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Naphthalene
Kinds of Naphthalene Terms modified by Naphthalene Selected AbstractsPredicting single and mixture toxicity of petrogenic polycyclic aromatic hydrocarbons to the copepod Oithona davisaeENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 11 2005Carlos Barata Abstract In the present study, the acute toxicity of 10 polycyclic aromatic hydrocarbons (PAH) associated with the Prestige fuel oil spill (Spain, 2002) were evaluated, either as single substances or in mixtures, in adults of the copepod Oithona davisae. All but dimethylphenanthrene had negative effects on O. davisae survival at concentrations below their water solubility, with 48-h median lethal concentrations for naphthalene and pyrene of 56.1 and 0.8 ,mol/L, respectively, making these the least and most toxic compounds. Polycyclic aromatic hydrocarbons had narcotic effects on copepods, as evidenced by the lack of motility at lower concentrations than those causing death. Naphthalene showed the greatest narcotic effects, and phenanthrene showed minor effects. Acute toxicity of the tested PAHs was inversely related (r2 = 0.9) with their octanol,water partition coefficient, thereby confirming the validity of the baseline quantitative structure,activity regression models for predicting the toxicity of PAH compounds in copepod species. When supplied in mixtures, the toxic effect of PAHs was additive. These results indicate that the many PAHs in an oil spill can be considered unambiguous baseline toxicants (class 1) acting additively as nonpolar narcotics in copepods; hence, their individual and combined toxicity can be predicted using their octanol,water partition coefficient. [source] Uptake and diverse effects of polycyclic aromatic hydrocarbons on the metabolic activity of Elliptio complanata measured by calorespirometryENVIRONMENTAL TOXICOLOGY & CHEMISTRY, Issue 5 2001Marcos A. Cheney Abstract Polycyclic aromatic hydrocarbons (PAHs) are important contaminants of world water resources, with effects on aquatic life. Metabolic responses to short-term acute toxicities of naphthalene, anthracene, and chrysene were investigated in the freshwater bivalve mollusk Elliptio complanata using differential scanning calorespirometry coupled with uptake and scanning electron microscopy. Comparing the uptakes of naphthalene, anthracene, and chrysene with that of inulin, which is known to occupy only extracellular space, showed that all compounds studied were taken up. The PAHs studied had diverse effects on the metabolic activity of E. complanata. Naphthalene and, to a lesser degree, chrysene caused stimulation of heat rates, possibly due to uncoupling of oxidative metabolism. Differential scanning calorespirometry coupled with studies of rates of oxygen consumption by the gill tissue exposed to the PAHs showed similar diverse patterns of respiratory rate stimulation and inhibition. Analysis of results of scanning electron microscopy suggested that irreversible damage to the gill tissue occurred in the presence of anthracene but not in the presence on naphthalene or chrysene. The batch calorespirometric method coupled with uptake and spectroscopy proved to be a useful technique to assess the toxicity of PAHs on the control of energy flux in gills of a freshwater bivalve mollusk. [source] Comparison of two capillary electrophoresis online stacking modes by analysis of polycyclic aromatic hydrocarbons in airborne particulatesJOURNAL OF SEPARATION SCIENCE, JSS, Issue 13 2006Guan-Qun Song Abstract Naphthalene, fluorene, pyrene, anthracene, phenanthrene, and chrysene were successfully separated by CD-modified MEKC (CD-MEKC) using 20 mM borate (pH 9.0) containing 90 mM SDS and 75 mM ,-CD. Two online stacking methods, i. e., sweeping and field-enhanced sample injection (FESI), were explored to enhance the detection sensitivity. The influences of some crucial parameters in sweeping and FESI procedures were investigated. For FESI method, a plug of water and low-conductivity sample matrix was used to increase the stacking efficiency. Compared with the sweeping method, FESI can increase the sensitivity in the range of 10,20-fold. The proposed method was used for the analysis of polycyclic aromatic hydrocarbons in airborne particulates. [source] Room-Temperature Freeze Casting for Ceramics with Nonaqueous Sublimable Vehicles in the Naphthalene,Camphor Eutectic SystemJOURNAL OF THE AMERICAN CERAMIC SOCIETY, Issue 11 2004Kiyoshi Araki Freeze casting for Al2O3 was accomplished at room temperature with nonaqueous sublimable vehicles in the naphthalene,camphor eutectic system with a eutectic temperature of 31°C. A fully dense sintered body (>99.5% of theoretical density (T.D.)) was obtained with a eutectic composition vehicle, whereas at most 90% T.D. was obtained with an off-eutectic (i.e., hypo- or hypereutectic) composition vehicle due to formation of large uniquely shaped voids. Microstructural observation suggested that growing pro-eutectic crystals rejected the suspended Al2O3 particles to form large voids during the solidification process. At the eutectic composition, formation of fine lamellar microstructure in a solidified vehicle is considered to inhibit particle rejection resulting in large voids. [source] Indigo production by naphthalene-degrading bacteriaLETTERS IN APPLIED MICROBIOLOGY, Issue 1 2000B. Bhushan A wild-type naphthalene-degrading strain Pseudomonas putida RKJ1 and two recombinant strains each of Ps. putida and Escherichia coli carrying the genes for naphthalene degradation on a recombinant plasmid pRKJ3, produced indigo and indirubin pigments from indole. Naphthalene, salicylate and IPTG induced cells of naphthalene-degrading recombinant bacteria produced up to two times higher indigo compared with the uninduced cells. The maximum rates of indigo formation by Ps. putida RKJ1, Ps. putida RKJ5/pRKJ3, Ps. putida KT2442/pRKJ3, E. coli TB1/pRKJ3 and E. coli AB1157/pRKJ3 were 0·60, 0·80, 0·60, 1·20 and 1·50 nmol min,1 mg dry biomass,1, respectively, using indole as the substrate. The apparent Km values of indigo formation by these same bacteria were 0·22, 0·15, 0·10, 0·21 and 0·20 mmol l,1, respectively, again using indole as the substrate. The present study revealed that E. coli AB1157 was the most efficient of the hosts tested for the expression of the plasmid encoded genes (pRKJ3) from the wild-type strain Ps. putida RKJ1. In addition, both recombinant E. coli strains were capable of producing indigo directly from nutrient medium. [source] Alkyl Naphthalenes and Phenanthrenes: Molecular Markers for Tracing Filling Pathways of Light Oil and Condensate ReservoirsACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2010LI Meijun Abstract: Condensates and light oils are generally characterized by high maturity, low concentration of sterane and terpane biomarkers and low content of non-hydrocarbon fraction. As a result, some commonly-used sterane, terpane and carbazole migration parameters in conventional oil reservoirs may have a certain limitation in condensate and light oil reservoirs for their poor signal-noise ratios in the gas chromatography-mass spectrometry (GC-MS). Naphthalene, phenanthrene and their methylated substituents, however, are present in significant concentrations in condensates and light oils. Taking the Fushan depression (in the Beibuwan Basin, Northern South China Sea) as an example, this paper attempts for the first time to use polycyclic aromatic hydrocarbon (PAH)-related parameters to trace migration directions and filling pathways for condensate and light oil reservoirs. The result shows that TMNr (i.e. 1,3,7-TMN/ (1,3,7-TMN + 1,2,5-TMN), TMN: trimethylnaphthalene)), MPI-1 (i.e. 1.5×(2-MP + 3-MP)/(P + 1-MP + 9-MP), P: phenanthrene MP: methylphenanthrene), MN/DMN (,methylnaphthalene/,dimethylnaphthalene, %) and MN/TMN (,methylnaphthalene/,trimethylnaphthalene, %) can be used to trace the filling pathways of condensate and light oil reservoirs. These parameters, together with geological consideration and other bulk oil properties (e.g. the gas to oil ratio and density), suggest that the condensates and light oils in the Huachang oil and gas field are mainly sourced from the Bailian sag that is located to the northeast of the Huachang uplift in the Fushan depression. [source] ChemInform Abstract: Diastereoselective Synthesis of ,-Dispiroiminolactone Bearing Naphthalene or Bipyridine Pendant GroupsCHEMINFORM, Issue 6 2010Malek T. Maghsoodlou Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Diastereodifferentiating [4 + 2]-Photocycloaddition of Tegafur with Naphthalene.CHEMINFORM, Issue 39 2007Kazue Ohkura Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] A Simple, Two-Step, Site-Specific Preparation of Fluorinated Naphthalene and Phenanthrene Derivatives from Fluorobromo-Substituted Alkenes.CHEMINFORM, Issue 5 2007Yi Wang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract, please click on HTML or PDF. [source] Hexa- and Heptasubstitution in the Interaction of Octafluoronaphthalene with Lithium Dialkylamides: A New Approach to the Naphthalene "Proton Sponges".CHEMINFORM, Issue 32 2004Vladimir I. Sorokin Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: ROMPGel-Supported Biphenyl and Naphthalene: Reagents for Lithiation Reactions with Minimal Purification.CHEMINFORM, Issue 23 2002Thomas Arnauld Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Acenaphtho[1,,2- c]phosphole P -Oxide: A Phosphole,Naphthalene ,-Conjugated System with High Electron MobilityCHEMISTRY - A EUROPEAN JOURNAL, Issue 39 2009Arihiro Saito One order of magnitude: Naphthalene- and acenaphthene-fused phosphole P -oxides (see figure) are shown to have reasonably high thermal and electrochemical stabilities and electron-accepting ability. The electron mobility of the naphthalene-fused phosphole P -oxide is about one order higher than that of tris(8-hydroxyquinoline)aluminium(III) Alq3 at any given electric field. [source] The Reaction of o -Alkynylarene and Heteroarene Carboxaldehyde Derivatives with Iodonium Ions and Nucleophiles: A Versatile and Regioselective Synthesis of 1H -Isochromene, Naphthalene, Indole, Benzofuran, and Benzothiophene CompoundsCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2006José Barluenga Prof. Dr. Abstract The reaction of o -alkynylbenzaldehydes 1 with different alcohols, silylated nucleophiles 5, electron-rich arenes 10, and heteroarenes 12 in the presence of the reagent IPy2BF4, at room temperature, gave functionalized 4-iodo-1H -isochromenes 2, 6, 11, and 13 in a regioselective manner. When alkynes 16 and alkenes 19 and 20 were used as nucleophiles, a regioselective benzannulation reaction took place to form 1-iodonaphthalenes 17 and 1-naphthyl ketones 18, respectively. Moreover, the latter process has been adapted to accomplish the synthesis of indole, benzofuran, and benzothiophene derivatives (23, 27, and 28, respectively). The three patterns of reactivity observed for the o -alkynylbenzaldehyde derivatives with IPy2BF4 stem from a common iodinated isobenzopyrylium ion intermediate, A, that evolves in a different way depending on the nucleophile present in the reaction medium. A mechanism is proposed and the different reaction pathways observed as a function of the type of nucleophile are discussed. Furthermore, the reaction of the o -hexynylbenzaldehyde 1,b with styrene was monitored by NMR spectroscopy. Compound III, a resting state for the common intermediate in the absence of acid, has been isolated. Its evolution in acid media has been also tested, thereby providing support to the proposed mechanism. [source] Solid Phase Extraction of Thallium(III) on Micro Crystalline Naphthalene Modified with N,N, -Bis(3-methylsalicylidene)- ortho -phenylenediamine and Determination by SpectrophotometryCHINESE JOURNAL OF CHEMISTRY, Issue 10 2008Ali MOGHIMI Abstract A novel, simple, sensitive and effective method has been developed for preconcentration of thallium on N,N, -bis(3-methylsalicylidene)- ortho -phenylenediamine (MSOPD) adsorbent in a pH range 5.0,10.0, prior to its spectrophotometric determination, based on the oxidation of bromopyrogallol red at ,=520 nm. This method makes it possible to quantitize thallium in a range of 3.6×10,9 to 2.0×10,5 mol/L, with a detection limit (S/N=3) of 1.42×10,9 mol/L. This procedure has been successfully applied to determine the ultra trace levels of thallium in the environmental samples, free from the interference of some diverse ions. The precision, expressed as relative standard deviation of three measurements, is better than 2.9%. [source] Protonation of Diarylacetylenes in Superacid HSO3F and Their Oxidation in the HSO3F/PbO2 System: One-Pot Synthesis of Polysubstituted NaphthalenesEUROPEAN JOURNAL OF ORGANIC CHEMISTRY, Issue 27 2008Aleksander V. Vasilyev Abstract In the superacid HSO3F, diarylacetylenes bearing one electron-withdrawing group (NO2, CN, COMe, CO2Me) in each arene ring form stable ions, protonated at these groups. Oxidation of such diarylacetylenes in the HSO3F/PbO2 system at ,75 to ,50 °C over 2,2.5 h, followed by quenching of the reaction mixture with hydrochloric (or hydrobromic) acid at ,60 to 25 °C, resulted in the formation of (E,E)-1,4-dichloro (or dibromo)-1,2,3,4-tetraarylbuta-1,3-dienes. These butadienes spontaneously undergo electrocyclic transformation into polysubstituted naphthalenes at room temperature. (© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2008) [source] A Facile Route to Polysubstituted Naphthalenes and Benzofluorenols via Scandium Triflate- and Triflic Acid- Catalyzed Benzannulation of 2-(2-Alkynylarylidene)- 1,3-Dicarbonyl CompoundsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 11-12 2010Lu Liu Abstract This paper describes an efficient scandium triflate- and triflic acid-catalyzed benzannulation of 2-(2-alkynylarylidene)-1,3-dicarbonyl compounds to afford polysubstituted naphthalenes and benzo[a]fluorenols. The product selectivity could be tuned by subtle choice of the catalyst. An unprecedented process between alkynes and ketones is also explored. [source] A Novel Process for Selective Ruthenium-Catalyzed Oxidation of Naphthalenes and PhenolsADVANCED SYNTHESIS & CATALYSIS (PREVIOUSLY: JOURNAL FUER PRAKTISCHE CHEMIE), Issue 10 2010Gerrit Wienhöfer Abstract Arenes are selectively oxidized to the corresponding quinones employing ruthenium(2,2,,6,:2,,-terpyridine)(2,6-pyridinedicarboxylate) [Ru(tpy)(pydic] as catalyst and hydrogen peroxide as the terminal oxidant. Applying alkylated naphthalenes and phenols, benzo- and naphthoquinones are obtained in up to 93% yield. The industrially interesting oxidation of 2-methylnaphthalene gave 74% of the corresponding quinones and 60% of menadione (vitamin K3). 2,3,5-Trimethylbenzoquinone which constitutes the key intermediate for vitamin E is obtained in 83% yield. [source] Quantitative Structure-retention Relationship for Gas Chromatography of Polychlorinated Naphthalenes by Ab initio Quantummechanical Calculations and a Cl Substitution Position MethodMOLECULAR INFORMATICS, Issue 1 2006Zhi-Cai Zhai Abstract Three quantitative structure-retention relationship (QSRR) models have been developed for gas chromatographic relative retention indices (RIs) of polychlorinated naphthalene (PCN) congeners. With computation at HF/6-31G* and B3LYP/6-31G* levels in Gaussian98 program, the structural parameters of PCNs were obtained and used as chemical descriptors to correlate with their gas chromatographic RIs by multiple linear regression analysis, resulting in model,1 and model,2. The squared correlation coefficients (r2) of the first two models are 0.9814 and 0.9957, and the cross-validation correlation coefficients (q2) are 0.9771 and 0.9948, respectively. On the other hand, the third model, model,3, was developed using the relative position of chlorine substitution as molecular descriptor, and its multiple squared correlation coefficient is r2,=,0.9967 and q2,=,0.9959, suggesting model,3 is practical and especially has a optimum predictive power. [source] Alkyl Naphthalenes and Phenanthrenes: Molecular Markers for Tracing Filling Pathways of Light Oil and Condensate ReservoirsACTA GEOLOGICA SINICA (ENGLISH EDITION), Issue 5 2010LI Meijun Abstract: Condensates and light oils are generally characterized by high maturity, low concentration of sterane and terpane biomarkers and low content of non-hydrocarbon fraction. As a result, some commonly-used sterane, terpane and carbazole migration parameters in conventional oil reservoirs may have a certain limitation in condensate and light oil reservoirs for their poor signal-noise ratios in the gas chromatography-mass spectrometry (GC-MS). Naphthalene, phenanthrene and their methylated substituents, however, are present in significant concentrations in condensates and light oils. Taking the Fushan depression (in the Beibuwan Basin, Northern South China Sea) as an example, this paper attempts for the first time to use polycyclic aromatic hydrocarbon (PAH)-related parameters to trace migration directions and filling pathways for condensate and light oil reservoirs. The result shows that TMNr (i.e. 1,3,7-TMN/ (1,3,7-TMN + 1,2,5-TMN), TMN: trimethylnaphthalene)), MPI-1 (i.e. 1.5×(2-MP + 3-MP)/(P + 1-MP + 9-MP), P: phenanthrene MP: methylphenanthrene), MN/DMN (,methylnaphthalene/,dimethylnaphthalene, %) and MN/TMN (,methylnaphthalene/,trimethylnaphthalene, %) can be used to trace the filling pathways of condensate and light oil reservoirs. These parameters, together with geological consideration and other bulk oil properties (e.g. the gas to oil ratio and density), suggest that the condensates and light oils in the Huachang oil and gas field are mainly sourced from the Bailian sag that is located to the northeast of the Huachang uplift in the Fushan depression. [source] ChemInform Abstract: Synthesis of Substituted Naphthalenes via a Catalytic Ring-Expansion Rearrangement.CHEMINFORM, Issue 12 2009Adam C. Glass Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: Gold-Catalyzed Double Migration,Benzannulation Cascade Toward Naphthalenes.CHEMINFORM, Issue 35 2008Alexander S. Dudnik Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 200 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Stereoselective Synthesis of Tetrahydronaphthocyclobuta[1,2-d]pyrimidinediones from 5-Fluoro-1,3-dimethyluracil and Naphthalenes.CHEMINFORM, Issue 32 2005Kazue Ohkura Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of Hexabromo, Hydroxy, Epoxy, Methoxy and Nitroxy Derivatives of Tetralins and Naphthalenes.CHEMINFORM, Issue 7 2005Ramazan Erenler No abstract is available for this article. [source] 1- And 2-Substituted Naphthalenes: A New Class of Potential Hypotensive Agents.CHEMINFORM, Issue 38 2004Vishnu K. Tandon Abstract For Abstract see ChemInform Abstract in Full Text. [source] Reductive Opening of 1H,3H-Benzo[de]isochromene: Synthesis of 1,8-Difunctionalized Naphthalenes.CHEMINFORM, Issue 37 2004Francisco Foubelo Abstract For Abstract see ChemInform Abstract in Full Text. [source] Regioselective Synthesis of Substituted Naphthalenes: A Novel de Novo Approach Based on a Metal-Free Protocol for Stepwise Cycloaddition of o-Alkynylbenzaldehyde Derivatives with Either Alkynes or Alkenes.CHEMINFORM, Issue 8 2004Jose Barluenga Abstract For Abstract see ChemInform Abstract in Full Text. [source] Synthesis of Substituted Naphthalenes and Carbazoles by the Palladium-Catalyzed Annulation of Internal Alkynes.CHEMINFORM, Issue 7 2004Qinhua Huang Abstract For Abstract see ChemInform Abstract in Full Text. [source] ChemInform Abstract: A Novel Synthesis of Substituted Naphthalenes via Claisen Rearrangement and RCM Reaction.CHEMINFORM, Issue 3 2002Keng-Shiang Huang Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] ChemInform Abstract: A Novel Synthesis of Polysubstituted Naphthalenes.CHEMINFORM, Issue 42 2001Alexander S. Kiselyov Abstract ChemInform is a weekly Abstracting Service, delivering concise information at a glance that was extracted from about 100 leading journals. To access a ChemInform Abstract of an article which was published elsewhere, please select a "Full Text" option. The original article is trackable via the "References" option. [source] Palladium-Catalyzed Formation of Highly Substituted Naphthalenes from Arene and Alkyne HydrocarbonsCHEMISTRY - A EUROPEAN JOURNAL, Issue 22 2008Yao-Ting Wu Prof. Abstract Several highly substituted naphthalenes 3 have been synthesized in a one-pot reaction by treatment of arenes 1 with alkynes 2 in the presence of palladium acetate and silver acetate. In this Pd-catalyzed protocol, an arene provides a benzo source for the construction of a naphthalene core through twofold aryl CH bond activation. Reaction of triphenylphosphine with diphenylethyne (2,a) under the catalysis of PdIV complexes produced 1,2,3,4-tetraphenylnaphthalene (3,ba) in 62,% yield. Here, triphenylphosphine undergoes one aryl CP bond cleavage and one aryl CH bond activation to serve as a benzo moiety. Crystal structures of cycloadducts 3,ea, 3,ga, and 3,ac have been analyzed. The twisted naphthalenes arise not only from the overcrowded substituents but also from the contribution of the CH3,, interaction. 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