Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

1

Discipline
Institution
Publication Year
Publication
Publication Type
File Type

Articles 1 - 30 of 233

Full-Text Articles in Physical Sciences and Mathematics

Environmental Dna Identifies Coastal Plant Community Shift 1,000 Years Ago In Torrens Island, South Australia, Nicole R. Foster, Alice R. Jones, Oscar Serrano, Anna Lafratta, Paul S. Lavery, Kor-Jent Van Dijk, Ed Biffin, Bronwyn M. Gillanders, Jennifer Young, Pere Masque, Patricia S. Gadd, Geraldine E. Jacobsen, Atun Zawadzki, Andria Greene, Michelle Waycott Dec 2024

Environmental Dna Identifies Coastal Plant Community Shift 1,000 Years Ago In Torrens Island, South Australia, Nicole R. Foster, Alice R. Jones, Oscar Serrano, Anna Lafratta, Paul S. Lavery, Kor-Jent Van Dijk, Ed Biffin, Bronwyn M. Gillanders, Jennifer Young, Pere Masque, Patricia S. Gadd, Geraldine E. Jacobsen, Atun Zawadzki, Andria Greene, Michelle Waycott

Research outputs 2022 to 2026

Anthropogenic activities are causing detrimental changes to coastal plants– namely seagrass, mangrove, and tidal marshes. Looking beyond recent times to past vegetation dynamics is critical to assess the response and resilience of an environment to change. Here, we develop a high-resolution multi-proxy approach, providing a new evidence base to decipher long-term change in coastal plant communities. Combining targeted environmental DNA analysis with chemical analysis of soils, we reconstructed 4,000 years of change at a temperate wetland on Torrens Island South Australia and identified an ecosystem shift that occurred ~ 1000 years ago. What was once a subtidal seagrass system shifted …


Regioselective Catalytic Synthesis Of Potentially Bioactive 1,3,4-Selenadiazole, Mohamed Ali Mahmoud Dec 2023

Regioselective Catalytic Synthesis Of Potentially Bioactive 1,3,4-Selenadiazole, Mohamed Ali Mahmoud

Theses

Isoselenocyanates have a crucial role as reactants in chemical processes, facilitating the efficient synthesis of significant chemical intermediates and physiologically active chemicals. The utilization of (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides in a one-step procedure for the synthesis of the core structure of various heterocyclic compounds has been widely explored. This study focuses on the synthesis of 5-arylimino-1,3,4-selenadiazole derivatives through the reaction of isoselenocyanates with various substituted (Z)-2-oxo-N-phenylpropanehydrazonoyl chlorides. The objective is to achieve selective and accurate formation of these derivatives. The derivatives exhibit a diverse range of functional groups on both aryl rings. The synthetic procedure is conducted under ambient conditions, promoting environmental …


Synthesis Of Alnustone-Like Diarylpentanoids Via A 4 + 1 Strategy And Assessment Of Their Potential Anticancer Activity, Nesli̇han Çelebi̇oğlu, Özlem Özdemi̇r Tozlu, Hasan Türkez, Hasan Seçen Oct 2023

Synthesis Of Alnustone-Like Diarylpentanoids Via A 4 + 1 Strategy And Assessment Of Their Potential Anticancer Activity, Nesli̇han Çelebi̇oğlu, Özlem Özdemi̇r Tozlu, Hasan Türkez, Hasan Seçen

Turkish Journal of Chemistry

Twelve compounds with a 1,5-diaryl-1-penten-3-one structure were synthesized and their cytotoxic activities were evaluated. The 1,5-diaryl-1-penten-3-one compounds were obtained via in situ enaminations of 4-phenyl-2-butanone and 4-(4-hydroxyphenyl)-2- butanone in the presence of pyrrolidine-AcOH, followed by condensation with six different benzaldehydes. The synthesized compounds were tested for their cytotoxic activity against human glioblastoma (U87-MG), breast (MCF-7), and prostate (PC-3) cancer cell lines. Some of the novel compounds exhibited remarkable cytotoxic action, especially against MCF-7 cancer cells.


Exploring New Horizons In Microwave-Promoted Iminyl Radical Chemistry And Synthesis Of Bulky Dehydroamino Acids, Jatinder Singh Aug 2023

Exploring New Horizons In Microwave-Promoted Iminyl Radical Chemistry And Synthesis Of Bulky Dehydroamino Acids, Jatinder Singh

Theses and Dissertations

The first project in this dissertation presents a simplified and efficient protocol for synthesizing pyrrolines through 5-exo iminyl radical cyclizations. The microwave irradiation of O-Phenyloximes tethered to alkenes causes N-O homolysis resulting in iminyl radical generation, which subsequently undergoes 5-exo-trig cyclizations furnishing pyrrolines. This eliminates the need for toxic radical initiators (AIBN, benzoyl peroxide), propagating agents (Bu3SnH, (Me3Si)3SiH), and expensive catalysts or single-electron transfer (SET) cycles. We explored the scope of diverse traps and substrates for iminyl radical cyclizations. The iminyl radical cyclizations formed versatile pyrrolines with moderate to excellent yields. The diastereoselectivity also ranged from low to high. Moreover, …


Global Minimum Search For The Largest Ge Cage Stabilized By A Single Interstitial Metal Atom, Alexis Kiefer Jan 2023

Global Minimum Search For The Largest Ge Cage Stabilized By A Single Interstitial Metal Atom, Alexis Kiefer

Williams Honors College, Honors Research Projects

Recent joint experimental and theoretical studies showed that the largest Ge cage-like cluster features 14 Ge atoms that encapsulate a single transition metal atom in the [Nb@Ge14]3- cluster. The next larger experimentally confirmed Ge cluster exhibiting a cage-like geometry was found to be viable only when stabilized by two transition metal atoms in the [Co2@Ge16]4- cluster. So, as of now, it is not clear whether a cage-like cluster made out of 15 Ge atom stabilized by a single transition metal is viable. Hence, the aim of this project is to find the …


The Affect Of Dha Concentration On Lipid Membrane Fluidity, Elise Rezabeck Jan 2023

The Affect Of Dha Concentration On Lipid Membrane Fluidity, Elise Rezabeck

Williams Honors College, Honors Research Projects

My proposed project will be creating large unilaminar vesicles with varying concentrations of DHA in the vesicles. The diffusion in and out of these vesicles will be tracked by using singular lipid molecules. These singular lipid molecules will be tagged with fluorescence and viewed using an internal reflection fluorescence microscope. The data collected over the course of this project will then be analyzed using Matlab. The result of the project will be to find the specific lipid diffusion constant of these unilaminar vesicles. The relationship between the concentration of DHA and lipid diffusion and membrane fluidity will be found as …


Fridge Tracker And Recipe Provider : Fridgechamp, Matt Dudek Jan 2023

Fridge Tracker And Recipe Provider : Fridgechamp, Matt Dudek

Williams Honors College, Honors Research Projects

FridgeChamp is a website to allow people to track their fridge/pantry contents while providing them recipes they can make with said ingredients. Currently there are few ingredient trackers and recipe matchers that exist as websites, and of those many lack simplistic recipes that a home chef would use. In addition to lacking some recipes, many tracker/recipe apps do not have a function to remove from your stock what a recipe requires, making you tediously update the stock every time you cook/use something.


Impacts Of Covid-19 On Industrial Growth In The United States, Emily G. Warthman, Charles J. Landis Jan 2023

Impacts Of Covid-19 On Industrial Growth In The United States, Emily G. Warthman, Charles J. Landis

Williams Honors College, Honors Research Projects

COVID-19 has caused massive ramifications on all parts of life in the world and industry growth/decline is not immune to it. This report will analyze nine different industries’ profit and revenue from quarterly data during the years 2009-2022. Forecast models will be generated using various methods and different techniques of validating to predict the values from Q2 2020- Q4 2022 based on historical data. After which, a comparison will be conducted between those predicted values to the actual average revenue and profit generated by order of greatest error percentage made. Thorough research will then be completed to determine if there …


Electron Beam Treatment For The Removal Of 1,4-Dioxane In Water And Wastewater, Robert Pearce, Xi Li, John Vennekate, Gianluigi Ciovati, Charles Bott Jan 2023

Electron Beam Treatment For The Removal Of 1,4-Dioxane In Water And Wastewater, Robert Pearce, Xi Li, John Vennekate, Gianluigi Ciovati, Charles Bott

Electrical & Computer Engineering Faculty Publications

Electron beam (e-beam) treatment uses accelerated electrons to form oxidizing and reducing radicals when applied to water without the use of external chemicals. In this study, electron beam treatment was used to degrade 1,4-dioxane in several water matrices. Removal improved in the progressively cleaner water matrices and removals as high as 94% to 99% were observed at a dose of 2.3 kGy in secondary effluent. 1,4-dioxane removal was confirmed to be primarily through hydroxyl radical oxidation. The calculated electrical energy per order was found to be 0.53, 0.26, and 0.08 kWh/m3/order for secondary effluent (Avg. total organic carbon …


Enabling Technologies For Chemical Synthesis: I. Selective Microwave Heating; Ii. Synthesis And Regioselective Cyclotrimerizations Of Tethered 1,6-Diynes, Amir Tavakoli Jan 2023

Enabling Technologies For Chemical Synthesis: I. Selective Microwave Heating; Ii. Synthesis And Regioselective Cyclotrimerizations Of Tethered 1,6-Diynes, Amir Tavakoli

Graduate Theses, Dissertations, and Problem Reports

Reaction discoveries, method developments, and technology advancements lie at the heart of synthetic organic chemistry. These innovations are essential for creating and manipulating complex molecules, which are the building blocks of many important chemical compounds, including pharmaceuticals, materials, and agrochemicals. Here, we first describe new methods to prepare neopentylene-tethered (NPT) 1,6-diynes which are valuable substrates for reaction discovery and target-oriented synthesis, especially in benzannulation strategies toward illudalane natural products. NPT 1,6-diynes have been employed as coupling partners in cyclotrimerization reactions for the synthesis of highly substituted benzene rings which present a persistent challenge in chemical synthesis and are underrepresented scaffolds …


Viscous Anisotropy Of Wet Olivine Aggregates, Megan Ryan Jan 2022

Viscous Anisotropy Of Wet Olivine Aggregates, Megan Ryan

Williams Honors College, Honors Research Projects

I will deform natural olivine aggregates (Anita Bay dunite) cores in various orientations relative to a natural mineral alignment in the rock under both dry and wet conditions. Different orientations in regards to this mineral alignment will produce deformation on different slip systems. Stress measurements will be taken during the deformation of the samples in order to characterize any changes in viscous anisotropy observed due to the changes in slip system. Anita Bay dunite is a proxy for the main mineral found in the mantle wedge of subduction zones. Therefore, understanding the transformation of viscosity and slip systems in this …


The Utility Of Electroencephalography For User Input, Caleb Maurice Jan 2022

The Utility Of Electroencephalography For User Input, Caleb Maurice

Williams Honors College, Honors Research Projects

The goal of this paper is to introduce the use of noninvasive brain-computer interfaces to prospective computer scientists. Electroencephalography is explained starting with how a user’s brain waves are measured and ending with how the data is parsed to software programs. To further expand on the ability to implement electroencephalography into software code, and example of a simple game is given. This game is an endless runner, meaning that it has no end and stops once the player’s game piece collides with an object. It is coded in the Python computer language.


Applying Machine Learning Algorithms For Face Mask Detections, Mackenzie Frato Jan 2022

Applying Machine Learning Algorithms For Face Mask Detections, Mackenzie Frato

Williams Honors College, Honors Research Projects

Goal: Apply multiple machine learning techniques to Face Mask images to detect if a student is wear a Face Mask and/or wearing it incorrectly or not at all. Methodology: Use 2-3 different machine learning techniques to develop this program. Will choose these techniques as I research over the semester. The best technique will be the final one used, but many will be explored. Validation techniques will be used to see which is the best technique. Timeline: Choose Dataset - October 1st, Choose techniques - October 31st, Research techniques/validation - November 31st, Begin writing code - December 13th, Finish code - …


Sequential Block Copolymers Of Polyisobutylene And Polyolefins, Manwel Labib Jan 2022

Sequential Block Copolymers Of Polyisobutylene And Polyolefins, Manwel Labib

Williams Honors College, Honors Research Projects

A two-step approach will be utilized to synthesize random polyolefin multiblock-copolymers. This strategy takes advantage of a,w-terminated telechelic polyolefins. Polypropylene (iPP)/polyethylene (PE) are picked because of their strength, and polyisobutylene (PIB) because of its hemocompatibility. This copolymer is theorized to make for robust bio-inert plastic, which can be used for surgical mesh implants.


Synthesis Of 2-Aryl-5-(Arylsulfonyl)-1,3,4-Oxadiazoles As Potent Antibacterial Andantioxidant Agents, S N Murthy Boddapati, Subrahmanyam Talari, A Emmanuel Kola, Bhuvaneswari Chalapaka Jan 2022

Synthesis Of 2-Aryl-5-(Arylsulfonyl)-1,3,4-Oxadiazoles As Potent Antibacterial Andantioxidant Agents, S N Murthy Boddapati, Subrahmanyam Talari, A Emmanuel Kola, Bhuvaneswari Chalapaka

Turkish Journal of Chemistry

Ten novel 2-aryl-5-(arylsulfonyl)-1,3,4-oxadiazoles were produced and assessed for their in vitro antibacterial and antioxidant activities. Diverse spectroscopic methods li1H NMR, 13C NMR, IR, and LCMS were used for the characterization of the prepared samples and all the data was in good agreement with the anticipated structures. The prepared compounds 6a-j were screened for their in vitro antibacterial activity against bacterial strains Pseudomonas aeruginosa, Enterobacter aerogenes, Escherichia coli (grampositive), and Bacillus cerus, Staphylococcus aureus, Bacillus subtilis (gram-negative). The antimicrobial screening outcome revealed that the prepared 2-(3,4-dimethylphenyl)-5-tosyl-1,3,4-oxadiazole (6j), 2-(3-isopropylphenyl)-5-tosyl-1,3,4-oxadiazole (6c), and 2-(2-ethylphenyl)-5-tosyl-1,3,4-oxadiazole (6i) are most potent among all the examined compounds. Furthermore, …


Synthesis Of Novel Oxadiazole Derivatives And Their Cytotoxic Activity Against Various Cancer Cell Lines, Bi̇lgesu Onur Sucu, Eli̇f Beyza Koç Jan 2022

Synthesis Of Novel Oxadiazole Derivatives And Their Cytotoxic Activity Against Various Cancer Cell Lines, Bi̇lgesu Onur Sucu, Eli̇f Beyza Koç

Turkish Journal of Chemistry

Caffeic acid (CA), ferulic acid (FA) and caffeic acid phenethyl ester (CAPE) have a broad anticancer effect on various cell lines. In this study, nine ferulic and caffeic acid-based 1,2,4 and 1,3,4 oxadiazole molecular hybrids were synthesized and their cytotoxic activity was evaluated mainly against Glioblastoma (GBM) cell lines. Compounds 1 and 5 exhibited the highest inhibitory activity against three different GBM cell lines (LN229, T98G, and U87), without toxicity to healthy human mesenchymal stem cells (hMSC). In addition, their cytotoxicity was also evaluated against three additional cancer cell lines and more inhibitory results were found than GBM cell lines. …


1,2-Diamination Of Alkenes Via Reduction Of 1,2,3-Triazolinium Ions, Setareh Saryazdi Jan 2022

1,2-Diamination Of Alkenes Via Reduction Of 1,2,3-Triazolinium Ions, Setareh Saryazdi

Theses and Dissertations--Chemistry

1,2-Diamine substructures are prevalent functional motifs in natural products, pharmaceutical compounds, and ligands. The interesting functionalities of 1,2-diamines have inspired many synthetic chemists to design various methodologies for preparing these structures from simple precursors such as alkenes. In this work, we described two different but related methods using simple and easily accessible reagents for 1,2-diamination of alkenes. In the first method, an alkene undergoes 1,3-dipolar cycloaddition with an organic azide to form a 1,2,3-triazoline. Subsequent N-alkylation of the generated 1,2,3-triazoline gives the 1,2,3-triazolinium ion, which is then hydrogenated over Raney Ni with a balloon of H2 to produce …


Applying Intensity-Based Methods To Disentangle Microwave Spectra Of Complex Mixtures: Analysis Of Weakly Bound Clusters Of 1,1-Difluoroethylene/Co2, Hannah Fino Jan 2022

Applying Intensity-Based Methods To Disentangle Microwave Spectra Of Complex Mixtures: Analysis Of Weakly Bound Clusters Of 1,1-Difluoroethylene/Co2, Hannah Fino

Masters Theses

Microwave spectroscopy is used to study the solvent-solute interactions between molecules of CO2 and fluoroethylenes by analyzing the formation of weakly-bound clusters in a gaseous mixture. One of the challenges to analyzing microwave spectra obtained for these weakly-bound species is that spectra for individual clusters are mixed together in an original complex spectrum. This prompts development of automated techniques that could separate complex data into subsets of related data to be more easily analyzed.

The techniques developed in this work are founded on intensity-based analyses, following the work of Dr. Robert Field on Extended Cross Correlation (XCC). The XCC …


Synthesis And Cyclotrimerization Of Sulfonyl Enynes, Alexa C. Martin Jan 2022

Synthesis And Cyclotrimerization Of Sulfonyl Enynes, Alexa C. Martin

Graduate Theses, Dissertations, and Problem Reports

The synthesis of complex, polysubstituted aromatic rings from simple, non-aromatic building blocks is a consistent challenge to the synthetic community. Neopentylene ring fusions are found in several natural products but are largely absent from synthetic compound libraries. This discrepancy reflects the limitations in modern chemical synthesis. Utilizing, in part, a thoroughly developed fragmentation/olefination methodology from the Dudley Lab, a library of novel 1-sulfonyl-1,6-enynes have been developed. In this methodology, they are prepared in three steps from dimedone (5,5-dimethyl-1,3-cyclohexanedione), an inexpensive starting material. A total of 14 novel 1-sulfonyl-1,6-enynes were synthesized. These substrates were subjected to a novel benzannulation reaction based …


1,2-Diazetidine As A New Amidomethylative Reagent To Control The Selectivity For The Synthesis Of N-Heterocycles And Ru(Ii)-Catalyzed Enantioselective Hydroarylation To Form Chromane Derivatives, Chaminda Lakmal Hetti Handi Dec 2021

1,2-Diazetidine As A New Amidomethylative Reagent To Control The Selectivity For The Synthesis Of N-Heterocycles And Ru(Ii)-Catalyzed Enantioselective Hydroarylation To Form Chromane Derivatives, Chaminda Lakmal Hetti Handi

Theses and Dissertations

1,2-Diazetidine is a four-membered ring heterocyclic compound which has two adjacent nitrogen atoms. However, the syntheses of C-unsubstituted 1,2-diazetidines are rarely reported in the literature. C-unsubstituted 1,2-diazetidines were synthesized through an operationally simple intermolecular vicinal disubstitution reaction between 1,2-dibromoethane and hydrazine with N-arylsulfonyl as the protecting group. Several different types of C-unsubstituted 1,2-diazetidines derivatives were synthesized with either two of the same or two different N-arylsulfonyl groups. The electronic and steric properties were analyzed using Raman spectroscopy and computational calculations. Then, several synthetic applications were demonstrated with 1,2-ditosyl-1,2-diazetidine (DTD). As a synthetic application, a nucleophilic ring-opening reaction of the diazetidine …


Synthesis And Characterization Of Re(I) Tricarbonyl Complexes Of 1,8-Naphthalimide, Priyanka Jagadeesa Prabhu Aug 2021

Synthesis And Characterization Of Re(I) Tricarbonyl Complexes Of 1,8-Naphthalimide, Priyanka Jagadeesa Prabhu

Electronic Thesis and Dissertation Repository

1,8-Naphthalimide fluorophores with amino-substituents absorb and emit in the visible region. The photophysical properties of this class of fluorophores can be modulated by altering the degree of Intramolecular Charge Transfer (ICT) in the excited state. Thus, several metal complexes with the 1,8-naphthalimide motif have been developed as cell imaging agents. In this project, four 1,8-naphthalimide ligands were synthesized by incorporating rigid linkers. Among these, three ligands also allowed the extension of π-conjugation to the naphthalimide moiety. In addition, a ligand was also synthesized without the use of a linker. Re(I) tricarbonyl complexes of these ligands were also synthesized and their …


A Multifunctional Solution Composed Of Tmpyp, 1,5-Dhn, And Fe(Iii) Ions That Produces Reactive Oxygen Species (Ros) In Aerobic, Anaerobic, And H2o2 Environments, Aqeeb Ali May 2021

A Multifunctional Solution Composed Of Tmpyp, 1,5-Dhn, And Fe(Iii) Ions That Produces Reactive Oxygen Species (Ros) In Aerobic, Anaerobic, And H2o2 Environments, Aqeeb Ali

Electronic Theses and Dissertations

Photodynamic therapy (PDT) has become a widely popular therapeutic approach for treating various types of cancer over the past several decades. PDT utilizes a photosensitizer, visible light, and oxygen, to produce reactive oxygen species (ROS) which can be used to treat cancer and inhibit growth of bacteria. In this study, a multifunctional solution that is comprised of Fe(III) ions, cationic meso-tetra(N-methyl-4-pyridyl)porphine tetrachloride (TMPyP), and 1,5-dihydroxynapthalene (1,5-DHN), was shown to produce reactive oxygen species (ROS) such as singlet oxygen (1O2) or hydroxyl radicals (ȮH) in aerobic or anaerobic environments, respectively, and in both environments, 1,5-DHN was oxidized …


Integrated 3d-Qsar, Molecular Docking, And Molecular Dynamics Simulation Studies On 1,2,3-Triazole Based Derivatives For Designing New Acetylcholinesterase Inhibitors, Khalil El Khatabi, Ilham Aanouz, Reda El-Mernissi, Atul Kumar Singh, Mohammed Aziz Ajana, Tahar Lakhlifi, Shashank Kumar, Mohammed Bouachrine Jan 2021

Integrated 3d-Qsar, Molecular Docking, And Molecular Dynamics Simulation Studies On 1,2,3-Triazole Based Derivatives For Designing New Acetylcholinesterase Inhibitors, Khalil El Khatabi, Ilham Aanouz, Reda El-Mernissi, Atul Kumar Singh, Mohammed Aziz Ajana, Tahar Lakhlifi, Shashank Kumar, Mohammed Bouachrine

Turkish Journal of Chemistry

Alzheimer's disease (AD) is a multifactorial and polygenic disease. It is the most prevalent reason for dementia in the aging population. A dataset of twenty-six 1,2,3-triazole-based derivatives previously synthetized and evaluated for acetylcholinesterase inhibitory activity were subjected to the three-dimensional quantitative structure-activity relationship (3D-QSAR) study. Good predictability was achieved for comparative molecular field analysis (CoMFA) (Q2 = 0.604, R2 = 0.863, rext2 = 0.701) and comparative molecular similarity indices analysis (CoMSIA) (Q2 = 0.606, R2 = 0.854, rext2 = 0.647). The molecular features characteristics provided by the 3D-QSAR contour plots were quite useful for designing and improving the activity of …


Synthesis, Spectral Characterization, And Biological Studies Of 3,5-Disubstituted- 1,3,4-Oxadiazole-2(3h)-Thione Derivatives, Tuğçe Özyazici, Fi̇kretti̇n Şahi̇n, Meri̇ç Köksal Akkoç Jan 2021

Synthesis, Spectral Characterization, And Biological Studies Of 3,5-Disubstituted- 1,3,4-Oxadiazole-2(3h)-Thione Derivatives, Tuğçe Özyazici, Fi̇kretti̇n Şahi̇n, Meri̇ç Köksal Akkoç

Turkish Journal of Chemistry

The reaction of 3,4-dichlorophenyl-1,3,4-oxadiazole-2(3H)-thione with piperidine derivatives via Mannich reaction was used to generate eleven novel compounds in moderate to good yields. Synthesized molecules were characterized according to their structure with 1H NMR, 13C NMR and FT-IR spectral foundations, which were compatible with literature informations. Antimicrobial activity and cytotoxicity studies were done by disc diffusion and NCI-60 sulphordamine B assay methods. The antimicrobial test results revealed that synthesized compounds have better activity against gram-positive species than gram-negative ones. A total analysis of the antibacterial, antifungal, and antiyeast activity revealed that newly synthesized compounds were really active against Bacillus cereus, Bacillus …


1,4-Dioxane Biodegradation In Propanotrophs: Molecular Foundations And Implications For Environmental Remediation, Li Fei Aug 2020

1,4-Dioxane Biodegradation In Propanotrophs: Molecular Foundations And Implications For Environmental Remediation, Li Fei

Dissertations

1,4-Dioxane (dioxane) has emerged with an escalating concern given its human carcinogenicity and widespread occurrence in groundwater. Bioremediation is promising as an effective and cost-efficient treatment alternative for in situ or ex situ cleanup of dioxane and co-existing pollutants in the field. Soluble di-iron monooxygenases (SDIMOs) are reputed for their essential roles in initiating the cleavage of dioxane and other pollutants. In this doctoral dissertation, molecular foundations for SDIMOs-mediated dioxane biodegradation are untangled to promote the development and implication of site-specific bioremediation and natural attenuation strategies. This dissertation focused on propanotrophic bacteria given their pivotal roles in dioxane metabolism and …


The Rotational Spectrum Of 1,1-Diiodoethane, Michael Joseph Carrillo Jul 2020

The Rotational Spectrum Of 1,1-Diiodoethane, Michael Joseph Carrillo

Theses and Dissertations

The first chapter of this thesis introduces the basic theory of rotational spectroscopy. This includes the theory of a rigid rotor, centrifugal distortion, and hyperfine effects. The theory behind diatomic systems is explained first, and then expanded to the asymmetric top system. The second chapter encompasses a brief overview on the development of microwave spectroscopy and discusses the instruments that were utilized during this study, namely the cavity-based and chirped-pulse Fourier transform microwave spectrometers. Chapter three describes the quantum chemical calculation methods and basis sets that were applied throughout this study. Chapter four discusses the progress of data analysis of …


Synthesis And Characterization Of Novel Derivatives Of 1, 3, 4- 0xadiazole And Isoniazid, Ranem Mohammad Kaddoura Apr 2020

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 synthesized compounds has …


Investigation Of The Intramolecular 1,3-Diaza-Claisen Rearrangement In The Ring Expansion Reactions Of Vinyl Pyrrolidines And Vinyl Piperidines, Teruki Watanabe Jan 2020

Investigation Of The Intramolecular 1,3-Diaza-Claisen Rearrangement In The Ring Expansion Reactions Of Vinyl Pyrrolidines And Vinyl Piperidines, Teruki Watanabe

Graduate College Dissertations and Theses

The 1,3-diaza-Claisen rearrangement was discovered and developed in the Madalengoitia group since 2004. The rearrangement is initiated by the desulfurization of the electron deficient thiourea and isothiourea to obtain the highly electrophilic carbodiimide which can be reacted with an allylic tertiary amine to form the zwitterionic intermediate which then undergoes [3,3]-sigmatropic rearrangement. Previous investigation includes multiple examples of successful formation of complex guanidines through intermolecular and intramolecular variants. Providing an easy access to guanidine which is one of the most prevalent functional groups in the biologically relevant system, the rearrangement can be a valuable tool in the organic synthesis.

The …


Synthesis, Characterization And Crystal Structures Of Platinum(Ii) Saccharinate Complexes With 1,5-Cyclooctadiene, Ceyda İçsel Jan 2020

Synthesis, Characterization And Crystal Structures Of Platinum(Ii) Saccharinate Complexes With 1,5-Cyclooctadiene, Ceyda İçsel

Turkish Journal of Chemistry

Two new platinum(II) complexes, namely [PtCl(sac)(COD)] (1) and [Pt(sac)$_{2}$(COD)] (2) (sac $=$ saccharinate and COD $=$ 1,5-cyclooctadiene), were synthesized and characterized by elemental analysis, IR, NMR, ESI-MS spectroscopic and thermal analysis (TG/DTA) methods. The platinum(II) complexes were prepared from the reaction of [PtCl$_{2}$(COD)] with Na(sac) • 2H$_{2}$O. The addition of the sac ligand resulted in the replacement of 1 and 2 chlorido ligands in [PtCl$_{2}$(COD)] to yield 1 and 2, respectively. The structures of the complexes were determined by single crystal X-ray diffraction and showed a distorted square planar coordination geometry around platinum(II). COD acted as a $\pi $-donor ligand, …


Exploration Of Cis-1,2-Diaminocyclohexane-Based Conformationally Locked Chiral Ligands In Asymmetric Synthesis, Carim Van Beek Jan 2020

Exploration Of Cis-1,2-Diaminocyclohexane-Based Conformationally Locked Chiral Ligands In Asymmetric Synthesis, Carim Van Beek

University of the Pacific Theses and Dissertations

Natural products have been demonstrated to be of great significance to the pharmaceutical industry in the development of new drugs and medicine. Unfortunately, synthetic approaches to obtain these natural products often prove increasingly challenging due to the complexity of synthesizing the target drug in the proper stereochemistry. The availability of enantioselective reactions can play a pivotal role in overcoming this challenge, yielding access to optically pure intermediates and products. Chiral ligands based on a trans-1,2-diaminocyclohexane motif are often employed for this purpose and their complexes with transition metals have been demonstrated to act as efficient chiral catalysts in asymmetric reactions. …