Bidentate Ferrocenyl-Dithiol Reagents For Nanocluster Surface Functionalization, Yiyi Liu

Electronic Thesis and Dissertation Repository

Previous work using monodentate ferrocenyl-chalcogen reagents for nanocluster surface functionalization has indicated an effective way to involve ferrocene moieties onto the surface of these frameworks. However, the abilities of the large polynuclear nanocluster with ferrocene rich surface to form crystalline materials suitable for single crystal X-ray analysis proved to be limited. New bidentate ferrocenyl-chalcogen reagents have been synthesized and characterized in order to probe their ability in this case.

The preparation of new bidentate ferrocenyl chalcogen reagents 1,1’-fc(C{O}OCH₂CH₂SH)₂ (fc = ferrocenyl) and 1,1’-fc(C{O}NHCH₂CH₂SH)₂ are presented. Furthermore, the preparation of silylated …

Synthesis And Thermodynamic Analysis Of Volatile Beta-Diketone Complexes Of Select Lanthanides Via Gas-Phase Separations, Daniel Hanson

Doctoral Dissertations

Rapid separation techniques for fission and activation products have long been desired to supplant the slow solution-based methodologies currently used. In this work, rare earth elements were derivatized with β [beta]-diketones to synthesize rare earth complexes with high volatility suitable for gas-phase separations. Rare earth elements samarium and dysprosium were combined with hfac (1,1,1,5,5,5-hexafluoro-2,4-pentadione) and fod (6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedione) and analyzed using a gas-phase separation technique. Rare earth elements praseodymium and europium were combined with dpm (2,2,6,6-tetra-methyl-3,5-heptanedione) and similarly analyzed. Employing the data from the separations, the entropy (Δ [delta] S) and enthalpy (Δ [delta] H) of adsorption were evaluated mathematically based …

Cellular Zinc Trafficking: The Zinc Proteome And Its Reactions With Cadmium, Mohammad Ali Namdarghanbari

Theses and Dissertations

Metals play a crucial role in living systems. Iron, zinc, copper, molybdenum, and manganese are involved in many essential biological activities. Among transition metals, zinc after iron is the most abundant transition metal in the human body and the most abundant in the brain. It exists in more than 3000 proteins, which comprise about 10% of the human proteome. Zn2+ dyshomeostasis is associated with chronic diseases such as metabolic syndrome, diabetes and related complications, bone loss, growth retardation in young children, and neurological and behavioral problems. Despite a good knowledge obtained for metabolism of some metal ions such as copper, …

Molecular Probes For The Detection Of Zn2+ And Fe3+ Ions, Erendra Manandhar

Dissertations

A number of molecular probes have been designed and synthesized for the detection of Zn²⁺ and Fe³⁺ ions. Two types of functional groups have been incorporated into the molecular scaffolds to utilize different fluorescent mechanisms. The first class of receptors contains a pyrene moiety. These molecular probes use the excimer mechanism for the detection of Zn²⁺ ion. The probes work well in an organic solvent with a detection limit of 20 nM (one ppb). Alternatives are made to make them water soluble, but this proved to be difficult. An interesting ion-induced self-assembly system will also be discussed. …

Metallopeptides From Design To Catalysis: Structure, Oxidative Activities, And Inhibition Studies Of Designed And Naturally Occurring Metallopeptides, Alaa Hassan Hashim

USF Tampa Graduate Theses and Dissertations

Structural and mechanistic complexities of copper-dioxygen systems have attracted much attention in the field of bioinorganic chemistry, both in model systems and trapped protein intermediates. The research presented herein is focused on model and naturally occurring metallopeptide systems, from its design to catalysis. Copper is used as the coordinating metal ion, with cobalt and zinc as probes for metal binding. The bioinorganic chemistry of copper proteins and its coordination and spectroscopic properties are briefly discussed in chapter 1. The next two chapters are centered on the de novo design of a minimalistic metallopeptide system with an amino acid sequence of …

Transformation Of Biomass Carbohydrates By Transition Metal Catalysts, Christine M Bohn

Open Access Dissertations

By selectively removing functional groups from biomass derived carbohydrates, valuable platform chemicals can be generated from renewable sources. Through dehydration chemistry glucose can be upgraded into 5-(Hydroxymethyl)-2-furfuraldehyde (HMF) and levulinic acid. Iron (III) chloride hexahydrate has shown moderate activity to transform glucose into HMF and has also shown high yields and selectivity for the production of levulinic acid. Typically synthesized from acidic solutions made with mineral acids, levulinic acid has now been produced in high yields with a metal salt. The difference between maximizing production for HMF or levulinic acid from the same catalyst relies on the control of the …

Investigation Of The Crystallization Of Dnl-6 And Ft-Raman Spectroscopic Investigation Of Guest Molecules In Mofs, Maxwell Goldman

Electronic Thesis and Dissertation Repository

Microporous solids are a widely used material in adsorption, storage and catalysis. In this thesis, the crystallization of the silcoaluminaphosphate DNL-6 was characterized using powder X-ray diffraction and solid state nuclear magnetic resonance. Two crystallization routes of the SAPO DNL-6 were studied, which are the hydrothermal method and the dry-gel conversion method. Both methods followed the same crystallization pathway and showed a layered intermediate that is then transformed into DNL-6. The reaction requires two templating agents to create the RHO topology and silicon substitutes into the framework by replacing single phosphorous atoms.

This thesis contains the conformational analysis of halocarbons …

Mechanistic Studies Of Salt Effects On Bimolecular Electron-Transfer Reactions Of Pentaamine Ruthenium Pyridyl Complexes Studied By 19f Nmr Line-Broadening And T2 Spin-Echo Techniques, Nicholas J. Magarian

Master's Theses

Kinetic salt effects on the bimolecular ET self-exchange reaction between pentaamineruthenium(II)(3-trifluoromethylpyridine)²⁺, (NH₃)₅Ru^IItfmp²⁺, and pentaamineruthenium(III)(3-trifluoromethylpyridine)³⁺, (NH₃)₅Ru^IIItfmp³⁺, have been measured using both ¹⁹F NMR line-broadening and CPMG T₂ spin-echo relaxation techniques in H₂O and D₂O. Over the equimolar reactants concentration range of 0.10 mM – 8.00 mM there was a definite “self-salting” rate increase arising from the increased solution ionic strengths due to the reactants and counterions themselves. The magnitude of this effect diverged significantly, however, …

Optimization Of P-Type Czts Nanocrystal Thin Film Layers For Applications In Low Cost Photovoltaic Devices, Kyle S.B. Jeffs

Electronic Thesis and Dissertation Repository

In this thesis Cu2ZnSnS4 nanocrystal synthesis was optimized by way of photoelectrochemical measurements through tuning the stoichiometry. Formation of a Cu2ZnSnS4 light-absorbing layer was studied using multiple depositions methods. These included dropcasting, electrophoretic deposition, and use of 3-mercaptopropyl trimethoxysilane as a chemical linker. Dropcasting samples were compared according to the solvents used to suspend the nanocrystals. Photoelectrochemical measurements were used to compare dropcasting with electrophoretic deposition and use of 3-mercaptopropyl trimethoxysilane as a chemical linker. Dropcasting was shown to be the least effective method of depositing the light-absorbing layer. Samples prepared by electrophoretic deposition were optimized according to a number …

Self-Assembly Of Gold Nanosphere Dimers By Inertial Force, George Andrew Christopher Sakhel

Graduate Theses and Dissertations

The morphology and composition of a nanoparticle (NP) play a critical role in determining the NP's properties and function. To date, researchers have created a myriad of NPs of different shapes, sizes, and compositions with interesting attributes and applications ushering a revolution in medicine, electronics, microscopy, and microfluidics.

In this study, gold (Au) nanosphere dimers (NSDs) have been synthesized through a novel self-assembly method. These particles were created from Au NPs mono-dispersed in aqueous solution via a process of centrifugation and capping agent replacement. Au NSDs consist of two Au NPs combined together with minimal gaps between them. Optical spectral …

Synthesis And Dna-Binding Studies With Two Stericallyfriendly Porphyrin Frameworks, Srijana Ghimire

Open Access Dissertations

Peripheral substituents on cationic porphyrins play a significant role during binding with DNA hosts. Possible applications of these systems in photodynamic therapy as well as in anti-bacterial and anti-cancer therapies motivate the binding studies. For characterizing DNA binding motifs different methods are useful including absorption, emission, and circular dichroism spectroscopies, as well as viscometry and X-ray crystallography. With the classic H₂ T₄ porphyrin, or 5,10,15,20-tetra(N-methylpyridinium-4-yl)porphyrin, the mode of binding varies with the base composition of the DNA host. The porphyrin binds adenine-thymine rich sequences externally whereas intercalation occurs in guanine-cytosine rich sequences. The McMillin group has made some …

Synthesis, Characterization And Reactivity Studies Of Fe(Ii) Complexes With Relevance To The Radical Sam Enzymes, Xixi Hong

Master's Theses (2009 -)

It is well-established that S-adenosylmethionine (SAM) serves as the methyl group donor in methylations of DNA, hormones, neurotransmitters and signal transduction systems. However, a new class of enzymatic reactions involving SAM has recently attracted considerable attention. In these systems, SAM initiates radical-based reactions at the active sites of enzymes via formation of an adenosyl radical, which further abstracts a H-atom from the substrate to initiate a radical-based mechanism. However, modeling studies of radical SAM enzymes have been hindered, by difficulties in preparing adequate synthetic [Fe4S4] clusters. We prepared a novel series of Fe(II) complexes with tripodal tris(2-hydroxybenzyl)amine ligands, which replicate …

Density Functional Theory Modeling Of It-Stacking And Electrophilic Donor-Acceptor Interactions With Application To Therapeutic Targeting Of Zinc-Finger Proteins, Patricia Beall Lutz

Chemistry & Biochemistry Theses & Dissertations

Several viruses, including viruses that cause cancer, contain conserved zinc finger (ZF) proteins that are essential for viral reproduction, making them attractive drug targets for cancer and viral treatment. ZFs are small protein domains that have Zn²⁺ tetrahedrally coordinated to at least 2 Cys and His. They form three classes of ZFs depending on the amino acid ligands, CCHH, CCCH, and CCCC. Zn²⁺ is stable towards redox reactions; however, the Cys thiolates are redox active. Oxidation of the Cys thiolates release Zn²⁺, and the ZF loses its tertiary structure and can no longer bind DNA or …

Synthesis, Characterization And Mechanistic Studies Of Biomolecules@Mesomofs, Yao Chen

USF Tampa Graduate Theses and Dissertations

Encapsulation of biomolecules is of great interest to research advances related to biology, physiology, immunology, and biochemistry, as well as industrial and biomedical applications such as drug delivery, biocatalysis, biofuel, food and cosmetics. Encapsulation provides functional characteristics that are not fulfilled by free biomolecules and stabilizes the fragile biomolecules. In terms of biocatalysis, solid support can often enhance the stability of enzymes, as well as facilitate separation and recovery for reuse while maintaining activity and selectivity. Various kinds of materials have been used for encapsulation of biomolecules, among which, porous materials are an important group. Metal-organic frameworks (MOFs) have attracted …

New Metal-Nhc Complexes: Synthesis, Characterization, And Uses, Roy A. Kelly Iii

University of New Orleans Theses and Dissertations

N-Heterocyclic Carbenes (NHC) present a viable alternative to traditional phosphine ligands in a variety of organometallic mediated catalytic reactions. Singlet ground-state carbenes are stabilized by the push-pull presence of two adjacent nitrogen atoms in an imidizolium 5-membered ring, allowing neutral electron donor properties. The ability to synthesize a variety of NHC ligands with differing steric and electronic properties is possible by changing the sustiuents on the nitrogen atoms of the imidizolium. Tunable characteristics and enhanced chemical and thermal stability give NHC’s an advantage over phosphines in many catalytic systems.

This dissertation focuses on the use N-Hetercyclic Carbenes in a variety …

Synthesizing Strong Donor Macrocyclic Tetracarbene Metal Complexes For Catalytic Aziridination, Steven Alan Cramer

Doctoral Dissertations

A small ringed macrocyclic tetracarbene ligand was developed due to the inherent ability of N-heterocyclic carbenes (NHCs) to stabilize high oxidation states of transition metals. This new strong donor ligand was prepared by first synthesizing an 18-atom ringed macrocyclic tetraimidazolium ligand precursor. The tetraimidazolium can be prepared by a two-step procedure. This ligand precursor was deprotonated to prepare a monomeric platinum tetracarbene complex.

A new iron macrocyclic tetra-carbene complex was synthesized by an in situ strong base deprotonation strategy of the ligand precursor. The iron tetracarbene complex was found to catalyze the aziridination of a wide array of functionalized aryl …

Template-Directed Synthesis And Post-Synthetic Modification Of Porphyrin-Encapsulating Metal-Organic Materials, Zhenjie Zhang

USF Tampa Graduate Theses and Dissertations

Metal-organic materials (MOMs) represent an emerging class of materials comprised of molecular building blocks (MBBs) linked by organic linker ligands. MOMs recently attract great attention because of their ability to exhibit permanent porosity, thereby enabling study of properties in the context of gas storage, gas separation, solid supports for sensors, catalysis and so on. Although MOMs have been studied for over 60 years, the porous nature of MOMs was not systematically and widely explored until the early 1990's. This may be one of the reasons why template-directed synthesis of MOMs remains relatively underexplored, especially when compared to other classes of …

Syntheses And Characterizations Of 4-Cyano-3-Tolylpyrazole And Its Metal Complexes, Molly M. Ketron

Undergraduate Honors Theses

Research on substituted polypyrazolylborate ligands could potentially lead to the development of useful compounds in the material sciences such as catalysis and metal ion extraction. A wide variety of substituents can be introduced to the pyrazole rings that modify the properties and reactivity of the complexes. Synthesis of 4-cyano-3-tolylpyrazole followed by the formation of a corresponding thallium(I) complex could allow one to examine the Tl-N bond length. When compared with other related complexes such as TlBp^{t-Bu, 4CN} and TlBp^{Ph, 4CN}, the Tl-N bond length in the synthesized complex will help determine the effect of the new …

The Analysis Of The Decomposition Of Hydrogen Peroxide Using A Schiff Base Copper Complex By Cyclic Voltammetry, Gavin James Rustin Mr.

Undergraduate Honors Theses

Copper(II) complexes of Schiff bases can be used in the catalysis of hydrogen peroxide to create water and oxygen. The mechanism and the kinetics of this disproportionation reaction by a dimeric copper(II) complex [CuSALAD]₂ are studied in this experiment, where SALAD refers to a Schiff Base ligand formed from salicyaldehyde and 1S,2S-D(+)-1-phenyl-2-amino-1,3-propanediol. By using cyclic voltammetry, the oxidation-reduction processes of a reaction may be monitored. The [CuSALAD]­₂ is initially reacted with a base such as imidazole to form the catalytic species, and the ratio of the copper(II) complex to the imidazole was found to be 1:4, consistent with …

Hydrothermal Synthesis Of Organically-Linked Polyoxometalates, Riyadh Alshammari

All Theses

One of the thrust areas of our research deals with exploratory synthesis of new inorganic-organic hybrid materials for energy storage. It is well-known that relevant to the research described later in this thesis, inorganic-organic hybrid solids studied thus far are largely made of coordination complexes where the organic molecules are acting like a ligand to coordinate around metal cations. In this research, we will employ polyoxometalate (POM) anions as an inorganic building block to replace otherwise oppositely charged metal cations in hopes to synthesize extended hybrid frameworks with rich redox chemistry. POM clusters are made of aggregates of transition-metal (TM) …

Double-Hinged Di-1,2,4-Triazoles For Synthesis Of Breathing Mofs, Christopher Ray Murdock

Doctoral Dissertations

Employing semi-rigid di-1,2,4-triazoles as ligands has led to the formation of a plethora of Metal-Organic Framework (MOF) architectures. The ability for the ligands to exhibit multiple conformations through a “hinge” effect allows for the formation of a multitude of MOF topologies and dimensionalities. Employment of a di-triazole containing a central trans-butene moiety was initially studied and led to the formation of two three-dimensional copper MOFs. The frameworks can be synthesized independently, but a reaction occurs in water wherein the kinetic product is used as a reagent to synthesize the topologically distinct thermodynamic product.

Additional testing of reaction conditions with …

Exploring The Synthesis And Coordination Chemistry Of Zwitterionic Main Group Compounds, Jonathan W. Dube

Electronic Thesis and Dissertation Repository

Traditionally low coordinate and low oxidation state main group compounds are isolated utilizing hard anionic donors based on carbon and nitrogen based ligands. Conversely, employing anionic phosphines for this role has been essentially unexplored. In this context, this dissertation describes the synthesis of a number of main group complexes, ranging from group 13 to group 15, utilizing the bis(phosphino)borate ligand class in a supporting role. The remote anionic borate backbone renders the complexes zwitterionic and provides access to unique compounds that possess structures, and exhibit onwards reactivity, that is very different to the analogous compounds stabilized with neutral phosphines. For …

The Electrochemistry Of Hydrogen Peroxide On Uranium Dioxide And The Modelling Of Used Nuclear Fuel Corrosion Under Permanent Disposal Conditions, Linda Wu

Electronic Thesis and Dissertation Repository

This thesis reports a series of investigations examining the corrosion process of used nuclear fuel under permanent disposal conditions. The motivation of the project is that the safety assessment of deep geological disposal of spent nuclear fuel requires a fundamental understanding of the processes controlling fuel corrosion which could lead to the release of radionuclides to the geosphere from a failed container.

One primary objective of this project was to develop a computational model in order to simulate fuel corrosion under the disposal conditions. A series of simulations based on COMSOL were designed and developed to determine the influence of …

The Development Of 6.7% Efficient Copper Zinc Indium Selenide Devices From Copper Zinc Indium Sulfide Nanocrystal Inks, Brian Kemp Graeser

Open Access Theses

As solar cell absorber materials, alloys of CuIn(S,Se)2 and Zn(S,Se) provide an opportunity to reduce the usage of indium along with the ability to tune the band gap. Here we report successful synthesis of alloyed (CuInS2 )0.5(ZnS)0.5 nanocrystals by a method that solely uses oleylamine as the liquid medium for synthesis. The reactive sintering of a thin film of these nanocrystals via selenization at 500 °C results in a uniform composition alloy (CuIn(S,Se)2 )0.5 (Zn(S,Se)) 0.5 layer with micron size grains. Due to the large amount of zinc in the film, the sintered grains exhibit the zinc blende structure instead …

[M3(Μ3-O)(O2cr)6] And Related Trigonal Prisms: Versatile Molecular Building Blocks For 2-Step Crystal Engineering Of Functional Metal-Organic Materials, Alexander Schoedel

USF Tampa Graduate Theses and Dissertations

Metal-organic materials (MOMs) assembled from metal-based building blocks and organic linkers have attracted much interest due to their large pore dimensions and their enormous structural diversity. In comparison to their inorganic counterparts (zeolites), these crystalline materials can be easily modified to tailor pore dimensions and functionality for specifically targeted properties.

The work presented herein encompasses the development of a synthetic 2-step process for the construction of novel families of MOMs or 'platforms' and allow us exquisite design and control over the resulting network topologies. Examples of cationic mesoporous structures were initially exploited, containing carboxylate based centers connected by metal-pyridine bonds. …

Diphosphine Carboxamide Ligands With Gold(I), Silver(I) And Platinum(Ii), Nasser Nasser

Electronic Thesis and Dissertation Repository

Abstract

This thesis describes the synthesis and characterization of monomeric and polymeric gold(I), silver(I) and platinum(II) complexes containing diphosphine dicarboxamide and pyridine carboxamide donor ligands. The major focus of the project was to characterize these complexes in the solid state using X-ray crystallography. Many of the complexes were also characterized in solution by NMR spectroscopy and electrospray ionization mass spectroscopy.

Chapter one serves as an overall introduction to the topic. Chapter two describes the preparation and characterization of gold(I) and silver(I) complexes with the chiral Trost ligand; R,R-trans-1,2-C₆H₁₀(NHCO-2-C₆H₄PPh₂)_{2 …}

Probing Proteasome Inhibition By Metal Copmplexes As A New Route For Anticancer Therapy, Dajena Tomco

Wayne State University Dissertations

The scope of this thesis is focused towards the development of metal-containing coordination compounds as potential therapeutic agents. Efforts of this research involve the design, synthesis, and purification of these complexes, as well as their evaluation by spectroscopic, spectrometric, and electrochemical characterization. The antineoplastic properties of these metal-containing pro-drugs are tested against the inhibition activity of the 26S proteasome. Selected metal ions ranging from transition to main group elements have been incorporated in various ligand systems containing phenolate and pyridyl donor sets. The mechanistic behavior of these complexes in solution has been thoroughly investigated along with their in vitro anticancer …

Anodic Strategies For The Covalent Attachment Of Molecules To Electrodes Through Ethynyl And Vinyl Linkages, Matthew Vincent Sheridan

Graduate College Dissertations and Theses

Substrates with localized, organic radicals have the ability to attack `inert' surfaces to form covalent bonds between the substrate and an atom at the surface. These radicals can be generated in electrochemical experiments with substrates bearing an electroactive moiety. The moiety after oxidation (loss of an electron) or reduction (gain of an electron) generates the active radical. Electron transfer reactions at an electrode surface generate a high population of these radicals, thereby facilitating attachment.

The electrochemical oxidations of compounds containing terminal alkynes and alkenes were found to be effective methods for covalent attachment to glassy carbon, gold, and platinum electrodes. …

Modified Seed Growth Of Iron Oxide Nanoparticles In Benzyl Alcohol: Magnetic Nanoparticles For Radio Frequency Hyperthermia Treatment Of Cancer, Stanley E. Gilliland Iii

Theses and Dissertations

Iron oxide nanoparticles have received sustained interest for biomedical applications as synthetic approaches are continually developed for precise control of nanoparticle properties. This thesis presents an investigation of parameters in the benzyl alcohol synthesis of iron oxide nanoparticles. A modified seed growth method was designed for obtaining optimal nanoparticle properties for magnetic fluid hyperthermia. With a one or two addition process, iron oxide nanoparticles were produced with crystallite sizes ranging from 5-20 nm using only benzyl alcohol and iron precursor. The effects of reaction environment, temperature, concentration, and modified seed growth parameters were investigated to obtain precise control over properties …

Modulation Of Water-Exchange Rates Of Lanthanide(Iii)-Containing Complexes Using Polyethylene Glycol, Buddhima Nirodhi Siriwardena-Mahanama

Wayne State University Dissertations

MODULATION OF WATER-EXCHANGE RATES OF LANTHANIDE(III)-CONTAINING COMPLEXES USING POLYETHYLENE GLYCOL

by

BUDDHIMA N. SIRIWARDENA-MAHANAMA

May 2014

Advisor: Dr. Matthew J. Allen

Major: Chemistry

Degree: Doctor of Philosophy

A modular system of lanthanide(III)-containing polyethylene glycol (PEG) conjugates was synthesized and characterized to investigate the influence of length and density of PEG on water-exchange rates of lanthanide(III)-containing complexes. The water-exchange rates of lanthanide(III)-containing complexes contribute to the efficiency of these complexes as T₁-shortening and paramagnetic chemical exchange saturation transfer (PARACEST) contrast agents for magnetic resonance imaging (MRI). Because the mechanism of these two MRI methods is vastly different, there is …