Chemistry Commons^™

Coordination Environment: A New Approach To The Sensing Of Lead (Ii) Itself, Kristina Marie Nespechal

Masters Theses

Lead(II) is a silent poison that has plagued society since 3800 B. C. The average intake of lead in the United States alone is 50 μg per day, which is approximately 100-1000 times greater than that of prehistoric lead levels. Regardless of the banning of lead in paints and gasoline, lead poisoning prevails as a major environmental health risk. Science has the ability to address the concern with this environmental contaminant. The future production of an economical and reliable test kit for lead(II) relies on the luminescence of the heavy metal itself.

The absorption and emission spectra for a series …

Model Studies Towards The Total Synthesis Of Lyconadin A Via An Acyl Radical Cascade Reaction, Koudi Zhu

Theses and Dissertations

Lyconadin A is an alkaloid possessing a unique structure and antitumor activity. The total synthesis of Lyconadin A was proposed via an acyl radical cascade reaction. To investigate the possibility and stereoselectivity of the cascade cyclization, phenyl selenoester 16 was chosen as a model substrate to study the 7-exo-5-exo radical cyclization. A synthetic route to phenyl selenoester 16 was developed. The 7-exo-5-exo radical cyclization was found to occur with a high yield and excellent stereoselectivty. Attempts were also tried to synthesize another radical precursor 14 albeit with less success. A synthetic pathway to the synthesis of 14 as well as …

Semiclassical Nonadiabatic Dynamics Based On Quantum Trajectories For The O(3P,1D)+H2 System, Sophya Garashchuk, Vitaly A. Rassolov, George C. Schatz

Faculty Publications

The O(³P,¹D)+H₂→OH+H reaction is studied using trajectory dynamics within the approximate quantum potential approach. Calculations of the wave-packet reaction probabilities are performed for four coupled electronic states for total angular momentum J = 0 using a mixed coordinate/polar representation of the wave function. Semiclassical dynamics is based on a single set of trajectories evolving on an effective potential-energy surface and in the presence of the approximate quantum potential. Population functions associated with each trajectory are computed for each electronic state. The effective surface is a linear combination of the electronic states with the contributions …

The Particle In A Box (And In A Circular Box), Carl W. David

Chemistry Education Materials

The particle in a box problem in 1 and 2 dimensions is treated both for the Cartesian problem (square, rectangle) but for circular boundary conditions.

The Importance Of The Strictly Conserved, C-Terminal Glycine Residue In Phosphoenolpyruvate Carboxylase For Overall Catalysis: Mutagenesis And Truncation Of Gly-961 In The Sorghum C4 Leaf Isoform, Wenxin Xu, Shaheen Ahmed, Hideaki Moriyama, Raymond Chollet

Hideaki Moriyama Publications

Phosphoenolpyruvate carboxylase (PEPC) is a “multifaceted,” allosteric enzyme involved in C4 acid metabolism in green plants/microalgae and prokaryotes. Before the elucidation of the three-dimensional structures of maize C4 leaf and Escherichia coli PEPC, our truncation analysis of the sorghum C4 homologue revealed important roles for the enzyme’s C-terminal α-helix and its appended QNTG⁹⁶¹ tetrapeptide in polypeptide stability and overall catalysis, respectively. Collectively, these functional and structural observations implicate the importance of the PEPC C-terminal tetrapeptide for both catalysis and negative allosteric regulation. We have now more finely dissected this element of PEPC structure-function by modification of the absolutely conserved …

The Hamiltonian And Schrodinger Equation For Helium's Electrons (Hylleraas), Carl W. David

Chemistry Education Materials

The Hylleraas forms for the kinetic energy operator for the two electrons of Helium in the ground singlet Sigma state are obtained explicitly.

The Mechanism Of Assembly Of The G-Protein Beta Gamma Subunit Dimer By Ck2 Phosphorylated Phosducin-Like Protein And The Chaperonin Containing Tcp-1, Christine M. Baker

Theses and Dissertations

Phosducin-like protein (PhLP) binds G-protein beta gamma subunits and is thought to assist in assembly of the G-protein beta gamma dimer. Phosphorylation of PhLP at serine residues 18-20 by the casein kinase 2 (CK2) appears to play an essential role in this process. PhLP has also been shown to interact with the chaperonin containing TCP-1 (CCT) atop its apical domain, not entering the substrate folding cavity. However, the physiological role of the PhLP-CCT interaction in G-protein beta gamma dimer formation remains unclear. This study addresses the mechanism of G-protein beta gamma assembly by exploring the specific roles of CCT and …

Energy Storage In Cold Non-Elastic Deformation Of Glassy Polymers, E.F. Oleinik, S.N. Rudnev, O.B. Salamatina, S.V. Shenogin, M.I. Kotelyanskii, T.V. Paramzina, S.I. Nazarenko

Faculty Publications

Experimental results on work W(epsilon), heat Q(epsilon) and stored energy U(epsilon) of deformation for glassy polymers such as linear PS, PC, PMMA, Polyimid, amorphous PET, thermotropic aromatic polyesters, Vectra T for example, crosslinked epoxy are presented. All the data was obtained by a deformation calorimetry technique. Loading and unloading of samples were performed at room temperature with strain rate epsilon = 10(-2) - 10(-4) sec(-1) under uniaxial compression up to engineering strains of epsilon(def) = 40-50%. During straining all polymers accumulate an excess of the latent energy U( e). Elastic fraction of the energy is released completely at sample unloading …

Characterizing The Potential Energy Surface Of The Water Dimer With Dft: Failures Of Some Popular Functionals For Hydrogen Bonding, Julie A. Anderson, Gregory S. Tschumper

Chemistry Faculty Research & Creative Works

Ten stationary points on the water dimer potential energy surface have been examined with ten density functional methods (X3LYP, B3LYP, B971, B98, MPWLYP, PBE1PBE, PBE, MPW1K, B3P86, and BHandHLYP). Geometry optimizations and vibrational frequency calculations were carried out with the TZ2P(f,d)+dif basis set. All'ten of the density functionals correctly describe the relative energies of the ten stationary points. However, correctly describing the curvature of the potential energy surface is far more difficult. Only one functional (BHandHLYP) reproduces the number of imaginary frequencies from CCSD(T) calculations. The other nine density functionals fail to correctly characterize the nature of at least one …

Fabrication Of Polymeric Microfluidic Devices For Protein Analysis, Jikun Liu

Theses and Dissertations

2-Bromoisobutyryl bromide was immobilized on poly(methyl methacrylate) (PMMA) substrates activated using an oxygen plasma. Atom-transfer radical polymerization was then performed to graft poly(ethylene glycol) (PEG) on the PMMA surface. PMMA micro capillary electrophoresis (µCE) devices made with the covalently modified surfaces exhibited substantially reduced electroosmotic flow and nonspecific adsorption of proteins. Both column efficiency and migration time reproducibility were one order of magnitude better with derivatized PMMA µCE devices compared to untreated versions. Fast, reproducible, and efficient separations of proteins and peptides were demonstrated using the PEG-grafted PMMA µCE chips. All analyses were completed in less than 60 seconds, and …

Chromatographic Analysis Of Carbamazepine Binding To Human Serum Albumin: Ii. Comparison Of The Schiff Base And N-Hydroxysuccinimide Immobilization Methods, Hee Seung Kim, Rangan Mallik, David S. Hage

David Hage Publications

Recent studies with carbamazepine on human serum albumin (HSA) columns have noted an appreciable degree of non-specific binding on supports prepared by the Schiff base immobilization method. This work examines an alternative immobilization method for HSA based on N-hydroxysuccinimide (NHS)-activated silica. This support was prepared by reacting HPLC-grade silica directly with disuccinimidyl carbonate. The resulting material was compared to an HSA support prepared by the Schiff base method in terms of its activity for carbamazepine and non-specific interactions with this drug. When examined by frontal analysis, both supports gave comparable association equilibrium constants for carbamazepine interactions with HSA ((0.53–0.55) …

(Review) Green Fluorescent Proteins, Marc Zimmer

Chemistry Faculty Publications

Reviews the book:Green Fluorescent Protein: Properties, Applications, and Protocols. Second Edition. Methods of Biochemical Analysis, Volume 47. Edited by Martin Chalfie and Steven R Kain.Green Fluorescent Protein: Properties, Applications, and Protocols. Second Edition. Methods of Biochemical Analysis, Volume 47. Edited by Martin Chalfie and Steven R Kain. Hoboken (New Jersey): Wiley-Interscience. $89.95. xv + 443 p + 24 pl; ill.; index. ISBN: 0–471–73682–1. 2006.

Studies Toward The Enantioselective Total Synthesis Of The Martinella Alkaloids, Vivek Badarinarayana

Chemistry & Biochemistry Dissertations - Archive

This dissertation consists of two parts. The first part describes the enantioselective total synthesis of martinellic acid. The Martinella alkaloids have attracted considerable attention in the synthetic community over the past few years. This interest is due in large part to their unique structure and useful biological activity (bradykinin receptor antagonist). In model systems we have successfully used the [3+2] azomethine ylide-alkene cycloaddition to construct the heterocyclic core of these alkaloids. The enantioselective approach described herein also involves the azomethine ylide-alkene cycloaddition as a key step in the total synthesis. The pyrrolo[3,2-c]quinoline core of this alkaloid was constructed in an …

Structure Determination Of A2m3+Tao6 And A2m3+Nbo6 Ordered Perovskites: Octahedral Tilting And Pseudosymmetry, Paris W. Barnes, Michael W. Lufaso, Patrick M. Woodward

Chemistry Faculty Research and Scholarship

The room-temperature crystal structures of six A₂M³⁺M⁵⁺O₆ ordered perovskites have been determined from neutron and X-ray powder diffraction data. Ba₂YNbO₆ adopts the aristotype high-symmetry cubic structure (space group Fm3̄m, Z = 4). The symmetries of the remaining five compounds were lowered by octahedral tilting distortions. Out-of-phase rotations of the octahedra about the c axis were observed in Sr₂CrTaO₆ and Sr₂GaTaO₆, which lowers the symmetry to tetragonal (space group = I4/m, Z = 2, Glazer tilt system = …

Structure Prediction Of Ordered And Disordered Multiple Octahedral Cation Perovskites Using Spuds, Michael W. Lufaso, Paris W. Barnes, Patrick M. Woodward

Chemistry Faculty Research and Scholarship

The software package SPuDS has previously been shown to accurately predict crystal structures of AMX₃ and A_{1 - x}A'_xMX₃ perovskites that have undergone octahedral tilting distortions. This paper describes the extension of this technique and its accuracy for A₂MM'X₆ ordered double perovskites with the aristotype Fm3̄m cubic structure, as well as those that have undergone octahedral tilting distortions. A survey of the literature shows that roughly 70% of all ordered double perovskites undergo octahedral tilting distortions. Of the 11 distinct types of octahedral tilting that can occur in …

Probing Synergism, Antagonism, And Additive Effects In Poly(Vinyl Ester) (Pve) Composites With Fire Retardants, Everson Kandare, Grace Chigwada, Dongyan Wang, Charles Wilkie, Jeanne Hossenlopp

Chemistry Faculty Research and Publications

Potential fire retardants, including copper hydroxy dodecyl sulfate (CHDS), organically-modified montmorillonite (Cloisite 15A), and resorcinol di-phosphate (RDP), were added to pure poly(vinyl ester) (PVE) individually or in combinations at low concentration formulations. Thermogravimetric analysis and cone calorimetry were used to study the thermal stability and fire performance of the composites. Synergistic, antagonistic, and additive effects were observed depending on the specific formulation. Time to self-sustained combustion is greatly reduced, but the flame extinguishes faster, for the composites containing CROS alone or in combination with either RDP or Cloisite 15A compared to the virgin polymer. The presence of copper in PVE …

Molecular Simulations Of Solid-Liquid Interfacial Tension Of Silicon, Yuk Wai Tang, Jun Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Silicon is an important semiconductor for manufacturing of microelectronic chips used in computers and other electronic devices. During the manufacturing process, liquid silicon is being solidified to make high-grade solid semiconductors. Thus, improved data of the solid-liquid interfacial properties of silicon will be useful towards optimizing the experiment condition for making better quality electronics. Yet it is difficult to perform experiments of liquid silicon due to its high melting point. Thus far, most experimental measurements of the solid-liquid interfacial tension are based on the measurement of rate of homogeneous crystal nucleation at a given undercooling. The first measurement of solidliquid …

Molecular Characterization Of Wetland Soil Bacterial Community In Constructed Mesocosms, Ethan C. Bishop

Theses and Dissertations

The use of wetlands to effectively remediate aquifers contaminated with chlorinated solvents is an emerging technique, which shows high promise. In order to better understand this process and test its legitimacy, a treatment wetland was constructed at Wright-Patterson AFB, Dayton, Ohio and, in a joint effort with Wright State University (WSU), has previously shown the effective removal of PCE. The purpose of this research was to characterize the soil bacterial community, pre-PCE injection, among three wetland plant species from the sedge family (Cyperaceae) within constructed wetland mesocosms and to identify any bacterial dominance. Carex comosa, Scirpus atrovirens, and Eleocharis erythropoda …

Kinetics Of The Dna Polymerase Pyrococcus Kodakaraensis, Mark A. Griep, Casey A. Kotera, R.M. Nelson, Hendrik J. Viljoen

Mark A. Griep Publications

The polymerase chain reaction is one of the most important reactions in molecular biology. Single stranded DNA is copied in a complex series of steps, at the core of which lies the action of the DNA polymerase. At each nucleotide along the template, the polymerase screens the dNTP pool until it finds the complementary dNTP. The insertion of each dNMP is a balance between high fidelity and rapid elongation. In this study the kinetics of the β type polymerase pyrococcus kodakaraensis (KOD) is analyzed. The kinetics is influenced by reaction conditions such as the dNTP pool composition and temperature. In …

Isotopes Tell Sun's Origin And Operation, Oliver Manuel, Sumeet A. Kamat, Michael Mozina

Chemistry Faculty Research & Creative Works

Modern versions of Aston's mass spectrometer enable measurements of two quantities - isotope abundances and masses - that tell the Sun's origin and operation. Isotope analyses of meteorites, the Earth, Moon, Mars, Jupiter, the solar wind, and solar flares over the past 45 years indicate that fresh, poorly-mixed, supernova debris formed the solar system. The iron-rich Sun formed on the collapsed supernova core and now itself acts as a magnetic plasma diffuser, as did the precursor star, separating ions by mass. This process covers the solar surface with lightweight elements and with the lighter isotopes of each element. Running difference …

Gas Chromatography On Self Assembled Single Walled Carbon Nanotubes, Mahesh Kumar Karwa

Dissertations

Carbon nanotubes (CNTs) are nano-sized carbon-based sorbents, which have high surface area, large aspect ratio, can be self-assembled and are known to be stable at high temperatures. It is therefore conceivable that separation techniques, such as, gas chromatography (GC) can benefit from their unique properties and nano-scale interactions. Self-assembly, in-contrast to packing these materials in a tube, prevents them from agglomeration and thus facilitates in retaining their nano-characteristics. In this research, novel substrates, such as, steel tubings, on a scaled-up level have been explored for the self-assembly process of CNTs, for applications such as gas chromatography, where the CNTs served …

Evidence Of Hollow Golden Cages, Satya S. Bulusu, Xi Li, Lai-Sheng Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

The fullerenes are the first “free-standing” elemental hollow cages identified by spectroscopy experiments and synthesized in the bulk. Here, we report experimental and theoretical evidence of hollow cages consisting of pure metal atoms, Au–_n (n = 16–18); to our knowledge, free-standing metal hollow cages have not been previously detected in the laboratory. These hollow golden cages (“bucky gold”) have an average diameter >5.5 Å, which can easily accommodate one guest atom inside.

Evidence Of Hollow Golden Cages: Supplementary Materials And Supporting Information, Satya S. Bulusu, Xi Li, Lai-Sheng Wang, Xiao Cheng Zeng

Xiao Cheng Zeng Publications

Figures 3A-3D: Simulated anion photoelectron spectra [based on the density-functional theory (DFT) calculation with the PBEPBE/LANL2DZ functional and basis set] for all of the candidate lowest-energy isomers of
Au¯₁₅ (A),
Au¯₁₆ (B),
Au¯₁₇ (C), and
Au¯₁₈ (D) identified in Fig. 3 A–D, respectively.

Figures 4A-4E: Top-10 lowest-energy isomers of Au¯₁₅, Au¯₁₆, Au¯₁₇, Au¯₁₈, and Au¯₁₉ obtained from a basin-hopping global search combined with DFT optimization and total-energy calculation.

Table 2: The experimental adiabatic detachment energies (ADEs) for Au¯_n (n = 15–19) measured from the threshold …

Electrochemical Preparation And Application Of Nanomaterials, Peng Liu, Ye-Xiang Tong, Qi-Qin Yang

Journal of Electrochemistry

Nano materials and nano technology receive great attention all over the world.While electrochemistry has already achieved a great application in industry and it has proved that electrochemistry will play an important role in the field,such as energy source,new materials,life sciences,information sciences,environment and nano sciences.In this paper,the recent developments of electrochemical techniques for the preparing nano materials,application of nano materials in the areas of electrodeposition,batteries,electrocatalysis,sensors are introduced in brief.

Application Of Electrolessplating Technology In Interconnection Manufacturing Of Ultralarge-Scale Integration, Zeng-Lin Wang, Zhi-Juan Liu, Hong-Yan Jiang, Xiu-Wen Wang, Shingubara Shoso

Journal of Electrochemistry

In this paper,research progresses in electroless plating for damascene copper process were reviewed.Electroless nickel ternary alloy deposition for barrier layer and electroless copper plating for seed layer were presented.Bottom-up copper fill high-aspect-via-hole and electroless plating after ICB-Pd catalytic layer for seed layer were mainly introduced.The applications of electroless plating in ultralarge-scale integration were discussed,and the developing tendency was also suggested.

Synthesis Of Zinc Polyhedral Microspheres And Applications In Alkaline Zn-Mno2 Battery, Hua Ma, Chun-Sheng Li, Fang-Yi Cheng, Chun-Yuan Zhou, Feng Gao, Jun Chen

Journal of Electrochemistry

The zinc polyhedral microspheres were synthesized by evaporation of pure zinc powders via a vapor-transport process.The results characterized by XRD and SEM show that the as-synthesized zinc powders are polyhedral microspheres with the diameter of 2~3 μm.The electrochemical investigation showed that the capacity of the as-assembled AA-size primary alkaline Zn-MnO₂ battery was increased to 3.14 Ah under the constant discharge current of 100 mA by using the as-deposited microspherical zinc powders as the anode active materials and γ-MnO₂ nanowires as the cathode active materials,indicating their potential application in high-energy batteries.

Compare Of The Behavior Of Different Sloth Filler Bipolar Packed Bed Cell In The Treatment Of Sodium P-Nitro-Phenolate, Shi-Yuan Guo, Ai-Li Zhang, Ji-Ti Zhou

Journal of Electrochemistry

Making use of sulphonated coal,fruit hull,plastic of PVC,old plastic in recovery,four kinds of sloth fillers which densities are equal to active carbon to substitute quartz sand which are applied in project extensively.And link with appropriate backwashing to resolve the problem of electrodes pollution and &lamination of the fillers in the bipolar packed bed cell.Then via the treatment of the waste water that contains sodium p-ni-tro-phenolate to investigate the possibility of application.The results are as follow.There are better resuk for the reactors packed with old plastics in recovery and sulphonated coal than the one filled with quartz sand,and the results of …

High Density Lifepo4/C Synthesized By Controlled Crystallization And Microwave Carbon Thermal Reduction, Chang-Ping Tang, Jie-Rong Ying, Min Lei, Wei Li, Chang-Yin Jiang, Chun-Rong Wan

Journal of Electrochemistry

The spherical FePO₄·xH₂O was prepared in the solution by controlled crystallization.The precursor FePO₄ was obtained in high temperatureceramic approach,then the high density LiFePO₄ /C was synthesized by microwave carbon thermal reduction.The structure and morphology of the materials were characterized by means of XRD and SEM techniques,and the electrochemical properties were studies by charge-discharge experiments.

Effect Of Cracks On Corrosion Of Rebar In Concrete Studied By Wire Beam Electrode, Guo-Xi Li, Xian-Lu Hou, Ri-Long Zhu, Jin-Feng Hu, Yan-Na Du

Journal of Electrochemistry

The effects of crack and ethanolamine on corrosion of rebar in concrete were studied by measuring the distribution of corrosion potential and polarization resistance of iron wires in 10% NaCl solution.The results showed that the diffusion of water,oxygen and chloric ion toward concrete was accelerated by the crack which intensified the nonuniform corrosion of iron wire with the regions near to crack as anode and the uncracked regions as cathode.Ethanolamine could diffuse into the body of concrete and absorb on the surface of iron wire,which reduced iron corrosion evidently and successfully inhibited the nonuniform corrosion caused by crack without changing …

Corrosion Behavior Of The Welding Seam Of The Q235 Steel Jointed By J420 Electrode In Ammonium Sulfite Solution, A-Li Lei, Qiao-Qin Guo, La-Jun Feng

Journal of Electrochemistry

The corrosion behavior of welding seam of the Q235 steel jointed by J420 electrode in ammonium sulfite solution was researched.The results of electrochemical method of welding seam and metallurgical structure analysis showed that the poor corrosion resisting property was determined by its structure after the Q235 steel was jointed by J420 electrode.The sulfite corrosion rate was accelerated by increasing the temperature and concentration of ammorium.