Chemistry Commons^™

Pyrene Pyrimidine Derivatives: Synthesis, Characterization And Applications, John Kihara Mathaga

LSU Master's Theses

In this thesis, development of new materials to the field of optoelectronics were studied. Optoelectronic devices based on organic semiconductors in order to replace their inorganic counterparts have been an increasing focus of research in recent decades. Organic light-emitting diodes (OLEDs) have gained commercial acceptance for their potential use in high-resolution displays and solid-state lighting. This general acceptance is despite the fact that organic electronic concepts (solar cells, transistors and detectors) are still in an early stage of development. OLEDs materials intrinsic advantages, like low power consumption as compared to LED counterparts, a tunable color range, ease of manufacturing, and …

Cellulose-Based Doped Carbon Materials For Removal Of Nitrophenols From Water, Ambar Bahadur Rangu Magar

Theses and Dissertations

Nitrophenols (NPs) and their derivatives are highly toxic, mutagenic, and bio-refractory pollutants commonly present in natural water resources and industrial wastewater. Various types of materials and methods have been practiced removing the NPs from polluted water. In this research, we are focusing on synthesizing of inexpensive doped carbon-based materials using renewable and biodegradable polymers such as microcrystalline cellulose and nanocrystalline cellulose. Current work has been undertaken to develop doped carbon-based materials using a low-cost and straightforward method and characterized using different analytical techniques. The synthesized materials were used for the sustainable and efficient removal of NPs from an aqueous environment …

Sufex Activation With Ca(Ntf2)2: A Unified Strategy To Access Sulfamides, Sulfamates, And Sulfonamides From S(Vi) Fluorides, Nicholas Ball, Subham Mahapatra, Cristian P. Woroch, Todd W. Butler, Sabrina N. Carneiro, Sabrina C. Kwan, Samuel R. Khasnavis, Junha Gu, Jason K. Dutra, Beth C. Vetelino, Justin Bellenger, Christopher W. Am Ende

Pomona Faculty Publications and Research

A method to activate sulfamoyl fluorides, fluorosulfates, and sulfonyl fluorides with calcium triflimide and DABCO for SuFEx with amines is described. The reaction was applied to a diverse set of sulfamides, sulfamates, and sulfonamides at room temperature under mild conditions. Additionally, we highlight this transformation to parallel medicinal chemistry to generate a broad array of nitrogen-based S(VI) compounds.

Challenges In Quantifying Air‐Water Carbon Dioxide Flux Using Estuarine Water Quality Data: Case Study For Chesapeake Bay, Maria Herrmann, Raymond G. Najjar, Fei Da, Jaclyn R. Friedman, Marjorie A. M. Friedrichs, Sreece Goldberger, Alana Menendez, Elizabeth H. Shadwick, Edward G. Stets, Pierre St-Laurent

Publications and Research

Estuaries play an uncertain but potentially important role in the global carbon cycle via CO₂ outgassing. The uncertainty mainly stems from the paucity of studies that document the full spatial and temporal variability of estuarine surface water partial pressure of carbon dioxide ( pCO₂). Here, we explore the potential of utilizing the abundance of pH data from historical water quality monitoring programs to fill the data void via a case study of the mainstem Chesapeake Bay (eastern United States). We calculate pCO₂ and the air-water CO₂ flux at monthly resolution from 1998 to …

Site-Selective, Catalytic, And Diastereoselective Sp3 C–H Hydroxylation And Alkoxylation Of Vicinally Functionalized Lactams, Timothy K. Beng, Victoria Shearer, Rachel Davey, Ivianne Redman

All Faculty Scholarship for the College of the Sciences

The C–H bond functionalization of sp³ carbon centres presents a significant challenge due to the inert nature of hydrocarbons as well as the need to selectively functionalize one of the numerous aliphatic C–H bonds embodied in organic molecules. Here, we describe catalytic, diastereoselective, and site-selective sp³ C–H hydroxylation/alkoxylation protocols featuring dihydroisoquinolones, γ-, and δ-lactams, which bear vicinal stereocenters. The hydroxylation strategy utilizes oxygen, a waste-free oxidant and affords attractive fragments for potential drug discovery. Fe-catalyzed dehydrative coupling of the resulting tertiary alcohols with simple primary alcohols has led to the construction of highly versatile unsymmetrical dialkyl ethers.

Synthesis Of The Natural Alkaloids Angustureine, Cuspareine, Galipeine, Galipinine Using Α-Aminocycloalkyl Copper Reagents, Zane Bertoli

Master of Science in Chemical Sciences Theses

Tetrahydroquinolines (THQs) are a group of N-heterocyclic molecules derived from natural sources. They show a wide range of interesting biological activity and have been the basis for a variety of different medications including antibacterial and antiparasitic drugs. The Hancock alkaloids, Galipinine, Galipeine, Cuspareine and Angustureine, are natural 1,2,3,4- tetrahydroquinoline compounds that are found in the South American Angostura tree. Extracts containing these alkaloids have been used to treat fever, dysentery and other ailments. Interestingly, These compounds have shows in vitro antimalarial activity. However, it does not appear in the literature that they have been evaluated for their potential antibiotic activity. …

Pyridyl Co2Fixation Enabled By A Secondary Hydrogen Bonding Coordination Sphere, Jacqueline N. Gayton, Qing Li, Lakeeta Sanders, Roberta R. Rodrigues, Glake Hill, Jared H. Delcamp

Faculty and Student Publications

Copyright © 2020 American Chemical Society. Reversible CO2 binders under ambient conditions are of significant interest for multiple applications in sensing and capture technologies. In this paper, a general systematic way to evaluate CO2 receptors with π-systems is put forward. A series of receptors (five pyridine-based and one triazine-based) are evaluated as CO2 binders in terms of number of hydrogen bonding sites, strength of hydrogen bond donors, and number of nucleophilic sites. The binding of CO2 to the receptors was probed by computational models, absorption spectroscopy, fluorescence spectroscopy, cyclic voltammetry, and 1H NMR studies. Multiple solvents with varying ionic strength …

Post-Treatment Of Synthetic Polyphenolic 1,3,4 Oxadiazole Compound A3, Attenuated Ischemic Stroke-Induced Neuroinflammation And Neurodegeneration, Arooj Mohsin Alvi, Lina Tariq Al Kury, Muhammad Umar Ijaz, Fawad Ali Shah, Muhammad Tariq Khan, Ahmed Sadiq Sheikh, Humaira Nadeem, Arif Ullah Khan, Alam Zeb, Shupeng Li

All Works

Ischemic stroke is categorized by either permanent or transient blood flow obstruction, impeding the distribution of oxygen and essential nutrients to the brain. In this study, we examined the neuroprotective effects of compound A3, a synthetic polyphenolic drug product, against ischemic brain injury by employing an animal model of permanent middle cerebral artery occlusion (p-MCAO). Ischemic stroke induced significant elevation in the levels of reactive oxygen species and, ultimately, provoked inflammatory cascade. Here, we demonstrated that A3 upregulated the endogenous antioxidant enzymes, such as glutathione s-transferase (GST), glutathione (GSH), and reversed the ischemic-stroke-induced nitric oxide (NO) and lipid peroxidation (LPO) …

Strong Temporal Variability In Methane Fluxes From Natural Gas Well Pad Soils, Seth N. Lyman, Huy N. Q. Tran, Marc L. Mansfield, Ric Bowers, Ann Smith

Bingham Research Center

We measured methane and carbon dioxide fluxes at natural gas well pad soils and undisturbed soils in the Rocky Mountain and Gulf Coast regions of the United States, including producing and gas storage wells. We collected both short-term (15 min) and multi-day (between 3 and 8), continuous measurements at 47 well pads and two undisturbed locations. Methane fluxes varied by more than an order of magnitude over periods as short as 30 min (e.g., 19–593 mg m⁻² h⁻¹ in one instance), and diurnal and seasonal variability was also significant (e.g., spring-to-fall change from 509 to 14174 mg m …

Thermotropic Liquid-Crystalline And Light-Emitting Properties Of Bis(4-Aalkoxyphenyl) Viologen Bis(Triflimide) Salts, Pradip K. Bhowmik, Muhammed Kareem M. Al-Karawi, Shane T. Killarney, Erenz J. Dizon, Anthony Chang, Jongin Kim, Si L. Chen, Ronald Carlo G. Principe, Andy Ho, Haesook Han

Chemistry and Biochemistry Faculty Research

A series of bis(4-alkoxyphenyl) viologen bis(triflimide) salts with alkoxy chains of different lengths were synthesized by the metathesis reaction of respective bis(4-alkoxyphenyl) viologen dichloride salts, which were in turn prepared from the reaction of Zincke salt with the corresponding 4-n-alkoxyanilines, with lithium triflimide in methanol. Their chemical structures were characterized by 1H and 13C nuclear magnetic resonance spectra and elemental analysis. Their thermotropic liquid-crystalline (LC) properties were examined by differential scanning calorimetry, polarizing optical microscopy, and variable temperature X-ray diffraction. Salts with short length alkoxy chains had crystal-to-liquid transitions. Salts of intermediate length alkoxy chains showed both crystal-to-smectic A (SmA) …

Synthesis And Evaluation Of Novel Biologically Active Compounds, Madhurima Das

LSU New Orleans Theses and Dissertations

SCP-1, a potent derivative of acetaminophen, exhibits significantly diminished hepatotoxicity and nephrotoxicity relative to acetaminophen and nitrate ester derivatives of acetaminophen. It was therefore of interest to explore the development of nitric oxide donor analogs of SCP-1 to identify compounds that could have enhanced analgesic and/or antipyretic activity while taking advantage of the very low liver and kidney toxicity inherent to SCP-1. In this project, a series of nitrate ester analogues of the SCP-1 were prepared as potential nitric oxide donors. The synthesis of SCP analogs was achieved by triflic acid catalyzed O-acylation of SCP-1 with chloroalkanoyl chlorides followed by …

Electron Ratchets: State Of The Field And Future Challenges, Bryan Lau, Ofer Kedem

Chemistry Faculty Research and Publications

Electron ratchets are non-equilibrium electronic devices that break inversion symmetry to produce currents from non-directional and random perturbations, without an applied net bias. They are characterized by strong parameter dependence, where small changes in operating conditions lead to large changes in the magnitude and even direction of the resulting current. This high sensitivity makes electron ratchets attractive research subjects, but leads to formidable challenges in their deeper study, and particularly to their useful application. This perspective reviews the progress that was made in the field starting from the first experimental electron ratchets in the late 1990s, and how the field …

Influence Of Adjuvants On Pesticide Soil-Air Partition Coefficients: Laboratory Measurements And Predicted Effects On Volatilization, Supta Das, Kimberly J. Hageman

Chemistry and Biochemistry Faculty Publications

A solid-phase fugacity meter was used to measure the soil–air partition coefficients of three semivolatile pesticides (chlorpyrifos, pyrimethanil, and trifluralin) in the absence of additional adjuvants (K_{soil–air,AI}), as part of commercial formulations (K_{soil–air,formulation}), and as formulation mixtures with an additional spray adjuvant added (K_{soil–air,formulation+spray adjuvant}). Chlorpyrifos K_{soil–air,formulation} values were also measured over 15–30 °C, allowing for the change in internal energy of the phase transfer reaction (Δ_soil–airU) to be calculated and compared to the Δ_soil–airU for K_{soil–air,AI} from the literature. Measured K_soil–air values …

Effect Of Different Phosphate Glass Compositions On The Process-Induced Macromolecular Dynamic Of Polyamide 66, Imane Belyami, Mohammad K. Hassan

Faculty Publications

The present study provides a fundamental understanding of the mechanism of action of special new phosphate glass (P-glass) systems, having different glass transition temperatures (T_g), in polyamide 66 (PA66). Dynamic mechanical analysis (DMA) revealed that the T_g of PA66/low T_g P-glass (ILT-1) was significantly shifted to a lower T_g (65 °C), and another transition appeared at high temperature (166 °C). This was supported by a drop in the melting point and the crystallinity of the PA66/ILT-1 hybrid material as detected by differential scanning calorimetry (DSC). The dielectric spectroscopic investigation on the networks’ molecular level structural …

Heavy Metals In Particulate Matter In Spokane County, Delaney M. White

2020 Symposium Posters

Heavy metals in particulate matter (e.g., dust) have multiple negative health ramifications for humans including cancer, infertility, and reduced lung function. The Spokane Regional Clean Air Agency (SRCAA) has seven air quality monitoring stations around Spokane County to measure total levels of PM2.5 (particles with a diameter less than 2.5 micrometers) and PM10 (particles with a diameter less than 10 micrometers). For comparison, the width of a human hair is between 50 and 70 micrometers. The objective of this research is to examine the heavy metal composition of the particulate matter including elements such as lead, copper, and zinc. We …

Synthesis, Characterization, And Investigation Of Metal Ion Quenching In Fluorescent Carbon Dot Surrogates For Particulate Matter Black Carbon And Evaluation Of Cellular Health Effects Due To The Surrogate Materials, Christopher Lee Sumner Jr

LSU Doctoral Dissertations

Black carbon (BC) is an environmental pollutant of particular concern to many international organizations for both its health effects and environmental effects. Probing health effects of BC as produced in the environment is difficult due to the complex nature of environmental pollutants found in their naturally occurring state. Fluorescent carbon dots (FCDs) were chosen to be used as a surrogate for BC. In the process of examining FCDs and their behavior as surrogates, information was gained on the health effects and behavior of FCDs as a class of nanomaterials for cell and tissue studies, which is outlined in this dissertation. …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

Designing Peptides To Bind Kappa B Dna And Mimic Nf-Kappa B Protein Complexes, Nicholas A. Markowich

Honors College Theses

Transcription factors are important proteins that regulate gene expression and protein synthesis. Transcription factors can either boost the gene’s transcription rate by helping RNA polymerase activate transcription or restrict it by interfering with RNA polymerase, thereby repressing transcription. Nuclear factor-kappa-B (NF-κB) transcription factors are a family of proteins that control the synthesis of proteins involved in many cellular processes such as inflammatory and immune responses, cell growth, and apoptosis. However, the overexpression and activation of these transcription factors is linked to deadly conditions such as cancer and neurodegenerative diseases which currently have few safe cures. The goal of this research …

N3-Ligated Nickel(Ii) Diketonate Complexes: Synthesis, Characterization And Evaluation Of O2 Reactivity, Josiah G. D. Elsberg, Austin Peterson, Amy L. Fuller, Lisa M. Berreau

Chemistry and Biochemistry Faculty Publications

Interest in O₂-dependent aliphatic carbon–carbon (C–C) bond cleavage reactions of first row divalent metal diketonate complexes stems from the desire to further understand the reaction pathways of enzymes such as DKE1 and to extract information to develop applications in organic synthesis. A recent report of O₂-dependent aliphatic C–C bond cleavage at ambient temperature in Ni(II) diketonate complexes supported by a tridentate nitrogen donor ligand [(MBBP)Ni(PhC(O)CHC(O)Ph)]Cl (7-Cl; MBBP = 2,6-bis(1-methylbenzimidazol-2-yl)pyridine) in the presence of NEt₃ spurred our interest in further examining the chemistry of such complexes. A series of new TERPY-ligated Ni(II) diketonate complexes of the …

Karena Mckinney: Mapping A Clearer Picture Of Air Pollution's Effects, Christina Nunez

Colby Magazine

"If we want to control air quality and address climate change, the solution won't involve fiddling with nature's emissions-it will be about cleaning up man-made ones." -Karena McKinney, associate professor of atmospheric chemistry

I. Non-Degradable Polysiloxane Networks For Controlled Release Applications, And Ii. Additive Free, Degradable Silyl-Ether Furyl-Maleimide Networks, Caleb M. Bunton

Chemistry Theses and Dissertations

I. Two different series of non–degradable polysiloxane networks were prepared for the encapsulation and controlled release of a small molecule agent. For the first series, hydrosilylation was utilized to prepare networks of varying crosslink densities, as determined from swelling studies, from vinyl terminated and silylhydride functional poly(dimethyl)siloxanes. For the second series, the thiol-ene reaction was utilized to prepare networks of varying crosslink densities, as determined from swelling studies, from vinyl terminated and mercaptopropyl functional poly(dimethyl)siloxanes. Nile red dye was used as an encapsulated agent and dye release from each series of networks was measured using UV–vis spectroscopy to determine controllability …

Effect Of Post-Consumer Content And Bioplastic Incorporation On Polymeric Resin In Consumer Applications, Shelby Bicknell

Electronic Theses & Dissertations

Controversy surrounds the use of plastic products, primarily due to their potentially negative impact on the environment at the end of their lifecycle. The most widely used plastics are manufactured from petrochemicals such as petroleum, coal or natural gas. Petrochemical plastics are not able to readily breakdown in the environment, which aggravates the existing pollution problems. Fortunately, there are eco-friendly alternatives to petrochemical-based plastics. Bioplastics may be derived from renewable sources, biodegradable, or both. Bio-based plastics are plastics that may be derived from renewable biomass sources including, but not limited to, vegetable oils, cornstarch, straw, woodchips, and food waste. They …

Facile Surface Exchange On 2d Cadmium Selenide Quantum Belts, Yuewei Yao

Arts & Sciences Graduate Student Theses and Dissertations

This dissertation presents various surface-ligand exchange reactions on cadmium selenide quantum belts (QBs), specifically between L-type, Z-type and bound-ion-pair AX salt type ligation. The surface ligation of nanocrystals determines their optical and transport properties, and thus purposeful control of nanocrystal surface chemistry is under active investigation. Colloidal 2D II-VI (specifically CdSe) QBs provide an ideal system for the study of rapid, complete, and reversible surface exchange at room temperature. Interchange of different types of ligands is observed. The surface exchanges are characterized by a variety of means, and the absorption and emission spectra of the QBs are extremely sensitive to …

Elucidation Of Radical Cation Trapping Chemistry: Using Electrochemical And Photochemical Techniques To Qualitatively Assess The Kinetics Behind Anodic Oxidative Cyclizations, Luisalberto Gonzalez

Arts & Sciences Graduate Student Theses and Dissertations

While the field of organic chemistry has grown throughout the decades, its primary concern has always been on the generation, conversion, and study of molecular structures. Within that philosophy, the development of new reactions affords chemists the ability to overcome previous synthetic barriers or develop more elegant and simple synthetic routes to difficult-to-construct molecules. Within that realm, electrochemistry is seeing increased attention due its ability to generate highly reactive intermediates, recycle chemical reagents, and reverse the polarity of known functional groups. One example of such an application is the use of electrochemistry to form radical cations. While radical cations have …

Spectroscopic Investigations Of Excited Charge Carriers In Ii-Vi Nanoparticles, William Matthew Sanderson

Arts & Sciences Graduate Student Theses and Dissertations

The large absorption cross sections and the tunability of the energetic spacings between the states in the conduction (CB) and valence band (VB) within a semiconductor nanoparticle (NP) make them promising media for capturing electromagnetic radiation and converting it into charge carriers, or electricity. In photovoltaic devices that incorporate semiconductor NPs, it would be ideal if every photon could be absorbed by a NP and the carriers could be collected with perfect efficiency and without loss of energy. The relaxation pathways of the carriers within the NPs down to the band edge and their fate at the band edge contribute …

Influence Of The Spatial Distribution Of Cationic Functional Groups At Nanoparticle Surfaces On Bacterial Viability And Membrane Interactions, Yongqian Zhang, Natalie V. Hudson-Smith, Seth D. Frand, Meghan S. Cahill, Larissa S. Davis, Vivian Feng, Christy L. Haynes, Robert J. Hamers

Faculty Authored Articles

While positively charged nanomaterials induce cytotoxicity in many organisms, much less is known about how the spatial distribution and presentation of molecular surface charge impact nanoparticle–biological interactions. We systematically functionalized diamond nanoparticle surfaces with five different cationic surface molecules having different molecular structures and conformations, including four small ligands and one polymer, and we then probed the molecular-level interaction between these nanoparticles and bacterial cells. Shewanella oneidensis MR-1 was used as a model bacterial cell system to investigate how the molecular length and conformation of cationic surface charges influence their interactions with the Gram-negative bacterial membranes. Nuclear magnetic resonance (NMR) …

Photofading Of Black Dyes In Cotton And Polyester Fibers Resulting From Environmental Exposure To Sunlight, Maggie E. Mahaney

Honors Theses

Color is one of the most important properties analyzed during forensic fiber examinations due to its discriminatory power. Differing colors in fibers are usually sufficient grounds for exclusion, but in cases where a lengthy period has passed between crime commission and evidence recovery, the high probability of environmental degradation having altered the questioned fibers’ properties could lead to false exclusions. Photofading, the loss of color resulting from exposure to light, is a common form of degradation observed in fibers. Although well-known in the dyeing industry, it is not typically factored into forensic fiber examinations. Published photofading research has been limited …

Fabrication Of Polymer Monoliths Within The Confines Of Non-Transparent 3d-Printed Polymer Housings, Noor Abdulhussain, Suhas H. Nawada, Sinéad Currivan, Marta Passamonti, Peter J. Schoenmakers

Articles

In the last decade, 3D-printing has emerged as a promising enabling technology in the field of analytical chemistry. Fused-deposition modelling (FDM) is a popular, low-cost and widely accessible technique. In this study, RPLC separations are achieved by in-situ fabrication of porous polymer monoliths, directly within the 3D-printed channels. Thermal polymerization was employed for the fabrication of monolithic columns in optically non-transparent column housings, 3D-printed using two different polypropylene materials. Both acrylate-based and polystyrene-based monoliths were created. Two approaches were used for monolith fabrication, viz. (i) in standard polypropylene (PP) a two-step process was developed, with a radical initiated wall-modification step …

Massive Peatland Carbon Banks Vulnerable To Rising Temperatures, A. M. Hopple, R. M. Wilson, M. Kolton, Cassandra A. Zalman, J. P. Chanton, J. Kostka, P. J. Hanson, Jason K. Keller, S. D. Bridgham

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Peatlands contain one-third of the world’s soil carbon (C). If destabilized, decomposition of this vast C bank could accelerate climate warming; however, the likelihood of this outcome remains unknown. Here, we examine peatland C stability through five years of whole-ecosystem warming and two years of elevated atmospheric carbon dioxide concentrations (eCO₂). Warming exponentially increased methane (CH₄) emissions and enhanced CH₄ production rates throughout the entire soil profile; although surface CH₄ production rates remain much greater than those at depth. Additionally, older deeper C sources played a larger role in decomposition following prolonged warming. Most …

Optimized Xanthene-Based Probes For Pancreatic Cancer Imaging, Ian Ruramai Munhenzva

Dissertations and Theses

Pancreatic Ductal Adenocarcinoma (PDAC) is one of the deadliest human malignancies with an extremely poor 5-year survival rate of below 5%. Surgical resection is the most effective treatment of choice because chemotherapy and radiation therapy do not improve life expectancy. Residual tumor after PDAC surgery is common due to a lack of PDAC targeted intraoperative contrast agents to confirm clear margins.

Fluorescence imaging has the potential to improve surgery outcome and PDAC patients' survival rate via the use of highly PDAC-specific molecular probes to facilitate tumor identification. This thesis describes the application of a focused library of benzoxanthene fluorophores for …