Chemistry Commons^™

Side-Chain Boron Difluoride Formazanate Polymers Via Ring-Opening Metathesis Polymerization, Samantha Novoa, Joseph A. Paquette, Stephanie M. Barbon, Ryan R. Maar, Joe Gilroy

Chemistry Publications

The synthesis, characterization, and ring-opening methathesis polymerization (ROMP) of a novel norbornene-based boron difluoride (BF₂) formazante monomer are described in detail. The polymerization studies confirmed ROMP to occur in the presence of BF₂ formazanates, and also demonstrated the controlled nature of the polymerization. The polymers retained many of the unique characteristics of the monomers in dichloromethane, including absorption and emission at maximum wavelengths of 518 and 645 nm, large Stoke's shifts (u_ST = 127 nm, 3,800 cm^-1), and the ability to act as electron reservoirs to form borataverdazyl-based poly(radical anions) (E°_{red1 …}

Solution-Printed Organic Semiconductor Blends Exhibiting Transport Properties On Par With Single Crystals, Muhammad R. Niazi, Ruipeng Li, Er Qiang Li, Ahmad R. Kirmani, Maged Abdelsamie, Qingxiao Wang, Wenyang Pan, Marcia M. Payne, John E. Anthony, Detlef-M. Smilgies, Sigurdur T. Thoroddsen, Emmanuel P. Giannelis, Aram Amassian

Chemistry Faculty Publications

Solution-printed organic semiconductors have emerged in recent years as promising contenders for roll-to-roll manufacturing of electronic and optoelectronic circuits. The stringent performance requirements for organic thin-film transistors (OTFTs) in terms of carrier mobility, switching speed, turn-on voltage and uniformity over large areas require performance currently achieved by organic single-crystal devices, but these suffer from scale-up challenges. Here we present a new method based on blade coating of a blend of conjugated small molecules and amorphous insulating polymers to produce OTFTs with consistently excellent performance characteristics (carrier mobility as high as 6.7 cm²V⁻¹s⁻¹, low threshold …

Applications Of High Performance Affinity Chromatography With High Capacity Stationary Phases Made By Entrapment, John A. Vargas Badilla

Department of Chemistry: Dissertations, Theses, and Student Research

High performance affinity chromatography (HPAC) is a technique that uses a biologically-related agent such as a transport protein or an antibody as the stationary phase in an HPLC system. In recent years, HPAC has been shown to be a valuable bioanalytical tool for studying solute-protein interactions. Human serum albumin (HSA), the most abundant protein in blood (with concentrations of 35 to 50 mg/mL in serum), has been shown to interact with many drugs, affecting their transport, excretion and metabolism. A physical method for immobilizing proteins in HPAC supports has been optimized in this dissertation by using HSA as a model …

Synthesis Of Agents For The Treatment And Analysis Of Tropical Diseases, Jeanine Yacoub

USF Tampa Graduate Theses and Dissertations

Toxoplasmosis is an opportunistic disease caused by the protozoan parasite Toxoplasma gondii. The parasite is usually staved off by a healthy immune system and remains dormant in the body. In immunocompromised patients, the parasite can become active and spread throughout the body causing symptoms such as encephalitis, cognitive disorders, seizures, and death. Combination drug therapy is the usual treatment for toxoplasmosis; however, patients suffer from problems of intolerance, allergic reactions, and cytotoxicity. In an effort to identify new drug targets for toxoplasmosis, a series of compounds have been synthesized that can be used as tools to probe the unique …

Erratum To: Zn (Ii) And Cu (Ii) Adsorption And Retention Onto Iron Oxyhydroxide Nanoparticles: Effects Of Particle Aggregation And Salinity, Rebecca B. Chesne, Christopher S. Kim

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

In the original version of this article errors in Figs. 5 and 9 were identified by the authors. The corrected figures are given.

Synthesis And Characterization Of Neo-Confused Porphyrins And Related Systems, Arwa Salem Almejbel

Theses and Dissertations

Carbaporphyrins have been the focus of many studies, and a wide variety of related carbaporphyrinoid systems have been reported. N-confused porphyrins are a class of carbaporphyrins where one pyrrole unit has been inverted. In this work, a newly discovered family of porphyrin isomers where one of the pyrrolic subunits is connected to the meso-bridges in a 1,3-fashion, called neo-confused porphyrins, has been investigated.

Reaction of pyrrole-3-carbaldehydes with acetoxymethylpyrroles and NaH in DMF gave neo-confused dipyrrylmethane dialdehydes. The resulting dialdehydes underwent an acid catalyzed condensation with a dipyrrylmethane to give neo-confused phlorins, and following oxidation with FeCl3 afforded new neo-confused porphyrins. …

Functionalized Nanodiamond Reinforced Biopolymers, Gongyao Zhou, Peter I. Lelkes, Yury Gogotsi, Vadym Mochalin

Chemistry Faculty Research & Creative Works

The present invention includes a composition for implantation in a patient, comprising surface-functionalized nanodiamonds and at least one biodegradable biocompatible polymer. The present invention also includes a surgical fixation device for use in a patient.

Biomaterial Compositions, Kathleen V. Kilway, Lynda F. Bonewald, Thomas P. Schuman

Chemistry Faculty Research & Creative Works

Biomaterial compositions comprising organosilicon monomers (such as silorane monomers) and chemical curing systems or dual chemical/light curing systems, in conjunction with optional tetraoxaspiro[5.5]undecanes (“TOSUs”) and/or fillers. The present invention is directed to biomaterial compositions, as well as methods for manufacturing the same, and methods of using the compositions. The biomaterial composition comprises one or more organosilicon monomers (such as a silorane) and a chemical curing system or dual chemicaVlight curing system for polymerizing the 10 monomer(s). The compositions may include one or more tetraoxaspiro[5.5]undecanes “TOSUs”) and/or fillers. Accelerators (such as photoacids), photosensitizers, and/or electron donors may also be included in …

Ion Trap Mass Analyzer Apparatus, Methods, And Systems Utilizing One Or More Multiple Potential Ion Guide (Mpig) Electrodes, Curtiss Dwight Hanson

Patents (University of Northern Iowa)

In one aspect of the invention, an ion trap mass analyzer includes a variable- or multi-potential type ion guide (MPIG) assembly which has been pre-configured to produce a parabolic-type potential field. Each MPIG electrode has a resistive coating of designed characteristics. In one example the coating varies in thickness along the length of an underlying uniform substrate. The MPIG assembly can be a single MPIG electrode or an array of a plurality of MPIG electrodes. An array can facilitate delocalization for improved performance. This chemical modification of a uniform underlying substrate promotes cheaper and flexible instruments. The modified MPIG electrodes …

Investigation Of Low Thermal Conductivity Materials With Potential For Thermoelectric Applications, Kaya Wei

USF Tampa Graduate Theses and Dissertations

Thermoelectric devices make it possible for direct energy conversion between heat and electricity. In order to achieve a high energy conversion efficiency, materials with a high thermoelectric figure of merit (ZT = S²σT/κ, where S is the Seebeck coefficient, σ is the electrical conductivity, T is the absolute temperature, and κ is the thermal conductivity) are in great demand. The standard approach is to optimize charge carrier transport while at the same time scatter the heat transport, a task that is easier said than done. Improving the electrical properties in order to increase ZT is limited since electrons …

Polymeric Porphyrins As Solar Photocatalysts, Nicholas Upton Day

Dissertations and Theses

Research concentrated on the absorption, transformation, and storage of light energy is useful for the energy challenges faced by humanity. In particular, photocatalysis using solar energy to generate useful fuels has become a primary research goal in the drive to replace fossil fuels for the future. In this dissertation it is shown that poly-tetra(4-aminophenyl)porphyrin (pTAPP) can be oxidatively polymerized using a variety of methods, including electropolymerization, chemical oxidation, and interfacial polymerization and that pTAPP has photocatalytic ability to reduce O₂ to H₂O₂ for a storable fuel.

Organic conductive polymers such as pTAPP are attractive catalysts because …

Progress Toward A Structure-Function Relationship For Novel, Small-Molecule Inhibitors Of Plasminogen Activator Inhibitor-1, Sarah Burke

Master's Theses and Doctoral Dissertations

Plasminogen activator inhibitor-1 (PAI-1) is a serpin protein whose function is to inhibit tissue-type plasminogen activator (tPA) and urokinase-type plasminogen activator (uPA), and hence, fibrinolysis. This inhibition leads to decreased plasminogen to plasmin conversion, which results in deleterious effects on the organism, such as blood clots. Elevated levels of PAI-1 are implicated in a variety of diseases and conditions. We have synthesized a variety of novel, small-molecule PAI-1 inhibitors in order to establish a structure-function relationship throughout the compounds. This goal was accomplished through an iterative process in which only one aspect of the molecule was altered at a time. …

Novel Enzyme Perspectives: Arylalkylamine N-Acyltransferases From Bombyx Mori & 1-Deoxy- D-Xylulose-5-Phosphate Synthase From Plasmodium Falciparum And Plasmodium Vivax, Matthew R. Battistini

USF Tampa Graduate Theses and Dissertations

This dissertation is dedicated to the research and investigation of novel enzymes and the methods used to study them, with physiological roles ranging from isoprenoid biosynthesis to neurotransmitter production. Using a combination of bioinformatics, recombinant cloning, enzymology, and proteomics, we have contributed to the understanding and exploration of several human illnesses, including malaria, cancer, and endocrine dysfunction.

Our first project involved studying the enzymes responsible for N-acylarylalkylamide biosynthesis in Bombyx mori. Very little is known how these potent signaling molecules are produced in vivo, however, one possible pathway is the direct conjugation of an acyl-CoA to a corresponding …

In Situ Measurements And Modeling Of Reactive Trace Gases In A Small Biomass Burning Plume, M. Muller, B. Anderson, A. Beyersdorf, J. H. Crawford, G. Diskin, P. Eichler, A. Fried, F. N. Keutsch, T. Mikoviny, K. L. Thornhill, J. G. Walega, A. J. Weinheimer, M. Yang, Robert Yokelson, A. Wisthaler

Chemistry and Biochemistry Faculty Publications

An instrumented NASA P-3B aircraft was used for airborne sampling of trace gases in a plume that had emanated from a small forest understory fire in Georgia, USA. The plume was sampled at its origin for deriving emission factors and followed ~ 13.6 km downwind for observing chemical changes during the first hour of atmospheric aging. The P-3B payload included a proton-transfer-reaction time-of-flight mass spectrometer (PTR-ToF-MS), which measured non-methane organic gases (NMOGs) at unprecidented spatio-temporal resolution (10m/0.1 s). Quantitative emission data are reported for CO₂, CO, NO, NO₂, HONO, NH₃ and 16 NMOGs (formaldehyde, methanol, …

Spectroscopic Evidence Of Nanodomains In Thf/Rtil Mixtures: Spectroelectrochemical And Voltammetric Study Of Nickel Porphyrins, Abderrahman Atifi, Michael D. Ryan

Chemistry Faculty Research and Publications

The presence and effect of RTIL nanodomains in molecular solvent/RTIL mixture were investigated by studying the spectroelectrochemistry and voltammetry of nickel octaethylporphyrin (Ni(OEP)) and nickel octaethylporphinone (Ni(OEPone)). Two oxidation and 2–3 reduction redox couples were observed, and the UV–visible spectra of all stable products in THF and RTIL mixtures were obtained. The E° values for the reduction couples that were studied were linearly correlated with the Gutmann acceptor number, as well as the difference in the E° values between the first two waves (ΔE₁₂° = |E₁° – E₂°|). The Δ …

Development Of The Regenerative Glycosylation Approach For Manual And Automated Oligosaccharide Synthesis, Swati Sudhir Nigudkar

Dissertations

It has been recognized that carbohydrates are involved in all phases of life beginning with the embryonic development and cell growth. However, it is the involvement of carbohydrates in the progression of various deadly diseases that gave these natural compounds significant roles in diagnostics and as pharmaceuticals. Although carbohydrates are highly desirable to the biological and medical communities, these molecules are still very challenging targets for chemists. Functionalization, derivatization, controlling anomeric stereoselectivity, purification, and characterization are all existing experimental hurdles towards producing synthetic carbohydrates in large quantities and high purity. Advances in chemistry and biochemistry have certainly facilitated the synthesis …

Assessing Density Functionals For The Prediction Of Thermochemistry Of Ti-O-Cl Species, Yingbin Ge, Douglas Deprekel, Kui-Ting Lam, Kevin Ngo, Phu Vo

All Faculty Scholarship for the College of the Sciences

Titanium dioxide (TiO2) nanoparticles are widely used in contaminant remediation, photocatalysis, and solar cell manufacturing. The low-cost production of TiO2 nanoparticles via the combustion of titanium tetrachloride (TiCl4) in oxygen is thus an important industrial process. To accurately model the flame synthesis of TiO2 nanoparticles, reliable thermodynamic data of Ti-O-Cl species are indispensable but often unavailable. We therefore carried out benchmark calculations, using the left-eigenstate completely renormalized singles, doubles, and perturbative triples (CR-CC(2,3), aka CR-CCL) method with the cc-pVTZ basis set, to obtain the equilibrium structures and vibrational frequencies of selected Ti-O-Cl species; we then performed single-point CCSD(T)/aug-cc-pVLZ …

Structural Characterization Of A Newly Identified Component Of Α-Carboxysomes: The Aaa+ Domain Protein Csocbbq, Markus Sutter, Evan W. Roberts, Raul C. Gonzalez, Cassandra Bates, Salma Dawoud, Kimberly Landry, Gordon C. Cannon, Sabine Heinhorst, Cheryl A. Kerfeld

Faculty Publications

Carboxysomes are bacterial microcompartments that enhance carbon fixation by concentrating ribulose-1,5-bisphosphate carboxylase/oxygenase (RuBisCO) and its substrate CO₂ within a proteinaceous shell. They are found in all cyanobacteria, some purple photoautotrophs and many chemoautotrophic bacteria. Carboxysomes consist of a protein shell that encapsulates several hundred molecules of RuBisCO and contain carbonic anhydrase and other accessory proteins. Genes coding for carboxysome shell components and the encapsulated proteins are typically found together in an operon. The α-carboxysome operon is embedded in a cluster of additional, conserved genes that are presumably related to its function. In many chemoautotrophs, products of the expanded carboxysome …

Design And Synthesis Of Novel Chloroquine-Based Antimalarials, Kevin Vincent Murphy

Dissertations and Theses

Malaria is an infectious, often fatal disease that afflicts nearly 200 million people every year. The disease, characterized by recurring and extreme flu-like symptoms, is caused by the protozoan parasite Plasmodium falciparum. Victims usually contract the disease through a mosquito vector. Chloroquine is a chemotherapeutic that was introduced in the 1940s. For many years the drug was the foremost treatment of malaria, being effective and producing few side effects. Unfortunately, tolerance to chloroquine developed when the parasite evolved a resistance mechanism. Newer drugs have been developed and implemented, but these medicines also show a decreasing effect with continued administration. …

Viral Infection Causes A Shift In The Self Peptide Repertoire Presented By Human Mhc Class I Molecules, Charles T. Spencer, Jelena S. Bezbradica, Mireya G. Ramos, Chenoa D. Arico, Stephanie B. Conant, Pavlo Gilchuk, Jennifer J. Gray, Mu Zheng, Xinnan Niu, William Hildebrand, Andrew J. Link, Sebastian Joyce

Chemistry Faculty Research

Purpose

MHC class I presentation of peptides allows T cells to survey the cytoplasmic protein milieu of host cells. During infection, presentation of self peptides is, in part, replaced by presentation of microbial peptides. However, little is known about the self peptides presented during infection, despite the fact that microbial infections alter host cell gene expression patterns and protein metabolism.

Experimental design

The self peptide repertoire presented by HLA-A*01;01, HLA-A*02;01, HLA-B*07;02, HLA-B*35;01, and HLA-B*45;01 (where HLA is human leukocyte antigen) was determined by tandem MS before and after vaccinia virus infection.

Results

We observed a profound alteration in the self …

Energy-Efficient Computational Chemistry: Comparison Of X86 And Arm Systems, Kristopher Keipert, Gaurav Mitra, Vaibhav Sunriyal, Sarom S. Leang, Masha Sosonkina, Alistair P. Rendell, Mark S. Gordon

Computational Modeling & Simulation Engineering Faculty Publications

The computational efficiency and energy-to-solution of several applications using the GAMESS quantum chemistry suite of codes is evaluated for 32-bit and 64-bit ARM-based computers, and compared to an x86 machine. The x86 system completes all benchmark computations more quickly than either ARM system and is the best choice to minimize time to solution. The ARM64 and ARM32 computational performances are similar to each other for Hartree-Fock and density functional theory energy calculations. However, for memory-intensive second-order perturbation theory energy and gradient computations the lower ARM32 read/write memory bandwidth results in computation times as much as 86% longer than on the …

An Electrodeposited Inhomogeneous Metal-Insulator-Semiconductor Junction For Efficient Photoelectrochemical Water Oxidation, James C. Hill, Alan T. Landers, Jay A. Switzer

Chemistry Faculty Research & Creative Works

The photoelectrochemical splitting of water into hydrogen and oxygen requires a semiconductor to absorb light and generate electron-hole pairs, and a catalyst to enhance the kinetics of electron transfer between the semiconductor and solution. A crucial question is how this catalyst affects the band bending in the semiconductor, and, therefore, the photovoltage of the cell. We introduce a simple and inexpensive electrodeposition method to produce an efficient n-Si/SiOx/Co/CoOOH photoanode for the photoelectrochemical oxidation of water to oxygen. The photoanode functions as a solid-state, metal-insulator-semiconductor photovoltaic cell with spatially non-uniform barrier heights in series with a low overpotential water-splitting electrochemical cell. …

Preparation And Preliminary Dielectric Characterization Of Structured C60-Thiol-Ene Polymer Nanocomposites Assembled Using The Thiol-Ene Click Reaction, Hanaa Mohammed Ahmed, Amber Danielle Windham, Maryam M. Al-Ejji, Noora H. Al-Qahtani, Mohammad K. Hassan, Kenneth A. Mauritz, Randy K. Buchanan, J. Paige Buchanan

Faculty Publications

Fullerene-containing materials have the ability to store and release electrical energy. Therefore, fullerenes may ultimately find use in high-voltage equipment devices or as super capacitors for high electric energy storage due to this ease of manipulating their excellent dielectric properties and their high volume resistivity. A series of structured fullerene (C₆₀) polymer nanocomposites were assembled using the thiol-ene click reaction, between alkyl thiols and allyl functionalized C₆₀ derivatives. The resulting high-density C₆₀-urethane-thiol-ene (C₆₀-Thiol-Ene) networks possessed excellent mechanical properties. These novel networks were characterized using standard techniques, including infrared spectroscopy (FTIR), differential scanning calorimetry …

Crystal Structures Of Tris­[1-Oxo­Pyridine-2-Olato(1-)]Silicon(Iv) Chloride Chloro­Form-D1 Disolvate, Tris­[1-Oxo­Pyridine-2-Olato(1-)]Silicon(Iv) Chloride Aceto­Nitrile Unqu­Anti­Fied Solvate, And Fac-Tris­[1-Oxo­Pyridine-2-Thiol­Ato(1-)]Silicon(Iv) Chloride Chloro­Form-D1 Disolvate, Bradley M. Kraft, William W. Brennessel, Amy E. Ryan, Candace K. Benjamin

Chemistry Faculty/Staff Publications

The cations in the title salts, [Si(OPO)3]Cl·2CDCl3, (I), [Si(OPO)3]Cl·xCH3CN, (II), and fac-[Si(OPTO)3]Cl·2CDCl3, (III) (OPO = 1-oxo-2-pyridin­one, C5H4NO2, and OPTO = 1-oxo-2-pyridine­thione, C5H4NOS), have distorted octa­hedral coordination spheres. The first two structures contain the same cation and anion, but different solvents of crystallization led to different solvates and packing arrangements. In structures (I) and (III), the silicon complex cations and chloride anions are well separated, while in (II), there are two C-HCl distances that fall just within the sum of the van der Waals radii of the C and Cl atoms. The pyridine portions of the OPO ligands …

Selective Iodination Using Diaryliodonium Salts, William H. Miller Iv

Department of Chemistry: Dissertations, Theses, and Student Research

Aryl iodides have become widely recognized as versatile synthetic intermediates, owing to aromatic iodine’s excellent ability to participate in oxidative addition reactions. Iodoarenes readily undergo a variety of synthetic transformations including metal catalyzed cross-coupling reactions, diaryliodonium chemistry, formation of organometallics through reduction or metal-halogen exchange, as well as classical S_N2 type chemistry. Because a wide array of transformations are available for aryl iodides, organic molecules containing this moiety often serve as vital precursors to highly desirable pharmaceuticals.

This thesis describes a simple and selective two-step approach to the formation of aryl iodides. This method proceeds through an easily …

Real-Time Supervised Detection Of Pink Areas In Dermoscopic Images Of Melanoma: Importance Of Color Shades, Texture And Location, Ravneet Kaur, P. P. Albano, Justin G. Cole, Jason R. Hagerty, Robert W. Leander, Randy Hays Moss, William V. Stoecker

Electrical and Computer Engineering Faculty Research & Creative Works

Background/Purpose: Early detection of malignant melanoma is an important public health challenge. In the USA, dermatologists are seeing more melanomas at an early stage, before classic melanoma features have become apparent. Pink color is a feature of these early melanomas. If rapid and accurate automatic detection of pink color in these melanomas could be accomplished, there could be significant public health benefits.

Methods: Detection of three shades of pink (light pink, dark pink, and orange pink) was accomplished using color analysis techniques in five color planes (red, green, blue, hue, and saturation). Color shade analysis was performed using a logistic …

The Homo Nodal Arrangement In Polychromophoric Molecules And Assemblies Controls The Interchromophoric Electronic Coupling, Marat R. Talipov, Tushar Navale, Rajendra Rathore

Chemistry Faculty Research and Publications

Triptycenes spontaneously assemble into two-dimensional networks in which long-range charge transport is facilitated by the extensive electronic coupling through the triptycene framework (intramolecularly) and by cofacial π-stacking (intermolecularly). While designing and synthesizing next-generation triptycenes containing polyaromatic chromophores, the electronic coupling amongst the chromophores was observed to be highly dependent on the nature and position of the substituents. Herein, we demonstrate using hexaalkoxytriptycenes that the electronic coupling amongst the chromophores is switched on and off by a simple repositioning of the substituents, which alters the nodal arrangement of the HOMOs of the individual chromophores. A visual inspection of the HOMOs can …

Tailoring The Pore Environment Of Metal-Organic And Molecular Materials Decorated With Inorganic Anions: Platforms For Highly Selective Carbon Capture, Patrick Stephen Nugent

USF Tampa Graduate Theses and Dissertations

Due to their high surface areas and structural tunability, porous metal-organic materials, MOMs, have attracted wide research interest in areas such as carbon capture, as the judicious choice of molecular building block (MBB) and linker facilitates the design of MOMs with myriad topologies and allows for a systematic variation of the pore environment. Families of MOMs with modular components, i.e. MOM platforms, are eminently suitable for targeting the selective adsorption of guest molecules such as CO₂ because their pore size and pore functionality can each be tailored independently. MOMs with saturated metal centers (SMCs) that promote strong yet reversible …

Collecting Our Wisdom And Working Together, Making The Journal Go Further ---On The 20 Years Anniversary Of The Journal Of Electrochemistry, Zong-Rang Zhang

Journal of Electrochemistry

On celebrating the 20 years anniversary of the founding of Journal of Electrochemistry (China), the author wishes to make a brief record of its historical events during the past years, and also to pay respect to the entire person who contributed a lot for the development of the journal. Some personal ideas related to the future development of the journal are proposed too.

Sulfonated-Graphene/Nafion Composite Membrane For All Vanadium Redox Flow Batteries, Da-Wei Yang, Yan-Qing Dong, Jing-Min Fan, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Nafion membrane has been widely used in fuel cells due to its good proton conductivity, chemical and mechanical stabilities. However, the well-developed water channels in Nafion membrane have restricted its application in all vanadium redox flow batteries owing to the high permeation of vanadium ions and the cost. In this work, the water adsorption rate, resistivity and transference number of vanadium ions of sulfonated-graphene/Nafion composite membrane were investigated and compared with those of Nafion membrane in an effort to overcome the abovementioned drawbacks. It was found that the area resistivity and permeation rate of sulfonated-graphene/Nafion composite membrane were significantly reduced …