Chemistry Commons^™

Frontiers In Fast Voltammetry: Novel Analytes And Applications, Jordan Holmes

Theses and Dissertations

Electrochemical sensors are beneficial towards the development and advancement of monitoring devices. As this type of technology progresses, so does our ability to create state-of-the-art sensing strategies to probe environmental and biological systems at the source. In the environment, it is essential to monitor particularly harmful contaminants like trace metals in order to better mitigate risk. Additionally, biological molecules are often times challenging to measure because matrices are complex and difficult to probe; Recent advancements in chemical ex vivo and in vivo sensing platforms have offered insight into physiological processes. The brain in particular requires a sophisticated, implantable sensor as …

Designing, Constructing, And Employing Two-Dimensional Ultrafast Spectroscopy To Resolve Complex Kinetics, Jason R. Darvin

Theses and Dissertations

Multiple population-period transient spectroscopy (MUPPETS) is a two dimensional ultrafast time resolved spectroscopy technique. MUPPETS uses three pairs of optical pulses over two time periods to separate homogeneous and heterogeneous causes of rate dispersion. This dissertation details improvements to the MUPPETS optical assembly enabling measurements on systems that previously fell outside of the MUPPETS 2-ns time window. In addition, the theoretical groundwork is laid to unveil the hidden coordinate controlling rate exchange using 2D and 3D correlation functions.

The first project details improvements made to the MUPPETS assembly. A detailed method was developed to eliminate astigmatism, coma, and spherical aberration …

Study Of Transition State Stabilization Using Molecular Rotors, Erik Carl Vik

Theses and Dissertations

Molecular devices that function as rotors and measurement devices are the main topic of this dissertation. Each study contains a device based on an N-phenylimide framework, which has restricted rotation about the N-C (imide-phenyl) single bond due to a steric clash from the imide carbonyl and the phenyl rings ortho substituent. In general, two ground states are observed by 1H NMR, which are separated by a single transition state (TS). Incorporation of non-covalent interactions into the TS led to measurable changes in the rate for rotation. While the molecules in this dissertation revealed details that could not have been predicted, …

Studies On The Mechanism And Application Of Steam Thermography, Raymond Gerard Belliveau Iii

Theses and Dissertations

The detection of blood on fabrics for forensic purposes is a widely studied topic in forensic science, and to that end, effort in this laboratory has been devoted to developing a thermal imaging method called steam thermography. Steam thermography is a method used to enhance chemical contrast in thermographic images by exposing a surface to water vapor during imaging. The exposure of water vapor to the surface generates heat, and can differentially increase the thermographically measured apparent temperature of imaged surfaces. This can result in thermographic contrast between surfaces with different chemical properties. Previously reported proposed mechanisms to describe the …

A Spatial Heterodyne Spectrometer For Raman Imaging And Remote Spectroscopy, Ashley Nicole Allen

Theses and Dissertations

Raman and Laser-Induced Breakdown Spectroscopy (LIBS) are optical techniques that provide information about the chemical makeup of a sample without any preparation or physical contact with it. For this reason, Raman and LIBS spectrometers are among the instruments selected for NASA’s Mars 2020 rover mission and are being considered for future missions to the Jovian moons, asteroids and comets. Such future missions will require smaller, more ruggedized Raman and LIBS spectrometers, and the new type of spectrometers discussed here, the spatial heterodyne Raman and LIBS spectrometers are being developed for this purpose. The SHS is a wide-field, Fourier transform, stationary …

Cationic Cobaltocene Derivatives And Polyelectrolyte Membranes For Energy Storage Applications, Tianyu Zhu

Theses and Dissertations

Metal-containing polyelectrolytes (or metallo-polyelectrolytes) represent a new class of polymeric materials with distinct properties compared to traditional organo- polyelectrolytes or neutral metallopolymers. This emerging class of synthetic materials is ubiquitous for a myriad of utilities ranging from traditional electrolyte chemistry to biomedicals to sustainable applications, to name just a few. This dissertation work is focused on the design, synthesis, characterization and application of advanced metallo- cations and metallo-polyelectrolytes for energy storage applications. First, a template method to prepare metallo-polyelectrolytes based on cationic cobaltocene and polyethylene backbone was described. The resulting membranes are mechanically tough, ionically conductive and chemically inert. Second, …

Elucidating The Mechanism Of Bone Morphogenetic Protein (Bmp) -Mediated Sox2 Downregulation In Ovarian Cancer, Zainab Motolani Shonibare

Theses and Dissertations

Sex determining region Y-box 2 (Sox2) is a transcription factor essential for maintaining self-renewal and pluripotency of undifferentiated embryonic stem cells. Sox2 is involved in multiple processes of cancer cells, however, regulation of Sox2 expression and the consequences of that regulation in cancer remains elusive. Previously, we demonstrated that BMP9/GDF2 is significantly reduced in expression in ovarian cancer (OVCA) cells, methylated in patient tumors and, promoted anoikis resistance in both breast and OVCA cell lines. In an attempt to identify genes downstream of BMP9 that may provide anoikis resistance, transcriptomics was performed leading to the identification of Sox2, a developmental …

Investigation Of Electrostatic Interactions Towards Controlling Silylation-Based Kinetic Resolutions And Exploring The Effect Of The Polymer Backbone On Silylation-Based Kinetic Resolutions Employing A Polymer-Supported Triphenylsilyl Chloride, Tian Zhang

Theses and Dissertations

This dissertation focuses on studies of silylation-based kinetic resolution methodology developed by the Wiskur group, which is a powerful method for the separation of a single enantiomer from a mixture of racemic secondary alcohols. Chapter 1 introduces the background of our silylation-based kinetic resolution..

Chapter 2 involves mechanistic studies of electrostatic interactions in controlling enantioselectivities of our silylation-based kinetic resolution. Electrostatic interactions between a silylated isothiourea intermediate and an ester π system is determined via linear free energy relationship study. To be specific, how variations in sterics and electronics affect the selectivity of a silylation-based kinetic resolution.

Chapter 3 is …

The Development Of Multi-Functional System That Combine Patterned Hydrogels, Plasmin-Degradable Nanoparticles And Stem Cells For Applications In Tissue Engineering And Growth Factors Delivery, Safaa I. Kader

Theses and Dissertations

This thesis spots the light on the development of a novel multi-functionalized system for application in tissue engineering and on-demand morphogens delivery. Three types of materials used in this study are synthetic polymer, biopolymer, and nanomaterials. Polyethylene glycol (PEG), a synthetic polymer was chosen in this study because of its high biocompatibility, non-immunogenicity, inert nature, ease of modification, and reduces protein denaturation to provide a wide range of physical and mechanical properties. Here, PEG is used one time as a hydrogel, linear polyethylene glycol-co-lactide (LPELA), and another time as peptide-PEG based nanoparticles (PxSPCP). Gelatin, a natural polymer has been widely …

Proton Transfer Versus Hydrogen Bonding In A Reduced Iron Porphyrin Nitrosyl Complex, Md. Hafizur Rahman, Yilin Liu, Michael D. Ryan

Chemistry Faculty Research and Publications

The ¹H NMR spectra of Fe(OEP)(HNO), which was formed from Fe(OEP)(NO)⁻ in the presence of 3,5-dichlorophenol, were studied as a function of temperature. The chemical shift of the HNO proton showed a unique behavior which could be explained based on the equilibrium between the protonated complex, Fe(OEP)(HNO), and the hydrogen-bonded complex, Fe(OEP)(NO)⁻···HOPh. This equilibrium was consistent with UV/visible spectroscopy and the voltammetric data. UV/visible stopped-flow experiments showed that the hydrogen-bonded complex, which was formed when weak acids such as phenol were added, and the Fe(OEP)(HNO) complex were quite similar. In addition to the HNO proton resonance, …

Mapping Of A Regulatory Site Of The Escherichia Coli Adp-Glucose Pyrophosphorylase, Jaina A. Bhayani, Benjamin L. Hill, Anisha Sharma, Alberto A. Iglesias, Kenneth W. Olsen, Miguel A. Ballicora

Chemistry: Faculty Publications and Other Works

The enzyme ADP-glucose pyrophosphorylase (ADP-Glc PPase) controls the biosynthesis of glycogen in bacteria and starch in plants. It is regulated by various activators in different organisms according to their metabolic characteristics. In Escherichia coli, the major allosteric activator is fructose 1,6-bisphosphate (FBP). Other potent activator analogs include 1,6-hexanediol bisphosphate (HBP) and pyridoxal 5′-phosphate (PLP). Recently, a crystal structure with FBP bound was reported (PDB ID: 5L6S). However, it is possible that the FBP site found is not directly responsible for the activation of the enzyme. We hypothesized FBP activates by binding one of its phosphate groups to …

Antibacterial Properties Of Mussel-Inspired Polydopamine Coatings Prepared By A Simple Two-Step Shaking-Assisted Method, Pegah Kord Fooroshani, Elizabeth Polega, Kevin Thomson, Mohammad Saleh Akram Bhuiyan, Rattapol Pinnaratip, Mikhail Trought, Chito E. Kendrick, Yuesheng Gao, Kathryn Perrine, Lei Pan, Bruce P. Lee

Michigan Tech Publications, Part 1

A simple two-step, shaking-assisted polydopamine (PDA) coating technique was used to impart polypropylene (PP) mesh with antimicrobial properties. In this modified method, a relatively large concentration of dopamine (20 mg ml⁻¹) was first used to create a stable PDA primer layer, while the second step utilized a significantly lower concentration of dopamine (2 mg ml⁻¹) to promote the formation and deposition of large aggregates of PDA nanoparticles. Gentle shaking (70 rpm) was employed to increase the deposition of PDA nanoparticle aggregates and the formation of a thicker PDA coating with nano-scaled surface roughness (RMS = 110 …

Aerobic C-C And C-O Bond Formation Reactions Mediated By High-Valent Nickel Species., Sofia Smith, Oriol Planas, Laura Gómez, Nigam Rath, Xavi Ribas, Liviu Mirica, Liviu Mirica

Chemistry & Biochemistry Faculty Works

Nickel complexes have been widely employed as catalysts in C–C and C–heteroatom bond formation reactions. While Ni(0), Ni(I), and Ni(II) intermediates are most relevant in these transformations, recently Ni(III) and Ni(IV) species have also been proposed to play a role in catalysis. Reported herein is the synthesis, detailed characterization, and reactivity of a series of Ni(II) and Ni(III) metallacycle complexes stabilized by tetradentate pyridinophane ligands with various N-substituents. Interestingly, while the oxidation of the Ni(II) complexes with various other oxidants led to exclusive C–C bond formation in very good yields, the use of O2 or H2O2 as oxidants led to …

Solution Of Simultaneous Chemical Equilibria In Heterogeneous Systems: Implementation In Matlab, D. Scott Smith

Chemistry Faculty Publications

A Matlab script to solve simultaneous equilibria in solution, including precipitation/dissolution equilibria is described.

Properties Of Concrete Modified With Ultra-Fine Slag, Panga Narasimha Reddy, Javed Ahmed Naqash

Karbala International Journal of Modern Science

The supplementary cementitious materials (SCM) can be used as a replacement of cement in the construction industry to minimize the drawbacks of normal concrete such as the emission of carbon dioxide so as to be eco-friendly. This paper presents the effect of ultra-fine slag (i.e. 25% of alccofine) as a replacement of cement for different water to binder ratios (i.e. 0.38, 0.4 and 0.45). The effect of alccofine on the concrete strength properties were studied at 7 and 28 days wherein considerable strength enhancement was observed compared to normal concrete. Thermogravimetric analysis was also carried out in which mass loss …

Analytical Approach To Investigation Of Free Vibration Of Thin Rectangular Plate Immersed In Fluid, Resting On Winkler And Pasternak Foundations, Obanishola Sadiq, Gbeminiyi Sobamowo, Saheed Salawu

Karbala International Journal of Modern Science

Dynamic behaviour of free vibration of rectangular plate is investigated. This study considered an analytical approach to investigation of free vibration of thin rectangular plate immersed in fluid, resting on Winkler and Pasternak foundations.The governing nonlinear partial differential equation is analyzed using two-dimensional differential transform method. The accuracy of the analytical solutions obtained is verified with existing results in literature and confirmed in excellent agreement. Thereafter, the analytical solutions are used for investigation of effect of elastic foundation, fluid and aspect ratio on vibrating plate.From the result, it is observed that, increase elastic foundation parameters increases natural frequency, increase aspect …

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

Literature Review: Biocement For Stabilization Of Expansive Soils In Las Vegas, Nevada, Silva Topchyan, Moses Karakouzian

LSAMP Poster Presentations

The aim of this study was to present a possibility for the use of biocementon expansive clay. Expansive soil is a type of clay when exposed to water and moisture changes its volume. Due to the clays swelling and shrinkage behavior itsdifficult to use it in engineering and construction projects, therefore costly and unhealthy techniques have been used to stabiliseexpansive soil in order to address the problem [12]. A possible healthy and environmentally friendly solution is Biocement which uses microbial induced calcite precipitation (MICP) in order to help aggregate soil to form a stable cementitiousmaterial. MICP isdependent on the innate …

What A Career In Teaching Could Look Like For Me: My Journey Of Self-Reflection And Self-Discovery, Jashaun D. Bottoms

STEM Instructional Graduate Teaching Assistant Posters

I started the STEM Instructional Program the summer before my first teaching experience as a graduate student at WMU, and I saw it as a great training opportunity for the upcoming school year. As a General Chemistry II lab instructor, I would encounter students from various majors and backgrounds, with different learning styles and attitudes toward chemistry and math.

In order to effectively engage these students in a pre-lab lecture and to prepare them to complete the experiments, I needed to learn how to keep their attention, clearly explain and relay information in an interesting way, check their understanding, and …

Definition Of The Chalcogen Bond (Iupac Recommendations 2019), Christer B. Aakeroy, David L. Bryce, Gautam R. Desiraju, Antonio Frontera, Anthony C. Legon, Francesco Nicotra, Kari Rissanen, Steve Scheiner, Giancarlo Terraneo, Pierangelo Metrangolo, Giuseppe Resnati

Chemistry and Biochemistry Faculty Publications

This recommendation proposes a definition for the term “chalcogen bond”; it is recommended the term is used to designate the specific subset of inter- and intramolecular interactions formed by chalcogen atoms wherein the Group 16 element is the electrophilic site.

Carving Plasmon Modes In Silver Sierpiński Fractals, Isobel C. Bicket, Edson P. Bellido, Danielle M. Mcrae, Francois Lagugne-Labarthet, Gianluigi A. Botton

Chemistry Publications

The surface plasmon resonance (SPR) modes of the first three generations of a Sierpiński fractal triangle are investigated using electron energy loss spectroscopy (EELS) complemented with finite difference time domain simulations. The Sierpiński fractal geometry is created in a subtractive manner, by carving triangular apertures into the triangular prism of the previous fractal generation. The ability of the fractal antenna to efficiently utilize space in coupling to long wavelength excitations is confirmed on the single nanostructure level via redshifting of the primary dipole mode as the fractal generation is increased. Through application of the Babinet principle, it is demonstrated that …

Molecular Modeling Studies On The Binding Mode Of The Pd-1/Pd-L1 Complex Inhibitors, Suliman Almahmoud, Haizhen A. Zhong

Chemistry Faculty Publications

The programmed cell death protein 1 (PD-1)/programmed cell death ligand 1 (PD-L1) is an immune checkpoint (ICP) overexpressed in various types of tumors; thus, it has been considered as an important target for cancer therapy. To determine important residues for ligand binding, we applied molecular docking studies to PD-1/PD-L1 complex inhibitors against the PD-L1 protein. Our data revealed that the residues Tyr56, Asp122, and Lys124 play critical roles in ligand binding to the PD-L1 protein and they could be used to design ligands that are active against the PD-1/PD-L1 complex. The formation of H-bonds with Arg125 of the PD-L1 protein …

Synthesis Of Functionalized Tetrahydropyridines By Sncl4-Mediated [4+2] Cycloaddition Between Donor–Acceptor Cyclobutanes And Nitriles, David Tong, Jackie Wu, Nathan Bazinski, Donghyun Koo, Naresh Vemula, Brian Pagenkopf

Chemistry Publications

Cycloadditions of strained carbocycles promoted by Lewis acids are powerful methods to construct heterocyclic frameworks. In fact, the formal [3+2] cycloadditions of donor-acceptor (DA) cyclopropanes with nitriles has seen particular success in synthesis. In this work, we report on the first [4+2] cycloaddition of nitriles with DA cyclobutanes via Lewis acid activation. Tetrahydropyridine derivatives were obtained in up to 91% yield from various aryl activated cyclobutane diesters and aliphatic or aromatic nitriles.

Low-Cost, Ambient-Dried, Superhydrophobic, High Strength, Thermally Insulating, And Thermally Resilient Polybenzoxazine Aerogels, Sadeq Malakooti, Guoqiang Qin, Chandana Mandal, Rushi Soni, Tahereh Taghvaee, Yao Ren, Huiluo Chen, Nicholas Tsao, James Shiao, Shameek Sushil Kulkarni, Chariklia Sotiriou-Leventis, Nicholas Leventis, Hongbing Lu

Chemistry Faculty Research & Creative Works

A family of ambient-dried poly benzoxazine aerogels is prepared with a facile and scalable process as a high-performance polymeric aerogel with strong and robust thermomechanical properties at elevated temperatures. Those materials are inherently flame-retardant and superhydrophobic over the entire bulk density range (0.24-0.46 g cm-3). In addition, they are mechanically strong with strengths (e.g., 1 MPa at 0.24 g cm-3 at room temperature) higher than those of other high-performance aerogels of similar density, including polyimide and polyamide (Kevlar-like) aerogels as well as polymer-cross-linked X-silica and X-Vanadia aerogels, at a significantly lower cost. Furthermore, unlike most other glassy polymeric materials, the …

Environmentally Responsible Land Use, Spring/Summer 2010, Issue 22

Sustain Magazine

No abstract provided.

Sustainable Communities, Fall/Winter 2010, Issue 21

Sustain Magazine

No abstract provided.

Sustainable Building, Spring/Summer 2009, Issue 20

Sustain Magazine

No abstract provided.

Environmental History, Fall/Winter 2009, Issue 19

Sustain Magazine

No abstract provided.

Student Research, Spring/Summer 2008, Issue 18

Sustain Magazine

No abstract provided.

Evolving Pollution Prevention, Fall/Winter 2008, Issue 17

Sustain Magazine

No abstract provided.