Chemistry Commons^™

Studies Aimed At The Synthesis Of Anti-Infective Agents, Ankush Kanwar

USF Tampa Graduate Theses and Dissertations

Infectious diseases continue to be a major concern worldwide. They are the second leading cause of death after heart disease. Factors such as an increasing global population, travel, urbanization, global climate change and evolution of pathogens have made infectious diseases more common. Infectious diseases, particularly neglected tropical diseases (NTDs) result in many deaths worldwide. Malaria and leishmaniasis are two common (NTDs) which affect low income countries around the globe. Low cost drugs with novel mechanism of action are required to tackle the growing resistances of parasites against current drugs used in the developing world, where most of the cases occur. …

Assessment Of Catalytic Function Of Gold Nanorod-Bound Tempo Under Nir Irradiation, Kristi L. St. Clair

Honors College Theses

Gold nanoparticles are of interest to a number of fields due to their size-dependent optical properties, high stability, and large surface area. The combination of these properties allows for a variety of uses including photothermal therapy, drug delivery and catalysis. Gold nanorods (GNR) absorb light of a given wavelength which stimulates the oscillation of electrons on the surface and is known as the surface plasmon resonance effect. The localized heating of rods via irradiation may cause enhanced effectiveness of an attached organic catalyst which allows the oxidation of alcohols to occur at room temperature. Previously, similar catalytic systems required high …

Contracted Schrödinger Equation And Kohn–Sham Effective Potentials, Viktor N. Staroverov

Chemistry Publications

The precise relationship between the exact expressions for the Kohn–Sham exchange-correlation potential, , deduced by Buijse, Baerends and Snijders and by Ryabinkin, Kohut and Staroverov is clarified. These two expressions differ nontrivially by a single term which in the former method generally involves the three-electron reduced density matrix, whereas in the latter approach the same term is expressed using the two-electron reduced density matrix at most. The link between the two expressions turns out to be the 1,3-contracted Schrödinger equation. An essential feature of these and other similar expressions for is that they produce different results in finite-basis-set calculations and …

Developing Kenya’S Educational Capacity In Nuclear Security Through Nuclear Forensics Research, Hudson Kalambuka Angeyo

International Journal of Nuclear Security

Nuclear energy’s distinctive characteristics give rise to special educational requirements. These requirements are necessary to not only address the danger of nuclear proliferation, but also to build capacity for a secure nuclear fuel circle. In this paper, I assess the status of educational capacity in nuclear security both in response to, and in support of, Kenya’s nuclear power program. I highlight the nuclear security educational infrastructure’s key features in the context of nuclear power, noting the low capacity at Kenyan universities. I identify the steps required to ensure that the country’s dynamic nuclear regulatory infrastructural framework is used effectively to …

Synthesis Of Symmetric And Unsymmetric Secondary Amines From The Ligand-Promoted Ruthenium-Catalyzed Deaminative Coupling Reaction Of Primary Amines, Pandula T. Kirinde Arachchige, Hanbin Lee, Chae S. Yi

Chemistry Faculty Research and Publications

The catalytic system generated in situ from the tetranuclear Ru–H complex with a catechol ligand (1/L1) was found to be effective for the direct deaminative coupling of two primary amines to form secondary amines. The catalyst 1/L1 was highly chemoselective for promoting the coupling of two different primary amines to afford unsymmetric secondary amines. The analogous coupling of aniline with primary amines formed aryl-substituted secondary amines. The treatment of aniline-d₇ with 4-methoxybenzylamine led to the coupling product with significant deuterium incorporation on CH₂ (18% D). The most pronounced carbon isotope effect …

Shaping Light In Backward-Wave Nonlinear Hyperbolic Metamaterials, Thomas George, Alexander Popov, Sergey Myslivets, Vitaly Slabko, Victor Tkachenko

Chemistry & Biochemistry Faculty Works

Backward electromagnetic waves are extraordinary waves with contra-directed phase velocity and energy flux. Unusual properties of the coherent nonlinear optical coupling of the phase-matched ordinary and backward electromagnetic waves with contra-directed energy fluxes are described that enable greatly-enhanced frequency and propagation direction conversion, parametrical amplification, as well as control of shape of the light pulses. Extraordinary transient processes that emerge in such metamaterials in pulsed regimes are described. The results of the numerical simulation of particular plasmonic metamaterials with hyperbolic dispersion are presented, which prove the possibility to match phases of such coupled guided ordinary and backward electromagnetic waves. Particular …

Cation Exchange Capacity Determination: Comparative Study Of Three Methods, Lillie Zech

Undergraduate Research Conference

No abstract provided.

Structural And Compositional Investigation Of Pottery Samples From Guatemala, Pressley S. Nicholson

Undergraduate Research Conference

Purpose of investigation: The composition and characteristics of Mayan pottery samples from Guatemala was investigated.

Spidr: Small-Molecule Peptide-Influenced Drug Repurposing, Matthew D. King, Thomas Long, Daniel L. Pfalmer, Timothy L. Andersen, Owen M. Mcdougal

Chemistry and Biochemistry Faculty Publications and Presentations

Background: Conventional de novo drug design is costly and time consuming, making it accessible to only the best resourced research organizations. An emergent approach to new drug development is drug repurposing, in which compounds that have already gone through some level of clinical testing are examined for efficacy against diseases divergent than their original application. Repurposing of existing drugs circumvents the time and considerable cost of early stages of drug development, and can be accelerated by using software to screen existing chemical databases to identify suitable drug candidates.

Results: Small-molecule Peptide-Influenced Drug Repurposing (SPIDR) was developed to identify small molecule …

Bioinformatics- And Phylogenetics-Guided Approaches To Understanding Sequence-Function Relationships Of Type Ii Polyketide Biosynthetic Gene Clusters, Han Bich Nguyen

Chemistry and Chemical Biology ETDs

Type II polyketides (PK-II) has made up a class of natural products that are structurally diverse and are clinically useful due to their wide-range of bioactivity. The work described in this dissertation focuses on developing approaches to facilitate our understanding of sequence-function relationships of PK-II biosynthetic gene clusters (BGCs). We have systematically summarized the previous characterizations of enzymes involved in the core structure biosynthesis, which have set a foundation for our developments of approaches to discover organisms harboring novel enzymes responsible for novel PK-II molecules. We have successfully developed bioinformatics tools to globally mine the PK-II BGCs in the NCBI …

Intermolecular-Trapping Of 1,3-Dialkyl Diaziridines With Hdda-Derived Benzynes, Ramitha Rupasinghe

Undergraduate Research Symposium 2018

The extent to which benzynes react with various trapping agents is an important question in synthetic chemistry due to its versatility to produce products that can be used as pharmaceuticals, dyes and other complex molecules. The hexadehydro-Diels-Alder (HDDA) reaction allows the generation of benzynes in situ which then can be efficiently trapped to synthesize complex products in one step with high yields. Reactions of HDDA - derived benzynes with trapping agents such as thioamides, alcohols, pyrroles, silyl ethers and multifunctional natural products have been studied in previous research. In this research, the reactions of HDDA-derived benzynes with diaziridines is explored …

Student Learning In Online Chemistry Textbooks, Jimmy Cerone

17th Annual Celebration of Undergraduate Research and Creative Performance (2018)

Rising textbook prices are pushing both students and professors to consider alternatives to the traditional textbook. The online medium is promising because of reduced prices and additional interactivity. One possible solution is an open textbook, which is freely available online. One feature of the online medium is that references within a textbook can be linked, and students can click these links to move easily between topics. The research performed here uses Google Analytics website traffic data to see how the over 2,000,000 visitors per month use intertext links (links to other parts of the textbook) on the 20 most popular …

Assessing The Impact On Learning Of Summer Science Camps, Kylie Dekryger

17th Annual Celebration of Undergraduate Research and Creative Performance (2018)

The Hope College Summer Science Camps were founded by Tod Gugino in 1997 to provide fun, engaging, hands-on science experiences for local K-5 students. The first summer involved 2 camps and served approximately 50 children. Over the past 20 years, the camps have expanded to the point where there are now 50 offerings, serving over 800 K-12 students during 6 weeks in the summer. In addition, 15-20 Hope College students gain experiential learning as they lead the camps and plan curriculum each summer. Recently, an effort has been made to align the science camp content with the Next Generation Science …

Steric Effects On The Formation Of Manganese Oxide Clusters And 2-Dimensional Ammonium Formate Architectures, Carl Oberle

Dissertations

It has been demonstrated by the Beatty group that altering the identity of the ortho-substituent of a dianiline counterion affects the assembly and dimensionality of a cadmium-chloride layer from 2-D to 0-D. This work seeks to extend this finding to metal oxide and organic hydrogen-bonded materials. By systematically increasing the ortho­-substituent’s size on the benzoate building block of reported manganese oxide clusters, of formula Mn_xO_y(O₂C-R)_zL_w (where R = Alkyl, L = neutral monodentate ligand), we aim to impact the self-assembly of these materials relative to their parent …

Environmentally Benign Catalysts By Design: Functional Mimics Of Meralloenzymes, Niharika Botcha, Brianna Sullivan, Nirupama Singh

Research Horizons Day Posters

No abstract provided.

Scalable Cation Exchange Reactions Of Metal Chalcogenide Quantum Dots, V.V.N. Manohar Devarasetty

Research Horizons Day Posters

No abstract provided.

Chloroform Extracts Of Ipomoea Alba And Ipomoea Tricolor Seeds Show Strong In-Vitro Antibacterial, Antifungal, And Cytotoxic Activity, Sims K. Lawson, Mary N. Davis, Carolyn Brazell

Research Horizons Day Posters

No abstract provided.

Evaluation Of Vaporization Enthalpies And Vapor Pressures Of Various Aroma And Pharmacologically Active Compounds By Correlation Gas Chromatography, Daniel Simmons

Theses

Scientists in the pharmaceutical, food, and aroma industries can benefit from reliable thermochemical data. Vaporization enthalpy and vapor pressure data are not available for all compounds. Furthermore, some literature data is conflicting. The goal of this work was to use a method called correlation gas chromatography (CGC) to generate reliable vaporization enthalpy data in instances where other experimental methods are not applicable. Vapor pressures of the targets were also calculated in cases where the required literature data on the standards used in this technique were available.

CGC involves making a standard cocktail that includes a mixture of standards and one …

Thermal Analytical Studies Of Azo-Tetrazolate Compounds For Htpb Based Hybrid Rocket Fuels, Muntaha Yousef

Theses and Dissertations

Azo-Tetrazolate salts and their derivatives have identical negatively conjugated nitrogen rings and two varied positively charged cations. The varied cations are Guanidinium, Aminoguanidinium, Diaminoguanidinium, Triaminoguanidinium and Ammonium. Azo-Tetrazolate salts and their derivatives were synthesized and fully characterized by multinuclear spectroscopy (NMR) and Fourier Transform Infrared Spectroscopy (FTIR). The thermal behavior and decomposition kinetics of Guanidinium Azo-Tetrazolate (GAT), Aminoguanidinium Azo-Tetrazolate monohydrate (AGATH), Diaminoguanidinium Azo-Tetrazolate (DAGAT), Triaminoguanidinium Azo-Tetrazolate (TAGAT)and Ammonium Azo-Tetrazolate (AZT), were investigated by Differential Scanning Calorimetry (DSC) and Thermogravimetric Analysis (TGA) techniques. The kinetic and thermodynamic parameters of these energetic materials were calculated non-isothermally by DSC instrument, under various heating …

Quantum Chemical Analysis Of Stable Noble Gas Cations For Astrochemical Detection, Carlie M. Novak

Honors College Theses

The search for possible, natural, noble gas molecules has led to quantum chemical, spectroscopic analysis of NeCCH+, ArNH+ ArCCH+, and ArCN+. Each of these systems have been previously shown to be a stable minimum on its respective potential energy surface. However, no spectroscopic data are available for laboratory detection or interstellar observation of these species, and the interstellar medium may be the most likely place, in nature, where these noble gas cations are found. The bent shape of NeCCH+ is confirmed here with a fairly large dipole moment and a bright C -- H stretching frequency at 3101.9 cm^{-1 …}

Sugar Analysis Of Mashing Process In Beer Brewing, Ken Overway, Heather Gibson

Chemistry Faculty Scholarship

In beer brewing, the mashing process produces the simple sugars that eventually become ethanol. Two important enzymes, α- and β-amylase, are most active at specific temperatures, and the mashing process tries to maximize the their efficacy. The most common sugars hydrolyzed during this process are maltose, glucose, sucrose, and fructose. Different grains require different mashing temperatures and will produce a unique amount of each sugar. Many studies have focused on the enzymatic activity to observe the mashing profile of common beer grains, such as barley or wheat. The focus of this study has been observing the enzymatic activity of barley. …

Extraction Of Ppix From Brown Eggshells For Use In Dye-Sensitized Solar Cells, Ken Overway, Carleigh Studtmann, Taylor Varner

Chemistry Faculty Scholarship

Dye-sensitized solar cells (DSSC) are a possible alternative to traditional solar energy technologies. Organic dyes such as porphyrins seem to be an especially promising option as a sensitizer due to their characteristic Soret band and smaller Q-bands in the visible spectrum. Protoporphyrin IX (PPIX) is a naturally occurring porphyrin found in sources such as hemoglobin, chlorophyll, and brown eggshells. PPIX exhibits a typical porphyrin absorbance spectrum, and the carboxylic acid substituents make it ideal for direct attachment to the TiO₂ of the DSSC. The purpose of the research project is to extract PPIX at a high enough concentration from …

From Flasks To Applications: Design And Optimization Of Giant Quantum Dots Using Traditional And Automated Synthetic Methods, Christina J. Hanson

Nanoscience and Microsystems ETDs

Semiconducting nanocrystals, also known as quantum dots (QDs), that emit light with near-unity quantum yield and are extremely photostable are attractive options as down-conversion and direct electricity-to-light materials for a variety of applications including solid-state lighting, display technologies, bio-imaging and optical tracking. Standard QDs with a core/thin shell structure display fluorescence intermittency (blinking) and photobleaching when exposed to prolonged room temperature excitation for single dot measurements, as well as significant reabsorption and energy transfer when densely packed into polymers or at high solution concentrations.

We have developed thick shell “giant” QDs (gQDs), ultra-stable photon sources both at the ensemble and …

Primary Phosphines: New Synthetic Methods And New Targets, Bethany Palen, Emily Landgreen, Joseph K. West

Undergraduate Research Celebration 2018

No abstract provided.

Combined Theoretical And Experimental Investigation Of Hydrogen Production Catalysis, Carolyn Noelle Virca

Dissertations and Theses

The widespread use of solar energy has been limited in part by the issue of effective storage. Water splitting is a means of converting solar energy into chemical fuel, in the form of hydrogen gas. It can be performed through both photochemical and electrochemical processes, via the two half reactions of water oxidation and proton reduction. Electrochemically, the catalyst receives electrons from an external circuit, which can be coupled to a renewable source such as a solar cell. Photochemically, a light-absorbing molecule provides an excited electron to a catalyst, which either generates oxygen or hydrogen gas. The work described herein …

Chemical Synthesis Of Staphylococcal Oligosaccharides, Satsawat Visansirikul

Dissertations

The Gram positive, cluster forming bacteria Staphylococcus aureus belongs to the family of opportunistic pathogens that may cause blood stream infections when the integrity of skin is broken and the immune system can no longer fight the infection. S. aureus has become one of the most frequent causes of infections in newborns, surgical patients, trauma and burn patients, patients receiving an implant, and dialysis patients with high mortality rates. As a matter of fact, S. aureus has become one of the largest public health and economic impacts amongst all bacterial infectious diseases worldwide. This situation is further complicated by the …

Identification Of Significant E0 Strength In The 22+ → 21+ Transitions Of 58,60,62Ni, L. J. Evitts, A. B. Garnsworthy, T. Kibédi, J. Smallcombe, M. W. Reed, B. A. Brown, A. E. Stuchbery, G. J. Lane, T. K. Eriksen, A. Akber, B. Alshahrani, M. De Vries, M. S. M. Gerathy, J. D. Holt, B. Q. Lee, B. P. Mccormick, A. J. Mitchell, M. Moukaddam, Sharmistha Mukhopadhyay, N. Palalani, T. Palazzo, Erin E. Peters, Anthony Paul D. Ramirez, S. R. Stroberg, T. Tornyi, Steven W. Yates

Chemistry Faculty Publications

The E0 transition strength in the 2₂⁺ → 2₁⁺ transitions of ^58,60,62Ni have been determined for the first time following a series of measurements at the Australian National University (ANU) and the University of Kentucky (UK). The CAESAR Compton-suppressed HPGe array and the Super-e solenoid at ANU were used to measure the δ(E2/M1) mixing ratio and internal conversion coefficient of each transition following inelastic proton scattering. Level half-lives, δ(E2/M1) mixing ratios and γ-ray branching ratios were measured at UK following inelastic neutron scattering. …

Structural Evidence For Rifampicin Monooxygenase Inactivating Rifampicin By Cleaving Its Ansa-Bridge, Li Kai Liu, Yumin Dai, Heba Abdelwahab, Pablo Sobrado, John J. Tanner

Chemistry Faculty Research & Creative Works

Rifampicin monooxygenase (RIFMO) decreases the potency of rifampicin (RIF) by converting it to oxidative products. Further decomposition of RIF has been observed in bacteria producing RIFMO and contributes to RIFMO-mediated drug resistance. Here we report the first crystal structure of RIFMO in complex with the hydroxylated RIF product. The 2.10 Å resolution structure reveals a breach of the ansa aliphatic chain of RIF between naphthoquinone C2 and amide N1. Our data suggest that RIFMO catalyzes the hydroxylation of RIF at the C2 atom followed by cleavage of the ansa linkage, which leads to inactivation of the antibiotic by preventing key …

Time-Dependent Efficiency Measurements Of Polymer Solar Cells With Dye Additives: Unexpected Initial Increase Of Efficiency, Kyle J. Bandaccari, Grace E. Chesmore, Mitchel Bugaj, Parisa Tajalli-Tehrani Valverde, Richard P. Barber Jr., Brian J. Mcnelis

Physics

We report the effects of the addition of two azo-dye additives on the time-dependent efficiency of polymer solar cells. Although the maximum efficiencies of devices containing different amounts of dye do not vary greatly over the selected concentration range, the time dependence results reveal a surprising initial increase in efficiency in some samples. We observe this effect to be correlated with a leakage current, although a specific mechanism is not yet identified. We also present the measured lifetimes of these solar cells, and find that variations in dye concentrations produce a small effect at most. Characterization of the bulk heterojunction …

Tuning The Hydrophobic Cores Of Self-Immolative Polyglyoxylate Assemblies, Bo Fan, Rebecca E. Yardley, John F. Trant, Aneta Borecki, Elizabeth R. Gillies

Chemistry Publications

Polyglyoxylates are a recently-introduced class of self-immolative polymers, that depolymerize to small molecules upon the cleavage of a stimuli-responsive end-cap from the polymer terminus. The incorporation of different pendant ester groups or other aldehyde monomers offers the potential to tune the polymer properties, but this remains largely unexplored. With the goal of tuning the self-assembly and drug-loading properties of polyglyoxylate block copolymers, we explored the polymerization and copolymerization of n-butyl glyoxylate, L-menthyl glyoxylate, and chloral with ethyl glyoxylate to form UV light-responsive polyglyoxylates. The resulting polymers were coupled to poly(ethylene glycol) to afford amphiphilic block copolymers. Self-assembly of the …