Chemistry Commons^™

Synthesis Of Fluorinated Indenofluorenediones And Bis(2-Fluorophenyl) Substituted Ppv, Jeffrey D. Fogle

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The compound 2,5-di(ethoxycarbonyl)-3,4-di(2-fluorophenyl)cyclopentadienone was successfully synthesized and led to the synthesis of terephthalates, di(hydroxymethyl)s, di(chloromethyl)s, diacids, diacid chlorides and indenofluorenediones having the pendent groups null, hexyl and 2-(4-benzothiazolyl)phenyl. All new compounds were characterized by melting point, IR, 1H NMR, 13C NMR, 19F NMR, GC/MS and combustion analysis. Most of the forementioned compounds showed an indication of restricted rotation with the appearance of trans and cis diastereomers. The asymmetric compounds showed the occurrence of four isomers. In some spectra, signals corresponding to all four isomers were visible. Through-space 1H-19F, 13C-19F and 19F-19F coupling was observed for most compounds in 1H NMR, …

Near Equilibrium Dissolution Of Calcite Using A Flow-Through Reactor (Ftr), Michael Mante

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In mineral dissolution reactions, surface morphologies play important roles particularly in near equilibrium fluids where generation of new sites of reactivity (e.g., pit nuclei) is thermodynamically disfavored. Following CO₂ injection in geologic formations, dissolution of primary carbonate minerals and crack-sealing cements will occur. The impact of these reactions on fluid chemistry requires better understanding of the reaction kinetics of major minerals at close-to-equilibrium conditions. Initial investigations have focused on quantifying calcite dissolution using short residence time (~ 10 min) flow through reactors to obtain dissolution rates at 60°C, pH = 8.33 and Pco₂ = 3.8 x 10^{-4 …}

Synthesis Of Isatin Derivatives Used For The Inhibition Of Pro-Apoptotic Jurkat T Cells, Charles Michael Clay

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A range of substituted 1H-indole-2,3-diones (isatins) was synthesized to assess their capability to inhibit caspases and prevent apoptosis in Jurkat T cells. The key steps in the synthesis of such molecules involved electrophilic substitution of the C-5 position of the isatin nucleus (if necessary), N-alkylation, Wolff-Kishner reduction of the C-3 carbonyl group and finally, Knoevenagel condensation. The design and synthesis of such potential inhibitors was guided by SAR studies of peptide based inhibitors such as "Q-VD-O-Ph", as well as small-molecule inhibitors based upon the isatins scaffold. Previously, 3-(2,6-difluorobenzylidene)-5-nitroindolin-2-one has been shown to inhibit apoptosis in human Jurkat T cells at …

Cetyltrimethylammonium Halide-Coated Electrodes For The Detection Of Dopamine In The Presence Of Interferents, Amber J. Yeary

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Specially constructed carbon paste electrodes were coated with 10 mM cetyltrimethylammonium halide (CTAX) solutions, bromide and chloride being the counter anions. These surfactant modified electrodes were used to detect the catecholamine neurotransmitter dopamine using cyclic voltammetry. The coated electrodes gave reproducible quasi-reversible behavior for the analyte dopamine over a range of concentrations from 1 mM to 200 mM. When combined in solution with common interferents ascorbic acid (1 mM) and uric acid (300 μM), all cathodic and anodic current peaks maintained resolution at the biological pH of 7.4. When the coating solutions were below the critical micelle concentration (0.5 mM), …

Routes To Acylated Sydnone Esters, Amanda Marie Balaguer

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Various 4-acyl-3-[2'-(carboalkoxy)phenyl]sydnones were synthesized by reaction of the parent sydnone with the corresponding anhydrides and Montmorillonite K-10. In the Q-tube, the acylation using acetic anhydride, which normally took 1.5 days for complete conversion thermally, was complete in 8.5 hours. Use of bismuth triflate as catalyst reduced the reaction time to 5 hours and, in the microwave, reactions were complete in 30 minutes and provided comparable yields. New sydnones were synthesized with acetic, propionic, butyric, and isobutyric anhydrides. Extension to various homogeneous metal triflates (lanthanum, yttrium, scandium, hafnium, gadolinium, and indium) was explored. Reactions were performed with 3-phenylsydnone as reactant, initially …

Establishing Open-Ended Assessments: Investigating The Validity Of Creative Exercises, Scott E. Lewis, Janet L. Shaw, Kathryn A. Freeman

Faculty Articles

Open-ended assessments, defined as assessments with a large set of possible correct answers, by nature lend themselves to concerns regarding accurate and consistent grading. This article describes one particular open-ended assessment, named Creative Exercises (CE), designed for promoting students' interconnection of concepts in a college general chemistry setting. The article presents evidence concerning several aspects of validity, including the extent scores represent chemistry knowledge and the extent scoring is consistent across three graders. The evidence is also presented in the context of what is known about concept maps, a commonly employed open-ended assessment in chemistry. Implications for the administration of …

The Synthesis, Reduction, And Chlorination Of 5-Alkoxy-2,3-Diphenylterephthalates, Rachel Marie Sayers

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A series of alkoxy, phenylated terephthalates has been synthesized as monomer precursors to the corresponding poly(phenylene vinylene)s (PPV). The hydroxy, phenylated terephthalate was synthesized via: 1) a Diels-Alder cycloaddition between an ethynyl boronic ester and a cyclopentadienone (CPD) with subsequent hydrolysis/oxidation of the boronate ester or 2) a Diels-Alder cycloaddition between vinylene carbonate and CPD followed by thermolysis of the bridged adduct. The hydroxy, phenylated terephthalate was alkylated via a phase-transfer reaction with iodomethane, propargyl bromide, benzyl chloride, allyl bromide, and bromobutane to produce the alkoxy, phenylated terephthalates in yields from 38.6- 91.1%. The alkoxyterephthlates were reduced with lithium aluminum …

Poly(Arylene Ether Sulfone)S Carrying Pendant(3-Sulfonated) Phenyl Sulfonyl Groups For Use As Proton Exchange Membranes, Kimberly E. Kern

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A series of poly(arylene ether)s, containing a pendant mono sulfonic acid group, was synthesized using 3-sulfonated-3', 5'-difluorodiphenyl sulfone and a variety of bisphenols for use in proton exchange membranes (PEM). Nucleophilic aromatic substitution was utilized for homo and copolymerizations. In addition, the relationship between perfectly alternating and random copolymers and their effects on overall properties was studied. Polymerization reactions yielded linear sulfonated poly(arylene ether)s, sPAEs, with molecular weights ranging from 15,400 to 212,000 g/mol. All of the polymers were characterized by gel permeation chromatography (GPC), 13C NMR spectroscopy, thermogravimetric analysis (TGA), and differential scanning calorimetry (DSC). All polymers exhibited excellent …

Effects Of Crystal Orientation On The Dissolution Kinetics Of Calcite By Chemical And Microscopic Analyses, Michael Edward Smith

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The purpose of this work was to examine the effects of polished crystal-surface orientation and degree of solution undersaturation (Ω_calcite) on the dissolution kinetics of calcite as a means of improving our understanding of fundamental reactions that may influence the efficacy of CO₂ sequestration in geological formations. Crystallographic surface orientations utilized in this study included ~ 1 cm² areas of natural calcite specimens polished approximately parallel to the (104) plane, giving rise to surfaces with flat terraces with few steps, as well as fully kinked surfaces created by sectioning approximately parallel to the (001) plane. Results …

Aerosol Jet Printing Of Lscf-Cgo Cathode For Solid Oxide Fuel Cells, Paul Gardner

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Solid oxide fuel cell (SOFC) technology has attracted great attention due to advantages such as low emissions and high efficiency. In this work, solid oxide fuel cells were fabricated by incorporating functional layers deposited by a novel aerosol jet® printing method. The buffer and cathode layers were printed from gadolinium doped ceria (Ce0.9Gd0.1)O1.95 (CGO) and La0.6Sr0.4Co0.2Fe0.8O3 (LSCF) inks, respectively. The CGO layer was deposited on the sintered electrolyte and then LSCF was subsequently deposited onto the CGO layer. The polarization curves showed a 19% improvement in current density using LSCF as the cathode instead of LSM. Cathode grain size was …

Water-Soluble Cuii And Mnii Bis-Phenanthroline Octanedioate Complexes With Unprecedented Nano And Picomolar In Vitro Cytotoxicity As Promising Leads For Chemotherapeutic Drug Development, Andrew Kellett, Mark O'Connor, Malachy Mccann, Orla L. Howe, Alan Casey, Pauric Mccarron, Kevin Kavanagh, Mary Mcnamara, Sean Kennedy, Donald D. May, Philip S. Skell, Denis O'Shea, Michael Devereux

Articles

Dinuclear Cu^II and Mn^II bis-phenanthroline octanedioate complexes exhibit rapid, unprecedented nano and picomolar in vitro cytotoxicity against colorectal cancer lines and are less toxic than cisplatin when examined in vivo. The complexes are potent generators of cellular reactive oxygen species, avid DNA binders and induce O₂ dependent cleavage of DNA. The Cu(II) complex was found to have self-cleaving nuclease activity.

Uranyl Reactions With Dithionite, L-Ascorbic Acid, And Supported Nanosized Zero-Valent Iron, Shanna Estes

All Theses

This work examined several reductants for remediation of low pH aqueous uranium contamination by reductive precipitation. Reductants included sodium dithionite, L-ascorbic acid, and nanosized zero-valent iron (nZVI). Additionally, the reductive capacity of nZVI successfully entrapped within a silicate matrix (cryogel) was also examined. This supported nZVI is expected to increase nZVI stability in the subsurface, and to provide a convenient in situ delivery mechanism for other remediation systems which may combine entrapped reductant and catalyst.
Fluorescence and absorbance spectroscopy were used to investigate the interaction between hexavalent uranium (U(VI), uranyl) and both sodium dithionite and L-ascorbic acid at pH 2. …

Ultrafast Rempi In Benzene And The Monohalobenzenes Without The Focal Volume Effect, Timothy D. Scarborough, James Strohaber, David B. Foote, Collin J. Mcacy, Cornelis J. Uiterwaal

C.J.G.J. Uiterwaal Publications

We report on the photoionization and photofragmentation of benzene (C₆H₆) and of the monohalobenzenes C₆H₅–X (X = F, Cl, Br, I) under intense-field, single-molecule conditions. We focus 50-fs, 804-nm pulses from a Ti:sapphire laser source, and record ion mass spectra as a function of intensity in the range ~10¹³ W/cm² to ~10¹⁵ W/cm². We count ions that were created in the central, most intense part of the focal area; ions from other regions are rejected. For all targets, stable parent ions (C₆H₅X+) are …

Transition From One-Dimensional Water To Ferroelectric Ice Within A Supramolecular Architecture, Hai-Xia Zhao, Xiang-Jian Kong, Hui Li, Yi-Chang Jin, La-Sheng Long, Xiao Cheng Zeng, Rong-Bin Huang, Lan-Sun Zheng

Xiao Cheng Zeng Publications

Ferroelectric materials are characterized by spontaneous electric polarization that can be reversed by inverting an external electric field. Owing to their unique properties, ferroelectric materials have found broad applications in microelectronics, computers, and transducers. Water molecules are dipolar and thus ferroelectric alignment of water molecules is conceivable when water freezes into special forms of ice. Although the ferroelectric ice XI has been proposed to exist on Uranus, Neptune, or Pluto, evidence of a fully protonordered ferroelectric ice is still elusive. To date, existence of ferroelectric ice with partial ferroelectric alignment has been demonstrated only in thin films of ice grown …

Elastic Properties Of Poly(Vinyldene Fluoride) (Pvdf) Crystals: A Density Functional Theory Study, Yong Pei, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

We computed structural and elastic properties of totally nine phases of poly(vinyldene fluoride) (PVDF) crystals using the density-functional theory (DFT) method with and without inclusion of the dispersion corrections. In addition to the four known crystalline forms, mechanic properties of five theoretically predicted crystalline forms of PVDF are also investigated. The all-trans form I_p exhibits the largest cohesive energy, bulk, and Young’s modulus among the nine crystalline forms. The DFT calculations suggest that the δ crystalline forms (III_au, III_pu, III_pd, and III_ad) possess poor chain rigidity among the nine PVDF …

Structure Evolution Of Gold Cluster Anions Between The Planar And Cage Structures By Isoelectronic Substitution: AuN− (N = 13–15) And MauN− (N = 12–14; M = Ag, Cu), Rhitankar Pal, Lei-Ming Wang, Wei Huang, Lai-Sheng Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The structural and electronic effects of isoelectronic substitution by Ag and Cu atoms on gold cluster anions in the size range between 13 and 15 atoms are studied using a combination of photoelectron spectroscopy and first-principles density functional calculations. The most stable structures of the doped clusters are compared with those of the undoped Au clusters in the same size range. The joint experimental and theoretical study reveals a new C_3v symmetric isomer for Au₁₃ ⁻, which is present in the experiment, but has hitherto not been recognized. The global minima of Au₁₄ ⁻ and Au …

Human Fatty Acid Transport Protein 2a/Very Long Chain Acyl-Coa Synthetase 1 (Fatp2a/Acsvl1) Has A Preference In Mediating The Channeling Of Exogenous N-3 Fatty Acids Into Phosphatidylinositol, Elaina M. Melton, Ronald Cerny, Paul A. Watkins, Concetta C. Dirusso, Paul N. Black

Ronald Cerny Publications

The trafficking of fatty acids across the membrane and into downstream metabolic pathways requires their activation to CoA thioesters. Members of the fatty acid transport protein/ very long chain acyl-CoA synthetase (FATP/Acsvl) family are emerging as key players in the trafficking of exogenous fatty acids into the cell and in intracellular fatty acid homeostasis.We have expressed two naturally occurring splice variants of human FATP2 (Acsvl1) in yeast and 293T-REx cells and addressed their roles in fatty acid transport, activation, and intracellular trafficking. Although both forms (FATP2a (Mr 70,000) and FATP2b (Mr 65,000 and lacking exon3, which encodes part of the …

Overexpression Of Galnac-Transferase Galnac-T3 Promotes Pancreatic Cancer Cell Growth, Keisuke Taniuchi, Ronald Cerny, Aki Tanouchi, Kimitoshi Kohno, Norihiro Kotani, Koichi Honke, Toshiji Saibara, Michael A. Hollingsworth

Ronald Cerny Publications

O-linked glycans of secreted and membrane bound proteins play an important role in the pathogenesis of pancreatic cancer by modulating immune responses, inflammation, and tumorigenesis. A critical aspect of O-glycosylation, the position at which proteins are glycosylated with N-acetyl-galactosamine on serine and threonine residues, is regulated by the substrate specificity of UDP-GalNAc: polypeptide N-acetylgalactosaminyl-transferases (GalNAc-Ts). Thus, GalNAc-Ts regulate the first committed step in O-glycosylated protein biosynthesis, determine sites of O-glycosylation on proteins, and are important for understanding normal and carcinoma-associated O-glycosylation. We have found that one of these enzymes, GalNAc-T3, is overexpressed in …

Identification And Characterization Of The Anti-Methicillin-Resistant Staphylococcus Aureus Wap-8294a2 Biosynthetic Gene Cluster From Lysobacter Enzymogenes Oh11, Wei Zhang, Yaoyao Li, Guoliang Qian, Yan Wang, Haotong Chen, Yue-Zhong Li, Fengquan Liu, Yuemao Shen, Liangcheng Du

Department of Chemistry: Faculty Publications

Lysobactor enzymogenes strain OH11 is an emerging biological control agent of fungal and bacterial diseases. We recently completed its genome sequence and found it contains a large number of gene clusters putatively responsible for the biosynthesis of nonribosomal peptides and polyketides, including the previously identified antifungal dihydromaltophilin (HSAF). One of the gene clusters contains two huge open reading frames, together encoding 12 modules of nonribosomal peptide synthetases (NRPS). Gene disruption of one of the NRPS led to the disappearance of a metabolite produced in the wild type and the elimination of its antibacterial activity. The metabolite and antibacterial activity were …

Characterizing Rna Dynamics At Atomic Resolution Using Solution-State Nmr Spectroscopy, Jameson R. Bothe, Evgenia N. Nikolova, Catherine D. Eichhorn, Jeetender Chugh, Alexandar L. Hansen, Hashim M. Al-Hashimi

Department of Chemistry: Faculty Publications

Many recently discovered non-coding RNAs do not fold into a single native conformation, but rather, sample many different conformations along their free energy landscape to carry out their biological function. Unprecedented insights into the RNA dynamic structure landscape are provided by solution-state NMR techniques that measure the structural, kinetic, and thermodynamic characteristics of motions spanning picosecond to second timescales at atomic resolution. From these studies a basic description of the RNA dynamic structure landscape is emerging, bringing new insights into how RNA structures change to carry out their function as well as applications in RNA-targeted drug discovery and RNA bioengineering.

Corrosion Rate Trajectories Of Concreted Iron And Steel Shipwrecks And Structures In Seawater— The Weins Number, Donald L. Johnson, D. J. Medlin, L. E. Murphy, J. D. Carr, D. L. Conlin

Department of Chemistry: Faculty Publications

The Weins number (Wn) concept is proposed to predict the long-term corrosion rate of wrought iron and steel in seawater for variable marine environments. Plotted as a function of reciprocal absolute temperature, Weins numbers generate a linear plot from which the corrosion rates are calculated when temperature, oxygen concentration, and concretion thickness are known. Application of the theory of absolute reaction rates is described.

Strategies For Labeling Proteins With Paracest Agents, Olga Vasalatiy, Piyu Zhao, Mark Woods, Andrei Marconescu, Aminta Castillo-Muzquiz, Philip Thorpe, Garry Kiefer, A. Dean Sherry

Chemistry Faculty Publications and Presentations

Reactive surface lysine groups on the chimeric monoclonal antibody (3G4) and on human serum albumin (HSA) were labeled with two different PARACEST chelates. Between 7.4 – 10.1 chelates were added per 3G4 molecule and between 5.6 – 5.9 chelates per molecule of HSA, depending upon which conjugation chemistry was used. The immunoreactivity of 3G4 as measured by ELISA assays was highly dependent upon the number of attached chelates: 88% immunoreactivity with 7.4 chelates per antibody versus only 17% immunoreactivity with 10.1 chelates per antibody. Upon conjugation to 3G4, the bound water lifetime of Eu-1 increased only marginally, up from …

Photo Retro Diels-Alder Reaction Of The Adducts Of Tetracyanoethylene And Polyaromatic Compounds, Siddthartha Banerjee

Electronic Theses and Dissertations

Thermally induced retro-Diels Alder (rDA) reaction has been extensively used for the preparation of many reactive intermediates in organic synthesis. But the uses of photo-retro Diels-Alder (PrDA) reaction in organic synthesis were sparingly reported in literature. Due to its spatial and temporal control, PrDA can be used in making of photosensitive materials, in drug delivery and also for mechanistic studies. Diels-Alder adducts of tetracyanoethylene (TCNE) and polyaromatic compounds (anthracene, napthacene, pentacene and phencyclone) were synthesized and were subjected to PrDA reaction through 254-nm irradiation. The quantum yield and the consequent photoreactivity of these DA adducts follow the following order. TCNE/naphthacene …

Studies On Silicon Nmr Characterization And Kinetic Modeling Of The Structural Evolution Of Siloxane-Based Materials And Their Applications In Drug Delivery And Adsorption, Jyotrhirmai Ambati

University of Kentucky Doctoral Dissertations

This dissertation presents studies of the synthetic processes and applications of siloxane-based materials. Kinetic investigations of bridged organoalkoxysilanes that are precursors to organic-inorganic hybrid polysilsesquioxanes are a primary focus. Quick gelation despite extensive cyclization is found during the polymerization of bridged silane precursors except for silanes with certain short bridges. This work is an attempt to characterize and understand some of the distinct features of bridged silanes using experimental characterization, kinetic modeling and simulation. In addition to this, the dissertation shows how the properties of siloxane- materials can be engineered for drug delivery and adsorption.

The phase behavior of polymerizing …

Novel Solution Processable Acceptors For Organic Photovoltaic Applications, Ying Shu

University of Kentucky Doctoral Dissertations

The field of organic electronics has become an increasingly important field of research in recent years. Organic based semiconductors have the potential for creating inexpensive, solution processed devices on flexible substrates. Some of the applications of organic semiconductors include organic field effect transistors, organic light emitting diodes and organic photovoltaics.

Functionalized pentacenes have been proven to be viable donor materials for use in organic photovoltaic devices. The goal of this research is to synthesize and test the viability of novel electron deficient pentacenes and pentacene based materials as acceptors to be used as drop-in replacements for PCBM in bulk-heterojunction organic …

Methionine-35 Of Aβ(1-42): Importance For Oxidative Stress In Alzheimer Disease, D. Allan Butterfield, Rukhsana Sultana

Chemistry Faculty Publications

Alzheimer disease (AD) is an age-related progressive neurodegenerative disorder. This devastating disease is characterized by the presence of senile plaques (SP), neurofibrillary tangles (NFTs), and loss of synapses. Amyloid beta-peptide 1–42 (Aβ(1–42)) is the main component of SP and is pivotal to AD pathogenesis. Brain of subjects with AD and arguably its earliest manifestation, mild cognitive impairment (MCI), demonstrate increased levels of oxidative stress markers. Our laboratory combined these two aspects of AD and MCI and proposed the Aβ(1–42)-associated free radical oxidative stress hypothesis to explain oxidative stress under which the MCI and AD brain exist …

Non Aggregated Colloidal Silver Nanoparticles For Surface Enhanced Resonance Raman Spectroscopy, Aoife Power, John Cassidy, Tony Betts

Articles

Silver nanoparticles with a tuneable l max were produced as colloids by heterogeneous nucleation. The synthesis process is both fast and repeatable, producing stable PVA capped nanoparticles. The colloid’s effectiveness in the SERRS system was investigated using Rhodamine 6G, R6G, Crystal Violet, CV, and Malachite Green, MG, as probe molecules. A clear sensing trend was observed, where the Raman signal emitted was significantly enhanced by the addition of silver nanoparticles. A build up of signal intensity is observed until an optimum ratio is achieved, followed by a decline in signal intensity as the concentration of nanoparticles is further increased. The …

Chromium Salen, Gráinne Hargaden, Pier Giorgio Cozzi

Articles

No abstract provided.

Diffuse-Charge Dynamics Of Ionic Liquids In Electrochemical Systems, Hui Zhao

Mechanical Engineering Faculty Research

We employ a continuum theory of solvent-free ionic liquids accounting for both short-range electrostatic correlations and steric effects (finite ion size) [Bazant et al., Phys. Rev. Lett. 106, 046102 (2011)] to study the response of a model microelectrochemical cell to a step voltage. The model problem consists of a 1-1 symmetric ionic liquid between two parallel blocking electrodes, neglecting any transverse transport phenomena. Matched asymptotic expansions in the limit of thin double layers are applied to analyze the resulting one-dimensional equations and study the overall charge-time relation in the weakly nonlinear regime. One important conclusion is that our …

The Release Of Calcium In Bacillus Anthracis Pathogenicity, Natiera Magnuson, Manomita Patra, Maria Elena Reynaga, Ernesto Abel-Santos

McNair Poster Presentations

Bacillus anthracis spores form in response to starvation and can withstand extremes of heat, radiation, and chemical toxins, making B. anthracis spores ideal vehicles for infections.1 The resistance and dormancy of bacterial spores are dependent on a largely dehydrated core.2 The spore core is not only devoid of water, but contains between 0.8 to 1M calcium complexed with 2,6-pyridinedicarboxylic acid (dipicolinic acid, DPA). The DPA-calcium complex (CaDPA) helps protect DNA, RNA, and the metabolic enzymes needed for the establishment of a vegetative cell cytoplasm.3 An anthrax infection starts with the germination of B. anthracis spores in a macrophage.4 The germinated …