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26,182 full-text articles. Page 707 of 708.

Bismuth Compounds In Organic Synthesis: Synthesis Of Dioxanes, Dioxepines, And Dioxolanes Catalyzed By Bismuth(Iii) Triflate, Ram Mohan, Daniel Podgorski, Scott Krabbe, Long Le, Paul Sierszulski 2009 Illinois Wesleyan University

Bismuth Compounds In Organic Synthesis: Synthesis Of Dioxanes, Dioxepines, And Dioxolanes Catalyzed By Bismuth(Iii) Triflate, Ram Mohan, Daniel Podgorski, Scott Krabbe, Long Le, Paul Sierszulski

Ram S. Mohan

A simple method for the synthesis of l,3-dioxolanes from carbonyl compounds has been developed using l,2-bis(trimethylsilyloxy) ethane in the presence of bismuth (III) triflate as a catalyst. The bismuth(III) triflate catalyzed synthesis of a range of dioxanes and dioxepines has also been developed. In these latter cases, the carbonyl compound is treated with a diol, and triethyl orthoformate is used as a water scavenger. All these methods avoid the use of a Dean-Stark trap.


The Effect Of Ion-Pairing On The Open Circuit Potential Of 3-Mercaptoproprionic Acid Modified Gold Electrodes, Mark Anderson, Alice Harper 2009 Kennesaw State University

The Effect Of Ion-Pairing On The Open Circuit Potential Of 3-Mercaptoproprionic Acid Modified Gold Electrodes, Mark Anderson, Alice Harper

Mark R. Anderson

Open circuit potential (OCP) measurement is used to monitor the charge of a monolayer of 3-mercaptopropionic acid. OCP is determined by the concentrations of the reduced and oxidized forms of a redox couple in the solution adjacent to the modified interface. OCP values were monitored in the presence of the one-electron redox couple Fe(CN)63-/4- as a function of solution pH. The OCP measured at basic pHs was different from the acidic OCP due to differences in electrostatic interactions between the interface and the redox species as described by the Nernst equation. The influence of ion-pairing with the ...


Kinetic And Mechanistic Studies Of The Deuterium Exchange In Classical Keto−Enol Tautomeric Equilibrium Reactions, Mark Waner, Michael Nichols 2009 John Carroll University

Kinetic And Mechanistic Studies Of The Deuterium Exchange In Classical Keto−Enol Tautomeric Equilibrium Reactions, Mark Waner, Michael Nichols

Mark J. Waner

An extension of the classic keto−enol tautomerization of β-dicarbonyl compounds into a kinetic analysis of deuterium exchange is presented. It is shown that acetylacetone and ethyl acetoacetate undergo nearly complete deuterium exchange of the α-methylene carbon when dissolved in methanol-d4. The extent of deuteration may be monitored via NMR spectroscopy as a function of time. A mechanism for deuterium exchange is presented and shown to be consistent with a consecutive first-order process. The data for acetylacetone are consistent with steady-state kinetics, whereas those of ethyl acetoacetate illustrate nonsteady-state behavior, offering an accessible example where students might collect and analyze ...


Phytoprotective Influence Of Bacteria On Growth And Cadmium Accumulation In The Aquatic Plant Lemna Minor, Julian Tyson, Lisa M. Stout, Elena N. Dodova, Klaus Nusslein 2009 University of Massachusetts - Amherst

Phytoprotective Influence Of Bacteria On Growth And Cadmium Accumulation In The Aquatic Plant Lemna Minor, Julian Tyson, Lisa M. Stout, Elena N. Dodova, Klaus Nusslein

Julian Tyson

Certain plants are known to accumulate heavy metals, and can be used in remediation of
polluted soil or water. Plant-associated bacteria, especially those that are metal tolerant,
may enhance the total amount of metal accumulated by the plant, but this process is still
unclear. In this study, we investigated metal enhancement vs. exclusion by plants, and the
phytoprotective role plant-associated bacteria might provide to plants exposed to heavy
metal. We isolated cadmium-tolerant bacteria from the roots of the aquatic plant Lemna
minor grown in heavy metal-polluted waters, and tested these isolates for tolerance to
cadmium. The efficiency of plants to ...


Mid-Gap Electronic States In Zn1-Xmnxo., C. A. Johnson, Kevin R. Kittilstved, T. C. Kaspar, T. C. Droubay, S. A. Chambers, G. M. Salley, D. R. Gamelin 2009 University of Massachusetts - Amherst

Mid-Gap Electronic States In Zn1-Xmnxo., C. A. Johnson, Kevin R. Kittilstved, T. C. Kaspar, T. C. Droubay, S. A. Chambers, G. M. Salley, D. R. Gamelin

Kevin R. Kittilstved

Electronic absorption, magnetic circular dichroism (MCD), photoconductivity, and valence-band x-ray photoelectron (XPS) spectroscopic measurements were performed on epitaxial Zn1−xMnxO films to investigate the origin of the mid-gap band that appears upon introduction of Mn2+ into the ZnO lattice. Absorption and MCD spectroscopies reveal Mn2+-related intensity at energies below the first excitonic transition of ZnO, tailing well into the visible energy region, with an onset at ∼2.2 eV. Photoconductivity measurements show that excitation into this visible band generates mobile charge carriers, consistent with assignment as a Mn2+/3+ photoionization transition. XPS measurements reveal the presence of occupied Mn2 ...


Array-Based Sensing Of Normal, Cancerous, And Metastatic Cells Using Conjugated Fluorescent Polymers, A Bajaj, OR Miranda, R Phillips, IB Kim, DJ Jerry, UHF Bunz, VM Rotello 2009 University of Massachusetts - Amherst

Array-Based Sensing Of Normal, Cancerous, And Metastatic Cells Using Conjugated Fluorescent Polymers, A Bajaj, Or Miranda, R Phillips, Ib Kim, Dj Jerry, Uhf Bunz, Vm Rotello

Vincent Rotello

A family of conjugated fluorescent polymers was used to create an array for cell sensing. Fluorescent conjugated polymers with pendant charged residues provided multivalent interactions with cell membranes, allowing the detection of subtle differences between different cell types on the basis of cell surface features. Highly reproducible characteristic patterns were obtained from different cell types as well as from isogenic cell lines, enabling the identification of the cell type as well differentiating between normal, cancerous, and metastatic isogenic cell types with high accuracy.


Anhang: Auszüge Aus Dem Späteren Leben Von Professor Dr. Otto Vogl, Otto Vogl 2009 University of Massachusetts - Amherst

Anhang: Auszüge Aus Dem Späteren Leben Von Professor Dr. Otto Vogl, Otto Vogl

Otto Vogl

No abstract provided.


My Italian Connections: Otto Vogl In Italy, Otto Vogl, Gerald S. Kirshenbaum 2009 University of Massachusetts - Amherst

My Italian Connections: Otto Vogl In Italy, Otto Vogl, Gerald S. Kirshenbaum

Otto Vogl

This document describes Otto Vogl's work in Italy. From 1975, Vogl served for 3 years as the Chairman of the Scientific Advisory Committee to the President Italo Trapasso of the Plastic Materials Company of Montedison SA, Milan, Italy. He was assigned to restructure the research activities and to organize the Research Division. He was responsible for the appointment of DiDrusco as the Vice President of Research and Paolo Galli as the Director of Research at the company’s facilities in Ferrara. Within a year of Vogl’s reorganization of the research organization the high yield catalyst for the polymerization ...


A Mild And Chemoselective Method For The Deprotection Of Tert-Butyldimethylsilyl (Tbdms) Ethers Using Iron(Iii) Tosylate As A Catalyst, Ram S. Mohan, Jason M. Bothwell, Veronica V. Angeles, James P. Carolan, Margaret E. Olson 2009 Illinois Wesleyan University

A Mild And Chemoselective Method For The Deprotection Of Tert-Butyldimethylsilyl (Tbdms) Ethers Using Iron(Iii) Tosylate As A Catalyst, Ram S. Mohan, Jason M. Bothwell, Veronica V. Angeles, James P. Carolan, Margaret E. Olson

Ram S. Mohan

The most common method for the deprotection ofTBDMS ethers utilizes stoichiometric amounts of tetrabutylammonium fluoride, n-Bu4N+F(TBAF), which is highly corrosive and toxic. We have developed a mild and chemoselective method for the deprotection ofTBDMS, TES, and TIPS ethers using iron(III) tosylate as a catalyst. Phenolic TBDMS ethers, TBDPS ethers and the BOC group are not affected under these conditions. Iron(III) tosylate is an inexpensive, commercially available, and non-corrosive reagent.


Iron(Iii) Tosylate-Catalyzed Deprotection Of Aromatic Acetals In Water, Ram S. Mohan, Margaret E. Olson, James P. Carolan, Michael V. Chiodo, Phillip R. Lazzara 2009 Illinois Wesleyan University

Iron(Iii) Tosylate-Catalyzed Deprotection Of Aromatic Acetals In Water, Ram S. Mohan, Margaret E. Olson, James P. Carolan, Michael V. Chiodo, Phillip R. Lazzara

Ram S. Mohan

The deprotection of aromatic as well as conjugated acetals and ketals in water is catalyzed by iron(III) tosylate (1.0–5.0 mol %). Iron(III) tosylate is an inexpensive and readily available catalyst. The use of water, the most environmentally benign solvent, makes this procedure especially attractive for acetal deprotection.


In Your Element: Green Bismuth, Ram S. Mohan 2009 Illinois Wesleyan University

In Your Element: Green Bismuth, Ram S. Mohan

Ram S. Mohan

No abstract provided.


Cyclohexane Oxidation And Cyclohexyl Hydroperoxide Decomposition By Poly(4-Vinylpyridine-Co-Divinylbenzene) Supported Cobalt And Chromium Complexes, Zeljko D. Cupic 2009 Institute of Chemistry, Technology and Metallurgy

Cyclohexane Oxidation And Cyclohexyl Hydroperoxide Decomposition By Poly(4-Vinylpyridine-Co-Divinylbenzene) Supported Cobalt And Chromium Complexes, Zeljko D. Cupic

Zeljko D Cupic

No abstract provided.


Bismuth(Iii) Bromide In Organic Synthesis. A Catalytic Method For The Allylation Of Tetrahydrofuranyl And Tetrahydropyranyl Ethers, Ram S. Mohan, Scott W. Krabbe, Veronica V. Angeles 2009 Illinois Wesleyan University

Bismuth(Iii) Bromide In Organic Synthesis. A Catalytic Method For The Allylation Of Tetrahydrofuranyl And Tetrahydropyranyl Ethers, Ram S. Mohan, Scott W. Krabbe, Veronica V. Angeles

Ram S. Mohan

A bismuth bromide-catalyzed (10.0 mol %) multicomponent reaction involving the allylation of THF- and THP-ethers, followed by in situ derivatization with acetic anhydride to generate highly functionalized esters has been developed under solvent-free conditions. To the best of our knowledge, this is the first report of a catalytic procedure for the allylation of THF- and THP-ethers to yield ring-opened products.


Impact Of The Australia-Us Free Trade Agreement On Australian Medicines Regulation And Prices, Thomas A. Faunce, James Bai, Duy Nguyen 2009 Australian National University

Impact Of The Australia-Us Free Trade Agreement On Australian Medicines Regulation And Prices, Thomas A. Faunce, James Bai, Duy Nguyen

Thomas A Faunce

The Australia – United States Free Trade Agreement (AUSFTA) came into force on 1 January 2005. Before and subsequently to the AUSFTA being concluded, controversy surrounded the debate over its impact on Australia ’ s health policy, specifically on regulation of pharmaceutical patents and Australia ’ s cost-effectiveness system relating to prescription medicine prices known as the Pharmaceutical Benefits Scheme (PBS). This article examines the expectations of both parties in the pharmaceutical sector with regard to the AUSFTA, as well as how successfully they were achieved. It seeks to analyse important relevant outcomes for regulators, the public and pharmaceutical industry, as well as ...


Nanotechnology And The International Law Of Weaponry: Towards International Regulation Of Nano-Weapons., Thomas A. Faunce, Hitoshi Nasu 2009 Australian National University

Nanotechnology And The International Law Of Weaponry: Towards International Regulation Of Nano-Weapons., Thomas A. Faunce, Hitoshi Nasu

Thomas A Faunce

The development of nanotechnology for military application is an emerging area of research and development, the pace and extent of which has not been fully anticipated by international legal regulation. Nano-weapons are referred to here as objects and devices using nanotechnology or causing effects in nano-scale that are designed or used for harming humans. Such weapons, despite their controversial human and environmental toxicity, are not comprehensively covered by specific, targeted regulation under international law. This article critically examines current international humanitarian law and arms control law regimes to determine whether significant gaps exist in the regulation of nanotechnology focused on ...


Interdependence Of In-Cell Xenon Density And Temperature During Rb/129xe Spin-Exchange Optical Pumping Using Vhg-Narrowed Laser Diode Arrays, Nicholas Whiting, Panayiotis Nikolaou, Neil A. Eschmann, Michael J. Barlow, Boyd M. Goodson 2009 Rowan University

Interdependence Of In-Cell Xenon Density And Temperature During Rb/129xe Spin-Exchange Optical Pumping Using Vhg-Narrowed Laser Diode Arrays, Nicholas Whiting, Panayiotis Nikolaou, Neil A. Eschmann, Michael J. Barlow, Boyd M. Goodson

Nicholas Whiting

The 129Xe nuclear spin polarization (PXe) that can be achieved via spin-exchange optical pumping (SEOP) is typically limited at high in-cell xenon densities ([Xe]cell), due primarily to corresponding reductions in the alkali metal electron spin polarization (e.g. PRb) caused by increased non-spin-conserving Rb–Xe collisions. While demonstrating the utility of volume holographic grating (VHG)-narrowed lasers for Rb/129Xe SEOP, we recently reported [P. Nikolaou et al., JMR 197 (2009) 249] an anomalous dependence of the observed PXe on the in-cell xenon partial pressure (pXe), wherein PXe values were abnormally low at decreased pXe, peaked at moderate pXe ...


New 2-Aminoethylimidazole-Based Dicarboxylic Acid Receptor Derived From Cholestane, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim 2009 Kyungpook National University

New 2-Aminoethylimidazole-Based Dicarboxylic Acid Receptor Derived From Cholestane, Jyoti Ramesh Jadhav, Md Wasi Ahmad, Hong Seok Kim

Dr. Mohammad Wasi Ahmad (Md Wasi Ahmad)

A new facial amphiphile cholestane-based receptor 1 containing a 2-imidazolylethylamino moiety at the 3a and 7a positions of cholestane was synthesized. Recognition selectivity of the new receptor 1 with various dicarboxylic acids was assessed by 1H NMR titration. Maleic acid showed the highest binding constant among all the tested acids


Molecular Characteristics Of Phosphoric Acid Treated Soils, Amin Eisazadeh, Khairul Anuar Kassim, Hadi Nur 2009 University Technology Malaysia

Molecular Characteristics Of Phosphoric Acid Treated Soils, Amin Eisazadeh, Khairul Anuar Kassim, Hadi Nur

Hadi Nur

The expansive nature of soils containing high amounts of clay minerals can be altered through chemical stabilization, resulting in a material suitable for construction purposes. The primary objective of this investigation was to study the changes induced in the molecular structure of phosphoric acid stabilized bentonite and lateritic soil using Nuclear Magnetic Resonance (NMR) and Fourier Transform Infrared (FTIR) spectroscopy. Based on the obtained data, it was found that a surface alteration mechanism was the main reason responsible for the improvement of treated soils. Furthermore, the results indicated that the Al present in the octahedral layer of clay minerals were ...


Physicochemical Characteristics Of Phosphoric Acid Stabilized Bentonite, Amin Eisazadeh, Khairul Anuar Kassim, Hadi Hadi 2009 University Technology Malaysia

Physicochemical Characteristics Of Phosphoric Acid Stabilized Bentonite, Amin Eisazadeh, Khairul Anuar Kassim, Hadi Hadi

Hadi Nur

The expansive nature of soils containing high amounts of montmorillonite mineral can be altered through chemical stabilization, resulting in a material suitable for construction purposes. In this paper, the physicochemical behaviour of phosphoric acid treated samples was studied using X-ray Diffractometry (XRD), Energy Dispersive X-ray Spectrometry (EDAX), Field Emission Scanning Electron Microscopy (FESEM), Fourier Transform Infrared Spectroscopy (FTIR), and Solid-State Nuclear Magnetic Resonance spectroscopy (SS-NMR). It was found that in acid stabilized montmorillonitic soil, clay alumina was more susceptible to dissolution and mostly responsible for the formation of aluminate phosphate hydrate compounds that bonded the soil particles together. Furthermore, since ...


Enhancement Of Brønsted Acidity In Sulfate-Vanadium Treated Silica-Titania Aerogel As Oxidative-Acidic Bifunctional Catalyst, Siew Ling Lee, Soo Chien Wei, Hadi Nur, Halimaton Hamdan 2009 University Technology Malaysia

Enhancement Of Brønsted Acidity In Sulfate-Vanadium Treated Silica-Titania Aerogel As Oxidative-Acidic Bifunctional Catalyst, Siew Ling Lee, Soo Chien Wei, Hadi Nur, Halimaton Hamdan

Hadi Nur

Enhancement of Brønsted acidity in silica-titania aerogel was achieved by loading both sulfate and vanadium onto the material. This phenomena could be due to formation of V(OSi)2OH-O-SO3 in the resulted sample. In contrast, no noticeable Brønsted acidity was detected in vanadium loaded silica-titania aerogel (V/ST). UV-vis DR analysis results showed that the amount of hydrated tetrahedral titanium species, which acts as oxidative site, increased significantly upon sulfation and vanadium loading on the surface of the aerogel. However, presence of vanadium in the samples tended to transform framework tetrahedral titanium to extra framework octahedral titanium structure. The catalytic ...


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