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Physical Chemistry

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2015

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Articles 31 - 60 of 220

Full-Text Articles in Physical Sciences and Mathematics

Theoretical Investigation Of A Reported Antibiotic From The 'Miracle Tree' Moringa Oleifera, Michael Horwath, Vladimir Benin Nov 2015

Theoretical Investigation Of A Reported Antibiotic From The 'Miracle Tree' Moringa Oleifera, Michael Horwath, Vladimir Benin

Vladimir Benin

Moringa oleifera, sometimes called the “Miracle Tree,” has received international attention for its potential to improve health in impoverished tropical areas. In addition to high vitamin content in the leaves and pods, the tree contains compounds with antioxidant and antibacterial properties. This study focused on the theoretical investigation of the suggested structure of one antibacterial compound, “pterygospermin,” whose existence was proposed after some studies of the roots of M. oleifera. The structure of pterygospermin was first proposed by a research group working in the 1950s, but later studies have not found evidence of this compound and have instead attributed the …

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Synthesis And Flame Retardant Testing Of New Boronated And Phosphonated Aromatic Compounds, Vladimir Benin, Sravanthi Durganala, Alexander Morgan Nov 2015

Synthesis And Flame Retardant Testing Of New Boronated And Phosphonated Aromatic Compounds, Vladimir Benin, Sravanthi Durganala, Alexander Morgan

Vladimir Benin

The present report describes the preparation and use of some dimethyl terephthalate derivatives in transition metal-catalyzed coupling reactions to produce new reactive flame retardants. Dimethyl iodoterephthalate and dimethyl 2,5-diiodoterephthalate were successfully employed in the preparation of phosphonic and boronic esters and acids. The latter were tested for heat release with a microcombustion calorimeter (ASTM D7309) to determine the potential for heat release reduction of these flame retardant molecules. The results showed that the addition of boronic or phosphonic acids greatly lowered the heat release, due to a condensed phase (char formation) mechanism. Adding ester groups to the boronic acids or …

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Heat Release Of Polyurethanes Containing Potential Flame Retardants Based On Boron And Phosphorus Chemistries, Vladimir Benin, Bastien Gardelle, Alexander Morgan Nov 2015

Heat Release Of Polyurethanes Containing Potential Flame Retardants Based On Boron And Phosphorus Chemistries, Vladimir Benin, Bastien Gardelle, Alexander Morgan

Vladimir Benin

Using a polyurethane of methylene diphenyl isocyanate and 1,3-propane diol, several new non-halogenated aromatic boron and phosphorus flame retardants were evaluated for heat release reduction potential using the pyrolysis combustion flow calorimeter (PCFC). The polyurethanes were prepared in the presence of the potential flame retardants via solvent mixing and copolymerization methods, and were then analyzed via spectroscopic methods to determine if the flame retardant was still present in the final product. PCFC testing on the resulting products showed that the flame retardant molecule can have different effects on heat release depending upon how it is mixed into the polyurethane. Some …

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Preparation, Characterization And Dft Studies Of Some New N-Nitrosocarbamates And N-Nitrosoureas, Ragavan Narayanan, Helene Hedian, Eric Shamo, Vladimir Benin Nov 2015

Preparation, Characterization And Dft Studies Of Some New N-Nitrosocarbamates And N-Nitrosoureas, Ragavan Narayanan, Helene Hedian, Eric Shamo, Vladimir Benin

Vladimir Benin

We are presenting the preparation, characterization and density functional theory (DFT) studies {B3LYP/6-31+G(d)) of several reiated classes of N-nitrosocarbamates and N-nitrosoureas. The iong-range goal is the design and preparation of compounds, which would undergo photochemical or hydrolytic decomposition, to yield stabilized cyclic cations that can serve as alkylating agents at various nucleophilic centers, including DNA bases.

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Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies, Howard Knachel, Vladimir Benin, Chadwick Barklay, Janine C. Birkbeck, Billy D. Faubion, William E. Moddeman Nov 2015

Reactions Of Methyl Perfluoroalkyl Ethers With Isopropyl Alcohol: Experimental And Theoretical Studies, Howard Knachel, Vladimir Benin, Chadwick Barklay, Janine C. Birkbeck, Billy D. Faubion, William E. Moddeman

Vladimir Benin

The reaction of an isomeric mixture of the methyl perfluoroalkyl ether, C4F9OCH3 (Novec-7100), in the presence of isopropyl alcohol (IPA) and/or water has been studied by measuring the rate of product formation using an ion-selective electrode (ISE) for fluoride ion, Karl Fisher coulometric titrations for water, and 1H and 19F NMR spectroscopy for product identification and rate studies. The results showed the methyl perfluoroalkyl ether to be very stable with products forming at the rate of ∼1 ppm per year at a laboratory temperature of 20 °C. Measurements over the temperature range of 6° to 100 °C were made on …

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Preparation Of Halogenated Derivatives Of Thiazolo[5,4-D]Thiazole Via Direct Electrophilic Aromatic Substitution, Vladimir Benin, Alan T. Yeates, Douglas Dudis Nov 2015

Preparation Of Halogenated Derivatives Of Thiazolo[5,4-D]Thiazole Via Direct Electrophilic Aromatic Substitution, Vladimir Benin, Alan T. Yeates, Douglas Dudis

Vladimir Benin

Chlorination and bromination reactions of thiazolo[5,4-d]thiazole led to the generation of its mono- and dihalogenated derivatives. These are the first instances of successful direct electrophilic aromatic substitution in the thiazolo[5,4-d]thiazole ring system. X-ray analysis demonstrates that both 2-bromothiazolo[5,4-d]-thiazole and 2,5-dibromothiazolo[5,4-d]thiazole are planar structures, with strongly manifested π-stacking in the solid state. Theoretical analysis of the pyridine-catalyzed halogenation (MP2/6-31+G(d) and B3LYP/6-31+G(d)calculations) reveals that introduction of one halogen actually leads to a slightly enhanced reactivity towards further halogenation. Several halogenation mechanisms have been investigated: 1) The direct C-halogenation with N-halopyridine as electrophile; 2) C-halogenation viaintermediate N-halogenation, and 3) C-halogenation following an addition …

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Structure, Theoretical Studies And Coupling Reactions Of Some New Cyclic Boronic Esters, Andrew Kuttler, Sravanthi Durganala, Albert Fratini, Alexander Morgan, Vladimir Benin Nov 2015

Structure, Theoretical Studies And Coupling Reactions Of Some New Cyclic Boronic Esters, Andrew Kuttler, Sravanthi Durganala, Albert Fratini, Alexander Morgan, Vladimir Benin

Vladimir Benin

The present report describes the X-ray structural and theoretical studies of some new pinacolboronate esters, and it also outlines the use of the target structures in Suzuki coupling reactions to produce new aromatic or heteroaromatic esters and amides. X-ray structural analysis of the studied compounds revealed that the pinacolborane ring's position with respect to the benzene ring varies, depending on the particular environment. An ortho-positioned carboxylic ester (methyl ester) causes a nearly perpendicular orientation of the pinacolborane unit with respect to the benzene ring, whereas an ortho-positioned amide (N,N-dimethylamide) causes the pinacolborane unit to orient itself nearly coplanar. A plausible …

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The Influence Of The Proximal Amide Hydrogen Bonds And The Proximal Helix Dipole On The Catalytic Activity Of Chloroperoxidase, Armando D. Pardillo Nov 2015

The Influence Of The Proximal Amide Hydrogen Bonds And The Proximal Helix Dipole On The Catalytic Activity Of Chloroperoxidase, Armando D. Pardillo

FIU Electronic Theses and Dissertations

Chloroperoxidase (CPO) is a heme-thiolate protein with exceptional versatility and great potential as a biocatalyst. The CPO reactive species, Compound I ( Cpd I) is of particular interest, as well as the Cytochrome P450 (P450) -type monoxygenase catalytic activity, which has significant biotechnological potential. Proximal hydrogen bonding of the axial sulfur with the backbone amides (NH•••S) is a conserved feature of heme-thiolate enzymes. In CPO, the effect of NH•••S bonds is amplified by the dipole moment of the proximal helix. The role of the proximal region has been disputed as to whether it simply protects the axial sulfur, or whether …

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Energy-Efficient Computational Chemistry: Comparison Of X86 And Arm Systems, Kristopher Keipert, Gaurav Mitra, Vaibhav Sunriyal, Sarom S. Leang, Masha Sosonkina, Alistair P. Rendell, Mark S. Gordon Nov 2015

Energy-Efficient Computational Chemistry: Comparison Of X86 And Arm Systems, Kristopher Keipert, Gaurav Mitra, Vaibhav Sunriyal, Sarom S. Leang, Masha Sosonkina, Alistair P. Rendell, Mark S. Gordon

Computational Modeling & Simulation Engineering Faculty Publications

The computational efficiency and energy-to-solution of several applications using the GAMESS quantum chemistry suite of codes is evaluated for 32-bit and 64-bit ARM-based computers, and compared to an x86 machine. The x86 system completes all benchmark computations more quickly than either ARM system and is the best choice to minimize time to solution. The ARM64 and ARM32 computational performances are similar to each other for Hartree-Fock and density functional theory energy calculations. However, for memory-intensive second-order perturbation theory energy and gradient computations the lower ARM32 read/write memory bandwidth results in computation times as much as 86% longer than on the …

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Collecting Our Wisdom And Working Together, Making The Journal Go Further ---On The 20 Years Anniversary Of The Journal Of Electrochemistry, Zong-Rang Zhang Oct 2015

Collecting Our Wisdom And Working Together, Making The Journal Go Further ---On The 20 Years Anniversary Of The Journal Of Electrochemistry, Zong-Rang Zhang

Journal of Electrochemistry

On celebrating the 20 years anniversary of the founding of Journal of Electrochemistry (China), the author wishes to make a brief record of its historical events during the past years, and also to pay respect to the entire person who contributed a lot for the development of the journal. Some personal ideas related to the future development of the journal are proposed too.

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Review For Applications Of "Lead Carbon" Batteries In Energy Storage System, Yong-Quan Ma, Ke Ke, Da-Ming Gu Oct 2015

Review For Applications Of "Lead Carbon" Batteries In Energy Storage System, Yong-Quan Ma, Ke Ke, Da-Ming Gu

Journal of Electrochemistry

Three types of “lead carbon” batteries are introduced by comparing their advantages and disadvantages. Then their applications in energy storage system (ESS), especially in the field of renewable energy power generation, are discussed. The prospects and potential applications of “lead carbon” batteries in EES for electric power supply system are analyzed by combining the state-of-the-art techniques in this field.

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Research Progress Of Secondary Sodium-Air Batteries, San-Pei Zhang, Zhao-Yin Wen, Jun Jin, Xiang-Wei Wu, Ying-Ying Hu, Mei-Fen Wu Oct 2015

Research Progress Of Secondary Sodium-Air Batteries, San-Pei Zhang, Zhao-Yin Wen, Jun Jin, Xiang-Wei Wu, Ying-Ying Hu, Mei-Fen Wu

Journal of Electrochemistry

Rechargeable sodium-air batteries have been the focus in the fields of batteries and energy storage recently, owing to their high specific energy density (1600 Wh?kg-1), an equilibrium discharge potential of 2.3 V and earth-abundant sodium element. However, research on sodium-air cells is still in an infant age and presents many scientific issues. Based on recently reported work and our own experience on sodium-based batteries, this review summarizes the research progress related to the critical scientific issues of secondary sodium-air batteries and the application prospect of sodium-air battery.

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Preparations And Properties Of Polybenzimidazole/Polyvinylbenzyl Crosslinked Composite Membranes For High Temperature Proton Exchange Membrane Fuel Cells, Jin-Kai Jin-Kai, Yong-Yi Jiang, Wang-Zhen Wang-Zhen, Xiao-Jin Li, Zhi-Gang Shao, Bao-Lian Yi Oct 2015

Preparations And Properties Of Polybenzimidazole/Polyvinylbenzyl Crosslinked Composite Membranes For High Temperature Proton Exchange Membrane Fuel Cells, Jin-Kai Jin-Kai, Yong-Yi Jiang, Wang-Zhen Wang-Zhen, Xiao-Jin Li, Zhi-Gang Shao, Bao-Lian Yi

Journal of Electrochemistry

In order to increase the chemical stability of polybenzimidazole (PBI) membrane, a highly stable polymer, poly vinylbenzyl chloride (PVBC), was chosen as the macromolecular crosslinker, and 1H-1,2,4-triazol was adopted to prepare the crosslinked PBI-based membranes. The influence of the PVBC amount on membrane characteristic was investigated in detail. The results indicated that the crosslinked structure of the membrane effectively improved the chemical stability, and at the same time, the membrane presented good mechanical property and proton conductivity. The fuel cell performance for the membrane was tested with hydrogen and oxygen single cell without humidification at 150 oC, and the maximum …

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Effects Of Microstructures Of Active Material On Performance Of Vrla Battery, Lei Jiang, Shou-Zhong Yi Oct 2015

Effects Of Microstructures Of Active Material On Performance Of Vrla Battery, Lei Jiang, Shou-Zhong Yi

Journal of Electrochemistry

The structure, morphology and content of the as-prepared and the processed samples were characterized by the means of SEM and XRD. The discharge capacities and cycle life performances of the as-prepared and the processed samples were tested by electrochemical measurements with different rates. The results indicated that the 4BS technology which can affect the plate design, deep cycle capability and cycle life is a basic technology for the VRLA batteries. It was also confirmed that the contents and structures of α-PbO2 and β-PbO2 formed with different processing conditions can affect the performance of the VRLA batteries, suggesting that the production …

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Sulfonated-Graphene/Nafion Composite Membrane For All Vanadium Redox Flow Batteries, Da-Wei Yang, Yan-Qing Dong, Jing-Min Fan, Ming-Sen Zheng, Quan-Feng Dong Oct 2015

Sulfonated-Graphene/Nafion Composite Membrane For All Vanadium Redox Flow Batteries, Da-Wei Yang, Yan-Qing Dong, Jing-Min Fan, Ming-Sen Zheng, Quan-Feng Dong

Journal of Electrochemistry

Nafion membrane has been widely used in fuel cells due to its good proton conductivity, chemical and mechanical stabilities. However, the well-developed water channels in Nafion membrane have restricted its application in all vanadium redox flow batteries owing to the high permeation of vanadium ions and the cost. In this work, the water adsorption rate, resistivity and transference number of vanadium ions of sulfonated-graphene/Nafion composite membrane were investigated and compared with those of Nafion membrane in an effort to overcome the abovementioned drawbacks. It was found that the area resistivity and permeation rate of sulfonated-graphene/Nafion composite membrane were significantly reduced …

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Latest Progresses In Vanadium Flow Battery Technologies And Applications, Xiao-Li Wang, Yu Zhang, Hua-Min Zhang Oct 2015

Latest Progresses In Vanadium Flow Battery Technologies And Applications, Xiao-Li Wang, Yu Zhang, Hua-Min Zhang

Journal of Electrochemistry

With virtues of high safety, long cycle life, friend environment and state of charge easy monitoring, vanadium flow battery has become an effective technique for large scale energy storage. United States, Japan, Europe and other developed countries are actively promoting the developments of vanadium flow battery technology and related equipments. In this paper, the performance of containerized vanadium flow battery, which was newly developed by Rongke Power (RKP) and Dalian Institute of Chemical Physics, was introduced. The operation data of 5 MW/10 MWh vanadium flow battery energy storage station was displayed. Finally, it is pointed out that reducing the cost, …

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Development Of Proton Conduction Membranes In Application Of Vanadium Flow Battery, Le-Tu Qingge, Wei-Nan Guo, Ping Liu, Bao-Guo Wang Oct 2015

Development Of Proton Conduction Membranes In Application Of Vanadium Flow Battery, Le-Tu Qingge, Wei-Nan Guo, Ping Liu, Bao-Guo Wang

Journal of Electrochemistry

The polymeric hydrophilic/hydrophobic interactions into membrane formation were introduced. A general and straightforward strategy for preparing membranes with nanometer-scale pores was suggested by utilization of hydrophilic/hydrophobic interactions to generate phase separation and removal of polyion aggregates through water immersion. Poly(vinylidene fluoride) (PVDF) and sodium allyl sulfonate (SAS) serve as the membrane material and pore-generator, respectively, resulting in chemically stable and oxidation-resistant membranes with various potential applications. Following the same procedure invented to produce the laboratory-scale membranes, the scale-up process to manufacture large-area membranes was completed. The obtained membrane exhibited the conductivity of 3.5×10-2 S•cm-1, thickness of 100 μm, …

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Preparation And Performance Of Lithium-Rich Manganese Layered Materials 0.6li[Li1/3mn2/3]O2·0.4linixmnyco1-X-Yo2(X < 0.6, Y > 0), Hai-Lan Feng, Ya-Fei Liu, Yan-Bin Chen Oct 2015

Preparation And Performance Of Lithium-Rich Manganese Layered Materials 0.6li[Li1/3mn2/3]O2·0.4linixmnyco1-X-Yo2(X < 0.6, Y > 0), Hai-Lan Feng, Ya-Fei Liu, Yan-Bin Chen

Journal of Electrochemistry

Lithium-rich manganese based cathode materials 0.6Li[Li1/3Mn2/3]O2•0.4LiNixMnyCo1-x-yO2 (x < 0.6, y > 0) were synthesized by carbonate co-precipitation and high temperature solid-state reaction. The structures and morphologies of the as-prepared materials were characterized by X-ray diffraction (XRD), scanning electron microscope (SEM). The results of high temperature in-situ XRD test show that the lattice parameters change significantly with increasing temperature and Ni content. The cation mixing gets serious and the spinel phase appears in the high Ni content samples when the temperature is up to 800 oC. Under voltages ranging from 2.0 to …

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Application Of Pd/Graphene Modified Electrode In The Detection Of 4-Chlorophenol, Peng Shi, Bo-Xuan Wang, Quan-Lin Song, Hui Wang, Xin Liu, Zhao-Yong Bian Oct 2015

Application Of Pd/Graphene Modified Electrode In The Detection Of 4-Chlorophenol, Peng Shi, Bo-Xuan Wang, Quan-Lin Song, Hui Wang, Xin Liu, Zhao-Yong Bian

Journal of Electrochemistry

The Pd/graphene composites were synthesized by a modified Hummers method and NaBH4 reduction process, and then were characterized using XRD, SEM, XPS, and TEM. The Pd/graphene modified glassy carbon electrode (Pd/graphene/GCE) was prepared based on this method. Cyclic voltammetry was used to study the optimum operation conditions for the 4-chlorophenol detection. It was shown that the surface of the graphene was smooth and Pd nanoparticles were uniformly dispersed on graphene. The average particle size was calculated to be 6.5 ± 0.05 nm. These nanoparticles exhibited high catalytic activity and sensitivity toward chlorophenols. PBS with a concentration of 0.1 mol?L-1 at …

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Short Review On Electrochemical Energy Storage, Hong Li, Ying-Chun Lyu Oct 2015

Short Review On Electrochemical Energy Storage, Hong Li, Ying-Chun Lyu

Journal of Electrochemistry

Energy storage is a critical supporting technology in many fields such as energy, information, transportation, and healthcare, aerospace, advanced manufacture, advanced equipment, national security. Electrochemical energy storage technique has been widely applied and is developing continuously. In this article, the energy storage mechanism, technical indicators and technology ready level in electrochemical energy storage are summarized. Mainly based on lithium ion batteries, untraditional electrochemical issues in electrochemical energy storage devices are described from the perspective of fundamental science. These issues deal mainly with thermodynamics, kinetics, size effect, asymmetric system, asymmetric reaction path, surface phenomenon, hybrid ion transportation, and solid state battery. …

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Characterization Of The Separator With Thermal-Shutdown Layer For Use In Lithium Batteries, Li Bai, Yong-Jian Huai, Xin-Ping Ai, Hai Jia Oct 2015

Characterization Of The Separator With Thermal-Shutdown Layer For Use In Lithium Batteries, Li Bai, Yong-Jian Huai, Xin-Ping Ai, Hai Jia

Journal of Electrochemistry

In this paper, the lithium ion battery coated with the thermal-shutdown functional layer has been introduced. The shutdown temperature of the separator could be decreased by using the melting point of thermal-shutdown functional layer. When the internal battery environment reached a critical temperature, the functional layer melted and coated the anode/separator with a non-conductive barrier, halting Li-ion transport and shutting down the cell permanently. The results showed that the functional layer did not affect the resistance, rate performance and cycle life. It was found the functional layer can significantly improve the safety of the battery when misused.

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Impact Of Water Content On The Performance Of Lifepo4 Based Lithium-Ion Battery, Jun-Ting Niu, Lin Sun, Shu-Wen Kang, Zhen-Wei Zhao, Zi-Feng Ma Oct 2015

Impact Of Water Content On The Performance Of Lifepo4 Based Lithium-Ion Battery, Jun-Ting Niu, Lin Sun, Shu-Wen Kang, Zhen-Wei Zhao, Zi-Feng Ma

Journal of Electrochemistry

Through different dry conditions and measuring by moisture test instrument, cathode pole pieces with different water contents of 0.3‰ ~ 0.7‰ were obtained to prepare lithium-ion batteries. Cycling performance and high rate performance at 1C ~ 5C discharge rates were tested. Moreover, ASR performances of LiFePO4 base lithium-ion batteries after 200 cycles with different water contents were investigated by EIS. The results showed that the cycle performance and rate performance were closely related to the water content of the electrode. When the water content went up to 0.6‰ the cycle stability and rate performance fell. Meanwhile, the internal resistance and …

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Great Success Of The 18thnational Conference On Electrochemistry In China (Harbin) Oct 2015

Great Success Of The 18thnational Conference On Electrochemistry In China (Harbin)

Journal of Electrochemistry

No abstract provided.

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Fused-Molecular Systems For Organic Light Emitting Diodes, Avinash Jami Oct 2015

Fused-Molecular Systems For Organic Light Emitting Diodes, Avinash Jami

Masters Theses & Specialist Projects

Organic light emitting diodes (OLEDs) are electronic devices made by sandwitching organic light emissive materials between two electrodes. When voltage is applied across the two conductors, a bright light is generated. The color of the emitting light depends on the band gap of the semiconducting material. The work described here focuses on designing and synthesizing narrow band gap molecular systems derived from fused-arene derivatives for producing organic blue light emitting diodes. Three molecular systems derived from anthracene, pyrene, and carbazole, were designed and synthesized. Two molecular systems of anthracen-9-ylmethyl anthracene-9- carboxylate and pyren-1-ylmethyl 4-bromobenzoate were synthesized through Steglich esterification reaction …

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Mixed Valent Metal Pincer Complexes And Reactivity Of Metal Complexes Of Extended Pincer Ligands, Jeewantha Sampath Hewage Oct 2015

Mixed Valent Metal Pincer Complexes And Reactivity Of Metal Complexes Of Extended Pincer Ligands, Jeewantha Sampath Hewage

Dissertations (1934 -)

Historically, the study of mixed valence complexes has been critical for advancing our understanding of electron transfer processes in biological and abiological systems. The recent use of mixed valence complexes in electrochromic materials, and the promise of their use in future technological or molecular electronic applications, has spurred further interest in this class of compound. Previous studies by our research group have shown that gallium(III) or tricarbonylrhenium(I) complexes of pincer-type ligands with diarylamido anchors and either pyrazol-1-yl (pz) or diarylphosphino (PAr2) flanking donors are electroactive species with quasi reversible ligand-centered oxidations. Moreover, the one-electron oxidized derivative with pz flankers, [Ga(L)(L+)]2+ …

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With Vibrationally Excited Thiophosgene Molecule And Double-Well Ion Traps, Dmytro Shyshlov Oct 2015

With Vibrationally Excited Thiophosgene Molecule And Double-Well Ion Traps, Dmytro Shyshlov

Dissertations (1934 -)

For practical realization of quantum information processing we need a quantum system that provides reliable preparation of the initial state, high-fidelity quantum gate operations, error tolerance, readout of the result of quantum computation and scalability of the system to increase the number of qubits. In this dissertation we show how these requirements can be addressed for molecular quantum computer. For computational study of quantum information processing with molecules we employ thiophosgene (SCCl2) molecule that has been used as a test system for quantum control experiments [Mol. Phys. 105, 1999 (2007)]. We investigate the gateway scheme of control in which transitions …

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S-Nitrosothiols: Electronic Structure And Substituent Effects, Matthew Flister Oct 2015

S-Nitrosothiols: Electronic Structure And Substituent Effects, Matthew Flister

Dissertations (1934 -)

S-nitrosothiols (RSNOs) are biologically important molecules involved in the storage and transport of nitric oxide (NO) and account for much of its signaling activity in living organisms. RSNOs have significant impact on NO signaling through, S-nitrosation, a major post-translational modification of proteins. These unstable thiol derivatives readily undergo homolytic dissociation of the S–N bond to release NO. RSNOs have potential therapeutic applications as NO donors, although the development of novel RSNOs has been slow due to the complex electronic structure of the –SNO group. A specific focus on the impact of the –R group on RSNO properties via substituent effect …

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Density Functional Theory For The Investigation Of Transition Metal Complexes: Structure, Binding, And Spectroscopy Of Metal-Siderophores And The Catalase-Peroxidase Enzyme, Bonnie I. Kruft Sep 2015

Density Functional Theory For The Investigation Of Transition Metal Complexes: Structure, Binding, And Spectroscopy Of Metal-Siderophores And The Catalase-Peroxidase Enzyme, Bonnie I. Kruft

Dissertations, Theses, and Capstone Projects

Since the development of quantum mechanics in the 1920's and with the introduction of the Schrödinger equation in 1926, various methods to solve the Schrödinger equation have evolved. With advances in these computational methods, we are now able to solve the Schrödinger equation for systems that did not seem possible less than a century ago. Density functional theory (DFT) is a valuable tool for the exploration of the molecular properties of biological systems, and is based upon the theory that the exact energy could be determined from the knowledge of the electron density. The purpose of this dissertation is to …

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Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman Sep 2015

Heterogeneous Oxidation Of Catechol, Elizabeth A. Pillar, Ruixin Zhou, Marcelo I. Guzman

Chemistry Faculty Publications

Natural and anthropogenic emissions of aromatic hydrocarbons from biomass burning, agro-industrial settings, and fossil fuel combustion contribute precursors to secondary aerosol formation (SOA). How these compounds are processed under humid tropospheric conditions is the focus of current attention to understand their environmental fate. This work shows how catechol thin films, a model for oxygenated aromatic hydrocarbons present in biomass burning and combustion aerosols, undergo heterogeneous oxidation at the air–solid interface under variable relative humidity (RH = 0–90%). The maximum reactive uptake coefficient of O3(g) by catechol γO3 = (7.49 ± 0.35) × 10–6 occurs for …

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Dynamic Studies Of Guest Molecules In Metal-Organic Frameworks Using Solid-State Nmr, Yuanjun Lu Sep 2015

Dynamic Studies Of Guest Molecules In Metal-Organic Frameworks Using Solid-State Nmr, Yuanjun Lu

Electronic Thesis and Dissertation Repository

Metal-organic frameworks (MOFs) are a new class of porous materials that possess large three-dimensional voids in their structures. In this work, Solid-state NMR (SSNMR) is used to examine the dynamics of guest molecules at various temperatures in MOFs that possess different types of channels. Chapter 2 introduces the 13CO2 adsorption behavior in α-Mg formate studied by 13C SSNMR in conjunction with molecular dynamic simulation. 1H-13C cross polarization technique has successfully determined the adsorption sites of CO2 in this type of MOF to be hydrogen atoms. The dynamic analysis detects that at low temperature, …

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