Chemistry Commons^™

Directional Dopant Migration By ‘Atomic Trapping’ In Core/Multi-Shell Quantum Dots, Chun Chu

Dissertations - ALL

The study of transition metal ion-doped semiconductor nanocrystals (NCs) has attracted increasing attention due to their unique optical, electronic, and magnetic properties which sparked considerable interest towards a wide range of applications in material science, renewable energy and biological systems. Besides the size- and shape-dependent behavior, doped nanomaterials exhibit new and/or enhanced optical properties, which are sensitive to the dopant location or dopant distribution throughout the solid crystal lattice. Our work primarily focuses on understanding and elucidating the mechanism of dopant ion migration inside the NCs during post-synthetic treatments, such as shell passivation and high-temperature annealing. Mn(II) dopants migration behavior …

Development And Application Of Photoresponsive Small Molecule Probes To Modulate And Characterize Neuroreceptors, Spencer Kim

Dissertations - ALL

The field of neuroscience is rapidly evolving and so the development of novel tools that support innovative research is urgently needed. Two tools that have proven to be particularly impactful to the field of neuroscience are activity-based protein profiling (ABPP) and optogenetics, both of which have seen widespread application but with relatively limited advancement of the underlying technology. Limitations of ABPP and optogenetics have become increasingly apparent and research output is stalling due to lack of technological advancement. For example, few systems exist for targeting low-abundance and unstable proteins via ABPP and application of ABPP and optogenetic systems thus far …

Development And Progress Towards Functional Photoresponsive Systems, Jasmine Gomez

Dissertations - ALL

Chapter 2: Surface Functionalization of Thermally-Expandable Microspheres with Gold Nanoparticles The advancement of methods for controlling motion on a variety of scales is significant in order to develop finely tuned next-generation devices. Here, we’ve created a micron-scale actuator system triggered via photothermal activation and capable of powering macro-scale movement in an elastomer matrix. This system fundamentally relies on thermally-expandable microspheres (TEMs) – a core-shell complex containing a polymeric shell and liquid core that expands dramatically upon heating. To improve the ability of TEMs as soft-actuators controlled via light, we grafted a secondary silicate-silane copolymer shell to attach gold nanoparticles. The …

A Molecular Toolbox To Study Dopamine And Serotonin Receptors For The Development Of Improved Therapeutics, Emma Joanna Doukmak

Dissertations - ALL

Dopaminergic and serotonergic signaling pathways are involved in numerous biological processes including behavior, mood regulation, and cognition. Dysfunction in these pathways can lead to neurological and mental health disorders, which are often treated with drugs targeting the dopamine and serotonin receptors. However, many of these drugs, along with those targeting other G protein couple receptors (GPCRs), suffer a lack of target specificity, leading to nonspecific binding and therefore side effects. In recent years, new advances in chemical biological techniques, including affinity-based protein profiling (ABPP) and optogenetics, have further elucidated the structure and function of GPCRs, which can in turn aid …

Comparison Of Various Theoretical Measures Of Aromaticity Within Monosubstituted Benzene, Caleb K. Swain, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The effects of monosubstitution on the aromaticity of benzene are assessed using a number of different quantitative schemes. The ability of the mobile π-electrons to respond to an external magnetic field is evaluated using several variants of the NICS scheme which calculate the shielding of points along the axis perpendicular to the molecule. Another class of measures is related to the drive toward the uniformity of C-C bond lengths and strengths. Several energetic quantities are devised to approximate an aromatic stabilization energy and the tendency of the molecule to maintain planarity. There is a lack of consistency in that the …

Exploring The Complex Landscape Of Proteins: From Intrinsically Disordered Proteins To Peptidomimetics Through Computational Approaches, Tongtong Li

Chemistry and Chemical Biology ETDs

Protein function is closely related to their three-dimensional structures. However, some proteins lack a well-defined structure, so-called intrinsically disordered proteins (IDPs). They prefer to interconvert among different conformations in isolation and undergo a disorder-to-order transition upon binding to a partner. IDPs or proteins with intrinsically disordered regions (IDRs), constituting a large portion of the human proteome, are involved in many cellular activities and are therefore highly relevant to our health. In my dissertation, I used computational methods to systematically study systems including dynamic proteins, disordered proteins in complex with their targets, and synthetic peptidomimetics to reveal the unique physical properties …

Advancing Coupled Cluster Methods: Tensor Factorization And Analytic Gradient Implementation, Tingting Zhao

Chemistry Theses and Dissertations

With the rapid advancement of computing capabilities, computational chemistry has become increasingly indispensable in both experiment design and the interpretation of experimental outcomes. Wave-function-based quantum mechanistic methods are highly sought after for their ability to provide high-accuracy data and their potential for systematic improvement. However, to extend their applicability to larger molecules, it is essential to employ rank-reducing approximations to these methods. This dissertation dedicates Chapters Three and Four to the development of rank-reduced methodologies. Additionally, beyond single-point energies, molecular geometries and properties of molecule-excited states hold paramount importance across diverse fields of chemistry. Hence, Chapter Five presents the work …

Cadmium Oxide Nanoparticles From New Organometallic Cd(Ii)-Schiff Base Complex And In Vitro Biological Potentials: Dual S. Aureus And E. Coli Dna Gyrase Inhibition By The Precursors Via In Silico Binding Modes’ Study, Ikechukwu P. Ejidike, Amani Direm, Cemal Parlak, Mercy O. Bamigboye, Olajumoke Oluade, Juliana B. Adetunji, Athar Ata, Michael O. Eze, Joshua W. Hollett, Hadley S. Clayton

Michigan Tech Publications

At the nanoscale level, several biological processes take place, owing to the potential that engineered nanomaterials might interrelate with bio-molecules and cellular procedures. This study aimed to synthesize cadmium oxide nanoparticles via a one-step calcination process of tetradentate Schiff base-Cd(II) complex at different temperature ranges. The as-synthesized compounds were carried out via a viz UV–visible, elemental analysis, 1H NMR, molar conductivity, transmission electron microscopy (TEM), FT-IR spectroscopy, and X-ray diffraction (PXRD). The band gap energy and average particle sizes of the CdO particles are respectively (2.69 eV, 3.54 eV), 26.88 nm for CdO@250, and (3.20 eV, 3.57 eV), 25.67 nm …

Cleaner, Green Oxidation Chemistry: Development Of New Oxoammonium- And Nitroxide- Mediated Transformations, Katrina Doherty

Honors Scholar Theses

This work investigates various key oxidation and oxidative functionalization reactions that occur using a bench-stable nitroxide and its oxoammonium nitrate salt congener. Such transformations include amidation of aldehydes to acyl azoles or hexafluoroisopropyl esters and oxidation of alcohols to ketones or aldehydes. These transformations are key, everyday reactions within organic chemistry, and the aim to make them cleaner and greener is essential to the future of chemistry. Novel compounds produced by these green methods will also be discussed, as well as the results of a scale-up protocol showing the efficacy of the reactions on a process chemistry level. As an …

Quaternary Diamond-Like Sulfides For Nonlinear Optical Applications: Investigation Into Composition-Structure-Property Relationships Of The I2-Ii-Iv-Vi4 And I4-Ii-Iv2-Vi7 Formulae, Jordan Kelly

Electronic Theses and Dissertations

The research work presented in this dissertation focuses on the synthesis, characterization, and property assessment of new and existing quaternary diamond-like semiconductor (DLS) materials for the potential application in infrared (IR) nonlinear optics (NLO). Chapter 2 discusses the previously discovered temperature-dependent polymorphs of Cu₂ZnGeS₄ (CZGS); however, the IR NLO properties, neutron powder diffraction data, and single crystal X-ray diffraction structures were previously undetermined. The high-temperature α-CZGS polymorph was superior to the low-temperature β-CZGS analog in both second harmonic generation (SHG) and laser-induced damage threshold (LIDT). Chapter 3 presents the discovery of Li₂MgGeS₄ and comparison …

Chemical Extraction Of Non-Exchangeable Radiocesium From Fukushima Soils Using Ion-Exchange And Selective Precipitation, Ian Danquah

Master's Theses

The Fukushima Daiichi Nuclear Power Plant meltdown in Japan resulted in the release of radionuclides into the environment. Soil in neighboring prefectures has been reported to be among the most contaminated. Since the event in 2011, a large volume of soil has been collected and stored in temporary storage facilities, awaiting decontamination. Numerous methods have been used and employed to remediate these soils, but most methods do not achieve the 90% removal target set by the Japanese government for safe disposal. Among all reported methods, the ion-exchange technique has been reported to be cost-efficient and effective. A study by Tamura …

Bio-Based Rigid Polyurethane Foams Using Modified Hemp Seed Oil Combined With Flame Retardants, Sagar Jariwala

Electronic Theses & Dissertations

In today's world, the idea is to synthesize bio-based polyurethane (PU) goods, which reduces reliance on petroleum-based products. As a result, we produced polyol from hemp seed oil (HSO) and evaluated it using FTIR, GPC, hydroxyl value, and acid value. Hemp seed oil polyol (HSOP) was successfully synthesized and combined with additional ingredients such as catalysts, blowing agents, hardeners, and flame-retardant chemicals to produce stiff polyurethane foams. The focus of this research was to synthesize high-quality flame-retardant rigid polyurethane foams (RPUFs) through the addition of flame retardants. The test results revealed that the HSO-based PU without flame retardants has 47.04 …

Hemp-Seed Oil-Based Polyurethane Composite Foam: Effect Of Fillers On The Properties Of Polyurethanes, Mansi Ahir

Electronic Theses & Dissertations

Over the past few decades, polymer composites have been receiving significant interest and become a protagonist due to their enhanced properties and wide range of applications. Herein, the study has been done on the effect of filler and flame-retardant in hemp seed oil-based rigid polyurethane foams (RPUFs) composite performance. First of all, hemp seed oil (HSO) was gone through an epoxidation process using hydrogen peroxide and acetic acid. After that, epoxidized hemp-seed oil (EHSO) was converted into hemp polyol (HSOP) by a ring-opening reaction with methanol. The synthesized HSOP was then reacted with diisocyanate monomer in the presence of commercial …

Examining The Authenticity Of The 'Ether Model' In Certain O-Glycosylation Reactions, Varad Vinayak Agarkar

LSU Doctoral Dissertations

Acinetobacter baumannii is a gram-negative bacterium species that is responsible for nosocomial infections. It has shown antibiotic resistance and has been designated an urgent threat by the CDC. In Chapter 1, I highlight my efforts in the synthesis of a Kdo building block in the journey towards the construction of an A. baumannii lipooligosaccharide (LOS) core pentasaccharide- a potential candidate for glycoconjugate vaccine against A. baumannii infection. I talk about various optimizations and improvements in the Kdo monosaccharide synthesis and the mechanistic insights I provided about a critical transformation in the synthetic sequence.

Chemical O-glycosylation is a significant research …

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 …

Removal Of Phenol From Oilfield Produced Water Using Non-Conventional Adsorbent Medium By An Eco-Friendly Approach, Salem Jawad Alhamd, Mohammed Nsaif Abbas, Hassan Jameel Jawad Al-Fatlawy, Thekra Atta Ibrahim, Zaid Nsaif Abbas

Karbala International Journal of Modern Science

Petroleum extraction generates substantial quantities of produced water, a challenge compounded by water scarcity in oil-producing regions, notably the Middle East. Leveraging produced water effectively, adhering to environmental standards, can offer a viable solution to the issue of water scarcity. This study explores the potential of mandarin peels as an available, cost-effective adsorbent for treating synthetic aqueous solution simulated to oil-field produced water, specifically targeting phenol, a dangerous pollutant. Employing a batch-mode adsorption unit, six operational factors—phenol concentration, acidity, agitation speed, contact time, adsorbent dose, and temperature—were investigated. Results revealed an inverse relationship between phenol removal and pH, concentration, and …

Theoretical Spectroscopic Predictions Of Electronically Excited States, Noah R. Garrett

Honors Theses

The quest for faster computation of anharmonic vibrational frequencies of both ground and excited electronic states has led to combining coupled cluster theory harmonic force constants with density functional theory (DFT) cubic and quartic force constants for defining a quartic force field (QFF) utilized in conjunction with vibrational perturbation theory at second order (VPT2). This work shows that explicitly correlated coupled cluster theory at the singles, doubles, and perturbative triples level [CCSD(T)-F12] provides accurate anharmonic vibrational frequencies and rotational constants when conjoined with any of B3LYP, CAM-B3LYP, BHandHLYP, PBE0, and ωB97XD for roughly one-quarter of the computational time of the …

Synthesis And Analysis Of A Novel Magnetic Surfactant, Donovan Turpin

Honors Theses

Researchers in the University of Mississippi Chemical Engineering Department have suggested that chelation of a large magnetic transition metal, namely dysprosium, into the large polar head group of a surfactant could result in a magnetic surfactant. This project was aimed at synthesizing a surfactant with a large enough head group and negative charge (specifically EDTA) to support this ion and demonstrating that the chelation process was successful. If so, the molecule would ideally be capable of forming micelles which could extract oily substances from water using a strong magnet—possibly applicable to environmental crises like oil spills.

NMR analysis has suggested, …

A Turn-Off Fluorescent Sensor For Metal Ions Quantifies Corrosion In An Organic Solvent, Lianlian Liu, Zechariah Pfaffenberger, Mark Siegel, Anuj Saini, Lydia Kisley

Faculty Scholarship

We demonstrate that the corrosion of AISI 1045 medium carbon steel and pure aluminum can be quantified by the turn-off fluorescent sensor Phen Green-SK (PGSK) in ethanol-based solutions. We first evaluate the dependence of the chelation enhanced quenching of PGSK on iron and aluminum ion concentrations. Subsequently, we apply PGSK to examine the anodic dissolution of metal corrosion. The observed time-dependent PGSK-quenching quantifies the corrosion rates of two metals over 24 h of immersion in ethanol-based solutions. The PGSK-based quantification of corrosion is compared to scanning electron microscopy and electrochemical techniques, including open circuit potential and Tafel extrapolation. The corrosion …

Αb-Crystallin Phosphorylation Induces A Condensatopathy To Worsen Post-Myocardial Infarction Cardiomyopathy, Md Moydul Islam

Arts & Sciences Graduate Student Theses and Dissertations

Rare genetic mutations in proteins expressed in cardiomyocytes lead to proteotoxic cardiomyopathies which are characterized by widespread protein-aggregate pathology. However, the mechanistic link between proteotoxicity and protein-aggregates in the more common ischemic cardiomyopathy remains unclear. Our study revealed the mis-localization of desmin, actin, and α-actinin to protein-aggregates in the myocardium of patients with ischemic cardiomyopathy and in mouse hearts undergoing post-myocardial infarction ventricular remodeling. These findings mimic observations in autosomal-dominant cardiomyopathy resulting from the R120G mutation in the chaperone protein CRYAB where desmin is mis-localized into the aggregates. Importantly, we observed increased phosphorylation of CRYAB at serine-59 (pS59-CRYAB) and its …

The Effect Of Metabolic Modulators On The Rate Of Steady State Water Exchange In S. Cerevisiae Grown In Chemostat Bioreactors, Samantha Mumford, Mark Woods, Johnathan Dutra

Student Research Symposium

Water transport across the lipid bilayer due to osmotic stress causes a change in intracellular volume over time. At isotonic equilibrium there is no change in cell volume and yet water exchange does not stop. Water molecules continue to exchange rapidly with those of the extracellular space. The rate constant for steady state water efflux (k_io) can be measured using contrast enhanced magnetic resonance (MR) and the two-site exchange (2SX) model. k_io is known to correlate with the cellular energy molecule ATP making it a probable biomarker for metabolic diseases such as cancer. Measurements of k …

Method Validation Of Metals In Environmental Soil Samples, Sofia Deangelis, Nana Nguyen

Student Research Symposium

Vehicles are a major source of metal accumulation in terrestrial environments. Green infrastructure, such as bioswales, has been implemented as a way to mitigate this damage. However, there is a limited understanding of the processes that occur in these bioswales as few go back after implementation to identify areas in the bioswale with accumulation of pollutants. Inductively coupled mass spectrometry (ICP-MS) has the potential to be used in this type of study due to the machine’s high sensitivity and selectivity. However complications can arise while using the ICP-MS to characterize complex environmental samples. This study seeks to optimize microwave assisted …

Competing Supramolecular Forces: Boron Coordination Vs Π-Π Stacking, Sidhaesh A. Agarwal, Gonzalo Campillo-Alvarado, Nicholas Lutz, Jesus Daniel Loya, Eric W. Reinheimer

Student Research Symposium

This study explores the impact of fluorination levels in azopyridine Lewis bases on their ability to direct the formation of B←N coordination adducts or cocrystals with phenylboronic ester. We hypothesize that the degree of fluorination can be used as a tool to control the outcome of supramolecular bonding competition, thus influencing complex self-assembly.

A series of azopyridines with varying degrees of fluorination were synthesized and reacted with phenylboronic ester. Their structures were analyzed using Hartree-Fock calculations, Hirshfeld surface analyses, and single crystal X-ray diffraction to assess the impact of fluorination on supramolecular interactions.

The study reveals that azopyridines with up …

Multiscale Variability Of Heavy Metals In A Western U.S. Snowpack, Kelsey Hefner

Student Research Symposium

Natural and anthropogenically sourced particulates are deposited from the atmosphere to landscapes via dry and wet deposition, making frozen winter snowpack a natural archive of atmospheric elemental composition. Wildfires in the Western United States are increasing in extent, duration, and severity, especially in alpine regions. Severe fires remove forest canopy and can impact how atmospheric elements are dispersed and stored across snow-dominated watersheds. We evaluated Al, V, Cr, Mn, Ni, Cu, As, Zn, Se, Mo, Cd, and Pb concentrations in 394 winter snow core samples. We collected samples in 2019 and 2020 from a chronosequence of eight forests that burned …

Computationally Assisted Mechanistic Analysis Of The Protonolysis Of A Pt–Me Bond, Clement Dasilva

Student Research Symposium

Mechanistic study of the protonolysis of (cod)PtMe2 could give insight into the activation of C-H bonds by platinum because it is the microscopic reverse reaction. Two possible mechanisms for the protonolysis of dimethyl platinum complexes have been proposed, with experimental and computational data supporting the single step, SE2, over the multistep, SE(ox) mechanism. New experimental work from our group supports a multi-step mechanism with multiple acid molecules. In this work, the SE2 mechanism as well as a proposed SE(ox) mechanism were computationally modeled with a single equivalent of acid, TFAH, and two equivalents using density functional theory. The modeled pathways …

Photocathodes From Aerobic Oxidation Of Tellurorhodamines, Amelia Jellison

Student Research Symposium

Contemporary dye-sensitized solar cells are far less efficient than silicon solar panels, therefore this project seeks to develop an improved dye sensitized photocathode. Tellurorhodamine dyes, including mesityl derivatives and tellurium black, have been chosen to increase efficiency through increased light harvesting. The photophysical and electrochemical properties of tellurorhodamines with varying structures are analyzed to quantify its efficiency to serve as a dye sensitized photo cathode. Dyes undergo aerobic oxidation facilitated by light, the absorption profile is obtained before and after. Mesityl derivatives are known to experience significant red-shifting following aerobic oxidation. At its base oxidation state, tellurium black experiences an …

Exploring The Potential Of Α-Aryl Substitution Of Gddota To Address Challenges Associated With Mri Contrast Agents., Charlene I. Kupara

Student Research Symposium

Gadolinium chelates have found widespread application as contrast agents in Magnetic Resonance Imaging (MRI) a cornerstone in modern medical diagnostics. In recent years two significant challenges have emerged to the use of Gd³⁺ chelates in MRI:

• The safety of these Gd³⁺-based agents, specifically related to the possible in vivo release of Gd³⁺.
• The environmental impact of anthropogenic Gd³⁺ pollution of surface waters arising from using contrast agents.

The escalating reports of Gd³⁺ presence in environmental matrices, and its adverse effects on marine life and human health, necessitate urgent intervention to mitigate consequential environmental …

Excellent Bifunctional Oxygen Evolution And Reduction Electrocatalysts (5a1/5)Co2o4 And Their Tunability, Xin Wang, Harish Singh, Manashi Nath, Kurt Lagemann, Katharine Page

Chemistry Faculty Research & Creative Works

Hastening the Progress of Rechargeable Metal-Air Batteries and Hydrogen Fuel Cells Necessitates the Advancement of Economically Feasible, Earth-Abundant, Inexpensive, and Efficient Electrocatalysts Facilitating Both the Oxygen Evolution Reaction (OER) and Oxygen Reduction Reaction (ORR). Herein, a Recently Reported Family of Nano (5A1/5) Co2O4 (A = Combinations of Transition Metals, Mg, Mn, Fe, Ni, Cu, and Zn) Compositionally Complex Oxides (CCOs) [Wang Et Al., Chemistry of Materials, 2023, 35 (17), 7283-7291.] Are Studied as Bifunctional OER and ORR Electrocatalysts. among the Different Low-Temperature Soft-Templating Samples, Those Subjected to 600 °C Post annealing Heat Treatment Exhibit Superior Performance in Alkaline Media. One …

Living Emission Abolish Filters (Leafs) For Methane Mitigation: Design And Operation, Richard Hamilton, Nicholas Griffith, Peter Salamon, Robert Handler, Marina G. Kalyuzhnaya

Michigan Tech Publications

As one of the most potent greenhouse gases, methane is a critical target for the near-term mitigation of global warming. Efficient, scalable, easy-to-implement, and robust mitigation technologies are urgently needed to assist in reaching methane abolishment. The goal of this research was to test the applicability of active, extremophilic methanotrophic cells as a baseline concept for engineered systems aiming at methane capturing. The system, named living emission abolish filters (LEAFs), represents an array of immobilized biomaterials capable of capturing methane directly from vent streams. The biomaterials were made using cells of Methylotuvimicrobium alcaliphilum 20ZR, a robust halophilic methanotrophic bacterium with …

Model To Demonstrate Effects Of Mass Transfer And Applied Current In An Electrolytic Cell, George Ankrah

Reviews, Analyses, and Instructional Studies in Electrochemistry (RAISE)

This study investigates the relationship between applied current and resulting cell potential in an electrolytic system, considering the transport of electroactive species. By applying Michael Faraday's laws of electrolysis and the Nernst-Planck equation, the behavior of electroactive species in diffusion-controlled systems with and without stirring is modeled. The plots demonstrate how stirring enhances ion transport and establishes a stable Nernst diffusion layer, affecting the kinetics of electrochemical reactions. Understanding these dynamics is crucial for optimizing electrolysis processes.