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Selected Works

Selected Works

2005

Articles 1 - 11 of 11

Full-Text Articles in Chemistry

1,4-Dimethyl-1,4-Diazoniabicyclo[2.2.2]Octane Diiodide Acetonitrile Solvate, Daron E. Janzen, Paul C. Ewbank, Kent R. Mann Nov 2005

1,4-Dimethyl-1,4-Diazoniabicyclo[2.2.2]Octane Diiodide Acetonitrile Solvate, Daron E. Janzen, Paul C. Ewbank, Kent R. Mann

Daron E Janzen, Ph.D.

No abstract provided.

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Application Of Correlation-Gas Chromatography To Evaluate The Vaporization Enthalpy Of A Component In An Equilibrium Mixture, Manuel Temprado, James S. Chickos Aug 2005

Application Of Correlation-Gas Chromatography To Evaluate The Vaporization Enthalpy Of A Component In An Equilibrium Mixture, Manuel Temprado, James S. Chickos

James Chickos

No abstract provided.

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Polymers With Pendant Coumarins: Synthesis And Characterization Of Polystyrenes And Polymethacrylates With Pendant Coumarin Moieties, T. Christopher Corkery Jun 2005

Polymers With Pendant Coumarins: Synthesis And Characterization Of Polystyrenes And Polymethacrylates With Pendant Coumarin Moieties, T. Christopher Corkery

Chris Corkery

No abstract provided.

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Amyloid-Β Protofibrils Differ From Amyloid-Β Aggregates Induced In Dilute Hexafluoroisopropanol In Stability And Morphology, Michael Nichols, Melissa A. Moss, Dana K. Reed, Stephanie Cratic-Mcdaniel, Jan H. Hoh, Terrone L. Rosenberry Jan 2005

Amyloid-Β Protofibrils Differ From Amyloid-Β Aggregates Induced In Dilute Hexafluoroisopropanol In Stability And Morphology, Michael Nichols, Melissa A. Moss, Dana K. Reed, Stephanie Cratic-Mcdaniel, Jan H. Hoh, Terrone L. Rosenberry

Michael Nichols

The brains of Alzheimer’s disease (AD) patients contain large numbers of amyloid plaques that are rich in fibrils composed of 40- and 42-residue amyloid-#1; (A#1;) peptides. Several lines of evidence indicate that fibrillar A#1; and especially soluble A#1; aggregates are important in the etiology of AD. Recent reports also stress that amyloid aggregates are polymorphic and that a single polypeptide can fold into multiple amyloid conformations. Here we demonstrate that A#1;-(1–40) can form soluble aggregates with predominant #1;-structures that differ in stability and morphology. One class of aggregates involved soluble A#1; protofibrils, prepared by vigorous overnight agitation of monomeric A#1;-(1–40) …

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Measurement Of The Vaporization Enthalpy Of Complex Mixtures By Correlation-Gas Chromatography. The Vaporization Enthalpy Of Rp-1, Jp-7, And Jp-8 Rocket And Jet Fuels At T = 298.15 K, James S. Chickos, Hui Zhao Jan 2005

Measurement Of The Vaporization Enthalpy Of Complex Mixtures By Correlation-Gas Chromatography. The Vaporization Enthalpy Of Rp-1, Jp-7, And Jp-8 Rocket And Jet Fuels At T = 298.15 K, James S. Chickos, Hui Zhao

James Chickos

No abstract provided.

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Cubane, Cuneane, And Their Carboxylates: A Calorimetric, Crystallographic, Calculational, And Conceptual Coinvestigation., Maria Victoria Roux, Juan Z. Davalos, Pilar Jimenez, Rafael Notario, Obis Castano, James S. Chickos, William Hanshaw, Hui Zhao, Nigam Rath, Joel F. Liebman, Behzad S. Farivar, A. Bashir-Hashemi Jan 2005

Cubane, Cuneane, And Their Carboxylates: A Calorimetric, Crystallographic, Calculational, And Conceptual Coinvestigation., Maria Victoria Roux, Juan Z. Davalos, Pilar Jimenez, Rafael Notario, Obis Castano, James S. Chickos, William Hanshaw, Hui Zhao, Nigam Rath, Joel F. Liebman, Behzad S. Farivar, A. Bashir-Hashemi

James Chickos

No abstract provided.

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The Thermochemistry Of 2,4-Pentanedione Revisited: Observance Of A Nonzero Enthalpy Of Mixing Between Tautomers And Its Effects On Enthalpies Of Formation, Manuel Temprado, Maria Victoria Roux, Patamaporn Umnahanant, Hui Zhao, James S. Chickos Jan 2005

The Thermochemistry Of 2,4-Pentanedione Revisited: Observance Of A Nonzero Enthalpy Of Mixing Between Tautomers And Its Effects On Enthalpies Of Formation, Manuel Temprado, Maria Victoria Roux, Patamaporn Umnahanant, Hui Zhao, James S. Chickos

James Chickos

No abstract provided.

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Environment Friendly Organic Synthesis Using Bismuth Compounds. An Efficient Method For Carbonyl-Ene Reactions Catalyzed By Bismuth Triflate, Ram S. Mohan, Erin D. Anderson, Justin J. Ernat, Mai P. Nguyen, Ann C. Palma Dec 2004

Environment Friendly Organic Synthesis Using Bismuth Compounds. An Efficient Method For Carbonyl-Ene Reactions Catalyzed By Bismuth Triflate, Ram S. Mohan, Erin D. Anderson, Justin J. Ernat, Mai P. Nguyen, Ann C. Palma

Ram S. Mohan

Bismuth triflate (0.1 mol %) is a highly efficient catalyst for the cyclization of citronellal 1, a reaction that yields a ratio of 80:20 of isopulegol 2 and neoisopulegol 3. This methodology has also been extended to the synthesis of substituted piperidines. The bismuth triflate catalyzed ene reaction of aldehyde 4 gives a 70:30 mixture of piperidines 5 and 6. The advantages of these methods include the use of a highly efficient catalyst that is relatively nontoxic, cheap and easy to handle.

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A Study Of Epoxyolefin Cyclizations Catalyzed By Bismuth Trifluoromethanesulfonate And Other Metal Triflates, Ram S. Mohan, Joshua R. Lacey, Peter W. Anzalone, Christopher M. Duncan, Matthew J. Hackert Dec 2004

A Study Of Epoxyolefin Cyclizations Catalyzed By Bismuth Trifluoromethanesulfonate And Other Metal Triflates, Ram S. Mohan, Joshua R. Lacey, Peter W. Anzalone, Christopher M. Duncan, Matthew J. Hackert

Ram S. Mohan

Epoxyolefin cyclizations have attracted considerable interest due to their importance in biosynthetic pathways. Bismuth trifluoromethanesulfonate as well as several other metal triflates are shown to be highly effective (0.1 mol %) catalysts for the cyclization of geraniolene oxide. The product composition is found to be more dependent on solvent and substrate concentration than on the nature of the metal triflate. Cyclization products are favored in CH2Cl2 and under high dilution conditions. Ether solvents favored acyclic products.

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The Discovery-Oriented Approach To Organic Chemistry. 6. Selective Reduction In Organic Chemistry: Reduction Of Aldehydes In The Presence Of Esters Using Sodium Borohydride, Ram S. Mohan, Ashvin R. Baru Dec 2004

The Discovery-Oriented Approach To Organic Chemistry. 6. Selective Reduction In Organic Chemistry: Reduction Of Aldehydes In The Presence Of Esters Using Sodium Borohydride, Ram S. Mohan, Ashvin R. Baru

Ram S. Mohan

Chemoselective reductions are valuable in organic synthesis and are routinely discussed in a sophomore organic chemistry course. Yet, there are few examples of laboratory experiments that illustrate such chemoselectivity. A reaction that is routinely discussed in sophomore organic chemistry is the selective reduction of aldehydes and ketones using sodium borohydride. Esters are typically not affected by NaBH4. However, none of the lab experiments reported to date illustrate this chemoselectivity (1). We have developed a discovery-oriented lab experiment that illustrates the chemoselective nature of reductions using sodium borohydride. The experiments involve the reduction of vanillin acetate (Scheme I) and methyl …

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Interactions Between Xenon And Phospholipid Bicelles Studied By 2h/129xe/131xe Nmr And Optical Pumping Of Nuclear Spins, Xiaoxia Li, Caitlin Newberry, Indrajit Saha, Panayiotis Nikolaou, Nicholas Whiting, Boyd M. Goodson Dec 2004

Interactions Between Xenon And Phospholipid Bicelles Studied By 2h/129xe/131xe Nmr And Optical Pumping Of Nuclear Spins, Xiaoxia Li, Caitlin Newberry, Indrajit Saha, Panayiotis Nikolaou, Nicholas Whiting, Boyd M. Goodson

Nicholas Whiting

The interactions between xenon and DMPC/DHPC bicelles (q = 3.5%,7.5% w/v) were studied via 2H, 129Xe, 131Xe, and optically enhanced 129Xe NMR. The chemical shifts, linewidths, and quadrupolar couplings of the xenon/bicelle NMR signals were correlated with different regions of the bicellar phase diagram. The addition of xenon (<70 mM) was observed to reduce the temperature-onset of bicelle alignment by several degrees, in quantitative agreement with effects previously observed with chloroform; however, the stable liquid-crystalline range was not significantly reduced. Preliminary laser-polarized xenon/bicelle studies yielded 129Xe T1 values of ~120 s, long enough to permit a variety of planned experiments.

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