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Full-Text Articles in Physical Sciences and Mathematics

The Effect Of Ion-Pairing On The Open Circuit Potential Of 3-Mercaptoproprionic Acid Modified Gold Electrodes, Mark Anderson, Alice Harper Apr 2010

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 monolayer is studied …


New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer Apr 2010

New Chiral Phosphoramidite Complexes Of Iron As Catalytic Precursors In The Oxidation Of Activated Methylene Groups, Pushkar Shejwalkar, Nigam P. Rath, Eike B. Bauer

Nigam Rath

New phosphoramidite complexes of iron were synthesized and structurally characterized. Reaction of the known chiral phosphoramidites (RO)2PNR’2 (R = binaphthyl, R’ = CH3, 1a; R = binaphthyl, R’ = benzyl, 1b) with [FeBr(Cp)(CO)2] afforded the title compounds [FeBr(Cp)(CO)(1a,b)] (4a,b) in 34 and 65 % isolated yields as mixtures of diastereomers, since both the metal and the ligand are stereogenic. Similarly, reaction of 1b with [Fe(Cp)I(CO)2] in the presence of catalytic [Fe(Cp)(CO)2]2 afforded [Fe(Cp)I(CO)(1b)] (5b) in 81% yield as a mixture of diastereomers. The molecular structures of 4a, 4b and 5 were determined, revealing a pseudo octahedral coordination geometry about the …


The Synthesis Of A Cyclic Peptide Library For The Discovery Of Sickle-Cell Hemoglobin Ligands, Brian Brennan, Jeremy Henle, '11 Apr 2010

The Synthesis Of A Cyclic Peptide Library For The Discovery Of Sickle-Cell Hemoglobin Ligands, Brian Brennan, Jeremy Henle, '11

Brian B. Brennan

No abstract provided.


Study Of The Anomalous Thermochemical Behavior Of 1,2-Diazines By Correlation-Gas Chromatography, Dmitry Lipkind, James S. Chickos, Joel F. Liebman Apr 2010

Study Of The Anomalous Thermochemical Behavior Of 1,2-Diazines By Correlation-Gas Chromatography, Dmitry Lipkind, James S. Chickos, Joel F. Liebman

James Chickos

No abstract provided.


Ferrinaphth: A Fluorescent Chemodosimeter For Redox Active Metal Ions, Shawn Burdette, Randy Jackson, Yu Shi, Xudong Yao Mar 2010

Ferrinaphth: A Fluorescent Chemodosimeter For Redox Active Metal Ions, Shawn Burdette, Randy Jackson, Yu Shi, Xudong Yao

Shawn C. Burdette

FerriNaphth, a fluorescent chemodosimeter for FeIII, has been prepared and characterized. The probe consists of a catechol ligand linked to a naphthalimide fluorophore by an aniline nitrogen linker. Upon exposure to FeIII, the aminocatechol of FerriNaphth is oxidized to the corresponding quinone, which in its imine-one tautomer, is hydrolyzed to liberate a fluorescent aminonaphthalimide derivative. The fluorescence behavior is consistent with oxidation being promoted by metal coordination.


Antimicrobial And Antioxidant Activities Of Essential Oil And Methanol Extract Of Jasminum Sambac From Djibouti, Fatou Abdoul-Latif, Prosper Edou, François Eba, Nabil Mohamed, Adwa Ali, Samatar Djama, Louis-Clément Obame, Mamoudou Hama Dicko Mar 2010

Antimicrobial And Antioxidant Activities Of Essential Oil And Methanol Extract Of Jasminum Sambac From Djibouti, Fatou Abdoul-Latif, Prosper Edou, François Eba, Nabil Mohamed, Adwa Ali, Samatar Djama, Louis-Clément Obame, Mamoudou Hama Dicko

Pr. Mamoudou H. DICKO, PhD

The essential oil of jasminum sambac from Djibouti was subjected to screening for their possible antioxidant activity by two complementary test systems, namely DPPH free radical scavenging and beta-carotene-linoleic acid assays. Butylated hydroxytoluene (BHT) was used as positive control in both test systems. In the DPPH test system, the IC50 value of essential oil and methanol extract were respectively 7.43 and 2.30 μg/ml. In the beta-carotene-linoleic acid system, oxidation was effectively inhibited by Jasminum sambac, the RAA value of essential oil and methanol extract were respectively 96.6 and 93.9%. When compared to BHT, the essential oil and methanol extract had …


Targeting Prostate Cancer Cells In Vivo Using A Rapidly Internalizing Novel Human Single-Chain Antibody Fragment., Arun K. Iyer Feb 2010

Targeting Prostate Cancer Cells In Vivo Using A Rapidly Internalizing Novel Human Single-Chain Antibody Fragment., Arun K. Iyer

Arun Iyer

Human antibodies targeting prostate cancer cell surface epitopes may be useful for imaging and therapy. The objective of this study was to evaluate the tumor targeting of an internalizing human antibody fragment, a small-size platform, to provide high contrast in a mouse model of human prostate carcinoma. METHODS: A prostate tumor-targeting single-chain antibody fragment (scFv), UA20, along with a nonbinding control scFv, N3M2, were labeled with (99m)Tc and evaluated for binding and rapid internalization into human prostate tumor cells in vitro and tumor homing in vivo using xenograft models. For the in vitro studies, the labeled UA20 scFv was incubated …


Beethoven: Patriotism And Social Justice, Fathi Habashi Feb 2010

Beethoven: Patriotism And Social Justice, Fathi Habashi

Fathi Habashi

The great composer Ludwig van Beethoven was not only an exceptional musician but also a man of great ideals who expressed social justice in his music


Potential Driven Deposition Of Polyelectrolytes Onto The Surface Of Cysteine Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson Feb 2010

Potential Driven Deposition Of Polyelectrolytes Onto The Surface Of Cysteine Monolayers Assembled On Gold, Wesley Sanders, Mark Anderson

Mark R. Anderson

Electrochemical impedance spectroscopy and the quartz crystal microbalance measurements are used to examine the ability of potential applied to a substrate to create, in situ, conditions favorable for the electrostatic deposition of polyelectrolytes onto a gold substrate modified by the self-assembly of cysteine. Cysteine is a zwitterionic compound that, when confined to a substrate, has the ability to establish either a net positive or a net negative interfacial charge, depending on the conditions. As such, cysteine modified interfaces could possibly be used as a versatile substrate for deposition of either cationic or anionic polyelectrolytes. The potential of zero charge of …


Synthesis And Characterization Of Allylic Dinuclear Molybdenum Complexes With Bridging Oxygen And Sulfur Containing Ligands., Mazin Shatnawi, Samer Tanash, Saleem Al-Ahmad, Paul Challen, Gerald Henkel Feb 2010

Synthesis And Characterization Of Allylic Dinuclear Molybdenum Complexes With Bridging Oxygen And Sulfur Containing Ligands., Mazin Shatnawi, Samer Tanash, Saleem Al-Ahmad, Paul Challen, Gerald Henkel

Paul R. Challen

No abstract provided.


An Examination Of Factors Influencing The Thermodynamics Of Correlation-Gas Chromatography As Applied To Large Molecules And Chiral Separations, Dmitry Lipkind, James S. Chickos Feb 2010

An Examination Of Factors Influencing The Thermodynamics Of Correlation-Gas Chromatography As Applied To Large Molecules And Chiral Separations, Dmitry Lipkind, James S. Chickos

James Chickos

No abstract provided.


Phase Transition Enthalpy Measurements Of Organic And Organometallic Compounds. Sublimation, Vaporization And Fusion Enthalpies From 1880 To 2010, William E. Acree, James S. Chickos Jan 2010

Phase Transition Enthalpy Measurements Of Organic And Organometallic Compounds. Sublimation, Vaporization And Fusion Enthalpies From 1880 To 2010, William E. Acree, James S. Chickos

James Chickos

No abstract provided.


Technology For The Organic Chemist: Three Exploratory Modules, John Esteb, Luanne Mcnulty, John Magers, Paul Morgan, Anne Wilson Dec 2009

Technology For The Organic Chemist: Three Exploratory Modules, John Esteb, Luanne Mcnulty, John Magers, Paul Morgan, Anne Wilson

John Esteb

The ability to use computer-based technology is an essential skill set for students majoring in chemistry. This exercise details the introduction of appropriate uses for this technology in the organic chemistry series. The incorporation of chemically appropriate online resources (module 1), scientific databases (module 2), and the use of a chemical drawing program (module 3) are detailed here.

Note: Link is to the article in a subscription database available to users affiliated with Butler University. Appropriate login information will be required for access. Users not affiliated with Butler University should contact their local librarian for assistance in locating a copy …


Bismuth(Iii) Triflate Catalyzed Allylation Of Cyclic Acetals And Dithianes Followed By In Situ Derivatization To Generate Highly Functionalized Esters, Ram Mohan, Scott Krabbe, Matthew Spafford Dec 2009

Bismuth(Iii) Triflate Catalyzed Allylation Of Cyclic Acetals And Dithianes Followed By In Situ Derivatization To Generate Highly Functionalized Esters, Ram Mohan, Scott Krabbe, Matthew Spafford

Ram S. Mohan

No abstract provided.


Separating Sub-Ensembles On Ultrafast Timescales: Multiple Population-Period Transient Spectroscopy (Muppets), Kalyanasis Sahu, Sean Kern, Mark Berg Dec 2009

Separating Sub-Ensembles On Ultrafast Timescales: Multiple Population-Period Transient Spectroscopy (Muppets), Kalyanasis Sahu, Sean Kern, Mark Berg

Sean J. Kern

No abstract provided.


Electrochemical Glucose Sensors—Developments Using Electrostatic Assembly And Carbon Nanotubes For Biosensor Construction, Alice Harper, Mark Anderson Dec 2009

Electrochemical Glucose Sensors—Developments Using Electrostatic Assembly And Carbon Nanotubes For Biosensor Construction, Alice Harper, Mark Anderson

Mark R. Anderson

In 1962, Clark and Lyons proposed incorporating the enzyme glucose oxidase in the construction of an electrochemical sensor for glucose in blood plasma. In their application, Clark and Lyons describe an electrode in which a membrane permeable to glucose traps a small volume of solution containing the enzyme adjacent to a pH electrode, and the presence of glucose is detected by the change in the electrode potential that occurs when glucose reacts with the enzyme in this volume of solution. Although described nearly 50 years ago, this seminal development provides the general structure for constructing electrochemical glucose sensors that is …


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

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

Michael A Nichols

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 real …


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 Dec 2009

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 Dec 2009

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 monolayer is studied …


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

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 real …


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 Dec 2009

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 Dec 2009

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 Dec 2009

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 Dec 2009

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 Dec 2009

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 Dec 2009

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, …


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

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 Dec 2009

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 (~300 torr), and remained surprisingly …


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

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


Degradation Of Organic Pollutants In Domestic Wastewaters By Concrete Plates Containing Of Photocatalyst Nanoparticles, Masoud Rastegar Dec 2009

Degradation Of Organic Pollutants In Domestic Wastewaters By Concrete Plates Containing Of Photocatalyst Nanoparticles, Masoud Rastegar

Masoud Rastegar

No abstract provided.