Chemistry Commons^™

Short Wavelength Infrared Spectral Characterization Of The Mineralogy Of Gokona And Nyabigena Andesite-Hosted Gold Deposits In North Mara, Tanzania, Emmanuel Kazimoto

Tanzania Journal of Science

The mineralogy of Gokona and Nyabigena gold deposits in Tanzania have been studied using Short Wavelength Infrared (SWIR) Spectrometry technique with an aim to fingerprint hydrothermal system responsible for the formation of the deposits and establish pertinent mineralogical signatures for gold deposition. Gokona and Nyabigena deposits are hosted in porphyritic andesite to basaltic andesite that contains plagioclase phenocrysts, pyroxene, hornblende and Fe-Ti oxides as primary minerals. Other minerals are actinolite, chlorite, epidote, albite and hematite, which indicate metamorphism of the rock under greenschist facies conditions. Hydrothermal alteration of the rock produced chlorite, sericite, carbonates (ankerite, siderite and calcite), pyrite and …

Geochemical Characteristics Of Soil In Relation To Occurrence Of Entomopathogenic Nematodes (Epns) In Osogbo, Osun State, Nigeria, Mohammed Rufai, Abidat Shittu, Monsuru Adeleke

Tanzania Journal of Science

The occurrence and abundance of entomopathogenic nematodes (EPNs) vary across locations, and this has been attributed to many factors including soil physico-chemical properties. This study examined the influence of selected soil chemicals on the occurrence of EPNs under different cultivated lands in Osun state, Southwestern Nigeria. EPNs were isolated from 23.33% of the soil samples in selected sites using decantation and centrifugation method and nematodes observed under standard microscopy were identified based on morphological analysis of infective juveniles (IJs). This study has revealed the presence of nematodes of the families Steinernema and Heterorhabditis in the sampled soils. Soil chemical properties, …

Leaf Traits Can Be Used To Predict Rates Of Litter Decomposition, Marc Rosenfield, Jennifer L. Funk, Jason K. Keller, Catrina Clausen, Kimberlee Cyphers

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Strong relationships exist between litter chemistry traits and rates of litter decomposition. However, leaf traits are more commonly found in online trait databases than litter traits and fewer studies have examined how well leaf traits predict litter decomposition rates. Furthermore, while bulk leaf nitrogen (N) content is known to regulate litter decomposition, few studies have explored the importance of N biochemistry fractions, such as protein and amino acid concentration. Here, we decomposed green leaves and naturally senesced leaf litter of nine species representing a wide range of leaf functional traits. We evaluated the ability of traits associated with leaf and …

Rapid Vertical Flow Assay On Aunp Plasmonic Paper For Sers-Based Point Of Need Diagnostics, Richard Frimpong

Theses and Dissertations

SERS based immunoassays for point-of-care diagnostics is a promising tool to facilitate biomarker detection for early disease diagnosis and control. The technique is based on a sandwiched system in which antigen is first captured by a selective substrate and then labeled by an extrinsic Raman label (ERL). Here, we report on the use of gold nanoparticle modified filter paper as a novel capture membrane in a vertical flow format. This vertical flow configuration affords reproducible flow of sample and label through the capture substrate to overcome diffusion limited kinetics and significantly reduced assay time. The filter paper was selected due …

Poly(Ethylene Oxide) Based Polymer Electrolytes For All-Solid-State Li-S Batteries, Xue Li, Zheng-Liang Gong

Journal of Electrochemistry

In recent years, research on lithium-sulfur (Li-S) batteries has received much attention because the sulfur positive electrode and the lithium metal negative electrode produce a high theoretical specific capacity (lithium metal ~ 3800 mAh·g^-1, sulfur ~ 1675 mAh·g^-1). In addition, sulfur is considered to be the most promising cathode material for secondary lithium batteries, due to its advantages of low price and environmental friendly. However, the practical application of conventional liquid Li-S batteries is still obstructed by several critical issues, such as lithium ploysulfides shuttle effect, long-term stability of lithium metal anode with organic liquid electrolytes, …

Synthesis And Raman Study Of Hollow Core-Shell Ni1.2Co0.8P@N-C As An Anode Material For Sodium-Ion Batteries, Jia-Hui Chen, Xiao-Bin Zhong, Chao He, Xiao-Xiao Wang, Qing-Chi Xu, Jian-Feng Li

Journal of Electrochemistry

With the increasing demand for large-scale energy storage, great progress has been made in discovering new advanced energy storage materials. Sodium-ion batteries (SIBs) have attracted much attention in recent years due to their use of abundant sodium resources and their comparable electrochemical capacity to lithium-ion batteries (LIBs). In this paper, we developed novel hollow core-shell Ni-Co bimetallic phosphide nanocubes with N-doped carbon coatings (Ni_1.2Co_0.8P@N-C) as the anode material for SIBs. The material was synthesized through a low-temperature phosphorization method using resorcinol formaldehyde (RF) resin coating with a Ni-Co Prussian blue analogue (PBA) as a template and …

Preparations Of Nano-MnoX/Ti Electrocatalytic Membrane Electrode For Catalytic Oxidation Of Cyclohexane Using Intermittent Electrodeposition, Xue Zhou, Hong Wang, Zhen Yin, Yu-Jun Zhang, Jian-Xin Li

Journal of Electrochemistry

Cyclohexanone and cyclohexanol (KA oil) obtained from highly selective oxidation of cyclohexane (CHA) show important industrial value and application prospects. In this work, the intermittent electrodeposition was developed to prepare nano-MnO_x catalyst loading porous tubular titanium membrane electrode (MnO_x/Ti), which was employed to constitute an electro-catalytic membrane reactor (ECMR) for the oxidation of cyclohexane to produce cyclohexanol and cyclohexanone. The surface morphology, crystal structure and electrochemical property of the catalysts were characterized by FESEM, XRD and electrochemical workstation, respectively. The results show that the catalyst prepared by the intermittent electrodeposition displayed nano-flower-like γ-MnO₂. Compared with …

Recent Advancement In Pseudo-Random Binary Sequence Signals-Based Fast Reconstruction Of Impedance Spectrum And Its Applications In Electrochemical Energy Sources, Wei-Heng Li, Qiu-An Huang, Wei-Ming Yang, Chang-Ping Yang, Jiu-Jun Zhang

Journal of Electrochemistry

With the extensive application of impedance spectroscopy, the time-consuming issue of its traditional testing methods has become more and more serious, which limits its application range. In the study of accelerating impedance measurement or reconstruction, the synthesis of wideband excitation signals and the design of high efficiency estimation algorithms have been identified as important ways. In view of the purpose of rapid impedance reconstruction, Pseudo-Random Binary Sequence (PRBS) has the advantages of flat power spectrum and easy generation, and has a good application prospect. This paper reviews three core issues in rapid reconstruction of impedance spectrum: PRBS signal types, different …

Preparation Of Α-Hydroxylated Acetal From 2-Butanone By Indirect Electrooxidation, Hai-Qing Huang, Ye Miao, Xin-Sheng Zhang

Journal of Electrochemistry

Acetoin (3-hydroxy-2-butanone) is an important food spice. As a platform compound, it is widely used in medicine, tobacco, cosmetics, chemical material and other industries. In this paper, α-hydroxylated acetal, an intermediate of acetoin, was prepared from 2-butanone by indirect electrooxidation in the plate and frame electrolytic cell, in which graphite plates were used as both an anode and a cathode, while KOH as an electrolyte and KI as a catalyst. Acetoin could be prepared by hydrolysis in acidic aqueous solution from acetoin intermediate. The effects of current density, electrolyte flow rate between the plates, 2-butanone concentration and electrolysis temperature …

Electrochemical Oxidation Of Metal Chromium In Odium Hydroxide Aqueous Solution, Ping Han, Hai-Tao Feng, Ya-Ping Dong, Sen Tian, Bo Zhang, Wu Li

Journal of Electrochemistry

Ferrochrome electrolysis technology is a novel method for preparing sodium chromate (Na₂CrO₄). Although the method performs well at soft reaction conditions, controllable process, environmentally friendly production process, etc., the electrochemical oxidation process of metal chromium in NaOH aqueous electrolyte is still unclear. At present, there are few research articles about specific electrochemical oxidation of metal chromium in NaOH aqueous electrolyte. It is, therefore, meaningful to carry out the research in electrochemical oxidation mechanism of chromium. The electrochemical oxidation of metal chromium in 0.01 mol·L^-1 ~ 10 mol·L^-1 NaOH aqueous electrolytes at 20 °C was …

Electrochemical Response Of A Single Wire-Electrode Ac Probe In 3.5wt.% Nacl, Zhen-Wen Zou, Da-Jiang Zheng, Zi-Ming Wang, Guang-Ling Song

Journal of Electrochemistry

In this paper, a recently developed single wire-electrode AC probe technology which does not need a reference or counter electrode was employed to investigate the electrochemical corrosion and sacrificial anode protection behaviors of steel and zinc in 3.5wt.% NaCl. With this simple, fast, reliable and stable probe, the instantaneous corrosion rate and accumulated corrosion loss of carbon steel in 3.5wt.% NaCl were measured, and the results revealed that both were greater than those of zinc. Furthermore, the observed different corrosion behaviors between carbon steel and zinc during the immersion could be caused by their different surface films. With the galvanic …

Stability Studies For A Membrane Electrode Assembly Type Co2 Electro-Reduction Electrolytic Cell, Qing Mao, Bing-Yu Li, Wei-Yun Jing, Jian Zhao, Song Liu, Yan-Qiang Huang, Zhao-Long Du

Journal of Electrochemistry

Electro-catalytic reduction is an efficient way to achieve resourcable transformation of CO₂, which is one of the important techniques to solve the global environmental problems originated from excessive CO₂ emission. In this study, a membrane electrode assembly(MEA) type CO₂ electro-reduction electrolytic cell was constucted, which enables CO₂ feeding and real-time KHCO₃ aqueous updating on both sides of the cathode gas diffusion electrode (GDE). By means of the electrolytic cell, effects of KHCO₃ concentration and updating inside the liquid electrolytic chamber on CO₂ electro-reduction activity, production distribution and stability were investigated. The experimental …

A Simple And Sensitive Aptamer-Based Electrochmical Sensor For Determination Of Aflatoxin B1, Bing Liu, Yao-Shuai Zhao, Yue Qin, Yi Wang, Yan-Jie Zhu, Shuo Wang

Journal of Electrochemistry

Aflatoxin B1 has attracted much attention because of its high toxicity and carcinogenicity, which has become a great concern in food safety. Based on the principle of specific binding between Aflatoxin B1 and its aptamer, an aptamer-based electrochemical sensor had been designed and developed for the determination of minor Aflatoxin B1 contained in grain. The mesoporous carbons were first modified on the surface of the working electrode, and then the gold nanoparticles were on-site electrodeposited at a constant potential. Each modified electrode was characteritised by scanning electron microscopy (SEM) and electrochemical impedance spectroscopy (EIS). As a result, the surface area …

Degradation Mechanism Of Lini0.83Co0.12Mn0.05O2 Cycled At 45 ℃, Hong-Yun Ma, Xiao-Hui Yao, Meng-Yao Miao, Yang Yi, Shao-Zhong Wu, Jiang Zhou

Journal of Electrochemistry

Nickel-rich layered material has been considered as the most promising one for lithium ion batteries due to its high specific capacity. To further improve the lifetime performance, it is significant to investigate the degradation mechanisms deeply. In this study, the degradation mechanism of NCM811 (LiNi_0.83Co_0.12Mn_0.05O₂) being cycled at 45^oC was systematically researched. Electrochemical impedance spectrum (EIS) results showed that the SEI resistance (R_SEI) and charge transfer resistance (R_ct) went up to 83.41% and 211.34% before and after the NCM811 material being cycled at 45^oC, …

Antimicrobial Strategies For Topical Applications, Kelsey Marie Lopez

LSU Doctoral Dissertations

Bacteria can thrive in diverse environments and are often harmless or beneficial. Bacteria in digestive tracts is one example of beneficial bacteria; however, bacteria can be harmful and when this type proliferates, it can cause infections within hosts. Bacterial infections are easily treated with antibiotics in most cases. However, bacteria are also capable of developing mutations which could cause them to become multi-drug resistant and eventually, “superbugs.” Therefore, the development of novel antimicrobial agents and materials capable of combating drug-resistant bacteria is necessary. Research presented in this dissertation focuses on different strategies for minimizing and preventing topical bacterial infections using …

Adsorption Behavior Of Chemically / Charged Modified Antibodies On Gold Nanoparticles, Samuel Okyem

Theses and Dissertations

Gold nanoparticles (AuNPs) have been exploited in the various domains of science such as drug delivery, bio-sensing, immunoassays and environmental sensors, due to their optical properties and intriguing surface chemistry. Different scientific procedures have been used to effectively immobilize antibodies onto AuNPs. Although acceptable outcomes have been achieved in the immobilization of antibodies onto AuNPs, the sensitivity of these immobilized antibodies to target antigen or binding sites is limited due to improper orientation of the antibodies. Also, the possibility of nanoparticle aggregation when exposed to proteins limits its biomedical applicability.

There is some evidence that the surface charge of antibodies …

The Interaction Of Ternary Components Of Ionic Liquid Gel Polymer Electrolytes For Lithium Metal Batteries, Xiao-Na Pan, Li-Lai Liu, Zhi-Pu Wang, Dan Wang, Yun Li, Pei-Xia Yang, Jin-Qiu Zhang, Mao-Zhong An

Journal of Electrochemistry

Ionically conductive gel polymer electrolyte is an excellent candidate due to its inflammable, nonvolatile and high thermal stability as compared to commercial liquid electrolytes which are usually flammable, volatile, and containing toxic organic solution as solvent, The synthesis and application of ionic gel polymer electrolytes in lithium ion/metal batteries have been previously reported. However, the interaction effects of N-methyl-N-propylpiperidinium bis(trifluoromethanesulfonyl)imide (PP13TFSI) ionic liquid (as plasticizer) and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) on PVDF-HFP polymer remain unclear. In this work, the molecular structure of ionic liquid gel polymer electrolyte (ILGPE) composed of PP13TFSI, LiTFSI and PVDF-HFP was studied by Raman spectroscopy and Fourier-transform …

Ordered Mesoporous Carbon/Graphene/Nickel Foam For Flexible Dopamine Detection With Ultrahigh Sensitivity And Selectivity, Lai-Yu Wang, Xin Xi, Dong-Qing Wu, Xiong-Yu Liu, Wei Ji, Rui-Li Liu

Journal of Electrochemistry

Electro-catalytic reduction is an efficient way to achieve resourcable transformation of CO₂, which is one of the important techniques to solve the global environmental problems originated from excessive CO₂ emission. In this study, a membrane electrode assembly(MEA) type CO₂ electro-reduction electrolytic cell was constucted, which enables CO₂ feeding and real-time KHCO₃ aqueous updating on both sides of the cathode gas diffusion electrode (GDE). By means of the electrolytic cell, effects of KHCO₃ concentration and updating inside the liquid electrolytic chamber on CO₂ electro-reduction activity, production distribution and stability were investigated. The experimental …

Heterometallic Multinuclear Nodes Directing Mof Electronic Behavior, Otega A. Ejegbavwo, Anna A. Berseneva, Corey R. Martin, Gabrielle A. Leith, Shubham Pandey, Amy J. Brandt, Kyoung Chul Park, Abhijai Mathur, Sharfa Farzandh, Vladislav V. Klepov, Brittany J. Heiser, Mvs Chandrashekhar, Stavros G. Karakalos, Mark D. Smith, Simon R. Phillpot, Sophya Garashchuk, Donna A. Chen, Natalia B. Shustova Prof. Dr.

Faculty Publications

Metal node engineering in combination with modularity, topological diversity, and porosity of metal–organic frameworks (MOFs) could advance energy and optoelectronic sectors. In this study, we focus on MOFs with multinuclear heterometallic nodes for establishing metal−property trends, i.e., connecting atomic scale changes with macroscopic material properties by utilization of inductively coupled plasma mass spectrometry, conductivity measurements, X-ray photoelectron and diffuse reflectance spectroscopies, and density functional theory calculations. The results of Bader charge analysis and studies employing the Voronoi–Dirichlet partition of crystal structures are also presented. As an example of frameworks with different nodal arrangements, we have chosen MOFs with mononuclear, …

Investigating The Reversibility Of Protein Adsorption On Gold Nanoparticles And The Role Of Free Thiol, Awosiji Olatunde Awotunde

Theses and Dissertations

Protein-gold nanoparticle (AuNP) bioconjugates have many potential applications in nanomedicine. A thorough understanding of the interaction between the protein and AuNP is critical to engineering these functional bioconjugates with desirable properties. In this work, we investigate the role of free thiols presented by the protein on the stability of the protein-AuNP conjugate. Human serum albumin (HSA) was modified with 2-iminothiolane (Traut’s reagent) to introduce additional thiols on the protein surface, and three variants of HSA were synthesized to present 1, 5, and 20 free thiols by controlling the molar excess of the chemical modifier. Protein exchange studies on AuNPs were …

Structural Basis For The Hydrolytic Dehalogenation Of The Fungicide Chlorothalonil, Daniel S. Catlin, Xinhang Yang, Brian Bennett, Richard C. Holz, Dali Liu

Chemistry: Faculty Publications and Other Works

Cleavage of aromatic carbon–chlorine bonds is critical for the degradation of toxic industrial compounds. Here, we solved the X-ray crystal structure of chlorothalonil dehalogenase (Chd) from Pseudomonas sp. CTN-3, with 15 of its N-terminal residues truncated (ChdT), using single-wavelength anomalous dispersion refined to 1.96 Å resolution. Chd has low sequence identity (<15%) compared with all other proteins whose structures are currently available, and to the best of our knowledge, we present the first structure of a Zn(II)-dependent aromatic dehalogenase that does not require a coenzyme. ChdT forms a “head-to-tail” homodimer, formed between two α-helices from each monomer, with three Zn(II)-binding sites, two of which occupy the active sites, whereas the third anchors a structural site at the homodimer interface. The catalytic Zn(II) ions are solvent-accessible via a large hydrophobic (8.5 × 17.8 Å) opening to bulk solvent and two hydrophilic branched channels. Each active-site Zn(II) ion resides in a distorted trigonal bipyramid geometry with His117, His257, Asp116, Asn216, and a water/hydroxide as ligands. A conserved His residue, His114, is hydrogen-bonded to the Zn(II)-bound water/hydroxide and likely functions as the general acid-base. We examined substrate binding by docking chlorothalonil (2,4,5,6-tetrachloroisophtalonitrile, TPN) into the hydrophobic channel and observed that the most energetically favorable pose includes a TPN orientation that coordinates to the active-site Zn(II) ions via a CN and that maximizes a π–π interaction with Trp227. On the basis of these results, along with previously reported kinetics data, we propose a refined catalytic mechanism for Chd-mediated TPN dehalogenation.

Teaching College Chemistry In The Time Of Covid-19 Pandemic: A Personal Account Of Teaching In The Old Normal Vs. The New Normal, Armando M. Guidote Jr

Chemistry Faculty Publications

The SARS CoV-2 (Severe Acute Respiratory Syndrome CoronaVirus 2), cause of COVID-19 (CoronaVirus Disease 2019) has afflicted close to 10 million people all over the world resulting to almost half a million deaths. This disease is severely contagious and necessitates social or physical distancing between persons. As such, traditional face-to-face learning is not advised and teachers need to shift to online teaching. There are challenges to online teaching and learning for students, teachers, and the higher education institute, e.g. hardware, bandwidth, and software issues. These will be difficult but these can be overcome eventually. This work is a personal account …

Crystal Structures Of Two Isostructural Compounds: A Second Polymorph Of Dipotassium Hydrogen Citrate, K2hc6h5o7, And Potassium Rubidium Hydrogen Citrate, Krbhc6h5o7, Diana Gonzalez '20, Joseph T. Golab, Andrew J. Cigler, James A. Kaduk

Student Publications & Research

No abstract provided.

Conversion Between Triplet Pair States Is Controlled By Molecular Coupling In Pentadithiophene Thin Films, Natalie A. Pace, Brandon K. Rugg, Christopher H. Chang, Obadiah G. Reid, Karl J. Thorley, Sean Parkin, John E. Anthony, Justin C. Johnson

Chemistry Faculty Publications

In singlet fission (SF) the initially formed correlated triplet pair state, ¹(TT), may evolve toward independent triplet excitons or higher spin states of the (TT) species. The latter result is often considered undesirable from a light harvesting perspective but may be attractive for quantum information sciences (QIS) applications, as the final exciton pair can be spin-entangled and magnetically active with relatively long room temperature decoherence times. In this study we use ultrafast transient absorption (TA) and time-resolved electron paramagnetic resonance (TR-EPR) spectroscopy to monitor SF and triplet pair evolution in a series of alkyl silyl-functionalized pentadithiophene (PDT) thin films …

Molecular Docking Study Of Itpa Protein Substrate Complex, Aulane F. Mpouli

2020 McNair Scholar Collection

ITPA is an enzyme that is responsible for maintaining a proper level of nonstandard nucleotides in cells. The enzyme is associated with adverse drug reactions for thiopurine or ribavirin therapy. The prediction of drug interactions sites in ITPA protein is important for modulating ITPA-related drug toxicity. There are a vast number of tools available to predict molecular interactions between receptors and ligands. The methods utilized in this study include computational docking to explore bound conformation and energy in the binding of ITP to ITPA protein. The docking results reveal how well ITPA and ITP bind together in comparison to the …

Fuzzy Synergetic Control Nonlinear Dynamic Objects, Isomiddin Sidikov, Noilakhon Yakubova, Komil Usmanov, Saparbay Kazakhbayev

Karakalpak Scientific Journal

The article deals with the synthesis of effective algorithms for controlling a chemical reactor and developed a fuzzy synergistic controller for a class of indefinite nonlinear dynamic systems. A synergetic control scheme is proposed for solving the control problem for nonlinear systems. Non-linear systems with configurations and parameters that change over time require a completely non-linear model and adaptive control scheme for a practical operating environment. The synthesis of control laws is performed by the method of analytical design of aggregated controllers (ACAR). Fuzzy logic systems are used to evaluate the unknown nonlinear behavior of the system, and a new …

Synergistic Effect Of Pad “Macroporous-Reactors” On Passivation Mechanisms To Modulate Cu Chemical Mechanical Planarization (Cmp) Performance, Katherine M. Wortman-Otto, Carolyn F. Graverson, Abigail N. Linhart, Rose K. Mcdonough, Amy L. Mlynarski, Jason J. Keleher

Chemistry Department Faculty Articles

Decoupling the key interfacial mechanisms (chemical and mechanical) present during Cu CMP is critical to the development of slurry/pad consumable sets to reduce defectivity at advanced technology nodes. Understanding the Prestonian relationship, or lack thereof, can give rise to correlations between film density as a result of passivation film kinetics and thermodynamics as they relate to Cu oxidation/electrochemistry under dynamic conditions. The efficiency of film removability is strongly correlated to the molecular structure of the passivating agent and its synergistic relationship with the macroporous-reactor sites presented in this work. Results indicate that passivation film activation energy (Ea) is altered by …

Characterizing College Science Instruction: The Three-Dimensional Learning Observation Protocol, Kinsley Bain, Lydia Bender, Paul Bergeron, Marcos D. Caballero, Justin H. Carmel, Erin M. Duffy, Diane Ebert-May, Cori L. Fata-Hartley, Deborah Herrington, James T. Laverty, Rebecca L. Matz, Paul C. Nelson, Lynmarie A. Posey, Jon R. Stoltzfus, Ryan L. Stowe, Ryan D. Sweeder, Stuart H. Tessmer, Sonia M. Underwood, Mark Urban-Lurain, Melanie M. Cooper

Peer Reviewed Articles

The importance of improving STEM education is of perennial interest, and to this end, the education community needs ways to characterize transformation efforts. Three-dimensional learning (3DL) is one such approach to transformation, in which core ideas of the discipline, scientific practices, and crosscutting concepts are combined to support student development of disciplinary expertise. We have previously reported on an approach to the characterization of assessments, the Three-Dimensional Learning Assessment Protocol (3D-LAP), that can be used to identify whether assessments have the potential to engage students in 3DL. Here we present the development of a companion, the Three-Dimensional Learning Observation Protocol …

Assembling Polyiodides And Iodobismuthates Using A Template Effect Of A Cyclic Diammonium Cation And Formation Of A Low-Gap Hybrid Iodobismuthate With High Thermal Stability, Evgeny V. Dikarev, Zheng Wei, Tatiana A. Shestimerova, Andrei V. Mironov, Mikhail A. Bykov, Anastasia V. Grigorieva, Andrei V. Shevelkov

Chemistry Department Faculty Scholarship

Exploiting a template effect of 1,4-diazacycloheptane (also known as homopiperazine, Hpipe), four new hybrid iodides, (HpipeH₂)₂Bi₂I₁₀·2H₂O, (HpipeH₂)I(I₃), (HpipeH₂)₃I₆·H₂O, and (HpipeH₂)₃(H₃O)I₇, were prepared and their crystal structures were solved using single crystal X-ray diffraction data. All four solid-state crystal structures feature the HpipeH₂²⁺ cation alternating with Bi₂I₁₀^4–, I₃^–, or I^– anions and solvent water or H₃O⁺ cation. …

Oxadiazinones As Chiral Auxiliaries: Chiral Templates For Asymmetric Conjugate Addition In The Synthesis Of ( R )-( + )-Tolterodine, Fatima Olayemi Obe

Theses and Dissertations

The stereoselective formation of carbon-carbon bonds through the process of conjugate addition has proven to be a very important methodology in synthetic organic chemistry. In this context, oxadiazinones are chiral auxiliaries that have been applied in the asymmetric aldol addition reaction to synthesize valuable synthetic fragments such as the aldol side chain of the multi-drug resistance medicinal agent, hapalosin. This thesis describes efforts that were directed towards employing oxadiazinones as chiral scaffolds for the process of asymmetric conjugate addition with the ultimate objective of using this methodology in the preparation of medicinal agents such as Tolterodine. Preliminary efforts focused on …