Chemistry Commons^™

Poly(Ionic Liquid)S For Magnetic, Ionic, And Electrical Stimuli-Responsive Applications, Kayla Ann Foley

Graduate Theses and Dissertations

Poly(ionic liquid)s (PILs) are a fascinating subclass of strong polyelectrolytes formed from polymerizable ionic liquids. As a result of their unique properties and counterion exchangeability, PILs can exhibit conformation structure or material property changes in response to external stimuli such as changes in pH/ionic environment, magnetic fields, and electric potentials. In Chapter 1, a comprehensive review of PILs design as well as their stimuli-responsive behavior is provided. Additional motivation for each dissertation chapter is also discussed. In Chapter 2, magnetically responsive PILs (MPILs) are developed from complexing paramagnetic salts with a random PIL copolymer containing a metal-coordinating co-monomer, acrylamide. A …

Crystal Structure Of A (Carboxymethyl) Triethylazanium Bromide–2-(Triethylazaniumyl) Acetate (1/1) Hydrogen-Bonded Dimer, Faith M. Carlson, Richard J. Staples, Shannon Biros

Open Access Publishing Support Funded Articles

The title compound, C₈H₁₈NO₂⁺·Br⁻·C₈H₁₇NO₂, crystallizes as the bromide salt of a 50:50 mixture of (tri­ethyl­azaniumyl)­carb­oxy­lic acid and the zwitterionic (tri­ethyl­azaniumyl)­carboxyl­ate. The two organic entities are linked by a half-occupied bridging carb­oxy­lic acid hydrogen atom that is hydrogen-bonded to the carboxyl­ate group of the second mol­ecule. The tetra­lkyl­ammonium group adopts a nearly perfect tetra­hedral shape around the nitro­gen atom with bond lengths that agree with known values. The carb­oxy­lic acid/carboxyl­ate group is oriented anti to one of the ethyl groups on the ammonium group, and the …

Aerosol Mutagenicity In San Bernardino, California Via Bacterial Fluctuation Tests, Sean Murphy

Electronic Theses, Projects, and Dissertations

San Bernardino, California’s poor air quality is a health risk to its population with some of the highest concentrations of ozone and aerosol in the United States. Aerosols are solid or liquid particles suspended in the air. Smaller aerosol particles are the most harmful as they are more likely to penetrate further into the respiratory system. These aerosols can cause respiratory issues and contain toxic compounds. One measure of aerosol toxicity is to study the mutagenicity of the aerosol. To study the mutagenicity of aerosol samples collected in San Bernardino in 2022, fluctuation tests (based on the Ames test for …

Leveraging Non-Covalent Interactions Between Small Organic Molecules And Inorganic Scaffolds In The Design Of Advanced Materials, Jonathan Lefton

Chemistry Theses and Dissertations

Powder diffraction is a powerful tool for studying crystal structures, especially as it relates to interactions of small organic molecules with inorganic compounds. The first part of this dissertation involves small organic ligands interacting with metal-organic framework, MOF-74. The first and simplest iteration involves the crystal structure solution of a neat, liquid loading of n-propylmercaptan to the open metal sites within the MOF-74 pores. Later studies investigate the leveraging of a similarly sized bitopic ligand in the solution loading of 1,2-ethanedithiol, which results in the amorphization of MOF-74. Having no crystallinity, amorphous or severely defected materials can be a …

The Emergence Of Zerovalent Carbon Compounds From Structural Curiosities To Organocatalysts, Allegra L. Liberman-Martin

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Low-valent main group compounds have reactivity patterns and properties reminiscent of transition metals. While divalent carbon compounds such as carbenes are widely studied ligands and organocatalysts, zerovalent carbon species have received considerably less attention. This perspective highlights the properties and reactivity of zerovalent carbon compounds, focusing on their first applications as organocatalysts for small molecule reduction and polymerization reactions.

The Driving Effects Of Common Atmospheric Molecules For Formation Of Clusters: The Case Of Sulfuric Acid, Formic Acid, Hydrochloric Acid, Ammonia, And Dimethylamine, Olivia M. Longsworth, Conor J. Bready, George C. Shields

Open Access Fund Publications

One of the main sources of uncertainty for understanding global warming is understanding the formation of larger secondary aerosols. The beginning stages start with the formation of prenucleation complexes from precursor monomers of acids, bases, and organic molecules. The detailed interactions responsible for prenucleation and subsequent aerosol formation are difficult to decipher experimentally. We present a computational chemistry study of the interactions between three different acid molecules and two different bases. By combining a comprehensive search routine covering many thousands of configurations at the semiempirical level with high level quantum chemical calculations of approximately 1000 clusters for every possible combination …

The Investigation Of Singlet Fission From The Perspective Of Hierarchy Of Pure States (Hops), Tao (James) Chen

Chemistry Theses and Dissertations

This thesis provides a preliminary investigation of singlet fission from the perspective of Hierarchy of pure states (HOPS), which provides a numerical exact solution for the investigation of a series of open quantum systems. Since the inception of the concept of singlet fission about half a century ago, this photo-physical process has attracted the attention of a multitude of researchers and has been extensively studied theoretically and experimentally. However, these previous methods for the investigation of singlet fission focus more or less on tackling the underlying mechanisms of singlet fission from the perspective of perturbation. So far, the HOPS method …

The Investigation Of Singlet Fission From The Perspective Of Hierarchy Of Pure States (Hops), Tao (James) Chen

Chemistry Theses and Dissertations

This thesis provides a preliminary investigation of singlet fission from the perspective of Hierarchy of pure states (HOPS), which provides a numerical exact solution for the investigation of a series of open quantum systems. Since the inception of the concept of singlet fission about half a century ago, this photo-physical process has attracted the attention of a multitude of researchers and has been extensively studied theoretically and experimentally. However, these previous methods for the investigation of singlet fission focus more or less on tackling the underlying mechanisms of singlet fission from the perspective of perturbation. So far, the HOPS method …

Elucidating The Impacts Of Learning Communities On Retention, Student Sense Of Belonging, And Self-Efficacy In Stem, Honour Williams

Master of Science in Chemical Sciences Theses

Student sense of belonging (SoB) and self-efficacy (SE) are necessary aspects of promoting achievement and success in the STEM fields. This study focuses on how learning communities affect students' SoB and SE in relation to STEM as well as demographics, including race, gender, and first-generation status. Students enrolled in either the introductory chemistry lecture or the first-year experience course (students grouped by similar STEM major) were asked to complete a STEM attributes survey (Likert scale) to assess their overall SoB to the university and their chosen major as well as their level of SE in relations to those fields. To …

Electrochemical Hydrogen Gas Production And Carbon Dioxide Sequestration Via In Situ Formation Of Nickel (Ii) Tris-(Pyridinethiolate) Derivatives, Dayalis Sv. Brown

Dissertations and Theses

In the research presented, we use electrochemical techniques, such as cyclic voltammetry and controlled potential electrolysis, to study in situ formation of hydrogen evolution catalysts which also reduce carbon dioxide. Using pyridinethiol-based ligands and a nickel (II) precursor, both homo- and heteroleptic complexes were investigated as catalysts to produce alternative fuels while mitigating greenhouse gas emissions. Existing synthetic procedures to obtain these Ni(II) catalysts lead to low yields of the complexes and difficulties in crystallizing samples for further analysis, limiting sample size and restricting the number of studies. While current research is heavily focused on photochemically-driven experiments, given that solar …

Synthesis And Reactivity Of Dihydrogen Diruthenium Complexes., Ryder J. Downey, Robert Chin

Summer Undergraduate Research Program (SURP) Symposium

Having two open coordination sites on the diruthenium complex makes for the ability to be able to be more precise when interacting with other compound. The side-on bonding of the bis(dihydrogen) gives it unique characteristics as well as unique capabilities. The Oganotransition Metal Chemistry book says that the dihydrogen is bonded by the donation of electrons from the H-H sigma bond as well as the back donation of electron density through the transition metal.3

In the past, many groups have studies on a mononuclear Ruthenium compound similar to the one we are synthesizing (see figure one). Our goal was to …

Watermark Hiding In Hdr Image Based On Visual Saliency And Tucker Decomposition, Roa'a M. Al-Airaji, Ibtisam A. Aljazaery, Haider Th. Salim Alrikabi

Karbala International Journal of Modern Science

Recently, great attention has been paid to high dynamic range (HDR) images because of their richly detailed and high dynamic range of intensity. The need for pre-processing of the HDR image format with tone mapping (TM) operators makes it unique; the TM operators are provided on display with a low dynamic range (LDR). On the other hand, TM can be regarded as an inevitable attack when protecting HDR image ownership is considered. An adaptive approach for concealing watermarks based on visual saliency and Tucker decomposition has been presented in this article. In the first step, three feature maps were produced …

Recent Progress Of Bifunctional Electrocatalysts For Oxygen Electrodes In Unitized Regenerative Fuel Cells, Tian-Long Zheng, Ming-Yu Ou, Song Xu, Xin-Biao Mao, Shi-Yi Wang, Qing-Gang He

Journal of Electrochemistry

Unitized regenerative fuel cells (URFCs), which oxidize hydrogen to water to generate electrical power under thefuel cells (FCs) mode and electrolyze water to hydrogen under the water electrolysis (WE) mode for recycling, areknown as clean and sustainable energy conversion devices. In contrast to the hydrogen oxidation reaction (HOR) andhydrogen evolution reaction (HER) on the hydrogen electrode side, the sluggish kinetics of oxygen reduction reaction(ORR) and oxygen evolution reaction (OER) on the oxygen electrode side requires highly efficient bifunctional oxygencatalysts. Conventional precious metal oxygen catalysts combine Pt and IrO₂ with excellent ORR and OER activities toachieve bifunctional electrocatalysis performance, but …

Ultramicroelectrode Experiments: Principles, Fabrications And Voltmmetric Behaviors, Zhen Ma, Jia-Yang Lin, Wen-Jing Nan, Lian-Huan Han, Dong-Ping Zhan

Journal of Electrochemistry

Due to the small size at least in one dimension (< 25 μm), ultramicroelectrode (UME) has small electric-double-layer capacitance, low IR drop, rapid mass transfer rate, fast response, high signal/noise ratio and high spatiotenporal resolution. UME is qualified not only to study the kinetics of fast electrode processes, but also to act as the probe of scanning electrochemical microscopies to obtain the localized chemical or electrochemical reactivity of the substrates. Thus, UMEs play a significant role in various research domains of electrochemistry, and have become an important electrochemical experimental method. Herein, we will introduce the basic principles, a simple fabrication method and voltammetric experimental protocols of UME, providing a guide to carry out the UME experiments.

Band Alignments Of Metal/Oxides-Water Interfaces Using Ab Initio Molecular Dynamics, Yong-Bin Zhuang, Jun Cheng

Journal of Electrochemistry

Band alignments of electrode-water interfaces are of crucial importance for understanding electrochemical interfaces. In the scenario of electrocatalysis, applied potentials are equivalent to the Fermi levels of metals in the electrochemical cells; in the scenario of photo(electro)catalysis, semiconducting oxides under illumination have chemical reactivities toward redox reactions if the redox potentials of the reactions straddle the conduction band minimums (CBMs) or valence band maximums (VBMs) of the oxides. Computational band alignments allow us to obtain the Fermi level of metals, as well as the CBM and VBM of semiconducting oxides with respect to reference electrodes. In this tutorial, we describe …

Electrochemical Scanning Tunneling Microscopy: Taking The Initial Stage Of Cu Electrodeposition On Au(111) As An Example, Zhuo Tan, Kai-Xuan Li, Bing-Wei Mao, Jia-Wei Yan

Journal of Electrochemistry

Electrochemical scanning tunneling microscopy (ECSTM) plays an important role in the field of electrochemistry, which can obtain potential-dependent structural information of electrode surface with high spatial resolution and observe some reaction processes in electrolyte solutions, and provide a powerful way to understand the interfacial structure and electrode processes from the perspective of high spatial resolution. In this article, the study of electrodeposition of Cu on Au (111) by ECSTM is taken as an example to introduce the experimental methods required for ECSTM and share our experience with other electrochemical groups. Firstly, the working principle of STM is introduced so that …

62nd Annual Rocky Mountain Conference On Magnetic Resonance

Rocky Mountain Conference on Magnetic Resonance

Final program, abstracts, and information about the 62nd annual meeting of the Rocky Mountain Conference on Magnetic Resonance, co-endorsed by the Colorado Section of the American Chemical Society and the Society for Applied Spectroscopy. Held in Sonesta Denver Downtown, Denver, Colorado, July 23-27, 2023.

Understanding Formation And Roles Of Niᴵᴵ Aryl Amido And Niiii Aryl Amido Intermediates In Ni-Catalyzed Electrochemical Aryl Amination Reactions, Jian Luo, Michael T. Davenport, Chad Callister, Shelley D. Minteer, Daniel H. Ess, T. Leo Liu

Chemistry Faculty Research & Creative Works

Ni-catalyzed electrochemical aryl amination (e-amination) is an attractive, emerging approach to building C-N bonds. Here, we report in-depth experimental and computational studies that examined the mechanism of Ni-catalyzed e-amination reactions. Key NiII-amine dibromide and NiII aryl amido intermediates were chemically synthesized and characterized. the combination of experiments and DFT calculations suggest (1) there is coordination of an amine to the NiII catalyst before the cathodic reduction and oxidative addition steps, (2) a stable NiII aryl amido intermediate is produced from the cathodic half-reaction, a critical step in controlling the selectivity between cross-coupling and undesired homo-coupling reaction pathways, (3) the diazabicycloundecene …

Exfoliation And Spray Deposition Of Graphene Nanoplatelets In Ethyl Acetate And Acetone: Implications For Additive Manufacturing Of Low-Cost Electrodes And Heat Sinks, Muhammed Ramazan Oduncu, Zhifan Ke, Bingyuan Zhao, Zhongxia Shang, Robin Simpson, Haiyan Wang, Alexander Wei

Department of Chemistry Faculty Publications

Nonaqueous dispersions of graphene nanoplatelets (GrNPs) can be used to prepare thin films and coatings free of surfactants, but typically involve polar organic solvents with high boiling points and low exposure limits. Here, we describe the mechanochemical exfoliation and dispersion of GrNPs in volatile aprotic solvents such as ethyl acetate (EtOAc) and acetone, which rank favorably in green solvent selection guides. GrNPs in powder form were exfoliated with a solvent on a horizontal ball mill for 48 h and then sonicated at moderate power to produce suspensions in excess of 300 μg/mL with minimum loss of dispersion stability over 7 …

C···O And Si···O Tetrel Bonds: Substituent Effects And Transfer Of The Sif3 Group, Zhihao Niu, Qiaozhuo Wu, Qingzhong Li, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The tetrel bond (TB) between 1,2-benzisothiazol-3-one-2-TF₃-1,1-dioxide (T = C, Si) and the O atom of pyridine-1-oxide (PO) and its derivatives (PO-X, X = H, NO₂, CN, F, CH₃, OH, OCH₃, NH₂, and Li) is examined by quantum chemical means. The Si···O TB is quite strong, with interaction energies approaching a maximum of nearly 70 kcal/mol, while the C···O TB is an order of magnitude weaker, with interaction energies between 2.0 and 2.6 kcal/mol. An electron-withdrawing substituent on the Lewis base weakens this TB, while an electron-donating group has the opposite …

Thieno[3,4-D]Pyrimidin-4(3h)-Thione: An Effective, Oxygenation Independent, Heavy-Atom-Free Photosensitizer For Cancer Cells, Luis A. Ortiz-Rodríguez, Sean J. Hoehn, Heather J. Folkwein, Liraz Levi, Carlos E. Crespo-Hernández

Faculty Scholarship

All-organic, heavy-atom-free photosensitizers based on thionation of nucleobases are receiving increased attention because they are easy to make, noncytotoxic, work both in the presence and absence of molecular oxygen, and can be readily incorporated into DNA and RNA. In this contribution, the DNA and RNA fluorescent probe, thieno[3,4-d]pyrimidin-4(1H)-one, has been thionated to develop thieno[3,4-d]pyrimidin-4(3H)-thione, which is nonfluorescent and absorbs near-visible radiation with about 60% higher efficiency. Steady-state absorption and emission spectra are combined with transient absorption spectroscopy and CASPT2 calculations to delineate the electronic relaxation mechanisms of both pyrimidine derivatives in aqueous and acetonitrile solutions. It is demonstrated that thieno[3,4-d]pyrimidin-4(3H)-thione …

Enhanced Quantum Chemistry With Machine Learning, Brock Dyer

Physics and Astronomy Summer Fellows

This file is a catalogue of the relevant quantum mechanical and computer programming topics that I learned during the summer which will be helping me to generate an artificial intelligence that will be able to perform computational chemical calculations at a much faster rate and comparable or better accuracy than current methods.

Carbon Nanotubes Animated, Nicholas Onyemeke

Chemistry Summer Fellows

In this project, I implemented the knowledge about carbon nanotubes into an animated short. The animated short is meant to simplify the research so that anyone can understand regardless of their background in science. The research I did was on how nanotubes can be used in the medical field as a measure to inhibit bacteria growth. A nanotube dye solution was synthesized to inoculate bacteria along with an antibiotic solution with the nanotubes. This was done to observe how well the nanotubes can inhibit bacteria growth without the need for a drug compared to the effectiveness when it has a …

Ortho-Fluoro Effect On The C–C Bond Activation Of Benzonitrile Using Zerovalent Nickel, Sébastien Lachaize, Dominique C. Gallegos, Juliana J. Antonio, Abdurrahman C. Atesin, Tülay A. Ateşin, William D. Jones

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Chemistry)

The effect of fluoro substitution on the C–C bond activation of aromatic nitriles has been studied by reacting a variety of fluorinated benzonitriles with the nickel(0) fragment [Ni(dippe)] and by locating the reaction intermediates and transition-state structures on the potential energy surface by using density functional theory calculations with the [Ni(dmpe)] fragment (dippe = 1,2-bis(diisopropylphosphino)ethane, dmpe = 1,2-bis(dimethylphosphino)ethane). As in the previous reports, the reaction of fluorinated benzonitriles with the [Ni(dippe)] fragment initially formed an η2-nitrile complex, which then converted to the C–CN bond activation product. Thermodynamic parameters for the equilibrium between these complexes have been determined experimentally in both …

Measuring And Enhancing The Ionic Conductivity Of Chloroaluminate Electrolytes For Al-Ion Batteries, Anthony J Lucio, Iwan Sumarlan, Elena Bulmer, Igor Efimov, Stephen Viles, A Robert Hillman, Christopher J Zaleski, Karl S Ryder

Faculty, Staff and Student Publications

At the core of the aluminum (Al) ion battery is the liquid electrolyte, which governs the underlying chemistry. Optimizing the rheological properties of the electrolyte is critical to advance the state of the art. In the present work, the chloroaluminate electrolyte is made by reacting AlCl3 with a recently reported acetamidinium chloride (Acet-Cl) salt in an effort to make a more performant liquid electrolyte. Using AlCl3:Acet-Cl as a model electrolyte, we build on our previous work, which established a new method for extracting the ionic conductivity from fitting voltammetric data, and in this contribution, we validate the method across a …

High Resolution Intracavity Laser Absorption Spectroscopy Of Transition Metal-Containing Diatomic Molecules, Kristin Bales

Dissertations

Three transition metal-containing diatomic molecules have been studied using intracavity laser spectroscopy. Many of the transitions were recorded using a Fourier-transform spectrometer for detection, allowing collection at Doppler-limited resolution for the gas phase molecules. Several vibrational bands in two electronic transition systems of tantalum fluoride (TaF) have been analyzed, and new molecular constants provided. Transitions involving six electronic states of tungsten sulfide (WS) have been analyzed, with new and updated constants provided, including a deperturbation analysis of three vibrational bands in two of the states. Finally, a fresh perspective on two electronic states of tungsten oxide (WO) included a deperturbation …

Degradation Of Oligo[Poly(Ethylene Glycol) Fumarate] Hydrogels Through Stimulus-Mediated Pendent Group Cyclization, Andrew Chung, Burak Tavsanli, Elizabeth Gillies

Chemistry Publications

Hydrogels are of interest for a wide range of applications including drug delivery, regenerative medicine, agriculture, and personal care products. Among the water-soluble synthetic polymers that can be processed to form hydrogels, oligo[poly(ethylene glycol) fumarate] (OPF) has attracted significant attention. The degradation of OPF can be tuned to some extent based on the poly(ethylene glycol) chain length and amount of cross-linker incorporated, but the degradation is generally quite slow, occurring over several months. Here we introduce a new approach to tune and trigger the degradation of OPF. Fumarate alkenes were functionalized to introduce protected pendent amines, that after deprotection could …

New Chemical Dopant And Counterion Mechanism For Organic Electrochemical Transistors And Organic Mixed Ionic–Electronic Conductors, Vianna N. Le, Joel H. Bombile, Gehan S. Rupasinghe, Kyle N. Baustert, Ruipeng Li, Iuliana P. Maria, Maryam Shahi, Paula Alacon Espejo, Iain Mcculloch, Kenneth R. Graham, Chad Risko, Alexandra F. Paterson

Chemistry Faculty Publications

Organic mixed ionic–electronic conductors (OMIECs) have varied performance requirements across a diverse application space. Chemically doping the OMIEC can be a simple, low-cost approach for adapting performance metrics. However, complex challenges, such as identifying new dopant materials and elucidating design rules, inhibit its realization. Here, these challenges are approached by introducing a new n-dopant, tetrabutylammonium hydroxide (TBA-OH), and identifying a new design consideration underpinning its success. TBA-OH behaves as both a chemical n-dopant and morphology additive in donor acceptor co-polymer naphthodithiophene diimide-based polymer, which serves as an electron transporting material in organic electrochemical transistors (OECTs). The combined effects enhance OECT …

Rhodium-Catalyzed Asymmetric Synthesis Of P-P And P-C Bonds, Sarah T. Chachula

Dartmouth College Ph.D Dissertations

Chapter 1: Synthesis, Structure, Dynamics, and Enantioface-Selective η3-Benzyl Coordination in the Chiral Rhodium Complexes Rh(diphos*)(η3-CH2Ph) Abstract: The rhodium benzyl complexes Rh(diphos*)(η3-CH2Ph) (1-14, diphos* = chiral bis(phosphine)) were prepared either by treatment of Rh(COD)(η3-CH2Ph) (15, COD = 1,5-cyclooctadiene) with diphos*, or from the reaction of [Rh(diphos*)(Cl)]2 (16- 20) with PhCH2MgCl. For C2-symmetric diphos*, observation of one set of NMR signals for complexes 1-12 suggested that the two diastereomers in which different 3-benzyl enantiofaces were coordinated to rhodium interconverted rapidly on the NMR time scale via suprafacial shifts; observation of five inequivalent aryl 1H NMR signals showed that antarafacial shifts were slow …

Synthesis Of Tools For The Investigation And Treatment Of Infectious Diseases, Grant Lawrence

USF Tampa Graduate Theses and Dissertations

Modern medicine’s ability to treat a wide array of diseases is due mainly to the development of small-molecule drug discovery. Thousands of years of traditional medicines have been dwarfed in less than a hundred years. In addition, drug discovery has becoming a more consistent process with the introduction of the clinical trials process as well.Plasmodium is a genus of tropical parasites that have the potential to wreak havoc on billions of people globally. Current methods of drug discovery aimed at defeating these parasites require expensive assays that use radioactive material. By using an alkyne-labeled agent instead of a tritium-labeled agent, …