Chemistry Commons^™

C-2/C-3 Annulation And C-2 Alkylation Of Indoles With 2-Alkoxycyclopropanoate Esters., Barbora Bajtos, Ming Yu, Hongda Zhao, Brian L Pagenkopf

Chemistry Publications

The annulation reaction between various indoles and 2-alkoxycyclopropanoate esters is reported. Both high efficiency and complete stereochemical control were observed in some cases with this annulation process. A single stereocenter on the cyclopropane controls the diastereoselective formation of up to four new stereocenters. A different reaction course was observed with 3-substituted indole substrates, and an intervening C-3 to C-2-migration process arose that gives synthetically useful C-2 alkylation indole products.

Synthesis And Structural Characterization Of Two Five Coordinate Aluminum Alkyl And Bis(Trimethylsilyl)Amino Complexes Bearing Acyclic Tetradentate Schiff Bases, C. R. Wade, B. J. Lamprecht, V. W. Day, John A. Belot

Department of Chemistry: Faculty Publications

Two acyclic Schiff-base ligands, bis-5,5′-(1,3-propanediyldiimino)-2,2-dimethyl-4-hexene-3-one and bis-5,5′-(1,3-ethanediyldiimino)- 2,2-dimethyl-4-hexene-3-one, were used to complex homoleptic triethylaluminum and tris[bis(trimethylsilyl)amino]alu minum, respectively. The acid–base reactions proceeded in excellent yields with elimination of ethane or bis(trimethylsilyl)amine during in situ deprotonation of the protio Schiff-base. The colorless aluminum complexes crystallized from n-pentane and were characterized by standard methods including single crystal X-ray diffraction. Polymerization of racemic lactide, with addition of alcohol, yielded PLA with narrow polydispersities but low molecular weights.

Post-Production Separation And Functionalization Of Single-Walled Carbon Nanotubes, Kurukulasuriya Fernando

All Dissertations

ABSTRACT
Single-walled carbon nanotubes (SWNTs) are considered to have many potential applications due to their unique structural, physical, chemical and electronic properties. Because the rigid structure of carbon nanotube determines its toughness in dissolution, the processing capability of carbon nanotube is strongly limited. My carbon nanotube functionalization research was mainly focused on developing innovative methods to functionalize nanotubes with various polymers and large aromatic molecules to make them soluble to study their interesting properties and applications. In this dissertation, different methods for the functionalization and solubilization of carbon nanotubes are described. The co-existence of metallic and semiconducting carbon nanotubes has …

Mixed Quantum-Classical Molecular Dynamics Study Of A Hydrated Electron And An Investigation Of Temperature Control Algorithms, Janet Aremu-Cole

All Dissertations

The use of classical and quantum mechanics has been employed in this dissertation to study temperature control algorithms and a hydrated electron. A comparison of the effects of four commonly used temperature control algorithms on the energetics and dynamics of liquid water has been executed, in efforts to better understand the non-equipartitioning effects caused by some thermostats. The Berendsen, Andersen, Langevin, and velocity rescaling temperature control algorithms were applied to both dimer and bulk water systems, using the TIP4P water model. The two deterministic thermostats, Berendsen and velocity rescaling, display the 'flying ice cube effect' that had been noticed earlier …

Compartmentalization Of Hiv-1 In The Secondary Lymphoid Tissues, James Peter Gregson

Theses and Dissertations

Follicular dendritic cells (FDCs) reside in the lymphoid follicles of the secondary lymphoid tissues (sLTs). Following the infection of an individual with human immunodeficiency virus type 1 (HIV-1), viral particles are trapped in massive quantities on the surfaces of FDCs. HIV-1 viral compartments are cell types or tissues between which there is a restriction of virus flow. Compartmentalization of HIV-1 creates numerous sites within the body in which the virus can undergo independent evolution, giving rise to a more diverse total viral population. Given the sessile nature of the FDC, I hypothesized that contrary to common assumptions, FDC-trapped HIV-1 is …

Spectral Data For "Synthesis Of Cyclopropanes Via Organoiron Methodology: Stereoselective Preparation Of Bi(Cyclopropyl)S", Rajesh K. Pandey, Sergey V. Lindeman, William A. Donaldson

Natural Products Synthesis via Organoiron Methodology

Spectral data created in the course of the research project. Supports specific findings in "Synthesis of Cyclopropanes via Organoiron Methodology: Stereoselective Preparation of Bi(cyclopropyl)s".

Cyclopropanation of [2-(alkenyl)pentenediyl]Fe(CO)₃ complexes (4) proceeds in a diastereoselective fashion to afford [2-(cyclopropyl)pentenediyl]Fe(CO)₃. The relative stereochemistry of the products was established by X-ray crystallography. The diastereoselectivity is rationalized on approach of the cyclopropanation reagent on the sterically more exposed face of 4. Oxidatively induced reductive elimination afforded stereodefined bi(cyclopropyl)s.

Delivery Of Itv Chemistry Classes, David Martin

Masters Theses & Specialist Projects

Western Kentucky University (WKU) offered a course entitled Biochemistry for the Health Sciences in the spring semester of 2007. The course was taught in Interactive Television (ITV) format, and was the first time a class had been taught in the format enabling two-way communication by the Chemistry Department. One section was present in an ITV broadcast classroom on the main campus in Bowling Green, Kentucky. Another section received the broadcast on the campus of Western Kentucky University-Owensboro (WKU-O), at Owensboro Community and Technical College (OCTC), located in Owensboro, Kentucky. The purpose of this thesis is to evaluate the delivery of …

Metal-Mediated Peptide Assembly: Use Of Metal Coordination To Change The Oligomerization State Of An Α-Helical Coiled-Coil, Mikhail V. Tsurkan, Michael Y. Ogawa

Chemistry Faculty Publications

Metal coordination is used to alter the oligomerization state of a designed peptide structure. The 30-residue polypeptide AQ-Pal21 4Pal21 contains two metal-binding 4-pyridylalanine (Pal) residues on its solvent-exposed surface and exists as a very stable two-stranded a-helical coiled-coil. Upon the addition of Pt(en)(NO3)(2), a significant conformational change to a metal-bridged, four-helix bundle is seen.

Department Of Chemistry News For Alumni And Friends, August 2007, Illinois State University, Department Of Chemistry

Chem Letter

Newsletter of the Illinois State University Department of Chemistry

Combustion Synthesis And Doping Of Titanium Dioxide, Walter Alexander Morales

Chemistry & Biochemistry Theses - Archive

A novel combustion technique was used for the preparation and doping of titanium dioxide (TiO2). This metal oxide of titanium is a large band gap semiconductor (3.0 - 3.2 eV) that primarily absorbs in the ultraviolet region of the electromagnietic spectrum. However, the combustion synthesized TiO2 (CS-TiO2) prepared here, presented a shift in the absorption of light to the visible region of the spectrum and a high photocatalytic activity toward the reduction of Cr(VI). The final product was characterized using X-ray powder difraction (XRD), difuse reectance spectroscopy, X-ray photoelectron spectroscopy (XPS) and scanning electron microscopy (SEM). Comparison to a commercial …

The Effect Of Chloramphenicol On Bb88 Murine Erythroleukemia Cells, Peter K. W. Harris

Dissertations

DNA microarrays can be used to measure genome-wide transcript levels. These measurements may be useful in understanding cellular changes induced by a chemical agent. In this study, Affymetrix microarray technology has been used to study the effects of chloramphenicol, an antibiotic that inhibits bacterial and mitochondrial protein synthesis, on the transcription profile in mammalian cells. Transcript levels in BB88 murine erythroleukemia cells treated with 50 micromolar ( mu M) chloramphenicol, a concentration shown to inhibit BB88 proliferation, are measured. Using total RNA from treated cells, biotin-labeled cRNA was prepared and hybridized to Affymetrix U74Av2 microarrays. From these hybridizations, expression levels …

Synthesis And Characterization Of Doped Core/Shell Quantum Dots, Elizabeth J. Sodt

Masters Theses

The central theme of the research performed is the systematic modification of the optical properties of quantum dots by the formation of a shell of another quantum dot of a different band gap energy. Core/shell quantum dots such as CdS:Mn/CdS, CdS:Mn/ZnS, and ZnS:Mn/CdS with various concentrations of dopant Mn²⁺ in the core and shell concentrations have been synthesized under mild conditions in the aqueous phase using stoichiometric amounts of the surfactant stabilizer dodecyl sulfate. These quantum dots exhibit UV-vis, emission, and electron paramagnetic resonance (EPR) spectral behavior that is dependent on the concentration of the shell and the dopant …

Fluorescent Photoinduced Electron Transfer (Pet) Proton Sensors, Risper Nyabeta

Theses, Dissertations and Culminating Projects

Two new fluorescent photoinduced electron transfer (PET) proton sensors based on anthracene and pyrazoline chromophores have been prepared. The anthracene sensor was prepared through alkylation of 2-pyridylcarbinol with 9-chloromethylanthracene and the pyrazoline sensor was prepared through an aldol condensation of 4- carboxybenzaldehyde and acetylpyridine followed by reaction with phenylhydrazine. The fluorescence of these sensors is modulated by the initiation or quenching of a PET process between the chromophore and a receptor due to protonation. The synthesis, characterization and proton binding studies of the new sensors are reported in this thesis.

Nitrogen Heterocyclic Compounds As Receptors In Nanosensors For Nerve Gas Agent Analogs, Swapna Katram

Masters Theses

The research is focused on developing nanosensors consisting of different components that are chemically linked, namely, nanoparticle, fluorescent monomer, and receptor (NMR sensors) and nanoparticle, monomer, nanomolecule, and receptor (NMNR sensors) for the sensitive and selective detection of nerve gas agents. These sensors detect the target toxins by fluorescence change which is amplified by signal transduction. Model nerve gas toxins (DCP) and (DMMP) and HCl were employed as analytes, and the nitrogen heterocyclic compounds, 5-aminoindazole and dipyrido[3,2-a:2',3'-c]phenazine (dppz) as receptors in the NMR and NNMR nanosensors. The monomers were (E)-4-(4- formylstyryl) benzoic acid (NMR sensor) and 2-mercaptosuccinic acid (NNMR sensor). …

Enhancing Forensic Science Context-Based Laboratory Activities For Undergraduate Chemistry Students, Sarah Cresswell, John Fox, Claire M. Mcdonnell, Christine O'Connor, Cora O'Donnell, Michael K. Seery

Conference Papers

This paper discusses the development of student centred context-based practical activities for use in third level Forensic Science/ Chemical Analysis courses.

Crystal And Electronic Structures Of The Complex Hydride Li₄Bn₃H₁₀, Jinbo Yang, X. J. Wang, Qingsheng Cai, William B. Yelon, William Joseph James

Physics Faculty Research & Creative Works

The crystal structure of Li4BN3H10 was investigated using powder neutron diffraction with high sensitivity. The compound crystallizes in the cubic space group 213 with lattice parameters a=10.645 19(52) Å with an ordered arrangement of [NH2]−1 and [BH4]−1 anions in a molar ratio of 3:1. The bond lengths between the nearest nitrogen and hydrogen atoms are 1.04(4) and 1.14(4) Å. The bond angle between H(1)-N-H(2) is about 126(6)°, while those between H(3)-B-H(3) and H(3)-B-H(4) are about 109(6)°-110(7)°. There are three different Li sites surrounded by [NH2]−1 and [BH4]−1 anions in distorted tetrahedral configurations. The Li(3)-B and Li(3)-N bond distances are about …

Chemomechanical Polymers As Sensors And Actuators For Biological And Medicinal Applications, Hans-Jörg Schneider, Kazuaki Kato, Robert M. Strongin

Chemistry Faculty Publications and Presentations

Changes in the chemical environment can trigger large motions in chemomechanical polymers. The unique feature of such intelligent materials, mostly in the form of hydrogels, is therefore, that they serve as sensors and actuators at the same time, and do not require any measuring devices, transducers or power supplies. Until recently the most often used of these materials responded to changes in pH. Chemists are now increasingly using supramolecular recognition sites in materials, which are covalently bound to the polymer backbone. This allows one to use a nearly unlimited variety of guest (or effector) compounds in the environment for a …

Exohedral Silicon Fullerenes: SiNPtN/2 (20≤N≤60), Yong Pei, Yi Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Using density functional theory method we show that hollow silicon fullerene cages, Si_N(20≤N≤60), can be fully stabilized by exohedrally coated platinum atoms (Pt_N/2), denoted as Si_NPt_N/2. The exohedral coating Pt_N/2 passivates the dangling bonds of the silicon cages, thereby making the silicon cages Si_N to retain the symmetry and structure of homologous carbon fullerenes C_N. In particular, the I_h symmetrical, 60-atom silicon buckminsterfullerene cage (Si60) can be fully stabilized by exohedrally coated 30 Pt atoms. Properties of Si_NPt_{N/2 …}

49th Rocky Mountain Conference On Analytical Chemistry

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 49th annual meeting of the Rocky Mountain Conference on Analytical Chemistry, co-endorsed by the Colorado Section of the American Chemical Society and the Rocky Mountain Section of the Society for Applied Spectroscopy. Held in Breckenridge, Colorado, July 22-26, 2007.

Methyl Esterification Of Fatty Acids And Eicosanoids With A Novel Reagent Trimethylsilyldiazomethane For Analysis By Gas Chromatography-Mass Spectrometry, Aditi Munmun Sengupta

Master's Theses and Doctoral Dissertations

Fatty acids are compounds with limited water solubility that belong to the lipid class of bio-organic compounds and can be utilized as a source of energy by the body or as precursors to oxidized compounds that have roles in inflammation and in the regulation of vascular tone. The prostaglandins are naturally occurring 20-carbon cyclopentano fatty acid derivatives produced in mammalian tissue from polyunsaturated fatty acids (PUFAs) and are generated from endoperoxide precursors of arachidonic acid and related polyunsaturated fatty acids by the enzyme cyclo-oxygenase (COX). The lipoxygenase (LOX) enzymes convert arachidonic acid into hydroperoxy derivatives of PUFAs termed leukotrienes, which …

Development Of Chemomechanical Functionalization And Nanografting On Silicon Surfaces, Michael Vernon Lee

Theses and Dissertations

Progress in chemomechanical functionalization was made by investigating the binding of molecules and surface coverage on the silicon surface, demonstrating functionalization of silicon with gases by chemomechanical means, analyzing atomic force microscopy probe tip wear in atomic force microscopy (AFM) chemomechanical nanografting, combining chemomechanical functionalization and nanografting to pattern silicon with an atomic force microscope, and extending chemomechanical nanografting to silicon dioxide. Molecular mechanics of alkenes and alkynes bound to Si(001)-2x1 as a model of chemomechanically functionalized surfaces indicated that complete coverage is energetically favorable and becomes more favorable for longer chain species. Scribing a silicon surface in the presence …

Topoisomerase Ii-Drug Interaction Domains: Identification Of Substituents On Etoposide That Interact With The Enzyme, Amy M. Wilstermann, Ryan P. Bender, Murrell Godfrey, Sungjo Choi, Clemens Anklin, David B. Berkowitz, Neil Osheroff, David E. Graves

David Berkowitz Publications

Etoposide is one of the most successful chemotherapeutic agents used for the treatment of human cancers. The drug kills cells by inhibiting the ability of topoisomerase II to ligate nucleic acids that it cleaves during the double-stranded DNA passage reaction. Etoposide is composed of a polycyclic ring system (rings A–D), a glycosidic moiety at the C4 position, and a pendant ring (E–ring) at the C1 position. Although drug-enzyme contacts, as opposed to drug-DNA interactions, mediate the entry of etoposide into the topoisomerase II-drug-DNA complex, the substituents on etoposide that interact with the enzyme have not been identified. Therefore, saturation transfer …

Synthesis Of Resveratrol And Its Analogs, Phase-Transfer Catalyzed Asymmetric Glycolate Aldol Reaction, And Total Synthesis Of 8,9-Methylamido-Geldanamycin, Jing Liu

Theses and Dissertations

The phytoalexin resveratrol and its acetyl analogs have been made using a decarbonylative Heck reaction. The acid chloride derived from 3,5-dihydroxybenzoic acid was coupled with suitable protected 4-hydroxystyrene in the presence of palladium acetate and N,N-bis-(2,6-diisopropylphenyl)-4,5-dihydro imidazolium chloride to give the substituted stilbene in good yield as the key step. Human HL-60 cell assays showed the 4'-acetyl resveratrol variant improved activity (ED50 17 μM) relative to resveratrol (24 μM). Cinchona phase-transfer catalysts (PTC) were developed for glycolate aldol reactions to give differentially protected 1,2-diol products. Silyl enol ether of diphenylmethoxy-2,5-dimethoxyacetophenone reacted to generate benzhydryl-protected products. O-Allyl trifluorobenzyl cinchonium hydrodifluoride (20 …

Synthesis And Antiviral Evaluation Of Some 3'-Carboxymethyl-3'-Deoxyadenosine Derivatives, Houguang Shi

Theses and Dissertations

3'-Carboxymethyl-3'-deoxyadenosine derivatives were prepared from 2'-O-TBDMS-3'-deoxy-3'-[(ethoxycarbonyl)methyl]adenosine (1) via simple and efficient procedures. Conversion of 1 to 5'-azido-2'-O-TBDMS-3', 5'-dideoxy -3'-[(ethoxycarbonyl) methyl] adenosine (4) was accomplished via a novel one-pot method employing 5'-activation (TosCl) followed by efficient nucleophilic displacement with tetramethylguanidinium azide. Compound 4 was converted to a 5'-[(N-methylcarbamoyl)amino] derivative (5) via one-pot reduction/acylation employing H2/Pd-C followed by treatment with p-nitrophenyl N-methylcarbamate. The latter step of this two-step process required an efficient source of p-nitrophenyl N-methylcarbamate, thus a highly efficient new method for preparing p-nitrophenyl N-alkylcarbamate was developed. N6-phenylcarbamoyl groups were introduced by treatment with phenylisocyanate, and an efficient new method for …

Additive-Assisted, Cerium-Based, Corrosion-Resistant E-Coating, James O. Stoffer, Thomas J. O'Keefe, Eric L. Morris, Xuan Lin, Scott A. Hayes, Pu Yu

Chemistry Faculty Research & Creative Works

Corrosion resistance of metallic components such as stainless steel components of vehicles, and especially aluminum- based components of aircraft, is enhanced by application of an e-coat paint or primer which is enhanced by incorporation of cerium ions into the e-coat electrolytic bath. The resulting overall coating includes a cerium-based layer under a cerium-enhanced e-coat paint or primer layer.

Linear, Redox Modified Dna Probes As Electrochemical Dna Sensors, Francesco Ricci, Rebecca Lai, Kevin W. Plaxco

Rebecca Lai Publications

We show here that hybridization-linked changes in the dynamics of a redox-modified, electrode-bound linear (as opposed to stem-loop) probe DNA produce large changes in Faradaic current, allowing for the ready detection of target oligonucleotides.

Mechanistic And Structural Studies Of H373q Flavocytochrome B2: Effects Of Mutating The Active Site Base, Chi Lin Tsai, Kuppan Gokulan, Pablo Sobrado, James C. Sacchettini, Paul F. Fitzpatrick

Chemistry Faculty Research & Creative Works

His373 in flavocytochrome b2 has been proposed to act as an active site base during the oxidation of lactate to pyruvate, most likely by removing the lactate hydroxyl proton. The effects of mutating this residue to glutamine have been determined to provide further insight into its role. The kcat and kcat/Klactate values for the mutant protein are 3 to 4 orders of magnitude smaller than the wild-type values, consistent with a critical role for His373. Similar effects are seen when the mutation is incorporated into the isolated flavin domain of the enzyme, narrowing the effects to lactate oxidation rather than …

Mechanism Of Rate-Limiting Motions In Enzyme Function, Eric D. Watt, Hiroko Shimada, Evgenii L. Kovrigin, J. Patrick Loria

Chemistry Faculty Research and Publications

The ability to use conformational flexibility is a hallmark of enzyme function. Here we show that protein motions and catalytic activity in a RNase are coupled and display identical solvent isotope effects. Solution NMR relaxation experiments identify a cluster of residues, some distant from the active site, that are integral to this motion. These studies implicate a single residue, histidine-48, as the key modulator in coupling protein motion with enzyme function. Mutation of H48 to alanine results in loss of protein motion in the isotope-sensitive region of the enzyme. In addition, k _cat decreases for this mutant and the kinetic …

Synthesis And Characterization Of Erbia Doped Metal Oxide Nanofibers For Applications In The Rmophotovoltaics, E. T. Bender, R. Wang, M. T. Aljarrah, Edward A. Evans, R. D. Ramsier

Chemical, Biomolecular, and Corrosion Engineering Faculty Research

Titania (TiO2) nanofibers doped with erbia (Er2O3) have been synthesized by electrospinning mixtures of polymers, titanium-containing materials, and erbia particles. These electrospun nanofibers are subsequently annealed at temperatures of 800, 900, 1000, and 1050 degrees C to remove the organics and leave behind the metal oxides. The crystal structure and optical properties of the metal oxides depend on the annealing temperature, and we characterize these nanofibers using x-ray diffraction and Fourier transform infrared spectroscopy (FTIR). An Er2Ti2O7 phase is formed in an amount which depends on the annealing temperature, and relationships between the nature of FTIR spectra and the relative …

The Voltammetric Study Of The Reduction Of Tetraalkylammonium Perchlorate By Fe(Tpp)2-, Chathra Shirani De Silva, Michael D. Ryan

Chemistry Faculty Research and Publications

Tetraalkylammonium ions react with Fe(TPP)²⁻ to form Fe(TPP)(R)⁻ and trialkylamine. The tetrabutylammonium cation was verified to be the source of the alkyl group in the product, Fe(TPP)(R)⁻, by using (¹H₅C₂)₃(2H₅C₂)N⁻ as the cation and ²H NMR. The reaction of Fe(TPP)²⁻ with Bu₄N⁻ was monitored by cyclic voltammetry and thin layer spectroelectrochemistry. The activation parameters were measured, and were most consistent with an electron transfer (ET) mechanism. The rate of the reaction of tetramethyl and tetraethylammonium ions with Fe(TPP) …