Physical Sciences and Mathematics Commons^™

Improved Synthesis Of 5-Methylbenz(A)Anthracene, Jia Che, Dominic T.C. Yang

Journal of the Arkansas Academy of Science

A revised synthesis of 5-methylbenz(a)anthracene is reported. It involves only three simple and convenient steps starting from a commercially available compound, and gives a 82% overall yield. Bromination of 5-methylbenz(a)anthracene with N-bromosuccinimide (NBS) in carbon tetrachloride furnishes 5-bromomethylbenz(a)anthracene in a 92% yield. When bromination is carried out using dimethylformamide as the solvent, 7-bromo-5-methylbenz(a)anthracene is formed as the exclusive product.

Molecular Dynamics In Hydrogen‐Bonded Interactions: A Preliminary Experimentally Determined Harmonic Stretching Force Field For Hcn‐‐‐Hf, B. A. Wofford, Shannon Lieb, J. W. Bevan

Scholarship and Professional Work - LAS

Observation of the 2ν₁ overtone band in the hydrogen‐bonded complex HCN‐‐‐HF permits evaluation of the anharmonicity constant X _{1 1}=−116.9(1) cm^{− 1} and determination of the anharmonicity corrected fundamental frequency ω₁. This information, and available data from previous rovibrational analyses in the common and perdeuterated isotopic species of HCN‐‐‐HF, offer an opportunity for calculation of an approximate stretching harmonic force field. With the assumptions f _{1 2}=f _{2 4}=0.0, the remaining force constants (in mdyn/Å) are evaluated as: f _{1 1}=8.600(20), f _{2 2}=6.228(9), f _{3 3}=19.115(40), f _{4 …}

Lamellar Liquid Crystal And Other Phases In The System Sodium Dodecyl Sulfate, Hexylamine, Water, And Heptane, Jiafu Fang, Raymond L. Venable

Chemistry Faculty Research & Creative Works

Phase equilibria have been studied for the system composed of sodium dodecyl sulfate, hexylamine, heptane, and water. Greatest emphasis has been placed on the lamellar liquid crystal region and X-ray diffraction measurements. Equations are developed or modified to allow determination of the degree of penetration of water into the amphiphilic double layer as a function of water or amphiphile concentration. It is found that the interfacial area occupied by the polar or ionic head groups of amphiphiles increases with increasing water content. © 1987 Academic Press, Inc. All rights reserved.

Surfactants And The Stratum Corneum Lipids, Stig E. Friberg, Lisa Goldsmith, Hamdan Suhaimi, Linda D. Rhein

Chemistry Faculty Research & Creative Works

A simplified mixture of model stratum corneum lipids was mixed with different surfactants to make a preliminary estimation of the influence of surfactants on the stratum corneum lipid structure. The results revealed differences between cationic and anionic surfactants and between anionic surfactants with different structures. © 1998.

A Mössbauer Effect Study Of The Structural And Magnetic Properties Of Y₂(Fe₁₋ₓalₓ)₁₄B, Ying-Chang Yang, Dwayne E. Tharp, Gary J. Long, Oran Allan Pringle, William Joseph James

Chemistry Faculty Research & Creative Works

The crystallographic and magnetic properties of Y₂(Fe₁₋ₓAlₓ)₁₄B, where x equals 0.00, 0.02, 0.04, 0.06, and 0.08, have been investigated by Mössbauer spectroscopy and magnetic measurements at room temperature and 85 K. Magnetic anisotropy and magnetization changes with aluminum substitution indicate that, because of size, the aluminum preferentially occupies the j₂ site over the remaining five crystallographically nonequivalent iron sites. This preferential occupation has been confirmed by Mössbauer spectral studies, which indicate that the compositional variation of the hyperfine field for each site is related to the number of near-neighbor aluminum atoms for the site. This compositional variation is helpful in …

The Reaction Of 2-Arylprop-1-En-3-Yltrimethylammonium Iodides With Sulfur Nucleophiles And Useful Synthetic Applications Of These Adducts, Steven J. Duranceau

Retrospective Theses and Dissertations

This report discusses research involving the reactions of 2-arylprop-1-en-3-yltrimethyl ammonium iodides with sulfur nucleophiles and the useful synthetic applications of the adducts formed. The present work may be subdivided into four sections: 1) reactions of several 2-arylprop-1-en-3-yltrimethylammonium iodides with benzenethiol; 2) reactions of several 2-arylprop-1-en-3-yltrimethylammonium iodides with the sodium salt of benzenesulfinic acid; 3) reactions of several 2-arylprop-1-en-3-yltrimethylammonium iodides with 2-mercapto-1-methyl imidazole; and 4) oxidation of 2-aryl-3-phenylthio-1-propenes and 2-aryl-3-phenylsulfonyl-1-propenes using sodium perborate. This report outlines the experimental conditions and procedures responsible for the synthesis of these products; in addition, this report describes the physical properties, NMR and IR spectra of …

Preparation Of Geminal Diflourodienes, Antonio Landavazo

Retrospective Theses and Dissertations

This report discusses research involving the preparation of germinal difluorodienes. Free radical addition of dibromodifluoromethane to 1-hexene and cyclohexene was performed, followed by a double dehydrohalogenation to yield 1,1-difluoro-1,3-heptadiene and 3-(difluoromethylene)cyclohexene, respectively. NMR, IR, and mass spectral data were obtained and presented as groundwork for further research. A study comparing the free radical initiators, benzoyl peroxide and 2,2’-azobis-(2-methyl)proprionitrile (AIBN) was included, showing neither as ideal initiators for the free radical additions performed. The relative stabilities of the bromodifluoromethyl and the difluoroiodomethyl radicals were approximated. A Diels-Alder reaction of 1,1-difluoro-1,3-heptadiene with 4-phenyl-1,2,4-triazoline-3,5-dione produced the expected [4 + 2] cycloadduct in good …

Determination Of Dissociation Energies And Thermal Functions Of Hydrogen‐Bond Formation Using High Resolution Ftir Spectroscopy, B. A. Wofford, M. E. Eliades, Shannon Lieb, J. W. Bevan

Scholarship and Professional Work - LAS

A technique which employs high resolution Fourier transform infrared spectroscopy is demonstrated for evaluation of hydrogen bonddissociation energiesD ₀ and D _e . Results for HCN‐‐HF give a D ₀=20.77(22) and D _e =28.77(45) kJ/mol which are compared with previously determined values obtained from microwave absolute intensity measurements and a b i n i t i o molecular orbital calculations. Rovibrational band information available for HCN‐‐HF also permits evaluation of thermal functions of dimer formation in kJ/mol: ΔU ^○ _298.2 =20.1(2), ΔH ^○ _298.2 =22.6(2), ΔG ^○ _298.2 =59.4(2), ΔS ^○ _298.2 =−0.1235.

Structure Of L-Benzyl-2,2,3,3-Tetramethyl-L-Phenylphosphetanium Bromide, A Cyelobutane Derivative, J. A. Campbell, R. Larsen, C. Campana, Sheldon E. Cremer

Chemistry Faculty Research and Publications

No abstract provided.

Primary And Secondary Basis Set Superposition Error At The Scf And Mp2 Levels. H3n‐‐Li+ And H2o‐‐Li+, Z. Latajka, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

The primary basis set superposition error (BSSE) results from the artificial lowering of the energy of each subunit of a pair by the presence of ‘‘ghost orbitals’’ of its partner. In addition, these ghost orbitals perturb the one‐electron properties of the molecule, causing a change in the interaction energy, an effect known as secondary BSSE which is not corrected by the counterpoise procedure. The primary and secondary BSSE are calculated for the interactions of NH₃ and H₂O with Li⁺, using a variety of different basis sets. It is found that the 2° BSSE can be …

Vibrational Frequencies And Intensities Of H-Bonded Systems. 1:1 And 1:2 Complexes Of Nh3 And Ph3 With Hfvibrational Frequencies And Intensities Of H‐Bonded Systems. 1:1 And 1:2 Complexes Of Nh3 And Ph3 With Hf, I. J. Kurnig, M. M. Szczesniak, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

Frequencies and intensities are calculated by ab initio methods for all vibrational modes of the 1:1 H₃X–HF and 1:2 H₃X–HF–HF complexes (X=N,P). The HF stretching frequencies are subject to red shifts, roughly proportional to the strength of the H bond, and to manyfold increases in intensity. Although the intramolecular frequency shifts within the proton acceptors are relatively modest, the intensities of the NH₃ stretches are magnified by several orders of magnitude as a result of H bonding (in contrast to PH₃ which exhibits little sensitivity in this regard). …

Structure, Energetics, And Vibrational Spectrum Of H2o–Hcl, Z. Latajka, Steve Scheiner

Chemistry and Biochemistry Faculty Publications

H₂O–HCl is studied using a number of basis sets including 6‐31G∗∗ and variants which are augmented by a diffuse sp shell and a second set of d functions on O and Cl. Optimization of the geometry of the complex is carried out including explicitly electron correlation and counterpoise correction of the basis set superposition error (BSSE) at both the SCF and correlated levels. Correlation strengthens and shortens the H bond while BSSE correction leads to an opposite trend; these two effects are of different magnitude and hence cancel one another only partially. ΔH°(298 K) is …

Applications Of The Semiclassical Spectral Method To Nuclear, Atomic, Molecular, And Polymeric Dynamics, M. L. Koszykowski, George A. Pfeffer, Donald W. Noid

Chemistry Faculty Publications

Nonlinear dynamics plays a dominant role in a variety of important problems in chemical physics. Examples are unimolecular reactions,’ infrared multiphoton decomposition of molecules,’ the pumping process of the gamma ray laser,’ dissociation of vibrationally excited state-selected van der Waals’s complexes,’ and many other chemical and atomic processes. The present article discusses recent theoretical studies on the quasi-periodic and chaotic dynamical aspects of vibrational-rotational states of atomic, nuclear, and molecular systems using the semiclassical spectral method (SSM).’ We note that the coordinates, momenta, and so on, are found using classical mechanics in the studies included in this review. Consequently, certain …

A Stereospecific Approach To The Synthesis Of Pyrans, Mark M. Fukuda

Dissertations, Theses, and Masters Projects

No abstract provided.

Barley Agronomy., K. J. Young

Experimental Summaries - Plant Research

Trial 87E6, 87MT45, 87SG11, 87ES8

Locations: Esperance Downs Research Station, Mount Barker Research Station, Salmon Gums Research Station, Melijinup Field Station,

Barley variety x time of planting

To study phenological development and its effect on yield in a range of barley cultivars at four planting dates.

Trial 87E42

Aphicide toxicology x barley variety.

Location: EDRS

To measure the effect of disulfoton (Disyston *R) applied as granules at seeding on barley, to determine if there is any phytotoxicity.

Trial 87ES40, 87E32

Barley variety x cereal aphids.

Location: Malijinup Field Station, Esperance Downs Research Station

To study the development of cereal aphids …

Synthesis Of N, N'-Bis-(3-Deoxy-Beta-Cyclodextrin)-Ethyl Endiamine And Potential Photochemical Applications, Ronald Koy Hann

Dissertations, Theses, and Masters Projects

No abstract provided.

A Stereoselective Synthesis Of Cis-2,5-Disubstituted Pyrrolidines: Precursors For The (5e, 8z)-3,5-Dialkyl Pyrrolizidines, Mehul Shantilal Shah

Dissertations, Theses, and Masters Projects

No abstract provided.

Synthesis, Characterization, And Reactivity Of Some Novel Peroxo Heteroligand Complexes Of Vanadium(V) And Molybdenum(Vi), Bruce Conrad Puryear

Dissertations, Theses, and Masters Projects

No abstract provided.

Synthesis And Characterization Of Some Sf₅- Containing Sulfonic Acids, Robert J. Willenbring

Dissertations and Theses

Pentafluorosulfur (VI) bromide (SF₅Br) adds to olefins of the form CX₂=CX₂, where X= H or F, with the pentafluorosulfur group usually adding to the carbon with more hydrogens attached to it. This series of compounds was used in an attempt to prepare the corresponding sulfonic acid hydrates of the general formula SF₅CX₂CX₂SO₃H·nH₂O, in order to have these compounds tested as possible fuel cell electrolytes. The reaction scheme involved reflux of the SF₅Br adduct with an equimolar amount of sodium sulfite in 50% …

Sequential Solvent Extraction Of Argonne Premium Coal Samples, Wanping Mai

Masters Theses

Five coals from the Argonne Premium Coal Sample program, ranging in rank from sub-bituminous to low volatile bituminous, before and following artificial weathering, were exhaustively extracted with solvents in the sequence: toluene, tetrahydrofuran, N,N-dimethyl-formamide, and pyridine.

Sequential solvent extraction reveals more insight into the coal structure than single solvent extraction because fractions are isolated on the basis of both molecular size and polarity. The recovered extracts and residue from the extraction are monitored by FT-IR spectroscopy, elemental analysis, phenol content, solvent swelling, and Gel Permeation Chromatography analysis (GPC). The extraction results show that for fresh coals, the total extract yields …

The Structure Of O-Antigen From Lipopolysaccharide Of Rhizobium Leguminosarum 128c53 And Its Nod-Fix-Mutant, Tong-Bin Chen

Masters Theses

The LPS of R. leguminosarum 128C53 sm^r rif^r (a streptomycin and rifampicin resistant strain of wild type 128C53) and its mutant ANU54 (nod^-, fix^-) were isolated from the bacterial pellet by hot phenol/water extraction followed by gel filtration chromatography. The O-antigen was isolated by mild-acid hydrolysis of the LPS and purified by gel filtration chromatography using a Sephadex G-50 or G-25. The following results were the same for both the parent and mutant. The composition and linkage of the O-antigen were determined by gas chromatography (GC), GC-mass spectrometry, ¹H and ¹³C nuclear …

Isolation And Partial Characterization Of Serogroup Specific Antigens From Bradyrhizobium Japonicum 61a123, Miguel Eduardo Carrion

Masters Theses

Serogroup specific antigens of Bradyrhizobium japonicum 61A123 were isolated using an immunochemical assay. Bacterial antigens were isolated by phenol-water extraction. These antigens were detected by inhibition of an enzyme linked immunosorbant assay (ELISA). Low pressure chromatography and digestion with proteinase K served to purify the antigens. Chemical composition was determined by gas chromatography (GC), mass spectrometry (MS), and colorimetric assays. The antigens were also characterized by sodium dodecyl sulfate (SDS)-polyacrylamide gel electrophoresis, and immunological properties determined by ELISA. These antigens were shown to be lipopolysaccharides (LPSs) containing fucose, a 2-amino-2,6-dideoxy hexose (unidentified), glucose and mannose as the major sugars, along …

Electrochemical Studies Of Iron, Cobalt, And Nickel Complexes Of Bidentate Phosphine Thioether Ligands, Robert L. Turner

Masters Theses

The electrochemical behavior of a series of cationic complexes, [Ni(S-P)₂]²⁺, [Fe(S-P)₂(CH₃CN)_2.5]²⁺ and [Co(S-P)₂CH₃CN]²⁺, where S-P= (C₆H₅)₂PCH₂CH₂SCH₂CH₃, has been examined in acetonitrile on mercury and platinum electrodes. The nickel compound was reduced in two reversible diffusion controlled, one-electron transfers. Addition of PPh₃ (Ph=C₆H₅) and S-P caused a positive potential shift in the nickel(I) to nickel(0) wave. An EC mechanism was postulated to account for this …

Microemulsions, Lyotropic Liquid Crystals, And Other Association Structures, Jiafu Fang

Doctoral Dissertations

"Phase diagrams have been determined showing the extent of the inverse micellar or microemulsion region for several ionic surfactants and some cosurfactants. Hexylamine has been found to be a very effective cosurfactant giving rise to very good water solubilizing capacity at extremely low surfactant concentrations and very low cosurfactant levels at rather high initial hydrocarbon levels.

A fairly extensive study of phase equilibria of the system composed of sodium dodecyl sulfate, hexylamine, heptane, and water has been carried out. The conductivity behavior of the inverse micellar or microemulsion phase of the system shows the percolation phenomenon. Low angle X-ray diffraction …

Amphiphile Association Structures, Yun Yang

Doctoral Dissertations

"The amphiphile association behavior of Aerosol OT (sodium di-w-ethylhexylsulfoccinate) and p-xylene in combination with mixtures of different ratios of glycerol/water systems was studied and compared to that in the corresponding water and glycerol systems. The presence of glycerol strongly destabilized the inverse hexagonal liquid crystal phase observed in the aqueous system. The glycerol showed more ability to penetrate into the amphiphile bilayer than water in the lamellar liquid crystal phase. The influences of water and glycerol on the organization of amphiphile in the lamellar liquid crystal phase are of the same order.

The gross diffusion coefficient of 1% 2,4-diamino-6-piperidinopyrimidine-3-oxide in …

The Synthesis And Characterization Of Polycarbonates Based On 1,1'-Dihydroxyethyl-2,2'-Biimidazole, Judith J. Garces

Masters Theses

"The synthesis of polycarbonates formed by the reaction of 1,1'-dihydroxyethyl-2,2'-biimidazole and diphenyl or diethyl carbonates was investigated and the products formed were characterized. The molecular weights of the polymers were dependent on catalyst, ratio of starting materials, nature of carbonate (aromatic or aliphatic) and method of polymerization. Isolated polymers exhibit a linear structure. They have no well-defined melting points (melting pt. range of 280- 330⁰C) indicating low degree of crystallization, and undergo less than 9% decomposition below 200⁰C"--Abstract, page ii.

Indirect Determination Of A Local Ph Change By Surface-Enhanced Raman Spectroscopy, Mark Anderson, Dennis Evans, Mary Wirth

Mark R. Anderson

No abstract is currently available.

Nuclease Activity Of 1,10-Phenanthroline-Copper Ion. Chemistry Of Deoxyribose Oxidation, Thomas Goyne, David Sigman

Thomas Goyne

No abstract provided.

Determination Of Electrochemical Kinetic Parameters Using The Bond-Henderson-Oldham Global Analysis, Mark Anderson, Dennis Evans

Mark R. Anderson

No abstract is currently available.

Theoretical Studies Of The Reactions Xhn → Xhn-1- + H+ And Xhn-1- + Sih4 → [Sih4xhn-1]-, Mark S. Gordon, Larry P. Davis, Larry W. Burggraf, Robert Damrauer

Mark S. Gordon

Ab initio and MNDO calculations have been carried out to evaluate the gas-phase acidities of closed-shell XHn compounds (X= C, N, 0, F, Si, P, S, Cl) and the affinities of silane for the XHn_1- anions. Fourth-order perturbation theory with extended basis sets reproduces the experimental gas-phase acidities to within 2 kcaljmol. Stable pentacoordinated silicon anions are found for X = H, C, N, 0, and F. In contrast, only marginally stable charge-dipole complexes are found for X = Si, S, and Cl.