Chemistry Commons^™

Design And Synthesis Of Non-Xanthone Structural Analogs Of Α-Mangostin, Maryam Foroozmehr

Theses and Dissertations

α-Mangostin belongs to a class of polyphenolic compounds called xanthones. The potential pharmacological effects such as anti-bacterial and anti-cancer effects of α-mangostin have made it an important natural product for medicinal chemistry evaluation. During this thesis research, we have designed and synthesized a series of non-xanthone analogs of α-mangostin for medicinal chemistry evaluation. A commercially available starting material, methyl-4-methoxysalicylate was used to synthesize these non-xanthone analogs. The analogs were designed as more flexible derivatives compared to the tricyclic motif within α-mangostin yet retain the hydroxybenzoate scaffold. Through a one-pot chemical synthesis, with relatively high yield (70%), we prepared eight different …

Forensic Genealogy: A Tool In Dna Analysis, Samantha Olsen

Undergraduate Honors College Theses 2016-

DNA is the basic unit of which differentiates one individual to the next. Short Tandem Repeats and Single Nucleotide Polymorphisms are two locations of DNA that have been the most successful in DNA analysis. Unique DNA profiles can be created so that interpretations can be made about the individual who contributed to the DNA sample. Systems like STRmix are currently being employed to give unbiased assumptions about the DNA profiles. There are several different statistical approaches in assigning probabilities to DNA evidence, likelihood ratio and random match probability are two common approaches. After assumptions are made, comparisons can be made …

Computational Analysis Beyond The Monomer Frontier Orbitals For Photovoltaic Donor-Polymer Candidates, Mitchell E. Lahm, Megan M. Niblock, John M. Migliore, Kendra M. Mckenzie, Hans P. Lüthi, Rollin A. King

Chemistry Faculty Publications

Scharber et al. proposed an efficiency model for organic photovoltaic cells based on the orbital energies of the monomers of the donor- and acceptor- polymers [Advanced Materials 18 (2006) 789–794]. We report theoretical extensions of this approach. First, the frontier-orbital energies and electronic spectra of n-length oligomers (n = 1 − 5) of 3-butylthiophene have been determined. The results show reasonable convergence with respect to system size at the point of a trimer with alkyl end caps. The HOMO-LUMO gap well matches computed excitation energies. Second, the structures and electronic spectra of dimers formed by three different monomers, with various …

The 3d Printing Of Dielectric Elastomer Films Assisted By Electrostatic Force, Yuhao Wang, Yanfen Zhou, Wenyue Li, Zhanxu Liu, Bangzi Zhou, Shipeng Wen, Liang Jiang, Shaojuan Che, Jianwei Ma, Tony Betts, Stephen Jerrams, Fenglei Zhou

Articles

ompared with traditional methods for preparing dielectric elastomer (DE) films, electrohydrodynamic (EHD) 3D printing displays many advantages, notably full automation, computer control and flexible design. It also confers high printing resolution, high preparation efficiency with minimal probability of nozzle clogging. In this article, EHD 3D printing was employed to fabricate silicone rubber (SR) based DE films. In order to increase their dielectric constant, high dielectric copper phthalocyanine (CuPc) particles were added into the SR ink. Optimal printing conditions were determined by analyzing the effects of printing voltage and ink properties on the formation of liquid cone and the printed line …

Stockton

United States Data - California

Relevant Publications

2021 Data Summary

Reversible Electrowetting Transitions On Superhydrophobic Surfaces, D. Vanzo, A. Luzar, D. Bratko

Chemistry Publications

Electric field applied across the interface has been shown to enable transitions from Cassie to Wenzel state on superhydrophobic surfaces with miniature corrugations. Molecular Dynamics (MD) simulations manifest the possibility of reversible cycling between the two states when narrow surface wells support spontaneous expulsion of water in the absence of the field. With approximately 1 nm sized wells between the surface asperities, response times to changes of electric field are of O(0.1) ns, allowing up to GHz frequency of the cycle. Because of orientation preferences of interfacial water in contact with the solid, the phenomenon depends on the polarity of …

Photoassisted Synthesis Of Complex Polyheterocycles Via Rational Design Of Tailored Photoprecursors, Tina Alanna Holt

Electronic Theses and Dissertations

Natural products remain the most common source for drug leads, although diversity-oriented synthesis of unnatural complex molecules is gaining momentum. Our lab has been developing experimentally simple and straightforward approaches to complex molecular architectures via photochemical reactions involving a minimal number of experimental steps. In order to achieve this, photoprecursors were assembled via high yielding reactions. Next, we deployed photoinduced cycloadditions to create complex 3-dimentional structures. Lastly, with this obtained primary photoproduct, post-photochemical transformations were used to further grow its scaffold complexity.

One method to increase scaffold complexity is the [4+2] intramolecular cycloadditions of azaxylylenes, which are developed through standard …

Epr Relaxation Of Modified Triphenylmethyl And Nitroxide Radicals, Whylder Moore

Electronic Theses and Dissertations

Trityl and nitroxide radicals are widely used as probes in chemical and biochemical systems. Understanding of factors that impact the electron spin relaxation for these radicals is important for selection of probes and experimental operating conditions. It has been previously reported that ¹³C isotope enrichment of the central carbon of the trityl yields a highly sensitive micro viscosity probe. It was important to characterize the impact of this substitution on the relaxation processes in fluid solution and immobilized samples.

Electron spin relaxation times for perdeuterated Finland trityl 99% enriched in ¹³C at the central carbon (¹³C …

Validation Of A Deployable Proteomic Assay For The Serological Screening Of Sexual Assault Samples, Catherine O'Sullivan Brown

Electronic Theses and Dissertations

Protein mass spectrometry (MS) has emerged as a technique to supplant traditional serological tests for body fluid identification. It was hypothesized that proteomic techniques would surpass the sensitivity and specificity of traditional serological techniques. An automated workflow coupled with protein MS has been developed for the confirmatory identification of five biological fluids. A developmental validation was completed, assessing parameters such as reproducibility, sensitivity, ion suppression, and limit of detection. Implementation was determined through tandem sample processing by MS, traditional serological tests, and standard DNA profiling methods. The MS approach offered superior detection limits while also providing true confirmatory results, producing …

Polyesters With Main And Side Chain Phosphoesters As Structural Motives For Biocompatible Electrospun Fibres, André E. Polloni, Viviane Chiaradia, Ronaldo José F.C. Do Amaral, Cathal Kearney, Brian Gorey, Débora De Oliveira, José V. De Oliveira, Pedro H.H. De Araújo, Claudia Sayer, Andreas Heise

Articles

Phosphoester containing polymers are promising materials in biomedical applications due to their biocompatibility and biodegradability. Utilising thiol-ene chemistry, the synthesis of two novel structural polymer motives combining polyesters and phophoester groups was explored. The first polymer was obtained by coupling ene-functional poly(thioether-phosphoester) with thiol functional poly(pentadecalactone). While the coupling reaction was successful, yields remained low presumably due to inadequate endgroup stoichiometry. The second polymer comprised phosphoester side groups conjugated to unsaturated poly(globalide). Double bond conversions up to 84% were achieved depending of the type of phosphoester thiol and relative reactant ratios. The resulting polymers transitioned from solid semicrystaline to liquid …

1,4,5,8-Naphthalene Tetracarboxylate Dianhydride/G-C3N4 Van Der Waals Heterojunctions Exhibit Enhanced Photochemical H2O2 Production And Antimicrobial Activity, John H. Thurston, Molly Vitale-Sullivan, Azhar Koshkimbayeva, Tyler R. Smith, Kenneth A. Cornell

Chemistry and Biochemistry Faculty Publications and Presentations

Organic semiconductors, including graphitic carbon nitride (g-C₃N₄, CN), represent an important class of materials for the development of novel antimicrobial or biomedical technologies. Of principal interest is the ability of these materials to catalyze the reduction of elemental oxygen to generate reactive oxygen species (ROS), including hydrogen peroxide (H₂O₂). Here, we describe the fabrication of photoactive van der Waals heterojunctions incorporating 1,4,5,8-naphthalene tetracarboxylic dianhydride (NTCDA) and CN. The composite heterojunction systems were characterized by a combination of physical (TEM, SEM, pXRD), spectroscopic (FT-IR, XPS, DRUV, photoluminescence, TCSPC) and kinetic experiments. Electronic interactions …

Big Data Analysis Of Nanoscience Bibliometrics, Patent, And Funding Data (2000-2019), Yuliang Zhao, Zhixiang Wei, Qing Dai, Hongwei Dong, Hongjun Xiao, Shuxian Wu, Xingxing He, Beverley Mitchell, Thomas A. Collins, Sarah Huggett, John Van Orden, Christiane Barranguet, Basak Candemir

Public Reports

Given the strategic significance of Nanoscience and nanotechnology, it is essential to evaluate and predict its developmental trends. This report is based on the largest abstract and citation database of peer-reviewed literature, Elsevier's Scopus, along with the research evaluation platform SciVal. The funding and patent analysis data for the report is from Funding Institutional and PatentSight, respectively. This report provides an evaluation of Nanoscience's scientific output, role, contribution, and impact through bibliometric analysis, combined with big data indicators of Nanoscience scientific results and patents from 2000 to 2019.

Conversation Among Physical Chemists: Strategies And Resources For Remote Teaching And Learning Catalyzed By A Global Pandemic, Andrea N. Giordano, David Gardner, William W. Kennedy, Chrystal D. Bruce

2021 Faculty Bibliography

In the midst of a global pandemic in spring 2020, physical chemistry faculty gathered to share strategies and resources for teaching remotely. During this conversation, instructors created a shared document compiling the challenges they faced in spring 2020 and ways to improve teaching and learning in the physical chemistry classroom and laboratory when institutions reopened in the fall. We present a content analysis of the shared document that provides a snapshot of physical chemists’ thoughts at that moment in June 2020. The themes that emerged from our analysis are assessment, choice of learning objectives, course management, opportunities, resources, student motivation, …

Synthesis And Reactivity Of Metal Bis(Alkoxide) Complexes In Nitrene Coupling And Polymerization Of Polar Monomers, Duleeka Chamini Wannipurage

Wayne State University Dissertations

The nitrene homocoupling to produce azoarenes was done using two different iron (II) alkoxide complexes, Fe(OCtBu2(3,5-Ph2C6H3)2(THF)2 and Fe[OO]Ph(THF)2. Due to the steric bulkiness of HOCtBu2(3,5-Ph2C6H3 ligand, this complex exhibited selectivity for the bis(alkoxide) ligation; no tris(alkoxide) complexes were observed. As a result, both bulky and non-bulky aryl nitrenes are coupled with Fe(OCtBu2(3,5-Ph2Ph)2(THF)2, albeit the coupling of the less bulky substrates requires higher temperatures and longer reaction times. Stoichiometric reactions of Fe(OCtBu2(3,5-Ph2C6H3)2(THF)2 with non-bulky aryl azides led to the observation of the iron(III) tetrazene radical anion complexes, that can produce azoarene products after heating. Tetrazene complexes likely serve as a “masked …

Synthetic Pathways For Potential Platinum 1,10-Phenanthroline Compounds, Jacob Young

Mahurin Honors College Capstone Experience/Thesis Projects

There are extremely important uses for platinum when it comes to the treatment of cancers and dementias. One potential therapeutic combines platinum with a structure known as phenanthroline. This platinum phenanthroline structure is normally extremely water-insoluble, rendering it difficult to study and use in biological systems. The Williams’ Biochemistry Laboratory endeavored to find a simpler synthetic pathway for a water-soluble phenanthroline product. While unsuccessful in identifying a product as of yet, many synthetic pathways have been ruled out, and more hypothetical pathways are being formulated for testing.

Among the strategies analyzed are varying solvent, reagents, apparatus, methodology, and temperature in …

Degradation Of Natural And Synthetic Fibers In Various Aqueous Environments, Jaylin Bryant

Honors Scholars Collaborative Projects

Fabrics are one variant of polymers, macromolecules that form the foundation of our society. They consist of small subunits called monomers, which are covalently bonded together and layered over each other through intermolecular attractions. There are natural fabrics, such as cotton and silk, and synthetic fabrics like polyester and rayon. Scientists in forensic taphonomy study postmortem changes made to human remains, which can also include clothes found at the scene. In this study, the degradation rates of four white fabrics (cotton, polyester, rayon, and silk) were observed in various aqueous environments (pure, chlorinated, sea, and lake) in order to observe …

The Formation Of Prenucleation Clusters For Calcium Fluoride, Taylor M. Muterspaw

Browse all Theses and Dissertations

There have been limited studies on the analysis of the nucleation and precipitation behind calcium fluoride. Earlier studies support a nucleation mechanism in agreement to classical nucleation theory (CNT) in which a surface nucleation mechanism is required for calcium fluoride. This experiment devised using the ISE method to calcium fluoride to find evidence of a nucleation mechanism like that of calcium carbonate (prenucleation cluster pathway). The potential and pH were recorded versus time and the potential data was converted to nCa2+ data of free calcium ions. It was determined that there was evidence of a similar nucleation mechanism for calcium …

Analyzing Single Ion Channel Activity In A Lipid Bilayer, David Ruiter, Loren Haarsma

Summer Research

Bilayers of lipid molecules form the basis of the cell membranes in living organisms. An ion channel is a type of molecule that can temporarily open a channel in a lipid bilayer in order to allow specific ions in and out. Problems with ion channels and their interactions with lipid bilayers are associated with several diseases, including osteoporosis. Carefully controlling the type of lipid in the bilayer, and its temperature, gives us tools to study the basic biophysics of these systems

Effects Of Resin Chemistries On The Selective Removal Of Industrially Relevant Metal Ions Using Wafer-Enhanced Electrodeionization, Humeyra B. Ulusoy Erol, Christa N. Hestekin, Jamie A. Hestekin

Chemical Engineering Faculty Publications and Presentations

Wafer-enhanced electrodeionization (WE-EDI) is an electrically driven separations technology that occurs under the influence of an applied electric field and heavily depends on ion exchange resin chemistry. Unlike filtration processes, WE-EDI can be used to selectively remove ions even from high concentration systems. Because every excess ion transported increases the operating costs, the selective separation offered by WE-EDI can provide a more energy-efficient and cost-effective process, especially for highly concentrated salt solutions. This work reports the performance comparison of four commonly used cation exchange resins (Amberlite IR120 Na⁺, Amberlite IRP 69, Dowex MAC 3 H⁺, and …

Ferrocenium Complex Aided O-Glycosylation Of Glycosyl Halides, Deva Saroja Talasila, Eike B. Bauer

Educator Preparation & Leadership Faculty Works

A new strategy for the activation of glycosyl halide donors to be utilized in glycosylation reactions is presented, utilizing the ferrocenium (Fc) complexes [FcB(OH)2]SbF6 and FcBF4 as promoters. The scope of the new system has been investigated using glycosyl chloride and glycosyl fluoride donors in combination with common glycosyl acceptors, such as protected glucose. The corresponding glycosylation products were formed in 95 to 10% isolated yields with α/β ratios ranging from 1/1 to β only (2 to 14 h reaction time at room temperature, 40 to 100% ferrocenium promoter load).

Soil Research Project, Kate Donaldson

Natural Sciences Student Research Presentations

My topic is how earthworms interact with soil. Most people learn from an early age that earthworms are an important part of soil and plant life, but many do not know the actual reasoning and evidence behind it. My audience would be interested in this topic because it is interesting to expand knowledge on things already considered well know. While many earthworms are not endangered, we still need to be carful and protect the animal that is vital to plant growth and soil health.

Semester Soil Project, Eden Mcavoy

Natural Sciences Student Research Presentations

What is the topic?

The topic I chose is how surrounding cities affect the minerals and integrity of the surrounding soil and how it can affect humans.

Why this topic?

I chose this topic because I wanted to learn how soil integrity differs from place to place.

Photophysical Properties Of Fluorescent Coumarins, Isaac Jonker, Leah Knoor, George Dulaney, Mark Muyskens

Summer Research

Coumarins are organic molecules that can be found in nature • The base coumarin seen in scheme below can have substituents added to the numbered areas • Changes in substituents cause great change in physical properties • 6 hydroxy 7 amino 4 methyl coumarin(HAMC) and 6,7 dihydroxy coumarin(aesculetin) are focused on

Sivvu - Performing Advanced Chemical Calculations On The Web, Dawson Buist, Coleman Ulry, Douglas A. Vander Griend

Summer Research

SIVVU is an application for calculating the concentration of chemical compounds based on data collected from a spectrometer. Before this summer, the application had gone through 2 iterations. One was a desktop application created in MatLab. The second was a website designed to make the application more accessible. These 2 applications had problems though. The first was slow when performing intensive calculations, and could take several hours. The second was limited in features, making the MatLab version the preferred one to use. The Spring prior, Nathan Wang and Dawson Buist were tasked with building a new website with a modern …

Structure Formation And Coupling Reactions Of Hexaphenylbenzene And Its Brominated Analog, Jacob D Teeter, Paulo S. Costa, Christoph Dobner, Mamun Sarker, Alexander Sinitskii, Axel Enders

Department of Chemistry: Faculty Publications

The on-surface coupling of the prototypical precursor molecule for graphene nanoribbon synthesis, 6,11-dibromo-1,2,3,4-tetraphenyltriphenylene (C₄₂Br₂H₂₆, TPTP), and its non-brominated analog hexaphenylbenzene (C₄₂H₃₀, HPB), was investigated on coinage metal substrates as a function of thermal treatment. For HPB, which forms non-covalent 2D monolayers at room temperature, a thermally induced transition of the monolayer’s structure could be achieved by moderate annealing, which is likely driven by π-bond formation. It is found that the dibrominated carbon positions of TPTP do not guide the coupling if the growth occurs on a substrate at temperatures that …

The Synthesis Of Hamc (6-Hydroxy-7-Amino4-Methylcoumarin), Liam Hoogewerf, Ronald Blankespoor, George Du Laney, Isaac Jonker, Leah Knoor, Mark Muyskens

Summer Research

HAMc is a synthetic trisubstituted coumarin. The image on the left shows the core coumarin structure as well as the numbered substitution locations. This compound has never been reported in the scientific literature before and we are planning on being the first to publish a letter about it in the near future.

Synthesis Of Cysteine-Tyrosine Crosslink, Samuel Braak, Michael Rettstatt, David Benson

Summer Research

Some posttranslationally-modified protein tyrosines, such as the crosslink between cysteine and tyrosine (Cys-Tyr) provide sites for reversible oxidation These crosslinks are formed by an adjacent, redox active metal center when reacted with O2 . While galactose oxidation was among the first documented cys-ty crosslinks, cross linked tyrosine PTM’s have three major functions.

A Strongly Lewis-Acidic And Fluorescent Borenium Cation Supported By A Tridentate Formazanate Ligand, Benjamin D. Katzman, Ryan R. Maar, Daniela Cappello, Madeleine O. Sattler, Paul D. Boyle, Viktor N. Staroverov, Joe B. Gilroy

Chemistry Publications

Lewis acids are highly sought after for their applications in sensing, small-molecule activation, and catalysis. When combined with π-conjugated molecular frameworks, Lewis acids with unique optoelectronic properties can be realized. Here, we use a tridentate formazanate ligand to create a planar, redox-active, fluorescent, and strongly Lewis-acidic borenium cation. We also demonstrate that this compound can act as a colourimetric probe for reactivity.

Corrosion Failure Of Titanium Tubes Of A Heat Exchanger For The Heating Of Dissolving Lye, Valentin Romanovski, Yolanda S. Hedberg, Andrei Paspelau, Vitali Frantskevich, James J. Noël, Elena Romanovskaia

Chemistry Publications

Corrosion of titanium heat exchangers in the processing of sylvinite ore is undesirable from economic, safety, and process sustainability perspectives. Triggered by an industrial case, we investigated the extent of corrosion during simulated contact with sylvinite ore (in dissolving lye) in relevant conditions. Detailed characterization of the failed tubes and corrosion products was carried out to understand the mechanism of failure. Corrosion of titanium (Grade 2) tubes was investigated at room temperature, 60, 70, 80, and 90 °C. After electrochemical and surface morphology analysis, we found that pitting corrosion of the titanium tube material sharply increased above 80 °C in …

Strained Alkyne Polymers Capable Of Spaac Via Ring-Opening Metathesis Polymerization, Rajeshwar Vasdev, Wilson Luo, Kyle Classen, Michael Anghel, Samantha Novoa, Mark S. Workentin, Joe B. Gilroy

Chemistry Publications

The incorporation of strained alkynes into polymers is generally achieved by employing step-growth polymerization methods or post-polymerization reactions. Here, we demonstrate that cyclopropenone-masked strained alkynes are tolerant to chain-growth ring-opening metathesis polymerization, and that, upon post-polymerization photochemical demasking with loss of CO, the strained alkyne group appended to each repeating unit can be used to prepare functional (e.g., fluorescent or redox-active) polymers from a common polymer backbone. We support our claims about polymer transformations throughout the manuscript through the inclusion of a complete set of model reactions and characterization data for analogous molecular species. The findings of this …