Inorganic Chemistry Commons^™

Resonant Energy Transfer From Argon Dimers To Atomic Oxygen In Microhollow Cathode Discharges, M. Moselhy, R. H. Stark, K. H. Schoenbach, U. Kogelschatz

Bioelectrics Publications

The emission of atomic oxygen lines at 130.2 and 130.5 nm from a microhollow cathode discharge in argon with oxygen added indicates resonant energy transfer from argon dimers to oxygen atoms. The internal efficiency of the vacuum-ultraviolet (VUV) radiation was measured as 0.7% for a discharge in 1100 Torr argon with 0.1% oxygen added. The direct current VUV point source operates at voltages below 300 V and at current levels of milliamperes.

The Synthesis And Characterization Of Cu(I) Networks With Heterocyclic Bridging Ligands, Jonathan Timothy Maeyer

Dissertations, Theses, and Masters Projects

No abstract provided.

Copper Complexation And Speciation In The Western South And Equatorial Atlantic Ocean, John A. Consolvo

Chemistry & Biochemistry Theses & Dissertations

Presented here are the first data on copper complexation and speciation in the South Atlantic Ocean. Samples were collected at six vertical profile stations and along the surface (1m) transect during the 1996 IOC Baseline Contaminant Survey. Copper complexation measurements were made for the surface transect (1m) samples and three of the six vertical profile stations (1m - ~500m) using differential pulse anodic stripping voltammetry (DPASV) with a thin mercury film, rotating glassy carbon disk electrode (TMFRGCDE).

A strong organic copper complexing ligand (L₁; log K' _cuL1/cu2+ > 11. 8 ± 0 .4) was detected in 57% of all …

Electric-Octupole And Pure-Electric-Quadrupole Effects In Soft X-Ray Photoemission, Andrei Derevianko, Oliver Hemmers, S. Oblad, P. Glans, H. Wang, S. B. Whitfield, R. Wehlitz, I. A. Sellin, W. R. Johnson, Dennis W. Lindle

Environmental Studies Faculty Publications

Second-order [O(k²), k = ω/c] nondipole effects in soft-x-ray photoemission are demonstrated via an experimental and a theoretical study of angular distributions of neon valence photoelectrons in the 100–1200 eV photon-energy range. A newly derived theoretical expression for nondipolar angular distributions characterizes the second-order effects using four new parameters with primary contributions from pure-quadrupole and octupole-dipole interference terms. Independent-particle calculations of these parameters account for a significant portion of the existing discrepancy between experiment and theory for Ne 2p first-order nondipole parameters.

One-Dimensional Chains In Sodium Tetraphenylphosphonium Bis(2-Mercapto-4-Methylphenolato-O,S)Oxo-Vanadate(Iv), Paul Challen, D. Mcconville, W. Youngs

Paul R. Challen

No abstract provided.

The Vaporization Enthalpies Of Some Crown And Polyethers By Correlation Gas Chromatography, Gary Nichols, Jennifer Orf, Sarah M. Reiter, James Chickos, George W. Gokel

James Chickos

No abstract provided.

Microhollow Cathode Discharge Excimer Lamps, Karl H. Schoenbach, Ahmed El-Habachi, Mohamed M. Moselhy, Wenhui Shi, Robert H. Stark

Bioelectrics Publications

Microhollow cathode discharges are high-pressure, nonequilibrium gas discharges between a hollow cathode and a planar or hollow anode with electrode dimensions in the 100 μm range. The large concentration of high-energy electrons, in combination with the high-gas density favors excimer formation. Excimer emission was observed in xenon and argon, at wavelengths of 128 and 172 nm, respectively, and in argon fluoride and xenon chloride, at 193 and 308 nm. The radiant emittance of the excimer radiation was found to increase monotonically with pressure. However, due to the decrease in source size with pressure, the efficiency (ratio of excimer radiant power …

Validity Of The Independent-Particle Approximation In X-Ray Photoemission: The Exception, Not The Rule, D. Hansen, Oliver Hemmers, H. Wang, Dennis W. Lindle, P. Focke, I. A. Sellin, Clemens Heske, H. S. Chakraborty, P. C. Deshmukh, S. T. Manson

Environmental Studies Faculty Publications

A combined experimental and theoretical study of argon valence photoionization illustrates the discovery of the broad lack of validity of the independent-particle approximation (IPA) for x-ray photoemission. In addition to previously known breakdowns of the IPA, which are limited to high photon energies and regions very near threshold, the observed breakdown in photoionization at intermediate energies demonstrates generally that the IPA is valid only in very restricted domains. These restrictions are expected to be relevant throughout the periodic table, with consequences for a wide variety of applications.

Zinc Speculation And Ligand Fluxes In Chesapeake Bay And Elizabeth River Pore Waters, Duncan Glover Byers

Chemistry & Biochemistry Theses & Dissertations

Presented here are the first data on the vertical concentrations, complexation, speciation, and fluxes of total dissolved zinc and zinc complexing ligands, and zinc speciation in sediment pore waters in the Chesapeake Bay and Elizabeth River, Virginia.

Sediment pore waters were collected in mid and southern Chesapeake Bay in November 1997 and in the Elizabeth River (Pinner's Point) in March, April, and July 1998. Flux experiments were conducted in Elizabeth River sediment cores in April and July 1998. [TDZn] and zinc complexation were determined using differential pulse anodic stripping voltammetry at a hanging mercury drop electrode (DPASV-HMDE).

[TDZn] in the …

Photochemistry And Pinhole Photography: An Interdisciplinary Experiment, Angeliki A. Rigos, Kevin Salemme

Visual & Performing Arts Faculty Publications

This interdisciplinary activity combines chemistry and art through the construction and use of a pinhole camera. We focused on the chemistry of the black and white photographic process as the science component of this activity. The reactions involved are good examples of photochemistry and multiphase chemical reactions, since the light sensitive materials (silver halides) are in the form of a gelatin emulsion of microscopic crystals.

Charge Density Wave Caused By Reducing Thse3 By One Electron. Superstructure And Short-Range Order In Ath2se6 (A = K, Rb) Studied By X-Ray Diffraction, Electron Diffraction, And Diffuse Scattering, Kyoung-Shin Choi, Rhonda Patschke, Simon Billinge, Mark Waner, Marcos Dantus, Mercouri Kanatzidis

Mark J. Waner

Charge Density Wave Caused by Reducing ThSe3 by One Electron. Superstructure and Short-Range Order in ATh2Se6 (A = K, Rb) Studied by X-ray Diffraction, Electron Diffraction, and Diffuse Scattering

A Method For The Determination Of Purity Of Pnu-10483 Bulk Drug By Capillary Zone Electrophoresis, Gavin Gibson

Honors Theses

In this investigation, a method was developed for the determination of purity of the drug PNU-10483 using the technique of capillary zone electrophoresis (CZE). CZE was seen as a potential alternative to the formerly used procedure of ion-pair reversed phase highperformance liquid chromatography (HPLC). Nearly five years earlier, a similar study was performed, in which an attempt was made to develop a method that used CZE to determine the purity of bulk drug and the potency of drug tablets. While this development was mostly successful, sporadically unpredictable results reduced the method's overall viability. These outliers were thought to be caused …

Generation Of Intense Excimer Radiation From High-Pressure Hollow Cathode Discharges, Ahmed El-Habachi, Karl H. Schoenbach

Bioelectrics Publications

By reducing the diameter of the cathode opening in a hollow cathode discharge geometry to values on the order of 100 μm, we were able to operate these discharges in noble gases in a direct current mode up to atmospheric pressure. High-pressure discharges in xenon were found to be strong sources of excimer radiation. Highest intensities at a wavelength of 172 nm were obtained at a pressure of 400 Torr. At this pressure, the vacuum ultraviolet (VUV) radiant power of a single discharge operating at a forward voltage of 220 V and currents exceeding 2 mA reaches values between 6% …

Mass Transfer With Chemical Reaction In The Process Of Ammonia Desorption From Aqueous Solutions Containing Carbon Dioxide, Wojciech M. Budzianowski

Wojciech Budzianowski

No abstract provided.

Platinized Tin Oxide: A Low-Temperature Oxidation Catalyst, Erik Joshua Kielin

Dissertations, Theses, and Masters Projects

Some combinations of noble metal and reducible metal oxide possess a synergistic level of activity for the catalytic oxidation of CO at lower temperatures and partial pressures of O2 than can be obtained by either component alone. The most promising candidates, Au on MnO2 and Pt on SnO 2, were investigated for the effects on activity of noble metal loading, of reductive pretreatment at elevated temperature, and of reaction gas mixture composition. Optimum activity was obtained at a noble metal loading of 28% Au/MnO2 and 17% Pt/SnO2. Both catalysts benefitted from reductive CO pretreatment at 125??C. Both catalysts showed enhanced …

Dichlorobis[1,3-Dimethylimidazole-2(3h)-Selone-Se]Cobalt(Ii), Daniel J. Williams, Timothy Jones, Edward D. Rice, Kerri J. Davis, John A. Ritchie, William T. Pennington, George L. Schimek

Faculty and Research Publications

The crystal structure of the title compound, [CoCl₂(C₅H₈N₂Se)₂], shows a discrete molecular structure with tetrahedral geometry around the cobalt ion. The mean Co-Cl and Co-Se distances are 2.277 (3) and 2.456 (3) Å, respectively. Bond angles around the Co atom range from 101.1 (1) to 120.0 (1)°. Ring distances and angles in the ligand compare favorably with the literature values of analogous compounds, and show significant increases from values observed in the uncoordinated selone. However, the mean C-Se bond distance of 1.88 (2) Å shows no significant difference from the …

Dichlorobis[1-Methyl-3-(Prop-2-Enyl)Imidazole-2(3h)-Thione-S]Zinc(Ii), Daniel J. Williams, Tuan A. Ly, Jeffrey W. Mudge, William T. Pennington, George L. Schimek

Faculty and Research Publications

The title compd. is monoclinic, space group P21/n, with a 14.0082(8), b 10.803(1), c 14.581(1) Å, and β 116.625(8)°; Z = 4, dc = 1.50; R = 0.043,Rw = 0.044 for 1935 reflections. The crystal structure shows a discrete mol. structure with tetrahedral geometry around the Zn ion. The mean Zn-Cl and Zn-S distances are 2.259(7) and 2.372(4) Å, resp. Bond angles around the Zn ion range from 102.8(1) to 113.7(1)°. Ring distances and angles in the ligand compare favorably with literature values of analogous compds., and the mean C-S bond distance of 1.71(1) Å is close to the av. …

A Niobium(V) Complex With Mixed O,S-Donor Ligands. Synthesis, Structure And Properties Of The Anion Tris(2-Mercapto-4-Methylphenolato)Niobate(V), Paul Challen, Diane Peapus, Karen Magnes

Paul R. Challen

Reaction of Nb(OEt)5 with 2-mercapto-4-methylphenol (mmpH2) in the presence of triethylamine gave the mononuclear tris complex (Et3NH)[Nb(mmp)3] which was structurally characterized. The coordination geometry around the niobium is between octahedral and trigonal prismatic, with a twist angle of 41.5°. The mercaptophenolate ligands are arranged around the metal in a “propeller” fashion. (Et3NH)[Nb(mmp)3] was characterized by IR, 1H NMR and UV-vis spectroscopies, and cyclic voltammetry. A reversible reduction wave found at −1.03 V is for reduction to the NbIV complex.

Experimental Evidence For Self-Similar Structures In The Aggregation Of Porphyrins In Aqueous Solutions, F. Mallamace, N. Micali, S. Trusso, L. M. Scolaro, A. Romeo, A. Terracina, Robert F. Pasternack

Chemistry & Biochemistry Faculty Works

We have studied the aggregation of the porphyrin t-H₂Pagg in aqueous solution by light scattering. The intensity profile of the elastically scattered light, studied in the exchanged wave-vector range 0.2 ≤ q ≤ 31.4 μ m⁻¹, indicates that the aggregation produces large monodisperse clusters having a fractal structure, and is driven by diffusion-limited aggregation kinetics. Additional measurements performed at different q values confirm such a picture giving a hydrodynamic radius R(H) consistent with the radius of gyration R(g) measured by elastic scattering. This is explained taking into account the q² dependence observed in the mean decay rate of the intensity-intensity …

Vanadium(Iv) Complexes With Mixed O,S Donor Ligands. Syntheses, Structures, And Properties Of The Anions Tris(2-Mercapto-4-Methylphenolato)Vanadate(Iv) And Bis(2-Mercaptophenolato)Oxovanadate(Iv), Paul Klich, Andrew Daniher, Paul Challen, David Mcconville, Wiley Youngs

Paul R. Challen

Reaction of VO(acac)2 with 2-mercaptophenol (mpH2) in the presence of triethylamine gives the mononuclear tris complex (Et3NH)2[V(mp)3] (1), in which the vanadyl oxygen has been displaced. An analogous reaction using 2-mercapto-4-methylphenol (mmpH2) afforded (Et3NH)(PNP)[V(mmp)3] (2), which was structurally characterized. 2 crystallizes in the orthorhombic space group Pna21 with unit cell parameters (at −163 °C) a = 23.974(7) Å, b = 9.569(4) Å, c = 25.101(6) Å, and Z = 4. The coordination geometry around the vanadium is between octahedral and trigonal prismatic. Reaction of VO(acac)2 with the sodium salt of 2-mercaptophenol produces the vanadyl(IV) complex Na(Ph4P)[VO(mp)2]·Et2O (3), which crystallizes in …

Microhollow Cathode Discharges, K. H. Schoenbach, R. Verhappen, R. Tessnow, F. E. Peterkin, W. W. Byszewski

Bioelectrics Publications

The current–voltage characteristics of hollow cathode discharges and their predischarges in argon under dc and pulsed conditions were found to have a positive slope at pressures up to approximately 50 Torr, and currents up to 20 mA, at a hole diameter of 0.7 mm. In this range of pressure and current, parallel operation of hollow cathode discharges, without ballast, was demonstrated. Scaling to higher pressure is possible by reducing the hole diameter. Pulsed experiments with an array of cathode rings of 75 μm diameter allowed us to obtain parallel operation of more than 50 discharges at a pressure of 350 …

Aggregation Of Chlorophyll A Probed By Resonance Light Scattering Spectroscopy, J. C. De Paula, J. H. Robblee, Robert F. Pasternack

Chemistry & Biochemistry Faculty Works

We report the resonance light scattering (RLS) spectra of chlorophyll a aggregated in a 9:1 solution of formamide and pH 6.8 phosphate buffer. The aggregate formed after 2 h of mixing, referred to as Chl(469), shows a strong scattering feature at 469 nm (Soret band) and a much weaker feature at 699 nm (Q(y) band). A kinetic investigation confirmed that the aggregation process is cooperative, and also detected one intermediate (Chl(458)) with a strong RLS spectrum but only a weak CD spectrum. We propose that aggregation proceeds via at least three steps: 1) formation of a nucleating species, probably a …

Continuous Electron Stimulated Oxygen Atom Emission From Ag Permeation Membranes, Gilda Ann Newton Miner

Dissertations, Theses, and Masters Projects

No abstract provided.

Ua35/11 Student Honors Research Bulletin, Wku Honors Program

WKU Archives Records

The WKU Student Honors Research Bulletin is dedicated to scholarly involvement and student research. These papers are representative of work done by students from throughout the university.

• Allen, Melody. Women in Control of Courtship in As You Like It, The Merchant of Venice and All's Well That Ends Well
• Amlani, Islamshah. Electron Stimulated Desorption of Alkali Halides
• Brillhart, Kelly. Women Without Men: Hemingway's Female Characters
• Burton, Lori. Financial Statements with Environmental Concerns: An Exploratory Study of the Impact on the Auditor's Role and Responsibilities
• Combs, Vicki. Dancing the Descent: Energy and Entrophy in William Carlos Williams
• Davis, Julie. Prelude to …

Electron Stimulated Desorption Of Alkali Halides, Islamshah Amlani

Mahurin Honors College Capstone Experience/Thesis Projects

No abstract provided.

Thermal Characterization Of Carbon Monoxide Oxidation Catalysts Using Thermogravimetric Analysts And Differential Scanning Calorimetry, Rene A. Bartgis

Chemistry & Biochemistry Theses & Dissertations

Catalysts composed of platinum and/or palladium on tin (IV) oxide supports, with and without silica gel, as well as catalysts composed of gold on manganese oxide, have been developed for the recombination of carbon monoxide and oxygen to form carbon dioxide for use in carbon dioxide lasers. A thermogravimetric method and a differential scanning calorimetric method have been developed for the thermal characterization of these catalysts. The mass loss data and the enthalpy changes determined as the catalysts lost water were then related to existing activity data for these catalysts. No relationship was found between the thermal data and the …

Nature Of The Si-N Bond In Silatranes, Mark S. Gordon, Marshall T. Carroll, Jan H. Jensen, Larry P. Davis, Larry W. Burggraf, R. Martin Guidry

Mark S. Gordon

Both ab initio and semiempirical calculations are used to investigate the structure and bonding in substituted silatranes. In agreement with gas-phase experiments, which fmd Si-N distances that are 0.25-0.35 A longer than those in the crystal phase, the Si-N distance (for example, in methylsilatrane) is predicted to be much larger than that observed in the crystal. Nonetheless, a bond critical point is found between Si and N, suggesting the existence of an Si-N bond in these compounds. It is found that the energy cost for constraining the Si-N distance in hydroxysilatrane to a value similar to that observed in the …

Evidence For An Unusual Kinetic Phenomenon In The Metallation Of Porphyrins, F. González-Vílchez, R. A. Vilaplana, Robert F. Pasternack

Chemistry & Biochemistry Faculty Works

Reaction of copper(II) with water soluble porphyrins (H₂porph) in the presence of ethylenediamine shows an unusual and so far unreported kinetic phenomenon that can be explained in terms of supramolecular assembly formation apparently involving all solute species as confirmed via light scattering and conductivity measurements.

A New Twist On Pseudorotation, Theresa L. Windus, Mark S. Gordon, Larry W. Burggraf, Larry P. Davis

Mark S. Gordon

For pentacoordinated structures in a trigonal bipyramidal ar· rangement, Berry1 proposed a "pseudorotation" mechanism whereby two such isomers can interconvert through a tetragonal transition state (TS). This Berry pseudorotation mechanism was demonstrated explicitly for SiH5- by following the MP22/6· 31G(d)3 minimum energy path4 (MEP).

Development Of Procedures To Determine The Fertilizer Requirements Of Annual Pasture Legumes Grown In Cereal Cropping Systems., B. H. Paynter

Experimental Summaries - Plant Research

Trials 88ME67, 88SC17, 90ME1 and 90ME2

Location: Merredin

To determine the phosphate (P) fertilizer requirements of burr medic on marginally acidic, medium textured soils and yellow serradella on acidic, light textured soils.

Trials 89ME52, 89ME55 and 86ME61

Location: Merredin

Determine the response of yellow serradella and burr medic to residual phosphate and freshly applied phosphate.

Trials 89ME50, 89ME54, 88ME67, 88SC17, 89ME60

Location: Merredin.

To measure the influence of different levels of pasture productivity (generated by different levels of P supply) and the different pasture legumes on subsequent wheat crops.