WorldWideScience

Sample records for auger-induced chemistry derived

  1. Oseltamivir derivatives suitable for click chemistry

    Czech Academy of Sciences Publication Activity Database

    Kožíšek, Milan; Konvalinka, Jan; Řezáčová, Pavlína; Machara, A.; Albinana, C. B.

    Praha: Czech Chemical Society, 2015. s. 56. [Liblice 2015. Advances in Organic , Bioorganic and Pharmaceutical Chemistry /50./. 06.11.2015-08.11.2015, Olomouc] R&D Projects: GA ČR GA13-19561S Institutional support: RVO:61388963 Keywords : oseltamivir * Tamiphosphor * virostatics Subject RIV: CC - Organic Chemistry

  2. Chemistry of Phosphorylated Formaldehyde Derivatives. Part I

    OpenAIRE

    Vasily P. Morgalyuk

    2014-01-01

    The underinvestigated derivatives of unstable phosphorylated formaldehyde acetals and some of the structurally related compounds, such as thioacetals, aminonitriles, aminomethylphosphinoyl compounds, are considered. Separately considered are halogen aminals of phosphorylated formaldehyde, acetals of phosphorylated formaldehyde of H-phosphinate-type and a phosphorylated gem-diol of formaldehyde. Synthetic methods, chemical properties and examples of practical applications are given.

  3. Sponge derived bromotyrosines: structural diversity through natural combinatorial chemistry.

    Science.gov (United States)

    Niemann, Hendrik; Marmann, Andreas; Lin, Wenhan; Proksch, Peter

    2015-01-01

    Sponge derived bromotyrosines are a multifaceted class of marine bioactive compounds that are important for the chemical defense of sponges but also for drug discovery programs as well as for technical applications in the field of antifouling constituents. These compounds, which are mainly accumulated by Verongid sponges, exhibit a diverse range of bioactivities including antibiotic, cytotoxic and antifouling effects. In spite of the simple biogenetic building blocks, which consist only of brominated tyrosine and tyramine units, an impressive diversity of different compounds is obtained through different linkages between these precursors and through structural modifications of the side chains and/or aromatic rings resembling strategies that are known from combinatorial chemistry. As examples for bioactive, structurally divergent bromotyrosines psammaplin A, Aplysina alkaloids featuring aerothionin, aeroplysinin-1 and the dienone, and the bastadins, including the synthetically derived hemibastadin congeners, have been selected for this review. Whereas all of these natural products are believed to be involved in the chemical defense of sponges, some of them may also be of particular relevance to drug discovery due to their interaction with specific molecular targets in eukaryotic cells. These targets involve important enzymes and receptors, such as histone deacetylases (HDAC) and DNA methyltransferases (DNMT), which are inhibited by psammaplin A, as well as ryanodine receptors that are targeted by bastadine type compounds. The hemibastadins such as the synthetically derived dibromohemibastadin are of particular interest due to their antifouling activity. For the latter, a phenoloxidase which catalyzes the bioglue formation needed for firm attachment of fouling organisms to a given substrate was identified as a molecular target. The Aplysina alkaloids finally provide a vivid example for dynamic wound induced bioconversions of natural products that generate highly

  4. Chemistry of Bicyclic Endoperoxides Derived from Dihydropyridine Derivatives: Attempted Synthesis of Polyhydroxypiperidine Derivatives

    OpenAIRE

    SALAMCI, Emine; BAYRAM, Beyhan

    2006-01-01

    To achieve the synthesis of azasugar derivatives with the utilization of singlet oxygen, pyridine was used as the starting material. The reduction of pyridine followed by a singlet oxygen reaction afforded cyclic aza-endoperoxides (14 and 16). However, many attempts were made to convert the aza-endoperoxides to the corresponding di- and triacetates without success. However, the base-catalyzed rearrangement of 14 gave unprecedented rearrangement products 23 and 24.

  5. Time-resolved techniques. Useful tools for fundamental investigations in radiation chemistry of derivatives of polysaccharides

    International Nuclear Information System (INIS)

    Time-resolved techniques such as pulse radiolysis with electron linear accelerator and flash photolysis with excimer laser have been utilized as useful tools for fundamental investigations in radiation chemistry of aqueous solutions of derivatives of polysaccharides. (author)

  6. A click chemistry approach to pleuromutilin derivatives. Part 3

    DEFF Research Database (Denmark)

    Dreier, Ida; Hansen, Lykke H; Nielsen, Poul;

    2014-01-01

    Five promising pleuromutilin derivatives from our former studies, all containing adenine on various linkers, were supplemented with two new compounds. The binding to Escherichia coli ribosomes was verified by extensive chemical footprinting analysis. The ability to inhibit bacterial growth was in...... investigated on two Staphylococcus aureus strains and compared to the pleuromutilin drugs tiamulin and valnemulin. Three of the compounds show an effect similar to tiamulin and one compound shows an excellent effect similar to valnemulin....

  7. Chemistry of zerumbone. 2. Regulation of ring bond cleavage and unique antibacterial activities of zerumbone derivatives.

    Science.gov (United States)

    Kitayama, T; Yamamoto, K; Utsumi, R; Takatani, M; Hill, R K; Kawai, Y; Sawada, S; Okamoto, T

    2001-10-01

    Further investigation of the chemistry of the eleven-membered cyclic sesquiterpene, zerumbone, the major component of the wild ginger, Zingiber zerumbet Smith, has revealed a new selective epoxidation process, a further example of a novel Favorskii-initiated double ring contraction, and a regiospecific fragmentation of zerumbone dibromide derivatives. Several zerumbone derivatives were found to be selective inhibitors of the growth of gram-positive bacteria. PMID:11758909

  8. An Introductory Organic Chemistry Review Homework Exercise: Deriving Potential Mechanisms for Glucose Ring Opening in Mutarotation

    Science.gov (United States)

    Murdock, Margaret; Holman, R. W.; Slade, Tyler; Clark, Shelley L. D.; Rodnick, Kenneth J.

    2014-01-01

    A unique homework assignment has been designed as a review exercise to be implemented near the end of the one-year undergraduate organic chemistry sequence. Within the framework of the exercise, students derive potential mechanisms for glucose ring opening in the aqueous mutarotation process. In this endeavor, 21 general review principles are…

  9. Polymer-Derived Boron Nitride: A Review on the Chemistry, Shaping and Ceramic Conversion of Borazine Derivatives

    Directory of Open Access Journals (Sweden)

    Samuel Bernard

    2014-11-01

    Full Text Available Boron nitride (BN is a III-V compound which is the focus of important research since its discovery in the early 19th century. BN is electronic to carbon and thus, in the same way that carbon exists as graphite, BN exists in the hexagonal phase. The latter offers an unusual combination of properties that cannot be found in any other ceramics. However, these properties closely depend on the synthesis processes. This review states the recent developments in the preparation of BN through the chemistry, shaping and ceramic conversion of borazine derivatives. This concept denoted as Polymer-Derived Ceramics (PDCs route allows tailoring the chemistry of precursors to elaborate complex BN shapes which cannot be obtained by conventional process. The effect of the chemistry of the molecular precursors, i.e., borazine and trichloroborazine, and their polymeric derivatives i.e., polyborazylene and poly[tri(methylaminoborazine], in which the specific functional groups and structural motifs determine the shaping potential by conventional liquid-phase process and plastic-forming techniques is discussed. Nanotubes, nano-fibers, coatings, monoliths and fiber-reinforced matrix composites are especially described. This leads to materials which are of significant engineering interest.

  10. Chemistry

    International Nuclear Information System (INIS)

    The chemical research and development efforts related to the design and ultimate operation of molten-salt breeder reactor systems are concentrated on fuel- and coolant-salt chemistry, including the development of analytical methods for use in these systems. The chemistry of tellurium in fuel salt is being studied to help elucidate the role of this element in the intergranular cracking of Hastelloy N. Studies were continued of the effect of oxygen-containing species on the equilibrium between dissolved UF3 and dissolved UF4, and, in some cases, between the dissolved uranium fluorides and graphite, and the UC2. Several aspects of coolant-salt chemistry are under investigation. Hydroxy and oxy compounds that could be formed in molten NaBF4 are being synthesized and characterized. Studies of the chemistry of chromium (III) compounds in fluoroborate melts were continued as part of a systematic investigation of the corrosion of structural alloys by coolant salt. An in-line voltammetric method for determining U4+/U3+ ratios in fuel salt was tested in a forced-convection loop over a six-month period. (LK)

  11. Expandable-graphite-derived graphene for next-generation battery chemistries

    Science.gov (United States)

    Zu, Chenxi; Li, Longjun; Qie, Long; Manthiram, Arumugam

    2015-06-01

    Lithium-sulfur and lithium-air batteries offer theoretical energy densities an order of magnitude higher than that of current lithium-ion batteries and are considered as promising candidates as the next-generation battery chemistries. For an efficient use of these new battery chemistries, careful selection of suitable electrode materials/structures is critical. Graphene, a unique two-dimensional nanomaterial, with its superior electronic conductivity, mechanical strength, and flexibility has been successfully applied in battery studies. Graphene, even with imperfect layers, will be of great interest to battery industrial applications if the manufacturing cost is reduced. Herein, we demonstrate the application of low-cost graphene sponge/sheets derived from expandable graphite in both lithium-sulfur and hybrid lithium-air batteries, respectively, as a cathode conductive matrix to accommodate the soluble polysulfides and as a catalyst for the oxygen reduction reaction. High utilization of active materials and good cycling stability are realized in lithium-sulfur and hybrid lithium-air batteries by employing this low-cost material, demonstrating its promise for use in next-generation battery chemistries.

  12. One-pot synthesis of quinaldine derivatives by using microwave irradiation without any solvent - A green chemistry approach

    Indian Academy of Sciences (India)

    Javad Safari; Sayed Hossein Banitaba; Sepehr Sadegh Samiei

    2009-07-01

    A convenient and efficient procedure for synthesis of quinaldine derivatives has been developed by a simple one-pot reaction of aniline derivatives and acetaldehyde on the surface of neutral alumina impregnated with hydrochloric acid under microwave irradiation without any solvent according to green chemistry.

  13. Chemistry

    International Nuclear Information System (INIS)

    Research progress is reported in programs on fuel-salt chemistry, properties of compounds in the Li--Te system, Te spectroscopy UF4--H equilibria, porous electrode studies of molten salts, fuel salt-coolant salt reactions, thermodynamic properties of transition-metal fluorides, and properties of sodium fluoroborate. Developmental work on analytical methods is summarized including in-line analysis of molten MSBR fuel, analysis of coolant-salts for tritium, analysis of molten LiF--BeF2--ThF4 for Fe and analysis of LiF--BeF--ThF4 for Te

  14. Chemistry

    International Nuclear Information System (INIS)

    Research and development activities dealing with the chemical problems related to design and ultimate operation of molten-salt reactor systems are described. An experimental test stand was constructed to expose metallurgical test specimens to Te2 vapor at defined temperatures and deposition rates. To better define the chemistry of fluoroborate coolant, several aspects are being investigated. The behavior of hydroxy and oxy compounds in molten NaBF4 is being investigated to define reactions and compounds that may be involved in corrosion and/or could be involved in methods for trapping tritium. Two corrosion products of Hastelloy N, Na3CrF6 and Na5Cr3F14, were identified from fluoroborate systems. The evaluation of fluoroborate and alternate coolants continued. Research on the behavior of hydrogen and its isotopes is summarized. The solubilities of hydrogen, deuterium, and helium in Li2BeF4 are very low. The sorption of tritium on graphite was found to be significant (a few milligrams of tritium per kilogram of graphite), possibly providing a means of sequestering a portion of the tritium produced. Development of analytical methods continued with emphasis on voltammetric and spectrophotometric techniques for the in-line analysis of corrosion products such as Fe2+ and Cr3+ and the determination of the U3+/U4+ ratio in MSBR fuel salt. Similar studies were conducted with the NaBF4--NaF coolant salt. Information developed during the previous operation of the CSTF has been assessed and used to formulate plans for evaluation of in-line analytical methods in future CSTF operations. Electroanalytical and spectrophotometric research suggests that an electroactive protonic species is present in molten NaBF4--NaF, and that this species rapidly equilibrates with a volatile proton-containing species. Data obtained from the CSTF indicated that tritium was concentrated in the volatile species. (JGB)

  15. Airborne Observations of Urban-Derived Water Vapor and Potential Impacts on Chemistry and Clouds

    Science.gov (United States)

    Salmon, O. E.; Shepson, P. B.; Grundman, R. M., II; Stirm, B. H.; Ren, X.; Dickerson, R. R.; Fuentes, J. D.

    2015-12-01

    Atmospheric conditions typical of wintertime, such as lower boundary layer heights and reduced turbulent mixing, provide a unique environment for anthropogenic pollutants to accumulate and react. Wintertime enhancements in water vapor (H2O) have been observed in urban areas, and are thought to result from fossil fuel combustion and urban heat island-induced evaporation. The contribution of urban-derived water vapor to the atmosphere has the potential to locally influence atmospheric chemistry and weather for the urban area and surrounding region due to interactions between H2O and other chemical species, aerosols, and clouds. Airborne observations of urban-derived H2O, carbon dioxide (CO2), methane, nitrogen dioxide (NO2), ozone, and aerosols were conducted from Purdue University's Airborne Laboratory for Atmospheric Research (ALAR) and the University of Maryland's (UMD) Twin Cessna research aircraft during the winter of 2015. Measurements were conducted as part of the collaborative airborne campaign, Wintertime INvestigation of Transport, Emissions, and Reactivity (WINTER), which investigated seasonal trends in anthropogenic emissions and reactivity in the Northeastern United States. ALAR and the UMD aircraft participated in mass balance experiments around Washington D.C.-Baltimore to determine total city emission rates of H2O and other greenhouse gases. Average enhancements in H2O mixing ratio of 0.048%, and up to 0.13%, were observed downwind of the urban centers on ten research flights. In some cases, downwind H2O concentrations clearly track CO2 and NO2 enhancements, suggesting a strong combustion signal. Analysis of Purdue and UMD data collected during the WINTER campaign shows an average urban-derived H2O contribution of 5.3%, and as much as 13%, to the local boundary layer from ten research flights flown in February and March of 2015. In this paper, we discuss the potential chemical and physical implications of these results.

  16. The conversion of furan derivatives from renewable resources into valuable building blocks and their application in synthetic chemistry

    OpenAIRE

    Ulbrich, Kathrin

    2015-01-01

    This work covers research on the utilization of renewable resources for the synthesis of building blocks in organic chemistry, especially the use of different furan derivatives which can be obtained from agricultural waste products. In the course of the first project a successful implementation of the Piancatelli rearrangement of furfuryl alcohol, one of the mentioned furan derivatives, in a dilute aqueous solution under subcritical conditions in a continuous flow system or under microwav...

  17. Impact of human presence on secondary organic aerosols derived from ozone-initiated chemistry in a simulated office environment

    DEFF Research Database (Denmark)

    Fadeyi, Moshood O.; Weschler, Charles J.; Tham, Kwok W.;

    2013-01-01

    's reactions with various indoor pollutants. The present study examines this possibility for secondary organic aerosols (SOA) derived from ozone-initiated chemistry with limonene, a commonly occurring indoor terpene. The experiments were conducted at realistic ozone and limonene concentrations in a 240 m3...

  18. The Abiotic Chemistry of Thiolated Acetate Derivatives and the Origin of Life.

    Science.gov (United States)

    Chandru, Kuhan; Gilbert, Alexis; Butch, Christopher; Aono, Masashi; Cleaves, H James

    2016-01-01

    Thioesters and thioacetic acid (TAA) have been invoked as key reagents for the origin of life as activated forms of acetate analogous to acetyl-CoA. These species could have served as high-energy group-transfer reagents and allowed carbon insertions to form higher molecular weight compounds such as pyruvate. The apparent antiquity of the Wood-Ljungdahl CO2 fixation pathway and its presence in organisms which inhabit hydrothermal (HT) environments has also led to suggestions that there may be a connection between the abiotic chemistry of compounds similar to TAA and the origins of metabolism. These compounds' apparent chemical simplicity has made their prebiotic availability assumed, however, although the kinetic behavior and thermochemical properties of TAA and analogous esters have been preliminarily explored in other contexts, the geochemical relevance of these compounds merits further evaluation. Therefore, the chemical behavior of the simplest thiolated acetic acid derivatives, TAA and methylthioacetate (MTA) were explored here. Using laboratory measurements, literature data, and thermochemical models, we examine the plausibility of the accumulation of these compounds in various geological settings. Due to the high free energy change of their hydrolysis and corresponding low equilibrium constants, it is unlikely that these species could have accumulated abiotically to any significant extant. PMID:27443234

  19. Click chemistry inspired synthesis and bioevaluation of novel triazolyl derivatives of osthol as potent cytotoxic agents.

    Science.gov (United States)

    Farooq, Saleem; Shakeel-u-Rehman; Hussain, Aashiq; Hamid, Abid; Qurishi, Mushtaq A; Koul, Surrinder

    2014-09-12

    A new series of diverse triazoles linked through the hydroxyl group of lactone ring opened osthol (1) were synthesized using click chemistry approach. All the derivatives were subjected to 3-(4,5-Dimethylthiazol-yl)-diphenyl tetrazoliumbromide (MTT) cytotoxicity screening against a panel of seven different human cancer cell lines viz. colon (colo-205), colon (HCT-116), breast (T47D), lung (NCI-H322), lung (A549), prostate (PC-3) and Skin (A-431) to check their cytotoxic potential. Interestingly, among the tested molecules, most of the analogs displayed better cytotoxic activity than the parent osthol (1). Of the synthesized triazoles, compounds 8 showed the best activity with IC50 of 1.3, 4.9, 3.6, 41.0, 35.2, 26.4 and 7.2 μM against colon (Colo-205 and HCT-116), breast (T47D), lung (NCI-H322 and A549), prostate (PC-3) and Skin (A-431) cancer lines respectively. Compound 8 induced potent apoptotic effects in Colo-205 cells. The population of apoptotic cells increased from 11.4% in case of negative control to 24.1% at 25 μM of 8. Compound 8 also induced a remarkable decrease in mitochondrial membrane potential (ΛΨm) leading to apoptosis of cancer cells used. The present study resulted in identification of broad spectrum cytotoxic activity of analogs bearing electron withdrawing substituents, besides the enhanced selective activity of analogs with electron donating moieties. PMID:25062005

  20. The Abiotic Chemistry of Thiolated Acetate Derivatives and the Origin of Life

    Science.gov (United States)

    Chandru, Kuhan; Gilbert, Alexis; Butch, Christopher; Aono, Masashi; Cleaves, H. James

    2016-01-01

    Thioesters and thioacetic acid (TAA) have been invoked as key reagents for the origin of life as activated forms of acetate analogous to acetyl-CoA. These species could have served as high-energy group-transfer reagents and allowed carbon insertions to form higher molecular weight compounds such as pyruvate. The apparent antiquity of the Wood-Ljungdahl CO2 fixation pathway and its presence in organisms which inhabit hydrothermal (HT) environments has also led to suggestions that there may be a connection between the abiotic chemistry of compounds similar to TAA and the origins of metabolism. These compounds’ apparent chemical simplicity has made their prebiotic availability assumed, however, although the kinetic behavior and thermochemical properties of TAA and analogous esters have been preliminarily explored in other contexts, the geochemical relevance of these compounds merits further evaluation. Therefore, the chemical behavior of the simplest thiolated acetic acid derivatives, TAA and methylthioacetate (MTA) were explored here. Using laboratory measurements, literature data, and thermochemical models, we examine the plausibility of the accumulation of these compounds in various geological settings. Due to the high free energy change of their hydrolysis and corresponding low equilibrium constants, it is unlikely that these species could have accumulated abiotically to any significant extant. PMID:27443234

  1. Synthesis of New 3-(2-Chloroquinolin-3-yl)-5-Phenylisoxazole Derivatives via Click-Chemistry Approach

    Energy Technology Data Exchange (ETDEWEB)

    Fernandez-Galleguillos, Carlos; Saavedra, Luis A.; Gutierrez, Margarita [Laboratorio de Sintesis Organica, Instituto de Quimica de Recursos Naturales, Universidad de Talca (Chile)

    2014-02-15

    Herein, we report the synthesis of new substituted 3-(2-chloroquinolin-3-yl)-5-phenylisoxazole (3a-j) by click chemistry in good to moderate yields. This approach is based on the regioselective copper(I)-catalyzed cycloaddition between different nitrile oxides derived from 2-chloroquinoline- 3-carbaldehyde (2a-j) and phenylacetylene. Finally these derivatives were screened for their antibacterial evaluation in vitro against three Gram-negative clinical bacteria: Escherichia coli, Pseudomonas aeruginosa and Acinetobacter baumannii using standard methods. (author)

  2. Cytotoxicity of magnetic nanoparticles derived from green chemistry against human cells

    Science.gov (United States)

    Hanumandla, Pranitha

    The core-shelled Fe3O4 magnetic nanoparticles (MNPs) have been extensively investigated by the researchers due to their diversified applications. Recently, the study on the toxicity of nanomaterials has been drawn increasing attention to reduce or mitigate the environmental hazards and health risk. The objectives of this thesis are three fold: 1) prepare series functionalized Fe3O4 MNPs and optimize the synthesis variables of; 2) characterize their nanostructures using the state-of-the-art instrumental techniques; and 3) evaluate their cytotoxicity by measurement of nitrogen monoxide (NO) release, reactive oxygen species (ROS) and single oxygen species (SOS) generation. In order to prepare the crystalline Fe3O4 MNPs, a cost-effective and user-friendly wet chemistry (Sol-Gel) method was used. Two Indian medicinal plants were extracted to derive the active chemicals, which were used to functionalize the Fe3O 4 MNPs. The results indicated that the Fe3O4 MNPs were well-indexed with the standard inverse spinel structure (PDF 65-3107, a=8.3905A, α = 90°). The particle's sizes varied from 6-10 nm with the Fe3O 4 MNPs acting as cores and medicinal extracts as shell. The active chemical components extracted from two Hygrophila auriculata/ Chlorophytum borivilianum are fatty acid, Saponins, sterols, carbohydrates and amino acids, which are in agreement with the reported data. Toxicological evaluations of MNPs indicated that the Fe3O4 MNPs functionalized with Hygrophila auriculata/ Chlorophytum borivilianum extract prepared at room temperature were toxic to the cells when compared to the control, and act in a mechanism similar to the actions of hydrogen peroxide (H2O2). These functionalized MNPs, which were prepared at 100 ° C, displayed similar mechanism of action to the anticancer drug (SN-38). It was also found that the MNPs prepared at lower temperatures are less toxic and showed similar mechanism of action as the sodium nitrite (NaNO 2).

  3. Synthesis and lanthanide coordination chemistry of trifluoromethyl derivatives of phosphinoylmethyl pyridine N-oxides

    Energy Technology Data Exchange (ETDEWEB)

    Pailloux, Sylvie [University of New Mexico, Albuquerque; Shirima, Cornel Edicome [University of New Mexico, Albuquerque; Duesler, Eileen N. [University of New Mexico, Albuquerque; Smith, Karen Ann [University of New Mexico, Albuquerque; Paine, Robert T. [University of New Mexico, Albuquerque; Klaehn, John D. [Idaho National Laboratory (INL); McIlwain, Michael E [Idaho National Laboratory (INL); Hay, Benjamin [ORNL

    2009-01-01

    A synthetic route for the formation of 2-[bis-(2-trifluoromethyl-phenyl)-phosphinoylmethyl]-pyridine N-oxide (1c) and 2-[bis-(3,5-trifluoromethyl-phenyl)-phosphinoylmethyl]-pyridine N-oxide (1d) was developed and the new ligands characterized by spectroscopic methods and single crystal X-ray diffraction analyses. The coordination chemistry of the ligands was examined with early and late lanthanide ions. The molecular structure of one complex, [Yb(1c)(NO3)3(DMF)](DMF)(H2O)0.5, was determined by single crystal X-ray diffraction methods and the ligand found to coordinate in a bidentate fashion. This coordination chemistry is compared against lanthanide coordination chemistry observed for the related ligand, [Ph2P(O)CH2] C5H4NO.

  4. 77 FR 14022 - Guidance for Industry on Chemistry, Manufacturing, and Controls Information-Fermentation-Derived...

    Science.gov (United States)

    2012-03-08

    ... HUMAN SERVICES Food and Drug Administration Guidance for Industry on Chemistry, Manufacturing, and... INFORMATION: I. Background In the Federal Register of March 14, 2011 (76 FR 13629), FDA published the notice...: The Food and Drug Administration (FDA) is announcing the availability of a guidance for industry...

  5. Preparation of 18F labeled octreotide derivatives 18F-Ta-Gluc-TOCA by click chemistry and its biological evaluation

    International Nuclear Information System (INIS)

    The preparation of 18F labeled peptides usually need many reaction steps, long time, harsh reaction conditions, which greatly limits the application of 18F labeled PET probe. Using click chemistry for the synthesis of 18F labeled peptides make the reaction conditions more reliable, efficient and selective. The reaction conditions are mild, low cost, and fast. The purpose of this research was to synthesize the glycosylated octreotide derivative quickly and easily, to develop a method of 18F labeled peptides by click chemistry. We also discussed the exploration of the feasibility with 18F labeled glycosylated octreotide derivatives as a somatostatin receptor positive tumor probe. This work prepared 2-18F-azide ethane precursor compounds by nucleophilic substitution and then labeled Pr-Gluc-TOCA by click chemistry, finally we got the product 18F-Ta-Gluc-TOCA by purification. In addition, the in vitro stability and octanol-water partition coefficient of 18F-Ta-Gluc-TOCA were measured. The biodistribution studies of 18F-Ta-Gluc-TOCA in normal mice and tumor bearing nude mice were investigated. The radiochemical purity of 18F-Ta-Gluc-TOCA was 91%. The vitro stability was good. The octanol-water partition coefficient was -0.43± 0.05. The results of biodistribution in normal mice showed rapid clearance from blood, and excreted mainly through the hepatobiliary metabolism, and also through the renal metabolism. The results of the biodistribution in tumor bearing nude mice showed high uptake in the tumor (4.34±0.47% ID/g, 60 min). The finding's suggest that 18F-Ta-Gluc-TOCA is a potential radiotracer for PET imaging of somatostatin receptor positive tumors. (authors)

  6. Incompatibility between plant-derived defensive chemistry and immune response of two sphingid herbivores.

    Science.gov (United States)

    Lampert, Evan C; Bowers, M Deane

    2015-01-01

    Herbivorous insects use several different defenses against predators and parasites, and tradeoffs among defensive traits may occur if these traits are energetically demanding. Chemical defense and immune response potentially can interact, and both can be influenced by host plant chemistry. Two closely related caterpillars in the lepidopteran family Sphingidae are both attacked by the same specialist endoparasitoid species but have mostly non-overlapping host plant ranges that differ in secondary chemistry. Ceratomia catalpae is a specialist on Catalpa and also will feed on Chilopsis, which both produce iridoid glycosides. Ceratomia undulosa consumes members of the Oleaceae, which produce seco-iridoid glycosides. Immune response of the two species on a typical host plant species (Catalpa bignonioides for C. catalpa; Fraxinus americana for C. undulosa) was compared using a melanization assay, and did not differ. In a second experiment, the iridoid glycoside catalpol was added to the diets of both insects, and growth rate, mass, chemical defense, and immune response were evaluated. Increased dietary catalpol weakened the immune response of C. undulosa and altered the development rate of C. catalpae by prolonging the third instar and accelerating the fourth instar. Catalpol sequestration was negatively correlated with immune response of C. catalpae, while C. undulosa was unable to sequester catalpol. These results show that immune response can be negatively influenced by increasing concentrations of sequestered defensive compounds. PMID:25516226

  7. Insights into the Coordination Chemistry of Phosphonate Derivatives of Hetero-poly-oxo-tungstates

    International Nuclear Information System (INIS)

    The coordination properties of vacant bis-phosphonate derivatives of poly-oxo-metalates, with easily tunable functions, have been explored. The preparation and crystallographic structure of their La3+ and Zr4+ complexes are described herein. (authors)

  8. Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer dataset

    Directory of Open Access Journals (Sweden)

    A. Jones

    2011-11-01

    Full Text Available The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS aboard the Canadian satellite SCISAT (launched in August 2003 was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month period and measurements are made with a vertical resolution of typically 3–4 km. A quality-controlled climatology has been created for each of these 14 baseline species, where individual profiles are averaged over the period of February 2004 to February 2009. Measurements used are from the ACE-FTS version 2.2 data set including updates for O3 and N2O5. The climatological fields are provided on a monthly and three-monthly basis (DJF, MAM, JJA, SON at 5 degree latitude and equivalent latitude spacing and on 28 pressure surfaces (26 of which are defined by the Stratospheric Processes And their Role in Climate (SPARC Chemistry Climate Model validation activity. The ACE-FTS climatological dataset is available through the ACE website.

  9. Observationally derived transport diagnostics for the lowermost stratosphere and their application to the GMI chemistry and transport model

    Directory of Open Access Journals (Sweden)

    S. E. Strahan

    2007-01-01

    Full Text Available Transport from the surface to the lowermost stratosphere can occur on timescales of a few months or less, making it possible for short-lived tropospheric pollutants to influence stratospheric composition and chemistry. Models used to study this influence must demonstrate the credibility of their chemistry and transport in the upper troposphere and lower stratosphere (UT/LS. Data sets from satellite and aircraft instruments measuring CO, O3, N2O, and CO2 in the UT/LS are used to create a suite of diagnostics of the seasonally-varying transport into and within the lowermost stratosphere, and of the coupling between the troposphere and stratosphere in the extratropics. The diagnostics are used to evaluate a version of the Global Modeling Initiative (GMI Chemistry and Transport Model that uses a combined tropospheric and stratospheric chemical mechanism and meteorological fields from the GEOS-4 general circulation model. The diagnostics derived from N2O and O3 show that the model lowermost stratosphere (LMS has realistic input from the overlying high latitude stratosphere in all seasons. Diagnostics for the LMS show two distinct layers. The upper layer (~350 K–380 K has a strong annual cycle in its composition, while the lower layer, just above the tropopause, shows no seasonal variation in the degree of tropospheric coupling or composition. The GMI CTM agrees closely with the observations in both layers and is realistically coupled to the UT in all seasons. This study demonstrates the credibility of the GMI CTM for the study of the impact of tropospheric emissions on the stratosphere.

  10. The gas phase ion/molecule chemistry of four carbanions generated from vinylene carbonate and its methyl and dimethyl derivatives

    Science.gov (United States)

    Robinson, Marin S.; Breitbeil, Fred W.

    1992-09-01

    The gas phase ion/molecule chemistry of four carbanions generated by the reaction of vinylene carbonate, and its methyl and dimethyl derivatives with hydroxide ion has been investigated. From the parent the sole product is the ketenyl anion, HC[triple bond; length as m-dash]C---O-, arising from vinylic proton abstraction and loss of CO2. From the dimethyl derivative, abstraction of an allylic proton from one of the methyl groups followed by loss of CO2 leads exclusively to CH2=CC(O)CH3. Both pathways are observed for the monomethyl derivative, leading to a mixture of the ions CH3C[triple bond; length as m-dash]C---O- and CH2=CCHO. The ketenyl and methyl ketenyl ions do not exchange hydrogen for deuterium with D2O or CH3OD, but they do react with CS2 and COS to form the corresponding thioketenyl anions, HC[triple bond; length as m-dash]C---S- and CH3C=C---S-. The ions CH2=CC(O)CH3 and CH2=CCHO exchange one and three hydrogen atoms for deuterium atoms with D2O respectively, and react with CS2 to form thioketenyl anions by addition and loss of thioformaldehyde. Possible mechanisms for these reactions are discussed.

  11. Preparation, chemistry and physical properties of bone-derived hydroxyapatite particles having a negative zeta potential

    International Nuclear Information System (INIS)

    Highlights: ► Natural and relatively pure hydroxyapatite particles can be obtained from bovine bone. ► A Complete characterization of bone-derived HA particles was carried out. ► Bone-derived HA particles reveal a negative zeta potential in physiological saline at 37 °C. - Abstract: Animal bone-derived calcium hydroxyapatite (HA) particles were produced and characterized. Adult bovine femoral bone was boiled, washed, cleaned and heated in air at 700 °C for 2 h. The resulting macro-porous solid was ground, crushed and sieved into particles −1 (MgCO3 or CaCO3) and 874 cm−1 (CaHPO4). Main elements by EDXRF were Ca and P (molar ratio 1.93 vs. theoretical ratio 1.67). Minor amounts of Si, Mg and Na were detected, plus traces of K, Sr, Zn, Ba, V, Al, Mn, Pb, Cu and Fe. EDX detected Ca, P, Na and Mg. BET gas adsorption surface area was ∼2.23 m2 g−1 and theoretical particle size ∼857 nm. Laser DLS indicated ∼40% of particles were ∼952 nm in diameter, plus ∼50% were ∼760 nm – in close agreement with BET calculations. By laser Doppler electrophoresis (LDE) the zeta potential of the bone-derived HA particles suspended in 0.154 M NaCl was negative for pH 6–11 and −9.25 ± 0.9 mV at pH 7.4. Negative zeta potential is reported to favor attachment and proliferation of bone cells. HA particles produced synthetically are reported to have positive zeta potentials. The source of the negative potential was not determined but may stem from factors peculiar to producing HA particles from bone. The results suggest further investigation for biomedical use.

  12. Chemistry of Nitroquinolones and Synthetic Application to Unnatural 1-Methyl-2-quinolone Derivatives

    Directory of Open Access Journals (Sweden)

    Nagatoshi Nishiwaki

    2010-07-01

    Full Text Available The 1-methyl-2-quinolone (MeQone framework is often found in alkaloids and recently attention was drawn to unnatural MeQone derivatives with the aim of finding new biologically active compounds, however, low reactivity of the MeQone framework prevents the syntheses of versatile derivatives. A nitro group is one of the useful activating groups for this framework that enables a concise chemical transformation. Among nitroquinolones, 1-methyl-3,6,8-trinitro-2-quinolone (TNQ exhibits unusual reactivity favoring region-selective cine-substitutions that afford 4-substituted 1-methyl-6,8-dinitro-2-quinolones upon treatment with nucleophilic reagents. Contrary to this, 1-methyl-3,6-dinitro-2-quinolone (3,6-DNQ does not undergo any reaction under the same conditions. The unusual reactivity of TNQ is caused by steric repulsion between the methyl group at the 1-position and the nitro group at the 8-position, which distorts the MeQone framework. As a result, the pyridone ring of TNQ loses aromaticity and acts rather as an activated nitroalkene. Indeed, the pyridone moiety of TNQ undergoes cycloaddition with electron-rich alkenes or dienes under mild conditions, whereby a new fused ring is constructed on the [c]-face of the MeQone. Consequently, TNQ can be used as a new scaffold leading to versatile unnatural MeQone derivatives.

  13. Modification of chitosan derivatives of environmental and biological interest: a green chemistry approach.

    Science.gov (United States)

    Abdelaal, Magdy Y; Sobahi, Tariq R; Al-Shareef, Hossa F

    2013-04-01

    Chitosan is a non-toxic polyaminosaccharide that is available in a variety of useful forms, and its chemical and biological properties make it a very attractive biomaterial that could be used in a wide variety of medicinal applications. This work focuses on the preparation of different chitosan derivatives by treatment with ethyl cellulose, cellulose triacetate and different carbohydrates in both neutral and slightly acidic media. It also addresses modification with glycidyltrimethyl ammonium chloride, phthalic anhydride and succinic acid derivatives. The obtained derivatives were crosslinked with glutaraldehyde. Thermo-gravimetric (TGA) and FT-IR spectroscopic analyses and electron scanning microscopy (SEM) were used to characterize the obtained products and demonstrate the success of the chitosan-modification process. The obtained products were tested for their ability to uptake transition metal ions from aqueous solutions, and their ion-uptake efficiency was determined with the aid of the ICP-AES technique. The bioactivity of some selected products was tested to study the effect of their concentrations on selected microorganisms. Burkholderia cepaci, Aspergillus niger, and Candida albicans were selected as representative examples of bacteria, yeasts and fungi, respectively. PMID:23376358

  14. Preparation, chemistry and physical properties of bone-derived hydroxyapatite particles having a negative zeta potential

    Energy Technology Data Exchange (ETDEWEB)

    Doostmohammadi, Ali, E-mail: alidm14@ma.iut.ac.ir [Biomaterials Research Center, Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Isfahan University of Medical Sciences, Isfahan 81746-73461 (Iran, Islamic Republic of); Monshi, Ahmad [Biomaterials Research Center, Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Salehi, Rasoul [Department of Genetics and Molecular Biology, School of Medicine, Isfahan University of Medical Sciences, Isfahan 81746-73461 (Iran, Islamic Republic of); Fathi, M.H. [Biomaterials Research Center, Department of Materials Engineering, Isfahan University of Technology, Isfahan 84156-83111 (Iran, Islamic Republic of); Karbasi, Saeed [Medical Physics and Biomedical Engineering Group, School of Medicine, Isfahan University of Medical Sciences, Isfahan (Iran, Islamic Republic of); Pieles, Uwe [Institute for Chemistry and Bioanalytics, School of Life Sciences, University of Applied Sciences of Northwestern Switzerland, Muttenz (Switzerland); Daniels, A.U. [Laboratory of Biomechanics and Biocalorimetry, Coaltion for Clinical Morphology and Biomedical Engineering, University of Basel Faculty of Medicine, Basel (Switzerland)

    2012-02-15

    Highlights: Black-Right-Pointing-Pointer Natural and relatively pure hydroxyapatite particles can be obtained from bovine bone. Black-Right-Pointing-Pointer A Complete characterization of bone-derived HA particles was carried out. Black-Right-Pointing-Pointer Bone-derived HA particles reveal a negative zeta potential in physiological saline at 37 Degree-Sign C. - Abstract: Animal bone-derived calcium hydroxyapatite (HA) particles were produced and characterized. Adult bovine femoral bone was boiled, washed, cleaned and heated in air at 700 Degree-Sign C for 2 h. The resulting macro-porous solid was ground, crushed and sieved into particles <50 {mu}m. SEM showed the particles were agglomerations of crystals {approx}50-500 nm across. XRD showed highly crystalline HA with nominal MgO and no detectable CaO. FTIR spectroscopy yielded typical HA absorptions, plus absorptions at 1457 and 1412 cm{sup -1} (MgCO{sub 3} or CaCO{sub 3}) and 874 cm{sup -1} (CaHPO{sub 4}). Main elements by EDXRF were Ca and P (molar ratio 1.93 vs. theoretical ratio 1.67). Minor amounts of Si, Mg and Na were detected, plus traces of K, Sr, Zn, Ba, V, Al, Mn, Pb, Cu and Fe. EDX detected Ca, P, Na and Mg. BET gas adsorption surface area was {approx}2.23 m{sup 2} g{sup -1} and theoretical particle size {approx}857 nm. Laser DLS indicated {approx}40% of particles were {approx}952 nm in diameter, plus {approx}50% were {approx}760 nm - in close agreement with BET calculations. By laser Doppler electrophoresis (LDE) the zeta potential of the bone-derived HA particles suspended in 0.154 M NaCl was negative for pH 6-11 and -9.25 {+-} 0.9 mV at pH 7.4. Negative zeta potential is reported to favor attachment and proliferation of bone cells. HA particles produced synthetically are reported to have positive zeta potentials. The source of the negative potential was not determined but may stem from factors peculiar to producing HA particles from bone. The results suggest further investigation for biomedical use.

  15. Atmospheric chemistry of polycyclic aromatic compounds with special emphasis on nitro derivatives

    Energy Technology Data Exchange (ETDEWEB)

    Feilberg, A.

    2000-04-01

    Field measurements of polycyclic aromatic compounds (PAC) have been carried out at a semi-rural site and at an urban site. Correlation analyses, PAC indicators, and PAC ratios have been used to evaluate the importance of various sources of nitro-PAHs. A major source of nitro-PAHs is atmospheric transformation of PAHs initiated by OH radicals. Especially during long-range transport (LRT) of air pollution from Central Europe, the nitro-PAH composition in Denmark is dominated by nitro-PAHs formed in the atmosphere. Locally emitted nitro-PAHs are primarily from diesel vehicles. Levels of unsubstituted PAHs can also be strongly elevated in connection with LRT episodes. The ratio of 2-nitrofluoranthene relative to 1-nitropyrene is proposed as a measure of the relative photochemical age of particulate matter. Using this ratio, the relative mutagenicity of particle extracts appears to increase with increasing photochemical age. In connection with the field measurements, a method for measuring nitro-PAHs in particle extracts based on MS-MS detection has been developed. The atmospheric chemistry of nitronaphthalenes has been investigated with a smog chamber system combined with simulation with photochemical kinetics software. A methodology to implement gas-particle partitioning in a model based on chemical kinetics is described. Equilibrium constants (KP) for gas-particle partitioning of 1- and 2-nitronaphthalene have been determined. Mass transfer between the two phases appears to occur on a very short timescale. The gas phase photolysis of the nitronaphthalenes depends upon the molecular conformation. Significantly faster photolysis of 1-nitronaphthalene than of 2-nitronaphthalene is observed. The photochemistry of nitro-PAHs, and to some extent other PAC, associated with organic aerosols, has been studied with model systems simulating organic aerosol material. A number of aerosol constituents, including substituted phenols, benzaldehydes, and oxy-PAHs, are demonstrated to

  16. Dynamic Covalent Chemistry-based Sensing: Pyrenyl Derivatives of Phenylboronic Acid for Saccharide and Formaldehyde

    Science.gov (United States)

    Chang, Xingmao; Fan, Jiayun; Wang, Min; Wang, Zhaolong; Peng, Haonan; He, Gang; Fang, Yu

    2016-08-01

    We synthesized two specially designed pyrenyl (Py) derivatives of phenylboronic acid, PSNB1 and PSNB2, of which PSNB2 self-assemble to form dynamic aggregate in methanol-water mixture (1:99, v/v) via intermolecular H-bonding and pi-pi stacking. Interestingly, the dynamic aggregate shows smart response to presence of fructose (F) as evidenced by fluorescence color change from green to blue. More interestingly, the fluorescence emission of the resulted PSNB2-F changes from blue to green with the addition of formaldehyde (FA). The reason behind is formation of a PSNB2-F dimer via FA cross-linking. Based upon the reactions as found, sensitive and fast sensing of F and FA in water was realized, of which the experimental DLs could be significantly lower than 10 μM for both analytes, and the response times are less than 1 min. It is believed that not only the materials as created may have the potential to find real-life applications but also the strategy as developed can be adopted to develop other dynamic materials.

  17. Chemistry and structure of coal derived asphaltenes and preasphaltenes. Interim report

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.

    1979-01-01

    It is the objective of this project to isolate the asphaltene and preasphaltene fractions from coal liquids from a number of liquefaction processes. These processes consist of in general: catalytic hydrogenation, staged pyrolysis and solvent refining. The asphaltene fractions may be further separated by both gradient elution through column chromatography, and molecular size distribution through gel permeation chromatography. These coal-derived asphaltene and preashpaltene fractions will then be investigated by various chemical and physical methods for characterization of their structures. After the parameters are obtained, these parameters will be correlated with the refining and conversion variables which control a given type of liquefaction process. The effects of asphaltene in catalysis, ash or metal removal, desulfurization and denitrification will also be correlated. It is anticipated that understanding the role of asphaltenes in liquefaction processes will enable engineers to both improve existing processes, and to make recommendations for operational changes in planned liquefaction units. The objective of Phase 1 was to complete the isolation and separation of coal liquid fractions and to initiate their characterization. The objective of Phase 2 is to continue the characterization of coal asphaltenes and other coal liquid fractions by use of physical and instrumental methods. The structural parameters obtained will be used to postulate hypothetical average structures for coal liquid fractions.The objective of Phase 3 is to concentrate on the characterization of the preasphaltene (benzene insoluble fraction) of coal liquid fraction by the available physical and chemical methods to obtain a number of structural parameters.

  18. Synthesis, characterization, and cure chemistry of renewable bis(cyanate) esters derived from 2-methoxy-4-methylphenol.

    Science.gov (United States)

    Meylemans, Heather A; Harvey, Benjamin G; Reams, Josiah T; Guenthner, Andrew J; Cambrea, Lee R; Groshens, Thomas J; Baldwin, Lawrence C; Garrison, Michael D; Mabry, Joseph M

    2013-03-11

    A series of renewable bis(cyanate) esters have been prepared from bisphenols synthesized by condensation of 2-methoxy-4-methylphenol (creosol) with formaldehyde, acetaldehyde, and propionaldehyde. The cyanate esters have been fully characterized by infrared spectroscopy, (1)H and (13)C NMR spectroscopy, and single crystal X-ray diffraction. These compounds melt from 88 to 143 °C, while cured resins have glass transition temperatures from 219 to 248 °C, water uptake (96 h, 85 °C immersion) in the range of 2.05-3.21%, and wet glass transition temperatures from 174 to 193 °C. These properties suggest that creosol-derived cyanate esters may be useful for a wide variety of military and commercial applications. The cure chemistry of the cyanate esters has been studied with FTIR spectroscopy and differential scanning calorimetry. The results show that cyanate esters with more sterically demanding bridging groups cure more slowly, but also more completely than those with a bridging methylene group. In addition to the structural differences, the purity of the cyanate esters has a significant effect on both the cure chemistry and final Tg of the materials. In some cases, post-cure of the resins at 350 °C resulted in significant decomposition and off-gassing, but cure protocols that terminated at 250-300 °C generated void-free resin pucks without degradation. Thermogravimetric analysis revealed that cured resins were stable up to 400 °C and then rapidly degraded. TGA/FTIR and mass spectrometry results showed that the resins decomposed to phenols, isocyanic acid, and secondary decomposition products, including CO2. Char yields of cured resins under N2 ranged from 27 to 35%, while char yields in air ranged from 8 to 11%. These data suggest that resins of this type may potentially be recycled to parent phenols, creosol, and other alkylated creosols by pyrolysis in the presence of excess water vapor. The ability to synthesize these high temperature resins from a phenol

  19. Designing green derivatives of β-blocker Metoprolol: a tiered approach for green and sustainable pharmacy and chemistry.

    Science.gov (United States)

    Rastogi, Tushar; Leder, Christoph; Kümmerer, Klaus

    2014-09-01

    The presences of micro-pollutants (active pharmaceutical ingredients, APIs) are increasingly seen as a challenge of the sustainable management of water resources worldwide due to ineffective effluent treatment and other measures for their input prevention. Therefore, novel approaches are needed like designing greener pharmaceuticals, i.e. better biodegradability in the environment. This study addresses a tiered approach of implementing green and sustainable chemistry principles for theoretically designing better biodegradable and pharmacologically improved pharmaceuticals. Photodegradation process coupled with LC-MS(n) analysis and in silico tools such as quantitative structure-activity relationships (QSAR) analysis and molecular docking proved to be a very significant approach for the preliminary stages of designing chemical structures that would fit into the "benign by design" concept in the direction of green and sustainable pharmacy. Metoprolol (MTL) was used as an example, which itself is not readily biodegradable under conditions found in sewage treatment and the aquatic environment. The study provides the theoretical design of new derivatives of MTL which might have the same or improved pharmacological activity and are more degradable in the environment than MTL. However, the in silico toxicity prediction by QSAR of those photo-TPs indicated few of them might be possibly mutagenic and require further testing. This novel approach of theoretically designing 'green' pharmaceuticals can be considered as a step forward towards the green and sustainable pharmacy field. However, more knowledge and further experience have to be collected on the full scope, opportunities and limitations of this approach. PMID:24997957

  20. Green Chemistry Approach for Efficient Synthesis of Schiff Bases of Isatin Derivatives and Evaluation of Their Antibacterial Activities

    Directory of Open Access Journals (Sweden)

    Jnyanaranjan Panda

    2013-01-01

    Full Text Available Microwave-assisted organic synthesis, a green chemistry approach, is nowadays widely used in the drug synthesis. Microwave-assisted synthesis improves both throughput and turnaround time for medicinal chemists by offering the benefits of drastically reduced reaction times, increased yields, and pure products. Schiff bases are the important class of organic compounds due to their flexibility, and structural diversities due to the presence of azomethine group which is helpful for elucidating the mechanism of transformation and rasemination reaction in biological system. This novel compound could also act as valuable ligands for the development of new chemical entities. In the present work, some Schiff bases of Isatin derivatives was synthesized using microwave heating method. Schiff base of Isatin were synthesized by condensation of the keto group of Isatin with different aromatic primary amines. They were characterized by means of spectral data and subsequently subjected to the in vitro antibacterial activities against gram positive and gram negative strains of microbes. It was observed that the compound with electron withdrawing substituents exhibited good antibacterial activities against almost all the micro organisms.

  1. A SYSTEMIC REVIEW: MICROWAVE SYNTHESIS AS A PART OF GREEN CHEMISTRY FOR THE SYNTHESIS OF NOVEL 1, 2, 4- TRIAZOLE DERIVATIVES

    Directory of Open Access Journals (Sweden)

    Anshul Chawla

    2013-01-01

    Full Text Available Microwave reactions are based on the basic principles of green chemistry, basically involve “Go Green” concept. Purpose of green synthesis is to proceed with all the synthetic procedures which are ecofriendly and economic. Great deal of better yield in lesser time than conventional methods are observed. In medicinal chemistry, 1,2,4- triazoles are the source for potent medicaments for different pharmacological activities. In connection with this, literature is being compiled up for the sake of synthesis of 1,2,4- triazoles derivatives by using microwave irradiations.

  2. Organic reactions for the electrochemical and photochemical production of chemical fuels from CO_2 – The reduction chemistry of carboxylic acids and derivatives as bent CO_2 surrogates

    OpenAIRE

    Luca, Oana R.; Fenwick, Aidan Q.

    2015-01-01

    The present review covers organic transformations involved in the reduction of CO_2 to chemical fuels. In particular, we focus on reactions of CO_2 with organic molecules to yield carboxylic acid derivatives as a first step in CO_2 reduction reaction sequences. These biomimetic initial steps create opportunities for tandem electrochemical/chemical reductions. We draw parallels between long-standing knowledge of CO_2 reactivity from organic chemistry, organocatalysis, surface science and elect...

  3. Chemistry of cobalt bis(1,2-dicarbollide) ion; the synthesis of carbon substituted alkylamino derivatives from hydroxyalkyl derivatives via methylsulfonyl or p-toluenesulfonyl esters

    Czech Academy of Sciences Publication Activity Database

    Nekvinda, Jan; Švehla, Jaroslav; Císařová, I.; Grüner, Bohumír

    2015-01-01

    Roč. 798, č. 1 (2015), s. 112-120. ISSN 0022-328X R&D Projects: GA ČR GA15-05677S Institutional support: RVO:61388980 Keywords : Boranes * Carboranes * Metallacarboranes * Dicarbollide * Building blocks Subject RIV: CA - Inorganic Chemistry Impact factor: 2.173, year: 2014

  4. Synthesis of two D-glucosamine derived 3,4-epoxides as potential scaffolds for combinatorial chemistry

    DEFF Research Database (Denmark)

    Svejgaard, L.; Fuglsang, H.; Jensen, P.B.;

    2003-01-01

    Combinatorial chemistry allows the synthesis of libraries of compounds by combination of building blocks or by combinatorial elaboration of a central scaffold.([1,2]) Carbohydrates hold great promise as scaffolds due to their high degree of functionalization, relative conformational rigidity, com...

  5. Cyclodextrin chemistry

    International Nuclear Information System (INIS)

    The chemistry of cyclodextrins was studied. This study included synthesising some cyclodextrin derivatives, preparing selected inclusion complexes with cyclodextrin and investigating the effects of gamma irradiation on cyclodextrins and certain linear oligosaccharides. This report presents a brief review of the structure and properties of cyclodextrins, the synthesis of cyclodextrin derivatives, their complexation and applications. This is followed by a description of the synthesis of some cyclodextrin derivatives and the preparation of inclusion complexes of cyclodextrin with some organic compounds. Finally, the effects of gamma irradiation on cyclodextrins, some of their derivatives and certain structurally related carbohydrates are discussed. The gamma irradiation studies were carried out for two reasons: to study the effects of gamma irradiation on cyclodextrins and their derivatives; and to investigate selectivity during the gamma irradiation of cyclodextrin derivatives

  6. Preparation and preliminary bioevaluation of {sup 99m}Tc(CO){sub 3}-11{beta}-progesterone derivative prepared via click chemistry route

    Energy Technology Data Exchange (ETDEWEB)

    Dhyani, Manish V.; Satpati, Drishty; Korde, Aruna [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Sarma, Haladhar Dev [Radiation Biology and Health Sciences Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Kumar, Chandan [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India); Banerjee, Sharmila, E-mail: sharmila@barc.gov.i [Radiopharmaceuticals Division, Bhabha Atomic Research Centre, Mumbai 400 085 (India)

    2010-11-15

    Introduction: Progesterone receptors (PRs) overexpressed in breast cancers serve as potential targets for developing radiotracers for use in nuclear medicine. Hence, suitably derivatized progesterone can be envisaged as a potential vector for targeting overexpression of receptors in breast cancer. In the present article, we report the preparation of a {sup 99m}Tc(CO){sub 3}-progesterone triazole using the Cu(I)-catalyzed novel click chemistry route. Preliminary evaluation of the radiolabeled derivative has been carried out in binding studies with MCF 7 cell lines. Methods: 11-Hydroxyprogesterone has been synthetically derivatized to 11-azidoprogesterone. Subsequently, the cycloaddition reaction between progesterone azide and propargyl glycine was carried out to prepare 1,4-bifunctionalized progesterone triazole analogue. The clicked progesterone triazole derivative was radiolabeled with {sup 99m}Tc and characterized by HPLC. The chemical characterization of {sup 99m}Tc(CO){sub 3}-progesterone triazole has been carried out by preparing its corresponding rhenium complex using the [NEt{sub 4}]{sub 2}[Re(CO){sub 3}Br{sub 3}] precursor. While in vitro studies were carried out in MCF7 cell lines, in vivo distribution studies were performed in female Swiss mice. Results: The radiolabeled complex could be prepared in >95% radiochemical yield as determined by HPLC. In vitro studies of {sup 99m}Tc(CO){sub 3}-progesterone complex in MCF7 cell lines overexpressing receptors for breast cancer showed binding up to 30%. In vivo distribution studies in female Swiss mice have shown uterine uptake of 0.41 (0.06) % ID/g at 3 h postinjection (pi) and retention therein till 24 h pi. Conclusion: The present study demonstrates a novel and facile route for preparation of {sup 99m}Tc-labeled progesterone complex using click chemistry. This strategy can be further extended towards preparation of radiolabeled complexes of other steroidal derivatives.

  7. Preparation and preliminary bioevaluation of 99mTc(CO)3-11β-progesterone derivative prepared via click chemistry route

    International Nuclear Information System (INIS)

    Introduction: Progesterone receptors (PRs) overexpressed in breast cancers serve as potential targets for developing radiotracers for use in nuclear medicine. Hence, suitably derivatized progesterone can be envisaged as a potential vector for targeting overexpression of receptors in breast cancer. In the present article, we report the preparation of a 99mTc(CO)3-progesterone triazole using the Cu(I)-catalyzed novel click chemistry route. Preliminary evaluation of the radiolabeled derivative has been carried out in binding studies with MCF 7 cell lines. Methods: 11-Hydroxyprogesterone has been synthetically derivatized to 11-azidoprogesterone. Subsequently, the cycloaddition reaction between progesterone azide and propargyl glycine was carried out to prepare 1,4-bifunctionalized progesterone triazole analogue. The clicked progesterone triazole derivative was radiolabeled with 99mTc and characterized by HPLC. The chemical characterization of 99mTc(CO)3-progesterone triazole has been carried out by preparing its corresponding rhenium complex using the [NEt4]2[Re(CO)3Br3] precursor. While in vitro studies were carried out in MCF7 cell lines, in vivo distribution studies were performed in female Swiss mice. Results: The radiolabeled complex could be prepared in >95% radiochemical yield as determined by HPLC. In vitro studies of 99mTc(CO)3-progesterone complex in MCF7 cell lines overexpressing receptors for breast cancer showed binding up to 30%. In vivo distribution studies in female Swiss mice have shown uterine uptake of 0.41 (0.06) % ID/g at 3 h postinjection (pi) and retention therein till 24 h pi. Conclusion: The present study demonstrates a novel and facile route for preparation of 99mTc-labeled progesterone complex using click chemistry. This strategy can be further extended towards preparation of radiolabeled complexes of other steroidal derivatives.

  8. Technical Note: A trace gas climatology derived from the Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS data set

    Directory of Open Access Journals (Sweden)

    A. Jones

    2012-06-01

    Full Text Available The Atmospheric Chemistry Experiment-Fourier Transform Spectrometer (ACE-FTS aboard the Canadian satellite SCISAT (launched in August 2003 was designed to investigate the composition of the upper troposphere, stratosphere, and mesosphere. ACE-FTS utilizes solar occultation to measure temperature and pressure as well as vertical profiles of over thirty chemical species including O3, H2O, CH4, N2O, CO, NO, NO2, N2O5, HNO3, HCl, ClONO2, CCl3F, CCl2F2, and HF. Global coverage for each species is obtained approximately over a three month period and measurements are made with a vertical resolution of typically 3–4 km. A quality-controlled climatology has been created for each of these 14 baseline species, where individual profiles are averaged over the period of February 2004 to February 2009. Measurements used are from the ACE-FTS version 2.2 data set including updates for O3 and N2O5. The climatological fields are provided on a monthly and three-monthly basis (DJF, MAM, JJA, SON at 5 degree latitude and equivalent latitude spacing and on 28 pressure surfaces (26 of which are defined by the Stratospheric Processes And their Role in Climate (SPARC Chemistry-Climate Model Validation Activity. The ACE-FTS climatological data set is available through the ACE website.

  9. Synthesis of liquid crystals derived from nitroazobenzene: a proposed multistep synthesis applied to organic chemistry laboratory classes; Sintese de cristais liquidos derivados do nitroazobenzeno: uma proposta de sintese multi-etapas aplicada as aulas de quimica organica experimental

    Energy Technology Data Exchange (ETDEWEB)

    Cristiano, Rodrigo; Cabral, Marilia Gabriela B.; Aquino, Rafael B. de; Cristiano, Claudia M.Z., E-mail: rcristiano@quimica.ufpb.br [Universidade Federal da Paraiba (UFPB), Joao Pessoa, PB (Brazil). Departamento de Quimica

    2014-07-01

    We describe a synthetic route consisting of five steps from aniline to obtain liquid crystal compounds derived from nitroazobenzene. Syntheses were performed during the second half of the semester in organic chemistry laboratory classes. Students characterized the liquid crystal phase by the standard melting point techniques, differential scanning calorimetry and polarized optical microscopy. These experiments allow undergraduate students to explore fundamentally important reactions in Organic Chemistry, as well as modern concepts in Chemistry such as self-assembly and self-organization, nanostructured materials and molecular electronics. (author)

  10. Computational and Experimental Assessment of Benzene Cation Chemistry for the Measurement of Marine Derived Biogenic Volatile Organic Compounds with Chemical Ionization Mass Spectrometry

    Science.gov (United States)

    Zoerb, M.; Kim, M.; Zimmermann, K.; Bertram, T. H.

    2013-12-01

    Chemical ionization mass spectrometry (CIMS) is a highly selective and sensitive technique for the measurement of trace gases in the atmosphere. However, competing side reactions and dependence on relative humidity (RH) can make the transition from the laboratory to the field challenging. Effective implementation of chemical ionization requires a thorough knowledge of the elementary steps leading to ionization of the analyte. We have recently investigated benzene cations for the detection of marine derived biogenic volatile organic compounds (BVOCs), such isoprene and terpene compounds, from algal bloom events. Our experimental results indicate that benzene ion chemistry is an attractive candidate for field measurements, and the RH dependence is weak. To further understand the advantages and limitations of this approach, we have also used electronic structure theory calculations to compliment the experimental work. These theoretical methods can provide valuable insight into the physical chemistry of ion molecule reactions including thermodynamical information, the stability of ions to fragmentation, and potential sources of interference such as dehydration to form isobaric ions. The combined experimental and computational approach also allows validation of the theoretical methods and will provide useful information towards gaining predictive power for the selection of appropriate reagent ions for future experiments.

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

    Science.gov (United States)

    Lasitha, P; Prasad, Edamana

    2016-07-18

    Perylene diimide (PDI) derivatives exhibit a high propensity for aggregation, which causes the aggregation-induced quenching of emission from the system. Host-guest chemistry is one of the best-known methods for preventing aggregation through the encapsulation of guest molecules. Herein we report the use of 18-crown-6 (18-C-6) as a host system to disaggregate suitably substituted PDI derivatives in methanol. 18-C-6 formed complexes with amino-substituted PDIs in methanol, which led to disaggregation and enhanced emission from the systems. Furthermore, the embedding of the PDI⋅18-C-6 complexes in poly(vinyl alcohol) (PVA) films generated remarkably high emission quantum yields (60-70 %) from the PDI derivatives. More importantly, the host-guest systems were tested for their ability to conduct electricity in PVA films. The electrical conductivities of the self-assembled systems in PVA were measured by electrochemical impedance spectroscopy (EIS) and the highest conductivity observed was 2.42×10(-5)  S cm(-1) . PMID:27319975

  12. Novel triazolyl bis-amino acid derivatives readily synthesized via click chemistry as potential corrosion inhibitors for mild steel in HCl

    Energy Technology Data Exchange (ETDEWEB)

    Deng Qiong; Shi Hongwei; Ding Nana; Chen Baoqin [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); He Xiaopeng, E-mail: xphe@ecust.edu.cn [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Liu Guixia; Tang Yun [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Long Yitao, E-mail: ytlong@ecust.edu.cn [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China); Chen Guorong, E-mail: mrs_guorongchen@ecust.edu.cn [Key Laboratory for Advanced Materials and Institute of Fine Chemicals, East China University of Science and Technology, Shanghai 200237 (China)

    2012-04-15

    Highlights: Black-Right-Pointing-Pointer Triazolyl bis-amino acids as new corrosion inhibitors. Black-Right-Pointing-Pointer EIS and polarization demonstrate their potency. Black-Right-Pointing-Pointer Inhibitor 4 obeys Langmuir isotherm. Black-Right-Pointing-Pointer Modeling study suggests the triazole ring essential for surface adsorption. - Abstract: Triazolyl bis-amino acid derivatives readily synthesized via click chemistry were identified as novel potent corrosion inhibitors for mild steel in HCl. The inhibitive characteristic of compound 4 was studied in detail via gravimetric measurement, electrochemical impedance spectroscopy, potentiodynamic polarization and scanning electron microscopy. In addition, a quantum chemical study suggests that the triazole ring involved in these inhibitors is structurally essential for the protection of metal surface.

  13. Chemical Architecture and Applications of Nucleic Acid Derivatives Containing 1,2,3-Triazole Functionalities Synthesized via Click Chemistry

    Directory of Open Access Journals (Sweden)

    Wei Gong

    2012-10-01

    Full Text Available There is considerable attention directed at chemically modifying nucleic acids with robust functional groups in order to alter their properties. Since the breakthrough of copper-assisted azide-alkyne cycloadditions (CuAAC, there have been several reports describing the synthesis and properties of novel triazole-modified nucleic acid derivatives for potential downstream DNA- and RNA-based applications. This review will focus on highlighting representative novel nucleic acid molecular structures that have been synthesized via the “click” azide-alkyne cycloaddition. Many of these derivatives show compatibility for various applications that involve enzymatic transformation, nucleic acid hybridization, molecular tagging and purification, and gene silencing. The details of these applications are discussed. In conclusion, the future of nucleic acid analogues functionalized with triazoles is promising.

  14. The vicinal difluoro motif in organic chemistry : the synthesis and behaviour of compounds derived from 2,3-diflurosuccinic acids

    OpenAIRE

    Schueler, Martin

    2006-01-01

    The following work describes the synthesis of compounds carrying a vicinal difluoro motif and the evaluation of this structural element to influence the conformation of organic molecules. The synthesis of erythro and threo 1,2-difluoro-1,2-diphenylethane was achieved by bromofluorination and subsequent halogen exchange from stilbene. Oxidative degradation of the phenyl rings allowed to access erythro and threo 2,3- difluorosuccinic acids and a variety of derivatives thereof. Th...

  15. Low-temperature structural phase transitions in crystalline bromo and iodo 9-hydroxyphenalenone derivatives: Quantum chemistry employment

    Science.gov (United States)

    Dolin, S. P.; Khrulev, A. A.; Polyakov, E. V.; Mikhailova, T. Yu.; Levin, A. A.

    The model approaches and quantum chemical calculations are employed to explain the peculiarities of the ferroelectric behavior of new ?zero-dimensional? H-bonded materials, i.e., 5-bromo and 5-iodo derivatives of 9-hydroxyphenalenone (9HPO) and its deuteroxy analogue (9DPO). The tunneling parameters ? (H/D) and the Ising model coupling parameters Jij are evaluated and discussed. Analysis of these parameters for the hydroxy and deuteroxy species demonstrates the quantum paraelectric behavior of both Br and I 9HPO derivatives due to the large values of the ?(H)/J0 relation, where J0 is the molecular field parameter describing the coupling of any given H-bond proton with all rest ones. In contrast, small values ?(D)/J0 for their 9DPO analogues favor the low-temperature structural phase transition into an ordered phase, which has a rather antiferroelectric than ferroelectric character. The estimates obtained and the resulting conclusions are in line with the overall observed trends in behavior of the substances under examination that emerge from the available experimental data.

  16. Annealing temperature modulated interfacial chemistry and electrical characteristics of sputtering-derived HfO2/Si gate stack

    International Nuclear Information System (INIS)

    Sputtering-derived HfO2 high-k gate dielectric thin films have been deposited on Si substrate by means of high vacuum physics vapor deposition method. Via characterization from x-ray photoelectron spectroscopy (XPS) and electrical measurements, the effect of post-deposition annealing temperature on the interfacial and electrical properties of HfO2/Si gate stack has been investigated. XPS analyses show that an interfacial layer between HfO2 and silicon substrate has been found in the post-deposition annealing process. Increase in Hf-silicate layer and reduction in SiO2 low-k interface layer have been detected. Electrical measurements of MOS capacitor based on Al/HfO2/Si gate stacks indicate that annealing HfO2 sample at 300 °C demonstrated the improved electrical performance. As a result, the leakage current of 3.60 × 10−5 A/cm2 at applied substrate voltage of 2 V, which is much lower than those samples annealed at other temperature, has been obtained. The leakage current mechanism for different annealing temperature has been discussed systematically. - Highlights: • Sputtering-derived HfO2/Si gate stack has been deposited on Si substrate. • Annealing lead to the increase in Hf silicate layer and reduction in SiO2 interface layer. • For substrate injection, Schottky emission dominates the conduction mechanism at the low fields. • For gate injection, Poole–Frenkle emission dominates the conduction mechanism at the high field

  17. Annealing temperature modulated interfacial chemistry and electrical characteristics of sputtering-derived HfO{sub 2}/Si gate stack

    Energy Technology Data Exchange (ETDEWEB)

    Gao, J. [School of Physics and Materials Science, Radiation Detection Materials & Devices Lab, Anhui University, Hefei 230601 (China); School of Sciences, Anhui University of Science and Technology, Huainan 232001 (China); He, G., E-mail: ganghe01@issp.ac.cn [School of Physics and Materials Science, Radiation Detection Materials & Devices Lab, Anhui University, Hefei 230601 (China); Zhang, J.W.; Deng, B.; Liu, Y.M. [School of Physics and Materials Science, Radiation Detection Materials & Devices Lab, Anhui University, Hefei 230601 (China)

    2015-10-25

    Sputtering-derived HfO{sub 2} high-k gate dielectric thin films have been deposited on Si substrate by means of high vacuum physics vapor deposition method. Via characterization from x-ray photoelectron spectroscopy (XPS) and electrical measurements, the effect of post-deposition annealing temperature on the interfacial and electrical properties of HfO{sub 2}/Si gate stack has been investigated. XPS analyses show that an interfacial layer between HfO{sub 2} and silicon substrate has been found in the post-deposition annealing process. Increase in Hf-silicate layer and reduction in SiO{sub 2} low-k interface layer have been detected. Electrical measurements of MOS capacitor based on Al/HfO{sub 2}/Si gate stacks indicate that annealing HfO{sub 2} sample at 300 °C demonstrated the improved electrical performance. As a result, the leakage current of 3.60 × 10{sup −5} A/cm{sup 2} at applied substrate voltage of 2 V, which is much lower than those samples annealed at other temperature, has been obtained. The leakage current mechanism for different annealing temperature has been discussed systematically. - Highlights: • Sputtering-derived HfO{sub 2}/Si gate stack has been deposited on Si substrate. • Annealing lead to the increase in Hf silicate layer and reduction in SiO{sub 2} interface layer. • For substrate injection, Schottky emission dominates the conduction mechanism at the low fields. • For gate injection, Poole–Frenkle emission dominates the conduction mechanism at the high field.

  18. Chemistry and structure of coal-derived asphaltenes, Phase III. Quarterly progress report, January--March 1978

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T. F.

    1978-01-01

    The solubility limits of Synthoil and PAMCO asphaltenes have been measured as a function of Hildebrand solubility parameters and hydrogen bonding. Solvents with moderate hydrogen bonding capacity such as dioxane, ethyl benzoate and dibutyl phthalate were found to be most effective in dissolving asphaltenes over the widest range of solubility parameters. VPO molecular weight studies of coal liquid derived carbenes, as a function of concentration in the solvent THF, indicate that these fractions are more strongly self-associated than the corresponding asphaltenes, and generally afford high infinite dilution number average molecular weights: Synthoil, 861; HRI H-Coal, 1156; Cat. Inc. SRC, 1228; PAMCO SRC, 1054. The variable ESR temperature dependence of the spin intensity for a Synthoil asphaltene-I/sub 2/ charge transfer followed a 1/T (Curie--Weiss) dependence over the temperature range from 25/sup 0/ to -114/sup 0/C suggesting that independent, non-interacting donor and acceptor doublets were formed. Weight percent OH values, determined from 'H NMR analysis of silylated asphaltenes, were found to provide a reasonably linear correlation with the absorbance of the monomeric OH infrared stretching bands of the asphaltenes.

  19. Investigation of NOx emissions and NOx-related chemistry in East Asia using CMAQ-predicted and GOME-derived NO2 columns

    Directory of Open Access Journals (Sweden)

    J. Y. Kim

    2009-02-01

    Full Text Available In this study, NO2 columns from the US EPA Models-3/CMAQ model simulations carried out using the 2001 ACE-ASIA (Asia Pacific Regional Aerosol Characterization Experiment emission inventory over East Asia were compared with the GOME-derived NO2 columns. There were large discrepancies between the CMAQ-predicted and GOME-derived NO2 columns in the fall and winter seasons. In particular, while the CMAQ-predicted NO2 columns produced larger values than the GOME-derived NO2 columns over South Korea for all four seasons, the CMAQ-predicted NO2 columns produced smaller values than the GOME-derived NO2 columns over North China for all seasons with the exception of summer (summer anomaly. It is believed that there might be some error in the NOx emission estimates as well as uncertainty in the NOx chemical loss rates over North China and South Korea. Regarding the latter, this study further focused on the biogenic VOC (BVOC emissions that were strongly coupled with NOx chemistry during summer in East Asia. This study also investigated whether the CMAQ-modeled NO2/NOx ratios with the possibly overestimated isoprene emissions were higher than those with reduced isoprene emissions. Although changes in both the NOx chemical loss rates and NO2/NOx ratios from CMAQ-modeling with the different isoprene emissions affected the CMAQ-modeled NO2 levels, the effects were found to be limited, mainly due to the low absolute levels of NO2 in summer. Seasonal variations of the NOx emission fluxes over East Asia were further investigated by a set of sensitivity runs of the CMAQ model. Although the results still exhibited the summer anomaly possibly due to the uncertainties in both NOx-related chemistry in the CMAQ model and the GOME measurements, it is believed that consideration of both the seasonal variations in NOx emissions and the correct BVOC emissions in East Asia are critical. Overall, it is estimated that the NOx emissions are underestimated by ~57.3% in North

  20. Design, synthesis, and anticancer activity of novel berberine derivatives prepared via CuAAC “click” chemistry as potential anticancer agents

    Directory of Open Access Journals (Sweden)

    Jin X

    2014-08-01

    Full Text Available Xin Jin1,2,* Tian-Hua Yan,3,* Lan Yan,1 Qian Li,4 Rui-Lian Wang,1 Zhen-Lin Hu,1 Yuan-Ying Jiang,1 Qing-Yan Sun,1 Yong-Bing Cao1 1School of Pharmacy, Second Military Medical University, Shanghai, People's Republic of China; 2School of Pharmacy, FuJian University of Traditional Chinese Medicine, Fuzhou, People's Republic of China; 3Department of Pharmacology, School of Pharmacy, China Pharmaceutical University, Nanjing, People's Republic of China; 4Diakite Biological Technology Co., Ltd, Shanghai, People's Republic of China *These authors contributed equally to this work Abstract: A series of novel derivatives of phenyl-substituted berberine triazolyls has been designed and synthesized via copper-catalyzed azide-alkyne cycloaddition click chemistry in an attempt to develop antitumor agents. All of the compounds were evaluated for anticancer activity against a panel of three human cancer cell lines, including MCF-7 (breast, SW-1990 (pancreatic, and SMMC-7721 (liver and the noncancerous human umbilical vein endothelial cell (HUVEC cell lines. The results indicated that most of the compounds displayed notable anticancer activities against the MCF-7 cells compared with berberine. Among these derivatives, compound 16 showed the most potent inhibitory activity against the SW-1990 and SMMC-7721 cell lines, with half-maximal inhibitory concentration (IC50 values of 8.54±1.97 µM and 11.87±1.83 µM, respectively. Compound 36 exhibited the most potent inhibitory activity against the MCF-7 cell line, with an IC50 value of 12.57±1.96 µM. Compound 16 and compound 36 exhibited low cytotoxicity in the HUVEC cell line, with IC50 values of 25.49±3.24 µM and 30.47±3.47 µM. Furthermore, compounds 14, 15, 16, 17, 18, 32, and 36 exhibited much better selectivity than berberine toward the normal cell line HUVEC. Keywords: berberine, anticancer, click chemistry, structure–activity relationship

  1. Bad chemistry

    OpenAIRE

    Petsko, Gregory A

    2004-01-01

    General chemistry courses haven't changed significantly in forty years. Because most basic chemistry students are premedical students, medical schools have enormous influence and could help us start all over again to create undergraduate chemistry education that works.

  2. Phosphaborane chemistry. Syntheses and calculated molecular structures of mono- and di-chloro derivatives of 1,2-diphospha-closo-dodecaborane(10)

    Czech Academy of Sciences Publication Activity Database

    Grüner, Bohumír; Hnyk, Drahomír; Císařová, I.; Plzák, Zbyněk; Štíbr, Bohumil

    č. 15 (2002), s. 2954-2959. ISSN 1472-7773 R&D Projects: GA ČR GA203/00/1042; GA MŠk LN00A028 Institutional research plan: CEZ:AV0Z4032918 Keywords : crystal-structure * phosphacarborane chemistry * polyhedral phosphaboranes Subject RIV: CA - Inorganic Chemistry Impact factor: 3.023, year: 2002

  3. Investigation of NOx emissions and NOx-related chemistry in East Asia using CMAQ-predicted and GOME-derived NO2 columns

    Directory of Open Access Journals (Sweden)

    J. H. Woo

    2008-09-01

    Full Text Available This study examined the estimation accuracy of NOx emissions over East Asia with particular focus on North China and South Korea due to their strong source (North China-receptor (South Korea relationship. In order to determine contributions of North China emissions to South Korean air quality accurately, it is important to examine the accuracy of the emission inventories of both regions. In this study, NO2 columns from the US EPA Models-3/CMAQ model simulations carried out using the 2001 ACE-ASIA (Asia Pacific Regional Aerosol Characterization Experiment emission inventory over East Asia were compared with the GOME-derived NO2 columns. There were large discrepancies between the CMAQ-predicted and GOME-derived NO2 columns in the fall and winter seasons. In particular, while the CMAQ-predicted NO2 columns produced larger values than the GOME-derived NO2 columns over South Korea (receptor region for all four seasons, the CMAQ-predicted NO2 columns produced smaller values than the GOME-derived NO2 columns over North China (source region for all seasons with the exception of summer. It is believed that there might be some estimation error in the NOx emissions as well as large uncertainty in NOx loss rates over North China and South Korea. Regarding the latter, this study further focused on the biogenic VOC emissions that were strongly coupled with NOx chemistry in East Asia. It was found that the rates of NOx loss determined by CMAQ modeling studies might be significantly low due to the possible overestimation of biogenic isoprene emissions during summer, particularly in China. In addition, due to the possible overestimation of isoprene emissions, the CMAQ-modeled NO2/NOx ratios might show an incorrectly high level, compared with the actual NO2/NOx ratios. In addition to the retarded NOx chemical loss rates and overestimated NO2/NOx ratios, the omission of soil NOx emissions over North China during summer can lead to an underestimation of NOx

  4. Complex chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Bong Gon; Kim, Jae Sang; Kim, Jin Eun; Lee, Boo Yeon

    2006-06-15

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  5. Complex chemistry

    International Nuclear Information System (INIS)

    This book introduces complex chemistry with ten chapters, which include development of complex chemistry on history coordination theory and Warner's coordination theory and new development of complex chemistry, nomenclature on complex with conception and define, chemical formula on coordination compound, symbol of stereochemistry, stereo structure and isomerism, electron structure and bond theory on complex, structure of complex like NMR and XAFS, balance and reaction on solution, an organo-metallic chemistry, biology inorganic chemistry, material chemistry of complex, design of complex and calculation chemistry.

  6. Mathematical Chemistry

    OpenAIRE

    Trinajstić, Nenad; Gutman, Ivan

    2002-01-01

    A brief description is given of the historical development of mathematics and chemistry. A path leading to the meeting of these two sciences is described. An attempt is made to define mathematical chemistry, and journals containing the term mathematical chemistry in their titles are noted. In conclusion, the statement is made that although chemistry is an experimental science aimed at preparing new compounds and materials, mathematics is very useful in chemistry, among other things, to produc...

  7. A SYSTEMIC REVIEW: MICROWAVE SYNTHESIS AS A PART OF GREEN CHEMISTRY FOR THE SYNTHESIS OF NOVEL 1, 2, 4- TRIAZOLE DERIVATIVES

    OpenAIRE

    Anshul Chawla; Prabhdeep Kaur

    2013-01-01

    Microwave reactions are based on the basic principles of green chemistry, basically involve “Go Green” concept. Purpose of green synthesis is to proceed with all the synthetic procedures which are ecofriendly and economic. Great deal of better yield in lesser time than conventional methods are observed. In medicinal chemistry, 1,2,4- triazoles are the source for potent medicaments for different pharmacological activities. In connection with this, literature is being compiled up for the sake ...

  8. Combinatorial chemistry

    DEFF Research Database (Denmark)

    Nielsen, John

    1994-01-01

    An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds.......An overview of combinatorial chemistry is presented. Combinatorial chemistry, sometimes referred to as `irrational drug design,' involves the generation of molecular diversity. The resulting chemical library is then screened for biologically active compounds....

  9. Positronium chemistry

    CERN Document Server

    Green, James

    1964-01-01

    Positronium Chemistry focuses on the methodologies, reactions, processes, and transformations involved in positronium chemistry. The publication first offers information on positrons and positronium and experimental methods, including mesonic atoms, angular correlation measurements, annihilation spectra, and statistical errors in delayed coincidence measurements. The text then ponders on positrons in gases and solids. The manuscript takes a look at the theoretical chemistry of positronium and positronium chemistry in gases. Topics include quenching, annihilation spectrum, delayed coincidence

  10. N-4-Acyl derivatives as lipophilic prodrugs of cidofovir and its 5-azacytosine analogue, (S)-HPMP-5-azaC: Chemistry and antiviral activity

    Czech Academy of Sciences Publication Activity Database

    Krečmerová, Marcela; Pohl, Radek; Masojídková, Milena; Balzarini, J.; Snoeck, R.; Andrei, G.

    2014-01-01

    Roč. 22, č. 10 (2014), s. 2896-2906. ISSN 0968-0896 R&D Projects: GA MPO FR-TI4/625 Institutional support: RVO:61388963 Keywords : acyclic nucleoside phosphonate * antivirals * 5-azacytosine * prodrug Subject RIV: CC - Organic Chemistry Impact factor: 2.793, year: 2014

  11. Expanding the structural chemistry of the weakly coordinating closo-carborane CB11H12 (-): its monoiodo derivatives with and without C (5v) symmetry

    Czech Academy of Sciences Publication Activity Database

    Hnyk, Drahomír; Holub, Josef; Růžička, A.; Padělková, Z.; Bühl, M.

    2013-01-01

    Roč. 24, č. 3 (2013), s. 927-932. ISSN 1040-0400 R&D Projects: GA ČR GAP208/10/2269 Institutional support: RVO:61388980 Keywords : Weakly-coordinating anions * X-Ray diffraction * B-11 Chemical shifts * Spin-orbit coupling * Acidity Subject RIV: CA - Inorganic Chemistry Impact factor: 1.900, year: 2013

  12. Deriving Derivatives

    OpenAIRE

    Soklakov, Andrei N.

    2013-01-01

    Quantitative Structuring is a rigorous framework for the design of financial products. We show how it incorporates traditional investment ideas while supporting a more accurate expression of clients' views on the market. We briefly touch upon adjacent topics regarding the safety of financial derivatives and the role of pricing models in product design.

  13. Social Chemistry

    OpenAIRE

    Lichtfouse, Eric; Schwarzbauer, Jan; Robert, Didier

    2012-01-01

    International audience This article is both an essay to propose social chemistry as a new scientific discipline, and a preface of the book Environmental Chemistry for a Sustainable World. Environmental chemistry is a fast emerging discipline aiming at the understanding the fate of pollutants in ecosystems and at designing novel processes that are safe for ecosystems. Past pollution should be cleaned, future pollution should be predicted and avoided (Lichtfouse et al., 2005a). Such advices ...

  14. Computational chemistry

    OpenAIRE

    Truhlar, Donald G.; McKoy, Vincent

    2000-01-01

    Computational chemistry has come of age. With significant strides in computer hardware and software over the last few decades, computational chemistry has achieved full partnership with theory and experiment as a tool for understanding and predicting the behavior of a broad range of chemical, physical, and biological phenomena. The Nobel Prize award to John Pople and Walter Kohn in 1998 highlighted the importance of these advances in computational chemistry. With massively parallel computers ...

  15. Bioinorganic Chemistry

    OpenAIRE

    Bertini, Ivano; Gray, Harry B.; Lippard, Stephen J.; Valentine, Joan Selverstone

    1994-01-01

    This book covers material that could be included in a one-quarter or one-semester course in bioinorganic chemistry for graduate students and advanced undergraduate students in chemistry or biochemistry. We believe that such a course should provide students with the background required to follow the research literature in the field. The topics were chosen to represent those areas of bioinorganic chemistry that are mature enough for textbook presentation. Although each chapter presents material...

  16. Chemistry in Protoplanetary Disks

    OpenAIRE

    Henning, Thomas; Semenov, Dmitry

    2013-01-01

    This comprehensive review summarizes our current understanding of the evolution of gas, solids and molecular ices in protoplanetary disks. Key findings related to disk physics and chemistry, both observationally and theoretically, are highlighted. We discuss which molecular probes are used to derive gas temperature, density, ionization state, kinematics, deuterium fractionation, and study organic matter in protoplanetary disks.

  17. The chemistry of glycerin

    International Nuclear Information System (INIS)

    This book dedicated to chemistry of polyatomic alcohols, in particular, to glycerin and its numerous derivatives. These compounds are very widespread in the natural objects and carry out several functions in alive organism. Big part of these matters are arrange in industry production of base organic synthesis

  18. The Chemistry of Griseofulvin

    DEFF Research Database (Denmark)

    Petersen, Asger Bjørn; Rønnest, Mads Holger; Larsen, Thomas Ostenfeld;

    2014-01-01

    Specific synthetic routes are presented in schemes to illustrate the chemistry, and the analogs are presented in a table format to give an accessible overview of the structures. Several patents have been published regarding the properties of griseofulvin and its derivatives including synthesis...

  19. Exploring Natural Product Chemistry and Biology with Multicomponent Reactions. 5. Discovery of a Novel Tubulin-Targeting Scaffold Derived from the Rigidin Family of Marine Alkaloids

    OpenAIRE

    Frolova, Liliya V.; Magedov, Igor V.; Romero, Anntherese E.; Karki, Menuka; Otero, Isaiah; Hayden, Kathryn; Evdokimov, Nikolai M.; Banuls, Laetitia Moreno Y; Rastogi, Shiva K.; Smith, W. Ross; Lu, Shi-Long; Kiss, Robert; Shuster, Charles B.; Hamel, Ernest; Betancourt, Tania

    2013-01-01

    We developed synthetic chemistry to access the marine alkaloid rigidins and over forty synthetic analogues based on the 7-deazaxanthine, 7-deazaadenine, 7-deazapurine and 7-deazahypoxanthine skeletons. Analogues based on the 7-deazahypoxanthine skeleton exhibited nanomolar potencies against cell lines representing cancers with dismal prognoses, tumor metastases and multidrug resistant cells. Studies aimed at elucidating the mode(s) of action of the 7-deazahypoxanthines in cancer cells reveale...

  20. Technetium chemistry

    International Nuclear Information System (INIS)

    Technetium chemistry is a young and developing field. Despite the limited knowledge of its chemistry, technetium is the workhorse for nuclear medicine. Technetium is also a significant environmental concern because it is formed as a byproduct of nuclear weapons production and fission-power generators. Development of new technetium radio-pharmaceuticals and effective environmental control depends strongly upon knowledge of basic technetium chemistry. The authors performed research into the basic coordination and organometallic chemistry of technetium and used this knowledge to address nuclear medicine and environmental applications. This is the final report of a three-year Laboratory-Directed Research and Development (LDRD) project at the Los Alamos National Laboratory (LANL)

  1. Good chemistry

    OpenAIRE

    Petsko, Gregory A

    2004-01-01

    The subject matter in chemistry courses reflects almost nothing of the issues that chemists are interested in. It is important to formulate a set of topics - and a Medical College Admissions Test reflecting them - that would leave chemistry departments no choice but to change their teaching.

  2. Quantum chemistry

    CERN Document Server

    Lowe, John P

    1993-01-01

    Praised for its appealing writing style and clear pedagogy, Lowe's Quantum Chemistry is now available in its Second Edition as a text for senior undergraduate- and graduate-level chemistry students. The book assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry, thus enabling students to comprehend much of the current chemical literature in which quantum chemical methods or concepts are used as tools. The book begins with a six-chapter introduction of standard one-dimensional systems, the hydrogen atom,

  3. Trace Chemistry

    Science.gov (United States)

    Radhakrishnan, Krishnan; Whitefield, Philip

    1999-01-01

    , in addition, of the pressure, temperature, and velocity. A near term goal of the experimental program should be to confirm the nonlinear effects of sulfur speciation, and if present, to provide an explanation for them. It is also desirable to examine if the particulate matter retains any sulfur. The recommendation is to examine the effects on SOx production of variations in fuel-bound sulfur and aromatic content (which may affect the amount of particulates formed). These experiments should help us to understand if there is a coupling between particulate formation and SO, concentration. Similarly, any coupling with NOx can be examined either by introducing NOx into the combustion air or by using fuel-bound nitrogen. Also of immediate urgency is the need to establish and validate a detailed mechanism for sulfur oxidation/aerosol formation, whose chemistry is concluded to be homogeneous, because there is not enough surface area for heterogeneous effects. It is envisaged that this work will involve both experimental and theoretical programs. The experimental work will require, in addition to the measurements described above, fundamental studies in devices such as flow reactors and shock tubes. Complementing this effort should be modeling and theoretical activities. One impediment to the successful modeling of sulfur oxidation is the lack of reliable data for thermodynamic and transport properties for several species, such as aqueous nitric acid, sulfur oxides, and sulfuric acid. Quantum mechanical calculations are recommended as a convenient means of deriving values for these properties. Such calculations would also help establish rate constants for several important reactions for which experimental measurements are inherently fraught with uncertainty. Efforts to implement sufficiently detailed chemistry into computational fluid dynamic codes should be continued. Zero- and one-dimensional flow models are also useful vehicles for elucidating the minimal set of species and

  4. Synthesis via “click chemistry" of new triazole analogues derivatives of grandisin and veraguensin neolignans with potential trypanocidal and leishmanicidal activity

    Directory of Open Access Journals (Sweden)

    Tatiana C Bortolo

    2012-06-01

    Full Text Available Using the concept of bioisosterism, new triazole analogs were designed from the molecular modification of grandisin and veraguensin neolignans   which have a furan group that is a bioisóstere of 1,2,3-triazoles ring. In order to obtain more potent compounds, with fewer side effects, and better physical and chemical characteristics in combating leishmaniasis and chagas disease, this research group synthesized, via "Click Chemistry", eight new triazole analogues of neolignans. Thus reactions 1,3-dipolar cycloaddition of Huisgen were performed between terminal acetylenes and azides previously synthesized. The catalytic system CuSO4.5H2O/Ascorbate Sodium / CH2Cl2/H2O was used and, under this reaction conditions eight triazole analogues were synthesized in good yields. Trypanocidal activity test showed positive for the eight molecules.

  5. Review of future plans of the MAP3S Precipitation Chemistry Network: Derived from a MAP3S workshop held April 18--20, 1989, Bethesda, Maryland

    Energy Technology Data Exchange (ETDEWEB)

    Wesely, M.L. (Argonne National Lab., IL (USA). Environmental Research Div.); McNaughton, D.J. (ENSR Consulting and Engineering, Glastonbury, CT (USA)); Artz, R.S. (National Oceanic and Atmospheric Administration, Silver Spring, MD (USA). Air Resources Lab.); Gibson, J.H. (National Atmospheric Deposition Program, Fort Collins, CO (USA)); Hansen, D.A. (Electric Power Research Inst., Palo Alto, CA (

    1990-02-01

    A workshop was held in April 1989 to review the future plans of the MAP3S Precipitation Chemistry Network program sponsored by the Department of Energy (DOE). A panel of scientists reviewed options for future activities with regard to meeting the needs of DOE for health and environmental research. The panel concluded that the program should be redirected in the 1990s toward climate change research concerned with the effects of energy-related emissions on the extent of cloud cover and the optical properties of clouds. In addition, the panel found that current operations could be improved, more scientific analysis of the collected data should be conducted, and that the program should be considered as a means of carrying out future research that might be needed to address new health and environmental issues. 37 refs., 5 tabs.

  6. Materials Chemistry

    CERN Document Server

    Fahlman, Bradley D

    2011-01-01

    The 2nd edition of Materials Chemistry builds on the strengths that were recognized by a 2008 Textbook Excellence Award from the Text and Academic Authors Association (TAA). Materials Chemistry addresses inorganic-, organic-, and nano-based materials from a structure vs. property treatment, providing a suitable breadth and depth coverage of the rapidly evolving materials field. The 2nd edition continues to offer innovative coverage and practical perspective throughout. After briefly defining materials chemistry and its history, seven chapters discuss solid-state chemistry, metals, semiconducting materials, organic "soft" materials, nanomaterials, and materials characterization. All chapters have been thoroughly updated and expanded with, for example, new sections on ‘soft lithographic’ patterning, ‘click chemistry’ polymerization, nanotoxicity, graphene, as well as many biomaterials applications. The polymer and ‘soft’ materials chapter represents the largest expansion for the 2nd edition. Each ch...

  7. Introductory Chemistry

    OpenAIRE

    Baron, Mark; Gonzalez-Rodriguez, Jose; Stevens, Gary; Gray, Nathan; Atherton, Thomas; Winn, Joss

    2010-01-01

    Teaching and Learning resources for the 1st Year Introductory Chemistry course (Forensic Science). 30 credits. These are Open Educational Resources (OER), made available for re-use under a Creative Commons license.

  8. Analytical chemistry

    International Nuclear Information System (INIS)

    This book is comprised of nineteen chapters, which describes introduction of analytical chemistry, experimental error and statistics, chemistry equilibrium and solubility, gravimetric analysis with mechanism of precipitation, range and calculation of the result, volume analysis on general principle, sedimentation method on types and titration curve, acid base balance, acid base titration curve, complex and firing reaction, introduction of chemical electro analysis, acid-base titration curve, electrode and potentiometry, electrolysis and conductometry, voltammetry and polarographic spectrophotometry, atomic spectrometry, solvent extraction, chromatograph and experiments.

  9. Cluster Chemistry

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Cansisting of eight scientists from the State Key Laboratory of Physical Chemistry of Solid Surfaces and Xiamen University, this creative research group is devoted to the research of cluster chemistry and creation of nanomaterials.After three-year hard work, the group scored a series of encouraging progresses in synthesis of clusters with special structures, including novel fullerenes, fullerene-like metal cluster compounds as well as other related nanomaterials, and their properties study.

  10. Green Chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Collison, Melanie

    2011-05-15

    Green chemistry is the science of chemistry used in a way that will not use or create hazardous substances. Dr. Rui Resendes is working in this field at GreenCentre Canada, an offshoot of PARTEQ Innovations in Kingston, Ontario. GreenCentre's preliminary findings suggest their licensed product {sup S}witchable Solutions{sup ,} featuring 3 classes of solvents and a surfactant, may be useful in bitumen oil sands extraction.

  11. Radiation Chemistry

    Science.gov (United States)

    Wojnárovits, L.

    Ionizing radiation causes chemical changes in the molecules of the interacting medium. The initial molecules change to new molecules, resulting in changes of the physical, chemical, and eventually biological properties of the material. For instance, water decomposes to its elements H2 and O2. In polymers, degradation and crosslinking take place. In biopolymers, e.g., DNS strand breaks and other alterations occur. Such changes are to be avoided in some cases (radiation protection), however, in other cases they are used for technological purposes (radiation processing). This chapter introduces radiation chemistry by discussing the sources of ionizing radiation (radionuclide sources, machine sources), absorption of radiation energy, techniques used in radiation chemistry research, and methods of absorbed energy (absorbed dose) measurements. Radiation chemistry of different classes of inorganic (water and aqueous solutions, inorganic solids, ionic liquids (ILs)) and organic substances (hydrocarbons, halogenated compounds, polymers, and biomolecules) is discussed in concise form together with theoretical and experimental backgrounds. An essential part of the chapter is the introduction of radiation processing technologies in the fields of polymer chemistry, food processing, and sterilization. The application of radiation chemistry to nuclear technology and to protection of environment (flue gas treatment, wastewater treatment) is also discussed.

  12. Chemistry and Application of Dicarbadodecaborane and Its Derivatives%碳十硼烷及其衍生物的反应性及应用

    Institute of Scientific and Technical Information of China (English)

    赵娟; 黄鹏程; 陈功; 詹茂盛

    2012-01-01

    碳十硼烷(C2B10H12)是由2个C原子和10个B原子组成的二十面体笼状结构大分子,有邻位、间位和对位三种异构体。碳十硼烷庞大的体积以及类芳香族三维刚性结构使它具有优异的高温稳定性和化学稳定性,良好的溶解性使其具有广泛而灵活的应用。本文总结了近年来碳十硼烷和碳十硼烷衍生物在C原子、B原子上的化学反应性以及在环加成和金属络合方面的研究。另外,由于碳十硼烷衍生物特殊的立体结构,优异的耐高温性、热氧化性及高硼含量,本文综述了碳十硼烷衍生物近年来在功能材料、催化剂及生物医药等多个领域的应用进展。%Dicarba-closo-dodecaborane (carborane, C2B10HI2) containing two carbon atoms and ten boron atoms adopts nearly icosahedral geometry in which the carbon and boron atoms are hexacoordinate. The compound exists as ortho-, meta-and para-isomers. Due to the strong electron-acceptor properties of the cluster, massive bulk and three-dimensional rigidity, carborane and its derivatives possess remarkable thermal and chemical stability. Besides, the ready solubility makes the compound and its derivatives widely applied. There are two common methods for synthesis of carborane and carborane derivatives, including the "alkyne insertion" methodology and the method based on the substitution reaction with carboranyl lithium. In this paper, the chemical reactions and functionalization of carborane and its derivatives are summarized, especially the substitution reactions on carbon atoms and boron atoms, the cycloaddition reaction and metal-carborane complexation. Futhermore, due to the excellent heat stability and high electronic delocalization, the carborane derivatives can be utilized as functional materials. Also, carborane derivatives can be applied in boron neutron capture therapy (BNCT) for the high boron content of carborane. Meanwhile, the metal-carborane complexes

  13. Quantum chemistry

    CERN Document Server

    Lowe, John P

    2006-01-01

    Lowe's new edition assumes little mathematical or physical sophistication and emphasizes an understanding of the techniques and results of quantum chemistry. It can serve as a primary text in quantum chemistry courses, and enables students and researchers to comprehend the current literature. This third edition has been thoroughly updated and includes numerous new exercises to facilitate self-study and solutions to selected exercises.* Assumes little initial mathematical or physical sophistication, developing insights and abilities in the context of actual problems* Provides thorough treatment

  14. Polymer Chemistry

    Science.gov (United States)

    Williams, Martha; Roberson, Luke; Caraccio, Anne

    2010-01-01

    This viewgraph presentation describes new technologies in polymer and material chemistry that benefits NASA programs and missions. The topics include: 1) What are Polymers?; 2) History of Polymer Chemistry; 3) Composites/Materials Development at KSC; 4) Why Wiring; 5) Next Generation Wiring Materials; 6) Wire System Materials and Integration; 7) Self-Healing Wire Repair; 8) Smart Wiring Summary; 9) Fire and Polymers; 10) Aerogel Technology; 11) Aerogel Composites; 12) Aerogels for Oil Remediation; 13) KSC's Solution; 14) Chemochromic Hydrogen Sensors; 15) STS-130 and 131 Operations; 16) HyperPigment; 17) Antimicrobial Materials; 18) Conductive Inks Formulations for Multiple Applications; and 19) Testing and Processing Equipment.

  15. Chemistry of Pyrones, Part 5: New Crown Ether and Podand Derivatives of 3,5-Bis(bromomethyl-2,6-diphenyl-4H-pyran-4-one

    Directory of Open Access Journals (Sweden)

    Alireza Banaei

    2001-08-01

    Full Text Available New podand and crown ether derivatives of 3,5-disubstituted 4H-pyran-4-one (8-11 were prepared by the nucleophilic substitution reaction of 3,5-bis(bromomethyl-2,6-diphenyl-4H-pyran-4-one with o-nitrophenol, 8-hydroxyquinoline, 2-hydroxymethyl pyridine and triethyleneglycol, respectively. The yield of 3,5-bis[(2-formylphenoxy methyl]-2,6-diphenyl-4H-pyran-4-one has been improved by modification of our previous method using NaOH instead of Et3N.

  16. Organic chemistry

    International Nuclear Information System (INIS)

    The activities of the mycotoxin research group are discussed. This includes the isolation and structure determination of mycotoxins, plant products, the biosyntheris of mycotoxins, the synthesis and characteristics of steroids, the synthesis and mechanistic aspects of heterocyclic chemistry and the functionality of steroids over long distances. Nmr spectra and mass spectroscopy are some of the techniques used

  17. Reinventing Chemistry

    OpenAIRE

    Whitesides, George McClelland

    2015-01-01

    Chemistry is in a period of change, from an era focused on molecules and reactions, to one in which manipulations of systems of molecules and reactions will be essential parts of controlling larger systems. This Essay traces paths from the past to possible futures.

  18. Chemistry Notes

    Science.gov (United States)

    School Science Review, 1972

    1972-01-01

    Short articles on the kinetics of the hydrogen peroxide-iodide ion reaction, simulation of fluidization catalysis, the use of Newman projection diagrams to represent steric relationships in organic chemistry, the use of synthetic substrates for proteolytic enzyme reactions, and two simple clock reactions"--hydrolysis of halogenoalkanes and…

  19. The chemistry of subcritical water reactions of a hardwood derived lignin and lignin model compounds with nitrogen, hydrogen, carbon monoxide and carbon dioxide

    Science.gov (United States)

    Hill Bembenic, Meredith A.

    added pressure is: 1) cleavage of ethers (via hydrolysis) to form smaller methoxy-substituted phenolic monomers with aldehyde- or ketone-substituents representative of lignin monomers; 2) cleavage of the methoxy-, aldehyde- and/or ketone-substituents to form primarily methoxy-substituted phenolic monomers; 3) rearrangement of these phenolic monomers due to the enhanced pressure at reaction temperature; 4) formation of oligomers due to interaction amongst the methoxy-substituted phenolic monomers, which is also due to the enhanced pressure at reaction temperature; and 5) repolymerization of the monomers and oligomers to form high molecular weight compounds (i.e., longer reactions times or different pressures seemed to enhance these reactions). Under these conditions, depolymerization seems to be the dominant reaction pathway versus repolymerization. Reactions with lignin and H2O at 365°C have not been previously reported nor has the reaction chemistry for lignin depolymerization at these conditions been established. The results with lignin (or lignin model compounds), subcritical H2O and CO also show that the desired product slate can be modified with different pressure and time conditions. In particular, increasing reaction time (from 15 to 60 min.) caused lignin conversion to decrease, and the products appeared to be reacting with each other. However, the longer reaction time also showed that more methanol is generated (along with more solids).

  20. Fine chemistry

    International Nuclear Information System (INIS)

    The 1988 progress report of the Fine Chemistry laboratory (Polytechnic School, France) is presented. The research programs are centered on the renewal of the organic chemistry most important reactions and on the invention of new, highly efficient and highly selective reactions, by applying low cost reagents and solvents. An important research domain concerns the study and fabrication of new catalysts. They are obtained by means of the reactive sputtering of the metals and metal oxydes thin films. The Monte Carlo simulations of the long-range electrostatic interaction in a clay and the obtention of acrylamides from anhydrous or acrylic ester are summarized. Moreover, the results obtained in the field of catalysis are also given. The published papers and the congress communications are included

  1. The chemistry of aminoguanidine derivatives - preparation, crystal structure, thermal properties, and molecular docking studies of aminoguanidinium salts of several carboxylic acids

    Science.gov (United States)

    Selvakumar, Rajendran; Geib, Steven J.; Muthu Sankar, Aathi; Premkumar, Thathan; Govindarajan, Subbaiah

    2015-11-01

    The reaction of aminoguanidine bicarbonate (Amg) with oxamic, oxalic, malonic and sulfoacetic acids yielded (AmgH)H2NOC-COO (1), OOC-CONHNHC(NH2)NH2 (2) (AmgH)HOOC-CH2-COO (3) and O3S-CH2-CONHNHC(NH2)NH2 (4), respectively. For the first time, we studied the salt-forming ability of aminoguanidine with several carboxylic acids, such as oxamic, oxalic, malonic and sulphoacetic acids. We also compared the structural and thermal properties of these salts. Oxamic and malonic acids form only mono-aminoguanidinium salts, whereas oxalic acid mainly forms di-aminoguanidinium oxalate. In addition, oxalic acid forms guanylhydrazido-oxalic acid which exists as zwitter ion. Unlike other acids, sulfoacetic acid readily forms only the zwitter ionic salts (2-guanylhydrazido-oxo-methanesulfonic acid) rather than the usual simple salt. This result may be a result of the highly acidic nature of the sulfonic group, which favors acid catalyzed condensation. More significantly, for the first time, the ability guanylhydrazido-oxalic acid (2) and 2-guanylhydrazido-oxo-methanesulfonic acid (4) to inhibit human butyrylcholinesterase (human BChE) receptor has been studied with a molecular docking approach. The binding of the compounds to human BChE was examined as it is crucial to understanding the biological significance of aminoguanidine derivatives. The compounds were identified and characterized by analytical, FT-IR spectroscopic and thermal studies. Furthermore, the structures of compounds 1, 2 and 4 were confirmed by single X-ray diffraction studies. Compounds 1 and 2 crystallized in a monoclinic crystal system with P21/c and Cc space groups, respectively, whereas compound 4 crystalized in an orthorhombic system with a Pbca space group. All the compounds (1-4) underwent endo- followed by exothermic decomposition in the temperature range from 130 to 600 °C to yield gaseous products.

  2. Organometallic chemistry

    OpenAIRE

    Bashkin, James K.; M.L.H. Green; Dr. M. L. H. Green

    1982-01-01

    Transition metal organometallic chemistry is a rapidly expanding field, which has an important relationship to industrial problems of petrochemical catalysis. This thesis describes studies of fundamental organometallic reaction processes, such as C-H and C-C bond formation and cleavage, and investigations of the structure and bonding of organometallic compounds. A number of techniques were used to pursue these studies, including synthesis, X-ray crystallography, and semi-em...

  3. Disk Chemistry*

    OpenAIRE

    Thi Wing-Fai

    2015-01-01

    The chemical species in protoplanetary disks react with each other. The chemical species control part of the thermal balance in those disks. How the chemistry proceeds in the varied conditions encountered in disks relies on detailed microscopic understanding of the reactions through experiments or theoretical studies. This chapter strives to summarize and explain in simple terms the different types of chemical reactions that can lead to complex species. The first part of the chapter deals wit...

  4. Interstellar chemistry

    OpenAIRE

    Klemperer, William

    2006-01-01

    In the past half century, radioastronomy has changed our perception and understanding of the universe. In this issue of PNAS, the molecular chemistry directly observed within the galaxy is discussed. For the most part, the description of the molecular transformations requires specific kinetic schemes rather than chemical thermodynamics. Ionization of the very abundant molecular hydrogen and atomic helium followed by their secondary reactions is discussed. The rich variety of organic species o...

  5. Analytical chemistry

    International Nuclear Information System (INIS)

    The division for Analytical Chemistry continued to try and develope an accurate method for the separation of trace amounts from mixtures which, contain various other elements. Ion exchange chromatography is of special importance in this regard. New separation techniques were tried on certain trace amounts in South African standard rock materials and special ceramics. Methods were also tested for the separation of carrier-free radioisotopes from irradiated cyclotron discs

  6. Computational chemistry

    Science.gov (United States)

    Arnold, J. O.

    1987-01-01

    With the advent of supercomputers, modern computational chemistry algorithms and codes, a powerful tool was created to help fill NASA's continuing need for information on the properties of matter in hostile or unusual environments. Computational resources provided under the National Aerodynamics Simulator (NAS) program were a cornerstone for recent advancements in this field. Properties of gases, materials, and their interactions can be determined from solutions of the governing equations. In the case of gases, for example, radiative transition probabilites per particle, bond-dissociation energies, and rates of simple chemical reactions can be determined computationally as reliably as from experiment. The data are proving to be quite valuable in providing inputs to real-gas flow simulation codes used to compute aerothermodynamic loads on NASA's aeroassist orbital transfer vehicles and a host of problems related to the National Aerospace Plane Program. Although more approximate, similar solutions can be obtained for ensembles of atoms simulating small particles of materials with and without the presence of gases. Computational chemistry has application in studying catalysis, properties of polymers, all of interest to various NASA missions, including those previously mentioned. In addition to discussing these applications of computational chemistry within NASA, the governing equations and the need for supercomputers for their solution is outlined.

  7. Green chemistry

    International Nuclear Information System (INIS)

    A grand challenge facing government, industry, and academia in the relationship of our technological society to the environment is reinventing the use of materials. To address this challenge, collaboration from an interdisciplinary group of stakeholders will be necessary. Traditionally, the approach to risk management of materials and chemicals has been through inerventions intended to reduce exposure to materials that are hazardous to health and the environment. In 1990, the Pollution Prevention Act encouraged a new tact-elimination of hazards at the source. An emerging approach to this grand challenge seeks to embed the diverse set of environmental perspectives and interests in the everyday practice of the people most responsible for using and creating new materials--chemists. The approach, which has come to be known as Green Chemistry, intends to eliminate intrinsic hazard itself, rather than focusing on reducing risk by minimizing exposure. This chapter addresses the representation of downstream environmental stakeholder interests in the upstream everyday practice that is reinventing chemistry and its material inputs, products, and waste as described in the '12 Principles of Green Chemistry'

  8. Green chemistry

    International Nuclear Information System (INIS)

    The depletion of world fossil fuel reserves and the involvement of greenhouse gases in the global warming has led to change the industrial and energy policies of most developed countries. The goal is now to reserve petroleum to the uses where it cannot be substituted, to implement renewable raw materials obtained from plants cultivation, and to consider the biodegradability of molecules and of manufactured objects by integrating the lifetime concept in their expected cycle of use. The green chemistry includes the design, development and elaboration of chemical products and processes with the aim of reducing or eliminating the use and generation of harmful compounds for the health and the environment, by adapting the present day operation modes of the chemical industry to the larger framework of the sustainable development. In addition to biofuels, this book reviews the applications of green chemistry in the different industrial processes in concern. Part 1 presents the diversity of the molecules coming from renewable carbon, in particular lignocellulose and the biotechnological processes. Part 2 is devoted to materials and treats of the overall available technological solutions. Part 3 focusses on functional molecules and chemical intermediates, in particular in sugar- and fats-chemistry. Part 4 treats of biofuels under the aspects of their production and use in today's technologies. The last part deals with the global approaches at the environmental and agricultural levels. (J.S.)

  9. Collaborative Physical Chemistry Projects Involving Computational Chemistry

    Science.gov (United States)

    Whisnant, David M.; Howe, Jerry J.; Lever, Lisa S.

    2000-02-01

    The physical chemistry classes from three colleges have collaborated on two computational chemistry projects using Quantum CAChe 3.0 and Gaussian 94W running on Pentium II PCs. Online communication by email and the World Wide Web was an important part of the collaboration. In the first project, students used molecular modeling to predict benzene derivatives that might be possible hair dyes. They used PM3 and ZINDO calculations to predict the electronic spectra of the molecules and tested the predicted spectra by comparing some with experimental measurements. They also did literature searches for real hair dyes and possible health effects. In the final phase of the project they proposed a synthetic pathway for one compound. In the second project the students were asked to predict which isomer of a small carbon cluster (C3, C4, or C5) was responsible for a series of IR lines observed in the spectrum of a carbon star. After preliminary PM3 calculations, they used ab initio calculations at the HF/6-31G(d) and MP2/6-31G(d) level to model the molecules and predict their vibrational frequencies and rotational constants. A comparison of the predictions with the experimental spectra suggested that the linear isomer of the C5 molecule was responsible for the lines.

  10. Surface chemistry

    CERN Document Server

    Desai, KR

    2008-01-01

    The surface Chemistry of a material as a whole is crucially dependent upon the Nature and type of surfaces exposed on crystallites. It is therefore vitally important to independently Study different, well - defined surfaces through surface analytical techniques. In addition to composition and structure of surface, the subject also provides information on dynamic light scattering, micro emulsions, colloid Stability control and nanostructures. The present book endeavour to bring before the reader that the understanding and exploitation of Solid state phenomena depended largely on the ability to

  11. Hypercarbon chemistry

    International Nuclear Information System (INIS)

    This text points out the emerging significance of higher-valent carbon compounds. It describes the compounds of carbon with coordination numbers greater than four and explores the delocalized bonds of π aromatic molecules as a basis for rational description of orbitals; localized multicentered orbitals; the interactions of metallic ions with other atoms and molecules; the skeletal electron counts as a guide for synthesis; and the isolobal concept. Illustrated are the ways in which these subjects bring together structure and reactivity in the great diversity of novel carbon chemistry and its relationship to that of boron, lithium, hydrogen, the metals, and others

  12. Theoretical chemistry periodicities in chemistry and biology

    CERN Document Server

    Eyring, Henry

    1978-01-01

    Theoretical Chemistry: Periodicities in Chemistry and Biology, Volume 4 covers the aspects of theoretical chemistry. The book discusses the stably rotating patterns of reaction and diffusion; the chemistry of inorganic systems exhibiting nonmonotonic behavior; and population cycles. The text also describes the mathematical modeling of excitable media in neurobiology and chemistry; oscillating enzyme reactions; and oscillatory properties and excitability of the heart cell membrane. Selected topics from the theory of physico-chemical instabilities are also encompassed. Chemists, mechanical engin

  13. To Form a Favorable Idea of Chemistry

    Science.gov (United States)

    Heikkinen, Henry W.

    2010-01-01

    "To confess the truth, Mrs. B., I am not disposed to form a very favorable idea of chemistry, nor do I expect to derive much entertainment from it." That 200-year-old statement by Caroline to Mrs. Bryan, her teacher, appeared on the first page of Jane Marcet's pioneering secondary school textbook, "Conversations on Chemistry". It was published 17…

  14. Preparação de derivados do lapachol em meio ácido e em meio básico: uma proposta de experimentos para a disciplina de Química Orgânica Experimental Preparation of lapachol derivatives in acid and base media: proposed experiments for Organic Chemistry laboratory classes

    Directory of Open Access Journals (Sweden)

    Ticiano Pereira Barbosa

    2013-01-01

    Full Text Available In this educational paper we describe the extraction of lapachol from its natural source according to acid-base concepts in organic chemistry and the use of its derivatives β-lapachone and hydroxy-hydrolapachol to exemplify intramolecular cyclization, carbocation stability, Michael addition reaction and chromatography. The experiments were performed during three different undergraduate organic chemistry laboratory classes using low cost material, while avoiding color reagents for TLC visualization, as well as small-scale column chromatography to isolate the mixture of lapachol and β-lapachone.

  15. Combustion chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brown, N.J. [Lawrence Berkeley Laboratory, CA (United States)

    1993-12-01

    This research is concerned with the development and use of sensitivity analysis tools to probe the response of dependent variables to model input variables. Sensitivity analysis is important at all levels of combustion modeling. This group`s research continues to be focused on elucidating the interrelationship between features in the underlying potential energy surface (obtained from ab initio quantum chemistry calculations) and their responses in the quantum dynamics, e.g., reactive transition probabilities, cross sections, and thermal rate coefficients. The goals of this research are: (i) to provide feedback information to quantum chemists in their potential surface refinement efforts, and (ii) to gain a better understanding of how various regions in the potential influence the dynamics. These investigations are carried out with the methodology of quantum functional sensitivity analysis (QFSA).

  16. Science Update: Inorganic Chemistry

    Science.gov (United States)

    Rawls, Rebecca

    1978-01-01

    This first in a series of articles describing the state of the art of various branches of chemistry reviews inorganic chemistry, including bioinorganic, photochemistry, organometallic, and solid state chemistries. (SL)

  17. Why Teach Environmental Chemistry?

    Science.gov (United States)

    Gardner, Marjorie H.

    1974-01-01

    Discusses the importance of teaching environmental chemistry in secondary school science classes, and outlines five examples of environmental chemistry problems that focus on major concepts of chemistry and have critical implications for human survival and well-being. (JR)

  18. 启发式教学法在有机化学“羧酸及其衍生物”教学中的应用%Heuristic Approach Their Derivatives in Carboxylic Acids and of Organic Chemistry

    Institute of Scientific and Technical Information of China (English)

    李长恭

    2012-01-01

    This paper is a description of the application of heuristic method on carboxylic acid and their derivatives of Organic Chemistry. After bringing forward the discussing topics, such as the activities of carbonyl, a-hydrogen and acidity related to carboxylic acid, the students are directed to compare the corresponding bond length of methanoic acid with formaldehyde and methanol. Focusing on carbon-oxygen bond length in the methanoic acid, which is between carbon-oxygen double bond and carbon-oxygen single bond, the students have comprehended the super-conjugated structure characteristic of carboxylic acid and the chemical property of carboxylic acid could be deduced based on structure understanding. Encouraged by director, the students' interest is greatly enhanced and good results have been achieved.%本文介绍了启发式教学法在有机化学"羧酸及其衍生物"课堂教学中的应用。在总结前期学习内容的基础上,针对羧酸分子中羰基活泼性,α-氢的活泼性及酸性等问题,我引导学生从比较甲酸与甲醛和甲醇分子结构入手,紧紧围绕甲酸分子结构中介于碳-氧双键与碳-氧单键之间的碳-氧键长,分析甲酸分子结构的特点,定性地解答甲酸与甲醛和甲醇化学性质的差异性,加深了学生对羧酸结构与化学性质的认识,提高了学生的学习积极性,取得了良好的教学效果。

  19. Public perception of chemistry

    OpenAIRE

    Stražar, Alenka

    2015-01-01

    The thesis deals with the perception of chemistry among the public, which reflects the stereotypes that people have about chemistry. It presents the existing classification of stereotypes about chemistry and their upgrade. An analysis of movies that reflect the existing perception of chemistry in the public is written. Literature on selected aspects of the application of chemistry in movies is collected and analyzed. A qualification of perception of chemistry in the movies is presented based ...

  20. Science Update: Inorganic Chemistry.

    Science.gov (United States)

    Rawls, Rebecca

    1981-01-01

    Describes areas of inorganic chemistry which have changed dramatically in the past year or two, including photochemistry, electrochemistry, organometallic complexes, inorganic reaction theory, and solid state chemistry. (DS)

  1. APPLICATIONS OF GREEN CHEMISTRY IN SUSTAINABLE DEVELOPMENT

    Directory of Open Access Journals (Sweden)

    Suresh D. Dhage

    2013-07-01

    Full Text Available Chemistry is really very helpful to us as its applications are used worldwide for several purposes. We cannot really imagine a world without chemistry and its applications such as medicines. However, we should now concentrate on green chemistry or sustainable chemistry, which refers to reducing or stopping the damage done to the environment around us. Hence, green chemistry could include anything from reducing waste to even disposing of waste in the correct manner. Another way to save the environment through sustainable chemistry is to make use of renewable food stocks. Yet another good move is to make use of catalysts in experiments rather than using stoichiometric reagents. Chemical derivatives must be avoided as far as possible in any type of application as they often prove to be harmful. All chemical wastes should be disposed of in the best possible manner without causing any damage to the environment and living beings. We have to develop materials that will aid in the infusion of green chemistry into the curriculum such as green chemistry laboratory experiments and short courses on green chemistry. This article presents a brief description on green chemistry principles and its developments.

  2. Migration chemistry

    International Nuclear Information System (INIS)

    Migration chemistry, the influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour of pollutants in the environment, is an interplay between the actual natur of the pollutant and the characteristics of the environment, such as pH, redox conditions and organic matter content. The wide selection of possible pollutants in combination with varying geological media, as well as the operation of different chemical -, biochemical - and physico-chemical reactions compleactes the prediction of the influence of these processes on the mobility of pollutants. The report summarizes a wide range of potential pollutants in the terrestrial environment as well as a variety of chemical -, biochemical - and physico-chemical reactions, which can be expected to influence the migration behaviour, comprising diffusion, dispersion, convection, sorption/desorption, precipitation/dissolution, transformations/degradations, biochemical reactions and complex formation. The latter comprises the complexation of metal ions as well as non-polar organics to naturally occurring organic macromolecules. The influence of the single types of processes on the migration process is elucidated based on theoretical studies. The influence of chemical -, biochemical - and physico-chemical reactions on the migration behaviour is unambiguous, as the processes apparently control the transport of pollutants in the terrestrial environment. As the simple, conventional KD concept breaks down, it is suggested that the migration process should be described in terms of the alternative concepts chemical dispersion, average-elution-time and effective retention. (AB) (134 refs.)

  3. Radiation chemistry research using PULAF

    International Nuclear Information System (INIS)

    The details of the recently installed 7 MeV Pune University LINAC Facility (PULAF) coupled with the optical absorption technique for pulse radiolysis studies at the National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune, India are described. The facility has a selection of electron pulse widths in the range 10 ns-3 μs with corresponding doses of about 5-144 Gy per pulse. The operation of the machine and the detection system are fully automated. Several researchers from various Indian universities and national laboratories use the PULAF and some of the projects that are currently undertaken by our group and others include the radiation chemistry of indole and chalcone derivatives, herbal antioxidants, structure-reactivity studies in cinnamates, redox chemistry of inorganic metal complexes, studies on oxidation of pyrimidine analogues and aromatic sulphur compounds. Some of them are briefly discussed here

  4. Radiation chemistry research using PULAF

    Science.gov (United States)

    Gaikwad, Parimal; Priyadarsini, K. I.; Rao, B. S. M.

    2008-10-01

    The details of the recently installed 7 MeV Pune University LINAC Facility (PULAF) coupled with the optical absorption technique for pulse radiolysis studies at the National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune, India are described. The facility has a selection of electron pulse widths in the range 10 ns-3 μs with corresponding doses of about 5-144 Gy per pulse. The operation of the machine and the detection system are fully automated. Several researchers from various Indian universities and national laboratories use the PULAF and some of the projects that are currently undertaken by our group and others include the radiation chemistry of indole and chalcone derivatives, herbal antioxidants, structure-reactivity studies in cinnamates, redox chemistry of inorganic metal complexes, studies on oxidation of pyrimidine analogues and aromatic sulphur compounds. Some of them are briefly discussed here.

  5. Radiation chemistry research using PULAF

    Energy Technology Data Exchange (ETDEWEB)

    Gaikwad, Parimal [National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune 411 007 (India); Priyadarsini, K.I. [Radiation and Photochemistry Division, Bhabha Atomic Research Centre, Trombay, Mumbai 400 085 (India); Rao, B.S.M. [National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune 411 007 (India)], E-mail: bsmr@chem.unipune.ernet.in

    2008-10-15

    The details of the recently installed 7 MeV Pune University LINAC Facility (PULAF) coupled with the optical absorption technique for pulse radiolysis studies at the National Centre for Free Radical Research, Department of Chemistry, University of Pune, Pune, India are described. The facility has a selection of electron pulse widths in the range 10 ns-3 {mu}s with corresponding doses of about 5-144 Gy per pulse. The operation of the machine and the detection system are fully automated. Several researchers from various Indian universities and national laboratories use the PULAF and some of the projects that are currently undertaken by our group and others include the radiation chemistry of indole and chalcone derivatives, herbal antioxidants, structure-reactivity studies in cinnamates, redox chemistry of inorganic metal complexes, studies on oxidation of pyrimidine analogues and aromatic sulphur compounds. Some of them are briefly discussed here.

  6. Prebiotic phosphorus chemistry reconsidered

    Science.gov (United States)

    Schwartz, A. W.; Orgel, L. E. (Principal Investigator)

    1997-01-01

    The available evidence indicates that the origin of life on Earth certainly occurred earlier than 3.5 billion years ago and perhaps substantially earlier. The time available for the chemical evolution which must have preceded this event is more difficult to estimate. Both endogenic and exogenic contributions to chemical evolution have been considered; i.e., from chemical reactions in a primitive atmosphere, or by introduction in the interiors of comets and/or meteorites. It is argued, however, that the phosphorus chemistry of Earth's earliest hydrosphere, whether primarily exogenic or endogenic in origin, was most likely dominated by compounds less oxidized than phosphoric acid and its esters. A scenario is presented for the early production of a suite of reactive phosphonic acid derivatives, the properties of which may have foreshadowed the later appearance of biophosphates.

  7. Environmental chemistry of technetium

    International Nuclear Information System (INIS)

    Safe disposal of waste is perceived by public opinion as probably the greatest technical problem of the nuclear industry. This concern derives from the large quantities of radioactivity involved and from the suspicion that man-made barriers are not completely reliable for the lifetime of such waste. Therefore, the biogeochemical cycling of long-lived radionuclides resulting from nuclear power generation represents an important factor influencing decisions regarding the future development of the nuclear industry. As far as technetium is concerned, it should be mentioned that the hazard from the isotope /sup 99/Tc remains practically unchanged for some 30,000 years because of its 2.1x10/sup 5/ year half-life. In this paper the information available on the environmental chemistry of technetium is discussed in order to evaluate the importance of chemical processes in determining the distribution of technetium in the biosphere

  8. Industrial Chemistry and School Chemistry: Making Chemistry Studies More Relevant

    Science.gov (United States)

    Hofstein, Avi; Kesner, Miri

    2006-01-01

    In this paper, we present the development and implementation over the period of more than 15 years of learning materials focusing on industrial chemistry as the main theme. The work was conducted in the Department of Science Teaching at the Weizmann Institute of Science, Israel. The project's general goal was to teach chemistry concepts in the…

  9. Wood products and green chemistry

    OpenAIRE

    Pizzi, Antonio

    2016-01-01

    Key message Green chemistry for and from wood has developed numerous industrial products, namely biosourced, green wood adhesives and preservatives, foams, composite matrices, laminates, hard and flexible plastics, flexible films, and abrasive grinding discs, and their number is still growing.IntroductionThis review addresses (1) the elimination of toxic aldehydes from the most common wood panel adhesive, the one based on urea, itself a natural product, (2) biosourced adhesives derived from w...

  10. From Matter to Life:Chemistry?Chemistry!

    Institute of Scientific and Technical Information of China (English)

    Jean-Marie; LEHN

    2007-01-01

    1 Results Animate as well as inanimate matter,living organisms as well as materials,are formed of molecules and of the organized entities resulting from the interaction of molecules with each other.Chemistry provides the bridge between the molecules of inanimate matter and the highly complex molecular architectures and systems which make up living organisms. Synthetic chemistry has developed a very powerful set of methods for constructing ever more complex molecules.Supramolecular chemistry seeks to con...

  11. Green chemistry: A tool in Pharmaceutical Chemistry

    OpenAIRE

    Smita Talaviya; Falguni Majumdar

    2012-01-01

    Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceut...

  12. How Much History Can Chemistry Take?

    Directory of Open Access Journals (Sweden)

    Lucasz Lamza

    2010-12-01

    Full Text Available Chemistry is typically considered to be a nomothetic science, i.e. a science interested in general laws rather than historical facts. Also, the unification of science is usually envisioned as an effort to connect particular scientific disciplines through their laws, e.g., the laws of chemistry are to be derived from the laws of physics. It is however equally sensible to combine the sciences through a single cosmic history. There is a large literature following this direction, albeit rarely focused on chemistry. In this paper some ideas concerning the possible role of a 'historical' (or 'idiographic' chemistry are presented, with special attention to the notion of a 'genetic' classification of chemical compounds, and to the counterintuitive proposition that many major branches of physics may in fact be explained by chemistry, not the opposite.

  13. Friendship chemistry: An examination of underlying factors☆

    Science.gov (United States)

    Campbell, Kelly; Holderness, Nicole; Riggs, Matt

    2015-01-01

    Interpersonal chemistry refers to a connection between two individuals that exists upon first meeting. The goal of the current study is to identify beliefs about the underlying components of friendship chemistry. Individuals respond to an online Friendship Chemistry Questionnaire containing items that are derived from interdependence theory and the friendship formation literature. Participants are randomly divided into two subsamples. A principal axis factor analysis with promax rotation is performed on subsample 1 and produces 5 factors: Reciprocal candor, mutual interest, personableness, similarity, and physical attraction. A confirmatory factor analysis is conducted using subsample 2 and provides support for the 5-factor model. Participants with agreeable, open, and conscientious personalities more commonly report experiencing friendship chemistry, as do those who are female, young, and European/white. Responses from participants who have never experienced chemistry are qualitatively analyzed. Limitations and directions for future research are discussed. PMID:26097283

  14. Combining Chemistry

    International Nuclear Information System (INIS)

    The last advances inside the field of the chemical synthesis involve mainly two classes of methods, the parallel and that of separation and it mixes. Each one of them offers different possibilities in the obtaining of the looked for substance. In this article it is described in succinct form the procedures that are continued in each case, the same thing that their advantages and disadvantages. In the synthesis process, especially in pharmacology, the main interest of the chemists is centered in finding indications of clinical activity in the compounds that synthesize. In the realization of this work class it leaves initially of the basic structure of a substance, in general derived of natural products as bacteria, mushrooms, etc; With well-known clinical activity the one which once selected, and fully identified, it takes as molecule mother or series head with the purpose of making different transformations in their structure it stops then to check if the new compound presents a bigger or smaller activity that the initial. Although this synthesis method has been refined with the use of different tests that they are made in a form but quick and reliable; the appearance of new illnesses and the necessity of quick treatments on the part of the drugs, the necessity of quick and efficient production of medications has increased with great biological activity that they allow to assure a better acting

  15. Algorithmic chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Fontana, W.

    1990-12-13

    In this paper complex adaptive systems are defined by a self- referential loop in which objects encode functions that act back on these objects. A model for this loop is presented. It uses a simple recursive formal language, derived from the lambda-calculus, to provide a semantics that maps character strings into functions that manipulate symbols on strings. The interaction between two functions, or algorithms, is defined naturally within the language through function composition, and results in the production of a new function. An iterated map acting on sets of functions and a corresponding graph representation are defined. Their properties are useful to discuss the behavior of a fixed size ensemble of randomly interacting functions. This function gas'', or Turning gas'', is studied under various conditions, and evolves cooperative interaction patterns of considerable intricacy. These patterns adapt under the influence of perturbations consisting in the addition of new random functions to the system. Different organizations emerge depending on the availability of self-replicators.

  16. Chemistry Rocks: Redox Chemistry as a Geologic Tool.

    Science.gov (United States)

    Burns, Mary Sue

    2001-01-01

    Applies chemistry to earth science, uses rocks in chemistry laboratories, and teaches about transition metal chemistry, oxidation states, and oxidation-reduction reactions from firsthand experiences. (YDS)

  17. How Much History Can Chemistry Take?

    OpenAIRE

    Lucasz Lamza

    2010-01-01

    Chemistry is typically considered to be a nomothetic science, i.e. a science interested in general laws rather than historical facts. Also, the unification of science is usually envisioned as an effort to connect particular scientific disciplines through their laws, e.g., the laws of chemistry are to be derived from the laws of physics. It is however equally sensible to combine the sciences through a single cosmic history. There is a large literature following this direction, albeit rarely fo...

  18. Crevice chemistry estimation from bulk water chemistry

    International Nuclear Information System (INIS)

    Since the first PWR plant in Japan started commercial operation in 1970, 22 plants are running in Japan as of the end of 1994. The main purpose of secondary water chemistry control is to minimize the corrosion possibility of the secondary system equipment, especially steam generators (SG). To achieve this objective, much effort has been concentrated on improving secondary water chemistry control. As a result of this effort, the recent secondary water chemistry in Japanese plants is well maintained in every stage of operation. However, to ensure and improve the reliability of SG, it is necessary to control crevice environments, which are located at tube/tube support plate intersections and under the sludge pile on the tube sheet. According to recent crevice monitoring examination results, the concentration behavior impurities in SG bulk water at the crevice is different for each species, and SG bulk water and crevice chemical compositions are not always equal. From these results, to control the crevice chemistry, improving bulk water chemistry control methods and a new type of molar ratio control index is needed. This paper introduces a brief summary of a recent crevice chemistry evaluation technique and bulk water chemistry control method, which is employed for crevice chemistry control, based on crevice monitoring examination results

  19. Green chemistry: A tool in Pharmaceutical Chemistry

    Directory of Open Access Journals (Sweden)

    Smita Talaviya

    2012-07-01

    Full Text Available Green chemistry expresses an area of research developing from scientific discoveries about pollution awareness and it utilizes a set of principles that reduces or eliminates the use or generation of hazardous substances in all steps of particular synthesis or process. Chemists and medicinal scientists can greatly reduce the risk to human health and the environment by following all the valuable principles of green chemistry. The most simple and direct way to apply green chemistry in pharmaceuticals is to utilize eco-friendly, non-hazardous, reproducible and efficient solvents and catalysts in synthesis of drug molecules, drug intermediates and in researches involving synthetic chemistry. Microwave synthesis is also an important tool of green chemistry by being an energy efficient process.

  20. Organometallic Chemistry of Molybdenum.

    Science.gov (United States)

    Lucas, C. Robert; Walsh, Kelly A.

    1987-01-01

    Suggests ways to avoid some of the problems students have learning the principles of organometallic chemistry. Provides a description of an experiment used in a third-year college chemistry laboratory on molybdenum. (TW)

  1. CHINESE JOURNAL OF CHEMISTRY

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    @@Chinese Journal of Chemistry is an international journal published in English by the Chinese Chemical Society with its editorial office hosted by Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences.

  2. Environmental chemistry: Volume A

    Energy Technology Data Exchange (ETDEWEB)

    Yen, T.F.

    1999-08-01

    This is an extensive introduction to environmental chemistry for engineering and chemical professionals. The contents of Volume A include a brief review of basic chemistry prior to coverage of litho, atmo, hydro, pedo, and biospheres.

  3. Tropospheric Halogen Chemistry

    Science.gov (United States)

    von Glasow, R.; Crutzen, P. J.

    2003-12-01

    Halogens are very reactive chemicals that are known to play an important role in anthropogenic stratospheric ozone depletion chemistry, first recognized by Molina and Rowland (1974). However, they also affect the chemistry of the troposphere. They are of special interest because they are involved in many reaction cycles that can affect the oxidation power of the atmosphere indirectly by influencing the main oxidants O3 and its photolysis product OH and directly, e.g., by reactions of the Cl radical with hydrocarbons (e.g., CH4).Already by the middle of the nineteenth century, Marchand (1852) reported the presence of bromine and iodine in rain and other natural waters. He also mentions the benefits of iodine in drinking water through the prevention of goitres and cretinism. In a prophetic monograph "Air and Rain: The Beginnings of a Chemical Climatology," Smith (1872) describes measurements of chloride in rain water, which he states to originate partly from the oceans by a process that he compares with the bursting of "soap bubbles" which produces "small vehicles" that transfer small spray droplets of seawater to the air. From deviations of the sulfate-to-chloride ratio in coastal rain compared to seawater, Smith concluded that chemical processes occur once the particles are airborne.For almost a century thereafter, however, atmospheric halogens received little attention. One exception was the work by Cauer (1939), who reported that iodine pollution has been significant in Western and Central Europe due to the inefficient burning of seaweed, causing mean gas phase atmospheric concentrations as high as or greater than 0.5 μg m-3. In his classical textbook Air Chemistry and Radioactivity, Junge (1963) devoted less than three pages to halogen gas phase chemistry, discussing chlorine and iodine. As reviewed by Eriksson (1959a, b), the main atmospheric source of halogens is sea salt, derived from the bursting of bubbles of air which are produced by ocean waves and other

  4. Frontiers in Gold Chemistry

    OpenAIRE

    Mohamed, Ahmed A.

    2015-01-01

    Basic chemistry of gold tells us that it can bond to sulfur, phosphorous, nitrogen, and oxygen donor ligands. The Frontiers in Gold Chemistry Special Issue covers gold complexes bonded to the different donors and their fascinating applications. This issue covers both basic chemistry studies of gold complexes and their contemporary applications in medicine, materials chemistry, and optical sensors. There is a strong belief that aurophilicity plays a major role in the unending applications of g...

  5. Green Chemistry and Education.

    Science.gov (United States)

    Hjeresen, Dennis L.; Schutt, David L.; Boese, Janet M.

    2000-01-01

    Many students today are profoundly interested in the sustainability of their world. Introduces Green Chemistry and its principles with teaching materials. Green Chemistry is the use of chemistry for pollution prevention and the design of chemical products and processes that are environmentally benign. (ASK)

  6. Environmental Chemistry Activities.

    Science.gov (United States)

    Jackland, Thomas; And Others

    The authors of this curriculum supplement believe in a laboratory approach to chemistry and express the feeling that environmental chemistry provides the students an opportunity to apply theoretical chemistry to important practical problems. There are eighteen activities presented, each accompanied with behavioral objectives, one or more suggested…

  7. Facets of coordination chemistry

    CERN Document Server

    Agarwala, BV

    1993-01-01

    A concise account of coordination chemistry since its inception is given here together with some of the newer significant facets. This book covers a broad spectrum of various topics on Environment, Cyclic Voltammetry, Chromatography, Metal Complexes of biological interest, Alkoxides, NMR spectroscopy and others. These are useful to the scientific community engaged in the field of Inorganic Chemistry and Analytical Chemistry.

  8. American Association for Clinical Chemistry

    Science.gov (United States)

    ... indispensable patient care tool. Learn more IN CLINICAL CHEMISTRY ddPCR Quantification of Lymphoma Mutations Researchers have developed ... Online Harmonization.net Commission on Accreditation in Clinical Chemistry American Board of Clinical Chemistry Clinical Chemistry Trainee ...

  9. The New Color of Chemistry: Green Chemistry

    Directory of Open Access Journals (Sweden)

    Zuhal GERÇEK

    2012-01-01

    Full Text Available Green chemistry which is the new application of chemistry rules provides solutions to problems that mankind is faced with climate changes, sustainable agriculture, energy, toxics, depletion of natural sources e.g. designing new chemicals and processes that production and utilization of hazardous matters. So, it is the indispensible tool for sustainable development. Current and future chemists should consider the human health and ecological issues in their professional life. In order to provide a solution for this requirement, green chemistry rules and under standings should be primarily taken in the university curriculum and at all educational levels.

  10. Surface chemistry essentials

    CERN Document Server

    Birdi, K S

    2013-01-01

    Surface chemistry plays an important role in everyday life, as the basis for many phenomena as well as technological applications. Common examples range from soap bubbles, foam, and raindrops to cosmetics, paint, adhesives, and pharmaceuticals. Additional areas that rely on surface chemistry include modern nanotechnology, medical diagnostics, and drug delivery. There is extensive literature on this subject, but most chemistry books only devote one or two chapters to it. Surface Chemistry Essentials fills a need for a reference that brings together the fundamental aspects of surface chemistry w

  11. Fundamentals of reactor chemistry

    International Nuclear Information System (INIS)

    In the Nuclear Engineering School of JAERI, many courses are presented for the people working in and around the nuclear reactors. The curricula of the courses contain also the subject material of chemistry. With reference to the foreign curricula, a plan of educational subject material of chemistry in the Nuclear Engineering School of JAERI was considered, and the fundamental part of reactor chemistry was reviewed in this report. Since the students of the Nuclear Engineering School are not chemists, the knowledge necessary in and around the nuclear reactors was emphasized in order to familiarize the students with the reactor chemistry. The teaching experience of the fundamentals of reactor chemistry is also given. (author)

  12. Annual report 1985 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. All particles and reports published and lectures given in 1985 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general. (author)

  13. Annual report 1984 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry , environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general. (author)

  14. Annual Report 1984. Chemistry Department

    OpenAIRE

    Funck, Jytte; Nielsen, Ole John

    1985-01-01

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general.

  15. The New Color of Chemistry: Green Chemistry

    OpenAIRE

    Zuhal GERÇEK

    2012-01-01

    Green chemistry which is the new application of chemistry rules provides solutions to problems that mankind is faced with climate changes, sustainable agriculture, energy, toxics, depletion of natural sources e.g. designing new chemicals and processes that production and utilization of hazardous matters. So, it is the indispensible tool for sustainable development. Current and future chemists should consider the human health and ecological issues in their professional life. In order to provid...

  16. Philosophy of Chemistry or Philosophy with Chemistry?

    OpenAIRE

    Bernadette Bensaude-Vincent

    2014-01-01

    Chemistry deserves more philosophical attention not so much to do justice to a long-neglected science or to enhance its cultural prestige, but to undermine a number of taken-for-granted assumptions about scientific rationality and more importantly to diversify our metaphysical views of nature and reality. In brief, this paper does not make the case for a philosophy of chemistry. It rather urges philosophers of science to listen to chemists and discuss what they learn from them. Because over t...

  17. Library Design in Combinatorial Chemistry by Monte Carlo Methods

    OpenAIRE

    Falcioni, Marco; Michael W. Deem

    2000-01-01

    Strategies for searching the space of variables in combinatorial chemistry experiments are presented, and a random energy model of combinatorial chemistry experiments is introduced. The search strategies, derived by analogy with the computer modeling technique of Monte Carlo, effectively search the variable space even in combinatorial chemistry experiments of modest size. Efficient implementations of the library design and redesign strategies are feasible with current experimental capabilities.

  18. Recent advances in the chemistry and biology of pyridopyrimidines.

    Science.gov (United States)

    Buron, F; Mérour, J Y; Akssira, M; Guillaumet, G; Routier, S

    2015-05-01

    The interest in pyridopyrimidine cores for pharmaceutical products makes this scaffold a highly useful building block for organic chemistry. These derivatives have found applications in various areas of medicine such as anticancer, CNS, fungicidal, antiviral, anti-inflammatory, antimicrobial, and antibacterial therapies. This review mainly focuses on the progress achieved since 2004 in the chemistry and biological activity of pyridopyrimidines. PMID:25794791

  19. Advances in electron transfer chemistry

    CERN Document Server

    Mariano, Patrick S

    1995-01-01

    Advances in Electron Transfer Chemistry, Volume 4 presents the reaction mechanisms involving the movement of single electrons. This book discusses the electron transfer reactions in organic, biochemical, organometallic, and excited state systems. Organized into four chapters, this volume begins with an overview of the photochemical behavior of two classes of sulfonium salt derivatives. This text then examines the parameters that control the efficiencies for radical ion pair formation. Other chapters consider the progress in the development of parameters that control the dynamics and reaction p

  20. Journal of Business Chemistry

    OpenAIRE

    2013-01-01

    The Journal of Business Chemistry examines issues associated with leadership and management for chemists and managers working in chemical research or industry. This journal is devoted to improving and developing the field of Business Chemistry. The Journal of Business Chemistry publishes peer-reviewed papers (including case studies) and essays. Areas for possible publication in include: leadership issues in the chemical and biochemical industry, such as teamwork, team building, mentoring, coa...

  1. Mathematical Thinking in Chemistry

    OpenAIRE

    José L. Villaveces; Guillermo Restrepo

    2012-01-01

    Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffro...

  2. Elementary physical chemistry

    CERN Document Server

    Linder, Bruno

    2010-01-01

    This book is designed for a one-semester course, for undergraduates, not necessarily chemistry majors, who need to know something about physical chemistry. The emphasis is not on mathematical rigor, but subtleties and conceptual difficulties are not hidden. It covers the essential topics in physical chemistry, including the state of matter, thermodynamics, chemical kinetics, phase and chemical equilibria, introduction to quantum theory, and molecular spectroscopy.

  3. Orbital interactions in chemistry

    CERN Document Server

    Albright, Thomas A; Whangbo, Myung-Hwan

    2013-01-01

    Explains the underlying structure that unites all disciplines in chemistry Now in its second edition, this book explores organic, organometallic, inorganic, solid state, and materials chemistry, demonstrating how common molecular orbital situations arise throughout the whole chemical spectrum. The authors explore the relationships that enable readers to grasp the theory that underlies and connects traditional fields of study within chemistry, thereby providing a conceptual framework with which to think about chemical structure and reactivity problems. Orbital Interactions

  4. The Chemistry Institute

    OpenAIRE

    Fontecave, Marc

    2015-01-01

    Chemistry at the Collège de France has received particular attention over the last few years. After the departures of Profs Jean-Marie Lehn and Jacques Livage, new ambition for developing this discipline has led to the creation of several Chairs: Prof. Marc Fontecave’s Chair of Chemistry of Biological Processes in 2008, Prof. Clément Sanchez’ Chair of Chemistry of Hybrid Materials in 2011, and the Chair of Chemistry of Materials and Energy, which Prof. Jean-Marie Tarascon has held since 2014....

  5. Advances in quantum chemistry

    CERN Document Server

    Sabin, John R

    2013-01-01

    Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features detailed reviews written by leading international researchers. This volume focuses on the theory of heavy ion physics in medicine.Advances in Quantum Chemistry presents surveys of current topics in this rapidly developing field that has emerged at the cross section of the historically established areas of mathematics, physics, chemistry, and biology. It features

  6. DOE fundamentals handbook: Chemistry

    International Nuclear Information System (INIS)

    This handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of chemistry. This volume contains the following modules: reactor water chemistry (effects of radiation on water chemistry, chemistry parameters), principles of water treatment (purpose; treatment processes [ion exchange]; dissolved gases, suspended solids, and pH control; water purity), and hazards of chemicals and gases (corrosives [acids, alkalies], toxic compounds, compressed gases, flammable/combustible liquids)

  7. Group theory and chemistry

    CERN Document Server

    Bishop, David M

    1993-01-01

    Group theoretical principles are an integral part of modern chemistry. Not only do they help account for a wide variety of chemical phenomena, they simplify quantum chemical calculations. Indeed, knowledge of their application to chemical problems is essential for students of chemistry. This complete, self-contained study, written for advanced undergraduate-level and graduate-level chemistry students, clearly and concisely introduces the subject of group theory and demonstrates its application to chemical problems.To assist chemistry students with the mathematics involved, Professor Bishop ha

  8. Touring the Tomato: A Suite of Chemistry Laboratory Experiments

    Science.gov (United States)

    Sarkar, Sayantani; Chatterjee, Subhasish; Medina, Nancy; Stark, Ruth E.

    2013-01-01

    An eight-session interdisciplinary laboratory curriculum has been designed using a suite of analytical chemistry techniques to study biomaterials derived from an inexpensive source such as the tomato fruit. A logical

  9. Alcohol combustion chemistry

    KAUST Repository

    Sarathy, Mani

    2014-10-01

    Alternative transportation fuels, preferably from renewable sources, include alcohols with up to five or even more carbon atoms. They are considered promising because they can be derived from biological matter via established and new processes. In addition, many of their physical-chemical properties are compatible with the requirements of modern engines, which make them attractive either as replacements for fossil fuels or as fuel additives. Indeed, alcohol fuels have been used since the early years of automobile production, particularly in Brazil, where ethanol has a long history of use as an automobile fuel. Recently, increasing attention has been paid to the use of non-petroleum-based fuels made from biological sources, including alcohols (predominantly ethanol), as important liquid biofuels. Today, the ethanol fuel that is offered in the market is mainly made from sugar cane or corn. Its production as a first-generation biofuel, especially in North America, has been associated with publicly discussed drawbacks, such as reduction in the food supply, need for fertilization, extensive water usage, and other ecological concerns. More environmentally friendly processes are being considered to produce alcohols from inedible plants or plant parts on wasteland. While biofuel production and its use (especially ethanol and biodiesel) in internal combustion engines have been the focus of several recent reviews, a dedicated overview and summary of research on alcohol combustion chemistry is still lacking. Besides ethanol, many linear and branched members of the alcohol family, from methanol to hexanols, have been studied, with a particular emphasis on butanols. These fuels and their combustion properties, including their ignition, flame propagation, and extinction characteristics, their pyrolysis and oxidation reactions, and their potential to produce pollutant emissions have been intensively investigated in dedicated experiments on the laboratory and the engine scale

  10. Atmospheric Chemistry Over Southern Africa

    Science.gov (United States)

    Gatebe, Charles K.; Levy, Robert C.; Thompson, Anne M.

    2011-01-01

    During the southern African dry season, regional haze from mixed industrial pollution, biomass burning aerosol and gases from domestic and grassland fires, and biogenic sources from plants and soils is worsened by a semi-permanent atmosphere gyre over the subcontinent. These factors were a driver of several major international field campaigns in the 1990s and early 2000s, and attracted many scientists to the region. Some researchers were interested in understanding fundamental processes governing chemistry of the atmosphere and interaction with climate change. Others found favorable conditions for evaluating satellite-derived measurements of atmospheric properties and a changing land surface. With that background in mind a workshop on atmospheric chemistry was held in South Africa. Sponsored by the International Commission for Atmospheric Chemistry and Global Pollution (ICACGP; http://www.icacgp.org/), the workshop received generous support from the South African power utility, Eskom, and the Climatology Research Group of the University of the Witwatersrand, Johannesburg, South Africa. The purpose of the workshop was to review some earlier findings as well as more recent findings on southern African climate vulnerability, chemical changes due to urbanization, land-use modification, and how these factors interact. Originally proposed by John Burrows, president of ICACGP, the workshop was the first ICACGP regional workshop to study the interaction of air pollution with global chemical and climate change. Organized locally by the University of the Witwatersrand, the workshop attracted more than 60 delegates from South Africa, Mozambique, Botswana, Zimbabwe, France, Germany, Canada, and the United States. More than 30 presentations were given, exploring both retrospective and prospective aspects of the science. In several talks, attention was focused on southern African chemistry, atmospheric pollution monitoring, and climate processes as they were studied in the field

  11. Open access and medicinal chemistry

    OpenAIRE

    Swain Chris

    2007-01-01

    Abstract Chemistry Central is a new open access website for chemists publishing peer-reviewed research in chemistry from a range of open access journals. A new addition, Chemistry Central Journal, will cover all of chemistry and will be broken down into discipline-specific sections, and Im delighted that Medicinal Chemistry will be a key discipline in this new journal.

  12. Annual report 1988 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1988 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, chemical reactivity, mineral processing, and general. (author)

  13. Annual report 1986 chemistry department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1986 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, radical chemistral, mineral processing, and general. (author)

  14. Annual report 1989 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1989 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, chemical reactivity, mineral processing, and general. (author)

  15. The Breath of Chemistry

    DEFF Research Database (Denmark)

    Josephsen, Jens

    The present preliminary text is a short thematic presentation in biological inorganic chemistry meant to illustrate general and inorganic (especially coordination) chemistry in biochemistry. The emphasis is on molecular models to explain features of the complicated mechanisms essential to breathing...

  16. Movies in Chemistry Education

    Science.gov (United States)

    Pekdag, Bulent; Le Marechal, Jean-Francois

    2010-01-01

    This article reviews numerous studies on chemistry movies. Movies, or moving pictures, are important elements of multimedia and signify a privileged or motivating means of presenting knowledge. Studies on chemistry movies show that the first movie productions in this field were devoted to university lectures or documentaries. Shorter movies were…

  17. Physical Chemistry of Molecular

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ Established in 2009, the group consists of six researchers and more than 70 research assistants and graduate students from the CAS Key Laboratory of Molecular Nanostructures and Nanotechnologies at the CAS Institute of Chemistry.Its research focuses on the physical chemistry involved in molecular assembly, molecular nanostructures, functional nanomaterials and conceptual nano-devices.

  18. Chemistry of americium

    Energy Technology Data Exchange (ETDEWEB)

    Schulz, W.W.

    1976-01-01

    Essential features of the descriptive chemistry of americium are reviewed. Chapter titles are: discovery, atomic and nuclear properties, collateral reading, production and uses, chemistry in aqueous solution, metal, alloys, and compounds, and, recovery, separation, purification. Author and subject indexes are included. (JCB)

  19. Exercises in Computational Chemistry

    DEFF Research Database (Denmark)

    Spanget-Larsen, Jens

    2016-01-01

    A selection of HyperChem© PC-exercises in computational chemistry. Answers to most questions are appended (Roskilde University 2014-16).......A selection of HyperChem© PC-exercises in computational chemistry. Answers to most questions are appended (Roskilde University 2014-16)....

  20. Titanocene sulfide chemistry

    Czech Academy of Sciences Publication Activity Database

    Horáček, Michal

    2016-01-01

    Roč. 314, MAY 2016 (2016), s. 83-102. ISSN 0010-8545 R&D Projects: GA ČR(CZ) GAP207/12/2368 Institutional support: RVO:61388955 Keywords : titanocene sulfide chemistry * photolysis * titanocene hydrosulfides Ti-(SH)n Subject RIV: CF - Physical ; Theoretical Chemistry Impact factor: 12.239, year: 2014

  1. Chemistry in Microfluidic Channels

    Science.gov (United States)

    Chia, Matthew C.; Sweeney, Christina M.; Odom, Teri W.

    2011-01-01

    General chemistry introduces principles such as acid-base chemistry, mixing, and precipitation that are usually demonstrated in bulk solutions. In this laboratory experiment, we describe how chemical reactions can be performed in a microfluidic channel to show advanced concepts such as laminar fluid flow and controlled precipitation. Three sets of…

  2. Mathematical Thinking in Chemistry

    Directory of Open Access Journals (Sweden)

    José L. Villaveces

    2012-05-01

    Full Text Available Mathematical chemistry is often thought to be a 20th-century subdiscipline of chemistry, but in this paper we discuss several early chemical ideas and some landmarks of chemistry as instances of the mathematical way of thinking; many of them before 1900. By the mathematical way of thinking, we follow Weyl's description of it in terms of functional thinking, i.e. setting up variables, symbolizing them, and seeking for functions relating them. The cases we discuss are Plato's triangles, Geoffroy's affinity table, Lavoisier's classification of substances and their relationships, Mendeleev's periodic table, Cayley's enumeration of alkanes, Sylvester's association of algebra and chemistry, and Wiener's relationship between molecular structure and boiling points. These examples show that mathematical chemistry has much more than a century of history.

  3. Korean Kimchi Chemistry: A Multicultural Chemistry Connection

    Science.gov (United States)

    Murfin, Brian

    2009-01-01

    Connecting science with different cultures is one way to interest students in science, to relate science to their lives, and at the same time to broaden their horizons in a variety of ways. In the lesson described here, students make kimchi, a delicious and popular Korean dish that can be used to explore many important chemistry concepts,…

  4. Third Chemistry Conference on Recent Trends in Chemistry

    International Nuclear Information System (INIS)

    The third chemistry conference 2011 on recent trends in chemistry was held from October 17-19, 2001 at Islamabad, Pakistan. More than 65 papers and oral presentation. The scope of the conference was wide open and provides and opportunity for participation of broad spectrum of chemists. This forum provided a platform for the dissemination of the latest research followed by discussion pertaining to new trends in chemistry. This con fence covered different aspects of subjects including analytical chemistry, environmental chemistry, polymer chemistry, industrial chemistry, biochemistry and nano chemistry etc. (A.B.)

  5. Lubrication Chemistry Viewed from DFT-Based Concepts and Electronic Structural Principles

    OpenAIRE

    Jin Yuansheng; Yang He; Li Shenghua

    2003-01-01

    Abstract: Fundamental molecular issues in lubrication chemistry were reviewed under categories of solution chemistry, contact chemistry and tribochemistry. By introducing the Density Functional Theory(DFT)-derived chemical reactivity parameters (chemical potential, electronegativity, hardness, softness and Fukui function) and related electronic structural principles (electronegativity equalization principle, hard-soft acid-base principle, and maximum hardness principle), their relevancy to lu...

  6. System approach to chemistry course

    OpenAIRE

    Lorina E. Kruglova; Valentina G. Derendyaeva

    2010-01-01

    The article considers the raise of chemistry profile for engineers and constructors training, discloses the system approach to chemistry course and singles out the most important modules from the course of general chemistry for construction industry.

  7. Annual report 1987 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. The names and abstracts of all articles and reports published and lectures given in 1987 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, analytical- and organic chemistry, environmental chemistry, polymer chemistry, radical chemistry, mineral processing, and general. 13 ills., (author)

  8. Annual report 1982 chemistry department

    International Nuclear Information System (INIS)

    The work going on in the Risoe National Laboratory, Chemistry Department is briefly surveyed by a presentation of all articles and reports published in 1982. The facilities and equipment are barely mentioned. The papers are divided into eight activities: 1. neutron activation analysis 2. analytical- and organic chemistry 3. environmental chemistry 4. polymer chemistry 5. geochemistry 6. radical chemistry 7. poitron annihilation 8. uranium process chemistry. (author)

  9. Moderator Chemistry Program

    International Nuclear Information System (INIS)

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation

  10. Moderator Chemistry Program

    Energy Technology Data Exchange (ETDEWEB)

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department's moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  11. Moderator Chemistry Program

    Energy Technology Data Exchange (ETDEWEB)

    Dewitt, L.V.; Gibbs, A.; Lambert, D.P.; Bohrer, S.R.; Fanning, R.L.; Houston, M.W.; Stinson, S.L.; Deible, R.W.; Abdel-Khalik, S.I.

    1990-11-01

    Over the past fifteen months, the Systems Chemistry Group of the Reactor Engineering Department has undertaken a comprehensive study of the Department`s moderator chemistry program at Savannah River Site (SRS). An internal review was developed to formalize and document this program. Objectives were as outlined in a mission statement and action plan. In addition to the mission statement and action plan, nine separate task reports have been issued during the course of this study. Each of these task reports is included in this document as a chapter. This document is an organized compilation of the individual reports issued by the Systems Chemistry Group in assessment of SRS moderator chemistry to determine if there were significant gaps in the program as ft existed in October, 1989. While these reviews found no significant gaps in that mode of operation, or any items that adversely affected safety, items were identified that could be improved. Many of the items have already been dear with or are in the process of completion under this Moderator Chemistry Program and other Reactor Restart programs. A complete list of the items of improvement found under this assessment is found in Chapter 9, along with a proposed time table for correcting remaining items that can be improved for the chemistry program of SRS reactors. An additional external review of the moderator chemistry processes, recommendations, and responses to/from the Reactor Corrosion Mitigation Committee is included as Appendix to this compilation.

  12. Annual Report 1984. Chemistry Department

    DEFF Research Database (Denmark)

    Funck, Jytte; Nielsen, Ole John

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry, an......, analytical- and organic chemistry, environmental chemistry, polymer chemistry, geochemistry and waste disposal, radical chemistry, positron annihilation, mineral processing, and general.......This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1984 are presented. The facilities and equipment are mentioned briefly. The activities are divided into the following groups: radioisotope chemistry...

  13. Chemistry in water reactors

    International Nuclear Information System (INIS)

    The international conference Chemistry in Water Reactors was arranged in Nice 24-27/04/1994 by the French Nuclear Energy Society. Examples of technical program areas were primary chemistry, operational experience, fundamental studies and new technology. Furthermore there were sessions about radiation field build-up, hydrogen chemistry, electro-chemistry, condensate polishing, decontamination and chemical cleaning. The conference gave the impression that there are some areas that are going to be more important than others during the next few years to come. Cladding integrity: Professor Ishigure from Japan emphasized that cladding integrity is a subject of great concern, especially with respect to waterside corrosion, deposition and release of crud. Chemistry control: The control of the iron/nickel concentration quotient seems to be not as important as previously considered. The future operation of a nuclear power plant is going to require a better control of the water chemistry than achievable today. One example of this is solubility control via regulation in BWR. Trends in USA: means an increasing use of hydrogen, minimization of SCC/IASCC, minimization of radiation fields by thorough chemistry control, guarding fuel integrity by minimization of cladding corrosion and minimization of flow assisted corrosion. Stellite replacement: The search for replacement materials will continue. Secondary side crevice chemistry: Modeling and practical studies are required to increase knowledge about the crevice chemistry and how it develops under plant operation conditions. Inhibitors: Inhibitors for IGSCC and IGA as well for the primary- (zinc) as for the secondary side (Ti) should be studied. The effects and mode of operation of the inhibitors should be documented. Chemical cleaning: of heat transfer surfaces will be an important subject. Prophylactic cleaning at regular intervals could be one mode of operation

  14. Mathematics for physical chemistry

    CERN Document Server

    Mortimer, Robert G

    2013-01-01

    Mathematics for Physical Chemistry is the ideal supplementary text for practicing chemists and students who want to sharpen their mathematics skills while enrolled in general through physical chemistry courses. This book specifically emphasizes the use of mathematics in the context of physical chemistry, as opposed to being simply a mathematics text. This 4e includes new exercises in each chapter that provide practice in a technique immediately after discussion or example and encourage self-study. The early chapters are constructed around a sequence of mathematical topics, wit

  15. Computational quantum chemistry website

    International Nuclear Information System (INIS)

    This report contains the contents of a web page related to research on the development of quantum chemistry methods for computational thermochemistry and the application of quantum chemistry methods to problems in material chemistry and chemical sciences. Research programs highlighted include: Gaussian-2 theory; Density functional theory; Molecular sieve materials; Diamond thin-film growth from buckyball precursors; Electronic structure calculations on lithium polymer electrolytes; Long-distance electronic coupling in donor/acceptor molecules; and Computational studies of NOx reactions in radioactive waste storage

  16. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 1 covers papers on the advances of gas phase ion chemistry. The book discusses the advances in flow tubes and the measurement of ion-molecule rate coefficients and product distributions; the ion chemistry of the earth's atmosphere; and the classical ion-molecule collision theory. The text also describes statistical methods in reaction dynamics; the state selection by photoion-photoelectron coincidence; and the effects of temperature and pressure in the kinetics of ion-molecule reactions. The energy distribution in the unimolecular decomposition of ions, as well

  17. Experiments in physical chemistry

    CERN Document Server

    Wilson, J M; Denaro, A R

    1968-01-01

    Experiments in Physical Chemistry, Second Edition provides a compilation of experiments concerning physical chemistry. This book illustrates the link between the theory and practice of physical chemistry. Organized into three parts, this edition begins with an overview of those experiments that generally have a simple theoretical background. Part II contains experiments that are associated with more advanced theory or more developed techniques, or which require a greater degree of experimental skill. Part III consists of experiments that are in the nature of investigations wherein these invest

  18. DOE fundamentals handbook: Chemistry

    International Nuclear Information System (INIS)

    The Chemistry Handbook was developed to assist nuclear facility operating contractors in providing operators, maintenance personnel, and the technical staff with the necessary fundamentals training to ensure a basic understanding of chemistry. The handbook includes information on the atomic structure of matter; chemical bonding; chemical equations; chemical interactions involved with corrosion processes; water chemistry control, including the principles of water treatment; the hazards of chemicals and gases, and basic gaseous diffusion processes. This information will provide personnel with a foundation for understanding the chemical properties of materials and the way these properties can impose limitations on the operation of equipment and systems

  19. Advanced fuel chemistry for advanced engines.

    Energy Technology Data Exchange (ETDEWEB)

    Taatjes, Craig A.; Jusinski, Leonard E.; Zador, Judit; Fernandes, Ravi X.; Miller, James A.

    2009-09-01

    Autoignition chemistry is central to predictive modeling of many advanced engine designs that combine high efficiency and low inherent pollutant emissions. This chemistry, and especially its pressure dependence, is poorly known for fuels derived from heavy petroleum and for biofuels, both of which are becoming increasingly prominent in the nation's fuel stream. We have investigated the pressure dependence of key ignition reactions for a series of molecules representative of non-traditional and alternative fuels. These investigations combined experimental characterization of hydroxyl radical production in well-controlled photolytically initiated oxidation and a hybrid modeling strategy that linked detailed quantum chemistry and computational kinetics of critical reactions with rate-equation models of the global chemical system. Comprehensive mechanisms for autoignition generally ignore the pressure dependence of branching fractions in the important alkyl + O{sub 2} reaction systems; however we have demonstrated that pressure-dependent 'formally direct' pathways persist at in-cylinder pressures.

  20. Bioinspired catecholic chemistry for surface modification.

    Science.gov (United States)

    Ye, Qian; Zhou, Feng; Liu, Weimin

    2011-07-01

    The attachment strategy based on catecholic chemistry has been arousing renewed interest since the work on polymerized catecholic amine (polydopamine) (Messersmith et al., Science, 2007, 318, 426) was published. Catechols and their derived compounds can self-assemble on various inorganic and organic materials, including noble metals, metals, metal oxides, mica, silica, ceramics and even polymers. It opens a new route to the modification of various substrates and the preparation of functional composite materials by simple chemistry. However, there is still not a full review so far about the attachment chemistry despite the dramatically increasing number of publications. This critical review describes the state-of-the-art research in the area: the design and synthesis of catecholic molecules, their adsorption mechanisms and the stability of assemblies in solution, and their applications etc. Some perspectives on future development are raised (195 references). PMID:21603689

  1. Chemistry at large

    OpenAIRE

    Sanders, Jeremy K. M.

    2007-01-01

    A new book introduces young researchers to supramolecular chemistry, starting from the basics and working up to the more complicated aspects of the topic. While the text is inspiring for new graduates, it lacks a critical view.

  2. General Chemistry for Engineers.

    Science.gov (United States)

    Kybett, B. D.

    1982-01-01

    Discusses the relationship between molecular structure, intermolecular forces, and tensile strengths of a polymer and suggests that this is a logical way to introduce polymers into a general chemistry course. (Author/JN)

  3. Bringing chemistry to life

    OpenAIRE

    Boyce, Michael; Bertozzi, Carolyn R.

    2011-01-01

    Bioorthogonal chemistry allows a wide variety of biomolecules to be specifically labeled and probed in living cells and whole organisms. Here we discuss the history of bioorthogonal reactions and some of the most interesting and important advances in the field.

  4. Supplemental instruction in chemistry

    Science.gov (United States)

    Lundeberg, Mary A.

    This study was designed to measure some effects of supplemental instruction in chemistry. Supplemental instruction is a peer-led cooperative learning program that encourages students to develop conceptual understanding by articulating both understandings and misconceptions in a think-aloud fashion. Supplemental instruction was offered three hours weekly outside of class and lab time for students in four classes of General Organic and Biological Chemistry. Over a two-year period 108 students volunteered to participate in this program; 45 students did not participate. As measured by final grades in chemistry and responses to a questionnaire, supplemental instruction was effective in increasing students' achievement in chemistry. Further research is needed to determine the in-depth effects of supplemental instruction on students' learning, problem solving, and self-esteem.

  5. Beauty in chemistry

    Directory of Open Access Journals (Sweden)

    Peter Atkins

    2006-03-01

    Full Text Available Though hard going for the general reader and highly personal in its selectivity, Elegant Solutions: Ten Beautiful Experiments in Chemistry provides reflections of a thoughtful author that will delight chemists

  6. Beauty in chemistry

    OpenAIRE

    Peter Atkins

    2006-01-01

    Though hard going for the general reader and highly personal in its selectivity, Elegant Solutions: Ten Beautiful Experiments in Chemistry provides reflections of a thoughtful author that will delight chemists

  7. Magnetism in Chemistry

    Science.gov (United States)

    Brookes, R. W.; McFadyen, W. D.

    1975-01-01

    Discusses the technical aspects of paramagnetism and an electrostatic model called Crystal Field Theory (CFT), very often used in the case of transition metal compounds. Suggests that this discussion be included as an option for college chemistry courses. (MLH)

  8. Enzymes in Analytical Chemistry.

    Science.gov (United States)

    Fishman, Myer M.

    1980-01-01

    Presents tabular information concerning recent research in the field of enzymes in analytic chemistry, with methods, substrate or reaction catalyzed, assay, comments and references listed. The table refers to 128 references. Also listed are 13 general citations. (CS)

  9. Forensic Chemistry Training

    OpenAIRE

    Zuhal GERÇEK

    2012-01-01

    Increasing the types of terrorism and crime nowadays, the importance of the forensic sciences can be bett er understood. Forensic science is the application of the wide spectrum of science to answer the question of legal system. It contains the application of the principles, techniques and methods of basic sciences and its main aim is the determination of the physical facts which are important in legal situations. Forensic chemistry is the branch of chemistry which performs the chemical analy...

  10. Applications of supramolecular chemistry

    CERN Document Server

    Schneider, Hans-Jörg

    2012-01-01

    ""The time is ripe for the present volume, which gathers thorough presentations of the numerous actually realized or potentially accessible applications of supramolecular chemistry by a number of the leading figures in the field. The variety of topics covered is witness to the diversity of the approaches and the areas of implementation…a broad and timely panorama of the field assembling an eminent roster of contributors.""-Jean-Marie Lehn, 1987 Noble Prize Winner in Chemistry

  11. Fundamentals of quantum chemistry

    CERN Document Server

    House, J E

    2004-01-01

    An introduction to the principles of quantum mechanics needed in physical chemistry. Mathematical tools are presented and developed as needed and only basic calculus, chemistry, and physics is assumed. Applications include atomic and molecular structure, spectroscopy, alpha decay, tunneling, and superconductivity. New edition includes sections on perturbation theory, orbital symmetry of diatomic molecules, the Huckel MO method and Woodward/Hoffman rules as well as a new chapter on SCF and Hartree-Fock methods. * This revised text clearly presents basic q

  12. Impact of surface chemistry

    OpenAIRE

    Somorjai, Gabor A.; Li, Yimin

    2010-01-01

    The applications of molecular surface chemistry in heterogeneous catalyst technology, semiconductor-based technology, medical technology, anticorrosion and lubricant technology, and nanotechnology are highlighted in this perspective. The evolution of surface chemistry at the molecular level is reviewed, and the key roles of surface instrumentation developments for in situ studies of the gas–solid, liquid–solid, and solid–solid interfaces under reaction conditions are emphasized.

  13. Quantitative analysis chemistry

    International Nuclear Information System (INIS)

    This book is about quantitative analysis chemistry. It is divided into ten chapters, which deal with the basic conception of material with the meaning of analysis chemistry and SI units, chemical equilibrium, basic preparation for quantitative analysis, introduction of volumetric analysis, acid-base titration of outline and experiment examples, chelate titration, oxidation-reduction titration with introduction, titration curve, and diazotization titration, precipitation titration, electrometric titration and quantitative analysis.

  14. Gas phase ion chemistry

    CERN Document Server

    Bowers, Michael T

    1979-01-01

    Gas Phase Ion Chemistry, Volume 2 covers the advances in gas phase ion chemistry. The book discusses the stabilities of positive ions from equilibrium gas-phase basicity measurements; the experimental methods used to determine molecular electron affinities, specifically photoelectron spectroscopy, photodetachment spectroscopy, charge transfer, and collisional ionization; and the gas-phase acidity scale. The text also describes the basis of the technique of chemical ionization mass spectrometry; the energetics and mechanisms of unimolecular reactions of positive ions; and the photodissociation

  15. EPA Environmental Chemistry Laboratory

    Science.gov (United States)

    1993-01-01

    The Environmental Protection Agency's (EPA) Chemistry Laboratory (ECL) is a national program laboratory specializing in residue chemistry analysis under the jurisdiction of the EPA's Office of Pesticide Programs in Washington, D.C. At Stennis Space Center, the laboratory's work supports many federal anti-pollution laws. The laboratory analyzes environmental and human samples to determine the presence and amount of agricultural chemicals and related substances. Pictured, ECL chemists analyze environmental and human samples for the presence of pesticides and other pollutants.

  16. Chemistry and nuclear technology

    International Nuclear Information System (INIS)

    The underlying principles of nuclear sciece and technology as based on the two basic phenomena, namely, radioactivity and nuclear reactions, with their relatively large associated energy changes, are outlined. The most important contributions by chemists in the overall historical development are mentioned and the strong position chemistry has attained in these fields is indicated. It is concluded that chemistry as well as many other scientific discplines (apart from general benefits) have largely benefitted from these nuclear developments

  17. 'Click chemistry' synthesis of a library of 1,2,3-triazole-substituted galactose derivatives and their evaluation against Trypanosoma cruzi and its cell surface trans-sialidase.

    Science.gov (United States)

    Carvalho, Ivone; Andrade, Peterson; Campo, Vanessa L; Guedes, Paulo M M; Sesti-Costa, Renata; Silva, João S; Schenkman, Sergio; Dedola, Simone; Hill, Lionel; Rejzek, Martin; Nepogodiev, Sergey A; Field, Robert A

    2010-04-01

    Trypanosoma cruzi trans-sialidase (TcTS) plays a key role in the recognition and invasion of host cells and in enabling the parasite to escape the human immune response. To explore this potential drug target, we have synthesized a small library of substrate analogues based on 1,4-disubstituted 1,2,3-triazole derivatives of galactose modified at either the C-1 or C-6 positions. This was achieved by coupling the appropriate azido-sugars with a panel of 23 structurally diverse terminal alkynes by using the copper(I)-catalyzed alkyne-azide cycloaddition (CuAAC) reaction, giving a library of 46 derivatives in good to excellent yield and with complete regioselectivity. The sugar triazoles showed weak inhibition towards TcTS-catalyzed hydrolysis of 2'-(4-methylumbelliferyl)-alpha-d-N-acetylneuraminic acid in vitro (<40% inhibition at 1mM concentration); many of the compounds assessed proved to be acceptor substrates for the enzyme. Despite this modest inhibitory activity, in vitro trypanocidal activity assays against the trypomastigote form of T. cruzi Y strain revealed several compounds active in the low 100s of muM range. Further assessment of these compounds against cultured mouse spleen cells suggests a specific mode of anti-parasite action rather than a generic cytotoxic effect. PMID:20335038

  18. Mathematical problems for chemistry students

    CERN Document Server

    Pota, Gyorgy

    2006-01-01

    Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistry students in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialists of the chemistry-related fields (physicists, mathematicians, biologists, etc.) into the world of the chemical applications. Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, other

  19. Annual report 1983 Chemistry Department

    International Nuclear Information System (INIS)

    This report contains a brief survey of the main activities in the Chemistry Department. All articles and reports published and lectures given in 1983 are presented. The facilities and equipment are barely mentioned. The activities are divided into nine groups: 1. radioisotope chemistry 2. analytical- and organic chemistry 3. environmental chemistry 4. polymer chemistry 5. geochemistry and waste disposal 6. radical chemstry 7. positron annihilation 8. mineral processing 9. general. (author)

  20. Spin-state chemistry of deuterated ammonia

    OpenAIRE

    Sipilä, O.; Harju, J.; Caselli, P.; Schlemmer, S.

    2015-01-01

    Aims. We aim to develop a chemical model that contains a consistent description of spin-state chemistry in reactions involving chemical species with multiple deuterons. We apply the model to the specific case of deuterated ammonia, to derive values for the various spin-state ratios. Methods. We apply symmetry rules in the complete scrambling assumption to calculate branching ratio tables for reactions between chemical species that include multiple protons and/or deuterons. Reaction sets for b...

  1. Mass spectrometry in natural product chemistry.

    Science.gov (United States)

    Clayton, E; Hill, H C; Reed, R I

    1966-01-01

    Some mass spectrometric techniques are described which seem applicable to investigating problems in natural product chemistry. One example is of a sample of 5 mcg of a compound being identified by comparison with an authentic sample of prostaglandin derivative. Compared were mass, ion content, and structure. In the prostaglandin/unknown substance comparison, high-resolution mass spectrometry resolved a quandary: apparent additional ions present in the unknown substance were shown to be an impurity. PMID:12262324

  2. Chemistry beyond positivism.

    Science.gov (United States)

    Brandt, Werner W

    2003-05-01

    Chemistry is often thought to be quite factual, and therefore might be considered close to the "positivist" ideal of a value-free science. A closer look, however, reveals that the field is coupled to the invisible realm of values, meanings, and purpose in various ways, and chemists interact with that realm loosely and unevenly. Tacit knowledge is one important locus of such interactions. We are concerned in this essay with two questions. What is the nature of the knowledge when we are in the early stages of discovery? and In what ways does the hidden reality we are seeking affect our search for an understanding of it? The first question is partly answered by Polanyi's theory of tacit knowledge, while the second one leads us to realize the limitations of our language when discussing "reality"-or certain chemical experimental results. A strictly positivist approach is of little use, but so is the opposite, the complete disregard of facts. The contrast between positivism and non-formulable aspects of scientific reasoning amounts to a paradox that needs to be analyzed and can lead to a "connected" chemistry. This in turn resembles networks described by Schweber and is more concerned than the chemistry "as it is" with aspects such as the image of chemistry, the challenges chemists face as citizens, and chemistry in liberal education. PMID:12796119

  3. Radiation chemistry of amino acids and peptides in aqueous solutions

    International Nuclear Information System (INIS)

    Radiation chemistry relevant to radiation preservation of high protein foods is reviewed. Some conclusions concerning the chemistry of irradiated amino acids, peptides, and proteins have been derived from product analysis of γ-irradiated solutions while the main mechanistic considerations result from the chemistry and kinetics of free radical intermediates observed by pulse radiolysis. The precursors of chemistry in not too concentrated solutions (-, OH, and H. Their reactivity with molecules and their preference for characteristic groups within the molecule are discussed. The reviewed reactions of the model systems are accountable for a variety of radiolytic products found in irradiated foods. From detailed understanding of radiation chemistry in aqueous and frozen systems formation of many classes of compounds can be predicted or entirely eliminated in order to corroborate and extend the conclusions reached from the animal feeding experiments concerning the formation of toxic, mutagenic, and carcinogenic compounds and/or reduction of the nutritional value of foods

  4. Reaction chemistry of cerium

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-01-01

    It is truly ironic that a synthetic organic chemist likely has far greater knowledge of the reaction chemistry of cerium(IV) than an inorganic colleague. Cerium(IV) reagents have long since been employed as oxidants in effecting a wide variety of organic transformations. Conversely, prior to the late 1980s, the number of well characterized cerium(IV) complexes did not extend past a handful of known species. Though in many other areas, interest in the molecular chemistry of the 4f-elements has undergone an explosive growth over the last twenty years, the chemistry of cerium(IV) has for the most part been overlooked. This report describes reactions of cerium complexes and structure.

  5. Chemistry of plutonium revealed

    International Nuclear Information System (INIS)

    In 1941 one goal of the Manhattan Project was to unravel the chemistry of the synthetic element plutonium as rapidly as possible. In this paper the work carried out at Berkeley from the spring of 1942 to the summer of 1945 is described briefly. The aqueous chemistry of plutonium is quite remarkable. Important insights were obtained from tracer experiments, but the full complexity was not revealed until macroscopic amounts (milligrams) became available. Because processes for separation from fission products were based on aqueous solutions, such solution chemistry was emphasized, particularly precipitation and oxidation-reduction behavior. The latter turned out to be unusually intricate when it was discovered that two more oxidation states existed in aqueous solution than had previously been suspected. Further, an equilibrium was rapidly established among the four aqueous oxidation states, while at the same time any three were not in equilibrium. These and other observations made while doing a crash study of a previously unknown element are reported

  6. Introductory quantum chemistry

    International Nuclear Information System (INIS)

    This book on quantum chemistry is primarily intended for university students at the senior undergraduate level. It serves as an aid to the basic understanding of the important concepts of quantum mechanics introduced in the field of chemistry. Various chapters of the book are devoted to the following : (i) Waves and quanta, (ii) Operator concept in quantum chemistry, (iii) Wave mechanics of some simple systems, (iv) Perturbation theory, (v) Many-electron atoms and angular momenta (vi) Molecular orbital theory and its application to the electronic structure of diatomic molecules, (vii) Chemical bonding in polyatomic molecules and (viii) Chemical applications of Hellmann-Feynman theorem. At the end of each chapter, a set of problems is given and the answers to these problems are given at the end of the book. (A.K.)

  7. Mathematics for physical chemistry

    CERN Document Server

    Mortimer, Robert G

    2005-01-01

    Mathematics for Physical Chemistry, Third Edition, is the ideal text for students and physical chemists who want to sharpen their mathematics skills. It can help prepare the reader for an undergraduate course, serve as a supplementary text for use during a course, or serve as a reference for graduate students and practicing chemists. The text concentrates on applications instead of theory, and, although the emphasis is on physical chemistry, it can also be useful in general chemistry courses. The Third Edition includes new exercises in each chapter that provide practice in a technique immediately after discussion or example and encourage self-study. The first ten chapters are constructed around a sequence of mathematical topics, with a gradual progression into more advanced material. The final chapter discusses mathematical topics needed in the analysis of experimental data.* Numerous examples and problems interspersed throughout the presentations * Each extensive chapter contains a preview, objectives, and ...

  8. Dynamic Combinatorial Chemistry

    DEFF Research Database (Denmark)

    Lisbjerg, Micke

    This thesis is divided into seven chapters, which can all be read individually. The first chapter, however, contains a general introduction to the chemistry used in the remaining six chapters, and it is therefore recommended to read chapter one before reading the other chapters. Chapter 1...... is a general introductory chapter for the whole thesis. The history and concepts of dynamic combinatorial chemistry are described, as are some of the new and intriguing results recently obtained. Finally, the properties of a broad range of hexameric macrocycles are described in detail. Chapter 2 gives...

  9. Cloud chemistry on Jupiter

    OpenAIRE

    Carlson, B. E.; Prather, M. J.; W. B. Rossow

    1987-01-01

    Aqueous chemistry on Uranus affects the atmospheric abundances of NH3 and H2S below the methane cloud base. Here a complete thermochemical equilibrium model for the H2O-NH3-H2S system is presented. Inclusion of H2S increases the aqueous removal of NH3 to 20-30 percent, but aqueous chemistry alone cannot account for the depletion of NH3 in the 150-200-K region of the atmosphere required to fit microwave observations. Formation of NH4SH clouds can account for the observed depletion provided the...

  10. Chemistry of Transactinides

    Science.gov (United States)

    Kratz, J. V.

    In this chapter, the chemical properties of the man-made transactinide elements rutherfordium, Rf (element 104), dubnium, Db (element 105), seaborgium, Sg (element 106), bohrium, Bh (element 107), hassium, Hs (element 108), and copernicium, Cn (element 112) are reviewed, and prospects for chemical characterizations of even heavier elements are discussed. The experimental methods to perform rapid chemical separations on the time scale of seconds are presented and comments are given on the special situation with the transactinides where chemistry has to be studied with single atoms. It follows a description of theoretical predictions and selected experimental results on the chemistry of elements 104 through 108, and element 112.

  11. Solvent effects in chemistry

    CERN Document Server

    Buncel, Erwin

    2015-01-01

    This book introduces the concepts, theory and experimental knowledge concerning solvent effects on the rate and equilibrium of chemical reactions of all kinds.  It begins with basic thermodynamics and kinetics, building on this foundation to demonstrate how a more detailed understanding of these effects may be used to aid in determination of reaction mechanisms, and to aid in planning syntheses. Consideration is given to theoretical calculations (quantum chemistry, molecular dynamics, etc.), to statistical methods (chemometrics), and to modern day concerns such as ""green"" chemistry, where ut

  12. Nanophotonics and supramolecular chemistry

    Science.gov (United States)

    Ariga, Katsuhiko; Komatsu, Hirokazu; Hill, Jonathan P.

    2013-10-01

    Supramolecular chemistry has become a key area in emerging bottom-up nanoscience and nanotechnology. In particular, supramolecular systems that can produce a photonic output are increasingly important research targets and present various possibilities for practical applications. Accordingly, photonic properties of various supramolecular systems at the nanoscale are important in current nanotechnology. In this short review, nanophotonics in supramolecular chemistry will be briefly summarized by introducing recent examples of control of photonic responses of supramolecular systems. Topics are categorized according to the fundamental actions of their supramolecular systems: (i) self-assembly; (ii) recognition; (iii) manipulation.

  13. Revitalizing chemistry laboratory instruction

    Science.gov (United States)

    McBride, Phil Blake

    This dissertation involves research in three major domains of chemical education as partial fulfillment of the requirements for the Ph.D. program in chemistry at Miami University with a major emphasis on chemical education, and concurrent study in organic chemistry. Unit I, Development and Assessment of a Column Chromatography Laboratory Activity, addresses the domain of Instructional Materials Development and Testing. This unit outlines the process of developing a publishable laboratory activity, testing and revising that activity, and subsequently sharing that activity with the chemical education community. A laboratory activity focusing on the separation of methylene blue and sodium fluorescein was developed to demonstrate the effects of both the stationary and mobile phase in conducting a separation. Unit II, Bringing Industry to the Laboratory, addresses the domain of Curriculum Development and Testing. This unit outlines the development of the Chemistry of Copper Mining module, which is intended for use in high school or undergraduate college chemistry. The module uses the learning cycle approach to present the chemistry of the industrial processes of mining copper to the students. The module includes thirteen investigations (three of which are web-based and ten which are laboratory experiments) and an accompanying interactive CD-ROM, which provides an explanation of the chemistry used in copper mining with a virtual tour of an operational copper mine. Unit III, An Alternative Method of Teaching Chemistry. Integrating Lecture and the Laboratory, is a project that addresses the domain of Research in Student Learning. Fundamental Chemistry was taught at Eastern Arizona College as an integrated lecture/laboratory course that met in two-hour blocks on Monday, Wednesday, and Friday. The students taking this integrated course were compared with students taking the traditional 1-hour lectures held on Monday, Wednesday, and Friday, with accompanying 3-hour lab on

  14. Computational organometallic chemistry

    International Nuclear Information System (INIS)

    In this article, the author highlights the tremendous impact that density functional theory has had on computational chemistry over the last decade. This robust and efficient theoretical technique (for which John Pople and Walter Kohn were awarded the Nobel Prize in 1998) has opened up many new possibilities for chemists, allowing to study large systems with a degree of reliability hitherto uncontemplated. Examples which illustrate how both density functional theory and hybrid method have been successfully used in solving difficult problems in quantum chemistry of catalysis are briefly discussed

  15. Spins in chemistry

    CERN Document Server

    McWeeny, Roy

    2004-01-01

    Originally delivered as a series of lectures, this volume systematically traces the evolution of the ""spin"" concept from its role in quantum mechanics to its assimilation into the field of chemistry. Author Roy McWeeny presents an in-depth illustration of the deductive methods of quantum theory and their application to spins in chemistry, following the path from the earliest concepts to the sophisticated physical methods employed in the investigation of molecular structure and properties. Starting with the origin and development of the spin concept, the text advances to an examination of sp

  16. Atmospheric pseudohalogen chemistry

    OpenAIRE

    Lary, D. J.

    2004-01-01

    There are at least three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. The first is well known, HCN is a product and marker of biomass burning. However, if a detailed ion chemistry of lightning is considered then it is almost certain than in addition to lightning producing NOx, it also produces HOx and HCN. Unlike NOx and HOx, HCN is long-lived and could therefore ...

  17. Chemistry WebBook

    Science.gov (United States)

    SRD 69 NIST Chemistry WebBook (Web, free access)   The NIST Chemistry WebBook contains: Thermochemical data for over 7000 organic and small inorganic compounds; thermochemistry data for over 8000 reactions; IR spectra for over 16,000 compounds; mass spectra for over 33,000 compounds; UV/Vis spectra for over 1600 compounds; electronic and vibrational spectra for over 5000 compounds; constants of diatomic molecules(spectroscopic data) for over 600 compounds; ion energetics data for over 16,000 compounds; thermophysical property data for 74 fluids.

  18. Chemistry in microelectronics

    CERN Document Server

    Le Tiec, Yannick

    2013-01-01

    Microelectronics is a complex world where many sciences need to collaborate to create nano-objects: we need expertise in electronics, microelectronics, physics, optics and mechanics also crossing into chemistry, electrochemistry, as well as biology, biochemistry and medicine. Chemistry is involved in many fields from materials, chemicals, gases, liquids or salts, the basics of reactions and equilibrium, to the optimized cleaning of surfaces and selective etching of specific layers. In addition, over recent decades, the size of the transistors has been drastically reduced while the functionalit

  19. Environmental chemistry. 3. ed.

    International Nuclear Information System (INIS)

    The book Environmental Chemistry deals with the basic aspects of environmental chemistry, the natural cycles of the environment, composition of atmosphere and various effects in it by pollutants due to human activities, like energy production, industrial endeavours etc. Details pertaining to the effect of various pollutants on ecosystem are also explained. A number of instrumented techniques in environmental chemical analysis including neutron activation analysis, spectroscopic methods are given. The correlation between energy and environment is dealt with consideration to the global aspects of it. Paper relevant to INIS database is indexed separately. (M.K.V.)

  20. The chemistry of silicon

    CERN Document Server

    Rochow, E G; Emeléus, H J; Nyholm, Ronald

    1975-01-01

    Pergamon Texts in Organic Chemistry, Volume 9: The Chemistry of Silicon presents information essential in understanding the chemical properties of silicon. The book first covers the fundamental aspects of silicon, such as its nuclear, physical, and chemical properties. The text also details the history of silicon, its occurrence and distribution, and applications. Next, the selection enumerates the compounds and complexes of silicon, along with organosilicon compounds. The text will be of great interest to chemists and chemical engineers. Other researchers working on research study involving s

  1. Progress in physical chemistry

    CERN Document Server

    Hempelmann, Rolf

    2008-01-01

    Progress in Physical Chemistry is a collection of recent ""Review Articles"" published in the ""Zeitschrift für Physikalische Chemie"". The second volume of Progress in Physical Chemistry is a collection of thematically closely related minireview articles written by the members of the Collaborative Research Centre (SFB) 277 of the German Research Foundation (DFG). These articles are based on twelve years of intense coordinated research efforts. Central topics are the synthesis and the characterization of interface-dominated, i.e. nanostructured materials, mainly in the solid state but also as

  2. Chemistry in Second Life

    Directory of Open Access Journals (Sweden)

    Bradley Jean-Claude

    2009-10-01

    Full Text Available Abstract This review will focus on the current level on chemistry research, education, and visualization possible within the multi-user virtual environment of Second Life. We discuss how Second Life has been used as a platform for the interactive and collaborative visualization of data from molecules and proteins to spectra and experimental data. We then review how these visualizations can be scripted for immersive educational activities and real-life collaborative research. We also discuss the benefits of the social networking affordances of Second Life for both chemists and chemistry students.

  3. Chemistry and lithography

    CERN Document Server

    Okoroanyanwu, Uzodinma

    2011-01-01

    This is a unique book, combining chemistry and physics with technology and history in a way that is both enlightening and lively. No other book in the field of lithography has as much breadth. Highly recommended for anyone interested in the broad application of chemistry to lithography. --Chris Mack, Gentleman Scientist. This book provides a comprehensive treatment of the chemical phenomena in lithography in a manner that is accessible to a wide readership. The book presents topics on the optical and charged particle physics practiced in lithography, with a broader view of how the marriage bet

  4. Frontiers in nuclear chemistry

    International Nuclear Information System (INIS)

    This book contains articles on the landmarks in nuclear and radiochemistry which takes through scientific history spanning over five decades from the times of Roentgen to the middle of this century. Articles on nuclear fission and back end of the nuclear fuel cycle give an insight into the current status of this subject. Reviews on frontier areas like lanthanides, actinides, muonium chemistry, accelerator based nuclear chemistry, fast radiochemical separations and nuclear medicine bring out the multidisciplinary nature of nuclear sciences. This book also includes an article on environmental radiochemistry and safety. Chapters relevant to INIS are indexed separately

  5. Estudio Teórico de la Reactividad Química y Biológica de Cisplatino y algunos Derivados con Actividad Anticancerosa Theoretical Study of Chemistry Reactivity and Biological of Cisplatin and some Derivatives with Anticancer Activity

    Directory of Open Access Journals (Sweden)

    Jesús M López

    2013-01-01

    Full Text Available Se investigó la estructura y reactividad química de algunos derivados del fármaco anticanceroso cisplatino coordinados a ligandos bioactivos al nivel mPW1PW/LANL2DZ en el marco conceptual de la teoría del funcional de la densidad. El conjunto de descriptores globales de la reactividad permitió analizar la naturaleza reactiva de estos complejos. La estabilidad de los complejos aumentó en la fase acuosa. Las geometrías predichas para cisplatino, carboplatino y cis-dicloro[L-N,O-Ornitina]platino(II mostraron concordancia con los datos de difracción de rayos X experimentales. Asimismo, las geometrías optimizadas en fase acuosa mostraron mejores resultados que las predichas en fase gas. El índice de electrofilicidad global calculado para los complejos cis-dicloro[(L,D-N,O-Ornitina]platino(II, fue mayor que el predicho para cisplatino, implicando que la unión de estos ligandos favorece la reactividad de estos complejos.The structure and chemical reactivity of some derivatives of the anticancer drug cisplatin coordinated with bioactive ligands was investigated at mPW1PW/LANL2DZ level theory in the conceptual density functional theory. Global descriptors allowed analyzing the reactive nature of these complexes. The stability of the complexes increases in aqueous phase. Calculated geometries of the complexes cisplatin, carboplatín and cis-dichloro[(L,D-Ornithine]platinum(II are in agreement with their available X-ray data. The electrophilicity index calculated for the complexes were higher than those predicted for cisplatin, implying that the binding of these ligands favors the reactivity of these complexes.

  6. How to teach chemistry? Is Chemistry a new universal language

    OpenAIRE

    López Guerrero, María del Mar; López Guerrero, Gema

    2015-01-01

    Chemistry has been developed greatly throughout the 20th century. Chemistry is included in the curriculum of elementary and secondary education. In general, students are not interested in science, and because of this ,students tend not to make an effort to learn and understand the meaning of concepts and the chemistry language that are being taught to them. If we consider that there is a little bit analogy between chemistry and foreign languages, we should learn the s...

  7. Array processors in chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Ostlund, N.S.

    1980-01-01

    The field of attached scientific processors (''array processors'') is surveyed, and an attempt is made to indicate their present and possible future use in computational chemistry. The current commercial products from Floating Point Systems, Inc., Datawest Corporation, and CSP, Inc. are discussed.

  8. Chromatin chemistry goes cellular.

    OpenAIRE

    W. Fischle; D. Schwarzer; Mootz, H.

    2015-01-01

    Analysing post-translational modifications of histone proteins as they occur within chromatin is challenging due to their large number and chemical diversity. A major step forward has now been achieved by using split intein chemistry to engineer functionalized histones within cells.

  9. Chemistry Education and Mythology

    OpenAIRE

    Sule Aycan

    2005-01-01

    This study aimed to investigate the effect of mythological story in teaching chemistry. To this end the students in the class were divided into two homogenous groups. While the first group was thought in a traditional way, using a mythological story thought the second group. The story used was based on a Mountain just opposite the faculty.

  10. Chemistry Cook-Off

    Science.gov (United States)

    McCormick, Cynthia

    2012-01-01

    For this activity, high school chemistry students compete in a cooking contest. They must determine the chemical and physical changes that occur in the food they prepare, present their recipe as a step-by-step procedure similar to a lab procedure, identify chemicals in the food, and present all measurements in both metric and English units. The…

  11. Symmetry in chemistry

    CERN Document Server

    Jaffé, Hans H

    1977-01-01

    This book, devoted exclusively to symmetry in chemistry and developed in an essentially nonmathematical way, is a must for students and researchers. Topics include symmetry elements and operations, multiple symmetry operations, multiplication tables and point groups, group theory applications, and crystal symmetry. Extensive appendices provide useful tables.

  12. Nuclear Chemistry, exercises

    International Nuclear Information System (INIS)

    Those exercises have as objective to introduce the student in the basic concepts of nuclear chemistry: a) way of decline b) balances of mass used in nuclear reactions c) how to calculate activities, activity concentrations and specific activity d) radiotracers use in biomedical sciences pharmaceutical

  13. Online Organic Chemistry

    Science.gov (United States)

    Janowicz, Philip A.

    2010-01-01

    This is a comprehensive study of the many facets of an entirely online organic chemistry course. Online homework with structure-drawing capabilities was found to be more effective than written homework. Online lecture was found to be just as effective as in-person lecture, and students prefer an online lecture format with shorter Webcasts. Online…

  14. Nobel Prize in Chemistry

    Science.gov (United States)

    2000-01-01

    The Royal Swedish Academy has awarded the 1999 Nobel Prize in Chemistry to Ahmed H. Zewail (California Institute of Technology, Pasadena, CA) "for his studies of the transition states of chemical reactions using femtosecond spectroscopy". Zewail's work has taken the study of the rates and mechanisms of chemical reactions to the ultimate degree of detail - the time scale of bond making and bond breaking.

  15. Chemistry and Heritage

    Science.gov (United States)

    Vittoria Barbarulo, Maria

    2014-05-01

    Chemistry is the central science, as it touches every aspect of the society we live in and it is intertwined with many aspects of our culture; in particular, the strong link between Chemistry and Archaeology and Art History is being explored, offering a penetrating insight into an area of growing interest from an educational point of view. A series of vital and vibrant examples (i.e., ancient bronzes composition, colour changes due to natural pigment decomposition, marble degradation) has been proposed, on one hand, to improve student understanding of the relationship between cultural and scientific issues arising from the examination, the conservation, and the maintenance of cultural Heritage, on the other, to illustrate the role of the underlying Chemistry. In some case studies, a survey of the most relevant atmospheric factors, which are involved in the deterioration mechanisms, has also been presented to the students. First-hand laboratory experiences have been providing an invaluable means of discovering the full and varied world of Chemistry. Furthermore, the promotion of an interdisciplinary investigation of a famous painting or fresco, involving the study of its nature and significance, the definition of its historical context, any related literature, the chemical knowledge of the materials used, may be an excellent occasion to experiment the Content and Language Integrated Learning (CLIL). The aim of this approach is to convey the important message that everyone has the responsibility to care for and preserve Heritage for the benefit of present and future generations.

  16. Metaphorical Models in Chemistry.

    Science.gov (United States)

    Rosenfeld, Stuart; Bhusan, Nalini

    1995-01-01

    What happens when students of chemistry fail to recognize the metaphorical status of certain models and interpret them literally? Suggests that such failures lead students to form perceptions of phenomena that can be misleading. Argues that the key to making good use of metaphorical models is a recognition of their metaphorical status. Examines…

  17. Spatially Resolved Artificial Chemistry

    DEFF Research Database (Denmark)

    Fellermann, Harold

    2009-01-01

    made a class of models accessible to the realms of artificial chemistry that represent reacting molecules in a coarse-grained fashion in continuous space. This chapter introduces the mathematical models of Brownian dynamics (BD) and dissipative particle dynamics (DPD) for molecular motion and reaction...

  18. Chemistry Education and Mythology

    Directory of Open Access Journals (Sweden)

    Sule Aycan

    2005-01-01

    Full Text Available This study aimed to investigate the effect of mythological story in teaching chemistry. To this end the students in the class were divided into two homogenous groups. While the first group was thought in a traditional way, using a mythological story thought the second group. The story used was based on a Mountain just opposite the faculty.

  19. Forensic Chemistry Training

    Directory of Open Access Journals (Sweden)

    Zuhal GERÇEK

    2012-01-01

    Full Text Available Increasing the types of terrorism and crime nowadays, the importance of the forensic sciences can be bett er understood. Forensic science is the application of the wide spectrum of science to answer the question of legal system. It contains the application of the principles, techniques and methods of basic sciences and its main aim is the determination of the physical facts which are important in legal situations. Forensic chemistry is the branch of chemistry which performs the chemical analysis of evidences that used in the courts. Forensic chemist is the professional chemist who analyzes the evidences from crime scene and reaches a result by application of tests. Th us, they have to have a special education. In forensic laboratories candidates who have chemistry/biochemistry undergraduate degree and took biology and forensic chemistry lectures are preferred. It is necessary to design graduate and undergraduate education to train a forensic chemist. Science education should be at the core of the undergraduate education. In addition to this strong laboratory education on both science and forensic science should be given. Th e graduate program of forensic science example should contain forensic science subjects, strong academic lectures on special subjects and research and laboratory components.

  20. Analytical Chemistry Laboratory

    Science.gov (United States)

    Anderson, Mark

    2013-01-01

    The Analytical Chemistry and Material Development Group maintains a capability in chemical analysis, materials R&D failure analysis and contamination control. The uniquely qualified staff and facility support the needs of flight projects, science instrument development and various technical tasks, as well as Cal Tech.

  1. Evaluating Environmental Chemistry Textbooks.

    Science.gov (United States)

    Hites, Ronald A.

    2001-01-01

    A director of the Indiana University Center for Environmental Science Research reviews textbooks on environmental chemistry. Highlights clear writing, intellectual depth, presence of problem sets covering both the qualitative and quantitative aspects of the material, and full coverage of the topics of concern. Discusses the director's own approach…

  2. Chemistry between the stars

    Science.gov (United States)

    Gammon, R. H.

    1976-01-01

    A unit is presented for the secondary school teacher of physics, chemistry, astronomy, or earth sciences. Included are a list of reference materials, teaching aids, and projects. Discussion questions and a glossary are also provided. Concepts developed are: the nature of interstellar space, spectroscopy, molecular signals from space and interstellar molecules and other areas of astronomy.

  3. Volatility Derivatives

    OpenAIRE

    Peter Carr; Roger Lee

    2009-01-01

    Volatility derivatives are a class of derivative securities where the payoff explicitly depends on some measure of the volatility of an underlying asset. Prominent examples of these derivatives include variance swaps and VIX futures and options. We provide an overview of the current market for these derivatives. We also survey the early literature on the subject. Finally, we provide relatively simple proofs of some fundamental results related to variance swaps and volatility swaps.

  4. Relevance and Significance of Extraterrestrial Abiological Hydrocarbon Chemistry.

    Science.gov (United States)

    Olah, George A; Mathew, Thomas; Prakash, G K Surya

    2016-06-01

    Astrophysical observations show similarity of observed abiological "organics"-i.e., hydrocarbons, their derivatives, and ions (carbocations and carbanions)-with studied terrestrial chemistry. Their formation pathways, their related extraterrestrial hydrocarbon chemistry originating from carbon and other elements after the Big Bang, their parent hydrocarbon and derivative (methane and methanol, respectively), and transportation of derived building blocks of life by meteorites or comets to planet Earth are discussed in this Perspective. Their subsequent evolution on Earth under favorable "Goldilocks" conditions led to more complex molecules and biological systems, and eventually to humans. The relevance and significance of extraterrestrial hydrocarbon chemistry to the limits of science in relation to the physical aspects of evolution on our planet Earth are also discussed. PMID:27045758

  5. Ice chemistry in starless molecular cores

    CERN Document Server

    Kalvans, Juris

    2015-01-01

    Starless molecular cores are natural laboratories for interstellar molecular chemistry research. The chemistry of ices in such objects was investigated with a three-phase (gas, surface, and mantle) model. We considered the center part of five starless cores, with their physical conditions derived from observations. The ice chemistry of oxygen, nitrogen, sulfur, and complex organic molecules (COMs) was analyzed. We found that an ice-depth dimension, measured, e.g., in monolayers, is essential for modeling of chemistry in interstellar ices. Particularly, the H2O:CO:CO2:N2:NH3 ice abundance ratio regulates the production and destruction of minor species. It is suggested that photodesorption during core collapse period is responsible for high abundance of interstellar H2O2 and O2H, and other species synthesized on the surface. The calculated abundances of COMs in ice were compared to observed gas-phase values. Smaller activation barriers for CO and H2CO hydrogenation may help explain the production of a number of...

  6. Mathematical problems for chemistry students

    CERN Document Server

    Pota, Gyorgy

    2011-01-01

    Mathematical Problems for Chemistry Students has been compiled and written (a) to help chemistrystudents in their mathematical studies by providing them with mathematical problems really occurring in chemistry (b) to help practising chemists to activate their applied mathematical skills and (c) to introduce students and specialistsof the chemistry-related fields (physicists, mathematicians, biologists, etc.) intothe world of the chemical applications.Some problems of the collection are mathematical reformulations of those in the standard textbooks of chemistry, others we

  7. Conference 'Chemistry of hydrides' Proceedings

    International Nuclear Information System (INIS)

    This collection of thesis of conference of Chemistry hydrides presents the results of investigations concerning of base questions of chemistry of nonorganic hydrides, including synthesis questions, studying of physical and chemical properties, thermodynamics, analytical chemistry, investigation of structure, equilibriums in the systems of metal-hydrogen, behaviour of nonorganic hydrides in non-water mediums and applying investigations in the chemistry area and technology of nonorganic hydrides

  8. Predictors of General Chemistry Grades.

    Science.gov (United States)

    Ozsogomonyan, Ardas; Loftus, Drew

    1979-01-01

    Chemistry pretest scores, high school chemistry grades and, to a greater extent, math SAT scores were useful predictors of college general chemistry grades. Regression analysis of all these predictors combined was used to construct an expectancy table which is being used to identify and advise underprepared students. (BB)

  9. Division of Analytical Chemistry, 1998

    DEFF Research Database (Denmark)

    Hansen, Elo Harald

    1999-01-01

    The article recounts the 1998 activities of the Division of Analytical Chemistry (DAC- formerly the Working Party on Analytical Chemistry, WPAC), which body is a division of the Federation of European Chemical Societies (FECS). Elo Harald Hansen is the Danish delegate, representing The Danish...... Chemical Society/The Society for Analytical Chemistry....

  10. Combinatorial chemistry and the Grid

    OpenAIRE

    Frey, J G; Bradley, M.; Essex, J.W.; Hursthouse, M. B.; Lewis, S. M.; Luck, M.M.; Moreau, L; De Roure, D C; Surridge, M.; Welsh, A. H.

    2003-01-01

    Chemistry has always made extensive use of the developing computing technology and available computing power though activities such as modelling, simulation and chemical structure interpretational - activities conveniently summarised as computational chemistry. Developing procedures in chemical synthesis and characterisation, particularly in the arena of parallel and combinatorial methodology, have generated ever increasing demands on both Computational Chemistry and Computer Technology. Si...

  11. HMI scientific report - chemistry 1987

    International Nuclear Information System (INIS)

    Results of the R and D activities of the Radiation Chemistry Department, Hahn-Meitner-Institut, are reported, primarily dealing with the following subjects: Interface processes and energy conversion, high-energy photochemistry and radiation chemistry as well as trace elements chemistry. A list of publications and lectures is added and gives a view on results obtained in research and development. (EF)

  12. Annual report 1985 Chemistry Department

    International Nuclear Information System (INIS)

    This annual report describes the activities carried out in 1985 by the Chemistry Department in the following fields: Chemistry, Inorganic Chemistry, Physicochemistry (Interphases, Surfaces), General Chemical Analysis, Active Materials Analysis, X Ray Fluorescence Analysis, Mass Spectroscopy (Isotopic Analysis, Instrumentation) and Optical Spectroscopy. A list of publications is enclosed. (M.E.L.)

  13. Carbohydrates in Supramolecular Chemistry.

    Science.gov (United States)

    Delbianco, Martina; Bharate, Priya; Varela-Aramburu, Silvia; Seeberger, Peter H

    2016-02-24

    Carbohydrates are involved in a variety of biological processes. The ability of sugars to form a large number of hydrogen bonds has made them important components for supramolecular chemistry. We discuss recent advances in the use of carbohydrates in supramolecular chemistry and reveal that carbohydrates are useful building blocks for the stabilization of complex architectures. Systems are presented according to the scaffold that supports the glyco-conjugate: organic macrocycles, dendrimers, nanomaterials, and polymers are considered. Glyco-conjugates can form host-guest complexes, and can self-assemble by using carbohydrate-carbohydrate interactions and other weak interactions such as π-π interactions. Finally, complex supramolecular architectures based on carbohydrate-protein interactions are discussed. PMID:26702928

  14. Radiation chemistry of oils

    International Nuclear Information System (INIS)

    Full text : Primary investigations have been conducted at the end of the 1950th years in the area of radiation chemistry of the oils, the physical-chemical properties of crude oil have been investigated the influence of ionizing rays. This report by M. Malikzadeh is about the results of investigations carried out in the field of development of radiation chemistry. The power of the radiation dose and temperature-thermal effect of the collapse of Phentadekan -Oil, and oil fractions (200-400 degrees Celsium, 230-310 degrees Celsium) of radiation-thermal separation of olefins - Conversion of hydrogen from the transormation of black oil, bitumen and tar Kinetics of the above-mentioned processes was studied, the technical-economic indicators of the products were determined

  15. Medicinal chemistry for 2020.

    Science.gov (United States)

    Satyanarayanajois, Seetharama D; Hill, Ronald A

    2011-10-01

    Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five main angles to be addressed are: protein-protein interactions; peptides and peptidomimetics; molecular diversity and pharmacological space; molecular pharmacodynamics (significance, potential and challenges); and early-stage clinical efficacy and safety. We then consider, in light of these, the future of medicinal chemistry and the educational preparation that will be required for future medicinal chemists. PMID:22004084

  16. Aqueous chemistry of iodine

    International Nuclear Information System (INIS)

    The chemistry of iodine has been examined in aqueous solutions of pH 6 to 10 containing 2500 ppM boron as H3BO3 at temperatures up to 1500C using absorption spectrophotometry to identify and monitor the iodine species present. Kinetic rate constants for the disproportionation of the HOI intermediate, 3HOI= IO3- + 2I- + 3H+, have been measured as a function of pH even though no direct spectral evidence for HOI itself has been observed. An HOI partition coefficient >104 has been estimated; results of ionic strength tests are consistent with HOI being present as an uncharged triatomic species in solution. Redox and radiation effects on the aqueous iodine chemistry have also been described. 11 refs., 2 figs., 3 tabs

  17. Chemistry space–time

    Directory of Open Access Journals (Sweden)

    David A. Winkler

    2015-12-01

    Full Text Available As Einstein identified so clearly, space and time are intimately related. We discuss the relationship between time and Euclidean space using spectroscopic and radioastronomical studies of interstellar chemistry as an example. Given the finite speed of light, we are clearly studying chemical reactions occurring tens of thousands of years ago that may elucidate the primordial chemistry of this planet several billion years ago. We also explore space of a different kind – chemical space, with many more dimensions than the four we associate as space–time. Vast chemical spaces also need very efficient (computational methods for their exploration to overcome this ‘curse of dimensionality’. We discuss methods by which the time to explore these new spaces can be very substantially reduced, opening the discovery useful new materials that are the key to our future.

  18. Heterogeneous atmospheric chemistry

    Science.gov (United States)

    Schryer, D. R.

    1982-01-01

    The present conference on heterogeneous atmospheric chemistry considers such topics concerning clusters, particles and microparticles as common problems in nucleation and growth, chemical kinetics, and catalysis, chemical reactions with aerosols, electron beam studies of natural and anthropogenic microparticles, and structural studies employing molecular beam techniques, as well as such gas-solid interaction topics as photoassisted reactions, catalyzed photolysis, and heterogeneous catalysis. Also discussed are sulfur dioxide absorption, oxidation, and oxidation inhibition in falling drops, sulfur dioxide/water equilibria, the evidence for heterogeneous catalysis in the atmosphere, the importance of heterogeneous processes to tropospheric chemistry, soot-catalyzed atmospheric reactions, and the concentrations and mechanisms of formation of sulfate in the atmospheric boundary layer.

  19. Organic Chemistry in Space

    Science.gov (United States)

    Charnley, Steven

    2009-01-01

    Astronomical observations, theoretical modeling, laboratory simulation and analysis of extraterrestrial material have enhanced our knowledge of the inventory of organic matter in the interstellar medium (ISM) and on small bodies such as comets and asteroids (Ehrenfreund & Charnley 2000). Comets, asteroids and their fragments, meteorites and interplanetary dust particles (IDPs), contributed significant amounts of extraterrestrial organic matter to the young Earth. This material degraded and reacted in a terrestrial prebiotic chemistry to form organic structures that may have served as building blocks for life on the early Earth. In this talk I will summarize our current understanding of the organic composition and chemistry of interstellar clouds. Molecules of astrobiological relevance include the building blocks of our genetic material: nucleic acids, composed of subunits such as N-heterocycles (purines and pyrimidines), sugars and amino acids. Signatures indicative of inheritance of pristine and modified interstellar material in comets and meteorites will also be discussed.

  20. Quo vadis, analytical chemistry?

    Science.gov (United States)

    Valcárcel, Miguel

    2016-01-01

    This paper presents an open, personal, fresh approach to the future of Analytical Chemistry in the context of the deep changes Science and Technology are anticipated to experience. Its main aim is to challenge young analytical chemists because the future of our scientific discipline is in their hands. A description of not completely accurate overall conceptions of our discipline, both past and present, to be avoided is followed by a flexible, integral definition of Analytical Chemistry and its cornerstones (viz., aims and objectives, quality trade-offs, the third basic analytical reference, the information hierarchy, social responsibility, independent research, transfer of knowledge and technology, interfaces to other scientific-technical disciplines, and well-oriented education). Obsolete paradigms, and more accurate general and specific that can be expected to provide the framework for our discipline in the coming years are described. Finally, the three possible responses of analytical chemists to the proposed changes in our discipline are discussed. PMID:26631024

  1. Nuclear analytical chemistry

    International Nuclear Information System (INIS)

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection

  2. Supramolecular chemistry and technology

    Directory of Open Access Journals (Sweden)

    HENRIQUE E. TOMA

    2000-03-01

    Full Text Available Supramolecular chemistry deals with the association of several chemical species, in an organized way and according to well defined purposes. Based on a molecular engineering approach, supramolecular structures can be designed from pre-formed building blocks, providing a promising route from chemistry to molecular nanotechnology. New supramolecular systems have been assembled in our laboratory with the use of bridging unities such as tetrapyridylporphyrins, porphyrazines and polypyrazines, connecting transition metal complexes and clusters. These systems display a very exciting electrochemical and catalytic behavior, and interact with DNA, generating ¹O2 and leading to efficient oxidative clivage for photodynamic terapy applications. Molecular interfaces have been developed, exhibiting photocurrent response in the presence of visible-UV light, and rectifying properties in the presence of electroactive species. Successful applications of the supramolecular species in chemical and bio-sensors have been developed.

  3. Muons in chemistry

    Science.gov (United States)

    Clayden, N. J.

    2013-12-01

    Positive muons have long been used as extrinsic probes in chemistry, offering unique properties for the investigation of local magnetism, dynamics, transport and radical kinetics. Exciting new developments in muon beam lines offer the opportunity of extending these studies selectively to surfaces permitting, for example, the detection of increased mobility of polymer chains at the surface of a polymer film. So called pump and probe methods, involving external perturbations by laser irradiation to manipulate vibrational and electronic states, can be followed by muon pulses allowing the probing of the properties of these states. Muoniated radical probes are finding greater use in soft matter. Selectivity is achieved in these complex systems through an appropriate target molecule giving the chance to measure partitioning and interfacial transfer in surfactant systems. Improvements in sample environments allow the observation of muons in increasingly extreme combinations of temperature and pressure, such as supercritical water, allowing the characterization of the chemistry in these systems.

  4. Tropical Soil Chemistry

    DEFF Research Database (Denmark)

    Borggaard, Ole K.

    A new book that is particularly relevant as tropical countries experience increased pressure on land resources to improve agricultural production. To ensure sustainable land use, the potentials and limitations of different kinds of tropical soils must be known in relation to crop production...... soil chemical issues are also presented to assess when, why, and how tropical soils differ from soils in other regions. This knowledge can help agricultural specialists in the tropics establish sustainable crop production. Readers are assumed to be familiar with basic chemistry, physics...... and environmental protection. Tropical Soil Chemistry by Ole K. Borggaard provides an overview of the composition, occurrence, properties, processes, formation, and environmental vulnerability of various tropical soil types (using American Soil Taxonomy for classification). The processes and the external factors...

  5. Nuclear analytical chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Brune, D.; Forkman, B.; Persson, B.

    1984-01-01

    This book covers the general theories and techniques of nuclear chemical analysis, directed at applications in analytical chemistry, nuclear medicine, radiophysics, agriculture, environmental sciences, geological exploration, industrial process control, etc. The main principles of nuclear physics and nuclear detection on which the analysis is based are briefly outlined. An attempt is made to emphasise the fundamentals of activation analysis, detection and activation methods, as well as their applications. The book provides guidance in analytical chemistry, agriculture, environmental and biomedical sciences, etc. The contents include: the nuclear periodic system; nuclear decay; nuclear reactions; nuclear radiation sources; interaction of radiation with matter; principles of radiation detectors; nuclear electronics; statistical methods and spectral analysis; methods of radiation detection; neutron activation analysis; charged particle activation analysis; photon activation analysis; sample preparation and chemical separation; nuclear chemical analysis in biological and medical research; the use of nuclear chemical analysis in the field of criminology; nuclear chemical analysis in environmental sciences, geology and mineral exploration; and radiation protection.

  6. Solvents and sustainable chemistry

    OpenAIRE

    Welton, Tom

    2015-01-01

    Solvents are widely recognized to be of great environmental concern. The reduction of their use is one of the most important aims of green chemistry. In addition to this, the appropriate selection of solvent for a process can greatly improve the sustainability of a chemical production process. There has also been extensive research into the application of so-called green solvents, such as ionic liquids and supercritical fluids. However, most examples of solvent technologies that give improved...

  7. Chemistry of sex attraction.

    OpenAIRE

    Roelofs, W L

    1995-01-01

    The chemical communication system used to attract mates involves not only the overt chemical signals but also indirectly a great deal of chemistry in the emitter and receiver. As an example, in emitting female moths, this includes enzymes (and cofactors, mRNA, genes) of the pheromone biosynthetic pathways, hormones (and genes) involved in controlling pheromone production, receptors and second messengers for the hormones, and host plant cues that control release of the hormone. In receiving ma...

  8. Current ADC Linker Chemistry

    OpenAIRE

    Jain, Nareshkumar; Smith, Sean W.; Ghone, Sanjeevani; Tomczuk, Bruce

    2015-01-01

    The list of ADCs in the clinic continues to grow, bolstered by the success of first two marketed ADCs: ADCETRIS® and Kadcyla®. Currently, there are 40 ADCs in various phases of clinical development. However, only 34 of these have published their structures. Of the 34 disclosed structures, 24 of them use a linkage to the thiol of cysteines on the monoclonal antibody. The remaining 10 candidates utilize chemistry to surface lysines of the antibody. Due to the inherent heterogeneity of conjugati...

  9. Advances in electroanalytical chemistry

    OpenAIRE

    Wang, Yijun; Compton, Richard

    2012-01-01

    This thesis concerns several advances in electroanalytical chemistry which are separated into four parts: the electrochemical investigation of diffusional behaviour, the mechanistic and kinetic study of electrochemistry with room temperature ionic liquids (RTILs), the study of weakly-supported electrochemistry and a comparison of the Butler-Volmer and Marcus-Hush kinetic theories of electron transfer. A study of the diffusional behaviour of electroactive species is essential for further s...

  10. Art and Chemistry

    OpenAIRE

    Walter, Philippe

    2015-01-01

    Philippe Walter’s teaching, which he delivered as holder of the Liliane Bettencourt Annual Chair of Technological Innovation, was completed with two lectures on “practical work” to deal with a real case. The conditions and challenges of interdisciplinary research combining analytical chemistry, art history and archaeology were thus discussed in relation to specific works. The Holy Family, Constantin Abraham (1785-1855) by Raphaël (aka), Sanzio Raffaello (1483-1520), hard porcelain, Sèvres, C...

  11. Chemistry of silybin

    Czech Academy of Sciences Publication Activity Database

    Biedermann, David; Vavříková, Eva; Cvak, L.; Křen, Vladimír

    2014-01-01

    Roč. 31, č. 9 (2014), s. 1138-1157. ISSN 0265-0568 R&D Projects: GA ČR(CZ) GAP301/11/0662; GA MŠk LH13097; GA MŠk(CZ) LD14096; GA MŠk(CZ) LD13042 Institutional support: RVO:61388971 Keywords : silybin * Silybum marianum * separation Subject RIV: CC - Organic Chemistry Impact factor: 10.107, year: 2014

  12. Medicinal chemistry for 2020

    OpenAIRE

    Satyanarayanajois, Seetharama D.; Hill, Ronald A

    2011-01-01

    Rapid advances in our collective understanding of biomolecular structure and, in concert, of biochemical systems, coupled with developments in computational methods, have massively impacted the field of medicinal chemistry over the past two decades, with even greater changes appearing on the horizon. In this perspective, we endeavor to profile some of the most prominent determinants of change and speculate as to further evolution that may consequently occur during the next decade. The five ma...

  13. Learning Chemistry from Bacteria

    OpenAIRE

    Clardy, Jon

    2013-01-01

    Dr. Jon Clardy Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, Harvard University All animals, including humans, originated and evolved on a planet already teeming with bacteria, and the two kingdoms of life have been competing and cooperating through their joint history. Although bacteria are most familiar as pathogens, some bacteria produce small molecules that are essential for the biology of animals and other eukaryotes. This lecture explores some of...

  14. Radioanalytical chemistry in Denmark

    International Nuclear Information System (INIS)

    Publications from Denmark in the field of radioanalytical chemistry are presented in 2 groups, one involving neutron activation and similar techniques, and one for other radioanalytical work. Altogether 258 references including books are given for the period 1936-1977, and the overall doubling time is 5.2 years. A significant deviation from a purely exponential growth was caused by the Second World War. (author)

  15. Actinide separative chemistry

    International Nuclear Information System (INIS)

    Actinide separative chemistry has focused very heavy work during the last decades. The main was nuclear spent fuel reprocessing: solvent extraction processes appeared quickly a suitable, an efficient way to recover major actinides (uranium and plutonium), and an extensive research, concerning both process chemistry and chemical engineering technologies, allowed the industrial development in this field. We can observe for about half a century a succession of Purex plants which, if based on the same initial discovery (i.e. the outstanding properties of a molecule, the famous TBP), present huge improvements at each step, for a large part due to an increased mastery of the mechanisms involved. And actinide separation should still focus R and D in the near future: there is a real, an important need for this, even if reprocessing may appear as a mature industry. We can present three main reasons for this. First, actinide recycling appear as a key-issue for future nuclear fuel cycles, both for waste management optimization and for conservation of natural resource; and the need concerns not only major actinide but also so-called minor ones, thus enlarging the scope of the investigation. Second, extraction processes are not well mastered at microscopic scale: there is a real, great lack in fundamental knowledge, useful or even necessary for process optimization (for instance, how to design the best extracting molecule, taken into account the several notifications and constraints, from selectivity to radiolytic resistivity?); and such a need for a real optimization is to be more accurate with the search of always cheaper, cleaner processes. And then, there is room too for exploratory research, on new concepts-perhaps for processing quite new fuels- which could appear attractive and justify further developments to be properly assessed: pyro-processes first, but also others, like chemistry in 'extreme' or 'unusual' conditions (supercritical solvents, sono-chemistry, could be

  16. Quantum mechanics in chemistry

    CERN Document Server

    Schatz, George C

    2002-01-01

    Intended for graduate and advanced undergraduate students, this text explores quantum mechanical techniques from the viewpoint of chemistry and materials science. Dynamics, symmetry, and formalism are emphasized. An initial review of basic concepts from introductory quantum mechanics is followed by chapters examining symmetry, rotations, and angular momentum addition. Chapter 4 introduces the basic formalism of time-dependent quantum mechanics, emphasizing time-dependent perturbation theory and Fermi's golden rule. Chapter 5 sees this formalism applied to the interaction of radiation and matt

  17. Chemistry in Bioinformatics

    OpenAIRE

    Mitchell John; Murray-Rust Peter; Rzepa Henry

    2005-01-01

    Abstract Chemical information is now seen as critical for most areas of life sciences. But unlike Bioinformatics, where data is openly available and freely re-usable, most chemical information is closed and cannot be re-distributed without permission. This has led to a failure to adopt modern informatics and software techniques and therefore paucity of chemistry in bioinformatics. New technology, however, offers the hope of making chemical data (compounds and properties) free during the auth...

  18. Food chemistry. 2. ed.

    International Nuclear Information System (INIS)

    This second edition of the textbook deals with all essential aspects of food chemistry. The revision improved in particular the chapters on food preservation, including irradiation of food, food additives, and pollutants and residues, including radionuclides. The chapter on the German legal regime for foodstuffs has been updated to cover the recent amendments of the law, and the information on processes applied in food technology has been largely enhanced. (VHE) With 153 figs., 78 tabs

  19. Green chemistry: development trajectory

    International Nuclear Information System (INIS)

    Examples of applications of green chemistry methods in heavy organic synthesis are analyzed. Compounds, which can be produced by the processing of the biomass, and the criteria for the selection of the most promising products are summarized. The current status of the ethanol production and processing is considered. The possibilities of the use of high fatty acid triglycerides, glycerol, succinic acid, and isoprene are briefly discussed. The bibliography includes 67 references

  20. Green chemistry: development trajectory

    Science.gov (United States)

    Moiseev, I. I.

    2013-07-01

    Examples of applications of green chemistry methods in heavy organic synthesis are analyzed. Compounds, which can be produced by the processing of the biomass, and the criteria for the selection of the most promising products are summarized. The current status of the ethanol production and processing is considered. The possibilities of the use of high fatty acid triglycerides, glycerol, succinic acid, and isoprene are briefly discussed. The bibliography includes 67 references.

  1. Atmospheric pseudohalogen chemistry

    Directory of Open Access Journals (Sweden)

    D. J. Lary

    2004-09-01

    Full Text Available There are at least three reasons why hydrogen cyanide is likely to be significant for atmospheric chemistry. The first is well known, HCN is a product and marker of biomass burning. However, if a detailed ion chemistry of lightning is considered then it is almost certain than in addition to lightning producing NOx, it also produces HOx and HCN. Unlike NOx and HOx, HCN is long-lived and could therefore be a useful marker of lightning activity. Observational evidence is considered to support this view. Thirdly, the chemical decomposition of HCN leads to the production of small amounts of CN and NCO. NCO can be photolyzed in the visible portion of the spectrum yielding N atoms. The production of N atoms is significant as it leads to the titration of nitrogen from the atmosphere via N+N→N2. Normally the only modelled source of N atoms is NO photolysis which happens largely in the UV Schumann-Runge bands. However, NCO photolysis occurs in the visible and so could be involved in titration of atmospheric nitrogen in the lower stratosphere and troposphere. HCN emission inventories are worthy of attention. The CN and NCO radicals have been termed pseudohalogens since the 1920s. They are strongly bound, univalent, radicals with an extensive and varied chemistry. The products of the atmospheric oxidation of HCN are NO, CO and O3. N+CH4 and N+CH3OH are found to be important sources of HCN. Including the pseudohalogen chemistry gives a small increase in ozone and total reactive nitrogen (NOy.

  2. Chemistry of superheavy elements

    Energy Technology Data Exchange (ETDEWEB)

    Schaedel, M. [Japan Atomic Energy Agency, Tokai, Ibaraki (Japan). Advanced Science Research Center; GSI Helmholtz Center for Heavy Ion Research, Darmstadt (Germany)

    2012-07-01

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  3. Chemistry of superheavy elements

    International Nuclear Information System (INIS)

    The chemistry of superheavy elements - or transactinides from their position in the Periodic Table - is summarized. After giving an overview over historical developments, nuclear aspects about synthesis of neutron-rich isotopes of these elements, produced in hot-fusion reactions, and their nuclear decay properties are briefly mentioned. Specific requirements to cope with the one-atom-at-a-time situation in automated chemical separations and recent developments in aqueous-phase and gas-phase chemistry are presented. Exciting, current developments, first applications, and future prospects of chemical separations behind physical recoil separators ('pre-separator') are discussed in detail. The status of our current knowledge about the chemistry of rutherfordium (Rf, element 104), dubnium (Db, element 105), seaborgium (Sg, element 106), bohrium (Bh, element 107), hassium (Hs, element 108), copernicium (Cn, element 112), and element 114 is discussed from an experimental point of view. Recent results are emphasized and compared with empirical extrapolations and with fully-relativistic theoretical calculations, especially also under the aspect of the architecture of the Periodic Table. (orig.)

  4. BWR chromium chemistry

    International Nuclear Information System (INIS)

    This report addresses the concern about higher total specific conductivity in the reactor recirculation loop water due to the chromate ion. This concern is particularly high at plants where all other ionic species have been reduced through careful attention to makeup and condensate polisher operations. An EPRI Chromate Workshop was held in November 1990 to consider the issues raised by observed levels of chromate ion (generally 5 to 50 ppB). While BWRs on normal water chemistry were the only ones observing chromate, even plants on hydrogen water chemistry (HWC) observe sharp spikes of conductivity due to chromate whenever the hydrogen supply was interrupted after a reasonably long HWC operational period. The consensus of the workshop attendees was that chromate was not a concern as an agent causing pipe cracking compared to the more common species such as chloride and sulfate. However, the data are somewhat ambiguous for levels of chromate above 50 ppB. Adjustments to the weighing factors for the various ionic species in the industry chemistry performance index are suggested to allow for the known relative higher aggressiveness of other species relative to that of chromate

  5. Dynamic combinatorial and protein-templated click chemistry in medicinal chemistry

    OpenAIRE

    Mondal, Milon

    2016-01-01

    We have highlighted throughout this thesis that fragment-based drug design (FBDD) and structure-based drug design (SBDD) still constitute a number of challenges such as the risk associated with de novo SBDD and are time-consuming as they involve synthesis and validation of the binding mode of each derivative in the fragment/hit-optimization cycle. To overcome these hurdles, we combined FBDD or de novo SBDD projects with dynamic combinatorial chemistry (DCC) or protein-templated click chemistr...

  6. Needs for cross sections in plasma chemistry

    International Nuclear Information System (INIS)

    Plasma chemistry is a quite new discipline, widely utilized in the last few years for different technological applications. Plasma chemistry started its life many years ago with the use of electrical arcs for the oxidation of nitrogen to NO. Its life continued for many years on a phenomenological basis: only recently has it achieved a position of true science by mixing methodologies stemming from both chemistry and physics. It is practically impossible to quote all the applications of plasma chemistry: to a first approximation we can distinguish plasma chemistry carried out under equilibrium conditions and under nonequilibrium ones. In the first case one can use thermodynamics for estimating the chemical composition of the medium under study and concepts derived from the kinetic theory of gases for estimating the transport properties of the medium. This approach has been discussed in several papers and applies to plasmas continuously running at atmospheric pressure. On the other hand, in these last years, a large effort has been devoted to the understanding of plasmas under nonequilibrium conditions, i.e., under conditions in which the electron energy distribution functions (eedf) are not Maxwellian, and the distributions among the internal degrees of freedom of molecules are non-Boltzmann. These conditions are typically met in plasma technology (plasma etching, plasma deposition, plasma treatment of materials), in gas discharge lasers (IR and excimer lasers), in the production of neutral and negative ion beams, in plasma ecology for the destruction of atmospheric pollutants, and in general in those plasmas in which the molecular component plays an essential role. 177 refs., 18 figs., 1 tab

  7. General chemistry students' understanding of the chemistry underlying climate science

    Science.gov (United States)

    Versprille, Ashley N.

    The purpose of this study is to investigate first-semester general chemistry students' understanding of the chemistry underlying climate change. The first part of this study involves the collection of qualitative data from twenty-four first-semester general chemistry students from a large Midwestern research institution. The semi-structured interview protocol was developed based on alternative conceptions identified in the research literature and the essential principles of climate change outlined in the U.S. Climate Change Science Program (CCSP) document which pertain to chemistry (CCSP, 2003). The analysis and findings from the interviews indicate conceptual difficulties for students, both with basic climate literacy and underlying chemistry concepts. Students seem to confuse the greenhouse effect, global warming, and the ozone layer, and in terms of chemistry concepts, they lack a particulate level understanding of greenhouse gases and their interaction with electromagnetic radiation, causing them to not fully conceptualize the greenhouse effect and climate change. Based on the findings from these interviews, a Chemistry of Climate Science Diagnostic Instrument (CCSI) was developed for use in courses that teach chemistry with a rich context such as climate science. The CCSI is designed for professors who want to teach general chemistry, while also addressing core climate literacy principles. It will help professors examine their students' prior knowledge and alternative conceptions of the chemistry concepts associated with climate science, which could then inform their teaching and instruction.

  8. Heterogeneous Chemistry in Global Chemistry Transport Models

    Science.gov (United States)

    Stadtler, Scarlet; Simpson, David; Schultz, Martin; Bott, Andreas

    2016-04-01

    The impact of six tropospheric heterogeneous reactions on ozone and nitrogen species was studied using two chemical transport models EMEP MSC-W and ECHAM6-HAMMOZ. Since heterogeneous reactions depend on reactant concentrations (in this study these are N_2O_5, NO_3, NO_2, O_3, HNO_3, HO_2) and aerosol surface area S_a, the modeled surface area of both models was compared to a satellite product retrieving the surface area. This comparison shows a good agreement in global pattern and especially the capability of both models to capture the extreme aerosol loadings in East Asia. Further, the impact of the heterogeneous reactions was evaluated by the simulation of a reference run containing all heterogeneous reactions and several sensitivity runs. One reaction was turned off in each sensitivity run to compare it with the reference run. As previously shown, the analysis of the sensitivity runs shows that the globally most important heterogeneous reaction is the one of N_2O_5. Nevertheless, NO_2, NO_3, HNO3 and HO2 heterogeneous reactions gain relevance particular in East China due to presence of high NOx concentrations and high Sa in the same region. The heterogeneous reaction of O3 itself on dust is compared to the other heterogeneous reactions of minor relevance. Evaluation of the models with northern hemispheric ozone surface observations yields a better agreement of the models with observations when the heterogeneous reactions are incorporated. Impacts of emission changes on the importance of the heterogeneous chemistry will be discussed.

  9. Financial Derivatives

    DEFF Research Database (Denmark)

    Wigan, Duncan

    2013-01-01

    Contemporary derivatives mark the development of capital and constitute a novel form of ownership. By reconfiguring the temporal, spatial and legal character of ownership derivatives present a substantive challenge to the tax collecting state. While fiscal systems are nationally bounded and inheren...

  10. Publicising chemistry in a multicultural society through chemistry outreach

    OpenAIRE

    Joyce D. Sewry; Norman, Nicholas C.; Dudley E. Shallcross; Harrison, Timothy G.; Davies-Coleman, Michael T.

    2011-01-01

    Given the emphasis in Higher Education on community engagement in South Africa and the importance of international collaboration, we discuss a joint approach to chemistry outreach in two countries on two continents with widely differing target school audiences. We describe the history of the partnership between the chemistry departments at Rhodes University and the University of Bristol and provide an outline of the chemistry content of their outreach initiatives, the modes of delivery, the a...

  11. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry

    OpenAIRE

    Marek Tobiszewski; Mariusz Marć; Agnieszka Gałuszka; Jacek Namieśnik

    2015-01-01

    The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-establis...

  12. From organic chemistry to fat and oil chemistry*

    OpenAIRE

    Deffense Etienne

    2009-01-01

    With his work on animal fat and identification of fatty acids, Chevreul was a pioneer in organic chemistry. As Chevreul, I had a passion for organic chemistry too. It was then, an honour and a pleasure to present in 2008 at EFL in Athens this presentation entitled “From organic chemistry to fat and oil chemistry” because my background in organic chemistry helped me all along my professional career to understand and implement new developments related to oil and fat technology and processing. A...

  13. Chemistry in Bioinformatics

    Directory of Open Access Journals (Sweden)

    Mitchell John

    2005-06-01

    Full Text Available Abstract Chemical information is now seen as critical for most areas of life sciences. But unlike Bioinformatics, where data is openly available and freely re-usable, most chemical information is closed and cannot be re-distributed without permission. This has led to a failure to adopt modern informatics and software techniques and therefore paucity of chemistry in bioinformatics. New technology, however, offers the hope of making chemical data (compounds and properties free during the authoring process. We argue that the technology is already available; we require a collective agreement to enhance publication protocols.

  14. Optimized random chemistry

    OpenAIRE

    Buzas, Jeffrey S.; Warrington, Gregory S.

    2013-01-01

    The random chemistry algorithm of Kauffman can be used to determine an unknown subset S of a fixed set V. The algorithm proceeds by zeroing in on S through a succession of nested subsets V=V_0,V_1,...,V_m=S. In Kauffman's original algorithm, the size of each V_i is chosen to be half the size of V_{i-1}. In this paper we determine the optimal sequence of sizes so as to minimize the expected run time of the algorithm.

  15. Chemistry of fast electrons

    OpenAIRE

    Maximoff, Sergey N.; Head-Gordon, Martin P.

    2009-01-01

    A chemicurrent is a flux of fast (kinetic energy ≳ 0.5−1.3 eV) metal electrons caused by moderately exothermic (1−3 eV) chemical reactions over high work function (4−6 eV) metal surfaces. In this report, the relation between chemicurrent and surface chemistry is elucidated with a combination of top-down phenomenology and bottom-up atomic-scale modeling. Examination of catalytic CO oxidation, an example which exhibits a chemicurrent, reveals 3 constituents of this relation: The localization of...

  16. Nanoscale surface chemistry

    OpenAIRE

    Madey, Theodore E.; Pelhos, Kalman; WU, QIFEI; Barnes, Robin; Ermanoski, Ivan; Chen, Wenhua; Kolodziej, Jacek J.; Rowe, John E.

    2002-01-01

    We report evidence in several experiments for nanometer-size effects in surface chemistry. The evidence concerns bimetallic systems, monolayer films of Pt or Pd on W(111) surfaces. Pyramidal facets with {211} faces are formed on annealing on physical monolayer of Pt, Pd on a W(111) substrate, and facet sizes increase with annealing temperature. We used synchrotron radiation-based soft x-ray photoemission to show that monolayer films of Pt, Pd, on W “float” on the outer surface, whereas multil...

  17. Radiochemistry and nuclear chemistry

    CERN Document Server

    Choppin, Gregory; RYDBERG, JAN; Ekberg, Christian

    2013-01-01

    Radiochemistry or nuclear chemistry is the study of radiation from an atomic and molecular perspective, including elemental transformation and reaction effects, as well as physical, health and medical properties. This revised edition of one of the earliest and best-known books on the subject has been updated to bring into teaching the latest developments in research and the current hot topics in the field. To further enhance the functionality of this text, the authors have added numerous teaching aids, examples in MathCAD with variable quantities and options, hotlinks to relevant text secti

  18. Principles of quantum chemistry

    CERN Document Server

    George, David V

    2013-01-01

    Principles of Quantum Chemistry focuses on the application of quantum mechanics in physical models and experiments of chemical systems.This book describes chemical bonding and its two specific problems - bonding in complexes and in conjugated organic molecules. The very basic theory of spectroscopy is also considered. Other topics include the early development of quantum theory; particle-in-a-box; general formulation of the theory of quantum mechanics; and treatment of angular momentum in quantum mechanics. The examples of solutions of Schroedinger equations; approximation methods in quantum c

  19. Chemistry in aircraft plumes

    Energy Technology Data Exchange (ETDEWEB)

    Kraabol, A.G.; Stordal, F.; Knudsen, S. [Norwegian Inst. for Air Research, Kjeller (Norway); Konopka, P. [Deutsche Forschungsanstalt fuer Luft- und Raumfahrt e.V. (DLR), Wessling (Germany). Inst. fuer Physik der Atmosphaere

    1997-12-31

    An expanding plume model with chemistry has been used to study the chemical conversion of NO{sub x} to reservoir species in aircraft plumes. The heterogeneous conversion of N{sub 2}O{sub 5} to HNO{sub 3}(s) has been investigated when the emissions take place during night-time. The plume from an B747 has been simulated. During a ten-hour calculation the most important reservoir species was HNO{sub 3} for emissions at noon. The heterogeneous reactions had little impact on the chemical loss of NO{sub x} to reservoir species for emissions at night. (author) 4 refs.

  20. Arene ruthenium chemistry

    OpenAIRE

    Bates, Richard Simon

    1990-01-01

    This thesis describes the synthesis and reactivity studies of new arene-ruthenium(II) and arene-ruthenium(O) complexes. Ultrasound has been investigated as an alternative energy source, with the overall aim of synthesising arene ruthenium clusters. Chapter 1 gives an introduction and summary of the known arene ruthenium chemistry reported to date. Chapter 2 reports the synthesis of (CGH6)Ru(C2H4)2 and (MeC6H4CHMe2)Ru(C2H4)2. Low temperature protonation studies generated (C6H6)Ru(H)(CZH4...

  1. Introduction to supramolecular chemistry

    CERN Document Server

    Dodziuk, Helena

    2007-01-01

    'A major strength of this work is its inclusion of literally hundreds of clearly drawn structures and diagrams to assist reader understanding of this complex area. In addition, the author has included hundreds of up-to-date references. It also has a useful and extensive index. The book is valuable not only to those working in the field of supramolecular chemistry, but also to chemists in unrelated areas of research who want a refreshingly well-written monograph on an emerging area of important research.' H.T. McKone, Saint Joseph College in Choice, September 2002

  2. Radiochemistry and actinide chemistry

    International Nuclear Information System (INIS)

    The analysis of trace amounts of actinide elements by means of radiochemistry, is discussed. The similarities between radiochemistry and actinide chemistry, in the case of species amount by cubic cm below 1012, are explained. The parameters which allow to define what are the observable chemical reactions, are given. The classification of radionuclides in micro or macrocomponents is considered. The validity of the mass action law and the partition function in the definition of the average number of species for trace amounts, is investigated. Examples illustrating the results are given

  3. Analytical chemistry in space

    CERN Document Server

    Wainerdi, Richard E

    1970-01-01

    Analytical Chemistry in Space presents an analysis of the chemical constitution of space, particularly the particles in the solar wind, of the planetary atmospheres, and the surfaces of the moon and planets. Topics range from space engineering considerations to solar system atmospheres and recovered extraterrestrial materials. Mass spectroscopy in space exploration is also discussed, along with lunar and planetary surface analysis using neutron inelastic scattering. This book is comprised of seven chapters and opens with a discussion on the possibilities for exploration of the solar system by

  4. Introduction to Coordination Chemistry

    CERN Document Server

    Lawrance, Geoffrey Alan

    2010-01-01

    Introduction to Coordination Chemistry examines and explains how metals and molecules that bind as ligands interact, and the consequences of this assembly process. This book describes the chemical and physical properties and behavior of the complex assemblies that form, and applications that may arise as a result of these properties. Coordination complexes are an important but often hidden part of our world?even part of us?and what they do is probed in this book. This book distills the essence of this topic for undergraduate students and for research scientists.

  5. Chemistry in space

    CERN Document Server

    Rehder, Dieter

    2010-01-01

    The dynamic field of extraterrestrial chemistry brings together ideas of chemistr, astrophysics, and biology to the study of molecules between stars, around stars, and on plantes. This book serves as an introduction to chemial processes under ?unearthly? and hence usually extreme conditions (temperature, pressure, high or low density, bombardment by cosmic rays), and their impact on the early development of our solar system, as well as providing a deeper understanding of processes in earthly regions where conditions approach those of extraterrestrial areas.A unique and extraordinary perspe

  6. Radiation chemistry in microemulsion

    International Nuclear Information System (INIS)

    Radiation chemistry can be used to study reactions of free radicals not only in homogeneous medium but also in micro-heterogeneous medium, microemulsion being typical example of this type of medium. This article intends to summarize some radiation chemical studies in microemulsion using pulse radiolysis as a tool. Attempt has been made to show that the reaction and self-decay of hydrated electron can lead to achieve useful results relating to the physical properties of micro-droplets. Moreover, free radical reactions with biomolecules in these media can sometime be extrapolated to living systems. (author)

  7. Quantum chemistry an introduction

    CERN Document Server

    Kauzmann, Walter

    2013-01-01

    Quantum Chemistry: An Introduction provides information pertinent to the fundamental aspects of quantum mechanics. This book presents the theory of partial differentiation equations by using the classical theory of vibrations as a means of developing physical insight into this essential branch of mathematics.Organized into five parts encompassing 16 chapters, this book begins with an overview of how quantum mechanical deductions are made. This text then describes the achievements and limitations of the application of quantum mechanics to chemical problems. Other chapters provide a brief survey

  8. Theme-Based Bidisciplinary Chemistry Laboratory Modules

    Science.gov (United States)

    Leber, Phyllis A.; Szczerbicki, Sandra K.

    1996-12-01

    methanol to effect transesterification (3) and examining the effect of variations in leaf type and season on lipid composition. A second "Plant Assay" study involves preparing and characterizing analogs of naphthalene-1-acetamide, which is the active growth-promoting ingredient in commercial preparations such as Transplantone® and Rootone®. There are two direct methods for synthesizing the amide from the native plant growth regulator ("auxin") or carboxylic acid: acid-catalyzed hydrolysis of the nitrile or ammonolysis of the acid chloride derivative, prepared in situ from the acid by treatment with thionyl chloride (4). In the spring of 1996, organic chemistry students synthesized the amide derivatives of a number of auxins via the acid chloride intermediate, which is more efficiently prepared using oxalyl chloride (40-60% overall yield) instead of thionyl chloride (20-40% overall yield), or via nitrile hydrolysis (72-99% yield). Plant bioassays, based on measurement of pea stem segment elongation (5) have only been performed on the acetamide derivatives of three auxins, indole-3-acetic acid (IAA), naphthalene-1-acetic acid (1-NAA), and naphthalene-2-acetic acid (2-NAA). In comparison with the control, indole-3-acetamide and naphthalene-1-acetamide promoted growth by 50% and 90%, respectively. The acetamide of 2-NAA impeded growth by 30% relative to the control, an observation consistent with the known antiauxin activity of 2-NAA (6). Acquisition of the necessary imaging system for the teaching laboratory will enable students to extend these quantitative studies to other auxin conjugates. Acknowledgment We are grateful to the NSF for financial support through the Division of Undergraduate Education (DUE-9455693 and DUE-9550890). Literature Cited 1. Mayo, D. W.; Pike, R. M.; Trumper, P. K. Microscale Organic Laboratory, 3rd ed; John Wiley & Sons: New York, 1994; pp 202-203. 2. Browse, J.; McCourt, P. J.; Somerville, C. R. Anal. Biochem. 1986, 152, 141. 3. Rodig, O. R

  9. From China to the world: Science China Chemistry celebrates the International Year of Chemistry

    Institute of Scientific and Technical Information of China (English)

    ZHU XiaoWen; XUE Zi-Ling

    2012-01-01

    1 Introduction Science China Chemistry is considered the best and most comprehensive chemistry journal in China,Its primary mission is to communicate the results of basic and innovative chemistry research.The subject areas include physical chemistry,organic chemistry,inorganic chemistry,polymer chemistry,biological chemistry,environmental chemistry,and chemical engineering in the form of Feature Articles,Reviews,Communications,Articles,and News & Comments.

  10. Students' Understanding of Mathematical Expressions in Physical Chemistry Contexts: An Analysis Using Sherin's Symbolic Forms

    Science.gov (United States)

    Becker, Nicole; Towns, Marcy

    2012-01-01

    Undergraduate physical chemistry courses require students to be proficient in calculus in order to develop an understanding of thermodynamics concepts. Here we present the findings of a study that examines student understanding of mathematical expressions, including partial derivative expressions, in two undergraduate physical chemistry courses.…

  11. Holographic entanglement chemistry

    CERN Document Server

    Caceres, Elena; Pedraza, Juan F

    2016-01-01

    We use the Iyer-Wald formalism to derive an extended first law of entanglement that includes variations in the cosmological constant, Newton's constant and --in the case of higher derivative theories-- all the additional couplings of the theory. In Einstein gravity, where the number of degrees of freedom $N^2$ of the dual field theory is a function of $\\Lambda$ and $G$, our approach allows us to vary $N$ keeping the field theory scale fixed or to vary the field theory scale keeping $N$ fixed. We also derive an extended first law of entanglement for Gauss-Bonnet and Lovelock gravity.

  12. MICROSCALE CHEMISTRY IN LATIN AMERICA

    Directory of Open Access Journals (Sweden)

    Jorge G. Ibáñez

    2005-06-01

    Full Text Available A brief account of the development of Microscale Chemistry in Latin America is here presented. The US National Microscale Chemistry Center (Merrimack College, Massachusetts was instrumental in the initiationof several centers. Its Mexican counterpart, the Mexican Microscale Chemistry Center (CMQM, has been a key player in this process. Other participating countries include Argentina, Bolivia, Brazil, Chile, Cuba,Guatemala, Perú and Uruguay.

  13. Six Phases of Cosmic Chemistry

    OpenAIRE

    Lukasz Lamza

    2014-01-01

    The article presents a conceptually unified, quantitative account of the development of chemical phenomena throughout the cosmic history, with a detailed discussion of the cosmological, astrophysical, geological, biological, and anthropological context. The totality of cosmic chemistry is represented by a list of 176 classes of phenomena, drawn from the Universal Decimal Classification (UDC) library cataloguing system, and divided into 6 phases: of no chemistry, of prestellar chemistry, of ga...

  14. NUCLEAR CHEMISTRY ANNUAL REPORT 1970

    Energy Technology Data Exchange (ETDEWEB)

    Authors, Various

    1971-05-01

    Papers are presented for the following topics: (1) Nuclear Structure and Nuclear Properties - (a) Nuclear Spectroscopy and Radioactivity; (b) Nuclear Reactions and Scattering; (c) Nuclear Theory; and (d) Fission. (2) Chemical and Atomic Physics - (a) Atomic and Molecular Spectroscopy; and (b) Hyperfine Interactions. (3) Physical, Inorganic, and Analytical Chemistry - (a) X-Ray Crystallography; (b) Physical and Inorganic Chemistry; (c) Radiation Chemistry; and (d) Chemical Engineering. (4) Instrumentation and Systems Development.

  15. Sixty Years of Chemistry at CAS

    Institute of Scientific and Technical Information of China (English)

    WAN Li-Jun

    2011-01-01

    @@ As one of the fundamental and key disciplines of natural sciences, chemistry deals with the properties, composition, structure, transformation and applications of substances.It could be further divided into several branches, such as inorganic chemistry, organic chemistry, physical chemistry, polymer chemistry, analytical chemistry and chemical engineering.In recent years, many new branches and fields have emerged amide the continuous development of chemistry and its interdisciplinary research with mathematics, physics, astronomy, earth science, biology, medical science, materials science, and environmental science.

  16. Complex Protostellar Chemistry

    Science.gov (United States)

    Nuth, Joseph A., III; Johnson, Natasha M.

    2012-01-01

    Two decades ago, our understanding of the chemistry in protostars was simple-matter either fell into the central star or was trapped in planetary-scale objects. Some minor chemical changes might occur as the dust and gas fell inward, but such effects were overwhelmed by the much larger scale processes that occurred even in bodies as small as asteroids. The chemistry that did occur in the nebula was relatively easy to model because the fall from the cold molecular cloud into the growing star was a one-way trip down a well-known temperature-pressure gradient; the only free variable was time. However, just over 10 years ago it was suggested that some material could be processed in the inner nebula, flow outward, and become incorporated into comets (1, 2). This outward flow was confirmed when the Stardust mission returned crystalline mineral fragments (3) from Comet Wild 2 that must have been processed close to the Sun before they were incorporated into the comet. In this week's Science Express, Ciesla and Sandford (4) demonstrate that even the outermost regions of the solar nebula can be a chemically active environment. Their finding could have consequences for the rest of the nebula.

  17. Materials Chemistry Studies

    International Nuclear Information System (INIS)

    In 2006, a new research group has been created at the SCK-CEN in order to focus more specifically on chemical issues relevant to the studies of materials. The integrated staff personnel has a long experience in many different fields of expertise such as radiochemistry (fuel cycles and radioisotopes), organic chemistry, electrochemistry (analytical techniques and corrosion) and sonochemistry. The previously running activities are now being reoriented according to a well-defined work programme. Each research line that was previously running had specific objectives. Fuel cycle studies were axed on the partitioning of lanthanides and actinides in aqueous solutions. Support to corrosion studies was devoted to the development of a new method for the treatment of electrochemical noise data for the detection and the classification of local corrosion events. New objectives for the future put a strong accent on radioisotopes for the pharmaceutical industry as well as the use of non-aqueous chemistry as a tool for several applications among which the treatment and the separation of radioisotopes, analytical measurements as well as the chemical control of impurities in liquid metals

  18. Solid state chemistry an introduction

    CERN Document Server

    Smart, Lesley E

    2012-01-01

    ""Smart and Moore are engaging writers, providing clear explanations for concepts in solid-state chemistry from the atomic/molecular perspective. The fourth edition is a welcome addition to my bookshelves. … What I like most about Solid State Chemistry is that it gives simple clear descriptions for a large number of interesting materials and correspondingly clear explanations of their applications. Solid State Chemistry could be used for a solid state textbook at the third or fourth year undergraduate level, especially for chemistry programs. It is also a useful resource for beginning graduate

  19. Graduate Education in Environmental Chemistry

    Science.gov (United States)

    Lee, G. Fred

    1974-01-01

    Describes the role chemistry departments should assume in the environmental quality control area. Includes problems of program design, course offerings, research problems, and career qualifications. (GS)

  20. A green chemistry lab course

    International Nuclear Information System (INIS)

    The traditional course content of chemistry classes must change to achieve better awareness of the important issues of sustainability in chemistry within the next generation of professional chemists. To provide the necessary material for the organic chemistry teaching lab course, which is part of almost all study programs in chemistry, material was developed and collected (http://www.oc-praktikum.de/en) that allows students and teachers to assess reactions beyond the experimental set up, reaction mechanism and chemical yield. Additional parameters like atom economy of chemical transformations, energy efficiency, and questions of waste, renewable feed stocks, toxicity and ecotoxicity, as well as the safety measures for the chemicals used are discussed. (author)

  1. Cross-Connections of Chemistry

    Science.gov (United States)

    Mason, Diana S.

    2002-02-01

    We are in desperate need of qualified chemistry teachers. Are the teachers who have biology, physics, or some psychology degrees qualified to teach chemistry? Have they taken enough chemistry to be prepared to teach outside their degree field? If remediation is necessary, what courses should be required? Attracting pre-service science teachers to the study of pure chemistry is not an easy task when more attractive course offerings are available. Maybe we should concentrate on cross-training in-service teachers by providing appropriate graduate courses to encourage them and bring them into the family. Many teachers with degrees outside the traditional discipline of chemistry have adequate backgrounds in the applications of chemistry. Requiring hours of undergraduate education before they enter the hallowed halls of the chemistry building as graduate students only serves to discourage a large segment of in-service teachers who wish to broaden their perspective. The National Science Education Standards make a compelling argument for connecting and integrating science courses for practicing teachers (3). We are at the crossroads. At a time when we so desperately need qualified chemistry teachers, shouldn't we be more open in our graduate teaching programs, inviting those with degrees in other disciplines to start on a graduate degree without insisting on undergraduate or survey coursework first? Many potential chemical education graduate students have a background in chemistry--it is just known by another name.

  2. Derivative Chameleons

    CERN Document Server

    Noller, Johannes

    2012-01-01

    We consider generalized chameleon models where the conformal coupling between matter and gravitational geometries is not only a function of the chameleon field \\phi, but also of its derivatives via higher order co-ordinate invariants. Specifically we consider the first such non-trivial conformal factor A(\\phi,X), where X is the canonical kinetic term for \\phi. The associated phenomenology is investigated and we show that such theories have a new generic mass-altering mechanism, potentially assisting the generation of a sufficiently large chameleon mass in dense environments. The most general effective potential is derived for such derivative chameleon setups and explicit examples are given. Interestingly this points us to the existence of a purely derivative chameleon protected by a shift symmetry for \\phi. We also discuss potential ghost-like instabilities associated with mass-lifting mechanisms and find another, mass-lowering and instability-free, branch of solutions. This suggests that, barring fine-tuning...

  3. Carbohydrate Green Chemistry: C-Glycoside Ketones as Potential Chiral Building Blocks

    Science.gov (United States)

    "Green chemistry" methods to produce new chemicals from renewable agricultural feedstocks will decrease our dependence on imported petroleum feedstocks and lower the environmental impact of consumer products. Our current research focuses on development of new carbohydrate-based derivatives, "locked...

  4. Financial derivatives

    OpenAIRE

    Simon Gray and Joanna Place

    2006-01-01

    Derivatives, ranging from relatively simple forward contracts to complicated options products, are an increasingly important feature of financial markets worldwide. They are already being used in many emerging markets, and as the financial sector becomes deeper and more stable, their use is certain to grow. This Handbook provides a basic guide to the different types of derivatives traded, including the pricing and valuation of the products, and accounting and statistical treatment. Also, it a...

  5. Synthesis, characterization and antibacterial activity of new fluorescent chitosan derivatives

    Czech Academy of Sciences Publication Activity Database

    Přichystalová, H.; Almonasy, N.; Abdel-Mohsen, A. M.; Abdel-Rahman, R. M.; Fouda, M. M. G.; Vojtova, L.; Kobera, Libor; Spotz, Z.; Burgert, L.; Jancar, J.

    2014-01-01

    Roč. 65, April (2014), s. 234-240. ISSN 0141-8130 Institutional support: RVO:61389013 Keywords : chitosan derivatives * fluorescence * antibacterial activity Subject RIV: CD - Macromolecular Chemistry Impact factor: 2.858, year: 2014

  6. Dynamics of forest soil chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Alveteg, M.

    1998-11-01

    Acidification caused by emissions of nitrogen and sulphur and associated adverse effects on forest ecosystems has been an issue on the political agenda for decades. Temporal aspects of soil acidification and/or recovery can be investigated using the soil chemistry model SAFE, a dynamic version of the steady-state model PROFILE used in critical loads assessment on the national level, e.g. for Sweden. In this thesis, possibilities to replace the use of apparent gibbsite solubility coefficients with a more mechanistic Al sub-model are investigated and a reconstruction model, MAKEDEP, is presented which makes hindcasts and forecasts of atmospheric deposition and nutrient uptake and cycling. A regional application of SAFE/MAKEDEP based on 622 sites in Switzerland is also presented. It is concluded that the quantitative information on pools and fluxes of Al in forest ecosystems is very limited and that there currently exists no mechanistic alternative in modelling soil solution Al. MAKEDEP is a valuable and operational tool for deriving input to dynamic soil chemistry models such as SMART, MAGIC and SAFE. For multi-layer models, e.g. the SAFE model, including nutrient cycling in MAKEDEP is shown to be important. The strength of the regional assessment strategy presented in this thesis lies in its transparency and modularity. All sub-modules, including models, transfer functions, assumptions in the data acquisition strategy, etc., can be checked and replaced individually. As the presented assessment strategy is based on knowledge and data from a wide range of scientists and fields it is of vital importance that the research community challenge the assumptions made. The many measurable intermediate results produced by the included models will hopefully encourage scientists to challenge the models through additional measurements at the calculation sites. It is concluded that current reduction plans are not sufficient for all forest ecosystems in Switzerland to recover from

  7. Influencing College Chemistry Success through High School Chemistry Teaching

    Science.gov (United States)

    Tai, Robert H.; Sadler, Philip M.; Loehr, John F.

    2006-01-01

    The connection between high school chemistry pedagogical experiences and introductory college chemistry performance has been a topic researched in published science education literature since the 1920s. However, analysis techniques have limited the generalizability of these results. This review discusses the findings of a large-scale,…

  8. Introducing Chemistry Students to the "Real World" of Chemistry

    Science.gov (United States)

    Brown, Michael E.; Cosser, Ronald C.; Davies-Coleman, Michael T.; Kaye, Perry T.; Klein, Rosalyn; Lamprecht, Emmanuel; Lobb, Kevin; Nyokong, Tebello; Sewry, Joyce D.; Tshentu, Zenixole R.; van der Zeyde, Tino; Watkins, Gareth M.

    2010-01-01

    A majority of chemistry graduates seek employment in a rapidly changing chemical industry. Our attempts to provide the graduates with skills in entrepreneurship and the ability to understand and communicate with their chemical engineering colleagues, in addition to their fundamental knowledge of chemistry, are described. This is done at…

  9. A Quantum Chemistry Concept Inventory for Physical Chemistry Classes

    Science.gov (United States)

    Dick-Perez, Marilu; Luxford, Cynthia J.; Windus, Theresa L.; Holme, Thomas

    2016-01-01

    A 14-item, multiple-choice diagnostic assessment tool, the quantum chemistry concept inventory or QCCI, is presented. Items were developed based on published student misconceptions and content coverage and then piloted and used in advanced physical chemistry undergraduate courses. In addition to the instrument itself, data from both a pretest,…

  10. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry

    Directory of Open Access Journals (Sweden)

    Marek Tobiszewski

    2015-06-01

    Full Text Available The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-established and recently developed green analytical chemistry metrics, including NEMI labeling and analytical Eco-scale, are presented. Additionally, this paper focuses on the possibility of the use of multivariate statistics in evaluation of environmental impact of analytical procedures. All the above metrics are compared and discussed in terms of their advantages and disadvantages. The current needs and future perspectives in green chemistry metrics are also discussed.

  11. Green Chemistry Metrics with Special Reference to Green Analytical Chemistry.

    Science.gov (United States)

    Tobiszewski, Marek; Marć, Mariusz; Gałuszka, Agnieszka; Namieśnik, Jacek

    2015-01-01

    The concept of green chemistry is widely recognized in chemical laboratories. To properly measure an environmental impact of chemical processes, dedicated assessment tools are required. This paper summarizes the current state of knowledge in the field of development of green chemistry and green analytical chemistry metrics. The diverse methods used for evaluation of the greenness of organic synthesis, such as eco-footprint, E-Factor, EATOS, and Eco-Scale are described. Both the well-established and recently developed green analytical chemistry metrics, including NEMI labeling and analytical Eco-scale, are presented. Additionally, this paper focuses on the possibility of the use of multivariate statistics in evaluation of environmental impact of analytical procedures. All the above metrics are compared and discussed in terms of their advantages and disadvantages. The current needs and future perspectives in green chemistry metrics are also discussed. PMID:26076112

  12. Physical and Structural Characterization of Biofield Treated Imidazole Derivatives

    OpenAIRE

    Mahendra Kumar Trivedi; Gopal Nayak; Alice Branton; Dahryn Trivedi

    2015-01-01

    Imidazole derivatives have attracted significant interests in recent time for their usefulness in synthetic heterocyclic chemistry, analytical chemistry and pharmacology. Aim of present study was to evaluate the impact of biofield treatment on two imidazole derivatives (i.e., imidazole and 2-methylimidazole) by various analytical methods. The biofield treatment was done by Mr. Trivedi on both the compounds and both control and treated samples of imidazole and 2-methylimidazole were characteri...

  13. Ice Chemistry in Starless Molecular Cores

    Science.gov (United States)

    Kalvāns, J.

    2015-06-01

    Starless molecular cores are natural laboratories for interstellar molecular chemistry research. The chemistry of ices in such objects was investigated with a three-phase (gas, surface, and mantle) model. We considered the center part of five starless cores, with their physical conditions derived from observations. The ice chemistry of oxygen, nitrogen, sulfur, and complex organic molecules (COMs) was analyzed. We found that an ice-depth dimension, measured, e.g., in monolayers, is essential for modeling of chemistry in interstellar ices. Particularly, the H2O:CO:CO2:N2:NH3 ice abundance ratio regulates the production and destruction of minor species. It is suggested that photodesorption during the core-collapse period is responsible for the high abundance of interstellar H2O2 and O2H and other species synthesized on the surface. The calculated abundances of COMs in ice were compared to observed gas-phase values. Smaller activation barriers for CO and H2CO hydrogenation may help explain the production of a number of COMs. The observed abundance of methyl formate HCOOCH3 could be reproduced with a 1 kyr, 20 K temperature spike. Possible desorption mechanisms, relevant for COMs, are gas turbulence (ice exposure to interstellar photons) or a weak shock within the cloud core (grain collisions). To reproduce the observed COM abundances with the present 0D model, 1%-10% of ice mass needs to be sublimated. We estimate that the lifetime for starless cores likely does not exceed 1 Myr. Taurus cores are likely to be younger than their counterparts in most other clouds.

  14. Clays in prebiological chemistry

    Science.gov (United States)

    Rao, M.; Oro, J.; Odom, D. G.

    1980-01-01

    The ways in which clays have been utilized in studies of prebiological chemistry are reviewed, and an assessment is given of the possible role of clays in prebiological systems. The adsorption of organic molecules on clays has been demonstrated, as has the synthesis of bioorganic monomers in the presence of clays. For instance, amino acids, purines and pyrimidines have been obtained from carbon monoxide and nitric acid in the presence of clays at relatively high temperatures (250-325 C). The oligomerization of biochemical monomers, mediated by clays, has also been shown to result in the formation of polymer molecules basic to life. Clays have also been found to affect the condensation of mononucleotides to oligonucleotides.

  15. Organic chemistry on Titan

    Science.gov (United States)

    Chang, S.; Scattergood, T.; Aronowitz, S.; Flores, J.

    1979-01-01

    Features taken from various models of Titan's atmosphere are combined in a working composite model that provides environmental constraints within which different pathways for organic chemical synthesis are determined. Experimental results and theoretical modeling suggest that the organic chemistry of the satellite is dominated by two processes: photochemistry and energetic particle bombardment. Photochemical reactions of CH4 in the upper atmosphere can account for the presence of C2 hydrocarbons. Reactions initiated at various levels of the atmosphere by cosmic rays, Saturn 'wind', and solar wind particle bombardment of a CH4-N2 atmospheric mixture can account for the UV-visible absorbing stratospheric haze, the reddish appearance of the satellite, and some of the C2 hydrocarbons. In the lower atmosphere photochemical processes will be important if surface temperatures are sufficiently high for gaseous NH3 to exist. It is concluded that the surface of Titan may contain ancient or recent organic matter (or both) produced in the atmosphere.

  16. Advances in analytical chemistry

    Science.gov (United States)

    Arendale, W. F.; Congo, Richard T.; Nielsen, Bruce J.

    1991-01-01

    Implementation of computer programs based on multivariate statistical algorithms makes possible obtaining reliable information from long data vectors that contain large amounts of extraneous information, for example, noise and/or analytes that we do not wish to control. Three examples are described. Each of these applications requires the use of techniques characteristic of modern analytical chemistry. The first example, using a quantitative or analytical model, describes the determination of the acid dissociation constant for 2,2'-pyridyl thiophene using archived data. The second example describes an investigation to determine the active biocidal species of iodine in aqueous solutions. The third example is taken from a research program directed toward advanced fiber-optic chemical sensors. The second and third examples require heuristic or empirical models.

  17. Prebiotic chemistry in clouds

    Science.gov (United States)

    Oberbeck, Verne R.; Marshall, John; Shen, Thomas

    1991-01-01

    The chemical evolution hypothesis of Woese (1979), according to which prebiotic reactions occurred rapidly in droplets in giant atmospheric reflux columns was criticized by Scherer (1985). This paper proposes a mechanism for prebiotic chemistry in clouds that answers Scherer's concerns and supports Woese's hypothesis. According to this mechanism, rapid prebiotic chemical evolution was facilitated on the primordial earth by cycles of condensation and evaporation of cloud drops containing clay condensation nuclei and nonvolatile monomers. For example, amino acids supplied by, or synthesized during entry of meteorites, comets, and interplanetary dust, would have been scavenged by cloud drops containing clay condensation nuclei and would be polymerized within cloud systems during cycles of condensation, freezing, melting, and evaporation of cloud drops.

  18. Rapid automated nuclear chemistry

    International Nuclear Information System (INIS)

    Rapid Automated Nuclear Chemistry (RANC) can be thought of as the Z-separation of Neutron-rich Isotopes by Automated Methods. The range of RANC studies of fission and its products is large. In a sense, the studies can be categorized into various energy ranges from the highest where the fission process and particle emission are considered, to low energies where nuclear dynamics are being explored. This paper presents a table which gives examples of current research using RANC on fission and fission products. The remainder of this text is divided into three parts. The first contains a discussion of the chemical methods available for the fission product elements, the second describes the major techniques, and in the last section, examples of recent results are discussed as illustrations of the use of RANC

  19. Nuclear chemistry progress report

    International Nuclear Information System (INIS)

    During the past year the Nuclear Chemistry Group at Indiana University has concentrated its efforts on (1) the analysis and publication of previous experimental studies and (2) the design and construction of ISiS, a 4π detector for multifragment emission studies. No new experiments were undertaken, rather all of our experimental effort has been directed toward component tests of ISiS, with a goal of beginning measurements with this device in 1992. Research projects that have been largely completed during the last year include: (1) multiple fragment emission studies of the 0.90 and 3.6 GeV 3He + natAg reaction; (2) intermediate-mass-fragment (IMF: 3 ≤ Z ≤ 15) excitation function measurements for the E/A = 20-to-100 MeV 14N + natAg and 197Au reactions, and (3) particle-particle correlation studies for the determination of space-time relationships energy collisions

  20. Beryllium chemistry and processing

    CERN Document Server

    Walsh, Kenneth A

    2009-01-01

    This book introduces beryllium; its history, its chemical, mechanical, and physical properties including nuclear properties. The 29 chapters include the mineralogy of beryllium and the preferred global sources of ore bodies. The identification and specifics of the industrial metallurgical processes used to form oxide from the ore and then metal from the oxide are thoroughly described. The special features of beryllium chemistry are introduced, including analytical chemical practices. Beryllium compounds of industrial interest are identified and discussed. Alloying, casting, powder processing, forming, metal removal, joining and other manufacturing processes are covered. The effect of composition and process on the mechanical and physical properties of beryllium alloys assists the reader in material selection. The physical metallurgy chapter brings conformity between chemical and physical metallurgical processing of beryllium, metal, alloys, and compounds. The environmental degradation of beryllium and its all...

  1. Rapid automated nuclear chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Meyer, R.A.

    1979-05-31

    Rapid Automated Nuclear Chemistry (RANC) can be thought of as the Z-separation of Neutron-rich Isotopes by Automated Methods. The range of RANC studies of fission and its products is large. In a sense, the studies can be categorized into various energy ranges from the highest where the fission process and particle emission are considered, to low energies where nuclear dynamics are being explored. This paper presents a table which gives examples of current research using RANC on fission and fission products. The remainder of this text is divided into three parts. The first contains a discussion of the chemical methods available for the fission product elements, the second describes the major techniques, and in the last section, examples of recent results are discussed as illustrations of the use of RANC.

  2. Synthesis and Herbicidal Activity of 3-Subsituted Amino-6-(substituted phenoxyl)pyridazine Derivatives

    Institute of Scientific and Technical Information of China (English)

    HU,Fang-Zhong; WANG,Zhan-Ping; LI,Yong-Hong; YANG,Hua-Zheng

    2004-01-01

    @@ In recent years, many pyridazine derivatives have shown highly biological activities, such as fungicides, insecticides and herbicides. Especially, the researches of 3-(substituted phenoxyl)pyridazine derivatives have become the focus of pesticidal chemistry.

  3. Modelling electric discharge chemistry

    International Nuclear Information System (INIS)

    The chemistry occurring in a electric discharge was modelled to predict how it would be influenced by discharge conditions. The discharge was characterized by a calculated Boltzmann electron-energy distribution, from which rate constants for electron-molecule processes in air were determined. These rate constants were used in a chemical kinetics calculation that also included reactions between neutral molecules, ions, free radicals and electronically excited species. The model describes how the discharge chemistry was influenced by humidity, electric field, electron number density, and concentrations of key reagents identified in the study. The use of an electric discharge to destroy airborne contaminant molecules was appraised, the targeted contaminants being CF2Cl2, HCN, and SO2. The modelling results indicate that an electric discharge should be able to remove HCN and CF2Cl2 effectively, especially if the discharge conditions have been optimized. Effective destruction is achieved with a moderate electric field (over 1 x 10-15 V.cm2), a substantial electron number density (over 1 x 1012 cm-3), and the presence of H20 in the process air. The residence time in the discharge was also shown to be important in contaminant destruction. An attempt was made to explain the results of the electric discharge abatement of SO2, a component of a simulated flue-gas mixture. Results from the model indicate that the discharge parameters that increase the concentration of hydroxyl radical also increase the rate of decomposition of SO2. An objective of the study was to explain the apparent enhancement of SO2 destruction by the presence of a small amount of NO2. It was thought that a likely explanation would be the stabilization of HOSO2, an important intermediate in the oxidation of SO2 by NO2. (49 figs., 14 tabs., 75 refs.)

  4. Nanoplasmonics tuned ``click chemistry''

    Science.gov (United States)

    Tijunelyte, I.; Guenin, E.; Lidgi-Guigui, N.; Colas, F.; Ibrahim, J.; Toury, T.; Lamy de La Chapelle, M.

    2016-03-01

    Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised ``click'' reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the ``click'' chemistry.Nanoplasmonics is a growing field of optical condensed matter science dedicated to optical phenomena at the nanoscale level in metal systems. Extensive research on noble metallic nanoparticles (NPs) has emerged within the last two decades due to their ability to keep the optical energy concentrated in the vicinity of NPs, in particular, the ability to create optical near-field enhancement followed by heat generation. We have exploited these properties in order to induce a localised ``click'' reaction in the vicinity of gold nanostructures under unfavourable experimental conditions. We demonstrate that this reaction can be controlled by the plasmonic properties of the nanostructures and we propose two physical mechanisms to interpret the observed plasmonic tuning of the ``click'' chemistry. Electronic supplementary information (ESI) available: NMR study on reaction initiation, SERS spectra and temperature calculations. See DOI: 10.1039/c5nr09018k

  5. Local Evaluation of Chemistry Journals

    Science.gov (United States)

    Kraus, Joseph R.; Hansen, Rachel

    2008-01-01

    This paper reports on the evaluation of local usage statistics of a specific set of chemistry journals at the University of Denver in Colorado, USA. The objective of the study is to demonstrate that commercial publishers in chemistry charge considerably more for their journals than those from the non-commercial sector. There are three variables…

  6. HMI scientific report - chemistry 1988

    International Nuclear Information System (INIS)

    Results of the R and D activities are reported, dealing with the following subjects: Interface processes and energy conversion, high-energy photochemistry and radiation chemistry as well as trace elements chemistry. A list of publications and lectures is added and gives a view on results obtained in research and development. (EF)

  7. Chemistry Teachers' Views of Creativity

    Science.gov (United States)

    Akkanat, Çigdem; Gökdere, Murat

    2015-01-01

    The purpose of this study was to determine chemistry teachers' views of creativity. In this study, phenomenology method, one of the qualitative research patterns, was used. The participants of this study were 13 chemistry teachers working in Amasya. A semi-structured interview form was used for data collection. By using NVivo 9 qualitative…

  8. News from Online: Green Chemistry

    Science.gov (United States)

    Uffelman, Erich S.

    2004-01-01

    Green chemistry closely relates to energy and environmental problems, and includes the promotion of environmental friendly products and systems within the framework of renewable resources. Various websites on green chemistry are reviewed, one of which lists the 12 commandments of this particular subject.

  9. Introducing Relativity into Quantum Chemistry

    Science.gov (United States)

    Li, Wai-Kee; Blinder, S. M.

    2011-01-01

    It is not often realized by chemists that the special theory of relativity is behind several aspects of quantum chemistry. The Schrdinger equation itself is based on relations between space-time and energy-momentum four vectors. Electron spin is, of course, the most obvious manifestation of relativity. The chemistry of some heavy elements is…

  10. A Cooperative Chemistry Project: Chemsource.

    Science.gov (United States)

    Giles, Catherine Y.

    1994-01-01

    Chemsource is a set of instructional materials designed as a resource for high school chemistry teachers, particularly those not trained in the discipline. Materials consist of a videotape demonstrating both generic and science-specific teaching skills and a textbook on varied chemistry topics, including suggested teaching techniques and…

  11. Contextualising Nanotechnology in Chemistry Education

    Science.gov (United States)

    O'Connor, Christine; Hayden, Hugh

    2008-01-01

    In recent years nanotechnology has become part of the content of many undergraduate chemistry and physics degree courses. This paper deals with the role of contextualisation of nanotechnology in the delivery of the content, as nanotechnology is only now being slowly integrated into many chemistry degree courses in Ireland and elsewhere. An…

  12. Crocodile Chemistry. [CD-ROM].

    Science.gov (United States)

    1999

    This high school chemistry resource is an on-screen chemistry lab. In the program, students can experiment with a huge range of chemicals, choosing the form, quantity and concentrations. Dangerous or difficult experiments can be investigated safely and easily. A vast range of equipment can be set up, and complex simulations can be put together and…

  13. Electricity derivatives

    CERN Document Server

    Aïd, René

    2015-01-01

    Offering a concise but complete survey of the common features of the microstructure of electricity markets, this book describes the state of the art in the different proposed electricity price models for pricing derivatives and in the numerical methods used to price and hedge the most prominent derivatives in electricity markets, namely power plants and swings. The mathematical content of the book has intentionally been made light in order to concentrate on the main subject matter, avoiding fastidious computations. Wherever possible, the models are illustrated by diagrams. The book should allow prospective researchers in the field of electricity derivatives to focus on the actual difficulties associated with the subject. It should also offer a brief but exhaustive overview of the latest techniques used by financial engineers in energy utilities and energy trading desks.

  14. Comet Halley and interstellar chemistry

    International Nuclear Information System (INIS)

    How complex is the chemistry of the interstellar medium? How far does it evolve and how has it interacted with the chemistry of the solar system? Are the galactic chemical processes destroyed, preserved, or even enhanced in comets? Are biogenic molecules formed in space and have the formation mechanisms interacted in any way with prebiotic organic chemical processes on the early earth? Radio molecular studies of comets are important for probing deep into the coma and nuclear region and thus may help answer these questions. Comets are believed to be pristine samples of the debris left from the formation of the solar system and may have been the carrier between interstellar and terrestrial prebiotic chemistries. Recent observations of Comet Halley and subsequent comets have given the author an excellent opportunity to study the relationship between interstellar molecular chemistry and cometary chemistry

  15. Plants and Medicinal Chemistry

    Science.gov (United States)

    Bailey, D.

    1977-01-01

    This is the first of two articles showing how plants that have been used in folk medicine for many centuries are guiding scientists in the design and preparation of new and potent drugs. Opium and its chemical derivatives are examined at length in this article. (Author/MA)

  16. Modeling skills of pre-service chemistry teachers in predicting the structure and properties of inorganic chemistry compounds

    Science.gov (United States)

    Nursa'adah, Euis; Liliasari, Mudzakir, Ahmad

    2016-02-01

    The focus of chemistry is learning about the composition, properties, and transformations of matters. Modeling skills are required to comprehend structure and chemical composition in submicroscopic size. Modeling skills are abilities to produce chemical structure and to explain it into the macroscopic phenomenon and submicroscopic representations. Inorganic chemistry is a study of whole elements in the periodic table and their compounds, except carbon compounds and their derivatives. Knowledge about the structure and properties of chemical substances is a basic model for students in studying inorganic chemistry. Furthermore, students can design and produce to utilize materials needed in their life. This research aimed to describes modeling skills of pre-service chemistry teachers. In order, they are able to determine and synthesize useful materials. The results show that students' modeling skills were in a low level and unable connecting skill categories, even the models of inorganic compounds common. These phenomena indicated that students only describe each element when they learn inorganic chemistry. So that it will make modeling skills of students low. Later, another researches are necessary to develop learning design of inorganic chemistry based on good modeling skills of students.

  17. Synergistic relationships between Analytical Chemistry and written standards.

    Science.gov (United States)

    Valcárcel, Miguel; Lucena, Rafael

    2013-07-25

    This paper describes the mutual impact of Analytical Chemistry and several international written standards (norms and guides) related to knowledge management (CEN-CWA 14924:2004), social responsibility (ISO 26000:2010), management of occupational health and safety (OHSAS 18001/2), environmental management (ISO 14001:2004), quality management systems (ISO 9001:2008) and requirements of the competence of testing and calibration laboratories (ISO 17025:2004). The intensity of this impact, based on a two-way influence, is quite different depending on the standard considered. In any case, a new and fruitful approach to Analytical Chemistry based on these relationships can be derived. PMID:23845474

  18. A Thematic Review of Studies into the Effectiveness of Context-Based Chemistry Curricula

    Science.gov (United States)

    Ültay, Neslihan; Çalık, Muammer

    2012-12-01

    Context-based chemistry education aims at making connections between real life and the scientific content of chemistry courses. The purpose of this study was to evaluate context-based chemistry studies. In looking for the context-based chemistry studies, the authors entered the keywords `context-based', `contextual learning' and `chemistry education' in well-known databases (i.e. Academic Search Complete, Education Research Complete, ERIC, Springer LINK Contemporary). Further, in case the computer search by key words may have missed a rather substantial part of the important literature in the area, the authors also conducted a hand search of the related journals. To present a detailed thematic review of context-based chemistry studies, a matrix was used to summarize the findings by focusing on insights derived from the related studies. The matrix incorporates the following themes: needs, aims, methodologies, general knowledge claims, and implications for teaching and learning, implications for curriculum development and suggestions for future research. The general knowledge claims investigated in this paper were: (a) positive effects of the context-based chemistry studies; (b) caveats, both are examined in terms of students' attitudes and students' understanding/cognition. Implications were investigated for practice in context- based chemistry studies, for future research in context- based chemistry studies, and for curriculum developers in context- based chemistry studies. Teachers of context-based courses claimed that the application of the context-based learning approach in chemistry education improved students' motivation and interest in the subject. This seems to have generated an increase in the number of the students who wish to continue chemistry education at higher levels. However, despite the fact that the majority of the studies have reported advantages of context-based chemistry studies, some of them have also referred to pitfalls, i.e. dominant

  19. Proceedings of the 17. Annual Meeting of the Brazilian Chemistry Society; 7. National Symposium on Inorganic Chemistry. Abstracts

    International Nuclear Information System (INIS)

    These 17. Annual Meeting of the Brazilian Chemistry Society and 7. National Symposium on Inorganic Chemistry present several subjects of different interests for the participants, including sections about inorganic chemistry; organic chemistry; environmental chemistry; technological chemistry; electrochemistry; physical chemistry; photochemistry; chemical education; natural products; analytical chemistry and biological chemistry. (C.G.C.)

  20. Benzhydroximic Acids - NMR Study of Trimethylsilyl Derivatives

    Czech Academy of Sciences Publication Activity Database

    Schraml, Jan; Kvíčalová, Magdalena; Soukupová, Ludmila; Blechta, Vratislav; Exner, Otto

    2000-01-01

    Roč. 597, 1-2 (2000), s. 200-205. ISSN 0022-328X R&D Projects: GA AV ČR IAA4072605; GA MŠk LB98233 Keywords : trimethylsilyl derivatives * substituted benzhydroximic acids * NMR chemical shifts Subject RIV: CC - Organic Chemistry Impact factor: 1.632, year: 2000

  1. Preparation of Soluble [n]Phenacene Derivatives

    Czech Academy of Sciences Publication Activity Database

    Jakubík, Pavel

    Prague : Institute of Chemical Process Fundamental of the CAS, v. v. i, 2015 - (Bendová, M.; Wagner, Z.), s. 33 ISBN 978-80-86186-70-2. [Bažant Postgraduate Conference 2015. Prague (CZ)] Institutional support: RVO:67985858 Keywords : polycyclic aromatic hydrocarbons * photocyclization apparatus * derivatives Subject RIV: CA - Inorganic Chemistry

  2. Derivation of the Ideal Gas Law

    Science.gov (United States)

    Laugier, Alexander; Garai, Jozsef

    2007-01-01

    Undergraduate and graduate physics and chemistry books usually state that combining the gas laws results in the ideal gas law. Leaving the derivation to the students implies that this should be a simple task, most likely a substitution. Boyle's law, Charles's law, and the Avogadro's principle are given under certain conditions; therefore, direct…

  3. Bentonite porewater chemistry

    International Nuclear Information System (INIS)

    Porewater composition in a compacted bentonite is dependent on the composition of the surrounding groundwater, and on the characteristics of the bentonite itself. Two mechanisms through which bentonite influences the respective porewater composition are distinguished: surface chemical reactions (ion exchange, surface complexation) on smectite and dissolution of minerals and soluble impurities included in bentonite. This report provides the results of different activities related to the definition of porewater chemistry through the use of geochemical models: 1) review of thermodynamic model on ion exchange reaction, 2) modeling of bentonite-water interactions under aerobic conditions, 3) performance of sensitivity analyses of key parameters in the bentonite model, 4) model simulation of bentonite porewater chemistry in the engineered barrier system under repository conditions. Experimental information of bentonite-water interaction allowed the determination of soluble impurities in the bentonite, and the knowledge of these impurities is important for predictive modeling. For the impurities of Kunigel-V1, 0.38% of CaSO4, 0.0011% of NaCl and 0.0044% of KCl were determined. The sensitivity analyses resulted in that the presence of calcite, CaSO4 and pyrite strongly influences the pH in the compacted bentonite, and the pH in compacted bentonite is buffered by the acid/base equilibria at the Na-smectite surface as well. Through the model calculations, some remarks on the expected trends for the long term behavior can be made like that the pH in compacted bentonite is expected to increase with increasing number of water exchange cycles, as long as CaCO3 contributes to the pH buffering capacity, due to slow depletion of the soluble impurities in the bentonite. The pH of the porewater, however, lies in all cases (but in the presence of CaCo3) between 5.6 and 9.5. Based on the findings discussed above, a large number of calculations were carried out to support the definition

  4. Chemistry of Technetium

    International Nuclear Information System (INIS)

    Precise and reliable thermodynamic constants for the oxidation/reduction relationships of the technetium ions in various environments are necessary to model the transport behaviour of 99 Tc from the nuclear waste repositories to the bio and geosphere. The current knowledge of the Tc chemistry indicates that the most important oxidation states of Tc in natural environment would be VII in oxidant conditions and IV, in an-oxidant media. However, even the value of the formal oxidation potential of the Tc O4-/Tc (IV) couple in simple media is questionable, because it relies only upon one kind of data: the values of the potential of the half electrochemical cell Tc O4-/Tc O2. These potentials are reversible, but sparingly soluble Tc O2 is not in fast equilibrium with other Tc (IV) complexes. The measured potentials are surely Tc O4-/Tc O2 potentials, but not the Tc O4-/Tc(IV) potentials if Tc O2 is not the thermodynamically stable form of Tc (IV). Quantitative data for the Tc O2 equilibria with Tc (IV) complexes are difficult to obtain because of the slowness of the ligand exchange reactions and the general lack of knowledge of the chemistry of the VIIb group tetravalent ions. The present investigation deals with a new approach for the determination of the formal oxidation potential of the Tc O4-/Tc (IV) couple. Tc was used at trace level, in order to avoid the kinetic and thermodynamic sinks made by insoluble Tc O2. Oxidation and reduction of Tc were governed by controlling the ion concentration of a fast electron exchanger couple of which the formal potential has been measured carefully, presently Fe (III)/Fe (II). Distribution ratios of Tc between aqueous and immiscible organic solution of tetra-phenyl arsenic chloride (TPA.Cl) into chloroform served as the probe for the advancement of oxidation and reduction reaction. In these solvent, only Tc (VII) as Tc O4- anions is extracted. (authors)

  5. COST : action chemistry conference on supramolecular chemistry in water

    OpenAIRE

    Magri, David C.

    2014-01-01

    Scientists and chemists from 18 countries gathered in Malta for the 3rd Scientific Meeting on Supramolecular Chemistry in Water between the 9 − 11th of November 2013 at the Old University Building on St Paul Street in Valletta

  6. Incorporation of Medicinal Chemistry into the Organic Chemistry Curriculum

    Science.gov (United States)

    Forbes, David C.

    2004-01-01

    Application of concepts presented in organic chemistry lecture using a virtual project involving the sythesis of medicinally important compounds is emphasized. The importance of reinforcing the concepts from lecture in lab, thus providing a powerful instructional means is discussed.

  7. Advanced Chemistry Basins Model

    Energy Technology Data Exchange (ETDEWEB)

    Blanco, Mario; Cathles, Lawrence; Manhardt, Paul; Meulbroek, Peter; Tang, Yongchun

    2003-02-13

    The objective of this project is to: (1) Develop a database of additional and better maturity indicators for paleo-heat flow calibration; (2) Develop maturation models capable of predicting the chemical composition of hydrocarbons produced by a specific kerogen as a function of maturity, heating rate, etc.; assemble a compositional kinetic database of representative kerogens; (3) Develop a 4 phase equation of state-flash model that can define the physical properties (viscosity, density, etc.) of the products of kerogen maturation, and phase transitions that occur along secondary migration pathways; (4) Build a conventional basin model and incorporate new maturity indicators and data bases in a user-friendly way; (5) Develop an algorithm which combines the volume change and viscosities of the compositional maturation model to predict the chemistry of the hydrocarbons that will be expelled from the kerogen to the secondary migration pathways; (6) Develop an algorithm that predicts the flow of hydrocarbons along secondary migration pathways, accounts for mixing of miscible hydrocarbon components along the pathway, and calculates the phase fractionation that will occur as the hydrocarbons move upward down the geothermal and fluid pressure gradients in the basin; and (7) Integrate the above components into a functional model implemented on a PC or low cost workstation.

  8. Exoplanet Equilibrium Chemistry Calculations

    Science.gov (United States)

    Blumenthal, Sarah; Harrington, J.; Bowman, M.; Blecic, J.

    2013-10-01

    Recently, Agundez et al. (2012, A&A 548, A73) used a chemical kinetics code to study a model HD 209458b (equilibrium temperature of 1450 K, assuming full redistribution and 0 albedo). They found that thermochemistry dominates most of the dayside, but that significant compositional gradients may exist across the dayside. We calculate equilibrium-chemistry molecular abundances for several model exoplanets, using NASA's open-source Chemical Equilibrium Abundances code (McBride and Gordon 1996). We vary the degree of radiation redistribution to the dark side, ranging from total redistribution to instantaneous reradiation. Atomically, both the solar abundance multiple and the carbon fraction vary. Planet substellar temperatures range from just above 1200 K, where photochemistry should no longer be important, to those of hot planets (3000 K). We present synthetic abundance images for the key spectroscopic molecules CO, CH4, and H2O for several hot-Jupiter model planets. This work was supported by the NASA Planetary Atmospheres grant NNX12AI69G.

  9. Nuclear chemistry progress report

    International Nuclear Information System (INIS)

    This is the annual progress report for the Indiana University nuclear chemistry program for the 1992/1993 year. Accomplishments include the construction, testing, and initial experimental runs of the Indiana Silicon Sphere (ISiS) 4π charged particle detector. ISiS is designed to study energy dissipation and multifragmentation phenomena in light-ion-induced nuclear reactions at medium-to-high energies. Its second test run was to examine 3.6 GeV 3He beam reactions at Laboratoire National Saturne (LNS) in Saclay. The development and deployment of this system has occupied a great deal of the groups effort this reporting period. Additional work includes: calculations of isotopic IMF yields in the 4He + 116,124Sn reaction; cross sections for A = 6 - 30 fragments from the 4He + 28Si reaction at 117 and 198 MeV; charging effects of passivated silicon detectors; neck emission of intermediate-mass fragments in the fission of hot heavy nuclei

  10. Atmospheric and aerosol chemistry

    International Nuclear Information System (INIS)

    This series presents critical reviews of the present position and future trends in modern chemical research. Short and concise reports on chemistry, each written by the world renowned experts. Still valid and useful after 5 or 10 years. More information as well as the electronic version of the whole content available at: springerlink.com. Christian George, Barbara D'Anna, Hartmut Herrmann, Christian Weller, Veronica Vaida, D. J. Donaldson, Thorsten Bartels-Rausch, Markus Ammann Emerging Areas in Atmospheric Photochemistry. Lisa Whalley, Daniel Stone, Dwayne Heard New Insights into the Tropospheric Oxidation of Isoprene: Combining Field Measurements, Laboratory Studies, Chemical Modelling and Quantum Theory. Neil M. Donahue, Allen L. Robinson, Erica R. Trump, Ilona Riipinen, Jesse H. Kroll Volatility and Aging of Atmospheric Organic Aerosol. P. A. Ariya, G. Kos, R. Mortazavi, E. D. Hudson, V. Kanthasamy, N. Eltouny, J. Sun, C. Wilde Bio-Organic Materials in the Atmosphere and Snow: Measurement and Characterization V. Faye McNeill, Neha Sareen, Allison N. Schwier Surface-Active Organics in Atmospheric Aerosols.

  11. Chemistry in one dimension.

    Science.gov (United States)

    Loos, Pierre-François; Ball, Caleb J; Gill, Peter M W

    2015-02-01

    We report benchmark results for one-dimensional (1D) atomic and molecular systems interacting via the Coulomb operator |x|(-1). Using various wavefunction-type approaches, such as Hartree-Fock theory, second- and third-order Møller-Plesset perturbation theory and explicitly correlated calculations, we study the ground state of atoms with up to ten electrons as well as small diatomic and triatomic molecules containing up to two electrons. A detailed analysis of the 1D helium-like ions is given and the expression of the high-density correlation energy is reported. We report the total energies, ionization energies, electron affinities and other physical properties of the many-electron 1D atoms and, using these results, we construct the 1D analog of Mendeleev's periodic table. We find that the 1D periodic table contains only two groups: the alkali metals and the noble gases. We also calculate the dissociation curves of several 1D diatomics and study the chemical bond in H2(+), HeH(2+), He2(3+), H2, HeH(+) and He2(2+). We find that, unlike their 3D counterparts, 1D molecules are primarily bound by one-electron bonds. Finally, we study the chemistry of H3(+) and we discuss the stability of the 1D polymer resulting from an infinite chain of hydrogen atoms. PMID:25518906

  12. Computational Chemistry and Lubrication

    Science.gov (United States)

    Zehe, Michael J.

    1998-01-01

    Members of NASA Lewis Research Center's Tribology and Surface Science Branch are applying high-level computational chemistry techniques to the development of new lubrication systems for space applications and for future advanced aircraft engines. The next generation of gas turbine engines will require a liquid lubricant to function at temperatures in excess of 350 C in oxidizing environments. Conventional hydrocarbon-based lubricants are incapable of operating in these extreme environments, but a class of compounds known as the perfluoropolyether (PFAE) liquids (see the preceding illustration) shows promise for such applications. These commercially available products are already being used as lubricants in conditions where low vapor pressure and chemical stability are crucial, such as in satellite bearings and composite disk platters. At higher temperatures, however, these compounds undergo a decomposition process that is assisted (catalyzed) by metal and metal oxide bearing surfaces. This decomposition process severely limits the applicability of PFAE's at higher temperatures. A great deal of laboratory experimentation has revealed that the extent of fluid degradation depends on the chemical properties of the bearing surface materials. Lubrication engineers would like to understand the chemical breakdown mechanism to design a less vulnerable PFAE or to develop a chemical additive to block this degradation.

  13. Computational chemistry research

    Science.gov (United States)

    Levin, Eugene

    1987-01-01

    Task 41 is composed of two parts: (1) analysis and design studies related to the Numerical Aerodynamic Simulation (NAS) Extended Operating Configuration (EOC) and (2) computational chemistry. During the first half of 1987, Dr. Levin served as a member of an advanced system planning team to establish the requirements, goals, and principal technical characteristics of the NAS EOC. A paper entitled 'Scaling of Data Communications for an Advanced Supercomputer Network' is included. The high temperature transport properties (such as viscosity, thermal conductivity, etc.) of the major constituents of air (oxygen and nitrogen) were correctly determined. The results of prior ab initio computer solutions of the Schroedinger equation were combined with the best available experimental data to obtain complete interaction potentials for both neutral and ion-atom collision partners. These potentials were then used in a computer program to evaluate the collision cross-sections from which the transport properties could be determined. A paper entitled 'High Temperature Transport Properties of Air' is included.

  14. Prebiotic chemistry - Lecture 2

    International Nuclear Information System (INIS)

    The nucleic acids and proteins are at the basis of all life. The energy source on the primitive earth acting on the earth's early atmosphere are believed to have produced all the molecules necessary for life. Laboratory experiments over the last four decades have clearly established the prebiotic synthesis of these components, amino acids, purines, pyrimidines, carbohydrates. The mechanisms of polymerization have also been outlined. We thus have a sequence from atoms to small molecules to the large molecules which are necessary for the emergence of life. The analysis of meteorites has given us fresh evidence that these reactions which we have presumed to have taken place on the primitive earth may have also occurred in the early solar system. The analysis of carbonaceous chondrites has given us unmistakable evidence for the presence of these molecules in outer space. Recent observational and theoretical studies have also pointed out that comets may be the location for prebiotic reactions and may also have contributed to organic matter on the primitive earth. The radio astronomers studying interstellar media have also provided us with ample evidence that there are a large number of organic molecules in interstellar space. Organic chemistry appears to be commonplace in the universe. (author)

  15. Pore-water chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Vinsot, A. [Agence Nationale pour la Gestion des Dechets Radioactifs, Lab. de Souterrain de Meuse/Haute-Marne, 55 - Bure (France); Appelo, C.A.J. [Valeriusstraat 11, Amsterdam (Netherlands); Cailteau, C. [LEM, ENSG/INPL, 54 - Vandoeuvre-les-Nancy (France); Cailteau, C. [G2R-CREGU, UMR 7566 CNRS, 54 - Vandoeuvre-les-Nancy (France); Cailteau, C. [Andra - Agence Nationale pour la Gestion des Dechets Radioactifs, 92 - Chatenay Malabry (France); Mettler, S.; Wersin, P. [NAGRA, CH-5430 Wettingen (Switzerland); Canniere, P. de [Studiecentrum voor Kernenergie - Centre d' Etude de l' Energie Nucleaire, Mol (Belgium); Gabler, H.E. [BGR, Hannover (Germany); Gaucher, E.C.; Tournassat, C. [Bureau de Recherches Geologiques et Minieres (BRGM), 45 - Orleans (France); Jacquot, E.; Altmann, S. [Agence Nationale pour la Gestion des Dechets Radioactifs (DS/TR), 92 - Chatenay Malabry (France); Vinsot, A. [Agence Nationale pour la Gestion des Dechets Radioactifs, Lab. de Recherche Souterrain de Meuse/Haute-Marne, 55 - Bure (France); Courdouan, A.; Christl, I.; Kretzschmar, R. [Institute of Biogeochemistry and Pollutant Dynamics, Dept. of Environmental Sciences, ETH Zurich, CHN (Switzerland); Wersin, P. [National Cooperative for the Disposal of Radioactive Waste (Nagra), Wettingen (Switzerland); Savoye, S.; Matray, J.M.; Wittebroodt, Ch.; Cabrera, J.; Bensenouci, F. [Institut de Radioprotection et de Surete Nucleaire, 92 - Fontenay aux Roses (France); Michelot, J.L.; Bensenouci, F. [Paris-11 Univ., UMR IDES CNRS, 91 - Orsay (France); Waber, H.S. [Rock-Water Interaction (RWI), Inst. of Geological Sciences, Bern (Switzerland); Wittebroodt, Ch. [Montpellier-2 Univ., MSE, 34 (France); Lavielle, B.; Gilabert, E.; Thomas, B.; Lavastre, V. [Bordeaux 1-2 Univ., (GdR FORPRO 0788), Chimie Nucleaire Analytique et Bioenvironnementale (CNAB), CNRS, 33 - Gradignan (France); Lavastre, V. [Nimes Univ., Geochimie Isotopique Environnementale (GIS/CEREGE), CNRS-RANCE, 30 (France)

    2007-07-01

    This session gathers 5 articles dealing with: CO{sub 2} data on gas and pore water sampled in-situ in the Opalinus clay at the Mont Terri rock laboratory (A. Vinsot, C.A.J. Appelo, C. Cailteau, S. Mettler, P. Wersin, P. De Canniere, H.E. Gaebler); the improvements in the modelling of the pore water chemistry of the Callovo-Oxfordian formation (E.C. Gaucher, C. Tournassat, E. Jacquot, S. Altmann, A. Vinsot) the nature and reactivity of dissolved organic matter in the Opalinus clay and Callovo-Oxfordian formations (A. Courdouan, I. Christl, P.Wersin, R. Kretzschmar); PH4: a 250 m deep borehole in Tournemire for assessing the reliability of chloride, helium and water stable isotopes profiles in the Toarcian/ Domerian shales (S. Savoye, J.L. Michelot, H.N. Waber, J.M. Matray, F. Bensenouci, Ch. Wittebroodt, J. Cabrera); and the development of a new facility for dating old groundwaters by using {sup 81}Kr (B. Lavielle, E. Gilabert, B. Thomas, V. Lavastre)

  16. Microfluidics in radiopharmaceutical chemistry

    International Nuclear Information System (INIS)

    The increased demand for molecular imaging tracers useful in assessing and monitoring diseases has stimulated research towards more efficient and flexible radiosynthetic routes, including newer technologies. The traditional vessel-based approach suffers from limitations concerning flexibility, reagent mass needed, hardware requirements, large number of connections and valves, repetitive cleaning procedures and overall big footprint to be shielded from radiation. For these reasons, several research groups have started to investigate the application of the fast growing field of microfluidic chemistry to radiosynthetic procedures. After the first report in 2004, many scientific papers have been published and demonstrated the potential for increased process yields, reduced reagent use, improved flexibility and general ease of setup. This review will address definitions occurring in microfluidics as well as analyze the different approaches under two macro-categories: microvessel and microchannel. In this perspective, several works will be collected, involving the use of positron emitting species (11C, 18F, 64Cu) and the fewer examples of gamma emitting radionuclides (99mTc, 125/131I). New directions in microfluidic research applied to PET radiochemistry, future developments and challenges are also discussed. -- Graphical abstract: Display Omitted

  17. Marine fragrance chemistry.

    Science.gov (United States)

    Hügel, Helmut M; Drevermann, Britta; Lingham, Anthony R; Marriott, Philip J

    2008-06-01

    The main marine message in perfumery is projected by Calone 1951 (7-methyl-2H-1,5-benzodioxepin-3(4H)-one). Kraft (Givaudan) and Gaudin (Firmenich) further maximized the marine fragrance molecular membership by extending the carbon chain of the 7-Me group. Our research targeted the polar group of the benzodioxepinone parent compound to investigate how this region of molecular makeup resonates with the dominant marine fragrance of the Calone 1951 structure. The olfactory evaluation of analogues prepared by chemical modification or removal of the CO group resulted in the introduction of aldehydic, sweet and floral-fruity notes with a diluted/diminished potency of the marine odor. To further analyze the olfactory properties of benzodioxepinones containing a diverse range of aromatic ring substituents, a novel synthesis route was developed. We found that a 7-alkyl group in Calone 1951 was essential for the maintenance of the significant marine odor characteristic, and our studies support the concept that the odorant structure occupying the hydrophobic binding pocket adjacent to the aromatic ring-binding site of the olfactory receptor is pivotal in the design and discovery of more potent and characteristic marine fragrances. How the structure of benzodioxepinones connects to marine sea-breeze fragrances is our continuing challenging research focus at the chemistry-biology interface. PMID:18618392

  18. Advances in electron transfer chemistry

    CERN Document Server

    Mariano, Patrick S

    1993-01-01

    Advances in Electron Transfer Chemistry, Volume 3 presents studies that discuss findings in the various aspects of electron chemistry. The book is comprised of four chapters; each chapter reviews a work that tackles an issue in electron transfer chemistry. Chapter 1 discusses the photoinduced electron transfer in flexible biaryl donor-acceptor molecules. Chapter 2 tackles light-induced electron transfer in inorganic systems in homogeneous and heterogeneous phases. The book also covers internal geometry relaxation effects on electron transfer rates of amino-centered systems. The sequential elec

  19. The radiation chemistry of macromolecules

    CERN Document Server

    1973-01-01

    The Radiation Chemistry of Macromolecules, Volume II is a collection of papers that discusses radiation chemistry of specific systems. Part 1 deals with radiation chemistry of substituted vinyl polymers, particularly polypropylene (PP) as its structure is intermediate between polyethylene and polyisobutylene. This part also discusses polypropylene oxide (PPOx) for it can be prepared in the atactic, isotactic, and optically active forms. One paper focuses on the fundamental chemical processes and the changes in physical properties that give rise to many different applications of polystyrene. An

  20. Catalysis and sustainable (green) chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Centi, Gabriele; Perathoner, Siglinda [Dipartimento di Chimica Industriale ed Ingegneria dei Materiali, University of Messina, Salita Sperone 31, 98166 Messina (Italy)

    2003-01-15

    Catalysis is a key technology to achieve the objectives of sustainable (green) chemistry. After introducing the concepts of sustainable (green) chemistry and a brief assessment of new sustainable chemical technologies, the relationship between catalysis and sustainable (green) chemistry is discussed and illustrated via an analysis of some selected and relevant examples. Emphasis is also given to the concept of catalytic technologies for scaling-down chemical processes, in order to develop sustainable production processes which reduce the impact on the environment to an acceptable level that allows self-depuration processes of the living environment.

  1. Novel nitrogen chemistry

    OpenAIRE

    Wheildon, Andrew R.

    1999-01-01

    Chapter One contains a brief overview of zeolites, their structure, uses and synthesis. Chapter Two relates to the attempted synthesis of quinuclidines via a novel 6-endo-trig radical cyclisation. Chapter Three contains a review of the 'Zip reaction' and the attempted synthesis of triazacyclopentadecane derivatives. Chapter Four relates to the synthesis of pyrrolidines via retro-Cope cyclisation methodology. Reviews of the Cope and retro-Cope reactions, nitrone synthesis and nucle...

  2. Synergistic relationships between Analytical Chemistry and written standards

    International Nuclear Information System (INIS)

    Graphical abstract: -- Highlights: •Analytical Chemistry is influenced by international written standards. •Different relationships can be established between them. •Synergies can be generated when these standards are conveniently managed. -- Abstract: This paper describes the mutual impact of Analytical Chemistry and several international written standards (norms and guides) related to knowledge management (CEN-CWA 14924:2004), social responsibility (ISO 26000:2010), management of occupational health and safety (OHSAS 18001/2), environmental management (ISO 14001:2004), quality management systems (ISO 9001:2008) and requirements of the competence of testing and calibration laboratories (ISO 17025:2004). The intensity of this impact, based on a two-way influence, is quite different depending on the standard considered. In any case, a new and fruitful approach to Analytical Chemistry based on these relationships can be derived

  3. Roles of the human occupant in indoor chemistry

    DEFF Research Database (Denmark)

    Weschler, Charles J.

    2016-01-01

    occupants scavenge ozone, the level of SOA derived from ozone/terpene chemistry decreases; the fraction of SVOCs in the gas-phase increases, and the fraction associated with airborne particles decreases. Occupants also remove organic compounds, including certain chemically active species, via bodily intake......Over the last decade, influences of the human occupant on indoor chemistry have been investigated in environments ranging from simulated aircraft cabins to actual classrooms. We have learned that ozone reacts rapidly with constituents of skin surface lipids on exposed skin, hair, and clothing....... Studies reviewed in this paper demonstrate the pronounced influences of humans on chemistry within the spaces they inhabit and the consequences of these influences on their subsequent chemical exposures....

  4. Synergistic relationships between Analytical Chemistry and written standards

    Energy Technology Data Exchange (ETDEWEB)

    Valcárcel, Miguel, E-mail: qa1vacam@uco.es; Lucena, Rafael

    2013-07-25

    Graphical abstract: -- Highlights: •Analytical Chemistry is influenced by international written standards. •Different relationships can be established between them. •Synergies can be generated when these standards are conveniently managed. -- Abstract: This paper describes the mutual impact of Analytical Chemistry and several international written standards (norms and guides) related to knowledge management (CEN-CWA 14924:2004), social responsibility (ISO 26000:2010), management of occupational health and safety (OHSAS 18001/2), environmental management (ISO 14001:2004), quality management systems (ISO 9001:2008) and requirements of the competence of testing and calibration laboratories (ISO 17025:2004). The intensity of this impact, based on a two-way influence, is quite different depending on the standard considered. In any case, a new and fruitful approach to Analytical Chemistry based on these relationships can be derived.

  5. Plants and Medicinal Chemistry--2

    Science.gov (United States)

    Bailey, D.

    1977-01-01

    Second of a two part article on the influence of plants on medicinal chemistry. This part considers how drugs work, the attempts to develop anaesthetics safer than cocaine, and useful poisons. (Author/SL)

  6. What Chemistry To Teach Engineers?

    Science.gov (United States)

    Hawkes, Stephen J.

    2000-01-01

    Examines possible general chemistry topics that would be most relevant and practical for engineering majors. Consults the Accreditation Board for Engineering and Technology (ABET), engineering textbooks, texts from other required subjects, and practicing engineers for recommendations. (Contains 24 references.) (WRM)

  7. International Year of Chemistry 2011

    Institute of Scientific and Technical Information of China (English)

    XUE Zi-Ling

    2011-01-01

    Science China Chemistry would like to dedicate this special issue to the International Year of Chemistry (IYC) 2011,as part of the celebrations of IYC in China.Scientists from Australia,Brazil,Britain,Canada,Chile,China,France,Germany,India,Israel,Japan,Nepal,Pakistan,Saudi Arabia,Singapore,South Africa,and the USA have contributed 28 papers marking the event.Our authors from across the globe include students,members (a corresponding member) and fellows of national academies of sciences in several countries (Australia,Chile,China,France,India,Israel,Pakistan,and the USA),fellows of the British and Canadian Royal Societies,and two Nobel Laureates (Robert Grubbs and Ada Yonath).Here they present their work contributing to the IYC 2011 theme "Chemistry-our life,our future" [1].These papers cover fundamental chemistry,the chemical bases of life processes,and their potential applications.

  8. Analytical Chemistry: A Literary Approach.

    Science.gov (United States)

    Lucy, Charles A.

    2000-01-01

    Provides an anthology of references to descriptions of analytical chemistry techniques from history, popular fiction, and film which can be used to capture student interest and frame discussions of chemical techniques. (WRM)

  9. Highlights of nuclear chemistry 1995

    International Nuclear Information System (INIS)

    In this report 9 topics of the work of the Nuclear Chemistry Group in 1995 are highlighted. A list of publications and an overview of the international cooperation is given. (orig.). 19 refs., 19 figs., 2 tabs., 2 app

  10. Organometallic chemistry of metal surfaces

    International Nuclear Information System (INIS)

    The organometallic chemistry of metal surfaces is defined as a function of surface crystallography and of surface composition for a set of cyclic hydrocarbons that include benzene, toluene, cyclohexadienes, cyclohexene, cyclohexane, cyclooctatetraene, cyclooctadienes, cyclooctadiene, cycloheptatriene and cyclobutane. 12 figures

  11. Part 7: Environmental Chemistry, Revised.

    Science.gov (United States)

    Douville, Judith A.

    2003-01-01

    Discusses resources on applied/interdisciplinary areas of chemistry available as books and electronic materials that mostly target graduate students, faculty, and chemists in the industry. (Author/YDS)

  12. Promoting sustainability through green chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Kirchhoff, Mary M. [American Chemical Society, 1155 Sixteenth Street, NW, Washington, DC 20036 (United States)

    2005-06-15

    Green chemistry is an important tool in achieving sustainability. The implementation of green chemistry, the design of chemical products and processes that reduce or eliminate the use and generation of hazardous substances, is essential if the expanding global population is to enjoy an increased standard of living without having a negative impact on the health of the planet. Cleaner technologies will allow the chemical enterprise to provide society with the goods and services on which it depends in an environmentally responsible manner. Green chemistry provides solutions to such global challenges as climate change, sustainable agriculture, energy, toxics in the environment, and the depletion of natural resources. A collaborative effort by industry, academia, and government is needed to promote the adoption of the green chemistry technologies necessary to achieve a sustainable society.

  13. Organometallic Chemistry. Final Progress Report

    Energy Technology Data Exchange (ETDEWEB)

    None

    2003-07-14

    The Gordon Research Conference (GRC) on Organometallic Chemistry was held at Salve Regina, Newport, Rhode Island, 7/21-26/02. Emphasis was placed on current unpublished research and discussion of the future target areas in this field.

  14. Atmospheric Chemistry and Air Pollution

    OpenAIRE

    Gaffney, Jeffrey S.; Marley, Nancy A.

    2003-01-01

    Atmospheric chemistry is an important discipline for understanding air pollution and its impacts. This mini-review gives a brief history of air pollution and presents an overview of some of the basic photochemistry involved in the production of ozone and other oxidants in the atmosphere. Urban air quality issues are reviewed with a specific focus on ozone and other oxidants, primary and secondary aerosols, alternative fuels, and the potential for chlorine releases to amplify oxidant chemistry...

  15. Overview of PWR chemistry options

    Energy Technology Data Exchange (ETDEWEB)

    Nordmann, F.; Stutzmann, A.; Bretelle, J.L. [Electricite de France, Central Labs. (France)

    2002-07-01

    EDF Central Laboratories, in charge of engineering in chemistry, of defining the chemistry specifications and studying the operation feedback and improvement for 58 PWR units, have the opportunity to evaluate many options of operation developed and applied all around the world. Thanks to these international relationships and to the benefit of a large feedback from many units, some general evaluation of the various options is discussed in this paper. (authors)

  16. Contextualising Nanotechnology in Chemistry Education

    OpenAIRE

    O'Connor, Christine; Hayden, Hugh

    2008-01-01

    This paper will give an example of a pedagogical approach taken in integrating nanotechnology into a chemistry degree course. In recent years nanotechnology has widely become part of the course content for undergraduate chemistry and physics degree curriculum. How contextualised the delivery of the subject matter may vary. The role of contextualisation of nanotechnology in the delivery of the content is the main focus of this paper, as to date in Ireland and many other countries nanotechnolog...

  17. Nonthermal plasma chemistry and physics

    CERN Document Server

    Meichsner, Jurgen; Schneider, Ralf; Wagner, Hans-Erich

    2013-01-01

    In addition to introducing the basics of plasma physics, Nonthermal Plasma Chemistry and Physics is a comprehensive presentation of recent developments in the rapidly growing field of nonthermal plasma chemistry. The book offers a detailed discussion of the fundamentals of plasma chemical reactions and modeling, nonthermal plasma sources, relevant diagnostic techniques, and selected applications.Elucidating interconnections and trends, the book focuses on basic principles and illustrations across a broad field of applications. Expert contributors address environmental aspects of plasma chemist

  18. Chemistry in all its States

    OpenAIRE

    Ruiz-Hitzky, Eduardo

    2015-01-01

    1 • The Microwave Oven: from the Kitchen to Synthesis Chemistry “A microwave oven is a domestic appliance that is mainly used to heat up food quickly, by agitating the water molecules contained in the food under the effect of a microwave radiation” (Wikipedia). From the outset, this technology was mainly used in the kitchen and sometimes in highly precise industrial applications. However, for the last twenty years or so microwave has also been used in chemistry laboratories, to activate chem...

  19. Creating a Context for Chemistry

    Science.gov (United States)

    Truman Schwartz, A.

    Until relatively recently, the teaching of chemistry at the college and university level in the United States has been quite traditional and oriented primarily toward the preparation of chemists. Students not concentrating in the sciences have often been poorly served by existing courses. Chemistry in Context: Applying Chemistry to Society, a textbook for nonscience majors developed under the sponsorship of the American Chemical Society, is an effort to address the needs and interests of this audience. The book introduces the phenomena and principles of chemistry within the context of socially significant issues such as global warming, ozone depletion, alternate energy sources, nutrition, and genetic engineering. The chemistry is presented as needed to inform an understanding of the central topics, and the text features student-centered activities designed to promote critical thinking and risk-benefit analysis as well as an understanding of chemical principles. This paper summarizes the origin, development, content, pedagogy, evaluation, and influence of Chemistry in Context and considers its potential implications for other disciplines and the instruction of science majors.

  20. Physical chemistry and the environment

    International Nuclear Information System (INIS)

    From the ozone hole and the greenhouse effect to plastics recycling and hazardous waste disposal, society faces a number of issues, the solutions to which require an unprecedented understanding of the properties of molecules. We are coming to realize that the environment is a coupled set of chemical systems, its dynamics determining the welfare of the biosphere and of humans in particular. These chemical systems are governed by fundamental molecular interactions, and they present chemists with an unparalleled challenge. The application of current concepts of molecular behavior and of up-to-date experimental and computational techniques can provide us with insights into the environment that are needed to mitigate past damage, to anticipate the impact of current human activity, and to avoid future insults to the environment. Environmental chemistry encompasses a number of separate, yet interlocking, areas of research. In all of these areas progress is limited by an inadequate understanding of the underlying chemical processes involved. Participation of all chemical approaches -- experimental, theoretical and computational -- and of all disciplines of chemistry -- organic, inorganic, physical, analytical and biochemistry -- will be required to provide the necessary fundamental understanding. The Symposium on ''Physical Chemistry and the Environment'' was designed to bring the many exciting and challenging physical chemistry problems involved in environmental chemistry to the attention of a larger segment of the physical chemistry community

  1. Radical chemistry of artemisinin

    Energy Technology Data Exchange (ETDEWEB)

    Denisov, Evgenii T; Solodova, S L; Denisova, Taisa G [Institute of Problems of Chemical Physics, Russian Academy of Sciences, Chernogolovka, Moscow Region (Russian Federation)

    2010-12-29

    The review summarizes physicochemical characteristics of the natural sesquiterpene peroxide artemisinin. The kinetic schemes of transformations of artemisinin radicals under anaerobic conditions are presented and analyzed. The sequence of radical reactions of artemisinin in the presence of oxygen is considered in detail. Special emphasis is given to the intramolecular chain oxidation resulting in the transformation of artemisinin into polyatomic hydroperoxide. The kinetic characteristics of elementary reaction steps involving alkyl, alkoxyl, and peroxyl radicals generated from artemisinin are discussed. The results of testing of artemisinin and its derivatives for the antimalarial activity and the scheme of the biochemical synthesis of artemisinin in nature are considered.

  2. The Brazilian medicinal chemistry from 1998 to 2008 in the Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters and European Journal of Medicinal Chemistry [A química medicinal brasileira de 1998 a 2008 nos periódicos Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters e European Journal of Medicinal Chemistry

    OpenAIRE

    Bárbara Vasconcellos da Silva; Renato Saldanha Bastos; Angelo da Cunha Pinto

    2009-01-01

    In this article we present the Brazilian publications, the research groups involved, the contributions per states and the main diseases studied from 1998 to 2008 in the following periodicals: Journal of Medicinal Chemistry, Bioorganic and Medicinal Chemistry, Bioorganic and Medicinal Chemistry Letters and European Journal of Medicinal Chemistry.

  3. Effective Chemistry Communication in Informal Environments

    Science.gov (United States)

    National Academies Press, 2016

    2016-01-01

    Chemistry plays a critical role in daily life, impacting areas such as medicine and health, consumer products, energy production, the ecosystem, and many other areas. Communicating about chemistry in informal environments has the potential to raise public interest and understanding of chemistry around the world. However, the chemistry community…

  4. Who is Teaching the History of Chemistry?

    Science.gov (United States)

    Everett, Kenneth G.; DeLoach, Will S.

    1987-01-01

    Reports on a study into how the history of chemistry is being taught in colleges and universities. Results indicate that courses on the history of chemistry are hardly ever required of chemistry majors, and they are offered in only 10 percent of American Chemical Society approved chemistry departments. (TW)

  5. Peer Mentoring in the General Chemistry and Organic Chemistry Laboratories: The Pinacol Rearrangement--An Exercise in NMR and IR Spectroscopy for General Chemistry and Organic Chemistry Laboratories

    Science.gov (United States)

    Arrington, Caleb A.; Hill, Jameica B.; Radfar, Ramin; Whisnant, David M.; Bass, Charles G.

    2008-01-01

    This article describes a discovery experiment for general chemistry and organic chemistry labs. Although the pinacol rearrangement has been employed in undergraduate organic laboratories before, in this application organic chemistry students act as mentors to students of general chemistry. Students work together using distillation--a new technique…

  6. 42 CFR 493.839 - Condition: Chemistry.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 5 2010-10-01 2010-10-01 false Condition: Chemistry. 493.839 Section 493.839... These Tests § 493.839 Condition: Chemistry. The specialty of chemistry includes for the purposes of proficiency testing the subspecialties of routine chemistry, endocrinology, and toxicology....

  7. Language Preferences of Freshman Chemistry Students: An Exploratory Study.

    Science.gov (United States)

    Hill, Douglas M.; And Others

    1980-01-01

    Ascertained whether chemistry instructors have a consistent preference for particular ways of idea expression by chemistry students. Comparisons of responses on a chemistry preference test were made among chemistry instructors, chemistry majors and nonscience majors. (CS)

  8. Advances in BWR water chemistry

    International Nuclear Information System (INIS)

    This paper reviews recent advances in Boiling Water Reactor (BWR) water chemistry control with examples of plant experiences at U.S. designed BWRs. Water chemistry advances provide some of the most effective methods for mitigating materials degradation, reducing fuel performance concerns and lowering radiation fields. Mitigation of stress corrosion cracking (SCC) of materials remains a high priority and improved techniques that have been demonstrated in BWRs will be reviewed, specifically hydrogen injection combined with noble metal chemical addition (NMCA) and the newer on-line noble metal application process (OLNC). Hydrogen injection performance, an important part of SCC mitigation, will also be reviewed for the BWR fleet, highlighting system improvements that have enabled earlier injection of hydrogen including the potential for hydrogen injection during plant startup. Water chemistry has been significantly improved by the application of pre-filtration and optimized use of ion exchange resins in the CP (condensate polishing) and reactor water cleanup (RWCU) systems. EPRI has monitored and supported water treatment improvements to meet water chemistry goals as outlined in the EPRI BWR Water Chemistry Guidelines, particularly those for SCC mitigation of reactor internals and piping, minimization of fuel risk due to corrosion and crud deposits and chemistry control for radiation field reduction. In recent years, a significant reduction has occurred in feedwater corrosion product input, particularly iron. A large percentage of plants are now reporting <0.1 ppb feedwater iron. The impacts to plant operation and chemistry of lower feedwater iron will be explored. Depleted zinc addition is widely practiced across the fleet and the enhanced focus on radiation reduction continues to emphasize the importance of controlling radiation source term. In addition, shutdown chemistry control is necessary to avoid excessive release of activated corrosion products from fuel

  9. Publicising chemistry in a multicultural society through chemistry outreach

    Directory of Open Access Journals (Sweden)

    Joyce D. Sewry

    2011-11-01

    Full Text Available Given the emphasis in Higher Education on community engagement in South Africa and the importance of international collaboration, we discuss a joint approach to chemistry outreach in two countries on two continents with widely differing target school audiences. We describe the history of the partnership between the chemistry departments at Rhodes University and the University of Bristol and provide an outline of the chemistry content of their outreach initiatives, the modes of delivery, the advantages to both departments and their students for involvement in various levels of outreach, the challenges they still face and additional opportunities that such work facilitated. The lecture demonstration ‘A Pollutant’s Tale’ was presented to thousands of learners all over the world, including learners at resource-deprived schools in South Africa. Challenges to extend outreach activities in South Africa include long travelling distances, as well as a lack of facilities (such as school halls and electricity at schools. Outreach activities not only impacted on the target audience of young learners, they also impacted upon the postgraduate and other chemistry students taking part in these initiatives. This collaboration strengthened both institutions and their outreach work and may also lead to chemistry research collaborations between the academics involved.

  10. Spin-state chemistry of deuterated ammonia

    CERN Document Server

    Sipilä, O; Caselli, P; Schlemmer, S

    2015-01-01

    Aims. We aim to develop a chemical model that contains a consistent description of spin-state chemistry in reactions involving chemical species with multiple deuterons. We apply the model to the specific case of deuterated ammonia, to derive values for the various spin-state ratios. Methods. We apply symmetry rules in the complete scrambling assumption to calculate branching ratio tables for reactions between chemical species that include multiple protons and/or deuterons. Reaction sets for both gas-phase and grain-surface chemistry are generated using an automated routine that forms all possible spin-state variants of any given reaction with up to six H/D atoms. Single-point and modified Bonnor-Ebert models are used to study the density and temperature dependence of ammonia and its isotopologs, and the associated spin-state ratios. Results. We find that the spin-state ratios of the ammonia isotopologs are, at late times, very different from their statistical values. The ratios are rather insensitive to varia...

  11. Sulfur chemistry in a copper smelter plume

    Energy Technology Data Exchange (ETDEWEB)

    Eatough, D.J.; Christensen, J.J.; Hill, M.W.; Major, T.D.; Mangelson, N.F.; Post, M.E.; Ryder, J.F.; Hansen, L.D.

    Sulfur transformation chemistry was studied in the plume of the Utah smelter of Kennecott Copper Corporation from April to October 1977. Samples were taken at up to four locations from 4 to 60 km from the stacks. Data collected at each station included: SO/sub 2/ concentration, low-volume collected total particulate matter, high-volume collected size fractionated particulate matter, wind velocity and direction, temperature, and relative humidity.The SO/sub 2/(g)-sulfate conversion process in the plume is described by a mechanism which is first order in SO/sub 2/(g). Equations are derived describing sulfur chemistry when both S(IV) and sulfate formation occur in a plume. The formation of sulfate results primarily in the formation of <0.5 ..mu..m particulates. The formation process is not correlated with plume expansion, particulate acidity, metal content, or S(IV) species. Due to meteorological restrictions on sampling, data were collected only during periods of maximum insolation. The formation of sulfate from SO/sub 2/(g) in the plume during periods of high insolation is temperature dependent with an apparent activation energy of 16.6 +/- 1.4 kcal mol/sup -1/ and k/sub 1/ value of 0.039 h/sup -1/ at 25/sup 0/C.

  12. Philosophy of Chemistry: An Emerging Field with Implications for Chemistry Education.

    Science.gov (United States)

    Erduran, Sibel

    Traditional applications of history and philosophy of science in chemistry education have concentrated on the teaching and learning of "history of chemistry". This paper considers the recent emergence of "philosophy of chemistry" as a distinct field and explores the implications of philosophy of chemistry for chemistry education in the context of…

  13. APPLICATIONS OF GREEN CHEMISTRY IN SUSTAINABLE DEVELOPMENT

    OpenAIRE

    Suresh D. Dhage; Komalsing K. Shisodiya

    2013-01-01

    Chemistry is really very helpful to us as its applications are used worldwide for several purposes. We cannot really imagine a world without chemistry and its applications such as medicines. However, we should now concentrate on green chemistry or sustainable chemistry, which refers to reducing or stopping the damage done to the environment around us. Hence, green chemistry could include anything from reducing waste to even disposing of waste in the correct manner. Another way to save the env...

  14. Infrared Spectroscopy in the General Chemistry Lab

    Science.gov (United States)

    Hill, Margaret A.

    2001-01-01

    Acquisition of infrared spectrometers for use in general chemistry lab was made possible through the NSF-sponsored Instrumentation and Laboratory Improvement (ILI) program. Three laboratory exercises suitable for first-year students are described in which students learn to interpret infrared spectra for simple structural identification. A polymer identification lab is the first of these with minimal sample preparation. It uses familiar household polymer samples and teaches students how to use infrared spectral data to determine what bond types are present in the polymers. In a second lab, students learn to prepare potassium bromide pellets of fluorene derivatives and identify them by their functional group differences. The final exercise combines IR with several other lab techniques to identify an organic acid from a field of fourteen possibilities.

  15. Quantum chemistry-assisted synthesis route development

    International Nuclear Information System (INIS)

    We have been investigating “quantum chemistry-assisted synthesis route development” using in silico screenings and applied the method to several targets. Another example was conducted to develop synthesis routes for a urea derivative, namely 1-(4-(trifluoromethyl)-2-oxo-2H-chromen-7-yl)urea. While five synthesis routes were examined, only three routes passed the second in silico screening. Among them, the reaction of 7-amino-4-(trifluoromethyl)-2H-chromen-2-one and O-methyl carbamate with BF3 as an additive was ranked as the first choice for synthetic work. We were able to experimentally obtain the target compound even though its yield was as low as 21 %. The theoretical result was thus consistent with that observed. The summary of transition state data base (TSDB) is also provided. TSDB is the key to reducing time of in silico screenings

  16. Chiral chemistry of metal-camphorate frameworks.

    Science.gov (United States)

    Gu, Zhi-Gang; Zhan, Caihong; Zhang, Jian; Bu, Xianhui

    2016-06-01

    This critical review presents the various synthetic approaches and chiral chemistry of metal-camphorate frameworks (MCamFs), which are homochiral metal-organic frameworks (MOFs) constructed from a camphorate ligand. The interest in this unique subset of homochiral MOFs is derived from the many interesting chiral features for both materials and life sciences, such as asymmetrical synthesis or crystallization, homochiral structural design, chiral induction, absolute helical control and ligand handedness. Additionally, we discuss the potential applications of homochiral MCamFs. This review will be of interest to researchers attempting to design other homochiral MOFs and those engaged in the extension of MOFs for applications such as chiral recognition, enantiomer separation, asymmetric catalysis, nonlinear sensors and devices. PMID:27021070

  17. Quantum chemistry-assisted synthesis route development

    Energy Technology Data Exchange (ETDEWEB)

    Hori, Kenji; Sumimoto, Michinori [Graduate School of Science and Engineering, Yamaguchi University, Tokiwadai, Ube, Yamaguchi 755-8611 (Japan); Murafuji, Toshihiro [Graduate School of Medicine, Yamaguchi University, Yamaguchi, Yamaguchi 753-8512 (Japan)

    2015-12-31

    We have been investigating “quantum chemistry-assisted synthesis route development” using in silico screenings and applied the method to several targets. Another example was conducted to develop synthesis routes for a urea derivative, namely 1-(4-(trifluoromethyl)-2-oxo-2H-chromen-7-yl)urea. While five synthesis routes were examined, only three routes passed the second in silico screening. Among them, the reaction of 7-amino-4-(trifluoromethyl)-2H-chromen-2-one and O-methyl carbamate with BF{sub 3} as an additive was ranked as the first choice for synthetic work. We were able to experimentally obtain the target compound even though its yield was as low as 21 %. The theoretical result was thus consistent with that observed. The summary of transition state data base (TSDB) is also provided. TSDB is the key to reducing time of in silico screenings.

  18. Atmospheric Chemistry of Micrometeoritic Organic Compounds

    Science.gov (United States)

    Kress, M. E.; Belle, C. L.; Pevyhouse, A. R.; Iraci, L. T.

    2011-01-01

    Micrometeorites approx.100 m in diameter deliver most of the Earth s annual accumulation of extraterrestrial material. These small particles are so strongly heated upon atmospheric entry that most of their volatile content is vaporized. Here we present preliminary results from two sets of experiments to investigate the fate of the organic fraction of micrometeorites. In the first set of experiments, 300 m particles of a CM carbonaceous chondrite were subject to flash pyrolysis, simulating atmospheric entry. In addition to CO and CO2, many organic compounds were released, including functionalized benzenes, hydrocarbons, and small polycyclic aromatic hydrocarbons. In the second set of experiments, we subjected two of these compounds to conditions that simulate the heterogeneous chemistry of Earth s upper atmosphere. We find evidence that meteor-derived compounds can follow reaction pathways leading to the formation of more complex organic compounds.

  19. Quantum chemistry-assisted synthesis route development

    Science.gov (United States)

    Hori, Kenji; Sumimoto, Michinori; Murafuji, Toshihiro

    2015-12-01

    We have been investigating "quantum chemistry-assisted synthesis route development" using in silico screenings and applied the method to several targets. Another example was conducted to develop synthesis routes for a urea derivative, namely 1-(4-(trifluoromethyl)-2-oxo-2H-chromen-7-yl)urea. While five synthesis routes were examined, only three routes passed the second in silico screening. Among them, the reaction of 7-amino-4-(trifluoromethyl)-2H-chromen-2-one and O-methyl carbamate with BF3 as an additive was ranked as the first choice for synthetic work. We were able to experimentally obtain the target compound even though its yield was as low as 21 %. The theoretical result was thus consistent with that observed. The summary of transition state data base (TSDB) is also provided. TSDB is the key to reducing time of in silico screenings.

  20. Logic and chemistry in Hegel's philosophy

    Directory of Open Access Journals (Sweden)

    Ulrich Ruschig

    2001-03-01

    Full Text Available Hegel's chef-d'œuvre, the Science of Logic, contains a section on 'measure'. As 'measure' unites the two categories 'quality' and 'quantity', it is a key aspect for determining qualitative and quantitative objects, and hence is the decisive category for natural sciences. In the chemical passages of this section, Hegel took concepts from chemistry (for example 'elective attraction', changed their function, and converted them into categories of logic. In this paper, the relationship between the development of categories by reflecting reason and the chemical material cited for this development is discussed. Hegel claimed that the chemical material presupposed in the logical development could be replaced with specified proportions of measures, derived from developing and specifying the category 'measure'. This claim is criticized.

  1. Cycloadditions in modern polymer chemistry.

    Science.gov (United States)

    Delaittre, Guillaume; Guimard, Nathalie K; Barner-Kowollik, Christopher

    2015-05-19

    Synthetic polymer chemistry has undergone two major developments in the last two decades. About 20 years ago, reversible-deactivation radical polymerization processes started to give access to a wide range of polymeric architectures made from an almost infinite reservoir of functional building blocks. A few years later, the concept of click chemistry revolutionized the way polymer chemists approached synthetic routes. Among the few reactions that could qualify as click, the copper-catalyzed azide-alkyne cycloaddition (CuAAC) initially stood out. Soon, many old and new reactions, including cycloadditions, would further enrich the synthetic macromolecular chemistry toolbox. Whether click or not, cycloadditions are in any case powerful tools for designing polymeric materials in a modular fashion, with a high level of functionality and, sometimes, responsiveness. Here, we wish to describe cycloaddition methodologies that have been reported in the last 10 years in the context of macromolecular engineering, with a focus on those developed in our laboratories. The overarching structure of this Account is based on the three most commonly encountered cycloaddition subclasses in organic and macromolecular chemistry: 1,3-dipolar cycloadditions, (hetero-)Diels-Alder cycloadditions ((H)DAC), and [2+2] cycloadditions. Our goal is to briefly describe the relevant reaction conditions, the advantages and disadvantages, and the realized polymer applications. Furthermore, the orthogonality of most of these reactions is highlighted because it has proven highly beneficial for generating unique, multifunctional polymers in a one-pot reaction. The overview on 1,3-dipolar cycloadditions is mostly centered on the application of CuAAC as the most travelled route, by far. Besides illustrating the capacity of CuAAC to generate complex polymeric architectures, alternative 1,3-dipolar cycloadditions operating without the need for a catalyst are described. In the area of (H)DA cycloadditions

  2. The Unity of Chemistry and Physics: Absolute Reaction Rate Theory

    OpenAIRE

    Hinne Hettema

    2012-01-01

    Henry Eyring's absolute rate theory explains the size of chemical reaction rate constants in terms of thermodynamics, statistical mechanics, and quantum chemistry. In addition it uses a number of unique concepts such as the 'transition state'. A key feature of the theory is that the explanation it provides relies on the comparison of reaction rate constant expressions derived from these individual theories. In this paper, the example is used to develop a naturalized notion of reduction and th...

  3. Expanding opportunities for mining bioactive chemistry from patents.

    Science.gov (United States)

    Southan, Christopher

    2015-07-01

    Bioactive structures published in medicinal chemistry patents typically exceed those in papers by at least twofold and may precede them by several years. The Big-Bang of open automated extraction since 2012 has contributed to over 15 million patent-derived compounds in PubChem. While mapping between chemical structures, assay results and protein targets from patent documents is challenging, these relationships can be harvested using open tools and are beginning to be curated into databases. PMID:26194581

  4. Logic, History, and the Chemistry Textbook: I. Does Chemistry Have a Logical Structure?

    Science.gov (United States)

    Jensen, William B.

    1998-01-01

    Presents the first of three invited keynote lectures from the 1995 conference of the New England Association of Chemistry Teachers. Discusses the relevance of the history of chemistry to the teaching of chemistry. Contains 27 references. (DDR)

  5. Radiation chemistry of heavy particles

    International Nuclear Information System (INIS)

    The physical aspects of the energy deposit of fast particles in matter initiate chemical effects which are merged with the early physical processes. Here only radiation chemistry and its relationship to the initial energy deposit are of concern. The primary objective of our track studies is, however, application to biology. In the radiolytic decomposition of water energy is absorbed almost exclusively in water, and the principal chemistry is that of radiation decomposition of water. The track structure in water is expected to be virtually the same as that in a biological system. The study of radiation chemistry of dilute solutions, therefore, provides another method to investigate the structure of tracks as they are likely to be present in an irradiated biological system but at times much longer than they are accessible to purely physical measurements

  6. Problems in structural inorganic chemistry

    CERN Document Server

    Li, Wai-Kee; Mak, Thomas Chung Wai; Mak, Kendrew Kin Wah

    2013-01-01

    This book consists of over 300 problems (and their solutions) in structural inorganic chemistry at the senior undergraduate and beginning graduate level. The topics covered comprise Atomic and Molecular Electronic States, Atomic Orbitals, Hybrid Orbitals, Molecular Symmetry, Molecular Geometry and Bonding, Crystal Field Theory, Molecular Orbital Theory, Vibrational Spectroscopy, and Crystal Structure. The central theme running through these topics is symmetry, molecular or crystalline. The problems collected in this volume originate in examination papers and take-home assignments that have been part of the teaching of the book's two senior authors' at The Chinese University of Hong Kong over the past four decades. The authors' courses include Chemical Bonding, Elementary Quantum Chemistry, Advanced Inorganic Chemistry, X-Ray Crystallography, etc. The problems have been tested by generations of students taking these courses.

  7. Making Decisions by Analytical Chemistry

    DEFF Research Database (Denmark)

    Andersen, Jens Enevold Thaulov

    discrepancies are very unfortunate because erroneous conclusions may arise from an otherwise meticulous and dedicated effort of research staff. This may eventually lead to unreliable conclusions thus jeopardizing investigations of environmental monitoring, climate changes, food safety, clinical chemistry......It has been long recognized that results of analytical chemistry are not flawless, owing to the fact that professional laboratories and research laboratories analysing the same type of samples by the same type of instruments are likely to obtain significantly different results. The European......, forensics and other fields of science where analytical chemistry is the key instrument of decision making. In order to elucidate the potential origin of the statistical variations found among laboratories, a major program was undertaken including several analytical technologies where the purpose was to...

  8. The migration chemistry of neptunium

    International Nuclear Information System (INIS)

    The chemistry of neptunium, including redox properties, complex chemistry and chemistry of neptunium in its five oxidation states, III, IV, V, VI and VII has been reviewed with special emphasis on factors, which may be of importance in controlling the environmental behaviour of this element. Under environmental conditions neptunium should exist predominantly in oxidation state V in the form NpO2+ and to some extent also as Np (IV) in the form of Np4+ and Np (VI) in the form of NpO22+, whereas the other oxidation states Np (III) and Np (VII) can not exist in the environment. However, experimental evidence is lacking as is any knowledge about the mobility of neptunium in the environment. (author) 15 tabs., 2 ills., 37 refs

  9. Mass spectrometry. [in organic chemistry

    Science.gov (United States)

    Burlingame, A. L.; Shackleton, C. H. L.; Howe, I.; Chizhov, O. S.

    1978-01-01

    A review of mass spectrometry in organic chemistry is given, dealing with advances in instrumentation and computer techniques, selected topics in gas-phase ion chemistry, and applications in such fields as biomedicine, natural-product studies, and environmental pollution analysis. Innovative techniques and instrumentation are discussed, along with chromatographic-mass spectrometric on-line computer techniques, mass spectral interpretation and management techniques, and such topics in gas-phase ion chemistry as electron-impact ionization and decomposition, photoionization, field ionization and desorption, high-pressure mass spectrometry, ion cyclotron resonance, and isomerization reactions of organic ions. Applications of mass spectrometry are examined with respect to bio-oligomers and their constituents, biomedically important substances, microbiology, environmental organic analysis, and organic geochemistry.

  10. Handbook of hot atom chemistry

    International Nuclear Information System (INIS)

    Hot atom chemistry is an increasingly important field, which has contributed significantly to our understanding of many fundamental processes and reactions. Its techniques have become firmly entrenched in numerous disciplines, such as applied physics, biomedical research, and all fields of chemistry. Written by leading experts, this comprehensive handbook encompasses a broad range of topics. Each chapter comprises a collection of stimulating essays, given an in-depth account of the state-of-the-art of the field, and stressing opportunities for future work. An extensive introduction to the whole area, this book provides unique insight into a vast subject, and a clear delineation of its goals, techniques, and recent findings. It also contains detailed discussions of applications in fields as diverse as nuclear medicine, geochemistry, reactor technology, and the chemistry of comets and interstellar grains. (orig.)

  11. Atmospheric Chemistry and Air Pollution

    Directory of Open Access Journals (Sweden)

    Jeffrey S. Gaffney

    2003-01-01

    Full Text Available Atmospheric chemistry is an important discipline for understanding air pollution and its impacts. This mini-review gives a brief history of air pollution and presents an overview of some of the basic photochemistry involved in the production of ozone and other oxidants in the atmosphere. Urban air quality issues are reviewed with a specific focus on ozone and other oxidants, primary and secondary aerosols, alternative fuels, and the potential for chlorine releases to amplify oxidant chemistry in industrial areas. Regional air pollution issues such as acid rain, long-range transport of aerosols and visibility loss, and the connections of aerosols to ozone and peroxyacetyl nitrate chemistry are examined. Finally, the potential impacts of air pollutants on the global-scale radiative balances of gases and aerosols are discussed briefly.

  12. The chemistry of plutonium revealed

    International Nuclear Information System (INIS)

    In 1941 one goal of the Manhattan Project was to unravel the chemistry of the synthetic element plutonium as rapidly as possible. Important insights were obtained from tracer experiments, but the full complexity of plutonium chemistry was not revealed until macroscopic amounts (milligrams) became available. Because processes for separation from fission products were aqueous solution based, such solution chemistry was emphasized, particularly precipitation and oxidation-reduction behavior. The latter turned out to be unusually intricate when it was discovered that two more oxidation states existed in aqueous solution than had previously been suspected. Further, it was found that an equilibrium was rapidly established among the four aqueous oxidation states while at the same time any three were not in equilibrium. These and other observations made while doing a crash study of a previously unknown element will be reported

  13. Covalent chemistry in graphene electronics

    Directory of Open Access Journals (Sweden)

    Santanu Sarkar

    2012-06-01

    Full Text Available The development of selective high precision chemical functionalization strategies for device fabrication, in conjunction with associated techniques for patterning graphene wafers with atomic accuracy would provide the necessary basis for a post-CMOS manufacturing technology. This requires a thorough understanding of the principles governing the reactivity and patterning of graphene at the sub-nanometer length scale. This article reviews our quest to delineate the principles of graphene chemistry – that is, the chemistry at the Dirac point and beyond, and the effect of covalent chemistry on the electronic structure, electrical transport, and magnetic properties of this low-dimensional material in order to enable the scalable production of graphene-based devices for low- and high-end technology applications.

  14. Towards Bildung-Oriented Chemistry Education

    Science.gov (United States)

    Sjöström, Jesper

    2013-07-01

    This paper concerns Bildung-oriented chemistry education, based on a reflective and critical discourse of chemistry. It is contrasted with the dominant type of chemistry education, based on the mainstream discourse of chemistry. Bildung-oriented chemistry education includes not only content knowledge in chemistry, but also knowledge about chemistry, both about the nature of chemistry and about its role in society. In 2004 Mahaffy suggested a tetrahedron model based on Johnstone's chemical triangle. The latter represents the formal aspects of chemistry teaching (macro, submicro, and symbolic) and the top of the tetrahedron represents a human element. In the present paper the following subdivision of the top is suggested (starting from the bottom): (1) applied chemistry, (2) socio-cultural context, and (3) critical-philosophic approach. The professional identity of the Bildung-oriented chemistry teacher differs from that of the chemist and is informed by research fields such as Philosophy of Chemistry, Science and Technology Studies, and Environmental Education. He/she takes a socio-critical approach to chemistry, emphasising both the benefits and risks of chemistry and its applications.

  15. The Application of SCC-DV-Xα Computational Method of Quantum Chemistry in Cement Chemistry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    It has been explored why quantum chemistry is applied to the research field of cement chemistry. The fundamental theory of SCC-DV-Xα computational method of quantum chemistry is synopsized. The results obtained by computational quantum chemistry method in recent years of valence-bond structures and hydration activity of some cement clinker minerals, mechanical strength and stabilization of some hydrates are summarized and evaluated. Finally the prospects of the future application of quantum chemistry to cement chemistry are depicted.

  16. Analytical chemistry and semiconductor materials

    Energy Technology Data Exchange (ETDEWEB)

    Bohn, P.W. (Univ. of Illinois at Urbana-Champaign (USA)); Harris, T.D. (AT T Bell Laboratories, Murray Hill, NJ (USA))

    1990-07-15

    Advances in analytical chemistry are crucial to the continued expansion of electronic and optoelectronic materials in device applications. This report explains the critical role that the defect chemistry of semiconductor material in a device and the difficulty of extracting chemical information about defects. The authors focus on the generic class of chemical analysis problems resulting from the fact that the spatial distribution of chemical composition is the single most important factor in determining the operative properties of electronic and optoelectronic materials. 31 refs., 7 figs., 1 tabs.

  17. Department of Chemistry, progress report

    International Nuclear Information System (INIS)

    The research activities in Department of Chemistry during the last 3 years from 1986 to 1988 were compiled. The researches and works of Department of Chemistry are mainly those concerned with important basic matters and items which are committed to the further development of the nuclear fuels and materials, to the establishment of the nuclear fuel cycle, and to the acquisition of data for the environmental safety studies. Intensive efforts were also made on chemical analysis service of various fuels and nuclear materials. (author)

  18. Molten fluoride fuel salt chemistry

    International Nuclear Information System (INIS)

    The chemistry of molten fluorides is traced from their development as fuels in the Molten Salt Reactor Experiment with important factors in their selection being discussed. Key chemical characteristics such as solubility, redox behavior, and chemical activity are explained as they relate to the behavior of molten fluoride fuel systems. Fission product behavior is described along with processing experience. Development requirements for fitting the current state of the chemistry to modern nuclear fuel system are described. It is concluded that while much is known about molten fluoride behavior, processing and recycle of the fuel components is a necessary factor if future systems are to be established

  19. Sustainable Chemistry at Sungkyunkwan University.

    Science.gov (United States)

    Park, Nam-Gyu

    2015-07-20

    Special Issue: Sustainable Chemistry at Sungkyunkwan University. Sustainable chemistry is key to the development of efficient renewable energies, which will become more and more important in order to combat global warming. In this Editorial, guest editor Prof. Nam-Gyu Park describes the context of this Special Issue on top-quality research towards sustainability performed at Sungkyunkwan University (SKKU) in Korea. Scientists at SKKU work on, for example, photovoltaic solar cells to generate low-cost electricity, lithium batteries and capacitors to store electricity, piezoelectric nanogenerators, thermoelectric devices, hydrogen generation, and fuel cells. PMID:26183687

  20. Hot atom chemistry of sulphur

    International Nuclear Information System (INIS)

    An attempt to cover all papers dealing with the hot atom chemistry of sulpphur is made. Publications which: a) only touch the problem, b) contain some data, indirectly connected with sulphur hot atom chemistry, c) deal with 35S-production from a chloride matrix, are included as well. The author's name and literature source are given in the original language, transcribed, when it is necessary, in latine. A number of primery and secondary documents have been used including Chemical Abstracts, INIS Atomindex, the bibliographies of A. Siuda and J.-P. Adloff for 1973 - 77, etc. (authors)

  1. The Doctorate in Chemistry. Carnegie Essays on the Doctorate: Chemistry.

    Science.gov (United States)

    Breslow, Ronald

    The Carnegie Foundation commissioned a collection of essays as part of the Carnegie Initiative on the Doctorate (CID). Essays and essayists represent six disciplines that are part of the CID: chemistry, education, English, history, mathematics, and neuroscience. Intended to engender conversation about the conceptual foundation of doctoral…

  2. Comparing Carbonyl Chemistry in Comprehensive Introductory Organic Chemistry Textbooks

    Science.gov (United States)

    Nelson, Donna J.; Kumar, Ravi; Ramasamy, Saravanan

    2015-01-01

    Learning the chemistry of compounds containing carbonyl groups is difficult for undergraduate students partly because of a convolution of multiple possible reaction sites, competitive reactions taking place at those sites, different criteria needed to discern between the mechanisms of these reactions, and no straightforward selection method…

  3. Integrating Particulate Representations into AP Chemistry and Introductory Chemistry Courses

    Science.gov (United States)

    Prilliman, Stephen G.

    2014-01-01

    The College Board's recently revised curriculum for advanced placement (AP) chemistry places a strong emphasis on conceptual understanding, including representations of particle phenomena. This change in emphasis is informed by years of research showing that students could perform algorithmic calculations but not explain those calculations…

  4. Chemistry on the inside: green chemistry in mesoporous materials

    OpenAIRE

    MacQuarrie, D.J.

    2000-01-01

    An overview of the rapidly expanding area of tailored mesoporous solids is presented. The synthesis of a wide range of the materials is covered, both inorganically and organically modified. Their applications, in particular those relating to green chemistry, are also highlighted. Finally, potential future directions for these materials are discussed.

  5. Integrating Computational Chemistry into the Physical Chemistry Curriculum

    Science.gov (United States)

    Johnson, Lewis E.; Engel, Thomas

    2011-01-01

    Relatively few undergraduate physical chemistry programs integrate molecular modeling into their quantum mechanics curriculum owing to concerns about limited access to computational facilities, the cost of software, and concerns about increasing the course material. However, modeling exercises can be integrated into an undergraduate course at a…

  6. Green chemistry at work

    Energy Technology Data Exchange (ETDEWEB)

    Frost, J. [Michigan State Univ., East Lansing, MI (United States)

    1994-12-31

    The 1.7 billion pounds of benzene produced each year in the US provide one measure of its utility. At the same time, there are a number of environmental reasons for avoiding the use of benzene in chemical manufacture. Perhaps most compelling: benzene is a potent carcinogen. Scrutiny of many of the chemicals derived from benzene reveals that each molecule contains at least one oxygen atom while benzene completely lacks oxygen atoms. Introduction of oxygen to make up for this lack can require processes that are environmentally problematic. One of the steps used to introduce oxygen atoms during manufacture of adipic acid, a component of Nylon 66, is responsible for 10% of the annual global increase in atmospheric nitrous oxide. This by-product is a causative agent of atmospheric ozone depletion and has been implicated in global warming. With support from EPA and the National Science Foundation, alternative manufacturing processes are being explored. By these new methods, chemicals usually created from benzene are made instead from nontoxic glucose, a component of table sugar. Unlike benzene, glucose is obtained from such renewable resources as plant starch and cellulose. ``Green`` manufacturing routes ideally should lead to chemicals that are economically competitive with chemicals produced by traditional methods. For two chemicals of roughly comparable cost, the consumer or producer can then be realistically expected to choose in favor of the chemical produced by a ``green`` process. Projections indicate that catechol and hydroquinone can be biocatalytically produced from glucose at a cost competitive with current market prices. Synthesis of chemicals from glucose using biocatalysis offers the premise of achieving fundamental environmental improvement while increasing the demand for agricultural products. In the final analysis, what is good for the environment can also be good for American agriculture.

  7. New reactions of cyclic oxygen, nitrogen and sulfur acetal derivatives

    OpenAIRE

    Mann, S. E.

    2011-01-01

    This thesis describes the development of new reactions of cyclic oxygen, nitrogen and sulfur acetal derivatives and their applications in a diverse range of synthetic organic and organometallic chemistry. Detailed herein are advances in three main areas of acetal chemistry, namely: studies towards a new methodology for the synthesis of medium ring heterocycles; the use of thioacetals as directing groups for the palladium-mediated oxidation of olefins; and multi-component reactions for the syn...

  8. Developing an online chemistry laboratory for non-chemistry majors

    Science.gov (United States)

    Poole, Jacqueline H.

    Distance education, also known as online learning, is student-centered/self-directed educational opportunities. This style of learning is expanding in scope and is increasingly being accepted throughout the academic curriculum as a result of its flexibility for the student as well as the cost-effectiveness for the institution. Nevertheless, the introduction of online science courses including chemistry and physics have lagged behind due to the challenge of re-creation of the hands-on laboratory learning experience. This dissertation looks at the effectiveness of the design of a series of chemistry laboratory experiments for possible online delivery that provide students with simulated hands-on experiences. One class of college Chemistry 101 students conducted chemistry experiments inside and outside of the physical laboratory using instructions on Blackboard and Late Nite Labs(TM). Learning outcomes measured by (a) pretests, (b) written laboratory reports, (c) posttest assessments, (d) student reactions as determined by a questionnaire, and (e) a focus group interview were utilized to compare both types of laboratory experiences. The research findings indicated learning outcomes achieved by students outside of the traditional physical laboratory were statistically greater than the equivalent face-to-face instruction in the traditional laboratory. Evidence from student reactions comparing both types of laboratory formats (online and traditional face-to-face) indicated student preference for the online laboratory format. The results are an initial contribution to the design of a complete sequence of experiments that can be performed independently by online students outside of the traditional face-to-face laboratory that will satisfy the laboratory requirement for the two-semester college Chemistry 101 laboratory course.

  9. A handbook of nuclear water chemistry

    International Nuclear Information System (INIS)

    This contents is divided three parts. The first part deals with chemistry which is related water nuclear energy. So it explains the role of water in atomic reactor including the basic properties of water, the oxide chemistry electricity chemistry, radiochemistry and measuring techniques of the quality of water in nuclear plant and radiation. The second part introduces technique of nuclear water chemistry, which explains purpose, definition and speciality of water chemistry in light-water reactor. The third part indicates application technology of water chemistry in nuclear energy including putting zinc in light-water reactor and technology of surveillance of leakage in steam generator.

  10. I Chemistry Conference of West Bahia

    Directory of Open Access Journals (Sweden)

    Boaz Oliveira

    2014-11-01

    Full Text Available The I Chemistry Conference of West Bahia [1] aimed the meeting of the academic community of west Bahia state developing research activities at graduate level and postgraduate ones in several chemistry areas, mainly the analytic chemistry, natural products, theoretical chemistry, medicinal chemistry, chemistry teaching, spectroscopy, materials science, photochemistry and catalysis. Through the plenary lectures, short courses and poster presentation, invited researchers from other institutions and mainly students could share experiences as well as plan collaborations from multi and interdisciplinar nature, enabling a greater scientific aggrandizement of the research developed by emergent groups distributed along the inland cities of Brazil.

  11. Developing nitrosocarborane chemistry.

    Science.gov (United States)

    Powley, Samuel L; Schaefer, Louise; Man, Wing Y; Ellis, David; Rosair, Georgina M; Welch, Alan J

    2016-02-28

    The new nitrosocarboranes [1-NO-2-R-1,2-closo-C2B10H10] [R = CH2Cl (1), CH3OCH2 (2) p-MeC6H4 (3), SiMe3 (4) and SiMe2tBu (5)] and [1-NO-7-Ph-1,7-closo-C2B10H10] (6) were synthesised by reaction of the appropriate lithiocarborane in diethyl ether with NOCl in petroleum ether followed by quenching the reaction with aqueous NaHCO3. These bright-blue compounds were characterised spectroscopically and, in several cases, crystallographically including structural determinations of 2 and 6 using crystals grown in situ on the diffractometer from liquid samples. In all cases the nitroso group bonds to the carborane as a 1e substituent (bent C–N–O sequence) and has little or no influence on , the weighted average 11B chemical shift, relative to that in the parent (monosubstituted) carborane. Mono- and dinitroso derivatives of 1,1′-bis(m-carborane), compounds 7 and 8 respectively, were similarly synthesised but attempts to prepare the mononitroso 1,1′-bis(o-carborane) by the same protocol led only to the hydroxylamine species [1-(1′-1′,2′-closo-C2B10H11)-2-N(H)OH-1,2-closo-C2B10H10] (9); the desired compound [1-(1′-1′,2′-closo-C2B10H11)-2-NO-1,2-closo-C2B10H10] (10) was only realised by switching to a non-aqueous work-up. The involvement of water in effecting the net reduction of the NO function in 10 to N(H)OH in 9 was confirmed by a series of experiments involving [1-N(H)OH-2-Ph-1,2-closo-C2B10H10] (11), [1-(1′-2′-D-1′,2′-closo-C2B10H10)-2-D-1,2-closo-C2B10H10] (12) and [1-(1′-2′-D-1′,2′-closo-C2B10H10)-2-N(H)OH-1,2-closo-C2B10H10] (13). It is suggested that during aqueous work-up a water molecule, H-bonded to the acidic C2′H of 10, is "delivered" to the adjacent C2NO unit. The ability of the NO group in nitrosocarboranes to undergo Diels-Alder cycloaddition reactions with cyclic 1,3-dienes was established via the syntheses of [1-(NOC10H14)-1,2-closo-C2B10H11] (14) and [1-(NOC6H8)-2-Ph-1,2-closo-C2B10H10] (15). This strategy was then

  12. Green Chemistry with Microwave Energy

    Science.gov (United States)

    Green chemistry utilizes a set of 12 principles that reduces or eliminates the use or generation of hazardous substances in the design, manufacture, and applications of chemical products (1). This newer chemical approach protects the environment by inventing safer and eco-friendl...

  13. Chemistry--The Big Picture

    Science.gov (United States)

    Cassell, Anne

    2011-01-01

    Chemistry produces materials and releases energy by ionic or electronic rearrangements. Three structure types affect the ease with which a reaction occurs. In the Earth's crust, "solid crystals" change chemically only with extreme heat and pressure, unless their fixed ions touch moving fluids. On the other hand, in living things, "liquid crystals"…

  14. Polymer Chemistry and Liposome Technology

    OpenAIRE

    Tirrell, David A.

    1988-01-01

    Polymer chemistry has a great deal to offer in the construction of synthetic liposomal membranes for use in biology and medicine. This chapter explores the preparation and properties of polymeric liposomes , with particular emphasis on the use of controlled polyelectrolyte adsorption to manipulate liposomal membrane properties.

  15. Protostellar accretion traced with chemistry

    DEFF Research Database (Denmark)

    Frimann, Søren; Jørgensen, Jes K.; Padoan, Paolo;

    2016-01-01

    used foranalysing the observations. Methods: Simple freeze-out andsublimation chemistry is added to the simulation, and syntheticC18O line cubes are created for a large number of simulatedprotostars. The spatial extent of C18O is measured for thesimulated protostars and compared directly to a sample of...

  16. Chemistry Teaching: Science or Alchemy?

    Science.gov (United States)

    Johnstone, A. H.

    1997-01-01

    Suggests that the development of good chemistry teaching and the pursuit of research have essentially the same structure. Similarities include the need for a clear focus, efficiency in time and effort, and a direction that is more often right than wrong. (DDR)

  17. Supramolecular chemistry and crystal engineering

    Indian Academy of Sciences (India)

    Ashwini Nangia

    2010-05-01

    Advances in supramolecular chemistry and crystal engineering reported from India within the last decade are highlighted in the categories of new intermolecular interactions, designed supramolecular architectures, network structures, multi-component host-guest systems, cocrystals, and polymorphs. Understanding self-assembly and crystallization through X-ray crystal structures is illustrated by two important prototypes - the large unit cell of elusive saccharin hydrate, Na16(sac)16 . 30H2O, which contains regular and irregular domains in the same structure, and by the Aufbau build up of zinc phosphate framework structures, e.g. ladder motif in [C3N2H12][Zn(HPO4)2] to layer structure in [C3N2H12][Zn2(HPO4)3] upon prolonged hydrothermal conditions. The pivotal role of accurate X-ray diffraction in supramolecular and structural studies is evident in many examples. Application of the bottomup approach to make powerful NLO and magnetic materials, design of efficient organogelators, and crystallization of novel pharmaceutical polymorphs and cocrystals show possible future directions for interdisciplinary research in chemistry with materials and pharmaceutical scientists. This article traces the evolution of supramolecular chemistry and crystal engineering starting from the early nineties and projects a center stage for chemistry in the natural sciences.

  18. Visualizing Chemistry: Investigations for Teachers.

    Science.gov (United States)

    Ealy, Julie B.; Ealy, James L., Jr.

    This book contains 101 investigations for chemistry classrooms. Topics include: (1) Physical Properties; (2) Reactions of Some Elements; (3) Reactions Involving Gases; (4) Energy Changes; (5) Solutions and Solubility; (6) Transition Metals and Complex Ions; (7) Kinetics and Equilibrium; (8) Acids and Bases; (9) Oxidation-Reduction; (10)…

  19. Radiation chemistry of ionic liquids

    International Nuclear Information System (INIS)

    Ionic liquids are expected as a replacement of processing media for the nuclear fuel cycle. Therefore, an understanding of the interactions of ionizing radiations and photons with ionic liquids is strongly needed. However, the radiation chemistry of ionic liquids is still a relatively unexplored topic although there has been a significant increase in the number of researchers in the field recently. (author)

  20. A Comprehensive General Chemistry Demonstration

    Science.gov (United States)

    Sweeder, Ryan D.; Jeffery, Kathleen A.

    2013-01-01

    This article describes the use of a comprehensive demonstration suitable for a high school or first-year undergraduate introductory chemistry class. The demonstration involves placing a burning candle in a container adjacent to a beaker containing a basic solution with indicator. After adding a lid, the candle will extinguish and the produced…

  1. Plasma chemistry and organic synthesis

    Science.gov (United States)

    Tezuka, M.

    1980-01-01

    The characteristic features of chemical reactions using low temperature plasmas are described and differentiated from those seen in other reaction systems. A number of examples of applications of plasma chemistry to synthetic reactions are mentioned. The production of amino acids by discharge reactions in hydrocarbon-ammonia-water systems is discussed, and its implications for the origins of life are mentioned.

  2. Organic chemistry in Titan's atmosphere

    Science.gov (United States)

    Scattergood, T.

    1982-01-01

    Laboratory photochemical simulations and other types of chemical simulations are discussed. The chemistry of methane, which is the major known constituent of Titan's atmosphere was examined with stress on what can be learned from photochemistry and particle irradiation. The composition of dust that comprises the haze layer was determined. Isotope fractionation in planetary atmospheres is also discussed.

  3. BWR water chemistry impurity studies

    International Nuclear Information System (INIS)

    Laboratory studies were made on the effect of water impurities on environmental cracking in simulated BWR water of stainless steel, low alloy steel and nickel-base alloys. Constant elongation rate tensile (CERT) tests were run in simulated normal water chemistry (NWC), hydrogen water chemistry (HWC), or start-up environment. Sulfate, chloride and copper with chloride added to the water at levels of a fraction of a ppM were found to be extremely deleterious to all kinds of materials except Type 316 NG. Other detrimental impurities were fluoride, silica and some organic acids, although acetic acid was beneficial. Nitrate and carbon dioxide were fairly inoccuous. Corrosion fatigue and constant load tests on compact tension specimens were run in simulated normal BWR water chemistry (NWC) or hydrogen water chemistry (HWC), without impurities or with added sulfate or carbon dioxide. For sensitized Type 304 SS in NWC, 0.1 ppM sulfate increased crack propagation rates in constant load tests by up to a factor of 100, and in fatigue tests up to a factor of 10. Also, cracking in Type 316 nuclear grade SS and Alloy 600 was enhanced, but to a smaller degree. Carbon dioxide was less detrimental than sulfate. 3 figs., 4 tabs

  4. Simplified Model for Reburning Chemistry

    DEFF Research Database (Denmark)

    Glarborg, Peter; Hansen, Stine

    2010-01-01

    In solid fuel flames, reburn-type reactions are often important for the concentrations of NOx in the near-burner region. To be able to model the nitrogen chemistry in these flames, it is necessary to have an adequate model for volatile/NO interactions. Simple models consisting of global steps or...

  5. Computational Chemistry of Adhesive Bonds

    Science.gov (United States)

    Phillips, Donald H.

    1999-01-01

    This investigation is intended to determine the electrical mechanical, and chemical properties of adhesive bonds at the molecular level. The initial determinations will be followed by investigations of the effects of environmental effects on the chemistry and properties of the bond layer.

  6. IV. Health physics and chemistry

    Energy Technology Data Exchange (ETDEWEB)

    Garden, N.B.; Moyer, B.J.

    1948-05-24

    This report describes progress on the development of equipment and techniques to accomplish the goal of control and trapping of radioactive sustances. Emphasis is on simplicity reproducibiolity, and universal use. Also illustrated is the Health Chemistry Organization set-up of personnel.

  7. Diverse applications of radiation chemistry

    International Nuclear Information System (INIS)

    Radiation chemistry began as early radiotherapists needed a reliable and appropriate dosimeter. The iron sulphate dosimeter, using ferrous iron in sulphuric acid and oxidation by irradiation, was a nasty brew of chemicals but it was sensitive, reliable and conveniently had the same density as human tissue. Water irradiation chemistry studies were driven by the need to understand the fundamental processes in radiotherapy; to control the corrosion problems in the cooling/ heat exchange systems of nuclear reactors and to find stable solvents and reagents for use in spent fuel element processing. The electrical and mechanical stability of materials in high radiation fields stimulated the attention of radiation chemists to the study of defects in solids. The coupled use of radiation and Electron Spin Resonance (ESR) enabled the identity of defect structures to be probed. This research led to the development of the sensitive Thermoluminescent Dosimeters, TLD's and a technique for dating of archaeological pottery artefacts. Radiation chemistry in the area of medicine is very active with fundamental studies of the mechanism of DNA strand breakage and the development of radiation sensitisers and protectors for therapeutic purposes. The major area of polymer radiation chemistry is one which Australia commands great international respect

  8. Chemistry of the transactinide elements

    International Nuclear Information System (INIS)

    The synthesis and decay of the elements 104, 105 and 106 are described as well as the chemistry of the elements in the gaseous and liquid phase. The electron configurations of the ground state of the elements 105 and higher are described, as well as further chemical properties. (SR)

  9. Organometallic chemistry: A new metathesis

    Science.gov (United States)

    Hennessy, Elisabeth T.; Jacobsen, Eric N.

    2016-08-01

    Carbonyls and alkenes, two of the most common functional groups in organic chemistry, generally do not react with one another. Now, a simple Lewis acid has been shown to catalyse metathesis between alkenes and ketones in a new carbonyl olefination reaction.

  10. Quantum Nanobiology and Biophysical Chemistry

    DEFF Research Database (Denmark)

    2013-01-01

    An introduction was provided in the first issue by way of an Editorial to this special two issue volume of Current Physical Chemistry – “Quantum Nanobiology and Biophysical Chemistry” [1]. The Guest Editors would like to thank all the authors and referees who have contributed to this second issue...

  11. Chemistry without borders: An overview

    Science.gov (United States)

    As chemistry becomes more globalized, it is important for an organization to be interconnected and adaptable, and for an individual to keep up with changes and latest scientific findings and keep options open. Many of the challenges and the opportunities of globalization are in the areas of jobs, re...

  12. Structural Chemistry of Functional Materials

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    @@ This innovative research group on structural chemistry of functional materials was approved by NSFC in 2005.Headed by Prof.HONG Maochun, the team consists of several young research scientists from the CAS Fujian Institute of Research on the Structures of Matter, including Profs CAO Rong, LU Canzhong, GUO Guocong, CHEN Zhongning, MAO Jianggao Mao and CHEN Ling.

  13. Green chemistry for chemical synthesis

    OpenAIRE

    Li, Chao-Jun; Trost, Barry M.

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign.

  14. Green chemistry for chemical synthesis

    Science.gov (United States)

    Li, Chao-Jun; Trost, Barry M.

    2008-01-01

    Green chemistry for chemical synthesis addresses our future challenges in working with chemical processes and products by inventing novel reactions that can maximize the desired products and minimize by-products, designing new synthetic schemes and apparati that can simplify operations in chemical productions, and seeking greener solvents that are inherently environmentally and ecologically benign. PMID:18768813

  15. Some advances in atmospheric chemistry

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    In the recent decade, researches have been carried out by our group on some aspects of atmospheric chemistry through field observation, mechanism analysis and model simulation. Here some main results on greenhouse gas (CH4, N2O) emission from Chinese agricultural fields, aerosol, global carbon cycle and ozone variation in surface laver over China are briefly reported.

  16. Teaching Techniques in Clinical Chemistry.

    Science.gov (United States)

    Wilson, Diane

    This master's thesis presents several instructional methods and techniques developed for each of eleven topics or subject areas in clinical chemistry: carbohydrate metabolism, lipid metabolism, diagnostic enzymology, endocrinology, toxicology, quality control, electrolytes, acid base balance, hepatic function, nonprotein nitrogenous compounds, and…

  17. Chemistry Perfumes Your Daily Life

    Science.gov (United States)

    Fortineau, Anne-Dominique

    2004-01-01

    A synopsis on the history of perfumery is presented, along with the various processes accessible for obtaining natural perfume constituents, and creation of synthetic chemicals. The important contribution of organic chemists in the invention of perfumes, aspects of fragrance chemistry, and general information on the perfume industry are…

  18. Chemistry of high temperature superconductors

    CERN Document Server

    1991-01-01

    This review volume contains the most up-to-date articles on the chemical aspects of high temperature oxide superconductors. These articles are written by some of the leading scientists in the field and includes a comprehensive list of references. This is an essential volume for researchers working in the fields of ceramics, materials science and chemistry.

  19. Protostellar accretion traced with chemistry

    DEFF Research Database (Denmark)

    Frimann, Søren; Jørgensen, Jes K.; Padoan, Paolo;

    2016-01-01

    methodology used for analysing the observations. Methods: Simple freeze-out and sublimation chemistry is added to the simulation, and synthetic C18O line cubes are created for a large number of simulated protostars. The spatial extent of C18O is measured for the simulated protostars, and compared directly to...

  20. On $n$-derivations

    Directory of Open Access Journals (Sweden)

    Mohammad Hossein Sattari

    2016-06-01

    Full Text Available In this article, the notion of $n-$derivation is introduced for all integers $ngeq 2$. Although all derivations are $n-$derivations,  in general these notions are not equivalent. Some properties of ordinary derivations are  investigated for $n-$derivations. Also, we show that under certain mild condition  $n-$derivations are derivations.