Design Of Single-Molecule Multiferroics For Efficient
Ultrahigh-Density Nonvolatile Memories,
2019
Huazhong University of Science and Technology Wuhan
Design Of Single-Molecule Multiferroics For Efficient Ultrahigh-Density Nonvolatile Memories, Qing Yang, Tingting Zhong, Zhengyuan Tu, Lin Zhu, Menghao Wu, Xiao Cheng Zeng
Department of Chemistry: Faculty Publications
It is known that an isolated single-molecule magnet tends to become super- paramagnetic even at an ultralow temperature of a few Kelvin due to the low spin switching barrier. Herein, single-molecule ferroelectrics/multiferroics is proposed, as the ultimate size limit of memory, such that every molecule can store 1 bit data. The primary strategy is to identify polar molecules that possess bistable states, moderate switching barriers, and polarizations fixed along the vertical direction for high-density perpendicular recording. First- principles computation shows that several selected magnetic metal porphyrin molecules possess buckled structures with switchable vertical polarizations that are robust at ambient conditions. …
Synthesis Of N-Heterocyclic Molecules And Their Applicability Towards Ion Sensing: Polymeric Chemosensors,
2019
Georgia Southern University
Synthesis Of N-Heterocyclic Molecules And Their Applicability Towards Ion Sensing: Polymeric Chemosensors, Aikohi M. Ugboya
College of Graduate Studies: Theses & Dissertations
Critical to biological and environmental processes are anions because often times their relative concentration in our body can be an indicator of one’s well-being. Therefore, highly sensitive and cost-efficient methods for ions recognition is necessary for human health. In recent times, polymeric chemosensors have become a vital tool for sensing ions because of its higher sensitivity and good mechanical properties compared to their monomeric counterparts. These sensors are designed to produce a measurable response in the presence of a targeted ion such as an electrochemical or optical signal. The unique structure and the photophysical properties of the 1,2,3-triazole core coupled …
Photoluminescent Zirconium Complexes For Visible Light Photoredox Catalysis,
2019
West Virginia University
Photoluminescent Zirconium Complexes For Visible Light Photoredox Catalysis, Yu Zhang
Graduate Theses, Dissertations, and Problem Reports (ETD)
Early transition metals like zirconium are attractive candidates for the design of luminescent molecules based on earth-abundant elements. Here, a series of zirconium complexes carrying two pyrrolyl-based ligands have been synthesized and characterized. These complexes are photoluminescent upon excitation with visible light and exhibit remarkably long emission lifetimes of hundreds of μs in solution at room temperature. Computational studies using time-dependent density functional theory (TD-DFT) were conducted to identify the nature of the luminescent excited states as mixed intra-ligand/ligand-to-metal charge-transfer (ILCT/LMCT) states. The electrochemistry studies revealed multiple reversible redox events for each zirconium complex. Furthermore, the excited state of the …
Identification Of Burnt Smokeless Gunpowders Through Physical Characteristics,
2019
West Virginia University
Identification Of Burnt Smokeless Gunpowders Through Physical Characteristics, Cameron Taylor Hartwig
Graduate Theses, Dissertations, and Problem Reports (ETD)
Firearms are one of the most commonly used weapons by violent criminals throughout the United States. In crimes involving the discharge of a firearm, residues from the combustion products are deposited on the shooter and in the firing direction. Some of the residues left behind are unburnt and partially burnt particles of the propellant. The most common propellant used in modern firearms is smokeless powder. The identification of particles as smokeless powder and the determination of the brand of the powder are two ways a forensic examiner may be able to utilize smokeless powder evidence. The determination of the brand …
Characterization Of The Microbial Phosphonate-Activating Pntc Enzymes,
2019
Wilfrid Laurier University
Characterization Of The Microbial Phosphonate-Activating Pntc Enzymes, Kyle Rice
Theses and Dissertations (Comprehensive)
New strategies are urgently needed to combat infectious diseases in an era of rising antibiotic resistance. Furthermore, an emerging appreciation for the human microbiome’s role in maintaining health motivates discovery of species-specific antibiotics that minimally disrupt our native bacterial communities. Small molecule modifications to bacterial cell surfaces represent a potentially rich source of new targets for next generation antibiotics, as these molecules mediate virulence and evasion of the host immune response. Phosphocholine (PCho) is a rare cell surface modification that contributes to virulence, and modifications with phosphonates like 2-aminoethylphosphonate (AEP) are even more unusual and therefore provide opportunities for species- …
Vibrational Analysis Of A Rate-Slowing Conformational Kinetic Isotope Effect,
2018
Chapman University
Vibrational Analysis Of A Rate-Slowing Conformational Kinetic Isotope Effect, O. Maduka Ogba, Zichen Liu, Daniel J. O'Leary
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
An enthalpy-entropy approach to analyzing a rate-slowing conformational kinetic isotope effect (CKIE) in a deuterated doubly-bridged biaryl system is described. The computed isotope effect (kH/kD = 1.075, 368 K) agrees well with the measured value (kH/kD = 1.06, 368 K). The rateslowing (normal isotope effect) nature of the computed CKIE is shown to originate from a vibrational entropy contribution defined by the twenty lowest frequency normal modes in the ground state and transition state structures. This normal entropy contribution is offset by an inverse vibrational enthalpy contribution, which also arises from the twenty lowest frequency normal modes. Zero point vibrational …
Atom-Specific Activation In Co Oxidation,
2018
Stockholm University
Atom-Specific Activation In Co Oxidation, Simon Schreck, Elias Diesen, Jerry Larue, Hirohito Ogasawara, Kess Marks, Dennis Nordlund, Matthew Weston, Martin Beye, Filippo Cavalca, Fivos Perakis, Jonas Sellberg, André Eilert, Kyung Hwan Kim, Giacomo Coslovich, Ryan Coffee, Jacek Krzywinski, Alex Reid, Stefan Moeller, Alberto Lutman, Henrik Öström, Lars G. M. Pettersson, Anders Nilsson
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
We report on atom-specific activation of CO oxidation on Ru(0001) via resonant X-ray excitation. We show that resonant 1s core-level excitation of atomically adsorbed oxygen in the co-adsorbed phase of CO and oxygen directly drives CO oxidation. We separate this direct resonant channel from indirectly driven oxidation via X-ray induced substrate heating. Based on density functional theory calculations, we identify the valence-excited state created by the Auger decay as the driving electronic state for direct CO oxidation. We utilized the fresh-slice multi-pulse mode at the Linac Coherent Light Source that provided time-overlapped and 30 fs delayed pairs of soft …
Stabilized, Hybrid Solid-State Photocatalysts For Water Purification: Preparation, Properties And Performance Under Visible Light Irradiation,
2018
Seton Hall University
Stabilized, Hybrid Solid-State Photocatalysts For Water Purification: Preparation, Properties And Performance Under Visible Light Irradiation, Karpagavalli Ramji
Seton Hall University Dissertations and Theses (ETDs)
Stabilized heterogeneous photocatalysts that use only solar light and air have been prepared and successfully employed to decontaminate water from organic pollutants. Organic dye pollutants present, for example in textile effluents, are one of the major sources of water pollution owing to their limited biodegradability, toxicity and potential carcinogenic risks. Before certifying water for public consumption, reuse in industries or for discharge in surface water the organic pollutants must be degraded, an effort that is energy intensive and currently requires complex methodologies. We report solid-state photocatalysts that use only visible light and air to treat wastewater. Perfluoroalkyl perfluoro-substituted zinc phthalocyanine …
Kcnq1/Kcne1 Interaction In The Cardiac Iks Channel And Its Physiological Consequences,
2018
Washington University in St. Louis
Kcnq1/Kcne1 Interaction In The Cardiac Iks Channel And Its Physiological Consequences, Jiajing Xu
McKelvey School of Engineering Graduate Student Theses & Dissertations
Dynamic conformational changes of ion channel proteins during activation gating determine their function as carriers of current. The relationship between these molecular movements and channel function over the physiological timescale of the action potential (AP) has not been fully established due to limitations of existing techniques. We constructed a library of possible cardiac IKs protein conformations and applied a combination of protein segmentation and energy linearization to study this relationship computationally. Simulations reproduced the effects of the beta-subunit (KCNE1) on the alpha-subunit (KCNQ1) dynamics and function, observed in experiments. Mechanistically, KCNE1 increased the probability of “visiting” conducting pore conformations on …
Syntheses Of A Tin (Iv) Meso-Tetra(4-Pyridyl) Porphyrin Dichloride-Tetrachlorobis (Bipy)2 Ruthenium (Ii) Complex And Studies Of Photophysical Properties Of 1-Nitropyrene,
2018
Stephen F. Austin State University
Syntheses Of A Tin (Iv) Meso-Tetra(4-Pyridyl) Porphyrin Dichloride-Tetrachlorobis (Bipy)2 Ruthenium (Ii) Complex And Studies Of Photophysical Properties Of 1-Nitropyrene, Phillip Sharp
Electronic Theses and Dissertations
Development of a photosensitizer that can work in both aerobic and anaerobic environments would increase the robustness of the cancer treatment known as photodynamic therapy. The development of a photosensitizer was first attempted by synthesizing a tin (IV) meso-tetra (4-pyridyl) porphyrin dichloride-tetrachlorobis (Bipy)2 ruthenium (II) complex. The synthesize of the tin porphyrin was done by a method from literature and had a percent error of 31.58 and 37.31 when comparing the theoretical percentages of carbon (55.39) and nitrogen (12.92) meaning that photosensitizer was not synthesized.
The second type of chromophore that was studied was 1-nitropyrene do determine if it …
My Experience Teaching General Chemistry To A Student Who Is Visually Impaired,
2018
Troy University
My Experience Teaching General Chemistry To A Student Who Is Visually Impaired, Katherine M E Stewart
Journal of Science Education for Students with Disabilities
This paper summarizes my experience with teaching a first-year, General Chemistry course to a visually impaired student. This includes accommodations and modifications for both the lecture material and the laboratory. Included are also examples of formats and syntax for txt-based quizzes, tests, and laboratory reports, as well as other general accommodations for both the student and the service dog.
‘Cassette’-Ises (In Situ Enzymatic Screening) Identifies Complementary Chiral Scaffolds For Hydrolytic Kinetic Resolution Across A Range Of Epoxides,
2018
University of Nebraska - Lincoln
‘Cassette’-Ises (In Situ Enzymatic Screening) Identifies Complementary Chiral Scaffolds For Hydrolytic Kinetic Resolution Across A Range Of Epoxides, Sangeeta Dey, Douglas R. Powell, Chunhua Hu, David B. Berkowitz
Department of Chemistry: Faculty Publications
‘Cassette’-ISES (In Situ Enzymatic Screening) Identifies Complementary Chiral Scaffolds for Hydrolytic Kinetic Resolution Across a Range of Epoxides
A new ‘Cassette’-In Situ Enzymatic Screen (ISES) for combinatorial catalysis is introduced. This allows the experimentalist to obtain an information-rich readout, in real time, providing an estimate of the sense and magnitude of enantioselectivity across more than one substrate. In its first iteration, the screen identified CoIII-salen catalysts with β-pinene- and α-naphthylalanine-derived chiral scaffolds with broad, yet complementary, substrate specificities.
Guanidinium Compounds,
2018
Lincoln, NE
Guanidinium Compounds, Stephen Dimagno, Bao Hu
Department of Chemistry: Faculty Publications
The present application provides , inter alia , chemical com pounds useful as synthesis intermediates , said compounds comprising one or more guanidinium moieties and a hyper valent iodine atom . Methods for making these compounds are also provided.
Nanoparticles And Their Use In Cancer Imaging, Prevention And Treatment,
2018
Taylor University
Nanoparticles And Their Use In Cancer Imaging, Prevention And Treatment, George Gray
Chemistry & Biochemistry Student Projects
No abstract provided.
Tomatine And Furocoumarins: Toxins In Commonly Consumed Plants,
2018
Taylor University
Tomatine And Furocoumarins: Toxins In Commonly Consumed Plants, Julia Noonan
Chemistry & Biochemistry Student Projects
No abstract provided.
Isolation Of Rna From A Mixture And Its Detection By Utilizing A Microgel-Based Optical Device,
2018
Chapman University
Isolation Of Rna From A Mixture And Its Detection By Utilizing A Microgel-Based Optical Device, Molla R. Islam, Shakiba Azimi, Faranak Teimoory, Glen Loppnow, Michael J. Serpe
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
In this investigation, we show that RNA can be separated from a solution containing DNA and RNA and the isolated RNA can be detected using poly (N-isopropylacrylamide-co-N-(3-aminopropyl) methacrylamide hydrochloride) microgel-based optical devices (etalons). The isolation of RNA was accomplished by using hairpin-functionalized magnetic beads (MMPDNA) and differential melting, based on the fact that the DNA–RNA hybrid duplex is stronger (i.e., high melting temperature) than the DNA–DNA duplex (i.e., low melting temperature). By performing concurrent etalon sensing and fluorescent studies, we found that the MMPDNA combined with differential melting was capable of selectively separating RNA from DNA. This selective separation and …
Radioiodinated Compounds,
2018
Lincoln, NE
Radioiodinated Compounds, Stephen Dimagno, Bao Hu
Department of Chemistry: Faculty Publications
This disclosure relates to reagents and methods useful in the synthesis of aryl iodines ,for example , in the preparation of iodine labeled radiotracers . The reagents and methods provided herein may be used to access a broad range of compounds , including aromatic compounds , heteroaromatic compounds , amino acids , nucleotides , and synthetic com pounds .
1h And 13c Nmr Assignments For (N-Methyl)-(−)-(Α)-Isosparteinium Iodide And (N-Methyl)-(−)-Sparteinium Iodide,
2018
Pomona College
1h And 13c Nmr Assignments For (N-Methyl)-(−)-(Α)-Isosparteinium Iodide And (N-Methyl)-(−)-Sparteinium Iodide, Kavoos Kolahdouzan, O. Maduka Ogba, Daniel J. O'Leary
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
(‒)-Sparteine (1) and (–)-(α)-isosparteine (2) are members of the lupine alkaloid family.[1-2] Sparteine has found extensive use in asymmetric organic transformations, including lithiations[3] and Pd-catalyzed oxidations.[4-7] (α)-Isosparteine, which can be made from sparteine, has been utilized as a chiral ligand for a limited number of stereoselective reactions.[8-9] The two compounds differ in that 1 displays an exo-endo arrangement of the bridgehead hydrogens at C-11 and C-6, respectively, while 2 retains an exo-exo arrangement of these atoms (Figure 1). This study is focused on assigning 1H chemical shifts and coupling constants and 13C chemical shifts for N-methyl …
Learning Chemistry In English: Challenges Faced By Non-Native English Speakers,
2018
Missouri State University
Learning Chemistry In English: Challenges Faced By Non-Native English Speakers, Arwa A. Alshehri
Graduate Theses/Dissertations
Every year many international students come to study in the United States. In addition to all the challenges associated with coming to a new country, non-native English speakers (NNES) face the additional challenge of having to learn their content in English. Therefore, in this project, I recruited NNES participants from general chemistry courses since preliminary inquiries indicated that they have the largest enrollments. Because there were relatively few students at MSU who are non-native English speakers studying chemistry, I used a case study design to be able to extract generalizations from an in-depth study of a few individuals. The aim …
Development Of Chemistry Activities For Local Outreach In Stem,
2018
Taylor University
Development Of Chemistry Activities For Local Outreach In Stem, Emily Knight
Chemistry & Biochemistry Student Projects
Introduction: This research project was started because of an increase in outreach opportunities for the Department of Chemistry and Biochemistry. For similar opportunities, we now have bins of content that are simple to use, encouraging more students to participate in volunteer research.
Purpose: to find, modify, and/or create grade-level appropriate labs and demonstration activities for 5th-8th graders, with a specific focus on activities hat involve easily available components. These activities are intended to be used for outreach to local schools by chemistry student volunteers and released online to act as a resource for teachers.
