Ditopic Dithiophosphonates And Their Related Rotaxanes, 2010 Eastern Illinois University
Ditopic Dithiophosphonates And Their Related Rotaxanes, Robert Ray Baum Jr.
No abstract provided.
Isomerization As A Key Path To Molecular Products In The Gas-Phase Decomposition Of Halons, 2010 Marquette University
Isomerization As A Key Path To Molecular Products In The Gas-Phase Decomposition Of Halons, Aimable Kalume, Lisa George, Scott Reid
Chemistry Faculty Research and Publications
The decomposition of halons remains controversial concerning the branching between radical and molecular products. The latter channel, where it has been found, is presumed to occur via a constrained symmetric multicenter transition state. Isomerization pathways in the gas-phase chemistry of halons have rarely been considered, despite the fact that the iso-halons, which feature a halogen−halogen bond, are widely recognized as important reactive intermediates in condensed phases. In this Letter, detailed calculations and modeling of the unimolecular decomposition of several important halons, including CF2Cl2, CF2Br2, and CHBr3, reveal that isomerization is a key ...
Synthesis Of Aza-Bridged Tetraphosphine Ligands For A Dirhodium Hydroformylation Catalyst, 2010 Louisiana State University and Agricultural and Mechanical College
Synthesis Of Aza-Bridged Tetraphosphine Ligands For A Dirhodium Hydroformylation Catalyst, Scott Michael Boudreaux
LSU Master's Theses
A novel tetraphosphine ligand rac-et,ph-P4 (et,ph-P4 = PEt2CH2CH2(Ph)PCH2P(Ph)CH2CH2PEt2) is used for the formation of a highly active and regioselective hydroformylation catalyst. The active catalytic species, Rh2H2(ƒÝ-CO)2(et,ph-P4)]2+, is formed in situ under H2/CO pressure. This is one of the most impressive examples of homobimetallic cooperativity in homogeneous catalysis. The fragmentation of this catalyst by CO has been investigated and confirmed by in situ NMR spectroscopic studies. A new tetraphosphine ligand rac-et,ph-P4-Ph (et,ph-P4-Ph = PEt2(o-C6H4)P(Ph)CH2(Ph)P(o-C6H4)PEt2) has been synthesized to combat this fragmentation ...
Molecular Dynamics Simulations Of Human Quadruplexes In K+ Solution And The Role Of The Carboxyl Terminus Of Bacteriorhodopsin In Protein Stability, Farah Rezae
Seton Hall University Dissertations and Theses (ETDs)
Analysis Of The Electron Withdrawing Capability Of Acetylene Groups For Promoting Nucleophilic Aromatic Substitution, Eric D. Braunstein
It is well known that electron withdrawing groups, such as nitro or carbonyl groups, activate benzene rings for nucleophilic aromatic substitution. However, little research has been done to investigate the electron withdrawing capability of acetylene groups for substitution of aromatic halides. Experimental and computational investigations on the reactivity of halogenated phenylacetylenes with oxygen and other nucleophiles will be described.
Energy Of The Conduction Band In Near Critical Point Fluids, 2010 CUNY Queens College
Energy Of The Conduction Band In Near Critical Point Fluids, Cherice M. Evans, G. L. Findley
Publications and Research
The study of the evolution of the conduction band in dense gases and supercritical fluids near the critical point has been complicated by a lack of precise experimental measurements. Both photoemission from an electrode immersed in the fluid and field ionization of a molecule doped into the fluid have been used to probe solvent density effects on the energy of an excess electron as a function of fluid number density and temperature. In this perspective, we present recent experimental results that show a strong critical point effect on the minimumconduction band energy near the critical density and temperature of a ...
Immobilization Of Motile Bacterial Cells Via Dip-Pen Nanolithography, 2010 Loyola University Chicago
Immobilization Of Motile Bacterial Cells Via Dip-Pen Nanolithography, Dorjderem Nyamjav, Sergey Rozhok, Richard C. Holz
Chemistry Faculty Research and Publications
A strategy to bind bacterial cells to surfaces in a directed fashion via dip-pen nanolithography (DPN) is presented. Cellular attachment to pre-designed DPN generated microarrays was found to be dependent on the shape and size of the surface feature. While this observation is likely due in part to a dense, well formed mercaptohexadecanoic acid (MHA) monolayer generated via DPN, it may also simply be due to the physical shape of the surface structure. Motile Pseudomonas aeruginosa bacterial cells were observed to bind to DPN generated mercaptohexadecanoic acid/poly-L-lysine (MHA/PLL) line patterns, 'blocks' made up of eight lines with 100 ...
Crossed-Beams And Theoretical Studies Of Hyperthermal Reactions Of O(3p) With Hcl, 2010 University of South Carolina - Columbia
Crossed-Beams And Theoretical Studies Of Hyperthermal Reactions Of O(3p) With Hcl, Jianming Zhang, Amy L. Brunsvold, Hari P. Upadhyaya, Timothy K. Minton, Jon P. Camden, Sophya V. Garashchuk, George C. Schatz
The reaction of O(3 P) with HCl at hyperthermal collision energies (45-116 kcal mol-1 ) has been investigated with crossed-molecular beams experiments and direct dynamics quasi-classical trajectory calculations. The reaction may proceed by two primary pathways, (1) H-atom abstraction to produce OH and Cl and (2) H-atom elimination to produce H and ClO. The H-atom abstraction reaction follows a stripping mechanism, in which the reagent O atom approaches the HCl molecule at large impact parameters and the OH product is scattered in the forward direction, defined as the initial direction of the reagent O atoms. The H-atom elimination reaction is ...
Tobacco Mosaic Virus Based Thin Film Sensor For Detection Of Volatile Organic Compounds, 2010 University of South Carolina - Columbia
Tobacco Mosaic Virus Based Thin Film Sensor For Detection Of Volatile Organic Compounds, M. A. Bruckman, J. Liu, G. Koley, Y. Li, Brian C. Benicewicz, Z. Niu, Qian Wang
A thin film sensor for the detection of volatile organic compounds (VOC) was fabricated by deposition of oligo-aniline grafted tobacco mosaic virus (TMV) onto a glass substrate. The oligo-aniline motifs were conjugated onto the TMV surface by a traditional diazonium coupling reaction to tyrosine residues followed by Cu(I) catalyzed alkyne-azide cycloaddition (CuAAC) reaction. The modified TMV was easily fabricated into a thin film by directly drop coating onto a glass substrate. Upon integration of the glass substrate into a prototypical device, the virus-based thin film exhibited good sensitivity and selectivity toward ethanol and methanol vapour.
Construction, Figures Of Merit And Testing Of A Single-Cell Fluorescence Excitation Spectroscopy System, 2010 University of South Carolina - Columbia
Construction, Figures Of Merit And Testing Of A Single-Cell Fluorescence Excitation Spectroscopy System, Laura S. Hill, Tammi L. Richardson, Louisa T.M. Profeta, Timothy J. Shaw, Christopher J. Hintz, Benjamin S. Twining, Evelyn Lawrenz, Micheal L. Myrick
Characterization of phytoplankton community composition is critical to understanding the ecology and biogeochemistry of the oceans. One approach to taxonomic characterization takes advantage of differing pigmentation between algal taxa and thus differences in fluorescence excitation spectra. Analyses of bulk water samples, however, may be confounded by interference from chromophoric dissolved organic matter or suspended particulate matter. Here, we describe an instrument that uses a laser trap based on a Nikon TE2000-U microscope to position individual phytoplankton cells for confocal fluorescence excitation spectroscopy, thus avoiding interference from the surrounding medium. Quantitative measurements of optical power give data in the form of ...
Silver Nanoparticle Polymer Composite Based Humidity Sensor, 2010 Technological University Dublin
Silver Nanoparticle Polymer Composite Based Humidity Sensor, Aoife Power, Tony Betts, John Cassidy
Silver nanoparticles were synthesised by a chemical reduction process in order to produce an aqueous colloidal dispersion. The resulting colloids were then characterised by a combination of UV-Vis spectroscopy, dynamic light scattering, X-ray diffraction and transmission electron microscopy and the nanoparticles were found to have an average diameter of 20–22 nm. The Ag/polymer nanocomposites were then applied to platinum interdigital electrodes as sensor coatings and the capability of the resulting sensor as a humidity detector investigated. With the application of 1 V, a current developed which was found to be directly proportional to humidity levels. The sensor gives ...
The Antioxidant Properties Of Whey Permeate Treated Fresh-Cut Tomatoes, 2010 Technological University Dublin
The Antioxidant Properties Of Whey Permeate Treated Fresh-Cut Tomatoes, Lubna Ahmed, Ana Belen Martin-Diana, Daniel Rico, Catherine Barry-Ryan
The aim of this research was to analyse the effects of three types of cheese whey permeate treatment on the antioxidant properties of fresh-cut tomatoes. Tomatoes were treated with whey permeate concentrate (PC), delactosed permeate (DP) and delactosed concentrate (DC), stored at 4 C for 10 days and compared to samples treated with the industry standard, chlorine (120 ppm). Samples treated with DP retained significantly higher antioxidant activity (FRAP) and total phenols (TP), when compared with those treated with PC and DC. DP showed significantly higher results than chlorine for DPPH, FRAP and TP. In DPPH assay, all whey permeate-treated ...
Technology For The Organic Chemist: Three Exploratory Modules, 2009 Butler University
Technology For The Organic Chemist: Three Exploratory Modules, John Esteb, Luanne Mcnulty, John Magers, Paul Morgan, Anne Wilson
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 ...
Excited Electronic States Of Auf, 2009 Macalester College
Excited Electronic States Of Auf, Elissa Butler, Benjamin Knurr, Kara Manke, Tyson Vervoort, Thomas Varberg
Thomas D. Varberg
No abstract provided.
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.
Total Synthesis Of Clathculins A And B, 2009 Macalester College
Total Synthesis Of Clathculins A And B, Rebecca Hoye, Gretchen Anderson, Susan Brown, Erica Schultz
Rebecca Hoye, Retired
No abstract provided.
Separating Sub-Ensembles On Ultrafast Timescales: Multiple Population-Period Transient Spectroscopy (Muppets), 2009 University of South Carolina
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
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, 2009 John Carroll University
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 ...
Bismuth Compounds In Organic Synthesis: Synthesis Of Dioxanes, Dioxepines, And Dioxolanes Catalyzed By Bismuth(Iii) Triflate, 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.