Chemistry Commons^™

A Dilute-And-Shoot Flow-Injection Tandem Mass Spectrometry Method For Quantification Of Phenobarbital In Urine, Ravali Alagandula, Xiang Zhou, Baochuan Guo

Chemistry Faculty Publications

RATIONALE: Liquid chromatography/tandem mass spectrometry (LC/MS/MS) is the gold standard of urine drug testing. However, current LC-based methods are time consuming, limiting the throughput of MS-based testing and increasing the cost. This is particularly problematic for quantification of drugs such as phenobarbital, which is often analyzed in a separate run because they must be negatively ionized.

METHODS: This study examined the feasibility of using a dilute-and-shoot flow-injection method without LC separation to quantify drugs with phenobarbital as a model system. Briefly, a urine sample containing phenobarbital was first diluted by 10 times, followed by flow injection of the diluted sample …

Neutral And Cationic Bis-Chelate Monoorganosilicon(Iv) Complexes Of 1-Hydroxy-2-Pyridinone, James Koch, William W. Brennessel, Bradley M. Kraft

Chemistry Faculty/Staff Publications

A series of spirocyclic monoorganosilicon compounds of the form RSi(OPO)₂Cl [R = phenyl (1); p-tolyl (2); benzyl (3); Me (4); ^tBu (5); thexyl (6)] (OPO = 1-oxo-2-pyridinone) was synthesized and characterized by ¹H , ¹³C, and ²⁹Si NMR spectroscopy, X-ray crystallography, and elemental analysis. In the solid state, complexes 1, 2, and 3 are neutral and possess cis-OPO ligands in an octahedral arrangement, and complexes 4, 5, and 6 are cationic and possess effectively trans­-OPO …

Cyclipostins And Cyclophostin Analogs As Promising Compounds In The Fight Against Tuberculosis, Phuong Nguyen, Vincent Delorme, Anaïs Bénarouche, Benjamin Martin, Rishi Paudel, Giri Gnawali, Abdeldjalil Madani, Rémy Puppo, Valérie Landry, Laurent Kremer, Priscille Brodin, Christopher Spilling, Jean-François Cavalier, Stéphane Canaan

Chemistry & Biochemistry Faculty Works

A new class of Cyclophostin and Cyclipostins (CyC) analogs have been investigated against Mycobacterium tuberculosis H37Rv (M. tb) grown either in broth medium or inside macrophages. Our compounds displayed a diversity of action by acting either on extracellular M. tb bacterial growth only, or both intracellularly on infected macrophages as well as extracellularly on bacterial growth with very low toxicity towards host macrophages. Among the eight potential CyCs identified, CyC 17 exhibited the best extracellular antitubercular activity (MIC50 = 500 nM). This compound was selected and further used in a competitive labelling/enrichment assay against the activity-based probe Desthiobiotin-FP in order …

The Statistical Mechanics Of Solar Wind Hydroxylation At The Moon, Within Lunar Magnetic Anomalies, And At Phobos, W. M. Farrell, D. M. Hurley, Vincent J. Esposito, J. L. Mclain, M. I. Zimmerman

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We present a new formalism to describe the outgassing of hydrogen initially implanted by the solar wind protons into exposed soils on airless bodies. The formalism applies a statistical mechanics approach similar to that applied recently to molecular adsorption onto activated surfaces. The key element enabling this formalism is the recognition that the interatomic potential between the implanted H and regolith-residing oxides is not of singular value but possess a distribution of trapped energy values at a given temperature, F(U,T). All subsequent derivations of the outward diffusion and H retention rely on the specific properties of this distribution. We …

Regenerative Electroless Etching Of Silicon, Kurt W. Kolasinski, Nathan J. Gimbar, Haibo Yu, Mark Aindow, Ermei Mäkilä, Jarno Salonen

Chemistry Faculty Publications

Regenerative electroless etching (ReEtching), described herein for the first time, is a method of producing nanostructured semiconductors in which an oxidant (Ox1) is used as a catalytic agent to facilitate the reaction between a semiconductor and a second oxidant (Ox2) that would be unreactive in the primary reaction. Ox2 is used to regenerate Ox1, which is capable of initiating etching by injecting holes into the semiconductor valence band. Therefore, the extent of reaction is controlled by the amount of Ox2 added, and the rate of reaction is controlled by the injection rate of Ox2. This general strategy is demonstrated specifically …

Palladium-Catalyzed Intramolecular Cross-Dehydrogenative Coupling: Synthesis Of Fused Imidazo[1,2‑A]Pyrimidines And Pyrazolo[1,5‑A]Pyrimidines, Siva K. Reddy Kotla, Jaya Kishore Vandavasi, Jeh-Jeh Wang, Keykavous Parang, Rakesh Tiwari

Pharmacy Faculty Articles and Research

A palladium-catalyzed intramolecular dehydrogenative coupling reaction was developed for the synthesis of fused imidazo[1,2-a]pyrimidines and pyrazolo[1,5-a]- pyrimidines. The developed protocol provides a practical approach for the synthesis of biologically important substituted pyrimidines from easily available substrates, with a broad substrate scope under mild reaction conditions.

Nitroxide-Based Macromolecular Contrast Agents With Unprecedented Transverse Relaxivity And Stability For Magnetic Resonance Imaging Of Tumors, Hung V.T. Nguyen, Qixian Chen, Joseph T. Paletta, Peter Harvey, Yivan Jiang, Hui Zhang, Michael Boska, M. Francesca Ottaviani, Alan Jasanoff, Andrzej Rajca, Jeremiah A. Johnson

Andrzej Rajca Publications

Metal-free magnetic resonance imaging (MRI) agents could overcome the established toxicity associated with metal-based agents in some patient populations and enable new modes of functional MRI in vivo. Herein, we report nitroxidefunctionalized brush-arm star polymer organic radical contrast agents (BASP-ORCAs) that overcome the low contrast and poor in vivo stability associated with nitroxide-based MRI contrast agents. As a consequence of their unique nanoarchitectures, BASP-ORCAs possess per-nitroxide transverse relaxivities up to ∼44-fold greater than common nitroxides, exceptional stability in highly reducing environments, and low toxicity. These features combine to provide for accumulation of a sufficient concentration of BASP-ORCA in murine subcutaneous …

Geometry-Driven Folding Of A Floating Annular Sheet, Joseph Paulsen, Vincent Démery, K. Buğra Toga, Zhanlong Qiu, Thomas P. Russell, Benny Davidovitch, Narayanan Menon

Physics - All Scholarship

Predicting the large-amplitude deformations of thin elastic sheets is difficult due to the complications of self contact, geometric nonlinearities, and a multitude of low-lying energy states. We study a simple twodimensional setting where an annular polymer sheet floating on an air-water interface is subjected to different tensions on the inner and outer rims. The sheet folds and wrinkles into many distinct morphologies that break axisymmetry. These states can be understood within a recent geometric approach for determining the gross shape of extremely bendable yet inextensible sheets by extremizing an appropriate area functional. Our analysis explains the remarkable feature that the …

Unusual Acylation Of Chloramphenicol In Lysobacter Enzymogenes, A Biocontrol Agent With Intrinsic Resistance To Multiple Antibiotics, Wei Zhang, Justin Huffman, Shengying Li, Yuemao Shen, Liangcheng Du

Liangcheng Du Publications

Background: The environmental gliding bacteria Lysobacter are emerging as a new group of biocontrol agents due to their prolific production of lytic enzymes and potent antibiotic natural products. These bacteria are intrinsically resistant to many antibiotics, but the mechanisms behind the antibiotic resistance have not been investigated.

Results: Previously, we have used chloramphenicol acetyltransferase gene (cat) as a selection marker in genetic manipulation of natural product biosynthetic genes in Lysobacter, because chloramphenicol is one of the two common antibiotics that Lysobacter are susceptible to. Here, we found L. enzymogenes, the most studied species of this genus, could …

Solar Energy Storage Using Earth-Abundant Materials, Christopher W. Roske

Link Foundation Energy Fellowship Reports

Among alternative energy technologies, solar is well suited to meet the grand energy challenge ahead if we can overcome the intermittent supply of sunlight.1,2 Storing solar energy in chemical bonds serves as an attractive technical solution that requires selecting suitable chemical reactions and building tailored systems.3 Many research groups are aiming to electrochemically reduce carbon dioxide to a solar fuel, such as ethanol, or split water into hydrogen and oxygen gas, but these groups have been unable to design efficient and cheap systems that navigate these complex multi-step chemical transformations without encountering significant parasitic overpotentials.4 While we fully expect further …

Monitoring A Simple Hydrolysis Process In An Organic Solid By Observing Methyl Group Rotation, Peter A. Beckmann, Joseph M. Bohen, Jamie Ford, William P. Malachowski, Clelia W. Mallory, Frank B. Mallory, Andrew R. Mcghie, Arnold L. Rheingold, Gilbert J. Sloan, Steven T. Szewczyk, Xianlong Wang, Kraig A. Wheeler

Physics Faculty Research and Scholarship

We report a variety of experiments and calculations and their interpretations regarding methyl group (CH3) rotation in samples of pure 3-methylglutaric anhydride (1), pure 3-methylglutaric acid (2), and samples where the anhydride is slowly absorbing water from the air and converting to the acid [C6H8O3(1) + H2O → C6H10O4(2)]. The techniques are solid state 1H nuclear magnetic resonance (NMR) spin-lattice relaxation, single-crystal X-ray diffraction, electronic structure calculations in both isolated molecules and in clusters of molecules that mimic the crystal structure, field emission scanning electron microscopy, differential scanning calorimetry, and high resolution …

A Redox-Neutral Catechol Synthesis, Q. Wu, D. Yan, Y. Chen, T. Wang, F. Xiong, W. Wei, Y. Lu, W. Sun, Jie Jack Li, J. Zhao

Chemistry Faculty Publications

Ubiquitous tyrosinase catalyses the aerobic oxidation of phenols to catechols through the binuclear copper centres. Here, inspired by the Fischer indole synthesis, we report an iridium-catalysed tyrosinase-like approach to catechols, employing an oxyacetamide-directed C–H hydroxylation on phenols. This method achieves one-step, redox-neutral synthesis of catechols with diverse substituent groups under mild conditions. Mechanistic studies confirm that the directing group (DG) oxyacetamide acts as the oxygen source. This strategy has been applied to the synthesis of different important catechols with fluorescent property and bioactivity from the corresponding phenols. Finally, our method also provides a convenient route to ¹⁸O-labelled catechols using …

Binding Mode Analyses Of Nap Derivatives As Mu Opioid Receptor Selective Ligands Through Docking Studies And Molecular Dynamics Simulation, Huiqun Wang, Saheem A. Zaidi, Yan Zhang

Chemistry Publications

Mu opioid receptor selective antagonists are highly desirable because of their utility as pharmacological probes for receptor characterization and functional studies. Furthermore, the mu opioid receptors act as an important target in drug abuse and addiction treatment. Previously, we reported NAP as a novel lead compound with high selectivity and affinity towards the mu opioid receptor. Based on NAP, we have synthesized its derivatives and further characterized their binding affinities and selectivity towards the receptor. NMP and NGP were identified as the two most selective MOR ligands among NAP derivatives. In the present study, molecular modeling methods were applied to …

Special Topic 1: Chemical Evolution- A Possible Origin Of Life, Gordon Gribble

Chemistry 52, Gordon Gribble lectures on Special Topics

No abstract provided.

Special Topic 3, Part 1: Pesticides: Natural And Manmade Pesticides, Gordon Gribble

Chemistry 52, Gordon Gribble lectures on Special Topics

No abstract provided.

Special Topic 5: Chemical Warfare, Gordon Gribble

Chemistry 52, Gordon Gribble lectures on Special Topics

No abstract provided.

The Synthesis And Characterization Of Double And Triple Tethered Indeno[2.1-C]Fluorendiones, Daniel K. Greene

Browse all Theses and Dissertations

A series of terephthalate esters was synthesized via a Diels-Alder reaction between 2,5-dicarboethoxy-3,4-diphenylcyclopentadienone and various alkynes in order to study reaction conditions necessary to synthesize poly(indeno[2,1-c]fluorene-5,8-dione)s. Diethyl 2,3-diphenyl-5-butylterephthalate, 1,4-bis(3,4-diphenyl-2,5-di(ethoxycarbonyl) phenyl)butane and N,N,N-tris(3,4-diphenyl-2,5-di(ethoxycarbonyl)phenylmethyl)amine were synthesized and characterized by IR, 1H NMR, 13C NMR, 13C NMR DEPT135 spectroscopies as well as elemental composition. Hydrolysis conditions of the terephthalates using potassium hydroxide were also investigated. It was found that large stoichiometric equivalents of base coupled with reaction times over twenty-four hours afforded only partially hydrolyzed products. The synthesis of 6-butylindeno[2,1-c]fluoren-5,8-dione was successfully carried out by the sulfuric acid catalyzed, intramolecular, Friedel-Crafts cyclization of …

Special Topic 2: Insect Pheromones, Supporting Images 1, Gordon Gribble

Chemistry 52, Gordon Gribble lectures on Special Topics

No abstract provided.

Synthesis And Reactivity Of Sydnone Derived 1,3,4-Oxadiazol-2(3h)-Ones, Jonathan Michael Tumey

Browse all Theses and Dissertations

5-(Bromomethyl)- and 5-(trichloromethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-ones were synthesized from bromocarbonyl hydrazine intermediate salts and acid halides to provide further evidence for our proposed mechanism for the formation of oxadiazolone ring systems from sydnones. 5-(Bromomethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-one was a compound of interest due to its SN2 possibilities and three potential sites of diversification. The procedure to synthesize 5-(bromomethyl)-3-phenyl-1,3,4-oxadiazol-2(3H)-one was developed originally by Madaram in the Turnbull lab, but was further optimized in the present work by altering the time, temperature and stoichiometric equivalents of the acid halide to provide high purity and excellent yields of the product. While this compound of interest had been isolated and …

Synthesis Of Sialic Acid Derivatives And Their Immune Cells Modulation, Joseph Keil, Lei Yuan, Yu Zhao

Undergraduate Research Posters 2017

The exterior cell surfaces of macrophages express a dense layer of glycans which are often terminated by sialic acid. Sialic acid is an acidic monosaccharide whose presence on the terminal ends of glycans affects cellular function and properties. In particular, due to its hydrophilic and electronegative features, SAs play important roles in both physiological and pathological processes, such as in regulating cellular interactions with ligands, microbes and neighboring cells and in controlling cellular activation, differentiation, transformation and migration. In this study two sialic acid derivatives were synthesized and characterized, the 5 amine derivative and the 9 amine derivative. This study …

Special Topic 2: Insect Pheromones And Chemical Defense Secretions, Gordon Gribble

Chemistry 52, Gordon Gribble lectures on Special Topics

No abstract provided.

Introduction To Special Topics, Gordon Gribble

Chemistry 52, Gordon Gribble lectures on Special Topics

No abstract provided.

Special Topic 4: Cancer And Chemical Carcinogenesis, Gordon Gribble

Chemistry 52, Gordon Gribble lectures on Special Topics

No abstract provided.

Special Topic 2: Insect Pheromones, Supporting Images 2, Gordon Gribble

Chemistry 52, Gordon Gribble lectures on Special Topics

No abstract provided.

Observations Of Bromine Monoxide Transport In The Arctic Sustained On Aerosol Particles, Peter K. Peterson, Denis Pöhler, Holger Sihler, Johannes Zielcke, Stephan General, Udo Frieß, Ulrich Platt, William R. Simpson, Son V. Nghiem, Paul B. Shepson, Brian H. Stirm, Suresh Dhaniyala, Thomas Wagner, Dana R. Caulton, Jose D. Fuentes, Kerri A. Platt

Chemistry

The return of sunlight in the polar spring leads to the production of reactive halogen species from the surface snowpack, significantly altering the chemical composition of the Arctic near-surface atmosphere and the fate of long-range transported pollutants, including mercury. Recent work has shown the initial production of reactive bromine at the Arctic surface snowpack; however, we have limited knowledge of the vertical extent of this chemistry, as well as the lifetime and possible transport of reactive bromine aloft. Here, we present bromine monoxide (BrO) and aerosol particle measurements obtained during the March 2012 BRomine Ozone Mercury EXperiment (BROMEX) near Utqiaġvik …

Snowmelt Onset Hinders Bromine Monoxide Heterogeneous Recycling In The Arctic, Peter K. Peterson, Justine A. Burd, Son V. Nghiem, Don K. Perovich, William R. Simpson

Chemistry

Reactive bromine radicals (bromine atoms, Br, and bromine monoxide, BrO) deplete ozone and alter tropospheric oxidation chemistry during the Arctic springtime (February–June). As spring transitions to summer (May–June) and snow begins to melt, reactive bromine events cease and BrO becomes low in summer. In this study, we explore the relationship between the end of the reactive bromine season and snowmelt timing. BrO was measured by Multi-AXis Differential Optical Absorption Spectrometer at Utqiaġvik (Barrow), AK, from 2012 to 2016 and on drifting buoys deployed in Arctic sea ice from 2011 to 2016, a total of 13 site and year combinations. The …

Horizontal And Vertical Structure Of Reactive Bromine Events Probed By Bromine Monoxide Max-Doas Spectroscopy, Peter K. Peterson, William R. Simpson, Udo Frieß, Holger Sihler, Johannes Lampel, Ulrich Platt, Chris Moore, Kerri Platt, Paul Shepson, John Halfacre, Son V. Nghiem

Chemistry

Heterogeneous photochemistry converts bromide (Br−) to reactive bromine species (Br atoms and bromine monoxide, BrO) that dominate Arctic springtime chemistry. This phenomenon has many impacts such as boundary-layer ozone depletion, mercury oxidation and deposition, and modification of the fate of hydrocarbon species. To study environmental controls on reactive bromine events, the BRomine, Ozone, and Mercury EXperiment (BROMEX) was carried out from early March to mid-April 2012 near Barrow (Utqiaġvik), Alaska. We measured horizontal and vertical gradients in BrO with multiple-axis differential optical absorption spectroscopy (MAX-DOAS) instrumentation at three sites, two mobile and one …

Flipped Learning In Synchronously-Delivered, Geographically-Dispersed General Chemistry Classrooms, Michael A. Christiansen, Louis Nadelson, Lianna K. Etchberger, Marilyn M. Cuch, Trish A. Kingsford, Leslie O. Woodward

Chemistry and Biochemistry Faculty Publications

In synchronously-delivered, multi-site classrooms, the physical separation between distance students and instructors may create a perceived divide that negatively affects learning. Building on prior experience in flipping organic chemistry in single-site face-to-face (F2F) classes, we decided to extend our approach to multi-site, synchronously-delivered general chemistry courses. Our thought was to narrow the perceived instructor-student divide in distance teaching by using the flexible in-class time that flipping affords to increase the number of positive teacher/distance-student interactions. In this effort, we gradually developed a technique called “bridging questions,” through which the instructor becomes more familiar with student interests and then connects those …

Highly Porous Photoluminescent Diazaborole-Linked Polymers: Synthesis, Characterization, And Application To Selective Gas Adsorption, Zafer Kahveci, Ali K. Sekizkardes, Ravi K. Arvapally, Logan Wilder, Hani M. El-Kaderi

Chemistry Publications

The formation of boron–nitrogen (B–N) bonds has been widely explored for the synthesis of small molecules, oligomers, or linear polymers; however, its use in constructing porous organic frameworks remains very scarce. In this study, three highly porous diazaborole-linked polymers (DBLPs) have been synthesized by condensation reactions using 2,3,6,7,14,15-hexaaminotriptycene and aryl boronic acids. DBLPs are microporous and exhibit high Brunauer–Emmett–Teller surface area (730–986 m2 g−1) which enable their use in small gas storage and separation. At ambient pressure, the amorphous polymers show high CO2 (DBLP-4: 4.5 mmol g−1 at 273 K) and H2 (DBLP-3: 2.13 wt% at 77 K) uptake while …

Incorporation Of Indeno[2,1-C]Fluorenes Into Polymers Via Nucleophilic Aromatic Substitution, Nathaniel Brackett

Browse all Theses and Dissertations

A difluoro indeno[2,1-c]fluorene monomer was synthesized by a four-step process. The first compound synthesized by a two-step process was 2,5- bis(ethoxycarbonyl)-3,4-di(4-fluorophenyl)cyclopentadienone. The next two compounds synthesized were diethyl 2,3-bis(fluorophenyl)-5-hexylterephthalate and 2,3- bis(fluorophenyl)-5-hexylterephthalic acid. The final step involved an intramolecular Friedel-Crafts acylation of the terephthalic acid derivative to form 3,10-difluoro-5,8- dioxo-5,8-dihydro-6-hexylindeno[2,1-c]fluorene. The difluoro monomer was reacted in a series of nucleophilic aromatic substitution (NAS) polymerization reactions with bisphenol-A in N-methyl-pyrrolidone (NMP) in an attempt to form novel poly(ether ether ketone ketone)s containing the indeno[2,1-c]fluorene structure. Analysis of the product by NMR and TLC showed the reaction was unsuccessful and the difluoro …