Inorganic Chemistry Commons^™

Tuning Ion Mobility And Molecular Confinement In High-Performance Polymer Electrolytes For Energy Storage, Ezzeldien Yousef Muhammed Yousef

Theses and Dissertations

This research addresses the critical energy density limitations of aqueous supercapacitors, which are traditionally constrained by the narrow electrochemical stability window (ESW) of water 1.23 V. By employing two distinct molecular engineering strategies, this study developed high-performance electrolyte systems that significantly extend voltage stability and thermal resilience.

The first system, CsBr@PAM/HA, utilizes a polyacrylamide and hyaluronic acid hydrogel matrix. This system exploits the chaotropic nature of Cs⁺ ions to disrupt the aqueous hydrogen-bonding network, enhancing ionic conductivity to 104 mS cm^-1. Through systematic salt screening, CsBr was identified as the optimal electrolyte, enabling a stable 2.0 V …

De Novo Protein Binding To Zinc Oxide Through Biomineralization Pathways, Jean-Mark A. Francis

Theses and Dissertations

De novo proteins are structurally distinct from proteins found in nature and thus capable of having their amino acid sequence modified to accomplish tasks such as increasing protein-nanoparticle binding without unfolding or decomposing. Zinc Oxide nanoparticles are functionally distinct from their bulk counterparts and are widely used as semiconductors in a variety of fields such as medicine and agriculture. With demand for these nanoparticles increasing, environmentally sustainable methods of Zinc Oxide nanoparticle synthesis are being investigated as an eco-friendly alternative to currently utilized but environmentally hazardous chemical and physical techniques. This research investigates the binding characteristics between Zinc Oxide nanoparticles …

Synthesis And Characterization Of Lanthanide Extended Structures And Their Novel Transuranic Analogues, Hunter Bernard Tisdale

Theses and Dissertations

The United States owns a substantial amount of radioactive waste as a result of decades of research, weapons manufacturing, and nuclear energy production. As nuclear energy and research continue to add to our stockpiles of waste, the issue of remediating this waste becomes more pressing. Many of the radioactive constituents of this waste, such as the transuranic (Z > 92) elements, will give off radioactivity at harmful levels for millennia. Thus, a robust method of storing this waste is paramount to ensuring public safety. Currently, nuclear waste is being processed by vitrifying it in borosilicate glass. However, this method has shortcomings …

Reactivity Of Redox-Active Carboranyl Diphosphines And Carboranyl Diphosphoniums: Metal-Free Pathways For Small Molecule Activations And Transformations, Amanda Lynn Humphries

Theses and Dissertations

Transition metal catalysis has been an integral part of synthetic chemistry for its ability to selectively activate strong substrate bonds, promoting numerous crucial transformations. Despite their utility, the precious metals that are often employed in these catalytic reactions suffer from several drawbacks (including high toxicity, low natural abundance, high costs, and low sustainability), increasing the motivation to design suitable metal-free alternatives. Towards this end, several ambiphilic main-group systems have been devised to show metal-like reactivity, such as carbenes, borylenes, and Frustrated Lewis Pairs. This manuscript will describe the ambiphilic reactivity of carborane-based phosphorus compounds, highlighting the unique metallomimetic reactivity that …

Determination Of Structure-Function Relationships In Hybrid Catalysts On Metal Oxide Supports, Joseph John Kuchta

Theses and Dissertations

Transition metal catalysis has revolutionized chemical synthesis, enabling efficient and selective transformations critical to the pharmaceutical, agricultural, and materials industries. However, traditional methods often rely on expensive, non-sustainable metals and harsh reaction conditions that generate significant waste. This dissertation explores a series of innovations aimed at bridging the gap between homogeneous and heterogeneous catalysis through the development of hybrid catalysts. These systems combine the molecular precision of homogeneous catalysts with the stability and practicality of heterogeneous supports, offering a pathway to more sustainable and scalable catalytic processes.

The first area of focus investigates nickel-based hybrid catalysts as a cost-effective and …

Synthesis Of Novel Schiff Bases And Their Metal Complexes, Ryan J. Lukkarinen

Theses and Dissertations

Presented in this thesis is the synthesis and characterization of multiple thiosemicarbazones and dithiocarbazates, as well as their corresponding metal complexes. Chapter 1 is an introductory chapter exploring the significance and potential applications of this work. Chapter 2 focuses on thiosemicarbazone synthesis and characterization. Chapter 3 describes the synthesis and characterization of dithiocarbazates. Chapter 4 details metal complex synthesis using the previously described ligands. Chapter 5 summarizes the conclusions of the research and future work that may stem from it.

Synergetic And Orthogonal Switching In Dual Photochromic Metal-Organic Frameworks, Gina Rene Wilson

Theses and Dissertations

Cooperative behavior and orthogonal responses of two classes of coordinatively integrated photochromic molecules towards distinct external stimuli were demonstrated on the first example of a photo-thermo-responsive hierarchical platform. Synergetic and orthogonal responses to temperature and excitation wavelength are achieved by confining the stimuli-responsive moieties within a metal-organic framework (MOF), leading to the preparation of a novel photo-thermo-responsive spiropyran-diarylethene based material. Synergistic behavior of two photoswitches enables the study of stimuli-responsive resonance energy transfer as well as control of the photoinduced charge transfer processes, milestones required to advance optoelectronics development. Spectroscopic studies in combination with theoretical modeling revealed a nonlinear effect …

Advances In Chalcogenide Crystal Growth, Anna Berseneva

Theses and Dissertations

Chalcogenides are the cornerstone of the semiconductor and thermoelectric industries and are up-and-coming materials for superconductors, catalysis, and battery applications. Challenges in the synthesis of those materials emerge from the chalcogen’s volatility and the tendencies of chalcogenide to react with even trace quantities of oxygen. Nonetheless, many techniques have been applied to the growth of chalcogenide single crystals, which are convenient for structure determinations and intrinsic property measurements. This dissertation will detail synthetic strategies applied to the crystal growth of novel chalcogenide materials via molten flux preparation (Chapters 2, 4, and 5), hydrothermal synthesis (Chapter 1 and 3), and single-crystal-to-single …

Controlling Properties Of Hybrid Materials: Leaching Kinetics And Electronic Structure, Anna Berseneva

Theses and Dissertations

Hybrid materials are a unique class of materials that merge the properties of organic and inorganic building blocks. These materials are at the frontier of material science due to their wide modularity and applicability in numerous fields, ranging from catalysis to nuclear waste treatment. Unprecedented tunability of physical properties via changes in organic, inorganic moieties and their connectivity, enables for hybrid materials to address current challenges in the materials’ applications improving energy landscape.

The presented work consists of six chapters where the synthesis and design of new hybrid materials, fundamental understanding of electronic behavior and its modulation in organic-inorganic materials, …

Molecular And Hybrid Catalysts For Selective Hydrodeoxygenation Of Lignin Model Compounds, Jacob G. Tillou

Theses and Dissertations

Lignin is a highly aromatic, branched polymer and could be utilized as a renewable source of liquid fuel. The advent of “lignin-first” depolymerization processes have allowed for the high-yield isolation of oxygenated aromatic monomers from lignin. These oxygenated aromatic compounds are lower in energy and stability than their deoxygenated counterparts. Selective deoxygenation of these compounds would result in stable, higher value liquid fuels. Using molecular catalysts, selective deoxygenation, or hydrodeoxygenation (HDO), of lignin-derived compounds in the presence of hydrogen is possible.

Immobilization of these molecular catalysts on metal oxide surfaces eliminates the possibility of bimolecular decomposition and allows for easier …

Modulating Covalency In A Ni-H-Al Subunit: Synthesis And Characterization Of A Series Of Electronically Differentiating Ni-Al Heterometallics, Aleida Guadalupe Gonzalez

Theses and Dissertations

Metal hydrides are moieties that are present in a variety of applications as intermediates in catalysis. Despite the vast utilization of metal hydrides, monometallic metal hydride complexes bear limitations in inert-bond activation and functionalization. A strategy to overcome these limitations and access more challenging reactivity is utilizing metal-metal cooperativity on a single platform to further activate hydride moieties. Although incorporating multiple metal centers on a single ligand scaffold has been realized, access to heterometallic hydride-bearing complexes is a greater synthetic challenge. Given the limitations in accessing such systems, the reactivity and electronic structure of heterometallic hydrides are seldom studied. Recently, …

Towards Carbon Dioxide Reduction: Synthesis And Characterization Of Ccc-Nhc Pincer Iron Complexes., Joshua Mensah

Theses and Dissertations

The industrial revolution came with its downside of emission of greenhouse gases into the atmosphere. The NOAA reported in 2019 that, of the greenhouse gases emitted into the atmosphere, CO2 contributed to about 80% of the increased greenhouse gases hence the need for CO2 Sequestering and Storage (CSS) and ultimately leading to Carbon Capture and Recycling (CCR) as a viable option to convert CO2 into useful forms. The race to find the best catalyst for CCR has led to the synthesis of many organometallic compounds. Pincer complexes catalyzed CO2 reduction has gained notoriety recently because of the tunability and robustness …

Studies Of Novel And Well-Defined Dinickel Architectures Utilizing An N-Atom Bridge, David Anthony De Los Santos

Theses and Dissertations

There has been a growing interest in organometallic chemistry to utilize late Earth-abundant metals towards challenging molecular functionalization of abundant feedstocks to value-added products. There is precedent of utilizing cooperativity to try and address some of the shortcomings of traditional mononuclear complexes by integrating metal-metal and or metal-ligand cooperativity to facilitate multi-electron transformations. The utility of a redox-noninnocent scaffold allows for the metal centers to be stable over a range of oxidation states, using the ligand to store electrons. Despite recent progress, complexes harnessing cooperative states towards challenging transformations is still an emerging field. Our group has synthesized a multinucleating …

Elucidation Of The Optical Properties Of Si And Si-Ge Alloy Nanostructures With Visible To Near-Ir Photoluminescence, Griffin Spence

Theses and Dissertations

Silicon and silicon-germanium alloy nanostructures have garnered increasing attention in the past 25 years due to their favorable optical properties, visible to near-IR luminescence, and inherently low toxicity. While many synthetic routes have been discussed in the literature, the high-temperature, solid-state disproportionation of hydrogen silsesquioxane (HSQ) has become the most popular way to produce highly crystalline, size-tunable Si and Si-based nanostructures (NCs). It has been shown in this work that maximum annealing temperature from 450°-1100°C and the addition of GeI₂or SnCl₄ precursors can be used to achieve different morphologies, alloying efficiency, and sizes. Directly annealing HSQ from …

Investigating The Magnetic And Electronic Properties Of Cobalt(Ii) Heteroscorpionate Isomers, Jamie Dawn Freeman

Theses and Dissertations

Cobalt(II) scorpionates possess distinct electronic and magnetic properties in comparison to other first-row transition metal complexes in this ligand class. One unique property is their significantly downfield paramagnetically shifted 11B NMR signals. The utilization of a heteroscorpionate ligand Tp’ introduces asymmetry to metal scorpionates, producing cis and trans isomers. cis- and trans-Co(Tp’)2 were synthesized and separated by column chromatography. 11B NMR data show cobalt(II) homoscorpionates resonances in a narrow 20 ppm shift range around 270 ppm while cis- and trans-Co(Tp’)2 differ with signals at 230 ppm and 140 ppm, respectively. Paramagnetic NMR studies indicate both isomers maintain the same spin …

Synthesis And Characterization Of Redox-Noninnocent Pyrazine(Diimine) Iron Complexes And An Inverted Pyridine(Diimine) Ligand, Jaylan Billups

Theses and Dissertations

Cooperativity between the metal center and the ligand has been shown in nature to be an important feature of systems that catalyze two-electron processes that first-row transition metals usually cannot catalyze on their own. In these cases, the ligand acts as a site of reactivity that in many instances can store electrons or react directly with substrates in solution. The design and study of systems where there is synergy between the metal and the ligand have been leveraged to catalyze polymerization and hydrogenation-type reactions as well as the activation of small molecules such as dihydrogen. Specifically, the pyridine(diimine) ligand scaffold …

Improved Stoichiometric Synthesis Of Ccc-Nhc Pincer Rh Complexes And Catalytic Activity Towards Dehydrogenative Silylation And Hydrosilylation Of Alkenes, Enock Amoateng

Theses and Dissertations

N-Heterocyclic carbenes (NHCs) have attracted growing interest not only as successful ancillary ligands in a wide variety of transition-metal-catalyzed reactions but have also shown to offer photophysical and electrochemical properties. The metalation/transmetalation strategy using [Zr(NMe₂)₄] as initial metalating reagent offers an efficient approach to the preparation of CCC-NHC pincer complexes of the late transition metals such as Rh and Ir. In the process of investigating an intermediate and the mechanism of the metalation/transmetalation to Rh sequence, a mixed valent bimetallic CCC-NHC pincer Rh complex with two chloro ligands bridged between a [(CCC-NHC)Rh(III)] and a [Rh(I)(COD)] fragment …

From Waste To Energy: The Electrochemical Reduction Of Co2 Using Recycled Nanostructured Catalysts, Ibrahim Badawy

Theses and Dissertations

The reduction of carbon dioxide (CO₂RR) using electrochemistry is a promising solution for the burgeoning global energy crisis. The overall vision of its implementation relies on renewable energy sources to power the reaction creating carbon neutral products and effectively closing the carbon cycle. Research in this field has come a long way since its inception in the mid-1900s. However, there remain significant hurdles and important considerations to overcome in order to reach full commercialization. Most electrocatalysts tested for CO₂RR have been designed solely for maximum performance while ignoring the environmental consequences if such a material were …

Halide Substitution Of Ternary Bismuth Chalcogenides For Photovoltaic Applications, Thomas Boggess

Theses and Dissertations

Semiconductors play an integral part in modern society. From computing to LEDs their use is ubiquitous, and no field is more reliant on them than that of power generation. Current political movements have seen a push to decrease reliance on traditional forms of power generation, which relies on fossil fuels, to renewable sources such as solar power. However, current commercial solar panels, based on silicon, are lacking in efficiency, only reaching between 18% and 22% efficiency.¹ In recent years, materials called perovskites have been garnering significant attention as possible replacements for silicon cells due to their favorable optoelectronic properties. …

Synthesis And Characterization Of Mixed Ligand Complexes Of Ruthenium(Ii) Containing 2,2’-Bipyridine And 3,3’-Dimethyl-1,1’- Methylenebisimidazolium Ligands; A New Synthetic Approach, Matthew Schneider

Theses and Dissertations

Research into solar cells has been prioritized given the global demand for better renewable energy technologies. This demand is a result of the long-term use of fossil fuels, which generates significant pollution in highly populated urban areas. One potential solar cell technology is the dye-sensitized solar cell (DSSC). This kind of solar technology utilizes organometallic dyes to expand the types of wavelengths solar cells can use to generate electricity.12 Ruthenium(II) metal complexes of this type have been investigated heavily for this purpose.13,14,36 The main reasoning behind this is the metal-to-ligand charge-transfer (MLCT) phenomenon that such complexes exhibit. MLCT has often …

Synthesis And Application Of Redox-Active Covalent Organic Frameworks In Rechargeable Batteries, Mohammad K. Shehab

Theses and Dissertations

Synthesis and Application of Redox-Active Covalent Organic Frameworks in Rechargeable Batteries

Mohammad K. Shehab

Department of Chemistry, Virginia Commonwealth University, Richmond, Virginia 23284, United States

Abstract

In recent years, lithium-ion batteries (LIBs) have been considered the dominant energy storage devices for portable electronics and electric vehicles due to their high energy density, low self-discharge rate, and long cycle life. In LIBs, the traditional positive electrodes employed are mainly derived from metal-containing inorganic compounds composed of cobalt, iron, nickel, or manganese (LiCoO₂, LiMn₂O₄, and LiFePO₄) coupled with graphite as the negative electrode. Despite …

The Chemistry And Catalytic Activity Of Dehydrogenative Silylation And Hydroboration Of Complexes Bearing Semirigid Ligands With Group 14 Elements, Niroshani S. Abeynayake

Theses and Dissertations

Incorporation of silicon in the ligand backbone would yield electron-rich metal complexes upon coordination to transition metal complexes. The coordination chemistry of semirigid benzyl phosphines bearing a single or multiple phosphorus atoms and varying number of Si−H moieties has gained interest in recent years. This dissertation focuses on synthesizing silyl and germyl transition metal complexes of groups 9 and 10. Chapter II presents the synthesis of a family of four coordinated 14-electron rhodium complexes. The newly synthesized complexes were characterized in solution by multinuclear NMR spectroscopy and in the solid-state by single-crystal X-ray diffraction. These d⁶ complexes possess sawhorse …

Synthesis, Characterization And Activity Of Palladium Catalysts On The Dual Support Of Cerium And Aluminum Oxides, Jihyeon Park

Theses and Dissertations

The effects of sequence of impregnation (Pd on cerium oxides -alumina and cerium oxides on Pd-alumina) and calcination temperature (500 ℃ and 850 ℃) on the catalytic oxidation of methane under lean conditions were investigated. The catalysts were prepared by a combination of impregnation, slurry and vortexing methods. The catalysts had 4.7 wt.% Pd and 10.7 wt.% Ce based on inductively coupled plasma optical emission spectrometry (ICP-OES) analysis. The catalysts were characterized by pulse chemisorption, temperature programmed reduction (TPD), scanning transmission electron microscopy (STEM), and X-ray photoelectron spectroscopy (XPS). The activity of the catalysts for methane combustion was measured in …

Transition Metal Phosphides For High Performance Electrochemical Energy Storage Devices, Amina Saleh

Theses and Dissertations

Electrochemical energy storage technologies are nowadays playing a leading role in the global effort to address the energy challenges. A lot of attention has been devoted to designing hybrid devices known as supercapatteries which combine the merits of supercapacitors (high power density) and rechargeable batteries (high energy density). Transition metal phosphides (TMP) are a rising star for supercapattery anode materials thanks to their high conductivity, metalloid characteristics, and kinetic favorability for fast electron transport. Herein, new TMP-based materials were synthesized for use as supercapattery positive electrodes, via a multifaceted approach to yield devices enjoying concurrently high power and energy densities. …

Synthesis And Modeling Of Manganese Ferrite Nanoparticles For Magnetic Hyperthermia Applications, Margaret E. Thornton

Theses and Dissertations

Biologically targeted magnetic hyperthermia (MH) is a promising cancer therapeutic that is both non-invasive and has the potential to serve as a single-modality cancer treatment. MH operates through the elevation of temperatures between 40-43 °C to induce apoptosis in malignant tumor cells, while the small size of the magnetic nanoparticles preserves the healthy surrounding tissue. At present, MH is limited by low heating efficiency and heterogenous outcomes, and treatment requires direct-injection of the nanoparticles, excluding deep-tissue and metastatic tumors from the therapy. The most popular candidates for MH are the spinel ferrites iron oxide and manganese iron oxide (MFO). These …

Antiviral Effects Of Metalloshielding: Differential Antiviral Activity Of Polynuclear Platinum And Cobalt Compounds, Mary Zoepfl

Theses and Dissertations

The majority of antiviral drug development has focused on virus-specific discovery targeting discrete steps in the individual life cycles. Although great strides have been made for a number of clinically relevant diseases such as human immunodeficiency virus, influenza virus, and hepatitis B, broad spectrum antivirals do not exist. Broad spectrum antivirals would offer (1) treatment for viruses without specifically-targeted antivirals, (2) treatment for viruses which have developed resistance to their available treatments, and (3) a rapidly deployable treatment option in viral epidemics. Many viruses including human cytomegalovirus (HCMV), HIV, and SARS-CoV-2. rely on heparan sulfate (HS), a highly sulfated glycosaminoglycan …

Conformational Modulation Of Α-Helical N-Acetylated Α-Synuclein, Ricardo Fernandez

Theses and Dissertations

Human N-acetylated α-synuclein (^NAcαSyn) has long been accepted as an intrinsically disordered protein (IDP) predominantly found in terminal nerve regions in healthy subjects. ^NAcαSyn structural fluidity enables the formation of transient or dynamic assemblies. Some of these assemblies may serve functional, yet undefined purposes. ^NAcαSyn is highly susceptible to the surrounding environment, leading to misfolding under high cytosolic oxidative stress conditions, which in turn assemble in the form of toxic oligomers or amyloid fibrils. These ^NAcαSyn inclusions along with their accretion and migration within neurons, are pathological hallmarks of Parkinson’s disease (PD), dementia, and multiple …

Streptococcus Sanguinis: The Good, The Bad, And The Metal-Binding Lipoprotein, Cody Murgas

Theses and Dissertations

Streptococcus sanguinis is an opportunistic bacterium living beneficially in the human mouth. When S. sanguinis gains access to the bloodstream, it can result in colonization on damaged tissue and generate heart valve vegetations that can develop into infective endocarditis. It has been suggested that Mn and Fe are cofactors in the pathogenic capacity of this bacterium, and that these redox active metals are imported by the metal binding lipoprotein S. sanguinis adhesin B (SsaB). The SsaB lipoprotein is an integral part of SsaACB, an ATP-binding cassette (ABC) transport system in S. sanguinis. When SsaB is deleted, the resulting strain displays …

The Rational Synthesis Of Lanthanum Manganite Nanomaterials For Magnetic Refrigeration Applications, Caitlin Hunt

Theses and Dissertations

Refrigeration systems for the cooling of commercial and residential buildings are a major drain on energy resources and source of greenhouse gas emissions. Magnetic refrigeration, which employs the magnetocaloric effect, has the potential to mitigate the energy drain and greenhouse gas emissions for air conditioning. In order to commercialize magnetic refrigerators, a material with a high magnetic entropy change, ΔS, near room temperature which is simple and inexpensive to create is needed.¹ Current options for this solid refrigerant are either expensive, difficult to synthesize, or have a ΔS or T_c (the Curie Temperature, where ΔS is maximized) below …

Development Of Supported Pd-Based Catalysts For Carbon-Carbon Cross-Coupling And Oxidation Reactions, Mrinmoy Das

Theses and Dissertations

Heterogeneous catalysts are a crucial part of chemistry used for various chemical synthesis stages, pharmaceutical, and environmental applications. The use of nanoparticles or rather nanocatalysts enhances the heterogeneous catalytic applications. Both chemical and physical methods can be used to synthesize nanocatalysts. Chemical synthesis methods require comparatively fewer instruments and can easily synthesize a large amount of nanocatalysts. Nevertheless, chemical synthesis methods require reducing agents and solvents that can be toxic or harmful materials. They often need harsh reaction conditions as well, like high temperature and pressure. On the other hand, physical synthesis methods often require complex instrument setup, but their …