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Acenaphthene and 1,10-Phenanthroline-Fused Βeta-Functionalized Porphyrins

Description: A series of acene-fused porphyrins and 1,10-phenanthroline-fused porphyrins were synthesized and characterized via NMR spectroscopy and mass spectrometry. The acene-fused porphyrins exhibit unique optoelectronic properties, most notably they exhibit highly red-shifted absorption bands. The 1,10-phenanthroline-fused porphyrins are of interest for their ability to bond to as variety of metals to form chelation complexes.
Date: December 2023
Creator: Arvidson, Jacob Randall
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

A Comprehensive Investigation of Photoinduced Electron Transfer and Charge Transfer Mechanisms in Push-Pull Donor-Acceptor Systems: Implications for Energy Harvesting Applications

Description: Donor-acceptor systems exhibit distinctive attributes rendering them highly promising for the emulation of natural photosynthesis and the efficient capture of solar energy. This dissertation is primarily devoted to the investigation of these unique features within diverse donor-acceptor system typologies, encompassing categories such as closely covalently linked, push-pull, supramolecular, and multi-modular donor- acceptor conjugates. The research encompasses an examination of photosynthetic an… more
Date: December 2023
Creator: Alsaleh, Ajyal Zaki
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Cross-Conjugation Effects on Fused β, β'–π–Extended Porphyrins

Description: Cross-conjugation in molecules has been seen in nature for many years but was not pursued due to the difficulty of their synthesis and their lack of stability. Recently, it has become more interesting due to the rise of molecular electronics. Linear conjugation serves well as the wires to conduct electrons, but molecular electronics are made up of more than just wires. Molecules are needed that possess an on/off switch that can allow or deter conduction. Cross-conjugated systems show promise in… more
Date: December 2023
Creator: Washburn, Spenser L.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Design and Development of a Paper Spray Air Sampling Device for Use in Clinical, Defense, and Environmental Applications

Description: Environmental monitoring is becoming increasingly important, primarily in urban areas due to the concentrated levels of human activities. The air sampling device presented is a novel method to sample air which harnesses the power of paper spray ionization paired with the intrinsic advantages of mass spectrometry such as high sensitivity, high selectivity, high throughput, and the ability to monitor multiple compounds at once.
This item is restricted from view until January 1, 2025.
Date: December 2023
Creator: Murillo, Wilbert Alberto
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Directing Transition Metal Catalysis of Second and Third Row Metals through Ligand Design

Description: Ligand design is important due to a ligand's ability to tune properties of the transition metals, such as catalytic activity and selectivity. Gold(I) catalysts can be directly impacted by ligands electronically as well as with steric bulk when undergoing enantioselective and regioselective reactions. In the dissertation, a series of gold(I) acyclic diaminocarbenes were synthesized and used to explore the 1,6 enyne cyclization/hydroarylation. The use of metal templated synthesis of the gold(I) a… more
This item is restricted from view until January 1, 2025.
Date: December 2023
Creator: Nguyen, John
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Homoleptic and Heteroleptic Platinum(II) Complexes for Organic Light Emitting Diodes and Humidity Sensors: Synthesis, Characterization, and Applications

Description: This dissertation focuses on the design, synthesis, characterization of platinum (II) pyridylazolate complexes and develop high performance organic light emitting diodes (OLEDs) and design and execute high-sensitivity humidity sensors based on the luminescent metal-organic complexes of platinum. A majority of existing platinum compounds do not dissolve in organic solvents, making it difficult to analyze the photophysical characteristics of complexes in solution, a key part of understanding chem… more
This item is restricted from view until January 1, 2029.
Date: December 2023
Creator: Farvid, Seyedmajid
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Kinetics and Atmospheric Chemistry Studies of Halogenated Species

Description: Quantitative information about halogenated hydrocarbons is important for understanding their impact on atmospheric ozone chemistry and climate change, their regulation, and the devising of improved substitutes. The Montreal Protocol aimed to regulate the utilization and manufacturing of hydrochlorofluorocarbon compounds (HCFCs), contributing to ozone layer depletion. The 2016 Kigali Amendment to the Montreal Protocol agreement, Annex C listed 274 HCFCs. Only 16 of them have been measured experi… more
Date: December 2023
Creator: Sapkota, Ramesh
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Kinetics and Thermochemistry of Halogen and Nitrogen Compounds

Description: Halogen and nitrogen containing compounds play a key role in the atmospheric chemistry of the Earth. Through a mixed computational and experimental approach, the kinetics of these compounds with radicals common to the atmosphere have been explored. Using fundamental measurements such as the IR absorption cross-section, the rate constants of atmospheric reactions and the properties of product molecules have been derived. These results have been further extended to environmental applications such… more
Date: December 2023
Creator: Rawling, George
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Metal Nitride Complexes as Potential Catalysts for C-H and N-H Bonds Activation

Description: Recognizing the dual ability of the nitride ligand to react as a nucleophile or an electrophile – depending on the metal and other supporting ligands – is a key to their broad-range reactivity; thus, three DFT studies were initiated to investigate these two factors effects (the metal and supporting ligands) for tuning nitride ligand reactivity for C-H and N-H bond activation/functionalization. We focused on studying these factors effects from both a kinetic and thermodynamic perspective in ord… more
Date: December 2023
Creator: Alharbi, Waad Sulaiman S.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Nitrogen Reduction Reaction: Deposition, Characterization and Selectivity of Transition Metal (V, Co and Ti) Oxynitrides as Electrocatalysts

Description: The electrocatalytic nitrogen reduction reaction (NRR) is of considerable interest due to its potential for less energy intensive and environmentally friendly ammonia production which is critical for agricultural and clean energy applications. However, the selectivity of NRR compared to the hydrogen evolution reaction (HER) often poses challenges for various catalysts, including Earth-abundant transition metal oxynitrides like Ti, V, and Co. In this work, a comparative analysis of the selectivi… more
This item is restricted from view until January 1, 2025.
Date: December 2023
Creator: Chukwunenye, Precious O.
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Surface Engineering of Materials for Beyond-Microelectronics

Description: All oxide heterostructure Cr2O3/TiO2-x was deposited on Al2O3(0001) single crystal via MBE. The analysis of interfacial interactions involving two metal oxides resulting in magnetic properties gave insights for using such heterostructures as potential spintronic device materials. The corundum phase epitaxial growth of TiO2-x on Al2O3 was characterized using XPS, AES, EELS, and LEED. The data obtained gives evidence of presence of two-dimensional electron gas at titania surface due to oxygen vac… more
This item is restricted from view until January 1, 2029.
Date: December 2023
Creator: Anwar, Fatima
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries

Synthesis, Characterization, Standardization, and Validation of Luminescence Optical Chemosensors for the Detection of Carbon Dioxide, Aluminum Ions, and Silver Ions for Real-Life Applications

Description: The presented dissertation encompasses three distinct investigations into novel complexes with diverse applications. Firstly, a Europium-based complex, K[Eu(hfa)4], exhibits remarkable potential for detecting dissolved CO2 in an ethylene glycol medium, offering a low limit of detection, rapid response times, and high signal-to-noise ratios. This complex demonstrates promise for quantifying CO2 concentrations and finds utility in sugar fermentation monitoring. Secondly, an innovative ratiometric… more
This item is restricted from view until January 1, 2025.
Date: December 2023
Creator: Perera, Nawagamu Appuhamilage Kasun
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

An Investigation into the Micromechanical and Corrosion Properties of Additively Manufactured Stainless Steel 316L

Description: In this thesis, micro-mechanical properties and corrosion resistance of laser powder bed fusion (L-PBF) processed additive manufactured (AM) 316L stainless steel parts were investigated for different combinations of processing parameters. Various laser powers were employed for the fabrication of all AM 316L stainless steel parts. Nanoindentation, areal roughness, and electron backscattered diffraction (EBSD) characterization were used to characterize the surface of the AM samples prior to corro… more
This item is restricted from view until January 1, 2028.
Date: December 2022
Creator: England, Jennifer
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

Nanofluidic Membrane Based on Covalent Organic Framework: Design Strategies and Applications

Description: Nanofluidic is an emerging field of applying fluid properties in nanochannels or nanostructures. The nanoporous channel with a pore size of less than 100 nm will strongly affect the motion of the fluid. Meanwhile, the pore environment, such as hydrophilic and hydrophobic properties, charge density, and host-guest recognition would be crucial for the transportation of molecules and ions in the pore. This thesis is focused on the synthesis, characterization of nanofluidic membranes and their appl… more
Date: December 2022
Creator: Zhu, Changjia
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

Porous Materials as Drug Delivery Systems

Description: The porous materials discussed in this dissertation are metal-organic frameworks (MOFs) and porous liquids. Due to their high surface areas, tunable structures, and controllable porosities, MOFs have been explored for a wide variety of drug delivery applications. In chapter 2, MOFs have been used as magnetothermal-triggered release carriers through spatially distributed iron oxide nanoparticles within MOF matrix as a magnetic heating mediator and surface-grafted thermal-responsive nanocap as an… more
This item is restricted from view until January 1, 2028.
Date: December 2022
Creator: Ge, Xueying
Item Type: Refine your search to only Thesis or Dissertation
Partner: UNT Libraries
open access

Ranaspumin Protein Characterization and Applications for Both Environmental and Medical Purposes

Description: The Túngara frog (Engystomops pustulosus) from Central America creates a bio-foam that protects their young from dehydration, microbial degradation, and even predators during early development. The foam is composed of unique proteins known as Ranaspumin 1-6 (RSN 1-6). These RSN proteins have been synthetically synthesized and verified with Circular Dichroism (CD) to determine their critical micelle concentration, antimicrobial properties, and stability at varying temperatures and pH ranges. Thr… more
Date: December 2022
Creator: Koerber, Rachel
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

Corrosion Mechanism and Prevention of Wire Bonded Device in Microelectronic Manufacturing and Spectroscopic Investigation of Copper Etch Chemical Equilibria for High Density Interconnect Application

Description: In the first part of this dissertation work, Al bond pad corrosion behavior was investigated in the presence of common industrial contaminants such as chloride (Cl-) and fluoride (F-). Al corrosion while in direct contact with Cu displayed rapid hydrogen (H2) gas evolution and dendrite propagation. In contrast, Al without bimetallic contact showed only minor surface roughening. This observed difference in the corrosion mechanism between Cl- and F- is attributed to the solubility of the corrosio… more
Date: December 2021
Creator: Ashok Kumar, Goutham Issac
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

Instrumental Development and Implementation of Portable Membrane Inlet Mass Spectrometry for Homeland Security and Environmental Applications

Description: A rapidly growing topic of great interest is the adaptation of benchtop analytical instrumentation for use in outdoor harsh environments. Some of the areas that stand to benefit from field instrumentation development include government agencies involved with the preservation of the environment and institutions responsible for the safety of the general public. Detection systems are at the forefront of the miniaturization movement as the interest in analyte identification and quantitation appears… more
Date: December 2021
Creator: Anguiano Virgen, Camila
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
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