Physical Sciences and Mathematics Commons^™

Synthesis Of Metal-Containing Polymers And Stable Organic Radical-Containing Polymers And Their Use As Advanced Functional Materials, Joseph A. Paquette

Electronic Thesis and Dissertation Repository

The work presented in this thesis details the synthesis and characterization of two different families of multifunctional polymers. The first family involved the incorporation of stable 6-oxoverdazyl radicals into polymer scaffolds. This was originally achieved by the polymerization of the radical precursors, phenyl- and isopropyl-6-oxotetrazanes, followed by post-polymerization oxidation to afford the phenyl- and isopropyl-6-oxoverdazyl polymers. A second methodology involved the direct polymerization of isopropyl-6-oxoverdazyl radicals using ring-opening metathesis polymerization (ROMP) to afford polymers with controlled molecular weights and narrow molecular weight distributions. The polymers were characterized by the close comparison of the physical and spectroscopic properties …

Design And Synthesis Of Dynamic Covalent Polymer Scaffolds With Controlled Architectures, Emily Annette Hoff

Dissertations

The design and synthesis of functional, controlled polymer architectures is essential to the development of new materials with precise and tailorable properties or applications. The work described in this dissertation focuses on the development of controlled polymer architectures with dynamic linkages for the design of multifunctional materials and surfaces via robust, efficient, and stimuli-responsive strategies.

In Chapter III, a post-polymerization modification strategy based on ambient temperature nucleophilic chemical deblocking of polymer scaffolds bearing N-heterocycle blocked isocyanate moieties is reported. Room temperature RAFT polymerization of three azole-N-carboxamide methacrylates, including 3,5-dimethyl pyrazole, imidazole, and 1,2,4-triazole derivatives, afforded reactive polymer scaffolds …

Part 1: Design, Synthesis, And Evaluation Of Novel Gram-Positive Antibiotics Part 2: Synthesis Of Dihydrobenzofurans Via A New Transition Metal Catalyzed Reaction Part 3: Design, Synthesis, And Evaluation Of Bz/Gabaa Α6 Positive Allosteric Modulators, Christopher Michael Witzigmann

Theses and Dissertations

Part 1. Lead compound SK-03-92 represents a new scaffold for antibiotic drug discovery. Development of a new process for the synthesis of analogs has led to the development of a number of new ligands with even more potent activity against gram-positive bacteria, including drug-resistant strains of S. aureus. Compounds 36 and 38 represent some of the most potent analogs developed thus far, and preliminary results indicate that they are also not cytotoxic. Research into a Heck-mediated transition metal catalyzed pathway towards electron-rich stilbenoid analogs has greatly expanded the scope of future SAR studies. This development has led to 14 new …

Design And Synthesis Of Lipid Probes Used For Membrane Derivatization And Fusion, Stuart Allen Whitehead

Doctoral Dissertations

Lipids control a variety of complex biological processes. Bulk lipids such as phosphatidylcholine (PC), phosphatidylserine (PS), and phosphatidylethanolamine (PE) represent the major components of cellular membranes. In addition, unilamellar vesicles composed of lipids (liposomes) are valuable for delivery applications since they can encapsulate and transport drugs and other agents. In order to maximize delivery efficiency and target specific membranes, the ability to trigger and control vesicle-vesicle fusion is desirable. Such approaches generally seek to mimic the membrane fusion machinery present in nature while imparting specificity in the membranes that undergo fusion. The goal of this work is selective drug delivery …

Bioorthogonal Reactions: Synthesis And Evaluation Of Different Ligands In Copper Catalyzed Azide-Alkyne1,3-Dipolar Cycloaddition (Cuaac), Zainab Abdullah Almansaf

Graduate Theses and Dissertations

The Copper CatalyzedAzide-Alkyne1,3-Dipolar Cycloaddition (CuAAC) reaction has unique features that qualify it to be one of the best click reactions. Its applications have been shown in different aspects and for multiple purposes. The oxidative degradation of biological systems (labile proteins and live cells) is, however, generally recognized as the major problem when using this reaction in living systems. Reactive oxidation species can be easily produced in the presence of copper(II), ascorbate and air, and this is the main cause of toxicity. However, the uses of ligands have shown a major impact on reducing copper toxicity, protecting Cu(I) from the redox …

Direct Attachment Of 4-Hydroxybenzoic Acid Polymers And Capture Agents To Flat Sheet And Microdialysis Membranes For Improved Mass Transport, Sarah Jane Phillips

Graduate Theses and Dissertations

Microdialysis (MD) sampling is a diffusion-based separation method which has the ability to sample any analyte that can diffuse across the semi-permeable membrane. However one challenge for MD is that for soluble proteins greater than 10 kDa, the relative recovery (RR) using a 100 kDa MD probe is between 1-5%.1 There are two major barriers that lead to these low recovery values - nonspecific adsorption (NSA) and poor solute mass transport. To overcome these two barriers, the modification of PES-based MD membranes has been initiated by laccase. Previous researchers have used laccase to modify PES flat sheet and hollow fiber …

Three Body Interactions Of Rare Gas Solids Calculated Within The Einstein Model, Dan D'Andrea

Masters Theses

Three body interactions can become important in solids at higher pressures and densities as the molecules can come into close contact. At low temperatures, accurate studies of three body interactions in solids require averaging the three-body terms over the molecules' zero point motions. An efficient, but approximate, averaging approach is based on a polynomial approximation of the three-body term. The polynomial approximation can be developed as a function of the symmetry coordinates of a triangle displaced from its average geometry and also as a function of the Cartesian zero point displacements from each atom’s average position. The polynomial approximation approach …

Synthesis And Characterization Of Novel Ligand For Use On Rhodium Paddlewheel Complexes, Gavin J. Rustin

Masters Theses

Dirhodium (II) paddlewheel complexes have proven to be useful catalysts in many transformations including C-H insertions, cyclopropanation, and silane insertion reactions. One deficiency of these catalysts is the inability to modulate the enantioselectivity with reactive diazo compounds. One avenue for potential improvement of paddlewheel complexes is coordinating ligands in the axial site to increase enantioselectivity. The axial site has been occupied by various ligands including Nheterocyclic carbenes, nitrogen compounds, and phosphorous compounds. This work examines compounds that can be used as ligands on dirhodium complexes that have a pendant chain containing a dibenzyl phosphite and dibenzyl phosphate, both of which …

Diazonium 4-(Trifluorovinyloxy) Perfluorobutanesulfonyl Benzenesulfonimide Zwitterionic Monomer Synthesis, Isaac D. Addo

Electronic Theses and Dissertations

3-Diazonium- 4-(trifluorovinyloxy) - perfluorobutanesulfonyl benzenesulfonimide zwitterionic monomer (see figure 1) is proposed to be polymerized and further act as a new electrolyte for Polymer exchange membrane fuel cells (PEMFCs). One reason is that, the aromatic trifluorovinyl aryl ether (TFVE) group can easily be homopolymerized to aromatic perfluorocyclobutane (PFCB) polymer. Furthermore, the diazonium moiety in the monomer is expected to covalently attach the electrolyte to the carbon electrodes support. The perfluoroalkyl(aryl) sulfonimide (PFSI) pendant provides good chemical and mechanical stability as well as better proton conductivity. Several multi-step synthetic schemes are designed to obtain such monomer from perfluoroalkyl(aryl) sulfonimide (PFSI). Among …

Asymmetric Transformations Catalyzed By Chiral Binol Alkaline Earth Metal Phosphate Complexes, Sri Krishna Nimmagadda

USF Tampa Graduate Theses and Dissertations

Small molecule hydrogen bond donors have emerged as versatile catalysts in asymmetric synthesis. Within this class, chiral BINOL phosphoric acid is regarded as one of the pioneer catalysts used in several asymmetric transformations. The ability of the catalyst to activate the substrates could be controlled in two different ways. (1) Dual activation/bifunctional activation of substrate by hydrogen bond interactions or ion pairing with phosphoric acid or (2) By forming chiral BINOL phosphate metal complex that could significantly alter the interactions in chiral space. In particular, chiral alkaline earth metal phosphate complexes have unique advantages as catalysts owing to the ubiquitous …

Design And Development Of Peptidomimetic Ligands For Targeting Radiopharmaceuticals, Imaging Probes, And Immunotherapeutics In Oncologic Disease, Michael Lawrence Doligalski

USF Tampa Graduate Theses and Dissertations

Cancer is a leading cause of morbidity and mortality in the developed world. While much has been learned about these diseases in the last few decades, one of the main barriers to widespread advancement is the heterogeneity of cancer biology. A growing body of evidence supports the idea that certain protein receptors are overexpressed on the surface of tumor cells as compared to normal tissues. These extracellular biomarkers provide a unique opportunity to selectively target the tumor with both imaging and therapeutic modalities. The research in this dissertation focuses on targeting proteins on the tumor cell surface with peptidomimetic ligands. …

Synthesis And Characterization Of Polycyclic Aromatic Hydrocarbon ( Pah )-Porphyrin Hybrids, Ruixiao Gao

Theses and Dissertations

Carbaporphyrins are porphyrin analogs where one or more pyrrole units are replaced with a carbocyclic ring. Benziporphyrins are porphyrin analogues with a 1,3-phenylene unit replacing one of the pyrrole subunits. Because of cross-conjugation, benziporphyrins are not aromatic species. However, protonation of benziporphyrins can afford some aromatic characteristics. Although the synthesis of many examples of monocarbaporphyrins have been successfully executed, no examples of porphyrinoids with pyrene subunits have been prepared. Pyrene-containing porphyrinoids, which have been named as pyreniporphyrins, are theoretically significant molecules that provide insights into the aromaticity and reactivity of porphyrinoid systems.

In this thesis, two projects were conducted to …

Photodynamic Killing Of Human Cancer Cells With Smart Photosensitizer Materials And An Endoscopic Implement For Singlet Oxygen Delivery, Mihaela N. Minnis

Dissertations, Theses, and Capstone Projects

The thesis describes progress on probe tips for a microoptic device for the precise delivery of the components necessary for photodynamic therapy (PDT) in a highly localized and controllable fashion. The thesis also summarizes results of a photosensitized oxidation study. The work focused on i) developing a photoactive fluoropolymer surface that will release sensitizer drug molecule for use in PDT, ii) designing new probe tips surfaces for use as sensitizer support for a microoptic PDT device, iii) exploring strategies for covalent attachment of sensitizers and model compounds to Teflon/PVA surfaces with the aim of being coupled with our microoptic device, …

I. Synthesis Of Diverse Structures From Quinone Monoketal And Quinone Imine Ketal With Efficiency And Control Ii. Synthetic Study Of Phalarine, Zhiwei Yin

Dissertations, Theses, and Capstone Projects

Quinonoids are quinone derivatives that have carbonyl or carbonyl equivalent and even number of double bonds embedded in six member rings. As a result of the intrinsic α,β-unsaturated ketone or imine structures, quinonoids, such as quinone monoketals, quinols, quinol ethers and quinone imine ketals, can accommodate a wide range of reactions including 1,2-additon, 1,4-addtion, SN2’ reaction (allylic substitution) to the α-carbon of the carbonyl or imine and cycloaddition reactions (e.g. Diels-Alder reaction). Quinonoids are effective building blocks for synthesizing heterocycles, which are ubiquitous in pharmaceutically useful agents. Developing new quinonoid based methodologies is essential to expanding the boundary of synthetic …

Novel Reactions Of Donor-Acceptor Cyclopropanes, And Diels-Alder Approach Towards Fargesine And Fumimycin, Polydoros Kyriacou

Electronic Thesis and Dissertation Repository

The first chapter of this thesis consists of two related projects that explore novel reactivity of donor-acceptor cyclopropanes, specifically 2-substituted cyclopropane 1,1-diesters. The first project involves the nucleophilic ring opening of donor-acceptor cyclopropanes with potassium organotrifluoroborates. It was found that during the ring opening of the cyclopropane, the diesters of the cyclopropane formed a malonyl-BF₂ complex. The complex could then be hydrolyzed to afford substituted malonates. The reaction was limited to aryl cyclopropanes and potassium alkynyltrifluoroborates. The second project in this chapter explores modifying the Kerr group’s previous synthesis of tetrahydro-1,2-oxazines, such that geminal allyl, methyl esters are now …

A Comparison Of Solvent And Water-Borne Alkyd Coatings And The History Of Voc Regulations In The United States, Molly Elise Burns

Master's Theses

A Comparison of Solvent and Water-Borne Alkyd Coatings Abstract

Conventional solvent based alkyd coatings have gone out of favor due to concerns over volatile organic compound (VOC) content. However, due to recent focus on renewable raw materials, alkyds are making a comeback in waterborne form. Water based alkyd coatings are known to have poor shelf stability and corrosion resistance, as well as other problems during the formulation process. This project focused on comparing solvent borne to two types of water-borne alkyds, water reducible alkyds and alkyds emulsions. The purpose was to understand the differences between the three types of alkyds …

Photo-Isomerizable Self-Complementary Hydrogen Bond Arrays, Iamnica Janic Linares Mendez

Electronic Thesis and Dissertation Repository

This thesis exploits the use of a photochromic system in a self-complementary hydrogen bond array; i.e. the azo group, -N=N. The novelty of the approach described in this thesis resides in the double function of the azo group within the array: as a hydrogen bond acceptor site and as an element that promotes a structural change capable of disrupting the complexation equilibrium when irradiated with light.

The photo-isomerizable self-complementary hydrogen bond arrays presented are obtained by a general and practical synthetic method from inexpensive starting materials. Their self-complementary recognition was corroborated by ¹H NMR dilution experiments and single crystal …

Cobalt Mediated Oxidative Cyclizations: The Diastereoselective Synthesis Of Trans-Tetrahydrofuran Rings, Cory D.N. Palmer

Electronic Thesis and Dissertation Repository

The Mukaiyama oxidative cyclization has been a major area of study within the Pagenkopf group and within the field of THF containing natural products. This document contains a brief discussion of the major divisions of THF synthesis; S_N2, cycloadditions, and transition mediated strategies. The development of the Mukaiyama cyclization is described from the earliest applications of cobalt acac type ligand in Mukaiyama’s work to the initial discovery of the cyclization reactivity. Initial finding from the Mukaiyama group is shown, accompanied by its applications to the synthesis of mucosin, aplysiallene, and bullatacin. Previous attempts at improved catalyst design are …

New Chemistry Of Donor-Acceptor Cycloalkanes And Studies Towards The Synthesis Of Streptorubin B, Naresh Vemula

Electronic Thesis and Dissertation Repository

This dissertation presents two separate chapters within the broad area of synthetic organic chemistry. The first chapter describes the annelation chemistry of donor-acceptor (DA) cyclopropanes and cyclobutanes for the synthesis of heterocycles. The Yb(OTf)₃-catalyzed [4+2] cycloaddition between DA cyclobutanes and nitrosoarenes facilitated the synthesis of tetrahydro-1,2-oxazines in good to excellent yields as single diastereomers. Additionally, an unexpected deoxygenation occurred with electron-rich nitrosoarenes under MgI₂-catalysis that afforded pyrrolidine products. The GaCl₃-catalyzed [4+2] cycloaddition of DA cyclobutanes and cis-diazenes provided hexahydropyridazine derivatives in good to excellent yields as single diastereomers. Furthermore, a procedure to make …

The Synthesis Of Chemosensors For Toxic Analytes, Johnathan Hugh Broome

Dissertations

A number of chemosensors have been designed and synthesized to target cations (Zn²⁺ions), neutral molecules (cathinones), charged molecules (aminoindanes), and anions. The Zn²⁺ ion sensor featured bistriazole designed binding unit and ferrocene signaling units. Characterization of Zn²⁺ ion binding was carried out with electrochemical techniques (CV and DPV), ¹H-NMR, mass spectrometry, and molecular modelling. It exhibited a 1:1 binding stoichiometry with Zn²⁺ and had an affinity for ZnCl₂ (Log K_1:1 = 4.1 ± 0.02) over other Zn²⁺ salts.

The cathinone probe was designed to selectively bind mephedrone over common street drugs …

Silver-Polymer Nanocomposites, Anita N. Paul

Electronic Theses and Dissertations

The objective of this research was the development of an efficient method for the preparation of silver-polymer nanocomposites containing finely dispersed silver nanoparticles. The surface of nanosilver was functionalized by thiolation with 2-aminoethanethiol. Amino-modified nanosilver was covalently bonded to polyacrylic acid, biodegradable polymers like acid terminated polylactic acid, ester terminated poly(DL-lactide-co-glycolide) and acid terminated poly(DL lactide-co-glycolide) in the presence of diisopropylcarbodiimide by carbodiimide method. Esterification of the carboxyl groups of Ag-polyacrylic acid by hydrochloric acid in methanol resulted in the formation of a stable colloidal dispersion of Ag nanoparticles in the polymer matrix. It was observed that not just acid …

Synthetic Studies Of Heparan Derivatives: Glycosyl Couplings And Post-Glycosylative Modifications, Hari Raj Khatri

Open Access Dissertations

Heparan sulfate (HS) and closely related heparin are comprised of alternating units of D-glucosamine and either D-glucuronic acid (D-GluA) or L-iduronic acid (L-IdoA), and support variable degrees of sulfation which can interact with a large number of proteins with diverse biological functions. HS oligosaccharides can be constructed from readily accessible D-GlcN and D-GlcA derivatives, but the inclusion of L-IdoA is less straightforward. To address this, our laboratory has developed alternative synthetic strategies for HS-like oligosaccharides to incorporate either D-GlcA or L-IdoA in a synthetically efficient manner by nucleophilic ring opening of 4-epoxypyranosides, which can be made from readily available D-hexoses …

Two Studies: Stereoselective C-C Bond Formations Of N-Boc-Piperidines Using Selected Organolithiums And Visible-Light-Mediated Synthesis Of Fused Indolines Using Tethered Styrenes, Scott Alan Morris

Graduate Theses and Dissertations

Chemists worldwide have accepted the challenge of developing methods to access a variety of compounds as single enantiomers, including the use of enzymes, chiral auxiliaries, and resolutions. In particular, dynamic resolutions offer a unique way to access chiral compounds using a few controllable steps, including the variation of both time and temperature. Many groups have implemented this methodology to generate various polysubstituted pyrrolidines and piperidines, which are substructures ranking high on the list of nitrogen–containing pharmaceuticals.

The Gawley group revealed a catalytic dynamic resolution (CDR) of N–Boc–piperidine using a chiral ligand. Impressively, the chemistry was tolerant of a variety of …

The Large-Scale Synthesis And Asymmetric Hydrosilylations Of Cuiphet, A C2-Symmetric N-Heterocyclic Carbene, Elizabeth Suzanne Spahn

Graduate Theses and Dissertations

CuIPhEt is a C2-symmetric N-heterocyclic carbene catalyst used in the asymmetric hydrosilylation of a variety of prochiral ketones with good yields and selectivities. The large-scale, five-step synthesis of this carbene has been devised. The second step of the synthetic plan includes a double asymmetric hydrogenation of a 1,1-diaryl alkene—a traditionally difficult transformation. The procedure for the use of CuIPhEt in asymmetric hydrosilylations has been optimized and used on both the originally published substrate scope and new compounds. This protocol for the hydrosilylation has been applied in a 10 g reduction to create an intermediate for use toward the total synthesis …

Mechanism Of Rapid Electron Transfer Reactions Involving Cytochrome Bc1, Cytochrome C And Cytochrome Oxidase, Jeremy Erik Durchman

Graduate Theses and Dissertations

Electron transfer between mitochondrial proteins complexes represents the primary means by which living things acquire the requisite energy for survival. The coupling of electron transfer to proton translocation creates an electrochemical gradient that drives the synthesis of highly energetic compounds such as ATP. The purpose of these studies is to measure rates of electron transfer and elucidate the important governing factors in the redox events involving cytochrome bc1, cytochrome c and cytochrome oxidase. Using rapid initiation of redox events triggered by laser flash excitation of ruthenium compounds, and strategically monitoring unique spectral properties of these proteins in the visible region …

[3+2] Annulation Of Cyclopropylanilines With Alkynes Under Photocatalysis, Theresa Ha Nguyen

Graduate Theses and Dissertations

Over the past decade, pharmaceutical industries have prioritized their focus on discovering new innovative drugs, yet the syntheses are often either inefficient or the approach of environmental sustainability presents a great deal of concern. Moreover, the methodology developments for amine syntheses have continued to flourish due to their important role and wide use in pharmaceutics. Yet their syntheses often lack sustainability and efficiency. Synthetic chemists have continued to explore potential innovative avenues for conducting chemical reactions more effectively and efficiently. One of the most abundant, renewable natural resources is solar energy and to harvest, use, and store it directly is …

Correlation Of Polymer Performance And Hansen Solubility Parameters, Daniel Jobse Mania

Master's Theses

Ready-to-use (RTU) grout is becoming more important to the finish and remodeling construction industry. Market research shows it is a fast-growing product that not only is creating its own space, but is beginning to supplant existing technology.

The original intent of this research was to investigate formulation parameters and how they affect grout performance. It was learned that particle size and oil absorption (OA) value are important filler properties that affect performance as much as adequate packing density and optimal pigment volume concentration (PVC) without going beyond critical PVC (CPVC).

Polymer architecture was also determined to be extremely important, but …

Investigation Of The Interaction Of Dimeric Ruthenium Complexes With Cytochrome B5, Christopher Dain Rupar

Graduate Theses and Dissertations

Photoreactive complexes to study the kinetics of electron transfer of proteins have been in use for a long time. It has always been speculated that complexes bind near the heme or the electron transfer reaction would not occur. But it is unkown exactly how the complex interacts with the protein. The structural, thermodynamic, and kinetic properties of rat liver microsomal cytochrome b5 were investigated when bound to ruthenium dimer complexes. Heteronuclear Single Quantum Coherence studies support a dynamic binding model of a dimer Ru complex bound near the protein’s heme involving residues H39, E44, G42, V61, G62, and H63. The …

Studies In The Asymmetric Synthesis Of The C21-C34 Fragment Of The Natural Product, Antascomicin B, Brian Lee Walker

Graduate Theses and Dissertations

This dissertation describes studies in the asymmetric synthesis of the C21 – C34 fragment of the natural product, antascomicin B. Antascomicin B is structurally related to FK506, binds strongly to FKBP12, yet does not shown immunosuppressive activity. Small ligand FKBP12 binding complexes were shown to have potent neuroprotective and neuroregenerative properties in mouse models of Parkinson’s disease. The highlighted chemical reactions include an asymmetric transfer hydrogenation (ATH), Ireland-Claisen rearrangement (ICR), directed hydrogenation and allylic diazene rearrangement.

Synthesis Of Subtype Selective Bz/Gabaa Receptor Ligands For The Treatment Of Anxiety, Epilepsy And Neuropathic Pain, As Well As Schizophrenia And Asthma, Michael M. Poe

Theses and Dissertations

The α2/α3 subtype selective Bz/GABAA receptor positive allosteric modulator HZ-166 (3) has been shown to be a nonsedating anxiolytic with anticonvulsant and antihyperalgesic activity. However, instability in vitro and in vivo has hindered its advancement into clinical trials. A series of ligands based off HZ-166 (3) were synthesized. Many of these ligands were designed to increase metabolic stability, while others were synthesized to study the effects that electronics and sterics have on the efficacy exerted when bound to the GABAA receptor. The α3 subtype selective methyl ester MP-III-024 (19) was shown to have increased resistance to metabolism in in vitro …