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Sample records for perylene monoimide derivative

  1. Visualization of Membrane Rafts Using a Perylene Monoimide Derivative and Fluorescence Lifetime Imaging

    PubMed Central

    Margineanu, Anca; Hotta, Jun-ichi; Van der Auweraer, Mark; Ameloot, Marcel; Stefan, Alina; Beljonne, David; Engelborghs, Yves; Herrmann, Andreas; Müllen, Klaus; De Schryver, Frans C.; Hofkens, Johan

    2007-01-01

    A new membrane probe, based on the perylene imide chromophore, with excellent photophysical properties (high absorption coefficient, quantum yield (QY) ≈ 1, high photostability) and excited in the visible domain is proposed for the study of membrane rafts. Visualization of separation between the liquid-ordered (Lo) and the liquid-disordered (Ld) phases can be achieved in artificial membranes by fluorescence lifetime imaging due to the different decay times of the membrane probe in the two phases. Rafts on micrometer-scale in cell membranes due to cellular activation can also be observed by this method. The decay time of the dye in the Lo phase is higher than in organic solvents where its QY is 1. This allows proposing a (possible general) mechanism for the decay time increase in the Lo phase, based on the local field effects of the surrounding molecules. For other fluorophores with QY < 1, the suggested mechanism could also contribute, in addition to effects reducing the nonradiative decay pathways, to an increase of the fluorescence decay time in the Lo phase. PMID:17573424

  2. Synthesis and Characterization of Unsymmetrical Perylene Derivatives and Perylene Oligomers

    NASA Astrophysics Data System (ADS)

    Sun, Runkun

    Since the discovery of high fluorescent property of perylene tetracarboxylic diimide (PDI) derivatives in 1959, more and more researchers' attention has been attracted to related fields. Ever since, many kinds of PDI derives has been synthesized and characterized. And many special properties of PDI derivatives also has been found, such as strong absorbance ability, special redox property and self assembly induced by pi-pi interaction etc. All these properties endow PDI derivatives wide applications in photovoltaic field and semi-conducting materials area. At the same time, those important applications also encourage researchers to do more exploration on the synthesis and characterization of PDI derivatives. As one of those researchers, my thesis also mainly focused on developing new synthetic methods and characterization of novel PDI derivatives. In Chapter 1, the history of perylene, PDI derivatives and PDI oligomers are introduced. Their corresponding properties and applications also are introduced. Furthermore, the synthetic methods for different kinds of PDI derivatives, both advantages and disadvantages, are discussed thoroughly. In Chapter 2, with the investigation of known reactions which were used to prepare the key intermediate, perylene monoimide monoanhydride, a new synthetic method was developed. The key intermediate could be prepared with high yield conveniently. With the key intermediate, several unsymmetric PDI derivatives were prepared with decent yield. The optical property of one unsymmetric PDI was studied. In Chapter 3, the synthesis of peryelene diester monoanhydride (PEA) and perylene monoimide monoanhydride (PIA) was discussed. We discovered a new way to prepare PEA and PEI. Several PEA and PEI with complex structure were prepared with decent yield. The first unsymmetric PEA was synthesized. In Chapter 4, the synthesis of several perylene oligomers was discussed. Base on our experience gained in the Chapter 3 and our investigation of Langhals

  3. Morphology Tuning of Self-Assembled Perylene Monoimide from Nanoparticles to Colloidosomes with Enhanced Excimeric NIR Emission for Bioimaging.

    PubMed

    Jana, Avijit; Bai, Linyi; Li, Xin; Ågren, Hans; Zhao, Yanli

    2016-01-27

    Organic near-infrared (NIR) fluorescent probes have been recognized as an emerging class of materials exhibiting a great potential in advanced bioanalytical applications. However, synthesizing such organic probes that could simultaneously work in the NIR spectral range and have large Stokes shift, high stability in biological systems, and high photostability have been proven challenging. In this work, aggregation induced excimeric NIR emission in aqueous media was observed from a suitably substituted perylene monoimide (PeIm) dye. Controlled entrapment of the dye into pluronic F127 micellar system to preserve its monomeric green emission in aqueous media was also established. The aggregation process of the PeIm dye to form organic nanoparticles (NPs) was evaluated experimentally by the means of transmission electron microscope imaging as well as theoretically by the molecular dynamics simulation studies. Tuning the morphology along with the formation of colloidosomes by the controlled self-aggregation of PeIm NPs in aqueous suspension was demonstrated successfully. Finally, both excimeric and monomeric emissive PeIm NPs as well as PeIm colloidosomes were employed for the bioimaging in vitro.

  4. Highly fluorescent platinum(II) organometallic complexes of perylene and perylene monoimide, with Pt σ-bonded directly to the perylene core.

    PubMed

    Lentijo, Sergio; Miguel, Jesús A; Espinet, Pablo

    2010-10-18

    3-Bromoperylene (BrPer) or N-(2,5-di-tert-butylphenyl)-9-bromo-perylene-3,4-dicarboximide (BrPMI) react with [Pt(PEt(3))(4)] to yield trans-[PtR(PEt(3))(2)Br] (R = Per, 1a; R = PMI, 1b). Neutral and cationic perylenyl complexes containing a Pt(PEt(3))X group have been prepared from 1a,b by substitution of the Br ligand by a variety of other ligands (NCS, CN, NO(3), CN(t)Bu, PyMe). The X-ray structures of trans-[PtR(PEt(3))(2)X] (R = Per, X = NCS (2a); R = PMI, X = NO(3) (4b); R = Per, X = CN(t)Bu (5a)) show that the perylenyl fragment remains nearly planar and is arranged almost orthogonal to the coordination plane: The three molecules appear as individual entities in the solid state, with no π-π stacking of perylenyl rings. Each platinum complex exhibits fluorescence associated to the perylene or PMI fragments with emission quantum yields, in solution at room temperature, in the range 0.30-0.80 and emission lifetimes ∼4 ns, but with significantly different emission maxima, by influence of the X ligands on Pt. The similarity of the overall luminescence spectra of these metalated complexes with the perylene or PMI strongly suggests a perylene-dominated intraligand π-π*emissive state, metal-perturbed by interaction of the platinum fragment mostly via polarization of the Ar-Pt bond.

  5. Spectrophotochemical and electrochemical characterization of perylene derivatives adsorbed on nanoporous metaloxide films

    NASA Astrophysics Data System (ADS)

    Kus, M.; Demic, S.; Zafer, C.; Saygili, G.; Bilgili, H.; Icli, S.

    2007-03-01

    Electrochemistry of perylene imide and anhydride derivatives adsorbed on semiconductor TiO{2} (NT) and insulator Al{2}O{3} (NA) metal oxide films were presented. Adsorption rates on metal oxide surface are observed to be strongly depending on molecular structure. Monoanhydride-monoimide derivatives show two reversible reductions in solution and one reversible reduction in films. Color change from red to blue and violet is observed indicating the formation of monoanion and dianion radicals. Spectroelectrochemical measurements support this interpretation. The color reversal is quite stable in NA films in comparison with NT films. This paper has been presented at “ECHOS06”, Paris, 28 30 juin 2006.

  6. Self-intermixed patterns of perylene derivatives

    NASA Astrophysics Data System (ADS)

    Stoehr, Meike; Wahl, Markus; Samuely, Tomas; Jung, Thomas A.; Gade, Lutz H.

    2006-03-01

    Self-assembled systems are in the focus of nanotechnology research because of their potential use in the ``bottom-up'' creation of functional supramolecular structures. Potential applications of such systems include several functional groups. Therefore, the intermixing of different molecular compounds will become a key issue. In our approach we made use of H-bonding to form well-ordered intermixed patterns of two different perylene derivatives - PTCDA and DPDI. In an UHV-setup thin films of DPDI and PTCDA were prepared by evaporation on Ag(111). The sample characterization was carried out with a homebuilt STM. For a ratio of 1:1 and a total coverage of about one monolayer, an ordered intermixed pattern was observed. Each PTCDA molecule is interacting via H-bonding with four neighbouring DPDI molecules and vice versa. Furthermore, different intermixed patterns were observed depending on the ratio of the molecules and on the total coverage.

  7. Pi-Stack Engineering of Semiconducting Perylene Tetracarboxylic Derivatives

    NASA Astrophysics Data System (ADS)

    Xue, Chenming

    In the past decades, there has been intensive research in generating novel perylene tetracarboxylic derivatives because of a vast number of applications based on their semiconducting characteristics. The properties of the new materials rely heavily on not only the single molecular structure, but also the way of molecular packing in condensed states. The formation of effective pi-stacking structures is the key issue. In this thesis, I focused in synthesizing novel perylene tetracarboxylic derivatives by attaching various substituents at the imide nitrogens. Consequently different phases appeared and exhibited different way of molecular packing. In Chapter 1, it is the general background of perylene tetracarboxylic derivatives including (a) synthesis routes, (b) optical and electronic properties, (c) the molecular packing in condensed phases or assembling in solutions; and also the introduction of condensed state phases including amorphous, crystalline and liquid crystalline (LC) phases. In Chapter 2, a series of solution processible amorphous glassy perylene tetracarboxylic diimides (PDIs) has been designed, synthesized and characterized. The pi-stacking order in the amorphous glass phase was successfully tailored by the steric means and qualitatively evaluated. In Chapter 3, the n-alkyl chain length dependence of a series of two-dimensional (2D) smectic LC PDIs has been explored. When the n-alkyl chain is no shorter than decyl group, the PDI could exhibit a novel 2D crystalline smectic LC phase. In this phase, the PDI cores microphase separate from flexible n-alkyl chains forming 2D crystalline layers. Thermoanalysis data quantitatively reveal that the n-alkyl chains in this phase have the essentially the same order as that in the isotropic liquid state. Such truly disordered n-alkyl chains effectively decouple the inter-layer molecular correlation and make the phase genuine LC. The PDI pi-stacking order in this LC phase is crystalline because it is a part of the 2

  8. Perylene Derivatives As Useful SERRS Reporters, Including Multiplexing Analysis.

    PubMed

    Tenori, Eleonora; Colusso, Andrea; Syrgiannis, Zois; Bonasera, Aurelio; Osella, Silvio; Ostric, Adrian; Lazzaroni, Roberto; Meneghetti, Moreno; Prato, Maurizio

    2015-12-30

    Five perylene bisimide (PBI) derivatives were designed and synthesized, on the basis of quantum-chemical calculations. The influence of halogen substituents on the shape and energy of the frontier orbitals and the Raman spectra were calculated, in the prospect use in surface-enhanced resonance Raman scattering (SERRS) studies. The corresponding experiments confirmed a very strong SERRS response in the presence of pristine (i.e., uncoated) gold nanoparticles. These spectra can be used for multiplexing measurements, namely measurements in which, by using a single laser excitation, one can recognize the simultaneous presence of several analytes.

  9. Perylene bisimide derivatives as innovative sensitizers for photorefractive composites

    NASA Astrophysics Data System (ADS)

    Schemme, Thomas; Ditte, Katharina; Travkin, Evgenij; Jiang, Wei; Wang, Zhaohui; Denz, Cornelia

    2012-06-01

    In photorefractive composites, we replace the commonly used fullerene derivative phenyl-C61-butyric acid methyl ester (PCBM) by the perylene bisimide dimer DiPBI. In samples, wherein poly-n-vinylcarbazole (PVK) is the charge transporting agent and 4-cyano-4-n-pentylbiphenyl (5CB) the nonlinear optical unit, we observe dramatic enhancements in the overall performance of the composites. When we replace PVK by N,N-diphenyl-N, N-bis(3-methylphenyl)-[1, 1-biphenyl]-4, 4-diamine (TPD) doped polystyrene (PS), the internal photocurrent efficiency is further improved by a factor 11.

  10. Complementary inverter using high mobility air-stable perylene di-imide derivatives

    NASA Astrophysics Data System (ADS)

    Ling, Mang-mang; Bao, Zhenan; Erk, Peter; Koenemann, Martin; Gomez, Marcos

    2007-02-01

    The authors report the fabrication and electrical characterization of organic complementary inverters using pentacene as p-type material and our previously reported air-stable perylene di-imide derivatives tetrachloro-perylene-tetracarboxyldi-imide (TC-PTCDI) and N ,N'-bis(2-phenylethyl)perylene-3,4:9:10-bis-(dicarboximide) (BPE-PTCDI) as n-type materials. Both p- and n-type thin film transistors were integrated onto the same substrate using a top contact configuration. The corresponding inverters show good performance with gains about 12 and 10 for TC-PTCDI and BPE-PTCDI inverters, respectively.

  11. Zinc(II)-selective ratiometric fluorescent probe based on perylene bisimide derivative.

    PubMed

    Zhao, Yingjie; Sun, Juanjuan; Shi, Zhiqiang; Pan, Cuicui; Xu, Maoyou

    2011-01-01

    A fluorescent probe of N,N'-biscyclohexyl-1,7-di(3-pyridoxy)-perylene-3,4:9,10-tetracarboxylic acid diimide has been synthesized, and exhibited excellent selectivity and sensitivity for Zn(2+) over other competing biological cations. The Zn(2+) -selective fluorescence blue-shift and enhancing property in conjunction with a visible colorimetric change from orange to green could be observed. With favorable photophysical properties in the visible region, the perylene bisimide derivatives remarkably improved the performance of the probe.

  12. Interactions of a Platinum-Modified Perylene Derivative with the Human Telomeric G-Quadruplex

    PubMed Central

    Rao, Lu; Dworkin, Joshua D.; Nell, William E.; Bierbach, Ulrich

    2012-01-01

    The interactions of a newly synthesized platinum-modified perylene derivative, compound 7 ([{Pt(dien)}2(μ-4-S,S')](NO3)4 (dien = diethylenetriamine, 4 = N,N'-bis(1-(2-aminoethyl)-1,3-dimethylthiourea)-3,4,9,10-perylenetetracarboxylic acid diimide), with the human telomeric repeat were studied using various model oligo(deoxy)ribonucleotides to mimic the polymorphic nature of the telomeric G-quadruplex. UV/visible spectroscopy, CD spectropolarimetry, electrospray mass spectrometry (ES-MS), and isothermal titration calorimetry (ITC) were used to demonstrate that compound 7 selectively recognizes the antiparallel form of the unimolecular telomeric G-quadruplex formed by the sequence d(TTAGGG)4 (dG-24), to which it binds with a 2:1 stoichiometry and nanomolar affinity. Compared with telomeric DNA, the first binding event of compound 7 in titrations with the RNA quadruplex formed by r(UUAGGG)4 (rG-24) is an order of magnitude weaker. Compound 7 does not induce the antiparallel G-quadruplex RNA, which invariably exists in a parallel form and dimerizes in solution. Based on the cumulative experimental data, two distinct mechanisms are proposed for the recognition of G-quadruplex DNA and RNA by compound 7. Potential biomedical and biochemical applications of the platinum–perylene technology are discussed. PMID:21999566

  13. Interactions of a platinum-modified perylene derivative with the human telomeric G-quadruplex.

    PubMed

    Rao, Lu; Dworkin, Joshua D; Nell, William E; Bierbach, Ulrich

    2011-11-24

    The interactions of a newly synthesized platinum-modified perylene derivative, compound 7 ([{Pt(dien)}(2)(μ-4-S,S')](NO(3))(4) (dien = diethylenetriamine, 4 = N,N'-bis(1-(2-aminoethyl)-1,3-dimethylthiourea)-3,4,9,10-perylenetetracarboxylic acid diimide), with the human telomeric repeat were studied using various model oligo(deoxy)ribonucleotides to mimic the polymorphic nature of the telomeric G-quadruplex. UV/visible spectroscopy, CD spectropolarimetry, electrospray mass spectrometry (ES-MS), and isothermal titration calorimetry (ITC) were used to demonstrate that compound 7 selectively recognizes the antiparallel form of the unimolecular telomeric G-quadruplex formed by the sequence d(TTAGGG)(4) (dG-24), to which it binds with a 2:1 stoichiometry and nanomolar affinity. Compared with telomeric DNA, the first binding event of compound 7 in titrations with the RNA quadruplex formed by r(UUAGGG)(4) (rG-24) is 1 order of magnitude weaker. Compound 7 does not induce the antiparallel G-quadruplex RNA, which invariably exists in a parallel form and dimerizes in solution. On the basis of the cumulative experimental data, two distinct mechanisms are proposed for the recognition of G-quadruplex DNA and RNA by compound 7. Potential biomedical and biochemical applications of the platinum-perylene technology are discussed. © 2011 American Chemical Society

  14. Morphology-controlled growth of perylene derivative induced by double-hydrophilic block copolymers

    NASA Astrophysics Data System (ADS)

    Huang, Minghua; Antonietti, Markus; Cölfen, Helmut

    2016-01-01

    Controlled growth of technically relevant perylene derivative 3, 4, 9, 10-perylenetetracarboxylic acid potassium salt (PTCAPS), with tuneable morpologies, has been successfully realized by a recrystallization method using a double-hydrophilic block copolymer poly (ethylene glycol)-block poly (ethyleneimine) (PEG-b-PEI) as the structure directing agent. The {001} faces of PTCAPS are most polar and adsorb the oppositively charged polymer additive PEG-b-PEI well by electrostatic attraction. By simply adjusting the PEG-b-PEI concentration, systematic morphogenesis of PTCAPS from plates to microparticles composed of various plates splaying outwards could be realized. Furthermore, the variation of pH value of the recrystallization solution could induce the change of the interaction strength between PEG-b-PEI additive and PTCAPS and thus modify the morphology of PTCAPS from microparticles composed of various plates to ultralong microbelts.

  15. Photophysical characterization of perylene derivatives and their interaction with human serum albumin

    NASA Astrophysics Data System (ADS)

    Farooqi, Mohammed Junaid

    The study of the binding and effects of polyaromatic hydro-carbons (PAH) to proteins remains one of the fundamental aspects of research in biophysics. Among other processes, ligand binding can regulate the function of proteins including inhibiting their action. Binding to small ligands remains a very important aspect in the study of the function of many proteins. We have investigated a number of novel perylene analogues. The investigation includes the photophysical characterization of perylene diimides and their interaction with HSA. In this study we have shown that 3,9-disubstitutes perylenes show weak affinity to binding with HSA and their irradiation produces no observable structural effects on the bound protein. Perylene Diimides were photophysically characterized in organic solvents. PDI phenylalanine and leucine are the only PDIs spectroscopically observable in aqueous solution and bind with HSA with great affinity. Resonance energy transfer was observed in PDIF bound to HSA with an energy efficiency of 0.268.

  16. Molecular organization and mixing in thin solid films of novel perylene tetracarboxylic dianhydride derivatives: Infrared and surface enhanced Raman studies

    NASA Astrophysics Data System (ADS)

    Kam, Alicia Patricia

    The present work focuses on the fabrication and spectroscopic characterization of submicron thin solid films of novel organic dyes. The synthesis, thin film fabrication, electronic and vibrational spectra of neat materials are described. The main group of organic dyes studied here are novel perylene tetracarboxylic derivatives. The fabrication of thin solid films on a variety of substrates is demonstrated and the long-range molecular organization in the films, extracted using mainly infrared techniques, is illustrated. The starting point in using vibrations as structural probes, is the vibrational assignments of the characteristic perylene tetracarboxylic fundamentals for each dye under study. The assigned vibrational spectra are employed as references to extract the molecular organization in the vacuum evaporated films using data from the complementary techniques: transmission infrared and reflection-absorption infrared spectroscopy. The understanding of the molecular organization opens the door to changing and controlling the molecular film structure with thermal annealing, and these studies are illustrated for bis(n-propylimido) perylene films. It is shown that reorientation can be induced in thin films of bisPTCD dye. The factors that may determine reorientation on thermal annealing are investigated. Surface-enhanced spectroscopic studies of metal island films coated with the dyes were carried out. The surface-enbanced vibrational spectroscopy (SEVS) used encompasses spectral data obtained from surface-enhanced Raman scattering (SERS), surface-enhanced-resonance Raman scattering- (SERRS) and surface-enhanced infrared (SEIR). The first systematic study of mixed thin solid films of PTDC materials and phthalocyanines, using vacuum co-evaporation, is presented. Mixed films of Perylene and phthalocyanine derivatives were fabricated and investigated using SERS, SERRS and SERRS imaging. It is demonstrated that SERRS global imaging is a powerful analytical tool that

  17. A perylene bisimide derivative with pyrene and cholesterol as modifying structures: synthesis and fluorescence behavior.

    PubMed

    Wang, Gang; Wang, Weina; Miao, Rong; Shang, Congdi; He, Meixia; Peng, Haonan; He, Gang; Fang, Yu

    2016-04-28

    A perylene bisimide (PBI) derivative (C-PBI-Py) of pyrene (Py) and cholesteryl residue (C) possessing intra-molecular energy transfer properties and three reference compounds (C-Py, C-PBI, PBI-Py) were designed and synthesized, where C was introduced in order to enhance the solubility of the relevant compounds in organic solvents. UV-vis absorption, steady-state fluorescence, cyclic voltammetric and theoretical calculation studies revealed that: (1) the PBI unit and Py moiety of C-PBI-Py could act as two individual chromophores, (2) the excited state energy of Py could transfer to PBI within a single molecule of the compound, and (3) the PBI moiety of the compound tends to form aggregates and shows PBI excimer emission. Time-resolved and temperature-dependent emission spectroscopy studies revealed the presence of both H-type excimer and J-type excimer, and formation of them via either the Birks' scheme or the pre-formed scheme due to strong π-π stacking that was elucidated by concentration-dependent (1)H NMR spectroscopy measurement. In addition, the studies also indicated that the energy transfer occurs via an electron exchange mechanism (Dexter scheme). Results of this study will be useful in the development of new solvatochromic and other environment-sensitive fluorophores based on alteration of intra-molecular energy transfer efficiency.

  18. Synthesis and predetermined supramolecular chirality of carbohydrate-functionalized perylene bisimide derivatives.

    PubMed

    Wang, Ke-Rang; Han, Dan; Cao, Guo-Jing; Li, Xiao-Liu

    2015-05-01

    Eight carbohydrate-modified perylene bisimides (PBI-4 lac-2 lac, PBI-4 lac-2 Man, PBI-4 lac-2 Gal, PBI-4 lac-2 Mal, PBI-4 Man-2 Man, PBI-4 Man-2 lac, PBI-4 Man-2 Gal and PBI-4 Man-2 Mal) were synthesized, and the following predetermined supramolecular chirality rule was found: perylene bisimides modified with disaccharides (D-lactose and D-maltose) at the imide position generated right-handed chirality, and those modified with monosaccharides (D-mannose and D-galactose) generated left-handed chirality, when D-lactose or D-mannose was substituted in the bay positions of perylene bisimides with amide bonds as the linking spacers. These results may be because of the difference in the stacking angle of the perylene bisimide backbones induced by the steric effect and the additional hydrogen bonds between the disaccharide residues. This study provides an important design rule for predetermined chiral self-assembly of perylene bisimides.

  19. Effect of five-membered ring and heteroatom substitution on charge transport properties of perylene discotic derivatives: A theoretical approach

    NASA Astrophysics Data System (ADS)

    Navarro, Amparo; Fernández-Liencres, M. Paz; Peña-Ruiz, Tomás; García, Gregorio; Granadino-Roldán, José M.; Fernández-Gómez, Manuel

    2016-08-01

    Density functional theory calculations were carried out to investigate the evolvement of charge transport properties of a set of new discotic systems as a function of ring and heteroatom (B, Si, S, and Se) substitution on the basic structure of perylene. The replacement of six-membered rings by five-membered rings in the reference compound has shown a prominent effect on the electron reorganization energy that decreases ˜0.2 eV from perylene to the new carbon five-membered ring derivative. Heteroatom substitution with boron also revealed to lower the LUMO energy level and increase the electron affinity, therefore lowering the electron injection barrier compared to perylene. Since the rate of the charge transfer between two molecules in columnar discotic systems is strongly dependent on the orientation of the stacked cores, the total energy and transfer integral of a dimer as a disc is rotated with respect to the other along the stacking axis have been predicted. Aimed at obtaining a more realistic approach to the bulk structure, the molecular geometry of clusters made up of five discs was fully optimized, and charge transfer rate and mobilities were estimated for charge transport along a one dimensional pathway. Heteroatom substitution with selenium yields electron transfer integral values ˜0.3 eV with a relative disc orientation of 25°, which is the preferred angle according to the dimer energy profile. All the results indicate that the tetraselenium-substituted derivative, not synthetized so far, could be a promising candidate among those studied in this work for the fabrication of n-type semiconductors based on columnar discotic liquid crystals materials.

  20. Effect of five-membered ring and heteroatom substitution on charge transport properties of perylene discotic derivatives: A theoretical approach.

    PubMed

    Navarro, Amparo; Fernández-Liencres, M Paz; Peña-Ruiz, Tomás; García, Gregorio; Granadino-Roldán, José M; Fernández-Gómez, Manuel

    2016-08-07

    Density functional theory calculations were carried out to investigate the evolvement of charge transport properties of a set of new discotic systems as a function of ring and heteroatom (B, Si, S, and Se) substitution on the basic structure of perylene. The replacement of six-membered rings by five-membered rings in the reference compound has shown a prominent effect on the electron reorganization energy that decreases ∼0.2 eV from perylene to the new carbon five-membered ring derivative. Heteroatom substitution with boron also revealed to lower the LUMO energy level and increase the electron affinity, therefore lowering the electron injection barrier compared to perylene. Since the rate of the charge transfer between two molecules in columnar discotic systems is strongly dependent on the orientation of the stacked cores, the total energy and transfer integral of a dimer as a disc is rotated with respect to the other along the stacking axis have been predicted. Aimed at obtaining a more realistic approach to the bulk structure, the molecular geometry of clusters made up of five discs was fully optimized, and charge transfer rate and mobilities were estimated for charge transport along a one dimensional pathway. Heteroatom substitution with selenium yields electron transfer integral values ∼0.3 eV with a relative disc orientation of 25°, which is the preferred angle according to the dimer energy profile. All the results indicate that the tetraselenium-substituted derivative, not synthetized so far, could be a promising candidate among those studied in this work for the fabrication of n-type semiconductors based on columnar discotic liquid crystals materials.

  1. Tuning morphology and fluorescence of aggregated nanostructures of derived perylene diimide molecules.

    PubMed

    He, Xiaorong; Zhou, Weidong; Li, Yuliang; Liu, Xiaofeng; Li, Cuihong; Liu, Huibiao; Zhu, Daoben

    2008-04-01

    In this paper, we report on the self-assembly of water-soluble N,N'-di(N,N'-dimethyl-dodecane-1, 12-diamide)-perylene-3,4,9,10-tetracarboxylic diimide (PDDoAM) in formic acid and chloride salts for producing varied nano-aggregates with different optical properties. Interestingly, the self-assembly can lead to nanocubic, microsheet and "tower-like" nanostructures respectively, as demonstrated by Scanning Electron Microscopy (SEM) images. The optical properties of molecular aggregates were investigated by means of Confocal Raman Microscopy, indicating the morphologies and fluorescence of these nanomaterials are dependent on acids, acid concentrations and casting methods.

  2. Fabrication and humidity sensing performance studies of a fluorescent film based on a cholesteryl derivative of perylene bisimide

    NASA Astrophysics Data System (ADS)

    Zhang, Shujuan; Zhou, Feng; Peng, Haonan; Liu, Taihong; Ding, Liping; Fang, Yu

    2016-08-01

    A fluorescent film based on a cholesteryl derivative of perylene bisimide (PTCDI-co-CholDEA) was fabricated via utilization of an electrostatic spinning technique on a glass plate surface. SEM studies revealed that the film was characterized by fibrous network structure. It is the structure and the chemical composition that make the fluorescence emission of the film sensitive to the variation of local environmental humidity. The sensitivity of the sensing is 0.1497 (× 104 a.u. of the intensity)/1% RH, of which RH is the abbreviation of relative humidity. The maximum quenching efficiency of the film is 55.4% when humidity reaches 97% RH. Furthermore, the sensing process is fully reversible, and presence of other commonly found liquids shows little effect to the monitoring process.

  3. High-Speed Organic Photodetectors Using Heterostructure with Phthalocyanine and Perylene Derivative

    NASA Astrophysics Data System (ADS)

    Morimune, Taichiro; Kajii, Hirotake; Ohmori, Yutaka

    2006-01-01

    Single-layered heterostructure (SLH) and multi-layered heterostructure (MLH) organic photodetectors using copper phthalocyanine (CuPc) and N,N'-bis(2,5-di-tert-butylphenyl)3,4,9,10-perylene dicarboximide (BPPC) were fabricated and characterized. The influence on the frequency response of the total thickness of the organic active layer and the incident square-wave pulse power was analyzed. For the SLH devices, a cutoff frequency of 22 MHz was obtained under an applied electric field of 0.8 MV/cm. The frequency response highly depends on the applied electric fields. However, it was not affected by the total thickness of the organic active layer. On the other hand, it was found that the frequency response speed in the MLH device was lower than that in the SLH device under a pulse light peak of 100 mW/cm2 at the same applied reverse voltage. The cutoff frequency in the MLH device increased with the intensity of the repetition pulse light. Differences in carrier density in the quantum well between the CuPc-BPPC and the trapping levels in the hetero interface relate to the response speed.

  4. Ultrafast photodriven intramolecular electron transfer from an iridium-based water-oxidation catalyst to perylene diimide derivatives

    PubMed Central

    Vagnini, Michael T.; Smeigh, Amanda L.; Blakemore, James D.; Eaton, Samuel W.; Schley, Nathan D.; D’Souza, Francis; Crabtree, Robert H.; Brudvig, Gary W.; Co, Dick T.; Wasielewski, Michael R.

    2012-01-01

    Photodriving the activity of water-oxidation catalysts is a critical step toward generating fuel from sunlight. The design of a system with optimal energetics and kinetics requires a mechanistic understanding of the single-electron transfer events in catalyst activation. To this end, we report here the synthesis and photophysical characterization of two covalently bound chromophore-catalyst electron transfer dyads, in which the dyes are derivatives of the strong photooxidant perylene-3,4:9,10-bis(dicarboximide) (PDI) and the molecular catalyst is the Cp∗Ir(ppy)Cl metal complex, where ppy = 2-phenylpyridine. Photoexcitation of the PDI in each dyad results in reduction of the chromophore to PDI•- in less than 10 ps, a process that outcompetes any generation of 3∗PDI by spin-orbit-induced intersystem crossing. Biexponential charge recombination largely to the PDI-Ir(III) ground state is suggestive of multiple populations of the PDI•--Ir(IV) ion-pair, whose relative abundance varies with solvent polarity. Electrochemical studies of the dyads show strong irreversible oxidation current similar to that seen for model catalysts, indicating that the catalytic integrity of the metal complex is maintained upon attachment to the high molecular weight photosensitizer. PMID:22586073

  5. Visible-light driven oxidation of gaseous aliphatic alcohols to the corresponding carbonyls via TiO2 sensitized by a perylene derivative.

    PubMed

    Guarisco, Chiara; Palmisano, Giovanni; Calogero, Giuseppe; Ciriminna, Rosaria; Di Marco, Gaetano; Loddo, Vittorio; Pagliaro, Mario; Parrino, Francesco

    2014-10-01

    Sensitized P25 TiO2 was prepared by wet impregnation with a home-prepared perylene dye, i.e., N,N'-bis(2-(1-piperazino)ethyl)-3,4,9,10-perylene-tetracarboxylic acid diimide dichloride (PZPER). Energy levels of PZPER were found to be compatible with those of TiO2 allowing fast electron transfer. The obtained catalyst has been characterized and used in the gas-phase partial oxidation of aliphatic primary and secondary alcohols, i.e., methanol, ethanol, and 2-propanol. The reaction was carried out under cut-off (λ > 400 nm) simulated solar radiation in O2 atmosphere. The perylene derivative allowed a good absorbance of visible radiation thanks to its low optical energy gap (2.6 eV) which was evaluated by cyclic voltammetry. The optimal organic sensitizing amount was found to be 5.6 % w/w in terms of yield in carbonyl derivatives. Moreover, no change in reactivity/selectivity was observed after 10-h irradiation thus confirming the catalyst stability. Yields into formaldehyde, acetaldehyde, and acetone were 67, 70, and 96 %, respectively. No significant amounts of organic byproducts were detected but for methanol oxidation, whereas a minor amount of the substrate degraded to CO2.

  6. Paradoxical solvent effects on the absorption and emission spectra of amino-substituted perylene monoimides.

    PubMed

    Zoon, Peter D; Brouwer, Albert M

    2005-08-12

    In N-(2,5-di-tert-butylphenyl)-9-pyrrolidinoperylene-3,4-dicarboximide (5PI) the absorption and emission spectra display large solvatochromic shifts, but, remarkably, the Stokes shift is practically independent of solvent polarity. This unique behavior is caused by the extraordinarily large ground-state dipole moment of 5PI, which further increases upon increasing the solvent polarity, whereas the excited-state dipole moment is less solvent dependent. In the corresponding piperidine compound, 6PI, this effect is much less important owing to the weaker coupling between the amino group and the aromatic imide moiety, and in the corresponding naphthalimide, 5NI, it is absent. The latter shows the conventional solvatochromic behavior of a push-pull substituted conjugated system, that is, minor shifts in absorption and a larger change in the emission energy with solvent polarity.

  7. A comparative study of one- and two-photon absorption properties of pyrene and perylene diimide derivatives.

    PubMed

    Liu, Xiao-Ting; Zhao, Yang; Ren, Ai-Min; Feng, Ji-Kang

    2011-06-01

    Two important classes of organic molecules, perylene diimide (PDI) and pyrene derivatives have been found to possess relatively excellent photophysical and photochemical properties and especially high two-photon absorption cross sections (δ(T)(max)). Herein, one-photon absorption (OPA) and two-photon absorption (TPA) properties of some novel PDI and pyrene derivatives were comparatively investigated by the density functional theory (DFT) and Zerner's intermediate neglect of differential overlap (ZINDO) methods. The calculated results indicate that with respect to PDI derivatives, the maximum TPA cross-sections for pyrene compounds increase obviously, the maximum peaks of OPA and TPA spectra are blue-shifted, the ΔE(H-L) (energy gaps between the highest occupied orbital and the lowest unoccupied orbital) increase. The different π-conjugated bridges (fluorene and pyrene) and terminal groups have slight effect on the OPA properties. Nevertheless, the molecules bearing 1,6-disubstituted pyrene as the π-conjugated bridge display the largest δ(T)(max) in both series of compounds 3 and 4. Moreover, the δ(T)(max) values of molecules with benzothiazole-substituted terminal groups are larger than those of the molecules with diphenylamine, which is attributed to benzothiazole groups stabilizing the planarity of the branch parts, extending the conjugated length and increasing the π-electron delocalized extent. Furthermore, the molecular size has marked effect on OPA and TPA properties. It is worthy to mention that cruciform 8 displays the largest δ(T)(max) among all the studied molecules in the range of 600-1100 nm. This research could provide a better understanding for the origin of the linear and nonlinear optical properties, and it would be helpful to gain more information about designing two-photon absorption materials with large δ(T)(max).

  8. Perylene imides for organic photovoltaics: yesterday, today, and tomorrow.

    PubMed

    Li, Chen; Wonneberger, Henrike

    2012-02-02

    Perylene imides have been an object of research for 100 years and their derivatives are key n-type semiconductors in the field of organic electronics. While perylene diimides have been applied in many electronic and photonic devices, their use can be traced back to the first efficient organic solar cell. By functionalizing different positions of the in total 12 positions (four peri, four bay, and four ortho-positions) on the perylene core, perylene imides with significantly different optical, electronic and morphological properties may be prepared. Perylene imides and their derivatives have been used in several types of organic photovoltaics, including flat-, and bulk-heterojunction devices as well as dye-sensitized solar cells. Additionally perylene imides-based copolymers or oligomers play an important role in single junction devices. In this review, the relationship between the photovoltaic performance and the structure of perylene imides is discussed.

  9. Perylene and coronene derivatives binding to G-rich promoter oncogene sequences efficiently reduce their expression in cancer cells.

    PubMed

    Micheli, Emanuela; Altieri, Alessandro; Cianni, Lorenzo; Cingolani, Chiara; Iachettini, Sara; Bianco, Armandodoriano; Leonetti, Carlo; Cacchione, Stefano; Biroccio, Annamaria; Franceschin, Marco; Rizzo, Angela

    2016-06-01

    A novel approach to cancer therapeutics is emerging in the field of G-quadruplex (G4) ligands, small molecules designed to stabilize four-stranded structures that can form at telomeres as well as in other genomic sequences, including oncogene promoter sequences, 5'-UTR regions and introns. In this study, we investigated the binding activity of perylene and coronene derivatives PPL3C, CORON and EMICORON to G4 structures formed within the promoter regions of two important cancer-related genes, c-MYC and BCL-2, and their biochemical effects on gene and protein expression. In order to fully characterize the ability of the selected ligands to bind and stabilize the G4 structures originated by the c-MYC and BCL-2 promoter sequences, we performed electrospray ionization mass spectrometry (ESI-MS), Fluorescence Resonance Energy Transfer (FRET) measurements, Circular Dichroism (CD) spectra and polymerase stop assay. Altogether our results showed that the ligands had a high capacity in binding and stabilizing the G4 structures within the c-MYC and BCL-2 promoter sequences in vitro. Notably, when we evaluated by quantitative real-time PCR and western blotting analysis, the effects of treatment with the different G4 ligands on c-MYC and BCL2 expression in a human melanoma cell line, EMICORON appeared the most effective compound in reducing the mRNA and protein levels of both genes. These results encourage to consider EMICORON as a promising example of multimodal class of an antineoplastic drug, affecting different tumor crucial pathways simultaneously: telomere maintenance (as previously described), cell proliferation and apoptosis via down-regulation of both c-MYC and BCL-2 (this paper).

  10. Impact of Fluorine Atoms on Perylene Diimide Derivative for Fullerene-Free Organic Photovoltaics.

    PubMed

    Zhao, Liang; Sun, Hua; Liu, Xiaoyuan; Liu, Changmei; Shan, Haiquan; Xia, Jiuxu; Xu, Zongxiang; Chen, Fei; Chen, Zhi-Kuan; Huang, Wei

    2017-08-17

    The incorporation of fluorine atoms in organic semiconducting materials has attracted much attention recently due to its unique function to manipulate the molecular packing, film morphology and molecular energy levels. In this work, two perylenediimide (PDI) derivatives FPDI-CDTph and FPDI-CDTph2F were designed and synthesized to investigate the impact of fluorination on non-fullerene acceptors. Both FPDI-CDTph and FPDI-CDTph2F exhibited strong and broad absorption profiles, suitable lowest unoccupied molecular orbital (LUMO) and highest occupied molecular orbital (HOMO) energy levels, and good electron transport ability. Compared with FPDI-CDTph, the fluorinated acceptor (FPDI-CDTph2F) afforded an optimal bulk heterojunction morphology with an interconnected and nanoscale phase separated structure that allowed more efficient exciton dissociation and balanced charge transport. Consequently, organic solar cells based on FPDI-CDTph2F showed a much higher power conversion efficiency (PCE) of 6.03 % than that of FPDI-CDTph based devices (4.10 %) without any post-fabrication treatment. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. Molecular organization in perylene tetracarboxylic di-imide solid films

    NASA Astrophysics Data System (ADS)

    Akers, K.; Aroca, R.; Hort, A. M.; Loutfy, R. O.

    The vibrational spectra of thin solid films of three perylene tetracarboxylic di-imide derivatives (phenyl, methyl, and unsubstituted) are reported. A preferred molecular orientation in the evaporated solid films emerged for all three perylene derivatives from the i.r. data. Raman spectra obtained in resonance with the absorption band were characteristic of scattering via a Herzberg—Teller mechanism.

  12. Electron Injection Dynamics of Perylene Derivatives into ZnO and TiO2 Particle Films

    NASA Astrophysics Data System (ADS)

    Szarko, J.; Neubauer, A.; Socaciu-Siebert, L.; Bartelt, A.; Birkner, F.; Schwarzburg, K.; Eichberger, R.

    The electron injection dynamics of two perylene dyes bound to ZnO and TiO2nanoparticles was investigated with femtosecond transient absorption simultaneously monitoring the rise of the cationic and the decay of the excited state. Electron transfer from the chromophores was slower when attached to ZnO compared to TiO2. The excited state decay and the cationic state rise showed very good agreement at early times, indicating direct electron injection into the conduction band for both semiconductors in absence of intermediate states.

  13. Water soluble cationic perylene derivatives as possible telomerase inhibitors: the search for selective G-quadruplex targeting.

    PubMed

    Micheli, Emanuela; D'Ambrosio, Danilo; Franceschin, Marco; Savino, Maria

    2009-12-01

    The search for telomerase inhibitors has been widely explored in the last few years, since telomerase activity in somatic cells can be considered as a general cancer mark. One of the possible strategies is the capping of telomere 3'-end (the enzyme substrate) in a conformation not available to the recognition of telomerase, with particular attention to G-quadruplex structures. Small organic molecules, able to induce and/or stabilize G-quadruplexes, have been synthesized and studied in many different research groups. Here, we mean to critically analyze the class of hydrosoluble perylene di-imides (HPDIs), which offers the intriguing possibility to fix the hydrophobic molecule moiety (perylene) able to bind to the terminal G-quartet of telomeric G-quadruplex, while widely varying the number and features of the hydrophilic side chains, which interact with the DNA grooves. We will show that, using the strategy, it is possible to significantly improve HPDIs efficiency in inhibiting telomerase and their selectivity for telomeric G-quadruplex with respect to duplex genomic DNA.

  14. Tuning the Electronic Structure and Properties of Perylene-Porphyrin-Perylene Panchromatic Absorbers.

    PubMed

    Amanpour, Javad; Hu, Gongfang; Alexy, Eric J; Mandal, Amit Kumar; Kang, Hyun Suk; Yuen, Jonathan M; Diers, James R; Bocian, David F; Lindsey, Jonathan S; Holten, Dewey

    2016-09-29

    Light-harvesting architectures that afford strong absorption across the near-ultraviolet to near-infrared region, namely, panchromatic absorptivity, are potentially valuable for capturing the broad spectral distribution of sunlight. One previously reported triad consisting of two perylene monoimides strongly coupled to a free base porphyrin via ethyne linkers (FbT) shows panchromatic absorption together with a porphyrin-like S1 excited state albeit at lower energy than that of a typical monomeric porphyrin. Here, two new porphyrin-bis(perylene) triads have been prepared wherein the porphyrin bears two pentafluorophenyl substituents. The porphyrin is in the free base (FbT-F) or zinc chelate (ZnT-F) forms. The zinc chelate (ZnT) of the original triad bearing nonfluorinated aryl rings also was prepared. The triads were characterized using static and time-resolved optical spectroscopy. The results were analyzed with the aid of molecular-orbital characteristics obtained using density functional theory calculations. Of the four triads, FbT is the most panchromatic in affording the most even distribution of absorption spectral intensity as well as exhibiting the largest wavelength span (380-750 nm). The triads exhibit fluorescence yields (0.35 for FbT-F in toluene) that are substantially greater than for the porphyrin benchmarks (0.049 for FbP-F). The singlet excited-state lifetimes (τS) for the triads in toluene decrease in the order FbT-F (2.7 ns) > FbT (2.0 ns) > ZnT (1.2 ns) ∼ ZnT-F (1.1 ns). The τS values in benzonitrile are FbT (1.3 ns) > FbT-F (1.2 ns) > ZnT-F (0.6 ns) > ZnT (0.2 ns). Thus, the free base triads exhibit relatively long (1.2-2.7 ns) excited-state lifetimes in both polar and nonpolar media. The combined photophysical characteristics indicate that FbT and FbT-F are the best choices for panchromatic light-harvesting systems. Collectively, the findings afford insights into the effects of electronic structure on the panchromatic behavior of ethynyl

  15. Host-Guest Chemistry between Perylene Diimide (PDI) Derivatives and 18-Crown-6: Enhancement in Luminescence Quantum Yield and Electrical Conductivity.

    PubMed

    Lasitha, P; Prasad, Edamana

    2016-07-18

    Perylene diimide (PDI) derivatives exhibit a high propensity for aggregation, which causes the aggregation-induced quenching of emission from the system. Host-guest chemistry is one of the best-known methods for preventing aggregation through the encapsulation of guest molecules. Herein we report the use of 18-crown-6 (18-C-6) as a host system to disaggregate suitably substituted PDI derivatives in methanol. 18-C-6 formed complexes with amino-substituted PDIs in methanol, which led to disaggregation and enhanced emission from the systems. Furthermore, the embedding of the PDI⋅18-C-6 complexes in poly(vinyl alcohol) (PVA) films generated remarkably high emission quantum yields (60-70 %) from the PDI derivatives. More importantly, the host-guest systems were tested for their ability to conduct electricity in PVA films. The electrical conductivities of the self-assembled systems in PVA were measured by electrochemical impedance spectroscopy (EIS) and the highest conductivity observed was 2.42×10(-5)  S cm(-1) . © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Multichromophoric hybrid species made of perylene bisimide derivatives and Ru(ii) and Os(ii) polypyridine subunits.

    PubMed

    Nastasi, Francesco; La Ganga, Giuseppina; Campagna, Sebastiano; Syrgiannis, Zois; Rigodanza, Francesco; Vitale, Stefania; Licciardello, Antonino; Prato, Maurizio

    2017-05-31

    Herein, the synthesis and the photophysical and redox properties of a new perylene bisimide (PBI) species (L), bearing two 1,10-phenanthroline (phen) ligands at the two imide positions of the PBI, and its dinuclear Ru(ii) and Os(ii) complexes, [(bpy)2Ru(μ-L)Ru(bpy)2](PF6)4 (Ru2; bpy = 2,2'-bipyridine) and [(Me2-bpy)2Os(μ-L)Os(Me2-bpy)2](PF6)4 (Os2; Me2-bpy = (4,4'-dimethyl)-2,2'-bipyridine), are reported. The absorption spectra of the compounds are dominated by the structured bands of the PBI subunit due to the lowest-energy spin-allowed π-π* transition. The spin-allowed MLCT transitions in Ru2 and Os2 are inferred by the absorption at 350-470 nm, where the PBI absorption is negligible. The absorption band extends towards the red region for Os2 due to the spin-forbidden MLCT transitions, intensified by the heavy osmium center. The reduction processes of the compounds are dominated by two successive mono-electronic PBI-based processes, which in the metal complexes are slightly shifted compared to the free ligand. On oxidation, both metal complexes undergo an apparent bi-electronic process (at 1.31 V vs. SCE for Ru2 and 0.77 V for Os2), attributed to the simultaneous one-electron oxidation of the two weakly-interacting metal centers. In Ru2 and Os2, the intense fluorescence of L subunit (λmax, 535 nm; τ, 4.3 ns; Φ, 0.91) is fully quenched, mainly by photoinduced electron transfer from the metal centers, on the ps timescale (time constant, 11 ps in Ru2 and 3 ps in Os2). Such photoinduced electron transfer leads to the formation of a charge-separated state, which directly decays to the ground state in about 70 ps in Os2, but produces the triplet π-π* state of the PBI subunit in 35 ps in Ru2. The results provide information on the excited-state processes of the hybrid species combining two dominant classes of chromophore/luminophore species, the PBI and the metal polypyridine complexes, and can be used for future design on new hybrid species with made

  17. A model for triple helix formation on human telomerase reverse transcriptase (hTERT) promoter and stabilization by specific interactions with the water soluble perylene derivative, DAPER.

    PubMed

    Rossetti, Luigi; D'Isa, Giuliana; Mauriello, Clementina; Varra, Michela; De Santis, Pasquale; Mayol, Luciano; Savino, Maria

    2007-08-01

    The promoter of human telomerase reverse transcriptase (hTERT) gene, in the region from -1000 to +1, contains two homopurine-homopyrimidine sequences (-835/-814 and -108/-90), that can be considered as potential targets to triple helix forming oligonucleotides (TFOs) for applying antigene strategy. We have chosen the sequence (-108/-90) on the basis of its unfavorable chromatin organization, evaluated by theoretical nucleosome positioning and nuclease hypersensitive sites mapping. On this sequence, anti-parallel triplex with satisfactory thermodynamic stability is formed by two TFOs, having different lengths. Triplex stability is significantly increased by specific interactions with the perylene derivative N,N'-bis[3,3'-(dimethylamino) propylamine]-3,4,9,10-perylenetetracarboxylic diimide (DAPER). Since DAPER is a symmetric molecule, the induced Circular Dichroism (CD) spectra in the range 400-600 nm allows us to obtain information on drug binding to triplex and duplex DNA. The drug-induced ellipticity is significantly higher in the case of triplex with respect to duplex and, surprisingly, it increases at decreasing of DNA. A model is proposed where self-stacked DAPER binds to triplex or to duplex narrow grooves.

  18. Probing electronic communication for efficient light-harvesting functionality: dyads containing a common perylene and a porphyrin, chlorin, or bacteriochlorin.

    PubMed

    Yang, Eunkyung; Wang, Jieqi; Diers, James R; Niedzwiedzki, Dariusz M; Kirmaier, Christine; Bocian, David F; Lindsey, Jonathan S; Holten, Dewey

    2014-02-13

    The synthesis, photophysical, redox, and molecular-orbital characteristics of three perylene-tetrapyrrole dyads were investigated to probe the efficacy of the arrays for use as light-harvesting constituents. Each dyad contains a common perylene-monoimide that is linked at the N-imide position via an arylethynyl group to the meso-position of the tetrapyrrole. The tetrapyrroles include a porphyrin, chlorin, and bacteriochlorin, which have zero, one, and two reduced pyrrole rings, respectively. The increased pyrrole-ring reduction results in a progressive red shift and intensification of the lowest-energy absorption band, as exemplified by benchmark monomers. The arylethyne linkage affords moderate perylene-tetrapyrrole electronic coupling in the dyads as evidenced by the optical, molecular-orbital, and redox properties of the components of the dyads versus the constituent parts. All three dyads in nonpolar solvents exhibit relatively fast (subpicosecond) energy transfer from the perylene to the tetrapyrrole. Competing charge-transfer processes are also absent in nonpolar solvents, but become active for both the chlorin and bacteriochlorin-containing dyads in polar solvents. Calculations of energy-transfer rates via the Förster, through-space mechanism reveal that these rates are, on average, 3-fold slower than the observed rates. Thus, the Dexter through-bond mechanism contributes more substantially than the through-space mechanism to energy transfer in the dyads. The electronic communication between the perylene and tetrapyrrole falls in a regime intermediate between those operative in other classes of perylene-tetrapyrrole dyads that have previously been studied.

  19. New insights into the origin of perylene in geological samples

    NASA Astrophysics Data System (ADS)

    Grice, Kliti; Lu, Hong; Atahan, Pia; Asif, Muhammad; Hallmann, Christian; Greenwood, Paul; Maslen, Ercin; Tulipani, Svenja; Williford, Kenneth; Dodson, John

    2009-11-01

    The origin of the polycyclic aromatic hydrocarbon (PAH) perylene in sediments and petroleum has been a matter of continued debate. Reported to occur in Phanerozoic organic matter (OM), fossil crinoids and tropical termite mounds, its mechanism of formation remains unclear. While a combustion source can be excluded, structural similarities to perylene quinone-like components present in e.g. fungi, plants, crinoids and insects, potentially suggest a product-precursor relationship. Here, we report perylene concentrations, 13C/ 12C, and D/H ratios from a Holocene sediment profile from the Qingpu trench, Yangtze Delta region, China. Perylene concentrations differ from those of pyrogenic PAHs, and rise to prominence in a stratigraphic interval that was dominated by woody vegetation as determined by palynology including fungal spores. In this zone, perylene concentrations exhibit an inverse relationship to the lignin marker guaiacol, D/H ratios between -284‰ and -317‰, similar to the methoxy groups in lignin, as well as co-variation with spores from wood-degrading fungi. 13C/ 12C of perylene differs from that of land plant wax alkanes and falls in the fractionation range expected for saprophytic fungi that utilise lignin, which is isotopically lighter than cellulose and whole wood. During progressive lignin degradation, the relative carbon isotopic ratio of the perylene decreases. We therefore hypothesise a relationship of perylene to the activity of wood-degrading fungi. To support our hypothesis, we analysed a wide range of Phanerozoic sediments and oils, and found perylene to generally be present in subordinate amounts before the evolutionary rise of vascular plants, and to be generally absent from marine-sourced oils, few exceptions being attributed perhaps to a contribution of marine and/or terrestrial-derived fungi, anoxia (especially under marine conditions) and/or contamination of core material by fungi. A series of low-molecular-weight aromatic quinones

  20. Polycyclic aromatic hydrocarbons obtained by lateral core extension of mesogenic perylenes: absorption and optoelectronic properties.

    PubMed

    Vollbrecht, Joachim; Bock, Harald; Wiebeler, Christian; Schumacher, Stefan; Kitzerow, Heinz

    2014-09-15

    Bilaterally extended perylenes were synthesized, characterized, and used to create organic light-emitting devices. A detailed investigation of the electronic and optical properties, and a comparison of perylene derivatives and compounds with unilaterally and bilaterally extended aromatic cores, reveal unexpected changes of the absorption spectrum, which are in agreement with simulations based on DFT.

  1. Perylene and its geochemical significance.

    NASA Technical Reports Server (NTRS)

    Aizenshtat, Z.

    1973-01-01

    Perylene was found in a variety of marine sediments, in a shale and in peat. It is suggested that its precursors arise predominantly from land organisms and are carried into oceanic traps along with detrital minerals. When rates of deposition are fast, and reducing conditions are established within the sediment, biogenic pigment precursors of perylene are converted to the polycyclic aromatic hydrocarbon, which is then stabilized by pi-bonding with metals and protected from degradation.

  2. Molecular Organization Induced Anisotropic Properties of Perylene - Silica Hybrid Nanoparticles.

    PubMed

    Sriramulu, Deepa; Turaga, Shuvan Prashant; Bettiol, Andrew Anthony; Valiyaveettil, Suresh

    2017-08-10

    Optically active silica nanoparticles are interesting owing to high stability and easy accessibility. Unlike previous reports on dye loaded silica particles, here we address an important question on how optical properties are dependent on the aggregation-induced segregation of perylene molecules inside and outside the silica nanoparticles. Three differentially functionalized fluorescent perylene - silica hybrid nanoparticles are prepared from appropriate ratios of perylene derivatives and tetraethyl orthosilicate (TEOS) and investigated the structure property correlation (P-ST, P-NP and P-SF). The particles differ from each other on the distribution, organization and intermolecular interaction of perylene inside or outside the silica matrix. Structure and morphology of all hybrid nanoparticles were characterized using a range of techniques such as electron microscope, optical spectroscopic measurements and thermal analysis. The organizations of perylene in three different silica nanoparticles were explored using steady-state fluorescence, fluorescence anisotropy, lifetime measurements and solid state polarized spectroscopic studies. The interactions and changes in optical properties of the silica nanoparticles in presence of different amines were tested and quantified both in solution and in vapor phase using fluorescence quenching studies. The synthesized materials can be regenerated after washing with water and reused for sensing of amines.

  3. A spiral designed surface based on amino-perylene grafted polyacrylic acid.

    PubMed

    Celia, Elena; Amigoni, Sonia; Taffin de Givenchy, Elisabeth; Pieters, Gregory; Gaucher, Anne; Prim, Damien; Audibert, Jean-Frederic; Méallet-Renault, Rachel; Pansu, Robert; Guittard, Frédéric

    2014-10-18

    This communication shows the possibility of inducing spontaneous special surface organisation by means of grafting a fluorescent aminobenzo[g,h,i]perylene derivative onto surface grown polyacrylic chains.

  4. A unique perylene-based DNA intercalator: localization in cell nuclei and inhibition of cancer cells and tumors.

    PubMed

    Xu, Zejun; Guo, Kunru; Yu, Jieshi; Sun, Haili; Tang, Jun; Shen, Jie; Müllen, Klaus; Yang, Wantai; Yin, Meizhen

    2014-10-29

    To date, perylene derivatives have not been explored as DNA intercalator to inhibit cancer cells by intercalating into the base pairs of DNA. Herein, a water-soluble perylene bisimide (PBDI) that efficiently intercalates into the base pairs of DNA is synthesized. Excitingly, PBDI is superior to the commercial DNA intercalator, amonafide, for specific nuclear accumulation and effective suppression of cancer cells and tumors.

  5. Polybenzofulvenes-based blends with benzothiadiazole and perylene diimide derivatives emitting from yellow to the deep-red by resonant energy transfer processes

    NASA Astrophysics Data System (ADS)

    Villafiorita-Monteleone, F.; Kozma, E.; Pasini, M.; Paolino, M.; Cappelli, A.; Bongiovanni, G.; Mura, A.; Botta, C.

    2017-05-01

    The ability of a π-stacked polybenzofulvene derivative to self-assemble with emissive dyes in supramolecular organizations that reduce unwanted microaggregation processes is demonstrated by a study of the photophysical properties of its blends with benzothiadiazole and two perylenediimide derivatives. Films displaying efficient emissions with quantum yields of 0.85 in the yellow, 0.54 in the red, and 0.39 in the deep-red regions are obtained thanks to combined homo- and hetero-resonant energy transfer processes from the polymer excimer-like π-stacked chromophores to the emitting dyes.

  6. Pedogenic Formation of Perylene in a Terrestrial Soil Profile: Evidence From Carbon Isotopic Ratios

    NASA Astrophysics Data System (ADS)

    Gocht, T.; Jochmann, M. A.; Blessing, M.; Barth, J.; Schmidt, T. C.; Grathwohl, P.

    2005-12-01

    Polycyclic aromatic hydrocarbons (PAHs) are persistent organic pollutants (POP), which are introduced into the environment mainly due to combustion of fossil fuel. Perylene is one compound of the PAHs that consists of 5 condensed rings like the well known carcinogenic benzo(a)pyrene. Apart from the pyrogenic formation, there are strong indications that it is produced biologically and/or diagenetically under anaerobic conditions. This conclusion was derived from the presence of perylene in deeper parts of marine and lacustrine sediment profiles, where the combustion-derived PAHs are almost absent ( Lima et al., 2003). 13C/12C compound-specific stable isotopic ratios were successfully applied for the differentiation of probably biologically generated perylene in tropical termite nests and pyrolytic perylene from surface soils of temperate regions ( Wilcke et al., 2002). Our study is the first aiming on the determination of the different processes of perylene formation at one location using carbon isotopic ratios such as 13C/12C. We determined PAHs in natural soils of southern Germany. At one location in the Black Forest we found for the first time evidence for natural perylene production in the subsoil of terrestrial environments. Apart from the combustion derived PAHs that accumulate at the top of all soil profiles, the depth distribution of perylene shows the highest peak in the subsoil about 1 m below the surface. Due to its very low solubility (0.4 μg l-1 at 25 °C) vertical transport of perylene with seepage water is very unlikely. Thus, we suggest atmospheric deposition of pyrogenic perylene at the top of the profile and in-situ generation in the subsoil, probably due to microbial activities. In order to distinguish between the pyrogenic and natural generation we employed 13C/12C compound-specific stable isotope analysis of perylene in soil samples from the top of the profile as well as from the subsoil. Preliminary measurements with soil extracts show strong

  7. [3+2] versus [4+2] cycloadditions of quinone monoimide with azadienes: a Lewis acid-free access to 5-amino-2,3-dihydrobenzofuranes.

    PubMed

    Lomberget, Thierry; Baragona, Fabien; Fenet, Bernard; Barret, Roland

    2006-08-31

    The reaction between p-quinone monoimide 1a and various azadienes 2 is described in the absence of a Lewis acid promoter. When alpha,beta-unsaturated hydrazones are substituted by proton or alkyl groups, 2,3-dihydrobenzofuranes 4, a motif that is present in numerous biologically active products, are obtained in moderate to excellent yields. The regio- and stereoselectivity of this reaction has been proved by a complete NMR study, including 1H-15N correlations.

  8. Structural and optical properties of a perylene bisimide in aqueous media

    NASA Astrophysics Data System (ADS)

    Burian, Max; Rigodanza, Francesco; Amenitsch, Heinz; Almásy, László; Khalakhan, Ivan; Syrgiannis, Zois; Prato, Maurizio

    2017-09-01

    The aggregation of a water soluble, dicationic perylene bisimide derivative was studied by means of absorption and emission spectroscopies, X-ray and neutron scattering techniques as well as electron microscopy. The results provide evidence for the existence of higher order molecular aggregates in solution, potentially utilizable in device fabrication as super molecular building blocks.

  9. Benzo[g,h,i]perylene

    Integrated Risk Information System (IRIS)

    Benzo [ g , h , i ] perylene ; CASRN 191 - 24 - 2 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Nonc

  10. Liquid-crystalline and electron-deficient coronene oligocarboxylic esters and imides by twofold benzogenic Diels-Alder reactions on perylenes.

    PubMed

    Alibert-Fouet, Sonia; Seguy, Isabelle; Bobo, Jean-François; Destruel, Pierre; Bock, Harald

    2007-01-01

    Alkyl esters, imides and imido-esters of coronene-tri-, -tetra- and -octacarboxylic acids are accessible by a twofold oxidative benzogenic Diels-Alder reaction. Alkyl acrylates add to perylene, and maleic alkyl imides react twice with perylene as well as with perylene-tetracarboxylic tetraesters. Coronenes substituted with a greatly variable number of electron-withdrawing substituents are thus accessible, and di- and tetraimide derivatives are shown to be very pronounced electron-acceptor materials. The tri- and tetraalkyl esters and imidoesters self-assemble into columnar liquid-crystalline phases.

  11. Reduction of molecular aggregation and its application to the high-performance blue perylene-doped organic electroluminescent device

    NASA Astrophysics Data System (ADS)

    Mi, B. X.; Gao, Z. Q.; Lee, C. S.; Lee, S. T.; Kwong, H. L.; Wong, N. B.

    1999-12-01

    A nonplanar derivative of perylene, 2,5,8,11-tetra-tertbutylperylene (TBPe), was synthesized via the Friedel-Crafts alkylation reaction. Electroluminescent (EL) devices were made using TBPe or perylene as a dopant in bis(2-methyl-8-quinolinolato)(para-phenylphenolato)aluminum(III) and their EL performance was compared. Similar to the device doped with the parent perylene molecule, the device doped with TBPe also emitted strongly in the blue. As the concentration of TBPe increased from 1% to 5%, the color coordinates in CIE 1931 chromaticity of the TBPe-doped device changed only slightly from (0.168,0.273) to (0.175,0.273), whereas the perylene-doped device exhibited a much larger shift from (0.165,0.196) to (0.178,0.252). The constancy of EL color and efficiency with respect to TBPe dopant concentration is attributable to diminishing molecular aggregation in the nonplanar perylene derivative, TBPe, due to the steric hindrance of the tert-butyl groups.

  12. "Helter-skelter-like" perylene polyisocyanopeptides.

    PubMed

    Schwartz, Erik; Palermo, Vincenzo; Finlayson, Chris E; Huang, Ya-Shih; Otten, Matthijs B J; Liscio, Andrea; Trapani, Sara; González-Valls, Irene; Brocorens, Patrick; Cornelissen, Jeroen J L M; Peneva, Kalina; Müllen, Klaus; Spano, Frank C; Yartsev, Arkady; Westenhoff, Sebastian; Friend, Richard H; Beljonne, David; Nolte, Roeland J M; Samorì, Paolo; Rowan, Alan E

    2009-03-02

    Exciton migration! Spectroscopic analyses and extensive molecular dynamics studies revealed a well-defined 4(1) helix in which the perylene molecules (see figure) form four "helter-skelter-like" overlapping pathways along which excitons and electrons can rapidly migrate.We report on a combined experimental and computational investigation on the synthesis and thorough characterization of the structure of perylene-functionalized polyisocyanides. Spectroscopic analyses and extensive molecular dynamics studies revealed a well defined 4(1) helix in which the perylene molecules form four "helter skelter-like" overlapping pathways along which excitons and electrons can rapidly migrate. The well-defined polymer scaffold stabilized by hydrogen bonding, to which the chromophores are attached, accounts for the precise architectural definition, and molecular stiffness observed for these molecules. Molecular-dynamics studies showed that the chirality present in these polymers is expressed in the formation of stable right-handed helices. The formation of chiral supramolecular structures is further supported by the measured and calculated bisignated Cotton effect. The structural definition of the chromophores aligned in one direction along the backbone is highlighted by the extremely efficient exciton migration rates and charge densities measured with Transient Absorption Spectroscopy.

  13. On the Origin of Photodynamic activity of Perylene Quinone Framework

    NASA Astrophysics Data System (ADS)

    Parida, Dibyajyoti; Pancharatna, Pattath D.; Balakrishnarajan, Musiri M.

    2016-10-01

    The basic skeleton of perylenequinone is surprisingly ubiquitous in several naturally occurring pigments, such as Hypocrellins, Cercosporin, etc. to name a few. Several of these molecules and their derivatives are also experimentally characterized as potent candidates for photodynamic therapy and are predicted to be aiding the formation singlet Oxygen. Theoretical calculations that unravel the mystery behind the perylenequinone motif in these bio-molecules. Perylenequinone framework has a unique frontier MOs that aid in facile intersystem crossing of the π-π* excitation. The resulting triplet state remarkably resists phosphorescence that presumably leads to high quantum yield of singlet oxygen production. The excitation assisted change in the nature of conjugation and the attendant out-of-plane distortion of the perylene framework is found to be the general characteristic of all these systems and the substituents at the bay region favourably assist the excited state behavior as shown by time dependent/ independent DFT calculations.

  14. Improvement of photovoltaic properties by addition of a perylene compound in P3HT:PCBM BHJ system.

    PubMed

    Jeong, Seonju; Woo, Sung-Ho; Lyu, Hong-Kun; Kim, Charm; Kim, Hoyoung; Han, Yoon Soo

    2012-05-01

    The synthesized n-type perylene derivative, N,N'-bis-(4-bromophenyl)-1,6,7,12-tetrakis(4-n-butoxy-phenoxy)-3,4,9,10-perylene tetracarboxdiimide (PIBr), was applied as an additive to polymer solar cells (PSCs) with P3HT [poly(3-hexylthiophene)]:PCBM [[6,6]-phenyl C61-butyric acid methyl ester] blend films. Without post thermal annealing, a considerable improvement of about 98% in power conversion efficiency was achieved by the addition of 1 wt% PIBr into a P3HT:PCBM layer, when compared with that of reference cell without the additive. The results, in combination with relevant data from UV-Vis. absorption, photoluminescence, X-ray measurements and carrier mobility studies, revealed that the addition of the perylene compound within active layer contributed to more effective charge transfer and enhanced electron mobility.

  15. High excimer-state emission of perylene bisimides and recognition of latent fingerprints.

    PubMed

    Wang, Ke-Rang; Yang, Zi-Bo; Li, Xiao-Liu

    2015-04-07

    High excimer-state emission in the H-type aggregate of a novel asymmetric perylene bisimide derivative, 6, with triethyleneglycol chains and lactose functionalization was achieved in water. Furthermore, its application for enhancing the visualization of transfer latent fingerprints from glass slides to the poly(vinylidene fluoride) (PVDF) membrane was explored, which showed clear images of the latent fingerprint in daylight and under 365 nm ultraviolet illumination.

  16. An Electron Acceptor with Porphyrin and Perylene Bisimides for Efficient Non-Fullerene Solar Cells.

    PubMed

    Zhang, Andong; Li, Cheng; Yang, Fan; Zhang, Jianqi; Wang, Zhaohui; Wei, Zhixiang; Li, Weiwei

    2017-03-01

    A star-shaped electron acceptor based on porphyrin as a core and perylene bisimide as end groups was constructed for application in non-fullerene organic solar cells. The new conjugated molecule exhibits aligned energy levels, good electron mobility, and complementary absorption with a donor polymer. These advantages facilitate a high power conversion efficiency of 7.4 % in non-fullerene solar cells, which represents the highest photovoltaic performance based on porphyrin derivatives as the acceptor.

  17. Structural and electronic properties of perylene from first principles calculations.

    PubMed

    Fedorov, I A; Zhuravlev, Y N; Berveno, V P

    2013-03-07

    The electronic structure of crystalline perylene has been investigated within the framework of density functional theory including van der Waals interactions. The computations of the lattice parameters and cohesive energy have good agreement with experimental values. We have also calculated the binding distance and energy of perylene dimers, using different schemes, which include van der Waals interactions.

  18. Three-dimensional electron-accepting compounds containing perylene bis(dicarboximide)s as n-type organic photovoltaic materials.

    PubMed

    Ie, Yutaka; Sakurai, Takahiro; Jinnai, Seihou; Karakawa, Makoto; Okuda, Kouichi; Mori, Shogo; Aso, Yoshio

    2013-09-28

    The synthesis of three-dimensional compounds containing perylene bis(dicarboximide) for application as acceptor materials in organic photovoltaics is reported. Physicochemical measurements as well as device evaluations revealed that the characteristic properties of these materials are derived from their three-dimensional structure.

  19. Source identification of perylene in surface sediments and waterbird eggs in the Anzali Wetland, Iran.

    PubMed

    Zamani, Mojtaba; Khorasani, Nematollah; Bakhtiari, Alireza Riyahi; Rezaei, Karamatollah

    2015-10-01

    Following the marked increase of perylene concentration in southern coast of Caspian Sea, waterbird eggs were used as biomonitoring agents. Surface sediments and eggs of five bird species were collected from colonies in Anzali Wetland in the above coast for perylene analysis. The perylene concentrations in sediment and egg samples ranged within 70.6-204.4 and 25.5-43.2 ng/g dw, respectively. Diagnostic perylene ratios showed that the perylene found in all samples was of biogenic origin, possibly developing from terrestrial materials. The combination pattern of perylene was found to be similar in all samples. Conclusively, perylene observed in the area was transmitted from sediments in breeding areas into the eggs, so the eggs are biomonitoring agents and the prevalence of oxic conditions in surface sediments limits formation of perylene, reflecting perylene formation in the catchment area. We found that perylene distribution in surface sediments follows irregular patterns, representing significant effects from local inputs.

  20. Interaction of albumin with perylene-diimides with aromatic substituents

    NASA Astrophysics Data System (ADS)

    Farooqi, Mohammed; Penick, Mark; Burch, Jessica; Negrete, George; Brancaleon, Lorenzo

    2015-03-01

    Polyaromatic hydrocarbons (PAH) binding to proteins remains one of the fundamental aspects of research in biophysics. Ligand binding can regulate the function of proteins. Binding to small ligands remains a very important aspect in the study of the function of many proteins. Perylene diimide or PDI derivatives have attracted initial interest as industrial dyes and pigments. Recently, much attention has been focused on their strong π - π stacks resulting from the large PDI aromatic core. These PDI stacks have distinct optical properties, and provide informative models that mimic the light-harvesting system and initial charge separation and charge transfer in the photosynthetic system. The absorption property of PDI derivatives may be largely tuned from visible to near-infrared region by chemical modifications at the bay-positions. We are currently studying a new class of PDI derivatives with substituents made of the side chains of aromatic amino acids (Tyrosine, Tryptophan and Phenylalanine). We have looked at the fluorescence absorption and emission of these PDIs in water and other organic solvents. PDIs show evidence of dimerization and possible aggregation. We also present binding studies of these PDIs with Human Serum Albumin (HSA). The binding was studied using fluorescence emission quenching of the HSA Tryptophan residue. Stern-Volmer equation is used to derive the quenching constants. PDI binding to HSA also has an effect on the fluorescence emission of the PDIs themselves by red shifting the spectra. Funded by RCMI grant.

  1. Synthesis and investigation of anticancer potential of radiolabeled naphthalene monoimide bearing imidazolium salt.

    PubMed

    Yurt Lambrecht, Fatma; Ocakoglu, Kasim; Gokhan Colak, Suleyman; Alp Ersoz, Onur; Er, Ozge

    2017-01-09

    Imidazolium salts and derivatives have antitumor efficacy and toxic effects in different micro-organisms. In this study, an imidazolium bromide salt (NMI) was synthesized, and its antitumor potential was investigated by in vitro studies. Radiolabeling of synthesized NMI was carried out by iodogen method using (131) I radionuclide. The yield of radiolabeling was determined as 98.5 ± 0.1%. After that, cytotoxicity and intracellular uptake studies were evaluated in various cell lines. The cytotoxicity of NMI was determined as 35, 20, 10, and 1 μm for HEK-293, PC-3, CaCo-2, and MCF-7 cells, respectively. In addition, the intracellular uptake of (131) I-NMI was investigated in the cell lines, and the uptake was significantly found as 4 hr for MCF-7 and 6 hr for PC-3. In future studies, antitumor efficacy of (131) I-NMI on tumor-bearing animal model might be studied in light of these results.

  2. Perylene-Based All-Organic Redox Battery with Excellent Cycling Stability.

    PubMed

    Iordache, Adriana; Delhorbe, Virginie; Bardet, Michel; Dubois, Lionel; Gutel, Thibaut; Picard, Lionel

    2016-09-07

    Organic materials derived from biomass can constitute a viable option as replacements for inorganic materials in lithium-ion battery electrodes owing to their low production costs, recyclability, and structural diversity. Among them, conjugated carbonyls have become the most promising type of organic electrode material as they present high theoretical capacity, fast reaction kinetics, and quasi-infinite structural diversity. In this letter, we report a new perylene-based all-organic redox battery comprising two aromatic conjugated carbonyl electrode materials, the prelithiated tetra-lithium perylene-3,4,9,10-tetracarboxylate (PTCLi6) as negative electrode material and the poly(N-n-hexyl-3,4,9,10-perylene tetracarboxylic)imide (PTCI) as positive electrode material. The resulting battery shows promising long-term cycling stability up to 200 cycles. In view of the enhanced cycling performances, the two organic materials studied herein are proposed as suitable candidates for the development of new all-organic lithium-ion batteries.

  3. Using an organic additive to manipulate sizes of perylene nanoparticles

    NASA Astrophysics Data System (ADS)

    Oliveira, Daniel; Baba, Koichi; Mori, Junichi; Miyashita, Yousuke; Kasai, Hitoshi; Oikawa, Hidetoshi; Nakanishi, Hachiro

    2010-01-01

    A new method has been successfully developed for the control of sizes of organic nanoparticles. The method, which relies on the use of stopped-flow UV-visible absorption spectroscopy to measure the rate of perylene nanoparticle formation by reprecipitation in water, is based on the systematic addition of an organic additive (N,N'-bis(2,6-dimethylphenyl)-3,4,9,10-perylenedicarboxyimide) to the target compound (perylene) solutions. Upon reprecipitation, a strong dependence between additive concentration and rate of perylene nanocrystallization is observed. Authors clearly demonstrated that, in the reprecipitation method, faster rates of organic nanoparticle formation is achieved with increasing additive concentration, and consequently to smaller organic nanoparticles. It is believed that N,N'-bis (2,6-dimethylphenyl)-3,4,9,10-perylenedicarboxyimide acts as "seeds" for further growth of perylene nanoparticles up to approximately 400 nm.

  4. Perylene occurrence, alkylation and possible sources in deep-ocean sediments

    NASA Astrophysics Data System (ADS)

    Louda, J. William; Baker, Earl W.

    1984-05-01

    81 deep-ocean sediment samples obtained from the DSDP/IPOD program Legs 63-66, and six gravity-cores from DSDP/IPOD Leg 64 Guaymas Basin, Gulf of California, site survey cruise (SIO) were analyzed for perylene(s). Perylene was found to be most abundant in anoxic diatomaceous sediments containing moderate amounts of silts and/or clays. Elevated perylene yields, normalized to organic carbon contents, coincided with enhanced preservation of autochthonous tetraterpenoid and tetrapyrrole pigments, indicating a requirement of anoxia in the formation of perylene. Strongly euxinic conditions correlate with decreased perylene yields but not its total absence, as found for strongly aerobic deposition and/or redeposition. Perylene alkylation occurs in response to increasing in situ temperatures (alt. sub-bottom depth). This alkylation was found to begin with the generation of methyl (C-1) perylene and to eventually yield a perylene-alkyl perylene homologous series, in decreasing abundance, through the equivalent of C-3 (trimethyl, methyl-ethyl, propyl?) perylene. The realm of most intense perylene alkylation for Quaternary or Pliocene/ Miocene sediments corresponds with present in situ temperatures of 40-50°C or 30-35°C, respectively. Thus, the degree of perylene alkylation may represent an organic indicator for the thermal history of immature sediments. Geological phenomena, such as reworking and igneous intrusions, were found to complicate downhole perylene alkylation patterns. A substituted (-C 4H 7O 2) perylene was isolated from several anoxically deposited diatomaceous oozes and may represent one of the many possible perylene precursors. The possible source compounds and biota for sedimentary perylene are discussed in light of the present study and review of past reports.

  5. Highly fluorescent complexes with gold, palladium or platinum linked to perylene through a tetrafluorophenyl group.

    PubMed

    Lentijo, Sergio; Aullón, Gabriel; Miguel, Jesús A; Espinet, Pablo

    2013-05-14

    Treatment of 3-(1-hexynyl)perylene with Co2(CO)8 resulted in the formation of the dinuclear cobalt complex [Co2(CO)6(μ-η(2)-C4H9C≡C-Per)] (Per = 3-perylenyl) (1). The perylene derivatives 3-(2,3,5,6-tetrafluorophenyl)perylene (PerC6F4H) and 3-(2,3,5,6-tetrafluorophenyl)-9(10)hexylperylene (C6-PerC6F4H) were prepared and used to synthesize [AuR(CN(t)Bu)] (R = PerC6F4 2a), [AuR(CN(C6H2)-3,4,5-(OC12H25)3)] (R = PerC6F4 (3a), R = C6-PerC6F4 (3b)), trans-[PdR(PR'3)2X] (R = PerC6F4, R' = Ph, X = I (4a)); (R = C6-PerC6F4, R' = Ph, X = I (4b)); (R = PerC6F4, R' = Et, X = I (5a)); (R = C6-PerC6F4, R' = Et, X = I (5b)); (R = PerC6F4, R' = Ph, X = NCS (6a)), and trans-[Pd(PerC6F4)(PEt3)2X] (X = Br (7a); X = I (8a)). The molecular structure of complexes 1, 2a and 6a has been determined by X-ray diffraction analysis. The perylenyl fragments of complexes 2a or 6a are essentially planar and make dihedral angles to the tetrafluorophenyl plane of 57.49° (2a) and 77.75° (6a). No π-π stacking of perylenyl rings is observed in any of the three molecules, but 2a shows association of two monomers (arranged almost antiparallel), with an Au···Au distance of 3.114 Å. DFT calculations were performed on the absorption spectra of representative PerC6F4Y (Y = H, F, Au(CNMe), PtBr(PMe3)2 and PdBr(PMe3)2). All complexes exhibit fluorescence associated with the perylene fragment with emission quantum yields, in solution at room temperature, in the range 0.20-0.90 and emission lifetimes ~4 ns, and no significant differences in the emission maxima, due to an efficient electronic decoupling of the metal fragment from the HOMO and LUMO of the perylene chromophore. The latter is confirmed by DFT calculations.

  6. Anti-cooperative supramolecular polymerization: a new K 2–K model applied to the self-assembly of perylene bisimide dye proceeding via well-defined hydrogen-bonded dimers† †Electronic supplementary information (ESI) available: Synthesis and characterization, NMR and UV/Vis experiments, VPO and ITC measurements, derivation of the K 2–K model. See DOI: 10.1039/c5sc03759j Click here for additional data file.

    PubMed Central

    Gershberg, Jana; Fennel, Franziska; Rehm, Thomas H.; Lochbrunner, Stefan

    2016-01-01

    A perylene bisimide dye bearing amide functionalities at the imide positions derived from amino acid l-alanine and a dialkoxy-substituted benzyl amine self-assembles into tightly bound dimers by π–π-stacking and hydrogen bonding in chloroform. In less polar or unpolar solvents like toluene and methylcyclohexane, and in their mixtures, these dimers further self-assemble into extended oligomeric aggregates in an anti-cooperative process in which even numbered aggregates are highly favoured. The stepwise transition from dimers into oligomers can not be properly described by conventional K 2–K model, and thus a new K 2–K aggregation model has been developed, which interpretes the present anti-cooperative supramolecular polymerization more appropriately. The newly developed K 2–K model will be useful to describe self-assembly processes of a plethora of other π-conjugated molecules that are characterized by a favored dimer species. PMID:28966774

  7. Chiral Perylene Diimides: Building Blocks for Ionic Self‐Assembly

    PubMed Central

    Echue, Geraldine; Lloyd‐Jones, Guy C.

    2015-01-01

    Abstract A chiral perylene diimide building block has been prepared based on an amine derivative of the amino acid l‐phenylalanine. Detailed studies were carried out into the self‐assembly behaviour of the material in solution and the solid state using UV/Vis, circular dichroism (CD) and fluorescence spectroscopy. For the charged building block BTPPP, the molecular chirality of the side chains is translated into the chiral supramolecular structure in the form of right‐handed helical aggregates in aqueous solution. Temperature‐dependent UV/Vis studies of BTPPP in aqueous solution showed that the self‐assembly behaviour of this dye can be well described by an isodesmic model in which aggregation occurs to generate short stacks in a reversible manner. Wide‐angle X‐ray diffraction studies (WXRD) revealed that this material self‐organises into aggregates with π–π stacking distances typical for π‐conjugated materials. TEM investigations revealed the formation of self‐assembled structures of low order and with no expression of chirality evident. Differential scanning calorimetry (DSC) and polarised optical microscopy (POM) were used to investigate the mesophase properties. Optical textures representative of columnar liquid–crystalline phases were observed for solvent‐annealed samples of BTPPP. The high solubility, tunable self‐assembly and chiral ordering of these materials demonstrate their potential as new molecular building blocks for use in the construction of chiro‐optical structures and devices. PMID:25689392

  8. Water-soluble and fluorescent dendritic perylene bisimides for live-cell imaging.

    PubMed

    Gao, Baoxiang; Li, Hongxia; Liu, Hongmei; Zhang, Licui; Bai, Qianqian; Ba, Xinwu

    2011-04-07

    We prepared dendritic perylene bisimide probes with triblock structures: perylene bisimides fluorescence cores, branched oligo(glutamic acid)s and polyethylene glycol chains. These probes showed good water solubility, low cytotoxicity and strong fluorescence in live cells.

  9. Unsymmetrically Extended Polyfused Aromatics Embedding Coronene and Perylene Frameworks: Syntheses and Properties.

    PubMed

    Kumar, Sushil; Ho, Man-Tzu; Tao, Yu-Tai

    2016-01-15

    A series of polyfused aromatics containing coronene and perylene in their frameworks was successfully constructed by a modified Ramirez-Corey-Fuchs reaction as the key reaction. Typical six-membered annulation and atypical five-membered annulation through controlled reaction conditions led to a range of extensively conjugate aromatics as possible candidates for organic semiconductors. A significant p-type field-effect mobility of 0.42-0.64 cm(2)/V·s was obtained from one of the derivatives, dibenzo[a,d]coronene.

  10. Thermodynamic balance of perylene self-assembly on Ag(110)

    NASA Astrophysics Data System (ADS)

    Bobrov, Kirill; Kalashnyk, Nataliya; Guillemot, Laurent

    2016-10-01

    We present a room temperature STM study of perylene adsorption on Ag(110) at the monolayer coverage regime. We found that structure and symmetry of the perylene monolayer are settled by thermodynamic balance of the three factors: (i) the ability of perylene molecules to recognize specific adsorption sites on the (110) lattice, (ii) the intermolecular interaction, and (iii) the accommodation of thermal motion of the molecules. The moderate strength of the site recognition and the intermolecular interaction, of the same order of magnitude as kT ˜ 25 meV, represents a key feature of the thermodynamic balance. It bestows to this system the unique quality to form the quasi-liquid monolayer of epitaxial as well as self-assembling character. The perylene monolayer accommodates the short-range motion of the molecules instead of quenching it. It precludes the formation of possible solid nuclei and maintains common registry of the included molecules. The surface registry of the quasi-liquid phase is provided by locking of a structure-related fraction of the perylene molecules into specific adsorption sites of the (110) lattice favorable in terms of intermolecular interaction.

  11. Photodegradation of polymer-dispersed perylene di-imide dyes

    NASA Astrophysics Data System (ADS)

    Tanaka, Nobuaki; Barashkov, Nikolay; Heath, Jerry; Sisk, Wade N.

    2006-06-01

    Polymer-dispersed perylene di-imide dye photodegradation is investigated by monitoring the fluorescence intensity as a function of 532 nm laser pulses. Anaerobically irradiated polymer-dye films exhibited an accelerated decrease in fluorescence intensity, which was partially recovered upon exposure to oxygen. Decelerated photodegradation rates were observed for perylene di-imide ethanol solutions upon the addition of a singlet oxygen quenching antioxidant. These observations suggest reversible photoreduction and type II photo-oxidation as important photodegradation mechanisms. Type II photo-oxidation for perylene red 532 nm irradiation is supported by a singlet oxygen quantum yield of 0.09±0.03, determined via detection of time-resolved O2 (a1Δg —> X3∑g-) infrared phosphorescence.

  12. Photodegradation of polymer-dispersed perylene di-imide dyes.

    PubMed

    Tanaka, Nobuaki; Barashkov, Nikolay; Heath, Jerry; Sisk, Wade N

    2006-06-01

    Polymer-dispersed perylene di-imide dye photodegradation is investigated by monitoring the fluorescence intensity as a function of 532 nm laser pulses. Anaerobically irradiated polymer-dye films exhibited an accelerated decrease in fluorescence intensity, which was partially recovered upon exposure to oxygen. Decelerated photodegradation rates were observed for perylene di-imide ethanol solutions upon the addition of a singlet oxygen quenching antioxidant. These observations suggest reversible photoreduction and type II photo-oxidation as important photodegradation mechanisms. Type II photo-oxidation for perylene red 532 nm irradiation is supported by a singlet oxygen quantum yield of 0.09+/-0.03, determined via detection of time-resolved O2 (a1delta(g) --> X3sigma(g)-) infrared phosphorescence.

  13. Novel EDTA-ligands containing an integral perylene bisimide (PBI) core as an optical reporter unit.

    PubMed

    Marcia, Mario; Singh, Prabhpreet; Hauke, Frank; Maggini, Michele; Hirsch, Andreas

    2014-09-28

    The synthesis, characterization and metal complexation of a new class of perylene bisimides (PBIs) as an integral part of ethylenediaminetetraacetic acid (EDTA) are reported. The simplest representative, namely derivative 1a, was synthesized both by a convergent as well as a direct approach while the elongated derivatives, 1b and 1c, were obtained only via a convergent synthetic pathway. All these new prototypes of water-soluble perylenes are bolaamphiphiles and were fully characterized by (1)H- and (13)C-NMR spectroscopy, matrix assisted laser desorption ionization-time of flight (MALDI-TOF) mass spectrometry and IR spectroscopy. In order to acquaint ourselves with the behaviour in solution of our PBIs bearing dendritic wedges, the simplest derivative, 1a, was chosen and tested by means of UV/Vis and fluorescence spectroscopy as well as by zeta-potential measurements. A photoexcitation induced intramolecular photo-electron transfer (PET) can be observed in these molecules. Therefore their potential applications as sensors can be imagined. Model compound 1a efficiently coordinates trivalent metal cations both in water and dimethyl sulfoxide (DMSO). Significantly, the effects of the complexation strongly depend on the aggregation state of the PBI molecules in solution. As a matter of fact, in water, the presence of M(3+) ions triggers the formation of light emitting supramolecular aggregates (excimers). On the other hand, in DMSO-rich solutions metal complexation leads to the suppression of the PET and leads to a strong fluorescence enhancement.

  14. Perylene-labeled silica nanoparticles: synthesis and characterization of three novel silica nanoparticle species for live-cell imaging.

    PubMed

    Blechinger, Julia; Herrmann, Rudolf; Kiener, Daniel; García-García, F Javier; Scheu, Christina; Reller, Armin; Bräuchle, Christoph

    2010-11-05

    The increasing exposure of humans to nanoscaled particles requires well-defined systems that enable the investigation of the toxicity of nanoparticles on the cellular level. To facilitate this, surface-labeled silica nanoparticles, nanoparticles with a labeled core and a silica shell, and a labeled nanoparticle network-all designed for live-cell imaging-are synthesized. The nanoparticles are functionalized with perylene derivatives. For this purpose, two different perylene species containing one or two reactive silica functionalities are prepared. The nanoparticles are studied by transmission electron microscopy, widefield and confocal fluorescence microscopy, as well as by fluorescence spectroscopy in combination with fluorescence anisotropy, in order to characterize the size and morphology of the nanoparticles and to prove the success and homogeneity of the labeling. Using spinning-disc confocal measurements, silica nanoparticles are demonstrated to be taken up by HeLa cells, and they are clearly detectable inside the cytoplasm of the cells.

  15. The number and distances of positive charges of polyamine side chains in a series of perylene diimides significantly influence their ability to induce G-quadruplex structures and inhibit human telomerase.

    PubMed

    Franceschin, Marco; Lombardo, Caterina Maria; Pascucci, Emanuela; D'Ambrosio, Danilo; Micheli, Emanuela; Bianco, Armandodoriano; Ortaggi, Giancarlo; Savino, Maria

    2008-03-01

    We have synthesized eight polyamine perylene diimides to conjugate the efficiency of perylene derivatives in stabilizing G-quadruplex structures and the polyamines' biological activity, due to specific interactions with different DNA domains. Our study was carried out by investigating the ability of these derivatives to induce inter- and intramolecular G-quadruplex structures by polyacrylamide gel electrophoresis (PAGE) and to inhibit telomerase in a modified TRAP assay. The two properties appear to be satisfactorily correlated and they show that the number and distances of positive charges in the side chains dramatically influence both these features. Although our previous studies on perylene derivatives with mono-positively charged side chains indicated that self assembly in aqueous solution leads to a major efficiency, the result observed with the spermine derivative suggests that a too strong aggregation is unfavourable, because it determines a lower solubility of the compounds.

  16. High Stokes shift perylene dyes for luminescent solar concentrators.

    PubMed

    Sanguineti, Alessandro; Sassi, Mauro; Turrisi, Riccardo; Ruffo, Riccardo; Vaccaro, Gianfranco; Meinardi, Francesco; Beverina, Luca

    2013-02-25

    Highly efficient plastic based single layer Luminescent Solar Concentrators (LSCs) require the design of luminophores having complete spectral separation between absorption and emission spectra (large Stokes shift). We describe the design, synthesis and characterization of a new perylene dye possessing Stokes shift as high as 300 meV, fluorescent quantum yield in the LSC slab of 70% and high chemical and photochemical stability.

  17. Perylene dominates the organic contaminant profile in the Berau delta, East Kalimantan, Indonesia.

    PubMed

    Booij, Kees; Arifin, Zainal; Purbonegoro, Triyoni

    2012-05-01

    The geographical distributions of polyaromatic hydrocarbons (PAHs), polychlorinated biphenyls (PCBs), hexachlorobenzene, and 1,1-dichloro-2,2-bis(4-chlorophenyl)ethene (4,4'-DDE) were studied in the Berau delta (East Kalimantan, Indonesia), using sediment sampling and passive water sampling with semipermeable membrane devices. High concentrations of perylene were observed in sediments (54-580 ng g(-1) dry weight), and water (1-680 pg L(-1)). Perylene accounted for about 60% of the total concentrations of PAHs in the sediment. The relative abundance of the other PAHs was indicative of petrogenic sources. Concentrations of PCBs, hexachlorobenzene, and 4,4'-DDE in sediments were below or close to the detection limit (∼ 0.02 ng g(-1)). The analysis of a sediment core revealed no appreciable changes in the concentration of target compounds over the past three decades. We show that sediment sampling and passive water sampling are complementary techniques, and propose to bring the results of both methods to the same concentration scale, using locally derived sediment-water partition coefficients.

  18. Building multistate redox-active architectures using metal-complex functionalized perylene bis-imides.

    PubMed

    Goretzki, Gudrun; Davies, E Stephen; Argent, Stephen P; Warren, John E; Blake, Alexander J; Champness, Neil R

    2009-11-02

    A series of multistate redox-active architectures has been synthesized, structurally characterized, and their optical and redox properties investigated. Specifically, two redox-active ferrocene or cobalt-dithiolene moieties have been introduced to the "bay" region of perylene-bisimides. Three of these disubstituted perylene-bisimide species have been structurally characterized by single crystal X-ray diffraction, confirming the twisted nature of the central perylene core. The first isomeric pair of disubstituted perylene-bisimide isomers, N,N'-di-(n-butyl)-1,7-diferrocenyl-perylene-3,4:9,10-tetracarboxylic acid bisimide (2) and N,N'-di-(n-butyl)-1,6-diferrocenyl-perylene-3,4:9,10-tetracarboxylic acid bisimide (3), structurally characterized by single crystal X-ray diffraction are reported and compared. Structural characterization of the cobalt-dithiolene substituted perylene-bisimide, N,N'-di-(n-butyl)-1,7-dicyclopentadienyl-cobalt(II)-dithiolenyl-perylene-3,4:9,10-tetracarboxylic acid bisimide (4), reveals the expected twisting of the perylene core and confirms the ene-dithiolate geometry of the cobalt dithiolene moiety. Cyclic voltammetry measurements, coupled with spectroelectrochemcial and electron paramagnetic resonance studies, of 1-4, where 1 is N,N'-di-(n-butyl)-1,7-diethynylferrocenyl-perylene-3,4:9,10-tetracarboxylic acid bisimide, reveal the two anticipated perylene-bisimide based reductions. In addition, for the ferrocene substituted compounds, 1-3, a single reversible two-electron oxidation is seen with only a small degree of communication between the ferrocene groups observed in the 1,6-isomer where the two ferrocene groups are attached to the same naphthyl moiety. In the case of 4, two reversible reductions associated with the cobalt-dithiolene moieties are observed, confirming communication across the reduced perylene core.

  19. Effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties.

    PubMed

    Dasgupta, Debarshi; Kendhale, Amol M; Debije, Michael G; Ter Schiphorst, Jeroen; Shishmanova, Ivelina K; Portale, Giuseppe; Schenning, Albertus P H J

    2014-08-01

    The effect of the ortho alkylation of perylene bisimides on the alignment and self-assembly properties has been studied. It was found that the dichroic properties of perylene bisimides in a liquid crystal host can be reversed with a single synthetic step by ortho alkylation. Furthermore, a solvent-induced growth of ultralong organic n-type semiconducting fibrils from non-ortho-alkylated perylene bisimide was observed. Ortho substitution of the perylene bisimide core alters the mode of fibrillar growth, leading to isotropic crystallization.

  20. Rigid Nonfullerene Acceptors Based on Triptycene-Perylene Dye for Organic Solar Cells.

    PubMed

    Meng, Dong; Fu, Huiting; Fan, Bingbing; Zhang, Jianqi; Li, Yan; Sun, Yanming; Wang, Zhaohui

    2017-06-19

    Three kinds of nonconjugated rigid perylene bisimide (PBI) derivatives based on a triptycene core were designed, synthesized and characterized. The unique three-dimensional (3D) conformation of triptycene could enable formation of polymer with the favorable morphology for organic polymer solar cells (PSCs) by relieving the self-aggregation of rigid PBI units. The low-lying LUMO energy levels of these compounds demonstrated that they are very suitable for use as acceptors in organic solar cells. A higher power conversion efficiency (PCE) of 6.15 % was obtained for the blend film using the compound with two PBI units (T-2) as the acceptor and commercial poly[[4,8-bis[5-(2-ethylhexyl)thiophene-2-yl]benzo[1,2-b:4,5-b']dithiophene-2,6-diyl][3-fluoro-2-[(2-ethylhexyl)-carbonyl]thieno[3,4-b]thiophenediyl

  1. Open-circuit voltage loss in annealed P3HT:perylene diimide bulk heterojunction solar cells

    NASA Astrophysics Data System (ADS)

    Solak, S.; Ricciardulli, A. G.; Lenz, T.; Crǎciun, N. I.; Blom, P. W. M.; Wetzelaer, G. A. H.

    2017-04-01

    Solar cells based on blends of regioregular poly(3-hexylthiophene) as a donor and a commercial perylene diimide derivative as a acceptor are investigated. Thermal annealing of the devices results in increased photocurrent generation but is simultaneously accompanied by a loss in open-circuit voltage. It is shown that the decreased open-circuit voltage is caused by the formation of a cathode barrier, as evidenced by injection-limited electron currents, a reduced built-in voltage, and a weaker light-intensity dependence of the open-circuit voltage. Device simulations show that the increased photocurrent after annealing is the result of an increased electron mobility.

  2. Efficient organic solar cells with helical perylene diimide electron acceptors.

    PubMed

    Zhong, Yu; Trinh, M Tuan; Chen, Rongsheng; Wang, Wei; Khlyabich, Petr P; Kumar, Bharat; Xu, Qizhi; Nam, Chang-Yong; Sfeir, Matthew Y; Black, Charles; Steigerwald, Michael L; Loo, Yueh-Lin; Xiao, Shengxiong; Ng, Fay; Zhu, X-Y; Nuckolls, Colin

    2014-10-29

    We report an efficiency of 6.1% for a solution-processed non-fullerene solar cell using a helical perylene diimide (PDI) dimer as the electron acceptor. Femtosecond transient absorption spectroscopy revealed both electron and hole transfer processes at the donor-acceptor interfaces, indicating that charge carriers are created from photogenerated excitons in both the electron donor and acceptor phases. Light-intensity-dependent current-voltage measurements suggested different recombination rates under short-circuit and open-circuit conditions.

  3. Comparative analysis of the energy levels of planar and core-twisted perylene bisimides in solution and solid state by UV/VIS, CV, and UPS/IPES

    NASA Astrophysics Data System (ADS)

    Arantes, C.; Scholz, M.; Schmidt, R.; Dehm, V.; Rocco, M. L. M.; Schöll, A.; Reinert, F.; Würthner, F.

    2012-09-01

    The frontier orbital energies of four different functionalized perylene bisimide derivatives, PBI-Ph(iPr)2, PBI-H4, PBI-F2 and PBI-Cl4, were directly determined by UV-photo electron spectroscopy (UPS) and inverse photo electron spectroscopy (IPES) and are compared to the results from cyclic voltammetry (CV) and optical absorption spectroscopy (UV/VIS). The optical spectra reveal significant differences between monomeric species in solution and assembled molecules in the condensed state for the nearly planar PBI-H4 and PBI-F2, which are attributed to significant π- π stacking interactions in the condensed phase. In contrast, for PBIs with bulky substituents or twisted core, i.e. 2,6-isopropylphenyl substituents at the imide positions (PBI-Ph(iPr)2) or four chlorine substituents at perylene bay positions (PBI-Cl4), similar spectra are observed in solution and in the condensed state, which suggests the absence of strong intermolecular π- π stacking interactions. An entirely different result is obtained for the HOMO/LUMO energy values obtained from UPS/IPES and CV measurements which do not reveal a significant impact of intermolecular π- π stacking interactions. When comparing CV and UPS/IPES results, an accentuated deviation was observed for the perylene bisimide derivatives as compared to correlations found in the literature.

  4. Rapid genotyping using pyrene−perylene locked nucleic acid complexes

    PubMed Central

    Kumar, T. Santhosh; Myznikova, Anna; Samokhina, Evgeniya; Astakhova, Irina Kira

    2013-01-01

    We have developed an assay for single strand DNA and RNA detection which is based on novel pyrene−perylene FRET pairs attached to short LNA/DNA probes. The assay is based on ratiometric emission upon binding of target DNA/RNA by three combinations of fluorescent LNA/DNA reporter strands. Specific geometry of the pyrene fluorophore attached to the 2′-amino group of 2′-amino-LNA in position 4 allows for the first time to efficiently utilize dipole−dipole orientation parameter for sensing of single-nucleotide polymorphisms (SNPs) in nucleic acid targets by FRET. Using novel probes, SNP detection is achieved with advantages of large Stokes shift (115 nm), high fluorescence quantum yields and low limit of target detection values (< 5 nM). Rapid and accurate genotyping of highly polymorphic HIV Pol cDNA and RNA fragments performed herein proves the possibility for broad application of the novel pyrene−perylene FRET pairs, e.g., in imaging and clinical diagnostics. PMID:24044052

  5. Characterization of novel perylene diimides containing aromatic amino acid side chains

    PubMed Central

    Farooqi, Mohammed J.; Penick, Mark A.; Burch, Jessica; Negrete, George R.; Brancaleon, Lorenzo

    2015-01-01

    Perylene diimide derivatives have attracted initial interest as industrial dyes. Recently, much attention has been focused on their strong π–π stacks resulting from the large PDI aromatic core. These PDI stacks have distinct optical properties, and provide informative models that could mimic light-harvesting systems and initial charge transfer typical of photosynthetic systems. The absorption property of PDI derivatives may be tuned from visible to near-infrared region by peripheral substitution. We have studied a new class of PDI derivatives with aryl substituents derived from the side chains of aromatic aminoacids (Tyrosine, Tryptophan and Phenylalanine). We have investigated their absorption and the fluorescence properties in a set of organic solvents and established their different tendencies to aggregate in solution despite their solubility. Most aggregation appears to be unordered. One PDI analogue (the one formed from Tyr) in Methanol, however, appears to form J-type aggregates. Based on our results the compounds appear to be promising for future investigations regarding the interaction of these dyes with biomolecules. PMID:26298679

  6. Characterization of novel perylene diimides containing aromatic amino acid side chains

    NASA Astrophysics Data System (ADS)

    Farooqi, Mohammed J.; Penick, Mark A.; Burch, Jessica; Negrete, George R.; Brancaleon, Lorenzo

    2016-01-01

    Perylene diimide derivatives have attracted initial interest as industrial dyes. Recently, much attention has been focused on their strong π- π stacks resulting from the large PDI aromatic core. These PDI stacks have distinct optical properties, and provide informative models that could mimic light-harvesting systems and initial charge transfer typical of photosynthetic systems. The absorption property of PDI derivatives may be tuned from visible to near-infrared region by peripheral substitution. We have studied a new class of PDI derivatives with aryl substituents derived from the side chains of aromatic aminoacids (Tyrosine, Tryptophan and Phenylalanine). We have investigated their absorption and the fluorescence properties in a set of organic solvents and established their different tendencies to aggregate in solution despite their solubility. Most aggregation appears to be unordered. One PDI analogue (the one formed from Tyr) in Methanol, however, appears to form J-type aggregates. Based on our results the compounds appear to be promising for future investigations regarding the interaction of these dyes with biomolecules.

  7. Perylene in Lake Biwa sediments originating from Cenococcum geophilum in its catchment area

    NASA Astrophysics Data System (ADS)

    Itoh, Nobuyasu; Sakagami, Nobuo; Torimura, Masaki; Watanabe, Makiko

    2012-10-01

    Perylene, which is composed of five benzene rings, is commonly found in sediments throughout the world at concentrations and distributions that are different from those of other polycyclic aromatic hydrocarbons. The only information available on the origin of perylene comes from 4,9-dihydroxyperylene-3,10-quinone (DHPQ), which originates from fungal component symbiosis or from parasites on plants; however, there is no direct evidence of a mechanism of perylene formation. In this study, we examined the relationship between sedimentary perylene and Cenococcum geophilum (C. geophilum) in a catchment area at Lake Biwa. Sclerotium grains of C. geophilum containing DHPQ were found in this catchment area (approximately 40 balls kg-1 dried soil for >1 mm-ϕ), and small sclerotium grains were frequently found in the sediment. In the sediment sample, we also found broken particles containing perylene, and they had a porous structure characteristic of sclerotium grains. Furthermore, the particles contained DHPQ in different transformation stages to perylene via 3,10-perylenequinone (3,10-PQ). This finding was consistent with results from elemental analysis (oxygen/carbon). Because a remarkable amount of DHPQ originating from C. geophilum also exists in the humic acids of soils and because the inputs of compounds to the lake depend strongly on the rivers, perylene in the Lake Biwa sediment originates mainly from the DHPQ of C. geophilum in its catchment area.

  8. High-Performance Solution-Processed Non-Fullerene Organic Solar Cells Based on Selenophene-Containing Perylene Bisimide Acceptor.

    PubMed

    Meng, Dong; Sun, Dan; Zhong, Chengmei; Liu, Tao; Fan, Bingbing; Huo, Lijun; Li, Yan; Jiang, Wei; Choi, Hyosung; Kim, Taehyo; Kim, Jin Young; Sun, Yanming; Wang, Zhaohui; Heeger, Alan J

    2016-01-13

    Non-fullerene acceptors have recently attracted tremendous interest because of their potential as alternatives to fullerene derivatives in bulk heterojunction organic solar cells. However, the power conversion efficiencies (PCEs) have lagged far behind those of the polymer/fullerene system, mainly because of the low fill factor (FF) and photocurrent. Here we report a novel perylene bisimide (PBI) acceptor, SdiPBI-Se, in which selenium atoms were introduced into the perylene core. With a well-established wide-band-gap polymer (PDBT-T1) as the donor, a high efficiency of 8.4% with an unprecedented high FF of 70.2% is achieved for solution-processed non-fullerene organic solar cells. Efficient photon absorption, high and balanced charge carrier mobility, and ultrafast charge generation processes in PDBT-T1:SdiPBI-Se films account for the high photovoltaic performance. Our results suggest that non-fullerene acceptors have enormous potential to rival or even surpass the performance of their fullerene counterparts.

  9. Development of novel fluorescent probe 3-perylene diphenylphosphine for determination of lipid hydroperoxide with fluorescent image analysis

    SciTech Connect

    Chotimarkorn, Chatchawan; Nagasaka, Reiko; Ushio, Hideki . E-mail: hushio@s.kaiyodai.ac.jp; Ohshima, Toshiaki; Matsunaga, Shigeki

    2005-12-16

    A novel fluorescent probe 3-perylene diphenylphosphine (3-PeDPP) was synthesized for the direct analysis of lipid hydroperoxides. The structure of 3-PeDPP was identified by the spectroscopic data, FAB-MS, {sup 1}H NMR, and {sup 13}C NMR. The reactivities of 3-PeDPP with lipid hydroperoxides were investigated in chloroform/MeOH homogeneous solutions and PC liposome model systems oxidized by either 2,2'-azobis(2-amidinopropane)dihydrochloride and photosensitized oxidation. The fluorescence intensity derived from 3-perylene diphenylphosphineoxide (3-PeDPPO) increased proportionally with amount of hydroperoxides produced in homogeneous solutions and liposome model systems. 3-PeDPP was easily incorporated into mouse myeloma SP2 cells and thin tissue section for dynamic membrane lipid peroxidation studies. Linear correlations between fluorescence intensity and amount of hydroperoxides in the cell membrane and tissue sections were obtained. The fluorescence intensity from 2-dimensional image analysis was also well correlated with lipid hydroperoxide level in these models. Thus, the novel probe 3-PeDPP is useful for the direct determination of lipid hydroperoxides in biological materials.

  10. Green and highly efficient synthesis of perylene and naphthalene bisimides in nothing but water.

    PubMed

    Baumgartner, Bettina; Svirkova, Anastasiya; Bintinger, Johannes; Hametner, Christian; Marchetti-Deschmann, Martina; Unterlass, Miriam M

    2017-01-19

    High-purity, symmetrically substituted perylene and naphthalene bisimides were obtained by hydrothermal condensation of monoamines with the corresponding bisanhydride. The hydrothermal imidization proceeds quantitatively, without the need for organic solvents, catalysts or excess of the amines.

  11. Cross-shaped photoluminescence of excimers in perylene crystals

    NASA Astrophysics Data System (ADS)

    Tanaka, Daichi; Numata, Yudai; Nakagawa, Kazuya; Kobayashi, Takayoshi; Tokunaga, Eiji

    2016-06-01

    Cross-shaped excimer (self-trapped exciton) luminescence from α- and β-perylene single crystals of 50-100 μm was found when they were excited at the center of the crystals with a continuous-wave (cw) laser resonant with the exciton absorption. The cross shape is formed by the two lines which intersect at the excited position and are perpendicular to the sides of the crystals of parallelogram shape. Luminescence is emitted from the excited spot and 4 side edges in the cross shape. The most striking feature is that the luminescence intensity at the edges was as high as or higher than at the excited spot. The possibility of the exciton propagation or the waveguide effect is rejected both experimentally and theoretically. This phenomenon can be reasonably explained only when the radiative transition probability of excimers is significantly enhanced at the crystals side edges than at the center due to the lower symmetry.

  12. Room-temperature Y-type emission of perylenes by encapsulation within single-walled carbon nanotubes

    NASA Astrophysics Data System (ADS)

    Tange, Masayoshi; Okazaki, Toshiya; Liu, Zheng; Suenaga, Kazu; Iijima, Sumio

    2016-04-01

    Fluorescent materials that exhibit large Stokes shifts are useful for suppressing aggregation-caused quenching. Controlling the self-trapped exciton (STE) states in organic dyes with a dimeric structure is one way of tuning Stokes shifts. However, this leads to the spectral broadening of the emissions at room temperature owing to the effects of the surrounding materials on the excited dimers. Here, we demonstrate the effects of confining organic dyes on their optical properties via the encapsulation of perylene molecules within single-walled carbon nanotubes. The encapsulated dimeric perylene exhibits fluorescence with large Stokes shifts and long lifetimes through the STE states. In particular, a noticeable emission of dimeric perylene is observed with a vibronic structure at room temperature; this resembles the Y-type emission of dimeric α-perylene crystals observed only at low temperatures. The results suggest that the isolation of the excited perylene dimers plays an important role in the occurrence of the room-temperature Y-emission.Fluorescent materials that exhibit large Stokes shifts are useful for suppressing aggregation-caused quenching. Controlling the self-trapped exciton (STE) states in organic dyes with a dimeric structure is one way of tuning Stokes shifts. However, this leads to the spectral broadening of the emissions at room temperature owing to the effects of the surrounding materials on the excited dimers. Here, we demonstrate the effects of confining organic dyes on their optical properties via the encapsulation of perylene molecules within single-walled carbon nanotubes. The encapsulated dimeric perylene exhibits fluorescence with large Stokes shifts and long lifetimes through the STE states. In particular, a noticeable emission of dimeric perylene is observed with a vibronic structure at room temperature; this resembles the Y-type emission of dimeric α-perylene crystals observed only at low temperatures. The results suggest that the

  13. Electron Acceptors Based on α-Substituted Perylene Diimide (PDI) for Organic Solar Cells

    SciTech Connect

    Zhao, Donglin; Wu, Qinghe; Cai, Zhengxu; Zheng, Tianyue; Chen, Wei; Lu, Jessica; Yu, Luping

    2016-02-20

    The ortho-position functionalized perylene diimide derivatives (αPPID, αPBDT) were synthesized and used as the electron acceptors in nonfullerene organic photovoltaics. Due to the good planarity of ortho-position functionalized PDI, the αPPID and αPBDT show strong tendency to form aggregate because of their enhanced intermolecular pie-pie interaction. Moreover, they maintain the pure domains and the same packing order as in the pure film if they are blended with PBT7-TH and the SCLC measurement also shows the high electron mobility. The inverted OPVs employing αPDI-based compounds as acceptor and PBT7-TH as the donor give the highest PCE of 4.92 % for αPBDT based device and 3.61 % for αPPID based device, which is 39 % and 4 % higher than that for their counterpart βPBDT and βPPID. The charge separation study shows the more efficient exciton dissociation at interfaces between PDI based compounds and PBT7-TH. In conclusion, the results suggest that compared to beta-substituted ones, alpha-substituted PDI derivatives are more promising electron acceptors for OPV.

  14. Electron Acceptors Based on α-Substituted Perylene Diimide (PDI) for Organic Solar Cells

    DOE PAGES

    Zhao, Donglin; Wu, Qinghe; Cai, Zhengxu; ...

    2016-02-20

    The ortho-position functionalized perylene diimide derivatives (αPPID, αPBDT) were synthesized and used as the electron acceptors in nonfullerene organic photovoltaics. Due to the good planarity of ortho-position functionalized PDI, the αPPID and αPBDT show strong tendency to form aggregate because of their enhanced intermolecular pie-pie interaction. Moreover, they maintain the pure domains and the same packing order as in the pure film if they are blended with PBT7-TH and the SCLC measurement also shows the high electron mobility. The inverted OPVs employing αPDI-based compounds as acceptor and PBT7-TH as the donor give the highest PCE of 4.92 % for αPBDTmore » based device and 3.61 % for αPPID based device, which is 39 % and 4 % higher than that for their counterpart βPBDT and βPPID. The charge separation study shows the more efficient exciton dissociation at interfaces between PDI based compounds and PBT7-TH. In conclusion, the results suggest that compared to beta-substituted ones, alpha-substituted PDI derivatives are more promising electron acceptors for OPV.« less

  15. Synthesis of Perylene Imide Diones as Platforms for the Development of Pyrazine Based Organic Semiconductors.

    PubMed

    de Echegaray, Paula; Mancheño, María J; Arrechea-Marcos, Iratxe; Juárez, Rafael; López-Espejo, Guzmán; López Navarrete, J Teodomiro; Ramos, María Mar; Seoane, Carlos; Ortiz, Rocío Ponce; Segura, José L

    2016-11-18

    There is a great interest in peryleneimide (PI)-containing compounds given their unique combination of good electron accepting ability, high abosorption in the visible region, and outstanding chemical, thermal, and photochemical stabilities. Thus, herein we report the synthesis of perylene imide derivatives endowed with a 1,2-diketone functionality (PIDs) as efficient intermediates to easily access peryleneimide (PI)-containing organic semiconductors with enhanced absorption cross-section for the design of tunable semiconductor organic materials. Three processable organic molecular semiconductors containing thiophene and terthiophene moieties, PITa, PITb, and PITT, have been prepared from the novel PIDs. The tendency of these semiconductors for molecular aggregation have been investigated by NMR spectroscopy and supported by quantum chemical calculations. 2D NMR experiments and theoretical calculations point to an antiparallel π-stacking interaction as the most stable conformation in the aggregates. Investigation of the optical and electrochemical properties of the materials is also reported and analyzed in combination with DFT calculations. Although the derivatives presented here show modest electron mobilities of ∼10(-4) cm(2)V(-1)s(-1), these preliminary studies of their performance in organic field effect transistors (OFETs) indicate the potential of these new building blocks as n-type semiconductors.

  16. Excited state electronic structures and photochemistry of heterocyclic annulated perylene (HAP) materials tuned by heteroatoms: S, Se, N, O, C, Si, and B.

    PubMed

    Zhao, Guang-Jiu; Han, Ke-Li

    2009-04-23

    Time-dependent density functional theory (TDDFT) method was performed to investigate the excited state electronic structures and photochemistry of a variety of heterocyclic annulated perylene (HAP) materials. The calculated electronic structures and photochemical properties of the newly synthesized S-, Se-, and N-heterocyclic annulated perylenes were in good agreement with the experimental results. Moreover, the O-, C-, Si-, and B-heterocyclic annulated perylenes were also theoretically designed and investigated by using the same computational methods in this work. As a result, we found that the electronic structures and photochemical properties of S-, Se-, N-, O-, and C-heterocyclic annulated perylenes are similar to each other. The energy levels of the LUMO orbital for the S-, Se-, N-, O-, and C-heterocyclic annulated perylenes become higher than those of unsubstituted perylene. At the same time, the energy gaps between LUMO and HOMO for these heterocyclic annulated perylenes are also increased in comparison with those of unsubstituted perylene. Hence, both absorption and fluorescence spectra of S-, Se-, N-, O-, and C-heterocyclic annulated perylenes are correspondingly blue-shifted relative to those of unsubstituted perylene. In addition, two bonds formed by heteroatoms with perylene are lengthened in the electronic excited state of S-, Se-, N-, O-, and C-heterocyclic annulated perylenes. On the contrary, these bonds formed by heteroatoms with perylene are shortened in the electronic excited state of Si- and B-heterocyclic annulated perylenes. Furthermore, energy levels of the LUMO orbital for Si- and B-heterocyclic annulated perylenes become significantly lowered in comparison with that of unsubstituted perylene. At the same time, energy gaps between LUMO and HOMO for Si- and B-heterocyclic annulated perylenes become decreased relative to those of unsubstituted perylene. Thus, both absorption and fluorescence spectra of Si- and B-heterocyclic annulated

  17. Controllable and stepwise synthesis of soluble ladder-conjugated bis(perylene imide) fluorenebisimidazole as a multifunctional optoelectronic material.

    PubMed

    Chen, Lingcheng; Zhang, Kaichen; Tang, Changquan; Zheng, Qingdong; Xiao, Yi

    2015-02-06

    By a controllable and stepwise strategy, a soluble ladder-conjugated perylene derivative BPI-FBI as the only product has been synthesized, which avoids the tough work to isolate regioisomers generated by a conventional one-step condensation method. BPI-FBI exhibits broad absorption spectra covering the whole visible region from 300 to 700 nm because of the large π-conjugation skeleton and has a low LUMO level inheriting the prototype PDI. In the steady-state space-charge-limited current (SCLC) devices, BPI-FBI exhibits an intrinsic electron mobility of 1.01 × 10(-5) cm(2) V(-1) s(-1). With a high two photon absorbing activity in the near-infrared region from 1200 to 1400 nm, BPI-FBI also exhibits good optical limiting performance, which will be useful for sensor or human eye protection and stabilization of light sources for optical communications.

  18. Energy flow dynamics within cofacial and slip-stacked perylene-3,4-dicarboximide dimer models of π-aggregates.

    PubMed

    Lindquist, Rebecca J; Lefler, Kelly M; Brown, Kristen E; Dyar, Scott M; Margulies, Eric A; Young, Ryan M; Wasielewski, Michael R

    2014-10-22

    Robust perylene-3,4-dicarboximide (PMI) π-aggregates provide important light-harvesting and electron-hole pair generation advantages in organic photovoltaics and related applications, but relatively few studies have focused on the electronic interactions between PMI chromophores. In contrast, structure-function relationships based on π-π stacking in the related perylene-3,4:9,10-bis(dicarboximides) (PDIs) have been widely investigated. The performance of both PMI and PDI derivatives in organic devices may be limited by the formation of low-energy excimer trap states in morphologies where interchromophore coupling is strong. Here, five covalently bound PMI dimers with varying degrees of electronic interaction were studied to probe the relative chromophore orientations that lead to excimer energy trap states. Femtosecond near-infrared transient absorption spectroscopy was used to observe the growth of a low-energy transition at ~1450-1520 nm characteristic of the excimer state in these covalent dimers. The excimer-state absorption appears in ~1 ps, followed by conformational relaxation over 8-17 ps. The excimer state then decays in 6.9-12.8 ns, as measured by time-resolved fluorescence spectroscopy. The excimer lifetimes reach a maximum for a slip-stacked geometry in which the two PMI molecules are displaced along their long axes by one phenyl group (~4.3 Å). Additional displacement of the PMIs by a biphenyl spacer along the long axis prevents excimer formation. Symmetry-breaking charge transfer is not observed in any of the PMI dimers, and only a small triplet yield (<5%) is observed for the cofacial PMI dimers. These data provide structural insights for minimizing excimer trap states in organic devices based on PMI derivatives.

  19. Random copolyesters containing perylene bisimide: flexible films and fluorescent fibers.

    PubMed

    Nisha, S Kumari; Asha, S K

    2014-08-13

    Random copolyesters of poly(l-lactic acid) (PLLA) and [poly(1,4-cyclohexylenedimethylene-1,4- cyclohexanedicarboxylate)] (PCCD) incorporating varying mol ratios of perylene bisimide (PBI) were developed via a high-temperature solution-blending approach. PCCD incorporating PBI was developed by melt polycondenzation followed by a polyester-polyester transesterification reaction between PCCD-PBI and PLLA. The polymers exhibited good solubility in common organic solvents and formed free-standing films, which showed bright red emission upon irradiation with ultraviolet radiation. A solid state fluorescence quantum yield of 10% was observed for this PBI based polyester, which was much higher than that reported in literature for PBI based polymers in the solid state (<1%). Strong red fluorescent nanofibers of these polymers were successfully constructed by electrospinning technique. A random copolyester incorporating donor based on oligo(p-pheneylenevinylene) (OPV) and PBI as acceptor chromophore was also synthesized and fluorescence microscopy images of the electrospun fibers of this polymer exhibited blue, green and red emission upon excitation at different wavelengths. The high temperature solution blending approach involving a high molecular weight polymer and a suitably functionalized π conjugated molecule described here is a unique method by which 1D nanostructures of a wide range of π-conjugated chromophores could be fabricated having strong fluorescence, with the scope of application in nanoscale optoelectronics, biological devices, as well as sensing.

  20. Assembly of DNA triangles mediated by perylene bisimide caps.

    PubMed

    Menacher, Florian; Stepanenko, Vladimir; Würthner, Frank; Wagenknecht, Hans-Achim

    2011-06-06

    Perylene bisimides (PBI) have been synthetically incorporated as caps onto a Y-shaped DNA triple strand. These PBI caps serve as "sticky" ends in the spontaneous assembly of larger DNA ensembles, linking the triangular DNA through stacking interactions. This, in turn, yields a hypsochromic shift in the absorption and a red shift in the fluorescence as characteristic optical readouts. This assembly occurs spontaneously without any enzymatic ligation process and without the use of overhanging DNA as sticky ends. Instead, dimerizations of the PBI chromophores in the assembly are controlled by the DNA as a structural scaffold. Thereby, the PBI-driven assembly is fully reversible. Due to the fact that PBI dimerization does not occur in the single strand, the aggregates can be destroyed by thermal dehybridization of the DNA scaffold and reassembled by reannealing of the DNA construct. In view of the fact that PBI forms stable radical anions, the presented DNA architectures are not only interesting optical biomaterials, but are also promising materials for molecular electronics with DNA.

  1. Tetrahedral Arrangements of Perylene Bisimide Columns via Supramolecular Orientational Memory.

    PubMed

    Sahoo, Dipankar; Peterca, Mihai; Aqad, Emad; Partridge, Benjamin E; Heiney, Paul A; Graf, Robert; Spiess, Hans W; Zeng, Xiangbing; Percec, Virgil

    2017-01-24

    Chiral, shape, and liquid crystalline memory effects are well-known to produce commercial macroscopic materials with important applications as springs, sensors, displays, and memory devices. A supramolecular orientational memory effect that provides complex nanoscale arrangements was only recently reported. This supramolecular orientational memory was demonstrated to preserve the molecular orientation and packing within supramolecular units of a self-assembling cyclotriveratrylene crown at the nanoscale upon transition between its columnar hexagonal and Pm3̅n cubic periodic arrays. Here we report the discovery of supramolecular orientational memory in a dendronized perylene bisimide (G2-PBI) that self-assembles into tetrameric crowns and subsequently self-organizes into supramolecular columns and spheres. This supramolecular orientation memory upon transition between columnar hexagonal and body-centered cubic (BCC) mesophases preserves the 3-fold cubic [111] orientations rather than the 4-fold [100] axes, generating an unusual tetrahedral arrangement of supramolecular columns. These results indicate that the supramolecular orientational memory concept may be general for periodic arrays of self-assembling dendrons and dendrimers as well as for other periodic and quasiperiodic nanoscale organizations comprising supramolecular spheres, generated from other organized complex soft matter including block copolymers and surfactants.

  2. Reactive matrix clean-up of naturally occurring perylene in young lignite.

    PubMed

    Spitzer, Torsten

    2008-08-01

    Young lignite from two locations in Sendai City, Japan, were analyzed for polynuclear aromatic compounds (PACs). Lignite samples were extracted with toluene and PACs were isolated by a compound-class-selective, reactive matrix clean-up. This clean-up separates all compounds of polynuclear aromatic structure, for example hydrocarbons and ketones and their primary metabolites, from interfering organic compounds. The result of this isolation procedure is, therefore, a group of a large number of polycyclic compounds with different functional groups. Further analysis is done by glass capillary gas chromatography. Perylene was identified as the only compound obtained by the reactive matrix clean-up of lignite samples from both locations. Concentrations were in the range of 1-10 mg kg(-1). Conversely, PACs resulting from particulate emissions from fossil fuel combustion always contain isomeric PAHs (polynuclear aromatic hydrocarbons) with some polycyclic aromatic ketones and thousands of primary and secondary metabolites at very low concentrations. This was demonstrated for a sample of urban air particulate matter, which is the source of PAC contamination of surface soil. The absence of accompanying PAHs and polynuclear aromatic ketones in the lignite samples confirms that perylene did not originate from a combustion process. It is assumed that the high concentrations of perylene are the result of a reduction of perylene quinone. Thus, the high perylene content of the lignite samples investigated is of biogenic origin.

  3. Studies on Structural, Optical, Thermal and Electrical Properties of Perylene-Doped p-terphenyl Luminophors.

    PubMed

    Desai, Netaji K; Mahajan, Prasad G; Bhopate, Dhanaji P; Dalavi, Dattatray K; Kamble, Avinash A; Gore, Anil H; Dongale, Tukaram D; Kolekar, Govind B; Patil, Shivajirao R

    2017-10-02

    A simple solid state reaction technique was employed for the preparation of polycrystalline luminophors of p-terphenyl containing different amounts of perylene followed by spectral characterization techniques viz. XRD, SEM, TGA-DSC, UV-Visible spectroscopy, thermo-electrical conductivity, fluorescence spectroscopy, fluorescence life time spectroscopy and temperature dependent fluorescence. X-ray diffraction profiles of the doped p-terphenyl reveal well-defined and sharp peaks indicate homogeneity and crystallinity. The SEM micrograph of pure p-terphenyl exhibit flakes like grains and then compact and finally gets separately with perylene amounts. The observed results indicate that closed packed crystal structures of doped p-terphenyl during crystal formation. The band gaps estimated from UV-visible spectroscopy decreased from 5.20 to 4.10 eV, while thermo-electrical conductivity increases with perylene content. The fluorescence spectra showed partial quenching of p-terphenyl fluorescence and simultaneously sensitization of perylene fluorescence at the excitation wavelength of p-terphenyl (290 nm) due to excitation energy transfer from p-terphenyl to perylene. The observed sensitization results are in harmony with intense blue color seen in fluorescence microscopy images and has high demand in scintillation process.

  4. Solution Processable n-Type Perylene Diimide Copolymers for Organic Photovoltaics

    SciTech Connect

    Liang, Z.; Cormier, R. A.; Nardes, A. M.; Gregg, B. A.

    2011-01-01

    Perylene diimides are known as promising n-type semiconductor building blocks. Here we report the synthesis and characterization of a set of three soluble poly(perylene diimide)s and their preliminary characterization in organic photovoltaic cells. These polymers are made through the polycondensation of perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) with a variety of poly(ethylene glycol) (PEG)- or poly(propylene glycol) (PPG)-based diamine comonomers. The flexible spacer offers increased solubility in organic solvents and allows the perylene core to assume a conformation that promotes favorable cofacial {pi}-{pi} interactions. Mixtures of these polymers with the hole-transporting polymer, poly(3-hexylthiophene) (P3HT) result in significant fluorescence quenching. However, the phase separation occurs on a scale too large for a bulk heterojunction solar cell. The PPGylated poly(perylene diimide) shows an unusually low free electron concentration ({approx}1.0 x 10{sup 12} cm{sup -3}) and therefore makes an excellent model system for future doping studies. These new polymers may have promise as stable electron-conductive layers with large light-absorptivities in solution-processable applications of organic electronics.

  5. White organic light-emitting diodes based on incomplete energy transfer from perylene to rubrene

    NASA Astrophysics Data System (ADS)

    Ding, Bangdong; Zhu, Wenqing; Jiang, Xueyin; Zhang, Zhilin

    2008-11-01

    This paper presents organic light-emitting diodes which generate white emission based on both perylene and rubrene doped in 9,10-di(2-naphthyl)anthracene (ADN). In this doping system, the blue dopant perylene not only emitted but also assisted the energy transfer from ADN to rubrene, which contributes to a lower doping concentration of rubrene. The optimal configuration of the device is ITO/TPD(50 nm)/ADN:0.5 wt% perylene:0.006 wt% rubrene(40 nm)/Bphen(25 nm)/LiF(1 nm)/Al. The maximum luminance of 11 665 cd/m 2 at 14 V according to a luminance efficiency of 2.9 cd/A was obtained. A CIE color coordinate of (0.30, 0.37) at 4 mA/cm 2 was also achieved.

  6. Photophysical properties of new bis-perylene dyads for potential upconversion use

    NASA Astrophysics Data System (ADS)

    Ribas, Marcos R.; Steer, Ronald P.; Rüther, Ricardo

    2014-06-01

    Two new bis-perylenes, BPC with a meta-disubstituted benzene linker, and BPD with a p,p‧-disubstituted biphenyl linker, have been synthesized and their photophysical parameters measured. Their singlet and triplet energies decrease incrementally in the order perylene, BPC, BPD, making them ideally matched with C60 for triplet-triplet energy transfer in sensitized photon upconversion schemes. Following photosensitization by triplet C60, BPC exhibits strong fluorescence upconversion by triplet-triplet annihilation, indicating that these bis-perylene dyads (and the multimers that can be constructed from them) will be interesting candidates for use in organic devices such as bulk-heterojunction and dye-sensitized solar cells employing non-coherent photon upconversion.

  7. MAJOR PRODUCTS IN THE PHOTOCHEMISTRY OF PERYLENE ADSORBED IN MODELS OF ATMOSPHERIC PARTICULATE MATTER

    PubMed Central

    Sotero, Pura

    2009-01-01

    The photodegradation of adsorbed perylene is strongly influenced by the environment in which it is found as demonstrated by the nature of the photoproducts characterized on the adsorbed state in comparison to its photochemical behavior in solution. The separation, characterization, and identification of the products were carried out using HPLC equipped with UV-Vis diode array and MS detection. Two of the products were identified as 1,12-perylenedione and 3,10-perylenedione. Three additional products were characterized as a perylenedione and two perylenediols based on their m/z ratio. Based on this information, two possible mechanisms of formation were proposed for the identified diones. The experimental data showed that both the radical cation and singlet oxygen participate in the route of photodegradation of perylene which occurs through a mixed Type I and Type II pathway. These results assist in the understanding of complex processes undergone by perylene and other PAHs in the environment. PMID:20339480

  8. Patterned Growth of Organic Semiconductors: Selective Nucleation of Perylene on Self-Assembled Monolayers.

    PubMed

    Pick, André; Witte, Gregor

    2016-08-16

    Organic semiconductors (OSC) have received a large amount of attention because they afford the fabrication of flexible electronic devices. However, the limited resistance to radiation and etching of such materials does not permit their patterning by photolithography, which has been a driving force for the development of integrated circuits and therefore requires alternative structuring techniques. One approach is based on precoating the substrate with self-assembled monolayers (SAMs) to control the nucleation of subsequently deposited OSC layers, but the underlying mechanism is barely understood. Here, we used alkanethiols with different chemical terminations to prepare SAMs on gold substrates serving as model systems to identify the mechanism of selective nucleation for the case of the OSC perylene. Using atomic force microscopy and fluorescence microscopy, we demonstrate that the chemical functionalization of the SAMs determines the adhesion forces for the OSC that are smallest for CF3-terminated and largest for OH-terminated SAMs, hence yielding distinctly different sticking probabilities upon perylene deposition at room temperature. Microcontact printing and immersion were employed to prepare SAM patterns that enable the selective growth of polycrystalline perylene films. A quite different situation is found upon printing long-chain thiols with low vapor pressure, which leads to the transfer of multilayers and favors the growth of perylene single crystallites. In a more abstract scenario, patterns of silicone oil droplets were printed on a gold substrate, which was previously covered with a repelling fluorinated SAM. Such droplets provide nucleation centers for liquid-mediated growth, often yielding platelet-shaped perylene single crystallites without unwanted perylene nucleation on the remaining surface.

  9. Promising fluorescent dye for solar energy conversion based on a perylene perinone.

    PubMed

    Debije, Michael G; Verbunt, Paul P C; Nadkarni, Pradeep J; Velate, Suresh; Bhaumik, Kankan; Nedumbamana, Sankaran; Rowan, Brenda C; Richards, Bryce S; Hoeks, Theo L

    2011-01-10

    We describe the synthesis of a dye based on a perylene perinone and evaluate its potential as the functional material for use in the luminescent solar concentrator (LSC). The dye extends the absorption wavelength of LSCs using the perylene-based dye Lumogen Red 305 by more than ~50 nm, translating into the collection of potentially 25% more photons at a reasonable fluorescent quantum yield and photostability. When the new perinone is used in a two-waveguide LSC in conjunction with Red 305, the integrated edge emission of the total LSC system may be increased more than 24% when compared to the Red 305 dye alone.

  10. Photoinduced charge transfer involving a MoMo quadruply bonded complex to a perylene diimide.

    PubMed

    Alberding, Brian G; Brown-Xu, Samantha E; Chisholm, Malcolm H; Epstein, Arthur J; Gustafson, Terry L; Lewis, Sharlene A; Min, Yong

    2013-04-21

    Evidence, based on femtosecond transient absorption and time resolved infrared spectroscopy, is presented for photoinduced charge transfer from the Mo2δ orbital of the quadruply bonded molecule trans-Mo2(T(i)PB)2(BTh)2, where T(i)PB = 2,4,6-triisopropyl benzoate and BTh = 2,2'-bithienylcarboxylate, to di-n-octyl perylene diimide and di-n-hexylheptyl perylene diimide in thin films and solutions of the mixtures. The films show a long-lived charge separated state while slow back electron transfer, τBET ~ 500 ps, occurs in solution.

  11. Dispersing perylene diimide/SWCNT hybrids: structural insights at the molecular level and fabricating advanced materials.

    PubMed

    Tsarfati, Yael; Strauss, Volker; Kuhri, Susanne; Krieg, Elisha; Weissman, Haim; Shimoni, Eyal; Baram, Jonathan; Guldi, Dirk M; Rybtchinski, Boris

    2015-06-17

    The unique properties of carbon nanotubes (CNT) are advantageous for emerging applications. Yet, the CNT insolubility hampers their potential. Approaches based on covalent and noncovalent methodologies have been tested to realize stable dispersions of CNTs. Noncovalent approaches are of particular interest as they preserve the CNT's structures and properties. We report on hybrids, in which perylene diimide (PDI) amphiphiles are noncovalently immobilized onto single wall carbon nanotubes (SWCNT). The resulting hybrids were dispersed and exfoliated both in water and organic solvents in the presence of two different PDI derivatives, PP2b and PP3a. The dispersions were investigated using cryogenic transmission electron microscopy (cryo-TEM), providing unique structural insights into the exfoliation. A helical arrangement of PP2b assemblies on SWCNTs dominates in aqueous dispersions, while a single layer of PP2b and PP3a was found on SWCNTs in organic dispersions. The dispersions were probed by steady-state and time-resolved spectroscopies, revealing appreciable charge redistribution in the ground state, and an efficient electron transfer from SWCNTs to PDIs in the excited state. We also fabricated hybrid materials from the PP2b/SWCNT dispersions. A supramolecular membrane was prepared from aqueous dispersions and used for size-selective separation of gold nanoparticles. Hybrid buckypaper films were prepared from the organic dispersions. In the latter, high conductivity results from enhanced electronic communication and favorable morphology within the hybrid material. Our findings shed light onto SWCNT/dispersant molecular interactions, and introduce a versatile approach toward universal solution processing of SWCNT-based materials.

  12. Higher fluorescence in platinum(iv) orthometallated complexes of perylene imine compared with their platinum(ii) or palladium(ii) analogues.

    PubMed

    Expósito, J Emilio; Álvarez-Paíno, Marta; Aullón, Gabriel; Miguel, Jesús A; Espinet, Pablo

    2015-09-28

    The reaction of 3-perylenylmethylen-4'-ethylaniline () with [Pt2Me4(μ-SMe2)2] (and subsequent addition of PPh3) or with [Pt2(η(3)-C4H7)2(μ-Cl)2] produced cyclometallated Pt(II) complexes [Pt(C^N)Me(PPh3)] () and, respectively, [Pt2(C^N)2(μ-Cl)2] () (HC^N = 3-C20H11CH[double bond, length as m-dash]NC6H4-p-C2H5), with Pt bound to the ortho site of the perylenyl fragment. From the mononuclear complexes [Pt(C^N)L2] (L2 = acac (); S2COMe (); S2CNEt2 () are easily formed. Oxidative addition of methyl iodide to the square-planar Pt(II) complexes , , and gave the corresponding cyclometallated Pt(IV) compounds [Pt(C^N)L2MeI] , and . The X-ray structures of , , and show that the perylenyl fragment remains essentially flat in and and slightly twisted in . Comparison of the optical properties of these Pt(II) complexes with those reported for similar Pd(II) derivatives reveals that the change of metal exerts a notable influence on the UV-vis spectra. In solution at room temperature, all the Pt complexes exhibit fluorescence associated with the perylene fragment with low emission quantum yields for the Pt(II) complexes (<1%) and remarkably higher emission values for the Pt(IV) complexes: up to 29%, with emission lifetimes of 1-5 ns. Time-dependent density functional theory (TD-DFT) calculations were performed on the perylene imine and on representative complexes [M(C^N)(acac)] (M = Pd, Pt) and [Pt(C^N)(acac)MeI] to analyse the absorption spectra. These calculations support a perylene-dominated intraligand π-π*emissive state based on the HOMO and LUMO orbitals of the perylene chromophore, and a ligand-to-ligand charge-transfer (more intense for the Pt(II) complex) that explains the observed influence of the metal on the absorption properties.

  13. Efficient energy-level modification of novel pyran-annulated perylene diimides for photocatalytic water splitting.

    PubMed

    Wang, Ran; Li, Gang; Zhang, Andong; Wang, Wen; Cui, Guanwei; Zhao, Jianfeng; Shi, Zhiqiang; Tang, Bo

    2017-06-22

    We design and synthesize four pyran-embedded perylene diimide (PDI) compounds through a straightforward methodology. UV-driven photocatalytic water splitting using the compounds as photocatalysts demonstrates that the highest photocatalytic H2 evolution rate under UV light is 0.90 mmol g(-1) h(-1), which paves the way towards organic photoresponsive materials.

  14. Multichromic Bis-Axially Extended Perylene Chromophore with Schiff Bases: Synthesis, Characterization and Electrochemical Studies.

    PubMed

    Shabir, Ghulam; Saeed, Aamer; Arshad, Muhammad; Zahid, Muhammad

    2016-11-01

    In the present paper a novel way of symmetric conjugation extension along molecular axes of perylene dianhydride chromophore has been devised to achieve lengthy delocalized electronic species exhibiting red shifted absorption and emission of UV-Visible radiations. During synthetic pathway free amino Schiff bases of novel aldehydes with 4-amino acetanilide have been condensed with perylene dianhydride in quinoline at high temperature. Bis perylene diimide Schiff bases (5a-e) have been synthesized which showed absorption λmax at 461-526 nm and emission at 525-550 nm. Structures of newly obtained compounds have been confirmed by (1)H and (13)C-NMR studies. Cyclic voltammetric analysis of these dyes exhibited oxidation and reduction peaks which provide indirect evidence for their potential utility as n-type material for sensitization of semiconductors in solar cells. LUMO and HOMO energy levels were found in the range of -4.21 to -5.20 and -6.75 to -7.57 eV, respectively. Graphical Abstract Multi chromic bis-axially extended perylene chromophore with Schiff bases, synthesis characterization and electrochemical studies. Ghulam Shabir, Aamer Saeed, Muhammad Arshad and Muhammad Zahid.

  15. Thionated perylene diimides with intense absorbance in the near-IR.

    PubMed

    Llewellyn, Ben A; Davies, E Stephen; Pfeiffer, Constance R; Cooper, Mick; Lewis, William; Champness, Neil R

    2016-02-04

    A synthetic strategy involving a combination of tetra-thionation and amine substitution in the bay region of a perylene diimide (PDI) leads to remarkable examples of neutral PDIs with intense absorption maxima in the near infrared. Generation of the corresponding monoanions red shifts the absorption profile to give short-wavelength infrared bands.

  16. Induced Crystallization of Perovskites by a Perylene Underlayer for High-Performance Solar Cells.

    PubMed

    Wang, Zhao-Kui; Gong, Xiu; Li, Meng; Hu, Yun; Wang, Jin-Miao; Ma, Heng; Liao, Liang-Sheng

    2016-05-24

    Perovskite crystallization and interface engineering are regarded as the most crucial factors in achieving high-performance planar heterojunction (PHJ) perovskite solar cells (PSCs). Herein, we demonstrate a thin perylene underlayer via a solution-processable method. By using branch-shaped perylene film as a seed-mediated underlayer, crystalline perovskites with fabric morphology can be formed, which allows for obvious improvement in absorption by a light scattering effect. With its deep highest occupied molecular orbital (HOMO) level, perylene also plays an important role in the energy-level tailoring of poly(3,4-ethylenedioxythiophene): poly(styrenesulphonate) ( PSS) and CH3NH3PbIxCl3-x. In addition, perylene and perovskites form a fully crystalline heterojunction, which is beneficial for minimizing the defect and trap densities. Due to these merits, a maximum power conversion efficiency of 17.06% with improved cell stability is achieved. The finding in this work provides a simple route to control perovskite crystallizaition and to optimize the interfaces in PHJ PSCs simultaneously.

  17. Photoinduced processes in self-assembled porphyrin/perylene bisimide metallosupramolecular boxes.

    PubMed

    Indelli, M Teresa; Chiorboli, Claudio; Scandola, Franco; Iengo, Elisabetta; Osswald, Peter; Würthner, Frank

    2010-11-18

    Two new supramolecular boxes, (ZnMC)(2)(rPBI)(2) and (ZnMC)(2)(gPBI)(2), have been obtained by axial coordination of N,N'-dipyridyl-functionalized perylene bisimide (PBI) dyes to the zinc ion centers of two 2+2 porphyrin metallacycles (ZnMC = [trans,cis,cis-RuCl(2)(CO)(2)(Zn·4'-cis-DPyP)](2)). The two molecular boxes involve PBI pillars with different substituents at the bay area: the "red" PBI (rPBI = N,N'-di(4-pyridyl)-1,6,7,12-tetra(4-tert-butylphenoxy)perylene-3,4:9,10-tetracarboxylic acid bisimide) containing tert-butylphenoxy substituents and the "green" PBI (gPBI = N,N'-di(4-pyridyl)-1,7-bis(pyrrolidin-1-yl)perylene-3,4:9,10-tetracarboxylic acid bisimide) bearing pyrrolidinyl substituents. Due to the rigidity of the modules and the simultaneous formation of four pyridine-zinc bonds, these discrete adducts self-assemble quantitatively and are remarkably stable in dichloromethane solution. The photophysical behavior of the new supramolecular boxes has been studied in dichloromethane by emission spectroscopy and ultrafast absorption techniques. A different photophysical behavior is observed for the two systems. In (ZnMC)(2)(rPBI)(2), efficient electron transfer quenching of both perylene bisimide and zinc porphyrin chromophores is observed, leading to a charge separated state, PBI(-)-Zn(+), in which a perylene bisimide unit is reduced and zinc porphyrin is oxidized. In the deactivation of the perylene bisimide localized excited state, an intermediate zwitterionic charge transfer state of type PBI(-)-PBI(+) seems to play a relevant role. In (ZnMC)(2)(gPBI)(2), singlet energy transfer from the Zn porphyrin chromophores to the perylene bisimide units occurs with an efficiency of 0.7. This lower than unity value is due to a competing electron transfer quenching, leading to the charge separated state PBI(-)-Zn(+). The distinct photophysical behavior of these two supramolecular boxes is interpreted in terms of energy changes occurring upon replacement of the "red" r

  18. Synthesis and spectroscopic studies of the aminoglycoside (neomycin)--perylene conjugate binding to human telomeric DNA.

    PubMed

    Xue, Liang; Ranjan, Nihar; Arya, Dev P

    2011-04-12

    Synthesis of a novel perylene-neomycin conjugate (3) and the properties of its binding to human telomeric G-quadruplex DNA, 5'-d[AG3(T2AG3)3] (4), are reported. Various spectroscopic techniques were employed to characterize the binding of conjugate 3 to 4. A competition dialysis assay revealed that 3 preferentially binds to 4, in the presence of other nucleic acids, including DNA, RNA, DNA-RNA hybrids, and other higher-order structures (single strands, duplexes, triplexes, other G-quadruplexes, and the i-motif). UV thermal denaturation studies showed that thermal stabilization of 4 increases as a function of the increasing concentration of 3. The fluorescence intercalator displacement (FID) assay displayed a significantly tighter binding of 3 with 4 as compared to its parent constituents [220-fold stronger than neomycin (1) and 4.5-fold stronger than perylene diamine (2), respectively]. The binding of 3 with 4 resulted in pronounced changes in the molar ellipticity of the DNA absorption region as confirmed by circular dichroism. The UV-vis absorption studies of the binding of 3 to 4 resulted in a red shift in the spectrum of 3 as well as a marked hypochromic change in the perylene absorption region, suggesting that the ligand-quadruplex interaction involves stacking of the perylene moiety. Docking studies suggest that the perylene moiety serves as a bridge that end stacks on 4, making contacts with two thymine bases in the loop, while the two neomycin moieties branch into the grooves of 4.

  19. Design of Acceptors with Suitable Frontier Molecular Orbitals to Match Donors via Substitutions on Perylene Diimide for Organic Solar Cells

    PubMed Central

    Lv, Xiaoli; Li, Zhuoxin; Li, Songyang; Luan, Guoyou; Liang, Dadong; Tang, Shanshan; Jin, Ruifa

    2016-01-01

    A series of perylene diimide (PDI) derivatives have been investigated at the CAM-B3LYP/6-31G(d) and the TD-B3LYP/6-31+G(d,p) levels to design solar cell acceptors with high performance in areas such as suitable frontier molecular orbital (FMO) energies to match oligo(thienylenevinylene) derivatives and improved charge transfer properties. The calculated results reveal that the substituents slightly affect the distribution patterns of FMOs for PDI-BI. The electron withdrawing group substituents decrease the FMO energies of PDI-BI, and the electron donating group substituents slightly affect the FMO energies of PDI-BI. The di-electron withdrawing group substituents can tune the FMOs of PDI-BI to be more suitable for the oligo(thienylenevinylene) derivatives. The electron withdrawing group substituents result in red shifts of absorption spectra and electron donating group substituents result in blue shifts for PDI-BI. The –CN substituent can improve the electron transport properties of PDI-BI. The –CH3 group in different positions slightly affects the electron transport properties of PDI-BI. PMID:27187370

  20. Design of Acceptors with Suitable Frontier Molecular Orbitals to Match Donors via Substitutions on Perylene Diimide for Organic Solar Cells.

    PubMed

    Lv, Xiaoli; Li, Zhuoxin; Li, Songyang; Luan, Guoyou; Liang, Dadong; Tang, Shanshan; Jin, Ruifa

    2016-05-13

    A series of perylene diimide (PDI) derivatives have been investigated at the CAM-B3LYP/6-31G(d) and the TD-B3LYP/6-31+G(d,p) levels to design solar cell acceptors with high performance in areas such as suitable frontier molecular orbital (FMO) energies to match oligo(thienylenevinylene) derivatives and improved charge transfer properties. The calculated results reveal that the substituents slightly affect the distribution patterns of FMOs for PDI-BI. The electron withdrawing group substituents decrease the FMO energies of PDI-BI, and the electron donating group substituents slightly affect the FMO energies of PDI-BI. The di-electron withdrawing group substituents can tune the FMOs of PDI-BI to be more suitable for the oligo(thienylenevinylene) derivatives. The electron withdrawing group substituents result in red shifts of absorption spectra and electron donating group substituents result in blue shifts for PDI-BI. The -CN substituent can improve the electron transport properties of PDI-BI. The -CH₃ group in different positions slightly affects the electron transport properties of PDI-BI.

  1. Alternate monolayers of CdSe nanocrystals and perylene tetracarboxylate: quantum dot hypersensitization for dye-sensitized solar cells.

    PubMed

    Vercelli, B; Zotti, G; Berlin, A

    2012-06-27

    Mono- and multilayers from CdSe nanocrystal dispersion and perylene tetracarboxylate solution are reported for the first time. The layers were investigated by UV-visible spectroscopy, cyclic voltammetry, photoconductivity, and photoelectrochemical techniques. The n-type organic semiconductor gives enhanced photoconductivity to the CdSe-NC multilayer structure. The photoactive perylene monolayer acts also as hypersensitizer of CdSe-NC structures. The perylene-modified CdSe-NC monolayer on indium tin oxide (ITO) electrode in a three-electrode photoelectrochemical cell upon illumination in the presence of oxygen generates an intense steady photocurrent as high as 10-20 times that expected from the individual contributions of perylene and CdSe-NCs. The hypersensitization mechanism is discussed on the basis of the energy level diagram of the components.

  2. Investigation of the spontaneous emission rate of perylene dye molecules encapsulated into three-dimensional nanofibers via FLIM method

    NASA Astrophysics Data System (ADS)

    Acikgoz, Sabriye; Demir, Mustafa M.; Yapasan, Ece; Kiraz, Alper; Unal, Ahmet A.; Inci, M. Naci

    2014-09-01

    The decay dynamics of perylene dye molecules encapsulated in polymer nanofibers produced by electrospinning of polymethyl methacrylate are investigated using a confocal fluorescence lifetime imaging microscopy technique. Time-resolved experiments show that the fluorescence lifetime of perylene dye molecules is enhanced when the dye molecules are encapsulated in a three-dimensional photonic environment. It is hard to produce a sustainable host with exactly the same dimensions all the time during fabrication to accommodate dye molecules for enhancement of spontaneous emission rate. The electrospinning method allows us to have a control over fiber diameter. It is observed that the wavelength of monomer excitation of perylene dye molecules is too short to cause enhancement within nanofiber photonic environment of 330 nm diameters. However, when these nanofibers are doped with more concentrated perylene, in addition to monomer excitation, an excimer excitation is generated. This causes observation of the Purcell effect in the three-dimensional nanocylindrical photonic fiber geometry.

  3. Investigation of intermolecular interactions in perylene films on Au(111) by infrared spectroscopy

    NASA Astrophysics Data System (ADS)

    Ding, Li; Schulz, Philip; Farahzadi, Azadeh; Shportko, Kostiantyn V.; Wuttig, Matthias

    2012-02-01

    Intermolecular interactions in crystalline perylene films on Au(111) have been investigated by Fourier transform infrared spectroscopy. Dimer modes of vibrations are observed in the crystalline film, in contrast to the monomer modes found for isolated perylene molecules. These dimers are formed via hydrogen bonding in the sandwich herringbone structure of the crystalline α-phase. Davydov splitting of both the monomer and the dimer modes is observed due to resonance dynamic intermolecular interaction. The splitting of monomer modes into three distinct vibrations and the occurrence of the dimer modes confirm that the film crystallizes in the α phase, which is in line with the x-ray diffraction results. The frequency shift and band broadening at elevated temperature have been attributed to the cubic and quartic anharmonic interactions.

  4. Self-assembled aggregates of amphiphilic perylene diimide-based semiconductor molecules: effect of morphology on conductivity.

    PubMed

    Chen, Yanli; Feng, Yajuan; Gao, Jian; Bouvet, Marcel

    2012-02-15

    Two amphiphilic perylenetetracarboxylic diimide derivatives modified with different side chains at imide nitrogen, N-n-hexyl-N'-(2-hydroxyethyl)-1,7-di(4'-t-butyl)phenoxy-perylene-3,4:9,10-tetracarboxylic diimide (PDI 1) and N,N'-di(2-hydroxyethyl)-1,7-di(4'-t-butyl)phenoxy-perylene-3,4:9,10-tetracarboxylic diimide (PDI 2), were fabricated into organic nanostructures via solution-phase self-assembly. Their self-assembling properties in methanol and n-hexane have been comparatively studied by electronic absorption, fluorescence, and Fourier transform infrared spectroscopy (FT-IR). The morphologies and structures of the self-assemblies were examined by scanning electronic microscopy (SEM), atomic force microscopy (AFM), as well as X-ray diffraction (XRD) techniques. The conducting properties were evaluated by current-voltage (I-V) measurements. Due to the presence of different number of hydroxyethyl groups in the molecule of PDI 1 and PDI 2, the self-assembly of the two molecules in methanol and n-hexane results in nanostructures with distinctly different morphology as follows: nanobelts and nanoleaves for PDI 1 and nanobelt dendrites and nanosheets for PDI 2, respectively. Analysis of the spectral change for the aggregates relative to that of monomeric PDI in solution revealed that in polar and apolar solvents, both nanobelts and nanoleaves precipitated from PDI 1 adopt the H aggregation mode, whereas nanobelt dendrites and nanosheets from PDI 2 adopt H and J aggregation mode, respectively, implying the effect of both side-chain substituent and solvent on tuning the intermolecular stacking. Furthermore, the conductivity of the aggregates of either PDI 1 or PDI 2 from methanol is more than ca. 1 order of magnitude higher than those from n-hexane. In particular, the well-defined, one-dimensional (1D) nanobelts of PDI 1 show excellent semiconducting property with the electrical conductivity as high as 3.3×10(-3) S cm(-1), which might serve as promising candidates for

  5. Highly Soluble Monoamino-Substituted Perylene Tetracarboxylic Dianhydrides: Synthesis, Optical and Electrochemical Properties

    PubMed Central

    Chen, Kew-Yu; Chang, Che-Wei

    2014-01-01

    Three dialkylamino-substituted perylene tetracarboxylic dianhydrides with different n-alkyl chain lengths (n = 6, 12 or 18), 1a–1c, were synthesized under mild conditions in high yields and were characterized by 1H NMR, 13C NMR and high resolution mass spectroscopy. Their optical and electrochemical properties were measured using UV-Vis and emission spectroscopic techniques, as well as cyclic voltammetry (CV). This is the first time that the structures and the properties of monoamino-substituted perylene tetracarboxylic dianhydrides have been reported. These molecules show a deep green color in both solution and the solid state and are soluble in most organic solvents. They all show a unique charge transfer emission in the near-infrared region, and the associated peaks exhibit solvatochromism. The dipole moments of the compounds have been estimated using the Lippert-Mataga equation, and upon excitation, they show slightly larger dipole moment changes than those of corresponding perylene diimides, 2a–2c. Additionally, Compounds 1a–1c undergo two quasi-reversible one-electron oxidations and two quasi-reversible one-electron reductions in dichloromethane at modest potentials. Complementary density functional theory calculations performed on these chromophores are reported in order to gain more insight into their molecular structures and optical properties. PMID:25493474

  6. Understanding ground- and excited-state properties of perylene tetracarboxylic acid bisimide crystals by means of quantum chemical computations.

    PubMed

    Zhao, Hong-Mei; Pfister, Johannes; Settels, Volker; Renz, Manuel; Kaupp, Martin; Dehm, Volker C; Würthner, Frank; Fink, Reinhold F; Engels, Bernd

    2009-11-04

    Quantum chemical protocols explaining the crystal structures and the visible light absorption properties of 3,4:9,10-perylene tetracarboxylic acid bisimide (PBI) derivates are proposed. Dispersion-corrected density functional theory has provided an intermolecular potential energy of PBI dimers showing several energetically low-lying minima, which corresponds well with the packing of different PBI dyes in the solid state. While the dispersion interaction is found to be crucial for the binding strength, the minimum structures of the PESs are best explained by electrostatic interactions. Furthermore, a method is introduced, which reproduces the photon energies at the absorption maxima of PBI pigments within 0.1 eV. It is based on time-dependent Hartree-Fock (TD-HF) excitation energies calculated for PBI dimers with the next-neighbor arrangement in the pigment and incorporates crystal packing effects. This success provides clear evidence that the electronically excited states, which determine the color of these pigments, have no significant charge-transfer character. The developed protocols can be applied in a routine manner to understand and to predict the properties of such pigments, which are important materials for organic solar cells and (opto-)electronic devices.

  7. Perylene bisimide dimer aggregates: fundamental insights into self-assembly by NMR and UV/Vis spectroscopy.

    PubMed

    Shao, Changzhun; Grüne, Matthias; Stolte, Matthias; Würthner, Frank

    2012-10-22

    A novel perylene bisimide (PBI) dye bearing one solubilizing dialkoxybenzyl and one bulky 2,5-di-tert-butylphenyl substituent was synthesized and its aggregation behavior was analyzed by NMR and UV/Vis spectroscopy in various chloroform/methylcyclohexane (MCH) solvent mixtures. In the presence of no less than 10 vol % chloroform, exclusive self-assembly of this PBI dye into π-stacked dimers was unambiguously confirmed by means of both concentration-dependent (1) H NMR and UV/Vis spectroscopic experiments. Based on ROESY NMR, a well-defined π-stacked dimer structure was determined and further corroborated by molecular modeling studies. By varying the solvent composition of chloroform and MCH, the solvent effects on the Gibbs free energy of PBI dimerization were elucidated and showed a pronounced nonlinearity between lower and higher MCH contents. This observation could be related to a further growth process of dimers into larger aggregates that occurs in the absence of chloroform, which is required to solvate the aromatic π surfaces. With the help of a single-crystal structure analysis for a related PBI dye, a structural model could be derived for the extended aggregates that are still composed of defined π-π-stacked PBI dimer entities.

  8. Detection of silver(I) ions based on the controlled self-assembly of a perylene fluorescence probe.

    PubMed

    Yang, Yue; Li, Wenying; Qi, Hong; Zhang, Qingfeng; Chen, Jian; Wang, Yan; Wang, Bin; Wang, Shujie; Yu, Cong

    2012-11-01

    In the current work, we report a label-free fluorescence turn-on approach for the sensitive and selective sensing of Ag(+). A cationic perylene derivative, compound A, was used as the fluorescence probe. Compound A monomer is strongly fluorescent, and the fluorescence can be efficiently quenched through self-aggregation (self-assembly). A cytosine (C)-rich oligonucleotide, oligo-C, was employed. In the absence of Ag(+), oligo-C induced strong compound A aggregation due to electrostatic interactions in aqueous media, and very weak fluorescence signal was detected. However, in the presence of Ag(+), the specific interactions between oligo-C and Ag(+) induced hairpin structure formation of oligo-C through C-Ag(+)-C bonding interactions. Oligo-C binding to compound A aggregates was weakened; therefore, compound A monomer could be released and detected. The intensity of the fluorescence signal was directly related to the amount of Ag(+) added to the assay solution. Our method is highly sensitive-a limit of detection of 5nM was obtained-and also very selective. Ag(+) detection in complex sample mixtures was also demonstrated.

  9. Label-free selective sensing of mercury(II) via reduced aggregation of the perylene fluorescent probe.

    PubMed

    Wang, Bin; Wang, Fangyuan; Jiao, Huping; Yang, Xiangyu; Yu, Cong

    2010-08-01

    In the present work, we report a fluorescence turn-on approach for the sensitive and selective detection of Hg(2+). A cationic perylene derivative (compound 1) was used as the fluorescence probe, and a thymine-rich oligonucleotide (oligo-M) was employed for the specific interaction with Hg(2+). Compound 1 shows strong tendency to self-aggregate into linear chain structures in aqueous media because of the pi-pi stacking interactions of its planar aromatic ring structure. The compound 1 free monomer is strongly fluorescent, whereas its aggregates are not fluorescent. When oligo-M and compound 1 were mixed, oligo-M induced strong compound 1 aggregation and resulted in significant fluorescence quenching. In the presence of Hg(2+), the specific interactions between oligo-M and Hg(2+) induced hairpin structure formation of oligo-M and thus weakened its binding to compound 1 aggregates. As a result, free probe monomers were released, and increased fluorescence was observed. The fluorescence intensity increase was in direct proportion to the concentration of Hg(2+) added. Our method provides a simple, fast, and efficient means for Hg(2+) quantification, it is highly sensitive with a limit of detection of 1 nM, and is also highly selective against other common metal ions.

  10. Core Perylene Diimide Designs via Direct Bay- and ortho-(Poly)trifluoromethylation: Synthesis, Isolation, X-Ray Structures, Optical and Electronic Properties

    SciTech Connect

    Clikeman, Tyler T.; Bukovsky, Eric V.; Wang, Xue-Bin; Chen, Yu-Sheng; Rumbles, Garry; Strauss, Steven H.; Boltalina, Olga V.

    2015-09-22

    We developed an efficient solvent- and catalyst-free direct polytrifluoromethylation of solid perylene-3,4,9,10-tetracarboxylic dianhydride that produced a new family of (poly)perfluoroalkyl bay- and ortho-substituted PDIs with two different imide substituents. Direct hydrogen substitution with CN group led to the synthesis of a cyanated perfluoroalkyl PDI derivative for the first time. Absorption, steady-state and time-resolved emission, X-ray diffraction, electrochemical, and gas-phase electron affinity data allowed for systematic studies of substitution effects at bay, ortho, and imide positions in the new PDIs. Solid-state packing showed remarkable variations in the intermolecular interactions that are important for charge transport and photophysical properties. Moreover, analysis of the electrochemical data for 143 electron poor PDIs, including newly reported compounds, revealed some general trends and peculiar effects from substituting electron-withdrawing groups at all three positions.

  11. Core Perylene Diimide Designs via Direct Bay and Ortho (Poly)trifluoromethylation: Synthesis, Isolation, X-ray Structures, Optical and Electronic Properties

    SciTech Connect

    Clikeman, Tyler T.; Bukovsky, Eric V.; Wang, Xue B.; Chen, Yu-Sheng; Rumbles, Garry; Strauss, Steven H.; Boltalina, Olga V.

    2015-09-22

    We developed an efficient solvent- and catalyst-free direct polytrifluoromethylation of solid perylene-3,4,9,10-tetracarboxylic dianhydride that produced a new family of (poly)perfluoroalkyl bay and ortho substituted PDIs with two different imide substituents. Direct hydrogen substitution with CN group led to the synthesis of a cyanated perfluoroalkyl PDI derivative for the first time. Absorption, steady-state and time-resolved emission, X-ray diffraction, electrochemical, and gas-phase electron affinity data allowed for systematic studies of substitution effects at bay, ortho, and imide positions in the new PDIs. Solid-state packing showed remarkable variations in the intermolecular interactions that are important for charge transport and photophysical properties. Analysis of the electrochemical data for 143 electron poor PDIs, including newly reported compounds, revealed some general trends and peculiar effects of electron withdrawing group substitution at all three positions.

  12. Molecular size, shape, and electric charges: essential for perylene bisimide-based DNA intercalator to localize in cell nuclei and inhibit cancer cell growth.

    PubMed

    Xu, Zejun; Cheng, Wenyu; Guo, Kunru; Yu, Jieshi; Shen, Jie; Tang, Jun; Yang, Wantai; Yin, Meizhen

    2015-05-13

    The molecular properties concerning size, shape, and electric charges of the planar aromatic DNA intercalators are still poorly understood. Herein, a series of water-soluble perylene bisimide (PBI) derivatives containing a rigid and planar aromatic nanoscaffold with different size, shape, and electric charges were synthesized. Using histochemistry and cell viability assays on animal tissues and cancer cells, we revealed the molecular properties required for successful DNA intercalators to localize in cell nuclei and inhibit cancer cells. Small molecular size and the strong polarity of hydrophilic substituents are prerequisites for PBI-based DNA intercalators. A large number of charges facilitate the nucleic accumulation of these DNA intercalators, while fewer charges and planar aromatic nanoscaffold more efficiently inhibit cancer cell growth.

  13. XPS and STEM Study of the Interface Formation between Ultra-Thin Ru and Ir OER Catalyst Layers and Perylene Red Support Whiskers

    SciTech Connect

    Atanasoska, Liliana; Cullen, David A; Hester, Amy E; Atanasoski, Radoslav

    2013-01-01

    The interface formation between perylene red (PR) and ruthenium or iridium OER catalysts has been studied systematically by XPS and STEM. The OER catalyst over-layers with thicknesses ranging from ~0.1 to ~50 nm were vapor deposited onto PR ex-situ. As seen by STEM, Ru and Ir form into nanoparticles, which agglomerate with increased loading. XPS data show a strong interaction between Ru and PR. Ir also interacts with PR although not to the extent seen for Ru. At low coverages, the entire Ru deposit is in the reacted state while a small portion of the deposited Ir remains metallic. Ru and Ir bonding occur at the PR carbonyl sites as evidenced by the attenuation of carbonyl photoemission and the emergence of new peak assigned to C-O single bond. The curve fitting analysis and the derived stoichiometry indicates the formation of metallo-organic bonds. The co-existence of oxide bonds is also apparent.

  14. Tuning the electronic nature of mono-bay alkynyl-phenyl-substituted perylene bisimides: synthesis, structure, and photophysical properties.

    PubMed

    Mishra, Ruchika; Lim, Jong Min; Son, Minjung; Panini, Piyush; Kim, Dongho; Sankar, Jeyaraman

    2014-05-05

    Perylene bisimide (PBI) derivatives with various alkynyl-phenyl substituents at a single bay position have been synthesised by Sonogashira coupling. NMR spectroscopic studies reveal the unsymmetric nature of the dyads. All of the dyads undergo two reversible reductions, which demonstrates their structural and electrochemical rigidity. The synthesised dyads show a remarkable redshift in their absorption maxima and sharp vibronic progression. Electron-rich substituents facilitate efficient charge transfer from the substituent HOMO to the electron-deficient PBI core. The most interesting spectral signatures were exhibited by a PBI with a strongly electron-donating ethynyl(dimethylaminophenyl) substituent. The steady-state features of this PBI showed a broad absorption that covered almost the whole visible region with no emission. A twisted intramolecular charge-transfer (TICT) process, related to the rotational motion of ethynyl(dimethylaminophenyl) PBI, was also demonstrated. Computational investigations shed light on the coplanarity of the various substituents with respect to the PBI core; the PBI core itself remains flat without any noticeable deformation even after mono-functionalisation. This illustrates that mono-functionalisation exerts meagre steric hindrance on the bay positions relative to disubstituted analogues. Despite several previous reports on the structural characterisation of 1,7-disubstituted PBI derivatives, we present the first structural characterisation of a mono-bay ethynyl-phenyl substituted PBI. The solid-state structure of the phenyl derivative has a flat PBI core without any noticeable steric constraints from the substituents, as predicted. In contrast, single-crystal X-ray analysis for the mono-bromo bay-substituted PBI shows that the bromine substituent is not in the plane of the PBI core. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  15. Room-Temperature Columnar Nematic and Soft Crystalline Columnar Assemblies of a New Series of Perylene-Centred Disc Tetramers.

    PubMed

    Bala, Indu; Gupta, Santosh Prasad; De, Joydip; Pal, Santanu Kumar

    2017-06-28

    Three new oligomeric perylene (PE) tetraester derivatives, consisting of a PE-based core with four pentaalkynylbenzene units attached through flexible alkyl spacers, are reported. These derivatives were investigated for their mesomorphic properties and thermal, photophysical, and electrochemical behaviour. Small- (SAXS) and wide-angle X-ray scattering (WAXS) studies were performed to deduce the exact nature of the phases. To resolve overlapping reflections and facilitate their indexing, grazing-incidence SAXS/WAXS experiments were carried out on oriented thin films on indium tin oxide (ITO)-coated glass substrate. The corresponding electron density maps were derived from the intensities observed in the diffraction pattern. Whereas compounds with shorter alkyl spacers (n=6 and 8) were found to self-organise into soft crystalline columnar assemblies, those with longer spacers (n=10) exhibited a liquid-crystalline columnar nematic mesophase. This is in contrast to previous reports that describe highly symmetric 2D hexagonal and rectangular columnar structures of PE-based mesogens. The morphology of self-assembly was found to transform from soft crystal columnar to nematic columnar phase through simple variation in the number of alkyl spacers. All compounds exhibited excellent fluorescence emission properties with a very good quantum yield and large band gap. Apart from high solubility and good quantum yield, these compounds can serve as standards to measure quantum yields of unknown samples. These compounds also display green luminescence and may find applications for various optoelectronic devices. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

  16. Fluorescence resonance energy transfer from pyrene to perylene labels for nucleic acid hybridization assays under homogeneous solution conditions

    PubMed Central

    Masuko, Masayuki; Ohuchi, Shohkichi; Sode, Koji; Ohtani, Hiroyuki; Shimadzu, Akira

    2000-01-01

    We characterized the fluorescence resonance energy transfer (FRET) from pyrene (donor) to perylene (acceptor) for nucleic acid assays under homogeneous solution conditions. We used the hybridization between a target 32mer and its complementary two sequential 16mer deoxyribonucleotides whose neighboring terminals were each respectively labeled with a pyrene and a perylene residue. A transfer efficiency of ~100% was attained upon the hybridization when observing perylene fluorescence at 459 nm with 347-nm excitation of a pyrene absorption peak. The Förster distance between two dye residues was 22.3 Å (the orientation factor of 2/3). We could change the distance between the residues by inserting various numbers of nucleotides into the center of the target, thus creating a gap between the dye residues on a hybrid. Assuming that the number of inserted nucleotides is proportional to the distance between the dye residues, the energy transfer efficiency versus number of inserted nucleotides strictly obeyed the Förster theory. The mean inter-nucleotide distance of the single-stranded portion was estimated to be 2.1 Å. Comparison between the fluorescent properties of a pyrene–perylene pair with those of a widely used fluorescein–rhodamine pair showed that the pyrene–perylene FRET is suitable for hybridization assays. PMID:10734211

  17. Synthesis, Characterization, Physical Properties, and OLED Application of Single BN-Fused Perylene Diimide.

    PubMed

    Li, Gang; Zhao, Yongbiao; Li, Junbo; Cao, Jun; Zhu, Jia; Sun, Xiao Wei; Zhang, Qichun

    2015-01-02

    It is very challenging to introduce azaborine into an electron-deficient arene system because of unfavorable intramolecular electrophilic borylation reaction. In this report, we adopted a straightforward methodology to construct a large BN-embedded π-system based on perylene diimide (PDI), which is the first BN-annulation example with highly electron-withdrawing polycyclic aromatic hydrocarbons. The physical properties of the as-prepared N,N-dicyclohexyl-1-aza-12-bora-benzoperylene diimide (PDI-1BN) have been fully studied, and its sensing behavior to fluoride ion as well as its OLED performance was also investigated.

  18. Understanding the emission pattern produced by focused laser beam excitation of perylene square single crystals

    NASA Astrophysics Data System (ADS)

    Takazawa, Ken

    2017-01-01

    Square single crystals of perylene (α-crystals) exhibit a peculiar emission pattern when excited by a focused laser beam. Fluorescence spots are observed at the point of excitation and at four edges, with the lines connecting the excitation point and edge emissions being perpendicular to the edges irrespective of the excitation position. Two different mechanisms explaining this emission pattern have been proposed so far. Our newly designed experiment and analysis revealed that the involved mechanism features a combination of the waveguide effect and total internal reflection by crystal edges.

  19. Fluorescent labelling of DNA on superparamagnetic nanoparticles by a perylene bisimide derivative for cell imaging.

    PubMed

    Maltas, Esra; Malkondu, Sait; Uyar, Pembegul; Ozmen, Mustafa

    2015-03-01

    N,N'-Bis[tris-(2-aminoethyl) amine]-3,4,9,10-perylenetetracarboxylic diimide (PBI-TRIS), nonfluorescent dye was used to fluorescent labelling of DNA. For this aim, (3-aminopropyl) triethoxysilane (APTS) modified superparamagnetic iron oxide nanoparticles (SPIONs) were synthesized to provide a suitable surface for binding of DNA. Amine functionalized nanoparticles showed a high immobilization capacity (82.70%) at 25mg of nanoparticle concentration for Calf thymus DNA. Binding capacity of PBI-TRIS to DNA-SPION was also found as 1.93μM on 25mg of nanoparticles by using UV-vis spectroscopy. Binding of PBI-TRIS to DNA onto nanoparticles was also characterized by scanning electron microscopy and infrared spectroscopy. The confocal images of PBI-TRIS labelled DNA-SPION and breast cells were taken at 488 and 561.7nm of excitation wavelengths. Cell image was also compared with a commercial dye, DAPI at 403.7nm of excitation wavelength. Results showed that PBI-TRIS can be used for cell staining. Copyright © 2014 Elsevier B.V. All rights reserved.

  20. Tuning the color and photostability of perylene diimides inside polymer nanoparticles: towards biodegradable substitutes of quantum dots

    NASA Astrophysics Data System (ADS)

    Trofymchuk, Kateryna; Reisch, Andreas; Shulov, Ievgen; Mély, Yves; Klymchenko, Andrey S.

    2014-10-01

    Fluorescent organic nanoparticles (NPs) are attractive alternatives to quantum dots due to their potential biodegradability. However, preparation of fluorescent organic NPs is challenging due to the problem of self-quenching of the encapsulated dyes. Moreover, the photostability of organic dyes is much lower than that of quantum dots. To address both problems, we studied encapsulation into biodegradable polymer PLGA NPs of perylene diimide (PDI) derivatives, which are among the most photostable dyes reported to date. Two PDIs were tested, one bearing bulky hydrophobic groups at the imides, while the other was substituted in both imide and bay regions (Lumogen Red). Encapsulation of the former resulted in aggregation, which was accompanied by the emission color change from green to red, some decrease in the fluorescence quantum yield and a significant drop in the photostability, unexpected for PDI dyes. In contrast, Lumogen Red showed nearly no aggregation inside polymer NPs and maintained high quantum yield and photostability. According to wide-field fluorescence microscopy with a 532 nm excitation laser, our 40 nm PLGA NPs loaded with 1 wt% Lumogen Red were >10-fold brighter than quantum dots (QD-585). These NPs were stable in biological media, including serum, and entered spontaneously into HeLa cells by endocytosis showing no sign of cytotoxicity. Due to excellent photostability, these nanoparticles could be considered as biodegradable substitutes of quantum dots in bioimaging.Fluorescent organic nanoparticles (NPs) are attractive alternatives to quantum dots due to their potential biodegradability. However, preparation of fluorescent organic NPs is challenging due to the problem of self-quenching of the encapsulated dyes. Moreover, the photostability of organic dyes is much lower than that of quantum dots. To address both problems, we studied encapsulation into biodegradable polymer PLGA NPs of perylene diimide (PDI) derivatives, which are among the most

  1. Ultrafast intramolecular charge transfer of formyl perylene observed using femtosecond transient absorption spectroscopy.

    PubMed

    Mohammed, Omar F

    2010-11-04

    The excited-state photophysics of formylperylene (FPe) have been investigated in a series of nonpolar, polar aprotic, and polar protic solvents. A variety of experimental and theoretical methods were employed including femtosecond transient absorption (fs-TA) spectroscopy with 130 fs temporal resolution. We report that the ultrafast intramolecular charge transfer from the perylene unit to the formyl (CHO) group can be facilitated drastically by hydrogen-bonding interactions between the carbonyl group oxygen of FPe and hydrogen-donating solvents in the electronically excited state. The excited-state absorption of FPe in methanol (MeOH) is close to the reported perylene radical cation produced by bimolecular quenching by an electron acceptor. This is a strong indication for a substantial charge transfer in the S(1) state in protic solvents. The larger increase of the dipole moment change in the protic solvents than that in aprotic ones strongly supports this observation. Relaxation mechanisms including vibrational cooling and solvation coupled to the charge-transfer state are also discussed.

  2. A turn-on fluorescent sensor for zinc and cadmium ions based on perylene tetracarboxylic diimide.

    PubMed

    Liu, Xiangjun; Zhang, Nan; Zhou, Jin; Chang, Tianjun; Fang, Canliang; Shangguan, Dihua

    2013-02-21

    In this paper, we describe a turn-on fluorescent probe for Zn(2+) and Cd(2+) ion detection and discrimination. This probe, N'-bis-(N,N-di-(2-pyridylmethyl)-ethane-1,2-diamine)-perylene-3,4,9,10-tetracarboxylic-diimide (PDI-DIDPA), exhibits very low fluorescence at pH above 6.0 due to the photo-induced electron transfer (PET) process from 2-pyridylmethyl-amine (DPA) to perylene tetracarboxylic diimide (PDI). Zn(2+) and Cd(2+) can chelate PDI-DIDPA to form a stable complex at pH 6.0-7.0 and 9.0 respectively, and inhibit the PET process, which result in the fluorescence recovery of PDI-DIDPA. This fluorescence turn-on behavior allows the detection of Zn(2+) in the range of 0.1-4.0 μM and Cd(2+) in the range of 0.1-5.0 μM. The limit of detection for Zn(2+) and Cd(2+) is as low as 32 nM and 48 nM. The high selectivity, high sensitivity and easy operation make this probe suitable for the rapid detection of Zn(2+) and Cd(2+) respectively. The different response of PDI-DIDPA to Zn(2+) and Cd(2+) at different pH makes it possible to discriminate Zn(2+) and Cd(2+) by simply adjusting the pH of the working solution.

  3. High resolution NEXAFS of perylene and PTCDI: a surface science approach to molecular orbital analysis.

    PubMed

    Fratesi, Guido; Lanzilotto, Valeria; Stranges, Stefano; Alagia, Michele; Brivio, Gian Paolo; Floreano, Luca

    2014-07-28

    We made use of synchrotron radiation to perform near edge X-ray absorption fine structure spectroscopy, NEXAFS, at the carbon K-edge of perylene and perylene-tetracarboxylic-diimide, PTCDI. Reference spectra measured for isolated molecules in the gas phase are compared with polarization dependent NEXAFS spectra measured on highly oriented thin films in order to study the symmetry of the molecular orbitals. The molecular overlayers are grown onto the rutile TiO2(110) surface for which the large anisotropic corrugation effectively drives the molecular orientation, while its dielectric nature prevents the rehybridization of the molecular orbitals. We employed density functional theory, DFT, calculations to disentangle the contribution of specific carbon atoms to the molecular density of states. Numerical simulations correctly predict the observed NEXAFS azimuthal dichroism of the σ* resonances above the ionization threshold, from which we determine the full geometric orientation of the overlayer molecules. A discrepancy observed for the spectral contribution of the imide carbon atom to the calculated unoccupied molecular orbitals has been explained in terms of initial state effects, as determined by Hartree-Fock corrections and in full agreement with the corresponding shift of the C 1s core level measured by X-ray photoelectron spectroscopy, XPS.

  4. Influence of a polarizable surrounding on the electronically excited states of aggregated perylene materials.

    PubMed

    Bellinger, Daniel; Settels, Volker; Liu, Wenlan; Fink, Reinhold F; Engels, Bernd

    2016-06-30

    To tune the efficiency of organic semiconductor devices it is important to understand limiting factors as trapping mechanisms for excitons or charges. An understanding of such mechanisms deserves an accurate description of the involved electronical states in the given environment. In this study, we investigate how a polarizable surrounding influences the relative positions of electronically excited states of dimers of different perylene dyes. Polarization effects are particularly interesting for these systems, because gas phase computations predict that the CT states lie slightly above the corresponding Frenkel states. A polarizable environment may change this energy order because CT states are thought to be more sensitive to a polarizable surrounding than Frenkel states. A first insight we got via a TD-HF approach in combination with a polarizable continuum model (PCM). These give limited insights because TD-HF overestimates excitation energies of CT states. However, SCS-CC2 approaches, which are sufficiently accurate, cannot easily be used in combination with continuum solvent models. Hence, we developed two approaches to combine gas phase SCS-CC2 results with solvent effects based on TD-HF computations. Their accuracies were finally checked via ADC(2)//COSMO computations. The results show that for perylene dyes a polarizable surrounding alone does not influence the energetic ordering of CT and Frenkel states. Variations in the energy order of the states only result from nuclear relaxation effects after the excitation process. © 2016 Wiley Periodicals, Inc.

  5. Thermo-reversible gelation of rod-coil and coil-rod-coil molecules based on poly(dimethyl siloxane) and perylene imides and self-sorting of the homologous pair.

    PubMed

    Dahan, Elianne; Sundararajan, Pudupadi R

    2014-08-07

    Organogels with perylene derivatives and phthalocyanines reported in the literature so far involve self-assembly promoted by hydrogen bonds, in addition to aromatic and van der Waals interactions. Although the self assembly of these types of molecules without a hydrogen bonding group in the structure occurs in solution or during crystallization, the gelation studies reported so far incorporated a hydrogen bonding pair of the type N-H···O=C in the structure of the molecule. We present a case of thermo-reversible gelation without a hydrogen bonding group in the structure of (1) a coil-rod-coil molecule based on perylenetetracarboxylic diimide (PTCDI) and poly(dimethyl siloxane) (PDMS) and (2) a rod-coil molecule with perylene dicarboxylic imide (PDI) and PDMS. However IR spectroscopy shows the presence of multiple types of hydrogen bonding between the solvents and the gelator molecules. In addition, publications so far on gelation of perylene diimide based molecules involve groups attached to both imide nitrogens and with or without substitution in the bay position. We discuss here the gelation with a Mono-substituted perylene imide. The PDMS segment was attached to one side of PDI (Mono-PDMS) or to both imide nitrogens of PTCDI (Di-PDMS). The Mono-PDMS is an inverse macromolecular surfactant applicable to non-aqueous systems, and the Di-PDMS is a Gemini surfactant. The PDMS segment that we attached to PTCDI here is longer than most substituents used by other authors. These molecules gel propylamine, as well as mixed solvents of hexane-water and diisopropylamine-water. Both hexane and diisopropylamine dissolve Mono-PDMS and Di-PDMS at room temperature and addition of water results in precipitation. However, heating the solution to about 70 °C, adding water (5-15 wt%) and slowly cooling the solution, lead to gelation. The Di-PDMS forms fibers which are not flat but curved as an eaves trough. The Mono-PDMS forms hollow spheres. Although the Mono-PDMS and Di

  6. Peptide-perylene diimide functionalized magnetic nano-platforms for fluorescence turn-on detection and clearance of bacterial lipopolysaccharides.

    PubMed

    Liu, Fang; Mu, Jing; Wu, Xiangyang; Bhattacharjya, Surajit; Yeow, Edwin Kok Lee; Xing, Bengang

    2014-06-14

    A simple and unique strategy has been successfully designed for sensitive detection and rapid clearance of bacterial lipopolysaccharides (LPS) by integration of core-shell Fe3O4@SiO2 magnetic nanoparticles with a perylene-diimide (PDI) conjugated LPS-recognition peptide.

  7. Synthesis of biocompatible glycodendrimer based on fluorescent perylene bisimides and its bioimaging.

    PubMed

    Wang, Ke-Rang; An, Hong-Wei; Rong, Rui-Xue; Cao, Zhi-Ran; Li, Xiao-Liu

    2014-04-01

    A novel water-soluble fluorescent glycodendrimer based on perylene bisimides is synthesized, which exhibits high fluorescence quantum yield of 54%. While the binding interactions of PBI-Man with Concanavalin A (Con A) are studied by fluorescence spectra and CD spectra, which show strong binding affinity for Con A with the binding constant of 3.8 × 10(7) m(-1) for monomeric mannose, nearly four orders of magnitude higher affinity than the monovalent mannose ligand. Furthermore, the fluorescence imaging of macrophage cell with PBI-Man is investigated, and shows selectively binding interaction with the mannose receptor-medicated cell entry. Moreover, the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl tetrazolium bromide (MTT) activities of PBI-Man show that PBI-Man as a biocompatible agent is noncytotoxic to living cells.

  8. Efficient host-guest energy transfer in polycationic cyclophane-perylene diimide complexes in water.

    PubMed

    Ryan, Seán T J; Del Barrio, Jesús; Ghosh, Indrajit; Biedermann, Frank; Lazar, Alexandra I; Lan, Yang; Coulston, Roger J; Nau, Werner M; Scherman, Oren A

    2014-06-25

    We report the self-assembly of a series of highly charged supramolecular complexes in aqueous media composed of cyclobis(4,4'-(1,4-phenylene)bispyridine-p-phenylene)tetrakis(chloride) (ExBox) and three dicationic perylene diimides (PDIs). Efficient energy transfer (ET) is observed between the host and guests. Additionally, we show that our hexacationic complexes are capable of further complexation with neutral cucurbit[7]uril (CB[7]), producing a 3-polypseudorotaxane via the self-assembly of orthogonal recognition moieties. ExBox serves as the central ring, complexing to the PDI core, while two CB[7]s behave as supramolecular stoppers, binding to the two outer quaternary ammonium motifs. The formation of the 3-polypseudorotaxane results in far superior photophysical properties of the central PDI unit relative to the binary complexes at stoichiometric ratios. Lastly, we also demonstrate the ability of our binary complexes to act as a highly selective chemosensing ensemble for the neurotransmitter melatonin.

  9. Atom Transfer Radical Polymerization of Functionalized Vinyl Monomers Using Perylene as a Visible Light Photocatalyst.

    PubMed

    Theriot, Jordan C; Ryan, Matthew D; French, Tracy A; Pearson, Ryan M; Miyake, Garret M

    2016-04-22

    A standardized technique for atom transfer radical polymerization of vinyl monomers using perylene as a visible-light photocatalyst is presented. The procedure is performed under an inert atmosphere using air- and water-exclusion techniques. The outcome of the polymerization is affected by the ratios of monomer, initiator, and catalyst used as well as the reaction concentration, solvent, and nature of the light source. Temporal control over the polymerization can be exercised by turning the visible light source off and on. Low dispersities of the resultant polymers as well as the ability to chain-extend to form block copolymers suggest control over the polymerization, while chain end-group analysis provides evidence supporting an atom-transfer radical polymerization mechanism.

  10. Rapid Energy Transfer Enabling Control of Emission Polarization in Perylene Bisimide Donor-Acceptor Triads.

    PubMed

    Menelaou, Christopher; ter Schiphorst, Jeroen; Kendhale, Amol M; Parkinson, Patrick; Debije, Michael G; Schenning, Albertus P H J; Herz, Laura M

    2015-04-02

    Materials showing rapid intramolecular energy transfer and polarization switching are of interest for both their fundamental photophysics and potential for use in real-world applications. Here, we report two donor-acceptor-donor triad dyes based on perylene-bisimide subunits, with the long axis of the donors arranged either parallel or perpendicular to that of the central acceptor. We observe rapid energy transfer (<2 ps) and effective polarization control in both dye molecules in solution. A distributed-dipole Förster model predicts the excitation energy transfer rate for the linearly arranged triad but severely underestimates it for the orthogonal case. We show that the rapid energy transfer arises from a combination of through-bond coupling and through-space transfer between donor and acceptor units. As they allow energy cascading to an excited state with controllable polarization, these triad dyes show high potential for use in luminescent solar concentrator devices.

  11. Quenching of the perylene fluorophore by stable nitroxide radical-containing macromolecules.

    PubMed

    Hughes, Barbara K; Braunecker, Wade A; Ferguson, Andrew J; Kemper, Travis W; Larsen, Ross E; Gennett, Thomas

    2014-10-30

    Stable nitroxide radical bearing organic polymer materials are attracting much attention for their application as next generation energy storage materials. A greater understanding of the inherent charge transfer mechanisms in such systems will ultimately be paramount to further advancements in the understanding of both intrafilm and interfacial ion- and electron-transfer reactions. This work is focused on advancing the fundamental understanding of these dynamic charge transfer properties by exploiting the fact that these species are efficient fluorescence quenchers. We systematically incorporated fluorescent perylene dyes into solutions containing the 2,2,6,6-tetramethylpiperidine-N-oxyl (TEMPO) radical and controlled their interaction by binding the TEMPO moiety into macromolecules with varying morphologies (e.g., chain length, density of radical pendant groups). In the case of the model compound, 4-oxo-TEMPO, quenching of the perylene excited state was found to be dominated by a dynamic (collisional) process, with a contribution from an apparent static process that is described by an ∼2 nm quenching sphere of action. When we incorporated the TEMPO unit into a macromolecule, the quenching behavior was altered significantly. The results can be described by using two models: (A) a collisional quenching process that becomes less efficient, presumably due to a reduction in the diffusion constant of the quenching entity, with a quenching sphere of action similar to 4-oxo-TEMPO or (B) a collisional quenching process that becomes more efficient as the radius of interaction grows larger with increasing oligomer length. This is the first study that definitively illustrates that fluorophore quenching by a polymer system cannot be explained using merely a classical Stern-Volmer approach but rather necessitates a more complex model.

  12. Synergetic Solvent Engineering of Film Nanomorphology to Enhance Planar Perylene Diimide-Based Organic Photovoltaics.

    PubMed

    Wang, Jialin; Liang, Ziqi

    2016-08-31

    Solvent additive has proven as a useful protocol for improving the film nanomorphology of polymer donor (D): fullerene acceptor (A) blends in bulk heterojunction (BHJ) photovoltaic cells. By contrast, the effect of such solvent additive on nonfullerene BHJ cells based on perylene diimide acceptor, for instance, is less effective because of their highly planar structure and strong π-aggregation in solid state. Here we choose N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (PDI) and thieno[3,4-b]thiophene-alt-benzodithiophene (PTB7) as a model D:A blend system to investigate how solvent engineering strategy synergistically impacts the blend film nanomorphology. Based on the differences of solvent volatility and solubility, various host solvents-chloroform (CF) and chlorobenzene (CB) and solvent additives-chloronaphthalene (CN) and 1,8-diiodooctane (DIO) are selected for comparative studies. It is found that the π-aggregation of PDIs can be largely suppressed by using low-boiling point (Tb) CF solvent, yet enlarged by using high-Tb CB. Moreover, CN additive provides good solubility of PDI molecules and hence reduces large PDI aggregates in CB system, while DIO exhibiting poor solubility works oppositely. By contrast, DIO that presents larger Tb difference with CF prolongs the film-forming, which assists in optimizing the PDI aggregation and increases the intermixed PTB7:PDI phases more significantly than CN in CF system, yielding the finest phase-separation morphology and balanced charge mobility. Consequently, the inverted BHJ cells based on CF-processed PTB7:PDI blend film with 0.4 vol % DIO exhibit the highest PCE of 3.55% with a fill factor of 56%, both of which are among the best performance for such a paradigm PTB7:PDI blend-based BHJ cells.

  13. Performance enhancement of top contact pentacene-based organic thin-film transistor (OTFT) using perylene interlayer between organic/electrode interface

    NASA Astrophysics Data System (ADS)

    Borthakur, Tribeni; Sarma, Ranjit

    2017-03-01

    We have investigated the effect of perylene interlayer between the organic/electrode interface on the electrical performance of a top contact pentacene-based OTFT. We have found the performance enhancement of the OTFT device. The OTFT devices with perylene layer show better field effect mobility and on-off ratio than that of having only metal electrodes. It also lowers the subthreshold slope and threshold voltage compared to single-layered OTFT devices.

  14. Perylene-diimide-based nanoparticles as highly efficient photoacoustic agents for deep brain tumor imaging in living mice.

    PubMed

    Fan, Quli; Cheng, Kai; Yang, Zhen; Zhang, Ruiping; Yang, Min; Hu, Xiang; Ma, Xiaowei; Bu, Lihong; Lu, Xiaomei; Xiong, Xiaoxing; Huang, Wei; Zhao, Heng; Cheng, Zhen

    2015-02-04

    In order to promote preclinical and clinical applications of photoacoustic imaging, novel photoacoustic contrast agents are highly desired for molecular imaging of diseases, especially for deep tumor imaging. Here, perylene-3,4,9,10-tetracarboxylic diiimide-based near-infrared-absorptive organic nanoparticles are reported as an efficient agent for photoacoustic imaging of deep brain tumors in living mice with enhanced permeability and retention effect.

  15. Perylene-diimide-based nanoparticles as highly efficient photoacoustic agents for deep brain tumor imaging in living mice

    DOE PAGES

    Fan, Quli; Cheng, Kai; Yang, Zhen; ...

    2014-11-06

    In order to promote preclinical and clinical applications of photoacoustic imaging, novel photoacoustic contrast agents are highly desired for molecular imaging of diseases, especially for deep tumor imaging. In this paper, perylene-3,4,9,10-tetracarboxylic diiimide-based near-infrared-absorptive organic nanoparticles are reported as an efficient agent for photoacoustic imaging of deep brain tumors in living mice with enhanced permeability and retention effect

  16. Excited singlet states of covalently bound, cofacial dimers and trimers of perylene-3,4:9,10-bis(dicarboximide)s.

    PubMed

    Giaimo, Jovan M; Lockard, Jenny V; Sinks, Louise E; Scott, Amy M; Wilson, Thea M; Wasielewski, Michael R

    2008-03-20

    Perylene-3,4:9,10-bis(dicarboximide) (PDI) and its derivatives are robust organic dyes that strongly absorb visible light and display a strong tendency to self-assemble into ordered aggregates, having significant interest as photoactive materials in a wide variety of organic electronics. To better understand the nature of the electronics states produced by photoexcitation of such aggregates, the photophysics of a series of covalent, cofacially oriented, pi-stacked dimers and trimers of PDI and 1,7-bis(3',5'-di-t-butylphenoxy)perylene-3,4:9,10-bis(dicarboximide) (PPDI) were characterized using both time-resolved absorption and fluorescence spectroscopy. The covalent linkage between the chromophores was accomplished using 9,9-dimethylxanthene spacers. Placing n-octyl groups on the imide nitrogen atoms at the end of the PDI chromophores not attached to the xanthene spacer results in PDI dimers having near optimal pi-stacking, leading to formation of a low-energy excimer-like state, while substituting the more sterically demanding 12-tricosanyl group on the imides causes deviations from the optimum that result in slower formation of an excimer-like excited state having somewhat higher energy. By comparison, PPDI dimers having terminal n-octyl imide groups have two isomers, whose photophysical properties depend on the ability of the phenoxy groups at the 1,7-positions to modify the pi stacking of the PPDI molecules. In general, disruption of optimal pi-stacking by steric interactions of the phenoxy side groups results in excimer-like states that are higher in energy. The corresponding lowest excited singlet states of the PDI and PPDI trimers are dimer-like in nature and suggest that structural distortions that accompany formation of the trimers are sufficient to confine the electronic interaction on two chromophores within these systems. This further suggests that it may be useful to build into oligomeric PDI and PPDI systems some degree of flexibility that allows the

  17. Differential self-assembly and tunable emission of aromatic peptide bola-amphiphiles containing perylene bisimide in polar solvents including water.

    PubMed

    Bai, Shuo; Debnath, Sisir; Javid, Nadeem; Frederix, Pim W J M; Fleming, Scott; Pappas, Charalampos; Ulijn, Rein V

    2014-07-01

    We demonstrate the self-assembly of bola-amphiphile-type conjugates of dipeptides and perylene bisimide (PBI) in water and other polar solvents. Depending on the nature of the peptide used (glycine-tyrosine, GY, or glycine-aspartic acid, GD), the balance between H-bonding and aromatic stacking can be tailored. In aqueous buffer, PBI-[GY]2 forms chiral nanofibers, resulting in the formation of a hydrogel, while for PBI-[GD]2 achiral spherical aggregates are formed, demonstrating that the peptide sequence has a profound effect on the structure formed. In water and a range of other polar solvents, self-assembly of these two PBI-peptides conjugates results in different nanostructures with highly tunable fluorescence performance depending on the peptide sequence employed, e.g., fluorescent emission and quantum yield. Organogels are formed for the PBI-[GD]2 derivative in DMF and DMSO while PBI-[GY]2 gels in DMF. To the best of our knowledge, this is the first successful strategy for using short peptides, specifically, their sequence/structure relationships, to manipulate the PBI nanostructure and consequent optical properties. The combination of controlled self-assembly, varied optical properties, and formation of aqueous and organic gel-phase materials may facilitate the design of devices for various applications related to light harvesting and sensing.

  18. Effect of Energy Alignment, Electron Mobility, and Film Morphology of Perylene Diimide Based Polymers as Electron Transport Layer on the Performance of Perovskite Solar Cells.

    PubMed

    Guo, Qiang; Xu, Yingxue; Xiao, Bo; Zhang, Bing; Zhou, Erjun; Wang, Fuzhi; Bai, Yiming; Hayat, Tasawar; Alsaedi, Ahmed; Tan, Zhan'ao

    2017-03-29

    For organic-inorganic perovskite solar cells (PerSCs), the electron transport layer (ETL) plays a crucial role in efficient electron extraction and transport for high performance PerSCs. Fullerene and its derivatives are commonly used as ETL for p-i-n structured PerSCs. However, these spherical small molecules are easy to aggregate with high annealing temperature and thus induce morphology stability problems. N-type conjugated polymers are promising candidates to overcome these problems due to the tunable energy levels, controllable aggregation behaviors, and good film formation abilities. Herein, a series of perylene diimide (PDI) based polymers (PX-PDIs), which contain different copolymeried units (X), including vinylene (V), thiophene (T), selenophene (Se), dibenzosilole (DBS), and cyclopentadithiophene (CPDT), are introduced as ETL for p-i-n structured PerSCs. The effect of energy alignment, electron mobility, and film morphology of these ETLs on the photovoltaic performance of the PerSCs are fully investigated. Among the PX-PDIs, PV-PDI demonstrates the deeper LUMO energy level, the highly delocalized LUMO electron density, and a better planar structure, making it the best electron transport material for PerSCs. The planar heterojunction PerSC with PV-PDI as ETL achieves a power conversion efficiency (PCE) of 10.14%, among the best values for non-fullerene based PerSCs.

  19. Reorganization of perylene bisimide J-aggregates: from delocalized collective to localized individual excitations

    NASA Astrophysics Data System (ADS)

    Tian, Yuxi; Stepanenko, Vladimir; Kaiser, Theo E.; Würthner, Frank; Scheblykin, Ivan G.

    2011-12-01

    Water-induced reorganization of individual one-dimensional J-aggregates of perylene bisimide (PBI) dyes was observed by fluorescence microscopy. Fluorescence spectra and decay kinetics of individual J-aggregates immobilized on glass surfaces were measured under a dry nitrogen atmosphere and under humid conditions. The fluorescence properties of PBI J-aggregates arisen from collective excitons under dry nitrogen atmosphere were changed to those of non-interacting dye monomers when water vapor was introduced into the environment (sample chamber). Time-dependent changes of the fluorescence spectra and lifetimes upon exposure to water vapor suggest an initial coordination of water molecules at defect sites leading to the formation of H-type dimer units that act as exciton quenchers, and a subsequent slower disintegration of the hydrogen-bonded J-aggregate into monomers that lack resonance coupling. Our present studies resulted in a direct demonstration of how drastically the optical properties of molecular ensembles and characteristics of their excited states can be changed by delicate reorganization of dye molecules at nanometre scales.Water-induced reorganization of individual one-dimensional J-aggregates of perylene bisimide (PBI) dyes was observed by fluorescence microscopy. Fluorescence spectra and decay kinetics of individual J-aggregates immobilized on glass surfaces were measured under a dry nitrogen atmosphere and under humid conditions. The fluorescence properties of PBI J-aggregates arisen from collective excitons under dry nitrogen atmosphere were changed to those of non-interacting dye monomers when water vapor was introduced into the environment (sample chamber). Time-dependent changes of the fluorescence spectra and lifetimes upon exposure to water vapor suggest an initial coordination of water molecules at defect sites leading to the formation of H-type dimer units that act as exciton quenchers, and a subsequent slower disintegration of the hydrogen

  20. Charge versus Energy Transfer Effects in High-Performance Perylene Diimide Photovoltaic Blend Films.

    PubMed

    Singh, Ranbir; Shivanna, Ravichandran; Iosifidis, Agathaggelos; Butt, Hans-Jürgen; Floudas, George; Narayan, K S; Keivanidis, Panagiotis E

    2015-11-11

    Perylene diimide (PDI)-based organic photovoltaic devices can potentially deliver high power conversion efficiency values provided the photon energy absorbed is utilized efficiently in charge transfer (CT) reactions instead of being consumed in nonradiative energy transfer (ET) steps. Hitherto, it remains unclear whether ET or CT primarily drives the photoluminescence (PL) quenching of the PDI excimer state in PDI-based blend films. Here, we affirm the key role of the thermally assisted PDI excimer diffusion and subsequent CT reaction in the process of PDI excimer PL deactivation. For our study we perform PL quenching experiments in the model PDI-based composite made of poly[4,8-bis(5-(2-ethylhexyl)thiophen-2-yl)benzo[1,2-b;4,5-b']dithiophene-2,6-diyl-alt-(4-(2-ethylhexanoyl)-thieno[3,4-b]thiophene)-2-6-diyl] (PBDTTT-CT) polymeric donor mixed with the N,N'-bis(1-ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (PDI) acceptor. Despite the strong spectral overlap between the PDI excimer PL emission and UV-vis absorption of PBDTTT-CT, two main observations indicate that no significant ET component operates in the overall PL quenching: the PL intensity of the PDI excimer (i) increases with decreasing temperature and (ii) remains unaffected even in the presence of 10 wt % content of the PBDTTT-CT quencher. Temperature-dependent wide-angle X-ray scattering experiments further indicate that nonradiative resonance ET is highly improbable due to the large size of PDI domains. The dominance of the CT over the ET process is verified by the high performance of devices with an optimum composition of 30:70 PBDTTT-CT:PDI. By adding 0.4 vol % of 1,8-diiodooctane we verify the plasticization of the polymer side chains that balances the charge transport properties of the PBDTTT-CT:PDI composite and results in additional improvement in the device efficiency. The temperature-dependent spectral width of the PDI excimer PL band suggests the presence of energetic disorder in the

  1. Modifying growth of perylene diimide nanocrystals with poly(3-hexyl thiophene) as additives

    NASA Astrophysics Data System (ADS)

    Bu, Laju; Hayward, Ryan

    2014-03-01

    The shape, size, and crystallinity of organic semiconductors play vital roles in their applications in optoelectronics. Various methods to control crystallization of organic semiconductors, including thermal/solvent annealing, addition of poor solvents, and chemical structure modification, have been applied to improve the performance of organic photovoltaics. While soluble additives controlled crystallization are commonly found in biomineralization, pharmaceutics, and food science, they have rarely been applied to organic semiconductors. Here, we show that a p-type polymer, P3HT, serves as a soluble additive in crystallization of a n-type semiconductor, perylene diimide (PDI), by preferentially adsorbing on lateral crystal faces, which reduce lateral growth of PDI crystals relative to longitudinal growth, yielding extended 1-D nanofibers. Upon subsequent crystallization of P3HT, the PDI nanofibers serve as efficient nucleation sties, resulting in shish-kebab like p/n heterostuctures. Using ultrasound to enhance nucleation of PDI crystals, variations in P3HT molecular weight and concentration, and sonication temperature, allow PDI nanocrystal size and uniformity to be tuned. The uniform PDI nanocrystals can act as seeds to crystallize additional PDI to get segmented nanocrystals.

  2. Simultaneous determination of benzo[k]fluoranthene and perylene using excitation-emission matrix fluorescence

    NASA Astrophysics Data System (ADS)

    Wang, Huan-Bo; Zhang, Yu-jun; Duan, Jing-Bo; Xiao, Xue; Yu, Shao-Hui; Zhang, Kai

    2010-10-01

    Benzo[k]fluoranthene (BkF) and perylene (Per) are among the sixteen priority pollutants of polycyclic aromatic hydrocarbons recommended by The United States Environment Protection Agency (EPA). In this paper, we report a simple and rapid method for quantitative analysis of BkF and Per using the three-dimensional excitation-emission matrix (EEM) fluorescence coupled with parallel factor analysis (PARAFAC). Before analyzing of two mixtures quantitatively, we study the fluorescence characterization of pure BkF and Per first. The maximal peak values are at 306 nm of the excitation wavelength and 406 nm of the emission wavelength for BkF, and 252 and 438nm for Per, the linear ranges of BkF and Per are 0.8~16~ L-1 and 0.6~20~ L-1 respectively. Finally the average recoveries are obtained using PARAFAC algorithm, which can reach 101.1% and 99.5% for BkF and Per respectively. In order to evaluate the accuracy of the PARAFAC algorithm, selectivity (SEL) and sensitivity (SEN) have also been presented. Results show that a good performance has been achieved using excitation-emission fluorescence coupled with PARAFAC algorithm.

  3. Interaction of alkali metals with perylene-3,4,9,10- tetracarboxylic-dianhydride thin films

    SciTech Connect

    Wuesten, J.; Berger, S.; Heimer, K.; Lach, S.; Ziegler, Ch.

    2005-07-01

    n doping of the molecular organic semiconductor perylene-3,4,9,10-tetracarboxylic-dianhydride (PTCDA) is often achieved by use of alkali metals as dopants. This doping process is commonly performed in two steps. In the first the dopant is evaporated onto the surface of the PTCDA film. As it has been believed that the dopant shows an inhomogeneous diffusion profile through the layer with most of the dopant accumulated in the first few layers, a subsequent annealing step has been performed in order to reach a homogeneous distribution of the dopant in the whole layer. In this paper experimental results concerning chemical composition ((angle resolved) X-ray photoemission spectroscopy, secondary-ion-mass spectrometry, Fourier transform infrared spectroscopy), electronic structure (ultraviolet photoemission spectroscopy, inverse photoemission spectroscopy), as well as electrical properties (conductivity, Seebeck coefficient) are shown before and after doping and before and after annealing. These results suggest that the deposited dopant is redistributed and partially removed during the annealing step. A model for the dopant distribution is suggested.

  4. Flexible and Patterned Thin Film Polarizer: Photopolymerization of Perylene-based Lyotropic Chromonic Reactive Mesogens.

    PubMed

    Im, Pureun; Kang, Dong-Gue; Kim, Dae-Yoon; Choi, Yu-Jin; Yoon, Won-Jin; Lee, Myong-Hoon; Lee, In-Hwan; Lee, Cheul-Ro; Jeong, Kwang-Un

    2016-01-13

    A perylene-based reactive mesogen (DAPDI) forming a lyotropic chromonic liquid crystal (LCLC) phase was newly designed and synthesized for the fabrication of macroscopically oriented and patterned thin film polarizer (TFP) on the flexible polymer substrates. The anisotropic optical property and molecular self-assembly of DAPDI were investigated by the combination of microscopic, scattering and spectroscopic techniques. The main driving forces of molecular self-assembly were the face-to-face π-π intermolecular interaction among aromatic cores and the nanophase separation between hydrophilic ionic groups and hydrophobic aromatic cores. Degree of polarization for the macroscopically oriented and photopolymerized DAPDI TFP was estimated to be 99.81% at the λmax = 491 nm. After mechanically shearing the DAPDI LCLC aqueous solution on the flexible polymer substrates, we successfully fabricated the patterned DAPDI TFP by etching the unpolymerized regions selectively blocked by a photomask during the photopolymerization process. Chemical and mechanical stabilities were confirmed by the solvent and pencil hardness tests, and its surface morphology was further investigated by optical microscopy, atomic force microscopy, and three-dimensional surface nanoprofiler. The flexible and patterned DAPDI TFP with robust chemical and mechanical stabilities can be a stepping stone for the advanced flexible optoelectronic devices.

  5. Single-Molecule Fluorescence Spectroscopy of Perylene Diimide Dyes in a γ-Cyclodextrin Film: Manifestation of Photoinduced H-Atom Transfer via Higher Triplet (n, π*) Excited States.

    PubMed

    Mitsui, Masaaki; Fukui, Hiroki; Takahashi, Ryoya; Takakura, Yasushi; Mizukami, Toshinari

    2017-03-02

    Supramolecular complexation of γ-cyclodextrin (γ-CD) with N,N'-bis(2,6-dimethylphenyl)perylene-3,4,9,10-tetracarboxylic diimide (DMP-PDI) or N,N'-bis(2,6-dioctyl)perylene-3,4,9,10-tetracarboxylic diimide (C8-PDI) dye in an aqueous solution and in a γ-CD solid film were investigated via ensemble and single-molecule fluorescence spectroscopy. These two perylene diimide derivatives possess almost the same electronic structure but have different terminal functional groups. This structural difference leads to formation of an inclusion complex of γ-CD with DMP-PDI but not with C8-PDI in aqueous solution. In a γ-CD solid film, the distributions of the wavelengths of emission maximum (λmax(em)) are strikingly different between these two dyes; a much narrower and blue-shifted λmax(em) distribution was observed for C8-PDI relative to DMP-PDI. This difference is attributed to the fact that the C8-PDI molecules are bound at the γ-CD/glass interface as a result of spin-coating of the sample solution, whereas the DMP-PDI molecules form 1:1 and 1:2 inclusion complexes with conformational heterogeneities in the film. In comparison to the case for C8-PDI, more frequent on-off blinking events were observed for DMP-PDI. The blinking statistics of DMP-PDI in the γ-CD film exhibit both single-exponential and nonexponential (i.e., dispersive) kinetics, revealed by robust statistical analysis. Energetic consideration with the aid of theoretical calculations suggests that the underlying photophysics most probably involves hydrogen atom transfer (HAT) between the DMP-PDI guest and γ-CD host via higher excited (n, π*) triplet states. The hypothesis of HAT in the inclusion complex reasonably explains the experimental results; however, a charge transfer hypothesis cannot explain the results. The dispersive kinetics is attributable to the effect of thermal fluctuation in the forward and backward HAT reactions.

  6. Competition between singlet fission and charge separation in solution-processed blend films of 6,13-bis(triisopropylsilylethynyl)pentacene with sterically-encumbered perylene-3,4:9,10-bis(dicarboximide)s.

    PubMed

    Ramanan, Charusheela; Smeigh, Amanda L; Anthony, John E; Marks, Tobin J; Wasielewski, Michael R

    2012-01-11

    The photophysics and morphology of thin films of N,N-bis(2,6-diisopropylphenyl)perylene-3,4:9,10-bis(dicarboximide) (1) and the 1,7-diphenyl (2) and 1,7-bis(3,5-di-tert-butylphenyl) (3) derivatives blended with 6,13-bis(triisopropylsilylethynyl)pentacene (TIPS-Pn) were studied for their potential use as photoactive layers in organic photovoltaic (OPV) devices. Increasing the steric bulk of the 1,7-substituents of the perylene-3,4:9,10-bis(dicarboximide) (PDI) impedes aggregation in the solid state. Film characterization data using both atomic force microscopy and X-ray diffraction showed that decreasing the PDI aggregation by increasing the steric bulk in the order 1 < 2 < 3 correlates with a decrease in the density/size of crystalline TIPS-Pn domains. Transient absorption spectroscopy was performed on ~100 nm solution-processed TIPS-Pn:PDI blend films to characterize the charge separation dynamics. These results showed that selective excitation of the TIPS-Pn results in competition between ultrafast singlet fission ((1*)TIPS-Pn + TIPS-Pn → 2 (3*)TIPS-Pn) and charge transfer from (1*)TIPS-Pn to PDIs 1-3. As the blend films become more homogeneous across the series TIPS-Pn:PDI 1 → 2 → 3, charge separation becomes competitive with singlet fission. Ultrafast charge separation forms the geminate radical ion pair state (1)(TIPS-Pn(+•)-PDI(-•)) that undergoes radical pair intersystem crossing to form (3)(TIPS-Pn(+•)-PDI(-•)), which then undergoes charge recombination to yield either (3*)PDI or (3*)TIPS-Pn. Energy transfer from (3*)PDI to TIPS-Pn also yields (3*)TIPS-Pn. These results show that multiple pathways produce the (3*)TIPS-Pn state, so that OPV design strategies based on this system must utilize this triplet state for charge separation.

  7. Hole-transfer induced energy transfer in perylene diimide dyads with a donor-spacer-acceptor motif.

    PubMed

    Kölle, Patrick; Pugliesi, Igor; Langhals, Heinz; Wilcken, Roland; Esterbauer, Andreas J; de Vivie-Riedle, Regina; Riedle, Eberhard

    2015-10-14

    We investigate the photoinduced dynamics of perylene diimide dyads based on a donor-spacer-acceptor motif with polyyne spacers of varying length by pump-probe spectroscopy, time resolved fluorescence, chemical variation and quantum chemistry. While the dyads with pyridine based polyyne spacers undergo energy transfer with near-unity quantum efficiency, in the dyads with phenyl based polyyne spacers the energy transfer efficiency drops below 50%. This suggests the presence of a competing electron transfer process from the spacer to the energy donor as the excitation sink. Transient absorption spectra, however, reveal that the spacer actually mediates the energy transfer dynamics. The ground state bleach features of the polyyne spacers appear due to the electron transfer decay with the same time constant present in the rise of the ground state bleach and stimulated emission of the perylene energy acceptor. Although the electron transfer process initially quenches the fluorescence of the donor it does not inhibit energy transfer to the perylene energy acceptor. The transient signatures reveal that electron and energy transfer processes are sequential and indicate that the donor-spacer electron transfer state itself is responsible for the energy transfer. Through the introduction of a Dexter blocker unit into the spacer we can clearly exclude any through bond Dexter-type energy transfer. Ab initio calculations on the donor-spacer and the donor-spacer-acceptor systems reveal the existence of a bright charge transfer state that is close in energy to the locally excited state of the acceptor. Multipole-multipole interactions between the bright charge transfer state and the acceptor state enable the energy transfer. We term this mechanism coupled hole-transfer FRET. These dyads represent a first example that shows how electron transfer can be connected to energy transfer for use in novel photovoltaic and optoelectronic devices.

  8. A Metal-Free Approach to 1,2-Diamines via Visible Light-Driven Reductive Coupling of Imines with Perylene as a Photoredox Catalyst.

    PubMed

    Okamoto, Shusuke; Ariki, Risako; Tsujioka, Hiroki; Sudo, Atsushi

    2017-09-15

    A simple, metal-free, and versatile approach to 1,2-diamines has been developed based on reductive coupling reactions of various imines, where perylene, an aromatic hydrocarbon, was used as a photoredox catalyst under visible light irradiation using a white light-emitting diode. The use of 1 mol % perylene enabled almost complete conversion of the imines, leading to the formation of their corresponding 1,2-diamines, which were isolated in good yields. The ratios between dl and meso diamines ranged from 31:69 to 82:18 depending on the substituents of the imines.

  9. A halochromic stimuli-responsive reversible fluorescence switching 3, 4, 9, 10-perylene tetracarboxylic acid dye for fabricating rewritable platform

    NASA Astrophysics Data System (ADS)

    Hariharan, P. S.; Pitchaimani, J.; Madhu, Vedichi; Anthony, Savarimuthu Philip

    2017-02-01

    3, 4, 9, 10-perylene tetracarboxylic acid (PTCA), a strongly fluorescent water soluble dye with halochromic functionality showed pH dependent reversible fluorescence switching. The strong fluorescence of PTCA (Φf = 0.67) in basic medium was completely quenched upon acidification. The fluorescent PTCA has been transferred on to a solid substrate (filter paper and glass plate) that also showed reversible off-on fluorescence switching by acid/base and drying/water vapor exposure. The reversible fluorescence switching of PTCA could be of potential interest for fabricating rewritable fluorescent medium.

  10. Perylene diimides with different side chains are selective in inducing different G-quadruplex DNA structures and in inhibiting telomerase.

    PubMed

    Rossetti, Luigi; Franceschin, Marco; Bianco, Armandodoriano; Ortaggi, Giancarlo; Savino, Maria

    2002-09-16

    Four N,N'-disubstituted perylene diimides, having different side chains, have been studied for their ability in inducing G-quadruplex DNA structures. We found that electrostatic interactions between ligands side chains and DNA grooves play a main role not only in the amount of G-quadruplex formed, but also in selecting its topology. Moreover, such compounds show also a different ability to inhibit telomerase. The correlation of these findings suggests the intriguing possibility that different G-quadruplex structures could differently inhibit the enzyme.

  11. Synthesis of perylene-porphyrin building blocks and polymers thereof for the production of light-harvesting arrays

    DOEpatents

    Loewe, Robert S.; Tomizaki, Kin-ya; Lindsey, Jonathan S.

    2005-07-12

    The present invention provides methods, compounds, and compositions for the synthesis of light harvesting arrays, such arrays comprising: (a) a first substrate comprising a first electrode; and (b) a layer of light harvesting rods electrically coupled to said first electrode, each of said light harvesting rods comprising a polymer of Formula I: wherein m is at least 1; X.sup.1 is a charge separation group, and X.sup.2 through X.sup.m+1 are chromophores. At least one of X.sup.2 through X.sup.m+1 has at least one perylene group coupled thereto.

  12. Self-assembly of dendronized perylene bisimides into complex helical columns.

    PubMed

    Percec, Virgil; Peterca, Mihai; Tadjiev, Timur; Zeng, Xiangbing; Ungar, Goran; Leowanawat, Pawaret; Aqad, Emad; Imam, Mohammad R; Rosen, Brad M; Akbey, Umit; Graf, Robert; Sekharan, Sivakumar; Sebastiani, Daniel; Spiess, Hans W; Heiney, Paul A; Hudson, Steven D

    2011-08-10

    The synthesis of perylene 3,4:9,10-tetracarboxylic acid bisimides (PBIs) dendronized with first-generation dendrons containing 0 to 4 methylenic units (m) between the imide group and the dendron, (3,4,5)12G1-m-PBI, is reported. Structural analysis of their self-organized arrays by DSC, X-ray diffraction, molecular modeling, and solid-state (1)H NMR was carried out on oriented samples with heating and cooling rates of 20 to 0.2 °C/min. At high temperature, (3,4,5)12G1-m-PBI self-assemble into 2D-hexagonal columnar phases with intracolumnar order. At low temperature, they form orthorhombic (m = 0, 2, 3, 4) and monoclinic (m = 1) columnar arrays with 3D periodicity. The orthorhombic phase has symmetry close to hexagonal. For m = 0, 2, 3, 4 ,they consist of tetramers as basic units. The tetramers contain a pair of two molecules arranged side by side and another pair in the next stratum of the column, turned upside-down and rotated around the column axis at different angles for different m. In contrast, for m = 1, there is only one molecule in each stratum, with a four-strata 2(1) helical repeat. All molecules face up in one column, and down in the second column, of the monoclinic cell. This allows close and extended π-stacking, unlike in the disruptive up-down alteration from the case of m = 0, 2, 3, 4. Most of the 3D structures were observed only by cooling at rates of 1 °C/min or less. This complex helical self-assembly is representative for other classes of dendronized PBIs investigated for organic electronics and solar cells.

  13. Influence of Molecular Aggregation on Electron Transfer at the Perylene Diimide/Indium-Tin Oxide Interface.

    PubMed

    Zheng, Yilong; Jradi, Fadi M; Parker, Timothy C; Barlow, Stephen; Marder, Seth R; Saavedra, S Scott

    2016-12-14

    Chemisorption of an organic monolayer to tune the surface properties of a transparent conductive oxide (TCO) electrode can improve the performance of organic electronic devices that rely on efficient charge transfer between an organic active layer and a TCO contact. Here, a series of perylene diimides (PDIs) was synthesized and used to study relationships between monolayer structure/properties and electron transfer kinetics at PDI-modified indium-tin oxide (ITO) electrodes. In these PDI molecules, one of the imide substituents is a benzene ring bearing a phosphonic acid (PA) and the other is a bulky aryl group that is twisted out of the plane of the PDI core. The size of the bulky aryl group and the substitution of the benzene ring bearing the PA were both varied, which altered the extent of aggregation when these molecules were absorbed as monolayer films (MLs) on ITO, as revealed by both attenuated total reflectance (ATR) and total internal reflection fluorescence spectra. Polarized ATR measurements indicate that, in these MLs, the long axis of the PDI core is tilted at an angle of 33-42° relative to the surface normal; the tilt angle increased as the degree of bulky substitution increased. Rate constants for electron transfer (ks,opt) between these redox-active modifiers and ITO were determined by potential-modulated ATR spectroscopy. As the degree of PDI aggregation was reduced, ks,opt declined, which is attributed to a reduction in the lateral electron self-exchange rate between adsorbed PDI molecules, as well as the heterogeneous conductivity of the ITO electrode surface. Photoelectrochemical measurements using a dissolved aluminum phthalocyanine as an electron donor showed that ITO modified with any of these PDIs is a more effective electron-collecting electrode than bare ITO.

  14. Supramolecularly engineered perylene bisimide assemblies exhibiting thermal transition from columnar to multilamellar structures.

    PubMed

    Yagai, Shiki; Usui, Mari; Seki, Tomohiro; Murayama, Haruno; Kikkawa, Yoshihiro; Uemura, Shinobu; Karatsu, Takashi; Kitamura, Akihide; Asano, Atsushi; Seki, Shu

    2012-05-09

    Perylene 3,4:9,10-tetracarboxylic acid bisimide (PBI) was functionalized with ditopic cyanuric acid to organize it into complex columnar architectures through the formation of hydrogen-bonded supermacrocycles (rosette) by complexing with ditopic melamines possessing solubilizing alkoxyphenyl substituents. The aggregation study in solution using UV-vis and NMR spectroscopies showed the formation of extended aggregates through hydrogen-bonding and π-π stacking interactions. The cylindrical fibrillar nanostructures were visualized by microscopic techniques (AFM, TEM), and the formation of lyotropic mesophase was confirmed by polarized optical microscopy and SEM. X-ray diffraction study revealed that a well-defined hexagonal columnar (Col(h)) structure was formed by solution-casting of fibrillar assemblies. All of these results are consistent with the formation of hydrogen-bonded PBI rosettes that spontaneously organize into the Col(h) structure. Upon heating the Col(h) structure in the bulk state, a structural transition to a highly ordered lamellar (Lam) structure was observed by variable-temperature X-ray diffraction, differential scanning calorimetry, and AFM studies. IR study showed that the rearrangement of the hydrogen-bonding motifs occurs during the structural transition. These results suggest that such a striking structural transition is aided by the reorganization in the lowest level of self-organization, i.e., the rearrangement of hydrogen-bonded motifs from rosette to linear tape. A remarkable increase in the transient photoconductivity was observed by the flash-photolysis time-resolved microwave conductivity (FP-TRMC) measurements upon converting the Col(h) structure to the Lam structure. Transient absorption spectroscopy revealed that electron transfer from electron-donating alkoxyphenyl groups of melamine components to electron-deficient PBI moieties takes place, resulting in a higher probability of charge carrier generation in the Lam structure

  15. Interference between Coulombic and CT-mediated couplings in molecular aggregates: H- to J-aggregate transformation in perylene-based π-stacks

    NASA Astrophysics Data System (ADS)

    Hestand, Nicholas J.; Spano, Frank C.

    2015-12-01

    The spectroscopic differences between J and H-aggregates are traditionally attributed to the spatial dependence of the Coulombic coupling, as originally proposed by Kasha. However, in tightly packed molecular aggregates wave functions on neighboring molecules overlap, leading to an additional charge transfer (CT) mediated exciton coupling with a vastly different spatial dependence. The latter is governed by the nodal patterns of the molecular LUMOs and HOMOs from which the electron (te) and hole (th) transfer integrals derive. The sign of the CT-mediated coupling depends on the sign of the product teth and is therefore highly sensitive to small (sub-Angstrom) transverse displacements or slips. Given that Coulombic and CT-mediated couplings exist simultaneously in tightly packed molecular systems, the interference between the two must be considered when defining J and H-aggregates. Generally, such π-stacked aggregates do not abide by the traditional classification scheme of Kasha: for example, even when the Coulomb coupling is strong the presence of a similarly strong but destructively interfering CT-mediated coupling results in "null-aggregates" which spectroscopically resemble uncoupled molecules. Based on a Frenkel/CT Holstein Hamiltonian that takes into account both sources of electronic coupling as well as intramolecular vibrations, vibronic spectral signatures are developed for integrated Frenkel/CT systems in both the perturbative and resonance regimes. In the perturbative regime, the sign of the lowest exciton band curvature, which rigorously defines J and H-aggregation, is directly tracked by the ratio of the first two vibronic peak intensities. Even in the resonance regime, the vibronic ratio remains a useful tool to evaluate the J or H nature of the system. The theory developed is applied to the reversible H to J-aggregate transformations recently observed in several perylene bisimide systems.

  16. Interference between Coulombic and CT-mediated couplings in molecular aggregates: H- to J-aggregate transformation in perylene-based π-stacks

    SciTech Connect

    Hestand, Nicholas J.; Spano, Frank C.

    2015-12-28

    The spectroscopic differences between J and H-aggregates are traditionally attributed to the spatial dependence of the Coulombic coupling, as originally proposed by Kasha. However, in tightly packed molecular aggregates wave functions on neighboring molecules overlap, leading to an additional charge transfer (CT) mediated exciton coupling with a vastly different spatial dependence. The latter is governed by the nodal patterns of the molecular LUMOs and HOMOs from which the electron (t{sub e}) and hole (t{sub h}) transfer integrals derive. The sign of the CT-mediated coupling depends on the sign of the product t{sub e}t{sub h} and is therefore highly sensitive to small (sub-Angstrom) transverse displacements or slips. Given that Coulombic and CT-mediated couplings exist simultaneously in tightly packed molecular systems, the interference between the two must be considered when defining J and H-aggregates. Generally, such π-stacked aggregates do not abide by the traditional classification scheme of Kasha: for example, even when the Coulomb coupling is strong the presence of a similarly strong but destructively interfering CT-mediated coupling results in “null-aggregates” which spectroscopically resemble uncoupled molecules. Based on a Frenkel/CT Holstein Hamiltonian that takes into account both sources of electronic coupling as well as intramolecular vibrations, vibronic spectral signatures are developed for integrated Frenkel/CT systems in both the perturbative and resonance regimes. In the perturbative regime, the sign of the lowest exciton band curvature, which rigorously defines J and H-aggregation, is directly tracked by the ratio of the first two vibronic peak intensities. Even in the resonance regime, the vibronic ratio remains a useful tool to evaluate the J or H nature of the system. The theory developed is applied to the reversible H to J-aggregate transformations recently observed in several perylene bisimide systems.

  17. Synthesis, spectra, and electron-transfer reaction of aspartic acid-functionalized water-soluble perylene bisimide in aqueous solution.

    PubMed

    Zhong, Lina; Xing, Feifei; Shi, Wei; Yan, Liuming; Xie, Liqing; Zhu, Shourong

    2013-04-24

    An aspartic acid-functionalized water-soluble perylene bisimide, N,N'-di(2-succinic acid)-perylene-3,4,9,10-tetracarboxylic bisimide (PASP) was synthesized and characterized. It has absorbance maximum A(0-0) and A(0-1) at 527 and 498 nm (ε ≈ 1.7 × 10(4) L cm(-1) mol(-1)) respectively in pH 7.20 HEPES buffer. Two quasi-reversible redox processes with E1/2 at -0.17 and -0.71 V (vs Ag/AgCl) respectively in pH 7-12.5 aqueous solutions. PASP can react with Na2S in pure aqueous solution to form monoanion radical and dianion species consecutively. PASP(-•) has EPR signal with g = 1.998 in aqueous solution, whereas PASP(2-) is EPR silent. The monoanion radical formation is a first-order reaction with k = 8.9 × 10(-2) s(-1). Dianion species formation is a zero-order reaction and the rate constant is 4.3 × 10(-8) mol L(-1) s(-1). The presence of H2O2 greatly increases the radical formation rate constant. PASP as a two-electron transfer reagent is expected to be used in the water photolysis.

  18. Real-Time Visualization of Perylene Nanoclusters in Water and Their Partitioning to Graphene Surface and Macrophage Cells.

    PubMed

    Guo, Xuejun; Jin, Xin; Lv, Xiaofang; Pu, Yingying; Bai, Fan

    2015-07-07

    Hydrophobic organic chemicals (HOCs) are of special ecotoxicological concern because they can be directly incorporated and bioconcentrated in living organisms. However, the effects of self-clustering of HOCs on their environmental behavior and toxicology have not yet received enough attention. With the use of a recently developed technique, single-molecule fluorescence microscopy, the motion and distribution of perylene nanoclusters (PNCs) formed in water at very low concentration (1 μM) were visualized with high temporal and spatial resolution. The liquid-solid interface process of PNCs adsorbing onto graphene was also recorded. Instead of the traditional view of HOC adsorption as a single molecule, our study revealed the characteristic of irreversible adsorption of perylene onto the carbonaceous surface in the form of nanoclusters, exhibiting random sequential "car-parking" events. More interestingly, the transport of PNCs across the cell membrane was also captured in real time, demonstrating that they entered macrophage cells by endocytosis. Supplementing the well-recognized routine of passive diffusion through a membrane lipid bilayer, the uptake of HOCs in the form of nanoclusters by endocytosis is proposed to be an additional but important mechanism for their uptake into living cells. The distribution of HOCs in environmental systems in the form of nanoclusters, exemplified by PNCs in this study, may have significant implications for understanding their environmental fate and potential toxicological effects.

  19. Influence of the preparation conditions on the morphology of perylene thin films on Si(111) and Si(100)

    SciTech Connect

    Casu, M. B.; Yu, X.; Schmitt, S.; Heske, C.; Umbach, E.

    2008-12-28

    Thin films of perylene on Si(111) and Si(100) substrates have been investigated using a variety of experimental techniques. We find that the structural and morphological properties as well as the growth modes strongly depend on the preparation parameters. In general, we observe the existence of a relatively weak coupling between perylene and the two single crystal substrates. However, under special preparation conditions, it is possible to obtain a multilayer phase on the Si(111) substrate that is characterized by flat-lying, parallel-oriented molecules, and strong coupling with the substrate in the first layer. This phase has different structural, electronic, and intermolecular bonding properties as compared to the known crystalline phases. On Si(100), by varying the deposition rate between 0.1 and 10 nm/min, it is possible to observe a transition from island growth mode, with large and isolated crystallites, to homogeneous film growth. These findings contribute to the basic knowledge for film engineering. Thus, the film morphology could be designed ranging from the growth of very large single grains suitable for a complete nanodevice to homogenous films for application in large displays.

  20. 21 CFR 73.3120 - 16,17-Dimethoxydinaphtho [1,2,3-cd:3′,2′,1′-lm] perylene-5,10-dione.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 21 Food and Drugs 1 2013-04-01 2013-04-01 false 16,17-Dimethoxydinaphtho perylene-5,10-dione. 73.3120 Section 73.3120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... to exceed the minimum reasonably required to accomplish the intended coloring effect....

  1. 21 CFR 73.3120 - 16,17-Dimethoxydinaphtho [1,2,3-cd:3′,2′,1′-lm] perylene-5,10-dione.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 21 Food and Drugs 1 2012-04-01 2012-04-01 false 16,17-Dimethoxydinaphtho perylene-5,10-dione. 73.3120 Section 73.3120 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN... to exceed the minimum reasonably required to accomplish the intended coloring effect....

  2. An ambient stable core-substituted perylene bisimide dianion: isolation and single crystal structure analysis† †Electronic supplementary information (ESI) available: Synthesis, spectroelectrochemistry, UV-vis, electrochemistry, X-ray diffraction, NMR and mass spectra. CCDC 1032959. For ESI and crystallographic data in CIF or other electronic format see DOI: 10.1039/c4sc03671a Click here for additional data file. Click here for additional data file.

    PubMed Central

    Seifert, Sabine; Schmidt, David

    2015-01-01

    Here we report the first example of an isolable, ambient stable perylene bisimide (PBI) dianion which was synthesized by catalytic reduction of a highly electron deficient PBI derivative. The remarkable stability of this unprecedented dianion in air for months facilitated its complete characterization by different methods, including single crystal X-ray analysis. Furthermore, solvent dependent cyclic and square wave voltammetry studies revealed that the formation of PBI dianions is preferred in more polar solvents, whereas the generation of PBI radical anions should be favoured in less polar solvents. PMID:28717450

  3. Supramolecular block copolymers by kinetically controlled co-self-assembly of planar and core-twisted perylene bisimides

    PubMed Central

    Görl, Daniel; Zhang, Xin; Stepanenko, Vladimir; Würthner, Frank

    2015-01-01

    New synthetic methodologies for the formation of block copolymers have revolutionized polymer science within the last two decades. However, the formation of supramolecular block copolymers composed of alternating sequences of larger block segments has not been realized yet. Here we show by transmission electron microscopy (TEM), 2D NMR and optical spectroscopy that two different perylene bisimide dyes bearing either a flat (A) or a twisted (B) core self-assemble in water into supramolecular block copolymers with an alternating sequence of (AmBB)n. The highly defined ultralong nanowire structure of these supramolecular copolymers is entirely different from those formed upon self-assembly of the individual counterparts, that is, stiff nanorods (A) and irregular nanoworms (B), respectively. Our studies further reveal that the as-formed supramolecular block copolymer constitutes a kinetic self-assembly product that transforms into thermodynamically more stable self-sorted homopolymers upon heating. PMID:25959777

  4. Synthesis, photophysics of two new perylene bisimides and their photovoltaic performances in quasi solid state dye sensitized solar cells

    NASA Astrophysics Data System (ADS)

    Mikroyannidis, John A.; Stylianakis, Minas M.; Roy, M. S.; Suresh, P.; Sharma, G. D.

    Two new symmetrical compounds A and P based on perylene-anthracene and perylene-pyrene, respectively, were synthesized and characterized by FT-IR, 1H NMR, TGA and TMA. These compounds contained tert-butyl groups which enhanced their solubility, decomposed above 400 °C and gave char yields of 46-65% at 800 °C in N 2. Compound A showed significantly higher glass transition temperature (124 °C) than P (75 °C). Their absorption spectra were broad with longer wavelength absorption at 467-525 nm and optical band gap of 2.05 eV. The solutions of the compounds emitted green-yellow light with maximum at 555 nm, while their films were not photoluminescent. The compound A shows better photovoltaic response than compound P. Quasi solid state dye sensitized solar cells (DSSCs) have been fabricated employing compound A as sensitizer and polymer sol gel as electrolyte and characterized through the current-voltage characteristics in dark as well as under illumination and electrochemical impedance spectra. We found that the Al 2O 3 modification of TiO 2 layer significantly improves the dye absorption resulting in enhancement of power conversion efficiency (PCE) (from 1.15 to 2.13%) which is attributed to the increase in electron lifetime and reduction in back transfer of electrons. Finally, the TiO 2 has been incorporated into the polymer electrolyte gel to improve the power conversion efficiency (3.42%) of the quasi solid state DSSC. The faster electron diffusion in the device, the high ionic conductivity and the low activation energy of the polymer electrolyte are also responsible for enhanced PCE, when TiO 2 nano-particles are incorporated in the polymer electrolyte.

  5. Rigidifying Nonplanar Perylene Diimides by Ring Fusion Toward Geometry-Tunable Acceptors for High-Performance Fullerene-Free Solar Cells.

    PubMed

    Zhong, Hongliang; Wu, Chen-Hao; Li, Chang-Zhi; Carpenter, Joshua; Chueh, Chu-Chen; Chen, Jung-Yao; Ade, Harald; Jen, Alex K-Y

    2016-02-03

    Rigid fused perylene diimide (PDI) dimers bridged with heterocycles exhibit superior photovoltaic performance compared to their unfused semiflexible analogues. Changing the chalcogen atoms in the aromatic bridges gradually increases the twist angles between the two PDI planes, leading to a varied morphology in which the one bridged by thiophene achieves a balance and shows the best efficiency of 6.72%. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  6. Subcomponent self-assembly of a 4 nm M4 L6 tetrahedron with Zn(II) vertices and perylene bisimide dye edges.

    PubMed

    Frischmann, Peter D; Kunz, Valentin; Stepanenko, Vladimir; Würthner, Frank

    2015-02-09

    Formation of a tetrahedron with >4 nm perylene bisimide (PBI) dye edges and Zn(II) vertices in a one-pot 22 component self-assembly reaction is reported. The luminescent polyhedron equilibrates to a Zn2 L3 helicate and disassembles upon dilution. Insights into the subcomponent self-assembly of extended PBI ligands help to refine design rules for constructing large photofunctional metallosupramolecular hosts.

  7. First identification of benzo[cd]phenanthro[1,2,3-lm]perylene by high-pressure liquid chromatography with ultraviolet-visible spectroscopy and mass spectrometry.

    PubMed

    Walker, Michelle S; Wornat, Mary J

    2010-07-02

    Benzo[cd]phenanthro[1,2,3-lm]perylene has been identified as a product of supercritical 1-methylnaphthalene pyrolysis from an experiment performed at 585 degrees C, 110atm, and 140s in a supercritical fluid flow reactor. The identification of benzo[cd]phenanthro[1,2,3-lm]perylene is based on the product's mass spectrum, HPLC elution time, and UV absorbance spectrum. The mass spectrum of the identified 1-methylnaphthalene pyrolysis product, called component I here, reveals a molecular weight of 426, corresponding to a C(34)H(18) polycyclic aromatic hydrocarbon (PAH). The extremely long HPLC elution time, 20-48min longer than those of the four other C(34)H(18) PAH components in this product mixture, indicates that component I has a planar structure with a high length-to-breadth ratio. Annellation theory is used to interpret and compare the UV spectrum of component I with those of the C(30)H(16) benzo[cd]naphtho[1,2,3-lm]perylene and the C(36)H(18) teropyrene, structures with one ring less and one ring more, respectively, than that of component I. This analysis of component I's UV spectrum, in conjunction with its mass spectrum and HPLC elution behavior, all lead to the identification of component I as the nine-ring PAH benzo[cd]phenanthro[1,2,3-lm] perylene, a molecule whose existence has never before been documented. Copyright 2010 Elsevier B.V. All rights reserved.

  8. D-A dyad and D-A-D triad incorporating triphenylamine, benzanthrone and perylene diimide: Synthesis, electrochemical, linear and nonlinear optical properties

    NASA Astrophysics Data System (ADS)

    Cao, Liu; Xu, Liang; Zhang, Dingfeng; Zhou, Yecheng; Zheng, Yusen; Fu, Qinrui; Jiang, Xiao-Fang; Lu, Fushen

    2017-08-01

    To study the relationship between donor (D)-acceptor (A) structures and the third-order nonlinear optical property, two types of D-A and D-A-D structures based on triphenylamine-substituted chromophores with benzanthrone or perylene diimide (PDI) acceptors have been designed and synthesized. Among them, D-A-D type chromophores with a linear configuration show relatively larger two-photon absorption (2 PA) coefficient and 2 PA cross section value.

  9. Molecular metals based on 1,2,7,8-tetrahydrodicyclopenta[cd:lm]perylene and iodine, (CPP){sub 2}(I{sub 3}){sub 1-{delta}}

    SciTech Connect

    Morgado, J. |; Santos, I.C.; Henriques, R.T.; Almeida, M.; Fourmigue, M.; Matias, P.; Veiros, L.F.; Duarte, M.T.; Alcacer, L.; Calhorda, M.J. |

    1994-12-01

    The synthesis and characterization of molecular metals derived from 1,2,7,8-tetrahydrodicyclopenta[cd:lm]perylene (CPP) by partial oxidation with iodine and with general formula (CPP){sub 2}(I{sub 3}){sub 1-{delta}}, {delta} = 0-0.13, are reported. Single crystals, obtained either by electrocrystallization or by diffusion-controlled iodine oxidation of CPP, present two types of morphologies, elongated diamond or thinner needle-shaped crystals, both with a monoclinic cell, space group P2{sub 1}/a, a = 4.3757(9), b = 19.3681(11), c = 10.0860(11) {angstrom}, {beta} = 98.050(8){degrees}, V = 846.4(2) {angstrom}{sup 3}, Z = 2. The structure of the diamond-shaped crystal was solved by X-ray diffraction to a final R(F) = 0.096, R{sub w}(F) = 0.069. It consists of regular stacks of CPP molecules along a with a 3.41 {angstrom} spacing and uncorrected one-dimensional chains of I{sub 3}{sup {minus}} located in channels between four CPP stacks corresponding to (CPP){sub 2}(I{sub 3}){sub 0.892}. The thin needle crystals have the same unit cell but an unspecified and slightly different iodine content. Band structure calculations in this structure by the extended Hueckel method indicate a one-dimensional conduction band 0.55 eV wide. These thin needle crystals present, at room temperature, an electrical conductivity along the a axis {alpha}{sub a}(RT) = 200 S/cm and thermopower S{sub a}(RT) = 30 {mu}V/K, while for the diamond-shaped crystals {alpha}{sub a}(RT) = 2 S/cm and S{sub a}(RT) = -8 {mu}V/K. These transport coefficients for both types of crystals indicate a metallic behavior from room temperature down to {approx_equal}63 K, where a metal-to-insular (M-I) transition takes place. EPR studies in single crystals show an almost isotropic line at g = 2.0044 and with a width of {approx_equal}6 G in the range 80-300 K and without significant differences between the two types of crystals. 53 refs., 9 figs., 4 tabs.

  10. Self-assembly of ferrocene-functionalized perylene bisimide bridging ligands with PtII corner to electrochemically active molecular squares.

    PubMed

    You, Chang-Cheng; Würthner, Frank

    2003-08-13

    Ferrocenyl-substituted N,N'-di(4-pyridyl)perylene bisimide ligands have been synthesized by the coupling reaction of hydroxyphenoxy-perylene bisimides with ferrocenyl carboxylic acids. By means of metallosupramolecular self-assembly, hitherto unprecedented multiredox active dendritic molecular squares with 16 ferrocene groups positioned in the bridging ligands are prepared from the perylene bispyridyl imide ligands and [Pt(dppp)][(OTf)(2)] (dppp = 1,3-bis(diphenylphosphano)propane; OTf = trifluoromethanesulfonate) corner in high yield. The isolated metallosupramolecular squares were characterized by elemental analysis, (1)H, (31)P[(1)H] NMR, and UV/vis spectroscopy. The electrochemical properties of the ligands and squares are investigated by cyclic voltammetry as well as spectroelectrochemistry. The results obtained show that the redox behavior of ferrocene units is influenced by the square superstructure. Furthermore, redox titration of free ligand and corresponding molecular square with the one-electron oxidant thianthrenium pentachloroantimonate reveals that ferrocene groups in these structures may be oxidized completely by this oxidant, and highly charged species generated through oxidation of ferrocenyl groups in molecular square cause decomposition of the assembly due to pronounced Coulombic repulsion.

  11. Non-covalent synthesis of thermo-responsive graphene oxide-perylene bisimides-containing poly(N-isopropylacrylamide) hybrid for organic pigment removal.

    PubMed

    Wang, Liang; Jiang, Lai; Su, Dan; Sun, Chen; Chen, Minfang; Goh, Kunli; Chen, Yuan

    2014-09-15

    In this work, thermo-responsive graphene oxide-perylene bisimides-containing poly(N-isopropylacrylamide) hybrid (TGO) was successfully prepared via non-covalent π-π stacking interactions of GO and perylene bisimides-containing poly(N-isopropylacrylamide) (PBI-PNIPAM). PBI-PNIPAM was synthesized by atom transfer radical polymerization of N-isopropylacrylamide, using bifunctional N,N'-bis[6-(2-chloropropionamide)hexyl] perylene-3,4,9,10-tetracarboxylic acid bisimide (PBI-Cl) as the initiator. The obtained polymer was then characterized by (1)H NMR and fluorescence spectroscopy. The surface chemical states, morphology, and composition of TGO were characterized by X-ray photoelectron spectroscopy (XPS), transmission electron microscopy (TEM), thermogravimetric analysis (TGA), respectively. This new hybrid showed reversible temperature-dependent self-assembly and disassembly at 35.9°C in water. Therefore, it may have great potentials as a convenient adsorbent for removing organic pigment, as exemplified as for removing methylene blue from water with excellent adsorption capacity of 568 mg/g, high removal efficiency of 99.5%, and facile temperature-controlled post-separation of the adsorbent.

  12. β-Cyclodextrin non-covalently functionalized single-walled carbon nanotubes bridged by 3,4,9,10-perylene tetracarboxylic acid for ultrasensitive electrochemical sensing of 9-anthracenecarboxylic acid.

    PubMed

    Zhu, Gangbing; Zhang, Xia; Gai, Pengbo; Zhang, Xiaohua; Chen, Jinhua

    2012-09-21

    We report a simple and facile approach for the synthesis of β-cyclodextrin non-covalently functionalized single-walled carbon nanotubes bridged by 3,4,9,10-perylene tetracarboxylic acid (β-CD-PTCA-SWCNTs). Fourier transform infrared spectroscopy, transmission electron microscopy, thermogravimetric analysis, Raman spectroscopy and electrochemical methods were used to characterize the as-prepared functionalized SWCNTs. Furthermore, the β-CD-PTCA-SWCNTs were applied successfully to detect 9-anthracenecarboxylic acid (9-ACA, one derivative of polycyclic aromatic hydrocarbons) by electrochemical methods. The results show that the oxidation peak current of 9-ACA on β-CD-PTCA-SWCNTs modified glassy carbon (GC) electrode is 4.0 and 31.2 times higher than that at the SWCNTs/GC and bare GC electrodes, respectively. The proposed modified electrode has a linear response range of 2.00 to 140.00 nM with a detection limit of 0.65 nM (S/N = 3) towards 9-ACA, which is due to the synergic effects of the SWCNTs (e.g. their good electrochemical properties and large surface area) and β-CD (e.g. a hydrophilic external surface and a high supramolecular recognition and enrichment capability).

  13. Molecular Packing Determines Charge Separation in a Liquid Crystalline Bisthiophene-Perylene Diimide Donor-Acceptor Material.

    PubMed

    Polkehn, Matthias; Tamura, Hiroyuki; Eisenbrandt, Pierre; Haacke, Stefan; Méry, Stéphane; Burghardt, Irene

    2016-04-07

    Combined electronic structure and quantum dynamical calculations are employed to investigate charge separation in a novel class of covalently bound bisthiophene-perylene diimide type donor-acceptor (DA) co-oligomer aggregates. In an earlier spectroscopic study of this DA system in a smectic liquid crystalline (LC) film, efficient and ultrafast (subpicosecond) initial charge separation was found to be followed by rapid recombination. By comparison, the same DA system in solution exhibits ultrafast resonant energy transfer followed by slower (picosecond scale) charge separation. The present first-principles study explains these contrasting observations, highlighting the role of an efficient intermolecular charge-transfer pathway that results from the molecular packing in the LC phase. Despite the efficiency of this primary charge-transfer step, long-range charge separation is impeded by a comparatively high Coulomb barrier in conjunction with small electron- and hole-transfer integrals. Quantum dynamical calculations are carried out for a fragment-based model Hamiltonian, parametrized by ab initio second-order Algebraic Diagrammatic Construction (ADC(2)) and Time-Dependent Density Functional Theory (TDDFT) electronic structure calculations. Simulations of coherent vibronic quantum dynamics for up to 156 electronic states and 48 modes are performed using the Multi-Layer Multi-Configuration Time-Dependent Hartree (ML-MCTDH) method. Excellent agreement with experimentally determined charge separation time scales is obtained, and the spatially coherent nature of the dynamics is analyzed.

  14. Direct observation of ultrafast coherent exciton dynamics in helical π-stacks of self-assembled perylene bisimides

    PubMed Central

    Sung, Jooyoung; Kim, Pyosang; Fimmel, Benjamin; Würthner, Frank; Kim, Dongho

    2015-01-01

    Ever since the discovery of dye self-assemblies in nature, there have been tremendous efforts to exploit biomimetic supramolecular assemblies for tailored artificial photon processing materials. This feature necessarily has resulted in an increasing demand for understanding exciton dynamics in the dye self-assemblies. In a sharp contrast with J-type aggregates, however, the detailed observation of exciton dynamics in H-type aggregates has remained challenging. In this study, as we succeed in measuring transient fluorescence from Frenkel state of π-stacked perylene tetracarboxylic acid bisimide dimer and oligomer aggregates, we present an experimental demonstration on Frenkel exciton dynamics of archetypal columnar π–π stacks of dyes. The analysis of the vibronic peak ratio of the transient fluorescence spectra reveals that unlike the simple π-stacked dimer, the photoexcitation energy in the columnar π-stacked oligomer aggregates is initially delocalized over at least three molecular units and moves coherently along the chain in tens of femtoseconds, preceding excimer formation process. PMID:26492820

  15. A combined study based on experiment and molecular dynamics: perylene tetracarboxylate intercalated in a layered double hydroxide matrix.

    PubMed

    Yan, Dongpeng; Lu, Jun; Wei, Min; Ma, Jing; Evans, David G; Duan, Xue

    2009-10-28

    This paper describes a combined experimental and theoretical simulation investigation on the photophysical properties, thermolysis, and orientation of 3,4,9,10-perylene tetracarboxylate (PTCB) intercalated Mg-Al-layered double hydroxide (PTCB/Mg-Al-LDH). UV-vis absorption and fluorescence spectroscopy show the existence of PTCB aggregates within the gallery of LDH, indicative of H-type (blue-shifted absorption band) and J-type dimers (red-shifted absorption band). In situ high-temperature X-ray diffraction (HT-XRD), thermogravimetry and differential thermal analysis (TG-DTA) and elemental analysis were used to study the thermal decomposition properties of PTCB/Mg-Al-LDH, and it was found that the decomposition temperature of the intercalated PTCB is lower than its pristine form (460 vs 565 degrees C), indicating that the strong pi-pi interaction among PTCB was weakened by the positively charged LDH host layers. Molecular dynamics (MD) calculations were employed to simulate the molecular arrangement and aggregation behavior of intercalated PTCB in the gallery of Mg-Al-LDH. The simulation results show that the intercalated PTCB anions exhibit a tendency from tilted to vertical orientation with respect to the layers as the interlayer water content increases, furthermore, the H and J-type dimer species are most likely populated under low and high hydration conditions, respectively. Moreover, the distribution of interlayer water molecules are also discussed.

  16. Tailoring ultrasound-induced growth of perylene diimide nanowire crystals from solution by modification with poly(3-hexyl thiophene).

    PubMed

    Bu, Laju; Dawson, Trenton J; Hayward, Ryan C

    2015-02-24

    Tailoring nanocrystalline morphologies of organic semiconductors holds importance for organic electronics due to the influence of crystal characteristics on optoelectronic properties. Soluble additives that control crystal growth are commonly found in a variety of contexts such as biomineralization, pharmaceutical processing, and food science, while the use of ultrasound to modify crystal nucleation and growth has been routinely employed in producing crystals of food ingredients, biomolecules, pharmaceuticals, and inorganic materials. However, both methods have been applied to the growth of organic semiconductor crystals only in limited fashion. Here, we combine these two approaches to show that colloidally stable nanowire suspensions of a n-type small molecule, perylene diimide (PDI), can be prepared with well-controlled structures by sonocrystallization in the presence of a p-type polymer, poly(3-hexyl thiophene) (P3HT), as a soluble additive. By preferentially adsorbing on lateral crystal faces, P3HT dramatically reduces PDI crystal growth rate in the lateral directions relative to that along the nanowire axis, yielding nanocrystals with widths below 20 nm and narrow width distributions. With the use of uniform short PDI nanowires as seeds and extension with metastable solutions, controlled growth of PDI nanowires by "living crystallization" is demonstrated, providing access to narrowed length distributions and tailored branched crystal morphologies.

  17. Can the Excited State Energy of a Pyrenyl Unit Be Directly Transferred to a Perylene Bisimide Moiety?

    PubMed

    Wang, Gang; Shang, Congdi; Wang, Li; Peng, Haonan; Yin, Shiwei; Fang, Yu

    2016-11-23

    A pyrenyl unit (Py) was chemically connected to a perylene bisimide (PBI) moiety through a long and flexible linker, 4,7,10-trioxa-1,13-tridecanediamine (TOA), resulting in a fluorescent dyad, PBI-TOA-Py. Ultraviolet-visible absorption and fluorescence studies revealed that the two fluorescent units of PBI-TOA-Py behave independently. However, efficient Förster resonance energy transfer (FRET) from the Py unit to the PBI moiety in solution state was also observed. Temperature and solvent effect studies demonstrated that the energy transfer efficiency is highly dependent upon solution temperature and solvent nature. Specifically, for the dimethylformamide (DMF) solution of PBI-TOA-Py, the FRET efficiency is close to 88% at temperatures below ∼40 °C, but the efficiency greatly decreases to nearly zero when the temperature exceeds ∼80 °C. Moreover, addition of HAc into the DMF solution at room temperature could reduce the energy transfer efficiency to nearly zero, suggesting that the excited state energy of Py cannot be directly transferred to the PBI structure even though they are properly and chemically bonded. On the basis of the observations and time-resolved studies, it is believed that the observed efficient FRET from the Py unit to the PBI moiety occurs mainly through Py excimer formation, which could be a result of intermolecular association of the compound. Thus, the applications of the fluorescent dyad in solvent discrimination and trace water determination in organic solvents were verified through example studies.

  18. Nickel(II) and iron(III) selective off-on-type fluorescence probes based on perylene tetracarboxylic diimide.

    PubMed

    Wang, Haixia; Wang, Delou; Wang, Qi; Li, Xiyou; Schalley, Christoph A

    2010-03-07

    Two novel "turn-on" fluorescent probes with perylene tetracarboxylic diimide (PDI) as the fluorophore and two different di-(2-picolyl)-amine (DPA) groups as the metal ion receptor (PDI-1 and PDI-2) were successfully synthesized with satisfactory yields. PDI-1 exhibited high selectivity toward Ni(2+) in the presence of various other metal cations including Zn(2+), Cd(2+) and Cu(2+) which were expected to interfere significantly. A 1 : 2 stoichiometry was found for the complex formed by PDI-1 and Ni(2+) by a Job's plot and by non-linear least square fitting of the fluorescence titration curves. By introducing an extra diamino ethylene group between DPA and the phenyl bridge, the receptor was modified and the high selectivity of the sensor toward Ni(2+) shifted to Fe(3+). The enhancement factor of the fluorescence response of PDI-2 to Fe(3+) was as high as 138. The binding behavior of the receptors in these two compounds is affected significantly by the PDI fluorophores. Most interestingly, both Ni(2+) and Fe(3+) are paramagnetic metal ions, which are known as fluorescence quenchers and are rarely targeted with "turn-on" fluorescence probes. This result suggests that PDIs are favorable fluorophores for a "turn-on" fluorescence probe for paramagnetic transition metal ions because of their high oxidation potential.

  19. Donor-linked di(perylene bisimide)s: arrays exhibiting fast electron transfer for photosynthesis mimics.

    PubMed

    Wu, Yishi; Zhen, Yonggang; Wang, Zhaohui; Fu, Hongbing

    2013-02-28

    The first example of donor-linked di(perylene bisimide)s is reported. UV-vis absorption spectra of these newly synthesized dyads showed intense absorption across the entire visible region, demonstrating their excellent light-harvesting activities. The severe fluorescence quenching event probed by steady-state fluorescence spectroscopy and the free-energy calculations suggested the possibility of electron transfer (ET) in these arrays upon photoexcitation. Further femtosecond transient absorption spectra clarified that the fluorescence quenching was due to fast intramolecular ET. The rate of the charge separation (CS) was found to be as high as 10(12) s(-1) in CH(2)Cl(2). It was suggested that the large ET driving forces, strong donor-acceptor electronic coupling, and relatively small reorganization energy of diPBI accounted for the rapid ET process in a synergic manner. The fate of the generated radical ion pair depended on the solvent used. Rapid charge recombination to ground state occurred for the dyads in polar CH(2)Cl(2) and for diPBI-TPA in nonpolar toluene. However, sufficient (3)diPBI* population was attained via efficient spin-orbit coupled intersystem crossing from the charge-separated state for diPBI-PdTPP in toluene. These photophysical properties are interpreted as the cooperation between thermodynamic feasibility and kinetic manipulation.

  20. Fluorescence turn-on sensing of protein based on mannose functionalized perylene bisimides and its fluorescence imaging.

    PubMed

    Wang, Ke-Rang; An, Hong-Wei; Rong, Rui-Xue; Cao, Zhi-Ran; Li, Xiao-Liu

    2014-08-15

    A new water-soluble glycocluster based on perylene bisimides PBI-12-Man has been designed and synthesized, and its specific and selective binding property with Concanavalin A (Con A) has been investigated by fluorescence spectroscopy and circular dichroism (CD) spectroscopy, which showed strong binding affinity for Con A with the binding constant of 8.2×10(5)M(-1) for monomeric mannose unit, two orders of magnitude higher than the corresponding monosaccharide ligand. Most interestingly, a fluorescence enhancement of PBI-12-Man was observed upon binding with Con A because of deaggregation of the self-assembly of PBI-12-Man induced by carbohydrate-protein interaction, and the further study of the fluorescence enhancement with macrophage cells showed that PBI-12-Man as a biocompatible agent had fluorescence imaging of the surface mannose receptor of the cells. Such fluorescence turn-on sensing of protein based on carbohydrate-protein interactions would facilitate the development of new protein-specific fluorescent probe for diagnosis and molecular imaging under live cell conditions.

  1. Modification of nanocrystalline WO3 with a dicationic perylene bisimide: applications to molecular level solar water splitting.

    PubMed

    Ronconi, Federico; Syrgiannis, Zois; Bonasera, Aurelio; Prato, Maurizio; Argazzi, Roberto; Caramori, Stefano; Cristino, Vito; Bignozzi, Carlo Alberto

    2015-04-15

    [(N,N'-Bis(2-(trimethylammonium)ethylene) perylene 3,4,9,10-tetracarboxylic acid bisimide)(PF6)2] (1) was observed to spontaneously adsorb on nanocrystalline WO3 surfaces via aggregation/hydrophobic forces. Under visible irradiation (λ > 435 nm), the excited state of 1 underwent oxidative quenching by electron injection (kinj > 10(8) s(-1)) to WO3, leaving a strongly positive hole (Eox ≈ 1.7 V vs SCE), which allows to drive demanding photo-oxidation reactions in photoelectrochemical cells (PECs). The casting of IrO2 nanoparticles (NPs), acting as water oxidation catalysts (WOCs) on the sensitized electrodes, led to a 4-fold enhancement in photoanodic current, consistent with hole transfer from oxidized dye to IrO2 occurring on the microsecond time scale. Once the interaction of the sensitizer with suitable WOCs is optimized, 1/WO3 photoanodes may hold potentialities for the straightforward building of molecular level devices for solar fuel production.

  2. In situ-generated nano-gold plasmon-enhanced photoelectrochemical aptasensing based on carboxylated perylene-functionalized graphene.

    PubMed

    Li, Jing; Tu, Wenwen; Li, Hongbo; Han, Min; Lan, Yaqian; Dai, Zhihui; Bao, Jianchun

    2014-01-21

    A novel in situ-generated nanogold plasmon-enhanced photoelectrochemical aptasensor for Hg(2+) ions was fabricated using a perylene-3,4,9,10-tetracarboxylic acid/graphene (PTCA-GR) heterojunction. The fabricated photoelectrochemical aptasensor was based on thymine-Hg(2+)-thymine coordination chemistry and the plasmonic near-field absorption enhancement effect of the subsequent specific catalytic formation of nanogold. The energetic electrons from the surface plasmons of the nanogold were injected into the LUMO orbit of the organic PTCA semiconductor and then rapidly transferred to the electrode through GR due to the possible Hg(2+)-DNA molecular wires following irradiation with the visible light (λ > 450 nm) and at a bias voltage of 0.2 V. The fabricated aptasensor was linear in its response to the concentration of Hg(2+) ions in the range of 5-500 pmol L(-1), with a detection limit of 2 pmol L(-1). The presence of up to 200-fold greater concentrations of other common metal ions did not interfere with the detection of Hg(2+) ions in an aqueous system, and the results corresponded well with those obtained by ICP-MS. This novel plasmon-enhanced photoelectrochemical aptasensor exhibited good performance with its high sensitivity, good selectivity, low cost, and portable features. The strategy of the localized surface plasmon resonance through the in situ generation of noble metal nanoparticles paves the way for improvements in PEC aptasensor performance.

  3. Improving the layer morphology of solution-processed perylene diimide organic solar cells with the use of a polymeric interlayer

    NASA Astrophysics Data System (ADS)

    Singh, Ranbir; Mróz, Marta M.; Di Fonzo, Fabio; Cabanillas-Gonzalez, Juan; Marchi, Enrico; Bergamini, Giacomo; Müllen, Klaus; Jacob, Josemon; Keivanidis, Panagiotis E.

    2013-10-01

    Herein we demonstrate a method to improve the power conversion efficiency (PCE) parameter of organic photovoltaic (OPV) devices based on the electron acceptor N,N'-bis(1- ethylpropyl)-perylene-3,4,9,10-tetracarboxylic diimide (PDI) blended with the electron donor poly(indenofluorene)-aryloctyl (PIF-Aryl). The device parameters of the short-circuit current, open-circuit voltage and fill factor are found increased after the insertion of a thin poly [9, 9-dioctylfluorene-co-N- [4-(3-methylpropyl)]-diphenylamine] (TFB) photoactive interlayer between the hole-collecting electrode and the photoactive layer of the device. Unlike to most of the cases where interlayers serve as charge extractors, in our system the polymeric interlayer serves as a morphology modifying agent that drives the PDI component to segregate better at the interface with the device cathode; that is at the carrier-collecting electrode interface, which is not in physical contact with the interlayer. The processes of energy/charge transfer of the TFB excitons to/with the PIF-Aryl:PDI top-layer are also addressed. Charge transfer reactions dominate at the TFB/PIF-Aryl:PDI interface but no significant contribution in the photocurrent generation is seen in the photoaction spectra of the bilayer device.

  4. Capacitance and Conductance-Frequency Characteristics of Au/ n-Si Schottky Structure with Perylene-Diimide (PDI) Organic Interlayer

    NASA Astrophysics Data System (ADS)

    Yüksel, Ö. F.; Kuş, M.; Yıldırım, M.

    2017-02-01

    We report the interface properties of a perylene-diimide thin film between Au and n-Si substrate fabricated by the spin coating method. The relaxation time ( τ) and interface trap density ( D it) characteristics of the fabricated structure were obtained across various voltage ranges (0.0 V-300 mV) and various frequency ranges (1 kHz-1 MHz). We observed a peak in G it/ ω versus log ( f) plots from 0.0 V to 300 mV. This peak shows the presence of the interface state and its relaxation time. We observed a decrease in values at the same time as an increase in N ss values with the increasing applied voltage for the sample. The N ss and τ values found to be in the ranges 1.50 × 1012 eV-1 cm-2-2.83 × 1012 eV-1 cm-2 and 2.83 × 10-6 s-4.82 × 10-7 s between 0.0 V and 0.3 V, respectively.

  5. A universal aptameric biosensor: Multiplexed detection of small analytes via aggregated perylene-based broad-spectrum quencher.

    PubMed

    Hu, Rong; Zhang, Xi; Xu, Qiang; Lu, Dan-Qing; Yang, Yun-Hui; Xu, Quan-Qing; Ruan, Qiong; Mo, Liu-Ting; Zhang, Xiao-Bing

    2017-06-15

    A universal aptameric system based on the taking advantage of double-stranded DNA/perylene diimide (dsDNA/PDI) as the signal probe was developed for multiplexed detection of small molecules. Aptamers are single-stranded DNA or RNA oligonucleotides which are selected in vitro by a process known as systematic evolution of ligands by exponential enrichment. In this work, we synthesized a new kind of PDI and reported this aggregated PDI could quench the double-stranded DNA (dsDNA)-labeled fluorophores with a high quenching efficiency. The quenching efficiencies on the fluorescence of FAM, TAMRA and Cy5 could reach to 98.3%±0.9%, 97.2%±0.6% and 98.1%±1.1%, respectively. This broad-spectrum quencher was then adopted to construct a multicolor biosensor via a label-free approach. A structure-switching-triggered enzymatic recycling amplification was employed for signal amplification. High quenching efficiency combined with autocatalytic target recycling amplification afforded the biosensor with high sensitivity towards small analytes. For other targets, changing the corresponding aptamer can achieve the goal. The quencher did not interfere with the catalytic activity of nuclease. The biosensor could be manipulated with similar sensitivity no matter in pre-addition or post-addition manner. Moreover, simultaneous and multiplexed analysis of several small molecules in homogeneous solution was achieved, demonstrating its potential application in the rapid screening of multiple biotargets. Copyright © 2017 Elsevier B.V. All rights reserved.

  6. Perylene Bisimide as a Promising Zinc Oxide Surface Modifier: Enhanced Interfacial Combination for Highly Efficient Inverted Polymer Solar Cells.

    PubMed

    Nian, Li; Zhang, Wenqiang; Wu, Siping; Qin, Leiqiang; Liu, Linlin; Xie, Zengqi; Wu, Hongbin; Ma, Yuguang

    2015-11-25

    We report the application of a perylene bisimide (PBI-H) as zinc oxide (ZnO) surface modifier to afford an organic-inorganic co-interlayer for highly efficient inverted organic photovoltaics (i-OPV). By thermal annealing, a N-Zn chemical bond formed between PBI-H and ZnO, inducing close organic-inorganic combination. In addition, this co-interlayer shows decreased work function and increased electron transportation and conductivity, which are benefits for the cathode to enhance charge extraction efficiency and decrease recombination losses. As a result a highly efficient i-OPV was achieved with a power conversion efficiency (PCE) of 9.43% based on this co-interlayer with PTB7:PC71BM as the active layer, which shows over 35% enhancement compared to that of the device without the PBI-H layer. Moreover, this co-interlayer was widely applicable for i-OPVs based on various material systems, such as P3HT:PC61BM and PTB7-Th:PC71BM, resulting in PCE as high as 4.78% and 10.31%, respectively.

  7. Synthesis, characterization and binding interactions of amino acids coupled perylene diimides with colloidal doped and undoped TiO2

    NASA Astrophysics Data System (ADS)

    Kavery, E.; Nagarajan, N.; Paramaguru, G.; Renganathan, R.

    2015-07-01

    Two sensitizers based on amino acids coupled with perylene moiety having absorption in the visible region have been designed and their interaction with doped and undoped TiO2 for the application of dye sensitized solar cells (DSSCs) has been studied. The synthesized compounds PDI-PA and PDI-AA were characterized using 1H and 13C NMR, Mass and FT-IR spectroscopic techniques. The optical properties and lifetime measurements of the sensitizers were analyzed using various solvents with different polarity. The solvatochromism effect was studied using Lippert-Mataga plot. The electrochemical studies of both dyes were investigated in DMF with various scan rate ranging from 200 to 1000 mV s-1. Colloidal doped and undoped TiO2 was prepared and characterized by using absorption measurements. Binding ability of the sensitizers with the nanoparticles was studied through absorption, fluorescence quenching, cyclic voltammetry and FT-IR measurements. Results obtained from all the above analysis suggest the mode of quenching may be static. The binding constant values were calculated using Kamat-Fox equation indicates the binding behavior of the sensitizers with the nanoparticles. The fluorescence quenching was mainly attributed to electron transfer from the excited state of PDI's to the conduction band of colloidal semiconductors. The electron transfer mechanism was explained based on the Rehm-Weller equation as well as the energy level diagram.

  8. Enhanced short-circuit current density in poly(3-hexylthiophene) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 based organic solar cells by doping small molecular perylene

    NASA Astrophysics Data System (ADS)

    Lou, Yanhui; Wang, Zhaokui; Naka, Shigeki; Okada, Hiroyuki

    2011-07-01

    The authors investigate the effects of a small molecular dye, perylene, on the performance of organic solar cells based on poly(3-hexylthiophene) (P3HT) and 1-(3-methoxycarbonyl)-propyl-1-phenyl-(6,6)C61 (PCBM) blends. The short-circuit current density is improved, and a maximum 27% enhancement in power conversion efficiency is achieved by doping suitable perylene into P3HT:PCBM blends. It is attributed to be the enhanced absorption of perylene doped P3HT:PCBM blends, which is also confirmed in single-carrier devices. Moreover, the barrier height at the anode/blend is largely lowered from 0.61 eV to 0.28 eV through evaluating temperature dependence of current-voltage characteristics.

  9. Fluorescence of the perylene radical cation and an inaccessible D0/D1 conical intersection: An MMVB, RASSCF, and TD-DFT computational study

    NASA Astrophysics Data System (ADS)

    Tokmachev, Andrei M.; Boggio-Pasqua, Martial; Mendive-Tapia, David; Bearpark, Michael J.; Robb, Michael A.

    2010-01-01

    The photophysics of the perylene radical cation (Pe•+) was studied using the molecular mechanics-valence bond (MMVB) hybrid force field. Potential energy surfaces of the first three electronic states were investigated. Geometry optimizations of critical points—including conical intersections between the relevant electronic states—were performed using the MMVB analytical energy gradient for cations. No accessible planar conical intersection between the D0 and D1 states of Pe•+ was found; this is consistent with the experimentally observed D1 lifetimes and the observation of D1 emission from this cation in the condensed phase. Benchmark RASSCF and TD-DFT calculations support the reliability of the MMVB results.

  10. Self-repairing complex helical columns generated via kinetically controlled self-assembly of dendronized perylene bisimides.

    PubMed

    Percec, Virgil; Hudson, Steven D; Peterca, Mihai; Leowanawat, Pawaret; Aqad, Emad; Graf, Robert; Spiess, Hans W; Zeng, Xiangbing; Ungar, Goran; Heiney, Paul A

    2011-11-16

    The dendronized perylene 3,4:9,10-tetracarboxylic acid bisimide (PBI), (3,4,5)12G1-3-PBI, was recently reported to self-assemble in complex helical columns containing tetramers of PBI as basic repeat unit. These tetramers contain a pair of two molecules arranged side-by-side and another pair in the next stratum of the column turned upside-down and rotated around the column axis. Intra- and intertetramer rotation angles and stacking distances are different. At high temperature, (3,4,5)12G1-3-PBI self-assembles via a thermodynamically controlled process in a 2D hexagonal columnar phase while at low temperature in a 3D orthorhombic columnar array via a kinetically controlled process. Here, we report the synthesis and structural analysis, by a combination of differential scanning calorimetry, X-ray and electron diffraction, and solid-state NMR performed at different temperatures, on the supramolecular structures generated by a library of (3,4,5)nG1-3-PBI with n = 14-4. For n = 11-8, the kinetically controlled self-assembly from low temperature changes in a thermodynamically controlled process, while the orthorhombic columnar array for n = 9 and 8 transforms from the thermodynamic product into the kinetic product. The new thermodynamic product at low temperature for n = 9, 8 is a self-repaired helical column with an intra- and intertetramer distance of 3.5 Å forming a 3D monoclinic periodic array via a kinetically controlled self-assembly process. The complex dynamic process leading to this reorganization was elucidated by solid-state NMR and X-ray diffraction. This discovery is important for the field of self-assembly and for the molecular design of supramolecular electronics and solar cell.

  11. Benzo[ghi]perylene activates the AHR pathway to exert biological effects on the NL-20 human bronchial cell line.

    PubMed

    Zaragoza-Ojeda, Montserrat; Eguía-Aguilar, Pilar; Perezpeña-Díazconti, Mario; Arenas-Huertero, Francisco

    2016-08-10

    Polycyclic aromatic hydrocarbons (PAH) are produced by incomplete combustion of organic material. In the Mexico City atmosphere, the most abundant PAH is benzo[ghi]perylene (BghiP), a gasoline combustion marker. At present, there are no reports of the effects of BghiP on human bronchial cells, so the aim of the study was to evaluate the effects in vitro of BghiP on the NL-20 cell line. Results showed that BghiP induced the formation of small vesicles throughout the cytoplasm, with absence of nuclear fragmentation. At 48h exposition, damage in cell membrane increased significantly at 1.24μg/mL of BghiP (p<0.05). Immunocytochemistry revealed that BghiP provokes nuclear translocation of AhR receptor, which indicates that this compound can induce transcription of genes via receptor binding (AhR pathway activation). BghiP induced a two-fold increase (p<0.05) in the expression of AhR and CYP4B1 (a lung-specific pathway effector). In the presence of the receptor antagonist CH-223191, the loss of viability, the nuclear translocation and the overexpression of genes decreased, though this did not prevent the formation of vesicles. BghiP induced oxidative stress and in presence of the receptor antagonist this increased significantly. In conclusion, BghiP can activate the overexpression of AhR and CYP4B1, and the effects are abated by the AhR receptor antagonist. This is the first report to prove that BghiP utilizes the AhR pathway to exert its toxic effects on the NL-20 human bronchial cell line .

  12. Perylene-Diimide Based Donor-Acceptor-Donor Type Small-Molecule Acceptors for Solution-Processable Organic Solar Cells

    NASA Astrophysics Data System (ADS)

    Ganesamoorthy, Ramasamy; Vijayaraghavan, Rajagopalan; Sakthivel, Pachagounder

    2017-08-01

    Development of nonfullerene acceptors plays an important role in the commercial availability of plastic solar cells. We report herein synthesis of bay-substituted donor-acceptor-donor (D-A-D)-type perylene diimide (PDI)-based small molecules (SM-1 to SM-4) by Suzuki coupling method and their use as acceptors in bulk heterojunction organic solar cells (BHJ-OSCs) with poly(3-hexylthiophene) (P3HT) polymer donor. We varied the number of electron-rich thiophene units and the solubilizing side chains and also evaluated the optical and electrochemical properties of the small molecules. The synthesized small molecules were confirmed by Fourier-transform infrared (FT-IR) spectroscopy, nuclear magnetic resonance (NMR) spectroscopy, and high-resolution mass spectroscopy (HR-MS). The small molecules showed extensive and strong absorption in the ultraviolet-visible (UV-Vis) region up to 750 nm, with bandgap (E_{{g}}^{{opt}} ) reduced below <2 eV. The energy levels of small molecules SM-1 to SM-4 were suitable for use as electron-accepting materials. The small molecules showed good thermal stability up to 300°C. BHJ-OSCs with SM-1 and P3HT polymer donor showed maximum power conversion efficiency (PCE) of 0.19% with V oc of 0.30 V, J sc of 1.72 mA cm-2, and fill factor (FF) of 37%. The PCE decreased with the number of thiophene units. The PCE of SM-2 was lower than that of SM-1. This difference in PCE can be explained by the higher aggregation tendency of the bithiophene compared with the thiophene unit. Introduction of the solubilizing group in the bay position increased the aggregation property, leading to much lower PCE than for the small molecules without solubilizing group.

  13. Aspartic acid functionalized water-soluble perylene diimide as "Off-On" fluorescent sensor for selective detection Cu(2+) and ATP.

    PubMed

    Zhong, Lina; Xing, Feifei; Bai, Yueling; Zhao, Yongmei; Zhu, Shourong

    2013-11-01

    Aspartic functionalized water-soluble perylene diimide, N,N'-di(2-succinic acid)-perylene-3,4,9,10-tetracarboxylic diimide (PASP) has two absorbance maximums at 527 and 498nm (ε≈1.7×10(4)Lcm(-1)mol(-1)) and two emission peaks at 547 and 587nm respectively. Emission intensities decrease with the increase of PASP concentrations in 20-100μM ranges. Spectral titrations demonstrate that each PASP can coordinate to two Cu(2+) ions in the absence of HEPES buffer. Its stability constant is estimated to be about 1.0×10(12)L(2)mol(-2) at pH 7.20 and its coordinate stoichiometry increased to 7.5 in the same pH in the presence of HEPES buffer. The emission of PASP will be completely quenched upon formation of Cu(2+) complex. The lowest "turn-off" fluorescence detection limit was calculated to be 0.3μM Cu(2+). PASP-Cu solution was used as a "turn-on" fluorescence biosensor to detect ATP. The sensitivity towards ATP is 0.3μM in 50mM HEPES buffer at pH 7.20, which is one of the most sensitive fluorescence sensors.

  14. Determination of the individual atomic site contribution to the electronic structure of 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA)

    NASA Astrophysics Data System (ADS)

    Cho, S. W.; Newby, D.; DeMasi, A.; Smith, K. E.; Piper, L. F. J.; Jones, T. S.

    2013-11-01

    We have studied the element and orbital-specific electronic structure of thin films of 3,4,9,10-perylene-tetracarboxylic-dianhydride (PTCDA) using a combination of synchrotron radiation-exited resonant x-ray emission spectroscopy, x-ray absorption spectroscopy, x-ray photoelectron spectroscopy, as well as density functional theory calculations. Resonant and non-resonant x-ray emission spectroscopies were used to measure the C and O 2p partial densities of state in PTCDA. Furthermore, resonant x-ray emission at the C and O K-edges is shown to be able to measure the partial densities of states associated with individual atomic sites. The flat molecular orientation of PTCDA on various substrates is explained in terms of the carbonyl O atom acting as a hydrogen-bond acceptor leading to multiple in-plane intermolecular C=O...H-C hydrogen bonding between carbonyl groups and the perylene core of the neighboring PTCDA molecules. We support this conclusion by comparison of our calculations to measurements of the electronic structure using element-, site-, and orbital-selective C and O K-edge resonant x-ray emission spectroscopy, and photoemission spectroscopy.

  15. Aspartic acid functionalized water-soluble perylene diimide as “Off-On” fluorescent sensor for selective detection Cu2+ and ATP

    NASA Astrophysics Data System (ADS)

    Zhong, Lina; Xing, Feifei; Bai, Yueling; Zhao, Yongmei; Zhu, Shourong

    2013-11-01

    Aspartic functionalized water-soluble perylene diimide, N,N‧-di(2-succinic acid)-perylene-3,4,9,10-tetracarboxylic diimide (PASP) has two absorbance maximums at 527 and 498 nm (ε ≈ 1.7 × 104 L cm-1 mol-1) and two emission peaks at 547 and 587 nm respectively. Emission intensities decrease with the increase of PASP concentrations in 20-100 μM ranges. Spectral titrations demonstrate that each PASP can coordinate to two Cu2+ ions in the absence of HEPES buffer. Its stability constant is estimated to be about 1.0 × 1012 L2 mol-2 at pH 7.20 and its coordinate stoichiometry increased to 7.5 in the same pH in the presence of HEPES buffer. The emission of PASP will be completely quenched upon formation of Cu2+ complex. The lowest "turn-off" fluorescence detection limit was calculated to be 0.3 μM Cu2+. PASP-Cu solution was used as a "turn-on" fluorescence biosensor to detect ATP. The sensitivity towards ATP is 0.3 μM in 50 mM HEPES buffer at pH 7.20, which is one of the most sensitive fluorescence sensors.

  16. The electronic character of PTCDA thin films in comparison to other perylene-based organic semi-conductors: ab initio-, TD-DFT and semi-empirical computations of the opto-electronic properties of large aggregates.

    PubMed

    Bellinger, Daniel; Pflaum, Jens; Brüning, Christoph; Engel, Volker; Engels, Bernd

    2017-01-18

    Perylene-based compounds are promising materials for opto-electronic thin film devices but despite intense investigations, important details of their electronic structure are still under debate. For perylene-3,4,9,10-tetracarboxylic dianhydrid (PTCDA), the theoretical models predict a different relative energetic order of Frenkel and Charge Transfer (CT) states. Additionally, while one model indicates strong differences between PTCDA on one hand and other perylene-based compounds on the other, recent ab initio computations indicate electronic properties of all perylene-based compounds to resemble each other. Finally, the models disagree about the amount of mixing between CT and Frenkel states. Definitive answers to these questions are difficult because the approaches use various approximations. Up to date, the ab initio based methods employ rather small model systems and neglect environmental effects. In the present work, we improve our former approach by analyzing the effects of the various simplifications. In more detail, we increase the size of the model systems, include environmental effects and investigate the influence of exciton-phonon couplings on the absorption spectrum. The computations for larger aggregates were performed with the ZINDO/S approach, because benchmark computations show that it provides accurate vertical excitation energies for Frenkel, as well as CT states.

  17. Structure of vacant electronic states of an oxidized germanium surface upon deposition of perylene tetracarboxylic dianhydride films

    NASA Astrophysics Data System (ADS)

    Komolov, A. S.; Lazneva, E. F.; Gerasimova, N. B.; Panina, Yu. A.; Baramygin, A. V.; Zashikhin, G. D.; Pshenichnyuk, S. A.

    2016-02-01

    This paper presents the results of the investigation of the interface potential barrier and vacant electronic states in the energy range of 5 to 20 eV above the Fermi level ( E F) in the deposition of perylene tetracarboxylic dianhydride (PTCDA) films on the oxidized germanium surface ((GeO2)Ge). The concentration of oxide on the (GeO2)Ge surface was determined by X-ray photoelectron spectroscopy. In the experiments, we used the recording of the reflection of a test low-energy electron beam from the surface, implemented in the mode of total current spectroscopy. The theoretical analysis involves the calculation of the energy and spatial distribution of the orbitals of PTCDA molecules by the density functional theory (DFT) using B3LYP functional with the basis 6-31G(d), followed by the scaling of the calculated values of the orbital energy according to the procedure well-proven in the studies of small organic conjugated molecules. The pattern of changes in the fine structure of the total current spectra with increasing thickness of the PTCDA coating on the (GeO2)Ge surface to 6 nm was studied. At energies below 9 eV above E F, there is a maximum of the density of unoccupied electron states in the PTCDA film, formed mainly by π* molecular orbitals. The higher density maxima of unoccupied states are of σ* nature. The formation of the interface potential barrier in the deposition of PTCDA at the (GeO2)Ge surface is accompanied by an increase in the work function of the surface, E vac- E F, from 4.6 ± 0.1 to 4.9 ± 0.1 eV. This occurs when the PTCDA coating thickness increases to 3 nm, and upon further deposition of PTCDA, the work function of the surface does not change, which corresponds to the model of formation of a limited polarization layer in the deposited organic film.

  18. A new fluorogenic sensing platform for salicylic acid derivatives based on π-π and NH-π interactions between electron-deficient and electron-rich aromatics

    NASA Astrophysics Data System (ADS)

    Pandith, Anup; Hazra, Giridhari; Kim, Hong-Seok

    2017-05-01

    A novel simple fluorescent probe was designed for the recognition of electron-rich salicylic acid derivatives (SAs). The imidazole-appended aminomethyl perylene probe 1 selectively differentiated between electron-rich amino-SAs and electron-deficient nitro-SAs in EtOH, exhibiting the highest selectivity and sensitivity toward 5-aminosalicylic acid (5-ASA) and showing strong 1:1 binding (Ka = 1.37 × 107 M- 1). This high selectivity and sensitivity resulted from the synergistic multiple hydrogen bonding interactions of secondary amine and imidazole units and π-π interactions between electron-rich and electron-deficient rings, along with the unusual NH-π interactions between 5-ASA and the perylene moiety of 1. The limit of detection (LOD) for 5-ASA in EtOH was 0.012 ppb.

  19. A new fluorogenic sensing platform for salicylic acid derivatives based on π-π and NH-π interactions between electron-deficient and electron-rich aromatics.

    PubMed

    Pandith, Anup; Hazra, Giridhari; Kim, Hong-Seok

    2017-02-03

    A novel simple fluorescent probe was designed for the recognition of electron-rich salicylic acid derivatives (SAs). The imidazole-appended aminomethyl perylene probe 1 selectively differentiated between electron-rich amino-SAs and electron-deficient nitro-SAs in EtOH, exhibiting the highest selectivity and sensitivity toward 5-aminosalicylic acid (5-ASA) and showing strong 1:1 binding (Ka=1.37×10(7)M(-1)). This high selectivity and sensitivity resulted from the synergistic multiple hydrogen bonding interactions of secondary amine and imidazole units and π-π interactions between electron-rich and electron-deficient rings, along with the unusual NH-π interactions between 5-ASA and the perylene moiety of 1. The limit of detection (LOD) for 5-ASA in EtOH was 0.012ppb.

  20. 60Co gamma irradiation effects on the the capacitance and conductance characteristics of Au/PMI/n-Si Schottky diodes

    NASA Astrophysics Data System (ADS)

    Tuğluoğlu, N.; Karadeniz, S.; Yüksel, Ö. F.; Şafak, H.; Kuş, M.

    2015-08-01

    In this work, the perylene-monoimide/n-Si (100) Schottky structures have been fabricated by spin coating process. We have studied the capacitance-voltage ( C- V) and conductance-voltage ( G- V) characteristics of the Au/perylene-monoimide/n-Si diodes at 500 kHz before and after 60Co γ-ray irradiation. The effects of 60Co γ -ray irradiation on the electrical characteristics of a perylene-monoimide/n-Si Schottky diode have been investigated. A decrease both in the capacitance and conductance has been observed after 60Co γ -ray irradiation. This has been attributed to a decrease in the net ionized dopant concentration that occurred as a result of 60Co γ-ray irradiation. Some contact parameters such as barrier height (Φ B ) interface state density ( N ss ) and series resistance ( R s ) have been calculated from the C- V and G- V characteristics of the diode before and after irradiation. It has been observed that the Φ B and N ss values are decreased after the applied radiation, while the R s value is increased.

  1. Triplet formation by charge recombination in thin film blends of perylene red and pyrene: developing a target model for the photophysics of organic photovoltaic materials.

    PubMed

    Williams, René M; Vân Anh, Nguyễn; van Stokkum, Ivo H M

    2013-09-26

    Photoinduced charge separation in a mixture of Perylene Red (N,N'-bis(2,6-di-isopropylphenyl)-1,6,7,12-tetraphenoxyperylene-3,4:9,10-tetracarboxylic acid bis-imide) and pyrene, organized in thin solid film on quartz, was studied by means of steady-state absorption and emission spectroscopy and by femtosecond transient absorption spectroscopy. Steady state spectroscopy shows substantial interaction between the two chromophores in the ground and excited states. Luminescence quenching indicates charge transfer interaction. Global and target analysis of the transient absorption data indicates a complex photophysical behavior with the formation of long-lived charges (free charge carriers) and of a triplet excited state species (with rates of ∼10.4 × 10(9) and 72.1 × 10(6) s(-1)) via charge recombination pathways from charged states. A generally applicable target model for the analysis of photophysical data of photovoltaic blends is developed.

  2. Effects of Side-Chain and Electron Exchange Correlation on the Band Structure of Perylene Diimide Liquid Crystals: A Density Functional Study

    SciTech Connect

    Arantes, J. T.; Lima, M. P.; Fazzio, A.; Xiang, H.; Wei, S. H.; Dalpian, G. M.

    2009-04-01

    The structural and electronic properties of perylene diimide liquid crystal PPEEB are studied using ab initio methods based on the density functional theory (DFT). Using available experimental crystallographic data as a guide, we propose a detailed structural model for the packing of solid PPEEB. We find that due to the localized nature of the band edge wave function, theoretical approaches beyond the standard method, such as hybrid functional (PBE0), are required to correctly characterize the band structure of this material. Moreover, unlike previous assumptions, we observe the formation of hydrogen bonds between the side chains of different molecules, which leads to a dispersion of the energy levels. This result indicates that the side chains of the molecular crystal not only are responsible for its structural conformation but also can be used for tuning the electronic and optical properties of these materials.

  3. Morphology and molecular arrangement of perylene-3,4,9,10-(n-pentylester) in thin layers obtained by zone-casting

    NASA Astrophysics Data System (ADS)

    Adamski, Adrian; Nowicka, Ariadna B.; Barszcz, Bolesław; Szybowicz, Mirosław; Piosik, Emilia; Wolarz, Eryk

    2016-08-01

    Liquid-crystalline perylene-3,4,9,10-tetra-(n-pentylester) zone-casted on hydrophilic glass substrates forms characteristic belt-like structures which are observed under optical microscope and atomic force microscope. Polarised Raman scattering spectra reveal the presence of anisotropic alignment of the molecules inside the obtained structures. Moreover, the absorption and fluorescence spectra confirm molecular aggregation in the belt-like structures. The research shows, that the belt-like structures are created by columns of molecules with the edge-on alignment on the glass substrate. Such organisation of the molecules is confirmed by spectroscopic methods. These structures can be interesting from the point of view of organic electronics.

  4. Deriving molecular bonding from a macromolecular self-assembly using kinetic Monte Carlo simulations

    NASA Astrophysics Data System (ADS)

    Silly, Fabien; Weber, Ulrich K.; Shaw, Adam Q.; Burlakov, Victor M.; Castell, Martin R.; Briggs, G. A. D.; Pettifor, David G.

    2008-05-01

    Macromolecules can form regular structures on inert surfaces. We have developed a combined empirical and modeling approach to derive the bonding. From experimental scanning tunneling microscopy images of structures formed on Au(111) by melamine, by 3,4,9,10-perylene-tetracarboxylic-dianhydride, and by a 2:3 mixture of the two, we determine the molecular bonding morphologies. Within these bonding morphologies and by recognizing the distinction between cohesive and adhesive molecular interactions, we simultaneously simulated different molecular structures by using a lattice Monte Carlo method.

  5. A novel water-soluble fluorescent polymer based on perylene bisimides dyes: one-pot preparation and its bio-imaging.

    PubMed

    Tan, Haijian; Liu, Hongmei; Liu, Yaojun; Duan, Wenfeng; Yi, Xuegang; Wu, Yonggang; Zhao, Hongchi; Bai, Libin

    2016-01-01

    Perylene bisimides dye-based water-soluble fluorescent polymer P3, N,N'-bis(3-amyl)-1-bromo-7-{4'-[3''-(S-poly(N-acryloyl ethylene diamine hydrochloride)-2'''-methyl propionic acid)propionyloxy hexyloxy]phenyl} perylene-3,4:9,10-tetracarboxylic bisimides, was synthesized with polyelectrolyte modification via one-pot reaction (the reduction reaction of trithioester and click reaction between the thiol group and carbon-carbon double bond were simultaneously conducted in one pot with high conversion). One-pot method can overcome the limitation that usual click reaction between thiol and other groups has low conversion because thiol group is subject to rapid oxidation during purification and storage. Chemical, structural, and optical properties of P3 and intermediate products were fully characterized by nuclear magnetic resonance spectroscopy, Fourier transform infrared, gel permeation chromatograph, UV-vis spectra, and fluorescence spectra, respectively. The results revealed that P3 displayed excellent water solubility and not only exhibited red strong fluorescence emission band in water but also had the similar photoluminescent spectra to those of intermediate products (M4 and P2) in chloroform. Allowing for the potential application in biological detection field, cell viability and live cell imaging with the presence of P3 were further investigated with Hela cells. The results showed that P3 had low cytotoxicity with strong intracellular fluorescence entry. Meanwhile, with the augment of concentration of P3 (0-0.500 mg mL(-1)), the cell uptake and accumulation of P3 increased and thereby result in enhancement of the intracellular fluorescence. These experiment results suggested that P3 had enormous potential as a fluorescence probe to be an important component in biological detection field.

  6. Bright Fluorescence and Host-Guest Sensing with a Nanoscale M₄L₆ Tetrahedron Accessed by Self-Assembly of Zinc-Imine Chelate Vertices and Perylene Bisimide Edges.

    PubMed

    Frischmann, Peter D; Kunz, Valentin; Würthner, Frank

    2015-06-15

    A highly luminescent Zn4L6 tetrahedron is reported with 3.8 nm perylene bisimide edges and hexadentate Zn(II)-imine chelate vertices. Replacing Fe(II) and monoamines commonly utilized in subcomponent self-assembly with Zn(II) and tris(2-aminoethyl)amine provides access to a metallosupramolecular host with the rare combination of structural integrity at concentrations <10(-7) mol L(-1) and an exceptionally high fluorescence quantum yield of Φ(em) =0.67. Encapsulation of multiple perylene or coronene guest molecules is accompanied by strong luminescence quenching. We anticipate this self-assembly strategy may be generalized to improve access to brightly fluorescent coordination cages tailored for host-guest light-harvesting, photocatalysis, and sensing.

  7. Push-Pull Type Oligo(N-annulated perylene)quinodimethanes: Chain Length and Solvent-Dependent Ground States and Physical Properties.

    PubMed

    Zeng, Zebing; Lee, Sangsu; Son, Minjung; Fukuda, Kotaro; Burrezo, Paula Mayorga; Zhu, Xiaojian; Qi, Qingbiao; Li, Run-Wei; Navarrete, Juan T López; Ding, Jun; Casado, Juan; Nakano, Masayoshi; Kim, Dongho; Wu, Jishan

    2015-07-08

    Research on stable open-shell singlet diradicaloids recently became a hot topic because of their unique optical, electronic, and magnetic properties and promising applications in materials science. So far, most reported singlet diradicaloid molecules have a symmetric structure, while asymmetric diradicaloids with an additional contribution of a dipolar zwitterionic form to the ground state were rarely studied. In this Article, a series of new push-pull type oligo(N-annulated perylene)quinodimethanes were synthesized. Their chain length and solvent-dependent ground states and physical properties were systematically investigated by various experimental methods such as steady-state and transient absorption, two-photon absorption, X-ray crystallographic analysis, electron spin resonance, superconducting quantum interference device, Raman spectroscopy, and electrochemistry. It was found that with extension of the chain length, the diradical character increases while the contribution of the zwitterionic form to the ground state becomes smaller. Because of the intramolecular charge transfer character, the physical properties of this push-pull system showed solvent dependence. In addition, density functional theory calculations on the diradical character and Hirshfeld charge were conducted to understand the chain length and solvent dependence of both symmetric and asymmetric systems. Our studies provided a comprehensive understanding on the fundamental structure- and environment-property relationships in the new asymmetric diradicaloid systems.

  8. High-mobility, air stable bottom-contact n-channel thin film transistors based on N,N′-ditridecyl perylene diimide

    SciTech Connect

    Ma, Lanchao; Guo, Yunlong; Wen, Yugeng; Liu, Yunqi E-mail: liuyq@iccas.ac.cn; Zhan, Xiaowei E-mail: liuyq@iccas.ac.cn

    2013-11-11

    Bottom-gate bottom-contact (BGBC) organic thin film transistors (OTFTs) based on N,N′-ditridecyl perylene diimide exhibit electron mobility as high as 3.54 cm{sup 2} V{sup −1} s{sup −1} in nitrogen, higher than that (1 cm{sup 2} V{sup −1} s{sup −1}) of bottom-gate top-contact devices. The better performance of BGBC configuration in N{sub 2} is attributed to lower contact resistance, which is further reduced by thermal annealing. After thermally annealing the BGBC OTFTs at 180 °C, electron mobility as high as 3.5 cm{sup 2} V{sup −1} s{sup −1}, current on/off ratio of 10{sup 6} and threshold voltage of 9 V are achieved in air, and the mobility retains above 1 cm{sup 2} V{sup −1} s{sup −1} after storage for two months in air. Thermal treatment enhanced crystalline grains, reduced grain boundaries, and suppressed the adsorption of H{sub 2}O and O{sub 2}, leading to excellent performance in air.

  9. Franck-Condon factors perturbed by damped harmonic oscillators: Solvent enhanced X 1Ag ↔ A1B1u absorption and fluorescence spectra of perylene

    NASA Astrophysics Data System (ADS)

    Wang, Chen-Wen; Yang, Ling; Zhu, Chaoyuan; Yu, Jian-Guo; Lin, Sheng-Hsien

    2014-08-01

    Damped harmonic oscillators are utilized to calculate Franck-Condon factors within displaced harmonic oscillator approximation. This is practically done by scaling unperturbed Hessian matrix that represents local modes of force constants for molecule in gaseous phase, and then by diagonalizing perturbed Hessian matrix it results in direct modification of Huang-Rhys factors which represent normal modes of solute molecule perturbed by solvent environment. Scaling parameters are empirically introduced for simulating absorption and fluorescence spectra of an isolated solute molecule in solution. The present method is especially useful for simulating vibronic spectra of polycyclic aromatic hydrocarbon molecules in which hydrogen atom vibrations in solution can be scaled equally, namely the same scaling factor being applied to all hydrogen atoms in polycyclic aromatic hydrocarbons. The present method is demonstrated in simulating solvent enhanced X 1Ag ↔ A1B1u absorption and fluorescence spectra of perylene (medium-sized polycyclic aromatic hydrocarbon) in benzene solution. It is found that one of six active normal modes v10 is actually responsible to the solvent enhancement of spectra observed in experiment. Simulations from all functionals (TD) B3LYP, (TD) B3LYP35, (TD) B3LYP50, and (TD) B3LYP100 draw the same conclusion. Hence, the present method is able to adequately reproduce experimental absorption and fluorescence spectra in both gas and solution phases.

  10. Exciton-Vibrational Couplings in Homo- and Heterodimer Stacks of Perylene Bisimide Dyes within Cyclophanes: Studies on Absorption Properties and Theoretical Analysis.

    PubMed

    Bialas, David; Brüning, Christoph; Schlosser, Felix; Fimmel, Benjamin; Thein, Johannes; Engel, Volker; Würthner, Frank

    2016-10-10

    The optical properties of a series of three cyclophanes comprising either identical or different perylene bisimide (PBI) chromophores were studied by UV/Vis absorption spectroscopy and their distinctive spectral features were analyzed. All the investigated cyclophanes show significantly different absorption features with respect to the corresponding constituent PBI monomers indicating strong coupling interactions between the PBI units within the cyclophanes. DFT calculations suggest a π-stacked arrangement of the PBI units at close van der Waals distance in the cyclophanes with rotational displacement. Simulations of the absorption spectra based on time-dependent quantum mechanics properly reproduced the experimental spectra, revealing exciton-vibrational coupling between the chromophores both in homo- and heterodimer stacks. The PBI cyclophane comprising two different PBI chromophores represents the first example of a PBI heterodimer stack for which the exciton coupling has been investigated. The quantum dynamics analysis reveals that exciton coupling in heteroaggregates is indeed of similar strength as for homoaggregates. © 2016 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

  11. An amplified electrochemiluminescent aptasensor using Au nanoparticles capped by 3,4,9,10-perylene tetracarboxylic acid-thiosemicarbazide functionalized C60 nanocomposites as a signal enhancement tag

    NASA Astrophysics Data System (ADS)

    Ma, Meng-Nan; Zhang, Xia; Zhuo, Ying; Chai, Ya-Qin; Yuan, Ruo

    2015-01-01

    A novel electrochemiluminescent (ECL) signal tag of Au nanoparticles capped by 3,4,9,10-perylene tetracarboxylic acid-thiosemicarbazide functionalized C60 nanocomposites (AuNPs/TSC-PTC/C60NPs) was developed for thrombin (TB) aptasensor construction based on the peroxydisulfate/oxygen (S2O82-/O2) system. For signal tag fabrication, the C60 nanoparticles (C60NPs) were prepared and then coated with 3,4,9,10-perylene tetracarboxylic acid (PTCA) by π-π stacking interactions. Afterwards, thiosemicarbazide (TSC) was linked with PTCA functionalized C60NPs via amidation for further assembling Au nanoparticles (AuNPs). Finally, detection aptamer of thrombin (TBA 2) was labeled on the ECL signal amplification tag of AuNPs/TSC-PTC/C60NPs. Herein, TSC, with the active groups of -NH2 and -SH, was selected and introduced into the ECL S2O82-/O2 system for the first time, which could not only offer the active groups of -SH to absorb AuNPs for TBA 2 anchoring but also remarkably enhance the ECL signal of the S2O82-/O2 system by the formation of TSC-PTC/C60NPs for signal amplification. Meanwhile, the sensing interface of a glassy carbon electrode (GCE) was modified by AuNPs/graphene (AuNPs/GR) nanocomposites with the large specific surface area and the active sites, followed by immobilization of thiol-terminated thrombin capture aptamer (TBA 1). With the formation of the sandwich-type structure of TBA 1, TB, and TBA 2 signal probes, a desirable enhanced ECL signal was measured in the testing buffer of an S2O82-/O2 solution for detecting TB. The aptasensor exhibited a good linear relationship for TB detection in the range of 1 × 10-5-10 nM with a detection limit of 3.3 fM.A novel electrochemiluminescent (ECL) signal tag of Au nanoparticles capped by 3,4,9,10-perylene tetracarboxylic acid-thiosemicarbazide functionalized C60 nanocomposites (AuNPs/TSC-PTC/C60NPs) was developed for thrombin (TB) aptasensor construction based on the peroxydisulfate/oxygen (S2O82-/O2) system. For signal

  12. Photovoltaic properties of interfaces of organic films of substituted perylene with TiO{sub 2} and SnO{sub 2} surfaces

    SciTech Connect

    Komolov, A. S. Lazneva, E. F.; Komolov, S. A.; Busin, I. S.; Zimina, M. V.

    2011-02-15

    The photovoltaic effect has been detected and studied in structures based on ultrathin vacuum-deposited organic films of perylene-3,4,9,10-tetracarboxylic acid dianhydride on the titanium and tin dioxide surfaces. The interfacial potential barrier shape in these structures is studied by low-energy electron total current spectroscopy. Changes in the surface potential upon exposure to visible light are recorded in situ using an electron-beam probe with energies from 0 to 25 eV. The photovoltage is detected at incident photon energies of 1.5-2.5 eV, which corresponds to the organic film absorption range and simultaneously to the transmission band of titanium and tin dioxides. An analysis of the spectral distributions and transient responses shows that two components of the observed photovoltage can be distinguished. The relation of one of the components to the excitation of interband transitions in the organic film and another component to electronic transitions involving interfacial energy states are discussed.

  13. Perylene Bisimide Cyclophanes with High Binding Affinity for Large Planar Polycyclic Aromatic Hydrocarbons: Host-Guest Complexation versus Self-Encapsulation of Side Arms.

    PubMed

    Spenst, Peter; Sieblist, Andreas; Würthner, Frank

    2017-01-31

    Binding of guest molecules with high affinity and selectivity requires well-designed hosts to provide optimized interactions in the host-guest complexes. Herein we report the design and synthesis of new cyclophanes 2PBI(2,6-iPr)2 and 2PBI(2,6-Ph)2 based on core-disubstituted perylene bisimide (PBI) chromophores bearing two phenoxy bay-substituents that evoke almost planar PBI scaffolds. This strategy afforded the new cyclophanes with conformationally rigid cavities to ensure strong binding to stiff planar polycyclic aromatic hydrocarbons (PAHs). Our detailed host-guest binding studies with different PAHs by UV/Vis and fluorescence titration experiments revealed record binding strengths for PAHs with binding constants of up to 1.6×10(6)  m(-1) in chloroform at room temperature. One- and two-dimensional NMR experiments and solvent-dependent titration studies revealed self-encapsulation of the side arms of PBI bay-substituents into the cavities that attained high fluorescence quantum yields of these cyclophanes close to unity by preventing the interaction of PBI subunits in the excited states. The binding constants and Gibbs free energies of host-guest complexations disclosed significant effects of PBI bay-substituents and core twist on the binding affinity of the cyclophanes.

  14. Electronic Absorption Spectra of Neutral Perylene (C20H12), Terrylene (C30H16), and Quaterrylene (C40H20) and their Positive and Negative Ions: Ne Matrix-Isolation Spectroscopy and Time Dependent Density Functional Theory Calculations

    NASA Technical Reports Server (NTRS)

    Halasinski, Thomas M.; Weisman, Jennifer L.; Lee, Timothy J.; Salama, Farid; Head-Gordon, Martin; Kwak, Dochan (Technical Monitor)

    2002-01-01

    We present a full experimental and theoretical study of an interesting series of polycyclic aromatic hydrocarbons, the oligorylenes. The absorption spectra of perylene, terrylene and quaterrylene in neutral, cationic and anionic charge states are obtained by matrix-isolation spectroscopy in Ne. The experimental spectra are dominated by a bright state that red shifts with growing molecular size. Excitation energies and state symmetry assignments are supported by calculations using time dependent density functional theory methods. These calculations also provide new insight into the observed trends in oscillator strength and excitation energy for the bright states: the oscillator strength per unit mass of carbon increases along the series.

  15. Transformation from kinetically into thermodynamically controlled self-organization of complex helical columns with 3D periodicity assembled from dendronized perylene bisimides.

    PubMed

    Percec, Virgil; Sun, Hao-Jan; Leowanawat, Pawaret; Peterca, Mihai; Graf, Robert; Spiess, Hans W; Zeng, Xiangbing; Ungar, Goran; Heiney, Paul A

    2013-03-13

    The dendronized perylene 3,4:9,10-tetracarboxylic acid bisimide (PBI), (3,4,5)12G1-1-PBI, was reported by our laboratory to self-assemble into complex helical columns containing dimers of dendronized PBI with one molecule in each stratum, with different intra- and interdimer rotation angles but identical intra- and interdimer distance of 3.5 Å, exhibiting a four-strata 2(1) helical repeat. A thermodynamically controlled 2D columnar hexagonal phase with short-range intracolumnar order represents the thermodynamic product at high temperature, while a kinetically controlled monoclinic columnar array with 3D periodicity is the thermodynamic product at low temperature. With heating and cooling rates higher than 10 °C/min to 1 °C/min, at low temperature the 2D columnar periodic array is the kinetic product for this dendronized PBI. Here the synthesis and structural analysis of a library of (3,4,5)nG1-m-PBI with n = 12 to 6 and m = 1 are reported. A combination of differential scanning calorimetry, X-ray diffraction on powder and orientated fibers, including pattern simulation and electron density map reconstruction, and solid-state NMR, all as a function of temperature and heating and cooling rate, was employed for their structural analysis. It was discovered that at low temperature the as-prepared n = 12 to 10 exhibit a 3D layered array that transforms irreversibly into columnar periodicities during heating and cooling. Also the kinetically controlled 3D columnar phase of n = 12 becomes thermodynamically controlled for n = 10, 9, 8, 7, and 6. This unprecedented transformation is expected to facilitate the design of functions from dendronized PBI and other self-assembling building blocks.

  16. Nanoparticle Self-Assembled Grain Like Curcumin Conjugated ZnO: Curcumin Conjugation Enhances Removal of Perylene, Fluoranthene, and Chrysene by ZnO

    NASA Astrophysics Data System (ADS)

    Moussawi, Rasha N.; Patra, Digambara

    2016-04-01

    Curcumin conjugated ZnO, referred as Zn(cur)O, nanostructures have been successfully synthesized, these sub-micro grain-like structures are actually self-assemblies of individual needle-shaped nanoparticles. The nanostructures as synthesized possess the wurtzite hexagonal crystal structure of ZnO and exhibit very good crystalline quality. FT-Raman and TGA analysis establish that Zn(cur)O is different from curcumin anchored ZnO (ZnO@cur), which is prepared by physically adsorbing curcumin on ZnO surfaces. Chemically Zn(cur)O is more stable than ZnO@cur. Diffuse reflectance spectroscopy indicates Zn(cur)O have more impurities compared to ZnO@cur. The solid-state photoluminescence of Zn(cur)O has been investigated, which demonstrates that increase of curcumin concentration in Zn(cur)O suppresses visible emission of ZnO prepared through the same method, this implies filling ZnO defects by curcumin. However, at excitation wavelength 425 nm the emission is dominated by fluorescence from curcumin. The study reveals that Zn(cur)O can remove to a far extent high concentrations of perylene, fluoranthene, and chrysene faster than ZnO. The removal depends on the extent of curcumin conjugation and is found to be faster for PAHs having smaller number of aromatic rings, particularly, it is exceptional for fluoranthene with 93% removal after 10 minutes in the present conditions. The high rate of removal is related to photo-degradation and a mechanism has been proposed.

  17. Nanoparticle Self-Assembled Grain Like Curcumin Conjugated ZnO: Curcumin Conjugation Enhances Removal of Perylene, Fluoranthene, and Chrysene by ZnO

    PubMed Central

    Moussawi, Rasha N.; Patra, Digambara

    2016-01-01

    Curcumin conjugated ZnO, referred as Zn(cur)O, nanostructures have been successfully synthesized, these sub-micro grain-like structures are actually self-assemblies of individual needle-shaped nanoparticles. The nanostructures as synthesized possess the wurtzite hexagonal crystal structure of ZnO and exhibit very good crystalline quality. FT-Raman and TGA analysis establish that Zn(cur)O is different from curcumin anchored ZnO (ZnO@cur), which is prepared by physically adsorbing curcumin on ZnO surfaces. Chemically Zn(cur)O is more stable than ZnO@cur. Diffuse reflectance spectroscopy indicates Zn(cur)O have more impurities compared to ZnO@cur. The solid-state photoluminescence of Zn(cur)O has been investigated, which demonstrates that increase of curcumin concentration in Zn(cur)O suppresses visible emission of ZnO prepared through the same method, this implies filling ZnO defects by curcumin. However, at excitation wavelength 425 nm the emission is dominated by fluorescence from curcumin. The study reveals that Zn(cur)O can remove to a far extent high concentrations of perylene, fluoranthene, and chrysene faster than ZnO. The removal depends on the extent of curcumin conjugation and is found to be faster for PAHs having smaller number of aromatic rings, particularly, it is exceptional for fluoranthene with 93% removal after 10 minutes in the present conditions. The high rate of removal is related to photo-degradation and a mechanism has been proposed. PMID:27080002

  18. Increasing 3D Supramolecular Order by Decreasing Molecular Order. A Comparative Study of Helical Assemblies of Dendronized Nonchlorinated and Tetrachlorinated Perylene Bisimides.

    PubMed

    Partridge, Benjamin E; Leowanawat, Pawaret; Aqad, Emad; Imam, Mohammad R; Sun, Hao-Jan; Peterca, Mihai; Heiney, Paul A; Graf, Robert; Spiess, Hans W; Zeng, Xiangbing; Ungar, Goran; Percec, Virgil

    2015-04-22

    A nonplanar, twisted, and flexible tetrachlorinated perylene bisimide (Cl4PBI) was functionalized with two AB3 minidendrons containing hydrogenated or semifluorinated dodecyl groups. The hydrogenated dendron was attached to the imide groups of Cl4PBI via m = 0, 1, and 2 methylenic units, whereas the dendron containing semifluorinated groups was attached via m = 3 or a di(ethylene oxide) linker (m = 2EO). The supramolecular structures of these compounds, determined by a combination of differential scanning calorimetry, X-ray diffraction, and solid-state NMR, were compared with those of nonchlorinated planar and rigid PBI reported previously, which demonstrated the thermodynamically controlled formation of 2D periodic arrays at high temperatures and 3D arrays at low temperatures. The molecularly less ordered Cl4PBI containing hydrogenated dendrons self-organize into exclusively 3D crystalline periodic arrays under thermodynamic control for m = 0 and 2, while the more highly molecularly ordered PBI produced less stable and ordered 3D crystals and also 2D assemblies. This induction of a higher degree of 3D order in supramolecular assemblies of the less well-ordered molecular building blocks was unanticipated. The semifluorinated dendronized Cl4PBI with m = 3 formed a 2D columnar hexagonal array under kinetic control, whereas the compound with m = 2EO formed an unusual 2D honeycomb-like hexagonal phase under thermodynamic control. These Cl4PBI compounds provide a new route to stable crystalline assemblies via thermodynamic control at lower temperatures than previously obtained with PBI, thus generating 3D order in an accessible range of temperature of interest for structural analysis and for technological applications.

  19. Phenylene ethynylene-tethered perylene bisimide folda-dimer and folda-trimer: investigations on folding features in ground and excited states.

    PubMed

    Fimmel, Benjamin; Son, Minjung; Sung, Young Mo; Grüne, Matthias; Engels, Bernd; Kim, Dongho; Würthner, Frank

    2015-01-07

    In this work, we have elucidated in detail the folding properties of two perylene bisimide (PBI) foldamers composed of two and three PBI units, respectively, attached to a phenylene ethynylene backbone. The folding behaviors of these new PBI folda-dimer and trimer have been studied by solvent-dependent UV/Vis absorption and 1D and 2D NMR spectroscopy, revealing facile folding of both systems in tetrahydrofuran (THF). In CHCl3 the dimer exists in extended (unfolded) conformation, whereas partially folded conformations are observed in the trimer. Temperature-dependent (1) H NMR spectroscopic studies in [D8 ]THF revealed intramolecular dynamic processes for both PBI foldamers due to, on the one hand, hindered rotation around CN imide bonds and, on the other hand, backbone flapping; the latter process being energetically more demanding as it was observed only at elevated temperature. The structural features of folded conformations of the dimer and trimer have been elucidated by different 2D-NMR spectroscopy (e.g., ROESY and DOSY) in [D8 ]THF. The energetics of folding processes for the PBI dimer and trimer have been assessed by calculations applying various methods, particularly the semiempirical PM6-DH2 and the more sophisticated B97D approach, in which relevant dispersion corrections are included. These calculations corroborate the results of NMR spectroscopic studies. Folding features in the excited states of these PBI foldamers have been characterized by using time-resolved fluorescence and transient absorption spectroscopy in THF and CHCl3 , exhibiting similar solvent-dependent behavior as observed for the ground state. Interestingly, photoinduced electron transfer (PET) process from electron-donating backbone to electron-deficient PBI core for extended, but not for folded, conformations was observed, which can be explained by a fast relaxation of excited PBI stacks in the folded conformation into fluorescent excimer states. © 2015 WILEY-VCH Verlag GmbH & Co

  20. n-Type semiconducting naphthalene diimide-perylene diimide copolymers: controlling crystallinity, blend morphology, and compatibility toward high-performance all-polymer solar cells.

    PubMed

    Hwang, Ye-Jin; Earmme, Taeshik; Courtright, Brett A E; Eberle, Frank N; Jenekhe, Samson A

    2015-04-08

    Knowledge of the critical factors that determine compatibility, blend morphology, and performance of bulk heterojunction (BHJ) solar cells composed of an electron-accepting polymer and an electron-donating polymer remains limited. To test the idea that bulk crystallinity is such a critical factor, we have designed a series of new semiconducting naphthalene diimide (NDI)-selenophene/perylene diimide (PDI)-selenophene random copolymers, xPDI (10PDI, 30PDI, 50PDI), whose crystallinity varies with composition, and investigated them as electron acceptors in BHJ solar cells. Pairing of the reference crystalline (crystalline domain size Lc = 10.22 nm) NDI-selenophene copolymer (PNDIS-HD) with crystalline (Lc = 9.15 nm) benzodithiophene-thieno[3,4-b]thiophene copolymer (PBDTTT-CT) donor yields incompatible blends, whose BHJ solar cells have a power conversion efficiency (PCE) of 1.4%. However, pairing of the new 30PDI with optimal crystallinity (Lc = 5.11 nm) as acceptor with the same PBDTTT-CT donor yields compatible blends and all-polymer solar cells with enhanced performance (PCE = 6.3%, Jsc = 18.6 mA/cm(2), external quantum efficiency = 91%). These photovoltaic parameters observed in 30PDI:PBDTTT-CT devices are the best so far for all-polymer solar cells, while the short-circuit current (Jsc) and external quantum efficiency are even higher than reported values for [70]-fullerene:PBDTTT-CT solar cells. The morphology and bulk carrier mobilities of the polymer/polymer blends varied substantially with crystallinity of the acceptor polymer component and thus with the NDI/PDI copolymer composition. These results demonstrate that the crystallinity of a polymer component and thus compatibility, blend morphology, and efficiency of polymer/polymer blend solar cells can be controlled by molecular design.

  1. Nanoparticle Self-Assembled Grain Like Curcumin Conjugated ZnO: Curcumin Conjugation Enhances Removal of Perylene, Fluoranthene, and Chrysene by ZnO.

    PubMed

    Moussawi, Rasha N; Patra, Digambara

    2016-04-15

    Curcumin conjugated ZnO, referred as Zn(cur)O, nanostructures have been successfully synthesized, these sub-micro grain-like structures are actually self-assemblies of individual needle-shaped nanoparticles. The nanostructures as synthesized possess the wurtzite hexagonal crystal structure of ZnO and exhibit very good crystalline quality. FT-Raman and TGA analysis establish that Zn(cur)O is different from curcumin anchored ZnO (ZnO@cur), which is prepared by physically adsorbing curcumin on ZnO surfaces. Chemically Zn(cur)O is more stable than ZnO@cur. Diffuse reflectance spectroscopy indicates Zn(cur)O have more impurities compared to ZnO@cur. The solid-state photoluminescence of Zn(cur)O has been investigated, which demonstrates that increase of curcumin concentration in Zn(cur)O suppresses visible emission of ZnO prepared through the same method, this implies filling ZnO defects by curcumin. However, at excitation wavelength 425 nm the emission is dominated by fluorescence from curcumin. The study reveals that Zn(cur)O can remove to a far extent high concentrations of perylene, fluoranthene, and chrysene faster than ZnO. The removal depends on the extent of curcumin conjugation and is found to be faster for PAHs having smaller number of aromatic rings, particularly, it is exceptional for fluoranthene with 93% removal after 10 minutes in the present conditions. The high rate of removal is related to photo-degradation and a mechanism has been proposed.

  2. Nonfullerene-Acceptor All-Small-Molecule Organic Solar Cells Based on Highly Twisted Perylene Bisimide with an Efficiency of over 6.

    PubMed

    Xin, Rui; Feng, Jiajing; Zeng, Cheng; Jiang, Wei; Zhang, Lei; Meng, Dong; Ren, Zhongjie; Wang, Zhaohui; Yan, Shouke

    2017-01-25

    Two twisted singly linked perylene bisimide (PBI) dimers with chalcogen bridges in the PBI cores, named C4,4-SdiPBI-S and C4,4-SdiPBI-Se, were synthesized as acceptors for nonfullerene all-small-molecule organic solar cells (NF all-SMSCs). A moderate-band-gap small-molecule DR3TBDTT used as the electron donor displayed complementary absorption with C4,4-SdiPBI-S and C4,4-SdiPBI-Se. It was found that solvent-vapor annealing (SVA) played a critical role in the photovoltaic performance in NF all-SMSCs, which improves the crystallinity of the donor and acceptors, promotes the proper phase segregation domain size, and therefore enhances charge transport. The power conversion efficiencies (PCEs) of NF all-SMSC devices based on DR3TBDTT/C4,4-SdiPBI-S and DR3TBDTT/C4,4-SdiPBI-Se increased from 2.52% to 5.81% (JSC = 11.12 mA cm(-2), VOC = 0.91 V, and FF = 57.32%) and from 2.65% to 6.22% (JSC = 11.55 mA cm(-2), VOC = 0.92 V, and FF = 58.72%), respectively, after exposure to chloroform vapor. The best efficiency of 6.22% is one of the highest PCEs for NF all-SMSC-based PBI acceptors so far. The studies illustrate that highly efficient NF all-SMSCs can be achieved by using a PBI acceptor with a suitable SVA process.

  3. Charge transport in fibre-based perylene-diimide transistors: effect of the alkyl substitution and processing technique.

    PubMed

    Savage, Rebecca C; Orgiu, Emanuele; Mativetsky, Jeffrey M; Pisula, Wojciech; Schnitzler, Tobias; Eversloh, Christian Lütke; Li, Chen; Müllen, Klaus; Samorì, Paolo

    2012-04-07

    We report a comparative study on the self-assembly from solution and electrical characterization of n-type semiconducting fibres obtained from five different perylenebis(dicarboximide) (PDI) derivatives. In particular we investigated the role of the nature of the alkyl chain covalently linked to the N,N' sites of the PDI in modulating the molecular solubility and aggregation capacity. We explored the morphologies of the self-assembled architectures physisorbed on dielectric surfaces and in particular how they can be modified by tuning the deposition and post-deposition procedures, i.e. by modulating the kinetics of the self-assembly process. To this end, alongside the conventional spin-coating, solvent vapour annealing (SVA) and solvent induced precipitation (SIP) have been employed. Both approaches led to fibres having widths of several hundred nanometres and lengths up to tens of micrometres. SVA formed isolated fibres which were tens of nanometres high, flat, and tapered at the ends. Conversely, SIP fibres exhibited nearly matching heights and widths, but organized into bundles. Despite these morphological differences, the same intermolecular packing is found by XRD in each type of structure, albeit with differing degrees of long-range order. The study of the electrical characteristics of the obtained low dimensional nano-assemblies has been accomplished by fabricating and characterizing organic field-effect transistors. This journal is © The Royal Society of Chemistry 2012

  4. Poly cyclic aromatic hydrocarbons in Recent lake sediments—II. Compounds derived from biogenic precursors during early diagenesis

    NASA Astrophysics Data System (ADS)

    Wakeham, Stuart G.; Schaffner, Christian; Giger, Walter

    1980-03-01

    Five groups of polycyclic aromatic hydrocarbons (PAH) thought to be derived by early-diagenetic transformations of biogenic precursors are apparently present in Recent sediments of four lakes (Lake Lucerne. Lake Zürich, and Greifensee. Switzerland, and Lake Washington, northwest U.S.A.) These natural PAH include: (1) perylene. (2) an extended series of phenanthrene homologs. (3) retene and pimanthrene derived from diterpenes. (4) a series of tetra- and pentacyclic PAH derived from pentacyclic triterpenes of the amyrin-type. (5) tetra- and pentacyclic PAH formed from pentacyclic triterpenes with five-membered E-rings. Since these PAH are abundant in very young sediment layers, the transformation reactions involved appear to be faster than previously thought and may be microbially mediated. There is no evidence that anthropogenic or petrogenic sources can account for the distributions of these groups of PAH in cores of Recent lake sediments.

  5. Impact of molecular solvophobicity vs. solvophilicity on device performances of dimeric perylene diimide based solution-processed non-fullerene organic solar cells.

    PubMed

    Lu, Zhenhuan; Zhang, Xin; Zhan, Chuanlang; Jiang, Bo; Zhang, Xinliang; Chen, Lili; Yao, Jiannian

    2013-07-21

    Because of their outstanding molecular optoelectronic properties, perylene diimides (PDIs) are promising alternatives to the commonly used PCBM. However, the overly strong aggregation ability, poor solution-processability and compatibility of PDIs severely limit their photovoltaic applications. We turned to borrowing the amphiphile concept to improve these supramolecular properties. Practically, we fine-tuned the molecular solvophobicity with respect to the molecular solvophilicity, e.g. F(solvophob/solvophil), by changing the number of the weakly solvophobic 2-methoxyethoxyl (EG) groups in the bay-region of the thienyl-bridged dimeric PDI backbone, forming three PDI dimers of Bis-PDI-T (0 EG), Bis-PDI-T-EG (2 EG) and Bis-PDI-T-di-EG (4 EG) (Scheme 1). The photovoltaic properties using these dimers as the solution-processed non-fullerene electron-acceptor and P3HT as the electron-donor were investigated via the device configuration of ITO/PEDOT:PSS/P3HT:PDI dimer/Ca/Al. Bis-PDI-T exhibited overly strong aggregation ability and very poor solution-processability, which severely limited compatibility, giving a very poor power conversion efficiency (PCE) of 0.007%. When two EG groups were attached at the 1,1'-positions, the resulted Bis-PDI-T-EG showed dramatically reduced aggregation ability, improved solution-processability, compatibility and proper phase separation. Small sized phases (∼20 nm) dominated in the active layer and the best PCE was increased to 0.39%. When four solvophobic EG functions were introduced, affording Bis-PDI-T-di-EG with excellent supramolecular properties, particularly, the improvement of the phase separation with an increased phase size of 24 nm and the enhanced electron and hole mobilities, by 2-4 times, with respect to that of Bis-PDI-T-EG. The best PCE was further enhanced to 0.88%. After using 1-chloronaphthalene as the co-solvent of 1,2-dichlorobenzene to further improve the compatibility, the PCE was improved further up to 0.41% for

  6. Substituent effect on supramolecular motifs in series of succinimide polycyclic keto derivatives - Spectroscopic, theoretical and crystallographic studies

    NASA Astrophysics Data System (ADS)

    Miroslaw, Barbara; Koziol, Anna E.; Bielenica, Anna; Dziuba, Kamil; Struga, Marta

    2014-09-01

    The substituent effect on the supramolecular arrangement in a series of polycyclic monoimide keto derivatives crystals was studied. Single crystal X-ray diffraction and IR spectroscopic experiments were performed for seven related compounds, as well as the Hirshfeld surface analysis and quantum chemical calculations at HF and DFT levels in vacuo, in solution and for small clusters. The presence of Cdbnd O group at the bridge of the main hydrocarbon skeleton implied the catemer motif of the Nimidesbnd H⋯Oimide hydrogen bond in case of smaller substituents (Hsbnd , MeOsbnd , EtOsbnd ). For more voluminous groups (iBuOsbnd ) or additional hydrogen bond acceptors (AcOsbnd , Odbnd ) the steric hindrance increased and the imide⋯imide interactions were no longer present in the solid state. The Nimidesbnd H⋯Oketo or Nimidesbnd H⋯Oester hydrogen bonds were formed instead. The binding energy per one Nsbnd H⋯O interaction calculated for supramolecular clusters at HF/6-31G(d,p) level was ca. 20 kJ mol-1, indicating moderate strength of this hydrogen bond. The solvation free energies and induced dipole moments were computed at B3LYP/6-311+G(d,p) level using the integral equation formalism model (IEF PCM) considering three solvents of various polarity: non-polar chloroform, polar aprotic dimethyl sulfoxide (DMSO) and polar protic water. The relations between the vibrational spectra and the crystal structure have been discussed. The following sequence of carbonyl stretching modes in IR spectra has been derived from quantum chemical calculations: (1) at the highest frequencies - the symmetric vibration of two imide Cdbnd O bonds, (2) the vibrations of keto Cdbnd O bonds attached directly to the polycyclic hydrocarbon skeleton, (3) the asymmetric vibration of two imide Cdbnd O bonds, and (4) at the lowest frequencies - the vibration of ester Cdbnd O group. The characteristic peaks observed in imide experimental IR spectra at about 3080 cm-1 have been

  7. Hemoglobin derivatives

    MedlinePlus

    ... this page: //medlineplus.gov/ency/article/003371.htm Hemoglobin derivatives To use the sharing features on this page, please enable JavaScript. Hemoglobin derivatives are altered forms of hemoglobin . Hemoglobin is ...

  8. Franck-Condon factors perturbed by damped harmonic oscillators: Solvent enhanced X {sup 1}A{sub g} ↔ A{sup 1}B{sub 1u} absorption and fluorescence spectra of perylene

    SciTech Connect

    Wang, Chen-Wen; Zhu, Chaoyuan Lin, Sheng-Hsien; Yang, Ling; Yu, Jian-Guo

    2014-08-28

    Damped harmonic oscillators are utilized to calculate Franck-Condon factors within displaced harmonic oscillator approximation. This is practically done by scaling unperturbed Hessian matrix that represents local modes of force constants for molecule in gaseous phase, and then by diagonalizing perturbed Hessian matrix it results in direct modification of Huang–Rhys factors which represent normal modes of solute molecule perturbed by solvent environment. Scaling parameters are empirically introduced for simulating absorption and fluorescence spectra of an isolated solute molecule in solution. The present method is especially useful for simulating vibronic spectra of polycyclic aromatic hydrocarbon molecules in which hydrogen atom vibrations in solution can be scaled equally, namely the same scaling factor being applied to all hydrogen atoms in polycyclic aromatic hydrocarbons. The present method is demonstrated in simulating solvent enhanced X {sup 1}A{sub g} ↔ A{sup 1}B{sub 1u} absorption and fluorescence spectra of perylene (medium-sized polycyclic aromatic hydrocarbon) in benzene solution. It is found that one of six active normal modes v{sub 10} is actually responsible to the solvent enhancement of spectra observed in experiment. Simulations from all functionals (TD) B3LYP, (TD) B3LYP35, (TD) B3LYP50, and (TD) B3LYP100 draw the same conclusion. Hence, the present method is able to adequately reproduce experimental absorption and fluorescence spectra in both gas and solution phases.

  9. Highly sensitive electrochemical sensor based on β-cyclodextrin-gold@3, 4, 9, 10-perylene tetracarboxylic acid functionalized single-walled carbon nanohorns for simultaneous determination of myricetin and rutin.

    PubMed

    Ran, Xin; Yang, Long; Zhang, Jianqiang; Deng, Guogang; Li, Yucong; Xie, Xiaoguang; Zhao, Hui; Li, Can-Peng

    2015-09-10

    The application of macrocyclic hosts for construction of different electrochemical devices and separation matrices has attracted much attentions due to their benign biocompatibility and simplicity of synthesis. Myricetin and rutin are considered two of the most bioactive flavonoids, which have been proved to exhibit various physiological functions. This work reports a simple and facile approach for the synthesis of β-cyclodextrin-gold@3, 4, 9, 10-perylene tetracarboxylic acid functionalized single-walled carbon nanohorns (β-CD-Au@PTCA-SWCNHs) nanohybrids. The simultaneous electrochemical determination of myricetin and rutin using a β-CD-Au@PTCA-SWCNHs-modified glassy carbon electrode was established. The results show that the β-CD-Au@PTCA-SWCNHs-modified electrode displayed electrochemical signal superior to those of Au@PTCA-;SWCNHs and SWCNHs towards myricetin and rutin. The proposed modified electrode has a linear response range of 0.01-10.00 μM both for myricetin and rutin with relatively low detection limits of 0.0038 μM for myricetin and 0.0044 μM (S/N = 3) for rutin, respectively. The excellent performance of the sensing platform is considered to be the synergic effects of the SWCNHs (e.g. their good electrochemical properties and large surface area) and β-CD (e.g. a hydrophilic external surface, a high supramolecular recognition, and a good enrichment capability).

  10. Highly sensitive and selective dopamine biosensor based on 3,4,9,10-perylene tetracarboxylic acid functionalized graphene sheets/multi-wall carbon nanotubes/ionic liquid composite film modified electrode.

    PubMed

    Niu, Xiuli; Yang, Wu; Guo, Hao; Ren, Jie; Gao, Jinzhang

    2013-03-15

    A sensitive and selective electrochemical sensor for determination of dopamine (DA) was fabricated based on 3,4,9,10-perylene tetracarboxylic acid functionalized graphene sheets, multi-wall carbon nanotubes and ionic liquid modified glass carbon electrode and the properties of modified electrode were characterized by scanning electron microscopy, transmission electron microscope and electrochemical impedance spectroscopy. The modified electrode showed excellent electrocatalytic activity toward the oxidation of DA. Meanwhile, a possible reaction mechanism related to the oxidation of DA was proposed. The differential pulse voltammetry was used for the determination of DA in the presence of 500 μM ascorbic acid and 330 μM uric acid under the optimum conditions and a good linear relationship between peak current and the concentration of DA was obtained in the concentration range from 0.03 μM to 3.82 mM with a detection limit of 1.2×10(-9) M (S/N=3). Moreover, the proposed method was successfully applied to determine DA in real sample and satisfactory results were obtained. The results showed that the modified electrode exhibits an excellent catalytic activity, good sensitivity, reproducibility and long-term stability.

  11. Derivative chameleons

    NASA Astrophysics Data System (ADS)

    Noller, Johannes

    2012-07-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field phi, but also of its derivatives via higher order co-ordinate invariants (such as ∂μphi∂μphi,squphi,...). Specifically we consider the first such non-trivial conformal factor A(phi,∂μphi∂μphi). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for phi → phi+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type.

  12. Derivative chameleons

    SciTech Connect

    Noller, Johannes

    2012-07-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field φ, but also of its derivatives via higher order co-ordinate invariants (such as ∂{sub μ}φ∂{sup μ}φ,□φ,...). Specifically we consider the first such non-trivial conformal factor A(φ,∂{sub μ}φ∂{sup μ}φ). The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for φ → φ+c. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning, stable derivative models are in fact typically anti-chameleons that suppress the field's mass in dense environments. Furthermore we investigate modifications to the thin-shell regime and prove a no-go theorem for chameleon effects in non-conformal geometries of the disformal type.

  13. Complex derivatives

    NASA Astrophysics Data System (ADS)

    Battiston, Stefano; Caldarelli, Guido; Georg, Co-Pierre; May, Robert; Stiglitz, Joseph

    2013-03-01

    The intrinsic complexity of the financial derivatives market has emerged as both an incentive to engage in it, and a key source of its inherent instability. Regulators now faced with the challenge of taming this beast may find inspiration in the budding science of complex systems.

  14. N-annulated perylene as an efficient electron donor for porphyrin-based dyes: enhanced light-harvesting ability and high-efficiency Co(II/III)-based dye-sensitized solar cells.

    PubMed

    Luo, Jie; Xu, Mingfei; Li, Renzhi; Huang, Kuo-Wei; Jiang, Changyun; Qi, Qingbiao; Zeng, Wangdong; Zhang, Jie; Chi, Chunyan; Wang, Peng; Wu, Jishan

    2014-01-08

    Porphyrin-based dyes recently have become good candidates for dye-sensitized solar cells (DSCs). However, the bottleneck is how to further improve their light-harvesting ability. In this work, N-annulated perylene (NP) was used to functionalize the Zn-porphyrin, and four "push-pull"-type NP-substituted and fused porphyrin dyes with intense absorption in the visible and even in the near-infrared (NIR) region were synthesized. Co(II/III)-based DSC device characterizations revealed that dyes WW-5 and WW-6, in which an ethynylene spacer is incorporated between the NP and porphyrin core, showed pantochromatic photon-to-current conversion efficiency action spectra in the visible and NIR region, with a further red-shift of about 90 and 60 nm, respectively, compared to the benchmark molecule YD2-o-C8. As a result, the short-circuit current density was largely increased, and the devices displayed power conversion efficiencies as high as 10.3% and 10.5%, respectively, which is comparable to that of the YD2-o-C8 cell (η = 10.5%) under the same conditions. On the other hand, the dye WW-3 in which the NP unit is directly attached to the porphyrin core showed a moderate power conversion efficiency (η = 5.6%) due to the inefficient π-conjugation, and the NP-fused dye WW-4 exhibited even poorer performance due to its low-lying LUMO energy level and nondisjointed HOMO/LUMO profile. Our detailed physical measurements (optical and electrochemical), density functional theory calculations, and photovoltaic characterizations disclosed that the energy level alignment, the molecular orbital profile, and dye aggregation all played very important roles on the interface electron transfer and charge recombination kinetics.

  15. Highly Soluble Benzo[ghi]perylenetriimide Derivatives: Stable and Air-Insensitive Electron Acceptors for Artificial Photosynthesis

    PubMed Central

    Chen, Hung-Cheng; Hsu, Chao-Ping; Reek, Joost N H; Williams, René M; Brouwer, Albert M

    2015-01-01

    A series of new benzo[ghi]perylenetriimide (BPTI) derivatives has been synthesized and characterized. These remarkably soluble BPTI derivatives show strong optical absorption in the range of λ=300–500 nm and have a high triplet-state energy of 1.67 eV. A cyanophenyl substituent renders BPTI such a strong electron acceptor (Ered=−0.11 V vs. the normal hydrogen electrode) that electron-trapping reactions with O2 and H2O do not occur. The BPTI radical anion on a fluorine-doped tin oxide|TiO2 electrode is persistent up to tens of seconds (t1/2=39 s) in air-saturated buffer solution. As a result of favorable packing, theoretical electron mobilities (10−2∼10−1 cm2 V−1 s−1) are high and similar to the experimental values observed for perylene diimide and C60 derivatives. Our studies show the potential of the cyanophenyl-modified BPTI compounds as electron acceptors in devices for artificial photosynthesis in water splitting that are also very promising nonfullerene electron-transport materials for organic solar cells. PMID:26395847

  16. Highly Soluble Benzo[ghi]perylenetriimide Derivatives: Stable and Air-Insensitive Electron Acceptors for Artificial Photosynthesis.

    PubMed

    Chen, Hung-Cheng; Hsu, Chao-Ping; Reek, Joost N H; Williams, René M; Brouwer, Albert M

    2015-11-01

    A series of new benzo[ghi]perylenetriimide (BPTI) derivatives has been synthesized and characterized. These remarkably soluble BPTI derivatives show strong optical absorption in the range of λ=300-500 nm and have a high triplet-state energy of 1.67 eV. A cyanophenyl substituent renders BPTI such a strong electron acceptor (Ered =-0.11 V vs. the normal hydrogen electrode) that electron-trapping reactions with O2 and H2 O do not occur. The BPTI radical anion on a fluorine-doped tin oxide|TiO2 electrode is persistent up to tens of seconds (t1/2 =39 s) in air-saturated buffer solution. As a result of favorable packing, theoretical electron mobilities (10(-2) ∼10(-1) cm(2) V(-1) s(-1)) are high and similar to the experimental values observed for perylene diimide and C60 derivatives. Our studies show the potential of the cyanophenyl-modified BPTI compounds as electron acceptors in devices for artificial photosynthesis in water splitting that are also very promising nonfullerene electron-transport materials for organic solar cells. © 2015 The Authors. Published by Wiley-VCH Verlag GmbH & Co. KGaA.

  17. Genotoxicity-related chemistry of human metabolites of benzo[ghi]perylene (B[ghi]P) investigated using electro-optical arrays and DNA/microsome biocolloid reactors with LC-MS/MS.

    PubMed

    Pan, Shenmin; Li, Dandan; Zhao, Linlin; Schenkman, John B; Rusling, James F

    2013-08-19

    There is limited and sometimes contradictory information about the genotoxicity of the polycyclic aromatic hydrocarbon benzo[ghi]perylene (B[ghi]P). Using recently developed metabolic toxicity screening arrays and a biocolloid reactor-LC-MS/MS approach, both featuring films of DNA and human metabolic enzymes, we demonstrated the relatively low reactivity of metabolically activated B[ghi]P toward DNA. Electro-optical toxicity screening arrays showed that B[ghi]P metabolites damage DNA at a 3-fold lower rate than benzo[a]pyrene (B[a]P), whose metabolites have a strong and well-understood propensity for DNA damage. Metabolic studies using magnetic bead biocolloid reactors coated with microsomal enzymes in 96-well plates showed that cyt P450s 1A1 and 1B1 provide high activity for B[ghi]P and B[a]P conversion. Consistent with published results, the major metabolism of B[ghi]P involved oxidations at 3,4 and 11,12 positions, leading to the formation of B[ghi]P 3,4-oxide and B[ghi]P 3,4,11,12-bisoxide. B[ghi]P 3,4-oxide was synthesized and reacted with deoxyadenosine at N6 and N7 positions and with deoxyguanosine at the N2 position. B[ghi]P 3,4-oxide is hydrolytically unstable and transforms into the 3,4-diol or converts to 3- or 4-hydroxy B[ghi]P. LC-MS/MS of reaction products from the magnetic biocolloid reactor particles coated with DNA and human enzymes revealed for the first time that a major DNA adduct results from the reaction between B[ghi]P 3,4,11,12-bisoxide and deoxyguanosine. Results also demonstrated 5-fold lower formation rates of the major DNA adduct for B[ghi]P metabolites compared to B[a]P. Overall, results from both the electro-optical array and biocolloid reactor-LC-MS/MS consistently suggest a lower human genotoxicity profile of B[ghi]P than B[a]P.

  18. Effects of vicinal steps on the island growth and orientation of epitaxially grown perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) thin film crystals on a hydrogen-terminated Si(1 1 1) substrate

    NASA Astrophysics Data System (ADS)

    Sazaki, Gen; Fujino, Takuho; Usami, Noritaka; Ujihara, Toru; Fujiwara, Kozo; Nakajima, Kazuo

    2005-01-01

    On flat and off-cut Si(1 1 1) substrates terminated with monohydride, thin film crystals of organic semiconductor perylene-3,4,9,10-tetracarboxylic dianhydride (PTCDA) were grown by molecular beam epitaxy (MBE) and were observed by atomic force microscopy (AFM). The thin film crystals on the hydrogen-terminated Si(1 1 1) surface (H-Si(1 1 1)) have a mesa-type island shape. On the flat H-Si(1 1 1) (average step distance >500 nm, off-angle <0.04°), with an increase in a thin film thickness, the size and number of the PTCDA islands were increased and decreased, respectively. These results show that the islands coalesced during the growth. After the coalescence of the islands, some islands became single crystals and the others became polycrystals. The ratio of the single crystal islands was estimated from the shapes of the islands. We found that the ratio of the single crystal islands after the coalescence was 48% and this value was much larger than a probability (1/6) estimated from an epitaxial relation. This result suggests that Ostwald ripening occurred in the PTCDA/H-Si(1 1 1) system. The PTCDA thin film crystals were also grown on the off-cut H-Si(1 1 1) (average step distance=10 nm, off-angle=1.8°). The number of the islands was much larger than that on the flat H-Si(1 1 1) and this result shows that the vicinal steps on the surface can work as effective nucleation sites. Coalescence of the islands was also observed on the off-cut H-Si(1 1 1). After the coalescence, the ratio of the single crystal islands on the off-cut H-Si(1 1 1) was 10% larger than that on the flat H-Si(1 1 1). This result shows that the orientation of the PTCDA islands can be controlled using the vicinal steps on the substrate surface.

  19. Genotoxicity-Related Chemistry of Human Metabolites of Benzo[ghi]perylene (B[ghi]P) Investigated using Electro-optical Arrays and DNA/Microsome Biocolloid Reactors with LC-MS/MS

    PubMed Central

    Pan, Shenmin; Li, Dandan; Zhao, Linlin; Schenkman, John B.; Rusling, James F.

    2013-01-01

    There is limited and sometimes contradictory information about the genotoxicity of polycyclic aromatic hydrocarbon benzo[ghi]perylene (B[ghi]P). Using recently developed metabolic toxicity screening arrays and a biocolloid reactor-LC-MS/MS approach, both featuring films of DNA and human metabolic enzymes, we demonstrated relatively low reactivity of metabolically activated B[ghi]P towards DNA. Electro-optical toxicity screening arrays showed that B[ghi]P metabolites damage DNA at a 3-fold lower rate than benzo[a]pyrene (B[a]P), whose metabolites have a strong and well-understood propensity for DNA damage. Metabolic studies using magnetic bead biocolloid reactors coated with microsomal enzymes in 96-well plates showed that cyt P450s 1A1 and 1B1 provide high activity for B[ghi]P and B[a]P conversion. Consistent with published results, the major metabolism of B[ghi]P involved oxidations at 3,4 and 11,12 positions, leading to formation of B[ghi]P 3,4-oxide and B[ghi]P 3,4,11,12-bisoxide. B[ghi]P 3,4-oxide was synthesized and reacted with deoxyadenosine at N6 and N7 positions and with deoxyguanosine at the N2 position. B[ghi]P 3,4-oxide is hydrolytically unstable and transforms into the 3,4-diol or converts to 3- or 4-hydroxy B[ghi]P. LC-MS/MS of reaction products from the magnetic biocolloid reactor particles coated with DNA and human enzymes revealed for the first time that a major DNA adduct results from reaction between B[ghi]P 3,4,11,12-bisoxide and deoxyguanosine. Results also demonstrated 5-fold lower formation rates of the major DNA adduct for B[ghi]P metabolites compared to B[a]P. Overall, results from both ECL array and biocolloid reactor-LC-MS/MS consistently suggest a lower human genotoxicity profile of B[ghi]P than B[a]P. PMID:23879290

  20. Spectroscopic and thermodynamic studies of light harvesting perylenediimide derivative - zinc porphyrin complex in aqueous media.

    PubMed

    El-Refaey, Ahmed; Shaban, Shaban Y; El-Kemary, Maged; El-Khouly, Mohamed E

    2017-11-05

    Self-assembly of perylene derivative such as N,N'-bis(2(trimethylammonium iodide) ethylene)perylene-3,4,9,10-tetracarboxyldiimide (TAIPDI) can produce one-dimensional form (1D) in an aqueous media. The ability of one-dimensional TAIPDI to form light harvesting complex with water-soluble zinc porphyrin (ZnTPPS4) via the π-π and electrostatic interactions has been described. Owing to electronic interactions between the π-systems, the complex formation is accompanied by pronounced absorption spectral changes in the UV/Vis absorption bands. The formation constant of the ZnTPPS4-TAIPDI complex has been determined as 2.60×10(4)M(-1) suggests a moderately stable complex. The steady-state fluorescence measurements exhibited fluorescence quenching of both the singlet TAIPDI and ZnTPPS4 because of the electron transfer process from the electron-donating ZnTPPS4 to the electron-accepting TAIPDI. Based on the picosecond time-resolved fluorescence, the rate and quantum yield of the electron transfer were found to be 2.47×10(10)s(-1) and 0.99, respectively, indicating fast and efficient electron transfer. The thermodynamic parameters of the complex formation have been determined from the stopped-flow measurements. The interaction between ZnTPPS4 and TAIPDI occurs in two steps, a fast and reversible step followed by a slow and irreversible one. The activation parameters for the complex formation (ΔH(#)=22±5kJmol(-1) and ΔS(#)=-123±18JK(-1)mol(-1)), (ΔH(#)=133±4kJmol(-1) and ΔS(#)=167±13Jmol(-1)K(-1)) were determined from variable temperature studies for the "on" and the "off" of the first step and ΔS(#)=246±37.89Jmol(-1)K(-1) and ΔH(#)=130±11kJmol(-1) for the second step. The negative and positive ΔS(#) values found for the interaction reactions are consistent with an associative interaction for the first step followed by dissociative mechanism for both the "off" and the second step. Copyright © 2017. Published by Elsevier B.V.

  1. Hydrocarbons derived from petroleum in bottled drinking water from Mexico City.

    PubMed

    Vega, Salvador; Gutiérrez, Rey; Ortiz, Rutilio; Schettino, Beatriz; Ramírez, Maria de Lourdes; Pérez, José Jesus

    2011-06-01

    This paper describes the concentrations of polycyclic aromatic hydrocarbons (PAHs) and aliphatic hydrocarbons (AHs) derived from petroleum in bottled drinking water samples that were collected over 1 year from Mexico City in two bottle sizes (1.5 and 19 L), all brought in supermarkets. The analysis was by gas chromatography with flame ionization detection. -Concentrations of AHs (9.26-1.74 μg/L) were greater than PAHs (20.15-12.78 ng/L). Individual concentrations of PAHs such as fluoranthene, benzo(b)fluoranthene, benzo(k)fluoranthene, indeno(1,2,3-cd)pyrene and benzo(ghi)perylene were comparable with data reported by the World Health Organization (WHO). Total concentrations of PAHs for all samples (BDW1: 12.78 μg/L, BDW2: 16.72 μg/L, BDW3: 14.62 μg/L, BDW4: 20.15 μg/L and BDW5: 13.23 ng/L) were below the maximum permissible European level of 100 ng/L; no regulations exist for AHs although their values were greater than PAHs (BDW1: 3.11 μg/L, BDW2: 8.45 μg/L, BDW3: 1.74 μg/L, BDW4: 4.75 μg/L and BDW5: 9.26 μg/L).

  2. Perylene bisimide hydrogels and lyotropic liquid crystals with temperature-responsive color change† †Electronic supplementary information (ESI) available: Detailed procedures and results for all reported experiments, along with synthetic details for PBI 1. See DOI: 10.1039/c6sc02249a Click here for additional data file.

    PubMed Central

    Görl, Daniel; Soberats, Bartolome; Herbst, Stefanie; Stepanenko, Vladimir

    2016-01-01

    The self-assembly of perylene bisimide (PBI) dyes bearing oligo ethylene glycol (OEG) units in water affords responsive functional nanostructures characterized by their lower critical solution temperature (LCST). Tuning of the LCST is realized by a supramolecular approach that relies on two structurally closely related PBI–OEG molecules. The two PBIs socially co-assemble in water and the resulting nanostructures exhibit a single LCST in between the transition temperatures of the aggregates formed by single components. This permits to precisely tune the transition from a hydrogel to a lyotropic liquid crystal state at temperatures between 26 and 51 °C by adjusting the molar fraction of the two PBIs. Owing to concomitant changes in PBI–PBI interactions this phase transition affords a pronounced color change with “fluorescence-on” response that can be utilized as a smart temperature sensory system. PMID:28451124

  3. D1((2)B2g) to D0((2)Au) Fluorescence from the Matrix-Isolated Perylene Cation Following Laser Excitation into the D5(2)B3g) and D2 ((2)B3g) Electronic States

    NASA Technical Reports Server (NTRS)

    Chillier, Xavier D. F.; Stone, Bradley M.; Joblin, Christine; Salama, Farid; Allamandola, Louis J.; DeVincenzi, Donald L. (Technical Monitor)

    2001-01-01

    Fluorescence spectra of the perylene cation, pumped by direct laser excitation via the D(sub 2)((2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) and D(sub 5)(2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) transitions, are presented. Direct excitation into the D5 or D2 states is followed by rapid non-radiative relaxation to D1 that, in turn,relaxes radiatively. Excitation spectroscopy across the D(sub 2)((2)B(sub 3g)) (left arrow) D(sub 0)((2)A(sub u)) transition near 730 nm shows that site splitting plays little or no role in determining the spectral substructure in the ion spectra. Tentative assignments for ground state vibrational frequencies are made by comparison of spectral intervals with calculated normal mode frequencies.

  4. D1(2B2g)→D0(2Au) fluorescence from the matrix-isolated perylene cation following laser excitation into the D5(2B3g) and D2(2B3g) electronic states

    NASA Astrophysics Data System (ADS)

    Chillier, Xavier D. F.; Stone, Bradley M.; Joblin, Christine; Salama, Farid; Allamandola, Louis J.

    2002-04-01

    Fluorescence spectra of the perylene cation, isolated in an argon matrix and pumped by direct laser excitation via the D2(2B3g)←D0(2Au) and D5(2B3g)←D0(2Au) transitions, are presented. Direct excitation into the D5 or D2 states is followed by rapid nonradiative relaxation to D1 that, in turn, relaxes radiatively. Excitation spectroscopy across the D2(2B3g)←D0(2Au) transition near 731 nm shows that site splitting plays little or no role in determining the spectral substructure in the ion spectra. Tentative assignments for ground state vibrational frequencies are made by a comparison of spectral intervals with calculated normal mode frequencies, with the strongest IR bands leading to the most intense vibronic bands.

  5. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

    Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

    1984-01-01

    Flame-resistant reinforced bodies are disclosed which are composed of reinforcing fibers, filaments or fabrics in a cured body of bis- and tris-imide resins derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, or of addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride.

  6. Weather Derivative Valuation

    NASA Astrophysics Data System (ADS)

    Jewson, Stephen; Brix, Anders

    2005-04-01

    Weather Derivative Valuation is the first book to cover all the meteorological, statistical, financial and mathematical issues that arise in the pricing and risk management of weather derivatives. There are chapters on meteorological data and data cleaning, the modelling and pricing of single weather derivatives, the modelling and valuation of portfolios, the use of weather and seasonal forecasts in the pricing of weather derivatives, arbitrage pricing for weather derivatives, risk management, and the modelling of temperature, wind and precipitation. Specific issues covered in detail include the analysis of uncertainty in weather derivative pricing, time-series modelling of daily temperatures, the creation and use of probabilistic meteorological forecasts and the derivation of the weather derivative version of the Black-Scholes equation of mathematical finance. Written by consultants who work within the weather derivative industry, this book is packed with practical information and theoretical insight into the world of weather derivative pricing.

  7. Self-assembling hydrogel scaffolds for photocatalytic hydrogen production

    NASA Astrophysics Data System (ADS)

    Weingarten, Adam S.; Kazantsev, Roman V.; Palmer, Liam C.; McClendon, Mark; Koltonow, Andrew R.; Samuel, Amanda P. S.; Kiebala, Derek J.; Wasielewski, Michael R.; Stupp, Samuel I.

    2014-11-01

    Integration into a soft material of all the molecular components necessary to generate storable fuels is an interesting target in supramolecular chemistry. The concept is inspired by the internal structure of photosynthetic organelles, such as plant chloroplasts, which colocalize molecules involved in light absorption, charge transport and catalysis to create chemical bonds using light energy. We report here on the light-driven production of hydrogen inside a hydrogel scaffold built by the supramolecular self-assembly of a perylene monoimide amphiphile. The charged ribbons formed can electrostatically attract a nickel-based catalyst, and electrolyte screening promotes gelation. We found the emergent phenomenon that screening by the catalyst or the electrolytes led to two-dimensional crystallization of the chromophore assemblies and enhanced the electronic coupling among the molecules. Photocatalytic production of hydrogen is observed in the three-dimensional environment of the hydrogel scaffold and the material is easily placed on surfaces or in the pores of solid supports.

  8. Fundamental Studies of Hydroporphyrin Architectures for Solar-Energy Applications

    SciTech Connect

    Lindsey, Jonathan S.; Bocian, David F.; Holten, Dewey; Kirmaier, Christine

    2013-10-30

    The long-term objective of the Bocian/Holten&Kirmaier/Lindsey research program is to design, synthesize, and characterize tetrapyrrole-based molecular architectures that absorb sunlight, funnel energy, and separate charge with high efficiency and in a manner compatible with current and future solar-energy conversion schemes. The synthetic tetrapyrroles include porphyrins and hydroporphyrins; the latter classes of molecules encompass analogues of the naturally occurring chlorophylls and bacteriochlorophylls (e.g., chlorins, bacteriochlorins, and their derivatives). The attainment of the goals of the research program requires the close interplay of molecular design and synthesis (Lindsey group), static and time-resolved optical spectroscopic measurements (Holten&Kirmaier group), and electrochemical, electron paramagnetic resonance, resonance Raman, and infrared studies, as well as density functional theory calculations (Bocian Group). The proposed research encompasses four interrelated themes: (i) Gain a deeper understanding of the spectral and electronic properties of bacteriochlorins, with a subsidiary aim of learning how to shift the long-wavelength absorption band deeper into the NIR region. Bacteriochlorins bearing diverse substituents, including annulated rings, will be prepared and examined. A set of bacteriochlorins with site-specific isotopic (13C, 2H) substitution patterns about the macrocycle perimeter will be prepared for studies of vibrational and electronic properties. (ii) Examine the underlying electronic origin of panchromatic absorption and excited-state behavior of strongly coupled rylene–tetrapyrrole arrays. The rylene constituents include a perylene-monoimide and a terrylene-monoimide. The tetrapyrroles include porphyrins (meso- or β-linked) and bacteriochlorins (β-linked). The objective is to achieve panchromatic absorption while preserving a viable, long-lived excited singlet state. (iii) Determine the rates of ground-state hole

  9. Neuroprotective Ganglioside Derivatives

    DTIC Science & Technology

    2002-09-01

    In this study, neuroprotective ganglioside derivatives are examined so they can be targeted to specific points in cell death pathways. GM1... ganglioside and several of its chemically modified derivatives are neuroprotective in several neurotoxic models. Here, ganglioside functional groups required... ganglioside derivatives intervene in the cell death process. In the first year, substantial quantities of GM1 have been isolated and purified.

  10. Endohedral Metallofullerene Derivatives

    NASA Technical Reports Server (NTRS)

    Dorn, Harry C. (Inventor); Iezzi, Erick B. (Inventor); Duchamp, James (Inventor)

    2008-01-01

    Trimetallic nitride endohedral metallofullerene derivatives and their preparation are described. The trimetallic nitride endohedral metallofullerene derivatives have the general formula A(sub 3-n)X(sub n)@C(sub m)(R) where n ranges from 0 to 3, A and X may be trivalent metals and may be either rare earth metal or group IIIB metals, m is between about 60 and about 200, and R is preferably an organic group. Derivatives where the R group forms cyclized derivatives with the fullerene cage are also described.

  11. Neuroprotective Ganglioside Derivatives

    DTIC Science & Technology

    2004-09-01

    In this study, neuroprotective ganglioside derivatives are studied in an attempt to devise neuroprotective agents targeted to specific points in cell...death pathways. GMl ganglioside and several of its chemically modified derivatives are neuroprotective in a variety of neurotoxic models. Here... ganglioside functional groups required for neuroprotection and blood-brain barrier (BBB) permeance are determined. Cell death mechanisms are also defined

  12. Amphetamine derivative related deaths.

    PubMed

    Lora-Tamayo, C; Tena, T; Rodríguez, A

    1997-02-28

    Amphetamine its methylendioxy (methylendioxyamphetamine methylenedioxymethylamphetamine, methylenedioxyethylamphetamine) and methoxy derivatives (p-methoxyamphetamine and p-methoxymethylamphetamine) are widely abused in Spanish society. We present here the results of a systematic study of all cases of deaths brought to the attention of the Madrid department of the Instituto Nacional de Toxicologia from 1993 to 1995 in which some of these drugs have been found in the cadaveric blood. The cases were divided into three categories: amphetamine and derivatives, amphetamines and alcohol, amphetamines and other drugs. Data on age, sex, clinical symptoms, morphological findings, circumstances of death, when known, and concentration of amphetamine derivatives, alcohol and other drugs in blood are given for each group. The information provided here may prove to be useful for the forensic interpretation of deaths which are directly or indirectly related to abuse of amphetamine derivatives.

  13. Derivations in a tetrahedron

    NASA Astrophysics Data System (ADS)

    Vladeva, Dimitrinka I.; Trendafilov, Ivan D.

    2015-11-01

    One of the natural questions which often appeared in algebra and analysis whether a map can be defined by its "local" properties. In this paper we consider maps which acts like a derivation on semirings of a special type.

  14. Neuroprotective Ganglioside Derivatives

    DTIC Science & Technology

    2006-09-01

    determined to have therapeutic potential were to be tested in vitro for their ability to cross a brain capillary endothelial cell culture model of...the BBB. Finally, derivatives that were both cytoprotective and that effectively crossed the in vitro BBB model were to be tested in vivo for their...phenylpyridinium (MPP+) and the SH-SY5Y human neuroblastoma cell line. Derivatives determined to have therapeutic potential are tested in vitro for their

  15. Semisynthetic Derivatives of Epothilones

    NASA Astrophysics Data System (ADS)

    Altmann, Karl-Heinz

    Semisynthetic derivatives of natural products traditionally occupy a prominent space in natural-product-based drug discovery (1, 2). As many biologically active natural products exhibit a high degree of structural complexity (3), the chemical derivatization of material isolated from natural sources often represents the only feasible means (or at least the only economically viable approach) to explore structure-activity-relationships (SAR) and to produce analogs with more favorable pharmacokinetic and pharmacological properties than the natural product lead. Examples of clinically important drugs that are semisynthetic derivatives of natural products exist in virtually all disease areas (1, 2); in the treatment of cancer this includes compounds such as etoposide or teniposide (derived from podophyllotoxin) (4-6), irinotecan and topotecan (derived from camptothecin) (7-9), or docetaxel (derived from 10-deacetylbaccatin III) (10, 11). Even for taxol (11), which is a natural product (12), the sustained supply of sufficient quantities of material for widespread clinical use could only be secured through the development of a semisynthetic production process from another natural product, namely, 10-deacetylbaccatin III (13). In light of these facts, it is not surprising that semisynthesis approaches have also featured prominently in the elucidation of the SAR for epothilones and in the discovery of a number of clinical development candidates.

  16. Epoxide-derived organosulfates

    NASA Astrophysics Data System (ADS)

    Schwier, A. N.; Woo, J.; McNeill, V. F.

    2011-12-01

    Organosulfates (OS) are a significant fraction of secondary organic aerosol (SOA) material in the atmosphere. OS are typically surface-active, and have been suggested to cause surface tension depression in aerosols. Recent field studies suggest that epoxide-derived OS are the most abundant OS type in aerosols. Time-dependent surface tension measurements and Aerosol-CIMS characterization of two epoxides and their organosulfate products are shown. α-pinene oxide, derived from α-pinene, shows significant surface tension depression in H2O and ammonium sulfate. Results from cis-2,3-epoxybutane-1,4-diol (BEPOX), a butadiene-derived analog to isoprene-derived epoxydiols, are also shown. In addition, using GAMMA, a photochemical box model using coupled gas- and aqueous-phase chemistry developed in the McNeill laboratory, we show the dominance of epoxide-derived OS formation over other competing OS formation mechanisms, such as radical chemistry, under both high-NOx and low-NOx scenarios.

  17. Oxygenated Derivatives of Hydrocarbons

    USDA-ARS?s Scientific Manuscript database

    For the book entitled “Insect Hydrocarbons: Biology, Biochemistry and Chemical Ecology”, this chapter presents a comprehensive review of the occurrence, structure and function of oxygenated derivatives of hydrocarbons. The book chapter focuses on the occurrence, structural identification and functi...

  18. 78 FR 32191 - Derivatives

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-29

    ... From the Federal Register Online via the Government Publishing Office NATIONAL CREDIT UNION ADMINISTRATION 12 CFR Parts 703, 715, and 741 RIN 3133-AD90 Derivatives AGENCY: National Credit Union Administration (NCUA). ACTION: Proposed Rule. SUMMARY: This proposed rule permits credit unions to engage...

  19. Biotechnology and derived products

    USDA-ARS?s Scientific Manuscript database

    Microorganisms able to infect and kill insect pests, metabolites from plants and microorganisms, and transgenic crops are biotechnologically derived products that are being promoted for use to control insect pests in lieu of chemical insecticides. Products based on these technologies effectively co...

  20. Derived enriched uranium market

    SciTech Connect

    Rutkowski, E.

    1996-12-01

    The potential impact on the uranium market of highly enriched uranium from nuclear weapons dismantling in the Russian Federation and the USA is analyzed. Uranium supply, conversion, and enrichment factors are outlined for each country; inventories are also listed. The enrichment component and conversion components are expected to cause little disruption to uranium markets. The uranium component of Russian derived enriched uranium hexafluoride is unresolved; US legislation places constraints on its introduction into the US market.

  1. Neuroprotective Ganglioside Derivatives

    DTIC Science & Technology

    2003-09-01

    In this study, neuroprotective ganglioside derivatives are examined so they can be targeted to specific points in cell death pathways. Here... ganglioside functional groups required for neuroprotection and blood-brain barrier permeance are determined. Cell death mechanisms and the mechanism(s) by...which semisynthetic gangliosides intervene in the cell death process are also studied. In the second year C2, C4, CS, C14, C20, and C26 fatty acid GMl

  2. Dynamic Stability Derivatives

    DTIC Science & Technology

    2015-06-01

    the needed characteristic motions while avoiding sting /support interference effects, keeping the model near the center of the test section (where the...mounted between the model and sting . Other methods have been used. One example is the free-oscillation technique where the model is free to rotate...technique, the model is connected to the sting through a "flexure" or torsion spring. Again the decay rate is related to the dynamic derivative

  3. Pushing schedule derivation method

    SciTech Connect

    Henriquez, B.

    1996-12-31

    The development of a Pushing Schedule Derivation Method has allowed the company to sustain the maximum production rate at CSH`s Coke Oven Battery, in spite of having single set oven machinery with a high failure index as well as a heat top tendency. The stated method provides for scheduled downtime of up to two hours for machinery maintenance purposes, periods of empty ovens for decarbonization and production loss recovery capability, while observing lower limits and uniformity of coking time.

  4. Carnitine derivatives: clinical usefulness.

    PubMed

    Malaguarnera, Mariano

    2012-03-01

    Carnitine and its derivatives are natural substances involved in both carbohydrate and lipid metabolism. This review summarizes the recent progress in the field in relation to the molecular mechanisms. The pool of different carnitine derivatives is formed by acetyl-L-carnitine (ALC), propionyl-L-carnitine (PLC), and isovaleryl-carnitine. ALC may have a preferential effect on the brain tissue. ALC represents a compound of great interest for its wide clinical application in various neurological disorders: it may be of benefit in treating Alzheimer's dementia, depression in the elderly, HIV infection, chronic fatigue syndrome, peripheral neuropathies, ischemia and reperfusion of the brain, and cognitive impairment associated with various conditions. PLC has been demonstrated to replenish the intermediates of the tricarboxylic acid cycle by the propionyl-CoA moiety, a greater affinity for the sarcolemmal carrier, peripheral vasodilator activity, a greater positive inotropism, and more rapid entry into myocytes. Most studies of the therapeutic use of PLC are focused on the prevention and treatment of ischemic heart disease, congestive heart failure, hypertrophic heart disease, and peripheral arterial disease. ALC and PLC are considered well tolerated without significant side-effects. A number of therapeutic effects possibly come from the interaction of carnitine and its derivatives with the elements of cellular membranes.

  5. Crystal structure of (2,11-di-aza-[3.3](2,6)pyridino-phane-κ (4) N,N',N'',N''')(1,6,7,12-tetra-aza-perylene-κ (2) N (1),N (12))ruthenium(II) bis-(hexa-fluorido-phosphate) aceto-nitrile 1.422-solvate.

    PubMed

    Brietzke, Thomas; Rottke, Falko Otto; Kelling, Alexandra; Schilde, Uwe; Holdt, Hans-Jürgen

    2014-10-01

    In the title compound, [Ru(C14H16N4)(C16H8N4)](PF6)2·1.422CH3CN, discrete dimers of complex cations, [Ru(L-N4H2)tape](2+) are formed {L-N4H2 = 2,11-di-aza-[3.3](2,6)pyridino-phane; tape = 1,6,7,12-tetra-aza-perylene}, held together by π-π stacking inter-actions via the tape ligand moieties with a centroid-centroid distance of 3.49 (2) Å, assisted by hydrogen bonds between the non-coordinating tape ligand α,α'-di-imine unit and the amine proton of a 2,11-di-aza-[3.3](2,6)-pyridino-phane ligand of the opposite complex cation. The combination of these inter-actions leads to an unusual nearly face-to-face π-π stacking mode. Additional weak C-H⋯N, C-H⋯F, N-H⋯F and P-F⋯π-ring (tape, py) (with F⋯centroid distances of 2.925-3.984 Å) inter-actions are found, leading to a three-dimensional architecture. The Ru(II) atom is coordinated in a distorted octa-hedral geometry, particularly manifested by the Namine-Ru-Namine angle of 153.79 (10)°. The counter-charge is provided by two hexa-fluorido-phosphate anions and the asymmetric unit is completed by aceto-nitrile solvent mol-ecules of crystallization. Disorder was observed for both the hexa-fluorido-phosphate anions as well as the aceto-nitrile solvate mol-ecules, with occupancies for the major moieties of 0.801 (6) for one of the PF6 anions, and a shared occupancy of 0.9215 (17) for the second PF6 anion and a partially occupied aceto-nitrile mol-ecule. A second CH3CN mol-ecule is fully occupied, but 1:1 disordered across a crystallographic inversion center.

  6. Space Derived Air Monitor

    NASA Technical Reports Server (NTRS)

    1983-01-01

    COPAMS, Commonwealth of Pennsylvania Air Monitoring System, derives from technology involved in building unmanned spacecraft. The Nimbus spacecraft carried experimental sensors to measure temperature, pressure, ozone, and water vapor, and instruments for studying solar radiation and telemetry. The process which relayed these findings to Earth formed the basis for COPAMS. The COPAMS system consists of data acquisition units which measure and record pollution level, and sense wind speed and direction, etc. The findings are relayed to a central station where the information is computerized. The system is automatic and supplemented by PAQSS, PA Air Quality Surveillance System.

  7. Sulphenamides and their derivatives

    NASA Astrophysics Data System (ADS)

    Petrov, K. A.; Rudnev, G. V.; Sorokin, V. D.

    1990-09-01

    Information has been presented systematically on the synthesis of sulphenamides and related compounds by reaction of sulphenyl chlorides and sulphur chlorides with amines and carboxylic acid amides; by reaction of chloramines with mercaptans; by transamination of N-acylsulphenamides; and by reaction of disulphides with amines. The following chemical reactions of sulphenamides have been examined: reaction with hydrogen halides; with acids and derivatives possessing coordinatively unsaturated atoms; and the addition of sulphenamides to the double bond of carbon disulphide, isocyanates, isothiocyanates and olefins. Data are given on the physical state of sulphenamides and on the region characteristic of the S-N bond vibrations. The bibliography includes 190 references.

  8. In defense of derivations

    NASA Astrophysics Data System (ADS)

    Mungan, Carl E.

    2016-05-01

    At the 2015 AAPT Summer Meeting, I presented four derivations of the formula for motional emf. Such physics derivations involve the construction of explanatory frameworks involving diagrams and mathematical models. Although textbooks devote considerable space to such explanations, many teachers and students spend their time on worksheets, end-of-chapter problems, and the like. The book is reduced to a bank of solved (i.e., example) and unsolved (i.e., homework) questions, along with equations in colored boxes that presumably are to be used to answer those questions. Such an approach encourages fragmentation of knowledge, the view that there is only one right answer to a problem with the goal of physics being to find that answer (neatly boxed of course), and the inability to reason about even a slightly different (much less a novel) situation. If we are to develop scientific literacy, significant course time must be devoted to explaining the structure of and support for the models and equations we use.

  9. Experts' Understanding of Partial Derivatives Using the Partial Derivative Machine

    ERIC Educational Resources Information Center

    Roundy, David; Weber, Eric; Dray, Tevian; Bajracharya, Rabindra R.; Dorko, Allison; Smith, Emily M.; Manogue, Corinne A.

    2015-01-01

    Partial derivatives are used in a variety of different ways within physics. Thermodynamics, in particular, uses partial derivatives in ways that students often find especially confusing. We are at the beginning of a study of the teaching of partial derivatives, with a goal of better aligning the teaching of multivariable calculus with the needs of…

  10. Experts' Understanding of Partial Derivatives Using the Partial Derivative Machine

    ERIC Educational Resources Information Center

    Roundy, David; Weber, Eric; Dray, Tevian; Bajracharya, Rabindra R.; Dorko, Allison; Smith, Emily M.; Manogue, Corinne A.

    2015-01-01

    Partial derivatives are used in a variety of different ways within physics. Thermodynamics, in particular, uses partial derivatives in ways that students often find especially confusing. We are at the beginning of a study of the teaching of partial derivatives, with a goal of better aligning the teaching of multivariable calculus with the needs of…

  11. Acquiring Knowledge of Derived Nominals and Derived Adjectives in Context

    ERIC Educational Resources Information Center

    Marinellie, Sally A.; Kneile, Lynn A.

    2012-01-01

    Purpose: This research investigated children's ability to acquire semantic and syntactic knowledge of derived nominals and derived adjectives in the context of short passages. The study also investigated the relation of morphological awareness and the ability to acquire knowledge of derived words in context. Method: A total of 106 children in…

  12. Photodriven hydrogen evolution by molecular catalysts using Al2O3-protected perylene-3,4-dicarboximide on NiO electrodes† †Electronic supplementary information (ESI) available: Experimental details; additional electrochemical and photoelectrochemical characterization, UV-Vis spectra, and fsTA results; quantification of evolved hydrogen; and DFT-computed ground state structure of PMI diester. See DOI: 10.1039/c6sc02477g Click here for additional data file.

    PubMed Central

    Kamire, Rebecca J.; Majewski, Marek B.; Hoffeditz, William L.; Phelan, Brian T.; Farha, Omar K.; Hupp, Joseph T.

    2017-01-01

    The design of efficient hydrogen-evolving photocathodes for dye-sensitized photoelectrochemical cells (DSPECs) requires the incorporation of molecular light absorbing chromophores that are capable of delivering reducing equivalents to molecular proton reduction catalysts at rates exceeding those of charge recombination events. Here, we report the functionalization and kinetic analysis of a nanostructured NiO electrode with a modified perylene-3,4-dicarboximide chromophore (PMI) that is stabilized against degradation by atomic layer deposition (ALD) of thick insulating Al2O3 layers. Following photoinduced charge injection into NiO in high yield, films with Al2O3 layers demonstrate longer charge separated lifetimes as characterized via femtosecond transient absorption spectroscopy and photoelectrochemical techniques. The photoelectrochemical behavior of the electrodes in the presence of Co(ii) and Ni(ii) molecular proton reduction catalysts is examined, revealing reduction of both catalysts. Under prolonged irradiation, evolved H2 is directly observed by gas chromatography supporting the applicability of PMI embedded in Al2O3 as a photocathode architecture in DSPECs. PMID:28616134

  13. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

    Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

    1983-01-01

    Bis- and tris-imides derived from tris (m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a mono-imide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride. Such monomers or their oligomes may be used to impregnate fibers and fabrics which when cured, are flame resistant. Also an improved method of producing tris (m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst is described.

  14. Phosphorus-containing imide resins

    NASA Technical Reports Server (NTRS)

    Varma, I. K.; Fohlen, G. M.; Parker, J. A. (Inventor)

    1985-01-01

    Cured polymers of bis and tris-imides derived from tris(m-aminophenyl) phosphine oxides by reaction with maleic anhydride or its derivatives, and addition polymers of such imides, including a variant in which a monoimide is condensed with a dianhydride and the product is treated with a further quantity of maleic anhydride prior to curing are disclosed and claimed. Such polymers are flame resistant. Also disclosed are an improved method of producing tris(m-aminophenyl) phosphine oxides from the nitro analogues by reduction with hydrazine hydrate using palladized charcoal or Raney nickel as the catalyst and fiber reinforced cured resin composites.

  15. 6-Bromocholesterol derivatives

    SciTech Connect

    Flanagan, R.J.

    1984-02-07

    Novel 6-bromo derivatives of cholesterol have the formula 3-(R-O-),6-BR,17-((H3C-)2-HC-H2C-H2C-H2C-HC(-CH3)-)-ESTR-5-ENE Such compounds are prepared from the known 6-iodocholesterol by treatment with cuprous bromide. These compounds, labelled with radioisotopes of Br-82 or Br-77, are localized in the adrenal, mammary and ovary tissue of female mammals and in the adrenal or prostate tissue of males when administered to such individuals. This provides a method for imaging adrenal, ovary or prostate tissue which is superior to use of the prior art 6-iodo-cholesterol.

  16. Algae Derived Biofuel

    SciTech Connect

    Jahan, Kauser

    2015-03-31

    One of the most promising fuel alternatives is algae biodiesel. Algae reproduce quickly, produce oils more efficiently than crop plants, and require relatively few nutrients for growth. These nutrients can potentially be derived from inexpensive waste sources such as flue gas and wastewater, providing a mutual benefit of helping to mitigate carbon dioxide waste. Algae can also be grown on land unsuitable for agricultural purposes, eliminating competition with food sources. This project focused on cultivating select algae species under various environmental conditions to optimize oil yield. Membrane studies were also conducted to transfer carbon di-oxide more efficiently. An LCA study was also conducted to investigate the energy intensive steps in algae cultivation.

  17. Derivation of Model Topography

    NASA Technical Reports Server (NTRS)

    Balgovind, R. C.

    1985-01-01

    The Fourth-Order model necessitates representation of the topography. The problem of the representation of the topography at grid points is addressed. The attempted was to derive an envelope topography. The TI is obtained by taking local mean plus one standard deviation at each grid point and sigma filtering it. The method was greatly influenced by large standard deviations at steep mountains. The O1 topography is the local mean. The S1 is obtained by Sigma filtering in both latitude and longitude the mean O1. The S2 is when the operation is applied twice and S3 thrice, the Q3 is the sigma filtered local mean of the upper third quantile of the source data.

  18. Experts' understanding of partial derivatives using the partial derivative machine

    NASA Astrophysics Data System (ADS)

    Roundy, David; Weber, Eric; Dray, Tevian; Bajracharya, Rabindra R.; Dorko, Allison; Smith, Emily M.; Manogue, Corinne A.

    2015-12-01

    [This paper is part of the Focused Collection on Upper Division Physics Courses.] Partial derivatives are used in a variety of different ways within physics. Thermodynamics, in particular, uses partial derivatives in ways that students often find especially confusing. We are at the beginning of a study of the teaching of partial derivatives, with a goal of better aligning the teaching of multivariable calculus with the needs of students in STEM disciplines. In this paper, we report on an initial study of expert understanding of partial derivatives across three disciplines: physics, engineering, and mathematics. We report on the central research question of how disciplinary experts understand partial derivatives, and how their concept images of partial derivatives differ, with a focus on experimentally measured quantities. Using the partial derivative machine (PDM), we probed expert understanding of partial derivatives in an experimental context without a known functional form. In particular, we investigated which representations were cued by the experts' interactions with the PDM. Whereas the physicists and engineers were quick to use measurements to find a numeric approximation for a derivative, the mathematicians repeatedly returned to speculation as to the functional form; although they were comfortable drawing qualitative conclusions about the system from measurements, they were reluctant to approximate the derivative through measurement. On a theoretical front, we found ways in which existing frameworks for the concept of derivative could be expanded to include numerical approximation.

  19. Polycyclic aromatic hydrocarbons (PAHs) and their derivatives (oxygenated-PAHs, nitrated-PAHs and azaarenes) in size-fractionated particles emitted in an urban road tunnel

    NASA Astrophysics Data System (ADS)

    Alves, C. A.; Vicente, A. M. P.; Gomes, J.; Nunes, T.; Duarte, M.; Bandowe, B. A. M.

    2016-11-01

    A sampling campaign of size segregated particulate matter (PM0.5, PM0.5-1, PM1-2.5 and PM2.5-10) was carried out at two sites, one in a road tunnel (Braga, Portugal) and another at an urban background location in the neighbourhood. Particle-bound polycyclic aromatic compounds were extracted with organic solvents and analysed by gas chromatography-mass spectrometry. Twenty six parent and alkyl-polycyclic aromatic hydrocarbons (PAHs), 4 azaarenes (AZAs), 15 nitrated and 15 oxygenated derivatives (NPAHs and OPAHs) were analysed. On average, submicron particles (PM1) in the tunnel comprised 93, 91, 96 and 71% of the total PAHs, OPAHs, NPAHs and AZAs mass in PM10, respectively. Tunnel to outdoor PAH concentration ratios between 10 and 14 reveal the strong contribution of fresh exhaust emissions to the PM loads. The dominant PAHs in the tunnel were pyrene, retene and benzo[ghi]perylene, accounting for 20, 17 and 8% of the total PAH levels in PM10, respectively. Isomer ratios indicated the importance of unburnt fuel as a significant PAH source. The only NPAH consistently present in all samples was 5-nitroacenaphthene. Indanone and 1,8-naphthalic anhydride were the most abundant OPAHs, accounting for 25 and 17% of the total concentrations of this organic class, respectively. Other abundant OPAHs were 1,4-naphthoquinone, 9-fluorenone, 1,2-acenaphthylenequinone and 7H-benz[de]anthracene-7-one. Individual emission factors (μg veh- 1 km- 1) were estimated and compared with those obtained in other tunnel studies.

  20. Weyl quantization of fractional derivatives

    SciTech Connect

    Tarasov, Vasily E.

    2008-10-15

    The quantum analogs of the derivatives with respect to coordinates q{sub k} and momenta p{sub k} are commutators with operators P{sub k} and Q{sub k}. We consider quantum analogs of fractional Riemann-Liouville and Liouville derivatives. To obtain the quantum analogs of fractional Riemann-Liouville derivatives, which are defined on a finite interval of the real axis, we use a representation of these derivatives for analytic functions. To define a quantum analog of the fractional Liouville derivative, which is defined on the real axis, we can use the representation of the Weyl quantization by the Fourier transformation.

  1. Piroxicam derivatives THz classification

    NASA Astrophysics Data System (ADS)

    Sterczewski, Lukasz A.; Grzelczak, Michal P.; Nowak, Kacper; Szlachetko, Bogusław; Plinska, Stanislawa; Szczesniak-Siega, Berenika; Malinka, Wieslaw; Plinski, Edward F.

    2016-02-01

    In this paper we report a new approach to linking the terahertz spectral shapes of drug candidates having a similar molecular structure to their chemical and physical parameters. We examined 27 newly-synthesized derivatives of a well-known nonsteroidal anti-inflammatory drug Piroxicam used for treatment of inflammatory arthritis and chemoprevention of colon cancer. The testing was carried out by means of terahertz pulsed spectroscopy (TPS). Using chemometric techniques we evaluated their spectral similarity in the terahertz range and attempted to link the position on the principal component analysis (PCA) score map to the similarity of molecular descriptors. A simplified spectral model preserved 75% and 85.1% of the variance in 2 and 3 dimensions respectively, compared to the input 1137. We have found that in 85% of the investigated samples a similarity of the physical and chemical parameters corresponds to a similarity in the terahertz spectra. The effects of data preprocessing on the generated maps are also discussed. The technique presented can support the choice of the most promising drug candidates for clinical trials in pharmacological research.

  2. DRS: Derivational Reasoning System

    NASA Technical Reports Server (NTRS)

    Bose, Bhaskar

    1995-01-01

    The high reliability requirements for airborne systems requires fault-tolerant architectures to address failures in the presence of physical faults, and the elimination of design flaws during the specification and validation phase of the design cycle. Although much progress has been made in developing methods to address physical faults, design flaws remain a serious problem. Formal methods provides a mathematical basis for removing design flaws from digital systems. DRS (Derivational Reasoning System) is a formal design tool based on advanced research in mathematical modeling and formal synthesis. The system implements a basic design algebra for synthesizing digital circuit descriptions from high level functional specifications. DRS incorporates an executable specification language, a set of correctness preserving transformations, verification interface, and a logic synthesis interface, making it a powerful tool for realizing hardware from abstract specifications. DRS integrates recent advances in transformational reasoning, automated theorem proving and high-level CAD synthesis systems in order to provide enhanced reliability in designs with reduced time and cost.

  3. Bicyclic glutamic acid derivatives.

    PubMed

    Meyer, Udo; Bisel, Philippe; Weckert, Edgar; Frahm, August Wilhelm

    2006-05-15

    For the second-generation asymmetric synthesis of the trans-tris(homoglutamic) acids via Strecker reaction of chiral ketimines, the cyanide addition as the key stereodifferentiating step produces mixtures of diastereomeric alpha-amino nitrile esters the composition of which is independent of the reaction temperature and the type of the solvent, respectively. The subsequent hydrolysis is exclusively achieved with concentrated H(2)SO(4) yielding diastereomeric mixtures of three secondary alpha-amino alpha-carbamoyl-gamma-esters and two diastereomeric cis-fused angular alpha-carbamoyl gamma-lactams as bicyclic glutamic acid derivatives, gained from in situ stereomer differentiating cyclisation of the secondary cis-alpha-amino alpha-carbamoyl-gamma-esters. Separation was achieved by CC. The pure secondary trans-alpha-amino alpha-carbamoyl-gamma-esters cyclise on heating and treatment with concentrated H(2)SO(4), respectively, to diastereomeric cis-fused angular secondary alpha-amino imides. Their hydrogenolysis led to the enantiomeric cis-fused angular primary alpha-amino imides. The configuration of all compounds was completely established by NMR methods, CD-spectra, and by X-ray analyses of the (alphaR,1R,5R)-1-carbamoyl-2-(1-phenylethyl)-2-azabicyclo[3.3.0]octan-3-one and of the trans-alphaS,1S,2R-2-ethoxycarbonylmethyl-1-(1-phenylethylamino)cyclopentanecarboxamide.

  4. Biomolecule derived nanostructured arrays

    NASA Astrophysics Data System (ADS)

    Yuan, Zhen

    During the last decade, intensive research have been reported on biomimetic approaches towards achieving mono-dispersed nanoparticles, and building self-assembled system out of those (organizing nanoparticles). However the development of this research avenue is being hindered by the limited knowledge and very few practical, efficient, cost-effective approaches for implementation of the bio-derived arrays into engineering practice. The objective of this work is to biomimeticaly form nanocomposite materials using a simple, rapid, inexpensive, scalable approach, which is general enough and not limited to colloidal particle self-assembly. Throughout the studies, we have developed a universally applicable process, which is to fabricate macro-biomolecular arrays on solid substrates based on the convective self-assembly of colloidal particles. We have demonstrated that protein (ferritin) and virus (phage) arrays were directly deposited onto solid substrates such as glass, silicon wafer, and gold substrate in closed or near closed-packed order. The arrays were further incorporated into a more robust silica matrix, in such that strengthens the thermal stability and provides porous accessibility. After treatment in controlled pyrolysis, the organic protein shell was removed, left mono-dispersed iron-oxide nanoparticles intact on the substrate or in the silica matrix. Both iron-oxide nanoparticles arrays with or without silica matrix have been further characterized to possess superferromagnetic properties at low temperature (15 K), same as that in bulk material. Initial work on protein patterning, through combining either lithography based top-down or bottom-up techniques with our novel deposition approach, was presented as well. Thin film deposition of mesoporous materials using convective self-assembly is another main part in this work. Both silica and carbon mesoporous thin films were successfully formed using the convective self-assembly horizontal-coating approach. We

  5. Phosphorus derivatives of salicylic acid

    NASA Astrophysics Data System (ADS)

    Chvertkina, L. V.; Khoklov, P. S.; Mironov, Vladimir F.

    1992-10-01

    The present state of work on the methods of synthesis, chemical properties, and practical applications of phosphorus-containing derivatives of salicylic acid has been reviewed. The characteristics of the chemical transformations of cyclic and acyclic phosphorus derivatives of salicylic acid related to the coordination state of the phosphorus atom have been examined. The bibliography includes 158 references.

  6. Thiamine phosphorylated derivatives and bioelectrogenesis.

    PubMed

    Schoffeniels, E

    1983-09-01

    Kinetic as well as thermodynamic considerations favour the idea that the change in sodium conductance explaining the action potential, must result from a bimolecular reaction system. The fact that thiamine phosphorylated derivatives are associated with the specific protein forming the sodium channel could well mean that these thiamine derivatives and more specifically thiamine triphosphate are directly involved in the conductance change.

  7. 6 CFR 7.26 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... that apply to the source information. Information is also derivatively classified when classification... original classification authority to derivatively classify information based on source documents or... INFORMATION Classified Information § 7.26 Derivative classification. (a) Derivative classification is defined...

  8. Cytochalasin derivatives from a jellyfish-derived fungus Phoma sp.

    PubMed

    Kim, Eun La; Wang, Haibo; Park, Ju Hee; Hong, Jongki; Choi, Jae Sue; Im, Dong Soon; Chung, Hae Young; Jung, Jee H

    2015-01-01

    Four new cytochalasin derivatives (1-4), together with proxiphomin (5), were isolated from a jellyfish-derived fungus Phoma sp. The planar structures and relative stereochemistry were established by analysis of 1D and 2D NMR data. The absolute configuration was defined by the modified Mosher's method. The compounds showed moderate cytotoxicity against a small panel of human solid tumor cell lines (A549, KB, and HCT116).

  9. Complex higher order derivative theories

    SciTech Connect

    Margalli, Carlos A.; Vergara, J. David

    2012-08-24

    In this work is considered a complex scalar field theory with higher order derivative terms and interactions. A procedure is developed to quantize consistently this system avoiding the presence of negative norm states. In order to achieve this goal the original real scalar high order field theory is extended to a complex space attaching a complex total derivative to the theory. Next, by imposing reality conditions the complex theory is mapped to a pair of interacting real scalar field theories without the presence of higher derivative terms.

  10. Quinazoline derivatives: synthesis and bioactivities

    PubMed Central

    2013-01-01

    Owing to the significant biological activities, quinazoline derivatives have drawn more and more attention in the synthesis and bioactivities research. This review summarizes the recent advances in the synthesis and biological activities investigations of quinazoline derivatives. According to the main method the authors adopted in their research design, those synthetic methods were divided into five main classifications, including Aza-reaction, Microwave-assisted reaction, Metal-mediated reaction, Ultrasound-promoted reaction and Phase-transfer catalysis reaction. The biological activities of the synthesized quinazoline derivatives also are discussed. PMID:23731671

  11. Quinazoline derivatives: synthesis and bioactivities.

    PubMed

    Wang, Dan; Gao, Feng

    2013-06-03

    Owing to the significant biological activities, quinazoline derivatives have drawn more and more attention in the synthesis and bioactivities research. This review summarizes the recent advances in the synthesis and biological activities investigations of quinazoline derivatives. According to the main method the authors adopted in their research design, those synthetic methods were divided into five main classifications, including Aza-reaction, Microwave-assisted reaction, Metal-mediated reaction, Ultrasound-promoted reaction and Phase-transfer catalysis reaction. The biological activities of the synthesized quinazoline derivatives also are discussed.

  12. Microscopic derivation of discrete hydrodynamics.

    PubMed

    Español, Pep; Anero, Jesús G; Zúñiga, Ignacio

    2009-12-28

    By using the standard theory of coarse graining based on Zwanzig's projection operator, we derive the dynamic equations for discrete hydrodynamic variables. These hydrodynamic variables are defined in terms of the Delaunay triangulation. The resulting microscopically derived equations can be understood, a posteriori, as a discretization on an arbitrary irregular grid of the Navier-Stokes equations. The microscopic derivation provides a set of discrete equations that exactly conserves mass, momentum, and energy and the dissipative part of the dynamics produces strict entropy increase. In addition, the microscopic derivation provides a practical implementation of thermal fluctuations in a way that the fluctuation-dissipation theorem is satisfied exactly. This paper points toward a close connection between coarse-graining procedures from microscopic dynamics and discretization schemes for partial differential equations.

  13. DALI: Derivative Approximation for LIkelihoods

    NASA Astrophysics Data System (ADS)

    Sellentin, Elena

    2015-07-01

    DALI (Derivative Approximation for LIkelihoods) is a fast approximation of non-Gaussian likelihoods. It extends the Fisher Matrix in a straightforward way and allows for a wider range of posterior shapes. The code is written in C/C++.

  14. Mutagenicities of nitrosated carboline derivatives.

    PubMed

    Lin, J K; Wu, S S; Chen, J T

    1986-10-01

    Food-borne amines have been considered as the potential precursors of endogenous carcinogenic N-nitroso compounds in humans. A compound which yields a direct mutagen after nitrite treatment was isolated from soy sauce and was identified as 1-methyl-1,2,3,4-tetrahydro-2-carboline-3-carboxylic acid (MTCA) (Wakabayashi, et al., 1983). The mutagenicities of other carboline derivatives such as harman, norharman, harmaline, harmalol, harmine, and harmol were studied. Like MTCA, the nitrosated carboline derivatives showed higher mutagenic activity as compared to their corresponding parent compounds. The demethylated analogue of MTCA, 1,2,3,4-tetrahydro-2-carboline-3-carboxylic acid was synthesized and its nitrosated products were shown to be mutagenic to Salmonella typhimurium TA 100 and TA 98. The potent mutagen Trp-P-2 is a typical 3-carboline derivative. The mutagenicity of Trp-P-2 was suppressed remarkably after nitrosation. Several 3-carboline derivatives also showed the similar property. Nitrosation of MTCA gave several derivatives which were isolated and showed direct mutagenicity to Salmonella typhimurium TA 98. Further characterization of these new carboline derivatives is in progress.

  15. Vapor pressures and enthalpies of sublimation of polycyclic aromatic hydrocarbons and their derivatives

    SciTech Connect

    Oja, V.; Suuberg, E.M.

    1998-05-01

    The vapor pressures of a series of polycyclic aromatic hydrocarbons (PAH) and heteroatom-containing PAH have been measured using the Knudsen effusion technique. Aromatic hydrocarbons examined included anthracene, phenanthrene, pyrene, 2,3-benzofluorene, naphthacene, perylene, pentacene, and coronene. Heteroatomic aromatic species examined included phenanthridine, perinaphthenone, 3-hydroxy-1-phenalen-1-one, benz[g]isoquinoline-5,10-dione, 1,2-benzodiphenylene sulfide, 1-hydroxypyrene, and 6,11-dihydroxy-5,12-naphthacenedione. The measurements were all made in the solid sublimation regime, and enthalpies of sublimation were calculated from the Clausius-Clapeyron equation.

  16. Bioactive steroid derivatives and butyrolactone derivatives from a gorgonian-derived Aspergillus sp. fungus.

    PubMed

    Chen, Min; Wang, Kai-Ling; Liu, Min; She, Zhi-Gang; Wang, Chang-Yun

    2015-09-01

    Six steroid derivatives, 1-6, and five butyrolactone derivatives, 7-11, were isolated from the fermentation broth of a gorgonian-derived Aspergillus sp. fungus. Their structures were elucidated on the basis of NMR and MS spectral data. Compound 1 is a new, highly conjugated steroid. The NMR and MS data of 7 and 8 are reported for the first time, as their structures were listed in SciFinder Scholar with no associated reference. Compounds 1, 4, 5, and 8-11 inhibited the larval settlement of barnacle Balanus amphitrite with EC50 values ranging from 0.63 to 18.4 μg ml(-1) . Butyrolactone derivatives 7 and 8 showed pronounced antibacterial activities against Staphylococcus aureus with the same MIC values as the positive control ciprofloxacin (MIC 1.56 μM for all three compounds).

  17. 12 CFR 390.352 - Financial derivatives.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Financial derivatives. 390.352 Section 390.352... Financial derivatives. (a) What is a financial derivative? A financial derivative is a financial contract... common types of financial derivatives are futures, forward commitments, options, and swaps. A...

  18. 12 CFR 390.352 - Financial derivatives.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Financial derivatives. 390.352 Section 390.352... Financial derivatives. (a) What is a financial derivative? A financial derivative is a financial contract... common types of financial derivatives are futures, forward commitments, options, and swaps. A...

  19. 12 CFR 390.352 - Financial derivatives.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Financial derivatives. 390.352 Section 390.352... Financial derivatives. (a) What is a financial derivative? A financial derivative is a financial contract... common types of financial derivatives are futures, forward commitments, options, and swaps. A...

  20. Variational approach and deformed derivatives

    NASA Astrophysics Data System (ADS)

    Weberszpil, J.; Helayël-Neto, J. A.

    2016-05-01

    Recently, we have demonstrated that there exists a possible relationship between q-deformed algebras in two different contexts of Statistical Mechanics, namely, the Tsallis' framework and the Kaniadakis' scenario, with a local form of fractional-derivative operators for fractal media, the so-called Hausdorff derivatives, mapped into a continuous medium with a fractal measure. Here, in this paper, we present an extension of the traditional calculus of variations for systems containing deformed-derivatives embedded into the Lagrangian and the Lagrangian densities for classical and field systems. The results extend the classical Euler-Lagrange equations and the Hamiltonian formalism. The resulting dynamical equations seem to be compatible with those found in the literature, specially with mass-dependent and with nonlinear equations for systems in classical and quantum mechanics. Examples are presented to illustrate applications of the formulation. Also, the conserved ​Noether current is worked out.

  1. Drugs derived from phage display

    PubMed Central

    Nixon, Andrew E; Sexton, Daniel J; Ladner, Robert C

    2014-01-01

    Phage display, one of today’s fundamental drug discovery technologies, allows identification of a broad range of biological drugs, including peptides, antibodies and other proteins, with the ability to tailor critical characteristics such as potency, specificity and cross-species binding. Further, unlike in vivo technologies, generating phage display-derived antibodies is not restricted by immunological tolerance. Although more than 20 phage display-derived antibody and peptides are currently in late-stage clinical trials or approved, there is little literature addressing the specific challenges and successes in the clinical development of phage-derived drugs. This review uses case studies, from candidate identification through clinical development, to illustrate the utility of phage display as a drug discovery tool, and offers a perspective for future developments of phage display technology. PMID:24262785

  2. Deriving Descriptions of the Mind.

    DTIC Science & Technology

    1987-07-07

    AiB6 647 DERIVING DESCRIPTIONS OF THE MIND (U) CARNEGIE-MELLON / UNIV PITTSBURGH PA DEPT OF PSYCHOLOGY S GARLICK ET AL 87 JUL 87 PCG-7 N88914-86-K...8149 UNCLASSIFIED F/G 12/9 MI. mN hEhhhh 1൘ ill 2.2 IIll O p4IuI 3. , ,- flhCILLCM Deriving Descriptions of the Mind Technical Report PCG-7 4 Steve...OCT 22 7 PSYCHOLOGY -6Apptoved I’o1 ubi -4V D~~~ifbuto~Iu1 * Carnegie-Mellon University Deriving Descriptions of the Mind Technical Report PCG-7 Steve

  3. Sol-gel derived sorbents

    DOEpatents

    Sigman, Michael E.; Dindal, Amy B.

    2003-11-11

    Described is a method for producing copolymerized sol-gel derived sorbent particles for the production of copolymerized sol-gel derived sorbent material. The method for producing copolymerized sol-gel derived sorbent particles comprises adding a basic solution to an aqueous metal alkoxide mixture for a pH.ltoreq.8 to hydrolyze the metal alkoxides. Then, allowing the mixture to react at room temperature for a precalculated period of time for the mixture to undergo an increased in viscosity to obtain a desired pore size and surface area. The copolymerized mixture is then added to an immiscible, nonpolar solvent that has been heated to a sufficient temperature wherein the copolymerized mixture forms a solid upon the addition. The solid is recovered from the mixture, and is ready for use in an active sampling trap or activated for use in a passive sampling trap.

  4. Relieving of Misconceptions of Derivative Concept with Derive

    ERIC Educational Resources Information Center

    Kaplan, Abdullah; Ozturk, Mesut; Ocal, Mehmet Fatih

    2015-01-01

    The purpose of this study is to determine students' learning levels in derivative subjects and their misconceptions. In addition, this study aims to compared to the effects of the computer based instruction and traditional instruction in resolving these misconceptions. For this purpose, 70 12th grade students were chosen from high schools in Agri…

  5. Relieving of Misconceptions of Derivative Concept with Derive

    ERIC Educational Resources Information Center

    Kaplan, Abdullah; Ozturk, Mesut; Ocal, Mehmet Fatih

    2015-01-01

    The purpose of this study is to determine students' learning levels in derivative subjects and their misconceptions. In addition, this study aims to compared to the effects of the computer based instruction and traditional instruction in resolving these misconceptions. For this purpose, 12th grade 70 students were chosen from high schools in Agri…

  6. Empirically derived injury prevention rules.

    PubMed Central

    Peterson, L; Schick, B

    1993-01-01

    This study describes a set of empirically derived safety rules that if followed, would have prevented the occurrence of minor injuries. Epidemiologists have criticized behavioral interventions as increasing "safe" behavior but failing to demonstrate a decrease in injury. The present study documents retrospectively the link between safe behavior and injury. It demonstrates that these empirically derived rules are very similar to rules for the prevention of serious injury. The study also shows that these rules are not widely accepted and implemented by parents. Suggestions for future research in this area are advanced. PMID:8307829

  7. "Clickable" vitamin B12 derivative.

    PubMed

    Chromiński, Mikołaj; Gryko, Dorota

    2013-04-15

    A "clickable" vitamin B12 derivative possessing the azide functionality at the 5'-position was synthesized by means of a two-step procedure on the gram scale. The reaction of cobalamin with mesyl chloride (MsCl) afforded the 5'-OMs derivative, which was subsequently transformed to the desired 5'-azide, the structure of which was confirmed using X-ray analysis. It proved to be reactive in the azide-alkyne 1,3-dipolar cycloaddition reaction to give substituted triazoles in high yields. A study of the reaction conditions and the scope of the process are reported.

  8. Magnetic cellulose-derivative structures

    DOEpatents

    Walsh, M.A.; Morris, R.S.

    1986-09-16

    Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorption agents can be incorporated during the manufacture of the structure. 3 figs.

  9. Magnetic cellulose-derivative structures

    DOEpatents

    Walsh, Myles A.; Morris, Robert S.

    1986-09-16

    Structures to serve as selective magnetic sorbents are formed by dissolving a cellulose derivative such as cellulose triacetate in a solvent containing magnetic particles. The resulting solution is sprayed as a fine mist into a chamber containing a liquid coagulant such as n-hexane in which the cellulose derivative is insoluble but in which the coagulant is soluble or miscible. On contact with the coagulant, the mist forms free-flowing porous magnetic microspheric structures. These structures act as containers for the ion-selective or organic-selective sorption agent of choice. Some sorbtion agents can be incorporated during the manufacture of the structure.

  10. Asymptotic aspect of derivations in Banach algebras.

    PubMed

    Roh, Jaiok; Chang, Ick-Soon

    2017-01-01

    We prove that every approximate linear left derivation on a semisimple Banach algebra is continuous. Also, we consider linear derivations on Banach algebras and we first study the conditions for a linear derivation on a Banach algebra. Then we examine the functional inequalities related to a linear derivation and their stability. We finally take central linear derivations with radical ranges on semiprime Banach algebras and a continuous linear generalized left derivation on a semisimple Banach algebra.

  11. Variational Derivation of Dissipative Equations

    NASA Astrophysics Data System (ADS)

    Sogo, Kiyoshi

    2017-03-01

    A new variational principle is formulated to derive various dissipative equations. Model equations considered are the damping equation, Bloch equation, diffusion equation, Fokker-Planck equation, Kramers equation and Smoluchowski equation. Each equation and its time reversal equation are simultaneously obtained in our variational principle.

  12. 5 CFR 1312.7 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Classification and Declassification of National Security Information § 1312.7 Derivative classification. A derivative...

  13. 5 CFR 1312.7 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Classification and Declassification of National Security Information § 1312.7 Derivative classification. A derivative...

  14. 5 CFR 1312.7 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ..., DOWNGRADING, DECLASSIFICATION AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION Classification and Declassification of National Security Information § 1312.7 Derivative classification. A derivative...

  15. A systematically-derived global glacier map derived from MODIS

    NASA Astrophysics Data System (ADS)

    Brodzik, M.; Painter, T. H.; Armstrong, R. L.

    2009-12-01

    A wealth of glacier data are contained in the archives of both the World Glacier Monitoring Service (WGMS), Zurich, Switzerland, and the National Snow and Ice Data Center (NSIDC), Boulder, USA. Types of data range from detailed, high resolution digital glacier outlines, to carefully compiled time series of terminus fluctuation and mass balance measurements, to glacier photograph pairs showing change through time. One fundamental missing component of a world glacier inventory is simply a single, systematically-derived base map of the world’s glaciers, at any scale. The MODICE project has developed a prototype example of such a consistently-derived base map, using 500 m MODIS data. The MODICE algorithm identifies surfaces with persistent snow and ice, derived from MODIS Snow-covered Area and Grain-Size Albedo (MODSCAG) subpixel snow fraction, during the annual period that includes the seasonal minimum snow cover. We describe the persistence algorithm approach that accounts for problems of transient snow or clouds that may incorrectly be identified as ice in any given scene. We demonstrate the algorithm results for the Himalayan Plateau (comprising 10 MODIS tiles) for the autumns of 2001 and 2002. We are validating the MODICE persistent ice map by comparing to areas of glaciers identified by Global Land Ice Measurements from Space (GLIMS). Our presentation includes standard image classification statistics as metrics of the accuracy of the MODICE approach.

  16. Generalized Molecular Descriptors Derived From Event-Based Discrete Derivative.

    PubMed

    Martínez-Santiago, Oscar; Cabrera, Reisel Millán; Marrero-Ponce, Yovani; Barigye, Stephen J; Le-Thi-Thu, Huong; Torres, F Javier; Zambrano, Cesar H; Yaber-Goenaga, Ivan; Cruz-Monteagudo, Maykel; López, Yoan Martínez; Giménez, Facundo Pérez; Torrens, Francisco

    2016-01-01

    In the present study, a generalized approach for molecular structure characterization is introduced, based on the relation frequency matrix (F) representation of the molecular graph and the subsequent calculation of the corresponding discrete derivative (finite difference) over a pair of elements (atoms). In earlier publications (22- 24), an unique event, named connected subgraphs, (based on the Kier-Hall's subgraphs) was systematically employed for the computation of the matrix F. The present report is a generalization of this notion, in which eleven additional events are introduced, classified in three categories, namely, topological (terminal paths, vertex path incidence, quantum subgraphs, walks of length k, Sach's subgraphs), fingerprints (MACCs, E-state and substructure fingerprints) and atomic contributions (Ghose and Crippen atom-types for hydrophobicity and refractivity) for F generation. The events are intended to capture diverse information by the generation or search of different kinds of substructures from the graph representation of a molecule. The discrete derivative over duplex atom relations are calculated for each event, and the resulting derivatives, local vertex invariants (LOVIs) are finally obtained. These LOVIs are subsequently employed as the basis for the calculation of global and local indices over groups of atoms (heteroatoms, halogens, methyl carbons, etc.), by using norms, means, statistics and classical algorithms as aggregator (fusion) operators. These indices were implemented in our house software DIVATI (Derivative Type Indices, a new module of TOMOCOMDCARDD system). DIVATI provides a friendly and cross-platform graphical user interface, developed in the Java programming language and is freely available at: http: //www.tomocomd.com. Factor analysis shows that the presented events are rather orthogonal and collect diverse information about the chemical structure. Finally, QSPR models were built to describe the logP and logK of 34

  17. Self-assembling hydrogel scaffolds for photocatalytic hydrogen production

    DOE PAGES

    Weingarten, Adam S.; Kazantsev, Roman V.; Palmer, Liam C.; ...

    2014-10-05

    Integration into a soft material of all the molecular components necessary to generate storable fuels is an interesting target in supramolecular chemistry. The concept is inspired by the internal structure of photosynthetic organelles, such as plant chloroplasts, which colocalize molecules involved in light absorption, charge transport and catalysis to create chemical bonds using light energy. We report in this paper on the light-driven production of hydrogen inside a hydrogel scaffold built by the supramolecular self-assembly of a perylene monoimide amphiphile. The charged ribbons formed can electrostatically attract a nickel-based catalyst, and electrolyte screening promotes gelation. We found the emergent phenomenonmore » that screening by the catalyst or the electrolytes led to two-dimensional crystallization of the chromophore assemblies and enhanced the electronic coupling among the molecules. Finally, photocatalytic production of hydrogen is observed in the three-dimensional environment of the hydrogel scaffold and the material is easily placed on surfaces or in the pores of solid supports.« less

  18. Self-assembling hydrogel scaffolds for photocatalytic hydrogen production

    SciTech Connect

    Weingarten, Adam S.; Kazantsev, Roman V.; Palmer, Liam C.; McClendon, Mark; Koltonow, Andrew R.; Samuel, Amanda P. S.; Kiebala, Derek J.; Wasielewski, Michael R.; Stupp, Samuel I.

    2014-10-05

    Integration into a soft material of all the molecular components necessary to generate storable fuels is an interesting target in supramolecular chemistry. The concept is inspired by the internal structure of photosynthetic organelles, such as plant chloroplasts, which colocalize molecules involved in light absorption, charge transport and catalysis to create chemical bonds using light energy. We report in this paper on the light-driven production of hydrogen inside a hydrogel scaffold built by the supramolecular self-assembly of a perylene monoimide amphiphile. The charged ribbons formed can electrostatically attract a nickel-based catalyst, and electrolyte screening promotes gelation. We found the emergent phenomenon that screening by the catalyst or the electrolytes led to two-dimensional crystallization of the chromophore assemblies and enhanced the electronic coupling among the molecules. Finally, photocatalytic production of hydrogen is observed in the three-dimensional environment of the hydrogel scaffold and the material is easily placed on surfaces or in the pores of solid supports.

  19. Supramolecular Packing Controls H2 Photocatalysis in Chromophore Amphiphile Hydrogels

    PubMed Central

    2015-01-01

    Light harvesting supramolecular assemblies are potentially useful structures as components of solar-to-fuel conversion materials. The development of these functional constructs requires an understanding of optimal packing modes for chromophores. We investigated here assembly in water and the photocatalytic function of perylene monoimide chromophore amphiphiles with different alkyl linker lengths separating their hydrophobic core and the hydrophilic carboxylate headgroup. We found that these chromophore amphiphiles (CAs) self-assemble into charged nanostructures of increasing aspect ratio as the linker length is increased. The addition of salt to screen the charged nanostructures induced the formation of hydrogels and led to internal crystallization within some of the nanostructures. For linker lengths up to seven methylenes, the CAs were found to pack into 2D crystalline unit cells within ribbon-shaped nanostructures, whereas the nine methylene CAs assembled into long nanofibers without crystalline molecular packing. At the same time, the different molecular packing arrangements after charge screening led to different absorbance spectra, despite the identical electronic properties of all PMI amphiphiles. While the crystalline CAs formed electronically coupled H-aggregates, only CAs with intermediate linker lengths showed evidence of high intermolecular orbital overlap. Photocatalytic hydrogen production using a nickel-based catalyst was observed in all hydrogels, with the highest turnovers observed for CA gels having intermediate linker lengths. We conclude that the improved photocatalytic performance of the hydrogels formed by supramolecular assemblies of the intermediate linker CA molecules likely arises from improved exciton splitting efficiencies due to their higher orbital overlap. PMID:26593389

  20. Type-2 fuzzy fractional derivatives

    NASA Astrophysics Data System (ADS)

    Mazandarani, Mehran; Najariyan, Marzieh

    2014-07-01

    In this paper, we introduce two definitions of the differentiability of type-2 fuzzy number-valued functions of fractional order. The definitions are in the sense of Riemann-Liouville and Caputo derivative of order β ɛ (0, 1), and based on type-2 Hukuhara difference and H2-differentiability. The existence and uniqueness of the solutions of type-2 fuzzy fractional differential equations (T2FFDEs) under Caputo type-2 fuzzy fractional derivative and the definition of Laplace transform of type-2 fuzzy number-valued functions are also given. Moreover, the approximate solution to T2FFDE by a Predictor-Evaluate-Corrector-Evaluate (PECE) method is presented. Finally, the approximate solutions of two examples of linear and nonlinear T2FFDEs are obtained using the PECE method, and some cases of T2FFDEs applications in some sciences are presented.

  1. Bioactive peptides derived from food.

    PubMed

    Rutherfurd-Markwick, Kay J; Moughan, Paul J

    2005-01-01

    As interest in the ability of functional foods to impact on human health has grown over the past decade, so has the volume of knowledge detailing the beneficial roles of food-derived bioactive peptides. Bioactive peptides from both plant and animal proteins have been discovered, with to date, by far the most being isolated from milk-based products. A wide range of activities has been described, including antimicrobial and antifungal properties, blood pressure-lowering effects, cholesterol-lowering ability, antithrombotic effects, enhancement of mineral absorption, immunomodulatory effects, and localized effects on the gut. Although there is still considerable research to be performed in the area of food-derived bioactive peptides, it is clear that the generation of bioactive peptides from dietary proteins during the normal digestive process is of importance. Therefore, it will become necessary when determining dietary protein quality to consider the potential effects of latent bioactive peptides that are released during digestion of the protein.

  2. Shuttle derived manned transportation systems

    NASA Technical Reports Server (NTRS)

    Ordway, Wayne L.

    1991-01-01

    Shuttle derivatives have been under study by the National Aeronautics and Space Administration (NASA) for a number of years. With Space Station Freedom and the Lunar/Mars Initiative established as national objectives, the demand for access to earth orbit is accelerating. These objectives have resulted in efforts to address additional launch requirements that must be met as the turn of the century approaches. Among the top level requirements are increased safety, higher reliability, lower cost, and the need for heavy lift launch capability. To satisfy these requirements, some of the largest technology demands will be placed upon the propulsion systems. Shuttle derived manned concepts are presented and the associated propulsion issues which arise from the top level requirements are discussed. These concepts are presented in terms of an overall architecture which can be achieved with modest up-front development.

  3. [Exosomes derived from dendritic cells].

    PubMed

    Amigorena, S

    2001-01-01

    Dendritic cells (DC) are potent antigen presenting cells and the only ones capable of inducing primary cytotoxic immune responses both in vivo and vitro. DCs secrete a 60-80 nm membrane vesicle population of endocytic origin, called exosomes. The protein composition of exosomes was analyzed using a systematic proteomic approach. Besides MHC and costimulatory molecules, exosomes bear several adhesion proteins, probably involved in their specific targeting. Exosomes also accumulate several cytosolic factors, most likely involved in exoxome's biogenesis in late endosomes. Like DCs, exosomes induce potent anti tumor immune responses in vivo. Indeed, a single injection of DC-derived exosomes sensitized with tumor peptides induced the eradication of established mouse tumors. Tumor-specific cytotoxic T lymphocytes were found in the spleen of exosome treated mice, and depletion of CD8+ T cells in vivo inhibited the anti tumor effect of exosomes. These results strongly support the implementation of human DC-derived exosomes for cancer immunotherapy.

  4. Derivative couplings in massive bigravity

    SciTech Connect

    Gao, Xian; Heisenberg, Lavinia E-mail: lavinia.heisenberg@eth-its.ethz.ch

    2016-03-01

    In this work we study the cosmological perturbations in massive bigravity in the presence of non-minimal derivative couplings. For this purpose we consider a specific subclass of Horndeski scalar-tensor interactions that live on the unique composite effective metric. For the viability of the model both metrics have to be dynamical. Nevertheless, the number of allowed kinetic terms is crucial. We adapt to the restriction of having one single kinetic term. After deriving the full set of equations of motion for flat Friedmann-Lemaitre-Robertson-Walker background, we study linear perturbations on top of it. We show explicitly that only four tensor, two vector and two scalar degrees of freedom propagate, one of which being the Horndeski scalar, while the Boulware-Deser ghost can be integrated out.

  5. Position Estimation Using Image Derivative

    NASA Technical Reports Server (NTRS)

    Mortari, Daniele; deDilectis, Francesco; Zanetti, Renato

    2015-01-01

    This paper describes an image processing algorithm to process Moon and/or Earth images. The theory presented is based on the fact that Moon hard edge points are characterized by the highest values of the image derivative. Outliers are eliminated by two sequential filters. Moon center and radius are then estimated by nonlinear least-squares using circular sigmoid functions. The proposed image processing has been applied and validated using real and synthetic Moon images.

  6. On Derivations Of Genetic Algebras

    NASA Astrophysics Data System (ADS)

    Mukhamedov, Farrukh; Qaralleh, Izzat

    2014-11-01

    A genetic algebra is a (possibly non-associative) algebra used to model inheritance in genetics. In application of genetics this algebra often has a basis corresponding to genetically different gametes, and the structure constant of the algebra encode the probabilities of producing offspring of various types. In this paper, we find the connection between the genetic algebras and evolution algebras. Moreover, we prove the existence of nontrivial derivations of genetic algebras in dimension two.

  7. Benzoylphloroglucinol derivatives from Hypericum scabrum.

    PubMed

    Matsuhisa, Michiko; Shikishima, Yasuhiro; Takaishi, Yoshihisa; Honda, Gisho; Ito, Michiho; Takeda, Yoshio; Shibata, Hirohumi; Higuti, Tomihiko; Kodzhimatov, Olimjon K; Ashurmetov, Ozodbek

    2002-03-01

    Nine new polyprenylated benzoylphloroglucinol derivatives, hyperibones A-I (1-9), were isolated from the aerial parts of the Uzbekistan medicinal plant Hypericum scabrum. Their structures were determined mainly on the basis of spectroscopic evidence (2D NMR and HRMS). Compounds 1, 2, and 4 showed mild in vitro antibacterial activity against methicillin-resistance Staphylococus aureus (MRSA) and methicillin-sensitive Staphylococus aureus (MSSA).

  8. 46 CFR 503.55 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 9 2010-10-01 2010-10-01 false Derivative classification. 503.55 Section 503.55... Security Program § 503.55 Derivative classification. (a) In accordance with Part 2 of Executive Order 12958... derivative classification. (1) Derivative classification includes the classification of information based...

  9. 12 CFR 163.172 - Financial derivatives.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 1 2014-01-01 2014-01-01 false Financial derivatives. 163.172 Section 163.172...-OPERATIONS Financial Management Policies § 163.172 Financial derivatives. (a) What is a financial derivative? A financial derivative is a financial contract whose value depends on the value of one or...

  10. 12 CFR 163.172 - Financial derivatives.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 1 2013-01-01 2013-01-01 false Financial derivatives. 163.172 Section 163.172...-OPERATIONS Financial Management Policies § 163.172 Financial derivatives. (a) What is a financial derivative? A financial derivative is a financial contract whose value depends on the value of one or...

  11. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 6 2012-01-01 2012-01-01 false Financial derivatives. 563.172 Section 563.172...-OPERATIONS Financial Management Policies § 563.172 Financial derivatives. (a) What is a financial derivative? A financial derivative is a financial contract whose value depends on the value of one or...

  12. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 6 2014-01-01 2012-01-01 true Financial derivatives. 563.172 Section 563.172...-OPERATIONS Financial Management Policies § 563.172 Financial derivatives. (a) What is a financial derivative? A financial derivative is a financial contract whose value depends on the value of one or...

  13. Synthesis of Novel Saccharin Derivatives.

    PubMed

    Rankin, Gregory M; Poulsen, Sally-Ann

    2017-03-23

    The synthesis of saccharin (1,2-benzisothiazol-3-one-1,1-dioxide) derivatives substituted on the benzene ring has seen limited development despite the longevity of this compound's use as an artificial sweetener. This type of saccharin derivative would however present attractive properties for the development of new bioactive, drug-like small molecule compounds. Here we report the derivatisation of the benzene ring of saccharin using Cu(I)-catalyzed azide alkyne cycloaddition (CuAAC) to synthesise a diverse library of novel saccharin-1,2,3-triazole conjugates. All library compounds retain the capability for interactions with biomolecules via the unmodified sulfonamide and lactam groups of the parent saccharin core heterocycle. The compounds also encompass alternate orientations of the 1,2,3-triazole heterocycle, thus further adding diversity to the potential hydrogen bonding interactions of these compounds with biomolecules of therapeutic interest. Our findings demonstrate that specifically functionalized derivatives of saccharin may be prepared from either saccharin azide or saccharin alkyne building blocks in high yield using CuAAC.

  14. Derivation of Hamiltonians for accelerators

    SciTech Connect

    Symon, K.R.

    1997-09-12

    In this report various forms of the Hamiltonian for particle motion in an accelerator will be derived. Except where noted, the treatment will apply generally to linear and circular accelerators, storage rings, and beamlines. The generic term accelerator will be used to refer to any of these devices. The author will use the usual accelerator coordinate system, which will be introduced first, along with a list of handy formulas. He then starts from the general Hamiltonian for a particle in an electromagnetic field, using the accelerator coordinate system, with time t as independent variable. He switches to a form more convenient for most purposes using the distance s along the reference orbit as independent variable. In section 2, formulas will be derived for the vector potentials that describe the various lattice components. In sections 3, 4, and 5, special forms of the Hamiltonian will be derived for transverse horizontal and vertical motion, for longitudinal motion, and for synchrobetatron coupling of horizontal and longitudinal motions. Hamiltonians will be expanded to fourth order in the variables.

  15. Binder enhanced refuse derived fuel

    DOEpatents

    Daugherty, Kenneth E.; Venables, Barney J.; Ohlsson, Oscar O.

    1996-01-01

    A refuse derived fuel (RDF) pellet having about 11% or more particulate calcium hydroxide which is utilized in a combustionable mixture. The pellets are used in a particulate fuel bring a mixture of 10% or more, on a heat equivalent basis, of the RDF pellet which contains calcium hydroxide as a binder, with 50% or more, on a heat equivalent basis, of a sulphur containing coal. Combustion of the mixture is effective to produce an effluent gas from the combustion zone having a reduced SO.sub.2 and polycyclic aromatic hydrocarbon content of effluent gas from similar combustion materials not containing the calcium hydroxide.

  16. Iron and iron derived radicals

    SciTech Connect

    Borg, D.C.; Schaich, K.M.

    1987-04-01

    We have discussed some reactions of iron and iron-derived oxygen radicals that may be important in the production or treatment of tissue injury. Our conclusions challenge, to some extent, the usual lines of thought in this field of research. Insofar as they are born out by subsequent developments, the lessons they teach are two: Think fastexclamation Think smallexclamation In other words, think of the many fast reactions that can rapidly alter the production and fate of highly reactive intermediates, and when considering the impact of competitive reactions on such species, think how they affect the microenvironment (on the molecular scale) ''seen'' by each reactive molecule. 21 refs., 3 figs., 1 tab.

  17. Contradictory correlations between derived scales.

    PubMed

    Thompson, M J; Hand, D J; Everitt, B S

    1991-08-01

    In a clinical trial one scale of pain relief is scored backwards relative to another (high on one corresponding to low on the other), with a consequent large negative correlation. But two derived scales of total pain, obtained by multiplying average pain relief on each scale by duration of pain (common to both pain relief measurements) gave an almost zero correlation. This apparent contradiction is explained by the inverse relationship between the pain relief scales and the large differences in duration of pain experienced by the patients.

  18. Boron Derivatives of 3-Methylpyrazole.

    DTIC Science & Technology

    1984-12-01

    AD-A14$ 988 BORON DERIVRTIYES OF 3 -IETHYLPYRRZOLECU) KENTUCKY UNIV i/i LEXINGTON DEPT OF CHEMISTRY K NIEDENZU ET AL. DEC 84 UK/DC/TR- 5 N8@814-83-K...REPORT DOCUMENTATION PAGE BEFORE CO.!?OVE~r;G FORM UK/DC/TR- 5 I - -_ E. ’and Subtitle) OF 21-P R & PZRIOD COVER=~ BORON DERIVATIVES OF 3 -METHYLPYRAZOLE...pathways for the latter process. In addition, the compounds 4 ,4 ,8,8-tetrabromo- and 4 ,4 ,8 ,8-tetrakis( 3 -methylpyrazole-l-yl)-l, 5 (7)-dimethyl

  19. Hypoxic radiosensitizers: substituted styryl derivatives.

    PubMed

    Nudelman, A; Falb, E; Odesa, Y; Shmueli-Broide, N

    1994-10-01

    A number of novel styryl epoxides, N-substituted-styryl-ethanolamines, N-mono and N,N'-bis-(2-hydroxyethyl)-cinnamamides--analogues to the known radiosensitizers RSU-1069, pimonidazole and etanidazole--display selective hypoxic radiosensitizing activity. The styryl group, especially when substituted by electron withdrawing groups, was found to be bioisosteric to the nitroimidazolyl functionality. The most active derivative 2-(2'-nitrophenyl)ethen-1-yl-oxirane 8a displayed a sensitizer enhancement ratio (SER) of 5 relative to misonidazole.

  20. Myeloid-derived suppressor cells

    PubMed Central

    Chandra, Dinesh; Gravekamp, Claudia

    2013-01-01

    While conventional anticancer therapies, including surgical resection, radiotherapy, and/or chemotherapy, are relatively efficient at eliminating primary tumors, these treatment modalities are largely ineffective against metastases. At least in part, this reflects the rather inefficient delivery of conventional anticancer agents to metastatic lesions. We have recently demonstrated that myeloid-derived suppressor cells (MDSCs) can be used as cellular missiles to selectively deliver a radioisotope-coupled attenuated variant of Listeria monocytogenes to both primary and metastatic neoplastic lesions in mice with pancreatic cancer. This novel immunotherapeutic intervention robustly inhibited tumor growth while promoting a dramatic decrease in the number of metastases. PMID:24427545

  1. Extending the short and long wavelength limits of bacteriochlorin near-infrared absorption via dioxo- and bisimide-functionalization.

    PubMed

    Vairaprakash, Pothiappan; Yang, Eunkyung; Sahin, Tuba; Taniguchi, Masahiko; Krayer, Michael; Diers, James R; Wang, Alfred; Niedzwiedzki, Dariusz M; Kirmaier, Christine; Lindsey, Jonathan S; Bocian, David F; Holten, Dewey

    2015-03-26

    Six new bacteriochlorins expanding the range of the strong near-infrared (NIR) absorption (Qy band) to both shorter and longer wavelengths (∼690 to ∼900 nm) have been synthesized and characterized. The architectures include bacteriochlorin-bisimides that have six-membered imide rings spanning the 3,5- and 13,15-macrocycle positions or five-membered imide rings spanning the β-pyrrolic 2,3- and 12,13-positions. Both bisimide types absorb at significantly longer wavelength than the bacteriochlorin precursors (no fused rings), whereas oxo-groups at the 7- or 7,17-positions shift the Qy band to a new short wavelength limit. Surprisingly, bacteriochlorin-bisimides with five-membered β-pyrrolic-centered imide rings have a Qy band closer to that of six-membered bacteriochlorin-monoimides. However, the five-membered bisimides (versus the six-membered bacteriochlorin-monoimides) have significantly enhanced absorption intensity that is paralleled by an ∼2-fold higher fluorescence yield (∼0.16 vs ∼0.07) and longer singlet excited-state lifetime (∼4 ns vs ∼2 ns). The photophysical enhancements derive in part from mixing of the lowest unoccupied frontier molecular orbitals of the five-membered imide ring with those of the bacteriochlorin framework. In general, all of the new bacteriochlorins have excited-state lifetimes (1-4 ns) that are sufficiently long for use in molecular-based systems for photochemical applications.

  2. Deriving Laws from Ordering Relations

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.

    2004-01-01

    The effect of Richard T. Cox's contribution to probability theory was to generalize Boolean implication among logical statements to degrees of implication, which are manipulated using rules derived from consistency with Boolean algebra. These rules are known as the sum rule, the product rule and Bayes Theorem, and the measure resulting from this generalization is probability. In this paper, I will describe how Cox s technique can be further generalized to include other algebras and hence other problems in science and mathematics. The result is a methodology that can be used to generalize an algebra to a calculus by relying on consistency with order theory to derive the laws of the calculus. My goals are to clear up the mysteries as to why the same basic structure found in probability theory appears in other contexts, to better understand the foundations of probability theory, and to extend these ideas to other areas by developing new mathematics and new physics. The relevance of this methodology will be demonstrated using examples from probability theory, number theory, geometry, information theory, and quantum mechanics.

  3. Anionic Derivatives of Perfluorinated Trimethylgold.

    PubMed

    Menjón, Babil; Pérez-Bitrián, Alberto; Martínez-Salvador, Sonia; Baya, Miguel; Casas, José María; Martín, Antonio; Orduna, Jesús

    2017-03-20

    The homoleptic compound [PPh₄][CF₃AuCF₃] cleanly undergoes photoinduced oxidative addition of CF₃I to afford the organogold(III) derivative [PPh₄][(CF₃)₃AuI] in good yield and under mild conditions. This compound provides a convenient entry to the chemistry of the perfluorinated (CF₃)₃Au fragment whose properties are analyzed with the aid of DFT methods and compared with those of the homologous non-fluorinated (CH₃)₃Au moiety. It is found that reductive elimination of CX₃-CX₃ in the former (X = F) requires a much higher energy barrier than in the latter (X = H) and is therefore considerably less favored. This can be considered as one of the main features underlying the significantly higher stability associated to the (CF₃)₃Au fragment and its derivatives. This unsaturated, 14-electron species can be stabilized by coordination of any of the halide ligands, including fluoride. In fact, the whole series of anionic [PPh₄][(CF₃)₃AuX] complexes (X = F, Cl, Br, I, CN) has now been isolated and conveniently characterized. Evidence for intermolecular decomposition pathways upon thermolysis in the condensed phase is presented.

  4. Fourth order spatial derivative gravity

    SciTech Connect

    Bemfica, F. S.; Gomes, M.

    2011-10-15

    In this work, we study a modified theory of gravity that contains up to fourth order spatial derivatives as a model for the Horava-Lifshitz gravity. The propagator is evaluated and, as a result, one extra pole is obtained, corresponding to a spin-2 nonrelativistic massless particle, an extra term which jeopardizes renormalizability, besides the unexpected general relativity unmodified propagator. Then unitarity is proved at the tree level, where the general relativity pole has been shown to have no dynamics, remaining only the 2 degrees of freedom of the new pole. Next, the nonrelativistic effective potential is determined from a scattering process of two identical massive gravitationally interacting bosons. In this limit, Newton's potential is obtained, together with a Darwin-like term that comes from the extra nonpole term in the propagator. Regarding renormalizability, this extra term may be harmful by power counting, but it can be eliminated by adjusting the free parameters of the model. This adjustment is in accord with the detailed balance condition suggested in the literature and shows that the way in which extra spatial derivative terms are added is of fundamental importance.

  5. New phenalenone derivatives from Pinellia ternata tubers derived Aspergillus sp.

    PubMed

    Gombodorj, Surenmandakh; Yang, Ming-Hua; Shang, Zhi-Chun; Liu, Rui-Huan; Li, Tian-Xiao; Yin, Guo-Ping; Kong, Ling-Yi

    2017-07-01

    Nine new phenalenone derivatives (1-9), along with two known analogues (10-11) have been isolated from the solid cultures of an endophytic fungus Aspergillus sp. which was obtained from Pinellia ternate. Their structures were established through interpretations of spectroscopic evidence, and some of their absolute configurations were determined by electronic circular dichroism (ECD) and Mo2(OCOCH3)4 induced ECD. All of the phenalenones are unusual acyclic diterpenoid adducts, which are diversely oxidized and partly epoxidized to form different heterocycles. In addition, compound 10 exhibited significant antimicrobial activity against Pseudomonas aeruginosa, Staphylococcus aureus, and Bacillus subtilis with MIC50 values of 1.87, 2.77, and 4.80μg/mL, respectively. Copyright © 2017. Published by Elsevier B.V.

  6. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section... Substances § 721.10039 Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic...

  7. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section... Substances § 721.10039 Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic...

  8. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section... Substances § 721.10039 Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic...

  9. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section... Substances § 721.10039 Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic...

  10. 40 CFR 721.10039 - Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative...

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic acid derivative, ammonium salt (generic). 721.10039 Section... Substances § 721.10039 Diethoxybenzenamine derivative, diazotized, coupled with aminonaphthalenesulfonic...

  11. Derivative Sign Patterns in Two Dimensions

    ERIC Educational Resources Information Center

    Schilling, Kenneth

    2013-01-01

    Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.

  12. Derivative Sign Patterns in Two Dimensions

    ERIC Educational Resources Information Center

    Schilling, Kenneth

    2013-01-01

    Given a function defined on a subset of the plane whose partial derivatives never change sign, the signs of the partial derivatives form a two-dimensional pattern. We explore what patterns are possible for various planar domains.

  13. Silsesquioxane-derived ceramic fibres

    NASA Technical Reports Server (NTRS)

    Hurwitz, F. I.; Farmer, S. C.; Terepka, F. M.; Leonhardt, T. A.

    1991-01-01

    Fibers formed from blends of silsesquioxane polymers were characterized to study the pyrolytic conversion of these precursors to ceramics. The morphology of fibers pyrolyzed to 1400 C revealed primarily amorphous glasses whose conversion to beta-SiC is a function of both blend composition and pyrolysis conditions. Formation of beta-SiC crystallites within the glassy phase is favored by higher than stoichiometric C/Si ratios, while carbothermal reduction of Si-O bonds to form SiC with loss of SiO and CO occurs at higher methyl/phenylpropyl silsesquioxane (lower C/Si) ratios. As the carbothermal reduction is assumed to be diffusion controlled, the fibers can serve as model systems to gain understanding of the silsesquioxane pyrolysis behavior, and therefore are useful in the development of polysilsesquioxane-derived ceramic matrices and coatings as well.

  14. Pandoraviruses are highly derived phycodnaviruses

    PubMed Central

    2013-01-01

    The recently discovered Pandoraviruses are by far the largest viruses known, with their 2 megabase genomes exceeding in size the genomes of numerous bacteria and archaea. Pandoraviruses show a distant relationship with other nucleocytoplasmic large DNA viruses (NCLDV) of eukaryotes, lack some of the NCLDV core genes and in particular do not appear to be specifically related to the other, better characterized family of giant viruses, the Mimiviridae. Here we report phylogenetic analysis of 6 core NCLDV genes that confidently places Pandoraviruses within the family Phycodnaviridae, with an apparent specific affinity with Coccolithoviruses. We conclude that, despite their many unusual characteristics, Pandoraviruses are highly derived phycodnaviruses. These findings imply that giant viruses have independently evolved from smaller NCLDV on at least two occasions. This article was reviewed by Patrick Forterre and Lakshminarayan Iyer. For the full reviews, see the Reviewers’ reports section. PMID:24148757

  15. Higgs potential from derivative interactions

    NASA Astrophysics Data System (ADS)

    Quadri, A.

    2017-06-01

    A formulation of the linear σ model with derivative interactions is studied. The classical theory is on-shell equivalent to the σ model with the standard quartic Higgs potential. The mass of the scalar mode only appears in the quadratic part and not in the interaction vertices, unlike in the ordinary formulation of the theory. Renormalization of the model is discussed. A nonpower-counting renormalizable extension, obeying the defining functional identities of the theory, is presented. This extension is physically equivalent to the tree-level inclusion of a dimension-six effective operator ∂μ(Φ†Φ)∂μ(Φ†Φ). The resulting UV divergences are arranged in a perturbation series around the power-counting renormalizable theory. The application of the formalism to the Standard Model in the presence of the dimension-six operator ∂μ(Φ†Φ)∂μ(Φ†Φ) is discussed.

  16. Derivatives of Black Knight Technology

    NASA Astrophysics Data System (ADS)

    Hill, N.; Wright, D.

    This paper traces the line of descent from Black Knight to Black Arrow, and at the same time looks at various proposed projects, both civil and military, which were to be Black Knight derivatives, but which for one reason or another never saw the light of day. Research in this area is rather akin to anthropological work, tracing fossils from Homo erectus (Black Knight) to Homo sapiens (Black Arrow), knowing that a lot of the fossils found will not be on the direct line of descent, but represent branches that became extinct. This article attempts to cover designs, which, although they never made it to hardware, are none the less interesting technically, or shine light on the evolution of design philosophy.

  17. Helminth-derived immunomodulatory molecules.

    PubMed

    Adisakwattana, Poom; Saunders, Sean P; Nel, Hendrik J; Fallon, Padraic G

    2009-01-01

    Infection of man with parasitic helminths leads to potent activation and modulation of the host immune response. This modulation of immunity by helminth infections may have bystander effects in altering, either suppressing or exacerbating, unrelated inflammatory processes. Various ongoing clinical trials are testing the therapeutic application of helminth infection of patients with inflammatory diseases, including inflammatory bowel disease and allergic disorders. Rather than the use of live helminth infection, with the potential for side effects, an alternative approach is to identify the immune modulatory molecules (IM) produced by helminths that can alter immune functions. In this review, we will focus on characterized helminth-derived IMs that may have potential to be developed as novel therapeutics for inflammatory diseases.

  18. Silsesquioxane-derived ceramic fibres

    NASA Technical Reports Server (NTRS)

    Hurwitz, F. I.; Farmer, S. C.; Terepka, F. M.; Leonhardt, T. A.

    1991-01-01

    Fibers formed from blends of silsesquioxane polymers were characterized to study the pyrolytic conversion of these precursors to ceramics. The morphology of fibers pyrolyzed to 1400 C revealed primarily amorphous glasses whose conversion to beta-SiC is a function of both blend composition and pyrolysis conditions. Formation of beta-SiC crystallites within the glassy phase is favored by higher than stoichiometric C/Si ratios, while carbothermal reduction of Si-O bonds to form SiC with loss of SiO and CO occurs at higher methyl/phenylpropyl silsesquioxane (lower C/Si) ratios. As the carbothermal reduction is assumed to be diffusion controlled, the fibers can serve as model systems to gain understanding of the silsesquioxane pyrolysis behavior, and therefore are useful in the development of polysilsesquioxane-derived ceramic matrices and coatings as well.

  19. Using derivatives to hedge against the unexpected.

    PubMed

    Aderholt, J M; Rasmussen, R H

    1996-02-01

    Derivatives--financial instruments with a rate of return derived from an underlying asset--have been used as investment instruments for decades. Many derivative products originally were created explicitly for the purpose of reducing financial risks and have become more widely used and more complex in recent years. Healthcare financial managers should have a basic understanding of derivatives as well as the ability to apply general guidelines for their appropriate use in healthcare financial management.

  20. Deriving Laws from Ordering Relations

    NASA Technical Reports Server (NTRS)

    Knuth, Kevin H.

    2003-01-01

    It took much effort in the early days of non-Euclidean geometry to break away from the mindset that all spaces are flat and that two distinct parallel lines do not cross. Up to that point, all that was known was Euclidean geometry, and it was difficult to imagine anything else. We have suffered a similar handicap brought on by the enormous relevance of Boolean algebra to the problems of our age-logic and set theory. Previously, I demonstrated that the algebra of questions is not Boolean, but rather is described by the free distributive algebra. To get to this stage took much effort, as many obstacles-most self-placed-had to be overcome. As Boolean algebras were all I had ever known, it was almost impossible for me to imagine working with an algebra where elements do not have complements. With this realization, it became very clear that the sum and product rules of probability theory at the most basic level had absolutely nothing to do with the Boolean algebra of logical statements. Instead, a measure of degree of inclusion can be invented for many different partially ordered sets, and the sum and product rules fall out of the associativity and distributivity of the algebra. To reinforce this very important idea, this paper will go over how these constructions are made, while focusing on the underlying assumptions. I will derive the sum and product rules for a distributive lattice in general and demonstrate how this leads to probability theory on the Boolean lattice and is related to the calculus of quantum mechanical amplitudes on the partially ordered set of experimental setups. I will also discuss the rules that can be derived from modular lattices and their relevance to the cross-ratio of projective geometry.

  1. Polymer-Derived Ceramic Fibers

    NASA Astrophysics Data System (ADS)

    Ichikawa, Hiroshi

    2016-07-01

    SiC-based ceramic fibers are derived from polycarbosilane or polymetallocarbosilane precursors and are classified into three groups according to their chemical composition, oxygen content, and C/Si atomic ratio. The first-generation fibers are Si-C-O (Nicalon) fibers and Si-Ti-C-O (Tyranno Lox M) fibers. Both fibers contain more than 10-wt% oxygen owing to oxidation during curing and lead to degradation in strength at temperatures exceeding 1,300°C. The maximum use temperature is 1,100°C. The second-generation fibers are SiC (Hi-Nicalon) fibers and Si-Zr-C-O (Tyranno ZMI) fibers. The oxygen content of these fibers is reduced to less than 1 wt% by electron beam irradiation curing in He. The thermal stability of these fibers is improved (they are stable up to 1,500°C), but their creep resistance is limited to a maximum of 1,150°C because their C/Si atomic ratio results in excess carbon. The third-generation fibers are stoichiometric SiC fibers, i.e., Hi-Nicalon Type S (hereafter Type S), Tyranno SA, and Sylramic™ fibers. They exhibit improved thermal stability and creep resistance up to 1,400°C. Stoichiometric SiC fibers meet many of the requirements for the use of ceramic matrix composites for high-temperature structural application. SiBN3C fibers derived from polyborosilazane also show promise for structural applications, remain in the amorphous state up to 1,800°C, and have good high-temperature creep resistance.

  2. 32 CFR 2001.22 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 32 National Defense 6 2014-07-01 2014-07-01 false Derivative classification. 2001.22 Section 2001... Identification and Markings § 2001.22 Derivative classification. (a) General. Information classified derivatively... § 2001.20 and § 2001.21, except as provided in this section. Information for these markings shall...

  3. 32 CFR 2001.22 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 32 National Defense 6 2012-07-01 2012-07-01 false Derivative classification. 2001.22 Section 2001... Identification and Markings § 2001.22 Derivative classification. (a) General. Information classified derivatively... § 2001.20 and § 2001.21, except as provided in this section. Information for these markings shall...

  4. On simple Shamsuddin derivations in two variables.

    PubMed

    Baltazar, Rene

    2016-01-01

    We study the subgroup of k -automorphisms of k ⁢ [ x , y ] which commute with a simple derivation d of k ⁢ [ x , y ] . We prove, for instance, that this subgroup is trivial when d is a shamsuddin simple derivation. in the general case of simple derivations, we obtain properties for the elements of this subgroup.

  5. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... underlying assets, indices, or reference rates. The most common types of financial derivatives are futures, forward commitments, options, and swaps. A mortgage derivative security, such as a collateralized mortgage... Interest Rate Risk, Investment Securities, and Derivatives Activities,” and other applicable...

  6. 32 CFR 2001.22 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... Intelligence. (4) When determining the most restrictive declassification instruction among multiple source... shall appear as: Derived From: Multiple Sources (ii) The derivative classifier shall include a listing... derivatively classified on the basis of a source document that is itself marked “Multiple Sources” shall...

  7. Bioactive terpenes from marine-derived fungi.

    PubMed

    Elissawy, Ahmed M; El-Shazly, Mohamed; Ebada, Sherif S; Singab, AbdelNasser B; Proksch, Peter

    2015-04-03

    Marine-derived fungi continue to be a prolific source of secondary metabolites showing diverse bioactivities. Terpenoids from marine-derived fungi exhibit wide structural diversity including numerous compounds with pronounced biological activities. In this review, we survey the last five years' reports on terpenoidal metabolites from marine-derived fungi with particular attention on those showing marked biological activities.

  8. 28 CFR 17.26 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 28 Judicial Administration 1 2014-07-01 2014-07-01 false Derivative classification. 17.26 Section... ACCESS TO CLASSIFIED INFORMATION Classified Information § 17.26 Derivative classification. (a) Persons need not possess original classification authority to derivatively classify information based on source...

  9. 6 CFR 7.26 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 6 Domestic Security 1 2014-01-01 2014-01-01 false Derivative classification. 7.26 Section 7.26... INFORMATION Classified Information § 7.26 Derivative classification. (a) Derivative classification is defined... already classified, and marking the newly developed material consistent with the classification markings...

  10. 6 CFR 7.26 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 6 Domestic Security 1 2013-01-01 2013-01-01 false Derivative classification. 7.26 Section 7.26... INFORMATION Classified Information § 7.26 Derivative classification. (a) Derivative classification is defined... already classified, and marking the newly developed material consistent with the classification markings...

  11. 12 CFR 403.4 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 12 Banks and Banking 5 2014-01-01 2014-01-01 false Derivative classification. 403.4 Section 403.4 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION § 403.4 Derivative classification. (a) Use of derivative...

  12. 12 CFR 403.4 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 12 Banks and Banking 5 2012-01-01 2012-01-01 false Derivative classification. 403.4 Section 403.4 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION § 403.4 Derivative classification. (a) Use of derivative...

  13. 28 CFR 17.26 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 28 Judicial Administration 1 2013-07-01 2013-07-01 false Derivative classification. 17.26 Section... ACCESS TO CLASSIFIED INFORMATION Classified Information § 17.26 Derivative classification. (a) Persons need not possess original classification authority to derivatively classify information based on source...

  14. 12 CFR 403.4 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 12 Banks and Banking 5 2013-01-01 2013-01-01 false Derivative classification. 403.4 Section 403.4 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION § 403.4 Derivative classification. (a) Use of derivative...

  15. 28 CFR 17.26 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 28 Judicial Administration 1 2012-07-01 2012-07-01 false Derivative classification. 17.26 Section... ACCESS TO CLASSIFIED INFORMATION Classified Information § 17.26 Derivative classification. (a) Persons need not possess original classification authority to derivatively classify information based on source...

  16. 22 CFR 9.6 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 22 Foreign Relations 1 2010-04-01 2010-04-01 false Derivative classification. 9.6 Section 9.6 Foreign Relations DEPARTMENT OF STATE GENERAL SECURITY INFORMATION REGULATIONS § 9.6 Derivative...'s classified Web site. ...

  17. 22 CFR 9.6 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 22 Foreign Relations 1 2011-04-01 2011-04-01 false Derivative classification. 9.6 Section 9.6 Foreign Relations DEPARTMENT OF STATE GENERAL SECURITY INFORMATION REGULATIONS § 9.6 Derivative...'s classified Web site. ...

  18. 28 CFR 17.26 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 28 Judicial Administration 1 2010-07-01 2010-07-01 false Derivative classification. 17.26 Section... ACCESS TO CLASSIFIED INFORMATION Classified Information § 17.26 Derivative classification. (a) Persons need not possess original classification authority to derivatively classify information based on source...

  19. 12 CFR 403.4 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 12 Banks and Banking 4 2011-01-01 2011-01-01 false Derivative classification. 403.4 Section 403.4 Banks and Banking EXPORT-IMPORT BANK OF THE UNITED STATES CLASSIFICATION, DECLASSIFICATION, AND SAFEGUARDING OF NATIONAL SECURITY INFORMATION § 403.4 Derivative classification. (a) Use of derivative...

  20. 28 CFR 17.26 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 28 Judicial Administration 1 2011-07-01 2011-07-01 false Derivative classification. 17.26 Section... ACCESS TO CLASSIFIED INFORMATION Classified Information § 17.26 Derivative classification. (a) Persons need not possess original classification authority to derivatively classify information based on source...

  1. 6 CFR 7.26 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 6 Domestic Security 1 2011-01-01 2011-01-01 false Derivative classification. 7.26 Section 7.26... INFORMATION Classified Information § 7.26 Derivative classification. (a) Derivative classification is defined... already classified, and marking the newly developed material consistent with the classification markings...

  2. 12 CFR 403.4 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ..., or summarize classified information, or who only apply classification markings derived from source... classification of the source material. (iii) If the source material is foreign government information bearing no... SAFEGUARDING OF NATIONAL SECURITY INFORMATION § 403.4 Derivative classification. (a) Use of derivative...

  3. Bioactive Terpenes from Marine-Derived Fungi

    PubMed Central

    Elissawy, Ahmed M.; El-Shazly, Mohamed; Ebada, Sherif S.; Singab, AbdelNasser B.; Proksch, Peter

    2015-01-01

    Marine-derived fungi continue to be a prolific source of secondary metabolites showing diverse bioactivities. Terpenoids from marine-derived fungi exhibit wide structural diversity including numerous compounds with pronounced biological activities. In this review, we survey the last five years’ reports on terpenoidal metabolites from marine-derived fungi with particular attention on those showing marked biological activities. PMID:25854644

  4. 40 CFR 721.5913 - Phenothiazine derivative.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Phenothiazine derivative. 721.5913... Substances § 721.5913 Phenothiazine derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenothiazine derivative (PMN P-96-813)...

  5. 40 CFR 721.9658 - Thiadiazole derivative.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Thiadiazole derivative. 721.9658... Substances § 721.9658 Thiadiazole derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a thiadiazole derivative (PMN P-94-1631) is subject...

  6. 40 CFR 721.9658 - Thiadiazole derivative.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Thiadiazole derivative. 721.9658... Substances § 721.9658 Thiadiazole derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a thiadiazole derivative (PMN P-94-1631) is subject...

  7. 40 CFR 721.9658 - Thiadiazole derivative.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Thiadiazole derivative. 721.9658... Substances § 721.9658 Thiadiazole derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a thiadiazole derivative (PMN P-94-1631) is subject...

  8. 40 CFR 721.5913 - Phenothiazine derivative.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Phenothiazine derivative. 721.5913... Substances § 721.5913 Phenothiazine derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenothiazine derivative (PMN P-96-813)...

  9. 40 CFR 721.5913 - Phenothiazine derivative.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Phenothiazine derivative. 721.5913... Substances § 721.5913 Phenothiazine derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenothiazine derivative (PMN P-96-813)...

  10. 40 CFR 721.9658 - Thiadiazole derivative.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Thiadiazole derivative. 721.9658... Substances § 721.9658 Thiadiazole derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a thiadiazole derivative (PMN P-94-1631) is subject...

  11. 40 CFR 721.9658 - Thiadiazole derivative.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Thiadiazole derivative. 721.9658... Substances § 721.9658 Thiadiazole derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified as a thiadiazole derivative (PMN P-94-1631) is subject...

  12. 40 CFR 721.5913 - Phenothiazine derivative.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Phenothiazine derivative. 721.5913... Substances § 721.5913 Phenothiazine derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenothiazine derivative (PMN P-96-813)...

  13. 40 CFR 721.5913 - Phenothiazine derivative.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Phenothiazine derivative. 721.5913... Substances § 721.5913 Phenothiazine derivative. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as a phenothiazine derivative (PMN P-96-813)...

  14. 37 CFR 42.404 - Derivation fee.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2014-07-01 2014-07-01 false Derivation fee. 42.404 Section 42.404 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE TRIAL PRACTICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Derivation § 42.404 Derivation...

  15. 37 CFR 42.404 - Derivation fee.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 37 Patents, Trademarks, and Copyrights 1 2013-07-01 2013-07-01 false Derivation fee. 42.404 Section 42.404 Patents, Trademarks, and Copyrights UNITED STATES PATENT AND TRADEMARK OFFICE, DEPARTMENT OF COMMERCE TRIAL PRACTICE BEFORE THE PATENT TRIAL AND APPEAL BOARD Derivation § 42.404 Derivation...

  16. Improved Second Derivative Test for Relative Extrema

    ERIC Educational Resources Information Center

    Wu, Yan

    2007-01-01

    In this note, a modified Second Derivative Test is introduced for the relative extrema of a single variable function. This improved test overcomes the difficulty of the second derivative vanishing at the critical point, while in contrast the traditional test fails for this case. A proof for this improved Second Derivative Test is presented,…

  17. Partial Derivatives of the Lambert Problem

    NASA Technical Reports Server (NTRS)

    Arora, Nitin; Russell, Ryan P.; Strange, Nathan

    2014-01-01

    A procedure for deriving analytic partial derivatives of the Lambert problem is presented. Using the universal, cosine based Lambert formulation; first order partial derivatives of the velocities with respect to the positions and times are developed. Taking advantage of inherent symmetries and intermediate variables, the derivatives are expressed in a computationally efficient form. The added cost of computing these partials is found to be approximately 10% to approximately 60% of the Lambert compute cost. The availability of analytic partial derivatives increases optimization speed, efficiency and allows for trajectory optimization formulations that implicitly enforce continuity constraints via embedded Lambert problems.

  18. Representations of partial derivatives in thermodynamics

    NASA Astrophysics Data System (ADS)

    Thompson, John R.; Manogue, Corinne A.; Roundy, David J.; Mountcastle, Donald B.

    2012-02-01

    One of the mathematical objects that students become familiar with in thermodynamics, often for the first time, is the partial derivative of a multivariable function. The symbolic representation of a partial derivative and related quantities present difficulties for students in both mathematical and physical contexts, most notably what it means to keep one or more variables fixed while taking the derivative with respect to a different variable. Material properties are themselves written as partial derivatives of various state functions (e.g., compressibility is a partial derivative of volume with respect to pressure). Research in courses at the University of Maine and Oregon State University yields findings related to the many ways that partial derivatives can be represented and interpreted in thermodynamics. Research has informed curricular development that elicits many of the difficulties using different representations (e.g., geometric) and different contexts (e.g., connecting partial derivatives to specific experiments).

  19. Space-Derived Sewer Monitor

    NASA Technical Reports Server (NTRS)

    1982-01-01

    The QuadraScan Longterm Flow Monitoring System is a second generation sewer monitor developed by American Digital Systems, Inc.'s founder Peter Petroff. Petroff, a former spacecraft instrumentation designer at Marshall Space Flight Center, used expertise based on principles acquired in Apollo and other NASA programs. QuadraScan borrows even more heavily from space technology, for example in its data acquisition and memory system derived from NASA satellites. "One-time" measurements are often plagued with substantial errors due to the flow of groundwater absorbed into the system. These system sizing errors stem from a basic informational deficiency: accurate, reliable data on how much water flows through a sewer system over a long period of time is very difficult to obtain. City officials are turning to "permanent," or long-term sewer monitoring systems. QuadraScan offers many advantages to city officials such as the early warning capability to effectively plan for city growth in order to avoid the crippling economic impact of bans on new sewer connections in effect in many cities today.

  20. Benzimidazole derivatives as kinase inhibitors.

    PubMed

    Garuti, Laura; Roberti, Marinella; Bottegoni, Giovanni

    2014-01-01

    Benzimidazole is a common kinase inhibitor scaffold and benzimidazole-based compounds interact with enzymes by multiple binding modes. In some cases, the benzimidazole acts as part of the hinge-binding motif, in others it has a scaffolding role without evidence for direct hinge binding. Several of these compounds are ATP-competitive inhibitors and show high selectivity by exploiting unique structural properties that distinguish one kinase from the majority of other kinases. However, the high specificity for a single target is not always sufficient. Thus another approach, called multi-target therapy, has been developed over the last few years. The simultaneous inhibition of various kinases may be useful because the disease is attacked at several relevant targets. Moreover, if a kinase becomes drug-resistant, a multitargeted drug can act on the other kinases. Some benzimidazole derivatives are multi-target inhibitors. In this article benzimidazole inhibitors are reported with their mechanisms of action, structure-activity relationship (SAR) and biological properties.

  1. Biological evaluation of androstene derivatives.

    PubMed

    Garrido, Mariana; Bratoeff, Eugene; García-Lorenzana, Mario; Heuze, Yvonne; Soriano, Juan; Valencia, Norma; Cortes, Francisco; Cabeza, Marisa

    2013-01-01

    The effect of several new dihydroepiandrosterone ester derivatives A2-A6 was demonstrated using female cycling mice, which were synchronized for estrus with luteinizing hormone-releasing hormone (LHRH) and injected with the steroids. The binding to the progesterone receptor (PR), was obtained from the cytosol of uteri from adult estrogen-primed rabbits. A1 binds to the PR and inhibited the ovulation in cycling mice stimulated with LHRH. The activity of the endometrium and mammary glands in these mice was markedly reduced as compared to the control. A2, A4, and A5 were not active; nevertheless, A3 binds to the PR with high affinity. However, this steroid did not produce any effect as compared to that observed for the control in the endometrial and mammary glands. A6 binds to the PR with the highest affinity and induces a synergistic activity with progesterone in these tissues. Furthermore, A6 inhibited the ovulation in the same manner as A1. These results suggested that A1 and A6 are blocking the gonadotropin secretion. A1 inhibited the conversion of progesterone to 5α-progesterone. As a result of this, a blockage of the ductal and alveolar epithelial cell proliferation in the mammary and endometrial glands, which depends on 5α-progesterone, was also observed.

  2. STS Derived Exploration Launch Operations

    NASA Technical Reports Server (NTRS)

    Best, Joel; Sorge, L.; Siders, J.; Sias, Dave

    2004-01-01

    A key aspect of the new space exploration programs will be the approach to optimize launch operations. A STS Derived Launch Vehicle (SDLV) Program can provide a cost effective, low risk, and logical step to launch all of the elements of the exploration program. Many benefits can be gained by utilizing the synergy of a common launch site as an exploration spaceport as well as evolving the resources of the current Space Shuttle Program (SSP) to meet the challenges of the Vision for Space Exploration. In particular, the launch operation resources of the SSP can be transitioned to the exploration program and combined with the operations efficiencies of unmanned EELVs to obtain the best of both worlds, resulting in lean launch operations for crew and cargo missions of the exploration program. The SDLV Program would then not only capture the extensive human space flight launch operations knowledge, but also provide for the safe fly-out of the SSP through continuity of system critical skills, manufacturing infrastructure, and ability to maintain and attract critical skill personnel. Thus, a SDLV Program can smoothly transition resources from the SSP and meet the transportation needs to continue the voyage of discovery of the space exploration program.

  3. STS Derived Exploration Launch Operations

    NASA Technical Reports Server (NTRS)

    Best, Joel; Sorge, L.; Siders, J.; Sias, Dave

    2004-01-01

    A key aspect of the new space exploration programs will be the approach to optimize launch operations. A STS Derived Launch Vehicle (SDLV) Program can provide a cost effective, low risk, and logical step to launch all of the elements of the exploration program. Many benefits can be gained by utilizing the synergy of a common launch site as an exploration spaceport as well as evolving the resources of the current Space Shuttle Program (SSP) to meet the challenges of the Vision for Space Exploration. In particular, the launch operation resources of the SSP can be transitioned to the exploration program and combined with the operations efficiencies of unmanned EELVs to obtain the best of both worlds, resulting in lean launch operations for crew and cargo missions of the exploration program. The SDLV Program would then not only capture the extensive human space flight launch operations knowledge, but also provide for the safe fly-out of the SSP through continuity of system critical skills, manufacturing infrastructure, and ability to maintain and attract critical skill personnel. Thus, a SDLV Program can smoothly transition resources from the SSP and meet the transportation needs to continue the voyage of discovery of the space exploration program.

  4. Clinical status of benzoporphyrin derivative

    NASA Astrophysics Data System (ADS)

    Levy, Julia G.; Chan, Agnes H.; Strong, H. Andrew

    1996-01-01

    Benzoporphyrin derivative monoacid ring A (BPD) is currently in Phase II clinical trials for the treatment of cutaneous malignancies (basal cell carcinoma and cutaneous metastases) and psoriasis. Results to date suggest that this photosensitizer has potential in both of these areas. Recently, a clinical trial with BPD was initiated for the treatment of age related macular degeneration, a neovascular condition in the eye which leads to blindness. BPD is a lipophilic photosensitizer which is rapidly taken up by activated cells and the vascular endothelium of neovasculature. The PDT effects seen with BPD appear to be a combination of vascular occlusion and direct killing of target cells. Since many diseases involve either activated cells and/or neovasculature, PDT with photosensitizer with characteristics like those of BPD, has applications far wider than oncology. A new area of interest involving photosensitizers is that of immune modulation. A number of photosensitizers have been shown to effect immune modulation in animal models of immune dysfunction including autoimmunity (rheumatoid arthritis, lupus), cutaneous hypersensitivity and allografts. BPD and PHOTOFRINR have both been shown to be effective in ameliorating arthritic symptoms in a number of animal models. The mechanisms by which immune modulation is affected in these studies still remains to be resolved.

  5. 21 CFR 184.1685 - Rennet (animal-derived) and chymosin preparation (fermentation-derived).

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... (fermentation-derived). 184.1685 Section 184.1685 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF... (animal-derived) and chymosin preparation (fermentation-derived). (a)(1) Rennet and bovine rennet are... clear solution containing the active enzyme chymosin (E.C. 3.4.23.4). It is derived, via fermentation...

  6. Drug laws and the 'derivative' problem.

    PubMed

    King, Leslie A; Ujváry, István; Brandt, Simon D

    2014-01-01

    The concept of a 'derivative' is used widely in chemistry, where its precise meaning depends on the circumstances. However, numerous examples of derivative also occur in domestic drugs legislation, some of which stem from the 1961 United Nations Single Convention on Narcotic Drugs. There is a commonly held view that only 'first-order' derivatives should be considered: substances that can be created from a parent structure in a single chemical reaction. In other words, 'derivatives of derivatives' are excluded. However, some substances related to ecgonine (e.g. 2-carbomethoxytropinone) are clearly convertible to cocaine, even though this may require more than one reaction step. It follows that 2-carbomethoxytropinone is a controlled drug, a situation that most chemists would regard as perverse. A more extreme example of the complexity of 'derivative' is shown by the conversion of thebaine to buprenorphine. Even though this requires six or more stages, the US Drug Enforcement Administration successfully argued in a 1986 case that for the purposes of the Controlled Substances Act, the number of steps required was irrelevant; buprenorphine was a derivative of thebaine. Because the term derivative is rarely defined in statutes, the legal status of some substances, such as 2-bromo-LSD, is uncertain. Although a number of definitions of derivative can be found in the chemical literature, no single definition is adequate to describe all situations where it occurs in legislation. Unless qualified, it is suggested that the term derivative should be avoided in any future legislation.

  7. Satellite-Derived Management Zones

    NASA Technical Reports Server (NTRS)

    Lepoutre, Damien; Layrol, Laurent

    2005-01-01

    The term "satellite-derived management zones" (SAMZ) denotes agricultural management zones that are subdivisions of large fields and that are derived from images of the fields acquired by instruments aboard Earth-orbiting satellites during approximately the past 15 years. "SAMZ" also denotes the methodology and the software that implements the methodology for creating such zones. The SAMZ approach is one of several products of continuing efforts to realize a concept of precision agriculture, which involves optimal variations in seeding, in application of chemicals, and in irrigation, plus decisions to farm or not to farm certain portions of fields, all in an effort to maximize profitability in view of spatial and temporal variations in the growth and health of crops, and in the chemical and physical conditions of soils. As used here, "management zone" signifies, more precisely, a subdivision of a field within which the crop-production behavior is regarded as homogeneous. From the perspective of precision agriculture, management zones are the smallest subdivisions between which the seeding, application of chemicals, and other management parameters are to be varied. In the SAMZ approach, the main sources of data are the archives of satellite imagery that have been collected over the years for diverse purposes. One of the main advantages afforded by the SAMZ approach is that the data in these archives can be reused for purposes of precision agriculture at low cost. De facto, these archives contain information on all sources of variability within a field, including weather, crop types, crop management, soil types, and water drainage patterns. The SAMZ methodology involves the establishment of a Web-based interface based on an algorithm that generates management zones automatically and quickly from archival satellite image data in response to requests from farmers. A farmer can make a request by either uploading data describing a field boundary to the Web site or else

  8. Amplified spontaneous emission in polymer films doped with a perylenediimide derivative.

    PubMed

    Calzado, Eva M; Villalvilla, José M; Boj, Pedro G; Quintana, José A; Gómez, Rafael; Segura, José L; Díaz García, María A

    2007-06-20

    The presence of amplified spontaneous emission (ASE) by optical pump in polystyrene films doped with N,N'-di(10-nonadecyl)perylene-3,4:9,10-tetracarboxylic diimide (PDI-N) in a range of PDI-N concentrations between 0.25 and 5 wt. % is reported. Gain coefficients up to 10 cm(-1), at a pump intensity of 74 kW/cm2, were obtained. The lowest thresholds (approximately 15 kW/cm2) and largest photostabilities measured at 50% (approximately 50 min, i.e., 30,000 pump pulses) were obtained for concentrations up to 1 wt. %. The observation of an increase in the ASE threshold and a decrease in the photostability for larger concentrations is attributed to the presence of aggregated species.

  9. Exfoliation and supramolecular functionalization of graphene with an electron donor perylenediimide derivative.

    PubMed

    Martín-Gomis, Luis; Karousis, Nikos; Fernández-Lázaro, Fernando; Petsalakis, Ioannis D; Ohkubo, Kei; Fukuzumi, Shunichi; Tagmatarchis, Nikos; Sastre-Santos, Ángela

    2017-02-06

    The liquid exfoliation of graphite to few layered graphene sheets together with the non-covalent supramolecular functionalization of exfoliated graphene by the synthesized N,N'-di(2-ethylhexyl)-1-(N''''-methylpiperazin-N'''-yl)perylene-3,4,9,10-tetracarboxydiimide (Pip-PDI) is reported. The aromatic Pip-PDI has the ability to non-covalently interact with the exfoliated graphene sheets, stabilizing them and preventing their reassembly. On the other hand, the presence of the piperazine moiety on the bay position of the PDI core makes it an ideal electron donor, nicely coupled with the electron accepting exfoliated graphene, hence, forming a novel donor-acceptor nanoensemble, which was characterized by complementary spectroscopic and microscopy techniques. Theoretical calculations predicted the absence of a meaningful charge-separated state within the Pip-PDI/graphene ensemble, which was also proven by time-resolved fluorescence and transient absorption measurements.

  10. Calculating the derivative of piecewise functions

    NASA Astrophysics Data System (ADS)

    Tomas Johansson, B.

    2016-01-01

    Exercises involving the calculation of the derivative of piecewise defined functions are common in calculus, with the aim of consolidating beginners' knowledge of applying the definition of the derivative. In such exercises, the piecewise function is commonly made up of two smooth pieces joined together at one point. A strategy which avoids using the definition of the derivative is to find the derivative function of each smooth piece and check whether these functions agree at the chosen point. Showing that this strategy works together with investigating discontinuities of the derivative is usually beyond a calculus course. However, we shall show that elementary arguments can be used to clarify the calculation and behaviour of the derivative for piecewise functions.

  11. Vectors derived from simian immunodeficiency virus (SIV).

    PubMed

    Nègre, Didier; Cosset, François-Loïc

    2002-11-01

    In contrast to other retroviruses, lentiviruses have the unique property of infecting non-proliferating cells. Thus vectors derived from lentiviruses are promising tools for in vivo gene delivery applications. Vectors derived from human primate and non-primate lentiviruses have recently been described and, unlike retroviral vectors derived from murine leukemia viruses, lead to stable integration of the transgene into quiescent cells in various organs. Despite all the safety safeguards that have been progressively introduced in lentiviral vectors, the clinical acceptance of vectors derived from pathogenic lentiviruses is subject to debate. It is therefore essential to design vectors derived from a wide range of lentivirus types and to comparatively examine their properties in terms of transduction efficiency and bio-safety. Here, we review the properties of lentiviral vectors derived from simian immunodeficiency virus (SIV).

  12. Anisotropic higher derivative gravity and inflationary universe

    SciTech Connect

    Kao, W. F.

    2006-08-15

    Stability analysis of the Kantowski-Sachs type universe in pure higher derivative gravity theory is studied in detail. The nonredundant generalized Friedmann equation of the system is derived by introducing a reduced one-dimensional generalized Kantowski-Sachs type action. Existence and stability of inflationary solution in the presence of higher derivative terms are also studied in detail. Implications to the choice of physical theories are discussed in detail in this paper.

  13. Transchromosomally derived Ig heavy chains

    SciTech Connect

    Knight, K.L.; Kingzette, M.; Crane, M.A.

    1995-07-15

    During an immune response, activated B cells undergo isotype switching and begin to express isotypes other than IgM and IgD. Isotype switching occurs when downstream C{gamma}, C{alpha}, or C{epsilon} genes are rearranged into the S{mu} chromosomal region, resulting in the deletion of the region in between. These rearrangements usually occur in cis, i.e., intrachromosomally. In previous studies, we analyzed allotypic specificities of rabbit secretory IgA and identified a substantial number of IgA heavy chains with V{sub h} and C{alpha} allotypes that were encoded by V{sub h} and C{alpha} genes in trans. In those studies, however, we could not determine whether the trans association of V{sub H} and C{alpha} occurred during VDJ gene rearrangement or during isotype switching. Here, we cloned rabbit cDNA which encodes these trans IgA heavy chains and determined the chromosomal origin of the V{sub H}, J{sub H}, and C{alpha} regions. To determine whether the trans association occurred during VDJ gene rearrangement, we analyzed the nucleotide polymorphism of the J{sub H} region and the V{sub H} allotype encoded by the cDNA. We found that the V{sub H} and J{sub H} genes used in the VDJ gene rearrangements were from the same chromosome, indicating that the V{sub H}, D, and J{sub H} gene rearrangements occurred in cis. Furthermore, we analyzed the DNA polymorphisms of J{sub H} and C{alpha} and showed that the VDJ and C{alpha} genes encoding the trans IgA molecules were derived from different parental chromosomes. We suggest that the trans association occurred during isotype switching. This study shows that V{sub H} and C{sub H} can associate transchromosomally as part of a normal immune response. 34 refs., 5 figs.

  14. Ophthalmic use of blood-derived products.

    PubMed

    Nugent, Ryan B; Lee, Graham A

    2015-01-01

    There is a wide spectrum of blood-derived products that have been used in many different medical and surgical specialties with success. Blood-derived products for clinical use can be extracted from autologous or allogeneic specimens of blood, but recombinant products are also commonly used. A number of blood derivatives have been used for a wide range of ocular conditions, from the ocular surface to the retina. With stringent preparation guidelines, the potential risk of transmission of blood-borne diseases is minimized. We review blood-derived products and how they are improving the management of ocular disease.

  15. Generalized gravitational entropy from total derivative action

    NASA Astrophysics Data System (ADS)

    Dong, Xi; Miao, Rong-Xin

    2015-12-01

    We investigate the generalized gravitational entropy from total derivative terms in the gravitational action. Following the method of Lewkowycz and Maldacena, we find that the generalized gravitational entropy from total derivatives vanishes. We compare our results with the work of Astaneh, Patrushev, and Solodukhin. We find that if total derivatives produced nonzero entropy, the holographic and the field-theoretic universal terms of entanglement entropy would not match. Furthermore, the second law of thermodynamics could be violated if the entropy of total derivatives did not vanish.

  16. Early alternative derivations of Fechner's law.

    PubMed

    Masin, Sergio Cesare; Zudini, Verena; Antonelli, Mauro

    2009-01-01

    Historians of psychology, notably Boring, fostered Fechner's idea that Weber's law is the indispensable basis for the derivation of the logarithmic psychophysical law. However, it is shown here that Bernoulli in 1738 and Thurstone in 1931 derived the logarithmic law using principles other than Weber's law and that Fechner and Thurstone based their derivations on the principles originally employed by Bernoulli. It is concluded that awareness of researchers about Bernoulli's and Thurstone's derivations could expand the directions of research on the form of the psychophysical law. (c) 2009 Wiley Periodicals, Inc.

  17. Catalytic synthesis of high-value chemicals from coal-derived liquids. Conversion of phenanthrene derivatives into anthracene derivatives

    SciTech Connect

    Song, C.; Lai, W.C.

    1998-12-31

    It is known that phenanthrene and its derivatives are abundant in coal-derived liquids from coal carbonization, pyrolysis, and liquefaction; however, they have found little use in industry. On the other hand, anthracene and its derivatives are more useful materials for industrial applications. Thus, it is highly desirable to convert phenanthrene derivatives to anthracene derivatives. The authors have found that some chemically modified mordenites and Y-zeolites can selectively promote the transformation of sym-octahydrophenanthrene (sym-OHP) into sym-octahydroanthracene (sym-OHA) at lower temperatures. In this work, the effects of zeolite catalysts and reaction conditions on the ring-shift isomerization of sym-OHP into sym-OHA were studied through experiments at 200--300 C under an initial pressure of 0.79 MPa N{sub 2} or H{sub 2}. They also explored the simultaneous hydrogenation-ring-shift isomerization of phenanthrene using zeolite-supported metal catalysts.

  18. 12 CFR 163.172 - Financial derivatives.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...-OPERATIONS Financial Management Policies § 163.172 Financial derivatives. (a) What is a financial derivative... guidance issued by the OCC on establishing a sound risk management program. (3) Your board of directors... continue to be appropriate to the nature and scope of your operations and existing market conditions. (4...

  19. 45 CFR 601.5 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 45 Public Welfare 3 2013-10-01 2013-10-01 false Derivative classification. 601.5 Section 601.5 Public Welfare Regulations Relating to Public Welfare (Continued) NATIONAL SCIENCE FOUNDATION CLASSIFICATION AND DECLASSIFICATION OF NATIONAL SECURITY INFORMATION § 601.5 Derivative classification. Distinct...

  20. Understanding the Derivative through the Calculus Triangle

    ERIC Educational Resources Information Center

    Weber, Eric; Tallman, Michael; Byerley, Cameron; Thompson, Patrick W.

    2012-01-01

    Typical treatments of the derivative do not clearly convey the idea that the derivative function represents the original function's rate of change. Revealing the relationship between a function and its rate-of-change function for static values of "x" does not facilitate productive ways of thinking about generating the rate-of-change function or…

  1. Understanding the Derivative through the Calculus Triangle

    ERIC Educational Resources Information Center

    Weber, Eric; Tallman, Michael; Byerley, Cameron; Thompson, Patrick W.

    2012-01-01

    Typical treatments of the derivative do not clearly convey the idea that the derivative function represents the original function's rate of change. Revealing the relationship between a function and its rate-of-change function for static values of "x" does not facilitate productive ways of thinking about generating the rate-of-change function or…

  2. Derivational Morphology and Base Morpheme Frequency

    ERIC Educational Resources Information Center

    Ford, M. A.; Davis, M. H.; Marslen-Wilson, W. D.

    2010-01-01

    Morpheme frequency effects for derived words (e.g. an influence of the frequency of the base "dark" on responses to "darkness") have been interpreted as evidence of morphemic representation. However, it has been suggested that most derived words would not show these effects if family size (a type frequency count claimed to reflect semantic…

  3. Derive Workshop Matrix Algebra and Linear Algebra.

    ERIC Educational Resources Information Center

    Townsley Kulich, Lisa; Victor, Barbara

    This document presents the course content for a workshop that integrates the use of the computer algebra system Derive with topics in matrix and linear algebra. The first section is a guide to using Derive that provides information on how to write algebraic expressions, make graphs, save files, edit, define functions, differentiate expressions,…

  4. Systematic method for deriving effective Hamiltonians

    NASA Astrophysics Data System (ADS)

    Swain, S.

    1994-04-01

    A systematic procedure for deriving effective Hamiltonians to any order is presented, which is applicable to any time-independent Hamiltonian. The method is based on a continued-fraction approach and avoids the singularities which may occur with perturbation theory. It is illustrated by deriving the effective Hamiltonian for the one-photon, dressed-state laser to second order.

  5. 22 CFR 9.6 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... 22 Foreign Relations 1 2013-04-01 2013-04-01 false Derivative classification. 9.6 Section 9.6... classification. (a) Definition. Derivative classification is the incorporating, paraphrasing, restating or... with the classification of the source material. Duplication or reproduction of existing classified...

  6. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 5 Administrative Personnel 3 2014-01-01 2014-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as the...

  7. 17 CFR 200.506 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 17 Commodity and Securities Exchanges 2 2012-04-01 2012-04-01 false Derivative classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.506 Derivative classification. Any document that includes paraphrases...

  8. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 5 Administrative Personnel 3 2013-01-01 2013-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as the...

  9. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 5 Administrative Personnel 3 2012-01-01 2012-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as the...

  10. 22 CFR 9.6 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 22 Foreign Relations 1 2014-04-01 2014-04-01 false Derivative classification. 9.6 Section 9.6... classification. (a) Definition. Derivative classification is the incorporating, paraphrasing, restating or... with the classification of the source material. Duplication or reproduction of existing classified...

  11. 17 CFR 200.506 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... 17 Commodity and Securities Exchanges 3 2014-04-01 2014-04-01 false Derivative classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.506 Derivative classification. Any document that includes paraphrases...

  12. 22 CFR 9.6 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ... 22 Foreign Relations 1 2012-04-01 2012-04-01 false Derivative classification. 9.6 Section 9.6... classification. (a) Definition. Derivative classification is the incorporating, paraphrasing, restating or... with the classification of the source material. Duplication or reproduction of existing classified...

  13. 17 CFR 200.506 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... 17 Commodity and Securities Exchanges 2 2011-04-01 2011-04-01 false Derivative classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.506 Derivative classification. Any document that includes paraphrases...

  14. 17 CFR 200.506 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-04-01

    ... 17 Commodity and Securities Exchanges 2 2010-04-01 2010-04-01 false Derivative classification. 200...; CONDUCT AND ETHICS; AND INFORMATION AND REQUESTS Classification and Declassification of National Security Information and Material § 200.506 Derivative classification. Any document that includes paraphrases...

  15. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 5 Administrative Personnel 3 2010-01-01 2010-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as...

  16. Few Fractional Order Derivatives and Their Computations

    ERIC Educational Resources Information Center

    Bhatta, D. D.

    2007-01-01

    This work presents an introductory development of fractional order derivatives and their computations. Historical development of fractional calculus is discussed. This paper presents how to obtain computational results of fractional order derivatives for some elementary functions. Computational results are illustrated in tabular and graphical…

  17. 5 CFR 2500.5 - Derivative classification.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 5 Administrative Personnel 3 2011-01-01 2011-01-01 false Derivative classification. 2500.5 Section 2500.5 Administrative Personnel OFFICE OF ADMINISTRATION, EXECUTIVE OFFICE OF THE PRESIDENT INFORMATION SECURITY REGULATION § 2500.5 Derivative classification. The Office of Administration serves only as...

  18. Tilt/Integral/Derivative Compensators For Controllers

    NASA Technical Reports Server (NTRS)

    Lurie, Boris J.

    1995-01-01

    Tilt/integral/derivative (TID) compensators for tunable feedback control systems offer advantages over proportional/integral/derivative compensators. Designed and adjusted more easily, and made to reject disturbances more strongly and less sensitive to variations in parameters of controlled system.

  19. Smoothing splines: Regression, derivatives and deconvolution

    NASA Technical Reports Server (NTRS)

    Rice, J.; Rosenblatt, M.

    1982-01-01

    The statistical properties of a cubic smoothing spline and its derivative are analyzed. It is shown that unless unnatural boundary conditions hold, the integrated squared bias is dominated by local effects near the boundary. Similar effects are shown to occur in the regularized solution of a translation-kernel intergral equation. These results are derived by developing a Fourier representation for a smoothing spline.

  20. Generalized Fractional Derivative Anisotropic Viscoelastic Characterization

    PubMed Central

    Hilton, Harry H.

    2012-01-01

    Isotropic linear and nonlinear fractional derivative constitutive relations are formulated and examined in terms of many parameter generalized Kelvin models and are analytically extended to cover general anisotropic homogeneous or non-homogeneous as well as functionally graded viscoelastic material behavior. Equivalent integral constitutive relations, which are computationally more powerful, are derived from fractional differential ones and the associated anisotropic temperature-moisture-degree-of-cure shift functions and reduced times are established. Approximate Fourier transform inversions for fractional derivative relations are formulated and their accuracy is evaluated. The efficacy of integer and fractional derivative constitutive relations is compared and the preferential use of either characterization in analyzing isotropic and anisotropic real materials must be examined on a case-by-case basis. Approximate protocols for curve fitting analytical fractional derivative results to experimental data are formulated and evaluated. PMID:28817038

  1. Integrating weather derivatives for managing risks

    SciTech Connect

    Bilski, B.

    1999-11-01

    As deregulation and customer choice loom on the horizon, many energy utilities and other energy suppliers are scrambling to find new services that add value for consumers. Many are also seeking opportunities for increasing efficiency to ensure that costs remain competitive. Integrating weather derivatives with marketing programs and financial management can produce attractive new services and increase efficiency. Weather derivatives can be used to create innovative consumer services, such as a guaranteed annual energy bill which is unaffected by weather and energy price changes. They can also be used to protect the earnings of energy suppliers from one of their most significant financial risks, unpredictable weather. There are three basic types of weather derivatives available today. Option or insurance based derivatives (options), swaps or hedge based derivatives (swaps) and packages where other services are combined with one or both of the above.

  2. High resolution derivative spectra in remote sensing

    NASA Technical Reports Server (NTRS)

    Demetriades-Shah, Tanvir H.; Steven, Michael D.; Clark, Jeremy A.

    1990-01-01

    The use of derivative spectra is an established technique in analytical chemistry for the elimination of background signals and for resolving overlapping spectral features. Application of this technique for tackling analogous problems such as interference from soil background reflectance in the remote sensing of vegetation or for resolving complex spectra of several target species within individual pixels in remote sensing is proposed. Methods for generating derivatives of high spectral resolution data are reviewed. Results of experiments to test the use of derivatives for monitoring chlorosis in vegetation show that derivative spectral indices are superior to conventional broad-band spectral indices such as the near-infrared/red reflectance ratio. Conventional broad-band indices are sensitive to both leaf cover as well as leaf color. New derivative spectral indices which were able to monitor chlorosis unambiguously were identified. Potential areas for the application of this technique in remote sensing are considered.

  3. Two new benzoate derivatives and one new phenylacetate derivative from a marine-derived fungus Engyodontium album.

    PubMed

    Wang, Weiyi; Chen, Ruixuan; Luo, Zhuhua; Wang, Wei; Chen, Jianming

    2017-04-01

    Two new benzoate derivatives, ethyl 3,5-dimethoxy-2-propionylbenzoate (1) and ethyl 3,5-dihydroxy-2-propionylbenzoate (2), and one new phenylacetate derivative, ethyl 3,5-dimethoxy-2-propionylphenylacetate (3), together with 9 known compounds, were isolated from the fermentation of Engyodontium album derived from deep sea sediment. Their structures were elucidated by spectroscopic techniques, such as NMR, IR and HRESIMS. Compound 3 exhibited inhibitory activities against methicillin-resistant Staphylococcus aureus ATCC 43300 (MRSA) and Vibrio vulnificus, with MIC values of 7.8 and 15.6 μg/mL, respectively.

  4. Stability-Derivative Determination from Flight Data

    NASA Technical Reports Server (NTRS)

    Holowicz, Chester H.; Holleman, Euclid C.

    1958-01-01

    A comprehensive discussion of the various factors affecting the determination of stability and control derivatives from flight data is presented based on the experience of the NASA High-Speed Flight Station. Factors relating to test techniques, determination of mass characteristics, instrumentation, and methods of analysis are discussed. For most longitudinal-stability-derivative analyses simple equations utilizing period and damping have been found to be as satisfactory as more comprehensive methods. The graphical time-vector method has been the basis of lateral-derivative analysis, although simple approximate methods can be useful If applied with caution. Control effectiveness has been generally obtained by relating the peak acceleration to the rapid control input, and consideration must be given to aerodynamic contributions if reasonable accuracy is to be realized.. Because of the many factors involved In the determination of stability derivatives, It is believed that the primary stability and control derivatives are probably accurate to within 10 to 25 percent, depending upon the specific derivative. Static-stability derivatives at low angle of attack show the greatest accuracy.

  5. Risk management, derivatives and shariah compliance

    NASA Astrophysics Data System (ADS)

    Bacha, Obiyathulla Ismath

    2013-04-01

    Despite the impressive growth of Islamic Banking and Finance (IBF), a number of weaknesses remain. The most important of this is perhaps the lack of shariah compliant risk management tools. While the risk sharing philosophy of Islamic Finance requires the acceptance of risk to justify returns, the shariah also requires adherents to avoid unnecessary risk-maysir. The requirement to avoid maysir is in essence a call for the prudent management of risk. Contemporary risk management revolves around financial engineering, the building blocks of which are financial derivatives. Despite the proven efficacy of derivatives in the management of risk in the conventional space, shariah scholars appear to be suspicious and uneasy with their use in IBF. Some have imposed outright prohibition of their use. This paper re-examines the issue of contemporary derivative instruments and shariah compliance. The shariah compatibility of derivatives is shown in a number of ways. First, by way of qualitative evaluation of whether derivatives can be made to comply with the key prohibitions of the sharia. Second, by way of comparing the payoff profiles of derivatives with risk sharing finance and Bai Salam contracts. Finally, the equivalence between shariah compliant derivatives like the IPRS and Islamic FX Currency Forwards with conventional ones is presented.

  6. Hyperbranched cationic amylopectin derivatives for gene delivery.

    PubMed

    Zhou, Yanfang; Yang, Bin; Ren, Xianyue; Liu, Zhenzhen; Deng, Zheng; Chen, Luming; Deng, Yubin; Zhang, Li-Ming; Yang, Liqun

    2012-06-01

    A series of hyperbranched cationic amylopectin derivatives conjugated with 1,2-ethylenediamine, diethylenetriamine and 3-(dimethylamino)-1-propylamine residues, named as EDA-Amp, DETA-Amp and DMAPA-Amp, were synthesized by the N,N'-carbonyldiimidazole activation method at room temperature. Their structures were characterized by FTIR and (1)H NMR analyses, and their buffering capability was assessed by acid-base titration. The amylopectin derivatives exhibited better blood compatibility and lower cytotoxicity when compared to branched polyethyleneimine (bPEI) in the hemolysis and MTT assays. Atomic force microscopy and optical microscopy confirmed that the amylopectin derivatives exhibited lower damage for erythrocytes than bPEI. The amylopectin derivatives could bind and condense plasmid DNA (pDNA) to form the complexes with the size ranging from 100 to 300 nm. The resultant complexes showed higher transfection efficiency in 293T cells than in A549 cells. The DMAPA-Amp derivative-mediated gene transfection for Forkhead box O1 exhibited higher protein expression than that of the EDA-Amp and DETA-Amp derivatives in 293T cells, which was analyzed by western blot, flow cytometry and Hoechst staining assay. On the basis of these data, amylopectin derivatives exhibit potential as nonviral gene vectors. Crown Copyright © 2012. Published by Elsevier Ltd. All rights reserved.

  7. Derived Categories and Zero-Brane Stability

    SciTech Connect

    Lawrence, Albion

    2001-07-25

    We define a particular class of topological field theories associated to open strings and prove the resulting D-branes and open strings form the bounded derived category of coherent sheaves. This derivation is a variant of some ideas proposed recently by Douglas. We then argue that any 0-brane on any Calabi-Yau threefold must become unstable along some path in the Kahler moduli space. As a byproduct of this analysis we see how the derived category can be invariant under a birational transformation.

  8. Monocyte-Derived Suppressor Cells in Transplantation.

    PubMed

    Ochando, Jordi; Conde, Patricia; Bronte, Vincenzo

    Myeloid-derived suppressor cells (MDSC) are cells of myeloid origin with enhanced suppressive function. They are negative regulators of the immune responses and comprise a heterogeneous mixture of immunosuppressive cells of monocytic (M-MDSC) and granulocytic (G-MDSC) origin. A more recent nomenclature proposes the term "suppressive monocyte derived cells" (suppressive MCs) to define CSF1/CSF2-dependent mouse suppressor cells that develop from common monocyte progenitors (cMoPs) after birth. Here, we review the literature about monocytic-derived cells with demonstrated suppressor function in vitro and in vivo within the context of solid organ transplantation.

  9. [Mechanism of Platinum Derivatives Induced Kidney Injury].

    PubMed

    Yan, Feifei; Duan, Jianchun; Wang, Jie

    2015-09-20

    Platinum derivatives are the most widely used chemotherapeutic agents to treat solid tumors including ovarian, head and neck, and testicular germ cell tumors, lung cancer, and colorectal cancer. Two major problems exist, however, in the clinic use of platinum derivatives. One is the development of tumor resistance to the drug during therapy, leading to treatment failure. The other is the drug's toxicity such as the cisplatin's nephrotoxicity, which limits the dose that can be administered. This paper describes the mechanism of platinum derivatives induced kidney injury.

  10. Derivation of GFDM Based on OFDM Principles

    SciTech Connect

    Hussein Moradi; Behrouz Farhang-Boroujeny

    2015-06-01

    This paper starts with discussing the principle based on which the celebrated orthogonal frequency division multiplexing (OFDM) signals are constructed. It then extends the same principle to construct the newly introduced generalized frequency division multiplexing (GFDM) signals. This novel derivation sheds light on some interesting properties of GFDM. In particular, our derivation seamlessly leads to an implementation of GFDM transmitter which has significantly lower complexity than what has been reported so far. Our derivation also facilitates a trivial understanding of how GFDM (similar to OFDM) can be applied in MIMO channels.

  11. Deodorization of sewage sludge-derived oils

    SciTech Connect

    Sawatzky, H.; Giddings, T.; Farnand, B.

    1993-07-06

    A method is described for treating a sewage sludge-derived oil comprising the steps of: (A) providing sewage sludge-derived oil having the following elemental composition: Nitrogen: about 2% to about 8%; Oxygen: about 3% to about 12%; Sulphur: about 0.1 % to about 4%; Hydrogen: about 8% to about 11%; Carbon: about 86.9% to about 65%; (B) distilling said sewage sludge-derived oil to a temperature of about 150 C. to remove water and volatile organic compounds; and (C) circulating a gas consisting essentially of carbon dioxide therethrough.

  12. A new Bisabolane Derivative of Leontopodium andersonii

    PubMed Central

    Schwaiger, Stefan; Hehenberger, Stefanie; Ellmerer, Ernst P.; Stuppner, Hermann

    2012-01-01

    Phytochemical investigations of the roots of Leontopodium andersonii C. B. Clarke (Asteraceae) resulted in the isolation of a new bisabolane sesquiterpene derivative. The structure of the highly substituted derivative (1R*, 5S*, 6S*)-5-(acetyloxy)-6-[3-(acetyloxy)-1,5-dimethylhex-4-enyl]-3-methylcyclohex-2-en-4-on-1-yl (2Z)-2-methyl-but-2-enoate was established by 1- and 2-D-NMR spectroscopy and is the first report of a bisabolone derivative of the genus Leontopodium. PMID:20521527

  13. Casimir Energy Associated With Fractional Derivative Field

    SciTech Connect

    Lim, S. C.

    2007-04-28

    Casimir energy associated with fractional derivative scalar massless field at zero and positive temperature can be obtained using the regularization based on generalized Riemann zeta function of Epstein-Hurwitz type.

  14. Polyimides Derived from Novel Asymmetric Benzophenone Dianhydrides

    NASA Technical Reports Server (NTRS)

    Chuang, Chun-Hua (Inventor)

    2015-01-01

    This invention relates to the composition and processes for preparing thermoset polyimides derived from an asymmetric dianhydride, namely 2,3,3',4'-benzophenone dianhydride (a-BTDA) with at least one diamine, and a monofunctional terminal endcaps. The monofunctional terminating groups include 4-phenylethynylphthalic anhydride ester-acid derivatives, phenylethyl trimellitic anhydride (PETA) and its ester derivatives as well as 3-phenylethynylaniline. The process of polyimide composite comprises impregnating monomer reactants of dianhydride or its ester-acid derivatives, diamine and with monofunctional reactive endcaps into glass, carbon, quartz or synthetic fibers and fabrics, and then stack up into laminates and subsequently heated to between 150-375.degree. C. either at atmosphere or under pressure to promote the curing and crosslinking of the reactive endcaps to form a network of thermoset polyimides.

  15. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    EPA Science Inventory

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  16. Patient-Derived Antibody Targets Tumor Cells

    Cancer.gov

    An NCI Cancer Currents blog on an antibody derived from patients that killed tumor cells in cell lines of several cancer types and slowed tumor growth in mouse models of brain and lung cancer without evidence of side effects.

  17. MANGROVE-DERIVED NUTRIENTS AND CORAL REEFS

    EPA Science Inventory

    Understanding the consequences of the declining global cover of mangroves due to anthropogenic disturbance necessitates consideration of how mangrove-derived nutrients contribute to threatened coral reef systems. We sampled potential sources of organic matter and a suite of sessi...

  18. Perspectives on Biologically Active Camptothecin Derivatives

    PubMed Central

    Liu, Ying-Qian; Li, Wen-Qun; Morris-Natschke, Susan L.; Qian, Keduo; Yang, Liu; Zhu, Gao-Xiang; Wu, Xiao-Bing; Chen, An-Liang; Zhang, Shao-Yong; Song, Zi-Long; Lee, Kuo-Hsiung

    2015-01-01

    Camptothecins (CPTs) are cytotoxic natural alkaloids that specifically target DNA topoisomerase I. Research on CPTs has undergone a significant evolution from the initial discovery of CPT in the late 1960s through the study of synthetic small molecule derivatives to investigation of macromolecular constructs and formulations. Over the past years, intensive medicinal chemistry efforts have generated numerous CPT derivatives. Three derivatives, topotecan, irinotecan, and belotecan, are currently prescribed as anticancer drugs, and several related compounds are now in clinical trials. Interest in other biological effects, besides anticancer activity, of CPTs is also growing exponentially, as indicated by the large number of publications on the subject during the last decades. Therefore, the main focus of the present review is to provide an ample but condensed overview on various biological activities of CPT derivatives, in addition to continued up-to-date coverage of anticancer effects. PMID:25808858

  19. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... may engage in a transaction involving a financial derivative if your charter or applicable State law..., provide for periodic reporting to the board of directors and management, segregation of duties, and...

  20. 12 CFR 563.172 - Financial derivatives.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... may engage in a transaction involving a financial derivative if your charter or applicable State law..., provide for periodic reporting to the board of directors and management, segregation of duties, and...

  1. Catalytic combustion of coal-derived liquids

    NASA Technical Reports Server (NTRS)

    Bulzan, D. L.; Tacina, R. R.

    1981-01-01

    A noble metal catalytic reactor was tested with three grades of SRC 2 coal derived liquids, naphtha, middle distillate, and a blend of three parts middle distillate to one part heavy distillate. A petroleum derived number 2 diesel fuel was also tested to provide a direct comparison. The catalytic reactor was tested at inlet temperatures from 600 to 800 K, reference velocities from 10 to 20 m/s, lean fuel air ratios, and a pressure of 3 x 10 to the 5th power Pa. Compared to the diesel, the naphtha gave slightly better combustion efficiency, the middle distillate was almost identical, and the middle heavy blend was slightly poorer. The coal derived liquid fuels contained from 0.58 to 0.95 percent nitrogen by weight. Conversion of fuel nitrogen to NOx was approximately 75 percent for all three grades of the coal derived liquids.

  2. Battery failure model derived from flaw theory

    NASA Technical Reports Server (NTRS)

    Schulman, I.

    1981-01-01

    A previously derived failure model for battery lifetime is discussed in terms of growth rate of the flaw, distribution of flaw sizes, and number of flaws. Equations are presented for determining the failure model for a nickel cadmium battery.

  3. Plant-derived nanostructures: types and applications

    EPA Science Inventory

    Plant-derived nanostructures and nanoparticles (NPs) have functional applications in numerous disciplines such as health care, food and feed, cosmetics, biomedical science, energy science, drug-gene delivery, environmental health, and so on. Consequently, it is imperative for res...

  4. 46 CFR 503.55 - Derivative classification.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... Shipping FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS PUBLIC INFORMATION Information Security Program § 503.55 Derivative classification. (a) In accordance with Part 2 of Executive Order 13526 and directives of the Information Security Oversight Office, the incorporation, paraphrasing...

  5. 46 CFR 503.55 - Derivative classification.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... Shipping FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS PUBLIC INFORMATION Information Security Program § 503.55 Derivative classification. (a) In accordance with Part 2 of Executive Order 13526 and directives of the Information Security Oversight Office, the incorporation, paraphrasing...

  6. 46 CFR 503.55 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... Shipping FEDERAL MARITIME COMMISSION GENERAL AND ADMINISTRATIVE PROVISIONS PUBLIC INFORMATION Information Security Program § 503.55 Derivative classification. (a) In accordance with Part 2 of Executive Order 13526 and directives of the Information Security Oversight Office, the incorporation, paraphrasing...

  7. Ionic liquid crystals derived from amino acids.

    PubMed

    Mansueto, Markus; Frey, Wolfgang; Laschat, Sabine

    2013-11-18

    Novel chiral amino acid derived ionic liquid crystals with amine and amide moieties as spacers between the imidazolium head group and the alkyl chain were synthesised. The key step in the synthesis utilised the relatively uncommon SO3 leaving group in a microwave-assisted reaction. The mesomorphic properties of the mesogens were determined by differential scanning calorimetry (DSC), polarising optical microscopy (POM) and X-ray diffraction. All liquid crystalline salts exhibit a smectic A mesophase geometry with strongly interdigitated bilayer structures. An increase of the steric bulk of the stereogenic centre hindered the formation of mesophases. In case of phenylalanine-derived derivatives a mesomorphic behaviour was observed for shorter alkyl chains as compared to other amino acid derivatives indicating an additional stabilising effect by the phenyl moiety.

  8. 32 CFR 2001.22 - Derivative classification.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... described in E.O. 12951, “Release of Imagery Acquired by Space-Based National Intelligence Reconnaissance... might appear as: Derived From: Report entitled, “New Weapons,” dated October 20, 2009, Department of...

  9. Plant-derived nanostructures: types and applications

    EPA Science Inventory

    Plant-derived nanostructures and nanoparticles (NPs) have functional applications in numerous disciplines such as health care, food and feed, cosmetics, biomedical science, energy science, drug-gene delivery, environmental health, and so on. Consequently, it is imperative for res...

  10. On Positive Functions with Positive Derivatives

    ERIC Educational Resources Information Center

    Dobbs, David E.

    2002-01-01

    Three proofs are given for the fact that the derivative of an everywhere-positive non-constant real polynomial function must change sign. This self-contained note could find classroom use in courses on calculus or abstract algebra.

  11. Catalytic combustion of coal-derived liquids

    NASA Astrophysics Data System (ADS)

    Bulzan, D. L.; Tacina, R. R.

    A noble metal catalytic reactor was tested with three grades of SRC 2 coal derived liquids, naphtha, middle distillate, and a blend of three parts middle distillate to one part heavy distillate. A petroleum derived number 2 diesel fuel was also tested to provide a direct comparison. The catalytic reactor was tested at inlet temperatures from 600 to 800 K, reference velocities from 10 to 20 m/s, lean fuel air ratios, and a pressure of 3 x 10 to the 5th power Pa. Compared to the diesel, the naphtha gave slightly better combustion efficiency, the middle distillate was almost identical, and the middle heavy blend was slightly poorer. The coal derived liquid fuels contained from 0.58 to 0.95 percent nitrogen by weight. Conversion of fuel nitrogen to NOx was approximately 75 percent for all three grades of the coal derived liquids.

  12. Proteomics Applications in Dental Derived Stem Cells.

    PubMed

    Li, Jie; Tian, Weidong; Song, Jinlin

    2017-07-01

    At present, the existence of a variety of dental derived stem cells has been documented. These cells displayed promising clinical application potential not only for teeth and its surrounding tissue regeneration, but also for other tissues, such as nerve and bone regeneration. Proteomics is an unbiased, global informatics tool that provides information on all protein expression levels as well as post-translational modification in cells or tissues and is applicable to dental derived stem cells research. Over the last decade, considerable progress has been made to study the global proteome, secrotome, and membrane proteome of dental derived stem cells. Here, we present an overview of the proteomics studies in the context of stem cell research. Particular attention is given to dental derived stem cell types as well as current challenges and opportunities. J. Cell. Physiol. 232: 1602-1610, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  13. Simplified Derivation Of Geometrical Dynamic Range Compression

    NASA Astrophysics Data System (ADS)

    Altman, W. P.

    1982-08-01

    A simplified derivation is presented which illustrates the effects of unmatched fields of view for a lidar system. The resultant equations are easily evaluated on a programmable calculator, and comparison with previous calculations are numerically similar.

  14. Spline Confidence Bands for Functional Derivatives

    PubMed Central

    Cao, Guanqun; Wang, Jing; Wang, Li; Todem, David

    2012-01-01

    We develop in this paper a new procedure to construct simultaneous confidence bands for derivatives of mean curves in functional data analysis. The technique involves polynomial splines that provide an approximation to the derivatives of the mean functions, the covariance functions and the associated eigenfunctions. We show that the proposed procedure has desirable statistical properties. In particular, we first show that the proposed estimators of derivatives of the mean curves are semiparametrically efficient. Second, we establish consistency results for derivatives of covariance functions and their eigenfunctions. Most importantly, we show that the proposed spline confidence bands are asymptotically efficient as if all random trajectories were observed with no error. Finally, the confidence band procedure is illustrated through numerical simulation studies and a real life example. PMID:22423174

  15. SCM Forcing Data Derived from NWP Analyses

    DOE Data Explorer

    Jakob, Christian

    2008-01-15

    Forcing data, suitable for use with single column models (SCMs) and cloud resolving models (CRMs), have been derived from NWP analyses for the ARM (Atmospheric Radiation Measurement) Tropical Western Pacific (TWP) sites of Manus Island and Nauru.

  16. Myeloid derived suppressor cells in transplantation.

    PubMed

    Lees, Jason R; Azimzadeh, Agnes M; Bromberg, Jonathan S

    2011-10-01

    Myeloid derived suppressor cells (MDSC) are a heterogeneous population of hematopoietic derived cell precursors that can suppress immune responses in a variety of inflammatory settings. Here we review recent studies detailing expansion of phenotypically and functionally disparate MDSC. Findings related to MDSC accumulation, activation, and mechanisms utilized in immune suppression are presented. Further, we discuss recent reports that suggest MDSC are expanded during transplantation and that modulation of MDSC can participate in preventing graft rejection.

  17. Generalized entropy and higher derivative gravity

    NASA Astrophysics Data System (ADS)

    Camps, Joan

    2014-03-01

    We derive an extension of the Ryu-Takayanagi prescription for curvature squared theories of gravity in the bulk, and comment on a prescription for more general theories. This results in a new entangling functional, that contains a correction to Wald's entropy. The new term is quadratic in the extrinsic curvature. The coefficient of this correction is a second derivative of the lagrangian with respect to the Riemann tensor. For Gauss-Bonnet gravity, the new functional reduces to Jacobson-Myers'.

  18. Synthesis of Pharmacological Heterocyclic Derivatives Based Surfactants.

    PubMed

    El-Sayed, Refat; Fadda, Ahmed A

    2016-01-01

    Synthesis of chromenopyrimidine derivatives and the related fused system carried out by the reaction of chromene derivative 1 with various reagents under suitable reaction conditions. Condensation of stearoyl chloride with these heterocycles, then, propoxylated the products using propylene oxide to produce surface active agents having a twofold capacity as surface and antimicrobial dynamic specialists which may be served in the production of medications, pesticides, beautifying agents or may be utilized as an antimicrobial. Some of the surface properties and antimicrobial activity were resolved.

  19. On computing Laplace's coefficients and their derivatives.

    NASA Astrophysics Data System (ADS)

    Gerasimov, I. A.; Vinnikov, E. L.

    The algorithm of computing Laplace's coefficients and their derivatives is proposed with application of recurrent relations. The A.G.M.-method is used for the calculation of values L0(0), L0(1). The FORTRAN-program corresponding to the algorithm is given. The precision control was provided with numerical integrating by Simpsons method. The behavior of Laplace's coefficients and their third derivatives whith varying indices K, n for fixed values of the α-parameter is presented graphically.

  20. Fokker Planck equation with fractional coordinate derivatives

    NASA Astrophysics Data System (ADS)

    Tarasov, Vasily E.; Zaslavsky, George M.

    2008-11-01

    Using the generalized Kolmogorov-Feller equation with long-range interaction, we obtain kinetic equations with fractional derivatives with respect to coordinates. The method of successive approximations, with averaging with respect to a fast variable, is used. The main assumption is that the correlation function of probability densities of particles to make a step has a power-law dependence. As a result, we obtain a Fokker-Planck equation with fractional coordinate derivative of order 1<α<2.