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

Chemistry Commons

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

PDF

2022

Discipline
Institution
Keyword
Publication
Publication Type

Articles 1 - 30 of 1493

Full-Text Articles in Chemistry

Coconut Shell Waste Treatment Technology For A Sustainable Waste Utilization: A Case Study Of The Smes In Bohol Village, Indonesia, Wahyu Anggo Rizal, Ria Suryani, Roni Maryana, Dwi Joko Prasetyo, Diah Pratiwi, Yuli Ary Ratnawati, Dini Ariani, Andri Suwanto Dec 2022

Coconut Shell Waste Treatment Technology For A Sustainable Waste Utilization: A Case Study Of The Smes In Bohol Village, Indonesia, Wahyu Anggo Rizal, Ria Suryani, Roni Maryana, Dwi Joko Prasetyo, Diah Pratiwi, Yuli Ary Ratnawati, Dini Ariani, Andri Suwanto

ASEAN Journal of Community Engagement

This project focused on the introduction of liquid smoke and bio briquette manufacturing technology to small and medium enterprises (SMEs) located in Bohol Village, Gunungkidul, Indonesia through technology transfer, training, and mentoring. These SMEs are engaged in the food business with the main product jenang ketan, a traditional food from Gunungkidul, especially in Rongkop District, and very popular among communities around and outside Gunungkidul. The traditional preparation of jenang ketan produces several by-products in the form of waste, which is dominated by coconut shell biomass. The project’s technology transfer was carried out through the procurement of a series of pyrolysis …


Combustion Soot Nanoparticles: Mechanism Of Restructuring And Mechanical Properties, Ali Hasani Dec 2022

Combustion Soot Nanoparticles: Mechanism Of Restructuring And Mechanical Properties, Ali Hasani

Dissertations

Soot, a product of incomplete combustion of fossil fuels, is a global warming agent. The effect of soot particles on climate depends on their morphology. Freshly released soot particles are fractal lacey aggregates, but they often appear collapsed in atmospheric samples collected away from emission sources. A body of work has concluded that the collapse is caused by liquid shells when they form by vapor condensation around soot aggregates. However, some recent studies argue that soot remains fractal even when engulfed by the shells, collapsing only when the shells evaporate. To reconcile this disagreement, the effects of the condensation and …


Non-Traditional Methods For The Green Synthesis Of Fine Chemicals, Tara Renée Mooney Dec 2022

Non-Traditional Methods For The Green Synthesis Of Fine Chemicals, Tara Renée Mooney

Graduate Masters Theses

Herein, the advancement of microwave-assisted flow synthesis is reviewed and the green nitration of arenes is investigated. First, microwave-assisted flow systems are described, followed by their synthetic and environmental applications. Microwave-assisted flow synthesis has been applied successfully in organic, inorganic, material, and biochemical syntheses as well as environmental applications such as water desalination and the removal of volatile organic compounds from the atmosphere. In the second part of the Thesis, the methodological development of the first catalyst and solvent-free nitration of m-xylene using only nitric acid is detailed. This environmentally friendly reaction proceeds without the use of harsh Brønsted acids, …


Palladium (Ii)-Catalyzed Selective Reduction Of 4’-(Phenylethynl)Acetophenone In The Presence Of A Formic Acid-Triethylamine Mixture, Suzanne Chayya, Akram Hijazi, Anis Daou, Ali Alaaeddine, Mohamad Sakr, Ghassan Younes, Mohammad El-Dakdouki Dec 2022

Palladium (Ii)-Catalyzed Selective Reduction Of 4’-(Phenylethynl)Acetophenone In The Presence Of A Formic Acid-Triethylamine Mixture, Suzanne Chayya, Akram Hijazi, Anis Daou, Ali Alaaeddine, Mohamad Sakr, Ghassan Younes, Mohammad El-Dakdouki

BAU Journal - Science and Technology

An efficient and straightforward palladium acetylacetonate-catalyzed hydrogen transfer of 4'- (phenylethynyl)acetophenone was developed in this study. Formic Acid was found to be the best hydrogen source in this catalytic system in the presence of triethylamine. Excellent conversions and selectivity were obtained in reducing the starting internal aromatic alkyne to either (E)-1-(4- styrylphenyl)ethanone or an interesting cyclic product, 1-(phenanthrene-3-yl)ethenone, over the ketone functional group present. Over-reduction was rarely seen. The reaction conditions were optimized in terms of the choice of the palladium catalyst, temperature, solvent, and the H-donor/base combination. Using this catalytic system, a one-step synthetic pathway of the …


Feasibility Studies For Use Of Copper Slag In Clinker Manufacture, Suresh Vanguri, Suresh Palla, Gonthi Prasad, Sanjeev Kumar Chaturvedi, Bibekananda Mohapatra Dec 2022

Feasibility Studies For Use Of Copper Slag In Clinker Manufacture, Suresh Vanguri, Suresh Palla, Gonthi Prasad, Sanjeev Kumar Chaturvedi, Bibekananda Mohapatra

Makara Journal of Science

This study investigated the feasibility of using copper slag (CS-C) as a raw material in the production of Portland cement (PC). The effect of addition of 0%-3.5% CS-C on the clinkerization process, mineralogy, microstructure, and compressive strength development was studied. The Presence of CS-C in the raw mix resulted in the reduced temperature of clinkerization by about 50 °C. The quality of clinker prepared from the raw mix containing 3% CS-C and burned at 1400 °C was comparable to that of clinker prepared from the raw mix containing no CS-C and burned at 1450 °C. Gradual polymorphic modification of alite …


Carbon-Al Interface Effect On The Performance Of Ionic Liquid-Based Supercapacitor At 3 V And 65 OC, Zhen-Zhen Ye, Shu-Ting Zhang, Xin-Qi Chen, Jin Wang, Ying Jin, Chao-Jie Cui, Lei Zhang, Lu-Ming Qian, Gang Zhang, Wei-Zhong Qian Dec 2022

Carbon-Al Interface Effect On The Performance Of Ionic Liquid-Based Supercapacitor At 3 V And 65 OC, Zhen-Zhen Ye, Shu-Ting Zhang, Xin-Qi Chen, Jin Wang, Ying Jin, Chao-Jie Cui, Lei Zhang, Lu-Ming Qian, Gang Zhang, Wei-Zhong Qian

Journal of Electrochemistry

Ionic liquid (IL) electrolyte-based supercapacitors (SCs) have advantages of high operating voltage window, high energy density and nonflammability, as compared to conventional acetonitrile-based organic electrolyte SCs, and are typically suitable for the large-scale energy storage in the era of carbon neutrality full of renewable, but unstable electricity. However, current efforts were concentrated on the study with coin-cell type of IL-SCs, and less has been reported on the pouch type of IL-SCs for a long cycling time yet. To fabricate a reliable SC for the life time test or for the accelerated aging test under high temperature, one should concern the …


Advances On Composite Cathodes For Lithium-Sulfur Batteries, Xi-Yao Li, Chang-Xin Zhao, Bo-Quan Li, Jia-Qi Huang, Qiang Zhang Dec 2022

Advances On Composite Cathodes For Lithium-Sulfur Batteries, Xi-Yao Li, Chang-Xin Zhao, Bo-Quan Li, Jia-Qi Huang, Qiang Zhang

Journal of Electrochemistry

Lithium-sulfur (Li-S) batteries are deemed as high-promising next-generation energy storage technique due to their ultrahigh theoretical energy density, where the sulfur cathodes with high specific capacity guarantee the energy density advantage and directly determine the battery performances. After decades of exploration, the most promising sulfur cathodes are sulfur/carbon composite (S/C) cathodes and sulfurized polyacrylonitrile (SPAN) cathodes. In this manuscript, recent advances on S/C and SPAN cathodes in Li-S batteries are comprehensively reviewed. The electrochemical reaction circumstances on S/C and SPAN cathodes are firstly introduced and compared to reveal the working mechanisms of the two types of Li-S batteries. The S/C …


Multi-Electron Reaction-Boosted High Energy Density Batteries: Material And System Innovation, Rui-Qi Guo, Feng Wu, Xin-Ran Wang, Ying Bai, Chuan Wu Dec 2022

Multi-Electron Reaction-Boosted High Energy Density Batteries: Material And System Innovation, Rui-Qi Guo, Feng Wu, Xin-Ran Wang, Ying Bai, Chuan Wu

Journal of Electrochemistry

The continuous development of the global energy structure transformation has put forward higher demands upon the development of batteries. The improvements of the energy density have become one of the important indicators and hot topic for novel secondary batteries. The energy density of existing lithium-ion battery has encountered a bottleneck due to the limitations of material and systems. Herein, this paper introduces the concept and development of multi-electron reaction materials over the past twenty years. Guided by the multi-electron reaction, light weight electrode and multi-ion effect, current development strategies and future trends of high-energy-density batteries are highlighted from the perspective …


Preparation Of Highly-Cyclized Sulfurized Polyacrylonitrile For Lithium-Sulfur Batteries, Xuan Ji, Jia-Yu Wang, An-Bang Wang, Wei-Kun Wang, Ming Yao, Ya-Qin Huang Dec 2022

Preparation Of Highly-Cyclized Sulfurized Polyacrylonitrile For Lithium-Sulfur Batteries, Xuan Ji, Jia-Yu Wang, An-Bang Wang, Wei-Kun Wang, Ming Yao, Ya-Qin Huang

Journal of Electrochemistry

Sulfurized polyacrylonitrile (SPAN) is regarded as an attractive cathode candidate of lithium-sulfur (Li-S) batteries for its non-dissolution mechanism and effective alleviation of polysulfides shuttling issue in Li-S batteries, displaying high utilization of cathode active material, outstanding cycle stability and structural stability. However, the relation between cyclization degree and cycle stability of SPAN is still unveiled. In this work, SPAN-C-V composites were synthesized by co-introduction of CuSO4 and zinc n-ethyl-n-phenyldithiocarbamate (ZDB) in the co-heating of sulfur and polyacrylonitrile. The co-introduction of CuSO4 and ZDB reduced the cyclization reaction onset temperature of PAN while increased the C—C/C=C …


Application Of Artificial Intelligence To Lithium-Ion Battery Research And Development, Zhen-Wei Zhu, Jing-Yi Qiu, Li Wang, Gao-Ping Cao, Xiang-Ming He, Jing Wang, Hao Zhang Dec 2022

Application Of Artificial Intelligence To Lithium-Ion Battery Research And Development, Zhen-Wei Zhu, Jing-Yi Qiu, Li Wang, Gao-Ping Cao, Xiang-Ming He, Jing Wang, Hao Zhang

Journal of Electrochemistry

Lithium-ion batteries (LIBs) have become one of the best solutions to the energy storage issue in modern society. However, the battery materials and device development are both complex, and involve multivariable problems. Traditional trial-and-error approach, which relies on researchers to conduct experiments, has encountered bottlenecks in the improvement of the battery performance. Artificial intelligence (AI) is the most potential technology to deal with this issue due to its powerful high-speed and capabilities of processing massive data. In particular, the capability of machine learning (ML) algorithms in assessing multidimensional data variables and discovering patterns in the sets are expected to assist …


Multiomics Approach Captures Hepatic Metabolic Network Altered By Chronic Ethanol Administration, Isin Tuna Sakallioglu, Bridget Tripp, Jacy Kubik, Carol A. Casey, Paul G. Thomes, Robert Powers Dec 2022

Multiomics Approach Captures Hepatic Metabolic Network Altered By Chronic Ethanol Administration, Isin Tuna Sakallioglu, Bridget Tripp, Jacy Kubik, Carol A. Casey, Paul G. Thomes, Robert Powers

Chemistry Department: Faculty Publications

Using a multiplatform and multiomics approach, we identified metabolites, lipids, proteins, and metabolic pathways that were altered in the liver after chronic ethanol administration. A functional enrichment analysis of the multiomics dataset revealed that rats treated with ethanol experienced an increase in hepatic fatty acyl content, which is consistent with an initial development of steatosis. The nuclear magnetic resonance spectroscopy (NMR) and liquid chromatography–mass spectrometry (LC-MS) metabolomics data revealed that the chronic ethanol exposure selectively modified toxic substances such as an increase in glucuronidation tyramine and benzoyl; and a depletion in cholesterol-conjugated glucuronides. Similarly, the lipidomics results revealed that ethanol …


Late-Stage Functionalization Through Click Chemistry Provides Glut5-Targeting Glycoconjugate As A Potential Pet Imaging Probe, Adelina Oronova, Marina Tanasova Dec 2022

Late-Stage Functionalization Through Click Chemistry Provides Glut5-Targeting Glycoconjugate As A Potential Pet Imaging Probe, Adelina Oronova, Marina Tanasova

Michigan Tech Publications

The targeting of facilitative sugar transporters (GLUTs) has been utilized in the development of tools for diagnostics and therapy. The interest in this area is promoted by the phenomenon of alterations in cellular metabolic processes that are linked to multitudes of metabolic disorders and diseases. However, nonspecific targeting (e.g., glucose-transporting GLUTs) leads to a lack of disease detection efficiency. Among GLUTs, GLUT5 stands out as a prominent target for developing specific molecular tools due to its association with metabolic diseases, including cancer. This work reports a non-radiolabeled fluoride (19F) coumarin-based glycoconjugate of 2,5-anhydro-D-mannitol as a potential PET imaging probe that …


Preparation Of Methanediamine (Ch2(Nh2)2)—A Precursor To Nucleobases In The Interstellar Medium, Joshua H. Marks, Jia Wang, Ryan C. Fortenberry, Ralf I. Kaiser Dec 2022

Preparation Of Methanediamine (Ch2(Nh2)2)—A Precursor To Nucleobases In The Interstellar Medium, Joshua H. Marks, Jia Wang, Ryan C. Fortenberry, Ralf I. Kaiser

Faculty and Student Publications

Although methanediamine (CH2(NH2)2) has historically been the subject of theoretical scrutiny, it has never been isolated to date. Here, we report the preparation of methanediamine (CH2(NH2)2)—the simplest diamine. Low-temperature interstellar analog ices composed of ammonia and methylamine were exposed to energetic electrons which act as proxies for secondary electrons produced in the track of galactic cosmic rays. These experimental conditions, which simulate the conditions within cold molecular clouds, . result in radical formation and initiate aminomethyl (ĊH2NH2) and amino (NH2) radical chemistry. Exploiting tunable photoionization reflectron time-of-flight mass spectrometry (PI-ReToF-MS) to make isomer-specific assignments, methanediamine was identified in the gas …


Determination Of Total Ammonia Nitrogen By Gas-Diffusion Flow Injection Analysis (Gd-Fia)-Spectrophotometry Using Minnieroot Flower (Ruellia Tuberosa) As Natural Reagent, Lani Artana Putri, Puspita Mufidah Sari, Hermin Sulistyarti, Akhmad Sabarudin, Erwin Sulistyo Dec 2022

Determination Of Total Ammonia Nitrogen By Gas-Diffusion Flow Injection Analysis (Gd-Fia)-Spectrophotometry Using Minnieroot Flower (Ruellia Tuberosa) As Natural Reagent, Lani Artana Putri, Puspita Mufidah Sari, Hermin Sulistyarti, Akhmad Sabarudin, Erwin Sulistyo

Makara Journal of Science

Total ammonia nitrogen (TAN) is a pollutant agent found in water and generated from the metabolisms of living organisms and the decomposition of organic matter. This research aims to develop an efficient, low-cost, and environmentally friendly TAN analysis method. The principle of this method is based on the reaction of TAN injected in the donor stream with NaOH to form alkaline gaseous ammonia. The gaseous ammonia diffuses through a hydrophobic membrane into an acceptor stream containing Ruellia tuberosa extract. The presence of NH3 gas in the acceptor stream changes the extract color from pinkish to green, which is monitored …


Compatibility Of Crude Oil Blends─Processing Issues Related To Asphaltene Precipitation, Methods Of Instability Prediction─A Review, Krzysztof Bambinek, Andrzej Przyjazny, Grzegorz Boczkaj Dec 2022

Compatibility Of Crude Oil Blends─Processing Issues Related To Asphaltene Precipitation, Methods Of Instability Prediction─A Review, Krzysztof Bambinek, Andrzej Przyjazny, Grzegorz Boczkaj

Natural Sciences Publications

Processing crude oil of variable composition, especially due to the need to process crude oil blends obtained from various sources, presents a tremendous process challenge. This is mainly due to the destabilization of the colloidal system manifested mostly by the precipitation of the asphaltene fraction. The precipitation of asphaltenes from crude oil is a serious problem during extraction, transport, and processing. In the latter case, engineers and scientists have spent a lot of time determining what mechanisms are conducive to the occurrence of this phenomenon. On the one hand, there was a scientific curiosity about the principles of the nanoworld …


Metallacycle-Mediated Cross-Coupling As An Enabling Tool For Studies In Carbocycle Synthesis And Functionalization, Adam Barry Millham Dec 2022

Metallacycle-Mediated Cross-Coupling As An Enabling Tool For Studies In Carbocycle Synthesis And Functionalization, Adam Barry Millham

Dartmouth College Ph.D Dissertations

Natural products, specifically complex, carbocyclic natural products, have served as the inspiration for novel methods development for decades. Over that time, metallacycle-mediated cross-coupling has arisen as a powerful means for the synthesis of fused carbocycles. This work details three methods for the synthesis and functionalization of carbocyclic motifs that have been enabled by Ti-mediated cross-coupling reactions. The first of these studies include a complementary method to the Pauson–Khand reaction for the synthesis of highly substituted cyclopentenones via Ti-mediated alkyne–β-ketoester coupling. The second project, a modern approach to steroidal tetracycles, will be discussed that features: (1) an alkoxide-directed metallacycle-mediated [2+2+2] annulation …


Arginine Methylation Of The Pgc-1Α C‑Terminus Is Temperature- Dependent, Meryl Mendoz, Mariel Mendoza, Tiffany Lubrino, Sidney Briski, Immaculeta Osuji, Janielle Cuala, Brendan Ly, Ivan Ocegueda, Harvey Peralta, Benjamin A. Garcia, Cecilia Zurita-Lopez Dec 2022

Arginine Methylation Of The Pgc-1Α C‑Terminus Is Temperature- Dependent, Meryl Mendoz, Mariel Mendoza, Tiffany Lubrino, Sidney Briski, Immaculeta Osuji, Janielle Cuala, Brendan Ly, Ivan Ocegueda, Harvey Peralta, Benjamin A. Garcia, Cecilia Zurita-Lopez

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

We set out to determine whether the C-terminus (amino acids 481–798) of peroxisome proliferator-activated receptor gamma coactivator-1 alpha (PGC-1α, UniProt Q9UBK2), a regulatory metabolic protein involved in mitochondrial biogenesis, and respiration, is an arginine methyltransferase substrate. Arginine methylation by protein arginine methyltransferases (PRMTs) alters protein function and thus contributes to various cellular processes. In addition to confirming methylation of the C-terminus by PRMT1 as described in the literature, we have identified methylation by another member of the PRMT family, PRMT7. We performed in vitro methylation reactions using recombinant mammalian PRMT7 and PRMT1 at 37, 30, 21, 18, and 4 °C. …


Effect Of Temperature And Sodium Chloride Addition On The Conductivity Of Sodium (Polystyrene Sulfonate) Aqueous Solutions, Saida Asfour, Ahmed Ayyad, Fahed Takrori Dec 2022

Effect Of Temperature And Sodium Chloride Addition On The Conductivity Of Sodium (Polystyrene Sulfonate) Aqueous Solutions, Saida Asfour, Ahmed Ayyad, Fahed Takrori

Hebron University Research Journal-A (Natural Sciences) - (مجلة جامعة الخليل للبحوث- أ (العلوم الطبيعيه

The conductivity of sodium (polystyrene sulfonate) (NaPSS) aqueous solutions as a function of NaPSS concentration 0.15 g – 2.0 g NaPSS in 100 mL of distilled water, sodium chloride concentration (NaCl) in the range of 0.1 M - 0.4 M and in temperature range of 278 K – 328 K have been studied. The study found that conductivity increases with increasing NaPSS concentration both in pure water and in salt solution. It is also found that conductivity increases with increasing either NaCl concentration or temperature. The interesting finding here is that additivity rule, that the conductivity of the polyelectrolyte kps …


Speciated Isotope Dilution Mass Spectrometry In Combination With Thor’S Hammer Metaspike Technology For The Assessment Of Low-Level Biomarkers For Human Health Evaluation, Ashley Ebert Dec 2022

Speciated Isotope Dilution Mass Spectrometry In Combination With Thor’S Hammer Metaspike Technology For The Assessment Of Low-Level Biomarkers For Human Health Evaluation, Ashley Ebert

Electronic Theses and Dissertations

Our research team has been focused on quantifying important biological analytes in human blood samples to delineate the biochemical processes underlying certain states of dysfunction and evaluate treatment efficacy. These efforts have been guided by laboratory measurements with the input of medical experts. Speciated isotope dilution mass spectrometry (SIDMS) explained in detail in EPA Method 6800 has been successfully applied in the quantification of an important biomarker analyte for immune function and detoxification processes: glutathione. Past research has proven the molecule a biomarker for autism spectrum disorder (ASD) in the form of the reduced/oxidized glutathione (GSH/GSSG) ratio, and literature has …


Quantum Computations And Molecular Dynamics Simulations: From The Fundamentals Of Antimicrobial Resistance To Neurological Diseases, Angel Tamez Dec 2022

Quantum Computations And Molecular Dynamics Simulations: From The Fundamentals Of Antimicrobial Resistance To Neurological Diseases, Angel Tamez

Electronic Theses and Dissertations

Biophysical phenomena are modeled using a combination of quantum and classical methods to interpret and supplement three distinct and diverse problems in this dissertation. In the first project, decarboxylation reactions are ubiquitous across chemical and biological disciplines, yet the origin of non-catalytic solvent effects remains elusive. Specific solvent structure and energetics have not been well described for the monoanion of malonate, nor corrected from the gas-phase charge-assisted intramolecular hydrogen bond model known as “pseudochair”. In the aqueous phase, a low-lying energy conformer known as the “orthogonal conformation” is computed to be preferred by a three-water cluster of hydrogen bonding over …


Possible Overestimation Of Nitrogen Dioxide Outgassing During The Beirut 2020 Explosion, Ashraf Farahat, Nayla El-Kork, Ramesh P. Singh, Feng Jing Dec 2022

Possible Overestimation Of Nitrogen Dioxide Outgassing During The Beirut 2020 Explosion, Ashraf Farahat, Nayla El-Kork, Ramesh P. Singh, Feng Jing

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

On 4 August 2020, a strong explosion occurred near the Beirut seaport, Lebanon and killed more than 200 people and damaged numerous buildings in the vicinity. As Amonium Nitrate (AN) caused the explosion, many studies claimed the release of large amounts of NO2 in the atmosphere may have resulted in a health hazard in Beirut and the vicinity. In order to reasonably evaluate the significance of NO2 amounts released in the atmosphere, it is important to investigate the spatio-temporal distribution of NO2 during and after the blast and compare it to the average day-to-day background emissions from …


Acetylacetone Oxidation At Room Temperature: A Multiplexed Photoionization Mass Spectrometric Investigation, Study Of The Russell Intermediates In Gas Phase Reactions, And The Investigation Of Oxidation Reaction Products Of Ethanol At Room Temperature, Sara Gallarati Dec 2022

Acetylacetone Oxidation At Room Temperature: A Multiplexed Photoionization Mass Spectrometric Investigation, Study Of The Russell Intermediates In Gas Phase Reactions, And The Investigation Of Oxidation Reaction Products Of Ethanol At Room Temperature, Sara Gallarati

Master's Theses

This thesis presents the combustion study of acetyl acetone using synchrotron radiation coupled with multiplexed photoionization mass spectrometry at 298 K. The experiments were performed at the Chemical Dynamics Beamline 9.0.2 at the Advanced Light Source of the Lawrence Berkeley National Laboratory. The reaction of acetyl acetone with chlorine (Cl) radicals was analyzed based on their photoionization spectra and reaction kinetic profiles.

Additionally, a study of the Russell intermediate has been performed. Previous to experimentation at the Advanced Light Source, computational analysis has been investigated to evaluate compounds that could possibly lead to the formation of a stable species. The …


Gold (I) Tetrathiomolybdate Clusters: Synthesis, Characterization, Computational Studies, And Reactivity With Thiophenol And Selenophenol, Dhirgam Humaidy Dec 2022

Gold (I) Tetrathiomolybdate Clusters: Synthesis, Characterization, Computational Studies, And Reactivity With Thiophenol And Selenophenol, Dhirgam Humaidy

Electronic Theses and Dissertations

This thesis describes the synthesis and reactivity of heterometallic complexes containing medicinally active Au(I) and tetrathiomolybdate, [MoS4]2-. The research is motivated by the idea of multifunctional drugs, which are designed to treat diseases through two or more mechanisms of action. Five clusters of the general form, [MoS4(AuL)2] were prepared: C-1 (L=IPr), C-2 (L=IBzMe), C-3 (L=IMes), C-4 (L=PPh3), and C-5 (L=PEt3). The clusters with NHC ligands, C-1, C-2, and C-3 were prepared for the first time and thoroughly characterized by 1H NMR,13C{1H} …


Chemical Elements, Flavor Chemicals, And Nicotine In Unused And Used Electronic Cigarettes Aged 5–10 Years And Effects Of Ph, Monique Williams, Wentai Luo, Kevin J. Mcwhirter, Omeka Ikegbu, Prue Talbot Dec 2022

Chemical Elements, Flavor Chemicals, And Nicotine In Unused And Used Electronic Cigarettes Aged 5–10 Years And Effects Of Ph, Monique Williams, Wentai Luo, Kevin J. Mcwhirter, Omeka Ikegbu, Prue Talbot

Chemistry Faculty Publications and Presentations

The concentrations of elements/metals, nicotine, flavor chemicals and acids were compared in the e-liquids of unused and used first-generation electronic cigarettes (ECs) that were stored for 5–10 years. Metal analysis was performed using inductively coupled plasma optical emission spectroscopy; nicotine and flavor chemical analyses were performed using gas chromatography/mass spectroscopy. Of the 22 elements analyzed, 10 (aluminum, chromium, copper, iron, lead, nickel, selenium, silicon, tin, zinc) were often found in the e-liquids. Five elements had the highest average concentrations: copper (1161.6 mg/L), zinc (295.8 mg/L), tin (287.6 mg/L), nickel (71.1 mg/L), and lead (50.3 mg/L). Nicotine concentrations were always lower …


Sunflower Oil-Based Polyol In Flame-Retardant Rigid Polyurethane Foams, Magdalene Asare Dec 2022

Sunflower Oil-Based Polyol In Flame-Retardant Rigid Polyurethane Foams, Magdalene Asare

Electronic Theses & Dissertations

The current shift from solely depending on petroleum sources to seeking renewable alternatives is due to their fast depletion, spike in prices, and the need to reduce our carbon footprint. For instance, the polyurethane industry currently calls for renewable and less toxic polyols and isocyanates for their synthesis over the traditionally used ones. To tackle an aspect of this matter, this work investigates the generation of polyol from sunflower oil, and further probes their use in rigid foams, one of the widely utilized polyurethanes. Epoxidation and ring-opening reactions were used to convert the sunflower oil into a more reactive form, …


Bio-Based Uv-Curable Films And The Effect Of Bio-Content On The Properties Of The Films, Sahilkumar Chaudhary Dec 2022

Bio-Based Uv-Curable Films And The Effect Of Bio-Content On The Properties Of The Films, Sahilkumar Chaudhary

Electronic Theses & Dissertations

The use of renewable resources in film formation has become a new focal point for industry because it is abundantly available and has less carbon emission during production than traditional ones. This has drawn researchers to investigate the functionality of bio-based raw materials and their end-usage. By modifying their chemical structures, the properties of these films like thermal resistance, impact resistance, and chemical resistance can be increased. In this research, limonene was used as a partial replacement for petroleum-based chemicals in film formation. A two-step chemical process was carried out to modify the limonene and the final product was used …


Development Of Novel Nucleophile-Intercepted Beckmann Fragmentations And Progress Toward The Total Synthesis Of 2(S)-Cathafoline, Evan M. Dunkley Dec 2022

Development Of Novel Nucleophile-Intercepted Beckmann Fragmentations And Progress Toward The Total Synthesis Of 2(S)-Cathafoline, Evan M. Dunkley

Dartmouth College Master’s Theses

This thesis is comprised of two chapters, the first being the discovery of a novel nucleophile-intercepted Beckmann fragmentation of [2.2.1] indoline systems that resulted in highly stereo- and regioselective reactions. Chapter one details the exploration of this reaction as well as its relevant background information detailing its significance. Chapter two describes the application of the novel nucleophile-intercepted Beckmann fragmentation in the context of a total synthesis of akuammilline alkaloid 2(S)-cathafoline. While the target natural product was never synthesized, unpredicted reactivity resulted in interesting discoveries worthy of discussion.


Local Spectroscopy Data Infrastructure: Solid State Nmr Crystallography With Experiment, First-Principal Analysis And Machine Learning, He Sun Dec 2022

Local Spectroscopy Data Infrastructure: Solid State Nmr Crystallography With Experiment, First-Principal Analysis And Machine Learning, He Sun

Arts & Sciences Electronic Theses and Dissertations

Solid-state magnetic resonance (SSNMR) spectroscopy is a powerful tool for obtaining precise information about the local bonding and morphology of materials. The detailed local structure of crystalline materials cannot be easily solved by traditional experimental methods such as X-ray diffraction (XRD). SSNMR combined with first principal calculation methods such as density functional theory (DFT) can be of great use in this research area. The methodology that is called “NMR crystallography” today has been widely applied to the determination of a wide range of solid materials with an increasing amount of computationally simulated NMR spectra. The construction of a well-established computational …


Development Of Redox-Responsive Phenazine-Based Foldamers. Acylative Kinetic Resolution Of Hydroxamic Acids, Jingwei Yin Dec 2022

Development Of Redox-Responsive Phenazine-Based Foldamers. Acylative Kinetic Resolution Of Hydroxamic Acids, Jingwei Yin

Arts & Sciences Electronic Theses and Dissertations

Two different research directions have been presented in this thesis. The first project is about phenazine-based foldamers as molecular actuators. Researchers have been interested in the design and synthesis of foldamers and molecular actuators for years. We began our exploration by demonstrating that phenazine-1,6-dicarboxamides can function as redox-responsive molecular switches. We then designed and synthesized two generations of phenazine-based interleafed foldamers and studied their stability and redox behaviors under chemical and electrochemical conditions. In the second project, we have developed the first acylative kinetic resolution on hydroxamic acids. Although chiral hydroxamic acids have extensive applications, synthetic methods towards them are …


Toward Enhancing The Synthesis Of Renewable Polymers: Feedstock Conversions And Functionalizable Copolymers, Tedd Casey Wiessner Dec 2022

Toward Enhancing The Synthesis Of Renewable Polymers: Feedstock Conversions And Functionalizable Copolymers, Tedd Casey Wiessner

Arts & Sciences Electronic Theses and Dissertations

This thesis describes research under the rubric of the Center for Sustainable Polymers that is aimed at two separate goals. The goal of the first project (Chapters 1 and 2) was to develop a deeper mechanistic understanding of a method for the synthesis of linear α-olefins, while the second aimed at synthesizing statistical copolymers that incorporate olefin-containing monomers through ring-opening transesterification polymerization and showing that these copolymers could be functionalized. In Chapter 1, published methods for the conversion of fatty acids to linear α-olefins are reviewed to provide context for the mechanistic work we accomplished (Chapter 2). In Chapter 2 …