Chemistry Commons^™

Chemical And Physical Studies Of Charge Transfer Excited States Of Ruthenium Complexes With Aromatic Ligands, Marim Khalifa Alnaed

Wayne State University Dissertations

The 3MLCT excited states generated from tris-bipyridineruthenium(II), [Ru(bpy)3]2+ and related complexes was ionized by 405 nm irradiation in ambient, acidic aqueous solutions. The photoionization product was Ru(bpy)3]3+ and an electron with a quantum yield of about 0.040.02 in 0.5 M acid. However, 532 nm radiation does not induce photoionization, and it generates the 3MLCT excited state that can be photoionized by 405 nm irradiation. The proton is a very good electron scavenger, and the rate of phoionization of the 3MLCT excited state was determined to be acid dependent and it increased about ten-fold for acid concentrations beween 0.001 and 4 …

Harnessing Radical Reactivity For The Construction Of Natural Product Frameworks And Transition Metal Catalyst Stability In A Modified Kochi Coupling Reaction, Mathes Hewage Hansamali Sakuntala Sirinimal

Wayne State University Dissertations

Polycyclic N-containing heterocycles play an important role in therapeutic

applications and as molecular tools in studying biological processes, making them

important synthetic targets. Current synthetic approaches are too lengthy, use toxic

reagents or are limited to accessing a particular framework and hence, their synthesis

warrant further study. We have recently developed conditions to avoid both reduction and

slow addition in aminyl radical cyclizations in our venture to access the constrained ABC

core of calyciphilline A, a Daphniphyllum alkaloid. An electron deficient enone with a

pendent internal alkyne as the neutral aminyl radical precursor was used for radical

cyclization. Based on …

Uncertainty In Combustion Reaction Rates And Its Effects On Combustion Simulations, Joshua Piehl

Wayne State University Theses

This work investigates the uncertainties in reaction rates of an n-dodecane model on turbulent spray combustion simulations. Six major reactions were found to significantly impact the ignition delay of the mechanism in a 0-D batch reactor model. These reactions’ rates were independently modified and placed into individual mechanisms. These newly developed mechanisms were simulated in a 3-D turbulent spray simulation and a 0-D batch reactor at a pressure of 60 bar and temperatures from 900 to 1100 K. The combustion characteristics (e.g. ignition delays, flame lift-off length, liquid and vapor penetration) of the modified mechanisms were compared to those produced …

Synthesis And Kinetic Activity Analysis Of Substituted Pyrazole, Pyrazoline, And Pyrazolidine Alcohol Dehydrogenase Inhibitors, Meagan E. Hackey

Chemistry Theses

Alcohol dehydrogenase inhibitors may be employed for the treatment of parasitic infection in humans. A series of substituted pyrazoline derivatives were synthesized to elucidate the pharmacophore for the inhibition of ADH. Targeted structure modification was used to alter the electronic and steric interactions associated with the enzyme active site. This study identified several effective N-aryl-carboxamide derivatives with horse liver ADH inhibition, comparable to that of 4-methylpyrazole, a known ADH inhibitor. The identification of pharmacophoric regions will allow for the methodological modification of these compounds to improve enzyme affinity and targeted inhibition. Future research may include additional solubility, toxicity and …

Hyperuniformity With No Fine Tuning In Sheared Sedimenting Suspensions, Joseph Paulsen, J. M. Schwarz, Jikai Wang

Physics - All Scholarship

Particle suspensions, present in many natural and industrial settings, typically contain aggregates or other microstructures that can complicate macroscopic flow behaviors and damage processing equipment. Recent work found that applying uniform periodic shear near a critical transition can reduce fluctuations in the particle concentration across all length scales, leading to a hyperuniform state. However, this strategy for homogenization requires fine tuning of the strain amplitude. Here we show that in a model of sedimenting particles under periodic shear, there is a well-defined regime at low sedimentation speed where hyperuniform scaling automatically occurs. Our simulations and theoretical arguments show that the …

Synthesis Of 5-Methyl-3-Phenyl-1,3,4-Oxadiazol-2(3h)-One Derivatives By Electrophilic Aromatic Substitution, Amanda Solis Conde

Browse all Theses and Dissertations

An important research element in the Turnbull laboratory has been the one-pot synthesis of 5-methyl-3-phenyl-1,3,4-oxadiazol-2(3H)-one from sydnone. The present study reexamined the reaction of 5-methyl-3-phenyl-1,3,4-oxadiazol-2(3H)-one with electrophiles and optimized methods for synthesis of oxadiazolinone derivatives. Further the oxadiazolinone derivatives were reacted with electrophiles to better comprehend the donating ability of the oxadiazolinone ring system in general with the expectation that the oxadiazolinone ring system is a slightly donating system. Additionally, when the structure assignment of the oxadiazolinone derivative was ambiguous, the corresponding oxadiazolinone or it’s isomer was synthesized from the appropriate sydnone to validate or refute the suggested structure. The …

Gas-Phase Studies Of Nucleophilic Substitution Reactions: Halogenating And Dehalogenating Aromatic Heterocycles, Leah L. Donham

Theses and Dissertations

Halogenated heterocycles are common in pharmaceutical and natural products and there is a need to develop a better understanding of processes used to synthesize them. Although the halogenation of simple aromatic molecules is well understood, the mechanisms behind the halogenation of aromatic heterocycles have been more problematic to elucidate because multiple pathways are possible. Recently, new, radical-based mechanisms have been proposed for heterocycle halogenation. In this study, we examine and test the viability of possible nucleophilic substitution, S_N2@X, mechanisms in the halogenation of anions derived from the deprotonation of aromatic heterocycles. All the experiments were done in a …

Solvent And Concentration Effects Governing The Hierarchical Organization Of Asphaltenes: A Small-Angle X-Ray Scattering Study, Hasan Rejoanur Rahman

Open Access Theses & Dissertations

Asphaltenes are a group of planar molecules found in crude oil and are prone to aggregation which often causes blockage of pipes along the oil production stream resulting a huge economic downside. In an effort to understand the hierarchical organization of asphaltene in different solvents and concentrations, the solution structure of various asphaltene solutions were studied using small-angle x-ray scattering (SAXS). Solvents were chosen based on miscibility maps. Such maps are generated on the critical value of the solubility parameter difference between asphaltenes or asphaltene components, and a range of solvents. The critical factors that affect asphaltene and asphaltene component …

Electrocatalysts Based On Organic Macrocycles For Electrochemical Water Splitting, Yanyu Wu

Open Access Theses & Dissertations

Water splitting, which is the dissociation of water into hydrogen and oxygen gases, can be separated into two half reactions corresponding to the hydrogen evolution reaction and oxygen evolution reaction (HER and OER, respectively). Both reactions offer a promising way for storing energy into the form of chemical bonds, which is an important strategy for the development of clean-energy technologies. A main area of interest while studying HER and OER is to design effective and robust electrocatalysts made from earth-abundant materials. This dissertation describes several homogeneous and heterogeneous systems for the electrocatalytic generation of hydrogen and oxygen gases.

In Chapter …

Geostatistical And Geospatial Distribution Of Multiple Metallic Elements In Agricultural Regions Of The Mid-Continental Usa, Najwah Alssaeidi Ahmed Almesleh

Open Access Theses & Dissertations

Regional geochemical mapping constitute the chemistry of the surface of the earth in a large scale and relatively low sample density. It is widely accepted scientific activity and man uses some cases to identify contamination. In the present study, data present in national geochemical survey database was used to investigate the chemical loading loading of the agricultural soil. In the mid-continent region of the United States. Several traditional parameters were used mainly the enrichment factor (EF), and geoaccumulation index (I geo). Total chemical influence (TCI) maps were used to guide sampling. In addition, regional trace element chemistry of bedrock was …

Electrochemical Investigation Of The Kinetics Of Chloride Substitution Upon Reduction Of [Ru(Porphyrin)(No)Cl] Complexes In Thf., Jeremy R. Zink, E G. Abucayon, Anthony R. Ramuglia, Arghavan Fadamin, James E. Eilers, George B. Richter-Addo, Michael J. Shaw

SIUE Faculty Research, Scholarship, and Creative Activity

The electrochemistry of several ruthenium porphyrin nitrosyl chloride complexes [Ru(por)(NO)Cl] have been examined in tetrahydrofuran. The complexes undergo 1-electron irreversible reductions which result in the diffusion-limited substitutions of the chloride ligands for THF. This chloride metathesis is reversible in the presence of added NBu₄Cl, and equilibrium constants and rate constants for chloride loss have been estimated. These parameters correlate with the NO stretching frequencies of the parent complexes, with more electron-donating porphyrin ligands favouring chloride loss from the reduced complexes. The [Ru(por)(NO)(THF)] products of the reductions can be detected by IR, EPR and visible spectroscopies. These species undergo …

Crystallographically Defined Silicon Macropore Membranes, Shannon C. Knight, Bret A. Unger, Kurt W. Kolasinski

Chemistry Faculty Publications

Laser ablation with nanosecond-pulsed Nd:YAG laser irradiation combined with anisotropic alkaline etching of Si wafers creates 4–20 µm macropores that extend all the way through the wafer. The walls of these macropores are crystallographically defined by the interaction of the anisotropy of the etchant with the orientation of the single-crystal silicon substrate: rectangular/octagonal on Si(001), parallelepiped on Si(110), triangular/hexagonal on Si(111). Laser ablation can create pillars with peak-tovalley heights of over 100 µm. However, with nanosecondpulsed irradiation at 532 nm, the majority of this height is created by growth above the original plane of the substrate whereas for 355 nm …

Plume And Nanoparticle Formation During Laser Ablation, Kurt W. Kolasinski, Mool C. Gupta, Leonid V. Zhigilei

Chemistry Faculty Publications

The processes that lead to material ejection when a solid sample is irradiated near and above the pulsed laser ablation threshold are discussed. Emphasis is placed on the thermal and mechanical mechanisms that occur during pulsed laser irradiation of metals and semiconductors. Distinctions are drawn between ultrafast-pulsed irradiation, which occurs under stress confinement, and shortpulsed irradiation, in which stress is released during the laser pulse. Similarly, the distinctions between the spallation and phase explosion regimes are discussed. Spallation is only possible when the time of the laser heating is shorter than the time needed for mechanical equilibration of the heated …

Hierarchical Porous Silicon And Porous Silicon Nanowires Produced With Regenerative Electroless Etching (Reetching) And Metal Assisted Catalytic Etching (Mace), Kurt W. Kolasinski, Bret A. Unger, Haibo Yu, Alexis T. Ernst, Mark Aindow, Ermei Mäkilä, Jarno Salonen

Chemistry Faculty Publications

ReEtching produces nanostructured silicon when a catalytic agent, e.g. dissolved V2O5, is used to facilitate etching between Si and H2O2. H2O2 regenerates dissolved V in a 5+ oxidation state, which initiates etching by injecting holes into the Si valence band. Independent control over the extent of reaction (controlled by the amount of H2O2 added) and the rate of reaction (controlled by the rate at which H2O2 is pumped into the etchant solution) allows us to porosify Si substrates of arbitrary size, shape and doping, including wafers, single-crystal powders, polycrystalline powders, metallurgical grade powder, Si nanowires, Si pillars and Si powders …

Silicon Surface Photochemistry, Kurt W. Kolasinski

Chemistry Faculty Publications

General concepts of photochemistry on metal and semiconductor surfaces are elucidated. These concepts are then applied more specifically to describe photochemical transformation of molecules on and with silicon surfaces. The mechanisms by which light can induce chemical reactions following electronic excitation are described. Processes reviewed include photodissociation of adsorbed molecules, photo-induced attachment of organic molecules and photo-induced corrosion.

Polyelectrolyte Complexes Based On Poly(Acrylic Acid): Mechanics And Applications, Xiaoyan Lu

Electronic Theses and Dissertations

Poly(acrylic acid) (PAA) is a weak polyelectrolyte presenting negative charge at basic condition when the carboxylic group loses a proton. These carboxylate group can interact with polycations and metal ions to form stable polyelectrolyte complexes (PECs), leading to tunable properties and multifunctional nanoscale structures through chemical reactions. This research focuses on nanofiber and nanoparticle fabricated by PAA-based PECs. We demonstrated the effect of ferric ion concentration on the mechanical properties of PAA-based single naonofiber by using dark field microscopy imaging and persistence length analysis. The application of PAA-based nanofiber mats loaded with MnO2 for supercapacitors was also explored. As a …

In Situ Treatment Systems For Remediation Of Polychlorinated Biphenyl-Contaminated Building Materials, Adibah Almutairi

Electronic Theses and Dissertations

Polychlorinated Biphenyls (PCBs) are a family of synthetic organohalides comprising 209 congeners which were used historically as additives in paint and caulking materials over a span of many years. Even though the production of PCBs in the USA has been banned since the late 1970s, their former prevalence and widespread use means many structures are still coated with PCB-laden paints. In addition, the presence of PCBs in elastic sealants has resulted in transport of PCBs into concrete structures and has caused soil contamination around buildings. PCB-contaminated building materials have become a significant concern for the environment and building occupants due …

Light Scattering Property Of Gold Nanoparticles With Applications To Biomolecule Detection And Analysis, Tianyu Zheng

Electronic Theses and Dissertations

Gold nanoparticles (AuNPs) have unique optical and chemical properties. Dynamic light scattering (DLS) is an analytical tool used routinely for nanoparticle size measurement. The combined use of AuNPs and DLS has led to a novel analytical assay technology called D2Dx (from diameter to diagnostics). Herein, my dissertation highlights the extended use of D2Dx for biomolecule detection and analysis. Under this general theme, Chapter 1 provides some background information of AuNPs, DLS, the principle of D2Dx technique and its potential applications. Chapter 2 summarizes a study on the effect of AuNP concentrations and laser power on the hydrodynamic size measurement of …

Sphingomyelin And Gm1 Influence Huntingtin Binding To, Disruption Of, And Aggregation On Lipid Membranes, Maxmore Chaibva, Xiang Gao, Pranav Jain, Warren A. Campbell, Shelli L. Frey, Justin Legleiter

Faculty & Staff Scholarship

Huntington disease (HD) is an inherited neurodegenerative disease caused by the expansion beyond a critical threshold of a polyglutamine (polyQ) tract near the N- terminus of the huntingtin (htt) protein. Expanded polyQ promotes the formation of a variety of oligomeric and fibrillar aggregates of htt that accumulate into the hallmark proteina- ceous inclusion bodies associated with HD. htt is also highly associated with numerous cellular and subcellular membranes that contain a variety of lipids. As lipid homeostasis and metabolism abnormalities are observed in HD patients, we investigated how varying both the sphingomyelin (SM) and ganglioside (GM1) contents modifies the interactions …

Student Integration Into Stem Careers And Culture: A Longitudinal Examination Of Summer Faculty Mentors And Project Ownership, Michelle Richards-Babb

Faculty & Staff Scholarship

It is widely recognized that the United States needs to attract and retain more people in science, technology, engineering, and mathematics (STEM) careers. Intensive undergraduate research experiences (UREs) are one of the few strategies shown to improve longitudinal student interest and persistence in STEM-related career pathways; however, less is known about the underlying process linking activities to positive outcomes. The tripartite integration model of social influences (TIMSI) provides a framework for understanding the social influence processes by which students integrate into STEM careers and culture. The current study used a longitudinal design and latent growth curve modeling to examine and …

Electroplating Pennies Lab, Ben Albrecht

A with Honors Projects

The purpose of this lab is to compare methods of electroplating pennies and to decide which method works best. The student also compares the electroplating of pennies made about 10 years apart between the years of 1960-2010, and including one from 2017.

Single-Site Catalyst Promoters Accelerate Metal- Catalyzed Nitroarene Hydrogenation, Liang Wang, Erjia Guan, Jian Zhang, Junhao Yang, Yihan Zhu, Yu Han, Ming Yang, Cheng Cen, Gang Fu, Bruce C. Gates, Feng-Shou Xiao

Faculty & Staff Scholarship

Atomically dispersed supported metal catalysts are drawing wide attention because of the opportunities they offer for new catalytic properties combined with efficient use of the metals. We extend this class of materials to catalysts that incorporate atomically dispersed metal atoms as promoters. The catalysts are used for the challenging nitroarene hydro- genation and found to have both high activity and selectivity. The promoters are single-site Sn on TiO2 supports that incorporate metal nanoparticle catalysts. Represented as M/Sn- TiO2 (M = Au, Ru, Pt, Ni), these catalysts decidedly outperform the unpromoted supported metals, even for hydrogenation of nitroarenes substituted with various …

Raman Spectroscopic And Computational Study Of Hydrogen Bond Interactions Between Guanidine Hydrochloride, Trimethylamine N-Oxide (Tmao), Urea, And Water, Andrew Kamischke

Honors Theses

Proteins are broken down in the body and produce water, CO2, and ammonia as by-products. Ammonia is toxic to cells, making it a priority to be excreted. Urea is the key route for the transportation of ammonia out of the body and is the main component of urine. Guanidine is another important nitrogen-containing molecule that is structural like urea and plays important biological roles in the stabilization of proteins. Guanidine hydrochloride and Urea are known to denature proteins and this functionality continues to be a topic of great interest. Urea and guanidine contain many hydrogen bonding sites and interactions with …

Assembly Of A Protein-Based Hydrogel As A Vehicle For In Situ Drug Delivery, Austin Carroll

Honors Theses

The goal of this work is to develop a self-assembling, protein-based gel to deliver drugs at the site of chronic inflammation. There are two engineered protomers that comprise the gel; calmodulin- and M13- are their critical components. Numerous enzymes have been shown to undergo calcium-dependent regulation by calmodulin, an intracellular protein highly resilient to its chemical environment. One of these enzymes, myosin light chain kinase, contains a remarkable 26 residue portion known as the M13 peptide that has been demonstrated to bind to calmodulin in the presence of calcium through hydrophobic interactions. Because the extracellular space in vivo constitutes an …

Studies Of Carbonaceous Materials Using Raman Spectroscopy, Cameron L. Smith

Honors Theses

Various carbonaceous materials including graphene, treated biochar, and C60 were studied using Raman spectroscopy with particular attention given to the treatment process and the Raman enhancement methods. Such studies that focus on the treatment process are useful in determining the extent to which the species was affected via shifts in the Raman peaks. Previous collaborations have proven successful when multiple samples were studied and analyzed. The attempt to create a novel Raman enhancement technique via combination of two previously recorded techniques was ultimately unsuccessful but further work is necessary.

Evidence That Speciation Of Oxovanadium Complexes Does Not Solely Account For Inhibition Of Leishmania Acid Phosphatases, Benjamin M. Dorsey, Craig C. Mclauchlan, Marjorie A. Jones

Faculty Publications – Chemistry

Leishmaniasis is an endemic disease affecting a diverse spectra of populations, with 1.6 million new cases reported each year. Current treatment options are costly and have harsh side effects. New therapeutic options that have been previously identified, but still underappreciated as potential pharmaceutical targets, are Leishmania secreted acid phosphatases (SAP). These acid phosphatases, which are reported to play a role in the survival of the parasite in the sand fly vector, and in homing to the host macrophage, are inhibited by orthovanadate and decavanadate. Here, we use L. tarentolae to further evaluate these inhibitors. Using enzyme assays, and UV-visible spectroscopy, …

Evsc 381-001: Geomorphology, Nancy Jackson

Chemistry, Environmental and Forensic Science Syllabi

No abstract provided.

Chem 236-001: Physical Chemistry For Chemical Engineers, Alisa Krishtal

Chemistry, Environmental and Forensic Science Syllabi

No abstract provided.

Structural Identification And Kinetic Analysis Of The In Vitro Products Formed By Reaction Of Bisphenol A‑3,4-Quinone With N‑Acetylcysteine And Glutathione, Douglas E. Stack, John A. Conrad, Bejan Mahmud

Chemistry Faculty Publications

Bisphenol A (BPA) has received considerable attention as an endocrine disrupting chemical and a possible substrate for genotoxic metabolites. BPA metabolism leads to formation of electrophilic o-quinones cable of binding to DNA and other endogenous nucleophiles. We have structurally identified the products resulting from the reaction of bisphenol A-3,4-quinone (BPAQ) with N-acetylcysteine (NAC) and glutathione (GSH). The major and minor isomers are both the result of 1,6-conjugate addition and are produced almost instantly in high yield. Reactions using 1.3 equiv of GSH showed the presence of a bis-glutathionyl adduct which was not observed using higher GSH concentration relative to BPAQ. …

Prediction Of Novel Anti-Ebola Virus Compounds Utilizing Artificial Neural Network (Ann), Ronald Bartzatt

Chemistry Faculty Publications

Artificial Neural Network (ANN) analysis is shown to predict the molecular properties of new anti-EBOLA compounds following training/learning by use of 60 previously known and studied drugs. Following training/learning by applying properties of 60 known drugs the TIBERIUS ANN system can efficiently predict the molecular properties of comparable new drugs. Molecular weight (MW) is an important and dominant property of perspective drugs considered for clinical trials. TIBERIUS ANN was able to predict comparable values of MW for drugs following training cycles. One-way ANOVA, F and T tests indicate that actual and predicted MW have the same means (P=.99). Passing-Bablok regression …