Physical Sciences and Mathematics Commons^™

Redox-Active Polymerization Catalysts And Their Applications, Nicholas M. Shawver

Masters Theses

Traditional catalyst systems are reliable means to produce polymers with well-defined architectures and thermomechanical properties; however, they are often limited by a narrow monomer scope and their ability access few, if any, advanced polymer architectures. To address this limitation, a new class of catalysts have recently emerged that feature redox-active moieties that may access advanced architectures through catalyst electronic modulation that arises from redox events occurring on the ligand scaffold or at the active metal center itself. For example, researchers have explored the ability of redox-active catalysts to impart “on-off” kinetic control during ring-opening polymerizations and their ability to access …

Synthesis And Characterization Of 2,6-Diisopropylphenoxy Tetrapyrazinoporphyrazines As Potential Molecular Qubits, Benjamin Marx

Masters Theses

This thesis reports the synthesis of metal-free and metal-containing phthalocyanine derivatives using methods typical for that class of functional dyes. A mixture of the target compounds prepared here, one paramagnetic and one diamagnetic tetrapyrazinoporphyrazine, will be tested for their potential use in spintronics – the application of spin-active species in molecular electronics. Phthalocyanines and their derivatives are well-known for their ease of preparation and tunability; they have been utilized as sensitizers for photodynamic therapy of cancer and solar cells, as well as in catalysis and chemical sensing. Tetrapyrazinoporphyrazine complexes are compared with the parent phthalocyanine as their chemistry is similar …

Pd-Based Photocatalysts For Heck C-C Cross-Coupling Reactions, Suha Ali Alshehri

Masters Theses

Heck C-C cross-coupling reaction has been widely employed in synthetic organic chemistry because of its high efficiency and simplicity, however the conventional Heck C-C cross-coupling reaction conditions involve the use of an expensive toxicant phosphine-ligated palladium complexes, and high temperature. To address these drawbacks, a highly efficient, homogeneous photocatalyst based on BODIPY for the Heck C-C cross-coupling reactions of aryl iodide and methyl acrylate in DMF solvent under inert conditions has been developed. The 4-Py-BDP-Pd, 3-Py-BDP-Pd and, 2-Py-BOD-Pd catalysts were synthesized and purified using column chromatography. The optical properties of products and intermediates were studied by UV/vis absorption and fluorescence …

Application Of Titrations For Verification Of Small Molecule Interaction In Relation To Amidoximated Fibers For Uranium Extraction From Seawater, Kc Michael Mote

Masters Theses

Nuclear energy is a promising substitute for fossil fuels due to possessing low carbon emissions and providing scalable base-load power. However, one major drawback of using nuclear fuel as an energy source is that it needs a steady source of uranium. While the most economical method of obtaining uranium is through conventional terrestrial mining of the ore uranite, mining uranium ores is both harmful to the environment and limited by the terrestrial uranium supply, which is estimated at only 100 more years. However, more than 1000× more uranium is dissolved in seawater than is reasonably inferred and assured in terrestrial …

A Novel Palladium Bodipy Photocatalyst For Sonogashira Carbon-Carbon Cross-Coupling, Prahadeesh Nagaretnam

Masters Theses

No abstract provided.

Synthesis And Characterization Of A Two Station Starburst Pseudorotaxane, Janaka Prasad Kaviraj Kavikarage

Masters Theses

Mechanically interlocked molecules (MIMs) are arranged with mechanical bonds. These molecules cannot be separated without breaking the required covalent bonds. There are different kinds of MIMs, such as rotaxanes, catenanes, suitanes, borromean rings, and molecular knots. These MIMs are stabilized by non-covalent interactions such as hydrogen bonds, π-π stacking, and ion-dipole interactions. Dialkylammonium ions, bis(pyridinium)ethane dications, viologen species, and naphthalene diimide π-deficient groups are typical examples of recognition motifs for crown ethers.

In the research described here, we synthesized a new axle, based on a combination of benzobis(imidazolium) (BBI) and viologen species. The axle contains two recognition sites: one is …

Metal Complexes Of Bis(Pyrazolyl)Methane-Based Ditopic Ligands, Pubudu Nuwan Perera Hapuarachchige

Masters Theses

No abstract provided.

Assessing The Robustness And Versatility Of Nanojars For Anion Binding, Mia Lily Ann Jawor

Masters Theses

Supramolecular chemistry is a field in chemistry that focuses on intermolecular bonds in a “host-guest complex” or supramolecular assemblies. Nanojars are supramolecular assemblies of the formula [anion⊂{Cu(μ-OH)(μ-pz)}_n] (n = 27‒33) which incarcerate kosmotropic anions, such as carbonate (CO₃^2‒), sulfate (SO₄^2‒) and hydrogen phosphate (HPO₄^2‒). Nanojars consist of three [Cu(μ-OH)(μ-pz)]_x (x = 6‒14, except 11) rings that are assembled similarly to Matryoshka dolls, where the top and bottom rings act as guests for the central ring. The larger central ring is bound to the two smaller rings by multiple …

Synthesis And Characterization Of Starburst Pseudorotaxanes And Their Metallic Derivatives, Shalini D. Kadinappulige

Masters Theses

Mechanically Interlocked Molecules (MIMs) are interlocked molecular architectures, characterized by the fact that they are linked through a mechanical bond. Catenanes, rotaxanes, molecular knots, and Borromean rings are typical examples for these molecules. Since MIMs are not connected by covalent bonds, hydrogen bonding, π- π stacking, and/or electrostatic interactions help bring the components together. Dialkyl-ammonium centers, bis(pyridinium)ethane dications, viologen species, and naphthalenediimide π-deficient groups are well known as recognition motifs for crown ethers. In the research described here, we have synthesized several pseudorotaxanes and their tricyclohexyltin metallic derivatives, based on benzobis(imidazolium) (BBI) salts as axles, in combination with the 15DN38C10 …

Research And Development Of Optically Transparent Join With Low Processing Temperatures, Eric Kevin Muskovin

Masters Theses

The purpose of this study was to investigate durable solar cell cover glass joins produced by diffusion bonding with deep eutectic solvents (DES) and to develop a novel process of joining optically transparent materials at low temperatures. A joined PV cell-glass specimen was characterized using Raman, μ-FTIR, SEM-EDS, and thin-film XRD. DESs were created with malonic acid (MAL) and choline chloride (ChCl) of varying composition factors (CF; CF=MAL/ChCl). Joining borosilicate glass coupons was attempted using DESs with CF = 0.65 and 1 at temperatures between 100-150 °C for 20 hours. Joining the glass coupons failed at all temperatures and oxygen …

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 …

Specific Phosphate Sorption Mechanisms Of Unaltered And Altered Biochar, Kathryn D. Szerlag

Masters Theses

Biochar has been shown to act as an effective sorbent for many organic and inorganic contaminants (including phosphate) and can help to improve the quality of our fresh water resources by preventing eutrophication. Most of the high efficiency biochar phosphate-adsorbent feedstocks are modified with chemical pretreatment, phytoremediation or anaerobic digestion to accumulate desired elements. The main objectives of this project were to first engineer magnesium (Mg) and calcium (Ca) altered biochar by chemical pretreatment followed by pyrolysis at either 350 or 550°C and evaluate their phosphate adsorption rate and potential as compared to their unaltered counterparts. Determination of surface physiochemical …

Cd Transport In Eutectic Licl-Kcl And Contamination Of Zr Metal And Thermal Dehydration Of Bulk Licl-Kcl, Nicholas Azoy Earle

Masters Theses

Researchers at Idaho National Labs have noted unexpectedly high Cd content in empty cladding hulls after processing in the Mark-IV ER. It has been theorized that Cd metal is transporting from the LCC pool through the eutectic LiCl-KCl salt bath to the anode baskets containing the empty hull where it is retained as a Zr-Cd intermetallic. This study sought to replicate the Cd contamination in a dry Ar glovebox using small-scale analogue of the Mark-IV ER salt-Cd metal system.

Anhydrous eutectic LiCl-KCl was an essential regent in this research and experiments were conducted to investigate the feasibility of dehydrating nominally …

Developing Synthetic Methods To Prepare Discrete Metal-Organic Nanotubes, Derek L. Mull

Masters Theses

Metal-organic nanotubes (MONTs) are an emerging class of discrete materials that are the 1D variant of metal-organic frameworks (MOFs). MONTs have potential to become an alternative 1D material to carbon nanotubes, metal oxide nanotubes, and boron nitride nanotubes because they possess an organic ligand that can be functionalized and tuned for specific applications. Despite this potential, only a handful of structures have been reported and only two examples of discrete MONTs exist in the literature. It is thus imperative to develop general methods to prepare and characterize discrete MONTs to bring them to the forefront of the scientific literature.

Efforts …

Synthesis Of A Bifunctional Heterogeneous Catalyst For The Conversion Of Lignocellulosic Biomass Into Precursors For Alternative Fuels And Fine Chemicals, Matthew David Dembo

Masters Theses

The overall goal of the research described here is to develop synthetic routes to bifunctional reagents that can be tethered into silicate matrices derived from the tin functionalized cube, Si₈O₂₀(SnMe₃)₈. The critical functional group required for reaction with cubic silicate building block is a chlorosilane, and we additionally wish to incorporate both acid and ionic liquid groups. Once in hand, a crosslinking metathesis reaction will incorporate these reagents into porous silicate matrices derived from the Si₈O₂₀ cube, creating platforms with both acid and ionic liquid groups tethered to their …

Determination Of Structural Stabilities Of Metal-Free Porphyrin Cytochrome C, Zinc Cytochrome C, And Cobalt Cytochrome C, Usha K. Tottempudi

Masters Theses

No abstract provided.

Synthesis Of Palladium-Based Electrocatalysis—From Pure Metal To Bimetallic Nanoparticles, Haijun Gao

Masters Theses

This thesis focuses on synthesis and characterization of palladium-based nanoparticles. Background information of the research in this thesis is provided in Chapter 1. Preparation and characterization of pure palladium nanoparticles are presented in Chapter 2. A fast and convenient method to prepare ultra small Pd nanoparticles via Pluronic P123 reduction is discussed in detail. Impregnation method and poly method are also studied in this chapter. Chapter 3 reports the studies of these methods to prepare ultra small bimetallic (bimetallic means a mixture of two metals) palladium-based nanoparticles. Oleylamine-mediated method used Pd nanoparticles prepared via P123 reduction as precursor. Ultra small …

Chlorobenzenes And Chloronitrobenzenes Interaction With Iron (O), Manuel Alejandro Serratos

Masters Theses

Degradation of chlorobenzene, dichlorobenzenes and chloronitrobenzenes (ClB, x-Cl2B and x-ClNO2B) was tested by trying to make them react with metallic iron, Fe (0), in water solvent.

The experiments consisted of optimizing the parameters of the reactions (like minimum mass of iron needed) and analytical detection conditions. Analytical techniques used were gas and liquid chromatography (GC and HPLC), mass spectrometry (MS) and UV-Vis spectroscopy.

No substances other than the initial ClB and x-Cl2B were detected in their tests with Fe (0) after shaking for periods of up to three days, although 10%weight average decreases in concentration were observed.

The ClNO2B isomers …