Chemistry Commons^™

Synthesis, Characterization, Electronic Structure Of Reduced Graphene Oxide And Nh₂-Mil-125(Ti) Modified Binbo₄ And Their Photocatalytic Activities, Maram Yahya Bakiro

Chemistry Theses

The present thesis focuses on the design and synthesis of novel visible light photocatalysts for CO₂ utilization. In recent years, Bi-based materials have shown remarkable photocatalytic activity in the field of CO₂ reduction. Particularly, BiNbO₄ has many promising applications as a visible light-harvesting material due to its bandgap position and orbital hybridization. In this study, an intensive effort has been made to study the effect of different reaction parameters such as temperature and pH of the different synthetic methodologies applied. The new photocatalytic materials have been characterized using different characterization techniques including PXRD, BET, SEM, EDX, and UV-Vis DRS. Since …

Synthesis, Characterization, Electronic Structure Of Reduced Graphene Oxide Modified Fenbo₄, Nh₂-Mil-125(Ti) Modified Fenbo₄ Composities And Their Photocatalytic Activities, Salwa Abdelrahim Hussein

Chemistry Theses

The production of value-added products through CO₂ utilization using photocatalysis offers an alternative green route for CO₂ fixation. Wide bandgap photocatalysts allow the absorption of light in the UV region, which represents the lowest percentage of the sunlight irradiation. On the other hand, narrow bandgap photocatalysts absorb light in the visible region, though the recombination rate of the generated electron-hole pairs affects their activity. In this thesis, the narrow bandgap FeNbO₄ is synthesized, studied and efforts are made to reduce the recombination rate and enhancing the photocatalytic activity.

Moreover, three FeNbO₄/NH₂-MIL-125(Ti) composites with different mole ratios are prepared, characterized and …

Synthesis And Characterization Of Novel Derivatives Of 1, 3, 4- 0xadiazole And Isoniazid, Ranem Mohammad Kaddoura

Chemistry Theses

This thesis describes the synthesis of novel derivatives of isoniazid and 1, 3, 4- oxadiazole piperazines and biological activities evaluation. The synthesis of the isoniazid derivatives (36a-Ɩ) was achieved by nucleophilic substitution of chloroacetylated isoniazid 34 with substituted piperazines (35a-Ɩ) produced isoniazidpiperazines (36a-Ɩ). On the other hand, cyclodehydration of chloroacetylated isoniazid 34 with POCl₃ give the corresponding 1, 3, 4-oxadiazole 37 which upon treatment with substituted piperazines (35a-m) gave 1, 3, 4-oxadiazole-piperazines (38a-m). All newly synthesized compounds were purified and characterized using spectroscopic techniques including ¹H-NMR, ¹³C-NMR, IR spectrometry and mass spectrometry.

The biological activity of the …

Fundamental Studies Of Bimetallic Model Surfaces And Metal Organic Framework Thin Films, Fathima Sharfa Farzandh

Theses and Dissertations

This work is mainly focused on gaining a fundamental understanding of conventional bimetallic catalysts in order to correlate their macroscopic properties with the observed kinetic properties. This is achieved by synthesizing and studying fundamental model surface analogues of conventional catalysts that are difficult to study due to their complex, ill-defined nature. A wide array of surface science techniques that use ultra-high vacuum (UHV) conditions are readily available for detailed studies that can be conducted on model surfaces. This work focuses on the synthesis and investigation of two fundamental bimetallic catalysts formed via the addition of a second metal to an …

Fundamental Studies Of Bimetallic Model Surfaces And Metal Organic Framework Thin Films, Fathima Sharfa Farzandh

Theses and Dissertations

This work is mainly focused on gaining a fundamental understanding of conventional bimetallic catalysts in order to correlate their macroscopic properties with the observed kinetic properties. This is achieved by synthesizing and studying fundamental model surface analogues of conventional catalysts that are difficult to study due to their complex, ill-defined nature. A wide array of surface science techniques that use ultra-high vacuum (UHV) conditions are readily available for detailed studies that can be conducted on model surfaces. This work focuses on the synthesis and investigation of two fundamental bimetallic catalysts formed via the addition of a second metal to an …

Chemistry Of A Biscarborane Dithiol And Its Nickel (Ii) Complex, Tyler Hemingway

Theses and Dissertations

Neutral biscarborane dithiol and its anionic dithiolate form were successfully synthesized and structurally characterized. The C–C intracluster bond lengths were found to be responsive to the electron density on the cluster. Introduction of two thiol groups on biscarborane led to the significant increase of intracluster C–C bond lengths compared to those of unsubstituted biscarborane. Furthermore, the anionic dithiolate form had even longer C–C cluster bonds. This comparison shows electronic effect of substituents attached to carbon atoms of biscarborane on the strength of its C–C bonds. Additionally, a novel Ni complex was obtained using this dithiolate as a ligand. This complex …

Tailored Multifunctional Heterometallic Metal-Organic Frameworks, Otega Anthonia Ejegbavwo

Theses and Dissertations

Metal-organic frameworks (MOFs), which are well-defined and porous extended structures consisting of organic linkers connected to inorganic secondary building units, are a class of materials that have received tremendous attention over the last decade. This geometrically growing interest in MOFs is attributed to their properties of porosity, tunability, modularity, crystallinity, flexibility, and long-term stability, which makes them attractive candidates for various applications. This dissertation focuses on two major studies, the first part encompasses the strategic design, preparation, and extensive studies of actinide containing MOFs (An-MOFs). This work, presented within the first two chapters, demonstrates the effective utilization of MOF modularity …

Gel Permeation Chromatography Purification And Surface Chemistry Of Technologically Relevant Colloidal Quantum Dots, Adam Roberge

Theses and Dissertations

Semiconductor quantum dots have received extensive research interest due to the size tunable band gap, large extinction coefficient, and ease of synthesis. These nanocrystals possess large surface to volume ratios and the chemistry at the surface of the nanocrystal greatly influences the resultant optoelectronic properties. Therefore, after synthesis, purification of the quantum dot samples to remove synthetic by-products that may alter these properties is of great importance. Gel permeation chromatography (GPC), a form of size exclusion chromatography, has been shown to reproducibly purify CdSe quantum dots. This work focuses on the expansion of purification by gel permeation chromatography to other …

Hybrid Metal/Covalent Organic Frameworks For Solar Fuel Conversion, Sizhuo Yang

Dissertations (1934 -)

Due to the harsh environment issues such as air pollution and global warming and global energy crisis raised by using fossil fuels, it is urgent to find an alternative sustainable energy source. How to utilize solar energy-the most clean and abundant energy source on earth is challenging. Convert solar energy to clean fuel energy like H2 or hydrocarbons is ideal energy conversion strategy. Thus, design new materials for hydrogen generation or CO2 reduction have attract researcher’s attention.The present study focuses on two types of materials of interest, the first of which is Metal Organic Frameworks (MOFs), including enhancing the …

Theoretical And Experimental Investigation Of Non-Covalent Interactions In S-Nitrosothiols And Thio-Carboxylic Acids, Niloufar Hendinejad

Dissertations (1934 -)

S-Nitrosothiols (RSNOs) are ubiquitous biomolecules whose chemistry is tightly controlled in unknown. In this work, we demonstrate, using high-level ab initio and DFT calculations, the ability of RSNOs to participate in intermolecular interactions with electron pair donors/Lewis bases (LBs) via a σ-hole, a region of positive electrostatic potential on the molecular surface at the extension of the N–S bond. Analysis of the nature of the intermolecular interactions in σ-hole bound RSNO-LB complexes shows the dominant role of electrostatic and dispersion interactions. Importantly, σ-hole binding is able to modulate the properties of RSNOs by changing the balance between two chemically opposite …

Biophysical And Structural Characterization Of Non-Canonical Dna Structures, Linda Yingqi Lin , '20

Senior Theses, Projects, and Awards

Non-canonical DNA structures known as G-quadruplexes (GQs) and i-motifs can form from G-rich and C-rich sequences within the genome, respectively, which are prominent within telomeres and oncogene promoters. These non-canonical quadruplexes likely play roles in regulating gene expression and in DNA replication and repair. However, much remains to be understood about their structural features and diversity. In this work, we investigate the interaction of a GQ-forming sequence with a water-soluble porphyrin, N-methyl mesoporphyrin IX (NMM). Biophysical studies revealed an impressively tight, thermodynamically favorable binding interaction. We then solved the GQ-NMM crystal structure at 2.39 Å, which showed that the DNA …

Development Of Electroanalytical Techniques To Quantify Silver Nanoparticle Dissolution, Aggregation, And Release Kinetics, Zachary J. O'Dell , '20

Senior Theses, Projects, and Awards

Recently, the manufacture of engineered nanomaterials has seen an increase worldwide. This is due to the desirable properties of materials at the nanoscale rather than the bulk scale, such as improved optical, electronic and magnetic properties. Silver nanoparticles (AgNPs) are one of the fastest growing nanomaterials to be incorporated into consumer products due to silver’s well known antibacterial and antimicrobial properties. AgNP-enhanced products represent the largest proportion of engineered nanomaterial products on the consumer market, despite questions regarding the life cycle of such products. AgNPs can undergo a number of transformations during their life cycle including dissolution, aggregation, and protein …

Lignin: A Likely Precursor Of A Significant Fraction Of Humic Substances Via Oxidative Transformations, Seyyedhadi Khatami

Chemistry & Biochemistry Theses & Dissertations

Lignin is a major component of decaying terrestrial vegetation in soils and has been arguably reported to contribute substantially to the formation of soil carbon humus, and natural dissolved organic matter (DOM). To better understand the process by which this humification occurs, lignin and lignin-derived monomers were subjected to both biotic and abiotic oxidation processes. Two well-known oxidative transformation strategies were employed. The first involved the fungal degradation of brown-rot degraded wood subjected to a white-rot fungus (Phanerochaete chrysosporium) whose enzymes are particularly effective in lignin degradation via enzymatic oxidation. This enzymatic attack was monitored by ultrahigh resolution …

Quantum Chemical Lipophilicities Of Antimalarial Drugs In Relation To Terminal Half-Life, Joseph D. Alia, Sheila Karl, Tyler D. Kelly

Chemistry Publications

According to the WHO, artemisinin-based combination therapies (ACTs) have been integral to the recent reduction in deaths due to Plasmodium falciparum malaria. ACT-resistant strains are an emerging problem and have evolved altered developmental stages, reducing exposure of the most susceptible stages to artemisinin drugs in popular ACTs. Lipophilicity, log K_ow, is a guide in understanding and predicting pharmacokinetic properties such as terminal half-life which alters drug exposure. Consistent log K_ow values are not necessarily available for artemisinin derivatives designed to extend terminal half-life, increase bioavailability, and reduce neurotoxicity. For other drugs used in ACTs, an assortment of …

Geochemical Characterization Of The Paleoproterozoic Massif-Type Anorthosites From The Ubendian Belt, Tanzania, Nelson Boniface

Tanzania Journal of Science

Paleoproterozoic massif-type anorthosites occur in Southern Ubendian Belt (Upangwa Terrane) in Tanzania, mainly as mafic-plutons (meta-anorthosite and meta-gabbro) associated with ultramafic stocks and titaniferous magnetite bodies. Variably metamorphosed silicic granitoids are also recorded in the area. This article presents geochemical characteristics of meta-anorthosites, meta-gabbros and the associated granitoids in order to determine their genetic links and geotectonic settings. The meta-anorthosites, meta-gabbros and meta-tonalite have indistinguishable chondrite normalized REE patterns displaying LREE-enriched patterns (e.g., (La/Sm)N = 1.97–6.10) and negatively sloping HREE ((La/Yb)N = 4.05–47.06) suggesting continental crustal affinity. The trace element patterns of the studied meta-anorthosites are characterized by enrichments of …

Brown Carbon Production By Aqueous-Phase Interactions Of Glyoxal And So2, David O. De Haan, Kevin Jansen, Alec D. Rynaski, W. Ryan P. Sueme, Ashley K. Torkelson, Eric T. Czer, Alexander K. Kim, Michael A. Rafla, Audrey C. De Haan, Margaret A. Tolbert

Chemistry and Biochemistry: Faculty Scholarship

Oxalic acid and sulfate salts are major components of aerosol particles. Here, we explore the potential for their respective precursor species, glyoxal and SO₂, to form atmospheric brown carbon via aqueous-phase reactions in a series of bulk aqueous and flow chamber aerosol experiments. In bulk aqueous solutions, UV- and visible-light-absorbing products are observed at pH 3–4 and 5–6, respectively, with small but detectable yields of hydroxyquinone and polyketone products formed, especially at pH 6. Hydroxymethanesulfonate (HMS), C₂, and C₃ sulfonates are major products detected by electrospray ionization mass spectrometry (ESI-MS) at pH 5. Past studies …

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 to crawfish. …

The Microbiota-Gut-Brain Axis Heart Shunt Part I: The French Paradox, Heart Disease And The Microbiota, M. Obrenovich, B. Siddiqui, B. Mccloskey, Prakash Reddy

Chemistry Faculty Research & Creative Works

It has been well established that a vegetarian and polyphenol-rich diet, including fruits, vegetables, teas, juices, wine, indigestible fiber and whole grains, provide health-promoting phytochemicals and phytonutrients that are beneficial for the heart and brain. What is not well-characterized is the affect these foods have when co-metabolized within our dynamic gut and its colonizing flora. The concept of a heart shunt within the microbiota-gut-brain axis underscores the close association between brain and heart health and the so-called "French paradox" offers clues for understanding neurodegenerative and cerebrovascular diseases. Moreover, oxidation-redox reactions and redox properties of so-called brain and heart-protective foods are …

Synthesis Of Novel Dicyclohexeno-Crown Ethers With Strategically Incorporated Double Bonds For Further Functionalization, Carim Van Beek, Vincent J. Catalano, Vyacheslav V. Samoshin

Pacific Faculty Work

The number of applications found for crown ether-based materials continues to expand. Many of these applications feature dicyclohexano-18-crown-6 (DC18C6). The number of its derivatives, however, is very limited. To provide a suitable starting structure for the preparation of diverse functionalized DC18C6, the trans-syn-trans and trans-anti-trans isomers of dicyclohexeno-18-crown-6 have been synthesized for the first time through a convenient three-step synthetic procedure, yielding both isomers simultaneously. An efficient chromatographic separation resulted in the isolation of the pure isomers, and single crystal X-ray crystallography determined the solid-state structure of these crown ethers.

Photo-Physical Properties Of Lanthanides Doped O-Bridged Conducting Indole Oligomer, Iffat Ameen, Raj Laxmi Mishra, Abhishek K. Tripathi, Afshan Siddiqui, Umesh N. Tripathi

Karbala International Journal of Modern Science

The indole oligomers were synthesized by an effective green route in the water medium. This is an effort to synthesize commercially important indole oligomers without using any harmful chemicals and artificial media. The lanthanide chlorides such as LaCl₃·7H₂O, CeCl₃·7H₂O, PrCl₃·6H₂O and NdCl₃·6H₂O were used in the synthesis procedure to minimize the reaction time. Unlike the previous works, these reactions occurred at somewhat elevated temperature. In the reaction, the salts of lanthanide metals acted as a catalyst and further behave as dopants. These dopants increased …

Study Of Deformation Parameters (Β2, Δ) For 18,20,22,24,26,28ne Isotopes In Sdpf Shell, Ahmed H. Ali, Maha Taha Idrees

Karbala International Journal of Modern Science

The quadrupole deformation is basic to study the shape transitions; it is possible to predict many important properties of even-even nuclei as a function of the deformation parameter. The deformations of nuclei are important for understanding their shapes prolate or oblate. The quadrupole deformation parameters were calculated by the transition probability B (E2) for ^{18, 20, 22, 24, 26,28}Ne isotopes, were adopted different interactions three. The calculations are performed with the Bohr-Mottelson (B-M) effective charges, which represent the effect of the core-polarizations. Also, the deformation parameters were calculated for different nuclei and adopted two methods of calculation: from reduced …

Investigation Of Glucose Oxidation At Gold Nanoparticles Deposited At Carbon Nanotubes Modified Glassy Carbon Electrode By Theoretical And Experimental Methods., Farhat Saira, Humaira Razzaq, Misbah Mumtaz, Safeer Ahmad, Muhammad Aftab Rafiq, Azra Yaqub, Nabiha Dilshad, Ayesha Ihsan, Muhammad Masood Ul Hasan

Karbala International Journal of Modern Science

In the current research work, AuNPs-CNTs nanocomposite was synthesized chemically and decoration of AuNPs on the surface of MWCNTs was confirmed by UV-Vis, SEM and XPS analysis. Synthesized nanocomposite was utilized for its application towards non-enzymatic glucose sensing by modifying glassy carbon electrode with nanocomposite employing electrochemical techniques. In addition, theoretical calculations were performed by Density Functional Theory (DFT), employing B3YLP with basis set 6- 311+G(d,p) in gaseous phase and LANL2DZ basis set. Both theoretical and experimental results predicted Au-CNTs composite as a better candidate for glucose oxidation as compared to CNTs and AuNPs alone, owing to the synergistic effect …

A Study To Explore The Ldlr Gene Polymorphisms Contribute To Atorvastatin Response In A Sample Of Iraqi Population With Atherosclerotic Coronary Artery Disease, Shaimaa Y. Abdulfattah, Salwa J. Abdullah, Hilal B. Alsaffar

Karbala International Journal of Modern Science

Genetic factors will determine the higher variability, which found in response to lipid reduction treatment (statins). However, due to ethnicity the frequency and effect of single nucleotide polymorphisms (SNPs) may differ. The main aim of lipid lowering medical treatment is to eventually prevent the endogenous production of cholesterol through inhibition of HMG-CoA reductase, The resulting decrease in hepatocyte cholesterol concentration triggers up-regulation of low-density lipoprotein (LDL)-receptor expression by inducing sterol regulatory element-binding protein (SREBP) 2 cleavage, as SREBP-2 activates LDL receptor transcription. The aim of this study was to evaluate the effects of low density lipoprotein receptor (LDL-R) …

Using Freak Descriptor To Classify Plasma Influence In Mice Sperm, Ekhlas Falih, Alaa Noori Mazhar

Karbala International Journal of Modern Science

Numerous classification mechanisms anticipate the class's instances to be carried out as the features' vectors, namely the points in a feature's space. It is oftentimes a chance to make an informative exemplification of an image's feature vector for classification problems in computer vision like utilizing global descriptors for the texture description or shape description. The proposed methodology is to classify the sperm image in mice that has been affected through plasma and this methodology consists of three stages. The points of interest could be elicited from sperm plasma images in the first stage by utilizing Adaptive and Generic Corner detector …

Editorial Board

Karbala International Journal of Modern Science

No abstract provided.

Assessing The Correlation Of Microscopy-Based And Volumetry-Based Measurements For Resin Swelling In A Range Of Potential Greener Solvents For Spps, Jordan K. Magtaan, Marc Devocelle, Fintan Kelleher

Articles

The degree of resin swelling in a particular solvent system is one of the critical parameters for SPPS, and for solid phase synthesis, in general. Methods used for measuring the degree of resin swelling include microscopy-based and volumetry-based methods. This study describes, and compares, the use of both methods for a number of commercially available resins commonly used in SPPS, with a range of solvents which have been identified in the literature as “greener” than DCM, DMF and NMP. The results were analysed by statistical methods and a significant correlation between the two distinct methods has been demonstrated for the …

Synthesis Of 12-Membered Tetra-Aza Macrocyclic Pyridinophanes Bearing Electron-Withdrawing Groups, Akop Yepremyan, Magy A. Mekhail, Brian P. Niebuhr, Kristof Pota, Nishanth Sadagopan, Timothy M. Schwartz, Kayla N. Green

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The number of substituted pyridine pyridinophanes found in the literature is limited due to challenges associated with 12-membered macrocycle and modified pyridine synthesis. Most notably, the electrophilic character at the 4-position of pyridine in pyridinophanes presents a unique challenge for introducing electrophilic chemical groups. Likewise, of the few reported, most substituted pyridine pyridinophanes in the literature are limited to electron-donating functionalities. Herein, new synthetic strategies for four new macrocycles bearing the electron-withdrawing groups CN, Cl, NO₂, and CF₃ are introduced. Potentiometric titrations were used to determine the protonation constants of the new pyridinophanes. Further, the influence of …

Electrochemical Nitrogen Reduction To Ammonia Using Molybdenum Disulfide-Based Nanocatalysts, Assem Omar M Basurrah

Theses and Dissertations

Ammonia is the basis for producing fertilizers for food production. The Haber-Bosch process is the main method to produce ammonia. Because of the energy and environmental problems associated with the Haber-Bosch process, extensive research is being explored for other ammonia production methods, including electrochemical methods based on nitrogen reduction reaction (NRR). In this thesis, molybdenum disulfide nanocatalysts (~4 nm) on carbon fibers were synthesized by hydrothermal reactions. The resulting composites were characterized by X-ray diffraction, scanning electron microscopy, and transmission electron microscopy. The electrochemical properties of the composites were measured by using linear sweep voltammetry, cyclic voltammetry, and controlled potential …

Laser-Induced Breakdown Spectroscopy For Elemental Analysis In Bioarchaeology And Forensic Anthropology, Kelsi N. Kuehn

USF Tampa Graduate Theses and Dissertations

Within bioarchaeology and forensic anthropology, the current processes of differentiating between individual human skeletal remains are imprecise, costly, and inefficient. A novel analytical technique within anthropology, laser-induced breakdown spectroscopy (LIBS) can aid in the identification of human remains using rapid laser ablation occurring at the micro-scale, making the technique virtually non-destructive to the sample. Considering this, LIBS could offer a superior method for materials discrimination and human identification. This research sought to examine whether LIBS can be used to obtain elemental signatures within bones to distinguish individuals from one another in a rapid, non-destructive manner. Seven human skeletal donors and …

Nf-Κb Inhibitors Attenuate Mcao Induced Neurodegeneration And Oxidative Stress—A Reprofiling Approach, Awais Ali, Fawad Ali Shah, Alam Zeb, Imran Malik, Arooj Mohsin Alvi, Lina Tariq Alkury, Sajid Rashid, Ishtiaq Hussain, Najeeb Ullah, Arif Ullah Khan, Phil Ok Koh, Shupeng Li

All Works

© Copyright © 2020 Ali, Shah, Zeb, Malik, Alvi, Alkury, Rashid, Hussain, Ullah, Ullah Khan, Koh and Li. Stroke is the leading cause of morbidity and mortality worldwide. About 87% of stroke cases are ischemic, which disrupt the physiological activity of the brain, thus leading to a series of complex pathophysiological events. Despite decades of research on neuroprotectants to probe for suitable therapies against ischemic stroke, no successful results have been obtained, and new alternative approaches are urgently required in order to combat this pathological torment. To address these problems, drug repositioning/reprofiling is explored extensively. Drug repurposing aims to identify …