Chemistry Commons^™

Synthesis Of Dinucleating Ligands And Their Dinuclear Metal Complxes:Applications In Sensing And Small Molecule Activation, Jeffrey William Beattie

Wayne State University Dissertations

Dinuclear metal complexes provide a route to interesting structure and reactivity. Two common uses of dinuclear metal complexes are sensing and activation of small molecules. Herein we describe a series of dinuclear metal complexes capable of sensing of oxalate and activation of carbon disulfide.

Sensing of oxalate is of great interest because high oxalate concentration (hypooxaluria) is a major cause of kidney stones. Dinuclear metal complexes can act as sensors for oxalate because the oxalate can bridge between the metal centers. Herein we describe a colorimetric oxalate sensor capable of regeneration. Upon addition of oxalate to a pink solution of …

Development Of Gamma-Modified Atp Analogs To Study Kinase-Catalyzed Phosphorylations, Ahmed Eid Fouda

Wayne State University Dissertations

Kinase-catalyzed protein phosphorylation is one of the most important post-translational modifications that controls cascades of biochemical reactions. Irregularities in phosphorylation result in many diseases, such as diabetes mellitus, Parkinsons, and cancer. The development of new methods to monitor kinase-catalyzed phosphorylation is needed to decipher details of normal and diseased cell signaling. The Pflum lab recently developed several -modified ATP analogs to study kinase catalyzed phosphorylation reactions. The -modified ATP analogs have different tags, such as biotin for substrate labeling or aryl-azide for kinase substrates identification. Unfortunately, use of -modified ATP analogs was limited to in vitro studies due to the …

Synthesis Of Apramycin And Paromomycin Derivatives As Potential Next Generation Aminoglycoside Antibiotics And Chemistry Of Isothiocyanato Sialyl Donors, Appi Reddy Mandhapati

Wayne State University Dissertations

AGAs are clinically important antibacterials for human therapy and have long been used as highly potent antibiotics for treating several bacterial infections. The fidelity of protein synthesis is affected by AGAs in the course of binding to specific sites of the bacterial rRNA. The clinical use of AGAs and their applications as therapeutics is restricted by toxicity (irreversible ototoxicity and reversible nephrotoxicity) and by the resistance of pathogens. The objective of this research was the development of proficient AGAs that are less toxic (i.e., more selective) and that evade resistance. The first three chapters of this thesis are aimed towards …

How Geometric Distortions Scatter Electronic Excitations In Conjugated Macromolecules: Towards Photoinduced Relaxation And Energy Transfer, Tian Shi

Wayne State University Dissertations

The exciton scattering (ES) approach has been developed to study electronic excitations in large branched conjugated molecules. It attributes excited states to standing waves in the quasi-one-dimensional system by assuming a quasi-particle picture of optical excitations. Tight binding models extend capability of the ES approach to investigate the exciton-phonon coupling.

The topological counting method plays a substantial role in constructing tight binding models. It depicts the ES equations as a topological intersection problem. Then, by applying the index theorem, we can get the total number of excited states, which is equal to the number of repeat units plus topological charges …

Novel Approaches For Assessment Of Copper Toxicity: Fast Scan Cyclic Voltammetry And Optical Bioassays, Annette R. Tremonti

Wayne State University Dissertations

Anthropogenic activities negatively impact fresh water ecosystems through toxic contaminants that are released into the environment. Copper (Cu) is a water contaminant that is fundamentally persistent once introduced into the environment that has the potential for bioaccumulation. Although Cu toxicity has been studied for decades, there is still a continuing problem with new sources and pathways. New approaches are needed to understand distribution and transport of Cu and its potential for complex biological impacts beyond the simple assessment of lethality. Several novel approaches were used in this research project to advance our understanding of Cu toxicity, including fast scan cyclic …

A Novel, Ultra-Fast Electrochemical Tool To Study Speciation Of Trace Metals In Aqueous Solution, Pavithra Pathirathna

Wayne State University Dissertations

Trace metals play important roles in biological and ecological systems. In biology, trace metals act as catalytic or structural cofactors and regulate biochemical processes. In the environment, natural and anthropogenic sources of trace metals mobilized into natural waters where they can create harmful and persistent pollution. Trace metal chemistry in physiological and environmental systems can fluctuate rapidly which makes it difficult to clearly define trace metals’ roles in these systems with traditional analytical methods. Furthermore, these systems are often chemically harsh and physically delicate (e.g. the brain), factors that add to the challenge of analysis in real systems. Fast scan …

Live, Attenuated Vaccines And Methods Of Making And Using, Jiantao Guo, Qingsheng Li, Wei Niu, Yue Li, Nanxi Wang

Department of Chemistry: Faculty Publications

A live, attenuated HIV vaccine is provided, and methods of making a atenuated HIV vaccine are provided.

Self-Assembly Of Gold Supraparticles With Crystallographically Aligned And Strongly Coupled Nanoparticle Building Blocks For Sers And Photothermal Therapy, S. Paterson, S. A. Thompson, J. Gracie, A. W. Wark, R. De La Rica

Publications and Research

A new method is introduced for self-assembling citrate-capped gold nanoparticles into supraparticles with crystallographically aligned building blocks. It consists in confining gld nanoparticles inside a cellulose acetate membrane. The constituent nanoparticles are in close contact in the superstructure, and therefore generate hot spots leading to intense Surface-Enhanced Raman Scattering (SERS) signals. They also generate more plasmonic heat than the nanoparticle building blocks. The supraparticles are internalized by cells and show low cytotoxicity, but can kill cancer cells when irradiated with a laser. This, along with the improved plasmonic properties arising from their assembly, makes the gold supraparticles promising materials for …

The Development Of Peptide Ligands To Target H69 Rrna, Danielle Nicole Dremann

Wayne State University Dissertations

ABSTRACT

THE DEVELOPMENT OF PEPTIDE LIGANDS TO TARGET H69

by

DANIELLE NICOLE DREMANN

December 2015

Advisor: Prof. Christine S. Chow

Major: Chemistry (Biochemistry)

Degree: Doctor of Philosophy

In the development of peptide ligands to target H69, SPPS and ESI MS was used to determine if 1) peptides could bind to modified H69 and 2) if increased affinity for the target RNA could be enhanced with modification. An alanine and arginine scan was synthesized and tested for this determination. Selected peptides were then tested using biophysical techniques such as circular dichroism and isothermal titration calorimetry. An assay was also designed to …

Development Of Single And Array Electro-Chemical Sensors For Real-Time Trace Metal Analysis In Aqueous Environmental Media, Yuanyuan Yang

Wayne State University Dissertations

Detection of trace metals has great importance in environmental and biological applications. While traditional electrochemical techniques have played critical roles in this field, their usefulness is limited by temporal resolution, Hg toxicity and stability concerns. Recently, we developed a method using fast-scan cyclic voltammetry (FSCV) at carbon-fiber microelectrodes (CFMs) to achieve rapid measurement of metal ions with high sensitivity, selectivity, and stability. Through optimizations this method showed strengths in real-time trace metal analysis. ‬‬‬‬‬‬

‪Analytical selectivity was improved via covalent functionalization on CFMs. We employed diazonium electrochemical reduction followed by click chemistry to create robust covalent attachments. We showcased its …

Nucleophile Promoted Gold Redox Catalysis With Diazonium Salts: C-Br, C-S And C-P Bond Formation Through Catalytic Sandmeyer Coupling, Haihui Peng, Rong Cai, Chang Xu, Hao Chen, Xiaodong Shi

Chemistry Faculty Publications

Gold-catalyzed C-heteroatom (C-X) coupling reactions are evaluated without using sacrificial oxidants. Vital to the success of this methodology is the nucleophile-assisted activation of aryldiazonium salts, which could be an effective oxidant for converting Au(i) to Au(iii) even without the addition of an assisting ligand or photocatalyst. By accelerating the reaction kinetics to outcompete C-C homo-coupling or diazonium dediazoniation, gold-catalyzed Sandmeyer reactions were achieved with different nucleophiles, forming C-Br, C-S and C-P bonds in high yields and selectivities.

Electron Transfer Studies In Langmuir-Blodgett Films Of Metallosurfactants For Current Rectification, Corrosion Mitigation, And Water Oxidation, Sunalee Gonawala Jayasundara Mudiyanselage

Wayne State University Dissertations

The work presented in this dissertation is focused on the design and synthesis of new redox-active amphiphilic architectures to optimize and understand the redox, electronic, and film formation properties for applications in current rectification, corrosion mitigation, and water oxidation. As such, new redox-active, and amphiphilic iron(III), cobalt(III), nickel(II), copper(II), and zinc(II) complexes were synthesized as precursors for Langmuir-Blodgett films used for the aforementioned applications.

For the use in molecular rectification, amphiphilic copper(II) and nickel(II) complexes with [N2O2] ligand environment were synthesized. Homogeneous film formation ability was observed between ~20-25 mN/m pressure, with a film collapse observed at ~35 mN/m for …

Synthesis And Heteroallene Reactivity Of Bis(Aldimino)Pyridine Nickel Complexes In Four Different Oxidation States, Blake Reed

Wayne State University Dissertations

A series of redox non-innocent bis(aldimino)pyridine ligands were synthesized. These were then reacted with nickel(II) salts to form Ni[NNN]X2 complexes. Cyclic voltammograms of these nickel(II) complexes suggest that more reduced states can be achieved. Reduction of these nickel(II) complexes lead to distorted square planar complexes with the halide bent ~20° out of the plane. EPR suggests that spin density is located on the metal as g-values of >2.01 were obtained. This differs from previously reported analogous bis(ketimino)pyridine complexes, which show a ligand-based radical and nickel(II). DFT confirms that as the Npyr-Ni-X angle decreases, spin density on the nickel increases. Because …

New Chemistry For The Growth Of First-Row Transition Metal Films By Atomic Layer Deposition, Joseph Peter Klesko

Wayne State University Dissertations

Thin films containing first-row transition metals are widely used in microelectronic, photovoltaic, catalytic, and surface-coating applications. In particular, metallic films are essential for interconnects and seed, barrier, and capping layers in integrated circuitry. Traditional vapor deposition methods for film growth include PVD, CVD, or the use of plasma. However, these techniques lack the requisite precision for film growth at the nanoscale, and thus, are increasingly inadequate for many current and future applications. By contrast, ALD is the favored approach for depositing films with absolute surface conformality and thickness control on 3D architectures and in high aspect ratio features. However, the …

Electrochemical Oxidation To Construct A Nickel Sulfide/Oxide Heterostructure With Improvement Of Capacitance, Xuan Liu, Bo You, Xin-Yao Yu, Jeffrey Chipman, Yujie Sun

Chemistry and Biochemistry Faculty Publications

Supercapacitors have been widely recognized as a promising device for the storage of renewable energy. Herein, a facile electrochemical oxidation strategy is described to construct a nickel sulfide/oxide heterostructure which enhances the specific areal capacitance of Ni₃S₂ electrode (2035 mF cm^-2 vs. 31 mF cm^-2 at a current density of 8 mA cm^-2), while still maintaining great stability, showing no performance degradation after 5000 charge-discharge cycles. Its exceptional capacitance, advanced rate capability, and superior cycling stability are attributed to the transformed composition and unique nanostructure achieved during electrochemical oxidation, which can provide a …

The Unusual Substrate Specificity Of A Virulence Associated Serine Hydrolase From The Highly Toxic Bacterium, Francisella Tularensis, Alexander M. Farberg, Whitney K. Hart, R. Jeremy Johnson

Scholarship and Professional Work - LAS

Francisella tularensis is the causative agent of the highly, infectious disease, tularemia. Amongst the genes identified as essential to the virulence of F. tularensis was the proposed serine hydrolase FTT0941c. Herein, we purified FTT0941c to homogeneity and then characterized the folded stability, enzymatic activity, and substrate specificity of FTT0941c. Based on phylogenetic analysis, FTT0941c was classified within a divergent Francisella subbranch of the bacterial hormone sensitive lipase (HSL) superfamily, but with the conserved sequence motifs of a bacterial serine hydrolase. FTT0941c showed broad hydrolase activity against diverse libraries of ester substrates, including significant hydrolytic activity across alkyl ester substrates from …

Determination Of Additives In Cigarettes Utilizing Evolved Gas Analysis (Ega), Karissa Ferguson, Michael J. Samide, Cierra Schmicker, Tyler Schenk, Anne Wilson

Scholarship and Professional Work - LAS

While additives to consumer products must be listed in order by amount, it is not required to report the actual amounts of these additives. Given that impacts on human health are dose dependent, knowledge of additive amounts would aid discussions of the safety of these compounds for inhalation. Additives for cigarettes include flavors, such as menthol, and propylene glycol, a humectant. Rapid determination of the amounts of menthol and propylene glycol additives in cigarettes was accomplished utilizing evolved gas analysis (EGA) – gas chromatography (GC) – flame ionization detection (FID). Careful preparation of samples and appropriate sample storage are critical …

Unraveling A Generic Growth Pattern In Structure Evolution Of Thiolate-Protected Gold Nanoclusters, Wen Wu Xu, Yadong Li, Yi Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Precise control of the growth of thiolate-protected gold nanoclusters is a prerequisite for their applications in catalysis and bioengineering. Here, we bring to bear a new series of thiolateprotected nanoclusters with a unique growth pattern, i.e., Au₂₀(SR)₁₆, Au₂₈(SR)₂₀, Au₃₆(SR)₂₄, Au₄₄(SR)₂₈, and Au₅₂(SR)₃₂. These nanoclusters can be viewed as resulting from the stepwise addition of a common structural motif [Au₈(SR)₄]. The highly negative values of the nucleus-independent chemical shift (NICS) in the center of the tetrahedral Au4 …

Tuning The Electronic Properties Of Monolayer And Bilayer Ptse2 Via Strain Engineering, Pengfei Li, Lei Li, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The recently synthesized monolayer PtSe₂ belongs to the class of two-dimensional transition metal dichalcogenide (TMDC) materials (Nano Lett., 2015, 15, 4013). Based on first-principles calculations, we show that the band gaps of monolayer and bilayer PtSe₂ can be tuned over a wide range via strain engineering. Both isotropic and uniaxial strains are investigated. For bilayer PtSe₂, the vertical out-of-plane strain is also considered. In most cases, the strain can reduce the band gap except for the bilayer PtSe₂ under the isotropic strain (Ɛ≤ 4%) for which the band gap can be slightly enlarged. Importantly, the …

Unraveling A Generic Growth Pattern In Structure Evolution Of Thiolate-Protected Gold Nanoclusters, Wen Wu Xu, Yadong Li, Yi Gao, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Precise control of the growth of thiolate-protected gold nanoclusters is a prerequisite for their applications in catalysis and bioengineering. Here, we bring to bear a new series of thiolateprotected nanoclusters with a unique growth pattern, i.e., Au₂₀(SR)₁₆, Au₂₈(SR)₂₀, Au₃₆(SR)₂₄, Au₄₄(SR)₂₈, and Au₅₂(SR)₃₂. These nanoclusters can be viewed as resulting from the stepwise addition of a common structural motif [Au₈(SR)₄]. The highly negative values of the nucleus-independent chemical shift (NICS) in the center of the tetrahedral Au …

Mechanistic Study Of Pressure And Temperature Dependent Structural Changes In Reactive Formation Of Silicon Carbonate, Bingyan Qu, Dongdong Li, Lei Wang, Jili Wu, Rulong Zhou, Bo Zhang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The discovery of the silicon carbonate through chemical reaction between porous SiO₂ and gaseous CO₂ addressed a long-standing question regarding whether the reaction between CO₂ and SiO₂ is possible. However, the detailed atomic structure of silicon carbonate and associated reaction mechanism are still largely unknown. We explore structure changes of silicon carbonate with pressure and temperature based on systematic ab initio molecular dynamics simulations. Our simulations suggest that the reaction proceeds at the surface of the porous SiO₂. Increasing number of CO₂ molecules can take part in the reaction by increasing either the …

Surprising Impact Of Remote Groups On The Folding–Unfolding And Dimer-Chain Equilibria Of Bifunctional H-Bonding Unimers, Rui Liu, Shuang Cheng, Erin S. Baker, Richard D. Smith, Xiao Cheng Zeng, Rui Liu

Xiao Cheng Zeng Publications

Oligoamide 1, consisting of two H-bonding units linked by a trimethylene linker, was previously found to form a very stable, folded dimer. In this work, replacing the side chains and end groups of 1 led to derivatives that show the surprising impact of end groups on the folding and dimer-chain equilibria of the resultant molecules.

Studies Toward A Detailed Understanding Of The Intrinsic Properties Of Nucleic Acid Constituents: Gas-Phase Conformations, Energetics, And Glycosidic Bond Stability, Ranran Wu

Wayne State University Dissertations

The gas-phase conformations of the protonated forms of the nucleic acid constituents: nucleosides and mononucleotides, were characterized by infrared multiple photon dissociation (IRMPD) action spectroscopy and theoretical calculations. The IRMPD spectroscopy experiments were performed using a Fourier transform ion cyclotron resonance mass spectrometer (FT-ICR MS) coupled to a free electron laser or a OPO/OPA laser system to measure the IRMPD action spectra over the IR fingerprint and hydrogen-stretching regions.

Theoretical calculations were performed using both mechanic dynamics and high level quantum chemical calculations to optimize structures, compute vibrational frequencies and IR intensities, and to obtain the relative stabilities of optimized …

Europium(Ii)-Containing Complexes For Responsive Magnetic Resonance Imaging, Levi Alexander Ekanger

Wayne State University Dissertations

The research projects described in this dissertation are focused on studying the oxidation of EuII-containing complexes within the context of responsive MRI. Prior to this research, EuII had not been explored within the context of oxidation-responsive MRI nor had the use of this ion been reported in vivo. The results of these studies enable predictions about the oxidation-responsive behavior of EuII-containing complexes in vitro and in vivo.

The EuII-containing cryptate 1.33 was used to evaluate EuII-based positive contrast enhancement after intravenous, intraperitoneal, and subcutaneous injections. The transitory behavior of the positive contrast enhancement correlated with reported levels of oxygenation and …

Crossed Beam Imaging Of The Reaction Dynamics Of Halogen Atoms With Selected Hydrocarbons, Yuanyuan Shi

Wayne State University Dissertations

This dissertation presents results of applying dc slice imaging in crossed molecular beams to probe the dynamics of the reactions of halogen atoms (chlorine and fluorine) with polyatomic hydrocarbons and alcohols such as deuterated propanes, butane isomers, pentane, alkenes and propanol. The full velocity-flux contour maps of the radical products were measured with 157nm single photon ionization at various collision eneriges. Secondary and tertiary abstractions were found in Cl with normal and deuterated propanes and butane isomers and show distinct differences. The differences were explained in terms of the nature of abstraction sites, energy disposal of the radical product, and …

An Ecotoxicological Survey Of Tributaries Of The Selenge River, Mongolia, August 2010, Viktor T. Komov, Ch. Javzan, William G. Brumbaugh

Erforschung biologischer Ressourcen der Mongolei / Exploration into the Biological Resources of Mongolia, ISSN 0440-1298

The biodiversity of the Selenga river basin and the receiving waters of the lake Baikal, are among the greatest in the world with over 1,700 known endemic species of plants and animals. Mining activities along the Selenga river and its tributaries pose a major threat of chemical contamination, potentially reducing habitat quality and suitability for aquatic species. Moreover, the Selenga river serves as a major water source for the lake Baikal. Little information exists on the chemical contaminant concentrations in the Selenga river basin. Thus, the objectives of our study were to evaluate the concentrations of metals in soil, sediment, …

The Utilization Of Liquid Chromatography Tandem Mass Spectrometry And Related Techniques For The Analysis And Identification Of Emerging Contaminants In Aqueous Matrices, Matthew Reichert

Dissertations

Environmental pollutants can be found in many ecosystems and cover many different compound classes. The Environmental Protection Agency is responsible for monitoring and regulating several of these classes of compounds which daily enter the environment. However, there are still hundreds, if not thousands, of compounds present in the environment which have yet to be regulated or even identified. The discovery and identification of these unknown emerging pollutants is crucial for the prevention of potential human health risks and irreversible ecological damage.

The research presented is divided into two projects. The first part of this research investigates the disinfectant 3-Bromo-1-chloro-5,5-dimethylhydantoin, which …

Peroxide Content Of Secondary Organic Aerosol, Ryan Caylor, Matthew Wise, John Shilling

CUP Undergraduate Research

Secondary organic aerosol (SOA) formed from the oxidation of monoterpenes can impact the Earth’s radiation balance, act as cloud condensation nuclei and negatively affect human health. In the summer of 2015, the Secondary Organic Aerosol From Forest Emission Experiment (SOAFFEE) laboratory campaign was launched in order to study the physical properties of SOA generated from the oxidation of α−pinene and Δ-carene. Both compounds are gas-phase monoterpenes emitted into the atmosphere via biogenic sources. In this study, the peroxide content of SOA was determined using an iodometricspectrophotometric (IS) technique. It was found that the peroxide content of SOA generated during the …

A Comprehensive Exploration Of The Conformational And Energetic Landscape Of A Rotaxane System: A Molecular Dynamics Study, Kentaro Bodzewski

CUP Undergraduate Research

Rotaxanes are composed of a dumbbell shaped molecule threaded through a ring shaped macrocycle; see Figure1. Rotaxanes are used in molecular machines due to the thread’s ability to rotate (pirouette) within the macrocycle. This rotation is often coupled with a shuttling movement as well making them especially useful. Unfortunately, rotaxanes are extremely difficult to synthesize, making it a challenge to study them. By being able to study them using molecular dynamics, one can predict their conformational energies before having to create them. In a previous study, energy barrier values were found for three DAP based rotaxane pirouettes using NMR spectroscopy. …

Digital Fabrication Of An Aerosol Impactor, Stefan Vincent

CUP Undergraduate Research

No abstract provided.