Inorganic Chemistry Commons^™

Perovskite Oxide Derivatives For Enhanced Electrochemical Water Splitting And Pseudocapacitor Applications., Md. Sofiul Alom

Electronic Theses and Dissertations

The global energy landscape is at a crossroads, marked by surging demand, finite fossil fuel reserves, and escalating environmental concerns stemming from carbon emissions. To address these challenges and transition towards a sustainable energy future, this dissertation embarks on a multidisciplinary exploration of perovskite oxides and their derivatives as catalysts and materials for advanced electrochemical water splitting and pseudocapacitive energy storage. In the quest for efficient water splitting catalysts, a series of quasi-2D oxides, SrLaAl_1/2M_1/2O₄ (M = Mn, Fe, Co), was synthesized and systematically studied where the B-site comprised of both transition metals and main …

Scalable Solution Processing Of Niox Nanoparticles., Peter James Armstrong

Electronic Theses and Dissertations

Perovskite solar cells (PSCs) are a promising alternative to silicon-based photovoltaics. However, PSCs face several challenges due to shortcomings in their stability, module efficiency, and scaled production. Although PSCs is still a young field of research, significant attention has been given to demonstrating power conversion efficiencies that are on par with traditional silicon. With that target reached, converting the laboratory demonstration into practical materials to increase access and abundance of solar energy are among the next large targets for the field. This comes with material challenges for perovskite and their companion charge transport layers (CTLs). Among the charge transport materials …

Hydrothermal Synthesis Of First-Row Transition Metal Polyanions Towards The Design Of Frustrated Magnetic Materials, Megan Smart

All Dissertations

Novel modern materials are constantly being discovered as humanity seeks constantly better improvement to the optics and electronics around us, from lasers used in medical therapies to the magnets and supercomputing chips in our phones. Inorganic oxides commonly draw inspiration from naturally occurring minerals to template new discoveries through substitution of similarly behaving elements with the goal of inducing certain desired properties, such as ferroelectricity or creating the elusive quantum spin liquid. While many minerals are silicates, its periodic table neighbor germanium(IV) has a rich and under-explored crystal chemistry that could contain many new structures and magnetic materials. Another common …

The Room Temperature Electrolysis Of F-Elements In Aqueous And Ionic Liquid Media: Synthesis, Dissolution, And Reduction, Phillip George Hammer

UNLV Theses, Dissertations, Professional Papers, and Capstones

Procuring F-element metals is no simple task and often requires the use of caustic and hazardous materials at high temperatures. These materials are invaluable for a variety of scientific missions ranging from the elucidation of fundamental properties, as fast spectrum nuclear fuel forms, to pit production modernizing our nuclear stockpiles. Metallic actinide materials are essential to strategic and critical materials recovery, the nuclear energy sector, and weapons production. Room temperature electrolysis is envisioned as a process to recover laboratory scale (milligram to gram) quantities of actinide metals. This process closes the uranium chemical loop allowing the reclamation of materials for …

Controlling Guest Binding To Transition Metal Hosts Via Redox Stimuli, Jasmine S. Sanford

LSU Doctoral Dissertations

Several metal complexes were investigated as potential hosts to execute controllable host- guest interactions using a redox stimulus. Previously, our group has synthesized new Cu^II m-xylylenebis(pyridyltriazole) (m-xpt) hosts and their redox properties were analyzed. In Chapter 2, we take advantage of the Cu^II host’s ability to perform redox to investigate its interaction with chloride guest ions. This study was executed with two main Cu-xpt hosts: [Cu₂(m- xpt)₂(NO₃)₂](PF₆)₂ and [Cu₂(m-xpt)₂Cl₂]Cl₂. The host-guest interaction was analyzed with additions …

Antibacterial Testing On Silver/Zinc Oxide Nanoparticles/Organoclay Reinforced Chitosan Biocomposites, Lisna Junaeni Muiz, Ariadne Lakshmidevi Juwono, Zulkarnaen Paputungan, Yuni Krisyuningsih Krisnandi

Makara Journal of Science

Herein, bionanocomposites of chitosan (CS)/silver nanoparticle/organoclay/zinc oxide nanoparticle (CS/Ag/OC/ZnO) were prepared for antibacterial food packaging. This study examines the time variation in the AgNP synthesis method by comparing local (74˗85% deacetylated) and commercial chitosan (75%˗85% deacetylated) as a reducing and capping agent and seeks to reconstruct the optimum ratio formulations of AgNPs and ZnONPs in bionanocomposites for food packaging. The results reveal that the synthesis of AgNPs was successfully carried out using a local chitosan solution as a reducing and capping agent. The CS/Ag/OC/ZnO films exhibit structural, mechanical, and optical properties suitable for food packaging and antibacterial activity on Staphylococcus …

Characterization And Electrolysis Of Zn And Cu 2,6-Diacetylpyridine Bis(2-Hydrazinopyridine), Bailee G. Duff, Christine Phipps, Craig Grapperhaus

The Cardinal Edge

With increasing demands for fuel and concerns over climate change, the search for sustainable energy sources is ever growing. Hydrogen is a potential solution to these issues, as it is clean, recyclable, and efficient. However, hydrogen must be generated, unlike other fuel sources that are naturally ready for use. The most sustainable method for hydrogen production involves water electrolysis, as no pollution is generated. The water splitting process contains a cathodic hydrogen evolution reaction (HER) and an anodic oxygen evolution reaction (OER). These reactions require a catalyst to overcome the kinetic barrier present and meet the high voltage requirements for …

Hydrogen Peroxide Disproportionation Activity Is Sensitive To Pyridine Substitutions On Manganese Catalysts Derived From 12-Membered Tetra-Aza Macrocyclic Ligands, David M. Freire, Hannah M. Johnston, Katherine J. Smith, Kristof Pota, Magy A. Mekhail, Sugam Kharel, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The abundance of manganese in nature and versatility to access different oxidation states have made manganese complexes attractive as catalysts for oxidation reactions in both biology and industry. Macrocyclic ligands offer the advantage of substantially controlling the reactivity of the manganese center through electronic tuning and steric constraint. Inspired by the manganese catalase enzyme, a biological catalyst for the disproportionation of H₂O₂ into water and O₂, the work herein employs 12-membered tetra-aza macrocyclic ligands to study how the inclusion of and substitution to the pyridine ring on the macrocyclic ligand scaffold impacts the reactivity of …

The Development Of Novel Radioscandium And Hydroxypyridinonate Based Radiopharmaceuticals, Michael Phipps

Dissertations, Theses, and Capstone Projects

The use of radiometals in radiopharmaceutical development has drastically increased over the last decade, owed in part to the diverse chemistry and emission characteristics of the radiometals, which allow chemists to create a toolbox of agents to better tailor patient care. Challenges with the use of radiometals include the selection of the metal and the development of optimized chelators to cover the diverse chemistry of the metals which make up the majority of the periodic table. Scandium is the first transition metal and has multiple radioisotopes whose emission characteristics have potential application in medicine. 3,4,3-LI(1,2-HOPO) is a chelator whose denticity, …

Syne1 Mutation Is Associated With Increased Tumor Mutation Burden And Immune Cell Infiltration In Ovarian Cancer, Laura M. Harbin, Nan Lin, Frederick R. Ueland, Jill M. Kolesar

Markey Cancer Center Faculty Publications

SYNE1, a nuclear envelope protein critical for cellular structure and signaling, is downregulated in numerous malignancies. SYNE1 alterations are found in 10% of gynecologic malignancies and 5% of epithelial ovarian cancers. Previous studies demonstrated an association between SYNE1 mutation, increased tumor mutation burden (TMB), and immunotherapy response. This study evaluates the SYNE1 mutation frequency, association with TMB, and downstream effects of SYNE1 mutation in ovarian cancer. Genetic information, including whole-exome sequencing, RNA analysis, and somatic tumor testing, was obtained for consenting ovarian cancer patients at an academic medical center. Mutation frequencies were compared between the institutional cohort and The Cancer …

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 …

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 …

Developing Strategies For The Integration Of Metal–Organic Frameworks (Mofs) Into E-Textiles For Chemical Sensing, Filtration, And Detoxification, Aileen Mary Eagleton

Dartmouth College Ph.D Dissertations

Metal-organic frameworks (MOFs) are crystalline porous materials that offer modularity through diverse combinations of metal nodes and linkers, as well as tailorable surface chemistry and structure, along with tunable conductivity. The integration of these framework materials onto fibers can result in robust and flexible MOF-based textiles with enhanced functionality and applicability. This thesis illustrates the versatility of multifunctional MOF-integrated textile systems, showcasing their unique properties and the advantages of installing MOFs at the fiber level.

Activation Of The Renin–Angiotensin–Aldosterone System Is Attenuated In Hypertensive Compared With Normotensive Pregnancy, Robin C. Shoemaker, Marko Poglitsch, Hong Huang, Katherine Vignes, Aarthi Srinivasan, Cynthia Cockerham-Morris, Aric Schadler, John Anthony Bauer, John O'Brien

UK CARES Faculty Publications

Hypertension during pregnancy increases the risk of adverse maternal and fetal outcomes, but the mechanisms of pregnancy hypertension are not precisely understood. Elevated plasma renin activity and aldosterone concentrations play an important role in the normal physiologic adaptation to pregnancy. These effectors are reduced in patients with pregnancy hypertension, creating an opportunity to define the features of the renin–angiotensin–aldosterone system (RAAS) that are characteristic of this disorder. In the current study, we used a novel LC-MS/MS-based methodology to develop comprehensive profiles of RAAS peptides and effectors over gestation in a cohort of 74 pregnant women followed prospectively for the development …

Synthesis And Characterization Of Cobalt(Iii) Complexes And A Vanadium(Iv) Complex With Flavonoids As Ligands, Ethan Schroeder

Chemistry & Biochemistry Theses & Dissertations

For many years now, transition metal complexes have been used as favorable additional chemotherapeutic approaches to medicine that were previously unexplored in the literature. One well-known chemotherapeutic drug, cisplatin, has been applied, but is limited in use due to its toxicity to the cells and its undesirable side effects to humans. Newly developed cobalt-based complexes with ligands known as flavonoids are being used to fight cancer. Flavonoids, compounds mainly found in fruits and vegetables, are shown to have antioxidative and anticancer properties. Use of flavonoids as ligands in transition metal complexes, e.g., those with a Ru(II) metal center, have been …

Structures Of The Insecticidal Toxin Complex Subunit Xpta2 Highlight Roles For Flexible Domains, Cole L. Martin, David W. Chester, Christopher D. Radka, Lurong Pan, Zhengrong Yang, Rachel C. Hart, Elad M. Binshtein, Zhao Wang, Lisa Nagy, Lawrence J. Delucas, Stephen G. Aller

Markey Cancer Center Faculty Publications

The Toxin Complex (Tc) superfamily consists of toxin translocases that contribute to the targeting, delivery, and cytotoxicity of certain pathogenic Gram-negative bacteria. Membrane receptor targeting is driven by the A-subunit (TcA), which comprises IgG-like receptor binding domains (RBDs) at the surface. To better understand XptA2, an insect specific TcA secreted by the symbiont X. nematophilus from the intestine of entomopathogenic nematodes, we determined structures by X-ray crystallography and cryo-EM. Contrary to a previous report, XptA2 is pentameric. RBD-B exhibits an indentation from crystal packing that indicates loose association with the shell and a hotspot for possible receptor binding or a …

Leveraging Non-Covalent Interactions Between Small Organic Molecules And Inorganic Scaffolds In The Design Of Advanced Materials, Jonathan Lefton

Chemistry Theses and Dissertations

Powder diffraction is a powerful tool for studying crystal structures, especially as it relates to interactions of small organic molecules with inorganic compounds. The first part of this dissertation involves small organic ligands interacting with metal-organic framework, MOF-74. The first and simplest iteration involves the crystal structure solution of a neat, liquid loading of n-propylmercaptan to the open metal sites within the MOF-74 pores. Later studies investigate the leveraging of a similarly sized bitopic ligand in the solution loading of 1,2-ethanedithiol, which results in the amorphization of MOF-74. Having no crystallinity, amorphous or severely defected materials can be a …

Synthesis And Reactivity Of Dihydrogen Diruthenium Complexes., Ryder J. Downey, Robert Chin

Summer Undergraduate Research Program (SURP) Symposium

Having two open coordination sites on the diruthenium complex makes for the ability to be able to be more precise when interacting with other compound. The side-on bonding of the bis(dihydrogen) gives it unique characteristics as well as unique capabilities. The Oganotransition Metal Chemistry book says that the dihydrogen is bonded by the donation of electrons from the H-H sigma bond as well as the back donation of electron density through the transition metal.3

In the past, many groups have studies on a mononuclear Ruthenium compound similar to the one we are synthesizing (see figure one). Our goal was to …

Rhodium-Catalyzed Asymmetric Synthesis Of P-P And P-C Bonds, Sarah T. Chachula

Dartmouth College Ph.D Dissertations

Chapter 1: Synthesis, Structure, Dynamics, and Enantioface-Selective η3-Benzyl Coordination in the Chiral Rhodium Complexes Rh(diphos*)(η3-CH2Ph) Abstract: The rhodium benzyl complexes Rh(diphos*)(η3-CH2Ph) (1-14, diphos* = chiral bis(phosphine)) were prepared either by treatment of Rh(COD)(η3-CH2Ph) (15, COD = 1,5-cyclooctadiene) with diphos*, or from the reaction of [Rh(diphos*)(Cl)]2 (16- 20) with PhCH2MgCl. For C2-symmetric diphos*, observation of one set of NMR signals for complexes 1-12 suggested that the two diastereomers in which different 3-benzyl enantiofaces were coordinated to rhodium interconverted rapidly on the NMR time scale via suprafacial shifts; observation of five inequivalent aryl 1H NMR signals showed that antarafacial shifts were slow …

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 …