Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- University of Nebraska - Lincoln (341)
- Chinese Chemical Society | Xiamen University (285)
- University of Nevada, Las Vegas (107)
- Governors State University (82)
- University of Kentucky (80)
-
- University at Albany, State University of New York (59)
- East Tennessee State University (55)
- University of Arkansas, Fayetteville (51)
- West Virginia University (50)
- Purdue University (46)
- City University of New York (CUNY) (45)
- Louisiana State University (45)
- Montclair State University (43)
- Old Dominion University (42)
- Clemson University (41)
- Virginia Commonwealth University (41)
- University of Texas at El Paso (39)
- Cleveland State University (38)
- Seton Hall University (38)
- Western Kentucky University (38)
- Technological University Dublin (35)
- Wayne State University (33)
- South Dakota State University (28)
- Western Michigan University (27)
- University of Dayton (25)
- Munster Technological University (24)
- Taylor University (24)
- University of Malaya (24)
- Marquette University (23)
- University of Louisville (22)
- Keyword
-
- Mass spectrometry (84)
- Electrochemistry (79)
- Chemistry (61)
- Pure sciences (49)
- Mass Spectrometry (47)
-
- Nanoparticles (37)
- Project (37)
- Raman spectroscopy (36)
- Spectroscopy (28)
- HPLC (25)
- Analytical chemistry (24)
- Chromatography (24)
- NMR (24)
- Chemometrics (21)
- Analytical Chemistry (20)
- Fluorescence (20)
- Metabolomics (20)
- Drug delivery (18)
- Cyclic voltammetry (17)
- Liquid chromatography (17)
- GC-MS (16)
- Proteomics (16)
- Atomic orbitals (15)
- Electrocatalysis (15)
- Microfluidics (15)
- Rare earth metals (15)
- SERS (15)
- Sensor (15)
- Separation (Technology) (15)
- Actinide elements (14)
- Publication Year
- Publication
-
- Journal of Electrochemistry (285)
- Department of Chemistry: Faculty Publications (232)
- Electronic Theses and Dissertations (116)
- Chemistry Faculty Publications (77)
- All Capstone Projects (74)
-
- Theses and Dissertations (68)
- Xiao Cheng Zeng Publications (56)
- Legacy Theses & Dissertations (2009 - 2024) (55)
- Graduate Theses, Dissertations, and Problem Reports (ETD) (50)
- Theses and Dissertations--Chemistry (50)
- Separations Campaign (TRP) (48)
- Department of Earth and Environmental Studies Faculty Scholarship and Creative Works (42)
- Masters Theses & Specialist Projects (37)
- Seton Hall University Dissertations and Theses (ETDs) (37)
- LSU Doctoral Dissertations (36)
- Graduate Theses and Dissertations (35)
- Chemistry and Biochemistry Faculty Research (34)
- Open Access Theses & Dissertations (34)
- Masters Theses (33)
- Dissertations (32)
- Open Access Dissertations (32)
- All Dissertations (31)
- Department of Chemistry: Dissertations, Theses, and Student Research (31)
- Articles (30)
- Wayne State University Dissertations (30)
- Dissertations, Theses, and Capstone Projects (29)
- Honors Theses (27)
- Chemistry & Biochemistry Student Projects (24)
- Chemistry & Biochemistry Theses & Dissertations (24)
- Theses (24)
- Publication Type
- File Type
Articles 2461 - 2490 of 2571
Full-Text Articles in Chemistry
Artificial Maturation Of Alginite And Organic Groundmass Separated From Torbanites, Michael A. Kruge, Patrick Landais, David F. Bensley
Artificial Maturation Of Alginite And Organic Groundmass Separated From Torbanites, Michael A. Kruge, Patrick Landais, David F. Bensley
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The two principal organic constituents — Botryococcus-related alginite and organic groundmass — were isolated by density separation from two torbanite samples (from the Stellarton Fm., Nova Scotia, Canada and the King Cannel, Utah, USA). The groundmass consisted of degraded algal, bacterial and terrestrial plant debris. Aliquots of alginite and groundmass were separately heated in gold tubes for 24 hr. with 70 MPa confining pressure, at fixed temperatures ranging between 250 and 375°C. The 250, 300 and 325°C experiments run on the alginite produced very low yields of CHCl3-extractable organic matter (EOM), indicating that very little of the generation potential …
Flash Pyrolysis Of Anthropogenic And Natural Organic Matter In Polluted Sediments, Sami T. Abdel Bagi, Michael A. Kruge, Gary L. Salmon
Flash Pyrolysis Of Anthropogenic And Natural Organic Matter In Polluted Sediments, Sami T. Abdel Bagi, Michael A. Kruge, Gary L. Salmon
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
INTRODUCTION - Combustion products along with spilled petroleum and industrial chemicals contribute to environmental degradation by contaminating soils and sediments. Such anthropogenic organic matter (OM), if preserved in sediments, can serve an archival function, documenting the local, history of industrial pollution. Christensen and Zhang (1993) determined the sources of polycyclic aromatic hydrocarbons (P AH) to Lake Michigan from sedimentary records, finding that coal combustion was a major source for PAHs in these sediments. Bodzek and Luks-Betlej (1993) reported that atmospheric deposition is the main source of PAH in soils of the heavily industrialized Upper Silesia region of Poland. Smith and …
Ohmic Drop Compensation In Voltammetry: Iterative Correction Of The Applied Potential, David O. Wipf
Ohmic Drop Compensation In Voltammetry: Iterative Correction Of The Applied Potential, David O. Wipf
CAS Publications
A new method of ohmic potential drop correction for use with potential step and sweep voltammetric methods is described. The method, iterative correction of the applied potential (ICAP), essentially replaces an electronic positive feedback correction with a digital positive feedback correction. This paper will present one form of the ICAP procedure, in which voltammetric current data acquired by a high-speed digital oscilloscope are used to iteratively generate a compensating potential waveform that is then synthesized by an arbitrary waveform generator. The ICAP method is advantageous for high-speed measurements, since many of the difficulties caused by electronic positive feedback compensation are …
Highly Reactive Zerovalent Metals From Metal Cyanides, Reuben D. Rieke
Highly Reactive Zerovalent Metals From Metal Cyanides, Reuben D. Rieke
Department of Chemistry: Faculty Publications
Novel zerovalent metal species and organometallic reagents are disclosed. The zerovalent metal species are directly produced by reaction of a reducing agent on a metal cyanide salt. Preferably, the zerovalent metal species are directly produced by reaction of an alkali metal reducing agent with a metal cyanide salt. The organometallic reagent results from the reaction of the zerovalent metal species and an organic compound having one or more stable anionic leaving groups.
Studies Of In-Situ Raman Spectroscopy On Deprotonation And Degeneration Of Ppy Films, Jinsong Gao, Jing Chen, Yanzhen Chen, Qi Xue, Zhongqun Tian
Studies Of In-Situ Raman Spectroscopy On Deprotonation And Degeneration Of Ppy Films, Jinsong Gao, Jing Chen, Yanzhen Chen, Qi Xue, Zhongqun Tian
Journal of Electrochemistry
By combining the in-situ Raman spectroscopic technique with the normal electrochemical measurements, the behavior and structure of PPY films in neutral or basic solutions were studied. The oxidized PPY loses protons on the N atoms of pyrrole rings and is deprotonated in these solutions, resulting the formation of the quinoid structure. It makes the C=C stretching vibration bonds of PPY split. Because this quinoid structure can′t be further oxidized, the PPY becomes more difficult to be oxidized and less reversible with the increasing of pH value of solutions and the degree of deprotonation of PPY. In the strong basic solution …
Application Of Electroanalytical Chemistry In Heteropoly Compounds System──Studies On The Redox Properties Of Bis(Undecatungstometalate) Lanthanates, Weiqing Wang, Xiumei Zhang, Jingfu Liu
Application Of Electroanalytical Chemistry In Heteropoly Compounds System──Studies On The Redox Properties Of Bis(Undecatungstometalate) Lanthanates, Weiqing Wang, Xiumei Zhang, Jingfu Liu
Journal of Electrochemistry
The redox properties of Ln(MW11)2 (M=As, Ti, Ga; Ln=La, Ce, Pr,Nd, Sm, Eu, Gd, Dy) are systematically studied. It has been found that the redox order is La(AsW11)2 > La(TiW11)2 >La(GaW11)2.The reduction process of Ln(MW11)2 anion has been discussed.
Simultaneous Detection System Combining Studies Of Programmedpotential Step Technique And Time-Resolved Ftir Spectroscopy, Shigang Sun, Xiaoyu Chen, Guoqiang Lu, Wenfeng Lin, Nanhai Li, Shenpei Chen, Hongping Dai, Jiqian Mu
Simultaneous Detection System Combining Studies Of Programmedpotential Step Technique And Time-Resolved Ftir Spectroscopy, Shigang Sun, Xiaoyu Chen, Guoqiang Lu, Wenfeng Lin, Nanhai Li, Shenpei Chen, Hongping Dai, Jiqian Mu
Journal of Electrochemistry
/
A Sutface-Enhanced Raman Spectroscopic Study On The Inhibition Mechanism Of Bmat On Stainless Steel In Hydrochloric Acid Solutions, Yinghua Zha, Baoming Wei, Zhongqun Tian, Changjian Lin
A Sutface-Enhanced Raman Spectroscopic Study On The Inhibition Mechanism Of Bmat On Stainless Steel In Hydrochloric Acid Solutions, Yinghua Zha, Baoming Wei, Zhongqun Tian, Changjian Lin
Journal of Electrochemistry
The absorbtion of some nitrogen and sulfur compounds such as BMAT on 18-8stainless steel (SS) in 0.5% HCl were investigated by surface enhanced Raman scattering (SERS) spectroscopy. The SERS spectra of BMAT adsorbed on SS were measured using a SS electro deposited with discontinuous silvet micro-islands. The results show that the inhibitor, BMAT, is chemisorbed on the SS surface through the N atom. Under the influence of π-electron interaction, BMAT can be adsorbed on SS surface at an angle. The allyls in BMAT molecules play the role of steric hindrance in the inhibition effect.
Application Of Voltammetry In Analysis Of Electroplating Baths, Jiayuan Xu, Shaomin Zhou
Application Of Voltammetry In Analysis Of Electroplating Baths, Jiayuan Xu, Shaomin Zhou
Journal of Electrochemistry
Based upon the electrochemical characteristics of the components or impurities tobe determined in the electroplating baths, and the inhibition or activation effect of the additives used on the electrodepcosition processes of metals and alloys, direct voltammetry, indirect voltammetry andvoltammetry with anodic stripping of metallic deposits, were suggested to determine the concentrationof some components, several impurities and the additives usually used in the electroplating baths. The procedure of those methtods are simple and rapid ,and are suitable to be used for in-situ control in electroplating workshops.
Study Of Electrochemical Properties Of Ni(Oh)2/Niooh With Spectroscopic Ellipsometry, Shengtao Zhang, Zongqing Huang
Study Of Electrochemical Properties Of Ni(Oh)2/Niooh With Spectroscopic Ellipsometry, Shengtao Zhang, Zongqing Huang
Journal of Electrochemistry
Electrochemical reactions of Ni(OH)2 /NiOOH system were studied by using in-situ spectroscopic ellipsometry and the conventional electrochemical metheds. By fitting data from ellipsometric measurements, a transformation medel of the surface film was obtained for cathedic and anodic processes. The results indicated that the transformation medel after cobalt implantation almost remained the same as that before cobalt implantation, but the electrochemical properties were affected obviously by implantation of cobalt.
Design And Performance Of The Advanced-Light-Source Double-Crystal Monochromator, G. Jones, S. Ryce, Dennis W. Lindle, B. A. Karlin, J. C. Woicik, Rupert C. Perera
Design And Performance Of The Advanced-Light-Source Double-Crystal Monochromator, G. Jones, S. Ryce, Dennis W. Lindle, B. A. Karlin, J. C. Woicik, Rupert C. Perera
Chemistry and Biochemistry Faculty Research
A new “Cowan type” double-crystal monochromator, based on the boomerang design used at National Synchrotron Light Source (NSLS) beamline X-24A, has been developed for beamline 9.3.1 at the Advanced Light Source (ALS), a windowless ultrahigh vacuum beamline covering the 1-6 keV photon-energy range. Beamline 9.3.1 is designed to simultaneously achieve the goals of high energy resolution, high flux, and high brightness at the sample. The mechanical design of the monochromator has been simplified, and recent developments in technology have been included. Measured mechanical precision of the monochromator shows significant improvement over existing designs. In tests with x-rays at NSLS beamline …
The Analysis And Isolation Of Diarrhetic Shellfish Poisoning Toxins, Seán S. Kelly
The Analysis And Isolation Of Diarrhetic Shellfish Poisoning Toxins, Seán S. Kelly
Theses
This research was initiated to examine the Diarrhetic Shellfish Poisoning (DSP) toxin profiles in mussels (Mytilus edulis) in south-west Ireland. Extensive sampling and testing of shellfish was conducted during the toxic periods of 1991 to 1994. This was the most comprehensive study ever undertaken of toxin profiles in shellfish from a single cultivation area.
A new toxin named dinophysistoxin-2 (DTX-2), which is an isomer of okadaic acid (OA), was the major toxin during prolonged DSP episodes. This toxicity in shellfish occuired soon after high cell counts of Dinophysis acuta were observed. As well as seasonal variability in toxin levels, substantial …
Preparations Of Polycarbynes, Reuben D. Rieke
Preparations Of Polycarbynes, Reuben D. Rieke
Department of Chemistry: Faculty Publications
Polycarbynes prepared from a soluble source of electrons and an organic monomer or co-monomer containing at least one carbyne group in an ethereal, polyethereal, or hydrocarbon solvent are presented. A wide variety of arylcarbyne and/or alkylcarbyne monomers and co-monomers can be combined with a source of electrons soluble in an ethereal, polyethereal, or hydro-carbon solvent to form novel polycarbyne polymers. These polycarbyne polymers can be used to form synthetic diamond materials, fibers, and other materials that can withstand extreme conditions.
Preparation Of Doped Polycarbynes, Reuben D. Rieke
Preparation Of Doped Polycarbynes, Reuben D. Rieke
Department of Chemistry: Faculty Publications
Polycarbynes, such as doped polycarbynes, prepared from a soluble source of electrons and an organic monomer or co-monomer containing at least one carbyne group and, optionally, containing a doping agent, in an ethereal, poly ethereal, or hydrocarbon solvent are presented. A wide variety of arylcarbyne and/or alkylcarbyne monomers and co-monomers can be combined with a source of electrons soluble in an ethereal, polyethereal, or hydrocarbon solvent to form novel polycarbyne polymers. These polycarbyne polymers can be used to form synthetic diamond materials, fibers, and other materials that can withstand extreme con ditions.
Electrochemical Enzyme Immunoassay Using Sequential Saturation Technique In A 20-Μl Capillary: Digoxin As A Model Analyte, Noriaki Kaneki, Yan Xu, Anu Kumari, H. Brian Halsall, William R. Heineman, Peter T. Kissinger
Electrochemical Enzyme Immunoassay Using Sequential Saturation Technique In A 20-Μl Capillary: Digoxin As A Model Analyte, Noriaki Kaneki, Yan Xu, Anu Kumari, H. Brian Halsall, William R. Heineman, Peter T. Kissinger
Chemistry Faculty Publications
Capillary enzyme immunoassay with flow-injection analysis for digoxin using the sequential saturation technique has been developed. Glass capillary tubes (10 cm × 0.53 mm i.d.) with immobilized digoxin antibody were used as the immunoassay reactor. The product of enzymatic reaction. 4-aminophenol, was detected amperometrically. The digoxin and the labeled digoxin binding reaction with the immobilized digoxin antibody were completed in 2 and 10 min, respectively. Digoxin was determined in a 20-μl sample with a detection limit of 10 pg ml−1 (200 fg or 260 attomoles) and a 3 orders of magnitude range.
Highly Reactive Forms Of Zinc And Reagents Thereof, Reuben D. Rieke
Highly Reactive Forms Of Zinc And Reagents Thereof, Reuben D. Rieke
Department of Chemistry: Faculty Publications
A novel zerovalent zinc species and an organozinc reagent are disclosed. The zerovalent zinc species is directly produced by reaction of a reducing agent on a zinc salt, preferably Zn(CN)2. The organozinc reagent results from the reaction of the zerovalent zinc species and an organic compound having one or more stable anionic leaving groups. These organozinc reagents include a wide spectrum of functional groups in the organic radical, and are useful in a variety of reactions schemes.
Speciation Of Heteroatoms In Coal By Sulfur- And Nitrogen-Selective Techniquestrogen-Selective Techniques, Stephen R. Palmer, Michael A. Kruge, Edwin J. Hippo, John C. Crelling
Speciation Of Heteroatoms In Coal By Sulfur- And Nitrogen-Selective Techniquestrogen-Selective Techniques, Stephen R. Palmer, Michael A. Kruge, Edwin J. Hippo, John C. Crelling
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The peroxyacetic acid oxidation products from a series of coals of organic sulfur content 0.5-9.8 wt% were examined. The distributions of organic S and N compounds were determined by gas chromatography with sulfur-selective flame photometric and nitrogen-selective thermionic specific detection respectively. A selected sample was also examined in greater detail using low-voltage high-resolution mass spectrometry. The distribution of organic sulfur compounds in the oxidation products was remarkably similar for all the coals. The number of sulfur compounds detected was small compared with that of organic nitrogen compounds detected. This suggests that the sulfur chemistry of coal is considerably simpler than …
Fossil Charcoal In Cretaceous-Tertiary Boundary Strata: Evidence For Catastrophic Firestorm And Megawave, Michael A. Kruge
Fossil Charcoal In Cretaceous-Tertiary Boundary Strata: Evidence For Catastrophic Firestorm And Megawave, Michael A. Kruge
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Organic matter separated from calcareous sandstone from the upper portion of a deep-water tsunami deposit at Arroyo el Mimbral, Taumalipas (Mexico), which marks the biostratigraphically-defined Cretaceous-Tertiary boundary, consists primarily of fossil charcoal, including semifusinite and pyrofusinite. Analytical pyrolysis-gas chromatography-mass spectrometry revealed the highly aromatic and polyaromatic character of the organic matter assemblage, typical of the products of partial combustion. The organic matter probably originated as terrestrial vegetation that was caught in a firestorm and subsequently transported far offshore in the backwash of a megawave. These data are consistent with the hypothesis of combustion of large masses of vegetation triggered by …
Flash Pyrolysis-Gas Chromatography/Mass Spectrometry Of Lower Kittanning Vitrinites: Changes In The Distributions Of Polyaromatic Hydrocarbons As A Function Of Coal Rank, Michael A. Kruge, David F. Bensley
Flash Pyrolysis-Gas Chromatography/Mass Spectrometry Of Lower Kittanning Vitrinites: Changes In The Distributions Of Polyaromatic Hydrocarbons As A Function Of Coal Rank, Michael A. Kruge, David F. Bensley
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
Chemical analyses restricted to a single coal maceral permit a focus on rank effects without concern for variations in organic matter type. Vitrinite concentrates of high purity were isolated from coal samples of the Lower Kittanning seam by multi-step density gradient centrifugation, with reflectances ranging from 0.66 to 1.39% Rmax. In addition to the previously recognized losses of phenolic compounds, the vitrinite pyrolyzates exhibit marked increases in relative concentrations of tri- and tetraaromatic hydrocarbons (especially benzo[a]fluorene, methyl-phenanthrenes, methylfluorenes and methylchrysenes) above 0.9% Rmax, i.e., beyond the "second coalification jump" of Teichmüller. Thus, petrographically-recognizable physical transformations are shown …
Initiation And Study Of Localized Corrosion By Scanning Electrochemical Microscopy, David O. Wipf
Initiation And Study Of Localized Corrosion By Scanning Electrochemical Microscopy, David O. Wipf
CAS Publications
This paper describes methods to study the initiation and formation of localized corrosion pits on stainless–steel and aluminum samples. These methods are based on the use of a scanned probe microscope, the scanning electrochemical microscope (SECM). The SECM is specifically designed for operation in electrolyte solution and so is uniquely suited for examination of corrosion processes. SECM imaging of a corrosion pit on stainless steel is presented. In addition, the initiation of single pits on aluminum and stainless steel by using the SECM tip to electrogenerate a local source of Cl– is described.
A Characterization Of Extractable, Hydroxylated Fatty Acid Bearing Components In Legionella Pneumophila, Jonathan R. Lane
A Characterization Of Extractable, Hydroxylated Fatty Acid Bearing Components In Legionella Pneumophila, Jonathan R. Lane
Electronic Theses and Dissertations
Extraction of the lipids of Legionella pneumophila yields phases unlike those produced from other Gram-negative bacteria. A viscous interface forms between the aqueous (wash) and organic phases. More than half of the hydroxylated fatty acids were found distributed between the aqueous phase and the interfacial material, fractions in which such constituents have not been reported in other Gram-negative species. It was further observed that after the material from the aqueous/interfacial phase was dissolved in methanol or chloroform/methanol (2:1 (V/V)), the addition of acetone would create a white, flocculent precipitate. Analyses showed that the supernatant contained fatty acids that were nonhydroxylated …
Processes For Producing Doxorubicin, Daunomycinone, And Derivatives Of Doxorubicin, Desmond M. S. Wheeler
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
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 …
Soluble Highly Reactive Form Of Calcium And Reagents Thereof, Reuben D. Rieke
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 …
Preparation Of Functionalized Polymers Utilizng A Soluble Highly Reactive Form Of Calcium, Reuben D. Rieke
Preparation Of Functionalized Polymers Utilizng A Soluble Highly Reactive Form Of Calcium, Reuben D. Rieke
Department of Chemistry: Faculty Publications
Calcium-substituted polymeric reagents are provided. These reagents can be prepared via the oxidative addition of a soluble highly reactive calcium species to organic and inorganic polymers containing alkyl, aryl, or alkylaryl pendent groups substituted with halide atoms, cyanide molecules, 1,3-dienes, or any conjugated poly unsaturated system. Preferably, the polymer is a cross linked p-bromopolystyrene, p-chloropolystyrene, p fluoropolystyrene, or chloromethylated polystyrene. Preferably, the soluble highly reactive calcium species is prepared from the reduction of Ca(II) salts with an alkali metal arene, such as lithium biphenylide. These calcium-substituted polymeric reagents react with a variety of electrophiles to yield functionalized polymers. Reaction with …
High-Energy Behavior Of The Double Photoionization Of Helium From 2 To 12 Kev, Jon C. Levin, Ivan A. Sellin, B. M. Johnson, Dennis W. Lindle, R. D. Miller, Y. Azuma, H. G. Berry, D.-H. Lee, N. Berrah
High-Energy Behavior Of The Double Photoionization Of Helium From 2 To 12 Kev, Jon C. Levin, Ivan A. Sellin, B. M. Johnson, Dennis W. Lindle, R. D. Miller, Y. Azuma, H. G. Berry, D.-H. Lee, N. Berrah
Chemistry and Biochemistry Faculty Research
We report the ratio of double-to-single photoionization of He at several photon energies from 2 to 12 keV. By time-of-Aight methods, we find a ratio consistent with an asymptote at 1.5%±0.2%, essentially reached by h v≈4 keV. Fair agreement is obtained with older shake calculations of Byron and Joachain [Phys. Rev. 164, 1 (1967)], of Aberg [Phys. Rev. A 2, 1726 (1970)], and with recent many-body perturbation theory (MBPT) of Ishihara, Hino, and McGuire [Phys. Rev. A 44, 6980 (1991)]. The result lies below earlier MPBT calculations by Amusia et al. [J. Phys. B 8 …
Telomere Processing In Euplotes, Joris Robert Vermeesch, Dewight Williams, Carolyn M. Price
Telomere Processing In Euplotes, Joris Robert Vermeesch, Dewight Williams, Carolyn M. Price
Department of Chemistry: Faculty Publications
In Euplotes crassus millions of telomeres are synthesized during the sexual phase of the life cycle. Since these newly synthesized telomeres are longer than normal macronuclear telomeres, they must be trimmed to the mature size. We have examined the timing and mechanism of this trimming step. We have shown that a sudden decrease in telomere length takes place at a specific time during macronuclear development. The decrease in telomere length is not caused by incomplete replication of the most terminal DNA sequences; rather it is the result of an active processing event that occurs independently of DNA replication. The developmentally …
Preparation Of Functionalized Polymers Utilizing A Soluble Highly Reactive Form Of Calcium, Reuben D. Rieke
Preparation Of Functionalized Polymers Utilizing A Soluble Highly Reactive Form Of Calcium, Reuben D. Rieke
Department of Chemistry: Faculty Publications
Calcium-substituted polymeric reagents are provided. These reagents can be prepared via the oxidative addition of a soluble highly reactive calcium species to organic and inorganic polymers containing alkyl, aryl, or alkylaryl pendent groups substituted with halide atoms, cyanide molecules, 1,3-dienes, or any conjugated poly unsaturated system. Preferably, the polymer is a cross linked p-bromopolystyrene, p-chloropolystyrene, p-fluoropolystyrene, or chloromethylated polystyrene. Preferably, the soluble highly reactive calcium species is prepared from the reduction of Ca(II) salts with an alkali metal arene, such as lithium biphenylide. These calcium-substituted polymeric reagents react with a variety of electrophiles to yield functionalized polymers. Reaction with Cu(I) …
Study Of The Hexamethylenetetramine, Ammonia, And Formaldehyde System: Quantitative Determinations, Gary Lee Madsen
Study Of The Hexamethylenetetramine, Ammonia, And Formaldehyde System: Quantitative Determinations, Gary Lee Madsen
Dissertations
No abstract provided.
Surface Structure Of √3x√3r 30 Cl/Ni(111) Determined Using Low-Temperature Angle-Resolved-Photoemission Extended Fine Structure, Li-Qiong Wang, Z. Hussain, Z. Q. Huang, A. E. Schach Von Wittenau, Dennis W. Lindle, D. A. Shirley
Surface Structure Of √3x√3r 30 Cl/Ni(111) Determined Using Low-Temperature Angle-Resolved-Photoemission Extended Fine Structure, Li-Qiong Wang, Z. Hussain, Z. Q. Huang, A. E. Schach Von Wittenau, Dennis W. Lindle, D. A. Shirley
Chemistry and Biochemistry Faculty Research
A surface structural study of the √3 × √3 R30° Cl/Ni(111) adsorbate system was made using low-temperature angle-resolved photoemission extended fine structure. The experiments were performed along two emission directions, [111] and [110], and at two temperatures, 120 and 300 K. The multiple-scattering spherical-wave analysis determined that the Cl atom adsorbs in the fcc threefold hollow site, 1.837(8) Å above the first nickel layer, with a Cl-Ni bond length of 2.332(6) Å, and an approximate 5% contraction between the first and the second nickel layers (the errors in parentheses are statistical standard deviations only).