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Ultrafast Charge Transfer in Donor-Acceptor Push-Pull Constructs

Description: Ultrafast charge and electron transfer, primary events in artificial photosynthesis, are key in solar energy harvesting. This dissertation provides insight into photo-induced charge and electron transfer in the donor and acceptor constructs built using a range of donor and acceptor entities, including transition metal dichalcogenides (TMDs, molybdenum disulfide (MoS2), and tungsten disulfide (WS2)), N-doped graphene, diketopyrrolopyrrol (DPP), boron-dipyrromethene (BODIPY), benzothiadiazole (BT… more
Date: August 2022
Creator: Jang, Young Woo
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Synthesis and Studies of Platinum- and Palladium-Based Porphyrin-Fullerene Conjugates to Study the Long-Lived Charge-Separated States

Description: The research presented in the dissertation deals with the synthesis, characterization, photophysical, electrochemical, and pump probe studies of porphyrin-fullerene based donor-acceptor conjugates. The first chapter provides insights into the introduction of the thesis, which explains the events that occur in natural photosynthesis and the mimicking process of an artificial photosynthesis based on natural photosynthesis, works done in covalently and non-covalently linked donor acceptor systems,… more
Date: July 2023
Creator: Subedi, Dili Raj
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Magnetron Sputtering of Transition Metal Oxynitrides and Their Characterization with Auger Electron Spectroscopy and X-ray Photoelectron Spectroscopy

Description: Transition metal oxynitrides are of growing interest for their use as electrocatalyst for nitrogen reduction reaction. The metals in the oxynitride used for catalytic process are stabilized in intermediate state for effective activation of nitrogen. Therefore, studying the interaction of metal oxynitrides films to ambient exposure is necessary. Here, sputter deposited vanadium oxynitride is compared to cobalt oxynitride using insitu Auger electron spectroscopy (AES), ex situ X-ray photoelectron… more
Date: May 2023
Creator: Adesope, Qasim Adewale
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

One-Step Synthesis of 1,3,4-Oxadiazines, 4,5,6,7-Tetrahydro-1h-Indoles, and Functionalized Benzo[B]Carbazoles Catalyzed by Rare Earth Metal Triflates and Cooperative Enamine-Bronsted Acid

Description: Design and development of novel one-step reactions that produce nitrogen-containing scaffolds is an invaluable area of chemistry due to the abundance of these moieties in natural products and biologically active molecules. Discovering novel methods using uncommon substrates and rare earth metals to access these significant scaffolds present a challenge. Over the course of my doctoral studies, I have designed, developed and optimized novel reactions by using rarely known substrates and rare eart… more
Date: May 2023
Creator: Cortes Vazquez, Jose
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Porous Organic Polymer-based Nanotraps for Metal Resource Recovery/Extraction from Water

Description: The recovery processes of critical metals from multiple sources have turned more and more attention due to the increasing demand and consumption of them in modern industry. Many metals are used as significant components in manufacturing of a variety of products and equipment, playing significant roles in the economic security and national security; those metals involve rare earth elements (REEs), precious metals which include gold, silver, and platinum group metals (PGMs), and other valuable me… more
This item is restricted from view until June 1, 2025.
Date: May 2023
Creator: Song, Yanpei
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Cleaner Futures: Covalent Organic Frameworks for Sustainable Degradation of Lignocellulosic Materials

Description: As countries pledge their commitment to a net-zero future, much of the previously forgotten climate change research were revitalized by efforts from both governmental and private sectors. In particular, the utilization of lignocellulosic materials saw a special spotlight in research interest for its abundance and its carbon removal capability during photosynthesis. The initial effort in mimicking enzymatic active sites of β-glucosidase will be explored. The crystalline covalent organic framewor… more
This item is restricted from view until June 1, 2028.
Date: May 2023
Creator: Lan, Pui Ching
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

β, β'-π-Extended Porphyrins: Exploration of Functionalization and Aromatic Character

Description: Seventeen new dithiophenyl- and napthodithiophenyl- fused porphyrins were synthesized; from these an additional 7 porphyrin oligomers were also synthesized. Additionally freebase 2,7-dimethoxytriphenylene fused porphyrin was also synthesized from a freebase precursor. Aromatic indices NICS and AICD were used to evaluate these new molecules.
Date: July 2023
Creator: Cooper, Courtney Taylor
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Theoretical Studies of Photoactive Metal Complexes with Applications in C-H Functionalization and Quantum Computing

Description: Previous work was successful at delineating reaction pathways for the photoactivated synthesis of an amine, [CztBu(PyriPr)(NH2−PyriPr)], by double intramolecular C−H activation and functionalization via irradiating a metal(II) azido complex, [CztBu(PyriPr)2NiN3. The present work seeks to expand upon earlier research, and to substitute the metal with iron or cobalt, and to expand the study to photocatalyzed intermolecular C−H activation and functionalization of organic substrates. Density functi… more
This item is restricted from view until June 1, 2024.
Date: May 2023
Creator: Alamo Velazquez, Domllermut C.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Design and Synthesis of Gold (I) Acyclic Diamino Carbene Complexes as Metallodrugs for Cancer and for Asymmetric Catalysis

Description: Many previous studies have demonstrated that gold compounds possess successful results in catalysis and in medicinal chemistry. The central aim of this dissertation is the design and synthesis of novel gold (I) acyclic diamino carbene complexes as a chemotherapeutic agent for triple-negative breast cancer (TNBC) and for catalysis. In this study, a series of chiral neutral and cationic gold (I) acyclic diamino carbene (ADC) complexes and neutral gold (I) bis- ADC complexes have been synthesize… more
This item is restricted from view until August 1, 2025.
Date: July 2023
Creator: Asuramana Pedi Durayalage, Roshani
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Application of Novel Microporous Polyolefin Silica-Based Substrate in Paper Spray Mass Spectrometry (PS-MS)

Description: This study addressed five key applications of paper spray mass spectrometry (PS-MS): (i) comparative analysis of the microporous substrate with the cellulose-based substrate in drug detection; (ii) detection of more than 190 fentanyl analogs with their fragmentation pattern can be implemented in the future reference for quicker, accurate and sensitive determination; (iii) exploring sweat in a fingerprint to be considered an alternate method to recognize non-invasive markers of metabolites, lip… more
Date: December 2020
Creator: Weligamage De Silva, Imesha
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Computational Study of Intermolecular Interactions in Complex Chemical Systems

Description: This work discusses applications of computational simulations to a wide variety of chemical systems, to investigate intermolecular interactions to develop force field parameters and gain new insights into chemical reactivity and structure stability. First, we cover the characterization of hydrogen-bonding interactions in pyrazine tetracarboxamide complexes employing quantum topological analyses. Second we describe the use of quantum mechanical energy decomposition analysis (EDA) and non-covalen… more
Date: May 2020
Creator: Vazquez Montelongo, Erik Antonio
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Atomic Layer Deposition of H-BN(0001) on Transition Metal Substrates, and In Situ XPS Study of Carbonate Removal from Lithium Garnet Surfaces

Description: The direct epitaxial growth of multilayer BN by atomic layer deposition is of critical significance forfo two-dimensional device applications. X-ray photoelectron spectroscopy (XPS) and low energy electron diffraction (LEED) demonstrate layer-by-layer BN epitaxy on two different substrates. One substrate was a monolayer of RuO2(110) formed on a Ru(0001) substrate, the other was an atomically clean Ni(111) single crystal. Growth was accomplished atomic layer deposition (ALD) cycles of BCl3/NH… more
Date: May 2020
Creator: Jones, Jessica C.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Donor-Acceptor Systems: Photochemistry and Energy Harvesting Applications

Description: Donor-acceptor systems have unique properties that make them ideal candidates for solar energy harvesting through mimicry of natural photosynthesis. This dissertation is focused on unraveling those unique properties in various types of donor-acceptor systems. The systems investigated are categorized as closely linked, push-pull, supramolecular, and multi-unit. As part of the study, photosynthetic analogues based on BF2-chelated dipyrromethene (BODIPY), porphyrin, phthalocyanine, truxene, ferroc… more
Date: May 2020
Creator: Thomas, Michael Brandon
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Atomic Layer Deposition of Boron Oxide and Boron Nitride for Ultrashallow Doping and Capping Applications

Description: The deposition of boron oxide (B₂O₃) films on silicon substrates is of significant interest in microelectronics for ultrashallow doping applications. However, thickness control and conformality of such films has been an issue in high aspect ratio 3D structures which have long replaced traditional planar transistor architectures. B₂O₃ films are also unstable in atmosphere, requiring a suitable capping barrier for passivation. The growth of continuous, stoichiometric B₂O₃ and boron nitride (BN) f… more
Date: December 2020
Creator: Pilli, Aparna
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Computational Modeling of Cancer-Related Mutations in DNA Repair Enzymes Using Molecular Dynamics and Quantum Mechanics/Molecular Mechanics

Description: This dissertation details the use of computational methods to understand the effect that cancer-related mutations have on proteins that complex with nucleic acids. Firstly, we perform molecular dynamics (MD) simulations of various mutations in DNA polymerase κ (pol κ). Through an experimental collaboration, we classify the mutations as more or less active than the wild type complex, depending upon the incoming nucleotide triphosphate. From these classifications we use quantum mechanics/molecula… more
Date: May 2022
Creator: Leddin, Emmett Michael
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Parameterization of Ionic Liquids and Applications in Various Chemical Systems

Description: In this work, the development of parameters for a series of imidazolium-based ionic liquids molecules, now included in the AMOEBA force field, is discussed. The quality of obtained parameters is tested in a variety of calculations to reproduce structural, thermodynamic, and transport properties. First, it is proposed a novel method to parameterize in a faster, and more efficient way parameters for the AMOEBA force field that can be applied to any imidazolim-based cation. Second, AMOEBA-IL polar… more
This item is restricted from view until January 1, 2028.
Date: December 2022
Creator: Vazquez Cervantes, Jose Enrique
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Donor-Acceptor Artificial Photosynthetic Systems: Ultrafast Energy and Electron Transfer

Description: Mother nature has laid out a beautiful blueprint to capture sunlight and convert to usable form of energy. Inspired by nature, donor-acceptor systems are predominantly studied for their light harvesting applications. This dissertation explores new donor-acceptor systems by studying their photochemical properties useful in building artificial photosynthetic systems. The systems studied are divided into phthalocyanine-porphyrin-fullerene-based, perylenediimide-based, and aluminum porphyrin-based … more
Date: December 2021
Creator: Seetharaman, Sairaman
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Linearly-Annulated, Functionalized, β,β'-π-Extended Porphyrins

Description: Benzannulation to porphyrin 2,3 positions has previously been accomplished using various methodologies in the past century, yet there remain limited methodologies to both annulate to the porphyrin periphery and add functional moieties that can then be derivatized for diverse applications. This dissertation describes the development of synthetic routes and characterization of a variety of linearly-annulated, functionalized, β,β'-π-extended porphyrins. There are five chapters in this dissertation… more
Date: December 2021
Creator: Moss, Austen Edmond
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Aromaticity, Supramolecular Stacks, and Luminescence Properties of Cyclic Trinuclear Complexes

Description: The dissertation covers three major topics: metal-assisted aromaticity, synthetic approaches to tailor donor-acceptor supramolecular stacks, and photoluminescence properties of cyclic trinuclear complexes (CTCs) of d10 metals. First, multiple theoretical approaches are adapted to discuss in detail the origin of aromaticity of CTCs, putting forward a metal-assisted aromaticity model. Next are the discoveries of donor-acceptor stacked CTC–CTC' complexes from both experimental and computational pe… more
Date: December 2022
Creator: Lu, Zhou
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Investigation of Ionic Liquid Phases for Chromatographic Separation of Fentanyl Analogues

Description: Opioid abuse and in particular fentanyl, a synthetic opioid, has been of concern in the last decade. Fentanyl is an illicit drug of concern to due to its prevalence and potency. Research to date has focused on supporting law enforcement by developing methods suitable for chemical profiling and identifying fentanyl from various matrices. However, methods geared towards analysis of fentanyl isomeric analogues are rare. Analysis of isomers is challenging due to similar mass spectral fragmentation … more
This item is restricted from view until January 1, 2028.
Date: December 2022
Creator: Smart, Katherine Rose
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Sulfur-Based Organic Compounds as Novel Corrosion Inhibitors for Brass and Aluminum Alloy Protection in Acid Cleaning Solutions

Description: In this study, thiol and two disulfide compounds have been tested as new corrosion inhibitors for brass and aluminum alloys. Pyridine-2-thiol and 2,2'-dipyridyl disulfide were tested for brass alloys in 0.5 M H2SO4 solution and both inhibitors showed excellent corrosion protection against the aggressive corrosive ion attack. Both inhibitors adsorbed to brass surface forming a protective film via a chemisorption process. XPS studies showed formation of Cu-S bond which allows these molecules to c… more
This item is restricted from view until January 1, 2028.
Date: December 2022
Creator: Karunarathne, Darshan Jayasinghe
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Photophysical Properties of Binuclear and Trinuclear Monovalent Coinage Metal Complexes for Applications in Molecular Devices

Description: Monovalent coinage metal complexes have been of significant interest due to their rich photophysical properties. This dissertation focuses on the design, synthesis, and characterization of gold, silver, and copper phosphors. Chapter 2 investigates new physical and photophysical properties of a gold diphosphine dimer in the solid state. Thermally activated luminescence switching between two structural states is discussed. Chapter 3 includes the photochemistry of closed shell group 11 transitio… more
Date: May 2020
Creator: Harris, Lauren Michelle
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Study the pKa of C–H Bonds and Proton-Coupled Electron Transfer Process by Transition Metal Complexes via Computational Methods

Description: Computational techniques, mostly density functional theory (DFT), were applied to study metal-based catalytic processes for energy conversion reactions. In the first and second projects, the main focus was on activation of the light alkanes such as methane, which have thermodynamically strong and kinetically inert C–H bonds plus very low acidity/basicity. Two Mo-oxo complexes with the different redox non-innocent supporting ligands, diamide-diimine and ethylene-dithiolate, were modeled. These M… more
Date: May 2020
Creator: Nazemi, Azadeh
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
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