Chemistry Commons^™

Vacancy Control In Acene Blends Links Exothermic Singlet Fission To Coherence, Clemens Zeiser, Chad Cruz, David R. Reichman, Michael Seitz, Jan Hagenlocher, Eric L. Chronister, Christopher J. Bardeen, Roel Tempelaar, Katharina Broch

Chemistry and Biochemistry Faculty Research

The fission of singlet excitons into triplet pairs in organic materials holds great technological promise, but the rational application of this phenomenon is hampered by a lack of understanding of its complex photophysics. Here, we use the controlled introduction of vacancies by means of spacer molecules in tetracene and pentacene thin films as a tuning parameter complementing experimental observables to identify the operating principles of different singlet fission pathways. Time-resolved spectroscopic measurements in combination with microscopic modelling enables us to demonstrate distinct scenarios, resulting from different singlet-to-triplet pair energy alignments. For pentacene, where fission is exothermic, coherent mixing between the …

Singlet Fission In Acene Blends, Katharina Broch, Clemens Zeiser, Chad Cruz, Luca Moretti, Margherita Maiuri, Eric Chronister, David Reichman, Roel Tempelaar, Giulio Cerullo, Christopher Bardeen

Chemistry and Biochemistry Faculty Research

Singlet fission (SF), the photophysical process converting an excited singlet exciton into two triplet excitons, is a promising approach to boost solar cell efficiencies. It is controlled by various parameters such as intermolecular interactions, energetics, entropy and vibronic coupling and a controlled modification of these parameters is key to a fundamental understanding. Blends of organic semiconductors present an interesting alternative to established methods of chemical functionalization and their potential for the study of SF pathways will be discussed using acene blends as example. Mixed thin films of SF chromophores and weakly interacting, high-bandgap spacer molecules allow one to study the …

Controllable Co2 Electrocatalytic Reduction Via Ferroelectric Switching On Single Atom Anchored In2se3 Monolayer, Lin Ju, Xin Tan, Xin Mao, Yuantong Gu, Sean Smith, Aijun Du, Zhongfang Chen, Changfeng Chen, Liangzhi Kou

Physics & Astronomy Faculty Research

Efficient and selective CO2 electroreduction into chemical fuels promises to alleviate environmental pollution and energy crisis, but it relies on catalysts with controllable product selectivity and reaction path. Here, by means of first-principles calculations, we identify six ferroelectric catalysts comprising transition-metal atoms anchored on In2Se3 monolayer, whose catalytic performance can be controlled by ferroelectric switching based on adjusted d-band center and occupation of supported metal atoms. The polarization dependent activation allows effective control of the limiting potential of CO2 reduction on TM@In2Se3 (TM = Ni, Pd, Rh, Nb, and Re) as well as the reaction paths and final products on …

Table Of Contents

Journal of the South Carolina Academy of Science

No abstract provided.

2021 Scas Annual Meeting Program And Bulletin

Journal of the South Carolina Academy of Science

No abstract provided.

Creation Of A Cip Method For The Heat Exchangers At Rolls-Royce, Melanie Howe, Austin Williams, Caroline Dempsey, Bethany Fralick

Journal of the South Carolina Academy of Science

Rolls-Royce produces various engines which must be tested prior to their distribution to ensure a high-quality product. The manufacturing plant contains four test cells where the engines can be subjected to high levels of torque and extreme temperatures. A heat exchanger is necessary in this testing system and over time, unwanted waste accumulates on the system’s plates. The team is tasked with developing and implementing a system mounted on a mobile cart which can provide data to determine whether the plates need to be cleaned. For this cleaning system to work, it must fully saturate the heat exchanger in cleaning …

The Effect Of Poverty Levels And Minority Percentages On Lead Content In South Carolina Midlands School Drinking Water, Kathleen L. Barfield

Journal of the South Carolina Academy of Science

No abstract provided.

Options And Experiences For Online Chemistry Laboratory Instruction, Emily Faulconer, Matt Morgan

Publications

While online course offerings have been on the rise for many years, there was a rapid transition to online courses due to campus closures and social distancing protocols associated with the COVID-19 pandemic. This has caused significant disruption in traditional chemistry laboratory activities. In this chapter, features of various distance laboratory approaches options are presented, including wet chemistry and dry laboratory options. Because the existing research comparing effectiveness of these strategies is scarce, no attempt is made to argue the effectiveness of one modality over the other, but rather advantages and disadvantages of each method are presented and discussed. The …

Software For The Frontiers Of Quantum Chemistry: An Overview Of Developments In The Q-Chem 5 Package, Evgeny Epifanovsky, Andrew T.B. Gilbert, Xintian Feng, Joonho Lee, Yuezhi Mao, Narbe Mardirossian, Pavel Pokhilko, Alec F. White, Marc P. Coons, Adiran L. Dempwolff, Zhengting Gan, Diptarka Hait, Paul R. Horn, Leif D. Jacobson, Ilya Kaliman, Jorg Kussmann, Adrian W. Lange, Ka Un Lao, Daniel S. Levine, Jie Liu, Simon C. Mckenzie, Adrian F. Morrison, Kaushik D. Nanda, Felix Plasser, Dirk R. Rehn, Marta L. Vidal, Zhi-Qiang You, Ying Zhu, Bushra Alam, Benjamin J. Albrecht, Abdulrahman Aldossary

Chemistry and Biochemistry Faculty Research

This article summarizes technical advances contained in the fifth major release of the Q-Chem quantum chemistry program package, covering developments since 2015. A comprehensive library of exchange–correlation functionals, along with a suite of correlated many-body methods, continues to be a hallmark of the Q-Chem software. The many-body methods include novel variants of both coupled-cluster and configuration-interaction approaches along with methods based on the algebraic diagrammatic construction and variational reduced density-matrix methods. Methods highlighted in Q-Chem 5 include a suite of tools for modeling core-level spectroscopy, methods for describing metastable resonances, methods for computing vibronic spectra, the nuclear–electronic orbital method, and …

Software For The Frontiers Of Quantum Chemistry: An Overview Of Developments In The Q-Chem 5 Package, Evgeny Epifanovsky, Andrew T. B. Gilbert, Xintian Feng, Joonho Lee, Yuezhi Mao, Shervin Fatehi

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

This article summarizes technical advances contained in the fifth major release of the Q-Chem quantum chemistry program package, covering developments since 2015. A comprehensive library of exchange–correlation functionals, along with a suite of correlated many-body methods, continues to be a hallmark of the Q-Chem software. The many-body methods include novel variants of both coupled-cluster and configuration-interaction approaches along with methods based on the algebraic diagrammatic construction and variational reduced density-matrix methods. Methods highlighted in Q-Chem 5 include a suite of tools for modeling core-level spectroscopy, methods for describing metastable resonances, methods for computing vibronic spectra, the nuclear–electronic orbital method, and …

Anthraquinone Extraction And Quantification, Modification Of The Pictet-Spengler Reaction For The Creation Of Useful Isotopes And Use In Protein Ligation, Jermell Williams

College of Science and Health Theses and Dissertations

The Pictet-Spengler reaction rates of three species known to exhibit the alpha effect will be compared to the rate of the amine functional group. This is part of a larger effort to to generate a bifunctional tool for protein ligation by attaching an alkyne or azide group to the amine. With this, the aldehyde tag method can be used to modify proteins in biological conditions cheaply, specifically, and efficiently.

Electrochemical Studies Of Organic And Organometallic Compounds In The Pursuit Of Electrocatalytic Carbon Dioxide Reduction, Joshua J. Ludtke

College of Science and Health Theses and Dissertations

Carbon dioxide is the main contributor to the greenhouse effect in the world today; developing renewable energy sources and addressing anthropogenic CO₂ release into the atmosphere are two key ways of addressing its increasing impact. Electrocatalytic reduction to products like methanol or carbon monoxide is one useful path to address the rapid increase of carbon dioxide, and the fac-M(bpy-R)(CO)₃X family of complexes (M = Mn or Re; bpy-R = substituted 2,2’-bipyridine; X = Cl, Br, etc.) is one class of effective CO₂ reduction catalysts. Although the capability of the rhenium complex Re(PyBimH)(CO)₃Cl (PyBimH …

Encirclement Of Moving Targets Using Noisy Range And Bearing Measurements, Cammy Peterson, Puneet Jain, Randal Beard

Faculty Publications

This paper presents theoretically justified controllers that use relative range and bearing measurements to steer a team of autonomous vehicles, operating without inertial position information, to circular trajectories around a constant-acceleration, constant-velocity, or stationary target. An extended Kalman filter is used to improve the noisy relative measurements and estimate the velocity of the moving target. These estimated values are used in the control laws to encircle constant-velocity moving targets. Lyapunov techniques are utilized to show that the vehicle will converge to the desired circular formations. Additionally, cooperating vehicles are shown to converge to a circular formation with equal temporal spacing …

Immobilized-Enzyme Reactors Integrated Into Analytical Platforms: Recent Advances And Challenges, Bert Wouters Dr, Sinead Currivan, Noor Abdulhussain, T. Hankemeier, Peter J. Schoenmakers

Articles

Immobilized-enzyme reactors (IMERs) are flow-through devices containing enzymes that are physically confined or localized with retention of their catalytic activities. IMERs can be used repeatedly and continuously and have been applied for (bio)polymer degradation, proteomics, biomarker discovery, inhibitor screening, and detection. Online integration of IMERs with analytical instrumentation, such as high-performance liquid chromatography (HPLC) systems, reduces the time needed for multi-step workflows, reduces the need for sample handling, and enables automation. However, online integration can also be challenging, as reaching its full potential requires complex instrumental setups and experienced users. This review aims to provide an assessment of recent advances …

Sd3 Ptov1 Ptms, Joshua Andersen

ScholarsArchive Data

MS data on PTOV1 PTMs

Sd1 14-3-3 Interactome For Ptov1 Manuscript, Joshua Andersen

ScholarsArchive Data

14-3-3 interactome

Sd2 Ptov1 Interactomics, Joshua Andersen

ScholarsArchive Data

PTOV1 interactome data

Sd1 14-3-3 Interactome For Ptov1 Manuscript, Joshua Andersen

ScholarsArchive Data

Excel data sheet of MS data from 14-3-3 interactomics

Social Constructivism In Chemistry Peer Leaders And Organic Chemistry Students, Aaron M. Clark

USF Tampa Graduate Theses and Dissertations

Social constructivist learning is a goal in many STEM programs. The goal of this dissertation is to shed light on what that pedagogy looks like in the context of organic chemistry courses and by peer leaders whose job is to implement this pedagogy with general chemistry and organic chemistry students. Learning is complex; the social constructivist ideas presented in this dissertation, however, are a straightforward means for promoting learning. Qualitative and quantitative methods used to explore social constructivist learning are outlined.

Three investigations were conducted: First, approaches to learning by students completing the first semester of a yearlong organic chemistry …

Heteroacene-Based Amphiphile As A Molecular Scaffold For Bioimaging Probes, Tharindu A. Ranathunge, Mahesh Loku Yaddehige, Jordan H. Varma, Cameron Smith, Jay Nguyen, Iyanuoluwani Owolabi, Wojciech Kolodziejczyk, Nathan I. Hammer, Glake Hill, Alex Flynt, Davita L. Watkins

Faculty Publications

The challenges faced with current fluorescence imaging agents have motivated us to study two nanostructures based on a hydrophobic dye, 6H-pyrrolo[3,2-b:4,5-b’]bis [1,4]benzothiazine (TRPZ). TRPZ is a heteroacene with a rigid, pi-conjugated structure, multiple reactive sites, and unique spectroscopic properties. Here we coupled TRPZ to a tert-butyl carbamate (BOC) protected 2,2-bis(hydroxymethyl)propanoic acid (bisMPA) dendron via azide-alkyne Huisgen cycloaddition. Deprotection of the protected amine groups on the dendron afforded a cationic terminated amphiphile, TRPZ-bisMPA. TRPZ-bisMPA was nanoprecipitated into water to obtain nanoparticles (NPs) with a hydrodynamic radius that was TRPZ-PG was encapsulated in pluronic-F127 (Mw …

Indicators Of Senescence And Their Relationship With The Antioxidant Response Element In Ovarian Cancer Cells—Toward A More Encompassing View Of Enzyme Activity Levels In Cells, Shaniqua Analycia Hayes

LSU Doctoral Dissertations

Enzymes and other related proteins are promising targets as biomarkers for cancer diagnostics, and it is therefore important to be able to quantify intracellular enzyme activity levels, not just presence of enzyme. Thus, there is a great need for the development of methods that offer spatiotemporal quantification of intracellular enzyme activity levels in respiring 2- and 3-dimensional cultures or their sample-processed variants. Previous studies have demonstrated that ß-gal is upregulated in senescence and in select ovarian cancers, and its expression/activity is upregulated when cells are under oxidative stress conditions. To that end, the primary goal of this work was to …

E-Cigarette Fluids And Aerosol Residues Cause Oxidative Stress And An Inflammatory Response In Human Keratinocytes And 3d Skin Models., Careen Khachatoorian, Wentai Luo, Kevin J. Mcwhirter, James F. Pankow, Prue Talbot

Chemistry Faculty Publications and Presentations

Our goal was to evaluate the effects of EC refill fluids and EC exhaled aerosol residue (ECEAR) on cultured human keratinocytes and MatTek EpiDerm™, a 3D air liquid interface human skin model. Quantification of flavor chemicals and nicotine in Dewberry Cream and Churrios refill fluids was done using GC-MS. The dominant flavor chemicals were maltol, ethyl maltol, vanillin, ethyl vanillin, benzyl alcohol, and furaneol. Cytotoxicity was determined with the MTT and LDH assays, and inflammatory markers were quantified with ELISAs. Churrios was cytotoxic to keratinocytes in the MTT assay, and both fluids induced ROS production in the medium (ROS-Glo™) and …

Mechanistic Investigation Of Neuropeptide S-Nitrosylation By Nitric Oxide Moieties: A Kinetic And Thermodynamic Approach, Vusumuzi Leroy Sibanda

Dissertations and Theses

This dissertation focuses on providing quantitative insights regarding kinetic, thermodynamic and mechanistic parameters of neuropeptide S-nitrosylation by nitrous acid (HNO₂), peroxynitrite (ONOO^-) and S-nitroso-N-acetyl-D,L-penicillamine (SNAP) to produce S-nitrosothiols (SNOs). Peptide thiol stability and the formation of SNOs from neuropeptides; arginine vasopressin (AVP), somatostatin-14 (SST-14) and urotensin II (U-II) was studied. Investigations into the effects of temperature, copper chelators and pH on peptide thiol autoxidation show that AVP, SST-14 and U-II thiols have half-lives of 30, 44 and 28.2 mins respectively at physiologically relevant temperature and pH in the absence of metal chelators. Target peptide thiols were …

Chemistry Card Games - Games For Learning And Enjoying Chemistry, Michelle M. Clark

Sabbatical Projects

Many chemistry students struggle due to a lack of basic math skills. My goal over sabbatical is to develop active learning modules that improve math literacy. I will be collaborating with Dr. Joan Cotter, a renowned math curriculum author whose comprehensive math program utilizes an innovative approach that could benefit chemistry students who have poor math literacy.

Enantioselective Synthesis Of Β-Amino Acid Derivatives Using Amidine-Based And Bifunctional Organocatalysts, Matthew Robert Straub

Arts & Sciences Graduate Student Theses and Dissertations

Two new enantioselective methodologies have been developed that have important implications for the asymmetric synthesis of β-amino acids and their derivatives. First, chiral amidine-based catalyst (ABC) HBTM-2 catalyzed an asymmetric cyclocondensation between in situ activated fluoroacetic acid and N-sulfonyl aldimines to give α-fluoro-β-lactams in highly enantioenriched form, achieving modest to excellent diastereoselectivities. These reactive lactams can then be quenched with various alcohols and amines to deliver the α-fluoro-β-amino acid derivatives in moderate isolated yields. Secondly, bifunctional double hydrogen bond donor-amine organocatalysts enable the catalytic alcoholysis of various racemic N-carbalkoxy-3-substituted isoxazolidin-5-ones, resulting in their kinetic resolution. The enantioenriched unreacted isoxazolidinone and …

Modeling Hyperpolarized Nmr Phenomena In Optically Pumped Semiconductors, Michael Eric West

Arts & Sciences Graduate Student Theses and Dissertations

Nuclear magnetic resonance (NMR) is a widely-used technique that measures the local environments of nuclei. It is able to detect small differences in energy, making it a highly-valued tool. However, the technique is challenged by inherently low sensitivities, requiring either large sample volumes or long periods of time to overcome this. In semiconductors, optical pumping (OP) can overcome this low sensitivity by creating incredibly large and dynamic nuclear spin polarizations (``hyperpolarization''), which is detectable as a large NMR signal. The combined technique of optically-pumped NMR (OPNMR) is a valuable tool that can explore electronic and nuclear phenomena within semiconductors. In …

Cr3+ Assisted Energy Transfer For Mn2+ Doped Zinc Gallogermanate With Narrow And Bright Green Emission, Bhupendra B. Srivastava, Santosh K. Gupta, Swati Mohan, Allen Abraham, Adrian Portales, Yuanbing Mao

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

The objective of this work is to obtain bright green and tunable emission by dopant engineering. It has been achieved in zinc gallogermanate (ZGG) nanodiscs by utilizing Mn2+ and Cr3+ ions as dopant and co-dopant, respectively. Based on photoluminescence measurement, we have found that the Cr3+ co-dopant triggers bright green emission of Mn2+ dopant in the nanodiscs by acting as a bridge to efficiently transfer the emission from the ZGG host to Mn2+ ion. We have validated the efficacy of energy transfer by concentration dependent photoluminescence and lifetime measurement. There are only a few reports on green emitting bulk Mn2+ …

Mechanisms Of Tetracycline Inactivation By Flavin-Dependent Tetracycline Destructases, Chanez Tiffany Valeena Symister

Arts & Sciences Graduate Student Theses and Dissertations

Antibiotic resistance is on track to become the next global pandemic. As the world grapples to return to normalcy after experiencing the devastating effects of Covid-19, it is evident that a proactive approach to public health crises can mitigate the mortality rate, economic cost, and the adverse effects to the mental wellbeing of the global population. With the rapidly increasing number of multidrug resistant pathogens invading the clinical environment, the problem exists that all existing antibiotic therapies will be obsolete. The ideal solutions to this problem would be to 1) develop new antibiotics that can overcome the current resistance mechanisms, …

Further Astrochemical Insights From Bond Strengths Of Small Molecules Containing Atoms From The First Three Rows Of The Periodic Table, Edmund S. Doerksen, Ryan C. Fortenberry

Faculty and Student Publications

The atoms contributing to the strongest “single bonds” on the periodic table do not continue to produce the strongest “double bonds” or “triple bonds.” In fact, the opposite appears to be the case. This quantum chemical examination of nominal X = Y and X ≡ Y bonds in model molecules of atoms from the first three rows of the periodic table shows that the strongest “double bond” is in formaldehyde once the astrophysically-depleted Be and B atoms are removed from consideration. The strongest “triple bond” is a close match between acetylene and N2. However, these results indicate that astrophysical regions …

Thermal Properties Of 18f-Fdg Uptake And Imaging In Positron Emission Tomography Scans Of Cancerous Cells, Carleigh R. Eagle

PANDION: The Osprey Journal of Research and Ideas

Positron Emission Tomography (PET) scans can utilize a radioactive tracer, in this case 2-deoxy2-[fluorine-18] fluoro-D-glucose (¹⁸F-FDG), to visualize malignant tumors in cancer patients. The uptake was compared to glucose to understand the difference in thermal properties, which contribute to the ability to image the cancerous cells. The uptake of ¹⁸F-FDG by cancer cells and the imaging process of positron emission tomography were reviewed from a thermodynamic perspective. Gastrointestinal and neurological imaging techniques were reviewed to understand the role of PET imaging in different areas of the human body.