N-Heterocyclic Carbene Ligated Group 11 Trimethylsilylchalcogenolates: Building Blocks For Heterometallic Chalcogenide Molecules, 2020 The University of Western Ontario
N-Heterocyclic Carbene Ligated Group 11 Trimethylsilylchalcogenolates: Building Blocks For Heterometallic Chalcogenide Molecules, Dickron Richard Nahhas
Electronic Thesis and Dissertation Repository
The synthesis of heterometallic chalcogenide molecules requires the continued investigation into the appropriate reagents necessary to introduce metal – chalcogen bonds in a controlled fashion. Trimethylsilyl metallochalcogenolates (MESiMe3) act as synthons introducing “ME–“ in solution upon reacting with an appropriate ternary metal reagent, MX (X= halide, acetate, etc.). Recent work makes use of N–heterocyclic carbenes (NHCs) as a class of ancillary ligand that can stabilize these reagents and the heterometallic chalcogenide molecules obtained with them. Building on previous work, this thesis describes the synthesis of group 11 trimethylsilyl metallochalcogenolates stabilized by bis–1,3–tritylimidazole–2–ylidene (abbreviated ITr ...
295— Biomimicry: Investigating The Active Site Model Of Lactate Racemase, 2020 SUNY Geneseo
295— Biomimicry: Investigating The Active Site Model Of Lactate Racemase, Stephanie Podguski, Maisy Ross
Because of humans’ heavy impact on nature with industrialization and resource extraction, biomimetics, also known as biomimicry, is a study that has emerged. Biomimetics utilizes observations from nature to comprehend the principles of underlying mechanisms and apply concepts that may benefit science, medicine, engineering and the like. An area of biochemistry we are applying this to is the lactate racemase enzyme.This metalloenzyme is found in many prokaryotic organisms and catalyzes the interconversion between the two optical isomers of lactic acid. The structure of this enzyme consists of a square-planar nickel (II) ion coordinated by a histidine residue and a ...
Inorganic Chemistry Faculty Value Student-Centered Learning, But Time Constraints And Student Evaluations Discourage Change, Jenna Savage, Hope Heideman
19th Annual Celebration of Undergraduate Research and Creative Activity (2020)
Improving student success in chemistry requires faculty change, but change is hard. The Interactive Online Network of Inorganic Chemists (IONiC) is a community of practice (CoP) that offers teaching resources for inorganic chemistry faculty. We are studying the ways in which CoPs can promote faculty change. IONiC is supporting twenty inorganic chemistry faculty in implementing effective teaching methods into their foundation-level inorganic chemistry courses. In order to better understand how faculty make decisions about teaching, these faculty were interviewed about their teaching beliefs, approaches, and dissatisfactions. The interview data were coded via thematic content analysis and have shown that inorganic ...
Battery Application Of Silver Molybdate Materials, 2020 Valparaiso University
Battery Application Of Silver Molybdate Materials, Brendan Michael Godsel
Undergraduate Honors Papers
As the demand for renewable energy grows, the investigation of potential battery materials continues to progress hastily. Many devices and machines of present day are operated by battery technology, and their energy requirements warrant which kinds of batteries will power them. The battery in a phone requires hundreds, possibly thousands, of uses and needs to be able to recharge quickly. The battery in the implantable cardiac defibrillator (ICD), the battery by which this product was inspired, is only used once, but it must last years before it is replaced. The cathode of the ICD battery is comprised of a silver ...
Scanning Electron Microscopy (Sem) Investigation Of Morphology Changes In The Reduction Of Silica Nanoparticles To Elemental Silicon, Allison M. Cairns
University Honors Theses
The application of silicon nanoparticles varies from energy storage materials, to drug-delivery, and molecular recognition. Various chemical and physical properties of the Si nanoparticles arise from their morphology. This paper aims to reveal the morphology of Si nanoparticles following magnesiothermic reduction of silica (SiO2) nanoparticles. Two sets of SiO2 nanoparticles were used, commercially available NanoXact nanoparticles and laboratory-synthesized Stöber nanoparticles. A Zeiss Sigma VP FEG SEM was used to examine the morphology. Following the magnesiothermic reduction, the nanoparticles were etched with HF. Ten sets of images were taken of both Stöber and NanoXact nanoparticles: 1,2: the SiO ...
Dissipation Of Benzobicyclon And Benzobicyclon Hydrolysate In A Louisiana Rice Field, 2020 Louisiana State University
Dissipation Of Benzobicyclon And Benzobicyclon Hydrolysate In A Louisiana Rice Field, Xavier Poole
LSU Master's Theses
Pesticide resistance in rice fields is an ongoing issue that has resulted in the development and use of pesticides with new modes of action. Benzobicyclon is the first registered hydroxyphenylpyruvate(HPPD)-inhibiting pesticide in the United States and has gained attention as a resistance management strategy to control weed pests in rice fields. Understanding the environmental fate and dissipation mechanisms of benzobicyclon is important due to the unique rotation of rice and crayfish in Louisiana on the same fields. Benzobicyclon persistence into the crayfish growing seasons may lead to unintended consequences for crayfish growth and production, assuming there is toxicity ...
Lithological And Geochemical Responses To Abrupt Global And Regional Paleoenvironmental Changes During The Aptian In A Hemipelagic Setting Of The Eastern Iberian Peninsula: A Multi-Proxy Approach, 2020 Florida International University
Lithological And Geochemical Responses To Abrupt Global And Regional Paleoenvironmental Changes During The Aptian In A Hemipelagic Setting Of The Eastern Iberian Peninsula: A Multi-Proxy Approach, Jander Socorro
FIU Electronic Theses and Dissertations
Intense episodes of environmental perturbations and regionally to globally distributed, oxygen-deprived marine facies characterize the Cretaceous sedimentary record. The Organyà Basin in the Spanish Pyrenees chronicles this period in expanded stratigraphic sequences that enabled high-resolution sampling and detailed analysis of disturbances poorly recorded in more lithologically condensed sections. Here, I present an integrated multi-proxy study aimed at understanding the Basin’s response to changing paleoenvironmental conditions during the early Aptian stage of the Cretaceous.
Results from the El Pui section indicate that large-scale (> 1‰), negative carbon isotope excursions (CIEs) that show no corresponding shifts in local sources of organic matter ...
Electrochemical Studies Of Cobalt(Ii) Diphenylazodioxide Complexes, 2020 Cleveland State University
Electrochemical Studies Of Cobalt(Ii) Diphenylazodioxide Complexes, Lakshmi Balarama, Kylin A. Emhoff, Ahmed M.H. Salem, Jovana Hanna, Mohamed N. Alsabony, Mekki Bayachou, Jerry Mundell, W. Christropher Boyd
Chemistry Faculty Publications
The electrochemical behavior of the unusual cobalt(II) diphenylazodioxide complex salts [Co(az)4](PF6)2 1 and [Co(bpy)(az)2](PF6)2 2 has been studied by cyclic voltammetry. Each complex displays two quasireversible redox couples, which are proposed to correspond to a reduction of Co(II) to Co(I), followed by a ligand-based reduction. Irreversible reductions of 1 are observed at more negative potentials, and are proposed to arise from deposition of elemental Co and the decomposition of transiently formed Co(-I) species. Spectroelectrochemical experiments on both 1 and 2, involving electrolytic reduction followed by ...
Synthesis, Crystal And Electronic Structure Of Layered Amsb Compounds (A = Rb, Cs; M = Zn, Cd), 2020 Iowa State University and Ames Laboratory
Synthesis, Crystal And Electronic Structure Of Layered Amsb Compounds (A = Rb, Cs; M = Zn, Cd), Bryan Owens-Baird, Lin-Lin Wang, Shannon Lee, Kirill Kovnir
Ames Laboratory Accepted Manuscripts
Synthesis, crystal structure, thermal stability, and electronic band structure of four new metal antimonides AMSb (A = Rb, Cs; M = Zn, Cd) are reported. CsZnSb and RbZnSb crystallize in the hexagonal ZrBeSi structure type, in a P63/mmc space group (no. 194, Z = 2) and unit cell dimensions of a = 4.5588(2)/4.5466(4) Å and c = 11.9246(6)/11.0999(10) Å. CsCdSb and RbCdSb crystallize in the tetragonal PbFCl structure type in a P4/nmm space group (no. 129; Z = 2) and unit cell parameters of a = 4.8884(5)/4.8227(3 ...
Reactions Of First-Row Transition Metal Complexes In Bis(Alkoxide) Ligand Environments With Diazoalkanes: Formation Of Carbenes Versus Reductive Coupling To Form Bridging Tetrazenes, 2020 Wayne State University
Reactions Of First-Row Transition Metal Complexes In Bis(Alkoxide) Ligand Environments With Diazoalkanes: Formation Of Carbenes Versus Reductive Coupling To Form Bridging Tetrazenes, Amanda Grass
Wayne State University Dissertations
This dissertation focuses on the design and reactions of novel late transition metal carbene complexes featuring alkoxide ligand environments. The high-valent cobalt carbene Co(OR)2(=CPh2) (OR = OCtBu2Ph), featuring short Co=C bond of 1.773(3) Å, was previously reported from the reaction of Co(OR)2(THF)2 with diphenyldiazoalkane. Magnetic and spectroscopic (EPR) studies demonstrated Co(OR)2(=CPh2) to be a low-spin S = ½ complex. Computational studies, in agreement with experimental data, suggested that the electronic structure of Co(OR)2(=CPh2) lies between intermediate spin Co(III) anti-ferromagnetically coupled to a carbene radical and ...
Investigations Of Graphene-Supported Single-Atom Catalyst Model Ions In The Gas Phase, 2020 Virginia Commonwealth University
Investigations Of Graphene-Supported Single-Atom Catalyst Model Ions In The Gas Phase, Michael Borrome
Theses and Dissertations
Recent developments in heterogeneous catalysis has led to the conception of single-atom catalysts (SACs), a class of catalysts based on isolated metal atoms anchored to a support scaffold. SACs are often much more reactive and can offer better selectivity when compared to nano-scale catalysts. In order to realize the full potential of SACs, a sound understanding of the underlying catalytic mechanisms is required. However, surface analysis tools can become less effective in studying catalytic mechanisms at the atomic scale. Mass spectrometry has proven to be a robust technique for studying organometallic catalytic mechanisms at the single-molecule level. Using mass spectrometry ...
Mechanistic Analysis Of Reductive Boracarboxylation Using Low Valent Copper And Co2, 2020 West Virginia University
Mechanistic Analysis Of Reductive Boracarboxylation Using Low Valent Copper And Co2, Notashia Nicole Baughman
Graduate Theses, Dissertations, and Problem Reports
The synthesis of organoboron compounds is of contemporary importance in the chemistry community given their utility in subsequent functionalization reactions as well as their growing therapeutic potential in the treatment of human disease. This, coupled with the ubiquity of carboxylic acid functional groups in pharmaceuticals and fine chemicals, has led to interest in one-pot difunctionalization reactions using CO2 and a boron source. An (ICy)copper(I)-catalyzed boracarboxylation reaction was recently developed wherein CO2 and a pinacolboryl group is added across the double bond of vinyl arenes was recently developed, providing access to α-aryl-β-boryl propionic acid derivatives. A ...
Greener Synthesis Of Chlorophosphazenes, 2020 The University of Akron
Greener Synthesis Of Chlorophosphazenes, Andrew Mcgee
Williams Honors College, Honors Research Projects
This project will attempt to synthesize chlorophosphazene molecules in the absence of solvents by using mechanochemical techniques in order to create a more environmentally friendly synthesis route. In this pursuit, various parameters will be changed including the milling ball to reagent ratios, the molar ratios of the reactants, and the addition of different catalysts. The products of each reaction will be characterized in order to determine success. This work builds upon existing efforts to utilize mechanochemical techniques in main group chemistry. The output of this project will be a report in ACS style and a poster to be presented for ...
Design Of Pigments For Use In “Cool” Coatings, 2020 The University of Akron
Design Of Pigments For Use In “Cool” Coatings, Tyler Laughorn
Williams Honors College, Honors Research Projects
This project was focused on the development and testing of several novel pigments that exhibit high NIR-reflectance and therefore show potential for use in “cool” coatings. A “cool” coating will reflect more solar radiation than other standard coatings, and so a coated structure would require less energy to keep cool. Four sets of pigments were synthesized: Co1-xMgxCr2O4 (teal), Co0.25Mg0.75Cr2-yAlyO4 (blue), Ti1-x-yNixSbyO2 (yellow), and Cr2-xFexO3 (black). NIR and TSR values were ...
Synthesis Of Supported Metal Nanoparticles On High Surface Area Supports For Application In Energy Conversion And Heterogeneous Catalysis, 2020 Virginia Commonwealth University
Synthesis Of Supported Metal Nanoparticles On High Surface Area Supports For Application In Energy Conversion And Heterogeneous Catalysis, Nazgol Norouzi
Theses and Dissertations
Precise control of metal nanoparticles’ size, composition, and dispersity over high surface area supports are highly desirable to address current challenges in energy storage and conversion as well as catalytic processes involving precious metals. Therefore, developing viable synthetic routes that enable new catalytic systems derived from inexpensive transition metals or limited use of precious metals is vital for clean energy applications such as fuel cells and rechargeable batteries or affordable drugs in the pharmaceuticals arena. In addition to metal components of heterogeneous catalysts, the catalyst support is an integral part of catalyst design as it can impart both physical stability ...
Synthesis And Reactivity Of A New Platinum(Ii) Complex, 2020 Claremont Colleges
Synthesis And Reactivity Of A New Platinum(Ii) Complex, Maria Lew
Scripps Senior Theses
Alkanes are some of the most abundant organic molecules, yet currently there are no efficient ways of directly converting them to more functional molecules. One viable method of direct functionalization is C–H bond activation by transition metal catalysts. The focus of this research has been the synthesis of a new Pt(II) pincer complex to be used in mechanistic investigations of C–H activation, as well as the beginnings of those investigations. The complex [NNON]PtMe was successfully synthesized. Reactions with various acids indicated that [NNON]PtMe is capable of reductively eliminating methane after addition ...
Identification Of Adsorbate Ft-Ir Bands Using In-Situ Techniques: Pd Speciation And Adsorption Chemistry Of Pd-Zeolites For Passive Nox Adsorption, Robert Bruce Pace Iii
Theses and Dissertations--Chemistry
To meet increasingly stringent automotive emissions standards, further improvements in catalytic converter design are necessary. Current automotive catalyst systems are effective at eliminating emission of nitrogen oxides (NOx) once the catalyst reaches operational temperature (~200 °C). NOx emitted at lower catalyst temperatures now comprises most of the NOx released during a typical test cycle. Referred to as “the cold start problem” this issue has come to the forefront of automotive catalyst development, as mitigating these emissions is necessary to further reduce automotive emissions. Passive NOx adsorbers present an appealing solution to the cold start problem, these ...
Biophysical And X-Ray Structural Studies Of The (Gggtt)3ggg G-Quadruplex In Complex With N-Methyl Mesoporphyrin Ix, Linda Yingqi Lin , '20, S. Mccarthy, Barrett M. Powell , '18, Yanti Manurung , '20, Irene M. Xiang , '18, W. L. Dean, B. Chaires, Liliya A. Yatsunyk
Chemistry & Biochemistry Faculty Works
The G-quadruplex (GQ) is a well-studied non-canonical DNA structure formed by G-rich sequences found at telomeres and gene promoters. Biological studies suggest that GQs may play roles in regulating gene expression, DNA replication, and DNA repair. Small molecule ligands were shown to alter GQ structure and stability and thereby serve as novel therapies, particularly against cancer. In this work, we investigate the interaction of a G-rich sequence, 5’-GGGTTGGGTTGGGTTGGG-3’ (T1), with a water-soluble porphyrin, N-methyl mesoporphyrin IX (NMM) via biophysical and X-ray crystallographic studies. UV-vis and fluorescence titrations, as well as a Job plot, revealed a 1:1 binding stoichiometry ...
Hypervalent Iodine Compounds With Carboxylate And Tetrazolate Ligands, 2019 Southern Methodist University
Hypervalent Iodine Compounds With Carboxylate And Tetrazolate Ligands, Avichal Vaish
Chemistry Theses and Dissertations
In modern organic chemistry, hypervalent (HV) iodine(III) compounds are frequently used as oxidizing agents but application of λ3-iodanes in polymer and material chemistry is still underexplored. This dissertation describes the preparation of dynamic and self-healing materials by employing ligand exchange reactions involving HV iodine(III) compounds of the type ArIL2 (Ar = Aryl, L = ligand, e.g., carboxylate or (pseudo)halide). These compounds can undergo ligand exchange reactions in presence of nucleophiles (Nu-) to form ArINu2. Diacetoxyiodo benzene was successfully employed as a crosslinker to prepare dynamic and self-healing gels derived from carboxylate-containing polymers. Furthermore, advantage ...
Greening Of Catalytic Processes Using First-Row Transition Metals For Atom Transfer Radical Addition And Transfer Hydrogenation, Gabrielle Pros
Electronic Theses and Dissertations
This work focused on “greening” catalytic processes, atom transfer radical addition (ATRA), which adds an alkyl halide across and alkene, and transfer hydrogenation/dehydrogenation, which reduces a carbonyl without needing direct H2 gas. Part of “greening” of these processes is through using abundant first row metals, Cu and Ni for catalysis. One aim was to design new ligands which would be more active in these systems; the second was investigation of additives for catalyst regeneration to reduce the catalyst loading necessary for high yields.
The TPMA* family was investigated in ATRA. Rate constants followed the expected trend, which increased ...