Chemistry Commons^™

Photoluminescent Studies Of Metal-Organic Frameworks For Small Molecule Sensing, Julia T. Dematteo

USF Tampa Graduate Theses and Dissertations

Metal–organic frameworks (MOFs) are highly tunable nanoporous materials with broad applications in gas separation, drug delivery, light harvesting, and chemical sensing. The incorporation of photoactive components into MOFs enables the development of optical sensors capable of detecting a wide range of analytes. Porphyrins and metalloporphyrins are particularly attractive for such applications due to their high molar absorptivity, strong emission quantum yields, and versatile interactions with chemical species.

In this work, two porphyrinic MOFs, PCN-222 and MOF1(Cd), are investigated. Both frameworks utilize tetrakis(4-carboxyphenyl)porphyrin (TCPP) as the organic linker, imparting optical functionality to the materials. Integration of TCPP into the framework induces …

Photophysical Behavior Of Ruthenium-Based Complexes: A Study Of Ligand Variation And Encapsulation In Metal-Organic Frameworks, Delaney S. Sellers

USF Tampa Graduate Theses and Dissertations

Ruthenium (II) polypyridyl complexes have emerged as a prominent class of compounds in inorganic photochemistry due to their structural robustness, reversible redox chemistry, and tunable excited-state dynamics. Central to the investigation of these systems is the ability to manipulate the triplet metal-to-ligand charge transfer state (3MLCT). In the context of photoactivated chemotherapy (PACT), the strategic deactivation of this MLCT state to populate a dissociative triplet ligand field state (3LF) can enable the controlled, light-triggered release of caged cytotoxic agents. This work focuses on understanding the caging mechanism of various ligands to optimize the eventual delivery of cytotoxic ligands. In this …

The Architecture Of Chemical Understanding: How Representation Selection, Ordering, And Feature Salience Shape Students' Conceptions In Chemistry, Isaiah Nelsen

USF Tampa Graduate Theses and Dissertations

Chemical representations play a central role in how students learn and reason aboutchemistry. While representations are routinely used in chemistry classrooms, students often struggle to extract relevant information, connect representations to underlying chemical principles, and apply this information to problem-solving. This dissertation investigates the role of representations in supporting students’ conceptual understanding and reasoning across general and organic chemistry through three qualitative studies.

The first study in this work explores how variation in chemical representation influences how students understand foundational chemistry principles. This study sought to characterize how second semester general chemistry students approach dipole–dipole interaction tasks with four distinct …

Chemical Design Strategies For Hybrid Metal Halide Semiconductors With Enhanced Stability And Optoelectronic Properties, Ali Azmy

USF Tampa Graduate Theses and Dissertations

Metal halide semiconductors have rejuvenated the attention of the scientific community for the last two decades owing to their photophysical and electronic properties. However, these materials have some limitations that hinder their commercialization and widespread application. One major limitation of these materials is their instability under ambient and operating conditions of moisture, head, light and radiation exposure. Here, we report multiple chemical design strategies to address the stability issues of these materials while simultaneously maintaining their exceptional optoelectronic properties. Such design strategies allowed the acquisition of the first members of the family of porous metal halide semiconductors which exhibit record …

From The Tropics To The Poles: Chemical Investigation Of Marine Invertebrates Through Elucidation And Synthesis, Benjamin Reed Smith

USF Tampa Graduate Theses and Dissertations

Society’s perpetual need for new disease treatments continuously leans on the shouldersof willing researchers. Even in modern day, many described diseases lack a cure or a symptomatic treatment; worse yet, the necessity for new drugs is amplified with rises in drug- resistant microbial infections, such as methicillin-resistant Staphylococcus aureus (MRSA). Historically, remedies and disease treatments have been rooted in the medicinal properties of plants and animals; naturally derived analgesics, like milk of the poppy or willow bark tea, date back thousands of years. With the developments of modern medicine, drug discovery, and natural product researchers found a wealth of potential …

Exploring Enacted Active Learning Practices In Postsecondary Chemistry Lecture And Laboratory Courses, Kendall M. Zammit

USF Tampa Graduate Theses and Dissertations

The work in this thesis begins to explore the enacted active learning practices in postsecondary chemistry lecture and laboratory courses. Chapter 1 explores the level of inquiry in postsecondary laboratories. Chapter 2 explores instructional and assessment practices at two-year institutions.

Chemistry postsecondary laboratories offer a unique opportunity to engage students in inquiry-based instruction. Inquiry-based instruction was categorized by the asking faculty members at four-institutions about six characteristics of laboratory design: choosing a problem, background research, designing procedures, analyzing data, communicating results, and interpreting results. As students have the freedom to make decisions on more characteristics of inquiry learning, the closer …

An Integrated Pcb-Based Heating And Auto-Ranging Platform For Volatile Organic Compound (Voc) Detection Using Carbon Nanotube Based Sensors, Thomas Kalach

USF Tampa Graduate Theses and Dissertations

This thesis presents the development, characterization, and integration of a novel low-cost, high-dynamic-range sensor platform for the detection of volatile organic compounds (VOCs), leveraging the unique electrical properties of carbon nanotube (CNT) thin films. The platform introduces a fully integrated auto-ranging analog front-end circuit capable of real-time resistance measurement spanning over eight orders of magnitude ranging from tens of ohms to hundreds of megaohms, without compromising signal resolution or precision. This was achieved through a digitally controlled, multi-path feedback architecture and controllable current source.

To further enhance sensor performance, the system incorporates a copper trace heater beneath the sensor array, …

Introductory Chemistry Student Success: Investigating Study Strategies And Evaluating An Informative Utility Value Intervention, Pallavi Nayyar

USF Tampa Graduate Theses and Dissertations

Improving retention in STEM (science, technology, engineering, and mathematics) programs is essential to meet the growing demand for skilled professionals in the domestic workforce. To achieve this, it is critical to understand and address the factors that influence student persistence in STEM degrees. Gateway courses such as general chemistry often serve as early barriers to STEM degree completion, with high rates of attrition that impact not only individual students but also institutions and society. Therefore, the aim of this work was to examine and influence the factors that contribute to student withdrawal from introductory chemistry courses in order to promote …

Investigating Factors Influencing Organic Chemistry Learners' Explanation Sophistication And Representational Competence, Caroline J. Crowder

USF Tampa Graduate Theses and Dissertations

The research presented in this dissertation has two themes: organic chemistry learners’ written explanations and representational competence. Chapters 3 and 4 explore how organic chemistry learners construct explanations of reaction mechanisms, specifically focusing on electrophile and nucleophile components. Chapter 5 investigates organic chemistry learners’ representational competence skills and the relationship between these skills and their performance in the course.

Understanding reaction mechanisms is critical for success in organic chemistry, yet learners often struggle to reason beyond explicit, surface-level features. Constructed-response prompts that ask learners to explain what is happening in a reaction mechanism and why it occurs can provide insight …

The Synthesis Of A Photo-Affinity Probe Library For The Fatty Acid Amide Proteome And The Endocannabinoid System Within, Robert E. Feeney Iii

USF Tampa Graduate Theses and Dissertations

Fatty acid amides are a large family of endogenous metabolites with significant biological activity, including that of the endocannabinoid system. Currently little is known about how this system of tightly regulated compounds works within humans. This work lays the foundation to explore the structure-activity relationship driving the selectivity of ligand-protein interactions involved with fatty acid amides. A library of activity-based proteomic profiling probes for fatty acid amides has been synthesized to this end. Additionally, progress towards phytocannabinoid probes has been made as well.

Development And Photophysical Characterization Of Bioinspired Materials, Qaisar Maqbool

USF Tampa Graduate Theses and Dissertations

Porphyrins are versatile aromatic macrocycles with unique photophysical properties that make them attractive for applications in light harvesting, photocatalysis, and sustainable energy conversion. Incorporating porphyrins into metal-organic frameworks (MOFs) offers a unique opportunity to modulate their photophysical behavior through spatial confinement and host–guest interactions. This thesis explores how structural modifications influence porphyrin excited-state behavior through a multi-stage investigation. The work begins by comparing the photophysical properties of two cationic porphyrins: tetra(N-methylpyridyl) porphyrin(TMPyP) and tetra(4-N,N,N-trimethylanilinium) porphyrin(4TANP). While TMPyP exhibits significant singlet–charge transfer (S₁–CT) state mixing due to charge delocalization onto peripheral pyridinium groups, 4TANP lacks comparable behavior. The localized nature of …

Development Of S(Vi) And S(Iv) Chemistry: From Asymmetric Synthesis To Covalent Reactive Groups, Chuan Shan

USF Tampa Graduate Theses and Dissertations

This dissertation mainly covers the development of synthetic methodologies related to several heteroatom functional groups, including phosphonates P(V), sulfoximines S(VI), sulfonimidamides S(VI), sulfonimidoyl fluorides S(VI), and sulfinamides S(IV). The interests in these functionalities are not only out of chemistry curiosity but also due to their pharmaceutical importance indicated by the existing drug molecules that contain these functional groups. The first chapter introduced the importance of phosphonates in biochemistry and organic synthesis, also provided some essential background of our synthetic efforts. The second chapter described the phosphonate synthesis from commercially available starting materials, with the purpose to obtain heterocyclic phosphonates in …

Efforts To Improve General Chemistry Student Success: Describing Stoichiometry Solution Patterns And Investigating Challenge Perceptions, Dianna Kim

USF Tampa Graduate Theses and Dissertations

There is a need for capable STEM graduates to fill needed STEM career gaps, particularly for people who have been historically under-represented in the STEM field (e.g., women, people of color, people of lower economic status, etc.). A course that have great impact would be General Chemistry which typically acts as a pre-requisite for manty STEM majors and careers. The efforts to be described in this thesis was conducted at a large, public doctoral granting university in the southeastern United States of America. The first effort described in this thesis explores how students solve different types of stoichiometry-based problems along …

Acoustic Energy For Use In Mass Spectrometry, Ashton N. Taylor

USF Tampa Graduate Theses and Dissertations

Analyzing lipid assemblies, including synthetically produced liposomes and naturally produced extracellular vesicles (EVs), is challenging due to their size, diverse composition, and tendency to aggregate. EVs contain a complex variety of lipids, proteins, and other metabolites. EVs composition can provide us insight into what is happening inside the body and a subcellular level and have potential for noninvasive biomarkers. Liposomes are vesicles that form with a simple phospholipid bilayer membrane and play important roles in drug delivery systems. The use of mass spectrometry (MS) allows for broad analysis of lipids from different classes but their release from the higher order …

Biodegradable And Green Controlled Release Formulations For Fertilizers, Srivalli Sriperambudur

USF Tampa Graduate Theses and Dissertations

This study aims to address environmental concerns associated with conventional fertilizers, and the persistence of synthetic polymers in soils and investigates the use of biodegradable cellulose esters as sustainable coatings for controlled-release fertilizers (CRFs). The focus is mainly on the synthesis of biodegradable cellulose esters as sustainable coatings for CRFs and applied as a coating on urea fertilizer prills to control nutrient release. The synthesized biodegradable coatings aim to provide effective nutrient delivery over time while minimizing environmental impact. Cellulose esters were synthesized using both saturated and unsaturated fatty acids, followed by crosslinking using thiols. Characterization techniques like FTIR, DSC, …

Development Of Peptidomimetics Based On Γ-Aapeptide Molecular Scaffolds To Modulate Amyloid Peptide Aggregation, Heng Liu

USF Tampa Graduate Theses and Dissertations

Many proteins contain fragments that become structured upon binding to specific targets or through self-association. Notable examples of such disorder-to-order transitions include amyloidogenic proteins like amyloid-β peptide (Aβ) and tau peptide in Alzheimer's disease, α-Synuclein in Parkinson's disease, and hIAPP in type 2 diabetes, and so on. These regions can aggregate into amyloid fibrils through β -sheet stacking, contributing to amyloidosis and related diseases. Although direct link between amyloid formation and neurodegenerative disease development is not fully understood, developing effective inhibitors of these amyloid peptides remains promising both for fundamental research and therapeutical advance.

We have developed a new class …

Regioselective Hydroamination Of Unactivated Olefins With Diazirine And Total Synthesis Of Nostodione A And Scytonemin, Qingyu Xing

USF Tampa Graduate Theses and Dissertations

As an atom-economic way of carbon-nitrogen bond formation, hydroaminations are great tool for make amines, hydrazines, and other nitrogen-containing heterocycles. Specifically, radical hydroamination is a useful approach for functionalization of unactivated olefins, especially in sterically hindered environments. Diversification remains a challenge for radical hydroaminated products, since the nitrogen sources are carefully designed. In the first chapter of this dissertation, we report a highly diversifiable radical hydroamination reaction with diazirine as a nitrogen source and its potential applications in synthesis of several pharmaceutical interested compounds. Cobalt catalyzed regioselective hydroamination with diazirine shows wide function group tolerance, like phenyl thioether, ketones, esters, …

The Discovery Of First Ret Protac With In Vivo Activity, Yafeng Wang

USF Tampa Graduate Theses and Dissertations

This report mainly discusses the development of RET Proteolysis targeting chimera PROTAC molecules based on Selpercatinib (LOXO-292) and Sulfono-γ-AApeptide PROTAC. A PROTAC molecule is a bifunctional molecule composed of two active domains and a linker. It works by inducing selective protein intracellular degradation. This technology was first discussed by Kathleen Sakamoto, Ray Deshaies and Craig Crews in 2001. Using various E3 Ligase, such as CRBN, pVHL, beta-TrCP1, Mdm2, DCAF15, DCAF16, RNF114, and c-IAP1, the PROTAC technology has been applied to several novel drug development,. Yale University licensed the PROTAC technology to Arvinas in 2013–14. For my research, Chapter one summarizes …

The Asymmetric Total Synthesis Of Membranolide And Efforts Towards The Oxeatamides, Sean Bradley

USF Tampa Graduate Theses and Dissertations

Total synthesis is a discipline within organic chemistry that is a constant force that propels the field forward. In our lab, we have immersed ourselves within the field of total synthesis to gain access to complex natural products, perform SAR studies, as well as highlight interesting methodology. Within these endeavors, we have completed the first asymmetric synthesis of membranolide. This has allowed us to explore potential biofilm eradication in our efforts to develop novel therapeutics to combat the ESKAPE pathogens and multi-drug resistance. We have also begun to pursue the first asymmetric total synthesis of the oxeatamides. By utilizing our …

Predicting Ph At In-Situ Temperature For Aquatic Environments, Sarah E. Bartoloni

USF Tampa Graduate Theses and Dissertations

pH is typically measured at a constant temperature and, as needed, converted to in-situ temperature using a system of thermodynamic equations. Using this equilibrium approach, adjustment of pH to in situ conditions requires two measured CO2 system parameters (pH, total alkalinity, dissolved inorganic carbon, or CO2 fugacity). Currently, when pH is the only measured CO2 system parameter, linear models are used to adjust the pH to in-situ temperature. Although many studies have attempted to optimize CO2 equilibrium constants (K1 and K2) for the CO2 system over a range of conditions, very little prior work has experimentally examined which CO2 system …

A Speleogenetic History Of Novoafonskaya Cave In The Western Caucasus, Olga Chervyatsova, Sergey Potapov, Jonathan Baker, Dmitry Gavryushkin, Victor Polyak, Matt Heizler, Sergey Tokarev, Sergey Sadykov, Roman Dbar, Yuri Dublyansky

International Journal of Speleology

Speleogenesis in hypogene karst settings may be closely tied to regional tectonic dynamics and concomitant hydrochemical evolution of karst waters. However, placing temporal constraints on these processes can require a wider array of field observations and techniques than for typical karst systems. Herein, we present a comprehensive study of Novoafonskaya Cave (Western Caucasus, Abkhazia). The updated speleogenetic history of the cave comprises four stages: (1) the most ancient, a low-T hydrothermal (ca. 40–50°C) priming stage; (2) the main stage enabled by mixing of upwelling thermomineral and locally recharged common karst waters; (3) the late sulfuric-acid speleogenesis (SAS) stage, which left …

Introductory Chemistry Student Success: Evaluating Peer-Led Team Learning And Describing Sense Of Belonging, Jessica D. Young

USF Tampa Graduate Theses and Dissertations

Identifying approaches that make science and engineering education broader and more inclusive is core to discipline based education research. Both fundamental and applied research are important in advancing a STEM education that retains the necessary scientists of the U.S.’s future. Thus, the major goal of this work was to evaluate and describe efforts that promote student success within introductory STEM courses. This began with applied research by utilizing quantitative analyses like case-matching, logistic regression, independent sample t-tests, and repeated measures while evaluating the efficacy of peer-led team learning (PLTL). Later, this work delves into qualitative approaches to answer fundamental research …

Explorations On Non-Covalent Interactions: From Supramolecules To Drug-Like Molecules, Zhanpeng Zhang

USF Tampa Graduate Theses and Dissertations

Non-covalent interactions are everywhere in our material world. From the microstructures of organisms to the functional materials used in industrial production, whenever matter exists, there are non-covalent interactions between the molecules that build up the matter.The exploration of non-covalent forces helps people understand the intrinsic principles of life processes, it can be applied to create new supramolecular materials as well. Supramolecular chemistry is a research field focusing on the properties and applications of non-covalent interactions. Various non-covalent interactions, such as hydrogen bonds, metal-ligand coordination, π-π interaction, hydrophobic interaction, etc., are objects of research in supramolecular chemistry.

Not only supramolecular chemists, …

Surface Modification Of Poly(4,4'-Oxydiphenilene Pyromellitimide) With Low-Pressure Plasma Treatment, Cihan Aktas

USF Tampa Graduate Theses and Dissertations

This study explores the change of the wetting characteristics of commercially availablepolyimide (PI), Kapton® HN, films a type of poly(4,4′-oxydiphenylene-pyromellitimide), following treatment with low-pressure plasmas of carbon tetrafluoride (CF4), air, hydrogen (H2), carbon-dioxide (CO2) and oxygen (O2) gases as well as the surface texturing via laser-exposure procedure. The water contact angle (CA) and surface free energy (SFE) of untreated PI films were determined as 82.4°±0.8 and 45.0±0.3 mN/m, respectively. After CF4 plasma gas treatment, the CA value of PI films increased to 110.2°±1.0, while it decreased to 9.3°±2.3 after O2 plasma gas treatment. The surface free energy (SFE) of PI …

Methods For Analytical And Biophysical Analysis For Investigation Of Stimulator Of Interferon Genes In Drug Discovery, William Emmett Brian Lawless

USF Tampa Graduate Theses and Dissertations

This work elaborates on analytical and biophysical techniques including high pressure liquid chromatography (HPLC), mass spectrometry quadrupole time-of-flight (MS-QToF), dynamic light scattering (DLS), microscale thermophoresis (MST), surface plasmon resonance (SPR), isothermal calorimetry (ITC), size exclusion chromatography, and native gel electrophoresis. A basic overview is described for each technique and is designed for easy understanding by both novice and experienced analysts. Best practices for each technique are discussed and suggestions are made for protocol improvements or troubleshooting. Protocol development is discussed, and a method is introduced for MST that can be adapted to any target protein for rapid screening of analog …

Syntheses, Photophysics, & Application Of Porphyrinic Metal-Organic Frameworks, Zachary L. Magnuson

USF Tampa Graduate Theses and Dissertations

Porphyrins are a group of heterocyclic macrocycles that play crucial roles in various biological processes such as electron transfer, catalysis, and sensing. Hemoglobin, which carries oxygen in the blood of mammals, and chlorophyll, which drives photosynthesis in plants and algae, are both porphyrins. The ability of porphyrins to bind metal ions and their unique electronic and photophysical properties make them an excellent platform for designing functional materials for various applications, often drawing inspiration from their function in nature. Metal-organic frameworks (MOFs) are a class of porous materials that have been extensively studied in recent years due to their high surface …

Synthetic Studies Of Potential New Ketogenic Molecules, Mohammad Nazmus Sakib

USF Tampa Graduate Theses and Dissertations

The ketogenic diet has gained popularity in the past few decades among people and physicians due to its various health benefits. A significant amount of research has been done for the modification of the original ketogenic diet and investigation of its potential health benefits. However, synthesis of novel ketogenic compounds as a dietary supplement has not received the same level of attention. That is the primary objective of this research project. The first chapter of this manuscript describes the synthesis of various short and medium chain esters of different polyols that have been done so far, and areas of their …

In Silico And In Vitro Drug Discovery Strategies And The Chemical Investigation Of Endophytic Fungi, Sarah Grace Dietrick

USF Tampa Graduate Theses and Dissertations

The biodiversity of our global marine ecosystems provides substantial treasure to discover: chemistry. Marine organisms that live in proximity to one another use their unique chemistry to compete with one another and thrive in their environment. Benthic invertebrates, specifically, that lack physical means of protection will produce secondary metabolites as a means of defense from their surroundings and predators. The compounds which they produce are ordinarily species-specific, highly diverse biomolecules. Biosynthetic processes within an organism construct these secondary metabolites from fragments of primary metabolites (amino acids, fatty acids, sugars, and so on). Their roles in protection have antibiotic, toxic, and …

Utilizing Binding-Based Proteomic Profiling And Mass Spectrometry Imaging As Innovative Tools For Lipid Research, Suzeeta Bhandari

USF Tampa Graduate Theses and Dissertations

Mass spectrometry-based omics research involves global identification and quantification of molecules in the biological system, which can form the basis of the multi-omics approach integrating multiple layers of information to provide a comprehensive overview of systems biology. The investigation of fatty acid amides (FAA) is one such research avenue that benefits significantly from the high-throughput, multi-level, and interdisciplinary approach of integrative omics. Currently, FAA research is dominated by lipidomic-based studies that have successfully identified and quantified >100 different FAAs in different model systems. Few studies are credited with exploring the biological function and evolution of FAA-dependent signaling pathways. Previous literature …

Coupling Chemical And Genomic Data Of Marine Sediment-Associated Bacteria For Metabolite Profiling, Stephanie P. Suarez

USF Tampa Graduate Theses and Dissertations

Marine sediment-associated bacteria house many new and exciting novel secondary metabolites. These metabolites can be tested for bioactivity against various types of cancer and fungal, bacterial, and viral infections. In this thesis, we investigated the combination of biosynthetic gene cluster information with mass spectra to perform a chemical profiling of sediment- associated bacteria. Furthermore, we utilized a scoring technique to provide an identification and confidence score to each annotated compound. The sediment was collected from east Arthur Harbor, Palmer Station, Antarctica, at depths of 20 ft and 60 ft. After plating on agar, 52 unique bacterial strains were isolated, with …