Inorganic Chemistry Commons^™

Hypervalent Iodine Compounds With Carboxylate And Tetrazolate Ligands, Avichal Vaish

Chemistry Theses and Dissertations

In modern organic chemistry, hypervalent (HV) iodine(III) compounds are frequently used as oxidizing agents but application of λ³-iodanes in polymer and material chemistry is still underexplored. This dissertation describes the preparation of dynamic and self-healing materials by employing ligand exchange reactions involving HV iodine(III) compounds of the type ArIL₂ (Ar = Aryl, L = ligand, e.g., carboxylate or (pseudo)halide). These compounds can undergo ligand exchange reactions in presence of nucleophiles (Nu^-) to form ArINu₂. Diacetoxyiodo benzene was successfully employed as a crosslinker to prepare dynamic and self-healing gels derived from carboxylate-containing polymers. Furthermore, …

Greening Of Catalytic Processes Using First-Row Transition Metals For Atom Transfer Radical Addition And Transfer Hydrogenation, Gabrielle Pros

Electronic Theses and Dissertations

This work focused on “greening” catalytic processes, atom transfer radical addition (ATRA), which adds an alkyl halide across and alkene, and transfer hydrogenation/dehydrogenation, which reduces a carbonyl without needing direct H₂ gas. Part of “greening” of these processes is through using abundant first row metals, Cu and Ni for catalysis. One aim was to design new ligands which would be more active in these systems; the second was investigation of additives for catalyst regeneration to reduce the catalyst loading necessary for high yields.

The TPMA^* family was investigated in ATRA. Rate constants followed the expected trend, which increased …

Self-Assembly Of 2d And 3d Metallo-Supramolecules With Increasing Complexity, Bo Song

USF Tampa Graduate Theses and Dissertations

Synthetic organic chemistry played a crucial role in the construction of molecules through the formation and dissociation of covalent bonds. However, the laborious synthetic procedures as well as the low yield after multiple steps have restricted the pursuit of complicated giant molecules with high efficiency. Being complementary to organic synthesis, self-assembly provided an alternative route to achieving the giant architectures using weak non-covalent interactions in high efficiency, which is in analog to natural systems such as DNA, peptide, and protein. Among the various interactions, coordination has shown unique advantages in terms of directionality, reversibility and strength. Serving as a bottom-up …

Providing Molecular Insight For Understanding Anion Exchange Membrane Conductivity, Michael Kwasny

Doctoral Dissertations

Anion exchange membranes (AEMs) are notorious for having both low alkaline stability and poor ion conductivity in fuel cell operation conditions, with solutions to these two challenges often being developed independent of each other. The chemical instability of an AEM is viewed through degradation of the polymer backbone and the cationic species and improving a material’s stability is approached by altering the polymer backbone, the cation, or both. On the other hand, poor ion conductivity is typically addressed by modifying bulk membrane properties such as increasing the ion exchange capacity (IEC), changing the morphology, or increasing the water uptake. These …

Methodologies For Metal Functionalization Of Phosphorus Based Photopolymer Networks, Vanessa Béland

Electronic Thesis and Dissertation Repository

Photopolymer networks with phosphonium cation, alkyl phosphine and olefin functionality were designed, synthesized and functionalized with metals by metathesis, coordination and hydrometallation reactions, respectively. The materials were strategically designed so that the metal functionalization step could be monitored and quantified. In some cases, this involved characterization by IR, NMR, or X-ray spectroscopic techniques, or by comparison to molecular analogues. It was found that by using a bi-functional photopolymer network, the material could be bi-metallized by orthogonal mechanisms. All metallized polymer networks were tested for their suitability as precursors to metal-containing ceramics. The polymers were pyrolyzed, and on analysis it was …

It's Elementary: A Review Of Forensic Analysis Techniques Of Inorganic Components Of Explosives, Sadie Schultz

Chemistry & Biochemistry Student Projects

No abstract provided.

Antioxidants And Beta-Carotene: A General Overview, A Research History, And Modern Scholarship, James Joseph Dickman Iv

Chemistry & Biochemistry Student Projects

This paper seeks to provide a cursory overview of oxidative stress and the accompanying biomolecules which are used to combat it. From there, the paper will provide a somewhat comprehensive list of major historical discoveries regarding antioxidant molecules, in particular beta-carotene. After this, an overview of more modern scholarship on the issue of these molecule’s antioxidant properties specific (from the 1970s onward) will be discussed up to modern times. The paper will conclude with an in depth look at the modern scholarship on beta-carotene that was performed here at Taylor University.

Bone Regeneration Via Inorganic/Organic Compatibility In A Newly Synthesized Hydrogel: Nhap-Bmp-2, Hannah Ewing

Chemistry & Biochemistry Student Projects

In this paper, nHAp-BMP-2 hydrogel is carefully synthesized in order to optimize the organic and inorganic compatibility which induces osteogenesis—the formation of new bone. This new method is a novel development within the medical field, giving more hope to those suffering from traumatic bone injuries. A drawback with using hydrogels is the difficulty of controlling peptide release in the affected areas. Too quick of a release alarms the human inflammatory response resulting in more substantial injury and an even prolonged recovery time. On the other hand, if the peptides that promote bioactivity are released too slowly, the bone will not …

Quantum Chemical Methods: Its History And Future, Erica Mitchell

Chemistry & Biochemistry Student Projects

No abstract provided.

Significance And Implications Of Vitamin B-12 Reaction Shema- Eth Zurich Variant: Mechanisms And Insights, David Joshua Ferguson

Chemistry & Biochemistry Student Projects

This is an undergraduate chemistry thesis document. This involves a discussion of the mechanisms and overall reactions involved in the total synthesis of vitamin B-12.

The History And Development Of Identification: Rediscovery And Application Of Egyptian Blue, Bailee Allen

Chemistry & Biochemistry Student Projects

The use of fingerprints as a form of identification in criminal cases has become a common method of conviction within the criminal justice system. However, with the recent rise in the number of people wrongly convicted, the typical sources of evidence have come into question about their reliability. Multiple common drawbacks found when using fingerprints dusting to obtain prints from crime scenes has led to researchers looking for more efficient ways to collect them that maintain high sensitivity and contrast. These are the two aspects that create the largest problem, especially on highly reflective and highly patterned surfaces. The discovery …

The Chemistry Of Jellybeans, Andrew Carter

Chemistry & Biochemistry Student Projects

Jellybeans are an amazing work of chemistry. In my paper, I outline the history and science behind this little candy. My paper describes taste receptors, molecular structure, and the analytical chemistry that help to make flavor science an interesting field of work.

Metallodrugs And Their Various Impacts On Disorders And Diseases, Paige Wagner

Chemistry & Biochemistry Student Projects

No abstract provided.

Development Of Ni-Catalyzed Alkene Dicarbofunctionalization Reactions, Shekhar Kc

Chemistry and Chemical Biology ETDs

Alkenes serve as one of the most important feedstocks for organic synthesis, having two vicinal sites for bond formation. In alkenes, both vicinal sites can be functionalized with two reagents in a process commonly known as alkene difunctionalization, which results in the formation of two new bonds. A number of alkenes difunctionalization reactions, such as diamination, dioxygenation, carboamination and carbooxygenation, are known. However, difunctionalization of alkenes with two carbon-based entities, termed alkene dicarbofunctionalization, is relatively less common. Development of such a process could provide a powerful method to introduce two different carbon fragments across an alkene in a regioselective manner, …

Synthesis, Characterization, And Applications Of Group 13 And 14 Complexes Of Chelating Formazanate Ligands, Ryan R. Maar

Electronic Thesis and Dissertation Repository

This thesis describes the synthesis and characterization of group 13 (boron and aluminum) and group 14 (silicon, germanium, and tin) complexes supported by chelating formazanate [R¹-N-N=C(R³)-N=N-R⁵]^‒ ligands. The resulting complexes are redox-active and often luminescent. Chapters two to four describe the synthesis and characterization of boron formazanate adducts. The work in these chapters demonstrates that through structural modification of the formazanate ligand, solid-state- and NIR photoluminescence can be achieved. Furthermore, the formation of an oxoborane (B=O) afforded a highly photoluminescent formazanate adduct due to the structural rigidity imposed by the B=O bond. These …

An Investigation Of Alkylboron Transmetallation In Palladium-Catalyzed Suzuki Reactions, Benjamin Murray

Dissertations, Theses, and Capstone Projects

Through the past 40 years, carbon-carbon cross-coupling reactions have greatly enhanced the ability of chemists to synthesize C(sp²)-C(sp²) bonds and more recently C(sp²)-C(sp³) bonds. In particular, the Suzuki reaction has proven to be invaluable with its high yields, good functional group tolerance, and low toxicity of reagents. One of the component steps of the catalytic cycle of this reaction is transmetallation, in which the nucleophilic species transfers its organic component to the metal center (generally palladium). The mechanism of transfer from primary alkylboron nucleophiles was studied in the 1990's via use of …

Preparation Of Enantioenriched Alkyltin Species And Their Application In Stereospecific Transformations, Glenn O. Ralph

Dissertations, Theses, and Capstone Projects

Organometallic reagents containing the tin-carbon bond are used extensively in modern synthetic chemistry for the formation of new bonds to carbon. Over recent decades, transition metal catalyzed cross coupling reactions between two C(sp²) centers have been widely developed. However, the introduction of a C(sp³) center complicates the catalytic cycle, and opens unproductive chemical pathways which lead to isomerization, elimination, and racemization. Our lab has developed a modified-Stille reaction to combat the deleterious effects of β-hydride elimination. Our protocol enables unactivated 2° alkyl organotin nucleophiles to undergo efficient cross coupling reactions with C(sp²) electrophiles, avoiding …

Drug Improvement And Design Involving G-Protein Coupled Receptors, Gabriel Saliba

Chemistry & Biochemistry Student Projects

No abstract provided.

A Chemical Overview Of Opioid Receptors And Their Agonists, Noah Kuszak

Chemistry & Biochemistry Student Projects

This work is a brief overview of the three main opioid receptors and some current research of the ways we can change the agonists and how they affect the opioid receptor pathway.

Dentin Biomodification Potency Of Proanthocyanidins, David J. Ryker

Chemistry & Biochemistry Student Projects

No abstract provided.

Facile And Efficient Synthesis Of Thiosemicarbazone Derivatives With Functionalized Pendant Amines., Anna E Davis

College of Arts & Sciences Senior Honors Theses

Bis-thiosemicarbazones are an important class of ligands for the synthesis of transition metal complexes with applications in medicine and electrochemistry.^1,2 Among the most studied of these complexation ligands is diacetyl-2,3-bis(N⁴-methyl-3-thiosemicarbazone) (denoted as ATSM, 1, Figure 1).^2,3 Derivatives of 1 with various amines in place of the methylamine of ATSM have previously been reported, including diacetyl (N⁴-methylthiosemicarbazone-N⁴′-dimethylthio-semicarbazone) (denoted as ATSM/DM, 2).⁴ In this work, we pursue the development of a library of ATSM derivatives with a variety of functionalized pendant amines with a range of electronic and steric …

Metal-Assisted Hydrolysis Reactions Involving Lipids: A Review, Dominique E. Williams, Kathryn B. Grant

Chemistry Faculty Publications

This report covers major advances in the use of metal ions and complexes to hydrolyze ester and phosphate ester lipid bonds. These metal-based Lewis acids have been investigated as catalysts to isolate fatty acids from biological sources, as probes to study phospholipid bilayer properties, as tools to examine signal transduction pathways, and as lead compounds toward the discovery of therapeutic agents. Metal ions that accelerate phosphate ester hydrolysis under mild conditions of temperature and pH may have the potential to mimic phospholipase activity in biochemical applications.

Development Of In Situ Forming Hydrogels For Intra-Articular Drug Delivery, Andy Prince

Electronic Thesis and Dissertation Repository

Hydrogels are 3-dimensional crosslinked polymer networks that can absorb significant amounts of water. The physical properties associated with hydrogels affords them resemblance to biological tissues making them good candidates for biomedical applications. Many pharmaceuticals, specifically non-steroidal anti-inflammatory drugs (NSAIDs), have poor aqueous solubility, which limits their bioavailability and efficacy. People suffering from chronic osteoarthritis (OA) are required to frequently take large doses to mitigate pain, which can lead to serious side effects. Hydrogels are good strategies to deliver NSAIDs via articular injection because they can form solid gels in situ. This thesis describes the synthesis, formulation, mechanical testing, in …

Acue Reflection From A Stem Perspective, Ashley Vizenor

Q2S Enhancing Pedagogy

The following document contains reflections from various activities of the ACUE workshop. Activities pertain to syllabus editing, classroom conduct, and effective teaching practices.

Photoluminescent Zirconium Complexes For Visible Light Photoredox Catalysis, Yu Zhang

Graduate Theses, Dissertations, and Problem Reports

Early transition metals like zirconium are attractive candidates for the design of luminescent molecules based on earth-abundant elements. Here, a series of zirconium complexes carrying two pyrrolyl-based ligands have been synthesized and characterized. These complexes are photoluminescent upon excitation with visible light and exhibit remarkably long emission lifetimes of hundreds of μs in solution at room temperature. Computational studies using time-dependent density functional theory (TD-DFT) were conducted to identify the nature of the luminescent excited states as mixed intra-ligand/ligand-to-metal charge-transfer (ILCT/LMCT) states. The electrochemistry studies revealed multiple reversible redox events for each zirconium complex. Furthermore, the excited state of the …

In Situ Infrared Spectroscopic Study Of Iron-Catalyzed Hydromagnesiation Of Vinyl Arenes, Jessica Ann Rogers

Graduate Theses, Dissertations, and Problem Reports

Iron catalysis, especially homogeneous catalysis, has been a resurging topic of organometallic chemistry research. Discussions of past and present mechanistic analyses for homogeneous iron catalysis will be discussed in Chapter 1. As an expansion of homogeneous iron catalysis, in situ infrared spectroscopy will be used to develop a full mechanistic study of iron-catalyzed hydromagnesiation of vinyl arenes. The kinetic analyses by both initial and observed rate measurements indicate complex concentration dependencies on the (PDI)iron catalyst as well as sacrificial Grignard reagent and styrene. These complexities are not limited to non-linear catalyst and Grignard initial rate and inhibition by styrene/Grignard at …

Oxidative Depolymerization Of Lignin To Low Molecular Weight Aromatics, Yang Song

Theses and Dissertations--Chemistry

To date, most lignocellulosic biorefinery strategies have focused on optimizing conversion of cellulose to ethanol, leaving lignin as an underutilized biomass constituent. Lignin is engineered by nature with the intent to protect plants from chemical and biological attack; this leaves lignin with high structural irregularity and recalcitrance, rendering conversion of the lignin macromolecule to valuable products particularly challenging. Nevertheless, given that the economics of cellulosic ethanol production are strongly dependent on the value that can be obtained for the lignin co-product, the successful valorization of lignin is a crucial step in the transition towards a bio-based economy.

This thesis focuses …