thieno[3,4-c]pyrrole-4,6-dione and Bithiopheneimide Photovoltaic Copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Zhou, Nanjia; Guo, Xugang; Ponce Ortiz, Rocio; Harschneck, Tobias; Manley, Eric F.; Lou, Sylvia J.; Hartnett, Patrick E.; Yu, Xinge; Horwitz, Noah E.; Mayorga Burrezo, Paula; Aldrich, Thomas J.; Lopez Navarrete, Juan T.; Wasielewski, Michael R.; Chen, Lin X.; Chang, Robert P. H.; Facchetti, Antonio; Marks, Tobin J.

    2015-10-07

    As effective building blocks for high-mobility transistor polymers, oligothiophenes are receiving attention for polymer solar cells (PSCs) because the resulting polymers can effectively suppress charge recombination. Here we investigate two series of in-chain donor-acceptor copolymers, PTPDnT and PBTInT, based on thieno[3,4-c]pyrrole-4,6-dione (TPD) or bithiopheneimide (BTI) as electron acceptor units, respectively, and oligothiophenes (nTs) as donor counits, for high-performance PSCs. Intramolecular S···O interaction leads to more planar TPD polymer backbones, however backbone torsion yields greater open-circuit voltages for BTI polymers. Thiophene addition progressively raises polymer HOMOs but marginally affects their band gaps. FT-Raman spectra indicate that PTPDnT and PBTInT conjugation lengths scale with nT catenation up to n = 3 and then saturate for longer oligomer. Furthermore, the effects of oligothiophene alkylation position are explored, revealing that the alkylation pattern greatly affects film morphology and PSC performance. The 3T with “outward” alkylation in PTPD3T and PBTI3T affords optimal π-conjugation, close stacking, long-range order, and high hole mobilities (0.1 cm2/(V s)). These characteristics contribute to the exceptional ~80% fill factors for PTPD3T-based PSCs with PCE = 7.7%. The results demonstrate that 3T is the optimal donor unit among nTs (n = 1-4) for photovoltaic polymers. Grazing incidence wide-angle X-ray scattering, transmission electron microscopy, and time-resolved microwave conductivity measurements reveal that the terthiophene-based PTPD3T blend maintains high crystallinity with appreciable local mobility and long charge carrier lifetime. These results provide fundamental materials structure-device performance correlations and suggest guidelines for designing oligothiophene-based polymers with optimal thiophene catenation and appropriate alkylation pattern to maximize PSC performance.

  11. Thieno[3,4-c]Pyrrole-4,6-Dione-Based Polymer Acceptors for High Open-Circuit Voltage All-Polymer Solar Cells

    KAUST Repository

    Liu, Shengjian

    2017-04-20

    While polymer acceptors are promising fullerene alternatives in the fabrication of efficient bulk heterojunction (BHJ) solar cells, the range of efficient material systems relevant to the “all-polymer” BHJ concept remains narrow, and currently limits the perspectives to meet the 10% efficiency threshold in all-polymer solar cells. This report examines two polymer acceptor analogs composed of thieno[3,4-c]pyrrole-4,6-dione (TPD) and 3,4-difluorothiophene ([2F]T) motifs, and their BHJ solar cell performance pattern with a low-bandgap polymer donor commonly used with fullerenes (PBDT-TS1; taken as a model system). In this material set, the introduction of a third electron-deficient motif, namely 2,1,3-benzothiadiazole (BT), is shown to (i) significantly narrow the optical gap (Eopt) of the corresponding polymer (by ≈0.2 eV) and (ii) improve the electron mobility of the polymer by over two orders of magnitude in BHJ solar cells. In turn, the narrow-gap P2TPDBT[2F]T analog (Eopt = 1.7 eV) used as fullerene alternative yields high open-circuit voltages (VOC) of ≈1.0 V, notable short-circuit current values (JSC) of ≈11.0 mA cm−2, and power conversion efficiencies (PCEs) nearing 5% in all-polymer BHJ solar cells. P2TPDBT[2F]T paves the way to a new, promising class of polymer acceptor candidates.

  12. 3-substituted and 1, 3-disubstituted pyrroles synthesis from {alpha}, {beta} insaturated Nitriles. Formal total synthesis of Danaidona; Sintesis de pirroles 3-sustituidos y 1, 3-disustituidos a partir de Nitrilos {alpha}, {beta}- insaturados. Sintesis total formal de la Danaidona

    Energy Technology Data Exchange (ETDEWEB)

    Garcia, Hector; Flores, Blas; Leon, Fernando; Mendez, Jose Manuel [Universidad Nacional Autonoma de Mexico, Mexico, D.F. (Mexico)

    1996-02-01

    We describe a short method to obtain 3-substituted and 1, 3-disubstituted pyrroles from {alpha}, {beta}-insaturated nitriles. We obtained the corresponding substituted succinonitriles from 1, 4-addition of hydrogen cyanide to {alpha}, {beta}-insaturated nitriles. [Spanish] Se describe un metodo corto para obtener pirroles 3-sustituidos y 1, 3-disustituidos a partir de nitrilos {alpha}, {beta}-insaturados. Se obtuvieron los correspondientes succinonitrilos sustituidos a partir de la adicion 1, 4 de acido cianhidrico a nitrilos {alpha}, {beta}-insaturados.

  13. A Dual-Responsive Bola-Type Supra-amphiphile Constructed from a Water-Soluble Calix[4]pyrrole and a Tetraphenylethene-Containing Pyridine Bis-N-oxide.

    Science.gov (United States)

    Chi, Xiaodong; Zhang, Huacheng; Vargas-Zúñiga, Gabriela I; Peters, Gretchen M; Sessler, Jonathan L

    2016-05-11

    Complexation between a water-soluble calix[4]pyrrole and a ditopic pyridine N-oxide derivative in aqueous media produces a bola-type supra-amphiphile that self-assembles to produce higher order morphologies, including multilamellar vesicles and micelles depending on the pH. The present bola-type supra-amphiphile exhibits strong fluorescence due to structural changes and aggregation induced by host-guest complexation. The resulting structures may be used to recognize, encapsulate, and release non-fluorescent, water-soluble small molecules.

  14. Molecular topology applied to the discovery of 1-benzyl-2-(3-fluorophenyl)-4-hydroxy-3-(3-phenylpropanoyl)-2H-pyrrole-5-one as a non-ligand-binding-pocket antiandrogen.

    Science.gov (United States)

    Caboni, Laura; Gálvez-Llompart, Maria; Gálvez, Jorge; Blanco, Fernando; Rubio-Martinez, Jaime; Fayne, Darren; Lloyd, David G

    2014-10-27

    We report the discovery of 1-benzyl-2-(3-fluorophenyl)-4-hydroxy-3-(3-phenylpropanoyl)-2H-pyrrole-5-one as a novel non-ligand binding pocket (non-LBP) antagonist of the androgen receptor (AR) through the application of molecular topology techniques. This compound, validated through time-resolved fluorescence resonance energy transfer and fluorescence polarization biological assays, provides the basis for lead optimization and structure-activity relationship analysis of a new series of non-LBP AR antagonists. Induced-fit docking and molecular dynamics studies have been performed to establish a consistent hypothesis for the interaction of the new active molecule on the AR surface.

  15. Ordering effects in benzo[1,2-b:4,5-b']difuran-thieno[3,4-c]pyrrole-4,6- dione polymers with >7% solar cell efficiency

    KAUST Repository

    Warnan, Julien

    2014-05-15

    Benzo[1,2-b:4,5-b\\']difuran-thieno[3,4-c]pyrrole-4,6-dione (PBDFTPD) polymers prepared by microwave-assisted synthesis can achieve power conversion efficiencies (PCEs) >7% in bulk-heterojunction solar cells with phenyl-C61/71-butyric acid methyl ester (PCBM). In "as-cast" PBDFTPD-based devices solution-processed without a small-molecule additive, high PCEs can be obtained in spite of the weak propensity of the polymers to self-assemble and form π-aggregates in thin films. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Property-based design and synthesis of new chloroquine hybrids via simple incorporation of 2-imino-thiazolidine-4-one or 1h-pyrrol-2, 5-dione fragments on the 4-amino-7-chloroquinoline side chain

    Energy Technology Data Exchange (ETDEWEB)

    Rojas, Fernando A.; Kouznetsov, Vladimir V., E-mail: kouznet@uis.edu.co [Laboratorio de Quimica Organica y Biomolecular, Escuela de Quimica, Universidad Industrial de Santander, Bucaramanga (Colombia)

    2011-09-15

    In the present work, the syntheses of new 4-amino-7-chloroquinoline N-derivatives were performed by selective modification of the side chain amino group of N-(7-chloroquinoline-4-yl) alkyldiamines, basis framework of chloroquine (CQ) drug through the incorporation of heterocyclic 2-imino-thiazolidine-4-one and {sup 1}H-pyrrol-2,5-dione systems. These potential activity modulators were selected thanks to their characteristic properties, and evaluated by virtual screening employing the OSIRIS and Molinspirations platforms. Designed and synthesized quinolinic derivatives could increase the antimalarial activity of CQ analogues without affecting the lipophilicity as described in literature, suggesting them as candidates for further biological assessments. (author)

  17. Synthesis and Properties of Heteroacenes Containing Pyrrole and Thiazine Rings as Promising n-Type Organic Semiconductor Candidates

    Institute of Scientific and Technical Information of China (English)

    HONG,Wei; WEI,Zhongming; XU,Wei; WANG,Quanrui; ZHU,Daoben

    2009-01-01

    PBBTZ (6H-pyrrolo[3,2-b:4,5-b']bis[1,4]benzothiazine) was a p-type semiconductor with high field-effect transistor (FET) performance that we have just reported.Two trifluoromethyl substituted PBBTZ derivatives 3a and 3b were synthesized from facile one-pot condensation.They were characterized by means of 1H NMR,IR,HRMS (EI-TOF) and elemental analysis,furthermore,the crystal structure of 3b was described and discussed.Their optical properties were studied by UV-Vis and fluorescence spectroscopy,electrochemical properties were investigated by cyclic voltammetry (CV),and thermal properties were evaluated by thermal gravimetric analysis (TGA).The energy gaps of 3a and 3b,taken directly from spectroscopic measurements,are as broad as 2.45 and 2.48 eV,leading to bluish green and green photoluminescence.The LUMO and HOMO energy levels are -5.73 and -3.28 eV for 3a,-5.67 and -3.19 eV for 3b,respectively.The low energy levels render them well air-stable,and to be promising n-type semiconductor candidates for use in organic electronics.

  18. Synthesis and Characterization of 2, 3, 7, 8, 12, 13, 17, 18, Octabromo 5, 10, 15, 20 tetra phenyl porphyrin

    Directory of Open Access Journals (Sweden)

    Kalpana Raikwar

    2015-06-01

    Full Text Available Chromium(III porphyrin and its derivative have been synthesized by bromination and demetallation of copper tetra phenyl porphyrin.All the complexes were characterized on the basis of their elemental analysis, UV-vis spectra and magnetic moment properties.The magnetic moment suggested that the complex in the range 3.79 BM indicating an octahedral structure. The comparison of the UV- vis spectra of the free base show that substitution of Br atom at β-pyrrole position lead to greater shift than substitution of electronegative group in the phenyl ring

  19. Synthesis and Characterization of 2, 3, 7, 8, 12, 13, 17, 18, Octabromo 5, 10, 15, 20 tetra phenyl porphyrin

    OpenAIRE

    Kalpana Raikwar

    2015-01-01

    Chromium(III) porphyrin and its derivative have been synthesized by bromination and demetallation of copper tetra phenyl porphyrin.All the complexes were characterized on the basis of their elemental analysis, UV-vis spectra and magnetic moment properties.The magnetic moment suggested that the complex in the range 3.79 BM indicating an octahedral structure. The comparison of the UV- vis spectra of the free base show that substitution of Br atom at β-pyrrole position lead to greater shift than...

  20. Determination of pyrazole and pyrrole pesticides in environmental water samples by solid-phase extraction using multi-walled carbon nanotubes as adsorbent coupled with high-performance liquid chromatography.

    Science.gov (United States)

    Ma, Jiping; Lu, Xi; Xia, Yan; Yan, Fengli

    2015-02-01

    A solid-phase extraction (SPE) method using multi-walled carbon nanotubes as adsorbent coupled with high-performance liquid chromatography was developed for the determination of four pyrazole and pyrrole pesticides (fenpyroximate, chlorfenapyr, fipronil and flusilazole) in environmental water samples. Several parameters, such as extraction adsorbent, elution solvent and volume and sample loading flow rate were optimized to obtain high SPE recoveries and extraction efficiency. The calibration curves for the pesticides extracted were linear in the range of 0.05-10 μg L(-1) for chlorfenapyr and fenpyroximate and 0.05-20 μg L(-1) for fipronil and flusilazole, with the correlation coefficients (r(2)) between 0.9966 and 0.9990. The method gave good precisions (relative standard deviation %) from 2.9 to 10.1% for real spiked samples from reservoir water and seawater; method recoveries ranged 92.2-105.9 and 98.5-103.9% for real spiked samples from reservoir water and seawater, respectively. Limits of detection (S/N = 3) for the method were determined to be 8-19 ng L(-1). The optimized method was successfully applied to the determination of four pesticides of pyrazoles and pyrroles in real environmental water samples. © The Author 2014. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  1. Effects of 5-Amyno-4-(1,3-benzothyazol-2-yn-1-(3-methoxyphenyl-1,2-dihydro-3H-pyrrol-3-one Intake on Digestive System in a Rat Model of Colon Cancer

    Directory of Open Access Journals (Sweden)

    Halyna M. Kuznietsova

    2015-01-01

    Full Text Available Introduction. Pyrrol derivate 5-amyno-4-(1,3-benzothyazol-2-yn-1-(3-methoxyphenyl-1,2-dihydro-3H-pyrrol-3-one (D1 has shown antiproliferative activities in vitro, so investigation of the impact of D1 intake on gut organs in rats that experienced colon cancer seems to be necessary. Materials and Methods. D1 at the dose of 2.3 mg/kg was administered per os daily for 27 (from the 1st day of experiment or 7 (from the 21st week of experiment weeks to rats that experienced 1,2-dimethylhydrazine (DMH-induced colon cancer for 20 weeks. 5-Fluorouracil (5FU was chosen as reference drug and was administered intraperitoneally weekly for 7 weeks (from the 21st week of experiment at the dose of 45 mg/kg. Results. Antitumor activity of D1 comparable with the 5FU one against DMH-induced colon cancer in rats was observed (decrease of tumor number and tumor total area up to 46%. D1 attenuated the inflammation of colon, gastric and jejunal mucosa, and the liver, caused by DMH, unlike 5FU, aggravating the latter. In addition, D1 partially normalized mucosa morphometric parameters suggesting its functional restore. Conclusions. D1 possesses, comparable with 5-fluorouracil antitumor efficacy, less damaging effects on the tissues beyond cancerous areas and contributes to partial morphological and functional gut organs recovery.

  2. Azocalix[4]pyrrole Amberlite XAD-2: new polymeric chelating resins for the extraction, preconcentration and sequential separation of Cu(II), Zn(II) and Cd(II) in natural water samples.

    Science.gov (United States)

    Jain, Vinod K; Mandalia, Hiren C; Gupte, Hrishikesh S; Vyas, Disha J

    2009-10-15

    Two novel azocalix[4]pyrrole Amberlite XAD-2 polymeric chelating resins were synthesized by covalently linking diazotized Amberlite XAD-2 with calix[4]pyrrole macrocycles. The chelating resins were used for extraction, preconcentration and sequential separation of metal ions such as Cu(II), Zn(II) and Cd(II) by column chromatography prior to their determination by UV/vis spectrophotometry or flame atomic absorption spectrophotometry (FAAS) or inductively coupled plasma atomic emission spectroscopy (ICP-AES). Various parameters such as effect of pH on absorption, concentration of eluting agents, flow rate, total sorption capacity, exchange kinetics, preconcentration factor, distribution coefficient, breakthrough capacity and resin stability, were optimized for effective separation and preconcentration. The resin showed good ability for the separation of metal ions from binary and ternary mixture on the basis of pH of absorption and concentration of eluting agents. The newly synthesized resins showed good potential for trace enrichment of Cu(II), Zn(II) and Cd(II) metal ions, especially for Cu(II), as compared to the earlier reported resins. The synthesized resins were recycled at least 8-10 times without much affecting column sorption capacity. The presented method was successfully applied for determination of Cu(II), Zn(II) and Cd(II) in natural and ground water samples.

  3. The activity of the pyrrole insecticide chlorfenapyr in mosquito bioassay: towards a more rational testing and screening of non-neurotoxic insecticides for malaria vector control.

    Science.gov (United States)

    Oxborough, Richard M; N'Guessan, Raphael; Jones, Rebecca; Kitau, Jovin; Ngufor, Corine; Malone, David; Mosha, Franklin W; Rowland, Mark W

    2015-03-24

    The rapid selection of pyrethroid resistance throughout sub-Saharan Africa is a serious threat to malaria vector control. Chlorfenapyr is a pyrrole insecticide which shows no cross resistance to insecticide classes normally used for vector control and is effective on mosquito nets under experimental hut conditions. Unlike neurotoxic insecticides, chlorfenapyr owes its toxicity to disruption of metabolic pathways in mitochondria that enable cellular respiration. A series of experiments explored whether standard World Health Organization (WHO) guidelines for evaluation of long-lasting insecticidal nets, developed through testing of pyrethroid insecticides, are suitable for evaluation of non-neurotoxic insecticides. The efficacy of WHO recommended cone, cylinder and tunnel tests was compared for pyrethroids and chlorfenapyr. To establish bioassay exposure times predictive of insecticide-treated net (ITN) efficacy in experimental hut trials, standard three-minute bioassays of pyrethroid and chlorfenapyr ITNs were compared with longer exposures. Mosquito behaviour and response to chlorfenapyr ITN in bioassays conducted at night were compared to day and across a range of temperatures representative of highland and lowland transmission. Standard three-minute bioassay of chlorfenapyr produced extremely low levels of mortality compared to pyrethroids. Thirty-minute day-time bioassay produced mortality closer to hut efficacy of chlorfenapyr ITN but still fell short of the WHO threshold. Overnight tunnel test with chlorfenapyr produced 100% mortality and exceeded the WHO threshold of 80%. The endogenous circadian activity rhythm of anophelines results in inactivity by day and raised metabolism and flight activity by night. A model which explains improved toxicity of chlorfenapyr ITN when tested at night, and during the day at higher ambient temperature, is that activation of chlorfenapyr and disruption of respiratory pathways is enhanced when the insect is more metabolically

  4. Molecular structure, heteronuclear resonance assisted hydrogen bond analysis, chemical reactivity and first hyperpolarizability of a novel ethyl-4-{[(2,4-dinitrophenyl)-hydrazono]-ethyl}-3,5-dimethyl-1H-pyrrole-2-carboxylate: a combined DFT and AIM approach.

    Science.gov (United States)

    Singh, R N; Kumar, Amit; Tiwari, R K; Rawat, Poonam; Baboo, Vikas; Verma, Divya

    2012-06-15

    A new ethyl-4-{[(2,4-dinitrophenyl)-hydrazono]-ethyl}-3,5-dimethyl-1H-pyrrole-2-carboxylate (EDPHEDPC) has been synthesized and characterized by FT-IR, (1)H NMR, UV-vis, DART-Mass spectroscopy and elemental analysis. Quantum chemical calculations have been performed by DFT level of theory using B3LYP functional and 6-31G(d,p) as basis set. The (1)H NMR chemical shifts are calculated using gauge including atomic orbitals (GIAO) approach in DMSO as solvent. The time dependent density functional theory (TD-DFT) is used to find the various electronic transitions and their nature within molecule. A combined theoretical and experimental wavenumber analysis confirms the existence of dimer. Topological parameters such as electron density (ρ(BCP)), Laplacian of electron density (nabla(2)ρ(BCP)), kinetic electron energy density (G(BCP)), potential electron density (V(BCP)) and the total electron energy density (H(BCP)) at bond critical points (BCP) have been analyzed by Bader's 'Atoms in molecules' AIM theory in detail. The intermolecular hydrogen bond energy of dimer is calculated as -12.51 kcal/mol using AIM calculations. AIM ellipticity analysis is carried out to confirm the presence of resonance assisted intra and intermolecular hydrogen bonds in dimer. The calculated thermodynamic parameters show that reaction is exothermic and non-spontaneous at room temperature. The local reactivity descriptors such as Fukui functions (f(k)(+), f(k)(-)), local softnesses (s(k)(-), s(k)(+)) and electrophilicity indices (ω(k)(+), ω(k)(-)) analyses are performed to determine the reactive sites within molecule. Nonlinear optical (NLO) behavior of title compound is investigated by the computed value of first hyperpolarizability (β(0)). Copyright © 2012 Elsevier B.V. All rights reserved.

  5. EFSA CEF Panel (EFSA Panel on Food Contact Materials, Enzymes, Flavourings and Processing Aids), 2014. Scientific Opinion on Flavouring Group Evaluation 77, Revision 1 (FGE.77Rev1): Consideration of Pyridine, Pyrrole and Quinoline Derivatives evaluated by JECFA (63rd meeting)

    DEFF Research Database (Denmark)

    Beltoft, Vibe Meister; Binderup, Mona-Lise; Frandsen, Henrik Lauritz;

    evaluation is necessary, as laid down in Commission Regulation (EC) No 1565/2000. The present consideration concerns a group of 22 pyridine, pyrrole and quinoline derivatives evaluated by the JECFA (63rd meeting). The revision of this consideration is made since additional toxicity data have become available...

  6. New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties.

    Science.gov (United States)

    Selivanova, Daria G; Gorbunov, Alexei A; Mayorova, Olga A; Vasyanin, Alexander N; Lunegov, Igor V; Shklyaeva, Elena V; Abashev, Georgii G

    2017-01-01

    In this paper we present a synthetic approach to six new D-π-A-D conjugated chromophores containing the N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment. Such readily functionalizable heterocycle as carbazole was used as a main starting compound for their preparation. The investigation of the optical properties has shown that the positive solvatochromism is inherent to the chromophores containing an electron-withdrawing prop-2-en-1-one fragment, while the compounds containing a 2-aminopyrimidine moiety exhibit both positive and negative solvatochromism. The fluorescence quantum yields were experimentally determined for some of the synthesized chromophores; e.g., 1-(5-arylthiophen-2-yl)ethanones quantum yields were found to lie in an interval of 60-80%. Electrochemical oxidation of the synthesized chromophores has resulted in the formation of colored thin oligomeric films that became possible due to the presence of carbazole or pyrrole fragments with free electron-rich positions.

  7. Theoretical study of photophysical properties of 1,4-dihydropyrrolo[3,2-b]pyrrole-cored branched molecules with thienylenevinylene arms toward broad absorption spectra for solar cells.

    Science.gov (United States)

    Tang, Shanshan; Tang, Binbin; Liang, Dadong; Chen, Guang; Jin, Ruifa

    2013-09-01

    A series of oligo(thienylenevinylene) derivatives with 1,4-dihydropyrrolo[3,2-b]pyrrole as core has been investigated at the PBE0/6-31G(d) and the TD-PBE0/6-31+G(d,p) levels to design materials with high performances such as broad absorption spectra and higher balance transfer property. The results show that position and amount of arm affect the electronic density contours of frontier molecular orbitals significantly. The molecule with four arms owns the narrowest energy gap and the largest maximum absorption wavelength, and the molecule with two arms in positions a and c has the broadest absorption region among the designed molecules. Calculated reorganization energies of the designed molecules indicate that the molecules with two arms can be good potential ambipolar transport materials under proper operating conditions.

  8. Crystal structure of (E)-N-{[3-methyl-1-phenyl-5-(1H-pyrrol-1-yl)-1H-pyrazol-4-yl]methyl-idene}hydroxyl-amine.

    Science.gov (United States)

    Mague, Joel T; Mohamed, Shaaban K; Akkurt, Mehmet; El-Emary, Talaat I; Albayati, Mustafa R

    2014-11-01

    The title compound, C15H14N4O, crystallizes with two mol-ecules in the asymmetric unit with similar conformations (r.m.s. overlay fit for the 20 non-H atoms = 0.175 Å). In the first mol-ecule, the dihedral angles between the planes of the central pyrazole ring and the pendant phenyl and pyrrole rings are 42.69 (8) and 51.88 (6)°, respectively, with corresponding angles of 54.49 (7) and 49.61 (9)°, respectively, in the second mol-ecule. In the crystal, the two mol-ecules, together with their inversion-symmetry counterparts, are linked into tetra-mers by O-H⋯N hydrogen bonds. The tetra-mers form layers parallel to (211) through pairwise C-H⋯π inter-actions.

  9. 含五氟苯的噻吩并吡咯二酮-苯并二噻吩共轭聚合物的合成及其性能%Synthesis and Properties of Pentafluorobenzene-substituted Thieno[3,4-c] pyrrole-4,6-dione and Benzo[1,2-b ∶5,5-b′] dithiophene Conjugated Polymers

    Institute of Scientific and Technical Information of China (English)

    黄燕春; 周铭露; 王淑惠; 陈惠敏; 李萍萍; 王文

    2016-01-01

    2,5-Dibromo-5-perfluorophenylthieno[3,4-c]pyrrole-4,6-dione(2) was obtained by the re-action of acylation, condensation and NBS-bromination, using thiophene-3, 4-dicarboxylic acid and pentafluoroaniline as starting materials.2-Bromine-2,5-dithiophene-5-pentafluorphenyl thiophene[3,4-c]pyrrole-4,6-dione(4) was prepared by a two-step reaction from 2.Three pentafluorobenzene-substi-tuted thieno[3,4-c] pyrrole-4,6-dione and benzo[1,2-b ∶5,5-b′] dithiophene conjugated polymers (5a~5c ) were synthesized by Stille coupling condenstation, using dibenzothiophene ( BDT1 and BDT2 ) as donors and 2 or 4 as acceptors, respectively.The structures and properties were character-ized by 1 H NMR, 13 C NMR, UV-Vis, TGA and CV.The results showed that λmax of 5a, 5b and 5c were at 559 nm, 559 nm and 547 nm, respectively.T5 of 5a~5c were 307~325℃.The optical band gaps of 5a~5c were 1.70 eV, 1.73 eV, 1.68 eV(film) and 1.84 eV, 1.83 eV, 1.81 eV(toluene), re-spectively.The initial oxidation potentials and initial reduction potentials were 1.14 V, 1.18 V, 1.03 V and -0.67 V, -0.67 V, -0.70 V, respectively.The HOMO and LUMO energy levels of 5a~5c were -5.54 eV, -5.58 eV, -5.43 eV and -3.73 eV, -3.73 eV, -3.70 eV, respectively.%以3,4-噻吩二甲酸和五氟苯胺为起始原料,经酰化、缩合和NBS溴代反应制得2,5-二溴-5-五氟苯基噻吩[3,4-c]吡咯-4,6-二酮(2);2经两步反应制得2-溴-2,5-二噻吩-5-五氟苯基噻吩[3,4-c]吡咯-4,6-二酮(4);以苯并二噻吩衍生物( BDT1和BDT2)为给体单元,2或4为受体单元,分别经Stille偶联缩聚反应合成了3个含五氟苯的噻吩并吡咯二酮-苯并二噻吩共轭共聚物(5a~5c),其结构和性能经1H NMR,13C NMR, UV-Vis, TGA和循环伏安法表征。结果表明:5a,5b和5c的最大吸收峰分别位于559 nm,559 nm和547 nm,光学带隙分别为1.70 eV,1.73 eV,1.68 eV(薄膜)和1.84 eV,1.83 eV,1.81 e

  10. Influence of the Terminal Electron Donor in D-D-π-A Organic Dye-Sensitized Solar Cells: Dithieno[3,2-b:2',3'-d]pyrrole versus Bis(amine).

    Science.gov (United States)

    Dai, Panpan; Yang, Lin; Liang, Mao; Dong, Huanhuan; Wang, Peng; Zhang, Chunyao; Sun, Zhe; Xue, Song

    2015-10-14

    With respect to the electron-withdrawing acceptors of D-A-π-A organic dyes, reports on the second electron-donating donors for D-D-π-A organic dyes are very limited. Both of the dyes have attracted significant attention in the field of dye-sensitized solar cells (DSCs). In this work, four new D-D-π-A organic dyes with dithieno[3,2-b:2',3'-d]pyrrole (DTP) or bis(amine) donor have been designed and synthesized for a investigation of the influence of the terminal electron donor in D-D-π-A organic dye-sensitized solar cells. It is found that DTP is a promising building block as the terminal electron donor when introduced in the dithiophenepyrrole direction, but not just a good bridge, which exhibits several characteristics: (i) efficiently increasing the maximum molar absorption coefficient and extending the absorption bands; (ii) showing stronger charge transfer interaction as compared with the pyrrole direction; (iii) beneficial to photocurrent generation of DSCs employing cobalt electrolytes. DSCs based on M45 with the Co-phen electrolyte exhibit good light-to-electric energy conversion efficiencies as high as 9.02%, with a short circuit current density (JSC) of 15.3 mA cm(-2), open circuit voltage (VOC) of 867 mV and fill factor (FF) of 0.68 under AM 1.5 illumination (100 mW cm(-2)). The results demonstrate that N,S-heterocycles such as DTP unit could be promising candidates for application in highly efficient DSCs employing cobalt electrolyte.

  11. Structures of hydrazones, (E)-2-(1,3-benzothiazolyl)-NHsbnd Ndbnd CHsbnd Ar, [Ar = 4-(pyridin-2-yl)phenyl, pyrrol-2-yl, thien-2-yl and furan-2-yl]: Difference in conformations and intermolecular hydrogen bonding

    Science.gov (United States)

    Lindgren, Eric B.; Yoneda, Julliane D.; Leal, Katia Z.; Nogueira, Antônio F.; Vasconcelos, Thatyana R. A.; Wardell, James L.; Wardell, Solange M. S. V.

    2013-03-01

    Structures of hydrazones, (E)-2-(1,3-benzothiazolyl)-NHsbnd Ndbnd CHsbnd Ar(Ar = pyridine-2-yl (1), pyrrol-2-yl (2), thien-2-yl (3) and furan-2-yl (4), prepared from 2-hydrazinyl-1,3-benzothiazole and ArCHO, followed by recrystallisation from alcohol solutions, are reported. No significant intramolecular hydrogen bonds are present in any of the four molecules. Different conformations were found between 2 and 3, on one hand and for 4, on the other. Thus for 4, the oxygen atom of the furanyl ring is on the same side of the molecule as is the sulfur atom of the benzothiazole unit, while in contrast, each of the heteroatoms of the thienyl and pyrrole rings lies on opposite sides to the benzothiazole sulphur atom. In addition to the conformational variations, differences are noted in the connections between molecules. Despite the presence in each case of N(hydrazono)sbnd H---N(benzothiazolo) intermolecular hydrogen bonds, molecules of 4 are linked into spiral chains, while molecules of 2 and 3 (and indeed all compounds having Ar = substituted phenyl) form symmetric dimers. Further intermolecular interactions, albeit weaker ones, are found in 2 [Csbnd H··N and Nsbnd H··π], 3 [Csbnd H··π] and 4 [π··π], while dimers of 1 remain essentially free. Calculations carried out using the DFT(B3LYP)/6-311++G(d,p) method indicated that the conformations determined by crystallography for 2-4 were the more stable.

  12. Characterization of Polypyrrole.

    Science.gov (United States)

    1983-04-07

    the importance of planarity for high conductivity can also be obtained from a study of substituted polythiophenes which of course have no hydrogen...attached to the heteroatom. Table 2 shows the conductivity of several polythiophenes and the corresponding pyrroles. It should be pointed out that the... polythiophene relative to the polypyrrole. However the demonstrated sensitivity of the conductivity of chemically polymerized thiophenes to small amounts of non

  13. Synthesis of novel 5-alkyl/aryl/heteroaryl substituted diethyl 3,4-dihydro-2H-pyrrole-4,4-dicarboxylates by aziridine ring expansion of 2-[(aziridin-1-yl-1-alkyl/aryl/heteroaryl-methylene]malonic acid diethyl esters

    Directory of Open Access Journals (Sweden)

    U. K. Syam Kumar

    2011-06-01

    Full Text Available A novel synthetic methodology has been developed for the synthesis of diethyl 5-alkyl/aryl/heteroaryl substituted 3,4-dihydro-2H-pyrrole-4,4-dicarboxylates (also called 2-substituted pyrroline-4,5-dihydro-3,3-dicarboxylic acid diethyl esters by iodide ion induced ring expansion of 2-[(aziridin-1-yl-1-alkyl/aryl/heteroaryl-methylene]malonic acid diethyl esters in very good to excellent yields under mild reaction conditions. The electronic and steric impact of the substituents on the kinetics of ring expansion of N-vinyl aziridines to pyrrolines has been studied. Various diversely substituted novel pyrroline derivatives have been synthesized by this methodology and the products can be used as key intermediates in the synthesis of substituted pyrrolines, pyrroles and pyrrolidines.

  14. 1,8-二(2-吡咯酰胺)-3,6-二氯咔唑的合成、晶体结构及阴离子识别研究%Synthesis, Crystal Structure and Anion Recognition of 1,8-Di(pyrrole-2-carboxamino)-3,6-dichlorocarbazole

    Institute of Scientific and Technical Information of China (English)

    苏冬冬; 牛浩涛; 王莹; 何家骐; 程津培

    2009-01-01

    设计并合成了1,8-二(2-吡咯酰胺)-3,6-二氯咔唑化合物(1), 利用X射线单晶衍射研究了该化合物的固态结构. 利用荧光和紫外-可见光谱技术及 1H NMR滴定法研究了其对阴离子的识别. 研究结果表明, 化合物1对H_2PO~-_4离子有较强的识别能力, 且对H_2PO~-_4离子有明显的荧光增强效应, 可用来识别H_2PO~-_4离子. 同时~1H NMR滴定结果显示, 化合物1在阴离子识别过程中发生了构型转化.%Due to the fundamental roles that anions play in a wide range of chemical and biological processes, numerous efforts have been devoted to the design of receptors capable of selectively binding and sensing anions. Herein, carbazole derivative (1) bearing two model amides was synthesized by coupling 1,8-diamino-3 ,6-dichlorocarbazole with pyrrole-2-carbonylchloride in the presence of triethylamine. The structure of compound 1 was characterized by X-ray crystallography. The anions recognition of the compound 1 was studied by the UV-Vis and fluorescent spectra method in highly polar solvent of DMSO. The results show that strong anion binding is observed for H_2PO_4~-. Obvious fluorescence "switched on" behavior is observed upon addition of H_2PO_4~- to receptor 1, which can be used to discriminate H_2PO_4~- from the other anions. 'H NMR analysis revealed that all the five NH of receptor 1 were involved in the hydrogen bonding interactions with the anions leading to a conformation exchange during the anion binding.

  15. Synthesis and characterization of nanocomposites ZnO / polypyrrole for anti corrosive application; Sintese e caracterizacao de nanocompositos ZnO/polipirrol para aplicacao anticorrosivas

    Energy Technology Data Exchange (ETDEWEB)

    Valenca, D.P.; Bouchonneau, N.; Vieira, M.R.S.; Alves, K.G.B.; Melo, C.P. de; Urtiga Filho, S.L., E-mail: demetriusvalenca@gmail.com [Universidade Federal de Pernambuco (UFPE), Recife, PE (Brazil)

    2014-07-01

    Nanoparticles of metal oxides and conductive polymers have been investigated as alternative additives in corrosion protection of oxidizable metals. In this hybrid nanocomposites work Polypyrrole-ZnO were synthesized and characterized as a potential application as industrial paint anti corrosive additive. The different steps of the synthesis and characterization of nanocomposites are described. The nanocomposites were obtained from the emulsion polymerization of aqueous solutions of pyrrole and sodium dodecyl sulfate containing ZnO nanoparticles dispersed in the mass. The nanoparticles were characterized by scanning electron microscopy and transmission, dynamic light scattering, diffraction of X-rays and techniques of infrared spectroscopy. From the characterization techniques, it was possible to determine the average size of nanoparticles of ZnO and ZnO-Polypyrrole. The peaks in the diffraction pattern of X-rays observed in the nanocomposite were the same as in ZnO, confirming the presence of ZnO in the composite. (author)

  16. Synthesis of pyrrolo[2,1-f][1,2,4]triazin-4(3H-ones: Rearrangement of pyrrolo[1,2-d][1,3,4]oxadiazines and regioselective intramolecular cyclization of 1,2-biscarbamoyl-substituted 1H-pyrroles

    Directory of Open Access Journals (Sweden)

    Kkonnip Son

    2016-08-01

    Full Text Available Pyrrolo[2,1-f][1,2,4]triazin-4(3H-ones 12 have been easily prepared via nucleophile-induced rearrangement of pyrrolooxadiazines 11 and regioselective intramolecular cyclization of 1,2-biscarbamoyl-substituted 1H-pyrroles 10. In this work, we demonstrated that the described synthetic approaches can be considered to be more facile and practical than previously reported procedures.

  17. Synthesis and Charge Transport Properties of Polymers Derived from Oxidation of 1-H-1’(6-pyrrol-1-yl)-hexyl-4,4’-bipyridinium Bis-hexafluorophosphate and Demonstration of a pH Sensitive Microelectrochemical Transistor Derived from the Redox Properties of a Conventional Redox Center.

    Science.gov (United States)

    1988-08-15

    platinized poly(3- methylthiophene), 7b a viologen /quinone polymer, 9 ferrocyanide-loaded protonated poly(4-vinylpyridine),10 and electroactive metal...number) FiELD GROUP SUB-GROUP Microelectrode array, redox polymer, polypyrrole, viologen 19. ABSTRACT (Continue on reverse if necessary and identify by...electrochemical properties of redox polymers, having a poly- pyrrole backbone and viologen subunits, derived from oxidative electropolymerization of l

  18. Synthesis and characterization of a novel meso-porphyrin and its metallo derivatives

    Directory of Open Access Journals (Sweden)

    Paulo Cesar Bega

    2014-02-01

    Full Text Available There has been a growing interest in the properties of substituted meso-tetraarylporphyrins and metallo porphyrins as catalysts for oxidation of hydrocarbons, oxygen detection, among others. This work describes the synthesis of a new porphyrin, 5,10,15,20-tetrakis(4-butoxy-3-methoxyphenylporphyrin, and its metallo complexes. Herein it was used a readily available reactant, vanillin, as starting material which was submitted to alkylation with n-bromobutane affording the synthetic precursor. The desired porphyrin was obtained by reacting the O-alkylated aldehyde with pyrrole in the presence of propionic acid (Alder-Longo method. The purified porphyrin was then subjected to the metallation process using iron (II and manganese (II salts. The synthesized compounds were characterized by IR, UV-Vis, NMR and EPR spectroscopy.

  19. Schiff bases of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane and its silatranes: Synthesis and characterization

    Indian Academy of Sciences (India)

    Gurjaspreet Singh; Amandeep Saroa; Sadhika Khullar; Sanjay K Mandal

    2015-04-01

    This paper aims at the introduction of azomethine group by the condensation reaction of N-(2-aminoethyl)-3-aminopropyltrimethoxysilane with different compounds containing carbonyl group such as 2’-hydroxyacetophenone, salicylaldehyde, pyrrole-2-carboxaldehyde, acetylacetone and ethyl acetoacetate. Further, transesterification reaction of these Schiff base modified silanes with triethanolamine as a tripodal ligand leads to the synthesis of corresponding silatranes 1–5 bearing Schiff base functionalized long chain in the axial position. All the synthesized compounds are characterized by spectroscopic methods, elemental analysis and mass spectrometry. The authentication of Schiff base modified silatranes is scrutinized by single X-ray crystal structure of silatrane 1. The thermal stability of the five silatranes is studied by thermo-gravimetric analysis (TGA).

  20. Switchable Synthesis of Pyrroles and Pyrazines via Rh(II)-Catalyzed Reaction of 1,2,3-Triazoles with Isoxazoles: Experimental and DFT Evidence for the 1,4-Diazahexatriene Intermediate.

    Science.gov (United States)

    Rostovskii, Nikolai V; Ruvinskaya, Julia O; Novikov, Mikhail S; Khlebnikov, Alexander F; Smetanin, Ilia A; Agafonova, Anastasiya V

    2017-01-06

    4-Aminopyrrole-3-carboxylates and pyrazine-2-carboxylates were synthesized from 5-alkoxyisoxazoles and 1-sulfonyl-1,2,3-triazoles by tuning the Rh(II) catalyst and the reaction conditions. The reaction in chloroform at 100 °C under Rh2(OAc)4 catalysis provides 4-aminopyrrole-3-carboxylates in good yields. The use of Rh2(Piv)4 in refluxing toluene results in the formation of 1,2-dihydropyrazine-2-carboxylates as the main products, which can be converted by a one-pot procedure to pyrazine-2-carboxylates by heating with catalytic amounts of TsOH. According to the NMR and DFT investigations of the reaction mechanism, pyrroles and dihydropyrazines are formed, respectively, via 1,5- and 1,6-cyclization of common (5Z)-1,4-diazahexa-1,3,5-triene intermediates. The influence of the nature of the catalyst on the product distribution is rationalized in terms of the Rh-catalyzed isomerization of a pyrrolin-2-ylium-3-aminide zwitterion, the primary product of 1,4-diazahexatriene 1,5-cyclization.

  1. Modelling of cytotoxicity data (CC50) of anti-HIV 1-[5-chlorophenyl) sulfonyl]-1H-pyrrole derivatives using calculated molecular descriptors and Levenberg-Marquardt artificial neural network.

    Science.gov (United States)

    Arab Chamjangali, M

    2009-04-01

    A nonlinear quantitative structure anti-HIV activity relationship study was presented for modelling and predicting pyrryl aryl sulfones cytotoxicity data. Levenberg-Marquardt artificial neural network was used to link molecular structures and cytotoxicity data. A data set consisting of 27 derivatives of 1-[5-chlorophenyl) sulfonyl]-1H-pyrrole was used in this study. Among a large number of calculated descriptors, only eight significant molecular descriptors were obtained by stepwise regression, as the most feasible descriptors, and then they were used as inputs for neural network. The data set was randomly divided into 20 training and 7 validation sets and the neural network architecture and its parameters were optimized. The prediction ability of the model was evaluated using the validation data set, leave-one-out cross-validation and response randomization method. The mean square errors and mean absolute errors for the validation data set were 0.0067 and 0.066, respectively, and for the leave-one-out method, they were 0.013 and 0.087, respectively. The results obtained showed the excellent prediction ability and stability of the proposed model in the prediction of cytotoxicity data of the corresponding anti-HIV analogues.

  2. Electron-deficient N-alkyloyl derivatives of thieno[3,4-c]pyrrole-4,6-dione yield efficient polymer solar cells with open-circuit voltages > 1 v

    KAUST Repository

    Warnan, Julien

    2014-05-13

    Poly(benzo[1,2-b:4,5-b′]dithiophene-thieno[3,4-c]pyrrole-4,6-dione) (PBDTTPD) polymer donors yield some of the highest open-circuit voltages (V OC, ca. 0.9 V) and fill factors (FF, ca. 70%) in conventional bulk-heterojunction (BHJ) solar cells with PCBM acceptors. Recent work has shown that the incorporation of ring substituents into the side chains of the BDT motifs in PBDTTPD can induce subtle variations in material properties, resulting in an increase of the BHJ device VOC to ∼1 V. In this contribution, we report on the synthesis of N-alkyloyl-substituted TPD motifs (TPD(CO)) and show that the electron-deficient motifs can further lower both the polymer LUMO and HOMO levels, yielding device VOC > 1 V (up to ca. 1.1 V) in BHJ solar cells with PCBM. Despite the high VOC achieved (i.e., low polymer HOMO), BHJ devices cast from TPD(CO)-based polymer donors can reach power conversion efficiencies (PCEs) of up to 6.7%, making these promising systems for use in the high-band-gap cell of tandem solar cells. © 2014 American Chemical Society.

  3. Discovery, synthesis and SAR analysis of novel selective small molecule S1P4-R agonists based on a (2Z,5Z)-5-((pyrrol-3-yl)methylene)-3-alkyl-2-(alkylimino)thiazolidin-4-one chemotype.

    Science.gov (United States)

    Urbano, Mariangela; Guerrero, Miguel; Velaparthi, Subash; Crisp, Melissa; Chase, Peter; Hodder, Peter; Schaeffer, Marie-Therese; Brown, Steven; Rosen, Hugh; Roberts, Edward

    2011-11-15

    High affinity and selective S1P(4) receptor (S1P(4)-R) small molecule agonists may be important proof-of-principle tools used to clarify the receptor biological function and effects to assess the therapeutic potential of the S1P(4)-R in diverse disease areas including treatment of viral infections and thrombocytopenia. A high-throughput screening campaign of the Molecular Libraries-Small Molecule Repository was carried out by our laboratories and identified (2Z,5Z)-5-((1-(2-fluorophenyl)-2,5-dimethyl-1H-pyrrol-3-yl)methylene)-3-methyl-2-(methylimino) thiazolidin-4-one as a promising S1P(4)-R agonist hit distinct from literature S1P(4)-R modulators. Rational chemical modifications of the hit allowed the identification of a promising lead molecule with low nanomolar S1P(4)-R agonist activity and exquisite selectivity over the other S1P(1-3,5)-Rs family members. The lead molecule herein disclosed constitutes a valuable pharmacological tool to explore the effects of the S1P(4)-R signaling cascade and elucidate the molecular basis of the receptor function.

  4. Linear side chains in benzo[1,2-b:4,5-b′]dithiophene-thieno[3,4-c] pyrrole-4,6-dione polymers direct self-assembly and solar cell performance

    KAUST Repository

    Cabanetos, Clement

    2013-03-27

    While varying the size and branching of solubilizing side chains in π-conjugated polymers impacts their self-assembling properties in thin-film devices, these structural changes remain difficult to anticipate. This report emphasizes the determining role that linear side-chain substituents play in poly(benzo[1,2-b:4,5-b′]dithiophene-thieno[3,4-c]pyrrole-4,6-dione) (PBDTTPD) polymers for bulk heterojunction (BHJ) solar cell applications. We show that replacing branched side chains by linear ones in the BDT motifs induces a critical change in polymer self-assembly and backbone orientation in thin films that correlates with a dramatic drop in solar cell efficiency. In contrast, we show that for polymers with branched alkyl-substituted BDT motifs, controlling the number of aliphatic carbons in the linear N-alkyl-substituted TPD motifs is a major contributor to improved material performance. With this approach, PBDTTPD polymers were found to reach power conversion efficiencies of 8.5% and open-circuit voltages of 0.97 V in BHJ devices with PC71BM, making PBDTTPD one of the best polymer donors for use in the high-band-gap cell of tandem solar cells. © 2013 American Chemical Society.

  5. 9-Glutathionyl-6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine Is the Major Pyrrolic Glutathione Conjugate of Retronecine-Type Pyrrolizidine Alkaloids in Liver Microsomes and in Rats.

    Science.gov (United States)

    Chen, Meixia; Li, Liang; Zhong, Dafang; Shen, Shuijie; Zheng, Jiang; Chen, Xiaoyan

    2016-02-15

    Retronecine-, otonecine-, and heliotridine-type pyrrolizidine alkaloids (PAs) are all reported to be hepatotoxic. These PAs are suggested to be metabolized to the corresponding electrophilic dehydropyrrolizidine alkaloids (dehydro-PAs) and subsequently conjugated with macromolecules, such as glutathione (GSH). In the present study, a total of five glutathione conjugates, named M1-M5, were detected in rat and human liver microsomal incubations with three retrornecine-type PAs (isoline, retrorsine, or monocrotaline) in the presence of glutathione, and were chemically synthesized. M1 and M3 were unambiguously identified as a pair of epimers of 7-glutathionyl-6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine (7-GSH-DHP), and M4 and M5 were epimers of 7,9-diglutathionyl-6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine (7,9-diGSH-DHP). M2, an extremely unstable conjugate, was proposed to be 9-glutathionyl-6,7-dihydro-1-hydroxymethyl-5H-pyrrolizine (9-GSH-DHP). It was the most abundant among the five GSH conjugates, and the finding corrects the mistake that 7-GSH-DHP is the predominant GSH conjugate derived from dehydro-PAs. Similar patterns in glutathione conjugate profile were observed in the bile of rats treated with the PAs. This is the first study to describe 9-GSH-DHP as a major pyrrolic GSH conjugate of retronecine-type PAs, providing insight into the interactions of dehydro-PAs with biomolecules.

  6. A Theoretical Study of the Relationships between Electronic Structure and CB1 and CB2 Cannabinoid Receptor Binding Affinity in a Group of 1-Aryl-5-(1-H-pyrrol-1-yl-1-H-pyrazole-3-carboxamides

    Directory of Open Access Journals (Sweden)

    Francisco Salgado-Valdés

    2014-01-01

    Full Text Available We report the results of a search for model-based relationships between hCB1 and hCB2 receptor binding affinity and molecular structure for a group of 1-aryl-5-(1-H-pyrrol-1-yl-1-H-pyrazole-3-carboxamides. The wave functions and local atomic reactivity indices were obtained at the B3LYP/6-31G(d,p levels of theory with full geometry optimization. Interaction pharmacophores were generated for both receptors. The main conclusions of this work are as follows. (1 We obtained statistically significant equations relating the variation of hCB1 and hCB2 receptor binding affinities with the variation of definite sets of local atomic reactivity indices. (2 The interaction of the molecules with the hCB1 and hCB2 receptors seems to be highly complex and mainly orbital controlled. (3 The interaction mechanisms seem to be different for each type of receptor. This study, contrarily to the statistically backed ones, is able to provide a microscopic insight of the mechanisms involved in the binding process.

  7. Crystal structure of the catalytic domain of PigE: a transaminase involved in the biosynthesis of 2-methyl-3-n-amyl-pyrrole (MAP) from Serratia sp. FS14.

    Science.gov (United States)

    Lou, Xiangdi; Ran, Tingting; Han, Ning; Gao, Yanyan; He, Jianhua; Tang, Lin; Xu, Dongqing; Wang, Weiwu

    2014-04-25

    Prodigiosin, a tripyrrole red pigment synthesized by Serratia and some other microbes through a bifurcated biosynthesis pathway, MBC (4-methoxy-2,2'-bipyrrole-5-carbaldehyde) and MAP (2-methyl-3-n-amyl-pyrrole) are synthesized separately and then condensed by PigC to form prodigiosin. MAP is synthesized sequentially by PigD, PigE and PigB. PigE catalyzes the transamination of an amino group to the aldehyde group of 3-acetyloctanal, resulting in an aminoketone, which spontaneously cyclizes to form H2MAP. Here we report the crystal structure of the catalytic domain of PigE which involved in the biosynthesis of prodigiosin precursor MAP for the first time to a resolution of 2.3Å with a homodimer in the asymmetric unit. The monomer of PigE catalytic domain is composed of three domains with PLP as cofactor: a small N-terminal domain connecting the catalytic domain with the front part of PigE, a large PLP-binding domain and a C-terminal domain. The residues from both monomers build the PLP binding site at the interface of the dimer which resembles the other PLP-dependent enzymes. Structural comparison of PigE with Thermus thermophilus AcOAT showed a higher hydrophobic and smaller active site of PigE, these differences may be the reason for substrate specificity.

  8. The formation of [M-H]+ ions in N-alkyl-substituted thieno[3,4-c]-pyrrole-4,6-dione derivatives during atmospheric pressure photoionization mass spectrometry

    KAUST Repository

    Sioud, Salim

    2014-10-09

    RESULTS [M-H]+ ions were observed under APPI conditions. The type of dopant and the length of the alkyl chain affected the formation of these ions. MS/MS fragmentation of [M-H]+ and [M + H]+ ions exhibited completely different patterns. Theoretical calculations revealed that the loss of hydrogen molecules from the [M + H]+ ions is the most favourable condition under which to form [M-H]+ ions.CONCLUSIONS [M-H]+ ions were detected in all the TPD derivatives studied here under the special experimental conditions during APPI, using a halogenated benzene dopant, and TPD containing substituted N-alkyl side chains with a minimum of four carbon atoms. Density functional theory calculations showed that for [M-H]+ ions to be formed under these conditions, the loss of hydrogen molecules from the [M + H]+ ions is proposed to be necessary.RATIONALE The formation of ions during atmospheric pressure photoionization (APPI) mass spectrometry in the positive mode usually provides radical cations and/or protonated species. Intriguingly, during the analysis of some N-alkyl-substituted thieno[3,4-c]pyrrole-4,6-dione (TPD) derivatives synthesized in our laboratory, unusual [M-H]+ ion peaks were observed. In this work we investigate the formation of [M-H]+ ions observed under APPI conditions.METHODS Multiple experimental parameters, including the type of ionization source, the composition of the solvent, the type of dopant, the infusion flow rate, and the length of the alkyl side chain were investigated to determine their effects on the formation of [M-H]+ ions. In addition, a comparison study of the gas-phase tandem mass spectrometric (MS/MS) fragmentation of [M + H]+ vs [M-H]+ ions and computational approaches were used.

  9. Bithiopheneimide-dithienosilole/dithienogermole copolymers for efficient solar cells: information from structure-property-device performance correlations and comparison to thieno[3,4-c]pyrrole-4,6-dione analogues.

    Science.gov (United States)

    Guo, Xugang; Zhou, Nanjia; Lou, Sylvia J; Hennek, Jonathan W; Ponce Ortiz, Rocío; Butler, Melanie R; Boudreault, Pierre-Luc T; Strzalka, Joseph; Morin, Pierre-Olivier; Leclerc, Mario; López Navarrete, Juan T; Ratner, Mark A; Chen, Lin X; Chang, Robert P H; Facchetti, Antonio; Marks, Tobin J

    2012-11-07

    Rational creation of polymeric semiconductors from novel building blocks is critical to polymer solar cell (PSC) development. We report a new series of bithiopheneimide-based donor-acceptor copolymers for bulk-heterojunction (BHJ) PSCs. The bithiopheneimide electron-deficiency compresses polymer bandgaps and lowers the HOMOs--essential to maximize power conversion efficiency (PCE). While the dithiophene bridge progression R(2)Si→R(2)Ge minimally impacts bandgaps, it substantially alters the HOMO energies. Furthermore, imide N-substituent variation has negligible impact on polymer opto-electrical properties, but greatly affects solubility and microstructure. Grazing incidence wide-angle X-ray scattering (GIWAXS) indicates that branched N-alkyl substituents increased polymer π-π spacings vs linear N-alkyl substituents, and the dithienosilole-based PBTISi series exhibits more ordered packing than the dithienogermole-based PBTIGe analogues. Further insights into structure-property-device performance correlations are provided by a thieno[3,4-c]pyrrole-4,6-dione (TPD)-dithienosilole copolymer PTPDSi. DFT computation and optical spectroscopy show that the TPD-based polymers achieve greater subunit-subunit coplanarity via intramolecular (thienyl)S···O(carbonyl) interactions, and GIWAXS indicates that PBTISi-C8 has lower lamellar ordering, but closer π-π spacing than does the TPD-based analogue. Inverted BHJ solar cells using bithiopheneimide-based polymer as donor and PC(71)BM as acceptor exhibit promising device performance with PCEs up to 6.41% and V(oc) > 0.80 V. In analogous cells, the TPD analogue exhibits 0.08 V higher V(oc) with an enhanced PCE of 6.83%, mainly attributable to the lower-lying HOMO induced by the higher imide group density. These results demonstrate the potential of BTI-based polymers for high-performance solar cells, and provide generalizable insights into structure-property relationships in TPD, BTI, and related polymer semiconductors.

  10. Sensitive and selective electrochemical determination of quinoxaline-2-carboxylic acid based on bilayer of novel poly(pyrrole) functional composite using one-step electro-polymerization and molecularly imprinted poly(o-phenylenediamine).

    Science.gov (United States)

    Yang, Yukun; Fang, Guozhen; Wang, Xiaomin; Pan, Mingfei; Qian, Hailong; Liu, Huilin; Wang, Shuo

    2014-01-01

    A facile and efficient molecularly imprinted polymer (MIP) recognition element of electrochemical sensor was fabricated by directly electro-polymerizing monomer o-phenylenediamine (oPD) in the presence of template quinoxaline-2-carboxylic acid (QCA), based on one-step controllable electrochemical modification of poly(pyrrole)-graphene oxide-binuclear phthalocyanine cobalt (II) sulphonate (PPY-GO-BiCoPc) functional composite on glassy carbon electrode (GCE). The MIP film coated on PPY-GO-BiCoPc functional composite decorated GCE (MIP/PPY-GO-BiCoPc/GCE) was presented for the first time. The synergistic effect and electro-catalytic activity toward QCA redox of PPY-GO-BiCoPc functional composite were discussed using various contrast tests. Also, the effect of experimental variables on the current response such as, electro-polymerization cycles, template/monomer ratio, elution condition for template removal, pH of the supporting electrolyte and accumulation time, were investigated in detail. Under the optimized conditions, the proposed MIP sensor possessed a fast rebinding dynamics and an excellent recognition capacity to QCA, while the anodic current response of square wave voltammetry (SWV) was well-proportional to the concentration of QCA in the range of 1.0×10(-8)-1.0×10(-4) and 1.0×10(-4)-5.0×10(-4) mol L(-1) with a low detection limit of 2.1 nmol L(-1). The established sensor was applied successfully to determine QCA in commercial pork and chicken muscle samples with acceptable recoveries (91.6-98.2%) and satisfactory precision (1.9-3.5% of SD), demonstrating a promising feature for applying the MIP sensor to the measurement of QCA in real samples.

  11. Synthesis, Crystal Structure and Properties of Monomeric Copper(Ⅱ) Complexes of Pyrrole-Containing Tridentate Schiff-Base Ligands%含吡咯三齿席夫碱配体的单核铜(Ⅱ)配合物的合成、晶体结构和性质

    Institute of Scientific and Technical Information of China (English)

    李荣清; 赵朴素; 张宇; 张载超; 刘仲雨; 赵振

    2012-01-01

    Two copper(Ⅱ) complexes of the homologous tridentate Schiff-base ligands (L1)- and (L2)-,[CuL1I] (1)and [CuL2I] (2),have been synthesised and characterised by IR,ES-MS,UV-Vis,single crystal X-ray diffraction and thermogravimetric analysis ((L1)- and (L2)- are the deprotonated forms of 2-(2-pyridyl)-N-[1-(1H-pyrrol-2-yl)ethylidene]ethanamine (HL1) and N-[1-(1H-pyrrol-2-yl)ethylidene](2-pyridyl)methanamine (HL2),respectively).X-ray crystal structure determination carried out on 1 reveals that it is a distorted square planar copper(Ⅱ) monomer.The crystal structure indicates that the intermolecular interaction is also a factor which can influence the structural properties of copper(Ⅱ) complexes in addition to ligand flexibility and steric constraints.CCDC:862124.%合成和表征了两个类似的三齿席夫碱配体(L1)-和(L2)-的铜(Ⅱ)配合物[CuL1I] (1)和[CuL2I] (2)(HL1为2-(2- pyridyl)-N-[1 -(1H-pyrrol-2-yl)ethylidene]ethanamine;HL2为N-[1-(1H-pyrrol-2-yl)ethylidene](2-pyridyl)methanamine),并用红外光谱、电喷雾质谱、紫外-可见光谱、单晶X-射线衍射和热重分析等手段对配合物进行了表征.对配合物1的X-射线晶体结构测定表明它是一个畸变的平面正方形单核铜(Ⅱ)配合物.晶体结构还表明,除了配体的柔性和空间限制外,分子间的相互作用也是影响铜(Ⅱ)配合物结构的因素.

  12. Synthesis, hydrolytic DNA-cleaving activities and cytotoxicities of EDTA analogue-tethered pyrrole-polyamide dimer-based Ce(IV) complexes.

    Science.gov (United States)

    Yang, Jian-Wei; Lin, Yan-Ling; Dong, Cheng; Zhou, Chun-Qiong; Chen, Jin-Xiang; Wang, Bo; Zhou, Zhong-Zhen; Sun, Bin; Chen, Wen-Hua

    2014-11-24

    Two EDTA analogue-tethered C2-symmetrical dimeric monopyrrole-polyamide 5 and dipyrrole-polyamide 6, and their corresponding Ce(IV) complexes Ce-5 and Ce-6 were synthesized and fully characterized. Agarose gel electrophoresis studies on pBR322 DNA cleavage indicate that complexes Ce-5 and Ce-6 exhibited potent DNA-cleaving activities under physiological conditions. The maximal first-order rate constants (kmax's) were (0.42 ± 0.02) h(-1) for Ce-5 and (0.52 ± 0.02) h(-1) for Ce-6, respectively, suggesting that both complexes catalyzed the cleavage of supercoiled DNA by up to approximately 10(8)-fold. Complex Ce-6 exhibited ca 10-fold higher overall catalytic activity (kmax/KM) than Ce-5, which may be ascribed to its higher DNA-binding affinity. Inhibition experiments and a model study convincingly suggest that both complexes Ce-5 and Ce-6 functioned as hydrolytic DNA-cleavers. In addition, both complexes were found to display moderate inhibitory activity toward A549 and HepG-2 cells. Copyright © 2014 Elsevier Masson SAS. All rights reserved.

  13. Detailed characterization of a Comparative Reactivity Method (CRM) instrument for ambient OH reactivity measurements: experiments vs. modeling

    Science.gov (United States)

    Michoud, Vincent; Locoge, Nadine; Dusanter, Sébastien

    2015-04-01

    The Hydroxyl radical (OH) is the main daytime oxidant in the troposphere, leading to the oxidation of Volatile Organic Compounds (VOCs) and the formation of harmful pollutants such as ozone (O3) and Secondary Organic Aerosols (SOA). While OH plays a key role in tropospheric chemistry, recent studies have highlighted that there are still uncertainties associated with the OH budget, i.e the identification of sources and sinks and the quantification of production and loss rates of this radical. It has been demonstrated that ambient measurements of the total OH loss rate (also called total OH reactivity) can be used to identify and reduce these uncertainties. In this context, the Comparative Reactivity Method (CRM), developed by Sinha et al. (ACP, 2008), is a promising technique to measure total OH reactivity in ambient air and has already been used during several field campaigns. This technique relies on monitoring competitive reactions of OH with ambient trace gases and a reference compound (pyrrole) in a sampling reactor to derive ambient OH reactivity. However, this technique requires a complex data processing chain that has yet to be carefully investigated in the laboratory. In this study, we present a detailed characterization of a CRM instrument developed at Mines Douai, France. Experiments have been performed to investigate the dependence of the CRM response on humidity, ambient NOx levels, and the pyrrole-to-OH ratio inside the sampling reactor. Box modelling of the chemistry occurring in the reactor has also been performed to assess our theoretical understanding of the CRM measurement. This work shows that the CRM response is sensitive to both humidity and NOx, which can be accounted for during data processing using parameterizations depending on the pyrrole-to-OH ratio. The agreement observed between laboratory studies and model results suggests a good understanding of the chemistry occurring in the sampling reactor and gives confidence in the CRM

  14. Chlorfenapyr (A Pyrrole Insecticide) Applied Alone or as a Mixture with Alpha-Cypermethrin for Indoor Residual Spraying against Pyrethroid Resistant Anopheles gambiae sl: An Experimental Hut Study in Cove, Benin.

    Science.gov (United States)

    Ngufor, Corine; Critchley, Jessica; Fagbohoun, Josias; N'Guessan, Raphael; Todjinou, Damien; Rowland, Mark

    2016-01-01

    Indoor spraying of walls and ceilings with residual insecticide remains a primary method of malaria control. Insecticide resistance in malaria vectors is a growing problem. Novel insecticides for indoor residual spraying (IRS) which can improve the control of pyrethroid resistant malaria vectors are urgently needed. Insecticide mixtures have the potential to improve efficacy or even to manage resistance in some situations but this possibility remains underexplored experimentally. Chlorfenapyr is a novel pyrrole insecticide which has shown potential to improve the control of mosquitoes which are resistant to current WHO-approved insecticides. The efficacy of IRS with chlorfenapyr applied alone or as a mixture with alpha-cypermeththrin (a pyrethroid) was evaluated in experimental huts in Cove, Southern Benin against wild free flying pyrethroid resistant Anopheles gambiae sl. Comparison was made with IRS with alpha-cypermethrin alone. Fortnightly 30-minute in situ cone bioassays were performed to assess the residual efficacy of the insecticides on the treated hut walls. Survival rates of wild An gambiae from the Cove hut site in WHO resistance bioassays performed during the trial were >90% with permethrin and deltamethrin treated papers. Mortality of free-flying mosquitoes entering the experimental huts was 4% in the control hut. Mortality with alpha-cypermethrin IRS did not differ from the control (5%, P>0.656). The highest mortality was achieved with chlorfenapyr alone (63%). The alpha-cypermethrin + chlorfenapyr mixture killed fewer mosquitoes than chlorfenapyr alone (43% vs. 63%, P<0.001). While the cone bioassays showed a more rapid decline in residual mortality with chlorfenapyr IRS to <30% after only 2 weeks, fortnightly mortality rates of wild free-flying An gambiae entering the chlorfenapyr IRS huts were consistently high (50-70%) and prolonged, lasting over 4 months. IRS with chlorfenapyr shows potential to significantly improve the control of malaria

  15. Synthesis, UV/vis, FT-IR and Mössbauer spectroscopic characterization and molecular structure of the Bis[4-(2-aminoethyl)morpholine](tetrakis(4-metoxyphenyl)porphyrinato) iron(II) complex

    Science.gov (United States)

    Ben Haj Hassen, Leila; Ezzayani, Khaireddine; Rousselin, Yoann; Stern, Christine; Nasri, Habib; Schulz, Charles E.

    2016-04-01

    The synthesis, the UV-visible, FT-IR and Mössbauer spectroscopy and the crystal structure characterizations of the bis[4-(2-Aminoethyl)morpholine]tetrakis(4-metoxyphenyl)porphy-rinato)iron(II) complex are described. The title compound crystallizes in the triclinic, space group P-1, with a = 11.1253(4) Å, b = 11.2379(4) Å, c = 11.5488(4) Å, α = 72.304(2)°, β = 86.002(2)°, γ = 72.066(2)°, V = 1308.28(8) Å3, Z = 1. The Môssbauer data are consistent with an iron(II) low-spin (S = 0) porphyin species. The spin-state is confirmed by the value of the average equatorial iron-nitrogen pyrrole distance (Fe__Np = 1.988(2) Å) which is in the normal range of low-spin iron(II) porphyrins. The supramolecular architecture involve hydrogen bonding including C__H … O and weak C__H … Cg π intermolecular interactions involving centroides (Cg) pyrrole and phenyl rings.

  16. Synthesis, spectroscopic characterizations, crystal structures and DFT studies of nalidixic acid carbonyl hydrazones derivatives

    Science.gov (United States)

    Bergamini, F. R. G.; Ribeiro, M. A.; Lancellotti, M.; Machado, D.; Miranda, P. C. M. L.; Cuin, A.; Formiga, A. L. B.; Corbi, P. P.

    2016-09-01

    This article describes the synthesis and characterization of the 1-ethyl-7-methyl-4-oxo-1,4-dihydro-1,8-naphthyridine-3-carbohydrazide (hzd) and six carbonyl hydrazones derivatives of the nalidixic with 1H-pyrrol-2-ylmethylidene (hpyrr), 1H-imidazol-2-ylmethylidene (h2imi), pyridin-2-ylmethylidene (h2py), pyridin-3-ylmethylidene (h3py), pyridin-4-ylmethylidene(h4py) and (2-hydroxyphenyl)methylidene (hsali). The carbonyl hydrazones were characterized by elemental and ESI-QTOF-MS analyses, IR and detailed NMR spectroscopic measurements. The 2D NMR experiments allowed the unambiguous assignment of the hydrogen, carbon and nitrogen atoms, which have not been reported for nalidixic acid carbonyl hydrazone derivatives so far. Crystal structures of hzd and the new carbonyl hydrazones h2imi, hpyrr and h3py were determined by X-ray diffraction studies. Although the synthesis of hzd was reported decades ago, the hzd crystal structure have not been reported yet. Geometric optimizations of all the characterized structures were performed with the aid of DFT studies. Despite the fact that the hydrazones with 2-pyridine carboxylic acid (h2py) and salicyl aldehyde (hsali) were already reported by literature, a detailed spectroscopic study followed by DFT studies are also reported for such compounds in this manuscript. Antimicrobial studies of the compounds are also presented.

  17. Detailed characterizations of a Comparative Reactivity Method (CRM) instrument: experiments vs. modelling

    Science.gov (United States)

    Michoud, V.; Hansen, R. F.; Locoge, N.; Stevens, P. S.; Dusanter, S.

    2015-04-01

    The Hydroxyl radical (OH) is an important oxidant in the daytime troposphere that controls the lifetime of most trace gases, whose oxidation leads to the formation of harmful secondary pollutants such as ozone (O3) and Secondary Organic Aerosols (SOA). In spite of the importance of OH, uncertainties remain concerning its atmospheric budget and integrated measurements of the total sink of OH can help reducing these uncertainties. In this context, several methods have been developed to measure the first-order loss rate of ambient OH, called total OH reactivity. Among these techniques, the Comparative Reactivity Method (CRM) is promising and has already been widely used in the field and in atmospheric simulation chambers. This technique relies on monitoring competitive OH reactions between a reference molecule (pyrrole) and compounds present in ambient air inside a sampling reactor. However, artefacts and interferences exist for this method and a thorough characterization of the CRM technique is needed. In this study, we present a detailed characterization of a CRM instrument, assessing the corrections that need to be applied on ambient measurements. The main corrections are, in the order of their integration in the data processing: (1) a correction for a change in relative humidity between zero air and ambient air, (2) a correction for the formation of spurious OH when artificially produced HO2 react with NO in the sampling reactor, and (3) a correction for a deviation from pseudo first-order kinetics. The dependences of these artefacts to various measurable parameters, such as the pyrrole-to-OH ratio or the bimolecular reaction rate constants of ambient trace gases with OH are also studied. From these dependences, parameterizations are proposed to correct the OH reactivity measurements from the abovementioned artefacts. A comparison of experimental and simulation results is then discussed. The simulations were performed using a 0-D box model including either (1) a

  18. Pyrrole-Based Conductive Polymers For Capacitors

    Science.gov (United States)

    Nagasubramanian, Ganesan; Di Stefano, Salvador

    1994-01-01

    Polypyrrole films containing various dopant anions exhibit superior capacitance characteristics. Used with nonaqueous electrolytes. Candidate for use in advanced electrochemical double-layer capacitors capable of storing electrical energy at high densities. Capacitors made of these films used in automobiles and pulsed power supplies.

  19. Unusual Fe(CN)₆³⁻/⁴⁻ capture induced by synergic effect of electropolymeric cationic surfactant and graphene: characterization and biosensing application.

    Science.gov (United States)

    Deng, Sheng-Yuan; Zhang, Tao; Shan, Dan; Wu, Xiao-Yan; Dou, Yan-Zhi; Cosnier, Serge; Zhang, Xue-Ji

    2014-12-10

    Herein, a special microheterogeneous system for Fe(CN)6(3-/4-) capture was constructed based on graphene (GN) and the electropolymeric cationic surfactant, an amphiphilic pyrrole derivative, (11-pyrrolyl-1-yl-undecyl) triethylammonium tetrafluoroborate (A2). The morphology of the system was characterized by scanning electron microscope. The redox properties of the entrapped Fe(CN)6(3-/4-) were investigated by cyclic voltammetry and UV-visible spectrometry. The entrapped Fe(CN)6(3-/4-) exhibited highly electroactive with stable and symmetrical cyclic voltammetric signal. A dramatic negative shift in the half wave potential can be obtained due to the unusual Fe(CN)6(3-/4-) partitioning in in this microheterogeneous system based on poly(A2+GN). Finally, the entrapped Fe(CN)6(3-/4-) was applied in the construction of the enhanced biosensors to hydrogen peroxide and sulfide.

  20. 2,4-二甲基吡咯-3,5-二羧酸二乙酯的合成--推荐一个大学有机化学实验%Synthesis of Diethyl 2,4-dimethyl-pyrrole-3,5-dicarboxylate:Recommending a University Organic Chemistry Experiment

    Institute of Scientific and Technical Information of China (English)

    汪剑波; 宗乾收; 沈锦锦; 毕成; 吴晨俊

    2016-01-01

    Using Knorr pyrrole synthesis, diethyl 2,4-dimethyl-pyrrole-3,5-dicarboxylate was synthesized via one-pot method with ethyl acetoacetate and sodium nitrite as starting materials in the presence of acetic acid and zinc powder. The experiment involves the experimental operation and analyses including temperature control, reflux, recrystal ization, melting point, IR and NMR spectroscopies. The advantages of the experiment are simple raw materials and high product yield. The experiment is helpful for cultivating and improving the synthesis ability of students, as wel as in-depth understanding of heterocyclic synthesis and spectral analysis.%采用Knorr吡咯合成法,以乙酰乙酸乙酯和亚硝酸钠为原料,在醋酸和锌粉作用下采用“一锅法”得到2,4-二甲基吡咯-3,5-二羧酸二乙酯。本实验涉及到控温、回流、重结晶、熔点测定、红外光谱及核磁共振等实验操作和分析检测方法。该实验原料简单易得、产物收率高,结合波谱解析方法,可以培养和提高学生合成实验的能力,加强学生对杂环合成和波谱解析的理解与分析。

  1. Metal based new triazoles: their synthesis, characterization and antibacterial/antifungal activities.

    Science.gov (United States)

    Sumrra, Sajjad H; Chohan, Zahid H

    2012-12-01

    A series of new triazoles and their oxovanadium(IV) complexes have been synthesized, characterized and evaluated for antibacterial/antifungal properties. The new Schiff bases ligands (L(1))-(L(5)) were prepared by the condensation reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde, 2-acetyl pyridine and 2-methoxy benzaldehyde. The structures of the ligands have been established on the basis of their physical, spectral (IR, (1)H and (13)C NMR and mass spectrometry) and elemental analytical data. The prepared ligands were used to synthesize their oxovanadium(IV) complexes (1)-(5) which were also characterized by their physical, spectral and analytical data and proposed to have a square pyramidal geometry. The ligands and their complexes were screened for in vitro antibacterial activity against six bacterial species such as, Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus, and Bacillus subtilis and for in vitro antifungal activity against six fungal strains, Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glabrata. Cytotoxic nature of the compounds was also reported using brine shrimp bioassay method against Artemia salina.

  2. Metal based new triazoles: Their synthesis, characterization and antibacterial/antifungal activities

    Science.gov (United States)

    Sumrra, Sajjad H.; Chohan, Zahid H.

    2012-12-01

    A series of new triazoles and their oxovanadium(IV) complexes have been synthesized, characterized and evaluated for antibacterial/antifungal properties. The new Schiff bases ligands (L1)-(L5) were prepared by the condensation reaction of 3,5-diamino-1,2,4-triazole with 2-hydroxy-1-naphthaldehyde, pyrrole-2-carboxaldehyde, pyridine-2-carboxaldehyde, 2-acetyl pyridine and 2-methoxy benzaldehyde. The structures of the ligands have been established on the basis of their physical, spectral (IR, 1H and 13C NMR and mass spectrometry) and elemental analytical data. The prepared ligands were used to synthesize their oxovanadium(IV) complexes (1)-(5) which were also characterized by their physical, spectral and analytical data and proposed to have a square pyramidal geometry. The ligands and their complexes were screened for in vitro antibacterial activity against six bacterial species such as, Escherichia coli, Shigella flexneri, Pseudomonas aeruginosa, Salmonella typhi, Staphylococcus aureus, and Bacillus subtilis and for in vitro antifungal activity against six fungal strains, Trichophyton longifusus, Candida albicans, Aspergillus flavus, Microsporum canis, Fusarium solani, and Candida glabrata. Cytotoxic nature of the compounds was also reported using brine shrimp bioassay method against Artemia salina.

  3. In-vitro investigations of the speed of pyrrole formation of 2,5-hexanedione and 2,5-heptanedione with N{alpha}-acetyl-L-lysine as a precondition for a comparative assessment of the neurotoxic potentials of the two {gamma}-diketones; In-vitro-Untersuchungen zur Pyrrolbildungsgeschwindigkeit von 2,5-Hexandion und 2,5-Heptandion mit N{alpha}-Acetyl-L-lysin als Voraussetzung fuer eine vergleichende Abschaetzung der neurotoxischen Potentiale beider {gamma}-Diketone

    Energy Technology Data Exchange (ETDEWEB)

    Richter, M.F.

    1997-09-01

    N-hexane and n-heptane are important solvents. Chronic exposure to n-hexane causes polyneuropathies, which are attributed to the metabolite 2,5-hexanedione, a {gamma} diketone. As a basis for a comparative assessment of the neurotoxic potentials of 2,5-hexanedione and 2,5-heptanedione, an in-vitro test was developed and used to investigate the speed of pyrrole formation of the two {gamma} diketones in reacting with the {epsilon} amino group of N{alpha}-acetyl L-lysine. The speed of the formation of pyrrole was always directly proportional to the respective reactant concentration. It consequently is subject to a second-order kinetics. As a further result, the pyrrole formation speed of 2,5-heptanedione was found to be only half that of 2,5-hexanedione. The results lead to the conclusion that 2,5-heptanedione poses a smaller risk of developing peripheral neuropathy than 2,5-hexanedione. (orig./MG) [Deutsch] n-Hexan und n-Heptan sind wichtige Loesungsmittel. Chronische Exposition gegenueber n-Hexan ruft Polyneuropathien hervor, die auf den Metaboliten 2,5-Hexandion, ein {gamma}-Diketon, zurueckgefuehrt werden. Als Grundlage fuer eine vergleichende Abschaetzung der neurotoxischen Potentiale von 2,5-Hexandion und 2,5-Heptandion wurde in der vorliegenden Arbeit ein In-vitro-Test entwickelt, mit dem die Pyrrolbildungsgeschwindigkeiten der beiden {gamma}-Diketone mit der {epsilon}-Aminogruppe von N{alpha}-Acetyl-L-Iysin untersucht wurden. Die Pyrrolbildungsgeschwindigkeit war stets direkt proportional zur jeweiligen Reaktantenkonzentration. Somit unterliegt sie einer Kinetik 2. Ordnung. Weiterhin wurde gezeigt, dass die Pyrrolbildungsgeschwindigkeit fuer 2,5-Heptandion nur etwa halb so gross ist wie fuer 2,5-Hexandion. Aus den Ergebnissen wird gefolgert, dass das von 2,5-Heptandion ausgehende Risiko an peripheren Neuropathien zu erkranken geringer ist, als das von 2,5-Hexandion ausgehende. (orig./MG)

  4. 7-Glutathione-pyrrole and 7-cysteine-pyrrole are potential carcinogenic metabolites of pyrrolizidine alkaloids.

    Science.gov (United States)

    He, Xiaobo; Xia, Qingsu; Fu, Peter P

    2017-04-03

    Many pyrrolizidine alkaloids (PAs) are hepatotoxic, genotoxic, and carcinogenic phytochemicals. Metabolism of PAs in vivo generates four (±)-6,7-dihydro-7-hydroxy-1-hydroxymethyl-5H-pyrrolizine (DHP)-DNA adducts that have been proposed to be responsible for PA-induced liver tumor formation in rats. In this present study, we determined that the same set of DHP-DNA adducts was formed upon the incubation of 7-glutathione-DHP and 7-cysteine-DHP with cultured human hepatocarcinoma HepG2 cells. These results suggest that 7-glutathione-DHP and 7-cysteine-DHP are reactive metabolites of PAs that can bind to cellular DNA to form DHP-DNA adducts in HepG2 cells, and can potentially initiate liver tumor formation.

  5. Synthesis and characterization of poly(N-methylpyrrole)/TiO2 composites on steel

    Science.gov (United States)

    Mahmoudian, M. R.; Basirun, W. J.; Alias, Y.

    2011-02-01

    Poly(N-methyl pyrrole) coating was successfully electrodeposited on steel substrates in mixed electrolytes of dodecyl benzene sulphonic acid (DBSA) with oxalic acid in the absence and the presence of TiO2 nanoparticles (NPs). The morphology and compositions were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray spectroscopy (EDX). X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) were used to calculate the size of nanoparticles. Electrode/polymer/electrolyte system was studied by Electrochemical Impedance Spectroscopy (EIS). The FESEM micrographs suggest that the incorporation of TiO2 nanoparticles affects the morphology of the film significantly and makes the TiO2 to be loosely piled up with PMPy. The results of EIS showed that synthesized PMPy in the presence of TiO2 NPs increases and decreases the Rpo and Cc of the coating respectively. The increase of the area of synthesized PMPy in the presence of nanoparticles can increase its ability to interact with the ions liberated during the corrosion reaction of steel in NaCl solution.

  6. Synthesis and characterization of poly(N-methylpyrrole)/TiO{sub 2} composites on steel

    Energy Technology Data Exchange (ETDEWEB)

    Mahmoudian, M.R., E-mail: M_R_mahmoudian@yahoo.com [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia); Basirun, W.J.; Alias, Y. [Department of Chemistry, University of Malaya, Kuala Lumpur 50603 (Malaysia)

    2011-02-01

    Poly(N-methyl pyrrole) coating was successfully electrodeposited on steel substrates in mixed electrolytes of dodecyl benzene sulphonic acid (DBSA) with oxalic acid in the absence and the presence of TiO{sub 2} nanoparticles (NPs). The morphology and compositions were characterized by Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), Energy-Dispersive X-ray spectroscopy (EDX). X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM) were used to calculate the size of nanoparticles. Electrode/polymer/electrolyte system was studied by Electrochemical Impedance Spectroscopy (EIS). The FESEM micrographs suggest that the incorporation of TiO{sub 2} nanoparticles affects the morphology of the film significantly and makes the TiO{sub 2} to be loosely piled up with PMPy. The results of EIS showed that synthesized PMPy in the presence of TiO{sub 2} NPs increases and decreases the R{sub po} and C{sub c} of the coating respectively. The increase of the area of synthesized PMPy in the presence of nanoparticles can increase its ability to interact with the ions liberated during the corrosion reaction of steel in NaCl solution.

  7. Synthesis, characterization and biological studies of Schiff bases derived from heterocyclic moiety.

    Science.gov (United States)

    Shanty, Angamaly Antony; Philip, Jessica Elizabeth; Sneha, Eeettinilkunnathil Jose; Prathapachandra Kurup, Maliyeckal R; Balachandran, Sreedharannair; Mohanan, Puzhavoorparambil Velayudhan

    2016-11-21

    Some new Schiff bases (H1-H7) have been synthesized by the condensation of 2-aminophenol, 2-amino-4-nitrophenol, 2-amino-4-methylphenol, 2-amino benzimidazole with thiophene-2-carboxaldehyde and pyrrole-2-carboxaldehyde. The structures of newly synthesized compounds were characterized by elemental analysis, FT-IR, (1)H NMR, UV-VIS, and single crystal X-ray crystallography. The in vitro antibacterial activity of the synthesized compounds has been tested against Salmonella typhi, Bacillus coagulans, Bacillus pumills, Escherichia coli, Bacillus circulans, Pseudomonas, Clostridium and Klebsilla pneumonia by disk diffusion method. The quantitative antimicrobial activity of the test compounds was evaluated using Resazurin based Microtiter Dilution Assay. Ampicillin was used as standard antibiotics. Schiff bases individually exhibited varying degrees of inhibitory effects on the growth of the tested bacterial species. The antioxidant activity of the synthesized compounds was determined by the 1,1-diphenyl-2-picrylhydrazyl(DPPH) method. IC50 value of synthesized Schiff bases were calculated and compared with standard BHA.

  8. Physiological Characterization and Comparative Transcriptome Analysis of White and Green Leaves of Ananas comosus var. bracteatus.

    Science.gov (United States)

    Li, Xia; Kanakala, Surapathrudu; He, Yehua; Zhong, Xiaolan; Yu, Sanmiao; Li, Ruixue; Sun, Lingxia; Ma, Jun

    2017-01-01

    Leaf coloration is one of the most important and attractive characteristics of Ananas comosus var. bracteatus. The chimeric character is not stable during the in vitro tissue culturing. Many regenerated plants lost economic values for the loss of the chimeric character of leaves. In order to reveal the molecular mechanisms involved in the albino phenotype of the leaf cells, the physiological and transcriptional differences between complete white (CWh) and green (CGr) leaf cells of A. comosus var. bracteatus were analyzed. A total of 1,431 differentially expressed unigenes (DEGs) in CGr and CWh leaves were identified using RNA-seq. A comparison to the COG, GO and KEGG annotations revealed DEGs involved in chlorophyll biosynthesis, chloroplast development and photosynthesis. Furthermore, the measurement of main precursors of chlorophyll in the CWh leaves confirmed that the rate-limiting step in chlorophyll biosynthesis, and thus the cause of the albino phenotype of the white cells, was the conversion of pyrrole porphobilinogen (PBG) to uroporphyrinogen III (Uro III). The enzyme activity of porphobilinogen deaminase (PBGD) and uroporporphyrinogn III synthase (UROS), which catalyze the transition of PBG to Uro III, was significantly decreased in the CWh leaves. Our data showed the transcriptional differences between the CWh and CGr plants and characterized key steps in chlorophyll biosynthesis of the CWh leaves. These results contribute to our understanding of the mechanisms and regulation of pigment biosynthesis in the CWh leaf cells of A. comosus var. bracteatus.

  9. Synthesis, characterization and a.c. conductivity of polypyrrole/Y2O3 composites

    Indian Academy of Sciences (India)

    T K Vishnuvardhan; V R Kulkarni; C Basavaraja; S C Raghavendra

    2006-02-01

    Conducting polymer composites of polypyrrole/yttrium oxide (PPy/Y2O3) were synthesized by in situ polymerization of pyrrole with Y2O3 using FeCl3 as an oxidant. The Y2O3 is varied in five different weight percentages of PPy in PPy/Y2O3 composites. The synthesized polymer composites are characterized by infrared and X-ray diffraction techniques. The surface morphology of the composite is studied by scanning electron microscopy. The glass transition temperature of the polymer and its composite is discussed by DSC. Electrical conductivity of the compressed pellets depends on the concentration of Y2O3 in PPy. The frequency dependent a.c. conductivity reveals that the Y2O3 concentration in PPy is responsible for the variation of conductivity of the composites. Frequency dependent dielectric constant at room temperature for different composites are due to interfacial space charge (Maxwell Wagner) polarization leading to the large value of dielectric constant. Frequency dependent dielectric loss, as well as variation of dielectric loss as a function of mass percentage of Y2O3 is also presented and discussed.

  10. Preparation and Characterization of Neutral and Oxidized Polypyrrole Films.

    Science.gov (United States)

    1981-08-31

    oxidation of the pyrrole was obtained from cyclic voltametry in a two-compartment electrochemical cell. If TBAP was used as the electrolyte salt in both...bronze color; thin transparent films are grey. The room temperature electrical conductivity of the films is -50 ohm ŕ cmŕ. Cyclic voltammetry showed that

  11. 阴道白假丝酵母菌的耐药性和ERG11基因突变关系研究%Research on the relationship between the mutations of ERG11 gene and the resistance of pyrrolic antifungal agents in vaginal candida albicans

    Institute of Scientific and Technical Information of China (English)

    谭皓妍; 李倩珺; 冯浩华; 何艳屏

    2014-01-01

    目的 探讨ERG11基因突变与白假丝酵母菌对吡咯类药物敏感性下降的关系.方法 收集VVC患者的白假丝酵母菌60株,用科玛嘉念珠菌显色培养基作菌种鉴定,纸片扩散法进行药敏试验,选取所有中度敏感株和耐药株用聚合酶链反应扩增(PCR)ERG11基因,将PCR产物进行测序分析和比对分析.结果 60株白假丝酵母菌对咪康唑、酮康唑和氟康唑敏感率分别为36.7%、56.1%和80%;将38株中度敏感株和耐药株进行ERG11基因分析后共发现29个有义突变和25个同义突变,其中,有义突变中发现多个新突变位点.结论 有些新发现的突变位点可能与耐药相关;多位点有义突变可能降低菌株对药物的敏感性.%Objective To invesigate the relationship between mutation of ERG11 gene and the decreased sensitivity to pyrrolic antifungal agents in vaginal Candida albicans.Methods sixty strains of Candida albicans from VVC patients were collected and identified by CHROM agar.The drug resistance was detected by disk diffusion method.The ERG11 gene of the moderately susceptible and resistant strains was amplified by PCR.The PCR products were analyzed by DNA sequencing.Results The sensitive rates of sixty strains of Candida albicans strains to miconazole,ketoconazole and fluconazole were 36.7%,56.1% and 80%,respectively.After comparison of ERG11 gene DNA sequences alignment,we found 29 missense mutations and 25 silent mutations in 38 strains of moderately susceptible and resistant strains.Several new mutations were found in ERG11 genein the missense mutations.Conclusion Some new mutations were found in ERG11 gene which might be associated with drug resistance.Multiple amino acid substitutions in Erg11 of vaginal Candida albicans may reduce the sensitivity to pyrrolic antifungal agents.

  12. Novel conductive polypyrrole/zinc oxide/chitosan bionanocomposite: synthesis, characterization, antioxidant, and antibacterial activities

    Science.gov (United States)

    Ebrahimiasl, Saeideh; Zakaria, Azmi; Kassim, Anuar; Basri, Sri Norleha

    2015-01-01

    An antibacterial and conductive bionanocomposite (BNC) film consisting of polypyrrole (Ppy), zinc oxide (ZnO) nanoparticles (NPs), and chitosan (CS) was electrochemically synthesized on indium tin oxide (ITO) glass substrate by electrooxidation of 0.1 M pyrrole in aqueous solution containing appropriate amounts of ZnO NPs uniformly dispersed in CS. This method enables the room temperature electrosynthesis of BNC film consisting of ZnO NPs incorporated within the growing Ppy/CS composite. The morphology of Ppy/ZnO/CS BNC was characterized by scanning electron microscopy. ITO–Ppy/CS and ITO–Ppy/ZnO/CS bioelectrodes were characterized using the Fourier transform infrared technique, X-ray diffraction, and thermogravimetric analysis. The electrical conductivity of nanocomposites was investigated by a four-probe method. The prepared nanocomposites were analyzed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl assay. The results demonstrated that the antioxidant activity of nanocomposites increased remarkably by addition of ZnO NPs. The electrical conductivity of films showed a sudden decrease for lower weight ratios of ZnO NPs (5 wt%), while it was increased gradually for higher ratios (10, 15, and 20 wt%). The nanocomposites were analyzed for antibacterial activity against Gram-positive and Gram-negative bacteria. The results indicated that the synthesized BNC is effective against all of the studied bacteria, and its effectiveness is higher for Pseudomonas aeruginosa. The thermal stability and physical properties of BNC films were increased by an increase in the weight ratio of ZnO NPs, promising novel applications for the electrically conductive polysaccharide-based nanocomposites, particularly those that may exploit the antimicrobial nature of Ppy/ZnO/CS BNCs. PMID:25565815

  13. Identification and characterization of antibacterial compound(s) of cockroaches (Periplaneta americana).

    Science.gov (United States)

    Ali, Salwa Mansur; Siddiqui, Ruqaiyyah; Ong, Seng-Kai; Shah, Muhammad Raza; Anwar, Ayaz; Heard, Peter J; Khan, Naveed Ahmed

    2017-01-01

    Infectious diseases remain a significant threat to human health, contributing to more than 17 million deaths, annually. With the worsening trends of drug resistance, there is a need for newer and more powerful antimicrobial agents. We hypothesized that animals living in polluted environments are potential sources of antimicrobials. Under polluted milieus, organisms such as cockroaches encounter different types of microbes, including superbugs. Such creatures survive the onslaught of superbugs and are able to ward off disease by producing antimicrobial substances. Here, we characterized antibacterial properties in extracts of various body organs of cockroaches (Periplaneta americana) and showed potent antibacterial activity in crude brain extract against methicillin-resistant Staphylococcus aureus and neuropathogenic Escherichia coli K1. The size-exclusion spin columns revealed that the active compound(s) are less than 10 kDa in molecular mass. Using cytotoxicity assays, it was observed that pre-treatment of bacteria with lysates inhibited bacteria-mediated host cell cytotoxicity. Using spectra obtained with LC-MS on Agilent 1290 infinity liquid chromatograph, coupled with an Agilent 6460 triple quadruple mass spectrometer, tissues lysates were analysed. Among hundreds of compounds, only a few homologous compounds were identified that contained the isoquinoline group, chromene derivatives, thiazine groups, imidazoles, pyrrole-containing analogs, sulfonamides, furanones, and flavanones and known to possess broad-spectrum antimicrobial properties and anti-inflammatory, anti-tumour, and analgesic properties. Further identification, characterization, and functional studies using individual compounds can act as a breakthrough in developing novel therapeutics against various pathogens including superbugs.

  14. Identification, characterization, and high-performance liquid chromatography quantification of process-related impurities in vonoprazan fumarate.

    Science.gov (United States)

    Liu, Lei; Cao, Na; Ma, Xingling; Xiong, Kaihe; Sun, Lili; Zou, Qiaogen

    2016-04-01

    High-performance liquid chromatography analysis of vonoprazan fumarate, a novel proton pump inhibitor drug revealed six impurities. These were identified by liquid chromatography with mass spectrometry. Further, the structures of the impurities were confirmed by synthesis followed by characterization by mass spectrometry, NMR spectroscopy, and infrared spectroscopy. On the basis of these data and knowledge of the synthetic scheme of vonoprazan fumarate, the previously unknown impurity was identified as 1-[5-(2-fluorophenyl)-1-(pyridin-3-ylsulfonyl)-1H-pyrrol-3-yl]-N-methyldimethylamine, which is a new compound. The possible mechanisms by which these impurities were formed were also discussed. A high-performance liquid chromatography method was optimized in order to separate, selectively detect, and quantify all process-related impurities of vonoprazan fumarate. The presented method has been validated in terms of linearity, limits of detection, and quantification, and response factors and, therefore, is highly suitable for routine analysis of vonoprazan fumarate related substances as well as stability studies.

  15. NiCrFe2-O4 ferrite nanoparticles and their composites with polypyrrole: synthesis, characterization and magnetic properties

    Indian Academy of Sciences (India)

    E H El-Ghazzawy; S N Alamri

    2015-08-01

    Nanocrystalline nickel chromium ferrite (NiCrFe2-O4, = 0.1, 0.2) have been prepared by the chemical co-precipitation method. Half of the samples have been sintered at 620°C and the other at 1175°C. Then polypyrrole (PPy)–NiCrFe2-O4 composites have been synthesized by polymerization of pyrrole monomer in the presence of NiCrFe2-O4 nanoparticles. The structure, morphology and magnetic properties of the samples have been characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and Fourier transform infrared (FT-IR) spectroscopy and vibrating sample magnetometer. Also, the initial magnetic permeability measurements as functions of temperature and frequency have been performed. The XRD and FT-IR studies have confirmed the well crystalline phase of ferrite nanoparticles, and the presence of amorphous PPy in the composite samples. The SEM and TEM images have obviously clarified the coating of ferrite nanoparticles by PPy in the composite samples. The hysteresis loop of the samples has proved that the samples are soft magnetic material because of their low coercivity.

  16. Synthesis and characterization of new platinum(II) and platinum(IV) triphyrin complexes.

    Science.gov (United States)

    Xue, Zhaoli; Kuzuhara, Daiki; Ikeda, Shinya; Okujima, Tetsuo; Mori, Shigeki; Uno, Hidemitsu; Yamada, Hiroko

    2013-02-18

    Metalation of 6,13,20,21-tetrakis(4-methylphenyl)-22H-tribenzo[14]triphyrin(2.1.1) with PtCl(2) gave a platinum(II) complex having a square-planar coordination structure with two pyrrolic nitrogen atoms and two chloride ions, with a saddle-shaped macrocycle. This platinum(II) complex was easily oxidized by air to an octahedral platinum(IV) complex coordinated by three pyrrolic nitrogen atoms as a tridentate monoanionic cyclic ligand and three chloride ions. When platinum(II) triphyrin was crystallized in air, an oxygen atom was incorporated between two α-carbon atoms of the pyrroles as an oxygen bridge to intercept the 14π aromatic system.

  17. Risk Characterization Handbook

    Science.gov (United States)

    This Handbook has two parts. The first is the Risk Characterization guidance itself. The second part comprises the Appendices which contain the Risk Characterization Policy, the risk characterization case studies and references.

  18. Electrosynthesis and characterization of conducting polypyrrole elaborated under high frequency ultrasound irradiation.

    Science.gov (United States)

    Et Taouil, A; Lallemand, F; Hihn, J Y; Blondeau-Patissier, V

    2011-07-01

    The effects of high frequency ultrasound (500kHz) on pyrrole electropolymerization in sodium perchlorate aqueous medium have been investigated. Cyclic voltametry studies showed that there is no influence on pyrrole oxidation potential. Scanning Electron Microscopy (SEM) imaging, and mechanical and optical profiling, revealed thinner, denser and more homogeneous surface structure for polypyrrole films elaborated under ultrasound irradiation. This is attributed to cavitation bubble asymmetric collapse close to the interface, which should induce changes in the nucleation-growth mechanism during the first polymerization stage. An increase of approximately 27% in doping level for sonicated films was revealed by X-ray Photoelectron Spectroscopy (XPS) analyses.

  19. Nanotechnology Characterization Lab

    Data.gov (United States)

    Federal Laboratory Consortium — The Nanotechnology Characterization Laboratory (NCL) at the Frederick National Laboratory for Cancer Research performs preclinical characterization of nanomaterials...

  20. Detailed characterizations of the new Mines Douai comparative reactivity method instrument via laboratory experiments and modeling

    Science.gov (United States)

    Michoud, V.; Hansen, R. F.; Locoge, N.; Stevens, P. S.; Dusanter, S.

    2015-08-01

    The hydroxyl (OH) radical is an important oxidant in the troposphere, which controls the lifetime of most air quality- and climate-related trace gases. However, there are still uncertainties concerning its atmospheric budget, and integrated measurements of OH sinks have been valuable to improve this aspect. Among the analytical tools used for measuring total OH reactivity in ambient air, the comparative reactivity method (CRM) is spreading rapidly in the atmospheric community. However, measurement artifacts have been highlighted for this technique, and additional work is needed to fully characterize them. In this study, we present the new Mines Douai CRM instrument, with an emphasis on the corrections that need to be applied to ambient measurements of total OH reactivity. Measurement artifacts identified in the literature have been investigated, including (1) a correction for a change in relative humidity between the measurement steps leading to different OH levels, (2) the formation of spurious OH in the sampling reactor when hydroperoxy radicals (HO2) react with nitrogen monoxide (NO), (3) not operating the CRM under pseudo-first-order kinetics, and (4) the dilution of ambient air inside the reactor. The dependences of these artifacts on various measurable parameters, such as the pyrrole-to-OH ratio and the bimolecular reaction rate constants of ambient trace gases with OH, have also been studied. Based on these observations, parameterizations are proposed to correct ambient OH reactivity measurements. On average, corrections of 5.2 ± 3.2, 9.2 ± 15.7, and 8.5 ± 5.8 s-1 were respectively observed for (1), (2) and (3) during a field campaign performed in Dunkirk, France (summer 2014). Numerical simulations have been performed using a box model to check whether experimental observations mentioned above are consistent with our understanding of the chemistry occurring in the CRM reactor. Two different chemical mechanisms have been shown to reproduce the magnitude

  1. Experimental and theoretical characterization of implantable neural microelectrodes modified with conducting polymer nanotubes.

    Science.gov (United States)

    Abidian, Mohammad Reza; Martin, David C

    2008-03-01

    Neural prostheses transduce bioelectric signals to electronic signals at the interface between neural tissue and neural microelectrodes. A low impedance electrode-tissue interface is important for the quality of signal during recording as well as quantity of applied charge density during stimulation. However, neural microelectrode sites exhibit high impedance because of their small geometric surface area. Here we analyze nanostructured-conducting polymers that can be used to significantly decrease the impedance of microelectrode typically by about two orders of magnitude and increase the charge transfer capacity of microelectrodes by three orders of magnitude. In this study poly(pyrrole) (PPy) and poly(3,4-ethylenedioxythiophene) (PEDOT) nanotubes were electrochemically polymerized on the surface of neural microelectrode sites (1250 microm(2)). An equivalent circuit model comprising a coating capacitance in parallel with a pore resistance and interface impedance in series was developed and fitted to experimental results to characterize the physical and electrical properties of the interface. To confirm that the fitting parameters correlate with physical quantities of interface, theoretical equations were used to calculate the parameter values thereby validating the proposed model. Finally, an apparent diffusion coefficient was calculated for PPy film (29.2+/-1.1 x 10(-6) cm(2)/s), PPy nanotubes (PPy NTs) (72.4+/-3.3 x 10(-6) cm(2)/s), PEDOT film (7.4+/-2.1 x 10(-6) cm(2)/s), and PEDOT nanotubes (PEDOT NTs) (13.0+/-1.8 x 10(-6) cm(2)/s). The apparent diffusion coefficient of conducting polymer nanotubes was larger than the corresponding conducting polymer films.

  2. Sequential ultrasonic extraction of a Chinese coal and characterization of nitrogen-containing compounds in the extracts using high-performance liquid chromatography with mass spectrometry.

    Science.gov (United States)

    Xia, Jun-Liu; Fan, Xing; You, Chun-Yan; Wei, Xian-Yong; Zhao, Yun-Peng; Cao, Jing-Pei

    2016-07-01

    Dongming lignite was sequentially extracted with petroleum ether, carbon disulfide, methanol, acetone, and isometric carbon disulfide/acetone mixed solvent at room temperature to afford extracts 1-5, respectively. High-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry was used to separate and characterize heteroatomic species in the extracts at molecular level. Molecular mass of compounds in the extracts is mainly distributed from 300 to 800 u, and the relative abundance of compounds with molecular mass over 800 u in the carbon disulfide extract is 135 times of that in the petroleum ether extract. The acetone extract has the highest relative abundance for organonitrogen compounds. Double bond equivalence numbers of detected species indicate that most of the organonitrogen compounds contain N-heterocyclic aromatic rings, including pyridine, quinoline and pyrrole. Some organonitrogen isomers in Dongming lignite were separated and identified by high-performance liquid chromatography coupled with electrospray ionization time-of-flight mass spectrometry, and the corresponding structural information was proposed.

  3. Practical materials characterization

    CERN Document Server

    2014-01-01

    Presents cross-comparison between materials characterization techniquesIncludes clear specifications of strengths and limitations of each technique for specific materials characterization problemFocuses on applications and clear data interpretation without extensive mathematics

  4. Waste Characterization Methods

    Energy Technology Data Exchange (ETDEWEB)

    Vigil-Holterman, Luciana R. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Naranjo, Felicia Danielle [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-02-02

    This report discusses ways to classify waste as outlined by LANL. Waste Generators must make a waste determination and characterize regulated waste by appropriate analytical testing or use of acceptable knowledge (AK). Use of AK for characterization requires several source documents. Waste characterization documentation must be accurate, sufficient, and current (i.e., updated); relevant and traceable to the waste stream’s generation, characterization, and management; and not merely a list of information sources.

  5. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    Science.gov (United States)

    Nan, Alexandrina; Bunge, Alexander; Turcu, Rodica

    2015-12-01

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  6. Hybride magnetic nanostructure based on amino acids functionalized polypyrrole

    Energy Technology Data Exchange (ETDEWEB)

    Nan, Alexandrina, E-mail: alexandrina.nan@itim-cj.ro; Bunge, Alexander; Turcu, Rodica [National Institute for Research and Development of Isotopic and Molecular Technologies, 67-103 Donat, 400293 Cluj-Napoca (Romania)

    2015-12-23

    Conducting polypyrrole is especially promising for many commercial applications because of its unique optical, electric, thermal and mechanical properties. We report the synthesis and characterization of novel pyrrole functionalized monomers and core-shell hybrid nanostructures, consisting of a conjugated polymer layer (amino acids functionalized pyrrole copolymers) and a magnetic nanoparticle core. For functionalization of the pyrrole monomer we used several amino acids: tryptophan, leucine, phenylalanine, serine and tyrosine. These amino acids were linked via different types of hydrophobic linkers to the nitrogen atom of the pyrrole monomer. The magnetic core-shell hybrid nanostructures are characterized by various methods such as FTIR spectroscopy, transmission electron microscopy (TEM) and magnetic measurements.

  7. Pyrrole-3-carboxamides as potent and selective JAK2 inhibitors.

    Science.gov (United States)

    Brasca, Maria Gabriella; Nesi, Marcella; Avanzi, Nilla; Ballinari, Dario; Bandiera, Tiziano; Bertrand, Jay; Bindi, Simona; Canevari, Giulia; Carenzi, Davide; Casero, Daniele; Ceriani, Lucio; Ciomei, Marina; Cirla, Alessandra; Colombo, Maristella; Cribioli, Sabrina; Cristiani, Cinzia; Della Vedova, Franco; Fachin, Gabriele; Fasolini, Marina; Felder, Eduard R; Galvani, Arturo; Isacchi, Antonella; Mirizzi, Danilo; Motto, Ilaria; Panzeri, Achille; Pesenti, Enrico; Vianello, Paola; Gnocchi, Paola; Donati, Daniele

    2014-09-01

    We report herein the discovery, structure guided design, synthesis and biological evaluation of a novel class of JAK2 inhibitors. Optimization of the series led to the identification of the potent and orally bioavailable JAK2 inhibitor 28 (NMS-P953). Compound 28 displayed significant tumour growth inhibition in SET-2 xenograft tumour model, with a mechanism of action confirmed in vivo by typical modulation of known biomarkers, and with a favourable pharmacokinetic and safety profile.

  8. Molecular containers based on calix[4]pyrrole scaffolds

    OpenAIRE

    Galán Coca, Albano

    2016-01-01

    Esta tesis comprende la síntesis y el estudio de diferentes contenedores moleculares basados en una estructura macrocíclica de calix[4]pirrol. Los contenedores moleculares poseen cavidades polares funcionalizadas ideales para el reconocimiento de moléculas polares i.e. aniones, N-oxidos… La creación de contenedores con cavidades permanentes (cavitandos) da lugar a la formación de complejos termodinámica y cinéticamente muy estables. Las conformaciones adoptadas en disolución por los complejos...

  9. Enzymatic Reductive Dehalogenation Controls the Biosynthesis of Marine Bacterial Pyrroles.

    Science.gov (United States)

    El Gamal, Abrahim; Agarwal, Vinayak; Rahman, Imran; Moore, Bradley S

    2016-10-12

    Enzymes capable of performing dehalogenating reactions have attracted tremendous contemporary attention due to their potential application in the bioremediation of anthropogenic polyhalogenated persistent organic pollutants. Nature, in particular the marine environment, is also a prolific source of polyhalogenated organic natural products. The study of the biosynthesis of these natural products has furnished a diverse array of halogenation biocatalysts, but thus far no examples of dehalogenating enzymes have been reported from a secondary metabolic pathway. Here we show that the penultimate step in the biosynthesis of the highly brominated marine bacterial product pentabromopseudilin is catalyzed by an unusual debrominase Bmp8 that utilizes a redox thiol mechanism to remove the C-2 bromine atom of 2,3,4,5-tetrabromopyrrole to facilitate oxidative coupling to 2,4-dibromophenol. To the best of our knowledge, Bmp8 is first example of a dehalogenating enzyme from the established genetic and biochemical context of a natural product biosynthetic pathway.

  10. Physicochemical and morphological properties of poly(aniline-co-pyrrole)

    CSIR Research Space (South Africa)

    Mavundla, SE

    2010-01-01

    Full Text Available . [2] Skotheim T, Pomerantz M, Elsenbaumer RL, Reynolds JR, editors. Handbook of Conducting Polymers. 2nd edn. New York: Marcel Dekker; 1998; p 277. [3] Novak P, Muller K, Santhanam KSV, Hass O. Chem Rev 1997; 97: 207-281. [4] Miller JS. Adv...

  11. Ethyl 5-methyl-1H-pyrrole-2-carboxylate

    Directory of Open Access Journals (Sweden)

    Zhao-Po Zhang

    2011-07-01

    Full Text Available In the title molecule, C8H11NO2, the r.m.s. deviation of non-H atoms from their best plane is 0.031 Å. Molecules are connected via a pair of N—H...O hydrogen bonds into a centrosymmetric dimer.

  12. Materials Characterization Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Materials Characterization Facility enables detailed measurements of the properties of ceramics, polymers, glasses, and composites. It features instrumentation...

  13. Nonlinear Materials Characterization Facility

    Data.gov (United States)

    Federal Laboratory Consortium — The Nonlinear Materials Characterization Facility conducts photophysical research and development of nonlinear materials operating in the visible spectrum to protect...

  14. Composites Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — The purpose of the Composites Characterization Laboratory is to investigate new and/or modified matrix materials and fibers for advanced composite applications both...

  15. Photovoltaic Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — NIST's PV characterization laboratory is used to measure the electrical performance and opto-electronic properties of solar cells and modules. This facility consists...

  16. High-level ab initio predictions for the ionization energies and heats of formation of five-membered-ring molecules: thiophene, furan, pyrrole, 1,3-cyclopentadiene, and borole, C4H4X/C4H4X+ (X = S, O, NH, CH2, and BH).

    Science.gov (United States)

    Lo, Po-Kam; Lau, Kai-Chung

    2011-02-10

    The ionization energies (IEs) and heats of formation (ΔH°(f0)/ΔH°(f298)) for thiophene (C(4)H(4)S), furan (C(4)H(4)O), pyrrole (C(4)H(4)NH), 1,3-cyclopentadiene (C(4)H(4)CH(2)), and borole (C(4)H(4)BH) have been calculated by the wave function-based ab initio CCSD(T)/CBS approach, which involves the approximation to the complete basis set (CBS) limit at the coupled-cluster level with single and double excitations plus a quasi-perturbative triple excitation [CCSD(T)]. Where appropriate, the zero-point vibrational energy correction (ZPVE), the core-valence electronic correction (CV), and the scalar relativistic effect (SR) are included in these calculations. The respective CCSD(T)/CBS predictions for C(4)H(4)S, C(4)H(4)O, C(4)H(4)NH, and C(4)H(4)CH(2), being 8.888, 8.897, 8.222, and 8.582 eV, are in excellent agreement with the experimental values obtained from previous photoelectron and photoion measurements. The ΔH°(f0)/ΔH°(f298) values for the aforementioned molecules and their corresponding cations have also been predicted by the CCSD(T)/CBS method, and the results are compared with the available experimental data. The comparisons between the CCSD(T)/CBS predictions and the experimental values for C(4)H(4)S, C(4)H(4)O, C(4)H(4)NH, and C(4)H(4)CH(2) suggest that the CCSD(T)/CBS procedure is capable of predicting reliable IE values for five-membered-ring molecules with an uncertainty of ±13 meV. In view of the excellent agreements between the CCSD(T)/CBS predictions and the experimental values for C(4)H(4)S, C(4)H(4)O, C(4)H(4)NH, and C(4)H(4)CH(2), the similar CCSD(T)/CBS IE and ΔH°(f0)/ΔH°(f298) predictions for C(4)H(4)BH, whose thermochemical data are not readily available due to its reactive nature, should constitute a reliable data set. The CCSD(T)/CBS IE(C(4)H(4)BH) value is 8.868 eV, and ΔH°(f0)/ΔH°(f298) values for C(4)H(4)BH and C(4)H(4)BH(+) are 269.5/258.6 and 1125.1/1114.6 kJ/mol, respectively. The highest occupied molecular orbitals

  17. Novel conductive polypyrrole/zinc oxide/chitosan bionanocomposite: synthesis, characterization, antioxidant, and antibacterial activities

    Directory of Open Access Journals (Sweden)

    Ebrahimiasl S

    2014-12-01

    Full Text Available Saeideh Ebrahimiasl,1,2 Azmi Zakaria,3 Anuar Kassim,4 Sri Norleha Basri4 1Department of Nanotechnology, Institute of Advanced Technology, Universiti Putra Malaysia, Serdang, Malaysia; 2Department of Chemistry, Ahar Branch, Islamic Azad University, Ahar, Iran; 3Department of Physics, Universiti Putra Malaysia, Serdang, Malaysia; 4Department of Chemistry, Universiti Putra Malaysia, Serdang, Malaysia Abstract: An antibacterial and conductive bionanocomposite (BNC film consisting of polypyrrole (Ppy, zinc oxide (ZnO nanoparticles (NPs, and chitosan (CS was electrochemically synthesized on indium tin oxide (ITO glass substrate by electrooxidation of 0.1 M pyrrole in aqueous solution containing appropriate amounts of ZnO NPs uniformly dispersed in CS. This method enables the room temperature electrosynthesis of BNC film consisting of ZnO NPs incorporated within the growing Ppy/CS composite. The morphology of Ppy/ZnO/CS BNC was characterized by scanning electron microscopy. ITO–Ppy/CS and ITO–Ppy/ZnO/CS bioelectrodes were characterized using the Fourier transform infrared technique, X-ray diffraction, and thermogravimetric analysis. The electrical conductivity of nanocomposites was investigated by a four-probe method. The prepared nanocomposites were analyzed for antioxidant activity using the 2,2-diphenyl-1-picrylhydrazyl assay. The results demonstrated that the antioxidant activity of nanocomposites increased remarkably by addition of ZnO NPs. The electrical conductivity of films showed a sudden decrease for lower weight ratios of ZnO NPs (5 wt%, while it was increased gradually for higher ratios (10, 15, and 20 wt%. The nanocomposites were analyzed for antibacterial activity against Gram-positive and Gram-negative bacteria. The results indicated that the synthesized BNC is effective against all of the studied bacteria, and its effectiveness is higher for Pseudomonas aeruginosa. The thermal stability and physical properties of BNC films were

  18. Studies of the biogenic amine transporters. VI. Characterization of a novel cocaine binding site, identified with [125I]RTI-55, in membranes prepared from whole rat brain minus caudate.

    Science.gov (United States)

    Rothman, R B; Silverthorn, M L; Baumann, M H; Goodman, C B; Cadet, J L; Matecka, D; Rice, K C; Carroll, F I; Wang, J B; Uhl, G R

    1995-07-01

    Previous studies showed that the cocaine analog [125I]RTI-55 labels dopamine and serotonergic (5-HT) biogenic amine transporters (BATs) with high affinity. Here we characterized [125I]RTI-55 binding to membranes prepared from whole rat brain minus the caudate nuclei. Paroxetine (50 nM) was used to block [125I]RTI-55 binding to 5-HT transporter sites. Initial experiments identified drugs that displaced [125I]RTI-55 binding with moderately low slope factors. Binding surface analysis of the interaction of 3 beta-(4-chlorophenyl)tropan-2 beta-carboxylic acid phenyl ester hydrochloride (RTI-113) and 3 beta-(4-iodophenyl)tropan-2 beta-carboxylic acid phenyl ester hydrochloride (RTI-122) with [125I]RTI-55 binding sites readily resolved two binding sites for [125I]RTI-55 with Kd values of 0.44 nM and 17 nM and Bmax values of 31 and 245 fmol/mg protein. Potent 5-HT and noradrenergic uptake inhibitors had low affinity for both sites. Whereas cocaine, CFT and WIN35,065-2 were 6.0-, 25- and 14-fold selective for the first site, benztropine, PCP and the novel pyrrole, (+-)-(2RS,3aSR,8bRS)-1,2,3,3a,4,8b-hexahydro- 2-benzyl-1-methylindeno-[1,2-b]pyrrole resorcylate [(+-)-HBMP, formerly called (+-)-RTI-4793-14], were moderately selective for the second site. A single binding site with the characteristics of site 1 was resolved using COS cells transiently expressing the cloned rat dopamine transporter. Lesion studies with 6-hydroxydopamine and 5,7-dihydroxytryptamine were conducted to test the hypothesis that site 1 and site 2 are physically distinct. The data showed that these neurotoxins differentially decreased [125I]RTI-55 binding to sites 1 and 2. The differential distribution of sites 1 and 2 in rat brain provides further support for this hypothesis. Viewed collectively, these data show that [125I]RTI-55 labels a novel binding site in rat brain membranes, termed DATsite2, which is not associated with the classic dopamine, serotonin or norepinephrine transporters.

  19. Chemical and morphological characterization of TSP and PM2.5 by SEM-EDS, XPS and XRD collected in the metropolitan area of Monterrey, Mexico

    Science.gov (United States)

    González, Lucy T.; Rodríguez, F. E. Longoria; Sánchez-Domínguez, M.; Leyva-Porras, C.; Silva-Vidaurri, L. G.; Acuna-Askar, Karim; Kharisov, B. I.; Villarreal Chiu, J. F.; Alfaro Barbosa, J. M.

    2016-10-01

    Total suspended particles (TSP) and particles smaller than 2.5 μm (PM2.5) were collected at four sites in the metropolitan area of Monterrey (MAM) in Mexico. The samples were characterized by X-ray Diffraction (XRD), X-ray Photoelectron Spectroscopy (XPS), and Scanning Electron Microscopy (SEM). In order to determine the possible sources of emissions of atmospheric particulate matter, a principal component analysis (PCA) was performed. The XRD results showed that the major crystalline compounds found in the TPS were CaCO3 and SiO2; while in the PM2.5 CaSO4 was found. The XPS analysis showed that the main elements found on the surface of the particles were C, O, Si, Ca, S, and N. The deconvolution carried out on the high-resolution spectra for C1s, S2p and N1s, showed that the aromatics, sulfates and pyrrolic-amides were the main groups contributing to the signal of these elements, respectively. The C-rich particles presented a spherical morphology, while the Ca- and Si-based particles mostly showed a prismatic shape. The PCA analysis together with the results obtained from the characterization techniques, suggested that the main contributors to the CaCO3 particles collected in the PM were most probably produced and emitted into the atmosphere by local construction industries and exploitation of rich-deposits of calcite. Meanwhile, the SiO2 found in the MAM originated from the suspension of geological material abundant in the region, and the carbon particles were mainly produced by the combustion of fossil fuels.

  20. Panel 3 - characterization

    Energy Technology Data Exchange (ETDEWEB)

    Erck, R.A.; Erdemir, A.; Janghsing Hsieh; Lee, R.H.; Xian Zheng Pan; Deming Shu [Argonne National Lab., IL (United States); Feldman, A. [National Inst. of Standards and Technology, Gaithersburg, MD (United States); Glass, J.T. [North Carolina State Univ., Raleigh (United States); Kleimer, R. [Coors Ceramics Co., Golden, CO (United States); Lawton, E.A. [JPL/Caltech, Pasadena, CA (United States); McHargue, C.J. [Univ. of Tennessee, Knoxville (United States)

    1993-01-01

    The task of this panel was to identify and prioritize needs in the area of characterization of diamond and diamond-like-carbon (DLC) films for use in the transportation industry. Until recent advances in production of inexpensive films of diamonds and DLC, it was not feasible that these materials could be mass produced. The Characterization Panel is restricting itself to identifying needs in areas that would be most useful to manufacturers and users in producing and utilizing diamond and DLC coatings in industry. These characterization needs include in-situ monitoring during growth, relation of structure to performance, and standards and definitions.

  1. Metric characterizations II

    CERN Document Server

    Blecher, David P

    2012-01-01

    The present paper is a sequel to our paper "Metric characterization of isometries and of unital operator spaces and systems". We characterize certain common objects in the theory of operator spaces (unitaries, unital operator spaces, operator systems, operator algebras, and so on), in terms which are purely linear-metric, by which we mean that they only use the vector space structure of the space and its matrix norms. In the last part we give some characterizations of operator algebras (which are not linear-metric in our strict sense described in the paper).

  2. How to characterize disorder

    Science.gov (United States)

    Egami, T.

    2016-05-01

    Researchers working on nuclear materials encounter disorder in the atomic structure all the time, usually caused by irradiation. The nature of disorder varies widely, from lattice defects to amorphous phase formation. Generally it is not easy to characterize the state of disorder with the accuracy necessary to elucidate the properties caused by structural disorder. However, owing to advances in the tools of characterization and rapid rise in computer power, significant progress has been made in characterizing structural disorder. We discuss how to describe and determine the structure and dynamics of disordered materials using scattering measurements and modeling. Lattice defects caused by irradiation usually has negative effects on properties, but glasses and highly disordered materials can be irradiation resistant, and could be useful as nuclear materials. Characterizing and controlling disorder is becoming an important endeavor in the field of nuclear materials.

  3. Characterization of complete denture

    National Research Council Canada - National Science Library

    Srivastava, Rajeev; Choukse, Vivek

    2011-01-01

    Characterization is a procedure in which the character or collective qualities of a person are introduced in the complete denture, either by modification of teeth or denture bases, to make it appear...

  4. Tank waste characterization basis

    Energy Technology Data Exchange (ETDEWEB)

    Brown, T.M.

    1996-08-09

    This document describes the issues requiring characterization information, the process of determining high priority tanks to obtain information, and the outcome of the prioritization process. In addition, this document provides the reasoning for establishing and revising priorities and plans.

  5. Site characterization handbook

    Energy Technology Data Exchange (ETDEWEB)

    1988-06-01

    This Handbook discusses both management and technical elements that should be considered in developing a comprehensive site characterization program. Management elements typical of any project of a comparable magnitude and complexity are combined with a discussion of strategies specific to site characterization. Information specific to the technical elements involved in site characterization is based on guidance published by the Nuclear Regulatory Commission (NRC) with respect to licensing requirements for LLW disposal facilities. The objective of this Handbook is to provide a reference for both NRC Agreement States and non-Agreement States for use in developing a comprehensive site characterization program that meets the specific objectives of the State and/or site developer/licensee. Each site characterization program will vary depending on the objectives, licensing requirements, schedules/budgets, physical characteristics of the site, proposed facility design, and the specific concerns raised by government agencies and the public. Therefore, the Handbook is not a prescriptive guide to site characterization. 18 refs., 6 figs.

  6. Site characterization handbook

    Energy Technology Data Exchange (ETDEWEB)

    1988-06-01

    This Handbook discusses both management and technical elements that should be considered in developing a comprehensive site characterization program. Management elements typical of any project of a comparable magnitude and complexity are combined with a discussion of strategies specific to site characterization. Information specific to the technical elements involved in site characterization is based on guidance published by the Nuclear Regulatory Commission (NRC) with respect to licensing requirements for LLW disposal facilities. The objective of this Handbook is to provide a reference for both NRC Agreement States and non-Agreement States for use in developing a comprehensive site characterization program that meets the specific objectives of the State and/or site developer/licensee. Each site characterization program will vary depending on the objectives, licensing requirements, schedules/budgets, physical characteristics of the site, proposed facility design, and the specific concerns raised by government agencies and the public. Therefore, the Handbook is not a prescriptive guide to site characterization. 18 refs., 6 figs.

  7. Space Solar Cell Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Measures, characterizes, and analyzes photovoltaic materials and devices. The primary focus is the measurement and characterization of solar cell response...

  8. Surfactant-directed polypyrrole/CNT nanocables: synthesis, characterization, and enhanced electrical properties.

    Science.gov (United States)

    Zhang, Xuetong; Zhang, Jin; Wang, Rongming; Zhu, Tao; Liu, Zhongfan

    2004-07-19

    We describe here a new approach to the synthesis of size-controllable polypyrrole/carbon nanotube (CNT) nanocables by in situ chemical oxidative polymerization directed by the cationic surfactant cetyltrimethylammonium bromide (CTAB) or the nonionic surfactant polyethylene glycol mono-p-nonylphenyl ether (Opi-10). When carbon nanotubes are dispersed in a solution containing a certain concentration of CTAB or Opi-10, the surfactant molecules are adsorbed and arranged regularly on the CNT surfaces. On addition of pyrrole, some of the monomer is adsorbed at the surface of CNTs and/or wedged between the arranged CTAB or Opi-10 molecules. When ammonium persulfate (APS) is added, pyrrole is polymerized in situ at the surfaces of the CNTs (core layer) and ultimately forms the outer shell of the nanocables. Such polypyrrole/CNT nanocables show enhanced electrical properties; a negative temperature coefficient of resistance at 77-300 K and a negative magnetoresistance at 10-200 K were observed.

  9. Monodisperse metal nanoparticle catalysts on silica mesoporous supports: synthesis, characterizations, and catalytic reactions

    Energy Technology Data Exchange (ETDEWEB)

    Somorjai, G.A.

    2009-09-14

    The design of high performance catalyst achieving near 100% product selectivity at maximum activity is one of the most important goals in the modern catalytic science research. To this end, the preparation of model catalysts whose catalytic performances can be predicted in a systematic and rational manner is of significant importance, which thereby allows understanding of the molecular ingredients affecting the catalytic performances. We have designed novel 3-dimensional (3D) high surface area model catalysts by the integration of colloidal metal nanoparticles and mesoporous silica supports. Monodisperse colloidal metal NPs with controllable size and shape were synthesized using dendrimers, polymers, or surfactants as the surface stabilizers. The size of Pt, and Rh nanoparticles can be varied from sub 1 nm to 15 nm, while the shape of Pt can be controlled to cube, cuboctahedron, and octahedron. The 3D model catalysts were generated by the incorporation of metal nanoparticles into the pores of mesoporous silica supports via two methods: capillary inclusion (CI) and nanoparticle encapsulation (NE). The former method relies on the sonication-induced inclusion of metal nanoparticles into the pores of mesoporous silica, whereas the latter is performed by the encapsulation of metal nanoparticles during the hydrothermal synthesis of mesoporous silica. The 3D model catalysts were comprehensively characterized by a variety of physical and chemical methods. These catalysts were found to show structure sensitivity in hydrocarbon conversion reactions. The Pt NPs supported on mesoporous SBA-15 silica (Pt/SBA-15) displayed significant particle size sensitivity in ethane hydrogenolysis over the size range of 1-7 nm. The Pt/SBA-15 catalysts also exhibited particle size dependent product selectivity in cyclohexene hydrogenation, crotonaldehyde hydrogenation, and pyrrole hydrogenation. The Rh loaded SBA-15 silica catalyst showed structure sensitivity in CO oxidation reaction. In

  10. Characterization of tribological materials

    CERN Document Server

    Glaeser, William A

    2014-01-01

    This classic text discusses the use of advanced surface science characterization techniques in friction, adhesive and abrasive wear, boundary lubrication, contact fatigue, and other important failure processes. Surface characterization of bearings, gears, seals, and other manufactured rolling and sliding surfaces are increasingly routine in advanced quality control of processes and in the manufacture of precision components. This book is an indispensable asset to scientists and engineers using tribological characterization techniques. New content in this edition include: four new figures to illustrate real surface contact added to Chapter 1. coverage of the use of the Environmental SEM (ESEM) in examining wear of fiber glass filled PTFE added to chapter 4. new information on the wear of ceramics added to Chapter 5. updates for new analytical systems added to Chapter 6. coverage of Atomic Force Microscope (ATM) and its usefulness in the field of nano-tribology, providing not only full microtopography of s...

  11. Tank characterization reference guide

    Energy Technology Data Exchange (ETDEWEB)

    De Lorenzo, D.S.; DiCenso, A.T.; Hiller, D.B.; Johnson, K.W.; Rutherford, J.H.; Smith, D.J. [Los Alamos Technical Associates, Kennewick, WA (United States); Simpson, B.C. [Westinghouse Hanford Co., Richland, WA (United States)

    1994-09-01

    Characterization of the Hanford Site high-level waste storage tanks supports safety issue resolution; operations and maintenance requirements; and retrieval, pretreatment, vitrification, and disposal technology development. Technical, historical, and programmatic information about the waste tanks is often scattered among many sources, if it is documented at all. This Tank Characterization Reference Guide, therefore, serves as a common location for much of the generic tank information that is otherwise contained in many documents. The report is intended to be an introduction to the issues and history surrounding the generation, storage, and management of the liquid process wastes, and a presentation of the sampling, analysis, and modeling activities that support the current waste characterization. This report should provide a basis upon which those unfamiliar with the Hanford Site tank farms can start their research.

  12. Characterizing Entanglement Sources

    CERN Document Server

    Lougovski, Pavel

    2009-01-01

    We discuss how to characterize entanglement sources with finite sets of measurements. The measurements do not have to be tomographically complete, and may consist of POVMs rather than von Neumann measurements. Our method yields a probability that the source generates an entangled state as well as estimates of any desired calculable entanglement measures, including their error bars. We apply two criteria, namely Akaike's information criterion and the Bayesian information criterion, to compare and assess different models (with different numbers of parameters) describing entanglement-generating devices. We discuss differences between standard entanglement-verificaton methods and our present method of characterizing an entanglement source.

  13. Characterization of Photovoltaic Generators

    Science.gov (United States)

    Boitier, V.; Cressault, Y.

    2011-01-01

    This paper discusses photovoltaic panel systems and reviews their electrical properties and use in several industrial fields. We explain how different photovoltaic panels may be characterized by undergraduate students at university using simple methods to retrieve their electrical properties (power, current and voltage) and compare these values…

  14. Pressure Core Characterization

    Science.gov (United States)

    Santamarina, J. C.

    2014-12-01

    Natural gas hydrates form under high fluid pressure and low temperature, and are found in permafrost, deep lakes or ocean sediments. Hydrate dissociation by depressurization and/or heating is accompanied by a multifold hydrate volume expansion and host sediments with low permeability experience massive destructuration. Proper characterization requires coring, recovery, manipulation and testing under P-T conditions within the stability field. Pressure core technology allows for the reliable characterization of hydrate bearing sediments within the stability field in order to address scientific and engineering needs, including the measurement of parameters used in hydro-thermo-mechanical analyses, and the monitoring of hydrate dissociation under controlled pressure, temperature, effective stress and chemical conditions. Inherent sampling effects remain and need to be addressed in test protocols and data interpretation. Pressure core technology has been deployed to study hydrate bearing sediments at several locations around the world. In addition to pressure core testing, a comprehensive characterization program should include sediment analysis, testing of reconstituted specimens (with and without synthetic hydrate), and in situ testing. Pressure core characterization technology can be used to study other gas-charged formations such as deep sea sediments, coal bed methane and gas shales.

  15. Characterization of Bacillus cereus

    NARCIS (Netherlands)

    Wijnands LM; Dufrenne JB; Leusden FM; MGB

    2002-01-01

    Bacillus cereus is a ubiquitary microorganism that may cause food borne disease. Pathogenicity, however, depends on various characteristics such as the ability to form (entero)-toxin(s) that can not be detected by microbiological methods. Further characterization of pathogenic properties is not only

  16. SYNTHESIS, CHARACTERIZATION AND ANTIMICROBIAL ...

    African Journals Online (AJOL)

    Preferred Customer

    Institute of Chemical Sciences, University of Peshawar, N.W.F.P., Pakistan ... The inverse process, i.e. coordinating a metal ion from an important biomolecule for instance, a zinc finger protein has been used to design novel .... earlier [34], whereas, the complexes were characterized on the basis of elemental analysis,.

  17. Spectroradiometry for LED characterization

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten

    Radiospectroscopy is the absolute measurement of electromagnetic radiation within a specific wavelength range. For characterization of LED components, light sources and lamps we are interested in absolute measurement of the spectral power distribution, SPD, in the visible and near infrared region...

  18. Synthesis and Characterization of Ag-Ag2O/TiO2@polypyrrole Heterojunction for Enhanced Photocatalytic Degradation of Methylene Blue

    Directory of Open Access Journals (Sweden)

    Rajeev Kumar

    2016-05-01

    Full Text Available Hybrid multi-functional nanomaterials comprising two or more disparate materials have become a powerful approach to obtain advanced materials for environmental remediation applications. In this work, an Ag-Ag2O/TiO2@polypyrrole (Ag/TiO2@PPy heterojunction has been synthesized by assembling a self-stabilized Ag-Ag2O (p type semiconductor (denoted as Ag and polypyrrole (π-conjugated polymer on the surface of rutile TiO2 (n type. Ag/TiO2@PPy was synthesized through simultaneous oxidation of pyrrole monomers and reduction of AgNO3 in an aqueous solution containing well-dispersed TiO2 particles. Thus synthesized Ag/TiO2@PPy was characterized using X-ray diffraction (XRD, X-ray photoelectron spectroscopy (XPS, field emission scanning electron microscopy (FE-SEM, transmission electron microscopy (TEM, and UV-Vis diffuse reflectance spectroscopy (UV-vis DSR. The photocatalytic activity of synthesized heterojunction was investigated for the decomposition of methylene blue (MB dye under UV and visible light irradiation. The results revealed that π-conjugated p-n heterojunction formed in the case of Ag/TiO2@PPy significantly enhanced the photodecomposition of MB compared to the p-n type Ag/TiO2 and TiO2@PPy (n-π heterojunctions. A synergistic effect between Ag-Ag2O and PPy leads to higher photostability and a better electron/hole separation leads to an enhanced photocatalytic activity of Ag/TiO2@PPy under both UV and visible light irradiations.

  19. Direct Characterization of Kerogen By X-Ray And Solid-State **13C Nuclear Magnetic Resonance Methods

    Energy Technology Data Exchange (ETDEWEB)

    Keleman, S.R.; Afeworki, M.; Gorbaty, M.L.; Sansone, M.; Kwiatek, P.J.; Walters, C.C.; Freund, H.; Siskin, M.; Bence, A.E.; Curry, D.J.; Solum, M.; Pugmire, R.J.; Vandenbroucke, M.; Leblond, M.; Behar, F.

    2007-07-09

    and S-XANES results indicate that the relative level of aromatic sulfur increases with an increasing amount of aromatic carbon for all kerogens. XPS show that the majority of nitrogen exists as pyrrolic forms in comparable relative abundances in all kerogens studied. The direct characterization results using X-ray and NMR methods for nitrogen, sulfur, oxygen, and carbon chemical structures provide a basis for developing both specific and general average chemical structural models for different organic matter type kerogens.

  20. Direct Characterization of Kerogen by X-ray and Solid-State [superscript 13]C Nuclear Magnetic Resonance Methods

    Energy Technology Data Exchange (ETDEWEB)

    Kelemen, S. R.; Afeworki, M.; Gorbaty, M.L.; Sansone, M.; Kwiatek, P.J.; Walters, C.C.; Freund, H.; Siskin, M.; Bence, A.E.; Curry, D.J.; Solum, M.; Pugmire, R.J.; Vandenbroucke, M.; Leblond, M.; Behar, F. (ExxonMobil); (ExxonMobil); (IFP); (Utah)

    2008-06-12

    kerogens. XPS and S-XANES results indicate that the relative level of aromatic sulfur increases with an increasing amount of aromatic carbon for all kerogens. XPS show that the majority of nitrogen exists as pyrrolic forms in comparable relative abundances in all kerogens studied. The direct characterization results using X-ray and NMR methods for nitrogen, sulfur, oxygen, and carbon chemical structures provide a basis for developing both specific and general average chemical structural models for different organic matter type kerogens.

  1. Characterizing European cultural landscapes

    DEFF Research Database (Denmark)

    Tieskens, Koen F.; Schulp, Catharina J E; Levers, Christian

    2017-01-01

    European cultural landscapes are mostly characterized by only one of the dimensions. Our paper can help to identify pressures to cultural landscapes and thus to target measures for the conservation of these landscapes, to link similar landscapes in different regions, and to inform policy design on the most......Almost all rural areas in Europe have been shaped or altered by humans and can be considered cultural landscapes, many of which now are considered to entail valuable cultural heritage. Current dynamics in land management have put cultural landscapes under a huge pressure of agricultural...... intensification and land abandonment. To prevent the loss of cultural landscapes, knowledge on the location of different types of cultural landscapes is needed. In this paper, we present a characterization of European cultural landscapes based on the prevalence of three key dimensions of cultural landscapes...

  2. S33138 (N-[4-[2-[(3aS,9bR)-8-cyano-1,3a,4,9b-tetrahydro[1] benzopyrano[3,4-c]pyrrol-2(3H)-yl)-ethyl]phenyl-acetamide), a preferential dopamine D3 versus D2 receptor antagonist and potential antipsychotic agent: III. Actions in models of therapeutic activity and induction of side effects.

    Science.gov (United States)

    Millan, Mark J; Loiseau, Florence; Dekeyne, Anne; Gobert, Alain; Flik, Gunnar; Cremers, Thomas I; Rivet, Jean-Michel; Sicard, Dorothée; Billiras, Rodolphe; Brocco, Mauricette

    2008-03-01

    In contrast to clinically available antipsychotics, the novel benzopyranopyrrolidine derivative, S33138 (N-[4-[2-[(3aS,9bR)-8-cyano-1,3a,4,9b-tetrahydro[1]benzopyrano[3,4-c]pyrrol-2(3H)-yl)-ethyl]phenyl-acetamide), behaves as a preferential antagonist of D(3) versus D(2) receptors and does not interact with histamine H(1) and muscarinic receptors. In contrast to haloperidol, clozapine, olanzapine, and risperidone, S33138 (0.16-2.5 mg/kg s.c.) did not disrupt performance in passive-avoidance and five-choice serial reaction time procedures. Furthermore, upon either systemic administration (0.04-2.5 mg/kg s.c.) or introduction into the frontal cortex (0.04-0.63 mug/side), S33138 potently attenuated the perturbation of social recognition by scopolamine or a prolonged intersession delay. Over a comparable and low-dose range, S33138 (0.04-0.63 mg/kg s.c.) elevated dialysis levels of acetylcholine in the frontal cortex of freely moving rats. At higher doses (2.5-10.0 mg/kg s.c.), S33138 also increased frontocortical levels of histamine, whereas monoamines, glutamate, glycine, and GABA were unaffected. By analogy to the other antipsychotics, S33138 (0.63-10.0 mg/kg s.c.) inhibited conditioned avoidance responses in rats, apomorphine-induced climbing in mice, and hyperlocomotion elicited by amphetamine, cocaine, dizocilpine, ketamine, and phencyclidine in rats. S33138 (0.16-2.5 mg/kg s.c.) also blocked the reduction of prepulse inhibition elicited by apomorphine. In comparison with the above actions, only "high" doses of S33138 (10.0-40.0 mg/kg s.c.) elicited catalepsy. To summarize, reflecting preferential blockade of D(3) versus D(2) receptors, S33138 preserves and/or enhances cognitive function, increases frontocortical cholinergic transmission, and is active in models of antipsychotic properties at doses well below those inducing catalepsy. In comparison with clinically available agents, S33138 displays, thus, a distinctive and promising profile of potential

  3. Graphene Synthesis and Characterization

    Science.gov (United States)

    2015-04-08

    AFRL-OSR-VA-TR-2015-0086 Graphene Synthesis and Characterization 130060 Andrea Cortes UNIVERSIDAD TECNICA FEDERICO SANTA MARIA Final Report 04/08...AND SUBTITLE Grant: Graphene synthesis and characterizatión 5a. CONTRACT NUMBER 5b. GRANT NUMBER FA9550-13-1-0060 5c. PROGRAM ELEMENT NUMBER 6...13. SUPPLEMENTARY NOTES 14. ABSTRACT Here is reported graphene synthesis by two methods, Chemical Vapor Deposition (CVD) using Acetylene as a

  4. A characterization of associativity

    Science.gov (United States)

    Charlesworth, Arthur

    1990-01-01

    A necessary and sufficient condition for associativity of a function is given, in terms of a particular relation being a function. The concept of an associative function is generalized to the concept of a function being asssociative relative to a sequence and a characterization of such relative associativity is also given. These two characteristics are applied to the problem of proving the associativity, or relative associativity, of a function.

  5. A Characterization of Polynomials

    DEFF Research Database (Denmark)

    Andersen, Kurt Munk

    1996-01-01

    Given the problem:which functions f(x) are characterized by a relation of the form:f[x1,x2,...,xn]=h(x1+x2+...+xn), where n>1 and h(x) is a given function? Here f[x1,x2,...,xn] denotes the divided difference on n points x1,x2,...,xn of the function f(x).The answer is: f(x) is a polynomial of degree...

  6. Probabilistic Logical Characterization

    DEFF Research Database (Denmark)

    Hermanns, Holger; Parma, Augusto; Segala, Roberto;

    2011-01-01

    Probabilistic automata exhibit both probabilistic and non-deterministic choice. They are therefore a powerful semantic foundation for modeling concurrent systems with random phenomena arising in many applications ranging from artificial intelligence, security, systems biology to performance model...... modeling. Several variations of bisimulation and simulation relations have proved to be useful as means to abstract and compare different automata. This paper develops a taxonomy of logical characterizations of these relations on image-finite and image-infinite probabilistic automata....

  7. Characterization of Metal Proteins

    Science.gov (United States)

    Unno, Masaki; Ikeda-Saito, Masao

    Some metals are essential for life. Most of these metals are associated with biological macromolecule like DNA (deoxyribonucleic acid), RNA (ribonucleic acid), and more often with proteins: metals bind or interact with them. A number of protein molecules intrinsically contain metals in their structure. Some of these proteins catalyze unique chemical reactions and perform specific physiological functions. In this chapter, we will shed light on the several metalcontaining proteins, termed metalloproteins, and other proteins interacting metals. We will also introduce several key techniques which have been used to characterize these proteins. Characterizing these proteins and to understand the relationships between their structures and functions shall continue to be one of the major avenues to solve the mysteries of life. At first, we introduce what are the protein structures and how these proteins interact with metals. In the next section, we discuss the physiological roles of some representative metals. Next, we show two examples of special metal cofactors those help the biological macromolecules to carry out their functions. Then we describe some functions of metalloproteins. Finally, we introduce some physical methods to characterize metalloproteins.

  8. On Characterizing Particle Shape

    Science.gov (United States)

    Ennis, Bryan J.; Rickman, Douglas; Rollins, A. Brent; Ennis, Brandon

    2014-01-01

    It is well known that particle shape affects flow characteristics of granular materials, as well as a variety of other solids processing issues such as compaction, rheology, filtration and other two-phase flow problems. The impact of shape crosses many diverse and commercially important applications, including pharmaceuticals, civil engineering, metallurgy, health, and food processing. Two applications studied here include the dry solids flow of lunar simulants (e.g. JSC-1, NU-LHT-2M, OB-1), and the flow properties of wet concrete, including final compressive strength. A multi-dimensional generalized, engineering method to quantitatively characterize particle shapes has been developed, applicable to both single particle orientation and multi-particle assemblies. The two-dimension, three dimension inversion problem is also treated, and the application of these methods to DEM model particles will be discussed. In the case of lunar simulants, flow properties of six lunar simulants have been measured, and the impact of particle shape on flowability - as characterized by the shape method developed here -- is discussed, especially in the context of three simulants of similar size range. In the context of concrete processing, concrete construction is a major contributor to greenhouse gas production, of which the major contributor is cement binding loading. Any optimization in concrete rheology and packing that can reduce cement loading and improve strength loading can also reduce currently required construction safety factors. The characterization approach here is also demonstrated for the impact of rock aggregate shape on concrete slump rheology and dry compressive strength.

  9. Characterizing Exoplanets with WFIRST

    Science.gov (United States)

    Robinson, Tyler D.; Stapelfeldt, Karl R.; Marley, Mark S.; Marchis, Franck; Fortney, Jonathan J.

    2017-01-01

    The Wide-Field Infrared Survey Telescope (WFIRST) mission is expected to be equipped with a Coronagraph Instrument (CGI) that will study and explore a diversity of exoplanets in reflected light. Beyond being a technology demonstration, the CGI will provide our first glimpses of temperate worlds around our nearest stellar neighbors. In this presentation, we explore how instrumental and astrophysical parameters will affect the ability of the WFIRST/CGI to obtain spectral and photometric observations that are useful for characterizing its planetary targets. We discuss the development of an instrument noise model suitable for studying the spectral characterization potential of a coronagraph-equipped, space-based telescope. To be consistent with planned technologies, we assume a baseline set of telescope and instrument parameters that include a 2.4 meter diameter primary aperture, an up-to-date filter set spanning the visible wavelength range, a spectroscopic wavelength range of 600-970 nm, and an instrument spectral resolution of 70. We present applications of our baseline model to a variety of spectral models of different planet types, emphasizing warm jovian exoplanets. With our exoplanet spectral models, we explore wavelength-dependent planet-star flux ratios for main sequence stars of various effective temperatures, and discuss how coronagraph inner and outer working angle constraints will influence the potential to study different types of planets. For planets most favorable to spectroscopic characterization—gas giants with extensive water vapor clouds—we study the integration times required to achieve moderate signal-to-noise ratio spectra. We also explore the sensitivity of the integration times required to detect key methane absorption bands to exozodiacal light levels. We conclude with a discussion of the opportunities for characterizing smaller, potentially rocky, worlds under a “rendezvous” scenario, where an external starshade is later paired with

  10. Characterization of solar cells

    Energy Technology Data Exchange (ETDEWEB)

    Haerkoenen, J.; Tuominen, E.; Nybergh, K.; Ezer, Y.; Yli-Koski, M.; Sinkkonen, J. [Helsinki Univ. of Technology, Otaniemi (Finland). Dept. of Electrical and Communications Engineering

    1998-10-01

    Photovoltaic research in the Electron Physics Laboratory started in 1993, when laboratory joined the national TEKES/NEMO 2 research program. Since the beginning of the project, characterization as well as experimentally orientated development of the fabrication process of the solar cells were carried out parallery. The process development research started by the initiatives of the Finnish industry. At the moment a large amount of the laboratory personnel works on solar cell research and the financing comes mainly from external projects. The funding for the research has come from TEKES, Ministry of Education, Finnish Academy, GETA graduate school, special equipment grants of the university, and from the laboratory

  11. Characterizing Black Hole Mergers

    Science.gov (United States)

    Baker, John; Boggs, William Darian; Kelly, Bernard

    2010-01-01

    Binary black hole mergers are a promising source of gravitational waves for interferometric gravitational wave detectors. Recent advances in numerical relativity have revealed the predictions of General Relativity for the strong burst of radiation generated in the final moments of binary coalescence. We explore features in the merger radiation which characterize the final moments of merger and ringdown. Interpreting the waveforms in terms of an rotating implicit radiation source allows a unified phenomenological description of the system from inspiral through ringdown. Common features in the waveforms allow quantitative description of the merger signal which may provide insights for observations large-mass black hole binaries.

  12. Network Characterization Service (NCS)

    Energy Technology Data Exchange (ETDEWEB)

    Jin, Guojun [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Yang, George [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Crowley, Brian [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Agarwal, Deborah [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)

    2001-06-06

    Distributed applications require information to effectively utilize the network. Some of the information they require is the current and maximum bandwidth, current and minimum latency, bottlenecks, burst frequency, and congestion extent. This type of information allows applications to determine parameters like optimal TCP buffer size. In this paper, we present a cooperative information-gathering tool called the network characterization service (NCS). NCS runs in user space and is used to acquire network information. Its protocol is designed for scalable and distributed deployment, similar to DNS. Its algorithms provide efficient, speedy and accurate detection of bottlenecks, especially dynamic bottlenecks. On current and future networks, dynamic bottlenecks do and will affect network performance dramatically.

  13. Battery Thermal Characterization

    Energy Technology Data Exchange (ETDEWEB)

    Keyser, Matthew; Saxon, Aron; Powell, Mitchell; Shi, Ying

    2016-06-07

    This poster shows the progress in battery thermal characterization over the previous year. NREL collaborated with U.S. DRIVE and USABC battery developers to obtain thermal properties of their batteries, obtained heat capacity and heat generation of cells under various power profiles, obtained thermal images of the cells under various drive cycles, and used the measured results to validate thermal models. Thermal properties are used for the thermal analysis and design of improved battery thermal management systems to support achieve life and performance targets.

  14. Characterization of Pixel Sensors

    CERN Document Server

    Oliveira, Felipe Ferraz

    2017-01-01

    It was commissioned at CERN ATLAS pixel group a fluorescence setup for characterization of pixel sensors. The idea is to measure the energies of different targets to calibrate your sensor. It was measured four matrices (80, 95, 98 and 106) of the Investigator1 sensor with different deep PW using copper, iron and titanium as target materials. The matrix 80 has a higher gain (0.065 ± 0.002) and matrix 106 has a better energy resolution (0.05 ± 0.04). The noise of the setup is around 3.6 mV .

  15. Ultrasonic materials characterization

    Science.gov (United States)

    Smith, R. L.

    1987-02-01

    The National NDT Center at Harwell has been developing methods for the characterization of materials using ultrasonics. This paper reviews the progress made in applying ultrasonic attenuation measurements to the determination of such quantities as grain size and dislocation content. A method, ultrasonic attenuation spectral analysis, has been developed, which enables the contributions of scattering and absorption to the total attenuation to be separated. The theoretical advances that have been made are also described. Some of the practical applications of the technique are illustrated and future development discussed.

  16. CHARACTERIZATION OF SOLID CONES

    Institute of Scientific and Technical Information of China (English)

    Qiu Jinghui

    2008-01-01

    The author gives a dual characterization of solid cones in locally convex spaces.From this the author obtains some criteria for judging convex cones to be solid in various inds of locally convex spaces. Using a general expression of the interior of a solid cone,the author obtains a number of necessary and sufficient conditions for convex cones to be solid in the framework of Banach spaces. In particular, the author gives a dual relationship between solid cones and generalized sharp cones. The related known results are improved and extended.

  17. Waste Characterization: Approaches and Methods

    DEFF Research Database (Denmark)

    Lagerkvist, A.; Ecke, H.; Christensen, Thomas Højlund

    2011-01-01

    Characterization of solid waste is usually a difficult task because of the heterogeneity of the waste and its spatial as well as temporal variations. This makes waste characterization costly if good and reliable data with reasonable uncertainty is to be obtained. Therefore, a waste characterization...

  18. Mound facility physical characterization

    Energy Technology Data Exchange (ETDEWEB)

    Tonne, W.R.; Alexander, B.M.; Cage, M.R.; Hase, E.H.; Schmidt, M.J.; Schneider, J.E.; Slusher, W.; Todd, J.E.

    1993-12-01

    The purpose of this report is to provide a baseline physical characterization of Mound`s facilities as of September 1993. The baseline characterizations are to be used in the development of long-term future use strategy development for the Mound site. This document describes the current missions and alternative future use scenarios for each building. Current mission descriptions cover facility capabilities, physical resources required to support operations, current safety envelope and current status of facilities. Future use scenarios identify potential alternative future uses, facility modifications required for likely use, facility modifications of other uses, changes to safety envelope for the likely use, cleanup criteria for each future use scenario, and disposition of surplus equipment. This Introductory Chapter includes an Executive Summary that contains narrative on the Functional Unit Material Condition, Current Facility Status, Listing of Buildings, Space Plans, Summary of Maintenance Program and Repair Backlog, Environmental Restoration, and Decontamination and Decommissioning Programs. Under Section B, Site Description, is a brief listing of the Site PS Development, as well as Current Utility Sources. Section C contains Site Assumptions. A Maintenance Program Overview, as well as Current Deficiencies, is contained within the Maintenance Program Chapter.

  19. FRACTURING FLUID CHARACTERIZATION FACILITY

    Energy Technology Data Exchange (ETDEWEB)

    Subhash Shah

    2000-08-01

    Hydraulic fracturing technology has been successfully applied for well stimulation of low and high permeability reservoirs for numerous years. Treatment optimization and improved economics have always been the key to the success and it is more so when the reservoirs under consideration are marginal. Fluids are widely used for the stimulation of wells. The Fracturing Fluid Characterization Facility (FFCF) has been established to provide the accurate prediction of the behavior of complex fracturing fluids under downhole conditions. The primary focus of the facility is to provide valuable insight into the various mechanisms that govern the flow of fracturing fluids and slurries through hydraulically created fractures. During the time between September 30, 1992, and March 31, 2000, the research efforts were devoted to the areas of fluid rheology, proppant transport, proppant flowback, dynamic fluid loss, perforation pressure losses, and frictional pressure losses. In this regard, a unique above-the-ground fracture simulator was designed and constructed at the FFCF, labeled ''The High Pressure Simulator'' (HPS). The FFCF is now available to industry for characterizing and understanding the behavior of complex fluid systems. To better reflect and encompass the broad spectrum of the petroleum industry, the FFCF now operates under a new name of ''The Well Construction Technology Center'' (WCTC). This report documents the summary of the activities performed during 1992-2000 at the FFCF.

  20. PULP FIBER SIZE CHARACTERIZATION

    Institute of Scientific and Technical Information of China (English)

    Shijie Liu

    2004-01-01

    Pulp fiber length distribution characterization has been examined in this study. Because of the fiber morphology: slender in shape, fiber size distribution characterization is a very difficult task. Traditional technique involves separation of the particles by size,such as Bauer-McNett fiber classifier, and measuring the weight fractions. The particle fractions obtained may or may not reflect the desired size classification.On the other hand, the more recent technique through optical measurement of fiber length is limited by its inability to measure the mass of the particle fractions.Therefore, not only the two techniques fail to generate identical results, either one was accepted to be of better value. Pure hardwood kraft, softwood kraft, and their mixture samples have been measured for their fiber length distributions using an optical fiber quality analyzer: FQA. The data obtained from FQA are extensively studied to investigate more reliable way of representing the fiber length data and thus examining the viable route for measuring the fiber size distributions. It has been found that the fiber length averaged length 11 is a viable indicator of the average pulp fiber length. The fiber size fraction and/or distribution can be represented by the fiber "length" fractions.

  1. PAU camera: detectors characterization

    Science.gov (United States)

    Casas, Ricard; Ballester, Otger; Cardiel-Sas, Laia; Castilla, Javier; Jiménez, Jorge; Maiorino, Marino; Pío, Cristóbal; Sevilla, Ignacio; de Vicente, Juan

    2012-07-01

    The PAU Camera (PAUCam) [1,2] is a wide field camera that will be mounted at the corrected prime focus of the William Herschel Telescope (Observatorio del Roque de los Muchachos, Canary Islands, Spain) in the next months. The focal plane of PAUCam is composed by a mosaic of 18 CCD detectors of 2,048 x 4,176 pixels each one with a pixel size of 15 microns, manufactured by Hamamatsu Photonics K. K. This mosaic covers a field of view (FoV) of 60 arcmin (minutes of arc), 40 of them are unvignetted. The behaviour of these 18 devices, plus four spares, and their electronic response should be characterized and optimized for the use in PAUCam. This job is being carried out in the laboratories of the ICE/IFAE and the CIEMAT. The electronic optimization of the CCD detectors is being carried out by means of an OG (Output Gate) scan and maximizing it CTE (Charge Transfer Efficiency) while the read-out noise is minimized. The device characterization itself is obtained with different tests. The photon transfer curve (PTC) that allows to obtain the electronic gain, the linearity vs. light stimulus, the full-well capacity and the cosmetic defects. The read-out noise, the dark current, the stability vs. temperature and the light remanence.

  2. Carbon Characterization Laboratory Report

    Energy Technology Data Exchange (ETDEWEB)

    David Swank; William Windes; D.C. Haggard; David Rohrbaugh; Karen Moore

    2009-03-01

    The newly completed Idaho National Laboratory (INL) Carbon Characterization Laboratory (CCL) is located in Lab-C20 of the Idaho National Laboratory Research Center. This laboratory was established under the Next Generation Nuclear Plant (NGNP) Project to support graphite research and development activities. The CCL is designed to characterize and test carbon-based materials such as graphite, carbon-carbon composites, and silicon-carbide composite materials. The laboratory is fully prepared to measure material properties for nonirradiated carbon-based materials. Plans to establish the laboratory as a radiological facility within the next year are definitive. This laboratory will be modified to accommodate irradiated materials, after which it can be used to perform material property measurements on both irradiated and nonirradiated carbon-based material. Instruments, fixtures, and methods are in place for preirradiation measurements of bulk density, thermal diffusivity, coefficient of thermal expansion, elastic modulus, Young’s modulus, Shear modulus, Poisson ratio, and electrical resistivity. The measurement protocol consists of functional validation, calibration, and automated data acquisition.

  3. JANUS characterization report

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    The JANUS Reactor was operated from 1965 to 1992. All of the fuel was removed and shipped offsite in 1993. To provide information for use in finalizing the planning for the decommissioning of the reactor, the Health Physics Section of Argonne National Laboratory performed a characterization of the facility in January and February 1996. The characterization included measurements for radioactivity, hazardous materials, lead in wall paint, and asbestos. Measurements and smear samples for surface contamination were collected from every wall, ceiling and floor of the facility. Samples to determine activity concentrations were collected from vertical and horizontal corings into the reactor shield and foundation, and from coring into walls of the high dose and low dose rooms. Soil samples were collected outdoors from two drill holes, one south and one north of the JANUS exhaust stack. The predominant radionuclides detected were {sup 60}Co, {sup 152}Eu, and {sup 154}Eu. The highest exposure rate was 175 mR/h at the center of the reactor core. No hazardous materials were found in pits or sumps. There are 20 identified areas with asbestos and 7 objects with lead based paint.

  4. Pultrusion process characterization

    Science.gov (United States)

    Vaughan, James G.; Hackett, Robert M.

    1991-01-01

    Pultrusion is a process through which high-modulus, lightweight composite structural members such as beams, truss components, stiffeners, etc., are manufactured. The pultrusion process, though a well-developed processing art, lacks a fundamental scientific understanding. The objective here was to determine, both experimentally and analytically, the process parameters most important in characterizing and optimizing the pultrusion of uniaxial fibers. The effects of process parameter interactions were experimentally examined as a function of the pultruded product properties. A numerical description based on these experimental results was developed. An analytical model of the pultrusion process was also developed. The objective of the modeling effort was the formulation of a two-dimensional heat transfer model and development of solutions for the governing differential equations using the finite element method.

  5. Optical characterization of muscle

    Science.gov (United States)

    Oliveira, Luís; Lage, Armindo; Pais Clemente, Manuel; Tuchin, Valery V.

    2012-03-01

    Optical characterization and internal structure of biological tissues is highly important for biomedical optics. In particular for optical clearing processes, such information is of vital importance to understand the mechanisms involved through the variation of the refractive indices of tissue components. The skeletal muscle presents a fibrous structure with an internal arrangement of muscle fiber cords surrounded by interstitial fluid that is responsible for strong light scattering. To determine the refractive index of muscle components we have used a simple method of measuring tissue mass and refractive index during dehydration. After performing measurements for natural and ten dehydration states of the muscle samples, we have determined the dependence between the refractive index of the muscle and its water content. Also, we have joined our measurements with some values reported in literature to perform some calculations that have permitted to determine the refractive index of the dried muscle fibers and their corresponding volume percentage inside the natural muscle.

  6. Molybdenum Tube Characterization report

    Energy Technology Data Exchange (ETDEWEB)

    Beaux II, Miles Frank [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Usov, Igor Olegovich [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2017-02-07

    Chemical vapor deposition (CVD) techniques have been utilized to produce free-standing molybdenum tubes with the end goal of nuclear fuel clad applications. In order to produce tubes with properties desirable for this application, deposition rates were lowered requiring long deposition durations on the order of 50 hours. Standard CVD methods as well as fluidized-bed CVD (FBCVD) methods were applied towards these objectives. Characterization of the tubes produced in this manner revealed material suitable for fuel clad applications, but lacking necessary uniformity across the length of the tubes. The production of freestanding Mo tubes that possess the desired properties across their entire length represents an engineering challenge that can be overcome in a next iteration of the deposition system.

  7. Spectroradiometry for LED characterization

    DEFF Research Database (Denmark)

    Dam-Hansen, Carsten

    Radiospectroscopy is the absolute measurement of electromagnetic radiation within a specific wavelength range. For characterization of LED components, light sources and lamps we are interested in absolute measurement of the spectral power distribution, SPD, in the visible and near infrared region....... Using integrating spheres for light collection setups for absolute total spectral flux is realized at the LED Light Lab at DTU Fotonik, Risø Campus. From these, both total radiant and luminous flux is determined and through electrical power measurement also the efficiency is determined. From the SPD...... colorimetric quantities like color coordinates, color temperature and color rendering indices are calculated. The facilities and special issues concerning LED measurements compared to traditional light sources are explained and examples from the “LED lighting quality program”, a project supported by the Danish...

  8. Land Cover Characterization Program

    Science.gov (United States)

    ,

    1997-01-01

    The U.S. Geological Survey (USGS) has a long heritage of leadership and innovation in land use and land cover mapping. The USGS Anderson system defined the principles for land use and land cover mapping that have been the model both nationally and internationally for more than 20 years. The Land Cover Characterization Program (LCCP) is founded on the premise that the Nation's needs for land cover and land use data are diverse and increasingly sophisticated. The range of projects, programs, and organizations that use land cover data to meet their planning, management, development, and assessment objectives has expanded significantly. The reasons for this are numerous, and include the improved capabilities provided by geographic information systems, better and more data-intensive analytic models, and increasing requirements for improved information for decision making. The overall goals of the LCCP are to:

  9. Characterization Challenges for Nanomaterials

    Energy Technology Data Exchange (ETDEWEB)

    Baer, Donald R.; Amonette, James E.; Engelhard, Mark H.; Gaspar, Daniel J.; Karakoti, Ajay S.; Kuchibhatla, Satyanarayana V N T; Nachimuthu, Ponnusamy; Nurmi, James; Qiang, You; Sarathy, Vaishnavi; Seal, Sudipta; Sharma, Amit M.; Tratnyek, P. G.; Wang, Chong M.

    2008-03-10

    Nanostructured materials are increasingly subject to nearly every type of chemical and physical analysis possible. Because of their small feature size there is a significant focus on tools with high spatial resolution. Because of their high surface area, it is also natural to characterize nanomaterials using tools designed to analyze surfaces. Regardless of the approach, nanostructured materials present a variety of obstacles to adequate, useful and needed analysis. This paper provides short overviews to some of the issues and complications including: particle stability, environmental effects, specimen handling, surface coating, contamination and time. Some specific examples are provided from a our work focused on ceria nanoparticles and iron metal-core/oxide-shell nanoparticles in which we use a combination of tools for routine analysis including XPS, TEM, and XRD and apply other methods as needed to obtain essential information.

  10. Characterization of dielectric materials

    Energy Technology Data Exchange (ETDEWEB)

    King, Danny J.; Babinec, Susan; Hagans, Patrick L.; Maxey, Lonnie C.; Payzant, Edward A.; Daniel, Claus; Sabau, Adrian S.; Dinwiddie, Ralph B.; Armstrong, Beth L.; Howe, Jane Y.; Wood, III, David L.; Nembhard, Nicole S.

    2017-06-27

    A system and a method for characterizing a dielectric material are provided. The system and method generally include applying an excitation signal to electrodes on opposing sides of the dielectric material to evaluate a property of the dielectric material. The method can further include measuring the capacitive impedance across the dielectric material, and determining a variation in the capacitive impedance with respect to either or both of a time domain and a frequency domain. The measured property can include pore size and surface imperfections. The method can still further include modifying a processing parameter as the dielectric material is formed in response to the detected variations in the capacitive impedance, which can correspond to a non-uniformity in the dielectric material.

  11. Radiation characterization summary :

    Energy Technology Data Exchange (ETDEWEB)

    Parma, Edward J.,; Quirk, Thomas J.; Lippert, Lance L.; Griffin, Patrick J; Naranjo, Gerald E.; Luker, Spencer Michael

    2013-04-01

    This document presents the facility-recommended characterization of the neutron, prompt gamma-ray, and delayed gamma-ray radiation fields in the Annular Core Research Reactor (ACRR) for the 44-inch-long lead-boron bucket in the central cavity on the 32-inch pedestal at the core centerline. The designation for this environment is ACRR-LB44-CC-32-cl. The neutron, prompt gamma-ray, and delayed gamma-ray energy spectra are presented as well as radial and axial neutron and gamma-ray flux profiles within the experiment area of the bucket. Recommended constants are given to facilitate the conversion of various dosimetry readings into radiation metrics desired by experimenters. Representative pulse and steady-state operations are presented with conversion examples.

  12. System Performance Characterization

    Energy Technology Data Exchange (ETDEWEB)

    van Dam, M A

    2004-05-26

    Characterizing an adaptive optics (AO) system refers to understanding its performance and limitations. The goal of an AO system is to correct wavefront aberrations. The uncorrected aberrations, called the residual errors and referred to in what follows simply as the errors, degrade the image quality in the science camera. Understanding the source of these errors is a great aid in designing an AO system and optimizing its performance. This chapter explains how to estimate the wavefront error terms and the relationship between the wavefront error and the degradation of the image. The analysis deals with the particular case of a HartmannShack wavefront sensor (WFS) and a continuous deformable mirror (DM), although the principles involved can be applied to any AO system.

  13. Characterization of piezoceramics

    Science.gov (United States)

    Brissaud, Michel

    1991-11-01

    A 3D approach to piezoelectric material characterization, based on the assumption that the coordinate axes are pure mode propagation directions, is described. In this case the general equations simplify and an analytical solution can be achieved. For two geometrical shapes (rectangular and cylindrical), stress and strain tensor components and the electrical impedance of the sample are obtained. These 3D equations show that the wave velocities and permittivity are intrinsic parameters of the medium and do not depend on either the sample geometry or the mode that is considered. This was not true for the 1D models where the wave velocities and permittivity are different for each of the modes or geometries.

  14. CHARACTERIZATION OF DAMAGED MATERIALS

    Energy Technology Data Exchange (ETDEWEB)

    Hsu, P C; Dehaven, M; McClelland, M; Chidester, S; Maienschein, J L

    2006-06-23

    Thermal damage experiments were conducted on LX-04, LX-10, and LX-17 at high temperatures. Both pristine and damaged samples were characterized for their material properties. A pycnometer was used to determine sample true density and porosity. Gas permeability was measured in a newly procured system (diffusion permeameter). Burn rate was measured in the LLNL strand burner. Weight losses upon thermal exposure were insignificant. Damaged pressed parts expanded, resulting in a reduction of bulk density by up to 10%. Both gas permeabilities and burn rates of the damaged samples increased by several orders of magnitude due to higher porosity and lower density. Moduli of the damaged materials decreased significantly, an indication that the materials became weaker mechanically. Damaged materials were more sensitive to shock initiation at high temperatures. No significant sensitization was observed when the damaged samples were tested at room temperature.

  15. Photoelectronic characterization of heterointerfaces.

    Energy Technology Data Exchange (ETDEWEB)

    Brumbach, Michael Todd

    2012-02-01

    In many devices such as solar cells, light emitting diodes, transistors, etc., the performance relies on the electronic structure at interfaces between materials within the device. The objective of this work was to perform robust characterization of hybrid (organic/inorganic) interfaces by tailoring the interfacial region for photoelectron spectroscopy. Self-assembled monolayers (SAM) were utilized to induce dipoles of various magnitudes at the interface. Additionally, SAMs of molecules with varying dipolar characteristics were mixed into spatially organized structures to systematically vary the apparent work function. Polymer thin films were characterized by depositing films of varying thicknesses on numerous substrates with and without interfacial modifications. Hard X-ray photoelectron spectroscopy (HAXPES) was performed to evaluate a buried interface between indium tin oxide (ITO), treated under various conditions, and poly(3-hexylthiophene) (P3HT). Conducting polymer films were found to be sufficiently conducting such that no significant charge redistribution in the polymer films was observed. Consequently, a further departure from uniform substrates was taken whereby electrically disconnected regions of the substrate presented ideally insulating interfacial contacts. In order to accomplish this novel strategy, interdigitated electrodes were used as the substrate. Conducting fingers of one half of the electrodes were electrically grounded while the other set of electrodes were electronically floating. This allowed for the evaluation of substrate charging on photoelectron spectra (SCOPES) in the presence of overlying semiconducting thin films. Such an experiment has never before been reported. This concept was developed out of the previous experiments on interfacial modification and thin film depositions and presents new opportunities for understanding chemical and electronic changes in a multitude of materials and interfaces.

  16. Synthesis by plasma and characterization of compounds derived from polyacetylene; Sintesis por plasma y caracterizacion de compuestos derivados del poliacetileno

    Energy Technology Data Exchange (ETDEWEB)

    Vasquez O, M

    2004-07-01

    This work presents a study on, the synthesis by plasma and the characterization of an aliphatic conjugated polymer, polyacetylene-chlorinated (Pac), and two aromatic polymers, Poly pyrrole (P Py-Cl) and Poly thiophene (Pth-Cl) synthesized with chlorine and the electrical conductivity. The last two polymers were synthesized to compare the chlorine-polymer interaction in aliphatic and aromatic polymers synthesized by plasma and their repercussion on the electrical transport of charges in the material. The structure and morphology of the polymers were studied using scanning electron microscopy (Sem), energy dispersive spectroscopy (EDS), infrared spectroscopy (Ft-IR), conductivity analysis and X-Ray photon spectroscopy (XPS). The results showed that Pac is soluble in acetone and other organic solvents, which indicates a low proportion of crosslinking in the polymers. This point is important because the crosslinking reduces the electrical conductivity in the material. The Pac conductivity is in the range of 1 x 10{sup -12} to 6 x 10{sup -4} S/cm in the internal of 35- 90% of relative humidity. A possible mechanism for the transport of electrical charges in Pac is by means of the double and simple conjugated bonds in the polymers. Pth-Cl and P Py-Cl present electric conductivity in the interval of 9 x 10{sup -5} to 1 x 10{sup -2} S/cm and show a great dependence on the relative humidity. The chlorine addition in these polymers was through simultaneous polymerization with chloroform. This last compound can decompose if the energy of the plasma is relatively high, and the fragments can link to the polymer in a hybrid process of copolymerization. An important point of this work is that the polymer is soluble, a difference of the obtained via plasma as the poli aniline, P Py-CI and Pth-Cl both studied in this work. If took in account that the Pac is single the monomer and that P Py-Cl and Pth-CI is affected by the chlorine that modifies the conductivity of the material

  17. Magnetic Characterization of Organic Materials

    Science.gov (United States)

    2016-12-12

    and lasers. Given this expectation, we believe that our research on magnetic characterization of organic materials will translate into innovative...AFRL-AFOSR-JP-TR-2017-0005 Magnetic Characterization of Organic Materials Dongho Kim YONSEI UNIVERSITY UNIVERSITY-INDUSTRY FOUNDATION Final Report 12...Final 3. DATES COVERED (From - To) 10 Sep 2015 to 09 Sep 2016 4. TITLE AND SUBTITLE Magnetic Characterization of Organic Materials 5a.  CONTRACT

  18. Axiomatic Characterizations of Information Measures

    Directory of Open Access Journals (Sweden)

    Imre Csiszár

    2008-09-01

    Full Text Available Axiomatic characterizations of Shannon entropy, Kullback I-divergence, and some generalized information measures are surveyed. Three directions are treated: (A Characterization of functions of probability distributions suitable as information measures. (B Characterization of set functions on the subsets of {1; : : : ;N} representable by joint entropies of components of an N-dimensional random vector. (C Axiomatic characterization of MaxEnt and related inference rules. The paper concludes with a brief discussion of the relevance of the axiomatic approach for information theory.

  19. Waste Characterization: Approaches and Methods

    DEFF Research Database (Denmark)

    Lagerkvist, A.; Ecke, H.; Christensen, Thomas Højlund

    2011-01-01

    related to individual treatment processes and waste products are dealt with in the following chapters: Characteristic data on residential waste (Chapter 2.2), commercial and institutional waste (Chapter 2.3), industrial waste (Chapter 2.4) and construction and demolition waste (Chapter 2...... with limited representation. This chapter describes common approaches and methods in waste characterization including common terms, sampling, characterization methods and data evaluation. The focus is on the characterization of waste as it is generated or collected, while specific issues on characterization...

  20. Nanometer Characterization/Manipulation Facility

    Data.gov (United States)

    Federal Laboratory Consortium — FUNCTION: Characterizes the nanometer scale of biological, chemical, physical, electronic, and mechanical properties of surfaces and thin films using scanning probe...

  1. Fracture Toughness Characterization

    Directory of Open Access Journals (Sweden)

    Manuel Beltrán Z

    2014-11-01

    Full Text Available This paper addresses the fracture toughness ( , or also known as critical stress intensity Factor, according to conditions of Lineal Elastic Fracture Mechanics (LEFM. The characterization of the mechanical properties in tensile and fracture toughness of structural steel pipes API-5L used in hydrocarbons transportation was performed. For fracture toughness, the material was tested through fatigue crack propagation on standardized compact specimen (CT according to ASTM E-399 norm. A thickness (B equal to and a crack size (a equal to 0.5w were used. With the porpoise of establishing the adequate conditions at the crack tip, the specimens were subjected to fatigue pre-cracking by application of repeated cycles of load in tensile-tensile and constant load amplitude with a load ratio of R = 0.1. The experimental Compliance method was used based on data obtained from load vs. Crack Mouth Opening Displacement (CMOD. The results show a Stress Intensity factor of 35.88 MPa√m for a 25 mm crack size specimen. The device used for testing is a MTS-810 machine with capacity of 100KN and 6 kHz sampling rate, which meets the conditions of the ASTM E-399 standard. The cracking susceptibility of steel is influenced by the size, morphology and distribution of non-metallic inclusions, thermochemical interaction with the environment and microstructure.

  2. Characterization of HI Filaments

    Science.gov (United States)

    Lubar, Emily; Verschuur, Gerrit L.

    2017-01-01

    We characterized the properties of dramatic interstellar HI filaments to learn more about the dynamics and structure of such features. Using Gauss fitting software, we searched the Effelsburg-Bonn HI Survey data for indications of a simple twisting (toroidal) motion across these filaments. Instead, we found that the structure was more complicated than expected. Apparent angular widths of several filaments were measured using the Galactic Arecibo L-band Feed Array HI (GALFA-HI), Bonn, and Leident/Argentine/Bonn (LAB) surveys. Based on filament widths and other parameters, we conclude that magnetism is the dominant force opposing internal motion and maintaining the structure of these filaments. The apparent width as a function of beam width closely follows a relationship reported in 1993 for HI features in general. They tend to subtend an angle two times the beam width, suggesting that the features remain unresolved.The Arecibo Observatory is operated by SRI International under a cooperative agreement with the National Science Foundation (AST-1100968), and in alliance with Ana G. Méndez-Universidad Metropolitana, and the Universities Space Research Association. The Arecibo Observatory REU is funded under grant AST-1559849 to Universidad Metropolitana.

  3. Plant Phenotype Characterization System

    Energy Technology Data Exchange (ETDEWEB)

    Daniel W McDonald; Ronald B Michaels

    2005-09-09

    This report is the final scientific report for the DOE Inventions and Innovations Project: Plant Phenotype Characterization System, DE-FG36-04GO14334. The period of performance was September 30, 2004 through July 15, 2005. The project objective is to demonstrate the viability of a new scientific instrument concept for the study of plant root systems. The root systems of plants are thought to be important in plant yield and thus important to DOE goals in renewable energy sources. The scientific study and understanding of plant root systems is hampered by the difficulty in observing root activity and the inadequacy of existing root study instrumentation options. We have demonstrated a high throughput, non-invasive, high resolution technique for visualizing plant root systems in-situ. Our approach is based upon low-energy x-ray radiography and the use of containers and substrates (artificial soil) which are virtually transparent to x-rays. The system allows us to germinate and grow plant specimens in our containers and substrates and to generate x-ray images of the developing root system over time. The same plant can be imaged at different times in its development. The system can be used for root studies in plant physiology, plant morphology, plant breeding, plant functional genomics and plant genotype screening.

  4. PULP FIBER SIZE CHARACTERIZATION

    Institute of Scientific and Technical Information of China (English)

    ShijieLiu

    2004-01-01

    Pulp fiber length distribution characterization hasbeen examined in this study. Because of the fibermorphology: slender in shape, fiber size distributioncharacterization is a very difficult task. Traditionaltechnique involves separation of the particles by size,such as Bauer-McNett fiber classifier, and measuringthe weight fractions. Themay or may not reflect theparticle fractions obtaineddesired size classification.On the other hand, the more recent technique throughoptical measurement of fiber length is limited by itsinability to measure the mass of the particle fractions.Therefore, not only the two techniques fail togenerate identical results, either one was accepted tobe of better value. Pure hardwood kraft, softwoodkraft, and their mixture samples have been measuredfor their fiber length distributions using an opticalfiber quality analyzer: FQA. The data obtained fromFQA are extensively studied to investigate morereliable way of representing the fiber length data andthus examining the viable route for measuring thefiber size distributions. It has been found that thefiber length averaged length 1~ is a viable indicator ofthe average pulp fiber length. The fiber size fractionand/or distribution can be represented by the fiber"length" fractions.

  5. Characterizing Nanoscale Transient Communication.

    Science.gov (United States)

    Chen, Yifan; Anwar, Putri Santi; Huang, Limin; Asvial, Muhamad

    2016-04-01

    We consider the novel paradigm of nanoscale transient communication (NTC), where certain components of the small-scale communication link are physically transient. As such, the transmitter and the receiver may change their properties over a prescribed lifespan due to their time-varying structures. The NTC systems may find important applications in the biomedical, environmental, and military fields, where system degradability allows for benign integration into life and environment. In this paper, we analyze the NTC systems from the channel-modeling and capacity-analysis perspectives and focus on the stochastically meaningful slow transience scenario, where the coherence time of degeneration Td is much longer than the coding delay Tc. We first develop novel and parsimonious models to characterize the NTC channels, where three types of physical layers are considered: electromagnetism-based terahertz (THz) communication, diffusion-based molecular communication (DMC), and nanobots-assisted touchable communication (TouchCom). We then revisit the classical performance measure of ϵ-outage channel capacity and take a fresh look at its formulations in the NTC context. Next, we present the notion of capacity degeneration profile (CDP), which describes the reduction of channel capacity with respect to the degeneration time. Finally, we provide numerical examples to demonstrate the features of CDP. To the best of our knowledge, the current work represents a first attempt to systematically evaluate the quality of nanoscale communication systems deteriorating with time.

  6. Structural characterization of nitrimyoglobin.

    Science.gov (United States)

    Bondoc, L L; Timkovich, R

    1989-04-15

    Nitrimyoglobin was formed in greater than 94% yield by a simple reaction between excess nitrite and horse heart metmyoglobin at pH 5.5. This dark green pigment was shown by 1H NMR spectroscopy to be a single, pure product with a well defined tertiary structure that is highly similar to the starting myoglobin. Electronic spin states parallel those of myoglobin, although the relaxation times differ. Ligand binding reactions of nitrimyoglobin parallel those of normal myoglobin, but lead to a unique series of UV-visible spectra. In the ferrous state, nitrimyoglobin reversibly binds O2 with half-saturation of sites at an O2 partial pressure of 10.4 +/- 1.4 mm Hg. 1H NMR data indicate that the altered heme of nitrimyoglobin has not undergone reaction at any meso proton position, nor has it been partially saturated to the level of a chlorin. 15N NMR spectra indicate that only a single nitrogen was added to the protein as a nitro group. Extraction of the modified heme from nitrimyoglobin and spectroscopic characterization of the nitriheme by infrared spectroscopy and of the free base porphyrin methyl ester derived from nitriheme by 1H NMR indicate that the modification is regiospecific. The heme in nitrimyoglobin is 3-(trans-2-nitrovinyl)-2,7,12,18-tetramethyl-8-vinylporphyrin-13,1 7-dipropionic acid. In the Fisher nomenclature scheme, the 2-vinyl substituent is the site of modification and has been converted to a nitrovinyl group by substitution of a proton by -NO2.

  7. Characterization Methods of Encapsulates

    Science.gov (United States)

    Zhang, Zhibing; Law, Daniel; Lian, Guoping

    , reliable methods which can be used to characterize these properties of encapsulates are vital. In this chapter, the state-of-art of these methods, their principles and applications, and release mechanisms are described as follows.

  8. Characterizations of univariate continuous distributions

    CERN Document Server

    Ahsanullah, Mohammad

    2017-01-01

    Provides in an organized manner characterizations of univariate probability distributions with many new results published in this area since the 1978 work of Golambos & Kotz "Characterizations of Probability Distributions" (Springer), together with applications of the theory in model fitting and predictions.

  9. Uruguayan tallow characterization

    Directory of Open Access Journals (Sweden)

    Cecilia Rodríguez

    2011-04-01

    Full Text Available Eatable tallow is the product  obtained fusing oily, from clean and  healthy tissues (included the fats of clippings, and from muscles or bones adherents of bovine animals (Bos tsurus,  lambs (Ovis aries in good conditions of health in the moment of its sacrifice and whose has been treated and therefore are considered suitable for the human consumption.To obtain fat from the raw, this material must surrender to a previous treatment that breaks the adipose cells, by  mechanical destruction, boiling or by treatment with alcáli. The easiest  way  consists of the mechanical disintegration (breakup under heat, using steam in direct or indirect form. This product can be obtained by one of the following : discontinuous merger, humid constant merger and  continues merger at low temperature. At present is used in the  cosmetic industry (production of soaps, for nutrition (raw material for margarine, ranching (for the manufacture of food concentrated for animals, for the self propelling industry (raw material for the production of biodiesel. The major purpose of this work is the tallow characterization from the determination of the following parameters :Moisture and Volatile Matter (g/100g of sample, Melting Point (1C, Free Acidity (g. Oleic acid /100g of sample, Colour (yellow and red and Insoluble Matter (g/100g.de shows of 15 samples of animal tallow from Uruguay, in order to provide useful information for the selection of the material. The Norm used as reference was the AOCS (American Oil Chemistry Society. With the obtained information it has been realized a statistical exploratory analysis. The preliminary results, due to the high variability of the studied factors, do not allow to establish with the current number of samples a  model who explains the above mentioned variability, neither at first, to reduce the quantity of factors to consider; in effect, the regression of the moisture against the rest of the factors determined the

  10. A NEW METHOD ON THE CHEMICAL SYNTHESIS OF DOPED POLYPYRROLE INITIATED BY CuCl2-C2H5OH SYSTEM

    Institute of Scientific and Technical Information of China (English)

    ZHANG Jie; SHE Yongbo; LU Bin; ZHOU Yuliang; FU Kejian

    1993-01-01

    Our objectives were to develop a new chemical method for the polymerization of pyrrole. CuCl2 dissolved in C2H5OH solvent is primarily used for the initiation polymerization of pyrrole. The polymers with different yield and conductivity were obtained by varing the initial concentration of Cu2+. The initial concentrations of Cu2+ varied from 1.2 × 10-4 mole to 6.48 ×10-3 mole Cu2+ with 2. 16 × 10-2mole pyrrole. The polypyrrole obtained was characterized with elemental analyzer, XPS, IR spectroscopy, Four-point probe and SEM.

  11. CCD characterization and measurements automation

    Energy Technology Data Exchange (ETDEWEB)

    Kotov, I.V., E-mail: kotov@bnl.gov [Brookhaven National Laboratory, Upton, NY 11973 (United States); Frank, J.; Kotov, A.I. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Kubanek, P. [Institute of Physics of the Academy of Sciences, Prague, CZ 18221 (Czech Republic); Image Processing Laboratory, Universidad de Valencia (Spain); O' Connor, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States); Prouza, M. [Institute of Physics of the Academy of Sciences, Prague, CZ 18221 (Czech Republic); Radeka, V.; Takacs, P. [Brookhaven National Laboratory, Upton, NY 11973 (United States)

    2012-12-11

    Modern mosaic cameras have grown both in size and in number of sensors. The required volume of sensor testing and characterization has grown accordingly. For camera projects as large as the LSST, test automation becomes a necessity. A CCD testing and characterization laboratory was built and is in operation for the LSST project. Characterization of LSST study contract sensors has been performed. The characterization process and its automation are discussed, and results are presented. Our system automatically acquires images, populates a database with metadata information, and runs express analysis. This approach is illustrated on {sup 55}Fe data analysis. {sup 55}Fe data are used to measure gain, charge transfer efficiency and charge diffusion. Examples of express analysis results are presented and discussed.

  12. Recent developments in QGP characterization

    Energy Technology Data Exchange (ETDEWEB)

    Jeon, Sangyong [Department of Physics, McGill University, Montréal (Canada)

    2016-01-22

    In recent years, great progress has been made in characterizing quark-gluon plasma (QGP) being created in ultra-relativistic heavy ion collisions. The article briefly reviews QGP characteristics found in hydrodynamic studies of the QGP collective flows.

  13. Characterization of Multiplicative Metric Completeness

    Directory of Open Access Journals (Sweden)

    Badshshah e Romer

    2016-03-01

    Full Text Available We established fixed point theorems in multiplicative metric spaces. The obtained results generalize Banach contraction principle in multiplicative metric spaces and also characterize completeness of the underlying multiplicative metric space.

  14. Multifractal approach for seafloor characterization

    Digital Repository Service at National Institute of Oceanography (India)

    Chakraborty, B.; Haris, K.; Latha, G.; Maslov, N.; Menezes, A.A.A.

    to characterize the seafloor. Two distinct multifractal formalisms are applied to determine the characteristics. The first formalism employs data analyses using generalized dimension D(q) and multifractal singularity spectrum f(alpha) linked shape parameters...

  15. 324 Building Baseline Radiological Characterization

    Energy Technology Data Exchange (ETDEWEB)

    R.J. Reeder, J.C. Cooper

    2010-06-24

    This report documents the analysis of radiological data collected as part of the characterization study performed in 1998. The study was performed to create a baseline of the radiological conditions in the 324 Building.

  16. Characterization of Nanostructured Polymer Films

    Science.gov (United States)

    2014-12-23

    AFRL-OSR-VA-TR-2015-0059 Characterization of Nanostructured Polymer Films RODNEY PRIESTLEY TRUSTEES OF PRINCETON UNIVERSITY Final Report 12/23/2014...Report 3. DATES COVERED (From - To) 06/01/2012-08/31/2014 4. TITLE AND SUBTITLE Characterization of Nanostructured Polymer Films 5a. CONTRACT...properties is due to the film morphology, i.e., the films are nanostructured . The aim of this proposal was to understand the mechanism of film formation and

  17. Vortex Characterization for Engineering Applications

    Energy Technology Data Exchange (ETDEWEB)

    Jankun-Kelly, M; Thompson, D S; Jiang, M; Shannahan, B; Machiraju, R

    2008-01-30

    Realistic engineering simulation data often have features that are not optimally resolved due to practical limitations on mesh resolution. To be useful to application engineers, vortex characterization techniques must be sufficiently robust to handle realistic data with complex vortex topologies. In this paper, we present enhancements to the vortex topology identification component of an existing vortex characterization algorithm. The modified techniques are demonstrated by application to three realistic data sets that illustrate the strengths and weaknesses of our approach.

  18. Proteomics Characterization of Exosome Cargo

    OpenAIRE

    Schey, Kevin L.; Luther, J. Matthew; Rose, Kristie L

    2015-01-01

    Characterization of exosomal cargo is of significant interest because this cargo can provide clues to exosome biogenesis, targeting, and cellular effects and may be a source of biomarkers for disease diagnosis, prognosis and response to treatment. With recent improvements in proteomics technologies, both qualitative and quantitative characterization of exosomal proteins is possible. Here we provide a brief review of exosome proteomics studies and provide detailed protocols for global qualitat...

  19. NMR characterization of thin films

    Science.gov (United States)

    Gerald, II, Rex E.; Klingler, Robert J.; Rathke, Jerome W.; Diaz, Rocio; Vukovic, Lela

    2008-11-25

    A method, apparatus, and system for characterizing thin film materials. The method, apparatus, and system includes a container for receiving a starting material, applying a gravitational force, a magnetic force, and an electric force or combinations thereof to at least the starting material, forming a thin film material, sensing an NMR signal from the thin film material and analyzing the NMR signal to characterize the thin film of material.

  20. Characterizing Financial and Statistical Literacy

    DEFF Research Database (Denmark)

    Di Girolamo, Amalia; Harrison, Glenn W.; Lau, Morten

    We characterize the literacy of an individual in a domain by their elicited subjective belief distribution over the possible responses to a question posed in that domain. We consider literacy across several financial, economic and statistical domains. We find considerable demographic heterogeneity...... approach to characterize financial capability, the consequences of non-literacy, social literacy, and the information content of hypothetical survey measures of literacy....

  1. Photovoltaics Characterization: An Overview; Preprint

    Energy Technology Data Exchange (ETDEWEB)

    Kao, Y. H. (State University of New York at Buffalo); Kazmerski, L.; Mascarenhas, A. (National Renewable Energy Laboratory); Lynn, K. G. (Washington State University)

    1999-04-01

    In order to move to a next generation of characterization methods, the requirements must be fully understood and documented. Presented herein are the required functionalities for the next generation of characterization methods. This paper is not meant to be exhaustive, but instead presents new developing characterization methods. The basic characterization requirements are outlined in the introduction. It is expected that in the future, phenomena will be understood on the atomic scale and applied to large-scale arrays for a complete understanding of the various affects that determine the real cell efficiency. There is a need for a fundamental understanding from atomic and nanoscale characterizations of impurities, native defects, extended defects and interfaces to provide the necessary understanding of these types of PV cells. This information from fundamental probes should be used for input to the performance characterization of the developing technologies, which include high-flux operation, multijunction and lower band-gap systems. These methods will allow new materials to come to realization at a much faster rate than was possible in previous years.

  2. Discrete Stein characterizations and discrete information distances

    CERN Document Server

    Ley, Christophe

    2012-01-01

    We construct two different Stein characterizations of discrete distributions and use these to provide a natural connection between Stein characterizations for discrete distributions and discrete information functionals.

  3. High Speed On-Wafer Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  4. High Speed On-Wafer Characterization Laboratory

    Data.gov (United States)

    Federal Laboratory Consortium — At the High Speed On-Wafer Characterization Laboratory, researchers characterize and model devices operating at terahertz (THz) and millimeter-wave frequencies. The...

  5. Image Analysis for Tongue Characterization

    Institute of Scientific and Technical Information of China (English)

    SHENLansun; WEIBaoguo; CAIYiheng; ZHANGXinfeng; WANGYanqing; CHENJing; KONGLingbiao

    2003-01-01

    Tongue diagnosis is one of the essential methods in traditional Chinese medical diagnosis. The ac-curacy of tongue diagnosis can be improved by tongue char-acterization. This paper investigates the use of image anal-ysis techniques for tongue characterization by evaluating visual features obtained from images. A tongue imaging and analysis instrument (TIAI) was developed to acquire digital color tongue images. Several novel approaches are presented for color calibration, tongue area segmentation,quantitative analysis and qualitative description for the colors of tongue and its coating, the thickness and moisture of coating and quantification of the cracks of the toilgue.The overall accuracy of the automatic analysis of the colors of tongue and the thickness of tongue coating exceeds 85%.This work shows the promising future of tongue character-ization.

  6. Biophysical characterization of GPCR oligomerization

    DEFF Research Database (Denmark)

    Mathiasen, Signe

    a quantitative characterization of GPCR oligomerization. The assay provided the first quantification of the association energy of the β2 Adrenergic Receptor (β2AR), a prototypical GPCR. Furthermore we directly observed the time-dependent dimerization of β2AR and Cannabinoid receptor 1 at the single molecule......The biophysical characterization of the fundamental molecular mechanisms behind G-protein coupled receptors (GPCRs) oligomerization is proposed to be paramount for understanding the pharmacological consequence of receptor self-association. Here we developed an in vitro assay that allowed...

  7. Optic probe for semiconductor characterization

    Science.gov (United States)

    Sopori, Bhushan L.; Hambarian, Artak

    2008-09-02

    Described herein is an optical probe (120) for use in characterizing surface defects in wafers, such as semiconductor wafers. The optical probe (120) detects laser light reflected from the surface (124) of the wafer (106) within various ranges of angles. Characteristics of defects in the surface (124) of the wafer (106) are determined based on the amount of reflected laser light detected in each of the ranges of angles. Additionally, a wafer characterization system (100) is described that includes the described optical probe (120).

  8. Smaragdyrins and Sapphyrins Analogues.

    Science.gov (United States)

    Chatterjee, Tamal; Srinivasan, A; Ravikanth, Mangalampalli; Chandrashekar, Tavarakere K

    2017-02-22

    Porphyrins and expanded porphyrins have attracted the attention of chemists for a long time in view of their diverse applications in catalysis; as anion, cation, and neutral substrate receptors; as ligands to coordinate large metal ions; as nonlinear optical materials, MRI contrasting agents, and sensitizers for photodynamic therapy (PDT); and more recently as models for aromaticity (both Hückel and Möbius). A diverse range of synthetic expanded porphyrins containing up to 96π electrons have been reported, and their properties have been exploited for various applications. The present Review is only confined to 22π electron expanded porphyrins containing five pyrrole/heterocyclic rings such as sapphyrins and smaragdyrins. Even though these two macrocycles contain 22π electrons and five pyrrole/heterocyclic rings, they are structurally different. In sapphyrins, the five pyrrole/heterocyclic rings are connected through four meso-carbon bridges and one direct pyrrole-pyrrole bond, whereas in smaragdyrins, the five pyrrole/heterocyclic rings are connected through three meso-carbon bridges and two direct pyrrole-pyrrole bonds. The chemistry of sapphyrins has been well-established in recent years due to the availability of easy and efficient synthetic methods. On the other hand, smaragdyrins are not explored significantly because of their unstable nature. However, recently it was shown that smaragdyrins can be stabilized if one of the pyrrole rings is replaced with a furan ring to afford stable oxasmaragdyrin. The availability of oxasmaragdyrin allowed the exploration of smaragdyrin in recent years. Thus, an attempt has been made in this Review to describe the chemistry of both sapphyrins and smaragdyrins in terms of their synthesis, characterization, metal ion coordination, and anion-recognition properties.

  9. Synthesis, FT–IR characterization and crystal structure of aqua(5,10,15,20-tetraphenylporphyrinato-κ4Nmanganese(III trifluoromethanesulfonate

    Directory of Open Access Journals (Sweden)

    Wafa Harhouri

    2016-05-01

    Full Text Available In the title salt, [Mn(C44H28N4(H2O](CF3SO3 or [MnIII(TPP(H2O](CF3SO3 (where TPP is the dianion of 5,10,15,20-tetraphenylporphyrin, the MnIII cation is chelated by the four pyrrole N atoms of the porphyrinate anion and additionally coordinated by an aqua ligand in an apical site, completing the distorted square-pyramidal coordination environment. The average Mn—N(pyrrole bond length is 1.998 (9 Å and the Mn—O(aqua bond length is 2.1057 (15 Å. The central MnIII ion is displaced by 0.1575 (5 Å from the N4C20 mean plane of the porphyrinate anion towards the apical aqua ligand. The porphyrinate macrocycle exhibits a moderate ruffling and strong saddle deformations. In the crystal lattice, the [MnIII(TPP(H2O]+ cation and the trifluoromethanesulfonate counter-ions are arranged in alternating planes packed along [001]. The components are linked together through O—H...O hydrogen bonds and much weaker C—H...O and C—H...F interactions. The crystal packing is further stabilized by weak C—H...π interactions involving the pyrrole and phenyl rings of the porphyrin moieties.

  10. Magnetic characterization techniques for nanomaterials

    CERN Document Server

    2017-01-01

    Sixth volume of a 40 volume series on nanoscience and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about Magnetic Characterization Techniques for Nanomaterials. Modern applications and state-of-the-art techniques are covered and make this volume an essential reading for research scientists in academia and industry.

  11. Characterizations of Graded Distributive Modules

    Institute of Scientific and Technical Information of China (English)

    Qinghua Chen; Chang'an Li

    2002-01-01

    In this paper, we give some characterizations of graded distributive modules, prove some interesting results between graded rings (modules) and lattices under finiteness conditions, and investigate the direct sum of graded distributive modules in terms of orders of graded submodules and homomorphisms of graded factor modules.

  12. Structure Characterization Using Mathematical Morphology

    NARCIS (Netherlands)

    Luengo Hendriks, C.L.

    2004-01-01

    This thesis deals with the application of mathematical morphology to images of some kind of structure, with the intention of characterizing (or describing) that structure. The emphasis is placed on measuring properties of the real-world scene, rather than measuring properties of the digital image. T

  13. Raman spectroscopy for nanomaterials characterization

    CERN Document Server

    2012-01-01

    First volume of a 40-volume series on nanoscience and nanotechnology, edited by the renowned scientist Challa S.S.R. Kumar. This handbook gives a comprehensive overview about Raman spectroscopy for the characterization of nanomaterials. Modern applications and state-of-the-art techniques are covered and make this volume essential reading for research scientists in academia and industry.

  14. Characterizing the human hematopoietic CDome

    DEFF Research Database (Denmark)

    Barnkob, Mike Stein; Simon, Christian; Olsen, Lars Rønn

    2014-01-01

    , we seek to give a preliminary characterization of the "human hematopoietic CDome." We encountered severe gaps in the knowledge of CD protein expression, mostly resulting from incomplete and unstructured data generation, which we argue inhibit both basic research as well as therapies seeking to target...

  15. FTIR characterization of advanced materials

    Science.gov (United States)

    Young, P. R.; Chang, A. C.

    1986-01-01

    This paper surveys the application of Fourier transform infrared spectroscopy to the characterization of advanced materials. FTIR sampling techniques including internal and external reflectance and photoacoustic spectroscopy are discussed. Representative examples from the literature of the analysis of resins, fibers, prepregs and composites are reviewed. A discussion of several promising specialized FTIR techniques is also presented.

  16. On Characterization of Quadratic Splines

    DEFF Research Database (Denmark)

    Chen, B. T.; Madsen, Kaj; Zhang, Shuzhong

    2005-01-01

    that the representation can be refined in a neighborhood of a non-degenerate point and a set of non-degenerate minimizers. Based on these characterizations, many existing algorithms for specific convex quadratic splines are also finite convergent for a general convex quadratic spline. Finally, we study the relationship...

  17. Composite materials processing, applications, characterizations

    CERN Document Server

    2017-01-01

    Composite materials are used as substitutions of metals/traditional materials in aerospace, automotive, civil, mechanical and other industries. The present book collects the current knowledge and recent developments in the characterization and application of composite materials. To this purpose the volume describes the outstanding properties of this class of advanced material which recommend it for various industrial applications.

  18. Characterization of moose intestinal glycosphingolipids.

    Science.gov (United States)

    Johansson, Miralda Madar; Dedic, Benjamin; Lundholm, Klara; Branzell, Filip Berner; Barone, Angela; Benktander, John; Teneberg, Susann

    2015-08-01

    As a part of a systematic investigation of the species-specific expression of glycosphingolipids, acid and non-acid glycosphingolipids were isolated from three small intestines and one large intestine of the moose (Alces alces). The glycosphingolipids were characterized by binding of monoclonal antibodies, lectins and bacteria in chromatogram binding assays, and by mass spectrometry. The non-acid fractions were complex mixtures, and all had glycosphingolipids belonging to the lacto- and neolactoseries (lactotriaosylceramide, lactotetraosylceramide, neolactotetraosylceramide, Galα3-Le(x) hexaosylceramide, and lacto-neolactohexaosylceramide), globo-series (globotriaosylceramide and globotetraosylceramide), and isogloboseries (isoglobotriaosylceramide). Penta- and heptaglycosylceramides with terminal Galili determinants were also characterized. Furthermore, glycosphingolipids with terminal blood group O determinants (H triaosylceramide, H type 2 pentaosylceramide, H type 1 penta- and heptaosylceramide) were characterized in two of the moose small intestines, and in the one large intestine, while the third small intestine had glycosphingolipids with terminal blood group A determinants (A tetraosylceramide, A type 1 hexa- and octaosylceramide, A dodecaosylceramide). The acid glycosphingolipid fractions of moose small and large intestine contained sulfatide, and the gangliosides GM3, GD3, GD1a, GD1b, and also NeuGc and NeuAc variants of the Sd(a) ganglioside and the sialyl-globopenta/SSEA-4 ganglioside. In humans, the NeuAc-globopenta/SSEA-4 ganglioside is a marker of embryonic and adult stem cells, and is also expressed in several human cancers. This is the first time sialyl-globopentaosylceramide/SSEA-4 has been characterized in a fully differentiated normal tissue, and also the first time NeuGc-globopentaosylceramide has been characterized.

  19. ELECTROCHEMICAL SYNTHEZIS AND CHARACTERIZATION OF POLYPYRROLE FOR DODECYLSULFATE SENSOR MEMBRANE

    Directory of Open Access Journals (Sweden)

    Abdul Haris Watoni

    2010-06-01

    Full Text Available A conducting polymer, polypyrrole, has been electrochemically synthesized from pyrrole monomer using cyclic voltammetry technique in aqueous solution in the presence of HDS dopant and KNO3 supporting electrolyte. The polymer was deposited on the surface of an Au-wire and the modified electrode obtained was then used as dodecylsulfate (DS- ion sensor electrode. The best performance PPy-DS modified-Au electrode conditioned in the air system without HDS or SDS solution gave linear potential response for the concentration range of 1.0 x 10-5 - 1.0 x 10-3 M, sensitivity of 54.5 mV/decade, detection limit of 1.0 x 10-5 M, and response time of 23 - 30 second.  The electrode showed good selectivity towards other anions, therefore can be used to determine SDS concentration in real samples system without any change of the samples matrix.   Keywords: polypyrrole, SDS, cyclic voltammetry

  20. Optical Characterization of Nanostructured Surfaces

    DEFF Research Database (Denmark)

    Feidenhans'l, Nikolaj Agentoft

    spectrum; the new method only evaluates the color of the reflected light using a standard RGB color camera. Color scatterometry provides the combined advantages of spectroscopic scatterometry, which provides fast evaluations, and imaging scatterometry that provides an overview image from which small...... implementation, a range of complementing characterization methods is needed to perform high-speed quality control of the nanostructures. This thesis concerns the development of a new method for fast in-line characterization of periodic nanostructures. The focus is on optical scatterometry, which uses inverse......, with trapezoidal profiles approximately ~200 nm high and with periods between 600 nm and 5000 nm. The heights and filling factors are determined with an accuracy of ~8 %, while the sidewall slopes have larger uncertainties due to a lower influence on the reflected light. The thesis also evaluates the use...

  1. Photoacoustic elastic oscillation and characterization.

    Science.gov (United States)

    Gao, Fei; Feng, Xiaohua; Zheng, Yuanjin

    2015-08-10

    Photoacoustic imaging and sensing have been studied extensively to probe the optical absorption of biological tissue in multiple scales ranging from large organs to small molecules. However, its elastic oscillation characterization is rarely studied and has been an untapped area to be explored. In literature, photoacoustic signal induced by pulsed laser is commonly modelled as a bipolar "N-shape" pulse from an optical absorber. In this paper, the photoacoustic damped oscillation is predicted and modelled by an equivalent mass-spring system by treating the optical absorber as an elastic oscillator. The photoacoustic simulation incorporating the proposed oscillation model shows better agreement with the measured signal from an elastic phantom, than conventional photoacoustic simulation model. More interestingly, the photoacoustic damping oscillation effect could potentially be a useful characterization approach to evaluate biological tissue's mechanical properties in terms of relaxation time, peak number and ratio beyond optical absorption only, which is experimentally demonstrated in this paper.

  2. Sturm-Liouville eigenvalue characterizations

    Directory of Open Access Journals (Sweden)

    Paul B. Bailey

    2012-07-01

    Full Text Available We study the relationship between the eigenvalues of separated self-adjoint boundary conditions and coupled self-adjoint conditions. Given an arbitrary real coupled boundary condition determined by a coupling matrix K we construct a one parameter family of separated conditions and show that all the eigenvalues for K and -K are extrema of the eigencurves of this family. This characterization makes it possible to use the well known Prufer transformation which has been used very successfully, both theoretically and numerically, for separated conditions, also in the coupled case. In particular, this characterization makes it possible to compute the eigenvalues for any real coupled self-adjoint boundary condition using any code which works for separated conditions.

  3. Aerosol characterization during project POLINAT

    Energy Technology Data Exchange (ETDEWEB)

    Hagen, D.E.; Hopkins, A.R.; Paladino, J.D.; Whitefield, P.D. [Missouri Univ., Rolla, MO (United States). Cloud and Aerosol Sciences Lab.; Lilenfeld, H.V. [McDonnell Douglas Aerospace-East, St. Louis, MO (United States)

    1997-12-31

    The objectives of the aerosol/particulate characterization measurements of project POLINAT (POLlution from aircraft emissions In the North ATlantic flight corridor) are: to search for aerosol/particulate signatures of air traffic emissions in the region of the North Atlantic Flight Corridor; to search for the aerosol/particulate component of large scale enhancement (`corridor effects`) of air traffic related species in the North Atlantic region; to determine the effective emission indices for the aerosol/particulate component of engine exhaust in both the near and far field of aircraft exhaust plumes; to measure the dispersion and transformation of the aerosol/particulate component of aircraft emissions as a function of ambient condition; to characterize background levels of aerosol/particulate concentrations in the North Atlantic Region; and to determine effective emission indices for engine exhaust particulates for regimes beyond the jet phase of plume expansion. (author) 10 refs.

  4. Ultrasonic techniques for fluids characterization

    CERN Document Server

    Povey, Malcolm J W

    1997-01-01

    This book is a comprehensive and practical guide to the use of ultrasonic techniques for the characterization of fluids. Focusing on ultrasonic velocimetry, the author covers the basic topics and techniques necessaryfor successful ultrasound measurements on emulsions, dispersions, multiphase media, and viscoelastic/viscoplastic materials. Advanced techniques such as scattering, particle sizing, and automation are also presented. As a handbook for industrial and scientific use, Ultrasonic Techniques for Fluids Characterization is an indispensable guide to chemists and chemical engineers using ultrasound for research or process monitoring in the chemical, food processing, pharmaceutical, cosmetic, biotechnology,and fuels industries. Key Features * Appeals to anyone using ultrasound to study fluids * Provides the first detailed description of the ultrasound profiling technique for dispersions * Describes new techniques for measuring phase transitions and nucleation, such as water/ice and oil/fat * Presents the l...

  5. Perceptual Color Characterization of Cameras

    Directory of Open Access Journals (Sweden)

    Javier Vazquez-Corral

    2014-12-01

    Full Text Available Color camera characterization, mapping outputs from the camera sensors to an independent color space, such as \\(XYZ\\, is an important step in the camera processing pipeline. Until now, this procedure has been primarily solved by using a \\(3 \\times 3\\ matrix obtained via a least-squares optimization. In this paper, we propose to use the spherical sampling method, recently published by Finlayson al., to perform a perceptual color characterization. In particular, we search for the \\(3 \\times 3\\ matrix that minimizes three different perceptual errors, one pixel based and two spatially based. For the pixel-based case, we minimize the CIE \\(\\Delta E\\ error, while for the spatial-based case, we minimize both the S-CIELAB error and the CID error measure. Our results demonstrate an improvement of approximately 3for the \\(\\Delta E\\ error, 7& for the S-CIELAB error and 13% for the CID error measures.

  6. Proteomics characterization of exosome cargo.

    Science.gov (United States)

    Schey, Kevin L; Luther, J Matthew; Rose, Kristie L

    2015-10-01

    Characterization of exosomal cargo is of significant interest because this cargo can provide clues to exosome biogenesis, targeting, and cellular effects and may be a source of biomarkers for disease diagnosis, prognosis and response to treatment. With recent improvements in proteomics technologies, both qualitative and quantitative characterization of exosomal proteins is possible. Here we provide a brief review of exosome proteomics studies and provide detailed protocols for global qualitative, global quantitative, and targeted quantitative analysis of exosomal proteins. In addition, we provide an example application of a standard global quantitative analysis followed by validation via a targeted quantitative analysis of urine exosome samples from human patients. Advantages and limitations of each method are discussed as well as future directions for exosome proteomics analysis.

  7. Photoacoustic elastic oscillation and characterization

    CERN Document Server

    Gao, Fei; Zheng, Yuanjin

    2014-01-01

    Photoacoustic imaging and sensing have been studied extensively to probe the optical absorption of biological tissue in multiple scales ranging from large organs to small molecules. However, its elastic oscillation characterization is rarely studied and has been an untapped area to be explored. In literature, photoacoustic signal induced by pulsed laser is commonly modelled as a bipolar "N-shape" pulse from an optical absorber. In this paper, the photoacoustic damped oscillation is predicted and modelled by an equivalent mass-spring system by treating the optical absorber as an elastic oscillator. The photoacoustic simulation incorporating the proposed oscillation model shows better agreement with the measured signal from an elastic phantom, than conventional photoacoustic simulation model. More interestingly, the photoacoustic damping oscillation effect could potentially be a useful characterization approach to evaluate biological tissue's mechanical properties in terms of relaxation time, peak number and ra...

  8. AFIP-6 Characterization Summary Report

    Energy Technology Data Exchange (ETDEWEB)

    Dr. Dennis D. Keiser

    2011-12-01

    The AFIP-6 (ATR Full-size-plate In center flux trap Position) Characterization Summary Report outlines the fresh fuel characterization efforts performed during the AFIP-6 experiment. The AFIP-6 experiment was designed to evaluate the performance of monolithic uranium-molybdenum (U-Mo) fuels at a scale prototypic of Advanced Test Reactor (ATR) fuel plates (45-inches long). The AFIP-6 test was the first test with plates that were swaged into the rails of the assembly. This test served to examine the effects of a plate in a swaged condition with longer fuel zones (22.5-inches long), that were centered in the plate. AFIP-6 test plates employed a zirconium interlayer that was co-rolled with the fuel foil. Previous mini-plate and AFIP irradiation experiments performed in ATR have demonstrated the stable behavior of the interface between the U-Mo fuel and the zirconium interlayer.

  9. What characterizes planetary space weather?

    OpenAIRE

    2014-01-01

    International audience; Space weather has become a mature discipline for the Earth space environment. With increasing efforts in space exploration, it is becoming more and more necessary to understand the space environments of bodies other than Earth. This is the background for an emerging aspect of the space weather discipline: planetary space weather. In this article, we explore what characterizes planetary space weather, using some examples throughout the solar system. We consider energy s...

  10. A Characterization of Prediction Errors

    OpenAIRE

    Meek, Christopher

    2016-01-01

    Understanding prediction errors and determining how to fix them is critical to building effective predictive systems. In this paper, we delineate four types of prediction errors and demonstrate that these four types characterize all prediction errors. In addition, we describe potential remedies and tools that can be used to reduce the uncertainty when trying to determine the source of a prediction error and when trying to take action to remove a prediction errors.

  11. Acoustical characterization of portuguese libraries

    OpenAIRE

    António Pedro Oliveira de Carvalho; António Eduardo Batista da Costa

    2010-01-01

    This paper presents the acoustical characterization of the main reading room of 28 public li-braries in Portugal. In situ measurements were held regarding the interior sound pressure lev-els (background noise, with and without the HVAC equipment working), the Noise Criteria and Noise Rating values (NC/NR), the objective speech intelligibility using the Rapid Speech Transmission Index (RASTI) and Reverberation Time (125 to 4k Hz). Two groups of librar-ies were formed (Classic and Modern librar...

  12. Fracturing fluid characterization facility (FFCF)

    Energy Technology Data Exchange (ETDEWEB)

    Evans, R.D.; Roegiers, J.C.; Fagan, J.

    1993-12-31

    The Fracturing Fluid Characterization Facility project has as its main focus the design, fabrication, and construction of a high pressure simulator (HPS) and a low pressure simulator (LPS) to be used to experimentally investigate the rheological properties and transport characteristics of proppant laden fracturing fluids. A discussion of each apparatus is provided as well as the auxiliary equipment, and data acquisition and control systems associated with the simulators.

  13. RF Characterization of Superconducting Samples

    CERN Document Server

    Junginger, T; Welsch, C

    2009-01-01

    At CERN a compact Quadrupole Resonator has been re-commissioned for the RF characterization of superconducting materials at 400 MHz. In addition the resonator can also be excited at multiple integers of this frequency. Besides Rs it enables determination of the maximum RF magnetic field, the thermal conductivity and the penetration depth of the attached samples, at different temperatures. The features of the resonator will be compared with those of similar RF devices and first results will be presented.

  14. Characterizing perception of ecological risk.

    Science.gov (United States)

    McDaniels, T; Axelrod, L J; Slovic, P

    1995-10-01

    Relatively little attention has been paid to the role of human perception and judgment in ecological risk management. This paper attempts to characterize perceived ecological risk, using the psychometric paradigm developed in the domain of human health risk perception. The research began by eliciting a set of scale characteristics and risk items (e.g., technologies, actions, events, beliefs) from focus group participants. Participants in the main study were 68 university students who completed a survey instrument that elicited ratings for each of 65 items on 30 characteristic scales and one scale regarding general risk to natural environments. The results are presented in terms of mean responses over individuals for each scale and item combination. Factor analyses show that five factors characterize the judgment data. These have been termed: impact on species, human benefits, impact on humans, avoidability, and knowledge of impacts. The factor results correspond with initial expectations and provide a plausible characterization of judgments regarding ecological risk. Some comparisons of mean responses for selected individual items are also presented.

  15. Instrumentation for CTA site characterization

    CERN Document Server

    Fruck, Christian; Ernenwein, Jean-Pierre; Mandát, Dušan; Schweizer, Thomas; Häfner, Dennis; Bulik, Tomasz; Cieslar, Marek; Costantini, Heide; Dominik, Michal; Ebr, Jan; Garczarczyk, Markus; Lorentz, Eckart; Pareschi, Giovanni; Pech, Miroslav; Puerto-Giménez, Irene; Teshima, Masahiro

    2015-01-01

    Many atmospheric and climatic criteria have to be taken into account for the selection of a suitable site for the next generation of imaging air-shower Cherenkov telescopes, the "Cherenkov Telescope Array" CTA. Such data are not available with sufficient precision or the comparability to allow for a comprehensive characterization of the proposed sites to be made. Identical cross-calibrated instruments have been developed which allow for precise comparison between sites, the cross-validation of existing data, and the ground-validation of satellite data. The site characterization work package of the CTA consortium opted to construct and deploy 9 copies of an autonomous multi-purpose weather sensor, incorporating an infrared cloud sensor a newly developed sensor for measuring the light of the night sky, and an All-Sky-Camera, the whole referred to as Autonomous Tool for Measuring Observatory Site COnditions PrEcisely (ATMOSCOPE). We present here the hardware that was combined into the ATMOSCOPE and characterize ...

  16. Ultrasonic Characterization of Aerospace Composites

    Science.gov (United States)

    Leckey, Cara; Johnston, Patrick; Haldren, Harold; Perey, Daniel

    2015-01-01

    Composite materials have seen an increased use in aerospace in recent years and it is expected that this trend will continue due to the benefits of reduced weight, increased strength, and other factors. Ongoing work at NASA involves the investigation of the large-scale use of composites for spacecraft structures (SLS components, Orion Composite Crew Module, etc). NASA is also involved in work to enable the use of composites in advanced aircraft structures through the Advanced Composites Project (ACP). In both areas (space and aeronautics) there is a need for new nondestructive evaluation and materials characterization techniques that are appropriate for characterizing composite materials. This paper will present an overview of NASA's needs for characterizing aerospace composites, including a description of planned and ongoing work under ACP for the detection of composite defects such as fiber waviness, reduced bond strength, delamination damage, and microcracking. The research approaches include investigation of angle array, guided wave, and phase sensitive ultrasonic methods. The use of ultrasonic simulation tools for optimizing and developing methods will also be discussed.

  17. Sustainability Characterization for Additive Manufacturing

    Science.gov (United States)

    Mani, Mahesh; Lyons, Kevin W; Gupta, SK

    2014-01-01

    Additive manufacturing (AM) has the potential to create geometrically complex parts that require a high degree of customization, using less material and producing less waste. Recent studies have shown that AM can be an economically viable option for use by the industry, yet there are some inherent challenges associated with AM for wider acceptance. The lack of standards in AM impedes its use for parts production since industries primarily depend on established standards in processes and material selection to ensure the consistency and quality. Inability to compare AM performance against traditional manufacturing methods can be a barrier for implementing AM processes. AM process sustainability has become a driver due to growing environmental concerns for manufacturing. This has reinforced the importance to understand and characterize AM processes for sustainability. Process characterization for sustainability will help close the gaps for comparing AM performance to traditional manufacturing methods. Based on a literature review, this paper first examines the potential environmental impacts of AM. A methodology for sustainability characterization of AM is then proposed to serve as a resource for the community to benchmark AM processes for sustainability. Next, research perspectives are discussed along with relevant standardization efforts. PMID:26601038

  18. Sustainability Characterization for Additive Manufacturing.

    Science.gov (United States)

    Mani, Mahesh; Lyons, Kevin W; Gupta, S K

    2014-01-01

    Additive manufacturing (AM) has the potential to create geometrically complex parts that require a high degree of customization, using less material and producing less waste. Recent studies have shown that AM can be an economically viable option for use by the industry, yet there are some inherent challenges associated with AM for wider acceptance. The lack of standards in AM impedes its use for parts production since industries primarily depend on established standards in processes and material selection to ensure the consistency and quality. Inability to compare AM performance against traditional manufacturing methods can be a barrier for implementing AM processes. AM process sustainability has become a driver due to growing environmental concerns for manufacturing. This has reinforced the importance to understand and characterize AM processes for sustainability. Process characterization for sustainability will help close the gaps for comparing AM performance to traditional manufacturing methods. Based on a literature review, this paper first examines the potential environmental impacts of AM. A methodology for sustainability characterization of AM is then proposed to serve as a resource for the community to benchmark AM processes for sustainability. Next, research perspectives are discussed along with relevant standardization efforts.

  19. Characterization system for resonant micro- and nanocantilevers

    DEFF Research Database (Denmark)

    Sandberg, Rasmus Kousholt; Boisen, Anja; Svendsen, Winnie Edith

    2005-01-01

    We present a system for characterization of the resonant properties of micro- and nanocantilever sensors. The system has been constructed as a vacuum chamber with capabilities for controlling environmental conditions such as pressure, temperature, and chemical constituents. Characterization can...

  20. Collector/Receiver Characterization (Fact Sheet)

    Energy Technology Data Exchange (ETDEWEB)

    2010-08-01

    Fact sheet describing NREL CSP Program capabilities for collector/receiver characterization: determining optical efficiency, measuring heat loss, developing and testing concentrators, concentrating the sun's power, and optically characterizing CSP plants.