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Full-Text Articles in Physical Chemistry

Effects Of Biradical Deuteration On The Performance Of Dnp: Towards Better Performing Polarizing Agents, Frédéric A. Perras, Regina R. Reinig, Igor I. Slowing, Aaron D. Sadow, Marek Pruski Sep 2019

Effects Of Biradical Deuteration On The Performance Of Dnp: Towards Better Performing Polarizing Agents, Frédéric A. Perras, Regina R. Reinig, Igor I. Slowing, Aaron D. Sadow, Marek Pruski

Igor I. Slowing

We study the effects of the deuteration of biradical polarizing agents on the efficiency of dynamic nuclear polarization (DNP) via the cross-effect. To this end, we synthesized a series of bTbK and TOTAPol biradicals with systematically increased deuterium substitution. The deuteration increases the radicals' relaxation time, thus contributing to a higher saturation factor and larger DNP enhancement, and reduces the pool of protons within the so-called spin diffusion barrier. Notably, we report that full or partial deuteration leads to improved DNP enhancement factors in standard samples, but also slows down the build-up of hyperpolarization. Improvements in DNP enhancements factors of ...


Effects Of Biradical Deuteration On The Performance Of Dnp: Towards Better Performing Polarizing Agents, Frédéric A. Perras, Regina R. Reinig, Igor I. Slowing, Aaron D. Sadow, Marek Pruski Sep 2019

Effects Of Biradical Deuteration On The Performance Of Dnp: Towards Better Performing Polarizing Agents, Frédéric A. Perras, Regina R. Reinig, Igor I. Slowing, Aaron D. Sadow, Marek Pruski

Aaron D. Sadow

We study the effects of the deuteration of biradical polarizing agents on the efficiency of dynamic nuclear polarization (DNP) via the cross-effect. To this end, we synthesized a series of bTbK and TOTAPol biradicals with systematically increased deuterium substitution. The deuteration increases the radicals' relaxation time, thus contributing to a higher saturation factor and larger DNP enhancement, and reduces the pool of protons within the so-called spin diffusion barrier. Notably, we report that full or partial deuteration leads to improved DNP enhancement factors in standard samples, but also slows down the build-up of hyperpolarization. Improvements in DNP enhancements factors of ...


In Silico Design Of Dnp Polarizing Agents: Can Current Dinitroxides Be Improved?, Frédéric A. Perras, Aaron D. Sadow, Marek Pruski Sep 2019

In Silico Design Of Dnp Polarizing Agents: Can Current Dinitroxides Be Improved?, Frédéric A. Perras, Aaron D. Sadow, Marek Pruski

Aaron D. Sadow

Numerical calculations of enhancement factors offered by dynamic nuclear polarization in solids under magic angle spinning (DNP‐MAS) were performed to determine the optimal EPR parameters for a dinitroxide polarizing agent. We found that the DNP performance of a biradical is more tolerant to the relative orientation of the two nitroxide moieties than previously thought. Generally, any condition in which the gyy tensor components of both radicals are perpendicular to one another is expected to have near‐optimal DNP performance. Our results highlight the important role of the exchange coupling, which can lessen the sensitivity of DNP performance to the ...


Minimalistic Peptide-Based Supramolecular Systems Relevant To The Chemical Origin Of Life, Daniela Kroiss Sep 2019

Minimalistic Peptide-Based Supramolecular Systems Relevant To The Chemical Origin Of Life, Daniela Kroiss

All Dissertations, Theses, and Capstone Projects

All forms of life are based on biopolymers, which are made up of a selection of simple building blocks, such as amino acids, nucleotides, fatty acids and sugars. Their individual properties govern their interactions, giving rise to complex supramolecular structures with highly specialized functionality, including ligand recognition, catalysis and compartmentalization. In this thesis, we aim to answer the question whether short peptides could have acted as precursors of modern proteins during prebiotic evolution. Using a combination of experimental and computational techniques, we screened a large molecular search space for peptide sequences that are capable of forming supramolecular complexes with adenosine ...


Synthesis And Characterization Of Multifunctional Transition Metal Oxide Nanoparticles Through A Modified Sol-Gel Method With Application In Energy Storage, Julien Lombardi Sep 2019

Synthesis And Characterization Of Multifunctional Transition Metal Oxide Nanoparticles Through A Modified Sol-Gel Method With Application In Energy Storage, Julien Lombardi

All Dissertations, Theses, and Capstone Projects

The Synthesis of transition metal oxide nanoparticles has been studied in great detail over the many years. The most studied transition metal oxide nanoparticles are perovskites of the ABO3 stoichiometry (A and B = transition metal) and more recently double perovskite crystal structures of the AA’BO6 or A2BB’O6 stoichiometry due to the many different properties arising from the many different combinations of elements possible. These materials have proven potentially useful in many fields, but due to properties such as ferroelectricity and ferromagnetism, the desire to integrate these materials into electronics is ever growing. Many ...


Modeling Chemical Reactivity In Aqueous And Organic Systems: From Electronic Structure Methods To Force Field Development, Caitlin Gibson Bresnahan Aug 2019

Modeling Chemical Reactivity In Aqueous And Organic Systems: From Electronic Structure Methods To Force Field Development, Caitlin Gibson Bresnahan

LSU Doctoral Dissertations

Modeling reactivity in chemical systems has evolved dramatically in line with the capabilities of modern computing. Despite the advances in computational ability, the level in which one can model a system depends on a number of factors including the region of reactivity, size of the system, level of sophistication required in the molecular description, and so on. Electronic structure methods allow for a detailed description of the potential energy surface and inherently include all essential physics required for reactivity to occur, however these methods are limited by their computational expense. On the other hand, force fields allow for an atomistic ...


The Analysis Of Trifluoromethylbenzimidazole (Tfmbi) Crystals Using Physical Chemistry Techniques To Explain Ferroelectric And Anti-Ferroelectric Properties Of The Compound, Kanwar Bhullar Aug 2019

The Analysis Of Trifluoromethylbenzimidazole (Tfmbi) Crystals Using Physical Chemistry Techniques To Explain Ferroelectric And Anti-Ferroelectric Properties Of The Compound, Kanwar Bhullar

Honors College Theses

Ferroelectrics are a group of materials possessing the unique chemical property of being able to switch their electrical polarity when exposed to an electric field. This property makes ferroelectrics a promising field of study with the potential to impact various future technologies in information and energy storage, as well as quantum mechanics. Understanding molecular structures of ferroelectric (and opposite anti-ferroelectric) materials, and how they relate to the compound’s properties is essential to harnessing the potential these materials carry. The report discusses analysis of anti-ferroelectric material trifluoromethylbenzimidazole (TFMBI), by subjecting the compound to various physical and computational chemistry techniques at ...


Solid-State Nmr Of Co2 Mineralization And Nmr Crystallography, Jinlei Cui Aug 2019

Solid-State Nmr Of Co2 Mineralization And Nmr Crystallography, Jinlei Cui

Arts & Sciences Electronic Theses and Dissertations

The work described in this dissertation has been accomplished by using solid-state nuclear magnetic resonance (SSNMR) spectroscopy to investigate CO2 mineralization and to refine the positions of protons in the crystalline system. The reaction of forsterite (Mg2SiO4) and 13CO2 is presented here, which is measured using in-situ 13C NMR spectroscopy without removing the sample from the reactor. 29Si SSNMR is used to investigate the reaction of forsterite with 13CO2 in the presence of water or NaCl brine as a function of depth in the sample. Additionally, we also show that NMR crystallography can significantly improve structure refinement of hydrogens’ positions ...


Erratum: "Imaging The Three‐Dimensional Orientation And Rotational Mobility Of Fluorescent Emitters Using The Tri‐Spot Point Spread Function", Oumeng Zhang, Jin Lu, Tianben Ding, Matthew D. Lew Aug 2019

Erratum: "Imaging The Three‐Dimensional Orientation And Rotational Mobility Of Fluorescent Emitters Using The Tri‐Spot Point Spread Function", Oumeng Zhang, Jin Lu, Tianben Ding, Matthew D. Lew

Electrical & Systems Engineering Publications and Presentations

In the original paper, a calibration error exists in the image-formation model used to analyze experimental images taken by our microscope, causing a bias in the orientation measurements in Figs. 2 and 3. The updated measurements are shown in Fig. E1. We have also updated the supplementary material for the original article to discuss the revised PSF model and estimation algorithms (supplementary material 2) and show the revised model and measurements (Figs. S1, S3, S7, S8, and S10–S13).


Computational Studies Of Thermal Properties And Desalination Performance Of Low-Dimensional Materials, Yang Hong Aug 2019

Computational Studies Of Thermal Properties And Desalination Performance Of Low-Dimensional Materials, Yang Hong

Student Research Projects, Dissertations, and Theses - Chemistry Department

During the last 30 years, microelectronic devices have been continuously designed and developed with smaller size and yet more functionalities. Today, hundreds of millions of transistors and complementary metal-oxide-semiconductor cells can be designed and integrated on a single microchip through 3D packaging and chip stacking technology. A large amount of heat will be generated in a limited space during the operation of microchips. Moreover, there is a high possibility of hot spots due to non-uniform integrated circuit design patterns as some core parts of a microchip work harder than other memory parts. This issue becomes acute as stacked microchips get ...


Quantum Chemical Calculations Applied To Somo-Homo Conversion And Vibrationally Averaged Nmr Shielding Parameters, Erik Johnson Aug 2019

Quantum Chemical Calculations Applied To Somo-Homo Conversion And Vibrationally Averaged Nmr Shielding Parameters, Erik Johnson

Student Research Projects, Dissertations, and Theses - Chemistry Department

The inversion of frontier orbitals of free radicals was studied using density functional theory calculations in Gaussian 09. Comparisons of images of orbitals in GaussView was used to assess the relative positions of singly occupied and doubly occupied orbitals and to determine which was the highest in energy. A variety of organic free radicals were studied including several radical anions and also a neutral radical. It was found that cross-conjugation appears to be a factor in whether or not molecules show SOMO-HOMO conversion. Cross-conjugation is when two unsaturated groups are conjugated to a third unsaturated group but are not conjugated ...


Computational Study On Binding Of Naturally Occurring Aromatic And Cyclic Amino Acids With Graphene, Dalia Daggag Jul 2019

Computational Study On Binding Of Naturally Occurring Aromatic And Cyclic Amino Acids With Graphene, Dalia Daggag

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

The knowledge on the conformations of amino acids is essential to understand the biochemical behaviors and physical properties of proteins. Comprehensive computational study is focused to understand the conformational landscape of three aromatic amino acids (AAAs): tryptophan, tyrosine, and phenylalanine. Three different density functionals (B3LYP, M06-2X and wB97X-D) were used with two basis sets of 6-31G(d) and 6-31+G(d,p) for geometry optimizations of the conformers of AAAs followed by the vibrational frequencies. The goal was to identify the right choice of density functional theory (DFT) level for conformational analysis of amino acids by comparing the computational data ...


Stereodynamical Control Of A Quantum Scattering Resonance In Cold Molecular Collisions, Pablo G. Jambrina, James F.E. Croft, Hua Guo, Mark Brouard, Balakrishnan Naduvalath, F. Javier Aoiz Jul 2019

Stereodynamical Control Of A Quantum Scattering Resonance In Cold Molecular Collisions, Pablo G. Jambrina, James F.E. Croft, Hua Guo, Mark Brouard, Balakrishnan Naduvalath, F. Javier Aoiz

Chemistry and Biochemistry Faculty Publications

Cold collisions of light molecules are often dominated by a single partial wave resonance. For the rotational quenching of HD (v=1, j=2) by collisions with ground state para-H2, the process is dominated by a single L=2 partial wave resonance centered around 0.1 K. Here, we show that this resonance can be switched on or off simply by appropriate alignment of the HD rotational angular momentum relative to the initial velocity vector, thereby enabling complete control of the collision outcome.


High-Field Mas Dynamic Nuclear Polarization Using Radicals Created By Γ-Irradiation, Scott L. Carnahan, Amrit Venkatesh, Frederic A. Perras, James F. Wishart, Aaron J. Rossini Jul 2019

High-Field Mas Dynamic Nuclear Polarization Using Radicals Created By Γ-Irradiation, Scott L. Carnahan, Amrit Venkatesh, Frederic A. Perras, James F. Wishart, Aaron J. Rossini

Chemistry Publications

High-field magic angle spinning dynamic nuclear polarization (MAS DNP) is often used to enhance the sensitivity of solid-state nuclear magnetic resonance (ssNMR) experiments by transferring spin polarization from electron spins to nuclear spins. Here, we demonstrate that γ-irradiation induces the formation of stable radicals in inorganic solids, such as fused quartz and borosilicate glasses as well as organic solids such as glucose, cellulose, and a urea/polyethylene polymer. The radicals were then used to polarize 29Si or 1H spins in the core of some of these materials. Significant MAS DNP enhancements (ε) greater than 400 and 30 were obtained for ...


Synchrotron Radiation Analysis Of Daguerreotypes: Surface Characterization, Electrocleaning, And Preservation, Madalena S. Kozachuk Jul 2019

Synchrotron Radiation Analysis Of Daguerreotypes: Surface Characterization, Electrocleaning, And Preservation, Madalena S. Kozachuk

Electronic Thesis and Dissertation Repository

The first commercially viable photographic image, the daguerreotype, captured images from 1839 to 1860. While daguerreotypes provide a significant historical record of 19th century individuals and events, deterioration now disfigures many of these images. This work describes the application of synchrotron radiation (SR) to the study of daguerreotypes.

Three goals were addressed in this thesis: 1) to utilize SR to further elucidate the physics and chemistry of the daguerreotype and how the surface varies with time, 2) to study the effects of the electrocleaning system on the daguerreotype surface, and 3) to propose suggestions to improve their preservation and ...


Using Forensics To Introduce Ir Spectroscopy & Molecular Modeling, Joe Golab Jul 2019

Using Forensics To Introduce Ir Spectroscopy & Molecular Modeling, Joe Golab

Faculty Publications & Research

A student activity is reported that analyzes “medical evidence” with experimental and computational methods. The lesson demonstrates benefits of solving practical problems with integrated tools.


Using Molecular Dynamics To Study Qs21 Interactions And Penetration Of Lipid-Cholesterol Bilayers, Sarai Guerrero, Mikko Karttunen Jun 2019

Using Molecular Dynamics To Study Qs21 Interactions And Penetration Of Lipid-Cholesterol Bilayers, Sarai Guerrero, Mikko Karttunen

Western Research Forum

Saponins have been used as adjuvant agents for decades in vaccines and therapies, but none are as well studied or heavily used as QS-21. This achievement is notwithstanding the fact that QS-21 usage is limited by its stability, toxicity, and scarcity. These shortcomings have only pushed researchers to develop and experiment with artificial recreations of the saponin to harness its unique benefits. A considerable number of research hours have been poured into this topic, but like QS-21 there is a shortcoming here as well. The number of articles that look at QS-21 interactions with the bilayer or the conditions under ...


The Spectroscopic And Computational Exploration Of Sulfur Hydrogen Bonding, Andrew Yoonkeun Lee Jun 2019

The Spectroscopic And Computational Exploration Of Sulfur Hydrogen Bonding, Andrew Yoonkeun Lee

Honors Projects

Hydrogen bonds are a subset of non-covalent interactions that occur between X-H — Y, in which X and Y are the very electronegative atoms. In our research, we examine the more unconventional hydrogen bond-like interactions of thiol (SH) containing molecules using vapor-phase infrared (IR) spectroscopy and ab initio computational chemistry. When the SH hydrogen bond donor complexes to a hydrogen bond acceptor, a red shift of the SH stretching mode emerges. An anharmonic oscillator local mode model is applied to the ethanethiol-trimethylamine dimer, and we determine that any IR evidence of dimerization in our experiment is likely obscured by the asymmetric ...


Ab Initio Calculations Of Changes In Sulfur’S Orbital Energies And Sizes With Oxidation State As A Means Of Explaining Hypervalency, Anton V. Taraskin Jun 2019

Ab Initio Calculations Of Changes In Sulfur’S Orbital Energies And Sizes With Oxidation State As A Means Of Explaining Hypervalency, Anton V. Taraskin

Honors Projects

The energetics and orbital sizes of sulfur’s valence 3d and fluorine’s valence 2p orbitals were measured using a closed active space self-consistent field calculation to determine the degree of possible bonding available to sulfur’s 3d. It was determined that for orbital energies, the cc-pVXZ and aug sets converged hyperbolically onto a single energy value as X increased and that for both fluorine and sulfur orbital energies scaled down linearly with oxidation state. This resulted in a 0.47 hartree difference between the sulfur 3d and fluorine 2p orbitals at S0.6+ and F-0.1, far exceeding the ...


Crystal Structure Of Zymonic Acid And A Redetermination Of Its Precursor, Pyruvic Acid, Dominik Heger, Alexis J. Eugene, Sean R. Parkin, Marcelo I. Guzman Jun 2019

Crystal Structure Of Zymonic Acid And A Redetermination Of Its Precursor, Pyruvic Acid, Dominik Heger, Alexis J. Eugene, Sean R. Parkin, Marcelo I. Guzman

Chemistry Faculty Publications

The structure of zymonic acid (systematic name: 4-hy­droxy-2-methyl-5-oxo-2,5-di­hydro­furan-2-carb­oxy­lic acid), C6H6O5, which had previously eluded crystallographic determination, is presented here for the first time. It forms by intra­molecular condensation of parapyruvic acid, which is the product of aldol condensation of pyruvic acid. A redetermination of the crystal structure of pyruvic acid (systematic name: 2-oxo­propanoic acid), C3H4O3, at low temperature (90 K) and with increased precision, is also presented [for the previous structure, see: Harata et al. (1977). Acta Cryst. B33, 210–212 ...


Monolayer Triphosphates Mp3 (M = Sn, Ge) With Excellent Basal Catalytic Activity For Hydrogen Evolution Reaction, Hong-Hui Wu, He Huang, Jie Zhong, Song Yu, Qiaobao Zhang, Xiao Cheng Zeng Jun 2019

Monolayer Triphosphates Mp3 (M = Sn, Ge) With Excellent Basal Catalytic Activity For Hydrogen Evolution Reaction, Hong-Hui Wu, He Huang, Jie Zhong, Song Yu, Qiaobao Zhang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Atomically thin two-dimensional (2D) materials have received intense research interest due to their novel properties and promising applications in nanodevices. By using density functional theory (DFT) calculations, we investigate catalytic activities of several newly predicted two-dimensional (2D) triphosphides GeP3, SnP3 and InP3 monolayers for hydrogen evolution reaction (HER). The calculation results show that GeP3 and SnP3 monolayers are active catalysts for HER with suitable free energy of hydrogen adsorption in the basal plane. In particular, the Gibbs free energy of hydrogen adsorption (ΔGH*) of GeP3 is 0.024 eV, a value even more ...


The Investigation Of Methylidyne Radical (Ch) Reactions With Furan, 2-Methylfuran, And 2,5-Dimethlyfuran And The Photoionization And Photodissociation Of Valeric Acid, Erica Carrasco May 2019

The Investigation Of Methylidyne Radical (Ch) Reactions With Furan, 2-Methylfuran, And 2,5-Dimethlyfuran And The Photoionization And Photodissociation Of Valeric Acid, Erica Carrasco

Master's Theses

This thesis presents the combustion study of three furanic compounds 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 reactions of the three furanic compounds with methylidyne (CH) radicals were analyzed based on their photoionization spectra and kinetic profiles.

Additionally, the unimolecular dissociation of valeric acid was also studied and presented in this work using the double imaging photoelectron photoion spectrometry (i2PEPICO) coupled with synchrotron radiation from the VUV beamline. The experiments were ...


Synchrotron Photoionization Study Of 2,5-Dimethylfuran Oxidation Initiated By O(3p) Atoms, And Computational Studies Of Superalkali Species: Li3f2, Heejune Park May 2019

Synchrotron Photoionization Study Of 2,5-Dimethylfuran Oxidation Initiated By O(3p) Atoms, And Computational Studies Of Superalkali Species: Li3f2, Heejune Park

Master's Theses

This thesis presents the experimental study of a 2,5-dimethylfuran oxidation reaction initiated by atomic oxygen (O(3P)) and the theoretical investigation of superalkalis properties. The experiments were performed at the Chemical Dynamics Beamline 9.0.2 of the Advanced Light Source (ALS) located at the Lawrence Berkeley National Laboratory in Berkeley, CA. The first chapter discusses world energy consumption and progress towards new sustainable energy sources, mainly focusing on biofuels, along with a basic description of combustion. A description of the superalkalis and a brief history of synchrotron radiation are also presented in Chapter 1. Chapter 2 describes ...


Dft Study On The Binding Of Selected Metal Ions With Phenylalanine Dipeptide, Ebtehal Alghamdi May 2019

Dft Study On The Binding Of Selected Metal Ions With Phenylalanine Dipeptide, Ebtehal Alghamdi

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

In this study, M06-2X/6-311+G(2d,2p) level calculations were performed to examine the binding energies and vibrational frequencies of different conformers of phenylalanine dipeptide interacting with metal ions (Na+, K+, Mg2+ and Ca2+). Four conformers were selected from the list of 20 most stable structures. The main goal was to understand the influence of conformers on the binding affinity of metal ions with different conformers of phenylalanine dipeptide. In agreement with experimental results, interactions of metal ions with two aromatic rings along with lone pair electrons of oxygen produced high stability. Binding energy was lowest for ...


A Theoretical Study Of The Electronic Structures Of Tetrahedral Boron-Halogen Complexes, Sahar Alshahrani May 2019

A Theoretical Study Of The Electronic Structures Of Tetrahedral Boron-Halogen Complexes, Sahar Alshahrani

Electronic Theses & Dissertations Collection for Atlanta University & Clark Atlanta University

This study addresses the structure and the bonding in the family of tetrahedral boranes. The specific molecules studied are the series B4X4 (X=H, F, Br, Cl, I), the series B4BrCl3, B4Br2Cl2, and B4Br3Cl and tetra-tert-butyl-tetraborane, t-Bu4B4. The research presented herein employs the Hartree-Fock Self Consistent Field (HFSCF), the Moller-Plesset second-order perturbation theory (MP2), and the Density Function Theory (DFT). A variety of basis sets was employed. Our calculations are the first theoretical studies of B4Br4, B4I ...


Defect Chemistry And Ion Intercalation During The Growth And Solid-State Transformation Of Metal Halide Nanocrystals, Bo Yin May 2019

Defect Chemistry And Ion Intercalation During The Growth And Solid-State Transformation Of Metal Halide Nanocrystals, Bo Yin

Engineering and Applied Science Theses & Dissertations

Abstract of the Dissertation

Defect Chemistry and Ion Intercalation During the Growth and Solid-State Transformation of Metal Halide Nanocrystals

Semiconductor metal halides as light-sensitive materials have applications in multiple areas, such as photographic film, antibacterial agents and photocatalysts. One focus of this dissertation is to achieve novel morphologies of ternary silver bromoiodide (AgBr1-xIx, 0

For the silver halide system, we demonstrate that the anion composition of AgBr1-xIx nanocrystals determines their shape through the introduction of twin defects as the nanocrystals are made more iodide-rich. AgBr1-xIx nanocrystals grow as single-phase, solid solutions with the rock salt crystal structure for anions compositions ...


Recycling Aluminum, Steffani Burwitz, Kristin M. Roe, Matthew L. Miller, Madhav P. Nepal, Larry B. Browning, P. Troy White May 2019

Recycling Aluminum, Steffani Burwitz, Kristin M. Roe, Matthew L. Miller, Madhav P. Nepal, Larry B. Browning, P. Troy White

Madhav Nepal

Students will investigate and compare the energy cost to produce aluminum products from aluminum ore and recycled aluminum. Students will perform an electrolysis activity to reinforce the idea that recycling metal requires less energy than mining and refining metals from their original source in the earth.


Optical Memory Behavior, Metallophilic Luminescence, And Chemical Sensing Ability Of Inorganic And Organometallic Complexes: Development Of Optoelectronic Materials, Aaron D. Nicholas May 2019

Optical Memory Behavior, Metallophilic Luminescence, And Chemical Sensing Ability Of Inorganic And Organometallic Complexes: Development Of Optoelectronic Materials, Aaron D. Nicholas

Electronic Theses and Dissertations

This dissertation is divided into three sections: (1) optical memory, (2) metallophilic-based luminescence, and (3) chemical sensors. (1) Optical memory behavior of d10metal Cu(I) thiocyanate salts are investigated to explore their potential use in the development of digital data storage devices. From this study we have discovered a new class of CuSCN(3-BrPy)2optical memory material which undergo a reduction in emission intensity upon laser irradiation. This loss of emission intensity can be reversed simply by heating the sample to room temperature. The mechanism by which this emission loss occurs has been studied, revealing a migrating ...


Characteristics Of Sulfur Atoms Adsorbed On Ag(100), Ag(110), And Ag(111) As Probed With Scanning Tunneling Microscopy: Experiment And Theory, Peter M. Spurgeon, Da-Jiang Liu, Holly Walen, Junepyo Oh, Hyun Jin Yang, Yousoo Kim, Patricia A. Thiel May 2019

Characteristics Of Sulfur Atoms Adsorbed On Ag(100), Ag(110), And Ag(111) As Probed With Scanning Tunneling Microscopy: Experiment And Theory, Peter M. Spurgeon, Da-Jiang Liu, Holly Walen, Junepyo Oh, Hyun Jin Yang, Yousoo Kim, Patricia A. Thiel

Chemistry Publications

In this paper, we report that S atoms on Ag(100) and Ag(110) exhibit a distinctive range of appearances in scanning tunneling microscopy (STM) images, depending on the sample bias voltage, VS. Progressing from negative to positive VS, the atomic shape can be described as a round protrusion surrounded by a dark halo (sombrero) in which the central protrusion shrinks, leaving only a round depression. This progression resembles that reported previously for S atoms on Cu(100). We test whether DFT can reproduce these shapes and the transition between them, using a modified version of the Lang–Tersoff–Hamann ...


Computational Studies Of Small Molecule Activation In Catylsis And Green Chemistry, Alexa N. Griffith Ms. May 2019

Computational Studies Of Small Molecule Activation In Catylsis And Green Chemistry, Alexa N. Griffith Ms.

Chancellor’s Honors Program Projects

No abstract provided.