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Existence Of High-Order Superlattices In Orientationally Ordered C_{60}, J. E. Fischer, D. E. Luzzi, K. Kniaź, A. R. Mcghie, D. A. Ricketts-Foot, W. R. Romanow, Gavin B. M. Vaughan, Dayin Li, Allan L. Smith, Robert M. Strongin, M. A. Cichy, Laurent Bard, Amos B. Smith Iii

Chemistry Faculty Publications and Presentations

We correlate the presence or absence of high-order modulated structures in solid C₆₀ with the differential scanning calorimetry signature of the orientational ordering transition and other diagnostic data. We have searched for, but not observed, the 2a face-centered cubic structure recently observed in low-temperature electron and single-crystal x-ray diffraction. We conclude that the intrinsic ground state is the previously reported simple cubic structure [space groupPa3¯, a(14 K)=14.06 Å], and that other structures may be stabilized by defects or impurities.

Investigation Of Electron Transfer From Carbonylmetallate Anions To Electron Acceptors, Joseph Kofi Agyin

Masters Theses

This study investigated electron transfer potential of the carbonyl-metallate anions cyclopentadienylirondicarbonyl and methylcyclopentadienyliron-dicarbonyl anions to the electron acceptors 2,2-dinitropropane, 1,1-dinitrocyclohexane, $\alpha$,p-dinitrocumene, methyl cyclopentadienyl-mercury(II) chloride and iodide.

The findings from this study indicated that: (a) the expected products could not be obtained from reactions of the anions with the dinitro-substrates, and (b) the mercurials reacted with the anions but the expected products, (ferrocene and methylferrocene), was the minor product and an unexpected (methyl) cyclopentadienylirondicarbonylmercury(II)-chloride or iodide was the major product.

Coherence Peak And Superconducting Energy Gap In Rb_{3}C_{60} Observed By Muon Spin Relaxation, R. F. Kiefl, W. A. Macfarlane, K. H. Chow, S. Dunsiger, T. L. Duty, T. M. S. Johnston, J. W. Schneider, J. Sonier, Laurent Brard, Robert M. Strongin, J. E. Fischer, Amos B. Smith Iii

Chemistry Faculty Publications and Presentations

Muon spin relaxation resulting from spin exchange scattering of endohedral muonium (μ+e-) with thermal electronic excitations has been observed in the fullerene superconductor Rb₃C₆₀. The temperature dependence of T₁^-1 shows a coherence peak just below T_c and can be fit to the conventional Hebel-Slichter theory for spin relaxation in a superconductor with a broadened BCS density of states. The average energy gap for electronic excitations, Δ/k_B=53(4) K or 2Δ/ k_BT_c=3.6(3), is consistent with the BCS weak coupling limit.

Remote Sensing Of Vehicle Emissions, Case Study: Thessaloniki, Greece (Presentation), Kostas Nikolaou, Donald H. Stedman

Fuel Efficiency Automobile Test Publications

Presented at the 4th International Conference on Advances in Communication and Control, Rhodes Greece, June 14-18, 1993.

An Elementary Reaction Model For Thermal Decomposition Of Cf2cl2 In A H2 Atmosphere And Experimental Studies On Oxidation Of Ch3oh Plus Ch4 Under Fuel Rich, Stoichiometric And Fuel Lean Conditions, Cheng Guo

Theses

Pyrolysis of CF₂CL₂ in an atmosphere of H₂, has been studied in a tubular flow reactor, 723 to 873 K. Overall eaction conversion proceeds via loss of Cl with CHF₂CL formation, then loss of the second Cl atom and CH₂F₂ product. Initiation occurs by unimolecular Cl atom loss. Subsequent chain propagation steps rapidly generate active H atoms which abstract Cl atoms, but abstraction of fluo-rine atoms by atomic hydrogen is slow at the temperatures of this study.

A small mechanism, about 35 elementary reaction steps, and a thermodynamic data base …

Photochemistry Of Nitrous Acid And Nitrite Ion, Kathryn E. Shanks '93

Honors Projects

Research is currently underway to elucidate the photochemical decomposition mechanism of nitrous acid and nitrite ion in aqueous and non-aqueous media. The quantum yield of the photochemical disappearance of nitrous acid and nitrite, as a function of pH and nitrous acid/nitrite ion concentration ratios, was examined. Spectroscopic studies have been done with nitrite ion in various aprotic organic solvents. Similar work has been started with molecular nitrous acid that was produced in aqueous solution and then extracted into organic solvents. These organic solvents were employed in order to study the quantum yield with respect to NO2- and HONO without the …

Development Of New Methods For Assessing Solidification/Stabilization Of Hazardous Waste Using Solid-State Nuclear Magnetic Resonance Techniques (Ph.D Dissertation, Lsu), Michael A. Janusa

Faculty Publications

New methods for assessing solidification/stabilization (S/S) of hazardous waste using solid-state nuclear magnetic resonance are developed for the purpose of diagnosing on a microscopic level the performance of S/S as a hazardous waste disposal technique. There are four techniques developed and described in this dissertation: (1) Solid-state deuterium NMR spectroscopy is used to determine if a particular deuterated organic waste is effectively solidified/stabilized and to determine the lower limit of the bond strength between the waste and the cement matrix; (2) Constant time pulsed field gradient ^ NMR spectroscopy is tested on a liquid waste encapsulated within a solidified matrix …

Examination Of Fat Oxidation Products By Ft-Nmr & Ft-Ir, De Chen

Masters Theses & Specialist Projects

Edible oils are easily oxidized when used for frying. Oxidation originates with double bonds present in unsaturated fatty acids. A new NMR method is presented which offers potential for determining the products of oil oxidation. High resolution fourier transform nuclear magnetic resonance (FT-NMR) and fourier transform infrared (FT-IR) spectroscopy have found increasing use in biochemistry. One pure fat, trioleoylglycerol, was heated at 160°C in the presence of air Samples were taken for FT-NMR and FT-IR analyses at 4, 10. 20. 25, 35, 50, 70 and 100 hours. Proton, Carbon-13 and several types of two-dimensional FT-NMR spectra were obtained using a …

Unusual Thermal Stability Of A Site-Ordered Mc60 Rocksalt Structure (M=K, Rb, Or Cs), Q. Zhu, O. Zhou, J. E. Fischer, Andrew R. Mcghie, W. R. Romanow, Robert M. Strongin, M. A. Cichy, Amos B. Smith Iii

Chemistry Faculty Publications and Presentations

X-ray diffraction and differential scanning calorimetry of M_xC₆₀, with x∼1 and M=K, Rb, or Cs, reveal an unusual T-dependent phase sequence. A low-symmetry ground state is found, while the high-T limit is an ordered rocksalt structure in which only the octahedral sites are occupied. The unusual high-T stability of this ordered phase is attributed to the entropy of molecular orientational disorder and/or thermal disorder of the alkali-metal ions within the octahedral sites. Unique to K_xC₆₀ with x≥1.4, we find at intermediate temperatures an fcc site-disordered lattice gas …

A Neutron Diffraction And Mössbauer Effect Study Of The Magnetic Structure Of Y₂(Fe₁₋ₓmnₓ)₁₄B, Gaya Kanishka Marasinghe, Oran Allan Pringle, Gary J. Long, William Joseph James, William B. Yelon, Fernande Grandjean

Physics Faculty Research & Creative Works

The magnetic structures of a series of Y₂(Fe _1-xMn_x)₁₄B samples, with x equal to 0.03, 0.10, 0.25, and 0.37, have been studied by powder neutron diffraction and Mössbauer spectroscopy. Y₂(Fe_0.97Mn _0.03)₁₄B and Y₂(Fe_0.9Mn _0.1)₁₄B are ferromagnetic at both 295 and 85 K, Y ₂(Fe_0.63Mn_0.37)₁₄B is paramagnetic at both 295 and 85 K, whereas Y₂(Fe_0.75Mn _0.25)₁₄B is paramagnetic at 295 K and is partially ordered at …

Derivatized Cyclodextrins Immobilized On Fused-Silica Capillaries For Enantiomeric Separations Via Capillary Electrophoresis, Gas Chromatography, Or Supercritical Fluid Chromatography, Daniel W. Armstrong, Yubing Tang, Timothy Ward, Molly Nichols

Chemistry Faculty Research & Creative Works

No abstract provided.

Chlorination Products Of Glycylphenylalanine In Model Solutions And A Wastewater, Daniel J. Keefe

Chemistry & Biochemistry Theses & Dissertations

Model solutions of the dipeptide glycylphenylalanine were chlorinated to five different chlorine-to-amino nitrogen (Cl/N) mole ratios and analyzed after 30 min by high performance liquid chromatography. At mole ratios of ≤ 1, N-chloroglycylphenylalanine (I) appeared to be the only major product. At a mole ratio ≤ 2, N, N-dichloroglycylphenylalanine (II) was the only product. Compound II decomposes in model solutions (t_1/2= 6.4 hr) at pH 7.0 to form a compound tentatively identified as an H-chloroaldimine (III). Compound III in turn decomposes (t_1/2= 36 hr) in model solutions at pH 7. o to (IV) . From ^{13 …}

Peroxyoxalate Chemiluminescence And Capillary Electrophoresis : New Methods For Bioanalytical Chemistry, Nian Wu

Graduate Dissertations and Theses

The general research objectives lie in the development of new approaches to improve chemical analysis in the area of bioanalytical chemistry. More specifically this thesis is focused on the development and application of new methodologies and instrumentation involving two potentially powerful techniques: 1) Chemiluminescence-a spectroscopic technique in which the generation of fluorescence from the electronically excited state of the molecule is provided by a chemical reaction and 2) Capillary electrophoresis-a separation technique in which small ions as well as large biomolecules can be separated with high efficiency within a narrow capillary under the influence of high voltage.

Studies Of The Solid-Phase Pauson-Khand Reaction Selective In-Situ Enone Reduction To 3-Azabicyclo[3.3.0]Oct-Anones, Daniel Becker, Daniel L. Flynn

Chemistry: Faculty Publications and Other Works

The Smit-Caple DSAC Pauson-Khand cyclization of a series of N-protected allyl propargyl amines in the absence of oxygen gave rise to formation of the saturated azabicyclo[3.3.0]octanones in excellent yields. Standard cyclization in air gave mixtures of saturated and unsaturated ketones.

Isolation Of A Highly Functionalized Troeger’S Base Derivative Via A Novel Reaction, Daniel Becker, Patricia M. Finnegan, Paul W. Collins

Chemistry: Faculty Publications and Other Works

Heating a solution of methyl 5-chloro-4-[(ethoxyoxoacetyl) amino]-2-methoxybenz-oate, 3 in DMSO gave rise to the formation of the highly substitute

2-Carboxybenzenediazonium Chloride Monohydrate, Christopher J. Horan, Charles Leslie Barnes, Rainer Glaser

Chemistry Faculty Research & Creative Works

C₇H₅N₂O₂ ⁺.Cl^-H₂O, M_r = 202.60, monoclinic, C2c, a = 25.62(3), b = 4.964(2), c = 14.900 (14)Å, β = 107.15 (4)°, V = 1811 (3)ų, Z = 8, D_x = 1.486 g cm^-3, λ(Mo Kα) = 0.71073 Å, µ = 3.9 cm^-1, F(000) = 832, T = 298 K, R = 0.035 for 1275 observed reflections. The terminal N atom of the diazonium group is bent away from the carboxyl group. The N₂ and the …

Multiplet-Changing Auger Transitions In Valence Double Photoionization, U. Becker, Oliver Hemmers, B. Langer, I. Lee, A. Menzel, R. Wehlitz, M. Ya Amusia

Environmental Studies Faculty Publications

The decay of valence satellite states in neon above the first double-ionization threshold has been studied experimentally and theoretically. Special emphasis was given to differentiate between two decay modes: valence Auger and valence-multiplet Auger decay. It is shown that the latter process is predominant in the low kinetic energy part of the spectrum. The main structures of this low-energy Auger spectrum could be designated by help of calculated transition energies and decay rates.

The Electrochemical Characterization Of A Platinum Cyclooctadiene Complex As A Guest Molecule In The Presence Of Ss-Cyclodextrin, Timothy S. Evenson

Opportunities for Undergraduate Research Experience Program (OURE)

The equilibrium constants for the complexation of the dichloroplatinum- cycloocta-1,5-diene complex with p-cyclodextrin in N,N-dimethyl- formamide was determined using electrochemical cyclic voltammetry. The constants for both the oxidized and reduced forms of the platinum compound were determined. Model redox experiments were conducted with ferrocene and 1,1 ’-dimethylferrocene before the platinum compound was studied in order to establish parameters for the experimental method. Also determined was the ratio of the diffusion constants of the guest molecule with and without being complexed with cyclodextrin. In addition to the platinum complex being electrochemically characterized as a guest of cyclodextrin, circular dichroism studies were …

Hypochlorite Oxidation Of Nitrilotriacetic Acid, Audrey P. Linville

Opportunities for Undergraduate Research Experience Program (OURE)

The chemical degradation of nitrilotriacetic acid (NTA) by sodium hypochlorite is examined. Preliminary work indicates that NTA undergoes decarboxylation. In the second phase of this investigation (S92), the work was mainly concerned with the products from the reaction of NTA with hypochlorite. The product of decarboxylation has been found to be iminodiacetic acid. The decrease in concentration of hypochlorite per unit time was studied over a pH range of 7-14 and in the presence of lead, calcium, zinc, and copper ions.

Homogeneous Nucleation In Supersaturated Vapors Of Polar Molecules: Acetonitrile, Benzonitrile, Nitromethane, And Nitrobenzene, D. Wright, R. Caldwell, C. Moxely, M. S. El-Shall

Chemistry Publications

The critical supersaturations (S _c ) required for the homogeneous nucleation of acetonitrile, benzonitrile, nitromethane, and nitrobenzene vapors have been measured over wide temperature ranges using a thermal diffusion cloud chamber. At T _r =0.44, the experimental results are higher than the predictions of the classical nucleation theory by 20% (CH₃NO₂), 50% (CH₃CN), 57% (C₆H₅NO₂), and 112% (C₆H₅CN). This trend correlates well with the dipole moments and to a lesser extent with the polarizabilities of these substances. Corresponding states of simple fluids and …

Investigation Of The Structural Heterogeneity Of Lipooligosaccharides From Pathogenic Haemophilus And Neisseria Species And Of R-Type Lipopolysaccharides From Salmonella Typhimurium By Electrospray Mass Spectrometry, B W. Gibson, William Melaugh, Nancy J. Phillips, M A. Apicella, A A. Campagnari, J M. Griffiss

Chemistry Faculty Publications

Heterogeneity in the lipooligosaccharides (LOS) of pathogenic Haemophilus and Neisseria species is evident from the multiplicity of components observed with electrophoretic analyses. Knowledge of the precise structures that make up these diverse LOS molecules is clearly the key to reaching an understanding of pathogenic processes such as phase variation and molecular mimicry. Except for a few cases, little is known about the specific structural features of LOS that underlie phase variation and molecular mimicry, partly because of the inherent difficulties in the structural elucidation of these complex glycolipids. In the lipopolysaccharides (LPS) from Salmonella typhimurium and Escherichia coli, rough, or …

Solid-State Deuterium Nmr Spectroscopy Of D5-Phenol In White Portland Cement: A New Method For Assessing Solidification/Stabilization, Michael A. Janusa

Faculty Publications

We have developed a new NMR-based procedure for studying waste/cement interactions. This is the first use of deuterium NMR spectroscopy to study waste solidification/ stabilization (S/S). The main feature of deuterium NMR spectroscopy is the ability to monitor molecular reorientations over a wide range of reorientation rates. This technique allows one to determine if a particular deuterated organic waste is effectively solidified/ stabilized and to determine the lower limit of the bond strength between the waste and the cement matrix. Comparison of the predicted and experimental deuterium NMR spectra show that phenol is mainly dissolved in pore waters and, thus, …

Analysis Of Homogeneous Nucleation Data Of Polar Molecules: Vapor Association, Dipole Orientation, And Elongated Clusters, D. Wright, M. S. El-Shall

Chemistry Publications

In this paper we present the results of several theoretical models examined in order to explain the observed systematic deviations of the homogeneous nucleation of highly polar substances from the predictions of the classical nucleation theory (CNT). It is found that molecular association in acetronitrile or nitromethane vapor cannot explain the observed higher supersaturations. Similarly, the use of virial coefficient data to obtain a size dependent surface energy correction factor does not reproduce the experimental results. It is shown that orientation of the surface dipoles within the spherical droplets results in higher supersaturations in agreement with the experimental findings. We …

Rapamycin Inhibition Of Interleukin-2-Dependent P33(Cdk2) And P34(Cdc2) Kinase Activation In T Lymphocytes, W. G. Morice, Gregory Wiederrecht, Gregory J. Brunn, John Siekierka, R. T. Abraham

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

The immunosuppressant rapamycin (RAP) is a potent inhibitor of the entry of interleukin (IL)-2-stimulated T cells into S-phase. Earlier results indicated that RAP treatment arrested the growth of the murine IL-2-dependent T cell line CTLL-2 in late G1-phase. To explore further the interactions of RAP with the cell cycle control machinery in T cells, we examined the effects of RAP treatment on the activation of the cyclin-dependent kinases p34(cdc2) and p33(cdk2) in G1-phase CTLL-2 cells. Stimulation of factor-deprived cells with IL-2 led to the assembly of high molecular weight complexes containing active p34(cdc2) and p33(cdk2). The appearance of these complexes …

Processes For Producing Doxorubicin, Daunomycinone, And Derivatives Of Doxorubicin, Desmond M. S. Wheeler

Department of Chemistry: Faculty Publications

To produce doxorubicin and its analogues methyl 3alpha, 5alpha-dihydroxy-5beta-(trimethylsilylethynyl)- 2alpha-nitromethylcyclohexane-1beta-carboxylate acetonide is condensed with 1,4-dihydro-4,4,5-trimethoxy-1-oxonaphthalene in the presence of 1,8-diazabicyclo-5.4.0]undec-7-ene in an aprotic solvent to produce 3-(2beta-carbomethoxy-4-beta-ethynyl-4-alpha, 6alpha-(di-O-isopropylidenyl)cyclohexanyl-1-yl)-nitromethyl-4,4,5-trimethoxy-1-oxo-1,2,3,4-tetrahydronaphthalene; which is cyclized to produce 9beta ethynyl-12-hydroxy-7alpha, 9alpha-(di-O-iso propylidenyl)-6-nitro-4,5,5-trimethoxy-5,5a,6- 6a,7,8,9,10,10a,11-decahydro -11-naphthacenone. The decahydro-11-naphthacenone is converted to 7alpha 9alpha,(di-O-isopropyl-idenyl)-4,5-dimethoxy-9beta ethynyl-12-hydroxy-6-nitro-6,6a,7,8,9,10,10a, 11 octahydro-11, -naphthacenone. The octahydro-11 naphthacenone is oxidized to 7alpha-9alpha, (di-O-iso propyl-idenyl)-9beta-ethynyl-11-hydroxy-4-methoxy-6- nitro-7,8,9,10-tetrahydro-5,12-naphthacenedione which is converted to 6-desoxy-6-nitrodaunomycinone, daunomycinone and related 6-substituted analogues of daunomycinone.

Preparation And Use Of (2-Butene-1,4-Diyl)Magnesium Complexes In Organic Synthess, Reuben D. Rieke

Department of Chemistry: Faculty Publications

The magnesium complexes of cyclic hydrocarbons, such as 1,2-dimethylenecycloalkanes, are readily prepared in high yields using highly reactive magnesium. Reactions of these (2-butene-1,4-diyl)magnesium reagents with electrophiles such as dibromoalkanes, alkyl ditosylates, or bromoalkylnitriles serve as a convenient method for synthesizing spirocyclic systems. Significantly, spirocarbocycles prepared by this method contain functional groups such as the exocyclic double bond or a keto group in one of the rings which could be used for further elaboration of these molecules. Furthermore, fused bicyclic systems containing a substituted five-membered ring can be conveniently prepared at high temperatures by the reactions of (2-butene-1,4- diyl)magnesium complexes with …

Synthesis, Characterization, And Crystal Structure Of The (Η5-C5ph5)Cr(Co)3 Radical, Ray J. Hoobler, Marc A. Hutton, Mills M. Dillard, Michael Castellani, Arnold L. Rheingold, Anne L. Rieger, Philip H. Rieger, Thomas C. Richards, William E. Geiger

Chemistry Faculty Research

The reaction between Cr(CO)₆ and Na(C₅Ph₅ ) in refluxing diglyme yields [Na(diglyme)_3/2][(C₅Ph₅)Cr(CO)₃], 1. Metathesis of 1 with [Ph₃P=N=PPh₃ ]Cl in CH₂Cl₂ yields [Ph₃P=N=PPh₃][(C₅Ph₅)Cr(CO)₃], 2. Oxidation of 1 by AgBF4 in cold THF under an argon atmosphere produces (C₅Ph₅)Cr(CO)₃, 3. Complexes 2 and 3 form a redox pair connected by a quasireversible one-electron process, E⁰ = -0.69 V vs ferrocene in CH₂Cl₂, …

Rapamycin-Induced Inhibition Of P34(Cdc2) Kinase Activation Is Associated With G1/S-Phase Growth Arrest In T Lymphocytes, W. G. Morice, Gregory J. Brunn, Gregory Wiederrecht, John Siekierka, R. T. Abraham

Department of Chemistry and Biochemistry Faculty Scholarship and Creative Works

The macrolide rapamycin (RAP) is a potent inhibitor of interleukin-2 (IL- 2)-induced T-cell proliferation. Current models suggest that RAP, when complexed to its intracellular receptor, FK506-binding protein, interferes with an IL-2 receptor-coupled signaling pathway required for cell-cycle progression from G1- to S-phase. Here we show that RAP treatment inhibits the growth of an IL-2-dependent cytotoxic T-cell line, CTLL-2, in late G1- phase, just prior to entry of the cells into S-phase. In contrast, RAP- treated CTLL-2 cells retained the ability to respond to IL-2 with enhanced cytolytic activity, indicating that RAP was not a general suppressant of cellular responsiveness to …

Soluble Highly Reactive Form Of Calcium And Reagents Thereof, Reuben D. Rieke

Department of Chemistry: Faculty Publications

A soluble highly reactive form of calcium, prepared from Ca(II) salts and a reducing agent in ethereal, polyethereal, or hydrocarbon solvents, is presented. This form of calcium can be used in the preparation of organocalcium reagents. The organocalcium reagents resulting from the reaction of the soluble highly reactive calcium with organic compounds containing either halide, cyanide, a 1,3-diene, or a polyunsaturated functionality, are stable, useful reagents for organic synthesis. The organocalcium halide reagents undergo Grignard-type reactions. They also undergo reactions with Cu(I) salts to form organocalcium cuprate reagents. The organocalcium cuprate reagents undergo a variety of cross-coupling reactions. The soluble …

Fullerene Derivatives And Fullerene Superconductors, H. H. Wang, J. A. Schlueter, A. C. Cooper, J. L. Smart, M. E. Whitten, U. Geiser, K. D. Carlson, J. M. Williams, U. Welp, J. D. Dudek, M. A. Caleca

Faculty Publications - Department of Biological & Molecular Science

A series of 1:1 Cgo cycloaddition adducts, CgoA (A = anthracene, butadiene, cyclopentadiene, and methylcyclopentadiene), has been synthesized. The products are cleanly separated and characterized by use of TGA, iH-NMR, IR, and mass spectrometry. Among these adducts, Cgodaethylcyclopentadiene) showed the highest thermal stability and was doped with three equivalents of rubidium. The resulting Rb3C6o(MeCp) is a semiconductor but can be thermally converted to the superconducting Rb3C6O through a retro-Diels-Alder reaction. A one-step doping process to prepare Rb3Ceo crystals has been developed. The optimal doping condition occurs at ~300°C. High superconducting shielding fractions: between 60 and 90% and sharp transition widths …