Chemistry Commons^™

Sol-Gel Synthesis Of Intermediate Composition, Nanocrystalline Olivine, Corbin Cannon

Theses and Dissertations

Olivine is one of the most important rock forming minerals in our solar system. It forms in a solid-solution series between a magnesium-rich end member, forsterite (Mg2SiO4), and an iron-rich end member, fayalite (Fe2SiO4). For this reason, it is commonly used for experiments regarding the formation and evolution of planetary objects. Scarcity of iron-rich phases and the desirability of pure materials for research force the use of synthetic minerals for these experiments. Previous forsterite and fayalite synthesis methods were reexamined and combined to develop a new synthesis method that can produce a specific composition of olivine within the solid solution …

Solid State Synthesis And Characterization Of The Rare Earth-Free Anti-Perovskites Sr2.5-Xba0.5 Al1-Xp Xo4 F ( 0 ≤ X ≤ 0.15 ), Sr3al1-Xy Xo 4 F ( 0 ≤ X ≤ 1 ), And Sr2.5-X/2ba0.5 Al1-Xhfxo4 F ( 0 ≤ X ≤ 0.1 ) As Potential Phosphor Materials, Sean Thomas Keil

Theses and Dissertations

Typical lighting systems such as incandescent and fluorescent bulbs are common in homes but are rather inefficient compared to the newer light emitting diodes (LEDs). LED-based lamps can be constructed to generate white light by combining a red, green, and blue LED, or by using an LED light source (typically with a low wavelength) with a complimentary phosphor coating to produce white light. The latter, known as phosphor-conversion (PC) LEDs, is the primary focus of this research, looking specifically at rare earth-free options for these phosphor coatings.

Anti-perovskites are a potential lattice type for this type of conversion, in particular …

Development And Validation Of A Sensitive Uplc-Ms/Ms Method For The Quantitation Of [13c]Sucrose In Rat Plasma, Blood, And Brain: Its Application To The Measurement Of Blood-Brain Barrier Permeability, Mohammad K. Miah, Ulrich Bickel, Reza Mehvar

Pharmacy Faculty Articles and Research

Accurate and reproducible measurement of blood-brain barrier (BBB) integrity is critical in the assessment of the pathophysiology of the central nervous system disorders and in monitoring therapeutic effects. The widely-used low molecular weight marker [14C]sucrose is non-specific in the absence of chromatographic separation. The purpose of this study was to develop and validate a sensitive and reproducible LC-MS/MS method for the analysis of stable isotopemodified [13C12]sucrose in brain, plasma, and blood to determine BBB permeability to sucrose. After addition of internal standard (IS, [13C6]sucrose), the marker and IS were recovered from diluted rat blood, plasma, and brain homogenate by protein …

In Crystallo Capture Of A Covalent Intermediate In The Udp-Galactopyranose Mutase Reaction, Ritcha Mehra-Chaudhary, Yumin Dai, Pablo Sobrado, John J. Tanner

Chemistry Faculty Research & Creative Works

UDP-galactopyranose mutase (UGM) plays an essential role in galactofuranose biosynthesis in pathogens by catalyzing the conversion of UDP-galactopyranose to UDP-galactofuranose. Here we report the first crystal structure of a covalent intermediate in the UGM reaction. The 2.3 Å resolution structure reveals UDP bound in the active site and galactopyranose linked to the FAD through a covalent bond between the anomeric C of galactopyranose and N5 of the FAD. The structure confirms the role of the flavin as nucleophile and supports the hypothesis that the proton destined for O5 of galactofuranose is shuttled from N5 of the FAD via O4 of …

One-Dimensional Nanostructure And Sensing Applications: Tin Dioxide Nanowires And Carbon Nanotubes, Hoang Anh Tran

Dissertations and Theses

The key challenge for a nanomaterial based sensor is how to synthesize in bulk quantity and fabricate an actual device with insightful understanding of operational mechanisms during performance. I report here effective, controllable methods that exploit the concepts of the "green approach" to synthesize two different one-dimensional nanostructures, including tin oxide nanowires and carbon nanotubes. The syntheses are followed by product characterization and sensing device fabrications as well as sensor performance understanding at the molecular level. Sensor-analyte response and recovery kinetics are also presented.

The first part of the thesis describes bulk-scale synthesis and characterization of tin oxide nanowires by …

Beyond Clickers, Next Generation Classroom Response Systems For Organic Chemistry, Kevin M. Shea

Chemistry: Faculty Publications

Web-based classroom response systems offer a variety of benefits versus traditional clicker technology. They are simple to use for students and faculty and offer various question types suitable for a broad spectrum of chemistry classes. They facilitate active learning pedagogies like peer instruction and successfully engage students in the learning environment. Example problems for Organic I and II are shown to highlight potential uses of one Web-based system

I Want To Be The Inquiry Guy! How Research Experiences For Teachers Change Beliefs, Attitudes, And Values About Teaching Science As Inquiry, Deborah Herrington, Senetta F. Bancroft, Molly M. Edwards, Caroline J. Schairer

Peer Reviewed Articles

This qualitative study examined how and why research experiences for teachers (RETs) influenced middle and high school science teachers’ beliefs, attitudes, and values about teaching science as inquiry. Changes teachers reported after participating in the RET ranged from modifying a few lessons (belief change) to a comprehensive revision of what and how they taught to better reflect inquiry (attitude change). Some teachers who described comprehensively changing their instruction also described implementing actions meant to change science education within their respective schools, not just their own classrooms (value change). We present how and why teachers went about changes in their practices …

Influence Of Rtil Nanodomains On The Voltammetry And Spectroelectrochemistry Of Fullerene C60 In Benzonitrile/Room Temperature Ionic Liquids Mixtures, Abderrahman Atifi, Michael D. Ryan

Chemistry Faculty Research and Publications

The cyclic voltammetry of fullerene C₆₀ was examined in mixed benzonitrile/RTIL solvents in order to probe the effect of nanodomains in the mixed RTIL/benzonitrile solutions and their effect upon the voltammetry. In probing the interactions of the fullerides (up to C₆₀³⁻) with RTILs, BMIm⁺ (1-butyl-3-methylimidazolium, mostly planar) and tetraalkylammonium (more spherical/flexible) salts were used. In order to investigate these shifts in more detail, the ΔE₁₂° (=E°₁–E°₂) and ΔE₂₃° (=E°₂–E°₃) values, which were independent of the reference potential, were used. At higher concentrations of …

Dissolved Organic Carbon From The Upper Rio Negro Protects Zebrafish (Danio Rerio) Against Ionoregulatory Disturbances Caused By Low Ph Exposure, Rafael M. Duarte, D. Scott Smith, Adalberto L. Val, Chris M. Wood

Chemistry Faculty Publications

The so-called “blackwaters” of the Amazonian Rio Negro are rich in highly coloured dissolved organic carbon (DOC), but ion-poor and very acidic, conditions that would cause fatal ionoregulatory failure in most fish. However these blackwaters support 8% of the world’s ichthyofauna. We tested the hypothesis that native DOC provides protection against ionoregulatory dysfunction in this extreme environment. DOCs were isolated by reverse-osmosis from two Rio Negro sites. Physico-chemical characterization clearly indicated a terrigenous origin, with a high proportion of hydroxyl and phenolic sites, high chemical reactivity to protons, and unusual proteinaceous fluorescence. When tested using zebrafish (a model organism), Rio …

Design, Synthesis And Screening Of Peptidomimetics For Anticancer And Antiviral Drug Candidates, Yi Liang

USF Tampa Graduate Theses and Dissertations

The high demand of novel peptide and peptidomimetics based on the amount of genomic and proteomic data need be matched by synthesis and screening. The design and synthesis of peptide and peptidomimetics are so important because the peptide and protein-protein interaction play a key role in molecule recognition and signaling. The modified peptides have better stability and pharmacokinetic properties which may be guided by rational design and molecular modeling. Now many organic and medicinal chemists have chosen peptide and peptidomimetics as potential drug candidates for many targets.

In this dissertation, research efforts in design and synthesis of cyclic peptides with …

New Urjc-1 Material With Remarkable Stability And Acid-Base Catalytic Properties, Pedro Leo, Ferdnando Martinez, Guillermo Calleja, David Briones, Lukasz Wojtas

Chemistry Faculty Publications

Emerging new metal-organic structures with tunable physicochemical properties is an exciting research field for diverse applications. In this work, a novel metal-organic framework Cu(HIT)(DMF)_0.5, named URJC-1, with a three-dimensional non-interpenetrated utp topological network, has been synthesized. This material exhibits a microporous structure with unsaturated copper centers and imidazole–tetrazole linkages that provide accessible Lewis acid/base sites. These features make URJC-1 an exceptional candidate for catalytic application in acid and base reactions of interest in fine chemistry. The URJC-1 material also displays a noteworthy thermal and chemical stability in different organic solvents of different polarity and boiling water. Its catalytic …

Reactivity Of Acyclic (Pentadienyl)Iron(1+) Cations With Phosphonate Stabilized Nucleophiles: Application To The Synthesis Of Oxygenated Metabolites Of Carvone, Do W. Lee, Charles Felix Manful, Jayapal Reddy Gone, Yuzhi Ma, William A. Donaldson

Chemistry Faculty Research and Publications

The addition of phosphonate stabilized carbon nucleophiles to acyclic (pentadienyl)iron(1+) cations proceeds predominantly at an internal carbon to afford (pentenediyl)iron complexes. Those complexes bearing an electron withdrawing group at the σ-bound carbon (i.e., 13/14) are stable and isolable, while complexes which do not contain an electron withdrawing group at the σ-bound carbon undergo CO insertion, reductive elimination and conjugation of the double bond to afford cyclohexenone products (21/22). Deprotonation of the phosphonate 13/14 or 21 and reaction with paraformaldehyde affords the olefinated products. This methodology was utilized to prepare oxygenated carvone metabolites (±)-25 and (±)-26.

Characterization And Comparative Analysis Of 2,4-Toluene Diisocyanate And 1,6-Hexamethylene Diisocyanate Haptenated Human Serum Albumin And Hemoglobin, Morgen Mhike, Ita Chipinda, Brandon F. Law, Toni A. Bledsoe, Angela R. Lemons, Ajay P. Nayak, Brett J. Green, Donald H. Beezhold, Reuben H. Simoyi, Paul D. Siegel

Chemistry Faculty Publications and Presentations

Diisocyanates (dNCOs) are lowmolecularweight chemical sensitizers that reactwith autologous proteins to produce neoantigens. dNCO-haptenated proteins have been used as immunogens for generation of dNCO-specific antibodies and as antigens to screen for dNCO-specific antibodies in exposed individuals. Detection of dNCOspecific antibodies in exposed individuals for diagnosis of dNCO asthma has been hampered by poor sensitivities of the assay methods in that specific IgE can only be detected in approximately 25% of the dNCO asthmatics. Apart from characterization of the conjugates used for these immunoassays, the choice of the carrier protein and the dNCO used are important parameters that can influence the …

Structural Dependence Of The In Vitro Cytotoxicity, Oxidative Stress And Uptake Mechanisms Of Poly(Propylene Imine) Dendritic Nanoparticles, Humza Khalid, Sourav Prasanna Mukherjee, Luke O'Neill, Hugh Byrne

Articles

The in vitro cytotoxic and intracellular oxidative stress responses to exposure to poly (propylene imine) (PPI) dendritic nanoparticles of increasing generation (number of repeated branching cycles) (G0-G4) were assessed in an immortal non-cancerous human keratinocyte cell-line (HaCaT). Confocal fluorescence microscopy with organelle staining was used to explore the uptake and intracellular trafficking mechanisms. A generation and dose dependent cytotoxic response was observed, increasing according to generation and therefore number of surface amino groups. A comparison of the cytotoxic response of G4 PPI and the related G4 Poly (amido amine) dendrimer indicates that the PPI with the same number of surface …

Neutron And Magnetic Studies Of La₀.₇Sr₀.₃Mn₁₋ₓcrₓo₃(X ≤ 0.7): A Homogeneous Charge-Ordered System, Thomas F. Creel, Jinbo Yang, Satish K. Malik, Sylvio Quezado, Oran Allan Pringle, William B. Yelon, William Joseph James

Physics Faculty Research & Creative Works

Structural and magnetic properties of La_0.7Sr_0.3Mn_1-xCr_xO₃ (0 < x ≤ 0.7) have been studied in order to determine the effect of substitution of Cr³⁺ for Mn³⁺. The data consist of neutron and x-ray powder-diffraction and magnetization measurements. We previously suggested these systems transition from ferromagnetic to antiferromagnetic ordering with the intermediate concentrations containing coexisting ferromagnetic and antiferromagnetic domains. Upon further detailed examination, we find that the neutron data can be fit using a single homogeneous long-range magnetically ordered state and compositionally dependent charge ordering. The magnetic structures are controlled by the competition between Mn-Mn, Mn-Cr, and Cr-Cr interactions (double exchange and superexchange). The metal to …

Calculated Vibrational States Of Ozone Up To Dissociation, Steve Alexandre Ndengué, Richard Dawes, Xiaogang Wang, Tucker Carrington Jr., Zhigang Sun, Hua Guo

Chemistry Faculty Research & Creative Works

A new accurate global potential energy surface for the ground electronic state of ozone [R. Dawes et al., J. Chem. Phys. 139, 201103 (2013)] was published fairly recently. The topography near dissociation differs significantly from previous surfaces, without spurious submerged reefs and corresponding van der Waals wells. This has enabled significantly improved descriptions of scattering processes, capturing the negative temperature dependence and large kinetic isotope effects in exchange reaction rates. The exchange reactivity was found to depend on the character of near-threshold resonances and their overlap with reactant and product wavefunctions, which in turn are sensitive to the potential. Here …

Metabolic Disorders, Drug Development, Drug Design And Biomarkers, Gjumrakch Aliev, Ramon Cacabelos, V. Prakash Reddy

Chemistry Faculty Research & Creative Works

No abstract provided.

Study Of Infrared Emission Spectroscopy For The B 1Δg- A 1Πu And B ′1Σg +- A 1Πu Systems Of C2, Wang Chen, Kentarou Kawaguchi, Peter F. Bernath, Jian Tang

Chemistry & Biochemistry Faculty Publications

Thirteen bands for the B¹Δ_g-A¹Π_u system and eleven bands for the B′¹Σ_g ⁺-A¹Πu system of C₂ were identified in the Fourier transform infrared emission spectra of hydrocarbon discharges. The B′¹Σ_g ⁺ v = 4 and the B¹Δ_g v = 6, 7, and 8 vibrational levels involved in nine bands were studied for the first time. A direct global analysis with Dunham parameters was carried out satisfactorily for the B¹Δ_g-A¹Π_u system except for a …

Binding Of Transcription Factor Gabr To Dna Requires Recognition Of Dna Shape At A Location Distinct From Its Cognate Binding Site, Dali Liu, Walid A. Al-Zyoud, Robert Mg. Hynson, Lorraine A. Ganuelas, Adelle Cf. Coster, Anthony P. Duff, Matthew Ab. Baker, Alastair G. Stewart, Eleni Giannoulatou, Joshua Wk> Ho, Katharina Gaus, Lawrence K. Lee, Till Böcking

Chemistry: Faculty Publications and Other Works

Mechanisms for transcription factor recognition of specific DNA base sequences are well characterized and recent studies demonstrate that the shape of these cognate binding sites is also important. Here, we uncover a new mechanism where the transcription factor GabR simultaneously recognizes two cognate binding sites and the shape of a 29 bp DNA sequence that bridges these sites. Small-angle X-ray scattering and multi-angle laser light scattering are consistent with a model where the DNA undergoes a conformational change to bend around GabR during binding. In silico predictions suggest that the bridging DNA sequence is likely to be bendable in one …

Targeting Antioxidant Pathways With Ferrocenylated N-Heterocyclic Carbene Supported Gold(I) Complexes In A549 Lung Cancer Cells, Jonathan Arambula, Rebecca Mccall, K, J, Sidoran, Darren Magda, Nicholas Mitchell, Christopher W. Bielawski, Vincent M. Lynch, Jonathan L. Sessler, Kuppuswamy Arumugam

Chemistry: Faculty Publications (1990-2023)

Ferrocene containing N-heterocyclic carbene (NHC) ligated gold(I) complexes of the type [Au(NHC)2]+ were prepared and found to be capable of regulating the formation of reactive oxygen species (ROS) via multiple mechanisms. Single crystal X-ray analysis of bis(1-(ferrocenylmethyl)-3-mesitylimidazol-2-ylidene)-gold(I) chloride (5) and bis(1,3-di(ferrocenylmethyl)imidazol-2-ylidene)-gold(I) chloride (6) revealed a quasi-linear geometry around the gold(I) centers (i.e., the C–Au–C bond angle were measured to be ∼177° and all the Au–Ccarbene bonds distances were in the range of 2.00 (7)–2.03 (1) Å). A series of cell studies indicated that cell proliferation inhibition and ROS generation were directly proportional to the amount of ferrocene contained within the …

Water Condensation And Protein Adsorption On Hybrid Superhydrophobic-Hydrophilic Surfaces, Bikash Mondal

Dissertations, Theses, and Capstone Projects

This thesis describes the study of protein adsorption and water condensation on hybrid superhydrophobic-hydrophilic surfaces for various technological applications such as diagnostics, artificial organs and medical devices, water collection, and heat transfer.

In the chapter 1, a general introduction to wetting theories, superhydrophobic surface, and hybrid surfaces is given. In chapter 2, design and fabrication of a hybrid superhydrophobic surface for studying dropwise condensation and heat transfer is discussed. Effect of surface chemistry and wettability on protein adsorption is discussed in the chapter 3. Finally, in chapter 4, the protein adsorption study on hybrid superhydrophobic surfaces made by 3D-printing and …

Design Rules For The Nucleation, Growth, And Encapsulation Of Gold Nanoparticles With Applications To Cancer Imaging, Matthew A. Wall

Dissertations, Theses, and Capstone Projects

Surface-enhanced Raman scattering (SERS) nanoparticles are exciting candidates for high-precision cancer imaging due to their highly specific spectral signature (Raman “fingerprint”) and propensity for passive targeting of cancerous tissues. However, the signal intensity of currently available SERS nanoparticles is insufficient for cancer imaging via passive targeting in most solid tumors. The overarching aim of this body of work is to develop a new generation of SERS nanoparticles with sufficiently low limits of detection to enable robust detection of various solid tumors in vivo.

The complexity of SERS nanoparticles requires significant advances to the theoretical and experimental understanding of metal …

Ultrafast Spectroscopy And Energy Transfer In An Organic/Inorganic Composite Of Zinc Oxide And Graphite Oxide, Jeff A. Secor

Dissertations, Theses, and Capstone Projects

The energy transfers and nature of defect levels of an organic/inorganic composite of Zinc Oxide and Graphite are studied with multidimensional spectroscopy. The edge and surface states of each composite are uncovered using excitation emission experiments showing which defect states are mediating the energy transfer from the metal oxide to the graphite oxide. Multidimensional time resolved spectroscopy further describes the effect of the carbon phase on the energy transfer pathways in the material.

Synthesis And Characterization Of Segmented Fluorescent Conjugated Polymers Via Acyclic Diene Metathesis (Admet), Gagandeep Singh

Dissertations, Theses, and Capstone Projects

This doctoral thesis is focused on the novel and facile synthesis and characterization of segmented conjugated polymers featuring various electro-optically active segments, with or without heteroatom linkages. The polymers were synthesized, via acyclic diene metathesis (ADMET) using ruthenium-based Grubbs-type catalysts. All products are soluble, and have a well-defined all-trans microstructure without defects. Some of the polymers were also synthesized via Suzuki polycondensation for comparison purposes. All monomers utilized were designed and synthesized in the laboratory.

Segmented conjugated polymers have received a great deal of attention in organic electronics, such as organic light emitting-diodes, organic field-effect transistors and organic solar …

The Elusive Quest For Rna Knots, Aaron S. Burton, Marco Di Stefano, Niles Lehman, Henri Orland, Cristian Micheletti

Chemistry Faculty Publications and Presentations

Physical entanglement, and particularly knots arise spontaneously in equilibrated polymers that are sufficiently long and densely packed. Biopolymers are no exceptions: knots have long been known to occur in proteins as well as in encapsidated viral DNA. The rapidly growing number of RNA structures has recently made it possible to investigate the incidence of physical knots in this type of biomolecule, too. Strikingly, no knots have been found to date in the known RNA structures. In this Point of View Article we discuss the absence of knots in currently available RNAs and consider the reasons why knots in RNA have …

Effects Of A Pyrrole-Based, Microtubule-Depolymerizing Compound On Raw 264.7 Macrophages, John A. Ciemnieckia, Clarke P. Lewis, John T. Gupton, Krista J. Stenger

Biology Faculty Publications

RAW 264.7 murine macrophages were exposed to the pyrrole-based compound 3,5-Dibromo-4-(3,4-dimethoxyphenyl)-1H-pyrrole-2-carboxylic acid ethyl ester (JG-03-14), which is a known microtubule depolymerizing agent with antitumor activity [1,2,3]. In this study exposure to JG-03-14 reduced the production of pro-inflammatory molecules by macrophages activated with lipopolysaccharide (LPS). Treatment with the pyrrole-based compound decreased the concentration of tumor necrosis factor-α (TNF-α) and nitric oxide (NO) released from the macrophages. Exposure to JG-03-14 also decreased TNF-α mRNA expression levels and the protein expression levels of inducible nitric oxide synthase (iNOS), the enzyme responsible for NO production in the activated macrophages. Furthermore, JG-03-14 treatment significantly changed …

Strain Effects On The Work Function Of An Organic Semiconductor, Yanfei Wu, Annabel R. Chew, Geoffrey A. Rojas, Gjergji Sini, Greg Haugstad, Alex Belianinov, Sergei V. Kalinin, Hong Li, Chad Risko, Jean-Luc Brédas, Alberto Salleo, C. Daniel Frisbie

Chemistry Faculty Publications

Establishing fundamental relationships between strain and work function (WF) in organic semiconductors is important not only for understanding electrical properties of organic thin films, which are subject to both intrinsic and extrinsic strains, but also for developing flexible electronic devices. Here we investigate tensile and compressive strain effects on the WF of rubrene single crystals. Mechanical strain induced by thermal expansion mismatch between the substrate and rubrene is quantified by X-ray diffraction. The corresponding WF change is measured by scanning Kelvin probe microscopy. The WF of rubrene increases (decreases) significantly with in-plane tensile (compressive) strain, which agrees qualitatively with density …

Determination Of Fine Particulate Matter Composition And Development Of The Organic Aerosol Monitor, Paul Michael Cropper

Theses and Dissertations

Tropospheric fine particulate matter (PM) poses serious health risks and has a significant impact on global climate change. The measurement of various aspects of PM is challenging due to its complex chemical nature. This dissertation addresses various aspects of PM, including composition, measurement, and visibility. The U.S. Environmental Protection Agency (EPA) proposed a new secondary standard based on visibility in urban areas using 24-h averaged measurements of either light scatter or PM concentration. However shorter averaging times may better represent human perception of visibility. Data from two studies conducted in Lindon, UT, 2012, and Rubidoux, CA, 2003, were used to …

Triplex Dna Receptor-Gold Nanoparticle Conjugates For Detection Of Oxidized Dna Base, Qingyu Xing

Theses

Oxidations of DNA nucleobases are believed to be one of the sources of aging and some age-dependent disease, such as cancer. Human body have various mechanisms to repair damaged DNA and base-excision-repair is one mechanism for removing those oxidized nucleobases. This mechanism processes in the cells by cutting the oxidized nucleobases from deoxyribose and letting them excrete though urine. Detection of those abnormal nucleobases in urine has been suggested as a convenient way of early cancer diagnosis. 5-OHU (5-hydroxyuracil), the oxidation product of cytosine, is one of those abnormal nucleobases and it potentially forms base pairs with all four DNA …

Preparation, Characterization, Electrochemistry, And Infrared Spectroelectrochemistry Of Ruthenium Nitrosyl Porphyrins Containing Η1-O Bonded Axial Carboxylates, Dennis Awasabisah, Nan Xu, Krishna P. Sharmah-Gautam, Douglas R. Powell, Michael J. Shaw, George B. Richter-Addo

SIUE Faculty Research, Scholarship, and Creative Activity

The synthesis, characterization and redox behavior of eight low-spin nitrosyl carboxylate compounds (por)Ru(NO)(η¹-OC(=O)R) (por = T(p-OMe)PP: R = Me (1), i-Pr (2), t-Bu (3), p-C₆H₄NO₂ (4), Fc (5), CF₃ (8); por = TTP: R = Fc (6)) and (T(p-OMe)PP)Ru(NO)(OC₆HF₄) (7) are reported. The compounds are moderately stable in air as solids. Their IR (KBr) spectral data show ʋNO's in the 1839-1861 range cm^-1. The X-ray crystal structures of compounds 1 …