Chemistry Commons^™

Sr3Znpto6 And Sr3Cdpto6, Mark D. Smith, Hans Conrad Zur Loye

Faculty Publications

The flux synthesis of single crystals of the isostructural compounds tristrontium zinc platinum hexaoxide, Sr₃ZnPtO₆, and tristrontium cadmium platinum hexaoxide, Sr₃CdPtO₆, is reported. The compounds adopt the pseudo-one-dimensional rhombohedral K₄CdCl₆ structure type, and feature chains of face-shared distorted ZnO₆ or CdO₆ trigonal prisms and PtO₆ octahedra, surrounded by columns of Sr²⁺ ions. All transition metals are located on the threefold axis of symmetry, while the Sr²⁺ cations lie on twofold axes.

Formula: Sr₃ZnPtO₆ and Sr₃CdPtO₆

Lewis Acid Catalyzed Reactions Of Aziridino-Olefins, Steven Tymonko '01

Honors Projects

Electrophilic reactions resulting in the formation of new carbon-carbon bonds are important tools in organic synthesis. For example, the acid catalyzed cyclization of epoxy olefins has been well documented, while similar cyclizations with aziridines have been largely unexplored. The aim of this project is to develop and demonstrate the formation of a carbocyclic compound from aziridino-olefins utilizing a Lewis acid to catalyze the cyclization. In working toward this goal, a number of aziridino-olefins were synthesized from isoprenoid start materials. These aziridino-olefins were then reacted with both Lewis and protic acids in an attempt to induce cyclization. As a result, we …

Adenosine Triphosphate-Dependent Degradation Of A Fluorescent Λ N Substrate Mimic By Lon Protease, Irene Lee, Anthony J. Berdis

Chemistry Faculty Publications

Escherichia coli Lon exhibits a varying degree of energy requirement toward hydrolysis of different substrates. Efficient degradation of protein substrates requires the binding and hydrolysis of ATP such that the intrinsic ATPase of Lon is enhanced during protein degradation. Degradation of synthetic tetrapeptides, by contrast, is achieved solely by ATP binding with concomitant inhibition of the ATPase activity. In this study, a synthetic peptide (FRETN 89-98), containing residues 89–98 of λ N protein and a fluorescence donor (anthranilamide) and quencher (3-nitrotyrosine), has been examined for ATP-dependent degradation by E. coli and human Lon proteases. The cleavage profile of FRETN 89-98 …

Effect Of A Modified Isoindole Backbone On The Electrical Optical And Physical Properties Of The Isoindole Organised Semiconductor System, Matthew Boylan

Doctoral

Primarily it was endeavoured to synthesise conducting polymers bearing a modified isoindole backbone with potentially enhanced electrical, optical and physical properties. The addition of electron donating methoxy groups on to the N-methylisoindole system results in alternations to the resultant polymer’s optical and physical properties. The synthesis of the new compounds 5-methoxy-N-methylisoindole and 5, 6-dimethoxy-N-methylisoindole was carried out via a devised route. Characterisation of the two new monomers 5-methoxy-N-methylisoindole and 5,6-dimethoxy-N-methylisoindole and the parent N-methylisoindole and their corresponding polymers has also been carried out initially by cyclic voltammetry studies. The oxidation of the monomers and corresponding polymers occurs at decreasing positive …

Interchannel Coupling In The Photoionization Of The M-Shell Of Kr Well Above Threshold: Experiment And Theory, H. S. Chakraborty, D. L. Hansen, Oliver Hemmers, P. C. Deshmukh, P. Focke, I. A. Sellin, Clemens Heske, Dennis W. Lindle, S. T. Manson

Environmental Studies Faculty Publications

Photoionization cross sections and asymmetry (β) parameters for Kr 3s, 3p, and 3d subshells have been measured and calculated in the 300–1300-eV photon energy range. Good agreement between experiment and theory is found for both cross-section branching ratios and β parameters. Interchannel coupling among the channels arising from 3s, 3p, and 3d subshells is found to be necessary for quantitative accuracy of the theory. This shows that the interchannel coupling phenomenology far above threshold, found previously for outer shells of Ne and Ar, is also operative for inner atomic shells.

Solution Structure Of B. Subtilis Acyl Carrier Protein, Guang-Yi Xu, Amy Tam, Laura Lin, Jeffrey Hixon, Christian C. Fritz, Robert Powers

Robert Powers Publications

Background: Acyl carrier protein (ACP) is a fundamental component of fatty acid biosynthesis in which the fatty acid chain is elongated by the fatty acid synthetase system while attached to the 4’-phosphopantetheine prosthetic group (4’- PP) of ACP. Activation of ACP is mediated by holo-acyl carrier protein synthase (ACPS) when ACPS transfers the 4’-PP moiety from coenzyme A (CoA) to Ser36 of apo-ACP. Both ACP and ACPS have been identified as essential for E. coli viability and potential targets for development of antibiotics.

Results: The solution structure of B. subtilis ACP (9 kDa) has been determined using two-dimensional and three-dimensional …

An Investigation Of Friedel-Crafts Alkylation Reactions In Super- And Subcritical Carbon Dioxide And Under Solventless Reaction Conditions, Kan Nie

Masters Theses

This study investigates the Friedel-Crafts alkylation reaction of triphenylmethanol with methoxybenzene (anisole) in supercritical and subcritical carbon dioxide, and under solventless reaction conditions. The reaction was initiated using trifluoroacetic acid to produce triphenylmethylcarbocation as the reaction intermediate. Isolated product yields of the Friedel-Crafts product, p-methoxytetraphenylmethane, are reported. The possibility of using the above reaction as an alternative synthesis in an undergraduate organic laboratory to teach some of the tenets of green chemistry is also presented. Additionally, we have investigated the use of benzhydrol, 9-hydroxyxanthene and 9-phenylxanthen-9- ol as potential carbocation sources for supercritical carbon dioxide synthesis and we report those …

An Efficient And Simple Synthesis Of Optically Pure Tricarbonyl(Methyl 6-Oxo-2,4-Hexadienoate)Iron, Kamil Godula, Heiko Bärmann, William A. Donaldson

Chemistry Faculty Research and Publications

No abstract provided.

Synthesis And Reactivity Of Tricarbonyl(1-Ethoxy-Carbonyl-2-Methylpentadienyl)Iron(1+) Cation, Young K. Yun, Heiko Bärmann, William A. Donaldson

Chemistry Faculty Research and Publications

The title cation was prepared in two steps from the known (ethyl 3-methyl-6-oxo-2,4-hexadienoate)Fe(CO)3. Reation of the cation with NaBH3CN, methyl cuprate, phthalimide, water, PPh3, or malonate anions gave predominantly the products from nucleophilic attack at the C5 pentadienyl carbon.

Optimization Of Palladium-Catalyzed In Situ Destruction Of Trichloroethylene-Contaminated Groundwater Using A Genetic Algorithm, Manuel Fernandez

Theses and Dissertations

Conventional technologies for the treatment of groundwater contaminated with chlorinated solvents have limitations that have motivated development of innovative technologies. One such technology currently under development involves using palladium-on-alumina (Pd/Al) as a catalyst to promote dechlorination. Pd/Al catalyst may be used in-well as part of a re-circulating horizontal flow treatment well (HFTW) system. An HFTW system involves two or more dual-screened wells, with in-well reactors, to capture and treat contaminated groundwater without the need to pump the water to the surface. In this study, objective and fitness functions, based on system costs and TCE concentration requirements, were developed to optimize …

Use Of Quantum Mechanical Calculations To Investigate Small Silicon Carbide Clusters, Jean W. Henry

Theses and Dissertations

Density Functional Theory (DFT) method was employed to model silicon carbide small clusters. Comparing the DFT calculation results with experimental results that observed by using photoelectron spectroscopy (PES), DFT predicts the same structures that experiment observed. For electron affinity, DFT results are in good agreement with experimental results, the root mean square negative offset 0.1 eV found using medium size of basis set (cc-pVDZ+) calculation. DFT results for vibrational frequencies are in good agreement with experiment results; the root mean square error is 72.5 cm^-1 wave number. 16 ground state structures of Si_mC_n (m ≤ 4, …

Dissolution Of Chromium From Inhalable Primer Paint Particles Into A Simulated Lung Fluid, David A. Kauth

Theses and Dissertations

The use of chromate as a corrosion inhibitor in primer paint is an essential component for the protection of aluminum-skinned aircraft and the primary source of hexavalent chromium (Cr (VI)) exposure to USAF aircraft painters. The objective of this research was to quantify the dissolution of chromate from freshly sprayed paint particles into a simulated lung fluid (SLF). Two primer paints were sprayed with a paint spray gun to generate overspray particles for collection into impingers filled with SLF. Particles were allowed to soak in SLF for 24 and 48 hours and then the particles were removed by centrifugation. The …

Surfactant-Assisted Synthesis Of Semiconductor Nanotubes And Nanowires, Chintamani Nagesa Ramachandra Rao, A. Govindaraj, F. L. Deepak, N. A. Gunari, Manashi Nath

Chemistry Faculty Research & Creative Works

Nanotubes and nanowires of CdSe and CdS have been obtained from solutions containing a surfactant such as Triton 100-X. They have been characterized by x-ray diffraction, electron microscopy, and optical spectroscopy.

The Development Of Microsystems And New Applications Of Electrochemistry, Zhao-Wu Tian, Hua-Shui Lin, Jian-Jun Sun, Yong-Liang Zhou, Yan-Bin Zu, Zhong-Qun Tian, Jin Luo, Zhong-Hua Lin, Zhao-Xiong Xie, Wei-Ling Hu, Yong-Gan Hu, Wen-Duan Su

Journal of Electrochemistry

1. Brief introduction to microsystems. 2. Discussions on the developments of microsystem technologies. 3. Applications of electrochemistry in microsystem. 4. Concluding remark

The Applications Of Confocal Raman Micro-Spectroscopy For Study Of Practical Electrode Materials, Yong Yang, Wei Chu, Jun-Min Nan, Xun-Guang Chen, Zu-Geng Lin

Journal of Electrochemistry

Some recent research work about applications of confocal Raman micro spectroscopy for study of practical electrode materials carried out in our lab has been briefly introduced. The examples include study of electrochemical Li⁺ intercalation process, characterization of surface oxide film on AB₅ type electrodes and passive film and pitting corrosion of Rebar electrodes.

Confocal Microprobe Raman Spectroscopy For Investigating The Electrochemical Interface, Bin Ren, Feng-Ming Liu, Xu-Feng Lin, Zhong-Qun Tian

Journal of Electrochemistry

The invention of the surface enhanced Raman spectroscopy (SERS) in the mid of 1970s, opened an entirely new and very promising area. However, it was found that SERS of practical application in electrochemistry can only be found on noble metal surfaces, such as Ag, Au and Cu that exhibit huge surface enhancement. This greatly limits the application of SERS in electrochemistry.

Raman And Afm Characterization Of Au And Cu Nanorod And Nanowire Arrays, Jing Tang, Jian-Lin Yao, Kuan-Hong Xue, De-Yin Wu, Long-Gang Lin, Yu-Xiong Jiang, Bin Ren, Xin Xu, Bing-Wei Mao, Zhong-Qun Tian

Journal of Electrochemistry

Recently metal nanowires (nanorods) have aroused tremendous interest because of their novel properties and potential applications in wide fields Many two-dimensional nanowire arrays of semiconductors and metals with different diameter and length have been made by using template synthesis method.

Surface-Enhanced Raman Spectroscopy Of Metallotetraphenyl Porphyrins Adsorbed On Ag2O And Silver Colloids, Ying-Hui Zhang, Dong-Ming Chen, Tian-Jing He, Fan-Chen Liu

Journal of Electrochemistry

The biological significance of porphyrins and metalloporphyrins has stimulated intensive investigations on these compounds for many years. On the other hand, porphyrins and metalloporphyrins also have extensive applications in many other fields such as chemical modified electrodes, organic photovoltaic devices and biomimetic catalysis. The adsorption behavior and chemical reactions of metalloporphyrins on surfaces or interfaces are very important for these applications.

Electrochemical Impedance Spectroscopy Studies On Inhibitive Performance Of Aluminum Triphosphate Pigment, Yong-Gui Liao, Zhi-Jun Gu, Zhi-Gang Zhang, Qi-Long Guo, Fang-Teng Su

Journal of Electrochemistry

The epoxy coatings on A₃ steel sheets containing calcite or aluminum triphosphate (AlTP), were investigated by Electrochemical Impedance Spectroscopy (EIS). The results showed that calcite pigment is not an inhibitor, but an extender pigment, and that AlTP pigment can considerably enhance the protective performance of epoxy coating. The triphosphate ion at the interface between the steel substrate and the coating can complex with the corrosion product, such as ferric and ferrous ions, and form a compact protective film which effectively separates the steel substrate from the aggressive media.

Study On Electrofusion Of Barley Protoplasts Using Fluorescent Dextra, Min-Yan Wang, Ye-Fang Gong, Zhi-Yu Jiang

Journal of Electrochemistry

The influence of interfacial active substance on the electrofusion of barley protoplasts was investigated using fluorescent dextra (F DX) as an anion additive. It was found that fluorescent dextra could inhibit the electrofusion process. The adsorption of fluorescent dextra on the membrane of protoplasts was detected by fluorescent microscopy technique. It was observed that after being stored in a solution containing fluorescent dextra a fluorescent ring appeared on the membrane of the protoplast, reflecting the adsorption of fluorescent dextra. The results of electrophoresis experiment also proved the adsorption of F DX on the surface of protoplasts, because the relative mobility …

Effects Of A Vanadium Compound On The Stability Of An Acidic Tin(Ii) Plating Solution, Zhen-Jiang Niu, Fei-Feng Lin, Fang-Zu Yang, Shi-Bing Yao, Shao-Min Zhou

Journal of Electrochemistry

The effects of a vanadium compound on the stability of an acidic solution of tin(Ⅱ) sulfate were studied. The electron spectra of the solutions of stabilizer showed that the vanadium existed mainly in VO²⁺ with a small amount of V³⁺ in the stabilizer. The results of cyclic voltammetry revealed that VO²⁺ can be further reduced to V³⁺ on the cathode surface in potential range -0.2～-0.55 V(vs. SCE) and V³⁺ to V²⁺ at the potential more negative than -0.55 V. Both V³⁺ and V²⁺ can effectively eliminate the dissolved oxygen in the bath …

A Study On The Performance Of Matrix Prepared By Tape Cast And Its Molten Carbonate Fuel Cells (Mcfcs), Hua-Xin Lin, Bao-Lian Yi, Li Zhou, Chang-Qing He, Lian-Ying Kong, En-Jun Zhang

Journal of Electrochemistry

The matrix prepared with γ-LiAlO₂ powder and by tape cast displayed higher ability of preventing from gas cross over and lower ohmic polarization. The voltages of the stack (three cells, 122 cm²) stacked with the matrix were 2.02 and 1.78 V at 200 and 246 mA/cm², respectively, and the output power reached 53.4 W. The cell (28 cm ²) voltages were 0.85 and 0.75 V at 200 and 300 mA/cm², respectively, and the output power was about 6.6 W. Compensating the shrinkage of matrix in stacking cells promoted the enhancement of the …

The New Developments Of Molten Salt Electrochemistry, Qi-Qin Yang, Shu-Zhen Duan

Journal of Electrochemistry

New developments in the areas of molten salt systems, molten salt batteries and power, electrodeposition of metals and alloys, electro synthesis of compound materials in molten salts are presented. Application of molten electrochemistry to the energy supply and consumption, global environment, resources and recycling are predicted.

Rhodium As A Ubiquitous Substrate For Surface Enhanced Raman Spectroscopy, Bin Ren, Xu-Feng Lin, Zhong-Qun Tian

Journal of Electrochemistry

Raman Spectroscopy is a powerful technique in characterizing the molecular structure at the molecular level. However, only after the discovery of surface enhanced Raman scattering (SERS) effect, has it become one of the most widely used technique in surface sciences. The limitation that only Ag, Au and Cu can produce prominent SERS signal of practical significance, greatly hinders the application of this technique. Recently our group has made great progress in extending SERS to pure transition metal surfaces, such as Pt, Ni, Fe, Co etc.

Two-Dimensional Surface Raman Imaging Of A Roughened Iron Electrode In Saline Water, Pei-Gen Cao, Jian-Lin Yao, Jun-Wei Zheng, Bin Ren, Ren-Ao Gu, Zhong-Qun Tian

Journal of Electrochemistry

The analysis of the composite and distribution of iron oxide due to pit corrosion in saline solutions (3.4% NaCl) is of great importance. Many electrochemical methods, XPS, and other photoelectronic techniques have been applied to this domain. Surface enhanced Raman scattering (SERS) spectroscopy can provide the vibrational information of surface species with high sensitivity and is very useful in the study of surface chemistry of iron. Notwithstanding, the application of SERS in iron corrosion is hampered for its SERS-inactivity. Efforts have been devoted to extend the use of SERS to the study of iron.

The Charge Transfer Effect Of Sers Induced By The Electrochemical Hydrogen Evolution Reaction, Feng-Ming Liu, Qi Han, Yan-Xia Chen, Qi-Ling Zhong, Bin Ren, Zhong-Qun Tian

Journal of Electrochemistry

As one of the important mechanisms of SERS, the charge transfer (CT) enhancement requires the strong interaction of the adsorbed species with the substrate in order to permit the transition of charge between the metal Fermi level (energy state) and the molecular orbital. The high enhancement needs the match of the energy gap between the Fermi level (or surface state) and the orbital energy level of the adsorbed molecules with the energy of the incident light. The electrode Fermi level is usually adjusted by the applied potential to satisfy the CT resonance. For the electrochemical reaction process, the frontier orbital …

Fabrications And Characterizations Of Porous Silicon By Two-Step Techniques Ii: Pulse Current Application, Xuan Cheng, Feng-Ming Liu, Zuo-Xin Wen, Chang-Jian Lin, Zhong-Qun Tian, Ru Xue

Journal of Electrochemistry

Porous silicon structures were formed by two-step technique consisting of pulse current applications in 1:1 hydrofluoric acid and ethanol solutions and chemical oxidation in 20% nitric acid solutions. Their surface morphologies and optical properties were characterized by scanning electron microscope (SEM) and Raman spectrometer, and compared with those obtained by constant current application. More uniform pore formation on p(100) silicon wafers was observed by pulse current application. Illumination with an ultraviolet lamp during the pulse current application accelerated the macropore formation, accordingly, the optical properties were changed.

Eis Characteristics Of Anodic Dissolution For P110 Steel Under Co2 Environment, Jing Li, Dong-Bai Sun, Hong-Ying Yu, Hui-Min Meng, Hui-Qin Li, De-Jun Yang

Journal of Electrochemistry

Effect of temperature on the electrochemical impedance spectroscopy for P110 steel at anodic polarized potential was investigated in simulated CO₂ saturated oil produced water. The results demonstrated that in the range from room temperature to 90 ℃, there was a critical temperature , below which a three time constant impedance spectrum was observed and above which a two time constant spectrum was shown. A reasonable explanation was given to this phenomenon in an effort to elucidate the mechanism of anodic dissolution and characteristics of CO₂ corrosion.

How Can Direct Mthanol Fuel Cell Benefit From Carbonate Media, Lin Zhuang, Yang Wang, Jun-Tao Lu

Journal of Electrochemistry

The kinetics of methanol oxidation and oxygen reduction in 0.5 mol/L K₂CO₃ were compared with those in 0.5 mol/L H₂SO ₄. Experiments revealed that carbonate media could be more beneficial to direct methanol fuel cell(DMFC). Firstly, both electrode reactions show better performance in the carbonate than in the acid; secondly, materials other than noble metals become possible to be used as the anodic and cathodic catalysts; thirdly, the potential dectease caused by methanol crossover could be depressed by using metal oxide catalysts not stable in acid, such as MnO₂.

Serrs And Electrochemical Study Of Yeast Iso-1-Cytochrome C Mutant F82h, Jun-Wei Zheng, Ren-Ao Gu, Tian-Hong Lu, Chumanov George, M. Cotton Therese

Journal of Electrochemistry

The redox properties of iso-1-yeast cytochrome c and its mutant F82H were studied by surface-enhanced Raman spectroscopy and cyclic voltammetry. The results showed that the replacement of phenylalanine-82 with histidine led to a more stable global structure of the protein. A negative shift in the redox potential of the mutant relative to that of wild type protein is ascribed to a ligand switching reaction during the redox processes.