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Limits of Inflammability and Ignition Temperatures of Hexone in Air and in Other Gaseous Atmospheres

Description: The following report summarizes the data taken from a series of measurements on the combustion and ignition properties of hexone. The experiments were taken at the Bureau of Mines Central Experiment Station by their personnel, and the samples were given to them by KAPL and Hanford.
Date: September 9, 1949
Creator: Alter, H. Ward
Partner: UNT Libraries Government Documents Department

Ketene Carbodiimide Cycloadditions

Description: It was proposed to study the cycloaddition of ketenes and carbodiimides in some detail. The first objective was to investigate the general applicability of the reaction as a tool for the synthetic organic chemist in the preparation of a new class of substituted β-lactams; i.e., imino-β-lactams. It was proposed for this part of the research problem to look for the intermediate, either directly or indirectly, by trapping experiments. It was further proposed to study substituent effects in the ketene and carbodiimide and also Investigate the effect of solvent polarity on the reaction rate. From these data, it was hoped that the mechanism of the cycloaddition reaction could be elucidated.
Date: August 1970
Creator: Dorsey, Edwin Darrell
Partner: UNT Libraries

Six-, Five-, and Four-Coordinate Ruthenium(II) Hydride Complexes Supported by N-Heterocyclic Carbene Ligands: Synthesis, Characterization, Fundamental Reactivity, and Catalytic Hydrogenation of Olefins, Aldehydes, and Ketones

Description: This article discusses six-, five-, and four-coordinate ruthenium(II) hydride complexes.
Date: February 20, 2009
Creator: Lee, John P.; Ke, Zhuofeng; Ramírez, Magaly A.; Gunnoe, T. Brent; Cundari, Thomas R., 1964-; Boyle, Paul D. et al.
Partner: UNT College of Arts and Sciences

OXYGEN 18 EXCHANGE REACTIONS OF ALDEHYDES AND KETONES

Description: Using infra-red spectroscopy, the equilibrium exchange times have been determined for a series of ketones, aromatic aldehydes, and {beta}-ketoesters reacting with oxygen 18 enriched water. These exchange times have been evaluated in terms of steric and electronic considerations, and applied to a discussion of the exchange times of chlorophylls a and b and chlorophyll derivatives.
Date: December 1, 1965
Creator: Byrn, Marianne & Calvin, Melvin
Partner: UNT Libraries Government Documents Department

The Path of Carbon in Photosynthesis, XV. Ribulose andSedoheptulose

Description: The intermediates of carbon dioxide reduction by plants include phosphorylated derivatives of hydroxy acids and sugars. Their identification becane possible when the use of labeled carbon dioxide permitted discrimination between the earliest products and the many other components of photosynthetic tissues. A number of compounds were identified by virtue of the chemical and physical properties of the radioactive compounds in tracer amounts and by direct comparison of these properties with those of suspected known metabolic intermediates. It became apparent that several labeled compounds found in short exposures to radioactive carbon dioxide were not substances previously identified as metabolic intermediates. Two phosphate esters in particular were observed in the products of the first few seconds of steady-state photosynthesis by all the photosynthetic microorganisms and higher plants examined in this laboratory. These esters have been isolated by paper chromatography in tracer quantities and enzymatically hydrolyzed to give two sugars, ribulose and sedoheptulose. This paper contains a description of the chemical identification of these sugars and some observations and suggestions regarding the function of their esters. The general importance of these compounds in photosynthesis was surmized before their identification. The products of photosynthesis with C{sup 14}O{sub 2} by each plant included phosphate esters of the same two then unknown compounds in addition to those of the expected glucose, fructose, dihydroxyacetone and glyceric acid. As the time of steady-state photosynthesis in C{sup 14}O{sub 2} decreased, the fractions of total fixed radiocarbon in the esters of the two unidentified compounds increased.
Date: January 1, 1952
Creator: Benson, A.A.; Bassham, J.A.; Calvin, M.; Hall, A.G.; Hirsch, H.; Kawaguchi, S. et al.
Partner: UNT Libraries Government Documents Department

Laser-induced reactions in a deep UV resist system: Studied with picosecond infrared spectroscopy

Description: One of the most technologically important uses of organic photochemistry is in the imaging industry where radiation-sensitive organic monomers and polymers are used in photoresists. A widely-used class of compounds for imaging applications are diazoketones; these compounds undergo a photoinduced Wolff rearrangement to form a ketene intermediate which subsequently hydrolyses to a base-soluble, carboxylic acid. Another use of organic molecules in polymer matrices is for dopant induced ablation of polymers. As part of a program to develop diagnostics for laser driven reactions in polymer matrices, we have investigated the photoinduced decomposition of 5-diazo-2,2-dimethyl-1,3-dioxane-4,6-dione (5-diazo Meldrum`s acid, DM) in a PMMA matrix using picosecond infrared spectroscopy. In particular, irradiation of DM with a 60 ps 266 nm laser pulse results in immediate bleaching of the diazo infrared band ({nu} = 2172 cm{sup -1}). Similarly, a new band appears within our instrument response at 2161 cm{sup -1} (FWHM = 29 cm{sup -1}) and is stable to greater than 6 ns.; we assign this band to the ketene photoproduct of the Wolff rearrangement. Using deconvolution techniques we estimate a limit for its rate of formation of {tau} < 20 ps. The linear dependence of the absorbance change with the pump power (266 nm) even above the threshold of ablation suggest that material ejection take place after 6ns.
Date: December 31, 1995
Creator: Lippert, T.; Koskelo, A. & Stoutland, P.O.
Partner: UNT Libraries Government Documents Department

Rapid, automated gas chromatographic detection of organic compounds in ultra-pure water

Description: An automated gas chromatography was used to analyze water samples contaminated with trace (parts-per-billion) concentrations of organic analytes. A custom interface introduced the liquid sample to the chromatography. This was followed by rapid chromatographic analysis. Characteristics of the analysis include response times less than one minute and automated data processing. Analytes were chosen based on their known presence in the recycle water streams of semiconductor manufacturers and their potential to reduce process yield. These include acetone, isopropanol, butyl acetate, ethyl benzene, p-xylene, methyl ethyl ketone and 2-ethoxy ethyl acetate. Detection limits below 20 ppb were demonstrated for all analytes and quantitative analysis with limited speciation was shown for multianalyte mixtures. Results are discussed with respect to the potential for on-line liquid process monitoring by this method.
Date: February 15, 2000
Creator: MOWRY,CURTIS DALE; BLAIR,DIANNA S.; MORRISON,DENNIS J.; REBER,STEPHEN D. & RODACY,PHILIP J.
Partner: UNT Libraries Government Documents Department

Energies of organic compounds

Description: The studies included hydrolysis of ketals, hydration of alkenes, barrier to rotation about C-O bonds in esters and acids, hydrolysis of lactones, reduction of ketones, non-bonded interactions, and enthalpies of vaporization of ketones, ketals, and other compounds.
Date: July 1, 1995
Creator: Wiberg, K.B.
Partner: UNT Libraries Government Documents Department

Rubisco Mechanism: Dissection of the Enolization Partial Reaction. Final Report

Description: To test experimentally, the prior theoretical deduction that active-site residue Lys166 of ribulose-bisphosphate carboxylase participates in the carboxylation step of overall catalysis, site-directed mutants and chemically rescued site-directed mutants were characterized by kinetics and product analysis. Although position-166 mutants are able to catalyze normal enolization of ribulose bisphosphate, the enediol intermediate does not undergo carboxylation but rather eliminates phosphate. Furthermore, the chemically rescued mutant (aminoethylation of the severely impaired Lys66Cys mutant) generates a highly active mimic, which displays an enhanced carboxylation/oxygenation partition ratio. These two distinct lines of experimentation document a crucial role of Lys166 in carboxylation and in discrimination between CO{sub 2} and O{sub 2}. To ascertain whether Lys166 functions as an acid or base in facilitation of enolization, the chemically rescued mutant bearing {sup 15}N was titrated by NM R. From pH 6.5-9.5, the amino group of Lys166 remains unprotonated, indicating that it promotes enolization by hydrogen bonding to the ketone group of the substrate.
Date: June 11, 2003
Creator: Hartman, F. C.
Partner: UNT Libraries Government Documents Department

Synthesis of Properties of Methylisoproplydiketone and 1,1 Dinitroisobutane and Their Analytical Determination in Hexone-Nitric Acid Systems

Description: Report discussing a study with the following objectives: "to synthesize pure specimens of both methylisoproplydiketone and 1,1 dinitroisobutane, to determine their physical and chemical properties, and to devise analytical methods which permit their quantitative determination in hexone-nitric acid systems to be encountered in the Redox Process."
Date: August 12, 1949
Creator: Wagner, Robert M.
Partner: UNT Libraries Government Documents Department

Cyclohexene Photo-oxidation over Vanadia Catalyst Analyzed by Time Resolved ATR-FT-IR Spectroscopy

Description: Vanadia was incorporated in the 3-dimensional mesoporous material TUD-1 with a loading of 2percent w/w vanadia. The performance in the selective photo-oxidation of liquid cyclohexene was investigated using ATR-FT-IR spectroscopy. Under continuous illumination at 458 nm a significant amount of product, i.e. cyclohexenone, was identified. This demonstrates for the first time that hydroxylated vanadia centers in mesoporous materials can be activated by visible light to induce oxidation reactions. Using the rapid scan method, a strong perturbation of the vanadyl environment could be observed in the selective oxidation process induced by a 458 nm laser pulse of 480 ms duration. This is proposed to be caused by interaction of the catalytic centre with a cyclohexenyl hydroperoxide intermediate. The restoration of the vanadyl environment could be kinetically correlated to the rate of formation of cyclohexenone, and is explained by molecular rearrangement and dissociation of the peroxide to ketone and water. The ketone diffuses away from the active center and ATR infrared probing zone, resulting in a decreasing ketone signal on the tens of seconds time scale after initiation of the photoreaction. This study demonstrates the high potential of time resolved ATR FT-IR spectroscopy for mechanistic studies of liquid phase reactions by monitoring not only intermediates and products, but by correlating the temporal behavior of these species to molecular changes of the vanadyl catalytic site.
Date: June 4, 2008
Creator: Frei, Heinz; Mul, Guido; Wasylenko, Walter; Hamdy, M. Sameh & Frei, Heinz
Partner: UNT Libraries Government Documents Department

Hexone Extraction-Coulometric Titration of Uranium

Description: Samples containing 5 to 10 mg of uranium were extracted with hexone (methyl isobutyl ketone) and titrated coulometrically in sulfate media. Relative standard deviations of 0.43% for samples containing 5 mg and 0.56% for 10 mg were determined by precision studies. (auth)
Date: June 22, 1959
Creator: Blevins, E. L.
Partner: UNT Libraries Government Documents Department

Predicting flammability of gas mixtures containing volatile organic compounds

Description: One requirement regarding the transportation of transuranic (TRU) radioactive waste containers currently limits the total concentration of potentially flammable volatile organic compounds (VOCs) and flammable gases in the headspace of the waste container. Typical VOCs observed in the drums include aromatic hydrocarbons, ketones, alcohols, cyclohexane, as well as chlorinated hydrocarbons (alkanes and alkenes). Flammable gases, such as hydrogen and methane, may be generated in the containers by radiation-induced decomposition (radiolysis) of water and hydrocarbon waste forms. An experimental program was initiated to identify an accurate means for predicting flammability for gas mixtures containing one or more of the following species: hydrogen, carbon tetrachloride, 1,2-dichloroethane, toluene, or 2-butanone. The lower flammability limits (LFL) of gas mixtures containing equimolar quantity for each species were determined in a 19-liter laboratory flammability chamber using a strong spark ignition source. The group factor contribution method was determined to be more accurate than the LeChatelier method for estimating the LFL for these gas mixtures.
Date: December 31, 1997
Creator: Liekhus, K.; Zlochower, I.; Djordjevic, S. & Loehr, C.
Partner: UNT Libraries Government Documents Department

Shale oil value enhancement research. Quarterly report, October 1, 1993--December 31, 1993

Description: A major push was made to identify the hydrocarbon and heteroatom types present in raw shale oil. A comprehensive, qualitative picture of the <400{degrees}C material has been obtained. In addition to the expected types, e.g., pyridines, pyrroles, indoles and phenols, the presence of aliphatic carboxylic acids, ketones and nitrites was confirmed. Most importantly, heteroatom types are able to be concentrated nearly quantitatively by liquid-liquid extraction with polar solvents. Compound types characterization of the >400{degrees}C material, as well as rapid, routine analysis of separations fractions, requires new methodologies founded in the Z-BASIC concept. Advances were made in establishing the interface protocol needed to utilize Z-BASIC methodologies for interpretation of gc-ms output data. It is anticipated that all interface protocols will be completed and a computerized reporting system will be in place by the end of the next quarter. Progress reports were made at the Contractor`s Review Meeting (METC), November 16th and at the Eastern Oil Shale Symposium (Lexington), November 17th. Research results continue to be well-received. The concept of a thermodynamically logical map of potential products from shale oil is a sound approach to value-enhancement research. From a commercial perspective, the concept of establishing a demand for raw shale oil at a reasonable purchase price of, say $30/bbl, is increasingly being recognized as the best means of pulling shale oil into the marketplace.
Date: May 1, 1997
Partner: UNT Libraries Government Documents Department

Dielectric constant measurements on n-heptane and 2-heptanone

Description: A liquid transfer station has been built and installed in a fume hood. The dielectric properties of n-heptane and 2-heptanone have been measured using the coaxial structure of the Model 100-1, S/N 1 as the liquid measurement cell. The low (10 kHz to 1 Mhz) frequency value of the relative dielectric constant {epsilon} r was measured with a HP 4275 Multifrequency LCR Meter. Also time domain reflection (TDR) and insertion time domain transmission (TDT) measurements were made using a HP 54120/54121A oscilloscope. The value of the quasi-static relative dielectric constant for n-heptane was found to be 1.923 while that for 2-heptanone was 11.735.
Date: January 12, 1994
Creator: Nahman, N.S.
Partner: UNT Libraries Government Documents Department

Integrated chemiresistor and work function microsensor array with carbon black/polymer composite materials

Description: An array of chemically-sensitive field-effect transistors (CHEMFETs) that measure both work function and bulk resistance changes in thin films was used to detect volatile organic compounds. Carbon black/organic polymer composite films were deposited onto the CHEMFETs using an automated microdispensing method.
Date: May 1, 1998
Creator: Domansky, K.; Zapf, V.S.; Grate, J.W.; Ricco, A.J.; Yelton, W.G. & Janata, J.
Partner: UNT Libraries Government Documents Department

A measurement technique for hydroxyacetone

Description: Hydroxyacetone (HA) is mainly produced in the atmosphere from oxidation of hydrocarbons of the type, CH{sub 3}(R)C{double{underscore}bond}CH{sub 2}. Tuazon and Atkinson (1990) reported HA yield of 41% from the OH-initiated oxidation of methacrolein in the presence of NOx. Since methacrolein is a major product of isoprene oxidation (Carter and Atkinson, 1996), isoprene, a key biogenic hydrocarbon, is therefore expected to be an important source for HA. Consequently, knowledge of ambient concentration of HA would provide information needed to examine the applicability of isoprene reaction mechanisms developed in laboratory and to assess the contribution of isoprene to photooxidant production. The commonly used GC-FID technique involving cryo-focusing is unsuitable for HA owing to HA's thermal instability. When subjected to a temperature of 100 C for only a few seconds, HA was found to disappear completely. Since HA is highly soluble in water, the authors developed a wet chemical technique similar in principle to the one they reported earlier, namely, derivatization following liquid scrubbing. To increase the sensitivity, they adopted a fluorescence detection scheme based on o-phthaldialdehyde (OPA) chemistry. The technique was deployed in the field during two measurement periods at a NARSTO site located on Long Island, New York. The authors report the principle and the operation of this technique and the results obtained from these field studies.
Date: October 4, 1999
Creator: Klotz, P.J.
Partner: UNT Libraries Government Documents Department