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Sample records for allyl glycidyl ether

  1. Epoxidation of allyl-glycidyl ether with hydrogen peroxide over Ti-SBA-15 catalyst and in methanol medium

    Directory of Open Access Journals (Sweden)

    Walasek Marika

    2016-12-01

    Full Text Available This work presents the studies on the epoxidation of allyl-glycidyl ether (AGE over the Ti-SBA-15 catalyst. In these studies an aqueous hydrogen peroxide was used as an oxidizing agent and as a solvent methanol was applied. The studies on the influence the following parameters: temperature (20–80°C, molar ratio of AGE/H2O2 (1:1.5–5:1, methanol concentration (10–90 wt%, catalyst content (1–9 wt% and reaction time (15–240 min. were carried out and the most favourable values of these parameters were chosen (temperature 80°C, molar ratio of AGE/H2O2 = 5:1, methanol concentration 30 wt%, catalyst content 3 wt% and the reaction time 240 min.. At these conditions the functions describing the process reached the following values: the selectivity of diglycidyl ether (DGE 9.2 mol%, the conversion of AGE 13.9 mol% and the efficiency of H2O2 conversion 89.9 mol%.

  2. Aliphatic polycarbonates based on carbon dioxide, furfuryl glycidyl ether, and glycidyl methyl ether: reversible functionalization and cross-linking.

    Science.gov (United States)

    Hilf, Jeannette; Scharfenberg, Markus; Poon, Jeffrey; Moers, Christian; Frey, Holger

    2015-01-01

    Well-defined poly((furfuryl glycidyl ether)-co-(glycidyl methyl ether) carbonate) (P((FGE-co-GME)C)) copolymers with varying furfuryl glycidyl ether (FGE) content in the range of 26% to 100% are prepared directly from CO2 and the respective epoxides in a solvent-free synthesis. All materials are characterized by size-exclusion chromatography (SEC), (1)H NMR spectroscopy, and differential scanning calorimetry (DSC). The furfuryl-functional samples exhibit monomodal molecular weight distributions with Mw/Mn in the range of 1.16 to 1.43 and molecular weights (Mn) between 2300 and 4300 g mol(-1). Thermal properties reflect the amorphous structure of the polymers. Both post-functionalization and cross-linking are performed via Diels-Alder chemistry using maleimide derivatives, leading to reversible network formation. This transformation is shown to be thermally reversible at 110 °C.

  3. 40 CFR 721.6181 - Fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl ether...

    Science.gov (United States)

    2010-07-01

    ... substituted oxirane, formaldehyde-phenol polymer glycidyl ether, substituted proplyamine and...-phenol polymer glycidyl ether, substituted proplyamine and polyethylenepolyamines (generic). (a) Chemical... as fatty acid, reaction product with substituted oxirane, formaldehyde-phenol polymer glycidyl...

  4. SYNTHESIS OF ALLYL PHENYL ETHER AND CLAISEN REARRANGEMENT

    Directory of Open Access Journals (Sweden)

    Gagik Torosyan

    2011-12-01

    Full Text Available It has been established the possibility for phenol allylation on natural zeolites and them analogs. Here is demonstrated the synthesis of allyl phenol, which has wide industrial applications. The offered method in comparison with the traditional methods has more advantages – higher selectivity, smaller material and power resources consumption. It has been obtained the mixture of allylating phenols (30% in general with allyl phenyl ether (1 with 80% yields. At 600 K is obtained allylphenyl ether, at 700 K beginning the formation of allyl phenols, which is the result of direct C-allylation of the aromatic ring. It has been investigated the possibility of Claisen rearrangement in the same conditions. All of that are established by gas-liquid chromatography and liquid chromatography data.

  5. Propargyl-functional aliphatic polycarbonate obtained from carbon dioxide and glycidyl propargyl ether.

    Science.gov (United States)

    Hilf, Jeannette; Frey, Holger

    2013-09-01

    The synthesis of propargyl-functional poly(carbonate)s with different content of glycidyl propargyl ether (GPE) units is achieved via the copolymerization of propargyl glycidyl ether and carbon dioxide. A new type of functional poly(carbonate) synthesized directly from CO(2) and the glycidyl ether is obtained. The resulting polymers show moderate polydispersities in the range of 1.6-2.5 and molecular weights in the range of 7000-10 500 g mol(-1). The synthesized copolymers with varying number of alkyne functionalities and benzyl azide are used for the copper-catalyzed Huisgen-1,3-dipolar addition. Moreover, the presence of vicinal alkyne groups opens a general pathway to produce functional aliphatic poly(carbonate)s from a single polymer scaffold.

  6. A convenient procedure for the synthesis of allyl and benzyl ethers from alcohols and phenols

    Indian Academy of Sciences (India)

    H Surya Prakash Rao; S P Senthilkumar

    2001-06-01

    Allyl and benzyl ethers of alcohols can be prepared conveniently and in high yield with allyl and benzyl bromide in the presence of solid potassium hydroxide without use of any solvent. Phenols can be converted to allyl ethers but are inert to benzylation under above conditions.

  7. 40 CFR 721.7000 - Polymer of disodium maleate, allyl ether, and ethylene oxide.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Polymer of disodium maleate, allyl... New Uses for Specific Chemical Substances § 721.7000 Polymer of disodium maleate, allyl ether, and... substance identified generically as a polymer of disodium maleate, allyl ether, and ethylene oxide...

  8. Synthesis and application of polyepoxide cardanol glycidyl ether as biobased polyepoxide reactive diluent for epoxy resin

    Science.gov (United States)

    Polyepoxide cardanol glycidyl ether (PECGE), a novel cardanol derivative, was synthesized and used as reactive diluent for petroleum-based epoxy resin in this work. The synthetic condition was first optimized, and the resultant PECGE diluent was characterized using Fourier transform infrared spectro...

  9. Biocatalytic resolution of benzyl glycidyl ether and its derivates by Talaromyces flavus: effect of phenyl ring substituents on enantioselectivity.

    Science.gov (United States)

    Wei, Chun; Chen, Yunyun; Shen, Honglei; Wang, Shan; Chen, Lin; Zhu, Qing

    2012-08-01

    Talaromyces flavus containing a constitutive epoxide hydrolase (EH) resolved racemic benzyl glycidyl ether and nine derivatives into their (R)-enantiomers. After optimization of the fermentation conditions, the specific EH activity and biomass concentration were improved from 13.5 U/g DCW and 14.8 g DCW/l to 26.2 U/g DCW and 31.3 g DCW/l, respectively, with final values for e.e. ( s ) of 96 % and E of 13 with (R)-benzyl glycidyl ether. Substituents on the phenyl ring, however, gave low enantioselectivities.

  10. Enantioselective Hydrolysis of Phenyl Glycidyl Ether Catalyzed by Newly Isolated Bacillus Megaterium ECU1001

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    @@Microbial epoxide hydrolases from bacterial and fungal sources?1? are hi ghly versatile catalysts for the asymmetric hydrolysis of chiral epoxides which are extensively employed as useful building blocks for the synthesis of various biologically active products in the pharmaceutical and agrochemical industries. Microorganism means allows an unlimited supply of these enzymes for preparative -scale applications. Phenyl glycidyl ether (PGE), an aryl epoxide, is a potenti ally useful compound in the synthesis of chiral amino alcohols and bioactive com pounds such as ?blockers. No suitable biocatalyst with sufficiently high enan tioselectivity (E?20) for the kinetic resolution of this compound was previ ously found among bacteria and fungi. This prompted us to screen epoxide hydrola se-producing microorganisms with higher enantioselectivity toward phenyl glycid yl ether from soil samples.

  11. Gold-catalyzed intermolecular coupling of sulfonylacetylene with allyl ethers: [3,3]- and [1,3]-rearrangements

    Directory of Open Access Journals (Sweden)

    Jungho Jun

    2013-08-01

    Full Text Available Gold-catalyzed intermolecular couplings of sulfonylacetylenes with allyl ethers are reported. A cooperative polarization of alkynes both by a gold catalyst and a sulfonyl substituent resulted in an efficient intermolecular tandem carboalkoxylation. Reactions of linear allyl ethers are consistent with the [3,3]-sigmatropic rearrangement mechanism, while those of branched allyl ethers provided [3,3]- and [1,3]-rearrangement products through the formation of a tight ion–dipole pair.

  12. Unusual selectivity-determining factors in the phosphine-free Heck arylation of allyl ethers

    DEFF Research Database (Denmark)

    Ambrogio, I.; Fabrizi, G.; Cacchi, S.

    2008-01-01

    The Heck reaction of aryl iodides and bromides with allyl ethers has been investigated. Using phosphinefree Pd(OAc)(2) in DNIF at 90 degrees C in the presence of Bu4NOAc, the reaction gave cinnamyl derivatives, usually in good to high yields, with a wide range of aryl halides. The reaction tolera...

  13. Preparation and solution behavior of a thermoresponsive diblock copolymer of poly(ethyl glycidyl ether) and poly(ethylene oxide).

    Science.gov (United States)

    Ogura, Michihiro; Tokuda, Hiroyuki; Imabayashi, Shin-ichiro; Watanabe, Masayoshi

    2007-08-28

    A thermoresponsive diblock copolymer, poly(ethyl glycidyl ether)-block-poly(ethylene oxide) (PEGE-b-PEO), is synthesized by successive anionic ring-opening polymerization of ethyl glycidyl ether and ethylene oxide using 2-phenoxyethanol as a starting material, and its solution behavior is elucidated in water. In a dilute 1 wt % solution, the temperature-dependent alteration in the polymer hydrodynamic radius (RH) is measured in the temperature range between 5 and 45 degrees C by pulse-gradient spin-echo NMR and dynamic light scattering. The RH value increased with temperature in two steps, where the first step at 15 degrees C corresponds to the core-shell micelle formation and the second step at 40 degrees C corresponds to the aggregation of the core-shell micelles. The formation of the core-shell micelles is supported by the solubilization of a dye (1,6-diphenyl-1,3,5-hexatriene) in the hydrophobic core, which is recognized for a copolymer solution in the temperature range between 20 and 40 degrees C. In this temperature range, the core-shell micelles and the unimers coexist and the fraction of the former gradually increases with increasing temperature, suggesting equilibrium between the micelles and the unimers. In the concentrated regime (40 wt % solution), the solution forms a gel and the small-angle X-ray scattering measurements reveal the successive formation of hexagonal and lamellar liquid crystal phases with increasing temperature.

  14. Synthesis of Aryl Allyl Ether in the Recyclable Ionic Liquid [bmim]PF6

    Institute of Scientific and Technical Information of China (English)

    Zhou Mei-Yun; Li Yi-Qun; Xu Xin-Ming

    2004-01-01

    Ionic liquids, especially imidazonium salts, have recently gained recognition as possible environmentally benign alternative chemical process solvents. This is mainly due to their nonvolatile nature, insolubility in some solvents as well as their ability to dissolve a wide range of organic and inorganic materials, allowing the ionic liquids easy recovery and recycling. Examples of their application in organic reactions have been summarized in a number of recent review articles.1Aryl allyl ether is very useful intermediate in organic synthesis. The Williamson reaction is a well knows method for the preparation ethers. However, the reaction of alkylating agents with the phenoxide ions was conventionally carried out in the organic solvents. The usual solvents for this type of reaction are DCM, 2 DMSO, 3 DMF, 4 CH3CN5 etc. With the current desire to avoid the use of organic molecular solvents in organic synthesis, we decide to investigate the use of the ionic liquid for the alternative solvent for the Williamson reaction to prepare the aryl allyl ethers. The ionic liquid employed here was the moisture stable 1-butyl-3-methylimidazolium hexafluorophosphate [bmim]PF6.6 The ionic liquid is non-volatile, thermally stable, and depending on the anion, can present low immiscible with water,alkanes and dialky ethers. We have now found that aryl allyl ethers can have been obtained from various phenols and allyl bromide in the presence of potassium hydroxide in [bmim]PF6 as a replacement for classical organic solvents in the ambient temperature. The results are shown in Scheme 1.The reaction were carried out by simple mixing the phenolwith the ally bromide and potassium hydroxide in [bmim]PF6 and stirred at room temperature for 4h. The results are summarized in Table 1.In conclusion, Williamson reaction can be successfully conducted in ionic liquid [bmim]PF6 with a number of advantages: the procedure is simple, the reaction condition is mild and the yields are excellent

  15. Oxidation-Responsive and "Clickable" Poly(ethylene glycol) via Copolymerization of 2-(Methylthio)ethyl Glycidyl Ether.

    Science.gov (United States)

    Herzberger, Jana; Fischer, Karl; Leibig, Daniel; Bros, Matthias; Thiermann, Raphael; Frey, Holger

    2016-07-27

    Poly(ethylene glycol) (PEG) is a widely used biocompatible polymer. We describe a novel epoxide monomer with methyl-thioether moiety, 2-(methylthio)ethyl glycidyl ether (MTEGE), which enables the synthesis of well-defined thioether-functional poly(ethylene glycol). Random and block mPEG-b-PMTEGE copolymers (Mw/Mn = 1.05-1.17) were obtained via anionic ring opening polymerization (AROP) with molecular weights ranging from 5 600 to 12 000 g·mol(-1). The statistical copolymerization of MTEGE with ethylene oxide results in a random microstructure (rEO = 0.92 ± 0.02 and rMTEG E = 1.06 ± 0.02), which was confirmed by in situ (1)H NMR kinetic studies. The random copolymers are thermoresponsive in aqueous solution, with a wide range of tunable transition temperatures of 88 to 28 °C. In contrast, mPEG-b-PMTEGE block copolymers formed well-defined micelles (Rh ≈ 9-15 nm) in water, studied by detailed light scattering (DLS and SLS). Intriguingly, the thioether moieties of MTEGE can be selectively oxidized into sulfoxide units, leading to full disassembly of the micelles, as confirmed by detection of pure unimers (DLS and SLS). Oxidation-responsive release of encapsulated Nile Red demonstrates the potential of these micelles as redox-responsive nanocarriers. MTT assays showed only minor effects of the thioethers and their oxidized derivatives on the cellular metabolism of WEHI-164 and HEK-293T cell lines (1-1000 μg·mL(-1)). Further, sulfonium PEG polyelectrolytes can be obtained via alkylation or alkoxylation of MTEGE, providing access to a large variety of functional groups at the charged sulfur atom.

  16. THE SYNTHESIS OF A—B BLOCK COPOLYMER OF STYRENE WITH β—CHLORO ETHYL GLYCIDYL ETHER BY ONE STEP METHOD

    Institute of Scientific and Technical Information of China (English)

    WangHongzuo; LiuZhilan; 等

    1997-01-01

    The A-B block copolymer of 0634-chloroethyl glycidyl ether with styrene can be got by the easy method of one-step polymerization.The structure of A-B block copolymer was confirmed by the elementary analysis,turbidity titration,molecular weight measurement,IR-spectra,13C-NMR,1H-NMR and DTA investigation of the products.Also,the effects of solvents,reaction time and temperature on the composition,Mn and yield of copolymer have been studied.

  17. Poly(glycidyl ether)-Based Monolayers on Gold Surfaces: Control of Grafting Density and Chain Conformation by Grafting Procedure, Surface Anchor, and Molecular Weight.

    Science.gov (United States)

    Heinen, Silke; Weinhart, Marie

    2017-03-07

    For a meaningful correlation of surface coatings with their respective biological response reproducible coating procedures, well-defined surface coatings, and thorough surface characterization with respect to layer thickness and grafting density are indispensable. The same applies to polymeric monolayer coatings which are intended to be used for, e.g., fundamental studies on the volume phase transition of surface end-tethered thermoresponsive polymer chains. Planar gold surfaces are frequently used as model substrates, since they allow a variety of straightforward surface characterization methods. Herein we present reproducible grafting-to procedures performed with thermoresponsive poly(glycidyl ether) copolymers composed of glycidyl methyl ether (GME) and ethyl glycidyl ether (EGE). The copolymers feature different molecular weights (2 kDa, 9 kDa, 24 kDa) and are equipped with varying sulfur-containing anchor groups in order to achieve adjustable grafting densities on gold surfaces and hence control the tethered polymers' chain conformation. We determined "wet" and "dry" thicknesses of these coatings by QCM-D and ellipsometry measurements and deduced anchor distances and degrees of chain overlap of the polymer chains assembled on gold. Grafting under cloud point conditions allowed for higher degrees of chain overlap compared to grafting from a good solvent like ethanol, independent of the used sulfur-containing anchor group for polymers with low (2 kDa) and medium (9 kDa) molecular weights. By contrast, the achieved grafting densities and thus chain overlaps of surface-tethered polymers with high (24 kDa) molecular weights were identical for both grafting methods. Monolayers prepared from an ethanolic solution of poly(glycidyl ether)s equipped with sterically demanding disulfide-containing anchors revealed the lowest degrees of chain overlap. The ratio of the radius of gyration to the anchor distance (2 Rg/l) of the latter coating was found to be lower than 1

  18. 蓖麻油缩水甘油醚合成工艺研究%Synthesis Process of Castor Oil Glycidyl Ether

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    Using castor oil and epoxy chloropropane( ECH) as the main raw materials under the alkali condition, a novel castor oil glycidyl ether ( COGE) was synthesized through two steps, namely open loop and closed loop reaction. The effects of process conditions on epoxy values were investigated. The results showed that the highest epoxy value the product achieved was 1. 56 mmol/g under the condition that the open loop reaction was set at 0. 4% catalyst dosage,3. 5 molar ratio of ECH and castor oil, and reaction temperature at 60 ℃ for 5 h, and as well as the close-loop reaction was set 0. 4% catalyst dosage, 1. 1 molar ratio of NaOH and ECH, and reaction temperature at 60 ℃ for 6 h. The chemical structure of the castor oil glycidyl ether was characterized by FT-IR and 1H NMR. TGA analysis showed that castor oil glycidyl ether had good thermal stability at high temperature. Viscosity test showed that the product could reduce the viscosity of epoxy resin.%以蓖麻油、环氧氯丙烷( ECH)和液碱为主要原料,经二步法开环闭环反应合成了蓖麻油缩水甘油醚( COGE),研究了开环、闭环工艺条件对产物环氧值的影响。结果表明,开环催化剂三氟化硼-二乙基醚用量0.4%,ECH与蓖麻油的物质的量比3.5∶1,反应温度60℃,反应时间5 h;闭环催化剂四甲基氯化铵用量0.4%,反应时间6 h,反应温度60℃,NaOH与ECH物质的量比1.1∶1时产物环氧值最高为1.56 mmol/g。采用红外光谱(FT-IR)、核磁共振氢谱(1H NMR)表征了合成产物的化学结构,热失重(TG)分析表明蓖麻油缩水甘油醚具有优良的高温热稳定性,黏度测试表明该产物可以降低环氧树脂的黏度,加入量15%时,黏度降低46%。

  19. Synthesis of Oxacyclic Scaffolds via Dual Ruthenium Hydride/Brønsted Acid‐Catalyzed Isomerization/Cyclization of Allylic Ethers

    DEFF Research Database (Denmark)

    Ascic, Erhad; Ohm, Ragnhild Gaard; Petersen, Rico;

    2014-01-01

    A ruthenium hydride/Brønsted acid‐catalyzed tandem sequence is reported for the synthesis of 1,3,4,9‐tetrahydropyrano[3,4‐b]indoles (THPIs) and related oxacyclic scaffolds. The process was designed on the premise that readily available allylic ethers would undergo sequential isomerization, first ...

  20. Enhancement in Mode II Interlaminar Fracture Toughness at Cryogenic Temperature of Glass Fiber/Epoxy Composites through Matrix Modification by Carbon Nanotubes and n-Butyl Glycidyl Ether

    Directory of Open Access Journals (Sweden)

    Yu Liu

    2015-01-01

    Full Text Available A typical diglycidyl ether of bisphenol-F (DGEBF/diethyl toluene diamine (DETD epoxy system modified by multiwalled carbon nanotubes (MWCNTs and a reactive aliphatic diluent named n-butyl glycidyl ether (BGE was used as the matrix for glass fiber composites. The glass fiber (GF reinforced composites based on the unmodified and modified epoxy matrices were prepared by the hand lay-up hot-press process. Mode II interlaminar fracture toughness at both room temperature (RT and cryogenic temperature (77 K of the GF reinforced epoxy composites was investigated to examine the effect of the matrix modification. The result showed that the introduction of MWCNTs and BGE at their previously reported optimal contents led to the remarkable enhancement in mode II interlaminar fracture toughness of the composites. Namely, the 22.9% enhancement at RT and the 31.4% enhancement at 77 K were observed for mode II interlaminar fracture toughness of the fiber composite based on the optimally modified epoxy matrix by MWCNTs and BGE compared to the unmodified case.

  1. The utilization of the mesoporous Ti-SBA-15 catalyst in the epoxidation of allyl alcohol to glycidol and diglycidyl ether in the water medium

    Directory of Open Access Journals (Sweden)

    Wróblewska Agnieszka

    2015-12-01

    Full Text Available This work presents the studies on the optimization the process of allyl alcohol epoxidation over the Ti-SBA-15 catalyst. The optimization was carried out in an aqueous medium, wherein water was introduced into the reaction medium with an oxidizing agent (30 wt% aqueous solution of hydrogen peroxide and it was formed in the reaction medium during the processes. The main investigated technological parameters were: the temperature, the molar ratio of allyl alcohol/hydrogen peroxide, the catalyst content and the reaction time. The main functions the process were: the selectivity of transformation to glycidol in relation to allyl alcohol consumed, the selectivity of transformation to diglycidyl ether in relation to allyl alcohol consumed, the conversion of allyl alcohol and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The analysis of the layer drawings showed that in water solution it is best to conduct allyl alcohol epoxidation in direction of glycidol (selectivity of glycidol 54 mol% at: the temperature of 10–17°C, the molar ratio of reactants 0.5–1.9, the catalyst content 2.9–4.0 wt%, the reaction time 2.7–3.0 h and in direction of diglycidyl ether (selectivity of diglycidyl ether 16 mol% at: the temperature of 18–33°C, the molar ratio of reactants 0.9–1.65, the catalyst content 2.0–3.4 wt%, the reaction time 1.7–2.6 h. The presented method allows to obtain two very valuable intermediates for the organic industry.

  2. Green synthesis of allyl isobornyl ether%烯丙基异冰片基醚绿色合成研究

    Institute of Scientific and Technical Information of China (English)

    王士康; 徐徐; 兰蓝; 樊媛媛; 王石发

    2012-01-01

    以莰烯和烯丙醇为原料,研究了烯丙基异冰片基醚的绿色合成工艺,探讨了催化剂种类及用量、反应温度、反应时间,以及烯丙醇与莰烯物质的量之比对莰烯醚化反应选择性及烯丙基异冰片基醚产物得率的影响.采用正交试验方法确定了烯丙基异冰片基醚的最适工艺条件:A-15型阳离子树脂为催化剂,催化剂用量为烯丙醇和莰烯原料总质量的5%,烯丙醇与莰烯物质的量之比为1.5:1,反应温度75℃,反应时间7h.在此条件下工业莰烯转化率为85.5%,反应选择性为97.5%,烯丙基异冰片基醚得率为83.4%.最后采用GC-MS、IR等分析技术对合成所得产物的结构进行了分析测定.%Green synthetic method of allyl isobornyl ether was investigated by using camphene and allyl alcohol as the raw materials in this paper. Influence of catalysts and their usages, reaction temperature, reaction time, and the molar ratio of allyl alcohol to camphene on the selectivity of etherification and the yield of allyl isobornyl ether were examined, and the optimum synthesis conditions were determined based on the orthogonal test results as follows: A-15 resin was used as the catalyst for etherification, and the amount of A-15 cationic exchange resin was 5 % (based on the total weight of camphene and allyl alcohol) ; molar ratio of allyl alcohol to camphene was 1. 5-1; reaction temperature and reaction time were 75 ℃ and 7 h, respectively. The conversion ratio of camphene and the reaction selectivity reached 85. 5 % and 97. 5 % respectively, and the yield of allyl isobornyl ether also reached 83. 4 %. The structure of allyl isobornyl ether was identified by GC-MS and IR spectra.

  3. Impact of a heteroatom in a structure-activity relationship study on analogues of phenyl glycidyl ether (PGE) from epoxy resin systems.

    Science.gov (United States)

    Niklasson, Ida B; Delaine, Tamara; Luthman, Kristina; Karlberg, Ann-Therese

    2011-04-18

    Epoxy resins are among the most common causes of occupational contact dermatitis. They are normally used in so-called epoxy resin systems (ERS). These commercial products are combinations of epoxy resins, curing agents, modifiers, and reactive diluents. The most frequently used resins are diglycidyl ethers based on bisphenol A (DGEBA) and bisphenol F (DGEBF). In this study, we have investigated the contact allergenic properties of a series of analogues to the reactive diluent phenyl glycidyl ether (PGE), all with similar basic structures but with varying heteroatoms or with no heteroatom present. The chemical reactivity of the compounds in the test series toward the hexapeptide H-Pro-His-Cys-Lys-Arg-Met-OH was investigated. All epoxides were shown to bind covalently to both cysteine and proline residues. The percent depletion of nonreacted peptide was also studied resulting in ca. 60% depletion when using either PGE, phenyl 2,3-epoxypropyl sulfide (2), or N-(2,3-epoxypropyl)aniline (3), and only 15% when using 1,2-epoxy-4-phenylbutane (4) at the same time point. The skin sensitization potencies of the epoxides using the murine local lymph node assay (LLNA) were evaluated in relation to the observed physicochemical and reactivity properties. To enable determination of statistical significance between structurally closely related compounds, a nonpooled LLNA was performed. It was found that all investigated compounds containing a heteroatom in the α-position to the epoxide were strong sensitizers, congruent with the reactivity data, indicating that the impact of a heteroatom is crucial for the sensitizing capacity for this type of epoxides.

  4. Preparation and properties of cardanol glycidyl ether%腰果酚基缩水甘油醚的制备及其性能研究

    Institute of Scientific and Technical Information of China (English)

    张俊珩; 闪洁; 秦小玉; 赵婷婷

    2015-01-01

    Reports on the synthesis of cardanol glycidyl ether( CGE )and the hybrid composite of CGE and diglycidyl ether of bisphenol-A( DGEBA). Studied was shown that,the mechanical performance of the CGE/DGEBA blends had maximum with the increase of CGE content. The tensile strength,flexural strength and impact strength of the cured system with 15% CGE can be enhanced respectively about 35 . 4%,43 . 3% and 109 . 5%. The toughness mechanism is the micro-phase separation during curing and sea-island microstructure appearing on the fractured surface.%以腰果酚、环氧氯丙烷为主要原料,制备腰果酚基缩水甘油醚( CGE ),并研究 CGE/双酚 A型环氧树脂( DGEBA)固化物的性能。研究表明,在CGE用量达15%时,环氧树脂固化物的机械性能达到最大值。与纯DGEBA的性能相比,复合材料的拉伸强度、弯曲强度、冲击强度分别提高了35.4%,43.3%和109.5%。随着CGE含量的增加,材料的玻璃化转变温度降低。固化微观相分离和断面出现“海岛”结构是腰果酚基缩水甘油醚的增韧机理。

  5. Novel Finding of Widespread Occurrence and Accumulation of Bisphenol A Diglycidyl Ethers (BADGEs) and Novolac Glycidyl Ethers (NOGEs) in Marine Mammals from the United States Coastal Waters.

    Science.gov (United States)

    Xue, Jingchuan; Kannan, Kurunthachalam

    2016-02-16

    Bisphenol A diglycidyl ether (BADGE)- and bisphenol F diglycidyl ether (BFDGE)-based epoxy resins have a broad range of applications, including serving as inner coatings of food and beverage cans and as protective coatings in marine construction. Prior to this study, no studies had examined the occurrence and bioaccumulation of BADGEs or BFDGEs in aquatic organisms. In this study, BADGE, BFDGE, and nine of their derivatives were determined in 121 tissue (liver, kidney, blubber, and brain) samples from eight species of marine mammals collected from the U.S. coastal waters of Florida, California, Washington, and Alaska. BADGE·2HCl was the predominant compound found in the majority (78.5%) of the marine mammal tissues analyzed, at concentrations of up to 2950 ng/g (wet weight (wt)) found in the liver of a sea otter from Kachemak Bay, Alaska. The measured concentrations of BADGE·2HCl in marine mammals were on the order of hundreds of nanograms per gram tissue, which are some of the highest concentrations ever reported for this compound in biota. Males contained greater concentrations of BADGE·2HCl than did females. BADGE·2HCl also was found in the brain tissues of sea otters. Trace levels of BADGE·2HCl were found in the livers of polar bears from Alaska, which suggested that BADGEs are widely distributed in the oceanic environment.

  6. Regio- and Stereospecific Formation of Protected Allylic Alcohols via Zirconium-Mediated SN2' Substitution of Allylic Chlorides

    OpenAIRE

    Fox, Richard J; Lalic, Gojko; Bergman, Robert G.

    2007-01-01

    A new, highly regio- and stereospecific SN2' substitution reaction between a zirconium oxo complex and allylic chloride has been achieved. The resulting allylic alcohol or TBS-protected allylic ether products were isolated in good to excellent yields with a wide range of E-allylic chlorides. A mechanism for the SN2' allylic substitution consistent with kinetic, stereochemical and secondary isotope effect studies was proposed.

  7. Ruthenium Catalyzed Diastereo- and Enantioselective Coupling of Propargyl Ethers with Alcohols: Siloxy-Crotylation via Hydride Shift Enabled Conversion of Alkynes to π-Allyls

    Science.gov (United States)

    Liang, Tao; Zhang, Wandi; Chen, Te-Yu; Nguyen, Khoa D.; Krische, Michael J.

    2015-01-01

    The first enantioselective carbonyl crotylations through direct use of alkynes as chiral allylmetal equivalents are described. Chiral ruthenium(II) complexes modified by Josiphos (SL-J009-1) catalyze the C-C coupling of TIPS-protected propargyl ether 1a with primary alcohols 2a-2o to form products of carbonyl siloxy-crotylation 3a-3o, which upon silyl deprotection-reduction deliver 1,4-diols 5a-5o with excellent control of regio-, anti-diastereo- and enantioselectivity. Structurally related propargyl ethers 1b and 1c bearing ethyl- and phenyl-substituents engage in diastereo- and enantioselective coupling, as illustrated in the formation of adducts 5p and 5q, respectively. Selective mono-tosylation of diols 5a, 5c, 5e, 5f, 5k and 5m is accompanied by spontaneous cyclization to deliver the trans-2,3-disubstituted furans 6a, 6c, 6e, 6f, 6k and 6m, respectively. Primary alcohols 2a, 2l and 2p were converted to the siloxy-crotylation products 3a, 3l and 3p, which upon silyl deprotection-lactol oxidation were transformed to the trans-4,5-disubstituted γ-butyrolactones 7a, 7l and 7p. The formation of 7p represents a total synthesis of (+)-trans-whisky lactone. Unlike closely related ruthenium catalyzed alkyne-alcohol C-C couplings, deuterium labeling studies provide clear evidence of a novel 1,2-hydride shift mechanism that converts metal-bound alkynes to π-allyls in the absence of intervening allenes. PMID:26418572

  8. 烯丙基-联苯醚的合成及其共聚合%Synthesis of allyl biphenyl ether and its copolymerization

    Institute of Scientific and Technical Information of China (English)

    赵梦奇; 田玉川; 司马义·努尔拉

    2012-01-01

    采用相转移催化法合成了一种新型的非离子型疏水单体烯丙基-联苯醚(ABE),通过傅里叶变换红外光谱、核磁共振氢谱等表征了单体的结构,并分别用乳液法和溶液法合成了ABE-丙烯酰胺(AM)-丙烯酸(AA)三元共聚物.溶液法合成的共聚物为细小颗粒,平均粒径为900 nm左右,比表面积为14.93 m2/g,水溶性较差;而乳液法制备的共聚物水溶性较好,特性黏数大,达37.69 dL/g,耐热性能优良.%A novel non-ionic hydrophobic monomer, allyl biphenyl ether (ABE), was synthesized via phase-transfer catalysis. The monomer's structure was characterized by Fourier transform infrared spectroscopy (FTIR) and hydrogen nuclear magnetic resonance (1H-NMR). A terpolymer was prepared from ABE, acrylic acid and acrylamide through emulsion polymerization and solution polymerization, respectively. The terpolymer synthesized with solution polymerization process took the shape of tiny particles that possessed average size of about 900 nm and specific surface area of 14.93 m2/g. The terpolymer exhibited inferior solubility in water. In contrast, the terpolymer prepared with emulsion polymerization process had good solubility in water, high intrinsic viscosity of 37.69 Dl/g and superior thermal stability.

  9. Application of nitrate ester of cellulose glycidyl ether in propellant%纤维素甘油醚硝酸酯在双基推进剂中的应用

    Institute of Scientific and Technical Information of China (English)

    袁荃; 邵自强; 张有德

    2012-01-01

    Nitrate ester of cellulose glycidyl ether ( NGEC) is one kind of modified nitrocelluloses. The NCEC-modified double-base propellants were prepared by using traditional solvent-free method. The properties of NGEC modified double base propellant including mechanical, combustion, ballistic and combustion wave structure were investigated. The results show that NGEC has good thermoplastic and NGEC modified double base propellant exhibits a better processing property. Compared with NC-based propellant, NGEC modified double base propellant possesses 1. 5 times higher elongation at low temperature ( - 40 ℃) , stable ballistic performance and similar combustion properties and combustion waves structure. So, as an energetic thermoplastic binder instead of NC, NGEC can be used in new modified double base propellant research.%纤维素甘油醚硝酸酯NGEC是一种改性硝化棉,以NGEC为粘合剂代替NC,采用传统的无溶剂法制备了NGEC基改性双基推进剂.研究了以NGEC为粘合剂的改性双基推进剂的力学、燃烧和弹道性能及燃烧波结构.结果表明,NGEC具有较好的热塑性,NGEC基改性双基推进剂加工性能优良,其低温-40℃延伸率可达相同配方NC基改性双基推进剂的1.5倍以上,其推进剂弹道性能稳定,燃烧性能和燃烧波结构与NC基推进剂相似.因此,NGEC作为含能粘合剂代替NC,可用于改善改性双基推进剂性能的研究.

  10. 含烯丙基侧基聚芳醚酮的制备及其表征%Preparation and Characterization of Poly ether ketone with Allyl Side Group

    Institute of Scientific and Technical Information of China (English)

    曹建伟; 王志鹏; 王红华; 周光远; 李存峰; 崔善子

    2012-01-01

    A novel type of poly(aryl ether ketone) bearing pendant allyl group (PEK-L-A) was prepared, first by SN2 nucleophilic polycondensation from phenolphthalin and 4,4'-difluorobenzophenone to prepare polyaryletherketone bearing pendant carboxyl group (PEK-L), followed by esterfication reaction with 2-hydroxyethyl acrylate (HEA). The ratio of allyl side group could be controlled by altering the amount of HEA. The structure and properties of PEK I. A were characterized and tested by FT-IR, 1H-NMR, DSC etc. Results showed that the heat resistant temperature of coating layer with PEK L-A as matrix resin after UV curing was up to 300 ℃, and impact strength higher than 100 kg · cm.%通过酚酞啉和二氟二苯酮的SN2亲核缩聚反应合成侧链含有羧基的聚芳醚酮(PEKL),再经与丙烯酸羟乙酯(HEA)的酯化反应得到了含有烯丙基侧基的聚芳醚酮树脂(PEK—L-A),通过改变反应物单体的加入量可调整烯丙基的接枝率。用FT—IR、^1H—NMR、DSC等手段表征和测试了聚合产物的结构与性能。结果表明:以该功能性聚芳醚酮为基体树脂配制的溶液涂层经紫外光固化后其涂层的耐热温度可达300℃,冲击强度高于100kg·cm。

  11. Synthesis and Solution Properties of a Sulfonated Allyl Biphenyl Ether-Acrylamide-Acrylic Acid Terpolymer%新型磺化共聚物的合成及其溶液性能

    Institute of Scientific and Technical Information of China (English)

    赵梦奇; 陈德军; 吐尼沙古丽·阿吾提; 司马义·努尔拉

    2012-01-01

    A novel allyl biphenyl ether(ABE)-acrylamide(AM)-acrylic acid(AA) terpolymer was synthesized by emulsion polymerization with ABE as the hydrophobic monomer, lauryl sodium sulfate as the surfactant and azodiisobutyronitrile as the initiator. Water-soluble sulfonated terpolymers with different sulfonated degree were synthesized with concentrated sulfuric acid and oleum as the sulfonating agents. The terpolymer and sulfonated terpolymers were characterized by means of FTIR, 'H NMR and TG. The results show that the sulfonated terpolymers contain the units of ABE, AM and sulfonic groups. The influence of the sulfonic groups on the thermal stability of the sulfonated terpolymers is little. The solubility of both the terpolymer and the sulfonated terpolymers, and the properties of their solutions were studied. The results indicate that the sulfonated terpolymer with the sulphonated degree of 0.56 possesses a good tackability. The sulfonated terpolymer has obvious critical association feature and exhibits better temperature-tolerance and salt-resistance due to the introduction of ABE.%以烯丙基-联苯基醚(ABE)为疏水单体、十二烷基硫酸钠为表面活性剂、偶氮二异丁腈为引发剂,采用乳液自由基聚合法合成了ABE-丙烯酰胺(AM)-丙烯酸(AA)三元共聚物,并以浓硫酸和发烟硫酸为磺化剂对ABE-AM-AA三元共聚物进行磺化改性得到了新型磺化共聚物.采用FTIR和1H NMR方法对磺化共聚物进行了结构表征,并采用TG方法分析了它的热稳定性.表征结果显示,磺化共聚物中含有ABE、AM和磺酸基结构单元;磺酸基的引入对磺化共聚物的热稳定性影响较小.考察了磺化共聚物的溶解性及其溶液性能.实验结果表明,当磺化度为0.56时,磺化共聚物的增黏效果较好;ABE单体的引入使磺化共聚物的溶液具有明显的临界缔合特征和良好的耐温抗盐性能.

  12. 改性3-十五碳烯基苯基缩水甘油醚对三元乙丙橡胶/炭黑/白炭黑复合材料性能的影响%Effects of modified glycidyl 3-pentadecenyl phenyl ether on properties of ethylene propylene diene monomer/carbon black/silica composite

    Institute of Scientific and Technical Information of China (English)

    王舒婷; 岑兰; 龚湛林; 陈福林; 周彦豪

    2014-01-01

    A cross-linked polymer(M-GPPE) was synthesized by maleic anhydride and glycidyl 3-pen-tadecenyl phenyl ether ( GPPE) , and the structure of the obtained product was characterized.The effects of M-GPPE amount on cure characteristics , mechan-ical and dynamic mechanical properties , and filler dispersity of ethylene propylene diene monomer ( EPDM)/carbon black/silica composite were studied.The results showed that the presence of some active groups , such as anhydride group , in the molecular chain of M-GPPE resulted in higher ther-mal stability of M-GPPE than GPPE.GPPE played the role of a plasticizer in EPDM composite , thus extending curing time.The addition of 6 phr M-GPPE led to lower minimum torque , shorter scorch time and curing time as well as higher damp-ing value of the composite.The tensile strength and tear strength of the composite with 6 phr M-GPPE were increased by 35% and 8%, respectively.Transmission electron microscope analysis indicated that the dispersion of the filler in matrix was im-proved by M-GPPE, which reduced agglomeration of silica.%合成并表征了马来酸酐/3-十五碳烯基苯基缩水甘油醚(GPPE)的交联物(M-GPPE),研究了其对三元乙丙橡胶/炭黑/白炭黑复合材料硫化特性、力学性能、动态力学性能和填料分散性的影响。结果表明,M-GPPE分子链上存在酸酐等活性基团,热稳定性比GPPE高;GPEE在复合材料中主要起增塑剂作用,并且可延缓硫化时间;在复合材料中加入6份(质量) M-GPPE可使其最小转矩下降,焦烧时间和正硫化时间缩短,拉伸强度和撕裂强度分别提高35%和8%,在40~70℃具有较高的损耗值;透射电镜的分析表明M-GPPE可改善填料在基质中的分散性,减少了白炭黑的团聚。

  13. CATALYTIC ENANTIOSELECTIVE ALLYLIC OXIDATION

    NARCIS (Netherlands)

    Rispens, Minze T.; Zondervan, Charon; Feringa, Bernard

    1995-01-01

    Several chiral Cu(II)-complexes of cyclic amino acids catalyse the enantioselective allylic oxidation of cyclohexene to cyclohexenyl esters. Cyclohexenyl propionate was obtained in 86% yield with e.e.'s up to 61%.

  14. Biodegradation of Glycidol and Glycidyl Nitrate †

    OpenAIRE

    1982-01-01

    When calcium hydroxide is used to desensitize glycerol trinitrate (nitroglycerine)-containing waste streams, the epoxides glycidol and glycidyl nitrate are formed. The epoxide rings of both compounds are unstable to heat in aqueous solutions, and they open to form glycerol 1-mononitrate and presumably glycerol. These transformations were accelerated by microbial activity. Glycerol 1-mononitrate was slowly denitrated to form glycerol. Glycidol and glycidyl nitrate caused base-pair substitution...

  15. 超高效液相色谱-串联质谱法同时测定鱼、肉类罐头食品中的BADGE、NOGE及其衍生物%Determination of Bisphenol a Diglycidyl Ether (BADGE), Novolac Glycidyl Ethers(NOGE) and Its Derivatives in Canned Fish and Meat by Ultra-performance Liquid Chromatography with Tandem Mass Spectrometry

    Institute of Scientific and Technical Information of China (English)

    林赛君; 陈思; 薛鸣; 张虹

    2011-01-01

    An ultra-performance liquid chromatography with tandem mass spectrometry method for determination of bisphenol A diglycidyl ether (BADGE) , novolac glycidyl ether (NOGE) and its derivatives from canned food has been developed. The proposed method includes microwave-assisted extraction followed by puri? cation by solid phase extraction (SPE). After separation by BEH Cls ( column 100 mm ×2.1 mm, 1.7 μm), the sample was detected by API 4000 - QTRAP mass spectrometry under positive electrospray ionization mode, with acetonitrile and 0.2% aqueous formic acid as mobile phase. The detection limits were 0. 010 2 - 0. 197 2 ng/g, and recoveries at three different concentrations ranged from 65.7% to 99. 1%. This method was successfully applied to canned fish and meat, the highest total contents of 3 -6 R-NOGE reached 209.03 mg/6 dm2.%建立了一种罐头食品中的BADGE(bisphenol A diglycidyl ether,双酚A-二环氧甘油醚)、NOGE(novolac glycidyl ether,酚醛清漆甘油醚)及其衍生物含量的超高效液相色谱-串联质谱检测法。前处理包括正己烷/丙酮微波辅助萃取,Varain-PS-DVB固相萃取柱净化等。样品经BEH C18色谱柱(100mm×2.1mm,1.7μm)分离,以乙腈和0.2%甲酸水为流动相,进行梯度洗脱,在API4000-Q TRAP质谱仪电喷雾正离子、多反应监测(MRM)模式下进行检测。分析物检出限达到0.0102ng/g到0.1972ng/g,三水平加标回收率在65.7%~99.1%。

  16. 用巨大芽孢杆菌ECU1001环氧水解酶在有机—水两相系统中高效生产(S)-缩水甘油苯基醚%Efficient Production of Enantiopure (S)-Glycidyl Phenyl Ether by an Epoxide Hydrolase from Bacillus megaterium ECU1001 in an Organic-Aqueous Two-Phase System

    Institute of Scientific and Technical Information of China (English)

    宫鹏飞; 许建和

    2002-01-01

    @@ Microbial epoxide hydrolases are highly versatile catalysts for the asymmetric hydrolysis of chiral epoxides, which are extensively employed as useful building blocks for the synthesis of various biologically active products in the pharmaceutical and agrochemical industries. Glycidyl phenyl ether (GPE) is one of the potentially useful aryloxy epoxides for the synthesis of chiral amino alcohols[1] and bioactive compounds such as β-blockers[2]. In our laboratory, a strain of Bacillus megaterium ECU1001, which produces a novel epoxide hydrolase for kinetic resolution of (R,S)-GPE with high enantioselectivity, was successfully isolated from soil for the first time and proved to be useful for chiral synthesis in an aqueous phase[3,4]. However, most epoxides including GPE can be spontaneously hydrolyzed into their vicinal diols without any enantioselectivity in an aqueous phase. In addition, the instability and low solubility of epoxides in a single aqueous phase may result in a marked decrease in the yield of kinetic resolution[5], thus limiting the application of these resolution processes on an industrial scale.

  17. 40 CFR 721.2950 - Carboxylic acid glycidyl esters.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Carboxylic acid glycidyl esters. 721... Substances § 721.2950 Carboxylic acid glycidyl esters. (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substance identified generically as carboxylic acid glycidyl...

  18. Biodegradation of Glycidol and Glycidyl Nitrate †

    Science.gov (United States)

    Kaplan, David L.; Cornell, John H.; Kaplan, Arthur M.

    1982-01-01

    When calcium hydroxide is used to desensitize glycerol trinitrate (nitroglycerine)-containing waste streams, the epoxides glycidol and glycidyl nitrate are formed. The epoxide rings of both compounds are unstable to heat in aqueous solutions, and they open to form glycerol 1-mononitrate and presumably glycerol. These transformations were accelerated by microbial activity. Glycerol 1-mononitrate was slowly denitrated to form glycerol. Glycidol and glycidyl nitrate caused base-pair substitutions in the Ames test for mutagenicity, whereas glycerol 1-mononitrate tests were negative. PMID:16345917

  19. Biodegradation of glycidol and glycidyl nitrate.

    Science.gov (United States)

    Kaplan, D L; Cornell, J H; Kaplan, A M

    1982-01-01

    When calcium hydroxide is used to desensitize glycerol trinitrate (nitroglycerine)-containing waste streams, the epoxides glycidol and glycidyl nitrate are formed. The epoxide rings of both compounds are unstable to heat in aqueous solutions, and they open to form glycerol 1-mononitrate and presumably glycerol. These transformations were accelerated by microbial activity. Glycerol 1-mononitrate was slowly denitrated to form glycerol. Glycidol and glycidyl nitrate caused base-pair substitutions in the Ames test for mutagenicity, whereas glycerol 1-mononitrate tests were negative.

  20. NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUP (Ⅳ) SYNTHESIS OF NETWORK CROWN ETHER POLYMER WITH PENDANT DIETHYLAMINO THIAALKYL GROUP AND ITS PLATINUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHEN Yuanyin; MENG Lingzhi; YIN Yihua; GENG Chengai

    1994-01-01

    The title polymer was prepared from 5-diethylamino-3-thia-pentyl glycidyl ether and diethylene glycol bisglycidyl ether via ring-opening copolymerization. It was found that this reaction could be catalyzed by sodium, but not Lewis acid. The obtained polymer can coordinate with platinum compound, and the platinum complex is a new kind of catalyst for the hydrosilylation of olefins with triethoxysilane.

  1. Allyl 4-hydroxyphenyl carbonate

    Directory of Open Access Journals (Sweden)

    Víctor Hugo Flores Ahuactzin

    2009-07-01

    Full Text Available The title molecule, C10H10O4, is a functionalized carbonate used in the synthetic route to organic glasses. The central CH fragment of the allyl group is disordered over two positions, with occupancies in a 0.758 (10:0.242 (10ratio. This disorder reflects the torsional flexibility of the oxygen–allyl group, although both disordered parts present the expected anticlinal conformation, with O—CH2—CH=CH2 torsion angles of −111 (2 and 119.1 (4°. The crystal structure is based on chains parallel to [010], formed by O...H—O hydrogen bonds involving hydroxyl and carbonyl groups as donors and acceptors, respectively. The molecular packing is further stabilized by two weak C—H...π contacts from the benzene ring of the asymmetric unit with two benzene rings of neighboring molecules.

  2. NETWORK CROWN ETHER POLYMERS WITH CENTRIC FUNCTIONAL GROUPS.Ⅱ.SYNTHESIS OF NETROWK CROWN ETHER POLYMER WITH PENDANT SULFIDE SIDE CHAIN AND ITS PLATINUM COMPLEX

    Institute of Scientific and Technical Information of China (English)

    CHENYuanyin; MENGLingzhi; 等

    1995-01-01

    Network crown ether polymer with pendant sulfide side chain in the network structure units has been synthesized via ring-opening copolymerization of β-ethylthioethyl glycidyl ether and diethylene glycol bisglycidyl ether.A kind of active catalyst suitable for this reaction was suggested.The title polymer was found to be a good ligand for platinous chloride,and the platinous complex could catalyze the hydrosilylation of ole fins with triethoxysilane efficiently.

  3. A New Route to Preparations of Silyl Ethers by Reactions of Silyl Triflimides with Alcohol or Ether

    Institute of Scientific and Technical Information of China (English)

    TANG Zi-Long

    2008-01-01

    A few of acyclic and cyclic silyl ethers were firstly synthesized in good yields by reactions of silyl triflimides with alcohol or ether. The corresponding silyl triflimides were easily produced by protodesilylation of phenyl or allyl silanes with HNTf2. All new compounds were characterized by 1H NMR, 13C NMR, MS, IR and HRMS.

  4. Surprisingly Mild Enolate-Counterion-Free Pd(0)-Catalyzed Intramolecular Allylic Alkylations

    DEFF Research Database (Denmark)

    Madec, David; Prestat, Guillaume; Martini, Elisabetta;

    2005-01-01

    Palladium-catalyzed intramolecular allylic alkylations of unsaturated EWG-activated amides can take place under phase-transfer conditions or in the presence of a crown ether. These new reaction conditions are milder and higher yielding than those previously reported. A rationalization for such an...

  5. Catalytic allylation of phenols : chloride-free route towards epoxy resins

    NARCIS (Netherlands)

    Rijn, Jimmy Antonius van

    2010-01-01

    An industrially applicable process was developed for the synthesis of epoxy resin components. A catalytic reaction was explored towards allyl phenyl ethers that prevents the use of chloride-containing starting materials and thus formation of chloride-containing side products. The preferred allylatin

  6. Tsuji-Trost N-allylation with allylic acetates using cellulose-Pd catalyst

    Science.gov (United States)

    Allylic amines are synthesized using heterogeneous cellulose-Pd catalyst via N-allylation of amines; aliphatic and benzyl amines undergo facile reaction with substituted and unsubstituted allyl acetates in high yields.

  7. Chemoselective and stereoselective lithium carbenoid mediated cyclopropanation of acyclic allylic alcohols.

    Science.gov (United States)

    Durán-Peña, M J; Flores-Giubi, M E; Botubol-Ares, J M; Harwood, L M; Collado, I G; Macías-Sánchez, A J; Hernández-Galán, R

    2016-03-01

    The reaction of geraniol with different lithium carbenoids generated from n-BuLi and the corresponding dihaloalkane has been evaluated. The reaction occurs in a chemo and stereoselective manner, which is consistent with a directing effect from the oxygen of the allylic moiety. Furthermore, a set of polyenes containing allylic hydroxyl or ether groups were chemoselectively and stereoselectively converted into the corresponding gem-dimethylcyclopropanes in one single step in moderate to good yields mediated by a lithium carbenoid generated in situ by the reaction of n-BuLi and 2,2-dibromopropane.

  8. Allylation of Aromatic Aldehyde under Microwave Irradiation

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Yu-Mei; JIA,Xue-Feng; WANG,Jin-Xian

    2004-01-01

    @@ Allylation of carbonyl compounds is one of the most interesting processes for the preparation of homoallylic alcohols. Over the past few decades, many reagents have been developed for such reactions[1~3]. In this paper, we first report allylic zinc reagent 1, which can be prepared from zinc dust and allyl bromide conveniently in THF, and reacted with aromatic aldehyde to give homo-allylic alcohols under microwave irradiation.

  9. Palladium-catalyzed amination of allyl alcohols.

    Science.gov (United States)

    Ghosh, Raju; Sarkar, Amitabha

    2011-10-21

    An efficient catalytic amination of aryl-substituted allylic alcohols has been developed. The complex [(η(3)-allyl)PdCl](2) modified by a bis phosphine ligand, L, has been used as catalyst in the reaction that afforded a wide range of allyl amines in good to excellent yield under mild conditions.

  10. Allyl strontium compounds: synthesis, molecular structure and properties.

    Science.gov (United States)

    Jochmann, Phillip; Davin, Julien P; Maslek, Stefanie; Spaniol, Thomas P; Sarazin, Yann; Carpentier, Jean-Francois; Okuda, Jun

    2012-08-14

    The synthesis and attempted isolation of neutral bis(allyl)strontium [Sr(C(3)H(5))(2)] (1) resulted in the isolation of potassium tris(allyl)strontiate K[Sr(C(3)H(5))(3)] (2). In situ generated 1 shows a pronounced Brønsted basicity, inducing polymerisation of THF. Ate complex 2 crystallises as [K(THF)(2){Sr(C(3)H(5))(3)}(THF)](∞) (2·(THF)(3)). The salt-like solid state structure of 2·(THF)(3) comprises a two-dimensional network of (μ(2)-η(3):η(3)-C(3)H(5))(-) bridged potassium and strontium centres. Synthesis of allyl complexes 1 and 2 utilised SrI(2), [Sr(TMDS)(2)] (3) (TMDS = tetramethyldisilazanide), and [Sr(HMDS)(2)] (HMDS = hexamethyldisilazanide) as strontium precursors. The solid state structure of previously reported [Sr(TMDS)(2)] (3) was established by X-ray single crystal analysis as a dissymmetric dimer of [Sr(2)(TMDS)(4)(THF)(3)] (3·(THF)(3)) with multiple Si-HSr agostic interactions. The presence of ether ligands (THF, 18-crown-6) influenced the Si-HSr resonances in the NMR spectra of the amido complex 3.

  11. Multifunktionelle Polyether basierend auf Glycidol und aliphatischen Epoxiden

    OpenAIRE

    2012-01-01

    This work deals with the synthesis of defined polymers with polyethylene oxide backbone. The basic monomer is glycidol and its protected derivatives. Protected glycidols such as allyl glycidyl ether, tert.butyl glycidyl ether and especially ethoxyethyl glycidyl ether give linear polymers which can me modified chemically in a second step. The first area of research with this kind of polymers was dying of keratine fibres and cotton with pigments. In industry, dye molecules are incorporated into...

  12. 29 CFR 1910.1000 - Air contaminants.

    Science.gov (United States)

    2010-07-01

    ...-Diethylaminoethanol 100-37-8 10 50 X Diethyl ether; see Ethyl ether. Difluorodibromomethane 75-61-6 100 860 Diglycidyl... 1000 2600 Ethyl ether 60-29-7 400 1200 Ethyl formate 109-94-4 100 300 Ethyl mercaptan 75-08-1 (C)10 (C... Aldrin 309-00-2 0.25 X Allyl alcohol 107-18-6 2 5 X Allyl chloride 107-05-1 1 3 Allyl glycidyl ether...

  13. Chirality Transfer in Gold(I)-Catalysed Direct Allylic Etherifications of Unactivated Alcohols: Experimental and Computational Study.

    Science.gov (United States)

    Barker, Graeme; Johnson, David G; Young, Paul C; Macgregor, Stuart A; Lee, Ai-Lan

    2015-09-21

    Gold(I)-catalysed direct allylic etherifications have been successfully carried out with chirality transfer to yield enantioenriched, γ-substituted secondary allylic ethers. Our investigations include a full substrate-scope screen to ascertain substituent effects on the regioselectivity, stereoselectivity and efficiency of chirality transfer, as well as control experiments to elucidate the mechanistic subtleties of the chirality-transfer process. Crucially, addition of molecular sieves was found to be necessary to ensure efficient and general chirality transfer. Computational studies suggest that the efficiency of chirality transfer is linked to the aggregation of the alcohol nucleophile around the reactive π-bound Au-allylic ether complex. With a single alcohol nucleophile, a high degree of chirality transfer is predicted. However, if three alcohols are present, alternative proton transfer chain mechanisms that erode the efficiency of chirality transfer become competitive.

  14. Iridium-Catalyzed Allylic Substitution

    Science.gov (United States)

    Hartwig, John F.; Pouy, Mark J.

    Iridium-catalyzed asymmetric allylic substitution has become a valuable method to prepare products from the addition of nucleophiles at the more substituted carbon of an allyl unit. The most active and selective catalysts contain a phosphoramidite ligand possessing at least one arylethyl substituent on the nitrogen atom of the ligand. In these systems, the active catalyst is generated by a base-induced cyclometalation at the methyl group of this substituent to generate an iridium metalacycle bound by the COD ligand of the [Ir(COD)Cl]2 precursor and one additional labile dative ligand. Such complexes catalyze the reactions of linear allylic esters with alkylamines, arylamines, phenols, alcohols, imides, carbamates, ammonia, enolates and enolate equivalents, as well as typical stabilized carbon nucleophiles generated from malonates and cyanoesters. Iridium catalysts for enantioselective allylic substitution have also been generated from phosphorus ligands with substituents bound by heteroatoms, and an account of the studies of such systems, along with a description of the development of iridium catalysts is included.

  15. MOLECULAR MUTAGENESIS INDUCED BY GLYCIDYL METHACRYLATE

    Institute of Scientific and Technical Information of China (English)

    高惠兰; 左谨; 谢大英; 方福德

    1994-01-01

    Glycidyl methacrylate(GMA)is a recently recognized mutagen.In order to explore the mutagenicity and mechanism of GMA,plasmid pBR322 was used for in vitro binding,mutant screening,restriction enzyme map-ping,and DNA sequencing.To explore the mechanism by which an initial premutational event is converted into a stable heritable mutation,pBR322 and GMA-bound pBR322 were transformed into E.coli HB101,and the follow-ing results were obtainge:1)GMA-bound pBR322 induced phenotype changes in competent cells.Two stable and heritable mutants were isolated (ApRTcS and ApSTcR).2)When restriction enzyme mapping was used to analyze the mutant ApRTcS,four of seven maps showed changes,but no large DNA insertion or deletion were observed.3)The frequency of deletion and insertion forms counted about 10%.Sequence specificity and hot spot regions were evident in the sequence analysis of mutated plasmid.The above results indicate that the premutagenic lesions of plasmid induced by GMA can be converted into point mutatons in vivo.

  16. The allylic chalcogen effect in olefin metathesis

    Directory of Open Access Journals (Sweden)

    Yuya A. Lin

    2010-12-01

    Full Text Available Olefin metathesis has emerged as a powerful tool in organic synthesis. The activating effect of an allylic hydroxy group in metathesis has been known for more than 10 years, and many organic chemists have taken advantage of this positive influence for efficient synthesis of natural products. Recently, the discovery of the rate enhancement by allyl sulfides in aqueous cross-metathesis has allowed the first examples of such a reaction on proteins. This led to a new benchmark in substrate complexity for cross-metathesis and expanded the potential of olefin metathesis for other applications in chemical biology. The enhanced reactivity of allyl sulfide, along with earlier reports of a similar effect by allylic hydroxy groups, suggests that allyl chalcogens generally play an important role in modulating the rate of olefin metathesis. In this review, we discuss the effect of allylic chalcogens in olefin metathesis and highlight its most recent applications in synthetic chemistry and protein modifications.

  17. The allylic chalcogen effect in olefin metathesis

    Science.gov (United States)

    Lin, Yuya A

    2010-01-01

    Summary Olefin metathesis has emerged as a powerful tool in organic synthesis. The activating effect of an allylic hydroxy group in metathesis has been known for more than 10 years, and many organic chemists have taken advantage of this positive influence for efficient synthesis of natural products. Recently, the discovery of the rate enhancement by allyl sulfides in aqueous cross-metathesis has allowed the first examples of such a reaction on proteins. This led to a new benchmark in substrate complexity for cross-metathesis and expanded the potential of olefin metathesis for other applications in chemical biology. The enhanced reactivity of allyl sulfide, along with earlier reports of a similar effect by allylic hydroxy groups, suggests that allyl chalcogens generally play an important role in modulating the rate of olefin metathesis. In this review, we discuss the effect of allylic chalcogens in olefin metathesis and highlight its most recent applications in synthetic chemistry and protein modifications. PMID:21283554

  18. Interplay of metal-allyl and metal-metal bonding in dimolybdenum allyl complexes

    Energy Technology Data Exchange (ETDEWEB)

    John, Kevin D [Los Alamos National Laboratory; Martin, Richard L [Los Alamos National Laboratory; Obrey, Steven J [Los Alamos National Laboratory; Scott, Brian L [Los Alamos National Laboratory

    2008-01-01

    Addition of PMe{sub 3} to Mo{sub 2}(allyl){sub 4} afforded Mo{sub 2}(allyl){sub 4}(PMe{sub 3}){sub 2}, in which two of the allyl groups adopt an unprecedented {mu}{sub 2{sup -}}{eta}{sup 1}, {eta}{sup 3} bonding mode; theoretical studies elucidate the role sof the {sigma}- and {pi}-donor ligands in the interplay of metal-allyl and metal-metal bonding.

  19. Glycidyl Azide Polymer-based Enhanced Energy LOVA Gun Propellant

    OpenAIRE

    R. R. Sanghavi; P. J. Kamale; M.A.R. Shaikh; T. K. Chakraborthy; S. N. Asthana; Amarjit Singh

    2006-01-01

    In this study, cyclotrimethylene trinitramine propellants with triacetin (TA)-plasticisedcellulose acetate (CA) and nitrocellulose (NC) combination as binders were evaluated for lowvulnerable ammunition (LOVA). Triacetin was replaced by energetic plasticiser; glycidyl azidepolymer (GAP) in increments to enhance the performance in terms of force constant . In additionto ballistics, parameters like vulnerability, mechanical and thermal properties of GAP-basedpropellants in comparison to those o...

  20. Highly enantio- and diastereoselective allylic alkylation of Morita-Baylis-Hillman carbonates with allyl ketones

    KAUST Repository

    Tong, Guanghu

    2013-05-17

    The asymmetric allylic alkylation of Morita-Baylis-Hillman (MBH) carbonates with allyl ketones has been developed. The α-regioselective alkylation adducts, containing a hexa-1,5-diene framework with important synthetic value, were achieved in up to 83% yield, >99% ee, and 50:1 dr by using a commercially available Cinchona alkaloid as the catalyst. From the allylic alkylation adduct, a cyclohexene bearing two adjacent chiral centers was readily prepared. © 2013 American Chemical Society.

  1. Compound list: allyl alcohol [Open TG-GATEs

    Lifescience Database Archive (English)

    Full Text Available allyl alcohol AA 00010 ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Human/in_vitro/allyl_alcohol....Human.in_vitro.Liver.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vitro/allyl_alcohol...dbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Liver/Repeat/allyl_alcohol.Rat.in_vivo.Liver.Repeat.zip ftp:/.../ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Single/allyl_alcohol.Rat.in_vivo.Kidney....Single.zip ftp://ftp.biosciencedbc.jp/archive/open-tggates/LATEST/Rat/in_vivo/Kidney/Repeat/allyl_alcohol.Rat.in_vivo.Kidney.Repeat.zip ...

  2. A novel synthesis of 2'-hydroxy-1',3'-xylyl crown ethers

    NARCIS (Netherlands)

    Leij, van der M.; Oosterink, H.J.; Hall, R.H.; Reinhoudt, D.N.

    1981-01-01

    Six novel 2' - hydroxy - 1',3' - xylyl crown ethers (8a–e and 13)1 have been synthesized utilizing the allyl group to protect the OH function during the cyclization reaction. The macrocycles 6a-e were formed in yields of 26 to 52%, by intermolecular reaction of 4 - chloro - 2,6 - bis(bromomethyl) -

  3. Synthesis of 3-Allyl-4-phosphachromones by Cyclized Coupling of Ethyl o-Hydroxyphenyl(ethynyl)phosphinate with Allyl Bromide

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    3-Allyl-4-phosphachromones as the phosphorus analogues of chromone were firstly prepared in good yields and high regioselectivity by the palladium(Ⅱ)-catalyzed cyclized coupling reaction of ethyl o-hydroxyphenyl(ethynyl)-phosphinate with allyl bromide.

  4. Rh-Catalyzed Chemo- and Enantioselective Hydrogenation of Allylic Hydrazones.

    Science.gov (United States)

    Hu, Qiupeng; Hu, Yanhua; Liu, Yang; Zhang, Zhenfeng; Liu, Yangang; Zhang, Wanbin

    2017-01-23

    A highly efficient P-stereogenic diphosphine-rhodium complex was applied to the chemo- and enantioselective hydrogenation of allylic hydrazones for the synthesis of chiral allylic hydrazines in 89-96 % yields and with 82-99 % ee values. This methodology was successfully applied to the preparation of versatile chiral allylic amine derivatives.

  5. Elementary reaction allyl radical with oxygen

    Institute of Scientific and Technical Information of China (English)

    DONG Feng; KONG Fanao

    2003-01-01

    The elementary reaction between allyl radical with oxygen molecule wasexperimentally investigated. The allyl radical was produced via laser photolysis of C3H5Br in gaseous phase. Nascent vibrational excited products HCO, CO2, CH3CHO and HCOOH were recorded by the time- resolved Fourier transform infrared spectroscopy. The product channels of C2H5+CO2, CH3CHO+HCO, and HCOOH + C2H3 have been identified. The vibrational populations of product CO2 are obtained by spectral simulation. A mechanism forming a series of three-membered ring-struc- ture intermediates is suggested.

  6. Ethyleneglycol ethers (ethyleneglycol monomethyl ether, ethyleneglycol monomethyl ether acetate, diethyleneglycol monomethyl ether, diethyleneglycol monoethyl ether and diethyleneglycol monobutyl ether).

    NARCIS (Netherlands)

    Maclaine Pont, M.A.

    1996-01-01

    The committee recommends the following exposure limits as concentrations in air averaged over 8 hours (8 h TWA): - ethyleneglycol monomethyl ether: 1 mg/m3 (0.3 ppm) - ethyleneglycol monomethyl ether acetate: 1.5 mg/3 (0.3 ppm) - diethyleneglycol monomethyl ether: 45 mg/m3 (9 ppm) - diethyleneglycol

  7. Polystyrene-divinylbenzene-glycidyl methacrylate stationary phase grafted with poly (amidoamine) dendrimers for ion chromatography.

    Science.gov (United States)

    Guo, Dandan; Lou, Chaoyan; Zhang, Peimin; Zhang, Jiajie; Wang, Nani; Wu, Shuchao; Zhu, Yan

    2016-07-22

    In this work, a novel ion exchange stationary phase based on different generations of poly (amidoamine) dendrimers (PAMAM) was developed for the determination of inorganic anions and carbohydrates. Synthesis of the PAMAM was carried out with the polymerization reaction of ethylenediamine and methyl acrylate. The synthesized PAMAM was then grafted to the polystyrene-divinylbenzene-glycidyl methacrylate (PS-GMA) to form PAMAM-based beads. These beads were finally modified with 1,4-butanediol diglycidyl ether (BDDE) to generate the anion exchanger, which were characterized by scanning electron microscopy (SEM), brunauer-emmett-teller (BET), fourier transform infrared spectroscopy (FTIR), and elemental analysis. Elemental analysis, breakthrough curves and capacity factors showed that more epoxy groups and higher PAMAM generations in stationary phase could result in higher anion exchange capacity. The efficiency, durability and stability of the proposed anion exchanger were investigated by using six inorganic anions (fluoride, chloride, nitrite, bromide, nitrate and sulfate) and four carbohydrates (trehalose, glucose, maltotriose and galacturonic acid) as analytes, respectively. The reliability of the proposed ion chromatographic stationary phase was demonstrated by determining the content of galacturonic acid in polysaccharides from Poria cocos and Atractylodes macrocephala. The relative standard deviations of retention time, peak height, and peak area for galacturonic acid were 0.39%, 1.22%, and 2.02%, respectively. The spiked recoveries were in the range of 88.29%-100.51% for plant polysaccharides. Due to the good structural homogeneity, intense internal porosity, biological compatibility and high density of active groups in PAMAM, this grafted stationary phase showed good ion-exchange characteristics, especially in biological charged molecules.

  8. Relative oral bioavailability of glycidol from glycidyl fatty acid esters in rats.

    Science.gov (United States)

    Appel, Klaus E; Abraham, Klaus; Berger-Preiss, Edith; Hansen, Tanja; Apel, Elisabeth; Schuchardt, Sven; Vogt, Carla; Bakhiya, Nadiya; Creutzenberg, Otto; Lampen, Alfonso

    2013-09-01

    In order to quantify the relative bioavailability of glycidol from glycidyl fatty acid esters in vivo, glycidyl palmitoyl ester and glycidol were orally applied to rats in equimolar doses. The time courses of the amounts of glycidol binding to hemoglobin as well as the excretion of 2,3-dihydroxypropyl mercapturic acids were determined. The results indicate that glycidol is released from the glycidyl ester by hydrolysis and rapidly distributed in the organism. In relation to glycidol, there was only a small timely delay in the binding to hemoglobin for the glycidol moiety released from the ester which may be certainly attributed to enzymatic hydrolysis. In both cases, however, an analogous plateau was observed representing similar amounts of hemoglobin binding. With regard to the urinary excretion of mercapturic acids, also similar amounts of dihydroxypropyl mercapturic acids could be detected. In an ADME test using a virtual double tag (³H, ¹⁴C) of glycidyl palmitoyl ester, a diverging isotope distribution was detected. The kinetics of the ¹⁴C-activity reflected the kinetics of free glycidol released after hydrolysis of the palmitoyl ester. In view of this experimental data obtained in rats, it is at present justified for the purpose of risk assessment to assume complete hydrolysis of the glycidyl ester in the gastrointestinal tract. Therefore, assessment of human exposure to glycidyl fatty acid ester should be regarded as an exposure to the same molar quantity of glycidol.

  9. Pressure Dependent Product Formation in the Photochemically Initiated Allyl + Allyl Reaction

    Directory of Open Access Journals (Sweden)

    Thomas Zeuch

    2013-11-01

    Full Text Available Photochemically driven reactions involving unsaturated radicals produce a thick global layer of organic haze on Titan, Saturn’s largest moon. The allyl radical self-reaction is an example for this type of chemistry and was examined at room temperature from an experimental and kinetic modelling perspective. The experiments were performed in a static reactor with a volume of 5 L under wall free conditions. The allyl radicals were produced from laser flash photolysis of three different precursors allyl bromide (C3H5Br, allyl chloride (C3H5Cl, and 1,5-hexadiene (CH2CH(CH22CHCH2 at 193 nm. Stable products were identified by their characteristic vibrational modes and quantified using FTIR spectroscopy. In addition to the (re- combination pathway C3H5+C3H5 → C6H10 we found at low pressures around 1 mbar the highest final product yields for allene and propene for the precursor C3H5Br. A kinetic analysis indicates that the end product formation is influenced by specific reaction kinetics of photochemically activated allyl radicals. Above 10 mbar the (re- combination pathway becomes dominant. These findings exemplify the specificities of reaction kinetics involving chemically activated species, which for certain conditions cannot be simply deduced from combustion kinetics or atmospheric chemistry on Earth.

  10. Cp*Co(III)-Catalyzed Dehydrative C-H Allylation of 6-Arylpurines and Aromatic Amides Using Allyl Alcohols in Fluorinated Alcohols.

    Science.gov (United States)

    Bunno, Youka; Murakami, Nanami; Suzuki, Yudai; Kanai, Motomu; Yoshino, Tatsuhiko; Matsunaga, Shigeki

    2016-05-01

    Cp*Co(III)-catalyzed C-H allylation of various aromatic C-H bonds using allyl alcohols as allylating reagents is described. Improved reaction conditions using fluorinated alcohol solvents afforded efficient directed C-H allylation of 6-arylpurines, benzamides, and a synthetically useful Weinreb amide with good functional group compatibility.

  11. Glycidyl Azide Polymer-based Enhanced Energy LOVA Gun Propellant

    Directory of Open Access Journals (Sweden)

    R. R. Sanghavi

    2006-07-01

    Full Text Available In this study, cyclotrimethylene trinitramine propellants with triacetin (TA-plasticisedcellulose acetate (CA and nitrocellulose (NC combination as binders were evaluated for lowvulnerable ammunition (LOVA. Triacetin was replaced by energetic plasticiser; glycidyl azidepolymer (GAP in increments to enhance the performance in terms of force constant . In additionto ballistics, parameters like vulnerability, mechanical and thermal properties of GAP-basedpropellants in comparison to those of TA-based propellants, were also determined. The studybrings out that the incorporation of 2-6 per cent GAP in place of TA resulted in the enhancementof force constant by 22-70 J/g and improved overall combustion characteristics. DSC revealedthat thermal decomposition of GAP-LOVA propellants evolved more energy than TA-LOVApropellants. GAP-based LOVA propellant similar to TA-plasticised LOVA propellant, was foundsuperior to NQ propellant in vulnerability tests as well as in hot fragment conductive ignition(HFCI studies. As regards mechanical properties, incorporation of GAP resulted in improvedcompression strength.

  12. Decomposition products of glycidyl esters of fatty acids by heating.

    Science.gov (United States)

    Kimura, Wataru; Endo, Yasushi

    2017-03-01

    In this study, decomposition products of glycidyl palmitate (GP) of fatty acids heated at high temperature such as deep frying were investigated. When GP and tripalmitin (TP) were heated at 180 and 200 °C, they were decreased with heating time. The weight of GP was less than that of TP, although both GP and TP were converted to polar compounds after heating. The decomposition rate of GP was higher than TP. Both GP and TP produced considerable amounts of hydrocarbons and aldehydes during heating. Aldehydes produced from GP and TP included saturated aldehydes with carbon chain length of 3-10, while hydrocarbons consisted of carbon chain length of 8-15. It was observed that major hydrocarbons produced from GP during heating were pentadecane. Moreover, the level of carbon dioxide (CO2) released from GP was higher than that of TP. It was suggested that fatty acids in GE might be susceptible to decarboxylation. From these results, GP might be quickly decomposed to hydrocarbons, aldehydes and CO2 besides polar compounds by heating, in comparison with TP.

  13. In vivo genotoxicity assessment of acrylamide and glycidyl methacrylate.

    Science.gov (United States)

    Dobrovolsky, Vasily N; Pacheco-Martinez, M Monserrat; McDaniel, L Patrice; Pearce, Mason G; Ding, Wei

    2016-01-01

    Acrylamide (ACR) and glycidyl methacrylate (GMA) are structurally related compounds used for making polymers with various properties. Both chemicals can be present in food either as a byproduct of processing or a constituent of packaging. We performed a comprehensive evaluation of ACR and GMA genotoxicity in Fisher 344 rats using repeated gavage administrations. Clastogenicity was measured by scoring micronucleated (MN) erythrocytes from peripheral blood, DNA damage in liver, bone marrow and kidneys was measured using the Comet assay, and gene mutation was measured using the red blood cell (RBC) and reticulocyte Pig-a assay. A limited histopathology evaluation was performed in order to determine levels of cytotoxicity. Doses of up to 20 mg/kg/day of ACR and up to 250 mg/kg/day of GMA were used. ACR treatment resulted in DNA damage in the liver, but not in the bone marrow. While ACR was not a clastogen, it was a weak (equivocal) mutagen in the cells of bone marrow. GMA caused DNA damage in the cells of bone marrow, liver and kidney, and induced MN reticulocytes and Pig-a mutant RBCs in a dose-dependent manner. Collectively, our data suggest that both compounds are in vivo genotoxins, but the genotoxicity of ACR is tissue specific.

  14. Chloromethylation of Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    Poly(ether ether ketone) (PEEK) is a high-performance engineering thermoplastic with good thermal stability, high chemical resistance and excellent mechanical properties. Chloromethylation reaction is one of the classical methods to introduce functional groups into polymers, because the chloromethyl group can be converted to many functional groups, such as - CH2 (CH3) + Cl.

  15. Amination of allylic alcohols in water at room temperature.

    Science.gov (United States)

    Nishikata, Takashi; Lipshutz, Bruce H

    2009-06-04

    The "trick" to carrying out regiocontrolled aminations of allylic alcohols in water as the only medium is use of a nanomicelle's interior as the organic reaction solvent. When HCO(2)Me is present, along with the proper base and source of catalytic Pd, allylic amines are cleanly formed at room temperature.

  16. Allyl borates: a novel class of polyhomologation initiators

    KAUST Repository

    Wang, De

    2016-12-24

    Allyl borates, a new class of monofunctional polyhomologation initiators, are reported. These monofunctional initiators are less sensitive and more effective towards polymethylene-based architectures. As an example, the synthesis of α-vinyl-ω-hydroxypolymethylenes is given. By designing/synthesizing different allylic borate initiators, and using 1H and 11B NMR spectroscopy, the initiation mechanism was elucidated.

  17. Radiation and thermal polymerization of allyl(p-allylcarbonate) benzoate

    Energy Technology Data Exchange (ETDEWEB)

    Lopez-V, D., E-mail: dlopez@siu.buap.m [Facultad de Ciencias Quimicas, Benemerita Universidad Autonoma de Puebla, Antiguo Edificio de la Fac. de Cs., Quimica. Av. San Claudio y Boulevard de la 14 sur, Col. San Manuel, Puebla, Pue., CP 72500 (Mexico); Herrera-G, A.M., E-mail: mherrera@uaeh.reduaeh.m [Centro de Inv. en Materiales y Metalurgia, UAEH. Km 4.5, C.U., CP 42184, Pachuca de S. Hidalgo (Mexico); Castillo-Rojas, S., E-mail: castillo@nucleares.unam.m [Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, 04510 DF (Mexico)

    2011-03-15

    Bulk polymerization of novel allyl(p-allylcarbonate) benzoate was investigated using different sources of energy, such as gamma rays, ultraviolet rays as well as thermal polymerization. The poly(allyl(p-allylcarbonate) benzoate) obtained is a cross-linking, transparent, thermoset polycarbonate. Compositions of the monomer and the polycarbonate were analyzed by infrared spectroscopy, elemental analysis, and {sup 1}H NMR spectroscopy.

  18. [Determination of eight bisphenol diglycidyl ethers in water by solid phase extraction-high performance liquid chromatography-tandem mass spectrometry].

    Science.gov (United States)

    Zhang, Haijing; Lin, Shaobin

    2014-07-01

    A solid phase extraction coupled with high performance liquid chromatography-tandem mass spectrometry (SPE-HPLC-MS/MS) method was developed for the determination of eight bisphenol diglycidyl ethers, including bisphenol A diglycidyl ether (BADGE), bisphenol A (3-chloro-2-hydroxypropyl) glycidyl ether (BADGE x HCl), bisphenol A bis (3-chloro-2-hydroxypropyl) ether (BADGE x 2HCl), bisphenol A (2, 3-dihydroxypropyl) glycidyl ether (BADGE x H2O), bisphenol A bis(2,3-dihydroxypropyl) ether (BADGE x 2H2O), bisphenol A (3-chloro-2-hydroxypropyl) (2,3-dihydroxypropyl) ether (BADGE x HCl x H2O), bisphenol F diglycidyl ether (BFDGE) and bisphenol F bis (3-chloro-2-hydroxypropyl) ether (BFDGE 2HCl) in water. A total of ten samples were collected from the leaching of the coatings for drinking water supply system. Then, 200 mL exposure water was preconcentrated on C18 solid-phase extraction cartridge. The eight compounds were analyzed by liquid chromatography-tandem mass spectrometry method on a C18 column by the gradient elution with methanol, water and 5 mmol/L ammonium acetate as mobile phases in the multiple reaction monitoring (MRM) scan mode. The external matrix standard solutions were used for the quantitative determination and the calibration curves of the eight compounds showed good linearity in the range of 0.007-5.00 microg/L with the correlation coefficients more than 0.999 0. The limits of quantification (LOQs) of the method were 7-91 ng/L. The spiked recoveries ranged from 79.1% to 101% with the relative standard deviations of 4.0% - 12%. The method is sensitive and accurate, and is applicable to the determination of bisphenol diglycidyl ethers in water.

  19. Macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) resins-Versatile immobilization supports for biocatalysts

    NARCIS (Netherlands)

    Miletic, Nemanja; Vukovic, Zorica; Nastasovic, Aleksandra; Loos, Katja; Miletić, Nemanja; Vuković, Zorica; Nastasović, Aleksandra

    2009-01-01

    Crosslinked macroporous hydrophilic poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)s [abbreviated poly(GMA-co-EGDMA)] with identical chemical structure (60% of glycidyl methacrylate) but with varied average pore sizes (from 30 to 560 nm), specific surface areas (from 13.2 to 106.0 m(2)

  20. Gelation of photopolymerized hyaluronic acid grafted with glycidyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Prado, S.S.; Weaver, J.M.; Love, B.J., E-mail: bjlove@umich.edu

    2011-12-01

    Experiments have tracked the ambient gelation of a series of hydrophilic hyaluronic acid (HA) resins grafted with glycidyl methacrylate (GM) and photopolymerized as a function of dose. The resin mixtures range in GMHA concentration between 0.5 and 1.5% w/w in phosphate buffered saline (PBS). Illuminated at 20 mW/cm{sup 2}, the dynamic viscosity ({eta}(t)) has been tracked and characterized using the Boltzmann log-sigmoidal model. A gelled viscosity of {approx} 10 Pa s was determined at 0.5% w/w which rose to {approx} 50 Pa s at or above 1% w/w. More curing agent marginally increased the gel viscosity at each concentration. Time constants associated with viscosity advancement were shortest at [GMHA] = 1.0%; higher concentrations are attributed with lower quantum efficiency when illuminated. Subsequent frequency sweeps replicated already published work using similar GHMA concentrations in PBS. G' values ranged from 100 to 500 Pa over the formulation range with expected sensitivity to GMHA and curing agent concentration. Overall, the sigmoidal model represented this advancing viscosity data well, and further analysis of the physical significance of these model parameters may help in understanding photopolymerization of this complicated formulation more broadly. Highlights: {yields} The ambient dynamic viscosity of photopolymerized GMHA gels has been measured. {yields} 2 physical parameters and two time constants were extracted from the sigmoidal model. {yields} Higher crosslinker content for a fixed GMHA concentration led to higher gel viscosity. {yields} The time to toggle between the initial and final viscosity ranged between 5 and 10 s. {yields} Dynamic frequency sweep tests on cured gels also revealed G' values between 100 and 500 Pa.

  1. Production of microencapsulate glycidyl methacrylate with melamine formaldehyde resin shell materials

    Science.gov (United States)

    Bel, T.; Ulku, G.; Kizilcan, N.; Cimenoglu, H.; Yahya, N.; Baydogan, N.

    2016-11-01

    This study gives some information about the preparation of Glycidyl Methacrylate (GMA) microcapsules with Melamine Formaldehyde (MF) resin as a shell material (MF-GMA). Melamine formaldehyde resin containing hydroxyl groups was synthesized in the first step. Second step includes the addition of GMA monomer along with Sodium Dodecyl Benzenesulfonate (SDBS) and Polyvinyl Alcohol (PVA) aqueous solution for getting emulsible solution. The resultant MF-GMA microcapsules had good enclosing performance and thermal stability. The characteristic properties and the morphology of microencapsulated Glycidyl Methacrylate were examined by using FTIR analysis and their morphology was investigated by using optical microscope.

  2. Modification of polyethylene films by radiation grafting of glycidyl methacrylate and immobilization of {beta}-cyclodextrin

    Energy Technology Data Exchange (ETDEWEB)

    Nava-Ortiz, C.A.B. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Burillo, G. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico)], E-mail: burillo@nucleares.unam.mx; Bucio, E. [Departamento de Quimica de Radiaciones y Radioquimica, Instituto de Ciencias Nucleares, Universidad Nacional Autonoma de Mexico, Circuito Exterior, Ciudad Universitaria, Mexico DF 04510 (Mexico); Alvarez-Lorenzo, C. [Departamento de Farmacia y Tecnologia Farmaceutica, Facultad de Farmacia, Universidad de Santiago de Compostela, 15782 Santiago de Compostela (Spain)

    2009-01-15

    Glycidyl methacrylate was grafted onto polyethylene films using a preirradiation method with {gamma} rays. The effect of absorbed dose, monomer concentration, and reaction time on the degree of grafting was determined. The grafted samples were verified by FTIR-ATR spectroscopy. {beta}-Cyclodextrin was immobilized onto polypropylene modified with glycidyl methacrylate, and the ability of the cavities of {beta}-cyclodextrin to form inclusion complexes was demonstrated using the typically organic compound approach with m-toluic acid (3-MBA) as a probe.

  3. Textural properties of poly(glycidyl methacrylate) : acid-modified bentonite nanocomposites

    NARCIS (Netherlands)

    Zunic, M.; Milutinovic-Nikolic, A.; Nastasovic, A.; Vukovic, Z.; Loncarevic, D.; Vukovic, I.; Loos, K.; ten Brinke, G.; Jovanovic, D.; Sharma, Bhaskar; Ubaghs, Luc; Keul, Helmut; Höcker, Hartwig; Loontjens, Ton; Benthem, Rolf van; Žunić, M.; Milutinović-Nikolić, A.; Nastasović, A.; Vuković, Z.; Lončarević, D.; Vuković, I.; Jovanović, D.

    2013-01-01

    The aim of this study was to obtain enhanced textural properties of macroporous crosslinked copolymer poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) by synthesizing nanocomposites with acid-modified bentonite. Nanocomposites were obtained by introducing various amounts of acid-modifie

  4. Zinc Mediated Tandem Fragmentation-Allylation of Methyl 5-Iodopentofuranosides

    DEFF Research Database (Denmark)

    Hyldtoft, Lene; Madsen, Robert

    1999-01-01

    In the presence of zinc and allyl bromide methyl 5-iodopentofuranosides undergo a tandem fragmentation alkylation to give functionalized dienes. These can undergo ring-closing olefin metathesis to produce cyclohexenes which on dihydroxylation give quercitols....

  5. Chiral allylic and allenic metal reagents for organic synthesis.

    Science.gov (United States)

    Marshall, James A

    2007-10-26

    This account traces the evolution of our work on the synthesis of chiral allylic and allenic organometal compounds of tin, silicon, zinc, and indium and their application to natural product synthesis over the past quarter century.

  6. Copper-catalyzed regioselective allylic substitution reactions with indium organometallics.

    Science.gov (United States)

    Rodríguez, David; Sestelo, José Pérez; Sarandeses, Luis A

    2003-03-21

    The first nucleophilic allylic substitution reactions of triorganoindium compounds with allylic halides and phosphates are reported. The reactions of trialkyl- and triarylindium reagents with cinnamyl and geranyl halides and phosphates, with the aid of copper catalysis [Cu(OTf)(2)/P(OEt)(3)], are described. In general, the reaction proceeds efficiently to give good yields and regioselectively to afford the S(N)2' product.

  7. Platinum(0)-mediated C-O bond activation of ethers via an SN2 mechanism.

    Science.gov (United States)

    Ortuño, Manuel A; Jasim, Nasarella A; Whitwood, Adrian C; Lledós, Agustí; Perutz, Robin N

    2016-11-29

    A computational study of the C(methyl)-O bond activation of fluorinated aryl methyl ethers by a platinum(0) complex Pt(PCyp3)2 (Cyp = cyclopentyl) (N. A. Jasim, R. N. Perutz, B. Procacci and A. C. Whitwood, Chem. Commun., 2014, 50, 3914) demonstrates that the reaction proceeds via an SN2 mechanism. Nucleophilic attack of Pt(0) generates an ion pair consisting of a T-shaped platinum cation with an agostic interaction with a cyclopentyl group and a fluoroaryloxy anion. This ion-pair is converted to a 4-coordinate Pt(ii) product trans-[PtMe(OAr(F))(PCyp3)2]. Structure-reactivity correlations are fully consistent with this mechanism. The Gibbs energy of activation is calculated to be substantially higher for aryl methyl ethers without fluorine substituents and higher still for alkyl methyl ethers. These conclusions are in accord with the experimental results. Further support was obtained in an experimental study of the reaction of Pt(PCy3)2 with 2,3,5,6-tetrafluoro-4-allyloxypyridine yielding the salt of the Pt(η(3)-allyl) cation and the tetrafluoropyridinolate anion [Pt(PCy3)2(η(3)-allyl)][OC5NF4]. The calculated activation energy for this reaction is significantly lower than that for fluorinated aryl methyl ethers.

  8. Molecular Mechanics and Quantum Chemistry Based Study of Nickel-N-Allyl Urea and N-Allyl Thiourea Complexes

    Directory of Open Access Journals (Sweden)

    P. D. Sharma

    2009-01-01

    Full Text Available Eigenvalue, eigenvector and overlap matrix of nickel halide complex of N-allyl urea and N-allyl thiourea have been evaluated. Our results indicate that ligand field parameters (Dq, B’ and β evaluated earlier by electronic spectra are very close to values evaluated with the help of eigenvalues and eigenvectors. Eigenvector analysis and population analysis shows that in bonding 4s, 4p, and 3dx2-y2, 3dyz orbitals of nickel are involved but the coefficient values differ in different complexes. Out of 4px, 4py, 4pz the involvement of either 4pz or 4py, is noticeable. The theoretically evaluated positions of infrared bands indicate that N-allyl urea is coordinated to nickel through its oxygen and N-allyl thiourea is coordinated to nickel through its sulphur which is in conformity with the experimental results.

  9. Vinyl ether silicones

    Energy Technology Data Exchange (ETDEWEB)

    Herzig, C.; Dauth, J.; Deubzer, B.; Weis, J. [Wacker-Chemie GmbH, Burghausen (Germany)

    1995-12-01

    Siloxanes with vinyl ether groups are prepared by hydrosilylation reaction of dihydrosiloxanes with divinyl ethers in excess. Different stoichiometry, produces linear copolymers of different viscosities and double bond concentrations always with an active vinyl ether group at each chain end. Polymerisations triggered by UV light were done with mixtures of these compounds and a series of onium salts. Very fast cure is observed even with low doses at 290 nm. V.E. silicones are found to cure essentially quantitative. The comparison with other highly reactive cationic monomers revealed that compounds are among the fastest curing prepolymers in cationic chemistry.

  10. Catalytic oxidation of dimethyl ether

    Science.gov (United States)

    Zelenay, Piotr; Wu, Gang; Johnston, Christina M.; Li, Qing

    2016-05-10

    A composition for oxidizing dimethyl ether includes an alloy supported on carbon, the alloy being of platinum, ruthenium, and palladium. A process for oxidizing dimethyl ether involves exposing dimethyl ether to a carbon-supported alloy of platinum, ruthenium, and palladium under conditions sufficient to electrochemically oxidize the dimethyl ether.

  11. Synthesis and Characterization of Novel Aliphatic Polycarbonates Bearing Pendant Allyl Ether Groups

    Institute of Scientific and Technical Information of China (English)

    Gang LIU; Feng HE; Yan Ping WANG; Jun FENG; Ren Xi ZHUO

    2006-01-01

    A new six-membered cyclic carbonate monomer, 5-allyloxytrimethylene carbonate (ATMC), was synthesized starting from glycerol, and the corresponding polycarbonates,poly(5-allyloxytrimethylene carbonate)(PATMC) were further synthesized by ring-opening polymerization in bulk at 150 ℃ using stannous octanoate as an initiator. The structures of the monomer and the polymers were confirmed by IR, 1H-NMR, 13C-NMR, and GPC analysis.

  12. Separation of heavy metals from water by functionalized glycidyl methacrylate poly (high internal phase emulsions).

    Science.gov (United States)

    Huš, Sebastjan; Kolar, Mitja; Krajnc, Peter

    2016-03-11

    Removal of silver, lead and cadmium ions from both model solutions and real contaminated water was achieved, in a flow through manner, by using highly porous functionalized poly(glycidyl methacrylate) materials, prepared by the polymerisation of high internal phase emulsions (polyHIPE), with significant sorption differences between metals allowing for selective removal. PolyHIPEs, initially prepared from glycidyl methacrylate as a functional monomer, were functionalized with pentaerythritol tetrakis(3-mercaptopropionate), 1,9-nonanedithiol and 2-aminobenzenethiol via the epoxy ring opening on the polymer supports and applied in a flow-through manner via encasements into dedicated disk holders. Capacity of 21.7mg Ag per gram of polymer was found for 1,9-nonanedithiol functionalized polymers, while the capacity was decreasing with the decreasing ionic radius of the metal; the dynamics of sorption also depended on metal ion size and furthermore on the thiol used for the polymer functionalization.

  13. Structurally defined allyl compounds of main group metals: coordination and reactivity.

    Science.gov (United States)

    Lichtenberg, Crispin; Okuda, Jun

    2013-05-10

    Organometallic allyl compounds are important as allylation reagents in organic synthesis, as polymerization catalysts, and as volatile metal precursors in material science. Whereas the allyl chemistry of synthetically relevant transition metals such as palladium and of the lanthanoids is well-established, that of main group metals has been lagging behind. Recent progress on allyl complexes of Groups 1, 2, and 12-16 now provides a more complete picture. This is based on a fundamental understanding of metal-allyl bonding interactions in solution and in the solid state. Furthermore, reactivity trends have been rationalized and new types of allyl-specific reactivity patterns have been uncovered. Key features include 1) the exploitation of the different types of metal-allyl bonding (highly ionic to predominantly covalent), 2) the use of synergistic effects in heterobimetallic compounds, and 3) the adjustment of Lewis acidity by variation of the charge of allyl compounds.

  14. Transition metal catalysed Grignard-like allylic activation across tetragonal tin(II) oxide

    Indian Academy of Sciences (India)

    Pradipta Sinha; Moloy Banerjee; Abhijit Kundu; Sujit Roy

    2002-08-01

    The reaction of allyl halide and a carbonyl compound under the aegis of tetragonal tin(II) oxide and catalytic 8, 10 metal complexes provides the corresponding homoallylic alcohol, via a novel allyl tin intermediate.

  15. Scalable and sustainable electrochemical allylic C-H oxidation

    Science.gov (United States)

    Horn, Evan J.; Rosen, Brandon R.; Chen, Yong; Tang, Jiaze; Chen, Ke; Eastgate, Martin D.; Baran, Phil S.

    2016-05-01

    New methods and strategies for the direct functionalization of C-H bonds are beginning to reshape the field of retrosynthetic analysis, affecting the synthesis of natural products, medicines and materials. The oxidation of allylic systems has played a prominent role in this context as possibly the most widely applied C-H functionalization, owing to the utility of enones and allylic alcohols as versatile intermediates, and their prevalence in natural and unnatural materials. Allylic oxidations have featured in hundreds of syntheses, including some natural product syntheses regarded as “classics”. Despite many attempts to improve the efficiency and practicality of this transformation, the majority of conditions still use highly toxic reagents (based around toxic elements such as chromium or selenium) or expensive catalysts (such as palladium or rhodium). These requirements are problematic in industrial settings; currently, no scalable and sustainable solution to allylic oxidation exists. This oxidation strategy is therefore rarely used for large-scale synthetic applications, limiting the adoption of this retrosynthetic strategy by industrial scientists. Here we describe an electrochemical C-H oxidation strategy that exhibits broad substrate scope, operational simplicity and high chemoselectivity. It uses inexpensive and readily available materials, and represents a scalable allylic C-H oxidation (demonstrated on 100 grams), enabling the adoption of this C-H oxidation strategy in large-scale industrial settings without substantial environmental impact.

  16. Radiation-grafting of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) onto silicone rubber

    Science.gov (United States)

    Flores-Rojas, G. G.; Bucio, E.

    2016-10-01

    Silicone rubber (SR) was modified with a graft of ethylene glycol dimethacrylate (EGDMA) and glycidyl methacrylate (GMA) using either gamma-radiation or azobisisobutyronitrile (AIBN). The graft efficiency was evaluated as a function of monomer concentration, absorbed dose, reaction temperature, and concentration of AIBN. The hydrophilicity of the grafted films was measured by contact angle and their equilibrium swelling time in ethanol. Additional characterization by infrared (FTIR-ATR) spectroscopy, thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) is also reported.

  17. Catalytic Enantioselective Allylic Amination of Olefins for the Synthesis of ent-Sitagliptin.

    Science.gov (United States)

    Bao, Hongli; Bayeh, Liela; Tambar, Uttam K

    2013-11-01

    The presence of nitrogen atoms in most chiral pharmaceutical drugs has motivated the development of numerous strategies for the synthesis of enantioenriched amines. Current methods are based on the multi-step transformation of pre-functionalized allylic electrophiles into chiral allylic amines. The enantioselective allylic amination of unactivated olefins represents a more direct and attractive strategy. We report the enantioselective synthesis of ent-sitagliptin via an allylic amination of an unactivated terminal olefin.

  18. Platform Approach to Produce Polymer Nanoparticles with Modular Functionality from Amphiphilic Block Copolymer Stabilizers

    Science.gov (United States)

    2014-04-01

    functionality, an amphiphilic BCP scaffold was devised to serve as an emulsion polymerization stabilizer. The PS-b-P(EO-co-AGE) BCP contained a PS...synthesized via emulsion polymerization using an amphiphilic block copolymer (BCP) surfactant. The polystyrene-block-poly(ethylene oxide-co-allyl...glycidyl ether) BCPs with various lengths and functional monomer incorporation were synthesized using anionic polymerization . Modification of the allyl

  19. Redox-Neutral Rh(III)-Catalyzed Olefination of Carboxamides with Trifluoromethyl Allylic Carbonate.

    Science.gov (United States)

    Park, Jihye; Han, Sangil; Jeon, Mijin; Mishra, Neeraj Kumar; Lee, Seok-Yong; Lee, Jong Suk; Kwak, Jong Hwan; Um, Sung Hee; Kim, In Su

    2016-11-18

    The rhodium(III)-catalyzed olefination of various carboxamides with α-CF3-substituted allylic carbonate is described. This reaction provides direct access to linear CF3-allyl frameworks with complete trans-selectivity. In particular, a rhodium catalyst provided Heck-type γ-CF3-allylation products via the β-O-elimination of rhodacycle intermediate and subsequent olefin migration process.

  20. PHOTOINDUCED GRAFTING OF ACRYLIC AND ALLYL MONOMERS ON POLYETHYLENE SURFACE

    Institute of Scientific and Technical Information of China (English)

    ZHANG Zhenfeng; HU Xingzhou; YAN Qing

    1995-01-01

    Photoinduced grafting of acrylic and allyl monomers on polyethylene surface was generally studied by using benzophenone (BP) as a photoinitiator. The grafting process was carried out either in vapor-phase or in solution of the monomers. In the vapor-phase reaction with a filter used to cut off the short wavelength UV light, allyl amine is the most reactive of the four monomers used and acrylic amide is comparatively more reactive than acrylic acid and allyl alcohol. Acetone, as a solvent and carrier for initiator and monomers, however, shows its reactivity to participate the reaction. The solution grafting with a filter is much faster than the corresponding vapor-phase reaction, and a fully covered surface by the grafted polymer can be achieved in this way.

  1. Direct activation of allylic alcohols in palladium catalyzed coupling reactions

    OpenAIRE

    Gümrükçü, Y.

    2014-01-01

    The direct use of allylic alcohols in substitution reactions without pre-activation of the hydroxyl-group into a better leaving group or the use of additional stoichiometric in situ activators remains challenging due to the poor leaving group ability of the hydroxyl-group. Hence, it is important to develop new methods to activate (bio-mass derived) allyl-alcohols, which allow ‘green’ chemical processes for a broad substrate range. This may have a considerable impact on the methodology for fin...

  2. Direct activation of allylic alcohols in palladium catalyzed coupling reactions

    NARCIS (Netherlands)

    Gümrükçü, Y.

    2014-01-01

    The direct use of allylic alcohols in substitution reactions without pre-activation of the hydroxyl-group into a better leaving group or the use of additional stoichiometric in situ activators remains challenging due to the poor leaving group ability of the hydroxyl-group. Hence, it is important to

  3. Sulfonium-based Ionic Liquids Incorporating the Allyl Functionality

    Directory of Open Access Journals (Sweden)

    Paul J. Dyson

    2007-04-01

    Full Text Available A series of sulfonium halides bearing allyl groups have been prepared andcharacterized. Anion metathesis with Li[Tf2N] and Ag[N(CN2] resulted in sulfonium-basedionic liquids which exhibit low viscosities at room temperature. The solid state structure ofone of the halide salts was determined by single crystal X-ray diffraction.

  4. Single pulse shock tube study of allyl radical recombination.

    Science.gov (United States)

    Fridlyand, Aleksandr; Lynch, Patrick T; Tranter, Robert S; Brezinsky, Kenneth

    2013-06-13

    The recombination and disproportionation of allyl radicals has been studied in a single pulse shock tube with gas chromatographic measurements at 1-10 bar, 650-1300 K, and 1.4-2 ms reaction times. 1,5-Hexadiene and allyl iodide were used as precursors. Simulation of the results using derived rate expressions from a complementary diaphragmless shock tube/laser schlieren densitometry study provided excellent agreement with precursor consumption and formation of all major stable intermediates. No significant pressure dependence was observed at the present conditions. It was found that under the conditions of these experiments, reactions of allyl radicals in the cooling wave had to be accounted for to accurately simulate the experimental results, and this unusual situation is discussed. In the allyl iodide experiments, higher amounts of allene, propene, and benzene were found at lower temperatures than expected. Possible mechanisms are discussed and suggest that iodine containing species are responsible for the low temperature formation of allene, propene, and benzene.

  5. Electrochemical Allylic Oxidation of Olefins: Sustainable and Safe.

    Science.gov (United States)

    Waldvogel, Siegfried R; Selt, Maximilian

    2016-10-01

    The power you're supplying: With the application of an optimized electrochemical approach, the allylic oxidation of olefins, which is an important C-H activation process that provides access to enones, becomes a sustainable, versatile, and potent key reaction for organic synthesis.

  6. 1-Allyl-5-chloroindoline-2,3-dione

    Directory of Open Access Journals (Sweden)

    Zineb Tribak

    2016-06-01

    Full Text Available In the title compound, C11H8ClNO2, the allyl side chain is almost perpendicular to the 5-chloroindoline-2,3-dione ring system, with a dihedral angle of 88.0 (3°. In the crystal, C—H...O interactions link the molecules into layers lying parallel to the bc plane.

  7. Spectrum of Glycidyl Methacrylate—induced Mutation in Plasmid—Escherichia coli System

    Institute of Scientific and Technical Information of China (English)

    GAOHui-Lan; ZuoJin; 等

    1994-01-01

    In order to characterize the spectrum of mutation induced by glycidyl methacrylate(GMA),the plasmid pBR322 was modified with this mutagen in vitro.transfected into appropriate Escherichia coli host HB101.The mutants were then screned and defined by DNA sequencing.Sequence analysis reveals that GMA induces two classes of mutations:deletion of the mono-,di-or tetra-base or the insertion of mono-or di-base.Both types of muations,with about 10% frequency,occur predominantly at C.G runs and at 5'-CNCCN-3' sequence,which are hotspots for GMA damage and may cause frameshift muation.

  8. (E) Enol ethers from the stereoselective reduction of α-alkoxy-β-ketophosphonates and Wittig type reaction

    Institute of Scientific and Technical Information of China (English)

    DAYOUB; Wissam; DOUTHEAU; Alain

    2010-01-01

    When α-alkoxy-β-ketophosphonates,prepared by the Rh(Ⅱ) mediated insertion reaction of α-diazo-β-ketophosphonates into the OH bond of primary alcohols,were reduced either by NaBH4 in the presence of CaCl2 or by DIBAL,they respectively gave the corresponding anti or syn stereomeric hydroxyphosphonates with pronounced to complete stereoselectivity.Submitted to the action of potassium tert-butoxyde,syn isomers led to the corresponding pure(E) enol ethers in moderate to good yields.Under the same conditions anti isomers led to a mixture of(Z) and(E) enol ethers in rather poor yields.The sequence was applied to the preparation of some allyl-vinyl ethers with a(E) configuration for the vinylic double bond.

  9. Thermoresponsive cellulose ether and its flocculation behavior for organic dye removal.

    Science.gov (United States)

    Tian, Ye; Ju, Benzhi; Zhang, Shufen; Hou, Linan

    2016-01-20

    A thermoresponsive polymer, 2-hydroxy-3-butoxypropyl hydroxyethyl cellulose (HBPEC), was prepared by grafting butyl glycidyl ether (BGE) onto hydroxyethyl cellulose (HEC). The lower critical solution temperature (LCST) and critical flocculation temperature (CFT) of HBPEC were varied by changing the molar substitution (MS) and salt concentrations. Transmission electron microscopy (TEM) images and fluorescence spectroscopy showed that HBPEC can assemble into micelles. Additionally, using Nile Red as a model dye, the performance of HBPEC for the removing Nile Red from aqueous solutions via cloud point extraction procedures was investigated in detail. The encapsulation behavior of dye in the aqueous solution of HBPEC was studied by fluorescence spectroscopy and fluorescence microscope. The experimental results indicated that 99.4% of dye was removed from the aqueous solutions, and the HBPEC was recycled and reused easily, Furthermore, the recycle efficiency (RE) and maximum loading capacity portrayed little loss with the number of cycles.

  10. Novel nitric oxide generating compound glycidyl nitrate enhances the therapeutic efficacy of chemotherapy and radiotherapy

    Energy Technology Data Exchange (ETDEWEB)

    Ning, Shoucheng [Department of Radiation Oncology, Stanford University Medical Center, Stanford, CA 94305 (United States); Bednarski, Mark [Department of Radiology, Stanford University Medical Center, Stanford, CA 94305 (United States); Oronsky, Bryan; Scicinski, Jan [RadioRx, Inc., Mountain View, CA 94040 (United States); Knox, Susan J., E-mail: sknox@stanford.edu [Department of Radiation Oncology, Stanford University Medical Center, Stanford, CA 94305 (United States)

    2014-05-09

    Highlights: • Glycidyl nitrate (GLYN) is a NO generating small molecule and has ability to release NO on bioactivation in tumor cells. • GLYN-induced intracellular NO generation was attenuated by NO scavengers. • GLYN increases tumor blood flow in tumor-bearing animal model. • GLYN significantly increased the anti-tumor efficacy of cisplatin and radiation therapy in mice. • GLYN is well tolerated with no obvious systemic toxicities at its effective therapeutic doses in preclinical animal studies. - Abstract: Selective release of nitric oxide (NO) in tumors could improve the tumor blood flow and drug delivery for chemotherapeutic agents and radiotherapy, thereby increasing the therapeutic index. Glycidyl nitrate (GLYN) is a NO generating small molecule, and has ability to release NO on bioactivation in SCC VII tumor cells. GLYN-induced intracellular NO generation was significantly attenuated by NO scavenger carboxy-PTIO (cPTIO) and NAC. GLYN significantly increases tumor blood flow, but has no effect on the blood flow of normal tissues in tumor-bearing mice. When used with cisplatin, GLYN significantly increased the tumor growth inhibition effect of cisplatin. GLYN also had a modest radiosensitizing effect in vitro and in vivo. GLYN was well tolerated and there were no acute toxicities found at its effective therapeutic doses in preclinical studies. These results suggest that GLYN is a promising new drug for use with chemotherapy and radiotherapy, and provide a compelling rationale for future studies of GLYN and related compounds.

  11. Immobilization of α-amylase onto poly(glycidyl methacrylate) grafted electrospun fibers by ATRP

    Energy Technology Data Exchange (ETDEWEB)

    Oktay, Burcu; Demir, Serap; Kayaman-Apohan, Nilhan, E-mail: napohan@marmara.edu.tr

    2015-05-01

    In this study, novel α-amylase immobilized poly(vinyl alcohol) (PVA) nanofibers were prepared. The PVA nanofiber surfaces were functionalized with 2-bromoisobutyryl bromide (BiBBr) and followed by surface initiated atom transfer radical polymerization (SI-ATRP) of glycidyl methacrylate (GMA). The morphology of the poly(glycidyl methacrylate) (PGMA) grafted PVA nanofibers was characterized by scanning electron microscopy (SEM). Also PGMA brushes were confirmed by X-ray photo electron microscopy (XPS). α-Amylase was immobilized in a one step process onto the PGMA grafted PVA nanofiber. The characteristic properties of the immobilized and free enzymes were examined. The thermal stability of the enzyme was improved and showed maximum activity at 37 °C by immobilization. pH values of the maximum activity of the free and immobilized enzymes were also found at 6.0 and 6.5, respectively. Free enzyme lost its activity completely within 15 days. The immobilized enzyme lost only 23.8% of its activity within 30 days. - Highlights: • Electrospun photocrosslinkable PVA nanofiber was prepared. • PGMA brushes were conducted on PVA nanofiber via SI-ATRP. • The immobilized enzyme showed maximum activity at pH 6.0 and at 37 °C. • Functionalized nanofibers may be used as promising supports for enzyme immobilization.

  12. Synthesis and Characterization of [60]Fullerene-Glycidyl Azide Polymer and Its Thermal Decomposition

    Directory of Open Access Journals (Sweden)

    Ting Huang

    2015-05-01

    Full Text Available A new functionalized [60]fullerene-glycidyl azide polymer (C60-GAP was synthesized for the first time using a modified Bingel reaction of [60]fullerene (C60 and bromomalonic acid glycidyl azide polymer ester (BM-GAP. The product was characterized by Fourier transform infrared (FTIR, ultraviolet-visible (UV-Vis, and nuclear magnetic resonance spectroscopy (NMR analyses. Results confirmed the successful preparation of C60-GAP. Moreover, the thermal decomposition of C60-GAP was analyzed by differential scanning calorimetry (DSC, thermogravimetric analysis coupled with infrared spectroscopy (TGA-IR, and in situ FTIR. C60-GAP decomposition showed a three-step thermal process. The first step was due to the reaction of the azide group and fullerene at approximately 150 °C. The second step was ascribed to the remainder decomposition of the GAP main chain and N-heterocyclic at approximately 240 °C. The final step was attributed to the burning decomposition of amorphous carbon and carbon cage at around 600 °C.

  13. Effect of Montmorillonite Modification on Ultra Violet Radiation Cured Nanocomposite Filled with Glycidyl Methacrylate Modified Kenaf

    Science.gov (United States)

    Rozyanty, A. R.; Rozman, H. D.; Zhafer, S. F.; Musa, L.; Zuliahani, A.

    2016-06-01

    In this study nanocomposite cured by ultra violet radiation, were produced using modified montmorillonite (MMT) as reinforcing agent, chemically modified kenaf bast fiber as filler and unsaturated polyester as the matrix. Kenaf bast fiber was chemically modified with glycidyl methacrylate (GMA) whilst MMT were modified with cetyl trimethyl ammonium bromide (CTAB) and glycidyl methacrylate (GMA). Fixed 12 percent of GMA modified kenaf bast fiber with different percentage (i.e., 1, 3 and 5) of unmodified and modified MMT loading was used to produce the composite. The performed of GMA reaction with hydroxyl group of cellulose in kenaf bast fiber was evaluated using Fourier Transform infrared (FTIR) spectroscopy. GMA-MMT filled composite showed higher mechanical properties than MMT and CTAB-MMT filled composite. However, the increase of MMT, CTAB-MMT and GMA- MMT loading resulted in the reduction of mechanical properties. Scanning electron microscopy (SEM) analysis showed the evidence of compatibility enhancement between MMT and kenaf bast fiber with unsaturated polyester matrix.

  14. Bio-based alternative to the diglycidyl ether of bisphenol A with controlled materials properties.

    Science.gov (United States)

    Maiorana, Anthony; Spinella, Stephen; Gross, Richard A

    2015-03-09

    A series of biobased epoxy monomers were prepared from diphenolic acid (DPA) by transforming the free acid into n-alkyl esters and the phenolic hydroxyl groups into diglycidyl ethers. NMR experiments confirmed that the diglycidyl ethers of diphenolates (DGEDP) with methyl and ethyl esters have 6 and 3 mol % of glycidyl ester. Increasing the chain length of DGEDP n-alkyl esters from methyl to n-pentyl resulted in large decreases in epoxy resin viscosity (700-to-11 Pa·s). Storage modulus of DPA epoxy resins, cured with isophorone diamine, also varied with n-alkyl ester chain length (e.g., 3300 and 2100 MPa for the methyl and n-pentyl esters). The alpha transition temperature of the cured materials showed a linear decrease from 158 to 86 °C as the ester length increases. The Young's modulus and tensile strengths were about 1150 and 40 MPa, respectively, for all the cured resins tested (including DGEBA) and varied little as a function of ester length. Degree of cure for the different epoxy resins, determined by FTIR and DSC, closely approached the theoretical maximum. The result of this work demonstrates that diglycidyl ethers of n-alkyl diphenolates represent a new family of biobased liquid epoxy resins that, when cured, have similar properties to those from DGEBA.

  15. Crystallization experiments with the dinuclear chelate ring complex di-μ-chlorido-bis[(η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))platinum(II)].

    Science.gov (United States)

    Nguyen Thi Thanh, Chi; Pham Van, Thong; Le Thi Hong, Hai; Van Meervelt, Luc

    2016-10-01

    Crystallization experiments with the dinuclear chelate ring complex di-μ-chlorido-bis[(η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))platinum(II)], [Pt2(C15H19O4)2Cl2], containing a derivative of the natural compound eugenol as ligand, have been performed. Using five different sets of crystallization conditions resulted in four different complexes which can be further used as starting compounds for the synthesis of Pt complexes with promising anticancer activities. In the case of vapour diffusion with the binary chloroform-diethyl ether or methylene chloride-diethyl ether systems, no change of the molecular structure was observed. Using evaporation from acetonitrile (at room temperature), dimethylformamide (DMF, at 313 K) or dimethyl sulfoxide (DMSO, at 313 K), however, resulted in the displacement of a chloride ligand by the solvent, giving, respectively, the mononuclear complexes (acetonitrile-κN)(η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))chloridoplatinum(II) monohydrate, [Pt(C15H19O4)Cl(CH3CN)]·H2O, (η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))chlorido(dimethylformamide-κO)platinum(II), [Pt(C15H19O4)Cl(C2H7NO)], and (η(2)-2-allyl-4-methoxy-5-{[(propan-2-yloxy)carbonyl]methoxy}phenyl-κC(1))chlorido(dimethyl sulfoxide-κS)platinum(II), determined as the analogue {η(2)-2-allyl-4-methoxy-5-[(ethoxycarbonyl)methoxy]phenyl-κC(1)}chlorido(dimethyl sulfoxide-κS)platinum(II), [Pt(C14H17O4)Cl(C2H6OS)]. The crystal structures confirm that acetonitrile interacts with the Pt(II) atom via its N atom, while for DMSO, the S atom is the coordinating atom. For the replacement, the longest of the two Pt-Cl bonds is cleaved, leading to a cis position of the solvent ligand with respect to the allyl group. The crystal packing of the complexes is characterized by dimer formation via C-H...O and C-H...π interactions, but no π-π interactions are observed despite the presence of

  16. ION EXCHANGE SUBSTANCES BY SAPONIFICATION OF ALLYL PHOSPHATE POLYMERS

    Science.gov (United States)

    Kennedy, J.

    1959-04-14

    An ion exchange resin having a relatively high adsorption capacity tor uranyl ion as compared with many common cations is reported. The resin comprises an alphyl-allyl hydrogen phosphate polymer, the alphyl group being either allyl or a lower alkyl group having up to 5 carbon atoins. The resin is prepared by polymerizing compounds such as alkyl-diallyl phosphate and triallyl phosphate in the presence of a free radical generating substance and then partially hydrolyzing the resulting polymer to cause partial replacement of organic radicals by cations. A preferred free radical gencrating agent is dibenzoyl peroxide. The partial hydrolysis is brought about by refluxing the polymer with concentrated aqueous NaOH for three or four hours.

  17. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Energy Technology Data Exchange (ETDEWEB)

    Solpan, Dilek; Guven, Olgun [Hacettepe Univ., Ankara (Turkey). Dept. of Chemistry

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by {gamma}-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tudos (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively. (Author).

  18. Radiation initiated copolymerization of allyl alcohol with acrylonitrile

    Science.gov (United States)

    Şolpan, Dilek; Güven, Olgun

    1996-07-01

    Copolymerization of allyl alcohol (AA) with acrylonitrile (AN) initiated by γ-rays has been investigated to determine the respective reactivity ratios. Three different experimental techniques, namely Fourier Transform Infrared (FTIR), Ultraviolet (UV/vis) and elemental analysis (EA) have been used for the determination of copolymer compositions. Fineman-Ross (FR), Kelen-Tüdös (KT), Non-Linear Least Square (NLLS) Analysis and Q-e methods have been applied to the three sets of experimental data. It has been concluded that data obtained from elemental analysis as applied to the Non-Linear Least Square approach gave the most reliable reactivity ratios as 2.09 and 0.40 for acrylonitrile and allyl alcohol, respectively.

  19. Rh2(esp)2-catalyzed allylic and benzylic oxidations.

    Science.gov (United States)

    Wang, Yi; Kuang, Yi; Wang, Yuanhua

    2015-04-07

    The dirhodium(II) catalyst Rh2(esp)2 allows direct solvent-free allylic and benzylic oxidations by T-HYDRO with a remarkably low catalyst loading. This method is operationally simple and scalable at ambient temperature without the use of any additives. The high catalyst stability in these reactions may be attributed to a dirhodium(II,II) catalyst resting state, which is less prone to decomposition.

  20. Gold(I)-Assisted α-Allylation of Enals and Enones with Alcohols.

    Science.gov (United States)

    Mastandrea, Marco Michele; Mellonie, Niall; Giacinto, Pietro; Collado, Alba; Nolan, Steven P; Miscione, Gian Pietro; Bottoni, Andrea; Bandini, Marco

    2015-12-01

    The intermolecular α-allylation of enals and enones occurs by the condensation of variously substituted allenamides with allylic alcohols. Cooperative catalysis by [Au(ItBu)NTf2] and AgNTf2 enables the synthesis of a range of densely functionalized α-allylated enals, enones, and acyl silanes in good yield under mild reaction conditions. DFT calculations support the role of an α-gold(I) enal/enone as the active nucleophilic species.

  1. An Unexpected Reaction of Allylic Propynoate under Palladium(Ⅱ) Catalysis

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Zhao-Guo(张兆国); LU,Xi-Yan(陆熙炎); LANG,Shen-Hui(郎深慧)

    2002-01-01

    Palladium (Ⅱ) catalyzed reactions of allyl propynoate in the presence of excess halide ions with or without allyl halide or acrolein were studied, yielding (E)-3-halo-2-allyl-acrylic acid as the sole product. A mechanism involving halopalladation, carbopalladation, ring opening and β-heteroatom elimination was prioposed and was further justified by the reaction with deuterated substrate.keywords palladium, enyne, halopalladation, carbopalladation,β-heteroatom elimination was proposed and was further justified by the reaction with deuterated substrate.

  2. Silver-Catalyzed Decarboxylative Allylation of Aliphatic Carboxylic Acids in Aqueous Solution.

    Science.gov (United States)

    Cui, Lei; Chen, He; Liu, Chao; Li, Chaozhong

    2016-05-06

    Direct decarboxylative radical allylation of aliphatic carboxylic acids is described. With K2S2O8 as the oxidant and AgNO3 as the catalyst, the reactions of aliphatic carboxylic acids with allyl sulfones in aqueous CH3CN solution gave the corresponding alkenes in satisfactory yields under mild conditions. This site-specific allylation method is applicable to all primary, secondary, and tertiary alkyl acids and exhibits wide functional group compatibility.

  3. Glycidyl fatty acid esters in refined edible oils: A review on occurrence, formation, analysis, and elimination methods

    Science.gov (United States)

    Glycidyl fatty acid esters (GEs), one of the groups of oil-processing contaminants, are mainly formed during the deodorization step of the oil refining process and, thus, found in almost all refined edible oils. GEs have been considered to be potentially carcinogenic because, in the gastrointestinal...

  4. Direct analysis of intact glycidyl fatty acid esters in edible oils using gas chromatography-mass spectrometry

    NARCIS (Netherlands)

    van Steenbergen, H.; Hrnčiřík, K.; Ermacora, A.; de Koning, S.; Janssen, H.-G.

    2013-01-01

    Glycidyl esters (GE), fatty acid esters of glycidol, are process contaminants formed during edible oil processing. A novel direct method for the determination of intact GE in oils and fats based on gas chromatography-mass spectrometry (GC-MS) is presented. The method consists of a simple extraction

  5. 40 CFR 721.10189 - Fatty acids, tall-oil, reaction products with (butoxymethyl) oxirane formaldehyde-phenol polymer...

    Science.gov (United States)

    2010-07-01

    ... products with (butoxymethyl) oxirane formaldehyde-phenol polymer glycidyl ether, morpholinepropanamine...-phenol polymer glycidyl ether, morpholinepropanamine, propylene glycol diamine and aliphatic polyamine, N... products with (butoxymethyl) oxirane formaldehyde-phenol polymer glycidyl ether,...

  6. Catalyst-free synthesis of skipped dienes from phosphorus ylides, allylic carbonates, and aldehydes via a one-pot SN2' allylation-Wittig strategy.

    Science.gov (United States)

    Xu, Silong; Zhu, Shaoying; Shang, Jian; Zhang, Junjie; Tang, Yuhai; Dou, Jianwei

    2014-04-18

    A catalyst-free allylic alkylation of stabilized phosphorus ylides with allylic carbonates via a regioselective SN2' process is presented. Subsequent one-pot Wittig reaction with both aliphatic and aromatic aldehydes as well as ketenes provides structurally diverse skipped dienes (1,4-dienes) in generally high yields and moderate to excellent stereoselectivity with flexible substituent patterns. This one-pot SN2' allylation-Wittig strategy constitutes a convenient and efficient synthetic method for highly functionalized skipped dienes from readily available starting materials.

  7. Thin-film type Li-ion battery, using a polyethylene separator grafted with glycidyl methacrylate

    Energy Technology Data Exchange (ETDEWEB)

    Ko, J.M.; Min, B.G.; Kim, D.-W. [Hanbat University, Taejon (Korea). Department of Chemical Technology; Ryu, K.S.; Kim, K.M.; Lee, Y.G.; Chang, S.H. [Electronic and Telecommunication Research Institute, Taejon (Korea)

    2004-11-30

    For the improvement of organic electrolyte holding ability, the hydrophobic surface of a porous polyethylene (PE)-membrane separator was modified by grafting a hydrophilic monomer, glycidyl methacrylate (GMA), PE-g-GMA, by using electron beam technology, and applied to a thin film type Li-ion battery to elucidate the effect of a surface modification of a PE membrane separator on the cyclic life of Li-ion batteries. The Li-ion battery using the PE-g-GMA membrane separator showed a better cycle life than that of the unmodified PE membrane separator, indicating that the surface hydrophilicity of the PE membrane separator improved the electrolyte holding capability between the electrodes in the Li-ion cell and prevented the electrolyte leakage. (author)

  8. Synthesis and adsorption performance of dithiocarbamate-modified glycidyl methacrylate starch.

    Science.gov (United States)

    Cheng, Xiumei; Cheng, Rumei; Ou, Shengju; Li, Yijiu

    2013-07-01

    The design of chelating polymers with fast complexation of the metal ions is particularly interest. In this work, the dithiocarbamate-modified glycidyl methacrylate starch was synthesized and characterized by FT-IR, (13)C NMR and XRD spectra. Its sorption performance for heavy metals fixation was studied. It was found that the removal process of metal ions involved a fast increase stage followed by a slower stage. There was a higher match between the pseudo-second-order equation and the experimental data. The sorption rate constants were related to the substitution rates of hydrated metal ions in aqueous solutions, showing typical chemisorption. The Langmuir isotherm gave satisfying fits to equilibrium data of metals adsorption. And the capacities followed the sequence Cu(2+)>Cd(2+)>Co(2+)>Zn(2+)>Ni(2+)>Mn(2+), which could be well demonstrated with chelating interaction caused by sulfur atoms. Such understanding provides new insights as how to synthesize and use the dithiocarbamate-based polysaccharides.

  9. Non-viscoelastic Alloy by Reactive Blending of Nylon with Poly(ethylene-co-glycidyl methacrylate)

    Science.gov (United States)

    Sato, Daisuke; Kadowaki, Yuji; Ishibashi, Junya; Kobayashi, Sadayuki; Inoue, Takashi

    Polyamide (PA) was blended with a reactive polyolefin, poly(ethylene-co-glycidyl methacrylate), using an extremely long (L/D=100, L: screw length, D: screw diameter) twin-screw extruder. The reactive blending yielded a unique morphology of the sub-μm polyolefin particles in which 20 nm PA micelles were occluded. It implies that the in situ-formed graft copolymer was pulled in the dispersed particles. The blend showed ultra-high toughness (non-break at Izod impact test) and non-viscoelastic tensile property: the higher deformation rate led to the lower modulus and the larger elongation at break. In the tensile stress-strain curve, the sharp yielding point characteristic to crystalline polymer was hardly seen and the necking stress was maintained almost constant without strain hardening. It suggests a potential application for the energy absorbing car parts, to be friendly for pedestrian and driver.

  10. RAFT Copolymerization of Glycidyl Methacrylate and N,N-Dimethylaminoethyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    曹俊; 张丽芬; 潘向强; 程振平; 朱秀林

    2012-01-01

    In this work, copolymerization of two functional monomers, glycidyl methacrylate (GMA) and N,N-dimethylaminoethyl methacrylate (DMAEMA), was firstly carried out via reversible addition-fragmentation chain transfer (RAFT) polymerization successfully. The copolymerization kinetics was investigated under the molar ratio of n[GMA+DMAEMA]o/n[AIBN]o/n[CPDN]o=300/1/3 at 60℃. The copolymerization showed typical "living" features such as first-order polymerization kinetics, linear increase of molecular weight with monomer conversion and narrow molecular weight distribution. The reactivity ratios of GMA and DMAEMA were calculated by the extended Kelen-Tudos linearization methods. The epoxy group of the copolymer PGMA-co-PDMAEMA remained intact under the conditions of RAFT copolymerization and could easily be post-modified by ethylenedia- mine. Moreover, the modified copolymer could be used as a gene carrier.

  11. Occurrence of 3-MCPD and glycidyl esters in edible oils in the United States.

    Science.gov (United States)

    MacMahon, Shaun; Begley, Timothy H; Diachenko, Gregory W

    2013-01-01

    Fatty acid esters of 3-monochloropropanediol (3-MCPD) and glycidol are processing contaminants found in a wide range of edible oils. While both 3 MCPD and glycidol have toxicological properties that at present has concerns for food safety, the published occurrence data are limited. Occurrence information is presented for the concentrations of 3-MCPD and glycidyl esters in 116 retail and/or industrial edible oils and fats using LC-MS/MS analysis of intact esters. The concentrations for bound 3-MCPD ranged from below the limit of quantitation (palm olein samples. Palm olein samples also contained a higher percentage of 3-MCPD in mono-ester form than any other type of oil.

  12. The effect of frying on glycidyl esters content in palm oil.

    Science.gov (United States)

    Aniołowska, Magda; Kita, Agnieszka

    2016-07-15

    The changes in palm oil, as affected by frying temperature, and content of the glycidyl esters (GEs) were studied. Potato chips were fried intermittently in palm oil, which was heated for 8 h daily over five consecutive days. Frying was conducted at three frying temperatures: 150, 165 and 180 °C. Thermo-oxidative alterations of the oil were measured by acid and anisidine values, changes in fatty acid composition, total polar components, polar fraction composition and colour components formation. Content of GE was measured by liquid chromatography-mass spectrometry. Results showed that amount of products of hydrolysis, oxidation and polymerization (excluding decrease of degree of unsaturation) increased significantly as a function of frying temperature and time. Between GEs of fatty acids the most abundant were esters of palmitic and oleic acids. With increasing temperature and frying time, the content of GE decreased. The extent of GE decrease was correlated with degree of oil degradation.

  13. Occurrence of 3-monochloropropanediol esters and glycidyl esters in commercial infant formulas in the United States.

    Science.gov (United States)

    Leigh, Jessica; MacMahon, Shaun

    2017-03-01

    This work presents occurrence data for fatty acid esters of 3-chloro-1,2-propanediol (3-MCPD) and glycidol in 98 infant formula samples purchased in the United States. These contaminants are considered potentially carcinogenic and/or genotoxic, making their presence in refined oils and foods a potential health risk. Recently, attention has focused on methodology to quantify MCPD and glycidyl esters in infant formula for risk-assessment purposes. Occurrence data for 3-MCPD and glycidyl esters were produced using a procedure for extracting fat from infant formula and an LC-MS/MS method for analysing fat extracts for intact esters. Infant formulas were produced by seven manufacturers, five of which use palm oil and/or palm olein in their formulations. In formulas containing palm/palm olein, concentrations for bound 3-MCPD and glycidol ranged from 0.021 to 0.92 mg kg(-)(1) (ppm) and from < LOQ to 0.40 mg kg(-)(1) (ppm), respectively. Formulas not containing palm/palm olein, bound 3-MCPD and glycidol concentrations ranged from 0.072 to 0.16 mg kg(-)(1) (ppm) and from 0.005 to 0.15 mg kg(-)(1) (ppm), respectively. Although formulas from manufacturers A and G did not contain palm/palm olein, formulas from manufacturer E (containing palm olein) had the lowest concentrations of bound 3-MCPD and glycidol, demonstrating the effectiveness of industrial mitigation strategies.

  14. Exogenous ether lipids predominantly target mitochondria

    DEFF Research Database (Denmark)

    Kuerschner, Lars; Richter, Doris; Hannibal-Bach, Hans Kristian;

    2012-01-01

    Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high...... amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine...... in ether lipid metabolism and intracellular ether lipid trafficking....

  15. Dimethyl Ether Sector Develops Rapidly

    Institute of Scientific and Technical Information of China (English)

    Zong Yangong

    2007-01-01

    @@ Rapid capacity expansion Dimethyl ether production in China has developed rapidly in recent years. The total capacity of dimethyl ether in China was only 31.8 thousand t/a in 2002, the output was around 20 thousand tons and the operating rate was 63%. The number of producers increased to over 30 in 2006.

  16. Catalytic membrane-installed microchannel reactors for one-second allylic arylation.

    Science.gov (United States)

    Yamada, Yoichi M A; Watanabe, Toshihiro; Torii, Kaoru; Uozumi, Yasuhiro

    2009-10-07

    A variety of catalytic membranes of palladium-complexes with linear polymer ligands were prepared inside a microchannel reactor via coordinative and ionic molecular convolution to provide catalytic membrane-installed microdevices, which were applied to the instantaneous allylic arylation reaction of allylic esters and aryl boron reagents under microflow conditions to afford the corresponding coupling products within 1 second of residence time.

  17. Copper-Catalyzed SN2'-Selective Allylic Substitution Reaction of gem-Diborylalkanes.

    Science.gov (United States)

    Zhang, Zhen-Qi; Zhang, Ben; Lu, Xi; Liu, Jing-Hui; Lu, Xiao-Yu; Xiao, Bin; Fu, Yao

    2016-03-04

    A Cu/(NHC)-catalyzed SN2'-selective substitution reaction of allylic electrophiles with gem-diborylalkanes is reported. Different substituted gem-diborylalkanes and allylic electrophiles can be employed in this reaction, and various synthetic valuable functional groups can be tolerated. The asymmetric version of this reaction was initially researched with chiral N-heterocyclic carbene (NHC) ligands.

  18. Allyl sulphides in olefin metathesis: catalyst considerations and traceless promotion of ring-closing metathesis.

    Science.gov (United States)

    Edwards, Grant A; Culp, Phillip A; Chalker, Justin M

    2015-01-11

    Allyl sulphides are reactive substrates in ruthenium-catalysed olefin metathesis reactions, provided each substrate is matched with a suitable catalyst. A profile of catalyst activity is described, along with the first demonstration of allyl sulphides as traceless promoters in relayed ring-closing metathesis reactions.

  19. Memory effects in palladium-catalyzed allylic Alkylations of 2-cyclohexen-1-yl acetate

    DEFF Research Database (Denmark)

    Svensen, Nina; Fristrup, Peter; Tanner, David Ackland;

    2007-01-01

    The objective of this work was to characterize the enantiospecificity of the allylic alkylation of enantioenriched 2-cyclohexen-1-yl acetate with the enolate ion of dimethyl malonate catalyzed by unsymmetrical palladium catalysts. The precatalysts employed were (eta(3)-allyl)PdLCl, where L is a m...

  20. Corn oil and milk enhance the absorption of orally administered allyl isothiocyanate in rats.

    Science.gov (United States)

    Ippoushi, Katsunari; Ueda, Hiroshi; Takeuchi, Atsuko

    2013-11-15

    Allyl isothiocyanate, a chief component of mustard oil, exhibits anticancer effects in both cultured cancer cells and animal models. The accumulation of the N-acetylcysteine conjugate of allyl isothiocyanate, the final metabolite of allyl isothiocyanate, in urine was evaluated in rats that were orally coadministered allyl isothiocyanate with fluids (e.g., water, green tea, milk, and 10% ethanol) or corn oil. The N-acetylcysteine conjugate of allyl isothiocyanate content in urine when allyl isothiocyanate (2 or 4μmol) was coadministered with corn oil or milk showed a greater increase (1.4±0.22 or 2.7±0.34μmol or 1.2±0.32 or 2.5±0.36μmol, 1.6- to 1.8-fold or 1.5-fold, respectively) than when allyl isothiocyanate (2 or 4μmol) was coadministered with water (0.78±0.10 or 1.7±0.17μmol). This result demonstrates that corn oil and milk enhance the absorption of allyl isothiocyanate in rats.

  1. Green Synthesis and Regioselective Control of Sn/I2 Mediated Allylation of Carbonyl Compounds with Crotyl Halide in Water

    Institute of Scientific and Technical Information of China (English)

    ZHANG,Yan; ZHA,Zhang-Gen; ZHOU,Yu-Qing; WANG,Zhi-Yong

    2004-01-01

    @@ Barbier-type carbonyl allylation is particularly useful due to ease of operation and the availability and tractability of allylic substrates,[1] Metals such as indium, zinc and tin are often used as the mediator. Here we present a green approach toward the synthesis, that is, Sn/I2 mediated allylation of carbonyl compounds with crotyl halide in water.

  2. Construction of an Asymmetric Quaternary Carbon Center via Allylation of Hydrazones

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jin Bum; Satyender, Apuri; Jang, Doo Ok [Yonsei Univ., Wonju (Korea, Republic of)

    2013-11-15

    Asymmetric indium-mediated allylation of imine derivatives bearing a chiral auxiliary is a reliable strategy for the synthesis of chiral homoallylic amines. Various techniques for indium-mediated stereoselective allylation of imines bearing a chiral auxiliary have been reported. In 1997 Loh and co-workers reported indium-mediated allylation with imines derived from L-valine methyl ester. Since then, many forms of indium-mediated allylation bearing a chiral auxiliary have been reported, including imines derived from (S)-valinol, (R)-phenylglycinol, uracil, (R)-phenylglycinol methyl ester, N-tert-butanesufinamide, and (1R,2S)-1-amino-2-indanol. However, the synthesis of chiral auxiliaries often involves a laborious multi-step synthesis with expensive reagents. Therefore, the development of readily accessible chiral auxiliaries for asymmetric indium-mediated all-ylation is in high demand.

  3. Synthesis, Molecular Structure and Characterization of Allylic Derivatives of 6-Amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]-triazin-8(7H-one

    Directory of Open Access Journals (Sweden)

    Gene-Hsiang Lee

    2006-06-01

    Full Text Available 1-Allyl- (2 and 7-allyl-6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H-one (3 were obtained via the 18-crown-6-ether catalyzed room temperature reactionof 6-amino-3-methyl-1,2,4-triazolo[3,4-f][1,2,4]triazin-8(7H-one (1 with potassiumcarbonate and allyl bromide in dry acetone. The structures of these two derivatives wereverified by 2D-NMR measurements, including gHSQC and gHMBC measurements. Theminor compound 2 may possess aromatic character. A single crystal X-ray diffractionexperiment indicated that the major compound 3 crystallizes from dimethyl sulfoxide in themonoclinic space group P21/n and its molecular structure includes an attached dimethylsulfoxide molecule, resulting in the molecular formula C10H16N6O2S. Molecular structuresof 3 are linked by extensive intermolecular N-H···N hydrogen bonding [graph set C 1 (7]. 1Each molecule is attached to the dimethyl sulfoxide oxygen via N-H···O intermolecularhydrogen bonding. The structure is further stabilized by π-π stacking interactions.

  4. NIOSH Manual of Analytical Methods (third edition). Fourth supplement

    Energy Technology Data Exchange (ETDEWEB)

    1990-08-15

    The NIOSH Manual of Analytical Methods, 3rd edition, was updated for the following chemicals: allyl-glycidyl-ether, 2-aminopyridine, aspartame, bromine, chlorine, n-butylamine, n-butyl-glycidyl-ether, carbon-dioxide, carbon-monoxide, chlorinated-camphene, chloroacetaldehyde, p-chlorophenol, crotonaldehyde, 1,1-dimethylhydrazine, dinitro-o-cresol, ethyl-acetate, ethyl-formate, ethylenimine, sodium-fluoride, hydrogen-fluoride, cryolite, sodium-hexafluoroaluminate, formic-acid, hexachlorobutadiene, hydrogen-cyanide, hydrogen-sulfide, isopropyl-acetate, isopropyl-ether, isopropyl-glycidyl-ether, lead, lead-oxide, maleic-anhydride, methyl-acetate, methyl-acrylate, methyl-tert-butyl ether, methyl-cellosolve-acetate, methylcyclohexanol, 4,4'-methylenedianiline, monomethylaniline, monomethylhydrazine, nitric-oxide, p-nitroaniline, phenyl-ether, phenyl-ether-biphenyl mixture, phenyl-glycidyl-ether, phenylhydrazine, phosphine, ronnel, sulfuryl-fluoride, talc, tributyl-phosphate, 1,1,2-trichloro-1,2,2-trifluoroethane, trimellitic-anhydride, triorthocresyl-phosphate, triphenyl-phosphate, and vinyl-acetate.

  5. Direct Dimethyl Ether Synthesis

    Institute of Scientific and Technical Information of China (English)

    Takashi Ogawa; Norio Inoue; Tutomu Shikada; Yotaro Ohno

    2003-01-01

    Dimethyl ether (DME) is a clean and economical alternative fuel which can be produced from natural gas through synthesis gas. The properties of DME are very similar to those of LP gas. DME can be used for various fields as a fuel such as power generation, transportation, home heating and cooking,etc. It contains no sulfur or nitrogen. It is not corrosive to any metal and not harmful to human body. An innovative process of direct synthesis of DME from synthesis gas has been developed. Newly developed catalyst in a slurry phase reactor gave a high conversion and high selectivity of DME production. One and half year pilot scale plant (5 tons per day) testing, which was supported by METI, had successfully finished with about 400 tons DME production.

  6. Polymer electrolyte based on crosslinked poly(glycidyl methacrylate) and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide

    Energy Technology Data Exchange (ETDEWEB)

    Fei, Beatrice Wong Chui; Hanifah, Sharina Abu; Ahmad, Azizan; Hassan, Nur Hasyareeda [School of Chemical Sciences and Food Technology, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, 43000 Bangi, Selangor Darul Ehsan (Malaysia)

    2015-09-25

    Polymer electrolytes based on crosslinked poly(glycidyl methacrylate) as polymer host and 1-butyl-3-methylimidazolium bis(trifluoromethylsulfonyl)imide (BmimTFSI) as incorporated salt were prepared by in-situ photopolymerization technique. The complexes with different mass ratio of glycidyl methacrylate (GMA) monomer to BmimTFSI were investigated. The ionic conductivity of the polymer electrolyte was increased and reach the highest value of 7.50 × 10{sup −4} S cm{sup −1} at the ratio of 3:7 (GMA: BmimTFSI). The interaction between the polymer host and ionic liquid was proved by Attenuated Total Reflectance-Fourier Transformation Infra-Red Spectroscopy (ATR-FTIR). Meanwhile, the X-ray diffraction analysis shows the amorphousity of the polymer electrolyte film increase with the ionic liquid ratio.

  7. 缩水甘油硝酸酯的一锅法合成%One-pot Synthesis of Glycidyl Nitrate

    Institute of Scientific and Technical Information of China (English)

    邱少君; 甘孝贤; 樊慧庆

    2005-01-01

    A mild, low cost synthetic method of glycidyl nitrate is developed via so called one-pot procedure. Epichlorohydrin added dropwise to the dilute nitric acid (35 wt%) resulted in ring-opening reaction at about 20 ℃. Ring-closing occurred then by the addition of aqueous sodium hydroxide. Glycidyl nitrate was obtained in moderate yield (60%) and its structure was characterized by Fourier transform infrared spectroscopy, hydrogen and carbon nuclear magnetic resonance and elemental analysis.%环氧氯丙烷滴加到35%的稀硝酸中,于20 ℃左右进行开环反应,然后用氢氧化钠溶液进行关环反应,得到缩水甘油硝酸酯,得率为60%.用FTIR,1H NMR,13C NMR和元素分析对产物进行了结构表征.

  8. Monomers for thermosetting and toughening epoxy resins. [glycidyl amine derivatives, propargyl-containing amines, and mutagenic testing of aromatic diamines

    Science.gov (United States)

    Pratt, J. R.

    1981-01-01

    Eight glycidyl amines were prepared by alkylating the parent amine with epichlorohydrin to form chlorohydrin, followed by cyclization with aqueous NaOH. Three of these compounds contained propargyl groups with postcuring studies. A procedure for quantitatively estimating the epoxy content of these glycidyl amines was employed for purity determination. Two diamond carbonates and several model propargly compounds were prepared. The synthesis of three new diamines, two which contain propargyloxy groups, and another with a sec-butyl group is in progress. These materials are at the dinitro stage ready for the final hydrogenation step. Four aromatic diamines were synthesized for mutagenic testing purposes. One of these compounds rapidly decomposes on exposure to air.

  9. Do garlic-derived allyl sulfides scavenge peroxyl radicals?

    Science.gov (United States)

    Amorati, Riccardo; Pedulli, Gian Franco

    2008-03-21

    The chain-breaking antioxidant activities of two garlic-derived allyl sulfides, i.e. diallyl disulfide (1), the main component of steam-distilled garlic oil, and allyl methyl sulfide (3) were evaluated by studying the thermally initiated autoxidation of cumene or styrene in their presence. Although the rate of cumene oxidation was reduced by addition of both 1 and 3, the dependence on the concentration of the two sulfides could not be explained on the basis of the classic antioxidant mechanism as with phenolic antioxidants. The rate of oxidation of styrene, on the other hand, did not show significant changes upon addition of either 1 or 3. This unusual behaviour was explained in terms of the co-oxidant effect, consisting in the decrease of the autoxidation rate of a substrate forming tertiary peroxyl radicals (i.e. cumene) upon addition of little amounts of a second oxidizable substrate giving rise instead to secondary peroxyl radicals. The relevant rate constants for the reaction of ROO(.) with 1 and 3 were measured as 1.6 and 1.0 M(-1) s(-1), respectively, fully consistent with the H-atom abstraction from substituted sulfides. It is therefore concluded that sulfides 1 and 3 do not scavenge peroxyl radicals and therefore cannot be considered chain-breaking antioxidants.

  10. Relaxation behavior and nonlinear properties of thermally stable polymers based on glycidyl derivatives of quercetin

    Science.gov (United States)

    Mishurov, Dmytro; Voronkin, Andrii; Roshal, Alexander; Brovko, Oleksandr

    2016-07-01

    Cross-linked polymers on the basis of di-, tri and tetraglycidyl ethers of quercetin (3,3‧,4‧,5,7-pentahydroxyflavone) were synthesized, and then, poled in electrical field of corona discharge. Investigations of structural, thermal and optical parameters of the polymer films were carried out. It was found that the polymers obtained from di- and triglycidyl quercetin ethers had high values of macroscopic quadratic susceptibilities and substantial stability of nonlinear optical (NLO) properties after the poling. Tetraglycidyl ether of quercetin forms the polymer of lower quadratic susceptibility, which demonstrates noticeable relaxation process resulting in decrease of the NLO effect. It is supposed that the difference of the NLO properties is due to peculiarities of physical network of the polymers, namely to the ratio between numbers of hydrogen bonds formed by hydroxyl groups of chromophore fragments and by the ones of interfragmental parts of the polymeric chains.

  11. Solvent-Induced Crystallization of Poly(ether ether ketone)

    OpenAIRE

    McPeak, Jennifer Lynne

    1999-01-01

    The purpose of this study was learn how the diffusion, swelling, and crystallization processes are coupled during solvent-induced crystallization of poly(ether ether ketone) (PEEK). Unoriented amorphous PEEK films were immersed in aprotic organic liquids at ambient temperature and bulk properties or characteristics were monitored as a function of immersion time. The sorption behavior, Tg and Tm° suppression, crystallinity, and dynamic mechanical response were correlated as a function of sol...

  12. Rearrangements of Cycloalkenyl Aryl Ethers

    Directory of Open Access Journals (Sweden)

    Mercedesz Törincsi

    2016-04-01

    Full Text Available Rearrangement reactions of cycloalkenyl phenol and naphthyl ethers and the acid-catalyzed cyclization of the resulting product were investigated. Claisen rearrangement afforded 2-substituted phenol and naphthol derivatives. Combined Claisen and Cope rearrangement resulted in the formation of 4-substituted phenol and naphthol derivatives. In the case of cycloocthylphenyl ether the consecutive Claisen and Cope rearrangements were followed by an alkyl migration. The mechanism of this novel rearrangement reaction is also discussed.

  13. Glyceryl guaiacol ether – review

    OpenAIRE

    Massone, Flávio; Universidade Estadual Paulista; Luna, Stélio Pacca Loureiro; Universidade Estadual Paulista; Castro, Gladys Bastos; Universidade Estadual Paulista

    1996-01-01

    The history, physical and chemical properties, pharmacodynamics, pharmacokinetics, adverse effects, toxicity, clinical use in wild and domestic species and drug interactions with glyceryl guaiacol ether, an a-glyceryt ether, is presented. Guaiphenesin produces muscle relaxation without affecting diaphragmatic function. Besides muscle relaxation, the drug produces hypocholesterolemia, hypouricemia and has antitussive and expectorant actions, among others. It is a safe agent, but can produce th...

  14. A Mechanistic Study of Direct Activation of Allylic Alcohols in Palladium Catalyzed Amination Reactions

    OpenAIRE

    Yasemin Gumrukcu; Bas de Bruin; Reek, Joost N. H.

    2015-01-01

    We here report a computational approach on the mechanism of allylicamination reactions using allyl-alcohols and amines as the substrates and phosphoramidite palladium catalyst 1a, which operates in the presence of catalytic amount of 1,3-diethylurea as a co-catalyst. DFT calculations showed a cooperative hydrogen-bonding array between the urea moiety and the hydroxyl group of the allyl alcohol, which strengthens the hydrogen bond between the O-H moiety of the coordinated allyl-alcohol and th...

  15. Highly stereoselective synthesis of functionalized 1,3-dienes from a new allyl bromide

    Directory of Open Access Journals (Sweden)

    Asma Fray

    2014-05-01

    Full Text Available New and highly functionalized 1,3-dienes 3 and 4 have been synthesized via two different pathways starting from allyl bromide 1. Firstly, the reaction of allyl bromide 1 with triethylphosphite leads to an allylphosphonate 2, which undergoes the Wittig-Horner reaction with a range of saturated and unsaturated aldehydes gives rise to the corresponding 1,3-dienes 3. Secondly, a highly stereoselective reaction between allyl bromide 1 and nitroalkane salts, offers the possibility to obtaining functionalized (E-1,3-dienes 4.

  16. SYNTHESIS AND CRYSTALLIZATION BEHAVIOR OF POLY(ETHER ETHER KETONE ETHER KETONE) (PEEKEK)

    Institute of Scientific and Technical Information of China (English)

    Zhao-bin Qiu; Zhi-shen Mo; Ying-ning Yu; Hong-fang Zhang; Xian-hong Wang

    2000-01-01

    In this paper, the synthesis and crystallization behavior of poly(ether ether ketone ether ketone) (PEEKEK) are reported. PEEKEK was prepared from 4,4'-bis(p-fluorobenzoyl) diphenyl ether (4,4'-FBDE) and hydroquinone along the nucleophilic substitution route. The thermal properties were investigated by using DSC and TGA. The crystallization behavior of PEEKEK under several conditions, i.e., crystallization from the molten state (melt crystallization), crystallization from a quenched sample (cold crystallization) and crystallization induced by exposing glassy sample to methylene chloride (solvent-induced crystallization) has also been investigated. The results show that crystallization of PEEKEK could be induced by the above methods, and no polymorphism was found. The differences in the crystallization of PEEKEK induced by the above methods are seen in their degree of crystallinity.

  17. Genes Differentially Expressed in Human Lung Fibroblast Cells Transformed by Glycidyl Methacrylate

    Institute of Scientific and Technical Information of China (English)

    XUE-JUN YIN; JIAN-NING XU; CHANG-QI ZOU; FENG-SHENG HE; FU-DE FANG

    2004-01-01

    To define the differences in gene expression patterns between glycidyl methacrylate (GMA)-transformed human lung fibroblast cells (2BS cells) and controls. Methods The mRNA differential display polymerase chain reaction (DD-PCR) technique was used. cDNAs were synthesized by reverse transcription and amplified by PCR using 30 primer combinations. After being screened by dot blot analysis, differentially expressed cDNAs were cloned, sequenced and confirmed by Northern blot analysis. Results Eighteen differentially expressed cDNAs were cloned and sequenced, of which 17 were highly homologous to known genes (homology = 89%-100%) and one was an unknown gene. Northern blot analysis confirmed that eight genes encoding human zinc finger protein 217 (ZNF217), mixed-lineage kinase 3 (MLK-3), ribosomal protein (RP) L15, RPL41, RPS16, TBX3, stanniocalcin 2 (STC2) and mouse ubiquitin conjugating enzyme (UBC), respectively, were up-regulated, and three genes including human transforming growth factor ( inducible gene (Betaig-h3), (-1,2-mannosidase 1A2 (MAN 1A2) gene and an unknown gene were down-regulated in the GMA-transformed cells. Conclusion Analysis of the potential function of these genes suggest that they may be possibly linked to a variety of cellular processes such as transcription, signal transduction, protein synthesis and growth, and that their differential expression could contribute to the GMA-induced neoplastic transformation.

  18. Cellulose functionalization via high-energy irradiation-initiated grafting of glycidyl methacrylate and cyclodextrin immobilization

    Energy Technology Data Exchange (ETDEWEB)

    Desmet, Gilles [Institute of Isotopes, Hungarian Academy of Sciences, H-1525 Budapest, Pf. 77 (Hungary); Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, H-1521 Budapest, Pf. 91 (Hungary); Takacs, Erzsebet, E-mail: takacs@iki.kfki.hu [Institute of Isotopes, Hungarian Academy of Sciences, H-1525 Budapest, Pf. 77 (Hungary); Wojnarovits, Laszlo [Institute of Isotopes, Hungarian Academy of Sciences, H-1525 Budapest, Pf. 77 (Hungary); Borsa, Judit [Faculty of Chemical Technology and Biotechnology, Budapest University of Technology and Economics, H-1521 Budapest, Pf. 91 (Hungary)

    2011-12-15

    Cotton-cellulose was functionalized using gamma-irradiation-induced grafting of glycidyl methacrylate (GMA) to obtain a hydrophobic cellulose derivative with epoxy groups suitable for further chemical modification. Two grafting techniques were applied. In pre-irradiation grafting (PIG) cellulose was irradiated in air and then immersed in a GMA monomer solution, whereas in simultaneous grafting (SG) cellulose was irradiated in an inert atmosphere in the presence of the monomer. PIG led to a more homogeneous fiber surface, while SG resulted in higher grafting yield but showed clear indications of some GMA-homopolymerization. Effects of the reaction parameters (grafting method, absorbed dose, monomer concentration, solvent composition) were evaluated by SEM, gravimetry (grafting yield) and FTIR spectroscopy. Water uptake of the cellulose decreased while adsorption of a pesticide molecule increased upon grafting. The adsorption was further enhanced by {beta}-cyclodextrin immobilization during SG. This method can be applied to produce adsorbents from cellulose based agricultural wastes. - Highlights: > Fundamentals of two grafting methods for biomass utilization as adsorbents. > Simultaneous grafting is more efficient and useful than the pre-irradiation one. > Methanol/water/surfactant combined solvent gives the best grafting yield. > Grafted cellulose increased hydrophobicity and adsorption of phenolic compounds. > Improved adsorption by bonding {beta}-cyclodextrin during simultaneous grafting.

  19. Glycidyl methacrylate macroporous copolymer grafted with diethylene triamine as sorbent for Reactive Black 5

    Directory of Open Access Journals (Sweden)

    Sandić Zvjezdana P.

    2014-01-01

    Full Text Available In this paper, macroporous glycidyl methacrylate and ethylene glycol dimethacrylate copolymer functionalized with diethylene triamine [PGME-deta], was evaluated as Reactive Black 5 (RB5 sorbent. Batch RB5 removal from aqueous solution by PGME-deta was investigated by varying pH, contact time, sorbent dosage, initial dye concentration and temperature. The sorption is pH sensitive having maximum at pH 2 (dye removal of 85%, decreasing with the increase of pH (dye removal of 24% at pH=11 after 60 min. Sorption kinetics was fitted to chemical-reaction and particle-diffusion models (pseudo-first-order, pseudo-second-order, intraparticle diffusion and Mckay models. The pseudo-second-order kinetic model accurately predicted the RB5 amount sorbed under all investigated operating conditions, while the intraparticle diffusion was the dominant rate-limiting mechanism. The diffusion mechanism was more prevalent with the decrease in temperature and the increase in concentration. The isotherm data was best fitted with the Langmuir model, indicating homogeneous distribution of active sites on PGME-deta and monolayer sorption, with the maximum sorption capacity of 353 mg g-1. The calculated sorption rates improved with increasing temperature and an activation energy close to 40 kJ mol-1 was determined, suggesting that chemisorption was also rate-controlling. [Projekat Ministarstva nauke Republike Srbije, br. III 43009, br. TR 37021 i br. III 45001

  20. Chemoselective allylation of ketones in ionic liquids containing sulfonate anions.

    Science.gov (United States)

    Galletti, Paola; Moretti, Fabio; Samorì, Chiara; Tagliavini, Emilio

    2009-01-01

    The chemoselective addition of tetraallyltin to dialkyl, alkenyl-alkyl, and alkynyl-alkyl ketones can be performed with high yields in N-methyl-N-butylpyrrolidinium trifuoromethansulfonate (MBP-Tf). Other room temperature ionic liquids (RTILs) can also be successfully employed if some sulfonic acid is added. The reaction is very sensitive to the electronic properties of the substrate. Aryl alkyl ketones bearing electron-withdrawing substituents behave like dialkyl ketones and react promptly; on the contrary, electron-rich aryl alkyl ketones react sluggishly, which allows selective competitive allylation of dialkyl substrates to occur. The ionic liquid solvent can be easily recycled, which meets the green chemistry principles of selectivity and reuse of chemicals. NMR spectroscopic data support the formation of tin-triflate catalysts in situ.

  1. Aerobic Linear Allylic C-H Amination: Overcoming Benzoquinone Inhibition.

    Science.gov (United States)

    Pattillo, Christopher C; Strambeanu, Iulia I; Calleja, Pilar; Vermeulen, Nicolaas A; Mizuno, Tomokazu; White, M Christina

    2016-02-03

    An efficient aerobic linear allylic C-H amination reaction is reported under palladium(II)/bis-sulfoxide/Brønsted base catalysis. The reaction operates under preparative, operationally simple conditions (1 equiv of olefin, 1 atm O2 or air) with reduced Pd(II)/bis-sulfoxide catalyst loadings while providing higher turnovers and product yields than systems employing stoichiometric benzoquinone (BQ) as the terminal oxidant. Pd(II)/BQ π-acidic interactions have been invoked in various catalytic processes and are often considered beneficial in promoting reductive functionalizations. When such electrophilic activation for functionalization is not needed, however, BQ at high concentrations may compete with crucial ligand (bis-sulfoxide) binding and inhibit catalysis. Kinetic studies reveal an inverse relationship between the reaction rate and the concentration of BQ, suggesting that BQ is acting as a ligand for Pd(II) which results in an inhibitory effect on catalysis.

  2. Synthesis of acrylic and allylic bifunctional cross-linking monomers derived from PET waste

    Science.gov (United States)

    Cruz-Aguilar, A.; Herrera-González, A. M.; Vázquez-García, R. A.; Navarro-Rodríguez, D.; Coreño, J.

    2013-06-01

    An acrylic and two novel allylic monomers synthesized from bis (hydroxyethyl) terephthalate, BHET, are reported. This was obtained by glycolysis of post-consumer PET with boiling ethylene glycol. The bifunctional monomer bis(2-(acryloyloxy)ethyl) terephthalate was obtained from acryloyl chloride, while the allylic monomers 2-(((allyloxi)carbonyl)oxy) ethyl (2-hydroxyethyl) terephthalate and bis(2-(((allyloxi)carbonyl)oxy)ethyl) terephthalate, from allyl chloroformate. Cross-linking was studied in bulk polymerization using two different thermal initiators. Monomers were analyzed by means of 1H NMR and the cross-linked polymers by infrared spectroscopy. Gel content higher than 90% was obtained for the acrylic monomer. In the case of the mixture of the allylic monomers, the cross-linked polymer was 80 % using BPO initiator, being this mixture 24 times less reactive than the acrylic monomer.

  3. Biomarkers derived from heterolytic and homolytic cleavage of allylic hydroperoxides resulting from alkenone autoxidation

    Digital Repository Service at National Institute of Oceanography (India)

    Rontania, J.F.; Harji, R.; Volkmanc, J.K.

    , hydroxyacids and alkyldiols resulted from the reduction during the NaBH4 treatment of the corresponding aldehydes, ketoxyacids and ketoxyaldehydes formed from heterolytic or hemolytic cleavages of allylic hydroperoxyl groups resulting from the oxidation...

  4. Facile synthesis of allyl resinate monomer in an aqueous solution under microwave irradiation

    Indian Academy of Sciences (India)

    Yanju Lu; Mixia Wang; Zhendong Zhao; Yuxiang Chen; Shichao Xu; Jing Wang; Liangwu Bi

    2015-07-01

    We have developed a facile method for production of allyl resinate monomer (allyl rosin ester) via a phase transfer reaction under microwave irradiation. The synthesis of allyl resinate was conducted using allyl chloride and sodium resinate as starting materials in aqueous solution at 50°C for 30 min with a yield of 94.7%, which is 20% higher than conventional heating method. The products precipitated spontaneously from the aqueous phase after reaction, which significantly facilitated the subsequent separation of monomer products. The synthesized monomer product appeared as a viscous liquid, with a viscosity of 460 mPa·s at 25°C and a density of 1.0469 g/cm3. The physical and chemical properties suggested that the synthesized monomer has great potential for free radical polymerization.

  5. Selective epoxidation of allylic alcohols with a titania-silica aerogel

    Energy Technology Data Exchange (ETDEWEB)

    Dusi, M.; Mallat, T.; Baiker, A. [Lab. of Technical Chemistry, Swiss Federal Inst. of Technology, ETH-Zentrum, Zuerich (Switzerland)

    1998-12-31

    An amorphous mesoporous titania-silica aerogel (20 wt%TiO{sub 2} - 80 wt% SiO{sub 2}) and tert.-butylhydroperoxide (TBHP) have been used for the epoxidation of various allylic alcohols. Allylic alcohols possessing an internal double bond were more reactive than those with a terminal C=C bond. Epoxide selectivities could be improved by addition of (basic) zeolite 4 A and NaHCO{sub 3} to the reaction mixture. (orig.)

  6. Direct use of allylic alcohols for platinum-catalyzed monoallylation of amines.

    Science.gov (United States)

    Utsunomiya, Masaru; Miyamoto, Yoshiki; Ipposhi, Junji; Ohshima, Takashi; Mashima, Kazushi

    2007-08-16

    A new direct catalytic amination of allylic alcohols promoted by the combination of platinum and a large bite-angle ligand DPEphos was developed in which the allylic alcohol was effectively converted to a pi-allylplatinum intermediate without the use of an activating reagent. The use of the DPEphos ligand was essential for obtaining high catalyst activity and high monoallylation selectivity of primary amines, allowing the formation of a variety of monoallylation products in good to excellent yield.

  7. Effect of allyl isothiocyanate on developmental toxicity in exposed Xenopus laevis embryos

    Directory of Open Access Journals (Sweden)

    John Russell Williams

    2015-01-01

    Full Text Available The pungent natural compound allyl isothiocyanate isolated from the seeds of Cruciferous (Brassica plants such as mustard is reported to exhibit numerous beneficial health-promoting antimicrobial, antifungal, anticarcinogenic, cardioprotective, and neuroprotective properties. Because it is also reported to damage DNA and is toxic to aquatic organisms, the objective of the present study was to determine whether it possesses teratogenic properties. The frog embryo teratogenesis assay-Xenopus (FETAX was used to determine the following measures of developmental toxicity of the allyl isothiocyanate: (a 96-h LC50, defined as the median concentration causing 50% embryo lethality; (b 96-h EC50, defined as the median concentration causing 50% malformations of the surviving embryos; and (c teratogenic malformation index (TI, equal to 96-h LC50/96-h EC50. The quantitative results and the photographs of embryos before and after exposure suggest that allyl isothiocyanate seems to exhibit moderate teratogenic properties. The results also indicate differences in the toxicity of allyl isothiocyanate toward exposed embryos observed in the present study compared to reported adverse effects of allyl isothiocyanate in fish, rodents, and humans. The significance of the results for food safety and possible approaches to protect against adverse effects of allyl isothiocyanate are discussed.

  8. PEGylation of magnetic poly(glycidyl methacrylate) microparticles for microfluidic bioassays

    Energy Technology Data Exchange (ETDEWEB)

    Kucerova, Jana; Svobodova, Zuzana [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Knotek, Petr [Joint Laboratory of Solid State Chemistry of IMC and University of Pardubice, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Palarcik, Jiri [Institute of Environmental and Chemical Engineering, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic); Vlcek, Milan; Kincl, Miloslav; Horak, Daniel [Institute of Macromolecular Chemistry, Academy of Sciences of the Czech Republic, Heyrovsky Sq. 2, 16206 Prague 6 (Czech Republic); Autebert, Julien; Viovy, Jean-Louis [Macromolecules and Microsystems in Biology and Medicine, Institute Curie, UMR 168, 26 Rue d' Ulm, 75005 Paris (France); Bilkova, Zuzana, E-mail: zuzana.bilkova@upce.cz [Department of Biological and Biochemical Sciences, Faculty of Chemical Technology, University of Pardubice, Studentska 573, 53210 Pardubice (Czech Republic)

    2014-07-01

    In this study, magnetic poly(glycidyl methacrylate) microparticles containing carboxyl groups (PGMA-COOH) were coated using highly hydrophilic polymer poly(ethylene glycol) (PEG). PEG was used to reduce nonspecific interactions with proteins and cells while decreasing adhesion of particles to the walls of a microfluidic devices from poly(dimethylsiloxane) (PDMS) and cyclic olefin copolymer (COC). Zeta potential measurement, infrared spectroscopy, scanning electron microscopy, anti-PEG ELISA assay, and bioaffinity interactions between biotin and streptavidin-HRP successfully proved the presence of PEG on the surface of microspheres. Both neat and PEGylated microspheres were then incubated with the inert protein bovine serum albumin or cells to evaluate the rate of nonspecific adsorption (NSA). PEG with Mr of 30,000 Da was responsible for 45% reduction in NSA of proteins and 74% for cells compared to neat particles. The microspheres' behavior in PDMS and COC microchannels was then evaluated. Aggregation and adhesion of PEGylated microspheres significantly decreased compared to neat particles. Finally, the model enzyme horseradish peroxidase was immobilized on the microspheres through the heterobifunctional PEG chain. The possibility for subsequent covalent coupling of the ligand of interest was confirmed. Such PEGylated microparticles can be efficiently used in PDMS microchips as a carrier for bioaffinity separation or of enzyme for catalysis. - Highlights: • Magnetic polymer microspheres with highly hydrophilic PEG coating were prepared. • PEG reduced microsphere adhesion in microchannels versus neat particles. • Suitability of methods for detecting PEG on magnetic microspheres was investigated. • PEG on microsphere surfaces decreased nonspecific adsorption of proteins and cells.

  9. Synthesis and characterization of monosize magnetic poly(glycidyl methacrylate) beads

    Institute of Scientific and Technical Information of China (English)

    Evrim Banu Alt1nta(s); Lokman Uzun; Adil Denizli

    2007-01-01

    Monosize, 1.6 μm, magnetic beads of poly(glycidyl methacrylate) [M-poly(GMA)], were prepared by dispersion polymerization in the presence of Fe3O4 nano-powder. Monosize M-poly(GMA) beads were characterized by swelling tests, density measurements, electron spin resonance (ESR), vibrating sample magnetometer (VSM) and scanning electron microscopy (SEM). The characteristic functional groups of M-poly(GMA)beads were analyzed by Fourier transform infrared spectrometer (FTIR). The M-poly(GMA) beads are highly uniform in size and have a spherical shape and non-porous structure. Polydispersity index (PDI) of M-poly(GMA) beads was calculated to be around 1.008. The hydrated density of the M-poly(GMA) beads measured at 25 ℃ was 1.14 g/cm3. The content of oxirane groups on the surface of the M-poly(GMA) sample was found to be 3.46 mmol/g by using perchloric acid titration. The specific surface area of the M-poly(GMA) beads was determined to be 3.2 m2/g.The equilibrium swelling ratio was 52%. The volume fraction of magnetite nanopowder in the M-poly(GMA) beads was found to be 4.5%. The g factor, that can be considered as a quantity characteristic of the molecules in which the unpaired electrons are located, was found to be 2.28for M-poly(GMA). The external magnetic field at resonance was calculated to be 2055 Gs which was found sufficient to excite all of the dipole moments present in 1.0 g of M-poly(GMA) sample.

  10. Composite glycidyl methacrylated dextran (Dex-GMA)/gelatin nanoparticles for localized protein delivery

    Institute of Scientific and Technical Information of China (English)

    Fa-ming CHEN; Zhi-wei MA; Guang-ying DONG; Zhi-fen WU

    2009-01-01

    Aim: Localized delivery of growth factors has significant potential as a future therapeutic strategy in tissue engineering and regenerative medicine. A nanoparticle vehicle was created and evaluated in this study with the intent to deliver growth factors for periodontal regeneration. Methods: Novel composite nanoparticles based on glycidyl methacrylate derivatized dextrans (Dex-GMA) and gelatin were fabricated by a facile method without using any organic solvents. The configurations of the resultant nanoparticles were evaluated by transmission electron microscopy, scanning electron microscopy, and atomic force microscope. Their surfaces were characterized by zeta-potential measurements, after which their properties including swelling, degradation, drug release, and cytotoxicity were also investigated using in vitro models,Results: The particle size of Dex-GMA/gelatin nanoparticles (DG-NPs) ranged from 20 to 100 nm and showed a mono-dis-perse size distribution (mean diameter 53.7 nm) and a strongly negative surface zeta potential (-20 mV). The DC,-NPs were characterized by good swelling and degradation properties in media including dextranase. The in vitro drug release stud-ies showed that the efficient bone morphogenetic protein (BMP) release from DG-NPs was maintained for more than 12 d under degradation conditions, where more than 90% of the loaded BMP was released. No any relevant cell damage caused by DG-NPs was found in the cytotoxicity tests for a period of 24 h.Conclusion: These combined results demonstrate that DG-NPs fulfill the basic prerequisites for growth factor delivery.With further in vivo studies, those nanoparticles may offer a promising vehicle for the delivery of active drugs to the perio-dontium.

  11. Luminescent Lariat Aza-Crown Ether

    Directory of Open Access Journals (Sweden)

    Burkhard König

    2010-03-01

    Full Text Available Lariat ethers are interesting recognition motifs in supramolecular chemistry. The synthesis of a luminescent lariat ether with triglycol chain by azide–alkyne (Huisgen cycloaddition is presented.

  12. Exogenous ether lipids predominantly target mitochondria.

    Directory of Open Access Journals (Sweden)

    Lars Kuerschner

    Full Text Available Ether lipids are ubiquitous constituents of cellular membranes with no discrete cell biological function assigned yet. Using fluorescent polyene-ether lipids we analyzed their intracellular distribution in living cells by microscopy. Mitochondria and the endoplasmic reticulum accumulated high amounts of ether-phosphatidylcholine and ether-phosphatidylethanolamine. Both lipids were specifically labeled using the corresponding lyso-ether lipids, which we established as supreme precursors for lipid tagging. Polyfosine, a fluorescent analogue of the anti-neoplastic ether lipid edelfosine, accumulated to mitochondria and induced morphological changes and cellular apoptosis. These data indicate that edelfosine could exert its pro-apoptotic power by targeting and damaging mitochondria and thereby inducing cellular apoptosis. In general, this study implies an important role of mitochondria in ether lipid metabolism and intracellular ether lipid trafficking.

  13. Small angle neutron scattering study of complex coacervate micelles and hydrogels formed from ionic diblock and triblock copolymers.

    Science.gov (United States)

    Krogstad, Daniel V; Choi, Soo-Hyung; Lynd, Nathaniel A; Audus, Debra J; Perry, Sarah L; Gopez, Jeffrey D; Hawker, Craig J; Kramer, Edward J; Tirrell, Matthew V

    2014-11-13

    A complex coacervate is a fluid phase that results from the electrostatic interactions between two oppositely charged macromolecules. The nature of the coacervate core structure of hydrogels and micelles formed from complexation between pairs of diblock or triblock copolymers containing oppositely charged end-blocks as a function of polymer and salt concentration was investigated. Both ABA triblock copolymers of poly[(allyl glycidyl ether)-b-(ethylene oxide)-b-(allyl glycidyl ether)] and analogous poly[(allyl glycidyl ether)-b-(ethylene oxide)] diblock copolymers, which were synthesized to be nearly one-half of the symmetrical triblock copolymers, were studied. The poly(allyl glycidyl ether) blocks were functionalized with either guanidinium or sulfonate groups via postpolymerization modification. Mixing of oppositely charged block copolymers resulted in the formation of nanometer-scale coacervate domains. Small angle neutron scattering (SANS) experiments were used to investigate the size and spacing of the coacervate domains. The SANS patterns were fit using a previously vetted, detailed model consisting of polydisperse core-shell micelles with a randomly distributed sphere or body-centered cubic (BCC) structure factor. For increasing polymer concentration, the size of the coacervate domains remained constant while the spatial extent of the poly(ethylene oxide) (PEO) corona decreased. However, increasing salt concentration resulted in a decrease in both the coacervate domain size and the corona size due to a combination of the electrostatic interactions being screened and the shrinkage of the neutral PEO blocks. Additionally, for the triblock copolymers that formed BCC ordered domains, the water content in the coacervate domains was calculated to increase from approximately 16.8% to 27.5% as the polymer concentration decreased from 20 to 15 wt %.

  14. Preconcentration and Determination of Mefenamic Acid in Pharmaceutical and Biological Fluid Samples by Polymer-grafted Silica Gel Solid-phase Extraction Following High Performance Liquid Chromatography

    OpenAIRE

    Bagheri Sadeghi, Hayedeh; Panahi, Homayon Ahmad; Mahabadi, Mahsa; Moniri, Elham

    2015-01-01

    Mefenamic acid is a nonsteroidal anti-inflammatory drug (NSAID) that has analgesic, anti-infammatory and antipyretic actions. It is used to relieve mild to moderate pains. Solid-phase extraction of mefenamic acid by a polymer grafted to silica gel is reported. Poly allyl glycidyl ether/iminodiacetic acid-co-N, N-dimethylacrylamide was synthesized and grafted to silica gel and was used as an adsorbent for extraction of trace mefenamic acid in pharmaceutical and biological samples. Different fa...

  15. Cp*Rh(III)-Catalyzed Low Temperature C-H Allylation of N-Aryl-trichloro Acetimidamide.

    Science.gov (United States)

    Debbarma, Suvankar; Bera, Sourav Sekhar; Maji, Modhu Sudan

    2016-12-02

    The readily synthesized trichloro acetimidamide was found to be an excellent directing group for the directed C-H-allylation reactions. Depending on the allylating agent used, selectively either mono- or diallylated products were readily synthesized. Moreover, the trichloro acetimidamide directing group was found to be highly efficient even at lower temperature for the C-H-allylation reaction. Due to mildness of the reaction conditions, double bond isomerization or cyclization to indole side product was not observed.

  16. Synthesis and Characterization of Nitrocellulose Azidonitrate Glycidyl Ether%硝化纤维素叠氮甘油醚的制备及表征

    Institute of Scientific and Technical Information of China (English)

    邵自强; 王文俊; 王飞俊; 谌凡更; 谭惠民

    2004-01-01

    利用高压蒸汽闪爆处理后的Novel纤维素为原料,经过碱化、醚化、硝化和叠氮化反应,得到了一种新型高能粘合剂--硝化纤维素叠氮甘油醚,并采用元素分析、DSC、FIT红外光谱和X-射线等对其含氮量、结构和性能进行了分析表征.结果表明,新型高能粘合剂同时含有-ONO2和-N3基团,其含氮量可达到15%~21%, 结晶性下降,在204 ℃分解,有较大的放热峰,在丙酮等有机溶剂中溶解性很好.

  17. Chiral Phosphoric Acid Catalyzed Enantioselective Allylation of Aldehydes with Allyltrichlorosilane%Chiral Phosphoric Acid Catalyzed Enantioselective Allylation of Aldehydes with Allyltrichlorosilane

    Institute of Scientific and Technical Information of China (English)

    程柯; 范甜甜; 孙健

    2011-01-01

    Easily accessible chiral phosphoric acid lb has been applied as efficient organocatalyst for the asymmetric al- lylation of aldehydes with allyltrichlorosilane. In the presence of 20 mol% of lb, the allylation of a broad range of aldehydes proceeded smoothly to give the corresponding homoallylic alcohol with up to 87% ee and 97% yield.

  18. SN2 reactions with allylic substrates--Trends in reactivity

    Science.gov (United States)

    Ochran, Richard A.; Uggerud, Einar

    2007-09-01

    The gas-phase identity SN2 reactions of allylic substrates has been studied by systematic altering of the nucleophile/nucleofuge X, the remote substituent Y, and the number of methyl substituents at the reaction centre: X- + YCHCHCZ2X --> YCHCHCZ2X + X- (X = H, CH3, NH2, F, Cl; Y = F, OH, H, CHO, BH2; Z = H, CH3). Key regions of the potential energy surfaces have been explored by MP2, B3LYP, G3B3 and G3 calculations; the latter two methods providing accurate estimates of the reaction barrier. The calculations show that irrespective of theoretical level, for the second row of the periodic table (X = CH3, NH2, OH, and F), the tendency is that the barrier height decreases in going from left to right in agreement with the previously observed trend for identity SN2 reactions at methyl. The barrier height decreases by introduction a [pi] electron withdrawing substituents, Y, remote 6rom the reaction centre. The barrier height increases by introducing methyl groups (Z = CH3) next to the reaction centre, but the effect is less than half of that of changing the remote substituent from Y = CHO to Y = OH. The trends cannot be explained by simplified valence bond theory and are discussed in light of a simple electrostatic bonding model of the transition structure.

  19. Allyl isothiocyanate induced stress response in Caenorhabditis elegans

    Directory of Open Access Journals (Sweden)

    Saini AkalRachna K

    2011-11-01

    Full Text Available Abstract Background Allyl isothiocyanate (AITC from mustard is cytotoxic; however the mechanism of its toxicity is unknown. We examined the effects of AITC on heat shock protein (HSP 70 expression in Caenorhabditis elegans. We also examined factors affecting the production of AITC from its precursor, sinigrin, a glucosinolate, in ground Brassica juncea cv. Vulcan seed as mustard has some potential as a biopesticide. Findings An assay to determine the concentration of AITC in ground mustard seed was improved to allow the measurement of AITC release in the first minutes after exposure of ground mustard seed to water. Using this assay, we determined that temperatures above 67°C decreased sinigrin conversion to AITC in hydrated ground B. juncea seed. A pH near 6.0 was found to be necessary for AITC release. RT-qPCR revealed no significant change in HSP70A mRNA expression at low concentrations of AITC ( 1.0 μM resulted in a four- to five-fold increase in expression. A HSP70 ELISA showed that AITC toxicity in C. elegans was ameliorated by the presence of ground seed from low sinigrin B. juncea cv. Arrid. Conclusions • AITC induced toxicity in C. elegans, as measured by HSP70 expression. • Conditions required for the conversion of sinigrin to AITC in ground B. juncea seed were determined. • The use of C. elegans as a bioassay to test AITC or mustard biopesticide efficacy is discussed.

  20. Equilibrium and kinetics study on hexavalent chromium adsorption onto diethylene triamine grafted glycidyl methacrylate based copolymers

    Energy Technology Data Exchange (ETDEWEB)

    Maksin, Danijela D., E-mail: dmaksin@vinca.rs [University of Belgrade, Vinca Institute of Nuclear Sciences, P.O. Box 522, Belgrade (Serbia); Nastasovic, Aleksandra B., E-mail: anastaso@chem.bg.ac.rs [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Njegoseva 12, Belgrade (Serbia); Milutinovic-Nikolic, Aleksandra D., E-mail: snikolic@nanosys.ihtm.bg.ac.rs [University of Belgrade, Institute of Chemistry, Technology and Metallurgy, Njegoseva 12, Belgrade (Serbia); Surucic, Ljiljana T., E-mail: ljilja_m@yahoo.com [University of Belgrade, Faculty of Forestry, Kneza Viseslava 1, Belgrade (Serbia); Sandic, Zvjezdana P., E-mail: zvjezdana.sandic@gmail.com [Faculty of Science, Mladena Stojanovica 2, Banja Luka, Bosnia and Herzegovina (Bosnia and Herzegowina); Hercigonja, Radmila V., E-mail: radah@ffh.bg.ac.rs [University of Belgrade, Faculty of Physical Chemistry, Studentski trg 12-16, 11001 Belgrade (Serbia); Onjia, Antonije E., E-mail: onjia@vinca.rs [University of Belgrade, Vinca Institute of Nuclear Sciences, P.O. Box 522, Belgrade (Serbia)

    2012-03-30

    Highlights: Black-Right-Pointing-Pointer Methacrylate based copolymers grafted with diethylene triamine as Cr(VI) sorbents. Black-Right-Pointing-Pointer Chemisorption and pore diffusion are characteristics of this sorption system. Black-Right-Pointing-Pointer Langmuir isotherm provided best fit and maximum adsorption capacity was 143 mg g{sup -1}. Black-Right-Pointing-Pointer Cr(VI) sorption onto amino-functionalized copolymer was endothermic and spontaneous. Black-Right-Pointing-Pointer A simple, efficient and cost-effective hexavalent chromium removal method. - Abstract: Two porous and one non-porous crosslinked poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) [abbreviated PGME] were prepared by suspension copolymerization and functionalized with diethylene triamine [abbreviated PGME-deta]. Samples were characterized by elemental analysis, mercury porosimetry, scanning electron microscopy with energy-dispersive X-ray spectroscopy, and transmission electron microscopy. Kinetics of Cr(VI) sorption by PGME-deta were investigated in batch static experiments, in the temperature range 25-70 Degree-Sign C. Sorption was rapid, with the uptake capacity higher than 80% after 30 min. Sorption behavior and rate-controlling mechanisms were analyzed using five kinetic models (pseudo-first order, pseudo-second order, Elovich, intraparticle diffusion and Bangham model). Kinetic studies showed that Cr(VI) adsorption adhered to the pseudo-second-order model, with definite influence of pore diffusion. Equilibrium data was tested with Langmuir, Freundlich and Tempkin adsorption isotherm models. Langmuir model was the most suitable indicating homogeneous distribution of active sites on PGME-deta and monolayer sorption. The maximum adsorption capacity from the Langmuir model, Q{sub max}, at pH 1.8 and 25 Degree-Sign C was 143 mg g{sup -1} for PGME2-deta (sample with the highest amino group concentration) while at 70 Degree-Sign C Q{sub max} reached the high value of 198

  1. Surface Heparinization of Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    SUN Hui; CHEN Rui-chao; LIU Shu; XU Guo-zhi

    2012-01-01

    Photo-grafting of hydrophilic monomer and space arms was used to enhance the hydrophilicity of poly(ether ether ketone)(PEEK) with the aim of extending its application to biological fields.PEEK films were surface modified by UV grafting of acrylic acid(AA) to introduce-COOH on PEEK surface.Adipic amine was used as a.space ann to introduce heparin on PEEK surface based on the condensation reaction between -NH2 and -COOH.The modified PEEK(PEEK-COOH,PEEK-NH2 and PEEK-Hep) was characterized by energy-disperse spectroscopy (EDS),X-ray photoelectron spectroscopy(XPS) and water contact angle measurements,which show that heparin was grafted on PEEK surface.The contact angles of modified PEEK films were lower than those of original films,demonstrating a significant improvement of surface hydrophilicity.

  2. ETG举办针对EtherCAT产品提供商的EtherCAT培训

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    随着EtherCAT技术的成功推广,越来越多的中国最终用户对EtherCAT技术及其应用感兴趣,并就EtherCAT产品的需求反馈给相关厂商。同时,EtherCAT的产品供应商将更多的ETherCAT投放到中国市场。因此,这些厂商感到更多更深入地了解EtherCAT技术及相关情况将有助于他们开发相关市场。于是,EtherCAT技术协会中国代表处适时举办针对EtherCAT产品提供商的EtherCAT培训。

  3. Scientific opinion: Risks for human health related to the presence of 3- and 2-monochloropropanediol (MCPD), and their fatty acid esters, and glycidyl fatty acid esters in food

    NARCIS (Netherlands)

    Hoogenboom, L.A.P.

    2016-01-01

    EFSA was asked to deliver a scientific opinion on free and esterified 3- and 2-monochloropropane-1,2-diol (MCPD) and glycidyl esters in food. Esters of 3- and 2-MCPD and glycidol are contaminants of processed vegetable oils; free MCPDs are formed in some processed foods. The Panel on Contaminants in

  4. Controllable Biotinylated Poly(Ethylene-co-Glycidyl Methacrylate) (PE-co-GMA) Nanofibers to Bind Streptavidin-Horseradish Peroxidase (HRP) for Potential Biosensor Applications

    Science.gov (United States)

    Poly(ethylene-co-glycidyl methacrylate) (PE-co-GMA) nanofibers with abundant active epoxy groups on surfaces were fabricated through a novel manufacturing process. The prepared PE-co-GMA nanofibers with different average diameters ranging from 100 to 400 nm were aminated by reacting the epoxy groups...

  5. Catalyst-Free Imidation of Allyl Sulfides with Chloramine-T and Subsequent [2,3]-Sigmatropic Rearrangement

    Institute of Scientific and Technical Information of China (English)

    江玉波; 莫凡洋; 邱迪; 匡春香; 张艳; 王剑波

    2012-01-01

    A facile synthesis of various allyl sulfonamides based on imidation of allyl sulfides with chloramine-T and sub- sequent [2,3]-sigmatropic rearrangement has been achieved without metal catalysts. The reaction completes smoothly within 10 min, providing excellent yields in environment friendly solvent of alcohol. Functional groups such as bromine, hydroxyl, protected amido and aldehyde are tolerant under this condition.

  6. An Efficient Synthesis of de novo Imidates via Aza-Claisen Rearrangements of N-Allyl Ynamides.

    Science.gov (United States)

    Dekorver, Kyle A; North, Troy D; Hsung, Richard P

    2010-10-01

    A novel thermal 3-aza-Claisen rearrangement of N-allyl ynamides for the synthesis of α-allyl imidates is described. Also, a sequential aza-Claisen, Pd-catalyzed Overman rearrangement is described for the synthesis of azapine-2-ones.

  7. Allyl isothiocyanate sensitizes TRPV1 to heat stimulation.

    Science.gov (United States)

    Alpizar, Yeranddy A; Boonen, Brett; Gees, Maarten; Sanchez, Alicia; Nilius, Bernd; Voets, Thomas; Talavera, Karel

    2014-03-01

    The powerful plant-derived irritant allyl isothiocyanate (AITC, aka mustard oil) induces hyperalgesia to heat in rodents and humans through mechanisms that are not yet fully understood. It is generally believed that AITC activates the broadly tuned chemosensory cation channel transient receptor potential cation channel subfamily A member 1 (TRPA1), triggering an inflammatory response that sensitizes the heat sensor transient receptor potential cation channel subfamily V member 1 (TRPV1). In the view of recent data demonstrating that AITC can directly activate TRPV1, we here explored the possibility that this compound sensitizes TRPV1 to heat stimulation in a TRPA1-independent manner. Patch-clamp recordings and intracellular Ca(2+) imaging experiments in HEK293T cells over-expressing mouse TRPV1 revealed that the increase in channel activation induced by heating is larger in the presence of AITC than in control conditions. The analysis of the effects of AITC and heat on the current-voltage relationship of TRPV1 indicates that the mechanism of sensitization is based on additive shifts of the voltage dependence of activation towards negative voltages. Finally, intracellular Ca(2+) imaging experiments in mouse sensory neurons isolated from Trpa1 KO mice yielded that AITC enhances the response to heat, specifically in the subpopulation expressing TRPV1. Furthermore, this effect was strongly reduced by the TRPV1 inhibitor capsazepine and virtually absent in neurons isolated from double Trpa1/Trpv1 KO mice. Taken together, these findings demonstrate that TRPV1 is a locus for cross sensitization between AITC and heat in sensory neurons and may help explaining, at least in part, the role of this channel in AITC-induced hyperalgesia to heat.

  8. How phenyl makes a difference: mechanistic insights into the ruthenium( ii )-catalysed isomerisation of allylic alcohols

    KAUST Repository

    Manzini, Simone

    2013-10-16

    [RuCl(η5-3-phenylindenyl)(PPh3)2] (1) has been shown to be a highly active catalyst for the isomerisation of allylic alcohols to the corresponding ketones. A variety of substrates undergo the transformation, typically with 0.25-0.5 mol% of catalyst at room temperature, outperforming commonly-used complexes such as [RuCl(Cp)(PPh3) 2] and [RuCl(η5-indenyl)(PPh3) 2]. Mechanistic experiments and density functional theory have been employed to investigate the mechanism and understand the effect of catalyst structure on reactivity. These investigations suggest a oxo-π-allyl mechanism is in operation, avoiding intermediate ruthenium hydride complexes and leading to a characteristic 1,3-deuterium shift. Important mechanistic insights from DFT and experiments also allowed for the design of a protocol that expands the scope of the transformation to include primary allylic alcohols. © 2013 The Royal Society of Chemistry.

  9. A Green Approach for Allylations of Aldehydes and Ketones: Combining Allylborate, Mechanochemistry and Lanthanide Catalyst

    Directory of Open Access Journals (Sweden)

    Viviane P. de Souza

    2016-11-01

    Full Text Available Secondary and tertiary alcohols synthesized via allylation of aldehydes and ketones are important compounds in bioactive natural products and industry, including pharmaceuticals. Development of a mechanochemical method using potassium allyltrifluoroborate salt and water, to successfully perform the allylation of aromatic and aliphatic carbonyl compounds is reported for the first time. By controlling the grinding parameters, the methodology can be selective, namely, very efficient for aldehydes and ineffective for ketones, but by employing lanthanide catalysts, the reactions with ketones can become practically quantitative. The catalyzed reactions can also be performed under mild aqueous stirring conditions. Considering the allylation agent and its by-products, aqueous media, energy efficiency and use of catalyst, the methodology meets most of the green chemistry principles.

  10. A Mechanistic Study of Direct Activation of Allylic Alcohols in Palladium Catalyzed Amination Reactions

    Directory of Open Access Journals (Sweden)

    Yasemin Gumrukcu

    2015-03-01

    Full Text Available We here report a computational approach on the mechanism of allylicamination reactions using allyl-alcohols and amines as the substrates and phosphoramidite palladium catalyst 1a, which operates in the presence of catalytic amount of 1,3-diethylurea as a co-catalyst. DFT calculations showed a cooperative hydrogen-bonding array between the urea moiety and the hydroxyl group of the allyl alcohol, which strengthens the hydrogen bond between the O-H moiety of the coordinated allyl-alcohol and the carbonyl-moiety of the ligand. This hydrogen bond pattern facilitates the (rate-limiting C-O oxidative addition step and leads to lower energy isomers throughout the catalytic cycle, clarifying the role of the urea-moiety.

  11. Synthesis and characterization of monosize magnetic poly(glycidyl methacrylate) beads

    Institute of Scientific and Technical Information of China (English)

    Evrim; Banu; Alt1nta

    2007-01-01

    [1]Akg(o)l,S.,& Denizli,A.(2004).Novel metal-chelate affinity sorbents for reversible use in catalase adsorption.Journal of Molecular Catalysis B,28(1),7-14.[2]Altintas,E.B.,& Denizli,A.(2006a).Efficient removal of albumin from human serum by monosize dye-affinity beads.Journal of Chromatography B,832(2),216-223.[3]Altintas,E.B.,& Denizli,A.(2006b).Monosize poly(glycidyl methacrylate)beads for dye-affinity purification of lysozyme.International Journal of Biological Macromolecules,38(2),99-106.[4]Arica,M.Y.,Yavuz,H.,Patir,S.,& Denizli,A.(2000).Immobilization of glucoamylase onto spacer-arm attached magnetic poly(methylmethacrylate)microspheres:Characterization and application to a continuous flow reactor.Journal of Molecular Catalysis B,11(2-3),127-138.[5]Bahar,T.,& Celebi,S.S.(1998).Characterization of glucoamylase immobilized on magnetic poly(styrene) particles.Enzyme and Microbial Technology,23(5),301-304.[6]Bilkova,Z.,Slovakova,M.,Lycka,A.,Horak,D.,Lenfeld,J.,Turkova,J.,et al.(2002).Oriented immobilization of galactose oxidase to bead and magnetic bead cellulose and poly(HEMA-co-EDMA) and magnetic poly(HEMA-coEDMA) microspheres.Journal of Chromatography B,770(1-2),25-34.[7]Bohm,D.,& Pittermann,B.(2000).Magnetically stabilized fluidized beds in biochemical engineering-Investigations in hydrodynamics.Chemical Engineering and Technology,23,309-312.[8]Burns,M.A.,Kvesitadze,G.I.,& Graves,D.J.(1985).Dried calcium alginate/magnetite spheres:A new support for chromatographic separations and enzyme immobilization.Biotechnology and Bioengineering,27(2),137-145.[9]Cherty,A.S.,Gabis,D.H.,& Burns,M.A.(1991).Overcoming support limitations in magnetically stabilized fluidized bed separators.Powder Technology,64(1-2),165-174.[10]Cocker,T.M.,Fee,C.J.,& Evans,R.A.(1997).Preparation of magnetically susceptible polyacrylamide/magnetite beads for use in magnetically stabilized fluidized bed chromatography.Biotechnology and Bioengineering,53(1),79-87.[11]Denizli

  12. Highly selective palladium–benzothiazole carbene-catalyzed allylation of active methylene compounds under neutral conditions

    Directory of Open Access Journals (Sweden)

    Antonio Monopoli

    2015-06-01

    Full Text Available The Pd–benzothiazol-2-ylidene complex I was found to be a chemoselective catalyst for the Tsuji–Trost allylation of active methylene compounds carried out under neutral conditions and using carbonates as allylating agents. The proposed protocol consists in a simplified procedure adopting an in situ prepared catalyst from Pd2dba3 and 3-methylbenzothiazolium salt V as precursors. A comparison of the performance of benzothiazole carbene with phosphanes and an analogous imidazolium carbene ligand is also proposed.

  13. Additive-Free Pd-Catalyzed α-Allylation of Imine-Containing Heterocycles.

    Science.gov (United States)

    Kljajic, Marko; Puschnig, Johannes G; Weber, Hansjörg; Breinbauer, Rolf

    2017-01-06

    An additive-free Pd-catalyzed α-allylation of different imino-group-ontaining heterocycles is reported. The activation of α-CH pronucleophiles (pKa (DMSO) > 25) occurs without the addition of strong bases or Lewis acids using only the Pd/Xantphos catalyst system. The reaction scope has been studied for various 5- and 6-membered nitrogen-containing heterocycles (yields up to 96%). Mechanistic investigations suggest an initial allylation of the imine-N followed by a Pd-catalyzed formal aza-Claisen rearrangement.

  14. Transient overexpression of adh8a increases allyl alcohol toxicity in zebrafish embryos.

    Directory of Open Access Journals (Sweden)

    Nils Klüver

    Full Text Available Fish embryos are widely used as an alternative model to study toxicity in vertebrates. Due to their complexity, embryos are believed to more resemble an adult organism than in vitro cellular models. However, concerns have been raised with respect to the embryo's metabolic capacity. We recently identified allyl alcohol, an industrial chemical, to be several orders of magnitude less toxic to zebrafish embryo than to adult zebrafish (embryo LC50 = 478 mg/L vs. fish LC50 = 0.28 mg/L. Reports on mammals have indicated that allyl alcohol requires activation by alcohol dehydrogenases (Adh to form the highly reactive and toxic metabolite acrolein, which shows similar toxicity in zebrafish embryos and adults. To identify if a limited metabolic capacity of embryos indeed can explain the low allyl alcohol sensitivity of zebrafish embryos, we compared the mRNA expression levels of Adh isoenzymes (adh5, adh8a, adh8b and adhfe1 during embryo development to that in adult fish. The greatest difference between embryo and adult fish was found for adh8a and adh8b expression. Therefore, we hypothesized that these genes might be required for allyl alcohol activation. Microinjection of adh8a, but not adh8b mRNA led to a significant increase of allyl alcohol toxicity in embryos similar to levels reported for adults (LC50 = 0.42 mg/L in adh8a mRNA-injected embryos. Furthermore, GC/MS analysis of adh8a-injected embryos indicated a significant decline of internal allyl alcohol concentrations from 0.23-58 ng/embryo to levels below the limit of detection (< 4.6 µg/L. Injection of neither adh8b nor gfp mRNA had an impact on internal allyl alcohol levels supporting that the increased allyl alcohol toxicity was mediated by an increase in its metabolization. These results underline the necessity to critically consider metabolic activation in the zebrafish embryo. As demonstrated here, mRNA injection is one useful approach to study the role of candidate enzymes

  15. SIDE CHAIN LIQUID CRYSTALLINE POLYSILOXANES CONTAINING CROWN ETHER AND BENZYL ETHER MOIETIES

    Institute of Scientific and Technical Information of China (English)

    1998-01-01

    Two kinds of side chain liquid crystalline polysiloxanes containing crown ether and benzyl ether were synthesized and characterized by optical polarization microscopy. Both the monomeric liquid crystals and polymeric liquid crystals show smectic phases.

  16. Ultrasound assisted free radical polymerization of glycidyl methacrylate by a new disite phase-transfer catalyst system: A kinetic study.

    Science.gov (United States)

    Sankar, Kavitha; Rajendran, Venugopal

    2012-11-01

    The kinetics of multi-site phase-transfer catalyzed free radical polymerisation of glycidyl methacrylate (GMA) using potassium peroxy disulphate (PDS) as water soluble initiator and newly synthesized 1,4-dihexadecylpyrazine-1,4-diium dibromide as multi-site phase-transfer catalyst (MPTC) has been investigated in ethyl acetate/water two phase system at constant temperature 65±1°C under nitrogen atmosphere and ultrasound irradiation conditions. The rate of polymerization increases with an increase in concentrations of GMA, PDS and MPTC. The order with respect to monomer, initiator and MPTC were found to be 1.0, 0.5 and 1.0, respectively. The comparative study reveals that the Rp of GMA determined in the presence of PTC combined with ultrasound has shown more enhancements in the activity than PTC alone. Based on the observed results a suitable mechanism has been proposed to account for the experimental observations and its significance was discussed.

  17. Multifunctional copolymer coating of polyethylene glycol, glycidyl methacrylate, and REDV to enhance the selectivity of endothelial cells.

    Science.gov (United States)

    Wei, Yu; Zhang, Jingxun; Li, Haolie; Zhang, Li; Bi, Hong

    2015-01-01

    Multifunctional polymer coatings have potential applications in biomaterials. These coatings possess reactive functional groups for the immobilization of specific biological factors that can influence cellular behavior. These coatings also display low nonspecific protein adsorption. In this study, we prepared a multifunctional polymer coating through the deposition of random copolymers of poly(ethylene glycol) methacrylate (PEGMA) and glycidyl methacrylate (GMA) to prevent nonspecific attachment and enable the covalence of Arg-Glu-Asp-Val (REDV) peptide with endothelial cells (ECs) selectivity. Coatings were characterized by X-ray photoelectron spectroscopy (XPS). The adhesion and proliferation of ECs and smooth muscle cells (SMCs) onto the REDV-modified surface were investigated to understand the synergistic action of antifouling PEG and EC selective REDV peptide conjugated GMA. The copolymers containing GMA and PEG groups are very useful as a multifunctional coating material with anti-fouling and ECs specific adhesion for implant materials surface modification.

  18. Characterization of amyloglucosidase immobilized on the copolymer of ethylene glycol dimethacrylate and glycidyl methacrylate in simulated industrial conditions

    Directory of Open Access Journals (Sweden)

    Milosavić Nenad B.

    2004-01-01

    Full Text Available The application of amyloglucosidase immobilized on the macroporous co-polymer of ethylene glycol dimethacrylate and glycidyl methacrylate (poly (GMA-co-EGDMA in an enzyme reactor was shown. The higher thermostability of immobilized glucoamylases than the soluble one was demonstrated. Immobilized amyloglucosidase obtained by the periodate method shows two times higher thermo stability than the soluble form. Glucoamylases immobilized on poly (GMA-co-EGDMA have good mechanical and chemical features in the reactor and when applied in a continuous flow reactor for 28 days no changes are observed. In this period periodate immobilized amyloglucosidase shows no decrease in activity. It showed potential for the continuous production of glucose from starch over a prolonged period of time.

  19. Rapid Estimation of Enantioselectivity in Lipase-catalyzed Resolution of Glycidyl Butyrate Using pH Indicator

    Institute of Scientific and Technical Information of China (English)

    WANG Ping; WANG Lei; WANG Li-cheng; LI Chun-yuan; WANG Ren; MIAO Qing-hua; YANG Ming; WANG Zhi

    2009-01-01

    A simple method for rapid estimation of the enantioselectivity of lipase in resolution of chiral esters is described. The enantioselectivity of lipase can be estimated rapidly through comparing the dif-ference of hydrolysis rates for the racemic ester and its slow reacting enantiomer under the same condition because the difference mainly depends on the enantioselective ratio(E values). The higher the enantiose-lectivity of enzyme, the larger the difference of hydrolysis rate. The bromothymol blue(BTB) can be used as pH indicator for microplate reader to monitor the formation of acid in lipase-catalyzed hydrolysis ofesters. This method has been successfully used to rapidly estimate the enantioselectivity of several lipases in the resolution of glycidyl butyrate.

  20. Functional polymers synthesized by grafting of glycidyl methacrylate onto swift heavy ions irradiated BOPP films using chemical initiator

    Energy Technology Data Exchange (ETDEWEB)

    Chawla, Shashi [Amity School of Engineering and Technology, New Delhi (India); Ghosh, Anup K. [Centre for Polymer Science and Engineering, Indian Institute of Technology, New Delhi (India); Avasthi, Devesh K.; Kulriya, Pawan K. [Inter University Accelerator Center, Aruna Asaf Ali Marg, New Delhi (India); Ahmad, Sharif [Materials Research Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi 110 025 (India)], E-mail: sharifahmad_jmi@yahoo.co.in

    2009-07-01

    Commercially available biaxially oriented polypropylene (BOPP) films were irradiated with 90 MeV Ni{sup 8+} ions and 120 MeV Ag{sup 11+} ions at different fluencies varying from 10{sup 10} to 3 x 10{sup 11} ions/cm{sup 2} and then grafted with glycidyl methacrylate (GMA) using benzoyl peroxide (BPO) as chemical initiator. As the reaction temperature was below the melting point, PP was modified in the solid phase. A comparative study for the GMA grafting using BPO initiator in virgin as well as in the SHI irradiated BOPP indicates that the heterogeneity of the grafted GMA domains on the BOPP surface was higher in SHI irradiated system. Contact angle measurements showed an increasingly hydrophilic nature in the direction from pure PP to grafted PP-g-GMA. These results are intended to benefit the synthesis and properties of a functional polymer, useful in developing a compatibilizer for PP/Cloisite 30B nanocomposites.

  1. Organocatalytic asymmetric allylic amination of Morita–Baylis–Hillman carbonates of isatins

    Directory of Open Access Journals (Sweden)

    Hang Zhang

    2012-08-01

    Full Text Available The investigation of a Lewis base catalyzed asymmetric allylic amination of Morita–Baylis–Hillman carbonates derived from isatins afforded an electrophilic pathway to access multifunctional oxindoles bearing a C3-quaternary stereocenter, provided with good to excellent enantioselectivity (up to 94% ee and in high yields (up to 97%.

  2. Polystyrene-supported Selenides and Selenoxide:Versatile Routes to Synthesize Allylic Alcohols

    Institute of Scientific and Technical Information of China (English)

    Wei Ming XU; You Chu ZHANG; Xian HUANG

    2003-01-01

    Several polystyrene-supported selenides and selenoxide have been prepared firstly. These novel reagents were treated with LDA to produce selenium stabilized carbanions, which reacted with aldehydes and alkyl halides, followed by selenoxide syn-elimination and [2,3] sigmatropic rearrangement respectively to give Z-allylic alcohols stereoselectively.

  3. Method of preparing water purification membranes. [polymerization of allyl amine as thin films in plasma discharge

    Science.gov (United States)

    Hollahan, J. R.; Wydeven, T. J., Jr. (Inventor)

    1974-01-01

    Allyl amine and chemically related compounds are polymerized as thin films in the presence of a plasma discharge. The monomer compound can be polymerized by itself or in the presence of an additive gas to promote polymerization and act as a carrier. The polymerized films thus produced show outstanding advantages when used as reverse osmosis membranes.

  4. Facile Formation of Ytterbium Diiodide and Its Use in the Synthesis of Allyl Selenides

    Institute of Scientific and Technical Information of China (English)

    SU,Wei-Ke(苏为科); ZHANG,Yong-Min(张永敏); ZHENG,Yun-Fa(郑云法); LI,Yong-Shu(李永曙)

    2002-01-01

    Ytterbium metal reacts with iodine to generate ytterbium diiodide directly, which can react with diselenides to form ytterbium selenolates (RSeYbI2). These species reacted smoothly with allyl bromide to give allylselenides in moderate to good yields under neutral conditions.

  5. Combined experimental and theoretical mechanistic investigation of the Barbier allylation in aqueous media

    DEFF Research Database (Denmark)

    Dam, Johan Hygum; Fristrup, Peter; Madsen, Robert

    2008-01-01

    -determining step. For Zn, In, Sn, Sb, and Bi, an inverse secondary kinetic isotope effect was found (k(H)/k(D) = 0.75-0.95), which was compatible with the formation of a discrete organometallic species prior to allylation via a closed six-membered transition state. With Mg, a significantly larger build...

  6. Rationalizing Ring-Size Selectivity in Intramolecular Pd-Catalyzed Allylations of Resonance-Stabilized Carbanions

    DEFF Research Database (Denmark)

    Norrby, Per-Ola; Mader, Mary M.; Vitale, Maxime

    2003-01-01

    Computational methods were applied to the Pd-catalyzed intramolecular allylations of resonance-stabilized carbanions obtained from amide and ketone substrates, with the aim of rationalizing the endo- vs. exo-selectivity in the cyclizations. In addition, ester substrates were prepared and subjecte...

  7. Synthesis of allyl esters of fatty acids and their ovicidal effect on Cydia pomonella (L.).

    Science.gov (United States)

    Escribà, Marc; Barbut, Montserrat; Eras, Jordi; Canela, Ramon; Avilla, Jesús; Balcells, Mercè

    2009-06-10

    Eight allyl esters of fatty acids were synthesized in moderate to high yields with a novel two-step procedure using glycerol as a starting material. The two-step methodology avoids the use of allyl alcohol. The first step consisted of heating at 80 degrees C for 48 h a 2:1:5 mmol mixture of glycerol, a fatty acid, and chlorotrimethylsilane in a solvent-free medium. The crude compound was then dissolved in butanone and heated at 115 degrees C in the presence of NaI. A tandem Finkelstein rearrangement-elimination reaction occurs, producing the corresponding allyl ester. The activity of these esters against Cydia pomonella (L.) (Lepidoptera: Tortricidae) eggs was tested in the laboratory by topical application of one 0.1 microL drop. All of the compounds showed a concentration-mortality response and caused 100% mortality at the highest concentration tested (10 mg/mL). There was an inverse relationship between the alkyl chain length and the ovicidal activity of the allyl ester; the LC(50) and the LC(90) of the two compounds that have the longer alkyl chains were significantly higher than those of the rest of the compounds. The ovicidal and IGR activities of this kind of compound appear to be unprecedented.

  8. Zirconium-allyl complexes as resting states in zirconocene-catalyzed α-olefin polymerization.

    Science.gov (United States)

    Panchenko, Valentina N; Babushkin, Dmitrii E; Brintzinger, Hans H

    2015-01-01

    UV-vis spectroscopic data indicate that zirconocene cations with Zr-bound allylic chain ends are generally formed during olefin polymerization with zirconocene catalysts. The rates and extent of their formation and of their re-conversion to the initial pre-catalyst cations depend on the types of zirconocene complexes and activators used.

  9. A Mechanistic Study of Direct Activation of Allylic Alcohols in Palladium Catalyzed Amination Reactions

    NARCIS (Netherlands)

    Gumrukcu, Y.; de Bruin, B.; Reek, J.N.H.

    2015-01-01

    We here report a computational approach on the mechanism of allylicamination reactions using allyl-alcohols and amines as the substrates and phosphoramidite palladium catalyst 1a, which operates in the presence of catalytic amount of 1,3-diethylurea as a co-catalyst. DFT calculations showed a cooper

  10. Cooperative catalysis by palladium and a chiral phosphoric acid: enantioselective amination of racemic allylic alcohols.

    Science.gov (United States)

    Banerjee, Debasis; Junge, Kathrin; Beller, Matthias

    2014-11-24

    Cooperative catalysis by [Pd(dba)2] and the chiral phosphoric acid BA1 in combination with the phosphoramidite ligand L8 enabled the efficient enantioselective amination of racemic allylic alcohols with a variety of functionalized amines. This catalytic protocol is highly regio- and stereoselective (up to e.r. 96:4) and furnishes valuable chiral amines in almost quantitative yield.

  11. In(OTf)3 catalyzed allylation reaction of imines with tetraallyltin

    Institute of Scientific and Technical Information of China (English)

    Xiao Ning Wei; Ling Yan Liu; Bing Wang; Wei Xing Chang; Jing Li

    2009-01-01

    In the presence of catalytic amount of In(OTf)3 (10 mol%), a series of aldimines reacted with tetraallyltin in a 2:1 molar ratio to afford the corresponding homoallylic amines in good yields. The good atom efficiency was achieved under mild reaction conditions and a new protocol (allyl)4Sn/In(OTf)3 for simple imines was developed.

  12. Electrochemical studies and self diffusion coefficients in cyclic ammonium based ionic liquids with allyl substituents

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Tzi-Yi [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China); Department of Polymer Materials, Kun Shan University, Tainan 71003, Taiwan (China); Su, Shyh-Gang [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China); Wang, H. Paul [Department of Environmental Engineering, National Cheng Kung University, Tainan, Taiwan (China); Lin, Yuan-Chung [Institute of Environmental Engineering, National Sun Yat-Sen University, Kaohsiung 804, Taiwan (China); Gung, Shr-Tusen; Lin, Ming-Wei [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China); Sun, I.-Wen, E-mail: iwsun@mail.ncku.edu.t [Department of Chemistry, National Cheng Kung University, Tainan 701, Taiwan (China)

    2011-03-30

    Research highlights: Cyclic ammonium-based ionic liquids with allyl substituent have high conductivity. Ionic liquids with allyl substituent have wide electrochemical window. Electrochemical and self diffusion coefficients are available for comparison. The Stokes-Einstein plots of DT{sup -1} vs. {eta}{sup -1} for redox couples in ILs are evaluated. Stokes-Einstein product of ferrocene is larger than that of cobaltocenium in ILs. - Abstract: Several cyclic ammonium-based ionic liquids (ILs) with allyl substituent are synthesized, these allyl substituent ILs have high ionic conductivity (up to 4.72 mS cm{sup -1} at 30 {sup o}C) and wide electrochemical window of 5 V. The electrochemical behaviors of two organometallic redox couples Fc/Fc{sup +} (ferrocene/ferrocenium) and Cc/Cc{sup +} (cobaltocene/cobaltocenium) have been studied in these ILs, the calculated Stokes-Einstein product (D{eta} T{sup -1}) of ferrocene in ILs is larger than that of cobaltocenium in ILs. The self-diffusion coefficients of cation and anion in these ILs are studied using pulsed gradient spin-echo NMR technique. There are very few reports where electrochemically derived diffusion coefficients and self diffusion coefficients are available for comparison, so a new key concept in electrochemistry could be developed in this paper.

  13. Palladium-catalyzed cross-coupling reactions of allylic halides and acetates with indium organometallics.

    Science.gov (United States)

    Rodríguez, David; Pérez Sestelo, José; Sarandeses, Luis A

    2004-11-12

    The palladium(0)-catalyzed cross-coupling reaction of allylic halides and acetates with indium organometallics is reported. In this synthetic transformation, triorganoindium compounds and tetraorganoindates (aryl, alkenyl, and methyl) react with cinnamyl and geranyl halides and acetates to afford the S(N)2 product regioselectively and in good yield. The reaction proceeds with net inversion of the stereochemical configuration.

  14. Enantioconvergent synthesis by sequential asymmetric Horner-Wadsworth-Emmons and palladium-catalyzed allylic substitution reactions

    DEFF Research Database (Denmark)

    Pedersen, Torben Møller; Hansen, E. Louise; Kane, John

    2001-01-01

    A new method for enantioconvergent synthesis has been developed. The strategy relies on the combination of an asymmetric Horner-Wadsworth-Emmons (HWE) reaction and a palladium-catalyzed allylic substitution. Different $alpha@-oxygen-substituted, racemic aldehydes were initially transformed...

  15. [N-allyl-Dmt1]-endomorphins are micro-opioid receptor antagonists lacking inverse agonist properties.

    Science.gov (United States)

    Marczak, Ewa D; Jinsmaa, Yunden; Li, Tingyou; Bryant, Sharon D; Tsuda, Yuko; Okada, Yoshio; Lazarus, Lawrence H

    2007-10-01

    [N-allyl-Dmt1]-endomorphin-1 and -2 ([N-allyl-Dmt1]-EM-1 and -2) are new selective micro-opioid receptor antagonists obtained by N-alkylation with an allyl group on the amino terminus of 2',6'-dimethyl-L-tyrosine (Dmt) derivatives. To further characterize properties of these compounds, their intrinsic activities were assessed by functional guanosine 5'-O-(3-[35S]thiotriphosphate) binding assays and forskolin-stimulated cyclic AMP accumulation in cell membranes obtained from vehicle, morphine, and ethanol-treated SK-N-SH cells and brain membranes isolated from naive and morphine-dependent mice; their mode of action was compared with naloxone or naltrexone, which both are standard nonspecific opioid-receptor antagonists. [N-allyl-Dmt1]-EM-1 and -2 were neutral antagonists under all of the experimental conditions examined, in contrast to naloxone and naltrexone, which behave as neutral antagonists only in membranes from vehicle-treated cells and mice but act as inverse agonists in membranes from morphine- and ethanol-treated cells as well as morphine-treated mice. Both endomorphin analogs inhibited the naloxone- and naltrexone-elicited withdrawal syndromes from acute morphine dependence in mice. This suggests their potential therapeutic application in the treatment of drug addiction and alcohol abuse without the adverse effects observed with inverse agonist alkaloid-derived compounds that produce severe withdrawal symptoms.

  16. A Novel, One-Step Palladium and Phenylsilane Activated Amidation from Allyl Ester on Solid Support

    Directory of Open Access Journals (Sweden)

    Zheming Ruan

    2008-01-01

    Full Text Available The direct conversion of solid-supported carboxylic acid allyl esters to carboxamides through the use of phenylsilane and catalytic Pd(PPh34 under mild reaction conditions is reported. The use of this methodology for the generation of a 48 compound solid-phase array is described herein.

  17. Copper-catalyzed asymmetric allylic substitution reactions with organozinc and Grignard reagents

    NARCIS (Netherlands)

    Geurts, Koen; Fletcher, Stephen P.; van Zijl, Anthoni W.; Minnaard, Adriaan J.; Feringa, Ben L.; Bignall, H. E.; Jauncey, D. L.; Lovell, J. E. J.; Tzioumis, A. K.; Kedziora-Chudczer, L. L.; MacQuart, J. P.; Tingay, S. J.; Rayner, D. P.; Clay, R. W.

    2008-01-01

    Asymmetric allylic alkylations (AAAs) are among the most powerful C-C bond-forming reactions. We present a brief overview of copper-catalyzed AAAs with organometallic reagents and discuss our own contributions to this field. Work with zinc reagents and phosphoramidite ligands provided a framework fo

  18. Theoretical Study on the Dark Oxidation Reaction Mechanism of Ethers

    Institute of Scientific and Technical Information of China (English)

    WANG Gui-Xiu; ZHU Rong-Xiu; ZHANG Dong-Ju; LIU Cheng-Bu

    2006-01-01

    The dark oxidation reactions of ethers including aether, isopropyl ether, phenyl isopropyl ether, and benzyl isopropyl ether have been studied by using density functional theory calculations. The structures of initial contact charge transfer complexes (CCTCs), transition states and caged radical intermediates have been located at the B3LYP/6-31G (d) level. The bonding nature of ethers with triplet O2 in CCTCs has been analyzed, and the detailed mechanism of dark oxidation reactions of ether is presented clearly.

  19. Synthesis and Characterization of Poly(ether amide)s Containing Bisphthalazinone and Ether Linkages

    Institute of Scientific and Technical Information of China (English)

    Cheng LIU; Shou Hai ZHANG; Ming Jing WANG; Qi Zhen LIANG; Xi Gao JIAN

    2005-01-01

    A novel aromatic diacid, 4, 4'-bis[2-(4-carboxyphenyl)phthalazin-1-one-4-yl]-bisphenyl ether Ⅲ, containing bisphthalazinone and ether linkages was prepared from nucleophilic substitution of p-chlorobenzonitrile with the bisphenol-like monomer Ⅰ, followed by alkaline hydrolysis of the intermediate dinitrile Ⅱ. A series of poly(ether amide)s containing bisphthalazinone and ether linkages derived from diacid Ⅲ and aromatic diamines were synthesized by one-step solution condensation polymerization using triphenyl phosphite and pyridine as condensing agents. Moreover, the properties of poly(ether amide)s including thermal stability,solubility and crystallinity were also studied.

  20. Synthesis, Characterization, and Some Properties of Cp*W(NO)(H)(η(3)-allyl) Complexes.

    Science.gov (United States)

    Baillie, Rhett A; Holmes, Aaron S; Lefèvre, Guillaume P; Patrick, Brian O; Shree, Monica V; Wakeham, Russell J; Legzdins, Peter; Rosenfeld, Devon C

    2015-06-15

    Sequential treatment at low temperatures of Cp*W(NO)Cl2 in THF with 1 equiv of a binary magnesium allyl reagent, followed by an excess of LiBH4, affords three new Cp*W(NO)(H)(η(3)-allyl) complexes, namely, Cp*W(NO)(H)(η(3)-CH2CHCMe2) (1), Cp*W(NO)(H)(η(3)-CH2CHCHPh) (2), and Cp*W(NO)(H)(η(3)-CH2CHCHMe) (3). Complexes 1-3 are isolable as air-stable, analytically pure yellow solids in good to moderate yields by chromatography or fractional crystallization. In solutions, complex 1 exists as two coordination isomers in an 83:17 ratio differing with respect to the endo/exo orientation of the allyl ligand. In contrast, complexes 2 and 3 each exist as four coordination isomers, all differing by the orientation of their allyl ligands which can have either an endo or an exo orientation with the phenyl or methyl groups being either proximal or distal to the nitrosyl ligand. A DFT computational analysis using the major isomer of Cp*W(NO)(H)(η(3)-CH2CHCHMe) (3a) as the model complex has revealed that its lowest-energy thermal-decomposition pathway involves the intramolecular isomerization of 3a to the 16e η(2)-alkene complex, Cp*W(NO)(η(2)-CH2═CHCH2Me). Such η(2)-alkene complexes are isolable as their 18e PMe3 adducts when compounds 1-3 are thermolyzed in neat PMe3, the other organometallic products formed during these thermolyses being Cp*W(NO)(PMe3)2 (5) and, occasionally, Cp*W(NO)(H)(η(1)-allyl)(PMe3). All new complexes have been characterized by conventional spectroscopic and analytical methods, and the solid-state molecular structures of most of them have been established by single-crystal X-ray crystallographic analyses.

  1. 27 CFR 21.108 - Ethyl ether.

    Science.gov (United States)

    2010-04-01

    ... 27 Alcohol, Tobacco Products and Firearms 1 2010-04-01 2010-04-01 false Ethyl ether. 21.108 Section 21.108 Alcohol, Tobacco Products and Firearms ALCOHOL AND TOBACCO TAX AND TRADE BUREAU, DEPARTMENT....108 Ethyl ether. (a) Odor. Characteristic odor. (b) Specific gravity at 15.56 °/15.56 °C. Not...

  2. The Wacker oxidation of allyl alcohol along cyclic-intermediate routes: An ab initio molecular dynamics investigation

    Science.gov (United States)

    Imandi, Venkataramana; Nair, Nisanth N.

    2016-09-01

    The absence of isotope scrambling observed by Henry and coworkers in the Wacker oxidation of deuterated allylic alcohol was used by them as support for the inner-sphere mechanism hydroxypalladation mechanism. One of the assumptions used to interpret their experimental data was that allyl alcohol oxidation takes place through non-cyclic intermediate routes as in the case of ethene. Here we verify this assumption through ab initio metadynamics simulations of the Wacker oxidation of allyl alcohol in explicit solvent. Importance of our results in interpreting the isotope scrambling experiments is discussed.

  3. Deconvoluting the memory effect in Pd-catalyzed allylic alkylation; effect of leaving group and added chloride

    DEFF Research Database (Denmark)

    Fristrup, Peter; Jensen, Thomas; Hoppe, Jakob;

    2006-01-01

    An analysis of product distributions in the Tsuji-Trost reaction indicates that several instances of reported memory effects can be attributed to slow interconversion of the initially formed syn- and anti-[Pd(eta3-allyl)] complexes. Addition of chloride triggers a true memory effect, in which...... the allylic terminus originally bearing the leaving group has a higher reactivity. The latter effect, termed regioretention, can be rationalized by ionization from a palladium complex bearing a chloride ion, forming an unsymmetrically substituted [Pd(eta3-allyl)] complex. DFT calculations verify...

  4. An expedient synthesis of linden ether.

    Science.gov (United States)

    Serra, Stefano; Cominetti, Alessandra A

    2014-03-01

    We here describe a comprehensive study on the preparation of the intensive flavor 3,9-epoxy-p-mentha-1,4(8)-diene (1). Key steps of the presented synthesis are the selective addition of MeLi to the keto-ester 7, the regioselective cyclization of the obtained triol to give the ethers 4 and 8 and the selective dehydration of ether 4 through the use of POCI3 and pyridine. It is worth noting that the presented synthesis represents the first expedient and reliable entry to ether 1. Being present in linden honey, 1 is also known as linden ether and it has been regarded as a potential marker for the authentication of the linden honey origin. Therefore, ether 1 can be used as a useful reference standard for the analysis of the natural flavors, as we demonstrated by means of its identification in a sample ofunifloral linden honey.

  5. Preparation of Novel Poly(hydroxyethyl methacrylate-co-glycidyl methacrylate-Grafted Core-Shell Magnetic Chitosan Microspheres and Immobilization of Lactase

    Directory of Open Access Journals (Sweden)

    Wendy Katiyo

    2013-06-01

    Full Text Available Poly(hydroxyethyl methacrylate-co-glycidyl methacrylate-grafted magnetic chitosan microspheres (HG-MCM were prepared using reversed-phase suspension polymerization method. The HG-MCM presented a core-shell structure and regular spherical shape with poly(hydroxyethyl methacrylate-co-glycidyl methacrylate grafted onto the chitosan layer coating the Fe3O4 cores. The average diameter of the magnetic microspheres was 10.67 μm, within a narrow size distribution of 6.6–17.4 μm. The saturation magnetization and retentivity of the magnetic microspheres were 7.0033 emu/g and 0.6273 emu/g, respectively. The application of HG-MCM in immobilization of lactase showed that the immobilized enzyme presented higher storage, pH and thermal stability compared to the free enzyme. This indicates that HG-MCM have potential applications in bio-macromolecule immobilization.

  6. Synthesis of New Elastomers with Controlled Structures Based on Alkylene Oxides, Grafted by ROMP

    Science.gov (United States)

    Spurcaciu, Bogdan; Dragutan, Ileana; Nicolae, Cristian-Andi; Buzdugan, Emil; Dragutan, Valerian

    Poly(propylene oxide-ran-allyl glycidyl ether) (PPO-AGE) copolymers have been prepared using as initiating system an alkyl aluminum compound, controlled amounts of water and different organic compounds that act as cocatalysts, e.g. ethers, diols, phosphines, salicylic acid derivatives, and organozinc compounds. Among the investigated catalysts the most productive systems showed to be the ternary systems derived from triisobutylaluminum (TIBA) and water having Zn(acac)2 as a third component. These copolymers have subsequently been grafted by ringopening metathesis polymerization (ROMP) with cyclooctene in the presence of Grubbs first-generation ruthenium (Ru) catalyst to produce new comblike copolymers.

  7. The magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group and its application to a highly stereoselective synthesis of (+/-)-matatabiether. Allylmagnesium compounds by reductive magnesiation of allyl phenyl sulfides.

    Science.gov (United States)

    Cheng, D; Zhu, S; Yu, Z; Cohen, T

    2001-01-10

    The first example of a magnesium-ene cyclization stereochemically directed by an allylic oxyanionic group is demonstrated by a highly stereoselective synthesis of the bicyclic terpene matatabiether 10. The synthetic method is particularly valuable, not only because of the stereochemical control and the utility of the versatile hydroxyl group introduced into the product, but also because the precursor of the allylmagnesium is an allyl phenyl sulfide, which is more stable and more easily prepared in a connective fashion than the usual allyl halide precursor. Since the presence of lithium ions encourages undesirable proton transfer to the cyclized organometallic and is detrimental to the stereochemical control, the conversion of the allylic thioether to the allylmagnesium utilizes a lithium-free method involving direct reductive magnesiation in the presence of the magnesium-anthracene complex.

  8. Macrokinetic calculation of the ignition of a solid-fuel charge of glycidyl azide polymer in the mini-engine of a microelectromechanical system

    Science.gov (United States)

    Fut'ko, S. I.; Ermolaeva, E. M.; Dobrego, K. V.; Bondarenko, V. P.; Dolgii, L. N.

    2011-11-01

    The process of ignition of the solid fuel from glycidyl azide polymer in the mini-engine of a microelectromechanical system has been considered. Macrokinetic calculations of the self-ignition temperature of the fuel and the induction period for different heat transfer conditions have been made. On the basis of the critical thermal flux determination, recommendations on the choice of the minimum power and size of the thermistor in the igniter of the solid-fuel mini-engine have been formulated.

  9. Poly(glycidyl methacrylate-co-N-methylolacrylamide-co-ethylene dimethacrylate) monolith coupled to high-performance liquid chromatography for the determination of adenosine phosphates in royal jelly.

    Science.gov (United States)

    Liu, Dan; Zhang, Tianbin; Cheng, Yechun; Jia, Qiong

    2014-07-01

    A polymer monolith microextraction method coupled with high-performance liquid chromatography was developed for the determination of adenosine triphosphate, adenosine diphosphate, and adenosine monophosphate. The monolithic column was synthesized inside fused-silica capillaries using thermal initiation free-radical polymerization with glycidyl methacrylate as the monomer, ethylene dimethacrylate as the cross-linker, cyclohexanol, and 1-dodecanol as the porogen. N-Methylolacrylamide, an important hydrophilic monomer, was incorporated into the polymerization mixture to enhance the hydrophilicity of the poly(glycidyl methacrylate-co-ethylene dimethacrylate) column. The obtained poly(glycidyl methacrylate-co-N-methylolacrylamide-co-ethylene dimethacrylate) monolith was characterized by scanning electron microscopy, Fourier-transform infrared spectra, and X-ray photoelectron spectroscopy. Optimum conditions for the preconcentration and separation of the target adenosines were also investigated. Under the optimum conditions, we obtained acceptable linearities, low limits of detection, and good relative standard deviations. The developed polymer monolith microextraction with high-performance liquid chromatography method exhibited a good performance with recovery values in the range of 76.9-104.7% when applied to the determination of the adenosines in five royal jelly samples.

  10. From the tunneling dimer to the onset of microsolvation: Infrared spectroscopy of allyl radical water aggregates in helium nanodroplets

    Science.gov (United States)

    Leicht, Daniel; Kaufmann, Matin; Pal, Nitish; Schwaab, Gerhard; Havenith, Martina

    2017-03-01

    The infrared spectrum of allyl:water clusters embedded in helium nanodroplets was recorded. Allyl radicals were produced by flash vacuum pyrolysis and trapped in helium droplets. Deuterated water was added to the doped droplets, and the infrared spectrum of the radical water aggregates was recorded in the frequency range 2570-2820 cm-1. Several absorption bands are observed and assigned to 1:1 and 1:2 allyl:D2O clusters, based on pressure dependent measurements and accompanying quantum chemical calculations. The analysis of the 1:1 cluster spectrum revealed a tunneling splitting as well as a combination band. For the 1:2 cluster, we observe a water dimer-like motif that is bound by one π-hydrogen bond to the allyl radical.

  11. Chemoenzymatic one-pot synthesis in an aqueous medium: combination of metal-catalysed allylic alcohol isomerisation-asymmetric bioamination.

    Science.gov (United States)

    Ríos-Lombardía, Nicolás; Vidal, Cristian; Cocina, María; Morís, Francisco; García-Álvarez, Joaquín; González-Sabín, Javier

    2015-07-11

    The ruthenium-catalysed isomerisation of allylic alcohols was coupled, for the first time, with asymmetric bioamination in a one-pot process in an aqueous medium. In the cases involving prochiral ketones, the ω-TA exhibited excellent enantioselectivity, identical to that observed in the single step. As a result, amines were obtained from allylic alcohols with high overall yields and excellent enantiomeric excesses.

  12. Photopolymerization of Glycerin Triglycidyl Ether Based Systems

    Institute of Scientific and Technical Information of China (English)

    HUANG Biwu; CHEN Yiwang; DENG Qilan

    2008-01-01

    Photopolymerization process of glycerin triglycidyl ether based systems was studied by an FT-IR spectrometer.An increase in the rate of polymerization for glycerin triglycidyl ether was evident when 3,4-epoxycyclohexylmethyl-3',4'-epoxycyclohexanecarboxylate was added to it.Its copolymerization mechanism was confirmed by using DSC analysis.The effect of ethoxylated trimethyol propane triacrylate on the rate of polymerization for glycerin triglycidyl ether was also studied,and the formation of interpenetrating network tightly cross-link was proposed.

  13. Atmospheric lifetimes of selected fluorinated ether compounds

    DEFF Research Database (Denmark)

    Heathfield, A.E.; Anastasi, C.; Pagsberg, Palle Bjørn;

    1998-01-01

    Atmospheric lifetimes have been estimated for a selection of ethers, the latter representing a class of compounds being considered as replacements for chlorofluorocarbons. The estimates are based on laboratory measurements of rate constants for the reaction of the OH radical with the ethers......, and a comparison with the behaviour of methyl chloroform in the atmosphere. The lifetimes for the ethers ranged from a few hours to half a year, significantly lower than those of chlorofluorocarbons and other replacements being considered. (C) 1998 Elsevier Science Ltd. All rights reserved....

  14. Synthesis, characterization and evaluation of antioxidant and anticancer activities of novel benzisoxazole-substituted-allyl derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Anand, Mohanam [Kingston Engineering College, Vellore (India); Selvaraj, Vaithialingam [University College of Engineering-Villupuram, Villupuram (India); Alagar, Muthukaruppan [Anna University, Chennai (India)

    2014-04-15

    A novel series of various 2-allylbenzo[d]isoxazol-3(2H)-ones were synthesized using benzo[d]isoxazol-3(2H)-one treated with different allyl bromides/chlorides in the presence of water-mediated cesium carbonate as a new catalyst 3(a-h). The structures of the newly synthesized Benzisoxazole-substituted-allyl derivatives were characterized by spectroscopic methods and mass spectrometry. These synthesized compounds were evaluated for their in vitro antioxidant and anticancer activity. Compounds 3b, d, f, h were identified as the best hit against HT-29 Human colon cancer cells. Similarly, compounds like 3b, d, f, h showed significant antioxidant activity compared to the standard drug butylated hydroxy toluene (BHT)

  15. Recent Advances in the Application of Chiral Phosphine Ligands in Pd-Catalysed Asymmetric Allylic Alkylation

    Directory of Open Access Journals (Sweden)

    Erika Martin

    2011-01-01

    Full Text Available One of the most powerful approaches for the formation of simple and complex chiral molecules is the metal-catalysed asymmetric allylic alkylation. This reaction has been broadly studied with a great variety of substrates and nucleophiles under different reaction conditions and it has promoted the synthesis of new chiral ligands to be evaluated as asymmetric inductors. Although the mechanism as well as the active species equilibria are known, the performance of the catalytic system depends on the fine tuning of factors such as type of substrate, nucleophile nature, reaction medium, catalytic precursor and type of ligand used. Particularly interesting are chiral phosphines which have proved to be effective asymmetric inductors in several such reactions. The present review covers the application of phosphine-donor ligands in Pd-catalysed asymmetric allylic alkylation in the last decade.

  16. Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso-ene mechanism.

    Science.gov (United States)

    Porter, David; Poon, Belinda M-L; Rutledge, Peter J

    2015-01-01

    Iron(II) complexes of the tetradentate amines tris(2-pyridylmethyl)amine (TPA) and N,N'-bis(2-pyridylmethyl)-N,N'-dimethylethane-1,2-diamine (BPMEN) are established catalysts of C-O bond formation, oxidising hydrocarbon substrates via hydroxylation, epoxidation and dihydroxylation pathways. Herein we report the capacity of these catalysts to promote C-N bond formation, via allylic amination of alkenes. The combination of N-Boc-hydroxylamine with either FeTPA (1 mol %) or FeBPMEN (10 mol %) converts cyclohexene to the allylic hydroxylamine (tert-butyl cyclohex-2-en-1-yl(hydroxy)carbamate) in moderate yields. Spectroscopic studies and trapping experiments suggest the reaction proceeds via a nitroso-ene mechanism, with involvement of a free N-Boc-nitroso intermediate. Asymmetric induction is not observed using the chiral tetramine ligand (+)-(2R,2'R)-1,1'-bis(2-pyridylmethyl)-2,2'-bipyrrolidine ((R,R')-PDP).

  17. [Surface modification of poly methyl methacrylate intraocular lens by alpha-allyl glucoside].

    Science.gov (United States)

    Qu, Chao; Yao, Ke; Kou, Ruiqiang; Xu, Zhikang

    2004-02-01

    A method for improving the biocompatibility of the intraocular lens (IOL) and reducing the cell attachment was adopted in this study. The alpha-Allyl glucoside was used for the surface modification of the poly methyl methacrylate (PMMA) IOL by way of plasma-induced in situ polymerization. The surfaces of the control and treatment IOLs were characterized by contact angle estimation and ESCA techniques. The resolution, diopter and anti-fatigue of loops were determined by physical and optical methods. Cell attachment on the surfaces was examined by light microscopy. The results indicated that all of the treatment groups had excellent physical and optical properties. The modification with the use of alpha-Allyl glucoside could improve the hydrophilicity of the anterior surface of the PMMA IOLs and reduce the cell attachment.

  18. Epoxidation of allyl alcohol to glycidol over the microporous TS-1 catalyst.

    Science.gov (United States)

    Wróblewska, Agnieszka; Fajdek, Anna

    2010-07-15

    The results of the epoxidation of allyl alcohol with 30% hydrogen peroxide over the TS-1 catalyst have been presented. The studies were carried out under the atmospheric pressure and at the presence of methanol as a solvent. The influence of the following technological parameters on the course of epoxidation was examined: the temperature of 20-60 degrees C, the molar ratio of AA/H(2)O(2) 1:1-5:1, the methanol concentration of 5-90 wt%, the catalyst content of 0.1-5.0 wt% and the reaction time 5-300 min. The main functions describing the process were the selectivity to glycidol in relation to allyl alcohol consumed, the conversion of substrates, and the selectivity of transformation to organic compounds in relation to hydrogen peroxide consumed. The parameters at which the functions describing the process reached the highest values were determined.

  19. Crystal structure of (E-3-allyl-2-sulfanylidene-5-[(thiophen-2-ylmethylidene]thiazolidin-4-one

    Directory of Open Access Journals (Sweden)

    Rahhal El Ajlaoui

    2015-06-01

    Full Text Available Molecules of the title compound, C11H9NOS3, are built up by one thiophene and one 2-thioxathiazolidin-4-one ring which are connected by a methylene bridge. In addition, there is an allyl substituent attached to nitrogen. The two rings are almost coplanar, making a dihedral angle between them of 0.76 (11°. The allyl group is oriented perpendicular to the mean plane through both ring systems. The crystal structure exhibits inversion dimers in which molecules are linked by pairs of C—H...O hydrogen bonds. Additional π–π interactions between neighboring thiophene and 2-thioxathiazolidin-4-one rings [intercentroid distance = 3.694 (2 Å] lead to the formation of a three-dimensional network.

  20. Synthetic Studies on Tricyclic Diterpenoids: Direct Allylic Amination Reaction of Isopimaric Acid Derivatives.

    Science.gov (United States)

    Timoshenko, Mariya A; Kharitonov, Yurii V; Shakirov, Makhmut M; Bagryanskaya, Irina Yu; Shults, Elvira E

    2016-02-01

    A selective synthesis of 7- or 14-nitrogen containing tricyclic diterpenoids was completed according to a strategy in which the key step was the catalyzed direct allylic amination of methyl 14α-hydroxy-15,16-dihydroisopimarate with a wide variety of nitrogenated nucleophiles. It was revealed that the selectivity of the reaction depends on the nature of nucleophile. The catalyzed reaction of the mentioned diterpenoid allylic alcohol with 3-nitroaniline, 3-(trifluoromethyl)aniline, and 4-(trifluoromethyl)aniline yield the subsequent 7α-, 7β- and 14αnitrogen-containing diterpenoids. The reaction with 2-nitroaniline, 4-nitro-2-chloroaniline, 4-methoxy-2-nitroaniline, phenylsulfamide, or tert-butyl carbamate proceeds with the formation of 7α-nitrogen-substituted diterpenoids as the main products.

  1. Posidonia oceanica as a Renewable Lignocellulosic Biomass for the Synthesis of Cellulose Acetate and Glycidyl Methacrylate Grafted Cellulose

    Directory of Open Access Journals (Sweden)

    Elena Vismara

    2013-05-01

    Full Text Available High-grade cellulose (97% α-cellulose content of 48% crystallinity index was extracted from the renewable marine biomass waste Posidonia oceanica using H2O2 and organic peracids following an environmentally friendly and chlorine-free process. This cellulose appeared as a new high-grade cellulose of waste origin quite similar to the high-grade cellulose extracted from more noble starting materials like wood and cotton linters. The benefits of α-cellulose recovery from P. oceanica were enhanced by its transformation into cellulose acetate CA and cellulose derivative GMA-C. Fully acetylated CA was prepared by conventional acetylation method and easily transformed into a transparent film. GMA-C with a molar substitution (MS of 0.72 was produced by quenching Fenton’s reagent (H2O2/FeSO4 generated cellulose radicals with GMA. GMA grafting endowed high-grade cellulose from Posidonia with adsorption capability. GMA-C removes β-naphthol from water with an efficiency of 47%, as measured by UV-Vis spectroscopy. After hydrolysis of the glycidyl group to glycerol group, the modified GMA-C was able to remove p-nitrophenol from water with an efficiency of 92%, as measured by UV-Vis spectroscopy. α-cellulose and GMA-Cs from Posidonia waste can be considered as new materials of potential industrial and environmental interest.

  2. Improvement of the Thermal, Photo and Mechanical Properties of Poly (Vinyl Chloride in Presence of Poly (Glycidyl Methacrylate

    Directory of Open Access Journals (Sweden)

    Abir S. Abdel-Naby

    2011-01-01

    Full Text Available Problem statement: Poly (vinyl chloride suffers from poor heat stability. The thermal degradation of the polymer leads to the evolution of hydrogen chloride gas, extensive discoloration of the polymer and lowering of physical and mechanical properties. Approach: Binary blends of Poly (Vinyl Chloride (PVC and Poly (Glycidyl Methacrylate (PGMA have been prepared by solution blending aimed at the improvement of thermal and mechanical properties. Results and Conclusion: Thermal properties of the blends were studied using Scanning Calorimetry (DSC, Thermogravimetry (TGA and potentiometric rate of dehydrochlorination. The increase of the PGMA content in the blend leads to thermal stability of the blend as shown from the thermogravimetry and the rate of dehydrochlorination results. All blends exhibited one major glass transition temperature (Tg whose position on the temperature scale was lowered with increased level of PGMA. The miscibility of blends was also confirmed by the use of Scanning Electron Microscope (SEM. The improvement of the mechanical properties of various blends of the two polymers was also obtained.

  3. The Effect of Type of Oil and Degree of Degradation on Glycidyl Esters Content During the Frying of French Fries.

    Science.gov (United States)

    Aniołowska, Magda; Kita, Agnieszka

    The aim of the study was to determine the effect of oil degradation on the content of glycidyl esters (GEs) in oils used for the frying of French fries. As frying media, refined oils such as rapeseed, palm, palm olein and blend were used. French fries were fried for 40 h in oils heated to 180 °C in 30-min cycles. After every 8 h of frying, fresh oil and samples were analyzed for acid and anisidine values, color, refractive index, fatty acid composition, and content and composition of the polar fraction. GEs were determined by LC-MS. Hydrolysis and polymerization occurred most intensively in palm olein, while oxidation was reported for rapeseed oil. The degradation of oil caused increased changes in the RI of frying oils. Losses of mono- and polyunsaturated fatty acids were observed in all samples, with the largest share in blend. The highest content of GE found in fresh oil was in palm olein (25 mg kg(-1)) and the lowest content of GE was found in rapeseed oil (0.8 mg kg(-1)). The palm oil, palm olein and blend were dominated by GEs of palmitic and oleic acids, while rapeseed oil was dominated by GE of oleic acid. With increasing frying time, the content of GEs decreased with losses from 47 % in rapeseed oil to 78 % in palm oil after finishing frying.

  4. Radiation grafting of glycidyl methacrylate and divinylbenzene onto polyethylene terephthalate fabrics for improving anti-dripping performance

    Science.gov (United States)

    Chen, Xu; Wang, Yue; Dai, Guoliang; Peng, Jing; Li, Jiuqiang; Shi, Meiwu; Zhai, Maolin

    2016-10-01

    A new kind of anti-dripping polyethylene terephthalate (PET) fabric was successfully prepared by simultaneous gamma radiation-induced grafting polymerization of glycidyl methacrylate (GMA) and divinylbenzene (DVB) onto the surface of PET fabrics. The grafting yield (GY) and anti-dripping effect were optimized by changing the total absorbed dose, dose rate, concentration and the feed ratio of GMA and DVB. The grafting yield increased with the increase of absorbed dose and GMA monomer concentration, and decreased with the dose rate. It is confirmed that PET fabrics had been modified by Fourier transform infrared spectroscopy analysis. The tensile strength and elongation at break of modified PET fabrics were improved compared with original PET fabrics. The limiting oxygen index (LOI) of modified PET fabrics with the GY of 23-25% was 21.5, which was similar to that of unmodified PET fabrics. However, the anti-dripping performance of PET fabrics was improved remarkably after radiation modification due to the crosslinking of the sidechains grafted on the PET surface. This anti-dripping fabric may be promising for fire protective clothing.

  5. Surface modification of glycidyl-containing poly(methyl methacrylate) microchips using surface-initiated atom-transfer radical polymerization.

    Science.gov (United States)

    Sun, Xuefei; Liu, Jikun; Lee, Milton L

    2008-02-01

    Fabrication of microfluidic systems from polymeric materials is attractive because of simplicity and low cost. Unfortunately, the surfaces of many polymeric materials can adsorb biological samples. Therefore, it is necessary to modify their surfaces before these polymeric materials can be used for separation and analysis. Oftentimes it is difficult to modify polymeric surfaces because of their resistance to chemical reaction. Recently, we introduced a surface-reactive acrylic polymer, poly(glycidyl methacrylate-co-methyl methacrylate) (PGMAMMA), which can be modified easily and is suitable for fabrication of microfluidic devices. Epoxy groups on the surface can be activated by air plasma treatment, hydrolysis, or aminolysis. In this work, the resulting hydroxyl or amino groups were reacted with 2-bromoisobutylryl bromide to introduce an initiator for surface-initiated atom-transfer radical polymerization (SI-ATRP). Polyethylene glycol (PEG) layers grown on the surface using this method were uniform, hydrophilic, stable, and resistant to protein adsorption. Contact angle measurement and X-ray photoelectron spectroscopy (XPS) were used to characterize activated polymer surfaces, initiator-bound surfaces, and PEG-grafted surfaces. We obtained excellent capillary electrophoresis (CE) separations of proteins and peptides with the PEG-modified microchips. A separation efficiency of 4.4 x 10(4) plates for a 3.5 cm long separation channel was obtained.

  6. 基于FPGA的EtherCAT从站节点开发%FPGA- based Development of EtherCAT Slave Node

    Institute of Scientific and Technical Information of China (English)

    李昆; 杨建武

    2011-01-01

    随着实时工业以太网技术在工业自动化领域的发展和应用,德国倍福公司推出的EtherCAT技术尤其备受瞩目.EtherCAT技术的核心在于EtherCAT通信机制、EtherCAT主站和EtherCAT从站节点.EtherCAT从站节点通常是采用EtherCAT从站控制芯片和从站控制微处理器来设计实现的,对此提出了一种使用FPGA技术开发实现EtherCAT从站节点功能的方法,并验证了方法的可行性.%With the development and application of the real - time industrial Ethernet technology in industrial automation, EtherCAT technology introduced by Beckhoff is especially well received. The core of EtherCAT technology is the EtherCAT communication mechanisms, EtherCAT Master and EtherCAT Slave Node. EtherCAT slave node is usually designed by using EtherCAT slave controller chip and slave control microprocessor chip to achieve its function, this paper presents a method which is using FPGA technology to develop the EtherCAT slave node, and verifies the feasibility of it.

  7. A transferable force field to predict phase equilibria and surface tension of ethers and glycol ethers.

    Science.gov (United States)

    Ferrando, Nicolas; Lachet, Véronique; Pérez-Pellitero, Javier; Mackie, Allan D; Malfreyt, Patrice; Boutin, Anne

    2011-09-15

    We propose a new transferable force field to simulate phase equilibrium and interfacial properties of systems involving ethers and glycol ethers. On the basis of the anisotropic united-atom force field, only one new group is introduced: the ether oxygen atom. The optimized Lennard-Jones (LJ) parameters of this atom are identical whatever the molecule simulated (linear ether, branched ether, cyclic ether, aromatic ether, diether, or glycol ether). Accurate predictions are achieved for pure compound saturated properties, critical properties, and surface tensions of the liquid-vapor interface, as well as for pressure-composition binary mixture diagrams. Multifunctional molecules (1,2-dimethoxyethane, 2-methoxyethanol, diethylene glycol) have also been studied using a recently proposed methodology for the calculation of the intramolecular electrostatic energy avoiding the use of additional empirical parameters. This new force field appears transferable for a wide variety of molecules and properties. It is furthermore worth noticing that binary mixtures have been simulated without introducing empirical binary parameters, highlighting also the transferability to mixtures. Hence, this new force field gives future opportunities to simulate complex systems of industrial interest involving molecules with ether functions.

  8. Tether-directed synthesis of highly substituted oxasilacycles via an intramolecular allylation employing allylsilanes

    Directory of Open Access Journals (Sweden)

    Cox Liam R

    2007-02-01

    Full Text Available Abstract Background Using a silyl tether to unite an aldehyde electrophile and allylsilane nucleophile into a single molecule allows a subsequent Lewis-acid-mediated allylation to proceed in an intramolecular sense and therefore receive all the benefits associated with such processes. However, with the ability to cleave the tether post allylation, a product that is the result of a net intermolecular reaction can be obtained. In the present study, four diastereoisomeric β-silyloxy-α-methyl aldehydes, which contain an allylsilane tethered through the β-carbinol centre, have been prepared, in order to probe how the relative configuration of the two stereogenic centres affects the efficiency and selectivity of the intramolecular allylation. Results Syn-aldehydes, syn-4a and syn-4b, both react poorly, affording all four possible diastereoisomeric oxasilacycle products. In contrast, the anti aldehydes anti-4a and anti-4b react analogously to substrates that lack substitution at the α-site, affording only two of the four possible allylation products. Conclusion The outcome of the reaction with anti-aldehydes is in accord with reaction proceeding through a chair-like transition state (T.S.. In these systems, the sense of 1,3-stereoinduction can be rationalised by the aldehyde electrophile adopting a pseudoaxial orientation, which will minimise dipole-dipole interactions in the T.S. The 1,4-stereoinduction in these substrates is modest and seems to be modulated by the R substituent in the starting material. In the case of the syn-substrates, cyclisation through a chair T.S. is unlikely as this would require the methyl substituent α to the reacting carbonyl group to adopt an unfavourable pseudoaxial position. It is therefore proposed that these substrates react through poorly-defined T.S.s and consequently exhibit essentially no stereoselectivity.

  9. Synthesis of alkenyl boronates from allyl-substituted aromatics using an olefin cross-metathesis protocol.

    Science.gov (United States)

    Hemelaere, Rémy; Carreaux, François; Carboni, Bertrand

    2013-07-01

    An efficient synthesis of 3-aryl-1-propenyl boronates from pinacol vinyl boronic ester and allyl-substituted aromatics by cross metathesis is reported. Although the allylbenzene derivatives are prone to isomerization reaction under metathesis conditions, we found that some ruthenium catalysts are effective for this methodology. This strategy thus provides an interesting alternative approach to alkyne hydroboration, leading to the preparation of unknown compounds. Moreover, the boron substituent can be replaced by various functional groups in good yields.

  10. Highly Regioselective Palladium-Catalyzed Carboxylation of Allylic Alcohols with CO2.

    Science.gov (United States)

    Mita, Tsuyoshi; Higuchi, Yuki; Sato, Yoshihiro

    2015-11-01

    Various allylic alcohols were carboxylated in the presence of a catalytic amount of PdCl2 and PPh3 using ZnEt2 as a stoichiometric transmetalation agent under a CO2 atmosphere (1 atm). This carboxylation proceeded in a highly regioselective manner to afford branched carboxylic acids predominantly. The β,γ-unsaturated carboxylic acid thus obtained was successfully converted into an optically active γ-butyrolactone, a known intermediate of (R)-baclofen.

  11. On the key role of water in the allylic activation catalysed by Pd (II) bisphosphinite complexes

    Indian Academy of Sciences (India)

    Rakesh Kumar Sharma; Ashoka G Samuelson

    2006-11-01

    Palladium and platinum complexes of bisphosphinites and bisphosphines derived from mandelic acid have been prepared and characterized. Their ability to catalyze allylation of imines with allyltributylstannane has been studied. Bisphophinite complexes of Pd (II) are shown to be ideal and they work best in the presence of one equivalent of water. The near neutral conditions employed make the catalysts suitable for a wide variety of substrates.

  12. Lewis base catalyzed enantioselective allylic hydroxylation of Morita-Baylis-Hillman carbonates with water

    KAUST Repository

    Zhu, Bo

    2011-08-19

    A Lewis base catalyzed allylic hydroxylation of Morita-Baylis-Hillman (MBH) carbonates has been developed. Various chiral MBH alcohols can be synthesized in high yields (up to 99%) and excellent enantioselectivities (up to 94% ee). This is the first report using water as a nucleophile in asymmetric organocatalysis. The nucleophilic role of water has been verified using 18O-labeling experiments. © 2011 American Chemical Society.

  13. Iron(III) chloride catalyzed glycosylation of peracylated sugars with allyl/alkynyl alcohols

    Energy Technology Data Exchange (ETDEWEB)

    Narayanaperumal, Senthil; Silva, Rodrigo Cesar da; Monteiro, Julia L.; Correa, Arlene G.; Paixao, Marcio W., E-mail: mwpaixao@ufscar.br [Universidade Federal de Sao Carlos (UFSCAR), SP (Brazil). Dept. de Quimica

    2012-11-15

    In this work, the use of ferric chloride as an efficient catalyst in glycosylation reactions of sugars in the presence of allyl and alkynyl alcohols is described. The corresponding glycosides were obtained with moderate to good yields. This new procedure presented greater selectivity when compared to classic methods found in the literature. Principal features of this simple method include non-hazardous reaction conditions, low-catalyst loading, good yields and high anomeric selectivity (author)

  14. Vacuum condensates and `ether-drift' experiments

    OpenAIRE

    Consoli, M.; Pagano, A.; Pappalardo, L.

    2003-01-01

    The idea of a `condensed' vacuum state is generally accepted in modern elementary particle physics. We argue that this should motivate a new generation of precise `ether-drift' experiments with present-day technology.

  15. Activity relationships for aromatic crown ethers

    CERN Document Server

    Wilson, M J

    1998-01-01

    This thesis involves an investigation of aromatic crown ethers and a study of their binding constants for alkali metals. The study was motivated by the current needs of the semiconductor industry to improve the scavenging of mobile ions from fabricated circuits. A number of aromatic crown ethers have been sulphonated in an attempt to improve their water solubility and cation binding activity. These materials have been extensively studied and their binding activity determined. In collaboration with a molecular modelling study, the effect of ionisable sulphonate groups on the macrocycles' behaviour has been investigated. The broader issue of the effect of substituents in aromatic crown ethers has also been studied with the preparation of a wide range of substituted crown ethers. The cation binding activity of these materials has been found to bear a simple relationship to the electron withdrawing nature of the aromatic substituents. This relationship can be accurately monitored using electronic charge densities...

  16. Direct Nucleophilic Substitution of Free Allylic Alcohols in Water Catalyzed by FeCl3⋅6 H2O: Which is the Real Catalyst?

    OpenAIRE

    Trillo Alarcón, María Paz; Baeza, Alejandro; Nájera Domingo, Carmen

    2013-01-01

    The allylic substitution reaction, and particularly the direct allylic amination reaction, of free allylic alcohols in water catalyzed by FeCl3⋅6 H2O is described. This novel environmentally-friendly methodology allows the use of a wide variety of nitrogenated nucleophiles such as sulfonamides, carbamates, benzamides, anilines, benzotriazoles, and azides, generally giving good yields of the corresponding substitution products. The synthetic applicability of the process is also demonstrated be...

  17. Optical anisotropy, molecular orientations, and internal stresses in thin sulfonated poly(ether ether ketone) films

    NARCIS (Netherlands)

    Koziara, B.T.; Nijmeijer, D.C.; Benes, N.E.

    2015-01-01

    The thickness, the refractive index, and the optical anisotropy of thin sulfonated poly(ether ether ketone) films, prepared by spin-coating or solvent deposition, have been investigated with spectroscopic ellipsometry. For not too high polymer concentrations (B5 wt%) and not too low spin speeds (C20

  18. Thin sulfonated poly(ether ether ketone) films for the dehydration of compressed carbon dioxide

    NARCIS (Netherlands)

    Koziara, B.T.

    2015-01-01

    In this thesis, the properties of thin films from highly sulfonated poly(ether ether ketone) (SPEEK) have been investigated within the context of their application as membranes for the dehydration of compressed carbon dioxide. Spectroscopic ellipsometry has been used as the predominant measurement t

  19. Thermodynamic equilibrium calculations of dimethyl ether steam reforming and dimethyl ether hydrolysis

    Science.gov (United States)

    Semelsberger, Troy A.; Borup, Rodney L.

    The production of a hydrogen-rich fuel-cell feed by dimethyl ether (DME) steam reforming was investigated using calculations of thermodynamic equilibrium as a function of steam-to-carbon ratio (0.00-4.00), temperature (100-600 °C), pressure (1-5 atm), and product species. Species considered were acetone, acetylene, carbon dioxide, carbon monoxide, dimethyl ether, ethane, ethanol, ethylene, formaldehyde, formic acid, hydrogen, isopropanol, methane, methanol, methyl-ethyl ether, n-propanol and water. Thermodynamic equilibrium calculations of DME steam reforming indicate complete conversion of dimethyl ether to hydrogen, carbon monoxide and carbon dioxide at temperatures greater than 200 °C and steam-to-carbon ratios greater than 1.25 at atmospheric pressure ( P = 1 atm). Increasing the operating pressure shifts the equilibrium toward the reactants; increasing the pressure from 1 to 5 atm decreases the conversion of dimethyl ether from 99.5 to 76.2%. The trend of thermodynamically stable products in decreasing mole fraction is methane, ethane, isopropyl alcohol, acetone, n-propanol, ethylene, ethanol, methyl-ethyl ether and methanol-formaldehyde, formic acid, and acetylene were not observed. Based on the equilibrium calculations, the optimal processing conditions for dimethyl ether steam reforming occur at a steam-to-carbon ratio of 1.50, a pressure of 1 atm, and a temperature of 200 °C. These thermodynamic equilibrium calculations show dimethyl ether processed with steam will produce hydrogen-rich fuel-cell feeds—with hydrogen concentrations exceeding 70%. The conversion of dimethyl ether via hydrolysis (considering methanol as the only product) is limited by thermodynamic equilibrium. Equilibrium conversion increases with temperature and steam-to-carbon ratio. A maximum dimethyl ether conversion of 62% is achieved at a steam-to-carbon ratio of 5.00 and a processing temperature of 600 °C.

  20. Reproductive toxicity evaluation of the dental resin monomer bisphenol a glycidyl methacrylate (CAS 1565-94-2) in mice.

    Science.gov (United States)

    Moilanen, Lori H; Dahms, Janell K; Hoberman, Alan M

    2013-01-01

    The reproductive toxicity potential of the dental resin monomer bisphenol A glycidyl methacrylate (BisGMA; CASRN 1565-94-2) was investigated in male and female Crl: CD1(ICR) mice, 4 dosage groups, and 25 mice/sex/group. Formulations of BisGMA (0, 0.008, 0.08, or 0.8 mg/kg/d) in 0.8% ethanol in deionized water were intubated once daily beginning 28 days before cohabitation and continuing through mating (males) or through gestation day 17. The following parameters were evaluated: viability, clinical signs, body weights, estrous cyclicity, necropsy observations, organ weights, sperm concentration/motility/morphology, cesarean sectioning and litter observations, and histopathological evaluation of select tissues. No deaths or clinical signs related to BisGMA occurred. No significant changes in male and female body weights and body weight gains were recorded at any of the administered dosages of BisGMA. All mating and fertility parameters, and all litter and fetal data, were considered to be unaffected by dosages of BisGMA as high as 0.8 mg/kg/d. Gross or histopathologic tissue changes attributable to the test article were not observed. Reproductive and developmental no observed effect levels (NOAELs) for BisGMA were 0.8 mg/kg/d, the highest dose tested. Comparison of this NOAEL value to published probabilistic estimates of human BisGMA exposure from dental products suggests a margin of safety of at least 280- to nearly 2000-fold. Under the conditions of this study, BisGMA is not a reproductive toxicant.

  1. Influence of exchange group of modified glycidyl methacrylate polymer on phenol removal: A study by batch and continuous flow processes.

    Science.gov (United States)

    Aversa, Thiago Muza; da Silva, Carla Michele Frota; da Rocha, Paulo Cristiano Silva; Lucas, Elizabete Fernandes

    2016-11-01

    Contamination of water by phenol is potentially a serious problem due to its high toxicity and its acid character. In this way some treatment process to remove or reduce the phenol concentration before contaminated water disposal on the environment is required. Currently, phenol can be removed by charcoal adsorption, but this process does not allow easy regeneration of the adsorbent. In contrast, polymeric resins are easily regenerated and can be reused in others cycles of adsorption process. In this work, the interaction of phenol with two polymeric resins was investigated, one of them containing a weakly basic anionic exchange group (GD-DEA) and the other, a strongly basic group (GD-QUAT). Both ion exchange resins were obtained through chemical modifications from a base porous resin composed of glycidyl methacrylate (GMA) and divinyl benzene (DVB). Evaluation tests with resins were carried out with 30 mg/L of phenol in water solution, at pH 6 and 10, employing two distinct processes: (i) batch, to evaluate the effect of temperature, and (ii) continuous flow, to assess the breakthrough of the resins. Batch tests revealed that the systems did not follow the model proposed by Langmuir due to the negative values obtained for the constant b and for the maximum adsorption capacity, Q0. However, satisfactory results for the constants KF and n allowed assuming that the behavior of systems followed the Freundlich model, leading to the conclusion that resin GD-DEA had the best interaction with the phenol when in a solution having pH 10 (phenoxide ions). The continuous flow tests corroborated this conclusion since the performance of GD-DEA in removing phenol was also best at pH 10, indicating that the greater availability of the electron pair in the resin with the weakly basic donor group contributed to enhance the resin's interaction with the phenoxide ions.

  2. Chemical Kinetics of Hydrogen Atom Abstraction from Allylic Sites by (3)O2; Implications for Combustion Modeling and Simulation.

    Science.gov (United States)

    Zhou, Chong-Wen; Simmie, John M; Somers, Kieran P; Goldsmith, C Franklin; Curran, Henry J

    2017-03-09

    Hydrogen atom abstraction from allylic C-H bonds by molecular oxygen plays a very important role in determining the reactivity of fuel molecules having allylic hydrogen atoms. Rate constants for hydrogen atom abstraction by molecular oxygen from molecules with allylic sites have been calculated. A series of molecules with primary, secondary, tertiary, and super secondary allylic hydrogen atoms of alkene, furan, and alkylbenzene families are taken into consideration. Those molecules include propene, 2-butene, isobutene, 2-methylfuran, and toluene containing the primary allylic hydrogen atom; 1-butene, 1-pentene, 2-ethylfuran, ethylbenzene, and n-propylbenzene containing the secondary allylic hydrogen atom; 3-methyl-1-butene, 2-isopropylfuran, and isopropylbenzene containing tertiary allylic hydrogen atom; and 1-4-pentadiene containing super allylic secondary hydrogen atoms. The M06-2X/6-311++G(d,p) level of theory was used to optimize the geometries of all of the reactants, transition states, products and also the hinder rotation treatments for lower frequency modes. The G4 level of theory was used to calculate the electronic single point energies for those species to determine the 0 K barriers to reaction. Conventional transition state theory with Eckart tunnelling corrections was used to calculate the rate constants. The comparison between our calculated rate constants with the available experimental results from the literature shows good agreement for the reactions of propene and isobutene with molecular oxygen. The rate constant for toluene with O2 is about an order magnitude slower than that experimentally derived from a comprehensive model proposed by Oehlschlaeger and coauthors. The results clearly indicate the need for a more detailed investigation of the combustion kinetics of toluene oxidation and its key pyrolysis and oxidation intermediates. Despite this, our computed barriers and rate constants retain an important internal consistency. Rate constants

  3. Genome wide association mapping in Arabidopsis thaliana identifies novel genes involved in linking allyl glucosinolate to altered biomass and defense

    Directory of Open Access Journals (Sweden)

    Marta Francisco

    2016-07-01

    Full Text Available A key limitation in modern biology is the ability to rapidly identify genes underlying newly identified complex phenotypes. Genome wide association studies (GWAS have become an increasingly important approach for dissecting natural variation by associating phenotypes with genotypes at a genome wide level. Recent work is showing that the Arabidopsis thaliana defense metabolite, allyl glucosinolate (GSL, may provide direct feedback regulation, linking defense metabolism outputs to the growth and defense responses of the plant. However, there is still a need to identify genes that underlie this process. To start developing a deeper understanding of the mechanism(s that modulate the ability of exogenous allyl GSL to alter growth and defense, we measured changes in plant biomass and defense metabolites in a collection of natural 96 A. thaliana accessions fed with 50 µM of allyl GSL. Exogenous allyl GSL was introduced exclusively to the roots and the compound transported to the leaf leading to a wide range of heritable effects upon plant biomass and endogenous GSL accumulation. Using natural variation we conducted GWAS to identify a number of new genes which potentially control allyl responses in various plant processes. This is one of the first instances in which this approach has been successfully utilized to begin dissecting a novel phenotype to the underlying molecular/polygenic basis.

  4. Palladacyclic imidazoline-naphthalene complexes: synthesis and catalytic performance in Pd(II)-catalyzed enantioselective reactions of allylic trichloroacetimidates.

    Science.gov (United States)

    Cannon, Jeffrey S; Frederich, James H; Overman, Larry E

    2012-02-17

    A new family of air- and moisture-stable enantiopure C,N-palladacycles (PIN-acac complexes) were prepared in good overall yield in three steps from 2-iodo-1-naphthoic acid and enantiopure β-amino alcohols. Three of these PIN complexes were characterized by single-crystal X-ray analysis. As anticipated, the naphthalene and imidazoline rings of PIN-acac complexes 18a and 18b were canted significantly from planarity and projected the imidazoline substituents R(1) and R(2) on opposite faces of the palladium square plane. Fifteen PIN complexes were evaluated as catalysts for the rearrangement of prochiral (E)-allylic trichloroacetimidate 19 (eq 2) and the S(N)2' allylic substitution of acetic acid with prochiral (Z)-allylic trichloroacetimidate 23. Although these complexes were kinetically poor catalysts for the Overman rearrangement, they were good catalysts for the allylic substitution reaction, providing branched allylic esters in high yield. However, enantioselectivities were low to moderate and significantly less than that realized with palladacyclic complexes of the COP family. Computational studies support an anti-acetoxypalladation/syn-deoxypalladation mechanism analogous to that observed with COP catalysts. The computational study further suggests that optimizing steric influence in the vicinity of the carbon ligand of a chiral C,N-palladacycle, rather than near the nitrogen heterocycle, is the direction to pursue in future development of improved enantioselective catalysts of this motif.

  5. A facile stereospecific synthesis of the ( sup 2 H sub 6 )-isopropyl-labelled metoprolol enantiomers from (2R)- and (2S)-glycidyl 3-nitrobenzenesulfonate

    Energy Technology Data Exchange (ETDEWEB)

    Murthy, S.S.; Nelson, W.L. (Washington Univ., Seattle, WA (USA). Dept. of Medicinal Chemistry)

    1990-12-01

    Enantiomers of metoprolol containing six deuterium atoms in the isopropyl methyl groups were prepared in two steps from the sodium salt of 4-(2-methoxyethyl)phenol (3) and the commercially available (2R)-and (2S)-glycidyl 3-nitrobenzenesulfonates ((2R)-2 and (2S)-2). The resulting (2R)- and (2S)-epoxides were opened using ({sup 2}H{sub 6})-isopropylamine. The enantiomeric excesses were 93 and 95% for the deuterated (2R)- and (2S)-enantiomers of metoprolol ((2R)-1 and (2S)-1), respectively, as determined by chiral column HPLC. (author).

  6. Synthesis of Tetrabromobispenol A-Diallyl Ether in Water%水相合成四溴双酚A-双烯丙基醚

    Institute of Scientific and Technical Information of China (English)

    夏科丹; 胡云; 张鹏; 杨锦飞; 职慧珍

    2012-01-01

    以四溴双酚A为原料,在水相中不使用相转移催化剂合成四溴双酚A双烯丙基醚,通过考察反应温度、氯丙烯的滴加速度、氯丙烯的用量等因素对反应的影响,在优化条件下得到98%的收率,而且只需简单的水洗、过滤就可得到高质量的产品.%Tetrabromobisphenol A was used as raw material for the synthesis of tetrabromobisphenol A-diallyl ether in water without phase transfer catalyst. Three factors such as temperature, dropping speed and dosage of allyl chloride were studied on the influence of the reaction. The target product was obtained in 98% yield with simple workup procedures.

  7. Resonance energies of the allyl cation and allyl anion: contribution by resonance and inductive effects toward the acidity and hydride abstraction enthalpy of propene.

    Science.gov (United States)

    Barbour, Josiah B; Karty, Joel M

    2004-02-06

    Density functional theory was employed to calculate the acidities and hydride abstraction enthalpies of propene (3) and propane (4), along with their vinylogues (5 and 6, respectively). The same reaction enthalpies were calculated for the propene vinylogues in which the terminal vinyl group was rotated perpendicular to the rest of the conjugated system (7). The contribution by resonance and inductive effects toward the acidity and hydride abstraction enthalpy of each vinylogue of 5 (n = 1-3) was computed and extrapolated to n = 0 (the parent propene system). The resonance energies of the allyl cation and anion were determined to be about 20-22 and 17-18 kcal/mol, respectively. Comparisons are made to resonance energies calculated using other methodologies.

  8. Scientific opinion on the risks for human health related to the presence of 3-and 2-monochloropropanediol (MCPD), and their fatty acid esters, and glycidyl fatty acid esters in food

    DEFF Research Database (Denmark)

    Petersen, Annette

    in the Food Chain (CONTAM Panel) evaluated 7,175 occurrence data. Esters of 3- and 2-MCPD and glycidyl esters were found at the highest levels in palm oil/fat, but most vegetable oil/fats contain substantial quantities. Mean middle bound (MB) dietary exposure values to total 3-MCPD, 2-MCPD and glycidol......EFSA was asked to deliver a scientific opinion on free and esterified 3- and 2-monochloropropane-1, 2-diol (MCPD) and glycidyl esters in food. Esters of 3- and 2-MCPD and glycidol are contaminants of processed vegetable oils; free MCPDs are formed in some processed foods. The Panel on Contaminants...

  9. EtherCAT协议分析

    Institute of Scientific and Technical Information of China (English)

    杨晓鸿

    2014-01-01

    <正>EtherCAT协议是德国倍福自动化有限公司(Beckhoff Automation GmbH)于2003年提出,并于2005年被定为IEC标准62407;2007年,IEC把EtherCAT协议加到工业现场总线标准61158。一、协议概述为提高通信效率以及实时性,EtherCAT协议的主要思想有两方面。简化协议,协议兼容以太网的MAC层协议,并由纯硬件完成解析,提高处理速度;而其他协议由软件

  10. S-Allyl cysteine improves nonalcoholic fatty liver disease in type 2 diabetes Otsuka Long-Evans Tokushima Fatty rats via regulation of hepatic lipogenesis and glucose metabolism.

    Science.gov (United States)

    Takemura, Shigekazu; Minamiyama, Yukiko; Kodai, Shintaro; Shinkawa, Hiroji; Tsukioka, Takuma; Okada, Shigeru; Azuma, Hideki; Kubo, Shoji

    2013-09-01

    It is important to prevent and improve diabetes mellitus and its complications in a safe and low-cost manner. S-Allyl cysteine, an aged garlic extract with antioxidant activity, was investigated to determine whether S-allyl cysteine can improve type 2 diabetes in Otsuka Long-Evans Tokushima Fatty rats with nonalcoholic fatty liver disease. Male Otsuka Long-Evans Tokushima Fatty rats and age-matched Long-Evans Tokushima Otsuka rats were used and were divided into two groups at 29 weeks of age. S-Allyl cysteine (0.45% diet) was administered to rats for 13 weeks. Rats were killed at 43 weeks of age, and detailed analyses were performed. S-Allyl cysteine improved hemoglobinA1c, blood glucose, triglyceride, and low-density lipoprotein cholesterol levels. Furthermore, S-allyl cysteine normalized plasma insulin levels. S-Allyl cysteine activated the mRNA and protein expression of both peroxisome proliferator-activated receptor α and γ, as well as inhibiting pyruvate dehydrogenase kinase 4 in Otsuka Long-Evans Tokushima Fatty rat liver. Sterol regulatory element-binding protein 1c and forkhead box O1 proteins were normalized by S-allyl cysteine in Otsuka Long-Evans Tokushima Fatty rat liver. In conclusions, these findings support the hypothesis that S-allyl cysteine has diabetic and nonalcoholic fatty liver disease therapeutic potential as a potent regulating agent against lipogenesis and glucose metabolism.

  11. Thermosetting composite matrix materials based on allyl and/or propargyl substituted cyclopentadiene, indene and fluorene

    Science.gov (United States)

    Tregre, Gregory Jude

    A series of all-hydrocarbon thermoset composite matrix resins was synthesized via electrophilic substitution of cyclopentadiene, indene, and fluorene ring systems with allyl and/or propargyl halides under phase transfer conditions. Reaction of cyclopentadiene with allyl chloride (ACP resin), propargyl bromide (PCP resin) or various feed ratios of allyl chloride and propargyl bromide (APCP resins) yielded mixtures of products with 2-6 substituents per cyclopentadiene ring. Reaction of indene with allyl chloride (Al resins) or propargyl bromide (PI resins) yielded mixtures of products with 2-4 substituents per indene. In both sets of resins the allyl functionality obtained a greater average degree of substitution than the analogous propargyl species. Differential scanning calorimetric (DSC) analysis of the multifunctional resins showed broad, high-energy thermal cures in all cases. The enthalpies of cure for ACP and PCP were 750 J/g and 805 J/g, respectively, with peak cure energies occurring at 310 and 248sp°C. The enthalpy of cure for APCP resins ranged from 750 J/g to 800 J/g with higher propargyl-functional resins yielding higher enthalpies of cure. Physically mixed ACP/PCP resin systems gave peak cure temperatures and energy values comparable to APCP resins. The enthalpies of cure for Al and PI-resins were 480 J/g and 630 J/g, respectively. Peak cure temperature for Al resin was 320sp°C, while the peak cure for PI resin occurred at 282sp°C. Infrared spectroscopy (IR) and nuclear magnetic resonance spectroscopy (NMR) were used to evaluate mechanisms of cure in the experimental resins. The allyl functional resins cured through a combination of ene reactions and polyaddition reactions. The propargyl functional resins cured through ene reactions and polyadditions but also underwent some cyclotrimerization of the propargyl functionalities. A small amount of autoxidation was seen in all of the resins. Thermal stability and carbon yields of the cured resins were

  12. Limonene ethers from tire pyrolysis oil

    Energy Technology Data Exchange (ETDEWEB)

    Stanciulescu, Maria; Ikura, Michio [CANMET Energy Technology Centre, Natural Resources Canada, 1 Haanel Drive, Ottawa, ON (Canada)

    2006-03-01

    Tire pyrolysis oil was produced by EnerVision Inc., Halifax, Canada using the continuous ablative reactor (CAR) system. The tire oil was separated by distillation into several fractions. Naphtha and limonene enriched naphtha were reacted with methanol over different catalysts. Batch experiments were carried out to separate limonene as methyl limonene ethers. Whole tire pyrolysis oil was distilled and the resulting distillates were redistilled to separate the limonene (bp about 176{sup o}C). Vacuum distillation yielded on average 25.5wt% naphtha containing 16.3wt% limonene (average). Redistillation increased the limonene concentration to approximately 32-37wt%. The conversion of limonene (mono-terpene) to limonene ethers (terpenoides) shifted the boiling point of the limonene derivatives out of the naphtha boiling range (IBP -190{sup o}C). This allowed the separation of fragrant limonene ethers from foul smelling naphtha. Alkoxylation reactions were performed mostly using methanol and acidic catalysts. The methyl ether [1-methyl-4-({alpha}-methoxy-isopropyl)-1-cyclohexene] has a boiling point of about 198{sup o}C which is higher than the end boiling point of the naphtha cut. Five heterogeneous catalysts (four zeolites and one ion exchange resin) were tested in a batch reactor. {beta}-Zeolite produced excellent results. The reaction of R-(+)-limonene with methanol in the presence of activated {beta}-zeolite yielded methyl ether, 87.5% at selectivity 89.7% with a maximum of 2h reaction time. Limonene conversion from whole naphtha to ethers was also high. (author)

  13. Study on the Preparation of Allyl-modified Starch in Isopropyl/Water Medium for Warp Sizing

    Institute of Scientific and Technical Information of China (English)

    LI Man-li; ZHU Zhi-feng; ZHANG Long-qiu

    2008-01-01

    A new method for the pretreatment of starch by etherification was developed to eliminate the problems of lower grafting efficiency associated with the preparation of starch graft copolymers as warp sizing agents.The etherification of starch with allyl chloride was investigated in order to effectively enhance the reaction efficiency.The technological variables of the reaction considered for evaluating the etherification included sodium hydroxide amount,water content in water-isopropyi alcohol medium,allyl cldoride concentration,reaction temperature and reaction time.The experimental result demonstrated that the variables considered showed evident effect on the reaction efficiency.For the etherification,a condition of 20% for the water content,1.5:1 for the molar ratio of sodium hydroxide to allyl chloride.and at 30℃ under 24h reaction is Sufficient to retain the reaction efficiency above 50%.Furthermore,a contrast test demonstrated that the graft efficiency can be increased with the etherification pretreatment.

  14. A Convenient and Efficient Procedure for Oxime Ethers

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    Acetophenone oxime and benzaldehyde oxime were converted to oxime ethers in the presence of alkyl halide or methyl sulfate and KOH in aqueous DMSO in 5 to 70 min. The yields of oxime ethers were 70 - 96%.

  15. A Convenient and Efficient Procedure fox Oxime Ethers

    Institute of Scientific and Technical Information of China (English)

    ChunBaoLI; MichaelC.K.CHOI; 等

    2002-01-01

    Acetophenone oxime and benzaldehyde oxime were converted to oxime ethers in the presence of alkyl halide or methyl sulfate and KOH in aqueous DMSO in 5 to 70 min. The yields of oxime ethers were 70-96%.

  16. Non-thermal plasma destruction of allyl alcohol in waste gas: kinetics and modelling

    Science.gov (United States)

    DeVisscher, A.; Dewulf, J.; Van Durme, J.; Leys, C.; Morent, R.; Van Langenhove, H.

    2008-02-01

    Non-thermal plasma treatment is a promising technique for the destruction of volatile organic compounds in waste gas. A relatively unexplored technique is the atmospheric negative dc multi-pin-to-plate glow discharge. This paper reports experimental results of allyl alcohol degradation and ozone production in this type of plasma. A new model was developed to describe these processes quantitatively. The model contains a detailed chemical degradation scheme, and describes the physics of the plasma by assuming that the fraction of electrons that takes part in chemical reactions is an exponential function of the reduced field. The model captured the experimental kinetic data to less than 2 ppm standard deviation.

  17. Direct asymmetric allylic alkenylation of N-itaconimides with Morita-Baylis-Hillman carbonates

    KAUST Repository

    Yang, Wenguo

    2012-08-03

    The asymmetric allylic alkenylation of Morita-Baylis-Hillman (MBH) carbonates with N-itaconimides as nucleophiles has been developed using a commercially available Cinchona alkaloid catalyst. A variety of multifunctional chiral α-methylene-β-maleimide esters were attained in moderate to excellent yields (up to 99%) and good to excellent enantioselectivities (up to 91% ee). The origin of the regio- and stereoselectivity was verified by DFT methods. Calculated geometries and relative energies of various transition states strongly support the observed regio- and enantioselectivity. © 2012 American Chemical Society.

  18. Lanthanum triflate triggered synthesis of tetrahydroquinazolinone derivatives of N-allyl quinolone and their biological assessment

    Directory of Open Access Journals (Sweden)

    Jardosh Hardik H.

    2012-01-01

    Full Text Available A series of 24 derivatives of tetrahydroquinazolinone has been synthesized by one-pot cyclocondensation reaction of N-allyl quinolones, cyclic β-diketones and (thiourea/N-phenylthiourea in presence of lanthanum triflate catalyst. This methodology allowed us to achieve the products in excellent yield by stirring at room temperature. All the synthesized compounds were investigated against a representative panel of pathogenic strains using broth microdilution MIC (minimum inhibitory concentration method for their in vitro antimicrobial activity. Amongst these sets of heterocyclic compounds 5h, 6b, 6h, 5f, 5l, 5n and 6g found to have admirable activity.

  19. N-(2-Allyl-4-ethoxy-2H-indazol-5-yl-4-methylbenzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Hakima Chicha

    2014-05-01

    Full Text Available The indazole ring system of the title compound, C19H21N3O3S, is almost planar (r.m.s. deviation = 0.0192 Å and forms dihedral angles of 77.99 (15 and 83.9 (3° with the benzene ring and allyl group, respectively. In the crystal, centrosymmetrically related molecules are connected by pairs of N—H...O hydrogen bonds into dimers, which are further linked by C—H...O hydrogen bonds, forming columns parallel to the b axis.

  20. Thermophysical properties and reaction kinetics of γ-irradiated poly allyl diglycol carbonates nuclear track detector

    Science.gov (United States)

    Elmaghraby, Elsayed K.; Seddik, Usama

    2015-07-01

    Kinetic thermogravimetric technique was used to study the effect of gamma irradiation on the poly allyl diglycol carbonates (PADC) within the dose range from 50 to ? Gy. The approach of Coats-Redfern was used to analyze the data. Results showed that low doses around 50 Gy make the polymer slightly more resistive to heat treatment. Higher radiation doses cause severe effects in the samples accompanied by the formation of lower molecular mass species and consequent crosslinking. Results support the domination of re-polymerization and crosslinking for the γ radiation interaction PADC at dose below about ? Gy, while the situation is inverted above ? Gy in which chain secession dominates.

  1. Synthesis of Aminophosphine Ligands with Binaphthyl Backbones for Silver(I)-catalyzed Enantioselective Allylation of Benzaldehyde

    Institute of Scientific and Technical Information of China (English)

    WANG,Yi(王以); JI,Bao-Ming(吉保明); DING,Kui-Ling(丁奎岭)

    2002-01-01

    A series of aminophosphine ligands was synthesized from 2amino-2′-hydroxy-1,1′-binaphthyl (NOBIN). Their asymmetric induction efficiency was examined for silver(I)catalyzed enantioselective allylation reaction of benzaldehyde with allyltributyltin.Under the optimized reaction conditions,quantitative yield as well as moderate ee value (54.5% ee)of product was achieved by the catalysis with silver(I)/3 complex. The effects of the binaphthyl backbone and the substituted situated at chelating N, Patoms on enantioselectivity of the reaction were also discussed.

  2. Catalytic enantioselective 1,6-conjugate additions of propargyl and allyl groups

    Science.gov (United States)

    Meng, Fanke; Li, Xiben; Torker, Sebastian; Shi, Ying; Shen, Xiao; Hoveyda, Amir H.

    2016-09-01

    Conjugate (or 1,4-) additions of carbanionic species to α,β-unsaturated carbonyl compounds are vital to research in organic and medicinal chemistry, and there are several chiral catalysts that facilitate the catalytic enantioselective additions of nucleophiles to enoates. Nonetheless, catalytic enantioselective 1,6-conjugate additions are uncommon, and ones that incorporate readily functionalizable moieties, such as propargyl or allyl groups, into acyclic α,β,γ,δ-doubly unsaturated acceptors are unknown. Chemical transformations that could generate a new bond at the C6 position of a dienoate are particularly desirable because the resulting products could then be subjected to further modifications. However, such reactions, especially when dienoates contain two equally substituted olefins, are scarce and are confined to reactions promoted by a phosphine-copper catalyst (with an alkyl Grignard reagent, dialkylzinc or trialkylaluminium compounds), a diene-iridium catalyst (with arylboroxines), or a bisphosphine-cobalt catalyst (with monosilyl-acetylenes). 1,6-Conjugate additions are otherwise limited to substrates where there is full substitution at the C4 position. It is unclear why certain catalysts favour bond formation at C6, and—although there are a small number of catalytic enantioselective conjugate allyl additions—related 1,6-additions and processes involving a propargyl unit are non-existent. Here we show that an easily accessible organocopper catalyst can promote 1,6-conjugate additions of propargyl and 2-boryl-substituted allyl groups to acyclic dienoates with high selectivity. A commercially available allenyl-boron compound or a monosubstituted allene may be used. Products can be obtained in up to 83 per cent yield, >98:2 diastereomeric ratio (for allyl additions) and 99:1 enantiomeric ratio. We elucidate the mechanistic details, including the origins of high site selectivity (1,6- versus 1,4-) and enantioselectivity as a function of the catalyst

  3. N-(1-Allyl-3-chloro-4-ethoxy-1H-indazol-5-yl-4-methylbenzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Hakima Chicha

    2014-06-01

    Full Text Available In the title compound, C19H20ClN3O3S, the benzene ring is inclined to the indazole ring system by 51.23 (8°. In the crystal, molecules are linked by pairs of N—H...O hydrogen bonds, forming inversion dimers which stack in columns parallel to [011]. The atoms in the allyl group are disordered over two sets of sites with an occupancy ratio of 0.624 (8:0.376 (8.

  4. Nano-Aluminum Powder Mediated Allylation of Carbonyl Compounds in Aqueous Media

    Institute of Scientific and Technical Information of China (English)

    YUAN Shi-Zhen; LIU Jin

    2008-01-01

    A new and effective Barbier-Grignard allylation of aldehydes or ketones has been carried out with nano-aluminum powder in aqueous 0.1 mol·L-1 NH4Cl (aq.) under an atmosphere of nitrogen. Aromatic carbonyl compounds gave homoallylic alcohols in good yields. The effectiveness of reaction was strongly influenced by the steric environment surrounding the carbonyl group. Aliphatic carbonyl compounds proceeded in low yields. The dominant stereoisomer was an erythro-isomer when an ortho-hydroxyl carbonyl compound was reacted under such a reaction condition.

  5. [3,3]-sigmatropic rearrangements of fluorinated allyl (Thio)cyanates - a tool for the synthesis of fluorinated (Thio)ureas.

    Science.gov (United States)

    Ramb, Daniel C; Kost, Lisa; Haufe, Günter

    2014-01-01

    The first (thio)cyanate to iso(thio)cyanate rearrangements based on 2-fluoroallylic alcohols are presented. Long-chain 2-fluoroallylic alcohols were converted to corresponding N-unsubstituted carbamates by treatment with trichloroacetyl isocyanate. Dehydration using trifluoroacetic anhydride in the presence of triethylamine formed intermediate allylic cyanates, which immediately underwent sigmatropic rearrangement to fluorinated allyl isocyanates. Without isolation the latter delivered fluorinated ureas by addition of amines. The thiocyanate to isothiocyanate rearrangements started from the same fluorinated allylic alcohols, which were first converted to mesylates. Heating in THF with potassium thiocyanate led to fluorinated allyl isothiocyanates, via [3,3]-sigmatropic rearrangement of intermediate allyl thiocyanates. The formed products were further reacted with amines to fluorinated thioureas.

  6. Real-Time Polymerase Chain Reaction as a Tool for Evaluation of Magnetic Poly(Glycidyl methacrylate)-Based Microspheres in Molecular Diagnostics.

    Science.gov (United States)

    Trachtová, Stepánka; Spanová, Alena; Horák, Daniel; Kozáková, Hana; Rittich, Bohuslav

    2016-01-01

    DNA amplification by real-time polymerase chain reaction (RT-PCR) was used for the evaluation of efficiency of polymer coating of magnetic hydrophilic poly(2-hydroxyethyl methacrylate-co-glycidyl methacrylate) (P(HEMA-co-GMA)) and poly(glycidyl methacrylate) (PGMA) microspheres with/without carboxyl groups. The inhibition effect of magnetic microspheres on real-time polymerase chain reaction (RT-PCR) course was evaluated by regression analysis after the addition of different concentrations of tested microspheres to PCR mixtures. Microspheres mostly did not interfere in RT-PCR till the concentration 50 µg/25 µl PCR mixture. No relationship between Fe content (and microsphere diameter) and inhibition effect was found. Microspheres containing carboxyl groups extinguished the fluorescence at lower concentrations (10-20 µg/25 µl PCR mixture) without inhibition of DNA amplification as PCR products were detected using agarose gel electrophoresis. Negative effect of maghemite on PCR course was partially reduced by coating of magnetic core by silica or polymers. Two inhibition mechanisms of DNA amplification were discussed in this work.

  7. Poly(glycidyl methacrylate) grafted CdSe quantum dots by surface-initiated atom transfer radical polymerization: Novel synthesis, characterization, properties, and cytotoxicity studies

    Energy Technology Data Exchange (ETDEWEB)

    Bach, Long Giang; Islam, Md. Rafiqul [Department of Imaging System Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of); Lee, Doh Chang [Department of Chemical and Biomolecular Engineering, KAIST Institute for the Nanocentury (KINC), Korea Advanced Institute of Science and Technology (KAIST), Daejeon 305-701 (Korea, Republic of); Lim, Kwon Taek, E-mail: ktlim@pknu.ac.kr [Department of Imaging System Engineering, Pukyong National University, Busan 608-737 (Korea, Republic of)

    2013-10-15

    A novel approach for the synthesis of poly(glycidyl methacrylate) grafted CdSe quantum dot (QDs) (PGMA-g-CdSe) was developed. The PGMA-g-CdSe nanohybrids were synthesized by the surface-initiated atom transfer radical polymerization of glycidyl methacrylate from the surface of the strategic initiator, CdSe-BrIB QDs prepared by the interaction of 2-bromoisobutyryl bromide (BrIB) and CdSe-OH QDs. The structure, morphology, and optical property of the PGMA-g-CdSe nanohybrids were analyzed by FT-IR, XPS, TGA, XRD, TEM, and PL. The as-synthesized PGMA-g-CdSe nanohybrids having multi-epoxide groups were employed for the direct coupling of biotin via ring-opening reaction of the epoxide groups to afford the Biotin-f-PGMA-g-CdSe nanobioconjugate. The covalent immobilization of biotin onto PGMA-g-CdSe was confirmed by FT-IR, XPS, and EDX. Biocompatibility and imaging properties of the Biotin-f-PGMA-g-CdSe were investigated by MTT bioassay and PL analysis, respectively. The cell viability study suggested that the biocompatibility was significantly enhanced by the functionalization of CdSe QDs by biotin and PGMA.

  8. 40 CFR 721.3435 - Butoxy-substituted ether alkane.

    Science.gov (United States)

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Butoxy-substituted ether alkane. 721... Substances § 721.3435 Butoxy-substituted ether alkane. (a) Chemical substance and significant new uses subject to reporting. (1) The chemical substance identified generically as butoxy-substituted ether...

  9. Finkelstein Reaction in Functionalized Crown-ether Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    Xiao Hua WANG; Han Zhi WANG; Hui LIU; Yuan KOU

    2006-01-01

    Functional crown-ether ionic liquids were used as catalytic green solvents of Finkelstein reaction of 1-bromooctane and iodide. The rate and yield of the reaction were obvious improved compared with that using crown ether in water. No free crown ether loss was observed after reaction.

  10. 46 CFR 151.50-42 - Ethyl ether.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Ethyl ether. 151.50-42 Section 151.50-42 Shipping COAST... LIQUID HAZARDOUS MATERIAL CARGOES Special Requirements § 151.50-42 Ethyl ether. (a)(1) Gravity tanks... liquid. (g) Precautions shall be taken to prevent the contamination of ethyl ether by strong...

  11. POLYBROMINATED DIPHENYL ETHERS IN SOUTHERN MISSISSIPPI CATFISH

    Science.gov (United States)

    Polybrominated diphenyl ethers (PBDEs) are used as flame retardants in a wide variety of consumer products. Concerns surrounding these compounds are primarily due do their ubiquitous presence in the environment as well as in human tissue, such as milk, coupled with evidence indi...

  12. Orphan enzymes in ether lipid metabolism.

    Science.gov (United States)

    Watschinger, Katrin; Werner, Ernst R

    2013-01-01

    Ether lipids are an emerging class of lipids which have so far not been investigated and understood in every detail. They have important roles as membrane components of e.g. lens, brain and testis, and as mediators such as platelet-activating factor. The metabolic enzymes for biosynthesis and degradation have been investigated to some extent. As most involved enzymes are integral membrane proteins they are tricky to handle in biochemical protocols. The sequence of some ether lipid metabolising enzymes has only recently been reported and other sequences still remain obscure. Defined enzymes without assigned sequence are known as orphan enzymes. One of these enzymes with uncharacterised sequence is plasmanylethanolamine desaturase, a key enzyme for the biosynthesis of one of the most abundant phospholipids in our body, the plasmalogens. This review aims to briefly summarise known functions of ether lipids, give an overview on their metabolism including the most prominent members, platelet-activating factor and the plasmalogens. A special focus is set on the description of orphan enzymes in ether lipid metabolism and on the successful strategies how four previous orphans have recently been assigned a sequence. Only one of these four was characterised by classical protein purification and sequencing, whereas the other three required alternative strategies such as bioinformatic candidate gene selection and recombinant expression or development of an inhibitor and multidimensional metabolic profiling.

  13. Based Design EtherCAT Slave%基于EtherCAT的从站设计

    Institute of Scientific and Technical Information of China (English)

    文辉

    2015-01-01

    Fieldbus has become an important part of the automatic control technology, through a large number of practical experiments and testing, now widely applied. EtherCAT has good real-time capability to adapt to the small amount of data communications, and affordable, the industrial control has been widely used. However, due to EtherCAT Slave design must use a special chip, leading from the station complex hardware design, commissioning difficulties, increasing costs. In this paper, AM3358 Cortex A8 processor plus Ethernet physical layer transceiver (PHY) program, due to the integrated chip inside AM3358 Industrial communications subsystem (PRU-ICSS) EtherCAT protocol can be achieved, so long as the external PHY can become EtherCAT Slave ..%现场总线已经成为自动化控制技术重要组成部分,通过大量的实践实验与测试,如今已经获得广泛的应用。EtherCAT具有良好的实时能力,适应小数据量通信,并且价格经济,在工业控制上得到广泛的应用。但由于EtherCAT从站设计必须使用专门的芯片,导致从站的硬件设计复杂、调试困难、成本增加。文章采用AM3358 Cortex A8处理器外加以太网物理层收发器(PHY)的方案,由于AM3358片内集成工业用通信子系统(PRU-ICSS)可以实现EtherCAT协议,因此只要外加PHY就可以成为EtherCAT从站。

  14. Synthesis of poly(vinyl ether)s with perfluoroalkyl pendant groups

    NARCIS (Netherlands)

    Höpken, Jens; Möller, Martin; Lee, Myongsoo; Percec, Virgil

    1992-01-01

    2-Perfluoro(alkyl)ethyl vinyl ethers, F(CF2)nCH2CH2OCHCH2, (n = 6 or 8), were synthesized and polymerized by means of cationic initiators (HI/ZnI2 and CF3SO3H/(CH3)2S). The perfluorohexyl-substituted poly(vinyl ether) is completely amorphous. The polymer with perfluorooctyl segments shows side chain

  15. Preparation and characterisation of monovalent ion selective cation exchange membranes based on sulphonated poly(ether ether ketone)

    NARCIS (Netherlands)

    Balster, J.; Krupenko, O.; Punt, I.G.M.; Stamatialis, D.; Wessling, M.

    2005-01-01

    This paper analyses the separation properties of various commercial cation exchange membranes (CEMs) and tailor made membranes based on sulphonated poly(ether ether ketone) and poly(ether sulphone) for binary electrolyte solutions containing protons and calcium ions. All membranes are thoroughly cha

  16. Role of allyl group in the hydroxyl and peroxyl radical scavenging activity of S-allylcysteine.

    Science.gov (United States)

    Maldonado, Perla D; Alvarez-Idaboy, J Raúl; Aguilar-González, Adriana; Lira-Rocha, Alfonso; Jung-Cook, Helgi; Medina-Campos, Omar Noel; Pedraza-Chaverrí, José; Galano, Annia

    2011-11-17

    S-Allylcysteine (SAC) is the most abundant compound in aged garlic extracts, and its antioxidant properties have been demonstrated. It is known that SAC is able to scavenge different reactive species including hydroxyl radical (•OH), although its potential ability to scavenge peroxyl radical (ROO•) has not been explored. In this work the ability of SAC to scavenge ROO• was evaluated, as well as the role of the allyl group (-S-CH(2)-CH═CH(2)) in its free radical scavenging activity. Two derived compounds of SAC were prepared: S-benzylcysteine (SBC) and S-propylcysteine (SPC). Their abilities to scavenge •OH and ROO• were measured. A computational analysis was performed to elucidate the mechanism by which these compounds scavenge •OH and ROO•. SAC was able to scavenge •OH and ROO•, in a concentration-dependent way. Such activity was significantly ameliorated when the allyl group was replaced by benzyl or propyl groups. It was shown for the first time that SAC is able to scavenge ROO•.

  17. Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

    Science.gov (United States)

    Shakoori, Alireza; Bremner, John B; Abdel-Hamid, Mohammed K; Willis, Anthony C; Haritakun, Rachada

    2015-01-01

    Summary Diversity-directed synthesis based on the cascade allylation chemistry of indigo, with its embedded 2,2’-diindolic core, has resulted in rapid access to new examples of the hydroxy-8a,13-dihydroazepino[1,2-a:3,4-b']diindol-14(8H)-one skeleton in up to 51% yield. Additionally a derivative of the novel bridged heterocycle 7,8-dihydro-6H-6,8a-epoxyazepino[1,2-a:3,4-b']diindol-14(13H)-one was produced when the olefin of the allylic substrate was terminally disubstituted. Further optimisation also produced viable one-pot syntheses of derivatives of the spiro(indoline-2,9'-pyrido[1,2-a]indol)-3-one (65%) and pyrido[1,2,3-s,t]indolo[1,2-a]azepino[3,4-b]indol-17-one (72%) heterocyclic systems. Ring-closing metathesis of the N,O-diallylic spiro structure and subsequent Claisen rearrangement gave rise to the new (1R,8aS,17aS)-rel-1,2-dihydro-1-vinyl-8H,17H,9H-benz[2',3']pyrrolizino[1',7a':2,3]pyrido[1,2-a]indole-8,17-(2H,9H)-dione heterocyclic system. PMID:25977722

  18. Further exploration of the heterocyclic diversity accessible from the allylation chemistry of indigo

    Directory of Open Access Journals (Sweden)

    Alireza Shakoori

    2015-04-01

    Full Text Available Diversity-directed synthesis based on the cascade allylation chemistry of indigo, with its embedded 2,2’-diindolic core, has resulted in rapid access to new examples of the hydroxy-8a,13-dihydroazepino[1,2-a:3,4-b']diindol-14(8H-one skeleton in up to 51% yield. Additionally a derivative of the novel bridged heterocycle 7,8-dihydro-6H-6,8a-epoxyazepino[1,2-a:3,4-b']diindol-14(13H-one was produced when the olefin of the allylic substrate was terminally disubstituted. Further optimisation also produced viable one-pot syntheses of derivatives of the spiro(indoline-2,9'-pyrido[1,2-a]indol-3-one (65% and pyrido[1,2,3-s,t]indolo[1,2-a]azepino[3,4-b]indol-17-one (72% heterocyclic systems. Ring-closing metathesis of the N,O-diallylic spiro structure and subsequent Claisen rearrangement gave rise to the new (1R,8aS,17aS-rel-1,2-dihydro-1-vinyl-8H,17H,9H-benz[2',3']pyrrolizino[1',7a':2,3]pyrido[1,2-a]indole-8,17-(2H,9H-dione heterocyclic system.

  19. Iron complexes of tetramine ligands catalyse allylic hydroxyamination via a nitroso–ene mechanism

    Directory of Open Access Journals (Sweden)

    David Porter

    2015-12-01

    Full Text Available Iron(II complexes of the tetradentate amines tris(2-pyridylmethylamine (TPA and N,N′-bis(2-pyridylmethyl-N,N′-dimethylethane-1,2-diamine (BPMEN are established catalysts of C–O bond formation, oxidising hydrocarbon substrates via hydroxylation, epoxidation and dihydroxylation pathways. Herein we report the capacity of these catalysts to promote C–N bond formation, via allylic amination of alkenes. The combination of N-Boc-hydroxylamine with either FeTPA (1 mol % or FeBPMEN (10 mol % converts cyclohexene to the allylic hydroxylamine (tert-butyl cyclohex-2-en-1-yl(hydroxycarbamate in moderate yields. Spectroscopic studies and trapping experiments suggest the reaction proceeds via a nitroso–ene mechanism, with involvement of a free N-Boc-nitroso intermediate. Asymmetric induction is not observed using the chiral tetramine ligand (+-(2R,2′R-1,1′-bis(2-pyridylmethyl-2,2′-bipyrrolidine ((R,R′-PDP.

  20. Mechanism of the cobalt oxazoline palladacycle (COP)-catalyzed asymmetric synthesis of allylic esters.

    Science.gov (United States)

    Cannon, Jeffrey S; Kirsch, Stefan F; Overman, Larry E; Sneddon, Helen F

    2010-11-03

    The catalytic enantioselective S(N)2' displacement of (Z)-allylic trichloroacetimidates catalyzed by the palladium(II) complex [COP-OAc](2) is a broadly useful method for the asymmetric synthesis of chiral branched allylic esters. A variety of experiments aimed at elucidating the nature of the catalytic mechanism and its rate- and enantiodetermining steps are reported. Key findings include the following: (a) the demonstration that a variety of bridged-dipalladium complexes are present and constitute resting states of the COP catalyst (however, monomeric palladium(II) complexes are likely involved in the catalytic cycle); (b) labeling experiments establishing that the reaction proceeds in an overall antarafacial fashion; (c) secondary deuterium kinetic isotope effects that suggest substantial rehybridization at both C1 and C3 in the rate-limiting step; and (d) DFT computational studies (B3-LYP/def2-TZVP) that provide evidence for bidentate substrate-bound intermediates and an anti-oxypalladation/syn-deoxypalladation pathway. These results are consistent with a novel mechanism in which chelation of the imidate nitrogen to form a cationic palladium(II) intermediate activates the alkene for attack by external carboxylate in the enantiodetermining step. Computational modeling of the transition-state structure for the acyloxy palladation step provides a model for enantioinduction.

  1. Tween as a Substitute for Diethyl Ether in the Formalin-Ether Sedimentation Technique

    Directory of Open Access Journals (Sweden)

    NA Ahmadi

    2007-10-01

    Full Text Available Background: Tween as a substitute for diethyl ether in the formalin-ether sedimentation technique was evaluated for para­site detection.Methods: Fresh fecal material free of parasites with 10% formalin to prepare standardized specimen was thoroughly pooled. This specimen was divided into 5 equal portions; one was without infection, and each of the others was individually seeded with Entamoeba coli, and Giardia lamblia cysts, ova of Ascaris lumbericoides, and Hymenolepis nana. Six hundred and eighty four slides including 228 stool samples for each of formalin-tween, formalin-ether and direct wet mount proce­dures were examined.Results: The sensitivity of above mentioned procedures were computed 72.1%, 55% and 30 %; their negative predictive value were 69.3%, 58.3% and 47.3%; and their false negative error rate were 27.9%, 45% and 70%, respectively. There were no false-positive results among the 264 specimens previously identified as negative for the presence of intestinal para­sites. Therefore, specificity for each technique was 100%.Conclusion: In the range of our study, formalin-tween method proved to be equivalent to or better than formalin-ether tech­nique in concentrating parasite eggs, and cysts, as well as in maintaining characteristic morphology. Tween is more stable, safer, cheaper, and less flammable than that of ether; and promises to be a useful alternative to ether.

  2. The genotoxic potential in vitro and in vivo of the allyl benzene etheric oils estragole, basil oil and trans-anethole.

    Science.gov (United States)

    Müller, L; Kasper, P; Müller-Tegethoff, K; Petr, T

    1994-12-01

    Estragole, trans-anethole and basil oil were tested for their ability to induce DNA repair in rat hepatocytes in vitro and in rat liver in an ex vivo test. There was a marked induction of UDS by estragole and basil oil in vitro (LOEC about 10(-5) mol/l). The basil oil we used contained about 88.2% estragole. It is evident from our results that the induction of UDS with basil oil could be directly related to its main constituent estragole. trans-Anethole was only slightly effective in the in vitro UDS test. The ex vivo UDS test led to clearly elevated DNA repair for estragole and basil oil in rats treated orally with doses up to 2 g/kg body weight. Estragole was not positive in a chromosomal aberration test with V79 cells either via direct treatment, with rat liver S9 mix or with rat hepatocytes as source of metabolism.

  3. Synthesis of thermosensitive magnetic nanocarrier for controlled sorafenib delivery

    Energy Technology Data Exchange (ETDEWEB)

    Heidarinasab, Amir [Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Ahmad Panahi, Homayon [Department of Chemistry, Central Tehran Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Faramarzi, Mehdi, E-mail: faramarzi.iaug@gmail.com [Department of Chemical Engineering, Science and Research Branch, Islamic Azad University, Tehran (Iran, Islamic Republic of); Farjadian, Fatemeh [Pharmaceutical Sciences Research Center, Faculty of Pharmacy, Shiraz University of Medical Sciences, Shiraz (Iran, Islamic Republic of)

    2016-10-01

    Allyl glycidyl ether/N-isopropylacrylamide-grafted magnetic nanoparticles were prepared using silica-coated magnetic nanoparticles as a substrate for radical copolymerization of allyl glycidyl ether and N-isopropylacrylamide. Chitosan was coupled with the prepared nanoparticles by opening the epoxy ring of the allyl glycidyl ether. The thermosensitive magnetic nanocarrier (TSMNC) obtained can be applied as a potent drug carrier. The TSMNC structure was characterized using Fourier transform infrared spectroscopy, X-ray diffraction, thermogravimetric analysis, differential scanning calorimetry, vibrating sample magnetometer, and elemental analysis. Its morphology and size were investigated using field emission scanning electron microscopy, transmission electron microscopy and dynamic light scattering. The feasibility of employing the TSMNC for adsorption and in vitro controlled release of the chemotherapeutic agent sorafenib was tested. The effect of the adsorption parameters of pH, temperature, and loading time of sorafenib onto TSMNC was evaluated. The adsorption data was fitted to the Langmuir and Freundlich isotherms and the relevant parameters derived. The drug release profile indicated that 88% of the adsorbed drug was released within 35 h at 45 °C and drug release was Fickian diffusion-controlled. The results confirmed that the TSMNC has a high adsorption capacity at low temperature and good controlled release in a slow rate at a high temperature and could be developed for further application as a drug nanocarrier. - Graphical abstract: Magnetic nanoparticles were functionalized with chitosan and N-isopropylacrylamide. It was evaluated for sorafenib (SFB) adsorption and tested as a controlled-release system in response to changes in temperature. The TSMNC showed superparamagnetic properties with a high adsorption capacity and desirable controlled release at below and above LCST. Display Omitted - Highlights: • A TSMNC was synthesized for controlled

  4. Asymmetric allylic alkylation in combination with ring-closing metathesis for the preparation of chiral N-heterocycles

    NARCIS (Netherlands)

    Teichert, Johannes F.; Zhang, Suyan; Zijl, Anthoni W. van; Slaa, Jan Willem; Minnaard, Adriaan J.; Feringa, Bernard

    2010-01-01

    Asymmetric copper-catalyzed allylic substitution with methylmagnesium bromide is employed in combination with ring-closing olefin metathesis or ene-yne metathesis to achieve the synthesis of chiral, unsaturated nitrogen heterocycles. The resulting six- to eight-membered chiral heterocycles are acces

  5. The NBS Reaction: A Simple Explanation for the Predominance of Allylic Substitution over Olefin Addition by Bromine at Low Concentrations.

    Science.gov (United States)

    Wamser, Carl C.; Scott, Lawrence T.

    1985-01-01

    Examines mechanisms related to use of N-bromosuccinimide (NBS) for bromination at an allylic position. Also presents derived rate laws for three possible reactions of molecular bromine with an alkene: (1) free radical substitution; (2) free radical addition; and (3) electrophilic addition. (JN)

  6. Synthesis of novel chiral phosphine-triazine ligand derived from α-phenylethylamine for Pd-catalyzed asymmetric allylic alkylation

    Institute of Scientific and Technical Information of China (English)

    Jia Di Huang; Xiang Ping Hu; Zhuo Zheng

    2008-01-01

    A novel chiral phosphine-triazine ligand was synthesized from chiral model reaction of Pd-catalyzed allylic alkylation of rac-l,3-diphenylprop-2-en-l-yl pivalate with dimethyl malonate, good enantioselectivity (90% e.e.) was obtained by using this ligand.

  7. New chiral N, S-ligands with Thiophenyl at Benzylic Position. Palladium(Ⅱ)-catalyzed Enantioselective Allylic Alkylation

    Institute of Scientific and Technical Information of China (English)

    WU,Hao(吴昊); WU,Xun-Wei(巫循伟); HOU,Xue-Long(侯雪龙); DAI,Li-Xin(戴立信); WANG,Quan-Rui(王全瑞)

    2002-01-01

    New chiral N, S-ligands with oxazoline and thiphenyl substituents at benzene ring and benzylic position have been prepared and applied in palladium-catalyzed asymmetric allylic alkylation reaction to provide the product with high yield and entantioselectivity (82%-93% ee).

  8. Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions

    Science.gov (United States)

    We evaluated the effects of storage and handling conditions on the antimicrobial activity of biodegradable composite films (polylactic acid and sugar beet pulp) coated with allyl isothiocyanate (AIT). Polylactic acid (PLA) and chitosan were incorporated with AIT and coated on one side of the film. T...

  9. Spectra of carbanions formed from allyl cyanide during isomerization in zeolite NaY-FAU with strong basic sites

    Science.gov (United States)

    Hannus, István; Förster, Horst; Tasi, Gyula; Kiricsi, Imre; Molnár, Árpád

    1995-03-01

    Double bond isomerization of allyl cyanide to crotononitrile over a basic zeolite catalyst was monitored by IR and UV-VIS spectroscopy in order to get information on the surface intermediates involved. Due to the spectral changes the occurence of a carbanionic intermediate seems to be highly probable characterized by an absorption at 400 nm.

  10. Phosphine-catalyzed [4 + 1] annulation between α,β-unsaturated imines and allylic carbonates: synthesis of 2-pyrrolines.

    Science.gov (United States)

    Tian, Junjun; Zhou, Rong; Sun, Haiyun; Song, Haibin; He, Zhengjie

    2011-04-01

    In this report, a phosphine-catalyzed [4 + 1] annulation between α,β-unsaturated imines and allylic carbonates is described. This reaction represents the first realization of catalytic [4 + 1] cyclization of 1,3-azadienes with in situ formed phosphorus ylides, which provides highly efficient and diastereoselective synthesis of 2-pyrrolines.

  11. Inhibition of diethyl ether degradation in Rhodococcus sp. strain DEE5151 by glutaraldehyde and ethyl vinyl ether.

    Science.gov (United States)

    Kim, Yong-Hak; Engesser, Karl-Heinrich

    2005-02-15

    Alkyl ether-degrading Rhodococcus sp. strain DEE5151, isolated from activated sewage sludge, has an activity for the oxidation of a variety of alkyl ethers, aralkyl ethers and dibenzyl ether. The whole cell activity for diethyl ether oxidation was effectively inhibited by 2,3-dihydrofurane, ethyl vinyl ether and glutaraldehyde. Glutaraldehyde of less than 30 microM inhibited the activity by a competitive manner with the inhibition constant, K(I) of 7.07+/-1.36 microM. The inhibition type became mixed at higher glutaraldehyde concentrations >30 microM, probably due to the inactivation of the cell activity by the Schiff-base formation. Structurally analogous ethyl vinyl ether inhibited the diethyl ether oxidation activity in a mixed manner with decreasing the apparent maximum oxidation rate, v(max)(app), and increasing the apparent Michaelis-Menten constant, K(M)(app). The mixed type inhibition by ethyl vinyl ether seemed to be introduced not only by the structure similarity with diethyl ether, but also by the reactivity of the vinyl ether with cellular components in the whole cell system.

  12. Enantiospecific total synthesis of (+)-tanikolide via a key [2,3]-Meisenheimer rearrangement with an allylic amine N-oxide-directed epoxidation and a one-pot trichloroisocyanuric acid N-debenzylation and N-chlorination.

    Science.gov (United States)

    Xie, Yangla; Sun, Moran; Zhou, Hang; Cao, Qiwei; Gao, Kaige; Niu, Changling; Yang, Hua

    2013-10-18

    The enantiospecific total synthesis of the δ-lactonic marine natural product (+)-tanikolide (1), isolated from Lyngbya majuscula , was achieved using a [2,3]-Meisenheimer rearrangement as the key reaction. During this rearrangement, we discovered that the allylic amine N-oxide could direct the m-CPBA double-bond epoxidation to the syn position. The resulting syn product 8 underwent epoxide ring opening under the m-CBA conditions to give the five- and six-membered cyclic ether amine N-oxides, which we further treated with Zn and conc. HCl to obtain the reduced bisbenzyl tertiary amines 23 and 22, respectively. When 23 and 22 were treated with trichloroisocyanuric acid (TCCA) in dichloromethane, oxidation at the benzyl position occurred, forming iminium ions. These intermediates were trapped by intramolecular reaction with the hydroxyls, and the resulting intermediates were then oxidized or shifted to afford 25 and 24, respectively. The entire one-pot process involves N-debenzylation, N-chlorination, and hemiacetal oxidation. The amine N-oxide-directed epoxidation complements Davies' ammonium-directed epoxidation. Thus, TCCA N-debenzylation is described for the first time and might be a useful N-debenzylation technique.

  13. Ether modifications to 1-[2-(3,4-dimethoxyphenyl)ethyl]-4-(3-phenylpropyl)piperazine (SA4503): effects on binding affinity and selectivity for sigma receptors and monoamine transporters.

    Science.gov (United States)

    Xu, Rong; Lord, Sarah A; Peterson, Ryan M; Fergason-Cantrell, Emily A; Lever, John R; Lever, Susan Z

    2015-01-01

    Two series of novel ether analogs of the sigma (σ) receptor ligand 1-[2-(3,4-dimethoxyphenyl)ethyl]-4-(3-phenylpropyl)piperazine (SA4503) have been prepared. In one series, the alkyl portion of the 4-methoxy group was replaced with allyl, propyl, bromoethyl, benzyl, phenethyl, and phenylpropyl moieties. In the second series, the 3,4-dimethoxy was replaced with cyclic methylenedioxy, ethylenedioxy and propylenedioxy groups. These ligands, along with 4-O-des-methyl SA4503, were evaluated for σ1 and σ2 receptor affinity, and compared to SA4503 and several known ether analogs. SA4503 and a subset of ether analogs were also evaluated for dopamine transporter (DAT) and serotonin transporter (SERT) affinity. The highest σ1 receptor affinities, Ki values of 1.75-4.63 nM, were observed for 4-O-des-methyl SA4503, SA4503 and the methylenedioxy analog. As steric bulk increased, σ1 receptor affinity decreased, but only to a point. Allyl, propyl and bromoethyl substitutions gave σ1 receptor Ki values in the 20-30 nM range, while bulkier analogs having phenylalkyl, and Z- and E-iodoallyl, ether substitutions showed higher σ1 affinities, with Ki values in the 13-21 nM range. Most ligands studied exhibited comparable σ1 and σ2 affinities, resulting in little to no subtype selectivity. SA4503, the fluoroethyl analog and the methylenedioxy congener showed modest six- to fourteen-fold selectivity for σ1 sites. DAT and SERT interactions proved much more sensitive than σ receptor interactions to these structural modifications. For example, the benzyl congener (σ1Ki=20.8 nM; σ2Ki=16.4 nM) showed over 100-fold higher DAT affinity (Ki=121 nM) and 6-fold higher SERT affinity (Ki=128nM) than the parent SA4503 (DAT Ki=12650 nM; SERT Ki=760 nM). Thus, ether modifications to the SA4503 scaffold can provide polyfunctional ligands having a broader spectrum of possible pharmacological actions.

  14. Synthesis of New Liquid Crystalline Diglycidyl Ethers

    Directory of Open Access Journals (Sweden)

    Issam Ahmed Mohammed

    2012-01-01

    Full Text Available The phenolic Schiff bases I–VI were synthesized by condensation reactions between various diamines, namely o-dianisidine, o-tolidine and ethylenediamine with vanillin or p-hydroxybenzaldehyde and subsequent reactions between these phenolic Schiff bases and epichlorohydrin to produce new diglycidyl ethers Ia–VIa. The structures of these compounds were confirmed by CHN, FT-IR, 1H-NMR, and 13C-NMR spectroscopy. Their thermotropic liquid crystalline behavior was studied using differential scanning calorimetry (DSC and polarizing optical microscopy (POM. All the diglycidyl ethers prepared exhibit nematic mesophases, except for Va and VIa, which did not show any transition mesophases, but simply flow to liquids.

  15. Emergent gravity and ether-drift experiments

    CERN Document Server

    Consoli, M

    2009-01-01

    In principle, ether-drift experiments could distinguish phenomenologically emergent-gravity approaches, where an effective curvature emerges from hydrodynamic distortions of the same physical, flat-space vacuum, from the more conventional scenario where curvature is considered a fundamental property of space-time down to extremely small length scales and the speed of light represents a universal constant. From an experimental point of view, in this particular context, besides time modulations that might be induced by the Earth's rotation (and its orbital revolution), one should also consider the possibility of random fluctuations of the signal. These might reflect the stochastic nature of the underlying 'quantum ether' and be erroneously interpreted as mere instrumental noise. To test the present interpretation, we have extracted the mean amplitude of the signal from various experiments with different systematics, operating both at room temperature and in the cryogenic regime. They all give the same consisten...

  16. Catalytic intermolecular hydroamination of vinyl ethers.

    Science.gov (United States)

    Pahadi, Nirmal K; Tunge, Jon A

    2009-12-01

    This manuscript details the development of a palladium-catalyzed hydroamination of vinyl ethers. It is proposed that palladium catalyzes the hydroamination via Bronsted base catalysis, where palladium is protonated by the relatively acidic sulfonamide to generate a palladium hydride as well as the active anionic sulfonamide nucleophile. Thus, this process is distinct from known palladium-catalyzed hydroaminations of styrene derivatives that utilize less acidic amines.

  17. Fluoroalkylation of aryl ether perfluorocyclobutyl polymers

    OpenAIRE

    Ligon, Clark; Ameduri, Bruno; Boutevin, Bernard; Smith, Dennis

    2008-01-01

    International audience; Post functionalization of aryl ether perfluorocyclobutyl (PFCB) polymers with fluoroalkyl side chains was accomplished with Umemoto's FITS reagents. The fluoroalkylated PFCB polymers (20 % functionalized) showed increases in both hydrophobicity and oleophobicity. Static contact angle for hexadecane was increased after fluoroalkylation from 0° to greater than 30° for the two PFCB polymers tested. Increased oil repellency makes these materials potential candidates for va...

  18. A mild method of amine-type adsorbents syntheses with emulsion graft polymerization of glycidyl methacrylate on polyethylene non-woven fabric by pre-irradiation

    Science.gov (United States)

    Ma, Hongjuan; Yao, Side; Li, Jingye; Cao, Changqing; Wang, Min

    2012-09-01

    A mild pre-irradiation method was used to graft glycidyl methacrylate (GMA) onto polyethylene (PE) non-woven fabric (NF). The polymer was irradiated by electron beam in air atmosphere at room temperature. The degree of grafting (Dg) was determined as a function of reaction time, absorbed dose, monomer concentration and temperature. After 30 kGy irradiation, with 5% GMA, surfactant Tween 20 (Tw-20) of 0.5% at 55 °C for 15 min, the trunk polymer was made grafted with a Dg of 150%. Selected PE-g-PGMA of different Dg was modified with aminated compounds such as ethylenediamine (EDA), diethylenetriamine (DETA), triethylenetetramine (TETA) and tetraethylenepentamine (TEPA). The obtained amine-type adsorbents were prepared to remove copper and uranium ions from solution. It was shown that at least 90% of copper and 60% of uranium with the initial concentration from 3 to 1000 ppb can be removed from water.

  19. Preparation and characterization of reactive blends of poly(lactic acid), poly(ethylene-co-vinyl alcohol), and poly(ethylene-co-glycidyl methacrylate)

    Energy Technology Data Exchange (ETDEWEB)

    Warangkhana, Phromma; Rathanawan, Magaraphan, E-mail: rathanawan.k@chula.ac.th [Chulalongkorn University, Petroleum and Petrochemical College - Bangkok (Thailand); Jana Sadhan, C., E-mail: janas@uakron.edu [The University of Akron, Department of Polymer Engineering, Ohio (United States)

    2015-05-22

    The ternary blends of poly(lactic acid) (PLA), poly(ethylene-co-vinyl alcohol) (EVOH), and poly(ethylene-co-glycidyl methacrylate) (EGMA) were prepared. The role of EGMA as a compatibilizer was evaluated. The weight ratio of PLA:EVOH was 80:20 and the EGMA loadings were varied from 5-20 phr. The blends were characterized as follows: thermal properties by differential scanning calorimetry, morphology by scanning electron microscopy, and mechanical properties by pendulum impact tester, and universal testing machine. The glass transition temperature of PLA blends did not change much when compared with that of PLA. The blends of PLA/EGMA and EVOH/EGMA showed EGMA dispersed droplets where the latter led to poor impact properties. However, the tensile elongation at break and tensile toughness substantially increased upon addition of EGMA to blends of PLA and EVOH. It was noted in tensile test samples that both PLA and EVOH domains fibrillated significantly to produce toughness.

  20. Nikola Tesla, the Ether and his Telautomaton

    Science.gov (United States)

    Milar, Kendall

    2014-03-01

    In the nineteenth century physicists' understanding of the ether changed dramatically. New developments in thermodynamics, energy physics, and electricity and magnetism dictated new properties of the ether. These have traditionally been examined from the perspective of the scientists re-conceptualizing the ether. However Nikola Tesla, a prolific inventor and writer, presents a different picture of nineteenth century physics. Alongside the displays that showcased his inventions he presented alternative interpretations of physical, physiological and even psychical research. This is particularly evident in his telautomaton, a radio remote controlled boat. This invention and Tesla's descriptions of it showcase some of his novel interpretations of physical theories. He offered a perspective on nineteenth century physics that focused on practical application instead of experiment. Sometimes the understanding of physical theories that Tesla reached was counterproductive to his own inventive work; other times he offered new insights. Tesla's utilitarian interpretation of physical theories suggests a more scientifically curious and invested inventor than previously described and a connection between the scientific and inventive communities.

  1. The Reaction of Allyl Isothiocyanate with Hydroxyl/Water and β-Cyclodextrin Using Ultraviolet Spectrometry

    Directory of Open Access Journals (Sweden)

    Zi-Tao Jiang

    2006-01-01

    Full Text Available The reaction of allyl isothiocyanate (AITC with hydroxyl/water and β-cyclodextrin (β-CD in different acidic-alkaline media has been investigated by ultraviolet spectrometry. The kinetic parameters of the reaction were measured. It was found that after AITC translating into thiourea, the absorption peak shifted from 240 to 226 nm and the molar absorptivity increased about 16 times. The reaction can be seen as a pseudo first order reaction because the concentration of hydroxyl was constant. β-CD can inhibit the reaction of AITC with hydroxyl/water, i.e. the hydrolysis of AITC. The formation constant (Ka and thermodynamic parameters of the complex reaction were calculated. Ka decreased with the increase of temperature. The experimental results indicated that the inclusive process was an exothermic and enthalpy-driven process accompanied with a negative entropic contribution.

  2. An Efficient Amide-Aldehyde-Alkene Condensation: Synthesis for the N-Allyl Amides.

    Science.gov (United States)

    Quan, Zheng-Jun; Wang, Xi-Cun

    2016-02-01

    The allylamine skeleton represents a significant class of biologically active nitrogen compounds that are found in various natural products and drugs with well-recognized pharmacological properties. In this personal account, we will briefly discuss the synthesis of allylamine skeletons. We will focus on showing a general protocol for Lewis acid-catalyzed N-allylation of electron-poor N-heterocyclic amides and sulfonamide via an amide-aldehyde-alkene condensation reaction. The substrate scope with respect to N-heterocyclic amides, aldehydes, and alkenes will be discussed. This method is also capable of preparing the Naftifine motif from N-methyl-1-naphthamide or methyl (naphthalene-1-ylmethyl)carbamate, with paraformaldehyde and styrene in a one-pot manner.

  3. Enantioselective construction of quaternary N-heterocycles by palladium-catalysed decarboxylative allylic alkylation of lactams

    KAUST Repository

    Behenna, Douglas C.

    2011-12-18

    The enantioselective synthesis of nitrogen-containing heterocycles (N-heterocycles) represents a substantial chemical research effort and resonates across numerous disciplines, including the total synthesis of natural products and medicinal chemistry. In this Article, we describe the highly enantioselective palladium-catalysed decarboxylative allylic alkylation of readily available lactams to form 3,3-disubstituted pyrrolidinones, piperidinones, caprolactams and structurally related lactams. Given the prevalence of quaternary N-heterocycles in biologically active alkaloids and pharmaceutical agents, we envisage that our method will provide a synthetic entry into the de novo asymmetric synthesis of such structures. As an entry for these investigations we demonstrate how the described catalysis affords enantiopure quaternary lactams that intercept synthetic intermediates previously used in the synthesis of the Aspidosperma alkaloids quebrachamine and rhazinilam, but that were previously only available by chiral auxiliary approaches or as racemic mixtures. © 2012 Macmillan Publishers Limited. All rights reserved.

  4. Low-temperature Electrodeposition of Aluminium from Lewis Acidic 1-Allyl-3-methylimidazolium Chloroaluminate Ionic Liquids

    Institute of Scientific and Technical Information of China (English)

    郑勇; 张锁江; 吕兴梅; 王倩; 左勇; 刘恋

    2012-01-01

    Lewis acidic 1-allyl-3-methylimidazolium chloroaluminate ionic liquids were used as promising electrolytes in the low-temperature electrodeposition of aluminium. Systematic studies on deposition process have been performed by cYClic voltammetry and chronoamperometry. The surface morphology and X-ray diffraction (XRD) patterns of deposits prepared at different experimental conditions were also investigated. It was shown that the nucleation density and growth rate of crystallites had a great effect on the structure of aluminium deposited. The crys- tallographic orientation of deposits was mainly influenced by temperature and current density. Smooth, dense and well adherent aluminium coatings were obtained on copper substrates at 10-25 mA.cm^-2 and 313.2-353.2 K. More- over, the current efficiency of deposition and purity of aluminium have been significantly improved, demonstrating that the ionic liquids tested have a prospectful potential in electroplating and electrorefining of aluminium.

  5. Decarboxylative-coupling of allyl acetate catalyzed by group 10 organometallics, [(phen)M(CH3)]+.

    Science.gov (United States)

    Woolley, Matthew; Ariafard, Alireza; Khairallah, George N; Kwan, Kim Hong-Yin; Donnelly, Paul S; White, Jonathan M; Canty, Allan J; Yates, Brian F; O'Hair, Richard A J

    2014-12-19

    Gas-phase carbon-carbon bond forming reactions, catalyzed by group 10 metal acetate cations [(phen)M(O2CCH3)](+) (where M = Ni, Pd or Pt) formed via electrospray ionization of metal acetate complexes [(phen)M(O2CCH3)2], were examined using an ion trap mass spectrometer and density functional theory (DFT) calculations. In step 1 of the catalytic cycle, collision induced dissociation (CID) of [(phen)M(O2CCH3)](+) yields the organometallic complex, [(phen)M(CH3)](+), via decarboxylation. [(phen)M(CH3)](+) reacts with allyl acetate via three competing reactions, with reactivity orders (% reaction efficiencies) established via kinetic modeling. In step 2a, allylic alkylation occurs to give 1-butene and reform metal acetate, [(phen)M(O2CCH3)](+), with Ni (36%) > Pd (28%) > Pt (2%). Adduct formation, [(phen)M(C6H11O2)](+), occurs with Pt (24%) > Pd (21%) > Ni(11%). The major losses upon CID on the adduct, [(phen)M(C6H11O2)](+), are 1-butene for M = Ni and Pd and methane for Pt. Loss of methane only occurs for Pt (10%) to give [(phen)Pt(C5H7O2)](+). The sequences of steps 1 and 2a close a catalytic cycle for decarboxylative carbon-carbon bond coupling. DFT calculations suggest that carbon-carbon bond formation occurs via alkene insertion as the initial step for all three metals, without involving higher oxidation states for the metal centers.

  6. From ether theory to ether theology: Oliver Lodge and the physics of immortality.

    Science.gov (United States)

    Raia, Courtenay Grean

    2007-01-01

    This article follows the development of physicist Oliver Lodge's religio-scientific worldview, beginning with his reticent attraction to metaphysics in the early 1880s to the full formulation of his "ether theology" in the late 1890s. Lodge undertook the study of psychical phenomena such as telepathy, telekinesis, and "ectoplasm" to further his scientific investigations of the ether, speculating that electrical and psychical manifestations were linked phenomena that described the deeper underlying structures of the universe, beneath and beyond matter. For Lodge, to fully understand the ether was to force from the universe an ultimate Revelation, and psychical research, as the most modern and probatory science, was poised to replace religion as the means of that disclosure.

  7. Synthesis of Diaryl Ethers, Diaryl Sulfides, Heteroaryl Ethers and Heteroaryl Sulfides under Microwave Heating

    Institute of Scientific and Technical Information of China (English)

    LI,Feng; ZOU,Jiong; WANG,Quan-Rui; TAO,Feng-Gang

    2004-01-01

    @@ Diaryl ether moiety is found in a pool of naturally occurring and medicinally important compounds.[1] As a consequent, considerable efforts have been devoted to the assembly of this framework.[2] Recently, we have developed a microwave heating version of the synthesis of diaryl ethers as well as aryl sulfides. Under our conditions, even the extremely electron-poor 4-nitrophenol works well and its reaction with 1-halo-4-nitrobenzenes produces 4-(nitrophenoxy)-benzonitriles in satisfactory yield. The scope of the present protocol has been expanded to hydroxylated six-membered heterocycles as well as 2-pyrimidinethiol with mildly activated aryl halides, affording heteroaryl ethers and respectively sulfides. The advantages of the present method include the wide substrate scope, no use of any metal catalysts, the ease of product isolation and high yields.

  8. 76 FR 38026 - Diethylene Glycol Mono Butyl Ether; Exemption From the Requirement of a Tolerance

    Science.gov (United States)

    2011-06-29

    ... butyl ether, also a glycol ether differing in only one ethyl group from DEGBE. These data were used to... monobutyl ether, also a glycol ether differing only in one ethyl group. This data was used to assess the... AGENCY 40 CFR Part 180 Diethylene Glycol Mono Butyl Ether; Exemption From the Requirement of a...

  9. On the Nature of the Intermediates and the Role of Chloride Ions in Pd-Catalyzed Allylic Alkylations: Added Insight from Density Functional Theory

    DEFF Research Database (Denmark)

    Fristrup, Peter; Ahlquist, Mårten Sten Gösta; Tanner, David Ackland

    2008-01-01

    The reactivity of intermediates in palladium-catalyzed allylic alkylation was investigated using DFT (B3LYP) calculations including a PB-SCRF solvation model. In the presence of both phosphine and chloride ligands, the allyl intermediate is in equilibrium between a cationic eta(3)-allylPd complex...... with two phosphine ligands, the corresponding neutral complex with one phosphine and one chloride ligand, and a neutral eta(1)-allylPd complex with one chloride and two phosphine ligands. The eta(1)-complex is unreactive toward nucleophiles. The cationic eta(3)-complex is the intermediate most frequently...... invoked in the title reaction, but in the presence of halides, the neutral, unsymmetrically substituted eta(3)-CoMplex will be formed rapidly from anionic Pd(0) complexes in solution. Since the latter will prefer both leaving group ionization and reaction with nucleophiles in the position trans...

  10. Modular access to vicinally functionalized allylic (thio)morpholinonates and piperidinonates by substrate-controlled annulation of 1,3-azadienes with hexacyclic anhydrides.

    Science.gov (United States)

    Braunstein, Hannah; Langevin, Spencer; Khim, Monique; Adamson, Jonathan; Hovenkotter, Katie; Kotlarz, Lindsey; Mansker, Brandon; Beng, Timothy K

    2016-09-21

    A modular substrate-controlled hexannulation of inherently promiscuous 1,3-azadienes with hexacyclic anhydrides, which affords versatile vicinally functionalized allylic lactams, in high yields, regio- and stereoselectivities is described.

  11. Azidated Ether-Butadiene-Ether Block Copolymers as Binders for Solid Propellants

    Science.gov (United States)

    Cappello, Miriam; Lamia, Pietro; Mura, Claudio; Polacco, Giovanni; Filippi, Sara

    2016-07-01

    Polymeric binders for solid propellants are usually based on hydroxyl-terminated polybutadiene (HTPB), which does not contribute to the overall energy output. Azidic polyethers represent an interesting alternative but may have poorer mechanical properties. Polybutadiene-polyether copolymers may combine the advantages of both. Four different ether-butadiene-ether triblock copolymers were prepared and azidated starting from halogenated and/or tosylated monomers using HTPB as initiator. The presence of the butadiene block complicates the azidation step and reduces the storage stability of the azidic polymer. Nevertheless, the procedure allows modifying the binder properties by varying the type and lengths of the energetic blocks.

  12. SYNTHESIS OF POLY ( ETHER-URETHANE) CONTAINING PENDANT AMINO GROUP

    Institute of Scientific and Technical Information of China (English)

    WU Jinhuang; SUN Yanhui; FENG Xinde

    1989-01-01

    This paper is concerned with the synthesis of poly (ether-urethane) with pendant amino groups. The copolyether produced by ring opening copolymerization of tetrahydrofuran and epibromohydrin was treated with sodium azide in dimethylformamide to form azido substituted copolyether. The poly (ether-urethane) made from it was subjected to reduction reaction to convert azido group to amino group. The stress-strain behavior and dynamic-mechanical properties of poly (ether-urethane) containing pendant amino groups were studied.

  13. Oxidation reaction of 4-allyl-4-hydroperoxy-2-methoxycyclohexa-2,5-dienone in the presence of potassium permanganate without a co-oxidant

    Directory of Open Access Journals (Sweden)

    Mehmet Serdar Gültekin

    2016-12-01

    Full Text Available 4-Allyl-4-hydroperoxy-2-methoxycyclohexa-2,5-dienone (5 was synthesized by photooxygenation of commercially available Eugenol in the presence of tetraphenylporphyrin (TPP as a singlet oxygen sensitizer. The brief and one-pot syntheses of some natural product skeletons were conducted using the corresponding allylic hydroperoxide at different temperatures (0 oC and room temperature with potassium permanganate (KMnO 4 in mild condition at N 2(g atm.

  14. A convenient and stereoselective synthesis of (Z)-allyl selenides via Sm/TMSCI system-promoted coupling of Baylis-Hillman adducts with diselenides

    Institute of Scientific and Technical Information of China (English)

    LIU Yun-kui; XU Dan-qian; XU Zhen-yuan; ZHANG Yong-min

    2006-01-01

    A simple and convenient procedure for stereoselective synthesis of (Z)-allyl selenides has been developed by a one-pot reaction of diselenides with Baylis-Hillman adducts in the presence of samarium metal-trimethylsilyl chloride under mild conditions. Presumably, the diselenides are cleaved by Sm/TMSCl system to form selenide anions, which then undergo SN2' substitution of Baylis-Hillman adducts to produce the (Z)-allyl selenides.

  15. Phenolic ethers in the organic polymer of the Murchison meteorite

    Science.gov (United States)

    Hayatsu, R.; Winans, R. E.; Scott, R. G.; McBeth, R. L.; Moore, L. P.; Studier, M. H.

    1980-03-01

    Results of the oxidation of the organic polymer of the Murchison meteorite with alkaline cupric oxide, a mild-oxidant specific for cleaving ether linkages, are reported. Qualitative analyses by gas chromatography-mass spectrometry, solid-probe mass spectrometry and high-resolution mass spectrometry reveal the presence of large amounts of meta-hydroxybenzoic acid and 3-hydroxy-1,5-benzenedicarboxylic acid, along with seven phenolic acids, in the oxidized solution, indicating the presence of phenolic ethers and of aryl alkyl ethers having no nuclear hydroxy group in the meteorite. The formation of phenolic ethers in the solar nebula by Fischer-Tropsch type reactions is then discussed.

  16. Alcohol dehydration: Mechanism of ether formation using an alumina catalyst

    Energy Technology Data Exchange (ETDEWEB)

    Shi, B.; Davis, B.H. [Univ. of Kentucky, Lexington, KY (United States)

    1995-12-01

    Ether formation during the dehydration of secondary alcohols, namely, 2-butanol, 3-pentanol, and 1-cyclopentylethanol, was investigated. Using the proper reaction conditions, the yield of di-2-butyl ether during the dehydration of 2-butanol on alumina can be as high as 40%. That ether is formed by adding an alcohol to the alkene is ruled out by the results from deuterium tracer studies. Results from experiments using S(+)- 2-butanol suggest that the formation of di-2-butyl ether occurs by a S{sub N}2-type mechanism. 33 refs., 5 figs., 3 tabs.

  17. Novel high T{sub g} high-strength poly(aryl ether)s

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Maier, G. [Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Makromolekulare Stoffe

    1999-08-01

    A novel 2-perfluoroalkyl-activated bisfluoro monomer has been synthesized successfully using a Pd(0)-catalyzed cross-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4{prime}-dibromodiphenylbenzene. This monomer was converted to novel poly(aryl ether)s by nucleophilic displacement of the fluorine atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight average molar masses up to 1.06 {times} 10{sup 5} g/mol in GPC. These poly(aryl ether)s showed outstanding thermooxidative stability up to 534 C for 5% weight loss in TGA under synthetic air and high glass transition temperatures (T{sub g}) even up to 300 C in DSC and DMTA. These polymers are soluble in a wide range of organic solvents, e.g., CHCl{sub 3}, THF, NMP, DMF, toluene, etc., and are insoluble in DMSO and acetone. Transparent thin films of these polymers cast from DMF exhibited tensile strengths up to 115 MPa, moduli up to 2.59 GPa, and elongations up to 120% depending on their exact repeating unit structures. These values are comparable to those of high performance thermoplastic materials such as PEEK or Ultem PEI.

  18. Novel high T[sub g] high-strength poly(aryl ether)s

    Energy Technology Data Exchange (ETDEWEB)

    Banerjee, S.; Maier, G. (Technische Univ. Muenchen, Garching (Germany). Lehrstuhl fuer Makromolekulare Stoffe)

    1999-08-01

    A novel 2-perfluoroalkyl-activated bisfluoro monomer has been synthesized successfully using a Pd(0)-catalyzed cross-coupling reaction of 4-fluoro-3-trifluoromethyl phenyl boronic acid with 4,4[prime]-dibromodiphenylbenzene. This monomer was converted to novel poly(aryl ether)s by nucleophilic displacement of the fluorine atoms on the benzene ring with several bisphenols. The products obtained by displacement of the fluorine atoms exhibit weight average molar masses up to 1.06 [times] 10[sup 5] g/mol in GPC. These poly(aryl ether)s showed outstanding thermooxidative stability up to 534 C for 5% weight loss in TGA under synthetic air and high glass transition temperatures (T[sub g]) even up to 300 C in DSC and DMTA. These polymers are soluble in a wide range of organic solvents, e.g., CHCl[sub 3], THF, NMP, DMF, toluene, etc., and are insoluble in DMSO and acetone. Transparent thin films of these polymers cast from DMF exhibited tensile strengths up to 115 MPa, moduli up to 2.59 GPa, and elongations up to 120% depending on their exact repeating unit structures. These values are comparable to those of high performance thermoplastic materials such as PEEK or Ultem PEI.

  19. Lithiated and sulphonated poly(ether ether ketone) solid state electrolyte films for supercapacitors

    Energy Technology Data Exchange (ETDEWEB)

    Chiu, K.-F.; Su, S.-H., E-mail: minimono42@gmail.com

    2013-10-01

    Poly(ether ether ketone) (PEEK) films have been synthesised and used as solid-state electrolytes for supercapacitors. In order to increase their ion conductivity, the PEEK films were sulphonated by sulphuric acid, and various amounts of LiClO{sub 4} were added. The solid-state electrolyte films were characterised by Fourier transform infrared spectroscopy, scanning electron microscopy, energy-dispersive X-ray spectroscopy, and thermogravimetric analysis. The ionic conductivities of the electrolyte films were analysed by performing electrochemical impedance spectroscopy. The obtained electrolyte films can be sandwiched or directly coated on activated carbon electrodes to form solid-state supercapacitors. The electrochemical characteristics of these supercapacitors were investigated by performing cyclic voltammetry and charge–discharge tests. Under an optimal content of LiClO{sub 4}, the supercapacitor can provide a capacitance as high as 190 F/g. After 1000 cycles, the supercapacitors show almost no capacitance fading, indicating high stability of the solid-state electrolyte films. - Highlights: • Poly(ether ether ketone) (PEEK) films have been used as solid-state electrolytes. • LiClO4 addition can efficiently improve the ionic conductivity. • Supercapacitors using PEEK electrolyte films deliver high capacitance.

  20. 75 FR 28804 - An Exposure Assessment of Polybrominated Diphenyl Ethers (PBDEs)

    Science.gov (United States)

    2010-05-24

    ... AGENCY An Exposure Assessment of Polybrominated Diphenyl Ethers (PBDEs) AGENCY: Environmental Protection...'s 2006 Polybrominated Diphenyl Ethers (PBDEs) Project Plan. This document ] provides an assessment of the exposure of Americans to polybrominated diphenyl ethers (PBDEs), a class of brominated...

  1. REDUCING NONSELECTIVE PROTEIN ADSORPTION AND CELL ADHESION ON POLYACRYLONITRILE FILMS BY COPOLYMERIZATION OF ACRYLONITRILE WITH α-ALLYL GLUCOSIDE

    Institute of Scientific and Technical Information of China (English)

    Rui-qiang Kou; Chao Qu; Zhi-kang Xu; You-yi Xu; Ke Yao

    2003-01-01

    In this work, the surface properties of novel sugar-containing polymers, α-allyl glucoside (AG)/acrylonitrile (AN)copolymers, were studied by contact angle, protein adsorption and cell adhesion measurements. It was found that the contact angle of the copolymer films decreased from 68° to 30° with the increase of AG content in the copolymer. The adsorption amount of bovine serum albumin (BSA) and the adhesive macrophage onto the film surface also decreased significantly with increasing α-allyl glucoside content from 0 to 42 wt% in the copolymer. These preliminary results reveal that both the hydrophilicity and the biocompatibility of polyacrylonitrile-based membranes could be improved by copolymerizing acrylonitrile with vinyl carbohydrates.

  2. Epoxidation of olefins and allylic alcohols with hydrogen peroxide catalyzed by heteropoly acids in the presence of cetylpyridinium chloride

    Energy Technology Data Exchange (ETDEWEB)

    Okabayashi, Takuji; Yamawaki, Kazumasa; Nishihara, Hideki; Yamada, Hiroshi; Ura, Toshikazu; Ishii, Yasutaka; Ogawa, Masaya

    1987-11-01

    The epoxidation of olefins and allylic alcohols with aqueous hydrogen peroxide could be achieved in good yield when 12-tungustophosphoric acid(WPA) was used with two phase condition using chloroform as the solvent. From the epoxidation result by 12-molybdophosphoric acid(MPA) and WPA catalysts, epoxidation activity of WPA catalyst was found to be remarkably higher than that of MPA. The rate of epoxidation by heteropoly acids catalyst depended markedly upon the activity of the reaction medium. Epoxidation of allylic alcohols with hydrogen peroxide proceeded under mild conditions, resulting good yield of epoxi-alcohols. Epoxidation of olefins by WPA/cetylpyridium chloride was confirmed to be promoted selectively with cheap and pure hydrogen peroxide, resulting good yield. (3 figs, 2 tabs, 18 refs)

  3. One-pot synthesis of enantiomerically pure N-protected allylic amines from N-protected α-amino esters

    Science.gov (United States)

    Silveira-Dorta, Gastón; Álvarez-Méndez, Sergio J; Martín, Víctor S

    2016-01-01

    Summary An improved protocol for the synthesis of enantiomerically pure allylic amines is reported. N-Protected α-amino esters derived from natural amino acids were submitted to a one-pot tandem reduction–olefination process. The sequential reduction with DIBAL-H at −78 °C and subsequent in situ addition of organophosphorus reagents yielded the corresponding allylic amines without the need to isolate the intermediate aldehyde. This circumvents the problem of instability of the aldehydes. The method tolerates well both Wittig and Horner–Wadsworth–Emmons organophosphorus reagents. A better Z-(dia)stereoselectivity was observed when compared to the previous one-pot method. The (dia)stereoselectivity of the process was affected neither by the reaction solvent nor by the amount of DIBAL-H employed. The method is compatible with the presence of free hydroxy groups as shown with serine and threonine derivatives. PMID:27340486

  4. Crystal structure of (Z-3-allyl-5-(3-bromobenzylidene-2-sulfanylidene-1,3-thiazolidin-4-one

    Directory of Open Access Journals (Sweden)

    Rahhal El Ajlaoui

    2015-12-01

    Full Text Available In the title compound, C13H10BrNOS2, the rhodanine (systematic name: 2-sulfanylidene-1,3-thiazolidin-4-one and the 3-bromobenzylidene ring systems are inclined slightly, forming a dihedral angle of 5.86 (12°. The rhodanine moiety is linked to an allyl group at the N atom and to the 3-bromobenzylidene ring system. The allyl group, C=C—C, is nearly perpendicular to the mean plane through the rhodanine ring, maling a dihedral angle of 87.2 (5°. In the crystal, molecules are linked by pairs of C—H...O hydrogen bonds, forming inversion dimers with an R22(10 ring motif.

  5. 糠醇缩水甘油醚稀释的环氧体系的性能研究%Study on properties of epoxy curing system with furfuryl glycidyl ether as diluent

    Institute of Scientific and Technical Information of China (English)

    黄坤; 王石发; 万厉

    2009-01-01

    通过力学性能和热性能测试研究了糠醇缩水甘油醚(FGE)稀释的双酚A环氧树脂(DGEBA)体系的固化性能和固化反应动力学.通过M61ek自催化机理模型求得添加10%FGE的DGEBA与脂肪族聚酰胺固化剂的固化反应平均活化能为64.66 kJ/mol,低于苄基缩水甘油醚(BGE)稀释体系.以FGE稀释的固化产物的拉伸强度达到62.93 MPa,比BGE体系高出20%左右.拉伸伸长率达4.66%,是BGE体系的4倍左右.添加FGE的固化物冲击强度达36.17 MPa,比BGE体系高出约70%左右.使用FGE和BGE的环氧固化物的玻璃化转变温度分别为46.32℃和52.36℃.FGE和BGE体系固化物的5%的热失重温度分别为260.79℃和194.59℃.FGE是1种良好的环氧树脂稀释剂.

  6. Allyl group as a protecting group for internucleotide phosphate and thiophosphate linkages in oligonucleotide synthesis: facile oxidation and deprotection conditions.

    Science.gov (United States)

    Manoharan, M; Lu, Y; Casper, M D; Just, G

    2000-02-10

    [reaction: see text] The allyl group, which serves as a protecting group for an internucleotide bond for both phosphates and phosphorothioates, can be easily removed by good nucleophiles under weakly basic or neutral conditions. For a practical synthesis on solid support, camphorsulfonyloxaziridine was used as the oxidizing agent for synthesizing DNA, while the Beaucage reagent was used for preparing phosphorothioate oligomers. Both types of oligonucleotides were easily deprotected by concentrated ammonium hydroxide containing 2% mercaptoethanol.

  7. Platinum-catalyzed direct amination of allylic alcohols under mild conditions: ligand and microwave effects, substrate scope, and mechanistic study.

    Science.gov (United States)

    Ohshima, Takashi; Miyamoto, Yoshiki; Ipposhi, Junji; Nakahara, Yasuhito; Utsunomiya, Masaru; Mashima, Kazushi

    2009-10-14

    Transition metal-catalyzed amination of allylic compounds via a pi-allylmetal intermediate is a powerful and useful method for synthesizing allylamines. Direct catalytic substitution of allylic alcohols, which forms water as the sole coproduct, has recently attracted attention for its environmental and economical advantages. Here, we describe the development of a versatile direct catalytic amination of both aryl- and alkyl-substituted allylic alcohols with various amines using Pt-Xantphos and Pt-DPEphos catalyst systems, which allows for the selective synthesis of various monoallylamines, such as the biologically active compounds Naftifine and Flunarizine, in good to high yield without need for an activator. The choice of the ligand was crucial toward achieving high catalytic activity, and we demonstrated that not only the large bite-angle but also the linker oxygen atom of the Xantphos and DPEphos ligands was highly important. In addition, microwave heating dramatically affected the catalyst activity and considerably decreased the reaction time compared with conventional heating. Furthermore, several mechanistic investigations, including (1)H and (31)P{(1)H} NMR studies; isolation and characterization of several catalytic intermediates, Pt(xantphos)Cl(2), Pt(eta(2)-C(3)H(5)OH)(xantphos), etc; confirmation of the structure of [Pt(eta(3)-allyl)(xantphos)]OTf by X-ray crystallographic analysis; and crossover experiments, suggested that formation of the pi-allylplatinum complex through the elimination of water is an irreversible rate-determining step and that the other processes in the catalytic cycle are reversible, even at room temperature.

  8. Direct Conversion of Aldehydes and Ketones to Allylic Halides by a NbX(5-)[3,3] Rearrangement.

    Science.gov (United States)

    Fleming, Fraser F; Ravikumar, P C; Yao, Lihua

    2009-01-01

    Sequential addition of vinylmagnesium bromide and NbCl(5), or NbBr(5), to a series of aldehydes and ketones directly provides homologated, allylic halides. Transposition of the intermediate vinyl alkoxide is envisaged through a metalla-halo-[3,3] rearrangement with concomitant delivery of the halogen to the terminal carbon. The [3,3] rearrangement is equally effective for the conversion of a propargyllic alcohol to the corresponding allenyl bromide.

  9. Direct Conversion of Aldehydes and Ketones to Allylic Halides by a NbX5-[3,3] Rearrangement

    Science.gov (United States)

    Fleming, Fraser F.; Ravikumar, P. C.; Yao, Lihua

    2009-01-01

    Sequential addition of vinylmagnesium bromide and NbCl5, or NbBr5, to a series of aldehydes and ketones directly provides homologated, allylic halides. Transposition of the intermediate vinyl alkoxide is envisaged through a metalla-halo-[3,3] rearrangement with concomitant delivery of the halogen to the terminal carbon. The [3,3] rearrangement is equally effective for the conversion of a propargyllic alcohol to the corresponding allenyl bromide. PMID:20046989

  10. Synchrotron Photoionization Mass Spectrometry Measurements of Kinetics and Product Formation in the Allyl Radical (H2CCHCH2)Self Reaction

    Science.gov (United States)

    Selby, Talitha M.; Melini, giovanni; Goulay, Fabien; Leone, Stephen R.; Fahr, Askar; Taatjes, Craig A.; Osborn, David L.

    2008-01-01

    Product channels for the self-reaction of the resonance-stabilized allyl radical, C3H5 + C3H5, have been studied with isomeric specificity at temperatures from 300-600 K and pressures from 1-6 Torr using time-resolved multiplexed photoionization mass spectrometry. Under these conditions 1,5-hexadiene was the only C6H10 product isomer detected. The lack of isomerization of the C6H10 product is in marked contrast to the C6H6 product in the related C3H3 + C3H3 reaction, and is due to the more saturated electronic structure of the C6H10 system. The disproportionation product channel, yielding allene + propene, was also detected, with an upper limit on the branching fraction relative to recombination of 0.03. Analysis of the allyl radical decay at 298 K yielded a total rate coefficient of (2.7 +/- 0.8) x 10(exp -11) cu cm/molecule/s, in good agreement with pre.vious experimental measurements using ultraviolet kinetic absorption spectroscopy and a recent theoretical determination using variable reaction coordinate transition state theory. This result provides independent indirect support for the literature value of the allyl radical ultraviolet absorption cross-section near 223 nm.

  11. Short and stereoselective total synthesis of furano lignans (+/-)-dihydrosesamin, (+/-)-lariciresinol dimethyl ether, (+/-)-acuminatin methyl ether, (+/-)-sanshodiol methyl ether, (+/-)-lariciresinol, (+/-)-acuminatin, and (+/-)-lariciresinol monomethyl ether and furofuran lignans (+/-)-sesamin, (+/-)-eudesmin, (+/-)-piperitol methyl ether, (+/-)-pinoresinol, (+/-)-piperitol, and (+/-)-pinoresinol monomethyl ether by radical cyclization of epoxides using a transition-metal radical source.

    Science.gov (United States)

    Roy, Subhas Chandra; Rana, Kalyan Kumar; Guin, Chandrani

    2002-05-17

    Intramolecular radical cyclization of suitably substituted epoxy ethers 4a-g using bis(cyclopentadienyl)titanium(III) chloride as the radical source resulted in trisubstituted tetrahydrofurano lignans and 2,6-diaryl-3,7-dioxabicyclo[3.3.0]octane lignans depending on the reaction conditions. The titanium(III) species was prepared in situ from commercially available titanocene dichloride and activated zinc dust in THF. Upon radical cyclization followed by acidic workup, epoxy olefinic ethers 4a-g afforded furano lignans dihydrosesamin 1a, lariciresinol dimethyl ether 1b, acuminatin methyl ether 1e, and sanshodiol methyl ether 1g directly and lariciresinol 1h, acuminatin 1i, and lariciresinol monomethyl ether 1j after removal of the benzyl protecting group by controlled hydrogenolysis of the corresponding cyclized products. The furofuran lignans sesamin 2a, eudesmin 2b, and piperitol methyl ether 2e were also prepared directly by using the same precursors 4a-f on radical cyclization followed by treatment with iodine and pinoresinol 2h, piperitol 2i, and pinoresinol monomethyl ether 2j after controlled hydrogenolysis of the benzyl protecting group of the corresponding cyclized products. Two naturally occurring acyclic lignans, secoisolariciresinol 5h and secoisolariciresinol dimethyl ether 5b, have also been prepared by exhaustive hydrogenolysis of 2h and 2b, respectively.

  12. Application of simplified PC-SAFT to glycol ethers

    DEFF Research Database (Denmark)

    Avlund, Ane Søgaard; Kontogeorgis, Georgios; Michelsen, Michael Locht

    2012-01-01

    The simplified PC-SAFT (sPC-SAFT) equation of state is applied for binary glycol ether-containing mixtures, and it is investigated how the results are influenced by inclusion of intramolecular association in the association theory. Three different glycol ethers are examined: 2-methoxyethanol, 2-e...

  13. Characterization of Poly(ether)urethanes - High Resolution Thermogravimetric Analysis

    Science.gov (United States)

    2004-02-01

    ether)urethanes.11 Table 5. Percent weight loss for steps in stepwise isothermal TGA analysis .......................... 14 viii DRDC Atlantic...Stepwise isothermal plots for the six poly(ether)urethanes. Table 5. Percent weight loss for steps in stepwise isothermal TGA analysis . SAMPLE/ % WT LOSS

  14. 烯丙基酚醛树脂的固化动力学%Curing Kinetics of Allyl Phenolic Resin

    Institute of Scientific and Technical Information of China (English)

    刘洋; 刘诗薇; 李志强; 于景坤

    2012-01-01

    The curing behavior of allyl phenolic resin was analyzed at different heating rates using differential scanning calorimetry.The obtained kinetic data were treated by Kissinger and KAS(Kissinger-Akahira-Sunose) methods to obtain the curing reaction kinetic parameters.A curing kinetics model was established for allyl phenolic resin.Compared with phenolic resin,the curing temperature of allyl phenolic resin is higher,the reaction order is closer to 1,and the average activation energy of the curing reaction is lower,111.45 kJ/mol.The activation energy of allyl phenolic resin is almost constant and changes little with temperature in the curing process.The curing kinetics model of allyl phenolic resin provides a theoretical basis for the study of curing process parameters.%利用差示扫描量热法分析了烯丙基酚醛树脂在不同升温速率下的固化行为,用Kissinger法和KAS(Kissinger-Akahira-Sunose)法对获得的动力学数据进行处理,得到了固化反应动力学参数,并建立了烯丙基酚醛树脂的固化动力学模型.结果表明:与纯酚醛树脂相比,烯丙基酚醛树脂固化温度较高,反应级数更接近于1,固化反应所需的平均表观活化能较低,为111.45kJ/mol;在整个固化过程中,烯丙基酚醛树脂的活化能较为恒定,随温度变化不大;烯丙基酚醛树脂固化动力学模型为研究该体系固化工艺参数提供了理论依据.

  15. Functionalized macroporous copolymer of glycidyl methacrylate: The type of ligand and porosity parameters influence on Cu(II ion sorption from aqueous solutions

    Directory of Open Access Journals (Sweden)

    Sandić Zvjezdana P.

    2009-01-01

    Full Text Available The removal of heavy metals from hydro-metallurgical and other industries' wastewaters, their safe storage and possible recovery from waste- water streams is one of the greater ecological problems of modern society. Conventional methods, like precipitation, adsorption and biosorption, electrowinning, membrane separation, solvent extraction and ion exchange are often ineffective, expensive and can generate secondary pollution. On the other hand, chelating polymers, consisting of crosslinked copolymers as a solid support and functional group (ligand, are capable of selectively loading different metal ions from aqueous solutions. In the relatively simple process, the chelating copolymer is contacted with the contaminated solution, loaded with metal ions, and stripped with the appropriate eluent. Important properties of chelating polymers are high capacity, high selectivity and fast kinetics combined with mechanical stability and chemical inertness. Macroporous hydrophilic copolymers of glycidyl methacrylate and ethylene glycol dimethacrylate modified by different amines show outstanding efficiency and selectivity for the sorption of precious and heavy metals from aqueous solutions. In this study poly(GMA-co-EGDMA copolymers were synthesized with different porosity parameters and functionalized in reactions with ethylene diamine (EDA, diethylene triamine (DETA and triethylene tetramine (TETA. Under non-competitive conditions, in batch experiments at room temperature, the rate of sorption of Cu(II ions from aqueous solutions and the influence of pH on it was determined for four samples of amino-functionalized poly(GMA-co-EGDMA. The sorption of Cu(II for both amino-functionalized samples was found to be very rapid. The sorption half time, t1/2, defined as the time required to reach 50% of the total sorption capacity, was between 1 and 2 min. The maximum sorption capacity for copper (2.80 mmol/g was obtained on SGE-10/12-deta sample. The sorption

  16. On the antioxidant, neuroprotective and anti-inflammatory properties of S-allyl cysteine: An update.

    Science.gov (United States)

    Colín-González, Ana Laura; Ali, Syed F; Túnez, Isaac; Santamaría, Abel

    2015-10-01

    Therapeutic approaches based on isolated compounds obtained from natural products to handle central and peripheral disorders involving oxidative stress and inflammation are more common nowadays. The validation of nutraceutics vs. pharmaceutics as tools to induce preventive and protective profiles in human health alterations is still far of complete acceptance, but the basis to start more solid experimental and clinical protocols with natural products has already begun. S-allyl cysteine (SAC) is a promising garlic-derived organosulfur compound exhibiting a considerable number of positive actions in cell models and living systems. An update, in the form of review, is needed from time to time to get access to the state-of-the-art on this topic. In this review we visited recent and refreshing evidence of new already proven and potential targets to explain the benefits of using SAC against toxic and pathological conditions. The broad spectrum of protective actions covered by this molecule comprises antioxidant, redox modulatory and anti-inflammatory activities, accompanied by anti-apoptotic, pro-energetic and signaling capacities. Herein, we detail the evidence on these aspects to provide the reader a more complete overview on the promising aspects of SAC in research.

  17. Merging allylic carbon-hydrogen and selective carbon-carbon bond activation

    Science.gov (United States)

    Masarwa, Ahmad; Didier, Dorian; Zabrodski, Tamar; Schinkel, Marvin; Ackermann, Lutz; Marek, Ilan

    2014-01-01

    Since the nineteenth century, many synthetic organic chemists have focused on developing new strategies to regio-, diastereo- and enantioselectively build carbon-carbon and carbon-heteroatom bonds in a predictable and efficient manner. Ideal syntheses should use the least number of synthetic steps, with few or no functional group transformations and by-products, and maximum atom efficiency. One potentially attractive method for the synthesis of molecular skeletons that are difficult to prepare would be through the selective activation of C-H and C-C bonds, instead of the conventional construction of new C-C bonds. Here we present an approach that exploits the multifold reactivity of easily accessible substrates with a single organometallic species to furnish complex molecular scaffolds through the merging of otherwise difficult transformations: allylic C-H and selective C-C bond activations. The resulting bifunctional nucleophilic species, all of which have an all-carbon quaternary stereogenic centre, can then be selectively derivatized by the addition of two different electrophiles to obtain more complex molecular architecture from these easily available starting materials.

  18. Non-Directed Allylic C-H Acetoxylation in the Presence of Lewis Basic Heterocycles.

    Science.gov (United States)

    Malik, Hasnain A; Taylor, Buck L H; Kerrigan, John R; Grob, Jonathan E; Houk, K N; Du Bois, J; Hamann, Lawrence G; Patterson, Andrew W

    2014-06-01

    We outline a strategy to enable non-directed Pd(II)-catalyzed C-H functionalization in the presence of Lewis basic heterocycles. In a high-throughput screen of two Pd-catalyzed C-H acetoxylation reactions, addition of a variety of N-containing heterocycles is found to cause low product conversion. A pyridine-containing test substrate is selected as representative of heterocyclic scaffolds that are hypothesized to cause catalyst arrest. We pursue two approaches in parallel that allow product conversion in this representative system: Lewis acids are found to be effective in situ blocking groups for the Lewis basic site, and a pre-formed pyridine N-oxide is shown to enable high yield of allylic C-H acetoxylation. Computational studies with density functional theory (M06) of binding affinities of selected heterocycles to Pd(OAc)2 provide an inverse correlation of the computed heterocycle-Pd(OAc)2 binding affinities with the experimental conversions to products. Additionally, (1)H NMR binding studies provide experimental support for theoretical calculations.

  19. Allyl functionalized phosphinite and phosphonite ligands: Synthesis, transition metal chemistry and orthopalladation reactions

    Indian Academy of Sciences (India)

    Singappagudem Govindaraju; Guddekoppa S Ananthnag; Susmita Naik; Shaikh M Mobin; Maravanji S Balakrishn

    2012-07-01

    Allyl functionalized phosphinite PPh2(OAr) [Ar=C6H4(-C3H5)] (1) and phosphonite PPh(OAr)2 (2) ligands were prepared by the reactions of 2-allylphenol with PPh2Cl and PPhCl2, respectively. The ruthenium(II) complexes, [Ru(6--cymene)(PPh2(OAr))Cl2] (3) and [Ru(6--cymene)(PPh(OAr)2Cl2)] (4) were obtained by reacting 1 or 2 with [Ru(6--cymene)Cl2]2 in 2:1 molar ratios, respectively. Reactions of 1 or 2 with AuCl(SMe2) gave [Au{PPh2(OAr)}Cl] (5) or [Au{PPh(OAr)2}Cl] (6) in good yield. The palladium complex, [Pd{PPh(OAr)2}2Cl2] (7) was prepared by reacting Pd(COD)Cl2 with 2 in 1:2 molar ratio. The reaction between Pd(COD)Cl2 and 1 yielded a mixture of orthopalladated cis- and trans-[Pd(Ph2P(OAr))Cl]2 (8a and 8b). The treatment of 8 with PPh3 and Ph2PCH2PPh2 resulted in the cleavage of chloro bridge to give respectively, [Ph2(OAr)PPd(PPh3)Cl] (9) and [Ph2(ArO)PPd(2-dppm)]OTf (10). Single crystal X-ray structure of the ruthenium complex 3 is described.

  20. Release and antibacterial activity of allyl isothiocyanate/β-cyclodextrin complex encapsulated in electrospun nanofibers.

    Science.gov (United States)

    Aytac, Zeynep; Dogan, Sema Y; Tekinay, Turgay; Uyar, Tamer

    2014-08-01

    Allyl isothiocyanate (AITC) is known as an efficient antibacterial agent but it has a very high volatility. Herein, AITC and AITC/β-cyclodextrin (CD)-inclusion complex (IC) incorporated in polyvinyl alcohol (PVA) nanofibers were produced via electrospinning. SEM images elucidated that incorporation of AITC and AITC/β-CD-IC into polymer matrix did not affect the bead-free fiber morphology of PVA nanofibers. (1)H-NMR and headspace GC-MS analyses revealed that very low amount of AITC was remained in PVA/AITC-NF because of the rapid evaporation of AITC during the electrospinning process. Nevertheless, much higher amount of AITC was preserved in the PVA/AITC/β-CD-IC-NF due to the CD inclusion complexation. The sustained release of AITC from nanofibers was evaluated at 30°C, 50°C and 75°C via headspace GC-MS. When compared to PVA/AITC-NF, PVA/AITC/β-CD-IC-NF has shown higher antibacterial activity against Escherichia coli and Staphylococcus aureus due to the presence of higher amount of AITC in this sample which was preserved by CD-IC.

  1. Hydrolysis of cellulose catalyzed by quaternary ammonium perrhenates in 1-allyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Wang, Jingyun; Zhou, Mingdong; Yuan, Yuguo; Zhang, Quan; Fang, Xiangchen; Zang, Shuliang

    2015-12-01

    Quaternary ammonium perrhenates were applied as catalyst to promote the hydrolysis of cellulose in 1-allyl-3-methylimidazolium chloride ([Amim]Cl). The quaternary ammonium perrhenates displayed good catalytic performance for cellulose hydrolysis. Water was also proven to be effective to promote cellulose hydrolysis. Accordingly, 97% of total reduced sugar (TRS) and 42% of glucose yields could be obtained under the condition of using 5mol% of tetramethyl ammonium perrhenate as catalyst, 70μL of water, ca. 0.6mmol of microcrystalline cellulose (MCC) and 2.0g of [Amim]Cl as solvent under microwave irradiation for 30min at 150°C (optimal conditions). The influence of quaternary ammonium cation on the efficiency of cellulose hydrolysis was examined based on different cation structures of perrhenates. The mechanism on perrhenate catalyzed cellulose hydrolysis is also discussed, whereas hydrogen bonding between ReO4 anion and hydroxyl groups of cellulose is assumed to be the key step for depolymerization of cellulose.

  2. Synergistic effect of allyl isothiocyanate (AITC) on cisplatin efficacy in vitro and in vivo.

    Science.gov (United States)

    Ling, Xiang; Westover, David; Cao, Felicia; Cao, Shousong; He, Xiang; Kim, Hak-Ryul; Zhang, Yuesheng; Chan, Daniel Cf; Li, Fengzhi

    2015-01-01

    Although in vitro studies have shown that isothiocyanates (ITCs) can synergistically sensitize cancer cells to cisplatin treatment, the underlying mechanisms have not been well defined, and there are no in vivo demonstrations of this synergy. Here, we report the in vitro and in vivo data for the combination of allyl isothiocyanate (AITC), one of the most common naturally occurring ITCs, with cisplatin. Our study revealed that cisplatin and AITC combination synergistically inhibits cancer cell growth and colony formation, and enhances apoptosis in association with the downregulation of antiapoptotic proteins Bcl-2 and survivin. Importantly, the in vivo combination treatment suppresses human tumor growth in animal models without observable increases in toxicity (body weight loss) in comparison with single agent treatment. Furthermore, our data revealed that addition of AITC to cisplatin treatment changes the profile of G2/M arrest (e.g. increase in M phase cell number) and significantly extends the duration of G2/M arrest in comparison with cisplatin treatment alone. To explore the underlying mechanism, we found that AITC treatment rapidly depletes b-tubulin. Combination of AITC and cisplatin inhibits the expression of G2/M checkpoint-relevant proteins including CDC2, cyclin B1 and CDC25. Together, our findings reveal a novel mechanism for AITC enhancing cisplatin efficacy and provides the first in vivo evidence to support ITCs as potential candidates for developing new regimens to overcome platinum resistance.

  3. Pharmacokinetics, Tissue Distribution, and Anti-Lipogenic/Adipogenic Effects of Allyl-Isothiocyanate Metabolites.

    Directory of Open Access Journals (Sweden)

    Yang-Ji Kim

    Full Text Available Allyl-isothiocyanate (AITC is an organosulfur phytochemical found in abundance in common cruciferous vegetables such as mustard, wasabi, and cabbage. Although AITC is metabolized primarily through the mercapturic acid pathway, its exact pharmacokinetics remains undefined and the biological function of AITC metabolites is still largely unknown. In this study, we evaluated the inhibitory effects of AITC metabolites on lipid accumulation in vitro and elucidated the pharmacokinetics and tissue distribution of AITC metabolites in rats. We found that AITC metabolites generally conjugate with glutathione (GSH or N-acetylcysteine (NAC and are distributed in most organs and tissues. Pharmacokinetic analysis showed a rapid uptake and complete metabolism of AITC following oral administration to rats. Although AITC has been reported to exhibit anti-tumor activity in bladder cancer, the potential bioactivity of its metabolites has not been explored. We found that GSH-AITC and NAC-AITC effectively inhibit adipogenic differentiation of 3T3-L1 preadipocytes and suppress expression of PPAR-γ, C/EBPα, and FAS, which are up-regulated during adipogenesis. GSH-AITC and NAC-AITC also suppressed oleic acid-induced lipid accumulation and lipogenesis in hepatocytes. Our findings suggest that AITC is almost completely metabolized in the liver and rapidly excreted in urine through the mercapturic acid pathway following administration in rats. AITC metabolites may exert anti-obesity effects through suppression of adipogenesis or lipogenesis.

  4. Allyl Isothiocyanate Inhibits Actin-Dependent Intracellular Transport in Arabidopsis thaliana

    Directory of Open Access Journals (Sweden)

    Bjørnar Sporsheim

    2015-12-01

    Full Text Available Volatile allyl isothiocyanate (AITC derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In this study, we present evidence of an AITC-induced inhibition of actin-dependent intracellular transport in A. thaliana. A transgenic line of A. thaliana expressing yellow fluorescent protein (YFP-tagged actin filaments was used to show attenuation of actin filament movement by AITC. This appeared gradually in a time- and dose-dependent manner and resulted in actin filaments appearing close to static. Further, we employed four transgenic lines with YFP-fusion proteins labeling the Golgi apparatus, endoplasmic reticulum (ER, vacuoles and peroxisomes to demonstrate an AITC-induced inhibition of actin-dependent intracellular transport of or, in these structures, consistent with the decline in actin filament movement. Furthermore, the morphologies of actin filaments, ER and vacuoles appeared aberrant following AITC-exposure. However, AITC-treated seedlings of all transgenic lines tested displayed morphologies and intracellular movements similar to that of the corresponding untreated and control-treated plants, following overnight incubation in an AITC-absent environment, indicating that AITC-induced decline in actin-related movements is a reversible process. These findings provide novel insights into the cellular events in plant cells following exposure to AITC, which may further expose clues to the physiological significance of the glucosinolate-myrosinase system.

  5. Allyl m-Trifluoromethyldiazirine Mephobarbital: An Unusually Potent Enantioselective and Photoreactive Barbiturate General Anesthetic

    Energy Technology Data Exchange (ETDEWEB)

    Savechenkov, Pavel Y.; Zhang, Xi; Chiara, David C.; Stewart, Deirdre S.; Ge, Rile; Zhou, Xiaojuan; Raines, Douglas E.; Cohen, Jonathan B.; Forman, Stuart A.; Miller, Keith W.; Bruzik, Karol S. (Harvard-Med); (Mass. Gen. Hosp.); (UIC)

    2012-12-10

    We synthesized 5-allyl-1-methyl-5-(m-trifluoromethyl-diazirynylphenyl)barbituric acid (14), a trifluoromethyldiazirine-containing derivative of general anesthetic mephobarbital, separated the racemic mixture into enantiomers by chiral chromatography, and determined the configuration of the (+)-enantiomer as S by X-ray crystallography. Additionally, we obtained the {sup 3}H-labeled ligand with high specific radioactivity. R-(-)-14 is an order of magnitude more potent than the most potent clinically used barbiturate, thiopental, and its general anesthetic EC{sub 50} approaches those for propofol and etomidate, whereas S-(+)-14 is 10-fold less potent. Furthermore, at concentrations close to its anesthetic potency, R-(-)-14 both potentiated GABA-induced currents and increased the affinity for the agonist muscimol in human {alpha}1{beta}2/3{gamma}2L GABA{sub A} receptors. Finally, R-(-)-14 was found to be an exceptionally efficient photolabeling reagent, incorporating into both {alpha}1 and {beta}3 subunits of human {alpha}1{beta}3 GABAA receptors. These results indicate R-(-)-14 is a functional general anesthetic that is well-suited for identifying barbiturate binding sites on Cys-loop receptors.

  6. Ethylated Urea - Ether - Modified Urea - Formaldehyde Resins,

    Directory of Open Access Journals (Sweden)

    Mathew Obichukwu EDOGA

    2006-07-01

    Full Text Available First, phenol - formaldehyde (PF and urea - formaldehyde (UFII resins were separately conventionally prepared in our laboratory. Also, UF resin synthesized from the acid modified synthesis procedure was synthesized in a purely acid medium of pH 1.0, FU molar ratio of 1.0 and at 50oC (one-stage acid modified-synthesis procedure. Subsequently, the UF resin II was modified during synthesis by incorporating ethylated urea-ether (EUER (i.e. UFIII and glycerol (GLYC (i.e. UFV cured with and without acid curing agent. The structural and physicochemical analyses of the various resin samples were carried out.The results showed that the unmodified UF resin (UF II synthesized in acid medium of pH 1.0, F/U molar ratio 1.0, and at 50oC, cured in absence of acid curing catalyst, showed features in their spectra which are consistent with a tri-, and/or tetra-substituted urea in the reaction to give a 3 - dimensional network cured UF resin. Modification of the UF resin(UF II with ethylated urea-ether and glycerol to produce UF resins III and respectively V prominently increased the absorbance of methylene and ether groups in the spectra which are consistent with increased hydrophobicity and improved hydrolytic stability. For the conventional UF resin (UF I, the only clear distinction between spectra for the UF resin II and UF resins (III/V is the presence of diminished peaks for methylene groups at 2.2 ppm. The relationship between the logarithmic viscosity of cured PF resin with time showed continuos dependence of viscosity with time during cure up to 70 minutes. Similar trends were shown by UF resins (III/V, cured in absence of acid catalyst. In contrast, the conventional UF resins I and UF IV (i.e. UF II cured with NH4CL showed abrupt discontinuity in viscosity with time just after about 20 minutes of cure.

  7. Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

    Science.gov (United States)

    Mai, Zhensheng; Zhang, Huamin; Li, Xianfeng; Bi, Cheng; Dai, Hua

    Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test.

  8. Evaluation of Stabilization Performances of Antioxidants in Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    ZHOU Zheng; ZHOU Fu-gui; ZHANG Shu-ling; MU Jian-xin; YUE Xi-gui; WANG Gui-bin

    2012-01-01

    Two types of antioxidants(a primary antioxidant and a secondary antioxidant) were used to improve the stability of poly(ether ether ketone)(PEEK).The effects of the antioxidants on the properties of PEEK and the stabilization mechanism were investigated by some characterization methods,such as rheometer,thermogravinetric analysis(TGA),universal tester and electron spin resonance(ESR).The results indicate that the efficiency of the phosphorous antioxidant(DS) in improving the stability of PEEK was better than that of the phenolic antioxidant(DN) in both melting stability and thermal stability,and the thermal stability of PEEK sample containing 0.07%(mass fraction) DS was the best among all the samples due to the decrease of the free radicals density,as proven by ESR measurement.Additionally,no obvious changes could be observed in mechanical properties of PEEK containing antioxidants compared to those of virgin PEEK.

  9. ELECTROCHEMICAL POLYMERIZATION OF 5-CYANOINDOLE IN MIXED ELECTROLYTES OF BORON TRIFLUORIDE DIETHYL ETHERATE AND DIETHYL ETHER

    Institute of Scientific and Technical Information of China (English)

    Jing-kun Xu; Wei-qiang Zhou; Jian Hou; Shou-zhi Pu; Jing-wu Wang; Liu-shui Yan

    2006-01-01

    High quality poly(5-cyanoindole) (P5CI) films were electrosynthesized by direct anodic oxidation of 5-cyanoindole on stainless steel sheet in the mixed electrolytes of boron trifluoride diethyl etherate (BFEE) and diethyl ether (EE) (by volume 1:1) + 0.05 mol L-1 Bu4NBF4. The film formed can be peeled off the electrode into freestanding films. The addition of EE into BFEE can improve the solubility of monomer. P5CI films obtained from this medium showed excellent electrochemical behavior with conductivity of 10-2 Scm-1. Structural studies showed that the polymerization of 5-cyanoindole occurred at the 2,3 position. As-formed P5CI films were thoroughly soluble in strong polar organic solvent dimethyl sulfoxide (DMSO) while partly soluble in tetrahydrofuran (THF) or acetone. Fluorescence spectral studies indicated that P5CI was a good blue-light emitter.

  10. Polymeric 32-channel arrayed waveguide grating multiplexer using fluorinated poly (ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    Fei Wang(王菲); Wei Sun(孙伟); Aize Li(李艾泽); Maobin Yi(衣茂斌); Zhenhua Jiang(姜振华); Daming Zhang(张大明)

    2004-01-01

    In wavelength division multiplexing (WDM) systems, an arrayed waveguide grating (AWG) multiplexer is a key component. A polymeric AWG multiplexer has recently attracted much attention due to its low cost processing and a potential of integration with other devices. Fluorinated poly (ether ether ketone)(FPEEK) is excellent material for fabrication of optical waveguides due to its low absorption loss at 1.55-μm wavelength and high thermal stability. A 32-channel AWG multiplexer has been designed based on the grating diffraction theory and fabricated using newly synthesized FPEEK. During the fabrication process of the Polymer/Si AWG device, spin coating, vaporizing, photolithographic patterning and reactive ion etching (RIE) are used. The AWG multiplexer measurement system is based on a tunable semiconductor laser, infrared camera and a Peltier-type heater. The device exhibits a wavelength channel spacing of 0.8nm and a center wavelength of 1548 nm in the room temperature.

  11. Modification of Poly(ether ether ketone Polymer for Fuel Cell Application

    Directory of Open Access Journals (Sweden)

    Devesh Shukla

    2013-01-01

    Full Text Available Polyelectrolyte membrane (PEM is an important part of PEM fuel cell. Nafion is a commercially known membrane which gives the satisfactory result in PEM fuel cell operating at low temperature. Present research paper includes functionalization of Poly(ether ether ketone (PEEK polymer with phosphonic acid group. The functionalization was done with the help of nickel-based catalyst. Further, the polymer was characterized by the FTIR, EDAX, DSC, TGA, and 1H NMR, and it was found that PEEK polymer was functionalized with phosphonic acid group with good thermal stability in comparison to virgin PEEK. Finally, the thin films of functionalized polymer were prepared by solution casting method, and proton conductivity of film samples was measured by impedance spectra whose value was found satisfactory with good thermal stability in comparison to commercially available Nafion membrane.

  12. Origin of mechanical modifications in poly (ether ether ketone)/carbon nanotube composite

    Energy Technology Data Exchange (ETDEWEB)

    Pavlenko, Ekaterina; Puech, Pascal; Bacsa, Wolfgang, E-mail: wolfgang.bacsa@cemes.fr [CEMES-CNRS and University of Toulouse, 29 Jeanne Marvig, 31055 Toulouse (France); Boyer, François; Olivier, Philippe [Université de Toulouse, Institut Clément Ader, I.U.T. Université Paul Sabatier - 133C Avenue de Rangueil - B.P. 67701, 31077 Toulouse CEDEX 4 (France); Sapelkin, Andrei [School of Physics and Astronomy, Queen Mary, University of London, Mile End Road, E1 4NS London (United Kingdom); King, Stephen; Heenan, Richard [ISIS Facility, Rutherford Appleton Laboratory, Chilton, OX11 0QX Didcot (United Kingdom); Pons, François; Gauthier, Bénédicte; Cadaux, Pierre-Henri [AIRBUS FRANCE (B.E. M and P Toulouse), 316 Route de Bayonne, 31060 Toulouse (France)

    2014-06-21

    Variations in the hardness of a poly (ether ether ketone) beam electrically modified with multi-walled carbon nanotubes (MWCNT, 0.5%-3%) are investigated. It is shown that both rupture and hardness variations correlate with the changes in carbon nanotube concentration when using micro indentation and extended Raman imaging. Statistical analysis of the relative spectral intensities in the Raman image is used to estimate local tube concentration and polymer crystallinity. We show that the histogram of the Raman D band across the image provides information about the amount of MWCNTs and the dispersion of MWCNTs in the composite. We speculate that we have observed a local modification of the ordering between pure and modified polymer. This is partially supported by small angle neutron scattering measurements, which indicate that the agglomeration state of the MWCNTs is the same at the concentrations studied.

  13. Sulfonated poly(tetramethydiphenyl ether ether ketone) membranes for vanadium redox flow battery application

    Energy Technology Data Exchange (ETDEWEB)

    Mai, Zhensheng; Bi, Cheng; Dai, Hua [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China); Graduate University of the Chinese Academy of Sciences, Beijing 100039 (China); Zhang, Huamin; Li, Xianfeng [PEMFC Key Materials and Technology Laboratory, Dalian Institute of Chemical Physics, Chinese Academy of Sciences, Zhongshan Road 457, Dalian 116023 (China)

    2011-01-01

    Sulfonated poly(tetramethydiphenyl ether ether ketone) (SPEEK) with various degree of sulfonation is prepared and first used as ion exchange membrane for vanadium redox flow battery (VRB) application. The vanadium ion permeability of SPEEK40 membrane is one order of magnitude lower than that of Nafion 115 membrane. The low cost SPEEK membranes exhibit a better performance than Nafion at the same operating condition. VRB single cells with SPEEK membranes show very high energy efficiency (>84%), comparable to that of the Nafion, but at much higher columbic efficiency (>97%). In the self-discharge test, the duration of the cell with the SPEEK membrane is two times longer than that with Nafion 115. The membrane keeps a stable performance after 80-cycles charge-discharge test. (author)

  14. Dielectric properties of poly (1,4-phenylene ether-ether-sulfone)

    CERN Document Server

    Spasevska, H

    2002-01-01

    Dielectric properties of Poly (1,4-phenylene ether-ether-sulfone) are obtained from dielectric spectroscopy of the polymer pellet. The values of relative dielectric constant epsilon', dielectric losses epsilon sup , dielectric dissipation factor tan delta and complex impedance are obtained at temperature of 75 sup o C. The temperature dependence of these parameters is investigated for three frequencies (8x10 sup 4 Hz; 8x10 sup 5 Hz; 8x10 sup 6 Hz) of applied electric field. The specific conductivity sigma, which depends on temperature, is related to the ohmic resistance R, at temperature in the interval from 66 to 83 sup o C. Fitting the experimental data, the value of the activation energy U is obtained. (Original)

  15. Mass transport of direct methanol fuel cell species in sulfonated poly(ether ether ketone) membranes

    Energy Technology Data Exchange (ETDEWEB)

    Silva, V.S.; Boaventura, M.; Mendes, A.M.; Madeira, L.M. [LEPAE, Chemical Engineering Department, Faculty of Engineering, University of Porto, Rua Dr. Roberto Frias, 4200-465 Porto (Portugal); Ruffmann, B.; Vetter, S.; Nunes, S.P. [GKSS Research Centre, Max-Planck Str., 21502 Geesthacht (Germany)

    2006-05-05

    Homogeneous membranes based on sulfonated poly(ether ether ketone) (sPEEK) with different sulfonation degrees (SD) were prepared and characterized. In order to perform a critical analysis of the SD effect on the polymer barrier and mass transport properties towards direct methanol fuel cell species, proton conductivity, water/methanol pervaporation and nitrogen/oxygen/carbon dioxide pressure rise method experiments are proposed. This procedure allows the evaluation of the individual permeability coefficients in hydrated sPEEK membranes with different sulfonation degrees. Nafion{sup (R)} 112 was used as reference material. DMFC tests were also performed at 50{sup o}C. It was observed that the proton conductivity and the permeability towards water, methanol, oxygen and carbon dioxide increase with the sPEEK sulfonation degree. In contrast, the SD seems to not affect the nitrogen permeability coefficient. In terms of selectivity, it was observed that the carbon dioxide/oxygen selectivity increases with the sPEEK SD. In contrast, the nitrogen/oxygen selectivity decreases. In terms of barrier properties for preventing the DMFC reactants loss, the polymer electrolyte membrane based on the sulfonated poly(ether ether ketone) with SD lower or equal to 71%, although having slightly lower proton conductivity, presented much better characteristics for fuel cell applications compared with the well known Nafion{sup (R)} 112. In terms of the DMFC tests of the studied membranes at low temperature, the sPEEK membrane with SD=71% showed to have similar performance, or even better, as that of Nafion{sup (R)} 112. However, the highest DMFC overall efficiency was achieved using sPEEK membrane with SD=52%. (author)

  16. Poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) membranes

    Energy Technology Data Exchange (ETDEWEB)

    Hwang, Mi-Lim; Choi, Jisun; Woo, Hyun-Su; Kumar, Vinod; Sohn, Joon-Yong; Shin, Junhwa, E-mail: shinj@kaeri.re.kr

    2014-02-15

    Highlights: • PEEK-g-PVBSA, a polymer electrolyte membrane was prepared by a radiation grafting technique. • Poly(ether ether ketone) (PEEK), an aromatic hydrocarbon polymer was used as a grafting backbone film. • The water uptake, proton conductivity, and methanol permeability of the membranes were evaluated. • PEEK-g-PVBSA membranes show considerably lower methanol permeability compared to a Nafion membrane. -- Abstract: In this study, an aromatic hydrocarbon based polymer electrolyte membrane, poly(vinylbenzyl sulfonic acid)-grafted poly(ether ether ketone) (PEEK-g-PVBSA), has been prepared by the simultaneous irradiation grafting of vinylbenzyl chloride (VBC) monomer onto a PEEK film and subsequent sulfonation. Each chemical conversion was monitored by FT-IR and SEM–EDX instruments. The physicochemical properties including IEC, water uptake, proton conductivity, and methanol permeability of the prepared membranes were also investigated and found that the values of these properties increase with the increase of degree of grafting. It was observed that the IEC values of the prepared PEEK-g-PVBSA membranes with 32%, 58%, and 80% DOG values were 0.50, 1.05, and 1.22 meq/g while the water uptakes were 14%, 20%, and 21%, respectively. The proton conductivities (0.0272–0.0721 S/cm at 70 °C) were found to be somewhat lower than Nafion 212 (0.126 S/cm at 70 °C) at a relative humidity of 90%. However, the prepared membranes showed a considerably lower methanol permeability (0.61–1.92 × 10{sup −7} cm{sup 2}/s) compared to a Nafion 212 membrane (5.37 × 10{sup −7} cm{sup 2}/s)

  17. Molecular dynamics model of dimethyl ether

    Energy Technology Data Exchange (ETDEWEB)

    Lin, B.; Halley, W.J. [Univ. of Minnesota, Minneapolis, MN (United States)

    1995-11-02

    We report a molecular dynamics model of the monomeric liquid dimethyl ether. The united atom approach is used to treat CH{sub 3} groups as point source centers. Partial charges are derived from the experimental dipole moment. Harmonic force constants are used for intramolecular interactions, and their values are so chosen that the model`s fundamental frequencies agree with experimental results. Because we are interested in solvation properties, the model contains flexible molecules, allowing molecular distortion and internal dynamical quantities. We report radial distribution functions and the static structure factors as well as some dynamical quantities such as the dynamical structure factor, infrared absorption, and Raman scattering spectra. Calculated results agree reasonably well with experimental and other simulation results. 25 refs., 8 figs., 1 tab.

  18. Microwave Spectrum of the Ethylmethyl Ether Molecule

    Directory of Open Access Journals (Sweden)

    Kojiro Takagi

    2003-01-01

    Full Text Available We have observed rotational transitions of ethylmethyl ether (CH3CH2OCH3 in the 24-110 GHz frequency range. We newly assigned the transitions of four Q-branch series for J=1-38 with Ka=0-5 and six R-branch series of b-type transitions for J=7-37 with Ka=0-3. All these assigned transitions were observed to be split into two or four components due to the internal rotations of the methyl groups. We analyzed the averaged frequencies of the split components on the basis of the Watson A-reduced Hamiltonian, neglecting the effect of the internal rotations. A total of 122 transitions were fitted to eight molecular parameters to a 1s standard deviation of 24 kHz. The parameters A, B, C and DJ were improved, and DJK, Dk, dJ and dK were determined for the first time.

  19. Thermolysis of phenethyl phenyl ether: A model of ether linkages in low rank coal

    Energy Technology Data Exchange (ETDEWEB)

    Britt, P.F.; Buchanan, A.C. III; Malcolm, E.A.

    1994-09-01

    Currently, an area of interest and frustration for coal chemists has been the direct liquefaction of low rank coal. Although low rank coals are more reactive than bituminous coals, they are more difficult to liquefy and offer lower liquefaction yields under conditions optimized for bituminous coals. Solomon, Serio, and co-workers have shown that: in the pyrolysis and liquefaction of low rank coals, a low temperature cross-linking reaction associated with oxygen functional groups occurs before tar evolution. A variety of pretreatments (demineralization, alkylation, and ion-exchange) have been shown to reduce these retrogressive reactions and increase tar yields, but the actual chemical reactions responsible for these processes have not been defined. In order to gain insight into the thermochemical reactions leading to cross-linking in low rank coal, we have undertaken a study of the pyrolysis of oxygen containing coal model compounds. Solid state NMR studies suggest that the alkyl aryl ether linkage may be present in modest amounts in low rank coal. Therefore, in this paper, we will investigate the thermolysis of phenethyl phenyl ether (PPE) as a model of 0-aryl ether linkages found in low rank coal, lignites, and lignin, an evolutionary precursor of coal. Our results have uncovered a new reaction channel that can account for 25% of the products formed. The impact of reaction conditions, including restricted mass transport, on this new reaction pathway and the role of oxygen functional groups in cross-linking reactions will be investigated.

  20. High temperature fuel cell membranes based on poly(arylene ether)s containing benzimidazole groups

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Dae Sik [Los Alamos National Laboratory; Kim, Yu Seung [Los Alamos National Laboratory; Lee, Kwan - Soo [Los Alamos National Laboratory; Boncella, James M [Los Alamos National Laboratory; Kuiper, David [Los Alamos National Laboratory; Guiver, Michael D [CANADA

    2009-01-01

    Development of new high-performance polymer membranes that retain their proton conductivity under low humidity conditions is one of the most critical requirements to commercialize PEMFC systems. Current sulfonated proton exchange membranes acquire proton conductivity by water that solvates ion and carries proton. Consequently, a loss of water under low RH conditions immediately results in a loss of proton conductivity. One approach to maintain proton conductivity under low RH conditions is to replace water with a less volatile proton solvent. Kreuer has pointed out the possibility to develop fully polymeric proton-conducting membranes based on nitrogen-containing heterocycles such as imidazole, benzimidazole, and pyrazole. We have attempted to blend those less volatile proton solvent with sulfonated copolymers such as polystyrene sulfonic acid, Nafion, poly(arylene ether sulfone, BPSH-xx). [Ref. DOE review meeting 2007 and 2008] However, we observed that imidazole was slowly sublimated out as temperature and humidity increases which could cause poisoning of electro-catalyst, corrosion and losing conductivity. In this presentation, we report the synthesis of novel poly(arylene ether sulfone)s containing benzimidazole groups These benzimidazole containing polymer was blended with sulfonated poly(arylene ether sulfone). In the blend system, benzimidazole group attached to the polysulfone acts as a medium through the basic nitrogen for transfer of protons between the sulfonic acid groups. Proton conductivity of the blend membranes was investigated as a function of water content at 80 C and compared the performance with water based proton conduction system.

  1. Facile Synthesis of Magnetic Copolymer Microspheres Based on Poly(glycidyl methacrylate-co-N-isopropylacrylamide/Fe3O4 by Suspension Photopolymerization

    Directory of Open Access Journals (Sweden)

    Siti Zulaikha Mazlan

    2014-01-01

    Full Text Available Magnetic copolymer based on poly(glycidyl methacrylate-co-N-isopropylacrylamide microspheres was prepared by 2,2-dimethoxy-2-phenylacetophenone- (DMPP- photo initiated and poly(vinyl alcohol- (PVA- stabilized single step suspension photopolymerization. The effect of chemical interaction, morphology, and thermal properties by adding 0.1% w/v Fe3O4 in the copolymer was investigated. Infrared analysis (FTIR showed that (C=C band disappeared after copolymerization, indicating that the magnetic copolymer microspheres were successfully synthesized and two important bands at 908 cm−1 and 1550 cm−1 appear. These are associated with the epoxy group stretching of GMA and secondary amide (N–H/C–H deformation vibration of NIPAAm in magnetic microspheres. The X-ray diffraction (XRD result proved the incorporation of Fe3O4 nanoparticles with copolymer microspheres as peak of Fe3O4 was observed. Morphology study revealed that magnetic copolymer exhibited uniform spheres and smoother appearance when entrapped with Fe3O4 nanoparticles. The lowest percentage of Fe3O4 nanoparticles leached from the copolymer microspheres was obtained at pH 7. Finally, thermal property of the copolymer microspheres was improved by adding a small amount of Fe3O4 nanoparticles that has been shown from the thermogram.

  2. Effect of immobilized amine density on cadmium(II) adsorption capacities for ethanediamine-modified magnetic poly-(glycidyl methacrylate) microspheres

    Science.gov (United States)

    Dong, Tingting; Yang, Liangrong; Pan, Feng; Xing, Huifang; Wang, Li; Yu, Jiemiao; Qu, Hongnan; Rong, Meng; Liu, Huizhou

    2017-04-01

    A series of ethanediamine (EDA) - modified magnetic poly-(glycidyl methacrylate) (m-PGMA-EDA)microspheres with different amine density were synthesized and their cadmium saturation adsorption capacities were examined. The results showed that the cadmium saturation adsorption capacity increased with the immobilized amine density. However, they did not show strong positive linear correlation in the whole range of amine density examined. The molar ratio of amine groups to the adsorbed cadmium decreased with the increase of amine density and eventually reached a minimum value about 4. It suggested that low immobilized amine density led to low coordination efficiency of the amine. It is hypothesized that the immobilized amine groups needed to be physically close enough to form stable amine-metal complex. When the amine density reached to a critical value 1.25 m mol m-2, stable amine-cadmium complex (4:1 N/Cd) was proposed to form. To illustrate the coordination mechanism (structure and number) of amine and Cd, FT-IR spectra of m-PGMA-EDA and m-PGMA-EDA-Cd , and X-ray photoelectron spectroscopy (XPS) of PGMA-EDA and PGMA-EDA-Cd were examined and analyzed.

  3. Mechanism of Cu(II), Cd(II) and Pb(II) ions sorption from aqueous solutions by macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate)

    Science.gov (United States)

    Nastasović, Aleksandra B.; Ekmeščić, Bojana M.; Sandić, Zvjezdana P.; Ranđelović, Danijela V.; Mozetič, Miran; Vesel, Alenka; Onjia, Antonije E.

    2016-11-01

    The mechanism of Cu(II), Cd(II) and Pb(II) ions sorption from aqueous solutions by macroporous poly(glycidyl methacrylate-co-ethylene glycol dimethacrylate) (PGME) functionalized by reaction of the pendant epoxy groups with diethylene triamine (PGME-deta) was studied using X-ray photoelectron spectroscopy (XPS) and Fourier transform infrared spectroscopy (FTIR) analysis. Atomic force microscopy (AFM) and scanning energy-dispersive X-ray spectroscopy (SEM-EDX) were used for the determination of surface morphology of the copolymer particles. The sorption behavior of heavy metals Cu(II), Cd(II) and Pb(II) ions sorption was investigated in batch static experiments under non-competitive conditions at room temperature (298 K). The obtained results were fitted to pseudo-first order, pseudo-second order and intraparticle diffusion kinetic model. The kinetics studies showed that Cu(II), Cd(II) and Pb(II) sorption obeys the pseudo-second-order model under all investigated operating conditions with evident influence of pore diffusion.

  4. Experimental Study onMalignant Transformation of Human Bronchial Epithelial CellsInduced by Glycidyl Methacrylate and Analysis on its Methylation

    Institute of Scientific and Technical Information of China (English)

    WANG An Na; WANG Quan Kai; YANG Min; HU Jie; DONG Lin; andXU Jian Ning

    2014-01-01

    ObjectiveTo establish the model of human bronchial epithelial cells(16HBE) malignant transformation induced by glycidyl methacrylate(GMA)and define the different methylation genes at different stages. MethodsDNA was extracted at different 16HBE malignant phasesandchanges of genes DNA methylation atdifferent stages weredetectedusing Methylation chip of‘NimbleGen HG18 CpG Promoter Microarray Methylation’. Methylation-specific PCR (MSP) was usedto observe the methylation status ofsome genes, and then compared with the control groups. ResultsThe resultshowed that GMA induced 16HBE morphorlogical transformation at the dose of 8µg/mL, and cell exposed to GMA had 1374 genes in protophase, 825 genes inmetaphase, 1149 genes in anaphase, respectively; 30 genes are all methylation in the 3 stages; 318 genes in protophase but not inmetaphase and anaphase; 272 genes in metaphase but not inprotophase and anaphase; 683 genes in anaphase but not inmetaphase and protophase; 73 genes inprotophase andmetaphase but not in anaphase; 67 genes in protophase and anaphase but not inmetaphase; 59 genes inmetaphase and anaphase but not in protophase. ConclusionThe pattern of DNA methylation could change in the process of 16HBEinduced by GMA.

  5. Sorption of different phenol derivatives on functionalized macroporous nanocomposite of poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate and acid modified bentonite

    Directory of Open Access Journals (Sweden)

    Marinović Sanja R.

    2014-01-01

    Full Text Available Macroporous nanocomposite of poly (glycidyl methacrylate-co-ethylene glycol dimethacrylate and acid modified bentonite was prepared by radical suspension copolymerization. Nanocomposite was functionalized with diethylene triamine (deta, by ring-opening reaction of the pendant epoxy groups. Functionalization was performed in order to enable phenol derivatives sorption. This new, not sufficiently investigated material, with developed porous structure was denoted CP-SA-deta. In this study, the influence of temperature on 4-nitrophenol (4NP sorption on CP-SA-deta was investigated. The chemisorption was estimated as dominant process since activation energy of sorption of 4NP of 54.8 kJ mol-1 was obtained. After determining the optimal sorption conditions for 4NP, the sorption of 2-nitrophenol (2NP and 2-chloro 4-nitrophenol (2Cl4NP on CP-SA-deta was investigated with respect to pH, initial concentration and contact time. The 2NP sorption was seldom tested, while according to our knowledge, the 2Cl4NP sorption was not investigated. The isotherm data were best fitted with Langmuir model, while the sorption dynamics obeyed the pseudo-second-order kinetic model for all derivatives. [Projekat Ministarstva nauke Republike Srbije, br. III 45001 i br. III 43009

  6. Mechanism of pretreatment using magnetic poly(glycidyl methacrylate) resin in an ultrafiltration membrane system used in algae-rich water treatment.

    Science.gov (United States)

    Liu, Yu; Chen, Wei; Dong, Changlong; Liu, Cheng; Liu, Hai Cheng

    2015-01-01

    Ultrafiltration (UF) membrane fouling brought by algae-rich water controlling has been the research focus in recent years. The pretreatment of magnetic poly(glycidyl methacrylate) (m-PGMA) for sedimental tank effluent was investigated as well as its performance in combined UF processes. The optimal dose of m-PGMA was found to be 5 mL/L, which can bring a significant improvement to the removal efficiency of natural organic matter. With regards to membrane fouling, the use of m-PGMA also resulted in lowered irreversible and reversible membrane resistances in comparison with results obtained when operating without m-PGMA. In addition, four classic filtration models were introduced to analyse the fouling mechanisms. The proportion of standard blocking of pores has been weakened in the mechanism of membrane fouling when the pretreatment of m-PGMA exists. A very loose cake layer and relieved pore blockage were observed by scanning electron microscopy during m-PGMA/UF process.

  7. Formation of Glycidyl Fatty Acid Esters Both in Real Edible Oils during Laboratory-Scale Refining and in Chemical Model during High Temperature Exposure.

    Science.gov (United States)

    Cheng, Weiwei; Liu, Guoqin; Liu, Xinqi

    2016-07-27

    In the present study, the formation mechanisms of glycidyl fatty acid esters (GEs) were investigated both in real edible oils (soybean oil, camellia oil, and palm oil) during laboratory-scale preparation and refining and in chemical model (1,2-dipalmitin (DPG) and 1-monopalmitin (MPG)) during high temperature exposure (160-260 °C under nitrogen). The formation process of GEs in the chemical model was monitored using attenuated total reflection-Fourier transform infrared (ATR-FTIR) spectroscopy. The results showed that the roasting and pressing process could produce certain amounts of GEs that were much lower than that produced in the deodorization process. GE contents in edible oils increased continuously and significantly with increasing deodorization time below 200 °C. However, when the temperature exceeded 200 °C, GE contents sharply increased in 1-2 h followed by a gradual decrease, which could verify a simultaneous formation and degradation of GEs at high temperature. In addition, it was also found that the presence of acylglycerol (DAGs and MAGs) could significantly increase the formation yield of GEs both in real edible oils and in chemical model. Compared with DAGs, moreover, MAGs displayed a higher formation capacity but substantially lower contribution to GE formation due to their low contents in edible oils. In situ ATR-FTIR spectroscopic evidence showed that cyclic acyloxonium ion intermediate was formed during GE formation derived from DPG and MPG in chemical model heated at 200 °C.

  8. Preparation of high-capacity, weak anion-exchange membranes by surface-initiated atom transfer radical polymerization of poly(glycidyl methacrylate) and subsequent derivatization with diethylamine

    Science.gov (United States)

    Qian, Xiaolei; Fan, Hua; Wang, Chaozhan; Wei, Yinmao

    2013-04-01

    Ion-exchange membrane is of importance for the development of membrane chromatography. In this work, a high-capacity anion-exchange membrane was prepared by grafting of glycidyl methacrylate (GMA) onto the surface of regenerated cellulose (RC) membranes via surface-initiated atom transfer radical polymerization (SI-ATRP) and subsequent derivatization with diethylamine. Attenuated total reflectance Fourier-transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM) were used to characterize changes in the chemical functionality, surface topography and pore morphology of the modified membranes. The static capacity of the prepared anion-exchange membrane was evaluated with bovine serum albumin (BSA) as a model protein. The results indicated that the anion-exchange membrane which could reach a maximum capacity of 96 mg/mL for static adsorption possesses a higher adsorption capacity, and the adsorption capacity increases with the polymerization time. The effect of pH and salt concentration confirmed that the adsorption of BSA followed ion-exchange mechanism. The established method would have potential application in the preparation of anion-exchange membrane.

  9. Vapor intrusion risk of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME) and ethyl tert-butyl ether (ETBE): A modeling study.

    Science.gov (United States)

    Ma, Jie; Xiong, Desen; Li, Haiyan; Ding, Yi; Xia, Xiangcheng; Yang, Yongqi

    2017-06-15

    Vapor intrusion of synthetic fuel additives represents a critical yet still neglected problem at sites contaminated by petroleum fuel releases. This study used an advanced numerical model to investigate the vapor intrusion potential of fuel ether oxygenates methyl tert-butyl ether (MTBE), tert-amyl methyl ether (TAME), and ethyl tert-butyl ether (ETBE). Simulated indoor air concentration of these compounds can exceed USEPA indoor air screening level for MTBE (110μg/m(3)). Our results also reveal that MTBE has much higher chance to cause vapor intrusion problems than TAME and ETBE. This study supports the statements made by USEPA in the Petroleum Vapor Intrusion (PVI) Guidance that the vertical screening criteria for petroleum hydrocarbons may not provide sufficient protectiveness for fuel additives, and ether oxygenates in particular. In addition to adverse impacts on human health, ether oxygenate vapor intrusion may also cause aesthetic problems (i.e., odour and flavour). Overall, this study points out that ether oxygenates can cause vapor intrusion problems. We recommend that USEPA consider including the field measurement data of synthetic fuel additives in the existing PVI database and possibly revising the PVI Guidance as necessary.

  10. Fluorinated alcohols as promoters for the metal-free direct substitution reaction of allylic alcohols with nitrogenated, silylated, and carbon nucleophiles.

    Science.gov (United States)

    Trillo, Paz; Baeza, Alejandro; Nájera, Carmen

    2012-09-01

    The direct allylic substitution reaction using allylic alcohols in 1,1,1,3,3,3-hexafluoroisopropanol (HFIP) and 2,2,2-trifluoroethanol (TFE) as reaction media is described. The developed procedure is simple, works under mild conditions (rt, 50 and 70 °C), and proves to be very general, since different nitrogenated nucleophiles and carbon nucleophiles can be used achieving high yields, especially when HFIP is employed as solvent and aromatic allylic alcohols are the substrates. Thus, sulfonamides, carbamates, carboxamides, and amines can be successfully employed as nitrogen-based nucleophiles. Likewise, silylated nucleophiles such as trimethylsilylazide, allyltrimethylsilane, trimethylsilane, and trimethylsilylphenylacetylene give the corresponding allylic substitution products in high yields. Good results for the Friedel-Crafts adducts are also achieved with aromatic compounds (phenol, anisole, indole, and anilines) as nucleophiles. Particularly interesting are the results obtained with electron-rich anilines, which can behave as nitrogenated or carbon nucleophiles depending on their electronic properties and the solvent employed. In addition, 1,3-dicarbonyl compounds (acetylacetone and Meldrum's acid) are also successfully employed as soft carbon nucleophiles. Studies for mechanism elucidation are also reported, pointing toward the existence of carbocationic intermediates and two working reaction pathways for the obtention of the allylic substitution product.

  11. Allyl/propenyl phenol synthases from the creosote bush and engineering production of specialty/commodity chemicals, eugenol/isoeugenol, in Escherichia coli.

    Science.gov (United States)

    Kim, Sung-Jin; Vassão, Daniel G; Moinuddin, Syed G A; Bedgar, Diana L; Davin, Laurence B; Lewis, Norman G

    2014-01-01

    The creosote bush (Larrea tridentata) harbors members of the monolignol acyltransferase, allylphenol synthase, and propenylphenol synthase gene families, whose products together are able to catalyze distinct regiospecific conversions of various monolignols into their corresponding allyl- and propenyl-phenols, respectively. In this study, co-expression of a monolignol acyltransferase with either substrate versatile allylphenol or propenylphenol synthases in Escherichia coli established that various monolignol substrates were efficiently converted into their corresponding allyl/propenyl phenols, as well as providing proof of concept for efficacious conversion in a bacterial platform. This capability thus potentially provides an alternate source to these important plant phytochemicals, whether for flavor/fragrance and fine chemicals, or ultimately as commodities, e.g., for renewable energy or other intermediate chemical purposes. Previous reports had indicated that specific and highly conserved amino acid residues 84 (Phe or Val) and 87 (Ile or Tyr) of two highly homologous allyl/propenyl phenol synthases (circa 96% identity) from a Clarkia species mainly dictate their distinct regiospecific catalyzed conversions to afford either allyl- or propenyl-phenols, respectively. However, several other allyl/propenyl phenol synthase homologs isolated by us have established that the two corresponding amino acid 84 and 87 residues are not, in fact, conserved.

  12. Characterization of Microsolvated Crown Ethers from Broadband Rotational Spectroscopy

    Science.gov (United States)

    Perez, Cristobal; Schnell, Melanie; Blanco, Susana; Lopez, Juan Carlos

    2016-06-01

    Since they were first synthetized, crown ethers have been extensively used in organometallic chemistry due to their unparalleled binding selectivity with alkali metal cations. From a structural point of view, crown ethers are heterocycles containing oxygen and/or other heteroatoms, although the most common ones are formed from ethylene oxide unit. Crown ethers are conventionally seen as being hydrophilic inside and hydrophobic outside when the structures found for the metal cation complexes are considered. However, crown ethers are extremely flexible and in isolation may present a variety of stable conformations so that their structure may be easily adapted in presence of a strong ligand as an alkali metal cation minimize the energy of the resulting complex. Water can be considered a soft ligand which interacts with crown ethers through moderate hydrogen bonds. It is thus interesting to investigate which conformers are selected by water to form complexes, the preferred interaction sites and the possible conformational changes due to the presence of one or more water molecules. Previous studies identified microsolvated crown ethers but in all cases with a chromophore group attached to the structure. Here we present a broadband rotational spectroscopy study of microsolvated crown ethers produced in a pulsed molecular jet expansion. Several 1:1 and 1:2 crown ether:water aggregates are presented for 12-crown-4, 15-crown-5 and 18-crown-6. Unambiguous identification of the structures has been achieved using isotopic substitution within the water unit. The subtle changes induced in the structures of the crown ether monomer upon complexation and the hydrogen-bonding network that hold them together will be also discussed. F. Gámez, B. Martínez-Haya, S. Blanco,J. C. López and J. L. Alonso, Phys. Chem. Chem. Phys. 2014, 14 12912-12918 V. A. Shubert, C.W. Müller and T. Zwier, J. Phys. Chem. A 2009, 113 8067-8079

  13. 德国赫优讯EtherCAT新产品

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    EtherCAT作为实时以太网协议之一,以其强大的性能和“On the fly”的速度,以及网络抖动小于1μs的同步功能.成为发展最快的实时网络协议。同时,EtherCAT全球组织在中国代表处的设立,表明了EtherCAT全球组织对中国市场的关心。

  14. Impact of cellulose ethers on the cement paste microstructure

    OpenAIRE

    Pourchez, Jérémie; Grosseau, Philippe; Rouèche-Pourchez, Emilie; Debayle, Johan; Pinoli, Jean-Charles; Maire, Eric; Boller, Elodie; Parra-Denis, Estelle

    2007-01-01

    ISBN = 3-87264-022-4 7 pages; International audience; Complementary investigation tools (2D and 3D observations by optical microscopy and fast X-ray microtomography and then image analysis) were developed in order to examine the effects of cellulose ethers on the cement paste microstructure. The obtained results show that the presence of cellulose ether may induce an increase of both 50-250 µm-diameter air voids. The chemistry of the cellulose ethers appears as a main controlling factor of th...

  15. Synthesis and Adsorption Property of Dihydroxyl Azacrown Ether-Grafted Chitosan

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    A novel dihydroxyl azacrown ether chitosan was synthesized by reacting dihydroxyl azacrown ether with epoxy activated chitosan. The adsorption property of the azacrown ether chitosan for Pb2+, Cr3+, and Ag+, were determined. The experimental results showed that the dihydroxyl azacrown ether grafted chitosan has high adsorption capacity and high selectivity for some metal ions.

  16. Two highly stable and selective solid phase microextraction fibers coated with crown ether functionalized ionic liquids by different sol-gel reaction approaches.

    Science.gov (United States)

    Shu, Jianjun; Xie, Pengfei; Lin, Danni; Chen, Rongfeng; Wang, Jiang; Zhang, Beibei; Liu, Mingming; Liu, Hanlan; Liu, Fan

    2014-01-02

    In this work, two novel crown ether functionalized ionic liquid (FIL)-based solid phase microextraction (SPME) fibers were prepared by sol-gel technology using the synthesized 1-(trimethoxysily)propyl 3-(6'-oxo-benzo-15-crown-5 hexyl) imidazolium bis(trifluoromethanesulphonyl)imide ([TMSP(Benzo15C5)HIM][N(SO2CF3)2]) and 1-allyl-3-(6'-oxo-benzo-15-crown-5 hexyl) imidazolium bis(trifluoromethanesulphonyl)imide ([A(Benzo15C5)HIM][N(SO2CF3)2]) as selective stationary phases. Owing to the introduction of trimethoxysilypropyl to the imidazole cation, the [TMSP(Benzo15C5)HIM][N(SO2CF3)2] could be chemically bonded to the formed sol-gel silica substrate through the hydrolysis and polycondensation reaction. Similarly, the [A(Benzo15C5)HIM][N(SO2CF3)2] was able to participate in the formation of the organic-inorganic copolymer coatings through the free radical crosslinking reaction. These two fibers were determined to have "bubble-like" surface characteristics analogous to a previously prepared [A(Benzo15C5)HIM][PF6]-based fiber. Their thermal stabilities were much higher than that of the [A(Benzo15C5)HIM][PF6]-based coating. They were capable of withstanding temperatures as high as 400°C without evident loss of the crown ether FILs. They also had strong solvent, acid and alkali resistance, good coating preparation reproducibility and high selectivity for medium polar to polar compounds. The high selectivity of these two fibers could be attributed to the strong ion-dipole, hydrogen bonding and π-π interactions provided by the synergetic effect of ILs and benzo-15-crown-5 functionalities. Moreover, the selectivity of these two fibers was rather different although the structures of these two crown ether FILs were very similar. This is maybe because the relative contents of the crown ether FILs chemically bonded to the organic-inorganic copolymer coatings were quite different when prepared by different sol-gel reaction approaches.

  17. S-Allyl-Cysteines Reduce Amelioration of Aluminum Induced Toxicity in Rats

    Directory of Open Access Journals (Sweden)

    Sadhana Shrivastava

    2011-01-01

    Full Text Available Problem statement: Aluminum (Al is a trivalent cation found in its ionic form in most kinds of animal tissues and in natural waters everywhere. Approach: It is a potent neurotoxin and has been associated in the pathogenesis of several clinical disorders including Alzheimer’s disease. Results: The aim of the study was to demonstrate the protective effect of S-Allyl-Cysteines (SAC against Al-induced toxicity in rat model on certain biochemical parameters, lipid peroxidation and oxidative stress enzymes of white albino rats. Six rats per group were divided into various treatment groups. Group one rats were given normal saline and served as control group. Group two animals received Al as aluminum nitrate 32.5 mg (i.p. for the induction of toxicity. Group three to five received different doses of SAC (25, 50 and 100 mg kg-1 for 3 days after 24 h of Al toxicity. Rats were orally administered their respective doses every day for 3 days. Evaluations were made in blood and tissues. The activity of Acetylcholinesterase (AchE was inhibited in all the parts of brain after Al intoxication. Significant rise were observed the Activities of Serum Transaminases (AST and ALT after toxicant exposure. The activity of â-Aminolevulinic acid Dehydratase (ALAD in blood and â-Aminolevulinic Acid Synthetase (ALAS in brain was decreased after Al exposure. Al significant increased cholesterol, triglyceride, creatinine and urea level in serum. TBARS level was significantly higher and GSH content were significantly lower during toxicity. Total and esterified cholesterol in liver, kidney and brain were increased after Al exposure. Histopathological changes in liver, kidney and brain were also recouped with the therapy. Conclusion/Recommendations: Our data proved that SAC which is a bioactive and bioavailable component of garlic has organosulfur compounds which regulates the thiol status of the cell and scavenges free radicals and work as an antioxidant. Thus SAC

  18. New copolymer of acrylamide with allyl methacrylate and its capacity for the removal of azo dyes

    Directory of Open Access Journals (Sweden)

    Yeliz Yildirim

    2015-04-01

    Full Text Available The copolymerization reactions of Acrylamide (AA with the different mole ratios of allyl methacrylate (AMA such as 25/75, 50/50 and 75/25 were studied by radical polymerization under argon atmosphere using 2,2’-Azobis (isobutyronitri1e (AIBN as initiator. The copolymers were characterized with Fourier transform infrared spectroscopy (FTIR and thermogravimetric analysis (TG. FTIR spectra showed that the C=O, C-N and N-H groups in copolymers remained during the copolymerization. It is concluded from the thermograms that Poly(AA-co-AMA copolymers which contained different ratios of monomer and comonomer exhibit similar thermal behavior. Adsorption capacity, kinetic and isotherm studies of Direct Brown 2 onto the copolymers have been evaluated. Different factors such as the monomer ratio, pH, initial dye concentration, copolymer dosage and contact time affecting the removal process were studied. It was found that the adsorption process agreed with the Freundlich and Dubinin-Raduskevich model and the adsorption of Direct Brown 2 depended on the acrylamide content and pH of the solution. The standard Gibb’s free energy was determined as - 14.7 kJ/mol, which means that adsorption occurred spontaneously and the process is feasible. Increasing the acrylamide content led to increased adsorption of Direct Brown 2 on the copolymer. Moreover, adsorption kinetic studies showed that the adsorption followed a pseudo-second-order kinetic model, indicating that the chemical adsorption was the rate-limiting step. These results show that Poly(AA-co-AMA can be used as adsorbent for water pollutants such as Direct Brown 2 and has potential applications in related industrial and environmental areas.

  19. Stereoselective coordination: a six-membered P,N-chelate tailored for asymmetric allylic alkylation.

    Science.gov (United States)

    Császár, Z; Farkas, G; Bényei, A; Lendvay, G; Tóth, I; Bakos, J

    2015-10-01

    Six-membered chelate complexes [Pd(1a-b)Cl2], (2a-b) and [Pd(1a-b)(η(3)-PhCHCHCHPh)]BF4, (3a-b) of P,N-type ligands 1a, ((2S,4S)-2-diphenyl-phosphino-4-isopropylamino-pentane) and 1b, ((2S,4S)-2-diphenyl-phosphino-4-methylamino-pentane) have been prepared. The Pd-complexes have been characterized in solution by 1D and 2D NMR spectroscopy. The observed structures were confirmed by DFT calculations and in the case of 2a also by X-ray crystallography. Unexpectedly, the coordination of the all-carbon-backbone aminophosphine 1a resulted in not only a stereospecific locking of the donor nitrogen atom into one of the two possible configurations but also the conformation of the six-membered chelate rings containing three alkyl substituents was forced into the same single chair structure showing the axially placed isopropyl group on the coordinated N-atom. The stereodiscriminative complexation of 1a led to the formation of a palladium catalyst with a conformationally rigid chelate having a configurationally fixed nitrogen and electronically different coordination sites due to the presence of P and N donors. The stereochemically fixed catalyst provided excellent ee's (up to 96%) and activities in asymmetric allylic alkylation reactions. In contrast, the chelate rings formed by 1b exist in two different chair conformations, both containing axial methyl groups, but with the opposite configurations of the coordinated N-atom. Pd-complexes of 1b provided low enantioselectivities in similar alkylations, therefore emphasizing the importance of the stereoselective coordination of N-atoms in analogous P-N chelates. The factors determining the coordination of the ligands were also studied with respect to the chelate ring conformation and the nitrogen configuration.

  20. Mechanisms of transient receptor potential vanilloid 1 activation and sensitization by allyl isothiocyanate.

    Science.gov (United States)

    Gees, Maarten; Alpizar, Yeranddy A; Boonen, Brett; Sanchez, Alicia; Everaerts, Wouter; Segal, Andrei; Xue, Fenqin; Janssens, Annelies; Owsianik, Grzegorz; Nilius, Bernd; Voets, Thomas; Talavera, Karel

    2013-09-01

    Allyl isothiocyanate (AITC; aka, mustard oil) is a powerful irritant produced by Brassica plants as a defensive trait against herbivores and confers pungency to mustard and wasabi. AITC is widely used experimentally as an inducer of acute pain and neurogenic inflammation, which are largely mediated by the activation of nociceptive cation channels transient receptor potential ankyrin 1 and transient receptor potential vanilloid 1 (TRPV1). Although it is generally accepted that electrophilic agents activate these channels through covalent modification of cytosolic cysteine residues, the mechanism underlying TRPV1 activation by AITC remains unknown. Here we show that, surprisingly, AITC-induced activation of TRPV1 does not require interaction with cysteine residues, but is largely dependent on S513, a residue that is involved in capsaicin binding. Furthermore, AITC acts in a membrane-delimited manner and induces a shift of the voltage dependence of activation toward negative voltages, which is reminiscent of capsaicin effects. These data indicate that AITC acts through reversible interactions with the capsaicin binding site. In addition, we show that TRPV1 is a locus for cross-sensitization between AITC and acidosis in nociceptive neurons. Furthermore, we show that residue F660, which is known to determine the stimulation by low pH in human TRPV1, is also essential for the cross-sensitization of the effects of AITC and low pH. Taken together, these findings demonstrate that not all reactive electrophiles stimulate TRPV1 via cysteine modification and help understanding the molecular bases underlying the surprisingly large role of this channel as mediator of the algesic properties of AITC.

  1. Facile coupling of propargylic, allylic and benzylic alcohols with allylsilane and alkynylsilane, and their deoxygenation with Et3SiH, catalyzed by Bi(OTf)3 in [BMIM][BF4] ionic liquid (IL), with recycling and reuse of the IL.

    Science.gov (United States)

    Kumar, G G K S Narayana; Laali, Kenneth K

    2012-09-28

    Allyltrimethylsilane (allyl-TMS) reacts with propargylic alcohols 1a-1d in the presence of 10% Bi(OTf)(3) in [BMIM][BF(4)] solvent to furnish the corresponding 1,5-enynes in respectable isolated yields (87-93%) at room temperature. The utility of Bi(OTf)(3) as a superior catalyst was demonstrated in a survey study on coupling of allyl-TMS with employing several metallic triflates (Bi, Ln, Al, Yb) as well as, B(C(6)F(5))(3), Zn(NTf(2))(2) and Bi(NO(3))(3)·5H(2)O. Coupling of cyclopropyl substituted propargylic alcohol with allyl-TMS gave the skeletally intact 1,5-enyne and a ring opened derivative as a mixture. Coupling of propargylic/allylic alcohol with allyl-TMS resulted in allylation at both benzylic (2 isomers) and propargylic positions, as major and minor products respectively. The scope of this methodology for allylation of a series of allylic and benzylic alcohols was explored. Chemoselective reduction of a host of propargylic, propagylic/allylic, bis-allylic, allylic, and benzylic alcohols with Et(3)SiH was achieved in high yields with short reaction times. The same approach was successfully applied to couple representative propargylic and allylic alcohols with 1-phenyl-2-trimethylsilylacetylene. The recovery and reuse of the ionic liquid (IL) was gauged in a case study with minimal decrease in isolated yields after six cycles.

  2. Elucidation of the regio- and chemoselectivity of enzymatic allylic oxidations with Pleurotus sapidus – conversion of selected spirocyclic terpenoids and computational analysis

    Directory of Open Access Journals (Sweden)

    Verena Weidmann

    2013-10-01

    Full Text Available Allylic oxidations of olefins to enones allow the efficient synthesis of value-added products from simple olefinic precursors like terpenes or terpenoids. Biocatalytic variants have a large potential for industrial applications, particularly in the pharmaceutical and food industry. Herein we report efficient biocatalytic allylic oxidations of spirocyclic terpenoids by a lyophilisate of the edible fungus Pleurotus sapidus. This ‘’mushroom catalysis’’ is operationally simple and allows the conversion of various unsaturated spirocyclic terpenoids. A number of new spirocyclic enones have thus been obtained with good regio- and chemoselectivity and chiral separation protocols for enantiomeric mixtures have been developed. The oxidations follow a radical mechanism and the regioselectivity of the reaction is mainly determined by bond-dissociation energies of the available allylic CH-bonds and steric accessibility of the oxidation site.

  3. Rheological and mechanical behavior of polyacrylamide hydrogels chemically crosslinked with allyl agarose for two-dimensional gel electrophoresis.

    Science.gov (United States)

    Suriano, R; Griffini, G; Chiari, M; Levi, M; Turri, S

    2014-02-01

    Two-dimensional (2-D) gel electrophoresis currently represents one of the most standard techniques for protein separation. In addition to the most commonly employed polyacrylamide crosslinked hydrogels, acrylamide-agarose copolymers have been proposed as promising systems for separation matrices in 2-D electrophoresis, because of the good resolution of both high and low molecular mass proteins made possible by careful control and optimization of the hydrogel pore structure. As a matter of fact, a thorough understanding of the nature of the hydrogel pore structure as well as of the parameters by which it is influenced is crucial for the design of hydrogel systems with optimal sieving properties. In this work, a series of acrylamide-based hydrogels covalently crosslinked with different concentrations of allyl agarose (0.2-1%) is prepared and characterized by creep-recovery measurements, dynamic rheology and tensile tests, in the attempt to gain a clearer understanding of structure-property relationships in crosslinked polyacrylamide-based hydrogels. The rheological and mechanical properties of crosslinked acrylamide-agarose hydrogels are found to be greatly affected by crosslinker concentration. Dynamic rheological tests show that hydrogels with a percentage of allyl agarose between 0.2% and 0.6% have a low density of elastically effective crosslinks, explaining the good separation of high molecular mass proteins in 2-D gel electrophoresis. Over the same range of crosslinker concentration, creep-recovery measurements reveal the presence of non-permanent crosslinks in the hydrogel network that justifies the good resolution of low molecular mass proteins as well. In tensile tests, the hydrogel crosslinked with 0.4% of allyl agarose exhibits the best results in terms of mechanical strength and toughness. Our results show how the control of the viscoelastic and the mechanical properties of these materials allow the design of mechanically stable hydrogels with improved

  4. Spatial trends of polybrominated diphenyl ether (PBDE) congeners

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Spatial trends of polybrominated diphenyl ether (PBDE) congeners were analyzed in young of the year bluefish collected along the U.S. Atlantic coastline from...

  5. Fluorinated Alkyl Ether Epoxy Resin Compositions and Applications Thereof

    Science.gov (United States)

    Wohl, Christopher J. (Inventor); Connell, John W. (Inventor); Smith, Joseph G. (Inventor); Siochi, Emilie J. (Inventor); Gardner, John M. (Inventor); Palmieri, Frank M. (Inventor)

    2017-01-01

    Epoxy resin compositions prepared using amino terminated fluoro alkyl ethers. The epoxy resin compositions exhibit low surface adhesion properties making them useful as coatings, paints, moldings, adhesives, and fiber reinforced composites.

  6. Evaluation of crystallization kinetics of poly (ether-ketone-ketone and poly (ether-ether-ketone by DSC

    Directory of Open Access Journals (Sweden)

    Gibran da Cunha Vasconcelos

    2010-08-01

    Full Text Available The poly (aryl ether ketones are used as matrices in advanced composites with high performance due to its high thermal stability, excellent environmental performance and superior mechanical properties. Most of the physical, mechanical and thermodynamic properties of semi-crystalline polymers depend on the degree of crystallinity and morphology of the crystalline regions. Thus, a study on the crystallization process promotes a good prediction of how the manufacturing parameters affect the developed structure, and the properties of the final product. The objective of this work was to evaluate the thermoplastics polymers PEKK e PEEK by DSC, aiming to obtain the relationship between kinetics, content, nucleation and geometry of the crystalline phases, according to the parameters of the Avrami and Kissinger models. The analysis of the Avrami exponents obtained for the studied polymers indicates that both showed the formation of crystalline phases with heterogeneous nucleation and growth geometry of the type sticks or discs, depending on the cooling conditions. It was also found that the PEEK has a higher crystallinity than PEKK.

  7. Antimicrobial activity of allyl isothiocyanate used to coat biodegradable composite films as affected by storage and handling conditions.

    Science.gov (United States)

    Li, Weili; Liu, Linshu; Jin, Tony Z

    2012-12-01

    We evaluated the effects of storage and handling conditions on the antimicrobial activity of biodegradable composite films (polylactic acid and sugar beet pulp) coated with allyl isothiocyanate (AIT). Polylactic acid and chitosan were incorporated with AIT and used to coat one side of the film. The films were subjected to different storage conditions (storage time, storage temperature, and packed or unpacked) and handling conditions (washing, abrasion, and air blowing), and the antimicrobial activity of the films against Salmonella Stanley in tryptic soy broth was determined. The films (8.16 μl of AIT per cm(2) of surface area) significantly (P packaging.

  8. SnCl2/Cu-Mediated Carbonyl Allylation Reaction in Water:Scope,Selectivity and Mechanism

    Institute of Scientific and Technical Information of China (English)

    TAN,Xiang-Hui(谭翔晖); HOU,Yong-Quan(侯永泉); LIU,Lei(刘磊); GUO,Qing-Xiang(郭庆祥)

    2004-01-01

    Copper was found to be able to promote the SnC12-mediated carbonyl allylation reactions in water,giving the corresponding homoallylic alcohol products in very high yields.Detailed studies showed that the reaction could be applied to a variety of carbonyl compounds including those with hydroxyl,amino and nitro groups.It was also found that this reaction showed good regioselectivities for some substrates.Furthermore,carefully controled experiments and in situ NMR measurements provided important insights into the mechanism of the newly developed reaction.

  9. Tandem SN2' nucleophilic substitution/oxidative radical cyclization of aryl substituted allylic alcohols with 1,3-dicarbonyl compounds.

    Science.gov (United States)

    Zhang, Zhen; Li, Cheng; Wang, Shao-Hua; Zhang, Fu-Min; Han, Xue; Tu, Yong-Qiang; Zhang, Xiao-Ming

    2017-03-23

    A novel and efficient tandem SN2' nucleophilic substitution/oxidative radical cyclization reaction of aryl substituted allylic alcohols with 1,3-dicarbonyl compounds has been developed by using Mn(OAc)3 as an oxidant, which enables the expeditious synthesis of polysubstituted dihydrofuran (DHF) derivatives in moderate to high yields. The use of weakly acidic hexafluoroisopropanol (HFIP) as the solvent rather than AcOH has successfully improved the yields and expanded the substrate scope of this type of radical cyclization reactions. Mechanistic studies confirmed the cascade reaction process involving a final radical cyclization.

  10. 烯丙基异硫氰酸酯的熏蒸毒力研究%FUMIGATION ACTIVITY OF THE ALLYL ISOTHIOCYANATE

    Institute of Scientific and Technical Information of China (English)

    陈春武; 谢令德; 陈雅群; 何君; 贺艳萍

    2012-01-01

    以玉米象和赤拟谷盗作为实验对象,采用熏蒸方式对烯丙基异硫氰酸酯的毒力进行测定.结果表明,烯丙基异硫氰酸酯对所研究的两种害虫有较好的快速致死作用,同时研究发现在相同熏蒸时间内烯丙基异硫氰酸酯对玉米象熏蒸的LC50和LC99均小于对赤拟谷盗的LC50和LC99,这说明烯丙基异硫氰酸酯对玉米象的熏蒸效果比对赤拟谷盗的好.%Chosing Si tophilus zesmais (Motschulsky) and Tribolium castaneun (Herbst) as experimental objects, the toxicity for the allyl isothiocyanate (AITC) is tested systematically by fumigation method. The result demonstrates that the allyl isothiocyanate presents rapid lethal effect against both of the two types of insects. The research also shows that both the LC50 and the LC99 of the fumigation of the allyl isothiocyanate to the Sitophilus zeamais are less than those of the allyl isothiocyanate to the Tribolium castaneum exposuring the same fumigating time, which indicates that the fumigating effect of the allyl isothiocyanate to the Sitophilus zeamais is more effective than that of the allyl isothiocyanate to the Tribolium castaneum.

  11. 德国赫优讯EtherCAT产品

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    德国赫优讯自动化系统有限公司作为EtherCAT国际组织的重要成员之一,推出基于实时以太网EtherCAT的计算机通信板卡cifX系列产品和嵌入式通信模块comX系列产品。

  12. Effect of diethyl ether on the biliary excretion of acetaminophen.

    Science.gov (United States)

    Watkins, J B; Siegers, C P; Klaassen, C D

    1984-10-01

    The biliary and renal excretion of acetaminophen and its metabolites over 8 hr was determined in rats exposed to diethyl ether by inhalation for 1 hr. Additional rats were anesthetized with urethane (1 g/kg ip) while control animals were conscious throughout the experiment (surgery was performed under hexobarbital narcosis: 150 mg/kg ip; 30-min duration). The concentration of UDP-glucuronic acid was decreased 80% in livers from ether-anesthetized rats but was not reduced in urethane-treated animals when compared to that in control rats. The concentration of reduced glutathione was not affected by either urethane or diethyl ether. Basal bile flow was not altered by the anesthetic agents. Bile flow rate after acetaminophen injection (100 mg/kg iv) was increased slightly over basal levels for 2 hr in hexobarbital-treated control rats, was unaltered in urethane-anesthetized animals, and was decreased throughout the 8-hr experiment in rats exposed to diethyl ether for 1 hr. In control and urethane-anesthetized animals, approximately 30-35% of the total acetaminophen dose (100 mg/kg iv) was excreted into bile in 8 hr, while only 16% was excreted in rats anesthetized with diethyl ether. Urinary elimination (60-70% of the dose) was not altered by exposure to ether. Separation of metabolites by reverse-phase high-pressure liquid chromatography showed that ether decreased the biliary elimination of unchanged acetaminophen and its glucuronide, sulfate, and glutathione conjugates by 47, 40, 49, and 73%, respectively, as compared to control rats. Excretion of unchanged acetaminophen and the glutathione conjugate into bile was depressed in urethane-anesthetized animals by 45 and 66%, respectively, whereas elimination of the glucuronide and sulfate conjugates was increased by 27 and 50%, respectively. These results indicate that biliary excretion is influenced by the anesthetic agent and that diethyl ether depresses conjugation with sulfate and glutathione as well as glucuronic

  13. Marine Sponge Dysidea herbacea revisited: Another Brominated Diphenyl Ether

    Directory of Open Access Journals (Sweden)

    Bruce F. Bowden

    2005-03-01

    Full Text Available Abstract: A pentabrominated phenolic diphenyl ether (1 that has not previously been reported from marine sources has been isolated from Dysidea herbacea collected at Pelorus Island, Great Barrier Reef, Australia. The structure was determined by comparison of NMR data with those of known structurally-related metabolites. NMR spectral assignments for (1 are discussed in context with those of three previously reported isomeric pentabrominated phenolic diphenyl ethers.

  14. Imide/Arylene Ether Copolymers Containing Phosphine Oxide

    Science.gov (United States)

    Jensen, Brian J.; Partos, Richard D.

    1993-01-01

    Phosphine oxide groups react with oxygen to form protective phosphate surface layers. Series of imide/arylene ether block copolymers containing phosphine oxide units in backbone synthesized and characterized. In comparison with commercial polyimide, these copolymers display better resistance to etching by oxygen plasma. Tensile strengths and tensile moduli greater than those of polyarylene ether homopolymer. Combination of properties makes copolymers attractive for films, coatings, adhesives, and composite matrices where resistance to atomic oxygen needed.

  15. Advanced hybrid fluoropolymers from the cycloaddition of aryl trifluorovinyl ethers

    Science.gov (United States)

    Ligon, S. Clark, Jr.

    This dissertation discusses the synthesis of aryl trifluorovinyl ethers and their cycloaddition polymerization to give perfluorocyclobutyl (PFCB) polymers. To explore the stereochemistry of these polymers, simple monomfunctional aryl trifluorovinyl ethers were dimerized and the resultant cis and trans isomers were separated. Differences in structure help to improve understanding of the amorphous nature of the bulk PFCB polymeric material. To apply this knowledge, crown ether containing perfluorocyclobutyl (PFCB) polymers were synthesized for use in lithium ion battery applications. While poor solubility has hindered further development of these materials, slight modifications to structure may provide a solution. Also described is a fluorinated aryl vinyl ether and its attempted copolymerization with chlorotrifluoroethylene. While this copolymerization did not yield the desired materials, novel semifluorinated phenol precursors have been utilized in reactions with carboxylic acids to give polyesters and most recently with phosgene like species to give polycarbonates. Next, PFCB polymers were post functionalized with fluoroalkyl tethers to improve oleophobicity and hydrophobicity without decreasing thermal stability or optical clarity. In addition, various silica nanostructures were functionalized with aryl trifluorovinyl ethers. This includes the reaction of aryl silanes to give trifluorovinyl ether functional POSS and their polymerization to provide PFCB hybrid materials. Silane coupling agents were also used to functionalize colloidal silica and fumed silica nanoparticles. These procedures allow excellent dispersion of the silica nanoparticles throughout the fluoropolymer matrix. Finally, the reaction of aryl trifluorovinyl ether with nonfluorinated alkenes and alkynes was explored. In these reactions, the fluorinated olefin adds with the hydrocarbon olefin to give semifluorinated cyclobutanes (SFCB) and with the alkyne to give semifluorinated cyclobutene. The

  16. Effects of the ether phospholipid AMG-PC on mast cells are similar to that of the ether lipid AMG but different from that of the analogue hexadecylphosphocholine

    DEFF Research Database (Denmark)

    Grosman, Nina

    1991-01-01

    Farmakologi, ether phospholipid, hexacylphosphocholine, miltefosine, protein kinase C, AMG-PC(alkyl-methyl-glycero-phosphocholine), Histamine release, mast cell......Farmakologi, ether phospholipid, hexacylphosphocholine, miltefosine, protein kinase C, AMG-PC(alkyl-methyl-glycero-phosphocholine), Histamine release, mast cell...

  17. [bmim][Br] as a solvent and activator for the Ga-mediated Barbier allylation: direct formation of an N-heterocyclic carbene from Ga metal.

    Science.gov (United States)

    Goswami, Dibakar; Chattopadhyay, Angshuman; Sharma, Anubha; Chattopadhyay, Subrata

    2012-12-21

    The room-temperature ionic liquid (RTIL) [bmim][Br] has been found to be an excellent green and inexpensive medium for the Ga-mediated allylation of aromatic and aliphatic aldehydes and ketones. The RTIL activated the metal via formation of a Ga-N-heterocyclic carbene complex that assisted in the completion of the reaction at ambient temperature with only 0.5 equiv of Ga and 1.2 equiv of allyl bromide with respect to the carbonyl substrates. The present protocol required a much shorter time than those reported in the literature using other metals and solvents and proceeded with good yields and excellent selectivity.

  18. Use of Cyclic Allylic Bromides in the Zinc–Mediated Aqueous Barbier–Grignard Reaction

    Directory of Open Access Journals (Sweden)

    Suzanne M. Perala

    2001-07-01

    Full Text Available The zinc–mediated aqueous Barbier–Grignard reaction of cyclic allylic bromide substrates with various aldehydes and ketones to afford homoallylic alcohols was investigated. Aromatic aldehydes and ketones afforded adducts in good yields (66–90% and with good diastereoselectivities. Non–aromatic aldehydes also reacted well under these conditions, but only poor yields were obtained with non–aromatic ketones. Regioselectivity was high when some substituted cyclic allylic bromides were investigated.

  19. Review on Modification of Sulfonated Poly (-ether-ether-ketone Membranes Used as Proton Exchange Membranes

    Directory of Open Access Journals (Sweden)

    Xiaomin GAO

    2015-11-01

    Full Text Available The proton exchange membrane fuel cell (PEMFC is a type of modern power, but the traditional proton exchange membranes (PEM of PEMFC are limited by high methanol permeability and water uptake. Poly-ether-ether-ketone (PEEK is a widely used thermoplastic with good cost-effective property. Sulfonated poly (-ether-ether-ketone (SPEEK has high electric conductivity and low methanol permeability, as well as comprehensive property, which is expected to be used as PEMs. However, the proton exchange ability, methanol resistance, mechanical property and thermal stability of SPEEK are closely related to the degree of sulfonation (DS of SPEEK membranes. Additionally, the proton conductivity, methanol permeability, and stability of SPEEK membranes applied in various conditions need to be further improved. In this paper, the research into modification of SPEEK membranes made by SPEEK and other polymers, inorganic materials are introduced. The properties and modification situation of the SPEEK and the composite membranes, as well as the advantages and disadvantages of membranes prepared by different materials are summarized. From the results we know that, the methanol permeability of SPEEK/PES-C membranes is within the order of magnitude, 10-7cm2/s. The proton conductivity of the SPPESK/SPEEK blend membrane reaches 0.212 S cm-1 at 80 °C. The cross-linked SPEEK membranes have raised thermal and dimensional stability. The non-solvent caused aggregation of the SPEEK ionomers. The proton conductivity of SPEEK/50%BMIMPF6/4.6PA membrane maintains stable as 2.0 x 10-2S cm-1 after 600 h at 160 °C. Incorporation of aligned CNT into SPEEK increases the proton conductivity and reduces the methanol permeability of the composite membranes. The PANI improves the hydrothermal stability. More proton transfer sites lead to a more compact structure in the composite membranes. According to the results, the proton exchange capacity, water uptake, and conductivity of

  20. Polybrominated diphenyl ethers and novel flame retardants

    DEFF Research Database (Denmark)

    Frederiksen, Marie; Vorkamp, Katrin; Nielsen, Jesper Bo

    ,4,6-tribromophenyl ether (TBP-DBPE) and dechlorane plus (DDC-CO) have been detected in the same dust samples previously analysed for PBDEs and are currently being analysed in the corresponding human milk samples. [1] Stapleon H.M., Eagle S., Sjödin A., Webster T.F. (2012). Serum PBDEs in a North Carolina Toddler......, the objectives were to study whether i) the associations observed for plasma also existed for human milk, ii) the PBDE profiles in dust and milk could provide insights into the bioavailability and bioaccumulation of individual congeners, iii) NFRs were measurable in human milk, and iv) infants were exposed...... to significant amounts of NFRs via breast feeding. PBDEs were detected in all of the 40 milk samples analysed in this study. ΣPBDEtri-hepta ranged from 0.98-45.8 ng/g lw, with a median of 2.26 ng/g lw. The main congener in milk was BDE-153, accounting for 35% of ΣPBDEtri-hepta. This is much higher than in dust...

  1. Dimethyl ether (DME) as an alternative fuel

    Science.gov (United States)

    Semelsberger, Troy A.; Borup, Rodney L.; Greene, Howard L.

    With ever growing concerns on environmental pollution, energy security, and future oil supplies, the global community is seeking non-petroleum based alternative fuels, along with more advanced energy technologies (e.g., fuel cells) to increase the efficiency of energy use. The most promising alternative fuel will be the fuel that has the greatest impact on society. The major impact areas include well-to-wheel greenhouse gas emissions, non-petroleum feed stocks, well-to-wheel efficiencies, fuel versatility, infrastructure, availability, economics, and safety. Compared to some of the other leading alternative fuel candidates (i.e., methane, methanol, ethanol, and Fischer-Tropsch fuels), dimethyl ether appears to have the largest potential impact on society, and should be considered as the fuel of choice for eliminating the dependency on petroleum. DME can be used as a clean high-efficiency compression ignition fuel with reduced NO x, SO x, and particulate matter, it can be efficiently reformed to hydrogen at low temperatures, and does not have large issues with toxicity, production, infrastructure, and transportation as do various other fuels. The literature relevant to DME use is reviewed and summarized to demonstrate the viability of DME as an alternative fuel.

  2. A General and Efficient Protocol for the Synthesis of Biaryl Ethers from Aryl Silyl Ethers Using Cs2CO3

    Institute of Scientific and Technical Information of China (English)

    CUI,Sun-Liang; WANG,Yan-Guang

    2004-01-01

    @@ Biary ethers are known to be important organic compounds for their biological interests and great presence in life science industries. A number of them have consequently provide a strong incentive for synthesis, which includes the classical Ullman reaction, metal-catalyzed substitution, SN-Ar based type, intramolecular oxidative coupling and MW-assisted methods. Although the above synthetic strategies are particularly important, a method is required for the direct conversion of phenoxy silane to biaryl ethers without recourse to hydrolytic conditions.

  3. Preparation and characterization of glycidyl methacrylate organo bridges grafted mesoporous silica SBA-15 as ibuprofen and mesalamine carrier for controlled release.

    Science.gov (United States)

    Rehman, Fozia; Rahim, Abdur; Airoldi, Claudio; Volpe, Pedro L O

    2016-02-01

    Mesoporous silica SBA-15 was synthesized and functionalized with bridged polysilsesquioxane monomers obtained by the reaction of 3-aminopropyltriethoxy silane with glycidyl methacrylate in 2:1 ratio. The synthesized mesoporous silica materials were characterized by elemental analysis, infrared spectroscopy, nuclear magnetic resonance spectroscopy, nitrogen adsorption, X-ray diffraction, thermogravimetry and scanning electron microscopy. The nuclear magnetic resonance in the solid state is in agreement with the sequence of carbon distributed in the attached organic chains, as expected for organically functionalized mesoporous silica. After functionalization with organic bridges the BET surface area was reduced from 1311.80 to 494.2m(2)g(-1) and pore volume was reduced from 1.98 to 0.89cm(3)g(-1), when compared to original precursor silica. Modification of the silica surface with organic bridges resulted in high loading capacity and controlled release of ibuprofen and mesalamine in biological fluids. The Korsmeyer-Peppas model better fits the release data indicating Fickian diffusion and zero order kinetics for synthesized mesoporous silica. The drug release rate from the modified silica was slow in simulated gastric fluid, (pH1.2) where less than 10% of mesalamine and ibuprofen were released in initial 8h, while comparatively high release rates were observed in simulated intestinal (pH6.8) and simulated body fluids (pH7.2). The preferential release of mesalamine at intestinal pH suggests that the modified silica could be a simple, efficient, inexpensive and convenient carrier for colon targeted drugs, such a mesalamine and also as a controlled drug release system.

  4. Glycidyl methacrylate-co-N-vinyl-2-pyrrolidone coated polypropylene strips: Synthesis, characterization and standardization for dot-enzyme linked immunosorbent assay

    Energy Technology Data Exchange (ETDEWEB)

    Tyagi, Charu; Tomar, Lomas [Centre for Biomedical Engineering, Indian Institute of Technology, Delhi 110016 (India); Singh, Harpal [Centre for Biomedical Engineering, Indian Institute of Technology, Delhi 110016 (India)], E-mail: tyagicharu11@rediffmail.com

    2009-01-26

    Glycidyl methacrylate and N-vinyl-2-pyrrolidone (GMA-co-NVP) copolymers with various GMA:NVP ratios were synthesized by solution polymerization technique in toluene using 2,2'-azobisisobutyronitrile (AIBN) as free radical initiator and dip coated onto polypropylene strips. The copolymer composition in polymeric coatings was confirmed by proton NMR spectroscopy. Various techniques like FTIR, SEM and contact angle were used for surface characterization of the polymer coatings. These polymer coated strips were evaluated and standardized for their application in dot-ELISA in two steps. In first step, specificity, sensitivity and reproducibility of the assay on developed polymer coated strips was evaluated through a model system using rabbit anti-goat IgG, goat anti-rabbit IgG and goat anti-rabbit IgG HRP (horseradish peroxidase)-conjugate. Polymer coating with GMA-NVP mol% ratio of 78:22 was able to detect rabbit anti-goat IgG antibody at a concentration as low as 2 ng mL{sup -1} with 1% BSA as blocking agent using antispecies IgG peroxidase conjugate diluted 1500 times. In the second step, the sensitivity and specificity of the developed system was established with human blood and finally used to identify the source of mosquito blood meal which is an important parameter in epidemiological studies, particularly in determining the role of mosquito in malaria transmission. The time duration of standardized assay with developed polymer coated strips was cut down to one hour compared to the 3-4 h required in usual dot-ELISA.

  5. Molecular Design of Crown Ethers.22.Synthesis of Benzocrown Ether Derivatives and Their Solvent Extraction with Univalent/Bivalent Metal Picrates

    Institute of Scientific and Technical Information of China (English)

    YANG,Ying-Wei(杨英威); LI,Chun-Ju(李春举); ZHANG,Heng-Yi(张衡益); LIU,Yu(刘育)

    2004-01-01

    Three novel benzocrown ether derivatives have been synthesized and their cation binding behavior with uniand bi-valent metal ions was evaluated by the solvent extraction of aqueous metal picrates. The obtained results indicate that the size-fit of crown ether and metal cation, and electron effect of the side arm attached to benzocrown ethers affect their cation binding ability and selectivity.

  6. Molecular detection and in vitro antioxidant activity of S-allyl-L-cysteine (SAC) extracted from Allium sativum.

    Science.gov (United States)

    Sun, Y-E; Wang, W-D

    2016-06-30

    It is well known that Allium sativum has potential applications to clinical treatment of various cancers due to its remarkable ability in eliminating free radicals and increasing metabolism. An allyl-substituted cysteine derivative - S-allyl-L-cysteine (SAC) was separated and identified from Allium sativum. The extracted SAC was reacted with 1-pyrenemethanol to obtain pyrene-labelled SAC (Py-SAC) to give SAC fluorescence properties. Molecular detection of Py-SAC was conducted by steady-state fluorescence spectroscopy and time-resolved fluorescence method to quantitatively measure concentrations of Py-SAC solutions. The ability of removing 1,1-diphenyl-2-picrylhydrazyl (DPPH) and hydroxyl radical using Py-SAC was determined through oxygen radical absorbance capacity (ORAC). Results showed the activity of Py-SAC and Vitamin C (VC) with ORAC as index, the concentrations of Py-SAC and VC were 58.43 mg/L and 5.72 mg/L respectively to scavenge DPPH, and 8.16 mg/L and 1.67 mg/L to scavenge •OH respectively. Compared with VC, the clearance rates of Py-SAC to scavenge DPPH were much higher, Py-SAC could inhibit hydroxyl radical. The ability of removing radical showed a dose-dependent relationship within the scope of the drug concentration.

  7. The - - and Submm-Wave Spectrum of Allyl Isocyanide and Radioastronomical Observations in Orion KL and the Primos Line Survey

    Science.gov (United States)

    Haykal, I.; Motiyenko, R. A.; Margules, L.; Huet, T. R.; Ecija, P.; Cocinero, E. J.; Basterretxea, F.; Fernandez, J. A.; Castano, F.; Tercero, B.; Cernicharo, J.; Lesarri, A.; Guillemin, J. C.

    2013-06-01

    Last year we presented the first rotational analysis of the ground state of the two conformers of allyl isocyanide from 4 GHz to 905 GHz. The analysis of the rotational spectrum of the cis conformer of allyl isocyanide was extended. We resolved Coriolis interactions of a and b types between the excited vibrational states ν_1=1 and ν_2=1, calculated to be at 156 cm^{-1} (A^{'}) and 167 cm^{-1} (A^{''}) respectively (MP2/aug-cc-pvtz), from 150 GHz to 600 GHz. Strong perturbations were observed in the 150-310 GHz range for low values of the quantum number K_a starting from K_a = 0, 1. The anharmonicities appeared as well at higher frequencies for larger quantum numbers. The two modes were fitted together with the SPFIT/SPCAT suite of programs and a set of Coriolis parameters was accurately determined. The fit contains more than 3000 lines up to J = 99 and K_a = 12 for both modes. We did not detect these species neither in the IRAM 30-m line survey of Orion KL nor in the PRIMOS survey towards SgrB2. Nevertheless, we provided upper limits to their column density in Orion KL. This work was supported by the CNES and the Action sur Projets de l'INSU, PCMI. I. Haykal et al. manuscript in preparation H. Pickett J. Mol. Spec.{148}, 371-377, 1991.

  8. UV-induced Self-initiated Graft Polymerization of Acrylamide onto Poly(ether ether ketone)

    Institute of Scientific and Technical Information of China (English)

    CHEN Rui-chao; SUN Hui; LI Ang; XU Guo-zhi

    2012-01-01

    Photo-grafting of hydrophilic monomer was used to enhance the hydrophilicity of poly(ether ether ketone)(PEEK) with the aim of extending its applications to biological fields.PEEK sheets were surface modified by grafting of acrylamide(AAm) with ultraviolet(UV) irradiation in the presence or absence of benzophenone(BP).The effects of BP,irradiation time and monomer concentration on the surface wettability of PEEK were investigated.Characterization of modified PEEK using scanning electron microscopy(SEM),energy-disperse spectrometer(EDS) and water contact angle measurements shows that AAm was successfully grafted on PEEK surface both in presence and absence of BP.With the increase in irradiation time and monomer concentration,contact angles decrease to as low as 30°,demonstrating a significant improvement of surface hydrophilicity.In agreement with the decrease in contact angle,under identical conditions,the nitrogen concentration increases,suggesting the increase in grafting degree of the grafting polymerization.This investigation demonstrates a self-initiation of PEEK due to its BP-like structure in the backbone of the polymer.Though the graft polymerization proceeds more readily in the presence of BP,the self-initiated graft polymerization is clearly observed.

  9. Molecular sieve/sulfonated poly(ether ketone ether sulfone) composite membrane as proton exchange membrane

    Science.gov (United States)

    Changkhamchom, Sairung; Sirivat, Anuvat

    2012-02-01

    A proton exchange membrane (PEM) is an electrolyte membrane used in both polymer electrolyte membrane fuel cells (PEMFC) and direct methanol fuel cells (DMFCs). Currently, PEMs typically used for PEMFCs are mainly the commercially available Nafion^ membranes, which is high cost and loss of proton conductivity at elevated temperature. In this work, the Sulfonated poly(ether ketone ether sulfone), (S-PEKES), was synthesized by the nucleophilic aromatic substitution polycondensation between bisphenol S and 4,4'-dichlorobenzophenone, and followed by the sulfonation reaction with concentrated sulfuric acid. The molecular sieve was added in the S-PEKES matrix at various ratios to form composite membranes to be the candidate for PEM. Properties of both pure sulfonated polymer and composite membranes were compared with the commercial Nafion^ 117 membrane from Dupont. S-PEKES membranes cast from these materials were evaluated as a polymer electrolyte membrane for direct methanol fuel cells. The main properties investigated were the proton conductivity, methanol permeability, thermal, chemical, oxidative, and mechanical stabilities by using a LCR meter, Gas Chromatography, Thermogravimetric Analysis, Fourier Transform Infrared Spectroscopy, Fenton's reagent, and Universal Testing Machine. The addition of the molecular sieve helped to increase both the proton conductivity and the methanol stability. These composite membranes are shown as to be potential candidates for use as a Proton Exchange Membrane (PEM).

  10. The Effects of Sulfonated Poly(ether ether ketone Ion Exchange Preparation Conditions on Membrane Properties

    Directory of Open Access Journals (Sweden)

    Rebecca S. L. Yee

    2013-08-01

    Full Text Available A low cost cation exchange membrane to be used in a specific bioelectrochemical system has been developed using poly(ether ether ketone (PEEK. This material is presented as an alternative to current commercial ion exchange membranes that have been primarily designed for fuel cell applications. To increase the hydrophilicity and ion transport of the PEEK material, charged groups are introduced through sulfonation. The effect of sulfonation and casting conditions on membrane performance has been systematically determined by producing a series of membranes synthesized over an array of reaction and casting conditions. Optimal reaction and casting conditions for producing SPEEK ion exchange membranes with appropriate performance characteristics have been established by this uniquely systematic experimental series. Membrane materials were characterized by ion exchange capacity, water uptake, swelling, potential difference and NMR analysis. Testing this extensive membranes series established that the most appropriate sulfonation conditions were 60 °C for 6 h. For mechanical stability and ease of handling, SPEEK membranes cast from solvent casting concentrations of 15%–25% with a resulting thickness of 30–50 µm were also found to be most suitable from the series of tested casting conditions. Drying conditions did not have any apparent impact on the measured parameters in this study. The conductivity of SPEEK membranes was found to be in the range of 10−3 S cm−1, which is suitable for use as a low cost membrane in the intended bioelectrochemical systems.

  11. Inhibition of bladder cancer cell proliferation by allyl isothiocyanate (mustard essential oil)

    Energy Technology Data Exchange (ETDEWEB)

    Sávio, André Luiz Ventura, E-mail: savio.alv@gmail.com [UNESP – Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, Departamento de Patologia, Botucatu, SP (Brazil); Nicioli da Silva, Glenda [UFOP – Universidade Federal de Ouro Preto, Escola de Farmácia, Departamento de Análises Clínicas, Ouro Preto, MG (Brazil); Salvadori, Daisy Maria Fávero [UNESP – Universidade Estadual Paulista, Faculdade de Medicina de Botucatu, Departamento de Patologia, Botucatu, SP (Brazil)

    2015-01-15

    Highlights: • AITC inhibits mutant and wild-type TP53 cell proliferation. • Morphological changes and cells debris were observed after AITC treatment in both cells. • BAX and BCL2 expression modulation was observed in wild-type TP53 cells. • BCL2, BAX and ANLN increased and S100P decreased expression was detected in mutated TP53 cells. • AITC effects in gene modulation are dependent TP53 gene status. - Abstract: Natural compounds hold great promise for combating antibiotic resistance, the failure to control some diseases, the emergence of new diseases and the toxicity of some contemporary medical products. Allyl isothiocyanate (AITC), which is abundant in cruciferous vegetables and mustard seeds and is commonly referred to as mustard essential oil, exhibits promising antineoplastic activity against bladder cancer, although its mechanism of action is not fully understood. Therefore, the aim of this study was to investigate the effects of AITC activity on bladder cancer cell lines carrying a wild type (wt; RT4) or mutated (T24) TP53 gene. Morphological changes, cell cycle kinetics and CDK1, SMAD4, BAX, BCL2, ANLN and S100P gene expression were evaluated. In both cell lines, treatment with AITC inhibited cell proliferation (at 62.5, 72.5, 82.5 and 92.5 μM AITC) and induced morphological changes, including scattered and elongated cells and cellular debris. Gene expression profiles revealed increased S100P and BAX and decreased BCL2 expression in RT4 cells following AITC treatment. T24 cells displayed increased BCL2, BAX and ANLN and decreased S100P expression. No changes in SMAD4 and CDK1 expression were observed in either cell line. In conclusion, AITC inhibits cell proliferation independent of TP53 status. However, the mechanism of action of AITC differed in the two cell lines; in RT4 cells, it mainly acted via the classical BAX/BCL2 pathway, while in T24 cells, AITC modulated the activities of ANLN (related to cytokinesis) and S100P. These data confirm

  12. EtherCAT bus application in CNC system%EtherCAT总线在数控系统中的应用

    Institute of Scientific and Technical Information of China (English)

    丁琳娜

    2012-01-01

    文章首先对应用EtherCAT的数控系统相关知识进行介绍,然后针对引入EtherCAT的数控系统的实现,提出了一种基于EtherCAT技术的实时通信及PC控制的可行系统方案,构建了EtherCAT主从站网络结构,并详细分析了EtherCAT主站与从站的软硬件设计.

  13. Biodegradation of ethyl t-butyl ether (ETBE), methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) by Gordonia terrae.

    Science.gov (United States)

    Hernandez-Perez, G; Fayolle, F; Vandecasteele, J P

    2001-01-01

    Gordonia terrae strain IFP 2001 was selected from activated sludge for its capacity to grow on ethyl t-butyl ether (ETBE) as sole carbon and energy source. ETBE was stoichiometrically degraded to t-butyl alcohol (TBA) and the activity was inducible. A constitutive strain, G. terrae IFP 2007, derived from strain IFP 2001, was also selected. Methyl t-butyl ether (MTBE) and t-amyl methyl ether (TAME) were not used as carbon and energy sources by the two strains, but cometabolic degradation of MTBE and TAME was demonstrated, to TBA and t-amyl alcohol (TAA) respectively, in the presence of a carbon source such as ethanol. No two-carbon compound was detected during growth on ETBE, but formate was produced during cometabolic degradation of MTBE or TAME. A monooxygenase was involved in the degradation of ethers, because no degradation of ETBE was observed under anaerobic conditions and the presence of a cytochrome P-450 was demonstrated in G. terrae IFP 2001 after induction by cultivation on ETBE.

  14. Exciton Coupling in Circular Dichroic Spectroscopy as a Tool for Establishing the Absolute Configuration of alpha,beta-Unsaturated Esters of Allylic Alcohols

    DEFF Research Database (Denmark)

    Lauridsen, A.; Cornett, Claus; Christensen, S. B.

    1991-01-01

    alpha-beta-Unsaturated esters of allylic alcohols have been shown to exhibit exciton coupling by circular dichroic spectroscopy. This coupling permits the establishment of the absolute configuration. The method was used to prove the absolute configuration at C-2 of archangelolide. Detailed NMR sp...

  15. Nickel-catalyzed enantioselective hydrovinylation of silyl-protected allylic alcohols:An efficient access to homoallylic alcohols with a chiral quaternary center

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    Asymmetric hydrovinylation of silyl-protected allylic alcohols catalyzed by nickel complexes of chiral spiro phosphoramidite ligands was developed.A series of homoallylic alcohols with a chiral quaternary center were produced in high yields(up to 97%) and high enantioselectivities(up to 95% ee).The reaction provides an efficient method for preparing bifunctional compounds with a chiral quaternary carbon center.

  16. γ‐ and δ-Lactams through Palladium-Catalyzed Intramolecular Allylic Alkylation: Enantioselective Synthesis, NMR Investigation, and DFT Rationalization

    DEFF Research Database (Denmark)

    Bantreil, Xavier; Prestat, Guillaume; Moreno, Aitor;

    2011-01-01

    the cyclization reactions to take place in up to 94:6 enantiomeric ratio. A model Pd-allyl complex has been prepared and studied through NMR spectroscopic analysis, which provided insight into the processes responsible for the observed enantiomeric ratios. DFT studies were used to characterize the diastereomeric...

  17. Crystal structures of bis[2-(diphenylphosphinothioylphenyl] ether and bis{2-[diphenyl(selanylidenephosphanyl]phenyl} ether

    Directory of Open Access Journals (Sweden)

    Daron E. Janzen

    2014-12-01

    Full Text Available The title compounds, C36H28OP2S2, (1, and C36H28OP2Se2, (2, exhibit remarkably similar structures although they are not isomorphous. The whole molecule of compound (2 is generated by twofold symmetry, with the ether O atom located on the twofold axis. Both compounds have intramolecular π–π interactions between terminal phenyl rings with centroid–centroid distances of 3.6214 (16 and 3.8027 (14 Å in (1 and (2, respectively. In the crystal of (1, short C—H...S hydrogen bonds link the molecules, forming chains along [001], while in (2 there are no analogous C—H...Se interactions present.

  18. Spontaneous Generation of Chirality in Simple Diaryl Ethers.

    Science.gov (United States)

    Lennartson, Anders; Hedström, Anna; Håkansson, Mikael

    2015-07-01

    We studied the spontaneous formation of chiral crystals of four diaryl ethers, 3-phenoxybenzaldehyde, 1; 1,3-dimethyl-2-phenoxybenzene, 2; di(4-aminophenyl) ether, 3; and di(p-tolyl) ether, 4. Compounds 1, 3, and 4 form conformationally chiral molecules in the solid state, while the chirality of 2 arises from the formation of supramolecular helices. Compound 1 is a liquid at ambient temperature, but 2-4 are crystalline, and solid-state CD-spectroscopy showed that they could be obtained as optically active bulk samples. It should be noted that the optical activity arise upon crystallization, and no optically active precursors were used. Indeed, even commercial samples of 3 and 4 were found to be optically active, giving evidence for the ease at which total spontaneous resolution may occur in certain systems.

  19. Influence of Cellulose Ethers on Hydration Products of Portland Cement

    Institute of Scientific and Technical Information of China (English)

    MA Baoguo; OU Zhihua; JIAN Shouwei; XU Rulin

    2011-01-01

    Cellulose ethers are widely used to mortar formulations, and it is significant to understand the interaction between cellulose ethers and cement pastes. FT-IR spectra, thermal analysis and SEM are used to investigate hydration products in the cement pastes modified by HEMC and HPMC in this article. The results show that the hydration products in modified cement pastes were finally identical with those in the unmodified cement paste, but the major hydration products, such as CH (calcium hydroxide), ettringite and C-S-H, appeared later in the modified cement pastes than in the unmodified cement paste. The cellulose ethers decrease the outer products and increase inner products of C-S-H gels. Compared to unmodified cement pastes, no new products are found in the modified cement pastes in the present experiment. The HEMC and HPMC investigation shows almost the same influence on the hydration products of Portland cement.

  20. Synthesis and characterization of novel cellulose ether sulfates.

    Science.gov (United States)

    Rohowsky, Juta; Heise, Katja; Fischer, Steffen; Hettrich, Kay

    2016-05-20

    The synthesis and characterization of novel cellulose sulfate derivatives was reported. Various cellulose ethers were prepared in a homogeneous reaction with common sulfating agents. The received product possess different properties in dependence on the reaction conditions like sulfating agent, solvent, reaction time and reaction temperature. The cellulose ether sulfates are all soluble in water, they rheological behavior could be determined by viscosity measurements and the determination of the sulfur content by elemental analysis lead to a resulting degree of substitution ascribed to sulfate groups (DSSul) of the product. A wide range of products from DSSul 0.1 to DSSul 2.7 will be obtained. Furthermore the cellulose sulfate ethers could be characterized by Raman spectroscopy.

  1. Highly efficient palladium-catalyzed hydrostannation of ethyl ethynyl ether.

    Science.gov (United States)

    Andrews, Ian P; Kwon, Ohyun

    2008-12-08

    The palladium-catalyzed hydrostannation of acetylenes is widely exploited in organic synthesis as a means of forming vinyl stannanes for use in palladium-catalyzed cross-coupling reactions. Application of this methodology to ethyl ethynyl ether results in an enol ether that is challenging to isolate from the crude reaction mixture because of incompatibility with typical silica gel chromatography. Reported here is a highly efficient procedure for the palladium-catalyzed hydrostannation of ethyl ethynyl ether using 0.1% palladium(0) catalyst and 1.0 equiv of tributyltin hydride. The product obtained is a mixture of regioisomers that can be carried forward with exclusive reaction of the beta-isomer. This method is highly reproducible; relative to previously reported procedures, it is more economical and involves a more facile purification procedure.

  2. Acid Catalyzed Condensation of Phenylethanal Enol or Thiol Enol Ether to 2-Phenylnaphthalene

    Institute of Scientific and Technical Information of China (English)

    CHANG, Yu-An

    2007-01-01

    Treatment of enol ether or thiol enol ether of phenylethanals with sulfuric or polyphosphoric acid in toluene or xylene gave 2-phenylnaphthalene in good yield. More importantly, a one-pot reaction has been developed.

  3. EtherCAT被纳入EUROMAP协议规范

    Institute of Scientific and Technical Information of China (English)

    2010-01-01

    7月10日,欧洲的塑料和橡胶机械制造商协会批准在其应用中采用EtherCAT技术:EtherCAT被纳入EUROMAP75协议规范,成为其底层的通讯技术。在该协议规范的第三部分,描述有该实时以太网系统的实施。

  4. EtherCAT以太网现场总线

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    EtherCAT为现场总线系统树立了新的性能标准。它具备灵活的网络拓扑结构,系统配置简单,和现场总线系统一样操作直观简便。另外,由于EtherCAT实现成本低廉,因此使系统得以在过去无法应用现场总线网络的应用场合中选用现场总线。

  5. ELMO驱动器获得EtherCAT审批

    Institute of Scientific and Technical Information of China (English)

    2012-01-01

    ELMO公司宣布其Gold伺服驱动器已通过严格的EtherCAT一致性测试,使得ELMO成为仅有的通过测试的六家公司之一。ELMO投入了大量的时间、财力和技术来遵守行业协议,如EtherCAT协议,以及诸如Safety和EMC这样的标准。ELMO认为,遵守协议是强制性的,以确保任何工业设备的可靠运行。

  6. Environmental analysis of higher brominated diphenyl ethers and decabromodiphenyl ethane.

    Science.gov (United States)

    Kierkegaard, Amelie; Sellström, Ulla; McLachlan, Michael S

    2009-01-16

    Methods for environmental analysis of higher brominated diphenyl ethers (PBDEs), in particular decabromodiphenyl ether (BDE209), and the recently discovered environmental contaminant decabromodiphenyl ethane (deBDethane) are reviewed. The extensive literature on analysis of BDE209 has identified several critical issues, including contamination of the sample, degradation of the analyte during sample preparation and GC analysis, and the selection of appropriate detection methods and surrogate standards. The limited experience with the analysis of deBDethane suggests that there are many commonalities with BDE209. The experience garnered from the analysis of BDE209 over the last 15 years will greatly facilitate progress in the analysis of deBDethane.

  7. IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) ...

    Science.gov (United States)

    The IRIS Toxicological Review of Ethyl Tertiary Butyl Ether (ETBE) was released for external peer review in April 2017. EPA’s Science Advisory Board’s (SAB) Chemical Assessment Advisory Committee (CAAC) will conduct a peer review of the scientific basis supporting the ETBE assessment and release a final report of their review. Information regarding the peer review can be found on the SAB website. EPA is conducting an Integrated Risk Information System (IRIS) health assessment for Ethyl Tertiary Butyl Ether (ETBE). The outcome of this project is a Toxicological Review and IRIS Summary for ETBE that will be entered into the IRIS database.

  8. Improved synthesis of cyclic tertiary allylic alcohols by asymmetric 1,2-addition of AlMe3 to enones.

    Science.gov (United States)

    Kolb, Andreas; Zuo, Wei; Siewert, Jürgen; Harms, Klaus; von Zezschwitz, Paultheo

    2013-11-25

    The development of an improved protocol for the enantioselective Rh(I) /binap-catalysed 1,2-addition of AlMe3 to cyclic enones is reported. (31)P NMR analysis of the reaction revealed that the catalyst in its resting state is a chloride-bridged dimer. This insight led to the use of AgBF4 as an additive for in situ activation of the dimeric precatalyst. Thus, the catalyst loading can now be reduced to only 1 mol% with respect to rhodium. Various 5-7-membered cyclic enones can be transformed into tertiary allylic alcohols with excellent levels of enantioselectivity and high yields. The obtained products are versatile synthetic building blocks, shown by a highly enantioselective formal total synthesis of the pheromone (-)-frontalin as well as formation of a bicyclic lactone that has the core structure of the natural flavour component "wine lactone".

  9. Practical and Broadly Applicable Catalytic Enantioselective Additions of Allyl-B(pin) Compounds to Ketones and α-Ketoesters.

    Science.gov (United States)

    Robbins, Daniel W; Lee, KyungA; Silverio, Daniel L; Volkov, Alexey; Torker, Sebastian; Hoveyda, Amir H

    2016-08-01

    A set of broadly applicable methods for efficient catalytic additions of easy-to-handle allyl-B(pin) (pin=pinacolato) compounds to ketones and acyclic α-ketoesters was developed. Accordingly, a large array of tertiary alcohols can be obtained in 60 to >98 % yield and up to 99:1 enantiomeric ratio. At the heart of this development is rational alteration of the structures of the small-molecule aminophenol-based catalysts. Notably, with ketones, increasing the size of a catalyst moiety (tBu to SiPh3 ) results in much higher enantioselectivity. With α-ketoesters, on the other hand, not only does the opposite hold true, since Me substitution leads to substantially higher enantioselectivity, but the sense of the selectivity is reversed as well.

  10. Isolation and recovery of cellulose from waste nylon/cotton blended fabrics by 1-allyl-3-methylimidazolium chloride.

    Science.gov (United States)

    Lv, Fangbing; Wang, Chaoxia; Zhu, Ping; Zhang, Chuanjie

    2015-06-05

    Development of a simple process for separating cellulose and nylon 6 from their blended fabrics is indispensable for recycling of waste mixed fabrics. An efficient procedure of dissolution of the fabrics in an ionic liquid 1-allyl-3-methylimidazolium chloride ([AMIM]Cl) and subsequent filtration separation has been demonstrated. Effects of treatment temperature, time and waste fabrics ratio on the recovery rates were investigated. SEM images showed that the cotton cellulose dissolved in [AMIM]Cl while the nylon 6 fibers remained. The FTIR spectrum of regenerated cellulose (RC) was similar with that of virgin cotton fibers, which verified that no other chemical reaction occurred besides breakage of hydrogen bonds during the processes of dissolution and separation. TGA curves indicated that the regenerated cellulose possessed a reduced thermal stability and was effectively removed from waste nylon/cotton blended fabrics (WNCFs). WNCFs were sufficiently reclaimed with high recovery rate of both regenerated cellulose films and nylon 6 fibers.

  11. Synthesis, spectroscopic characterization and solution behavior of new tin tetrachloride adducts with γ-keto allyl phosphonates

    Science.gov (United States)

    Elleuch, Haitham; Sanhoury, M. A. K.; Rezgui, F.

    2017-01-01

    Four new octahedral complexes of the type [SnCl4L2] (L = γ-keto allyl phosphonate) (1-4) were prepared and characterized by multinuclear (1H, 13C, 31P and 119Sn) NMR, IR spectroscopy and elemental analysis. The NMR data show, as expected, that these complexes exist in solution as mixtures of cis and trans isomers. More importantly, the solution structure was confirmed by 119Sn NMR spectra which show two triplets corresponding to the two isomers. In addition, the solution behavior of these complexes in the presence of excess ligand was studied by variable temperature NMR using the coalescence temperature method. The metal-ligand exchange activation energies were therefore determined and found to be in the range 57-60 kJ/mol. The effect of remote substituents on the metal-ligand interaction was studied and compared with closely related tin-phosphoryl complexes.

  12. Crystal structure of (E-4-(acetoxyimino-N-allyl-3-isopropyl-2,6-diphenylpiperidine-1-carbothioamide

    Directory of Open Access Journals (Sweden)

    T. Mohandas

    2015-08-01

    Full Text Available The title compound, C26H31N3O2S, crystallizes with two molecules (A and B in the asymmetric unit. In each case, the piperidine ring exists in a twist-boat conformation. The dihedral angle between the phenyl rings is 46.16 (12° in molecule A and 44.95 (12° in molecule B. In both molecules, the allyl side chain is disordered over two orientations in a 0.649 (9:0.351 (9 ratio for molecule A and 0.826 (10:0.174 (10 ratio for molecule B. In the crystal, neither molecule forms a hydrogen bond from its N—H group, presumably due to steric hindrance. A+A and B+B inversion dimers are formed, linked by pairs of weak C—H...O hydrogen bonds enclosing R22(22 ring motifs.

  13. Crystal structure of N-(1-allyl-3-chloro-4-ethoxy-1H-indazol-5-yl-4-methoxybenzenesulfonamide

    Directory of Open Access Journals (Sweden)

    Hakima Chicha

    2014-09-01

    Full Text Available In the title compound, C19H20ClN3O4S, the benzene ring is inclined to the indazole ring system (r.m.s. deviation = 0.014 Å by 65.07 (8°. The allyl and ethoxy groups are almost normal to the indazole ring, as indicated by the respective torsion angles [N—N—C—C = 111.6 (2 and C—C—O—C = −88.1 (2°]. In the crystal, molecules are connected by N—H...N hydrogen bonds, forming helical chains propagating along [010]. The chains are linked by C—H...O hydrogen bonds, forming a three-dimensional network.

  14. Crystal structure of (Z-3-allyl-5-(4-chlorobenzylidene-2-sulfanylidene-1,3-thiazolidin-4-one

    Directory of Open Access Journals (Sweden)

    Rahhal El Ajlaoui

    2015-12-01

    Full Text Available In the title compound, C13H10ClNOS2, the dihedral angle between the rhodanine (r.m.s. deviation = 0.008 Å and 4-chlorobenzylidene rings is 1.79 (11°. The allyl group attached to the N atom, which lies almost perpendicular to the rhodanine ring, is disordered over two orientations in a 0.519 (13:0.481 (13 ratio. A short intramolecular C—H...S interaction closes an S(6 ring. In the crystal, molecules are linked by π–π stacking interactions [centroid–centroid separation = 3.600 (15 Å], generating inversion dimers.

  15. Two Reaction Mechanisms via Iminium Ion Intermediates: The Different Reactivities of Diphenylprolinol Silyl Ether and Trifluoromethyl-Substituted Diarylprolinol Silyl Ether.

    Science.gov (United States)

    Gotoh, Hiroaki; Uchimaru, Tadafumi; Hayashi, Yujiro

    2015-08-24

    The reactions of α,β-unsaturated aldehydes with cyclopentadiene in the presence of diarylprolinol silyl ethers as catalyst proceed via iminium cations as intermediates, and can be divided into two types; one involving a Michael-type reaction (type A) and one involving a cycloaddition (type B). Diphenylprolinol silyl ethers and trifluoromethyl-substituted diarylprolinol silyl ethers, which are widely used proline-type organocatalysts, have been investigated in this study. As the LUMO of the iminium ion derived from trifluoromethyl-substituted diarylprolinol silyl ether is lower in energy than that derived from diphenylprolinol silyl ether, as supported by ab initio calculations, the trifluoromethyl-substituted catalyst is more reactive in a type B reaction. The iminium ion from an α,β-unsaturated aldehyde is generated more quickly with diphenylprolinol silyl ether than with the trifluoromethyl-substituted diarylprolinol silyl ether. When the generation of the iminium ion is the rate-determining step, the diphenylprolinol silyl ether catalyst is the more reactive. Because acid accelerates the generation of iminium ions and reduces the generation of anionic nucleophiles in the Michael-type reaction (type A), it is necessary to select the appropriate acid for specific reactions. In general, diphenylprolinol silyl ether is a superior catalyst for type A reactions, whereas the trifluoromethyl-substituted diarylprolinol silyl ether catalyst is preferred for type B reactions.

  16. Sulfoalkyl ether-alkyl ether cyclodextrin derivatives, their synthesis, NMR characterization, and binding of 6alpha-methylprednisolone.

    Science.gov (United States)

    Tongiani, Serena; Velde, David Vander; Ozeki, Tetsuya; Stella, Valentino J

    2005-11-01

    The objective of this study is to see if random alkyl ethers of various sulfoalkyl ether cyclodextrins can be synthesized and characterized. The purpose of the alkylation was to test the hypothesis that an increase in the "height" of a cyclodextrins cavity would help in the binding/complexation of larger more structurally complex molecules. The synthesis of new cyclodextrin derivatives comprising a mixture of sulfoalkyl ether and alkyl ether substituents on the same cyclodextrin ring was performed in aqueous alkaline solutions using various sultones and alkylsulfates. The method presented provided an easy and efficient way to modify cyclodextrins avoiding the use of organic solvents and high quantities of alkylating agents and could be carried out in either a two step or "one pot" single step process. Purification was by neutralization followed by ultrafiltration. The derivatives were characterized by 1D, ((1)H and (13)C), and a 2D NMR technique (HMQC, Heteronuclear Multiple Quantum Coherence). The combination of these techniques allowed an analysis of the degree of substitution and the site of substitution on the cyclodextrin (CD) nucleus. For both beta- and gamma-CD, sulfoakylation was preferred on the 2 > 3 > 6 hydroxyls while alkylation was preferred 6 > 2 > 3. Due to the simultaneous presence of short alkyl ether chains and negatively charged sulfoalkyl ether chains, these mixed water-soluble cyclodextrin derivatives, especially those of gamma-cyclodextrin, should be able to bind more complex drugs. The improved binding capacity of these new modified CDs with the model drug 6alpha-methylprednisolone is reported.

  17. 21 CFR 177.1970 - Vinyl chloride-lauryl vinyl ether copolymers.

    Science.gov (United States)

    2010-04-01

    ... 21 Food and Drugs 3 2010-04-01 2009-04-01 true Vinyl chloride-lauryl vinyl ether copolymers. 177... for Use as Basic Components of Single and Repeated Use Food Contact Surfaces § 177.1970 Vinyl chloride-lauryl vinyl ether copolymers. The vinyl chloride-lauryl vinyl ether copolymers identified in...

  18. EtherCAT技术协会宣布成立中国代表处

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    在北京一年一度的自动化展会FA/PA2007的高峰论坛上。EtherCAT技术协会(EtherCAT Technology Group,ETG)主席Martin Rostan先生宣布了EtherCAT技术协会中国代表处的成立。

  19. 40 CFR 721.10017 - Amine terminated bisphenol A diglycidyl ether polymer (generic).

    Science.gov (United States)

    2010-07-01

    ... diglycidyl ether polymer (generic). 721.10017 Section 721.10017 Protection of Environment ENVIRONMENTAL... ether polymer (generic). (a) Chemical substances and significant new uses subject to reporting. (1) The chemical substances identified generically as amine terminated bisphenol A diglycidyl ether polymer (PMNs...

  20. Synthesis and Properties of New-type Troponoid Dithio-Crown Ethers

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Condensation of 3,7-dichloromethyl-5-isopropyl-2-methoxytropone 4 with bis (mer-captoethyl) ether 5a and mono, di, and tri-ethylene glycol bis(mercaptoethyl) ethers 5b-5d gave troponoid-annexed dithiocrown ethers 6a-6d. Compounds 6a-6d have selective and reversible mercury salt capturing ability.

  1. Research of EtherCAT master based on Linux-RTAI%基于Linux-RTAI的EtherCAT主站研究

    Institute of Scientific and Technical Information of China (English)

    张少勋; 郗晓田

    2013-01-01

    工业以太网EtherCAT具有很好的实时性.为了进一步提高工业控制的实时性,本文创新性提出了基于Linux-RTAI的EtherCAT主站新架构;同时,详细阐述了其工作原理.最后在凌动D520工控机上进行测试,实验结果表明该架构具有极佳的实时性,非常适用于高实时控制场合.

  2. SULPHONATED POLY ETHER ETHER KETONE/POLYVINYL ALCOHOL/PHOSPHOTUNGSTIC ACID COMPOSITE MEMBRANES FOR PEM FUEL CELLS

    Institute of Scientific and Technical Information of China (English)

    S. Guhan; N.Arun Kumar; D.Sangeetha

    2009-01-01

    Composite membranes with polyvinyl alcohol (PVA),sulphonated poly ether ether ketone (SPEEK) and phosphotungstic acid (PWA) were prepared using solvent casting method.The proton conductivities of such membranes were found to be in the order of 10-3 S/cm in the fully hydrated condition at room temperature as measured by impedance spectroscopy.The crystalline properties were studied by X-ray diffraction analysis.The thermal properties were determined by TGA and DSC techniques.The tensile strength and percentage elongation were obtained from UTM studies.Water and methanol uptake of these membranes were studied.

  3. Determination of bisphenol diglycidyl ether residues in canned foodstuffs by high performance liquid chromatographytandem mass spectrometry%高效液相色谱-串联质谱法同时测定肉类罐头中双酚-二缩水甘油醚

    Institute of Scientific and Technical Information of China (English)

    赵晓亚; 付晓芳; 王鹏; 李晶; 胡小钟

    2012-01-01

    An accurate quantitative determination and confirmative method for bisphenol diglycidyl ether residues, bisphenol A diglycidyl ether ( BADGE) , bisphenol F diglycidyl ether (BFDGE), bisphenol A (2,3-dihydroxypropyl)glycidyl ether (BADGE -H2O) , bisphenol A bis (2,3-dihydroxypropyl) ether (BADGE -2H2O) , bisphenol A (3-chloro-2-hydroxy propyl) (2,3-dihydroxypropyl) ether (BADGE -H2O -HC1) , bisphenol A (3-chloro-2-hydroxypropyl)glycidyl ether (BADGE -HC1) , bisphenol A bis(3-chloro-2-hydroxypropyl) ether (BADGE -2HC1) , bisphenol F bis ( 2, 3-dihydroxypropyl) ether (BFDGE -2H2O), bisphenol F bis ( 3-chloro-2-hydroxypropyl) ether ( BFDGE -2HC1) in canned foodstuffs by high performance liquid chroma-tography-tandem mass spectrometry ( HPLC-MS/MS) has been established. The sample was extracted with teri-butylmethyl ether and the extract was cleaned-up and concentrated on a Waters Oasis HLB column. The target compounds were analyzed by HPLC-MS/MS on a C18column by the gradient elution with methanol and 5 mmol/L ammonium acetate containing 0. 1 % formic acid in a multiple reaction monitoring (MRM) scan mode. External matrix standard solutions were used for the quantitative determination and the calibration curves showed good linearity in the concentration range of 10. 0 -2 000. 0 μg/L for the nine target compounds. The limits of quantification of the nine compounds were 10.0 jxg/kg (S/N≥10). The average recoveries of the nine compounds ranged from 79. 6% to 100. 9% at the spiked levels of 10. 0, 100. 0, 1 000. 0 μg/kg with the relative standard deviations (RSDs) of 6. 3% - 12. 1%. The method is sensitive, accurate, and suitable for the rapid determination of bisphenol diglycidyl ether residues in canned foodstuffs.%建立了同时测定肉类罐头中双酚A-二缩水甘油醚(BADGE)、双酚F-二缩水甘油醚(BFDGE)及其衍生物双酚A-(2,3-二羟丙基)甘油醚(BADGE·H2O)、双酚A-双(2,3-二羟丙基)醚(BADGE·2H2O)、双酚A-(3-氯-2-羟丙基)(2,3-

  4. Stereochemistry of Pd(II)-Catalyzed THF Ring Formation of ε-Hydroxy Allylic Alcohols and Synthesis of 2,3,5-Trisubstituted and 2,3,4,5-Tetrasubstituted Tetrahydrofurans.

    Science.gov (United States)

    Murata, Yuki; Uenishi, Jun'ichi

    2016-09-02

    Pd(II)-catalyzed ring formation of 2,3,5-trisubstituted and 2,3,4,5-tetrasubstituted tetrahydrofurans is described. Oxypalladation of a chiral ε-hydroxy allylic alcohol provides a 5-alkenyltetrahydrofuran ring in excellent yields via a 5-exo-trigonal process. Nine substrates including six secondary allylic alcohols and three primary allylic alcohols with or without an additional secondary hydroxy substituent at the γ-position have been examined. Their structures are restricted by a 2,2,4,4-tetraisopropyl-1,3,5,2,4-trioxadisilocane ring. The stereochemistry of the resulting tetrahydrofuran products was determined by chemical transformation. The reaction mechanism is discussed on the basis of the stereochemical results. The steps in the chiral allylic alcohol directed or the nucleophilic alcohol directed facial selection for the formation of the alkene-Pd(II)-π-complex, the cis-oxypalladation, and a syn-elimination mechanism account for the observed stereochemistry of the reaction.

  5. 超硬材料磨具用烯丙基化酚醛改性双马来酰亚胺树脂的研究%Bismaleimide Modified by Allyl Novolak for Superabrasives

    Institute of Scientific and Technical Information of China (English)

    郑红飞; 李志宏; 朱玉梅

    2007-01-01

    A novel thermosetting resin system for superabrasives based on novolak and bismaleimide (BMI) was developed.The novolak resin was allylated and then copolymerized with BMI.The structure of allyl novolak and reaction mechanism were analyzed by FTIR.Thermal and mechanical properties were characterized by using comprehensive thermal analyzer (DSC-TG) and strength tester,respectively.The results showed that high molecular weight of novolak was advantageous for heat-resistance,but was unfavorable for the bending strength.High allyl content improved the heat-resistance but lowered the bending strength.When the molecular weight of novolak was 450 and allyl content was 50%,the best resin system with good heat-resistance and bending strength was obtained.It was suitable for the manufacturing of superabrasive tools.

  6. A one-pot stereoselective synthesis of 1,4-dienyl selenides by hydrostannylation-Stille tandem reaction of acetylenic selenides with Bu3SnH and allylic bromides

    Institute of Scientific and Technical Information of China (English)

    La Mei Yu; Wen Yan Hao; Ming Zhong Cai

    2008-01-01

    1,4-Dienyl selenides can be stereoselectively synthesized in one pot under mild conditions in good yields by the palladium-catalyzed hydrostannylation of acetylenic selenides, followed by Stille coupling with allylic bromides.

  7. Selection and identification of bacterial strains with methyl-tert-butyl ether, ethyl-tert-butyl ether, and tert-amyl methyl ether degrading capacities.

    Science.gov (United States)

    Purswani, Jessica; Pozo, Clementina; Rodríguez-Díaz, Marina; González-López, Jesús

    2008-11-01

    Nine bacterial strains isolated from two hydrocarbon-contaminated soils were selected because of their capacity for growth in culture media amended with 200 mg/L of one of the following gasoline oxygenates: Methyl-tert-butyl ether (MTBE), ethyl-tert-butyl ether (ETBE), and tert-amyl methyl ether (TAME). These strains were identified by amplification of their 16S rRNA gene, using fDl and rD1 primers, and were tested for their capacity to grow and biotransform these oxygenates in both mineral and cometabolic media. The isolates were classified as Bacillus simplex, Bacillus drentensis, Arthrobacter sp., Acinetobacter calcoaceticus, Acinetobacter sp., Gordonia amicalis (two strains), Nocardioides sp., and Rhodococcus ruber. Arthrobacter sp. (strain MG) and A. calcoaceticus (strain M10) consumed 100 (cometabolic medium) and 82 mg/L (mineral medium) of oxygenate TAME in 21 d, respectively, under aerobic conditions. Rhodococcus ruber (strain E10) was observed to use MTBE and ETBE as the sole carbon and energy source, whereas G. amicalis (strain T3) used TAME as the sole carbon and energy source for growth. All the bacterial strains transformed oxygenates better in the presence of an alternative carbon source (ethanol) with the exception of A. calcoaceticus (strain M10). The capacity of the selected strains to remove MTBE, ETBE, and TAME looks promising for application in bioremediation technologies.

  8. Role of cluster size and substrate in the gas phase CC bond coupling reactions of allyl halides mediated by Agn+ and Agn-1H+ cluster cations

    Science.gov (United States)

    Wang, Farrah Qiuyun; Khairallah, George N.; O'Hair, Richard A. J.

    2009-06-01

    Previous studies have demonstrated that the silver hydride cluster cation Ag4H+ promotes CC bond coupling of allylbromide [G.N. Khairallah, R.A.J. O'Hair, Angewandte Chemie International Edition 44 (2005) 728]. Here the influence of both the nature and the size of the silver cluster cation and the substrate on CC bond coupling are examined. Thus each of the cations Ag2H+, Ag4H+, Ag3+, and Ag5+ were allowed to react with three different halides: allyl chloride, allyl bromide and allyl iodide. No CC bond coupling is observed in the reactions of the cluster cations with allyl chloride. There are four main reaction sequences that result in CC bond coupling for allyl bromide and allyl iodide mediated by Agn+ and Agn-1H+ clusters: (i) A sequence involving the reactions of silver cluster cations with two molecules of C3H5X: Agn+ --> Agn(C3H5X)+ --> AgnX2+. This only occurs in the cases of: n = 3 and X = I; n = 5 and X = Br. (ii) A sequence involving the reactions of silver cluster cations with two molecules of C3H5X via an organometallic intermediate: Agn+ --> Agn-1(C3H5)+ --> Agn-1X+. This only occurs in the cases of: n = 5 and X = Br and I. (iii) A sequence involving the reactions of silver hydride cluster cations with three molecules of C3H5X: Agn-1H+ --> Agn-1X+ --> Agn-1X(C3H5X)+ --> Ag(C3H5)2+ and Agn-1X3+. This only occurs in the cases of: n = 5 and X = Br and I. (iv) A sequence involving the reactions of silver hydride cluster cations with three molecules of C3H5X via an organometallic intermediate: Agn-1H+ --> Agn-1X+ --> Agn-3(C3H5)+ --> Ag(C3H5)2+ and Agn-3X+. This only occurs in the cases of: n = 5 and X = I.

  9. Dimethyl ether in diesel engines - progress and perspectives

    DEFF Research Database (Denmark)

    Sorenson, Spencer C

    2001-01-01

    A review of recent developments related to the use of dimethyl ether (DME) in engines is presented Research work discussed is in the areas of engine performance and emissions, fuel injection systems, spray and ignition delay, and detailed chemical kinetic modeling. DME's properties and safety...

  10. The effect of gasses on the viscosity of dimethyl ether

    DEFF Research Database (Denmark)

    Sivebæk, Ion Marius; Jakobsen, Jørgen

    2008-01-01

    Dimethyl ether (DME) has been recognised as a clean substitute for diesel oil as it does not form soot during combustion. DME has a vapour pressure of 6 bar at 25 degrees C; so pressurisation is necessary to keep DME liquid at ambient temperature. Inert gases are good candidates as pressurising m...

  11. Photodegradation of poly(ether sulphone). Part 2

    DEFF Research Database (Denmark)

    Norrman, K.; Krebs, Frederik C

    2004-01-01

    The photodegradation of poly(ether sulphone) (PES) was investigated systematically by time-of-flight SIMS (ToF-SIMS) and x-ray photoelectron spectroscopy (XPS). The effect of varying the irradiation dose, wavelength and the atmosphere was studied along with mechanistic photooxidation studies using...

  12. Anthracylmethyl Benzoazacrown Ether as Selective Fluorescence Sensors for Zn2+

    Institute of Scientific and Technical Information of China (English)

    Li Hua JIA; Xiang Feng GUO; Yuan Yuan LIU; Xu Hong QIAN

    2004-01-01

    A new benzoazacrown ether fluorescence sensor was synthesized with 9-anthrylmethyl chloride and benzoaza-15-crown-5 in CH3CN, which particularly shows a strong affinity for Zn2+. Its fluorescence quantum yield increase more than one order of magnitude and a red shift could be noticed when passing from the apolar to the polar solvent.

  13. Functionalization of thiocrown ethers containing the thioacetal unit

    NARCIS (Netherlands)

    Buter, Jan; Meijer, Renzo H.; Kellogg, Richard M.; Meijer, H.C.

    1998-01-01

    Thiocrown ethers containing thioacetal units are readily prepared by reaction of the cesium salts of long chain dithiols with methylene dibromide. Preparation of the trimethylsilyl derivatives followed by condensation with aldehydes under basic conditions (Peterson reaction) leads to the expected ma

  14. Why do crown ethers activate enzymes in organic solvents?

    NARCIS (Netherlands)

    Unen, van Dirk-Jan; Engbersen, Johan F.J.; Reinhoudt, David N.

    2002-01-01

    One of the major drawbacks of enzymes in nonaqueous solvents is that their activity is often dramatically low compared to that in water. This limitation can be largely overcome by crown ether treatment of enzymes. In this paper, we describe a number of carefully designed new experiments that have im

  15. Direct dimethyl ether high temperature polymer electrolyte membrane fuel cells

    DEFF Research Database (Denmark)

    Vassiliev, Anton; Jensen, Jens Oluf; Li, Qingfeng

    A high temperature polybenzimidazole (PBI) polymer fuel cell was fed with dimethyl ether (DME) and water vapour mixture on the anode at ambient pressure with air as oxidant. A peak power density of 79 mW/cm2 was achieved at 200°C. A conventional polymer based direct DME fuel cell is liquid fed...

  16. Conversion Excess Coal Gas to Dimethyl Ether in Steel Works

    Institute of Scientific and Technical Information of China (English)

    2002-01-01

    With the technical progress of metallurgical industry, more excess gas will be produced in steel works. The feasibility of producing dimethyl ether by gas synthesis was discussed, which focused on marketing, energy balance, process design, economic evaluation, and environmental protection etc. DME was considered to be a new way to utilize excess coal gas in steel works.

  17. Synthesis of Hydroxytyrosyl Alkyl Ethers from Olive Oil Waste Waters

    Directory of Open Access Journals (Sweden)

    Juan Fernández-Bolaños

    2009-05-01

    Full Text Available The preparation of a new type of derivatives of the naturally occurring antioxidant hydroxytyrosol is reported. Hydroxytyrosyl alkyl ethers were obtained in high yield by a three-step procedure starting from hydroxytyrosol isolated from olive oil waste waters. Preliminary results obtained by the Rancimat method have shown that these derivatives retain the high protective capacity of free hydroxytyrosol.

  18. Antiknock evaluation of hydrocarbons and ethers as aviation fuel components

    Science.gov (United States)

    Barnett, Henry C

    1950-01-01

    The results of a NACA investigation conducted over a period of several years to evaluate the anti-knock characteristics of organic compounds are summarized. Included are data for 18 branched paraffins and olefins, 27 aromatics, and 22 ethers. The factors of performance investigated were blending characteristics, temperature sensitivity, lead response, and relation between molecular structure and antiknock ratings. Four engines were used.

  19. Ether lipids of planktonic archae in the marine water column

    NARCIS (Netherlands)

    Sinninghe Damsté, J.S.; Hoefs, M.J.L.; Schouten, S.; King, L.L.; Wakeham, S.G.; Leeuw, J.W. de

    1997-01-01

    Acyclic and cyclic biphytanes derived from the membrane ether lipids of archaea were found in water column particulate and sedimentary organic matter from several oxic and anoxic marine environments. Compound-specific isotope analyses of the carbon skeletons suggest that planktonic archaea utilize a

  20. Lithium air batteries having ether-based electrolytes

    Science.gov (United States)

    Amine, Khalil; Curtiss, Larry A.; Lu, Jun; Lau, Kah Chun; Zhang, Zhengcheng; Sun, Yang-Kook

    2016-10-25

    A lithium-air battery includes a cathode including a porous active carbon material, a separator, an anode including lithium, and an electrolyte including a lithium salt and polyalkylene glycol ether, where the porous active carbon material is free of a metal-based catalyst.

  1. Isotope effects of hafnium in solvent extraction using crown ethers

    Energy Technology Data Exchange (ETDEWEB)

    Fujii, Toshiyuki; Moriyama, Hirotake [Research Reactor Institute, Kyoto University, Osaka (Japan); Hirata, Takafumi [Laboratory for Planetary Sciences, Tokyo Institute of Technology, Tokyo (Japan); Nishizawa, Kazushige [Department of Nuclear Engineering, Graduate School of Engineering, Osaka University, Osaka (Japan)

    2001-06-01

    Hafnium isotopes were fractionated in a liquid-liquid extraction system by using seven types of crown ethers, tributyl phosphate, or {omicron}-diethoxybenzene. The largest isotope effect was observed in the isotope pair of {sup 177}Hf-{sup 179}Hf with dibenzo-24-crown-8; the isotope enrichment factor was observed to be 0.0129{+-}0.0032. (author)

  2. Bio-inspired ion selective crown-ether polymer membranes

    NARCIS (Netherlands)

    Tas, Sinem

    2016-01-01

    Development of unctional membranes that are capable of selectively recognizing and transporting ions have key importance for the recovery and separation of specific icons (e.d. K+, Li+, Na+) from multicomponent mixtures. In this thesis, new membrane materials based on crown ether-metal ion host-gues

  3. Study on the Multi-axis Motion Controller Based on EtherCAT%基于EtherCAT的多轴运动控制器研究

    Institute of Scientific and Technical Information of China (English)

    刘艳强; 王健; 单春荣

    2008-01-01

    研究了EtherCAT技术的原理、技术特点、性能以及EtherCAT主站和从站的实现方法.并在此基础上实现了一种基于EtherCAT的多轴运动控制器,用于数控设备和工业机器人的控制.

  4. EtherCAT-Industrial Ethernet Fieldbus and Its Driver Design%工业以太网现场总线EtherCAT及驱动程序设计

    Institute of Scientific and Technical Information of China (English)

    单春荣; 刘艳强; 郇极

    2007-01-01

    EtherCAT是一种新型的实时工业以太网现场总线.文章介绍了EtherCAT技术的原理、技术特点、性能以及EtherCAT主站和从站的配置方法、主站和从站驱动程序设计技术等.

  5. 全氟丁基磺酸锡催化醛烯丙基化和Mukaiyama-aldol反应%Bisperfluorobutylsulfonate Bisbutyltin Catalyzed Allylation and Mukaiyama-aldol Reaction of Aldehyde

    Institute of Scientific and Technical Information of China (English)

    刘毅; 王勰; 陈锦杨; 李宁波; 许新华

    2012-01-01

    二丁基二氯化锡与全氟丁基磺酸银在丙酮中室温反应,得到二丁基二全氟丁基磺酸锡.该配合物在空气中放置2d,1H NMR表明其结构未发生变化,TG-DSC表明在220℃是稳定的;配合物C4F9SO3)2SnBu2能溶解在乙酸乙酯、丙酮、乙腈、四氢呋喃、乙醚等极性有机溶剂中,但室温下,在非极性溶剂己烷、二氯甲烷、甲苯中不溶.以乙腈作溶剂,室温下,(C4F9SO3)2SnBu2的用量分别为1.0和5.0 mol%,醛的烯丙基化反应和Mukaiyama-aldol反应有效进行,高产率得到对应产物.%Bisperfluorobutylsulfonate bisbutyltin complex was successfully synthesized by treating C4F9SO3Ag with Bu2SnCl2 in acetone at room temperature. When the complex was exposed to air two days, 1H NMR spectra showed that its structure had no change. TG-DSC showed that the complex was stable below 220 ℃. The complex had a good solubility in polar solvents, such as ethyl acetate, acetone, acetonitrile, THF, ethyl ether. But it was poor soluble in hexane, CH2Cl2, toluene at room temperature. In the presence of 1.0 and 5.0 mol% of bisperfluorobutylsulfonate bisbutyltin respectively, allylation of aldehyde and Mukaiyama aldol reaction could efficiently occur in CH3CN at room temperature and give high yield of the corresponding products.

  6. Ether CAT总线在数控系统中的应用

    Institute of Scientific and Technical Information of China (English)

    丁琳娜

    2012-01-01

    文章首先对应用EtherCAT的数控系统相关知识进行介绍,然后针对引入EtherCAT的数控系统的实现,提出了一种基于EtherCAT技术的实时通信及PC控制的可行系统方案,构建了EtherCAT主从站网络结构,并详细分析了EtherCAT主站与从站的软硬件设计。

  7. A mild and efficient procedure for the synthesis of ethers from various alkyl halides

    Directory of Open Access Journals (Sweden)

    Mosstafa Kazemi

    2013-10-01

    Full Text Available A simple, mild and practical procedure has been developed for the synthesis of symmetrical and unsymmetrical ethers by using DMSO, TBAI in the presence of K2CO3. We extended the utility of Potassium carbonate as an efficient base for the preparation of ethers. A wide range of alkyl aryl and dialkyl ethers are synthezied from treatment of aliphatic alcohols and phenols with various alkyl halides in the prescence of efficient base Potassium carbonate. Secondary alkyl halides were easily converted to corresponding ethers in releatively good yields . This is a mild, simple and practical procedure for the preparation of ethers in high yields and suitable times under mild condition.

  8. Comparative photophysical behaviour of naphthalene-linked crown ethers and aza crown ethers of varying cavity dimensions

    Indian Academy of Sciences (India)

    Subhodip Samanta; Pinki Saha Sardar; Shyam Sundar Maity; Anirban Pal; Maitrayee Basu Roy; Sanjib Ghosh

    2007-03-01

    A comparative time-resolved emission studies of several naphtho-crown ethers I-V, where metal ions can be complexed in a predetermined orientation with respect to the naphthalene (Naph) - plane and naphthalene-linked aza crown ethers (L1 and L2) have been presented. In both the systems, crown ethers and aza crown ethers, naphthalene fluorescence gets quenched. In the systems I to V, the quenching is mainly due to efficient spin-orbit coupling (SOC) leading to greater population of the lowest triplet state of naphthalene. This SOC depends on the orientation of the crown ring with respect to the Naph--plane. However, in the systems L1 and L2, the quenching is due to photoinduced electron transfer (PET) from nitrogen lone pair of the aza crown ring to naphthalene moiety and consequent exciplex formation. The results have been interpreted using the time-resolved emission studies of all the compounds in various solvents, their alkali metal ion complexes, and protonated ligands.

  9. Enhanced response of microbial fuel cell using sulfonated poly ether ether ketone membrane as a biochemical oxygen demand sensor

    Energy Technology Data Exchange (ETDEWEB)

    Ayyaru, Sivasankaran; Dharmalingam, Sangeetha, E-mail: sangeetha@annauniv.edu

    2014-03-01

    Graphical abstract: - Highlights: • Sulfonated poly ether ether ketone (SPEEK) membrane in SCMFC used to determine the BOD. • The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm. • This sensing range was 62.5% higher than that of Nafion{sup ®}. • SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}. • Nafion{sup ®} shows high anodic internal resistance (67 Ω) than the SPEEK (39 Ω). - Abstract: The present study is focused on the development of single chamber microbial fuel cell (SCMFC) using sulfonated poly ether ether ketone (SPEEK) membrane to determine the biochemical oxygen demand (BOD) matter present in artificial wastewater (AW). The biosensor produces a good linear relationship with the BOD concentration up to 650 ppm when using artificial wastewater. This sensing range was 62.5% higher than that of Nafion{sup ®}. The most serious problem in using MFC as a BOD sensor is the oxygen diffusion into the anode compartment, which consumes electrons in the anode compartment, thereby reducing the coulomb yield and reducing the electrical signal from the MFC. SPEEK exhibited one order lesser oxygen permeability than Nafion{sup ®}, resulting in low internal resistance and substrate loss, thus improving the sensing range of BOD. The system was further improved by making a double membrane electrode assembly (MEA) with an increased electrode surface area which provide high surface area for electrically active bacteria.

  10. Designed poly(ether-imide)s and fluoro-copoly(ether-imide)s: Synthesis, characterization and their film properties

    Energy Technology Data Exchange (ETDEWEB)

    Vora, Rohitkumar H. [Advanced Polymer Research and Technologies, 505 Cinder Road, Edison, NJ 08820 (United States)]. E-mail: rohitvora@apr-technologies.com; Goh, Suat Hong [Department of Chemistry, National University of Singapore, 10 Kent Ridge Crescent, Singapore 119260 (Singapore)

    2006-07-25

    Two series of amorphous fluoro-poly(ether-imide) (6F-PEI) and one series of fluoro-coploy(ether-imide) (6F-CoPEI) polymers based on 2,2'-bis(3,4-dicarboxyphenyl) hexafluropropane dianhydride (6FDA) and di-ether-containing diamines: 1,2'-bis(4-aminophenoxy)benzene (o-BAPOB) and 4,4'-bis(4-aminophenoxy)diphenyl sulfone (p-SED) were synthesized. The solution properties, chemical resistance, thermal stability, mechanical properties, thermo-oxidative and hydrolytic stability of selected 6F-PEIs and 6F-CoPEIs were studied. The dielectric constant ({epsilon}') values of 6F-PEI and 6F-CoPEI were estimated by additive group contribution calculation using mathematical equations defined by the Lorentz-Lorenz's theory and the Vogel's theory, and by Vora-Wang equations, respectively. These polymers not only showed excellent electrical properties but also excellent long-term thermo-oxidative stability and reduced water absorption relative to non-fluorinated polyimides. The estimated dielectric constant of these polymers ({epsilon}' < 3.15) were lower than those of commercially available poly(ether-imide) ULTEM[reg] 1000 and polyimides Kapton[reg] H, respectively at 1 kHz. The analytical results are summarized and discussed.

  11. Use of fluorinated polybrominated diphenyl ethers and simplified cleanup for the analysis of polybrominated diphenyl ethers in house dust

    Science.gov (United States)

    A simple, cost-effective method is described for the analysis of polybrominated diphenyl ethers (PBDEs) in house dust using pressurized fluid extraction, cleanup with modified silica solid phase extraction tubes, and fluorinated internal standards. There are 14 PBDE congeners inc...

  12. A Review on Mutagenicity Testing for Hazard Classification of Chemicals at Work: Focusing on in vivo Micronucleus Test for Allyl Chloride.

    Science.gov (United States)

    Rim, Kyung-Taek; Kim, Soo-Jin

    2015-09-01

    Chemical mutagenicity is a major hazard that is important to workers' health. Despite the use of large amounts of allyl chloride, the available mutagenicity data for this chemical remains controversial. To clarify the mutagenicity of allyl chloride and because a micronucleus (MN) test had not yet been conducted, we screened for MN induction by using male ICR mice bone marrow cells. The test results indicated that this chemical is not mutagenic under the test conditions. In this paper, the regulatory test battery and several assay combinations used to determine the genotoxic potential of chemicals in the workplace have been described. Further application of these assays may prove useful in future development strategies of hazard evaluations of industrial chemicals. This study also should help to improve the testing of this chemical by commonly used mutagenicity testing methods and investigations on the underlying mechanisms and could be applicable for workers' health.

  13. Structure and stability of acrolein and allyl alcohol networks on Ag(111) from density functional theory based calculations with dispersion corrections

    Science.gov (United States)

    Ferullo, Ricardo M.; Branda, Maria Marta; Illas, Francesc

    2013-11-01

    The interaction of acrolein and allyl alcohol with the Ag(111) surface has been studied by means of periodic density functional theory based calculations including explicitly dispersion terms. Different coverage values have been explored going from isolated adsorbed molecules to isolated dimers, interacting dimers or ordered overlayers. The inclusion of the dispersion terms largely affects the calculated values of the adsorption energy and also the distance between adsorbed molecule and the metallic surface but much less the adsorbate-adsorbate interactions. Owing to the large dipole moment of acrolein, the present calculations predict that at high coverage this molecule forms a stable extensive two-dimensional network on the surface, caused by the alignment of the adsorbate dipoles. For the case of allyl alcohol, dimers and complex networks exhibit similar stability.

  14. A formal [3,3]-sigmatropic rearrangement route to quaternary alpha-vinyl amino acids: use of allylic N-PMP trifluoroacetimidates.

    Science.gov (United States)

    Berkowitz, David B; Wu, Bin; Li, Huijie

    2006-03-01

    Pd(II)-mediated rearrangement of allylic N-PMP (p-methoxyphenyl) trifluoroacetimidates provides the first formal sigmatropic route to quaternary, alpha-vinylic amino acids, potential suicide substrates for PLP enzymes. The amino acid side chains enter via transition-metal-mediated C-C bond constructions, including (i) Cu(I)-mediated conjugate addition (Ala); (ii) Pd(0)/AsPh3-mediated Stille coupling (allyl-Gly, Phe, DOPA, m-Tyr); and (iii) Pd(0)/Pt-Bu3-mediated Negishi coupling (Leu). In the synthesis of the DOPA decarboxylase inactivator, alpha-vinyl-m-tyrosine, the new N-PMP trifluoroacetimidate rearranges much more efficiently than the corresponding trichloroacetimidate.

  15. Remarkable rate acceleration of SmI3-mediated iodination of acetates of Baylis-Hillman adducts in ionic liquid: facile synthesis of (Z)-allyl iodides

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    Stereoselective transformation of Baylis-Hillman acetates 1 into corresponding (Z)-allyl iodides 2 has been achieved by treatment of 1 with samarium triiodide in THF. Remarkable rate acceleration of samarium triiodide-mediated iodination of 1 was found when ionic liquid 1-n-butyl-3-methyl-imidazolium tetrafluroborate ([bmim]BF4) was used as reaction media in stead of THF. This novel approach proceeds readily at 50 ℃ within a few minutes to afford (Z)-allyl iodides 2 in excellent yields. A mechanism involving stereoselective iodination of the acetates of Baylis-Hillman adducts by samarium triiodide is described, in which a six-membered ring transition state played a key role in the stereoselective formation of 2.

  16. Biodegradability of fuel-ethers in environment; Biodegradabilite des ethers-carburants dans l'environnement

    Energy Technology Data Exchange (ETDEWEB)

    Fayolle-Guichard, F.

    2005-04-01

    Fuel ethers (methyl tert-butyl ether or MTBE, ethyl tert-butyl ether or ETBE and tert-amyl methyl ether or TAME have been used as gasoline additives since about twenty years in order to meet the requirements for the octane index and to limit the polluting emission in exhaust pipe gas (unburnt hydrocarbons and carbon monoxide). The high water solubility and the poor biodegradability of these compounds make them pollutants frequently encountered in aquifers. The present manuscript summarizes the knowledge concerning the biodegradability of fuel ethers obtained both at IFP and during collaborations with the Pasteur Institute (Paris), the Biotechnology Research Institute (Montreal, Canada) and the Center for Environmental Biotechnology (University of Tennessee, USA). Rhodococcus ruber IFP 2001 and Mycobacterium austroafricanum IFP 2012, two microorganisms isolated at IFP for their ability to grow, respectively, on ETBE and MTBE, were studied in order to determine the intermediates produced during MTBE and ETBE biodegradation and the enzymes required for each biodegradation step, thus allowing us to propose MTBE and ETBE catabolic pathways. A proteomic approach, from the protein induced during the degradation of ETBE or MTBE to the genes encoding these different enzymes, was carried out. The isolation of such genes is required:1) to use them for help in determining the bio-remediation capacities in polluted aquifers (DNA micro-arrays), 2) to monitor the microorganisms isolated for their degradative capacities during bio-remediation processes (fluorescent in situ hybridization or FISH) and 3) to create new tools for the detection and the quantification of ETBE or MTBE in contaminated aquifers (bio-sensor). The manuscript also describes the different ways for the adaptation of microorganisms to the presence of a xenobiotic compound. (author)

  17. Degradation of various alkyl ethers by alkyl ether-degrading Actinobacteria isolated from activated sludge of a mixed wastewater treatment.

    Science.gov (United States)

    Kim, Yong-Hak; Cha, Chang-Jun; Engesser, Karl-Heinrich; Kim, Sang-Jong

    2008-11-01

    Various substrate specificity groups of alkyl ether (AE)-degrading Actinobacteria coexisted in activated sewage sludge of a mixed wastewater treatment. There were substrate niche overlaps including diethyl ether between linear AE- and cyclic AE-degrading strains and phenetole between monoalkoxybenzene- and linear AE-degrading strains. Representatives of each group showed different substrate specificities and degradation pathways for the preferred substrates. Determining the rates of initial reactions and the initial metabolite(s) from whole cell biotransformation helped us to get information about the degradation pathways. Rhodococcus sp. strain DEE5311 and Rhodococcus rhodochrous strain 117 both were able to degrade anisole and phenetole through aromatic 2-monooxygenation to form 2-alkoxyphenols. In contrast, diethyl ether-oxidizing strain DEE5311 capable of degrading a broad range of linear AE, dibenzyl ether and monoalkoxybenzenes initially transformed anisole and phenetole to phenol via direct O-dealkylation. Compared to this, cyclic AE-degrading Rhodococcus sp. strain THF100 preferred tetrahydrofuran (265 ± 35 nmol min(-1)mg(-1) protein) to diethyl ether (diethoxybenzene-degrading Rhodococcus sp. strain DEOB100 and Gordonia sp. strain DEOB200 transformed 1,3-/1,4-dialkoxybenzenes to 3-/4-alkoxyphenols by similar manners in the order of rates (nmol min(-1) mg(-1) protein): 1,4-diethoxybenzene (11.1 vs. 3.9)>1,4-dimethoxybenzene (1.6 vs. 2.6)>1,3-dimethoxybenzene (0.6 vs. 0.6). This study suggests that the AE-degrading Actinobacteria can orchestrate various substrate specificity responses to the degradation of various categories of AE pollutants in activated sludge communities.

  18. Immobilization of Chiral Ferrocenyl Ligands on Silica Gel and their Testing in Pd-catalyzed Allylic Substitution and Rh-catalyzed Hydrogenation

    Directory of Open Access Journals (Sweden)

    Duncan J. Macquarrie

    2005-07-01

    Full Text Available Five different silica gels containing two chiral ferrocenyl ligands were prepared by various synthetic routes and tested in an enantioselective Pd(0-catalyzed allylic substitution and Rh-catalyzed hydrogenation. All the prepared anchored ligands were characterized by porosimetry data, DRIFTS spectra, thermal data and AAS. The aim of the work was to compare the influence of the carrier, surface properties and immobilization strategy on the performance of the catalyst.

  19. Palladium complexes with a tridentate PNO ligand. Synthesis of eta1-allyl complexes and cross-coupling reactions promoted by boron compounds.

    Science.gov (United States)

    Crociani, Bruno; Antonaroli, Simonetta; Burattini, Marcello; Paoli, Paola; Rossi, Patrizia

    2010-04-21

    The iminophosphine 2-(2-Ph(2)P)C(6)H(4)N=CHC(6)H(4)OH (P-N-OH) reacts with [Pd(mu-Cl)(eta(3)-C(3)H(5))](2) yielding [PdCl(P-N-O)] and propene. In the presence of NEt(3), the reaction of P-N-OH with [Pd(mu-Cl)(eta(3)-1-R(1),3-R(2)C(3)H(3))](2) (R(1) = R(2) = H, Ph; R(1) = H, R(2) = Ph) affords the eta(1)-allyl derivatives [Pd(eta(1)-1-R(1),3-R(2)C(3)H(3))](P-N-O)] (R(1) = R(2) = H: 1; R(1) = H, R(2) = Ph: 2; R(1) = R(2) = Ph: 3). In solution, the complexes 1 and 3 undergo a slow dynamic process which interconverts the bonding site of the allyl ligand. The X-ray structural analysis of 1 indicates a square-planar coordination geometry around the palladium centre with a P,N,O,-tridentate ligand and a sigma bonded allyl group. The complexes [PdR(P-N-O)] (R = C(6)H(4)Me-4, C[triple bond]CPh) react slowly with p-bromoanisole in the presence of p-tolylboronic acid to give [PdBr(P-N-O)] and the coupling product RC(6)H(4)OMe-4. The latter reactions also proceed at a low rate under catalytic conditions. The coupling of allyl bromide with p-tolylboronic acid is catalyzed by [PdCl(P-N-O)]/K(2)CO(3) to give 4-allyltoluene.

  20. Divergent synthetic routes for ring expansion or cyclization from 1,4-allylic diol derivatives via gold(I) catalysis or zinc(II) mediation.

    Science.gov (United States)

    Zhu, Li-Li; Li, Xiao-Xiao; Zhou, Wen; Li, Xin; Chen, Zili

    2011-11-04

    A new efficient method was developed to transform cyclic alkanols into one-carbon higher homologated ketones using various esters as the leaving groups through gold-catalyzed allylic cation-promoted pinacol-type rearrangement. This reaction, coupled with oxy-Cope rearrangement, provided a new strategy to synthesize five-carbon homologated ring ketones. In addition, using ZnBr(2), 2,5-dihydrofuran products were obtained in moderate to good yields via an intramolecular cyclization process.