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Synthesis and characterization of 2-chloro-3-benzylthiopyrrolo[1,2-a]- benzimidazol-1-one and 2,3-di(benzylthio)pyrrolo[1,2-a]benzimidazol-1-one.

Description: The reaction between o-phenylenediamine and 2,3-dichloromaleic anhydride has been probed and found to give 2,3-dichloropyrrolo[1,2-a]- benzimidazol-1-one as the major product. Chlorine substitution in 2,3-dichloropyrrolo[1,2-a]benzimidazol-1-one by added benzylthiol occurs in the presence of pyridine to provide the corresponding monosulfide and disulfide derivatives. The first benzylthiol ligand undergoes reaction at the C-3 position of the five-membered pyrrolo-1-one ring, with the addition of the second benzylthiol ligand occurring at the remaining chlorine-substituted carbon. The mono- and disulfide derivatives have been isolated and characterized in solution by NMR, IR, and UV-vis spectroscopies, and the solid-state structure of 2,3-di(benzylthio)pyrrolo[1,2-a]benzimidazol-1-one has been established by X-ray crystallography.
Date: December 2003
Creator: Huang, Shih-Huang
Partner: UNT Libraries

Optimum Conditions for the "Hot Zone" Volatilization of TCl₄

Description: Abstract: "The data reported herein furnish a qualitative comparison of the rapidity of vaporization of TCl4 at various "hot zone" temperatures as well as a measure of the chlorine evolution attributed to its thermal decomposition. The presence of impurities in the TCl4 detracts from the significance of the reported chlorine evolution. The temperature recommended for rapid volatilization is 750 C at which TCl4 underwent thermal decomposition amounting to no more than 0.2% by weight."
Date: February 19, 1946
Creator: Crompton, C. E.; Calkins, V. P. & Larson, C. E.
Partner: UNT Libraries Government Documents Department

Heat of Reaction of Chlorine Trifluoride with Water

Description: Abstract: "A measurement of the heat liberated when chlorine trifluoride reacts with water has been made in a simple Dewar calorimeter. The chlorine trifluoride vapor was bubbled into approximately 20 moles of water; the weight of material used, heat equivalent of the calorimeter, and the temperature rise of the water and calorimeter were determined. From these data an average value for the heat of reaction was calculated to be 81.0 +/- 0.4 kcal/mole. Analysis of the reaction solution and evolved gas showed the following to be present: hydrogen fluoride, hydrogen chloride, chlorine, oxygen, and probably oxygen-chlorine compounds."
Date: October 24, 1950
Creator: Oliver, G. D. & Grisard, J. W.
Partner: UNT Libraries Government Documents Department

The Detection of Small Amounts of Fluorine in Large Amounts of Chlorine

Description: Abstract: "Tests have been developed for both the qualitative detection and quantitative determination of fluorine in chlorine. The qualitative test is made by passing the gas through manganous chloride. If the pink solid tubes brown there is greater than 0.5 percent of fluorine in the gas. The quantitative test is a modification of the Steiger and Marvin Test with oxidized titanium solution."
Date: April 1, 1946
Creator: Lafferty, Robert H., Jr. & Winget, Rasho
Partner: UNT Libraries Government Documents Department

The Preparation of TCl₄ With Hexachloropropylene

Description: Report discussing various reaction methods for preparing TCl₄ with hexachloropropylene, as well as various methods for drying the TCl₄ after the reaction. Experimental methods are described in detail, and experimental results are presented.
Date: July 27, 1945
Creator: Pitt, B. M.; Curran, W. F.; Schmitt, J. M.; Wagner, E. L. & Miller, A. J.
Partner: UNT Libraries Government Documents Department

The Determination of Organic-Bound Chlorine Levels in Municipal Wastewaters After Treatment with Heavy Chlorine Doses

Description: The development of an analytical method for the determination of total organic-bound chlorine (TOCl) produced during the chlorination of municipal wastewater effluents is presented. Sewage effluent from the Denton, Texas municipal treatment plant was chlorinated at high chlorine doses (1000 - 4000 ppm), as well as typical treatment levels. Chlororganics present in the wastewater, before and after chlorination, were concentrated by adsorption on Amberlite XAD-2 macroreticular resin, followed by elution with diethyl ether. After concentration, the extracts were analyzed for TOC1 by microcoulometry. Analysis of wastewater extracts revealed the production of substantial amounts of new chlorinated organics when effluents were treated with chlorine. The method shows good precision and estimated accuracy is favorable.
Date: May 1976
Creator: Smith, Garmon B.
Partner: UNT Libraries

Fundamental Investigations of C1O2 Delignification - Final Report - 07/10/1996 - 07/09/1999

Description: The overall objective of this project was to develop a fundamental understanding of the mechanisms of chlorine dioxide delignification of low kappa kraft pulps and identify new methods of improving the efficiency and effectiveness of this bleaching agent. The approach adopted was to investigate the fundamental structural components of lignin that contribute to delignification reactions with chlorine dioxide. These results were then used to examine new bleaching technologies that will permit enhanced delignification while simultaneously reducing the generation of chlorinated organic compounds.
Date: May 18, 2001
Creator: Ragauskas, Arthur J. & McDonough, T. J.
Partner: UNT Libraries Government Documents Department

Chlorine Nuclear Quadrupole Resonance Absorption of 3, 4, 5, 6 - Tetrachlorophthalimide and 1, 3, 6, 8 - Tetrachloropyrene

Description: In this study frequency modulation was used with a regenerative spectrometer and a super-regenerative spectrometer to detect the nuclear quadrupole resonance frequencies of chlorine in two commercially available compounds, 1, 3, 6, 8 - tetrachlorophyrene and 3, 4, 5, 6 - tetrachlorophthalimide.
Date: January 1968
Creator: Reeves, Jerry Byron
Partner: UNT Libraries

Kinetic studies and computational modeling of atomic chlorine reactions in the gas phase.

Description: The gas phase reactions of atomic chlorine with hydrogen sulfide, ammonia, benzene, and ethylene are investigated using the laser flash photolysis / resonance fluorescence experimental technique. In addition, the kinetics of the reverse processes for the latter two elementary reactions are also studied experimentally. The absolute rate constants for these processes are measured over a wide range of conditions, and the results offer new accurate information about the reactivity and thermochemistry of these systems. The temperature dependences of these reactions are interpreted via the Arrhenius equation, which yields significantly negative activation energies for the reaction of the chlorine atom and hydrogen sulfide as well as for that between the phenyl radical and hydrogen chloride. Positive activation energies which are smaller than the overall endothermicity are measured for the reactions between atomic chlorine with ammonia and ethylene, which suggests that the reverse processes for these reactions also possess negative activation energies. The enthalpies of formation of the phenyl and β-chlorovinyl are assessed via the third-law method. The stability and reactivity of each reaction system is further rationalized based on potential energy surfaces, computed with high-level ab initio quantum mechanical methods and refined through the inclusion of effects which arise from the special theory of relativity. Large amounts of spin-contamination are found to result in inaccurate computed thermochemistry for the phenyl and ethyl radicals. A reformulation of the computational approach to incorporate spin-restricted reference wavefunctions yields computed thermochemistry in good accord with experiment. The computed potential energy surfaces rationalize the observed negative temperature dependences in terms of a chemical activation mechanism, and the possibility that an energized adduct may contribute to product formation is investigated via RRKM theory.
Date: August 2009
Creator: Alecu, Ionut M.
Partner: UNT Libraries

Chlorine-36 abundance in natural and synthetic perchlorate

Description: Perchlorate (ClO{sub 4}{sup -}) is ubiquitous in the environment. It occurs naturally as a product of atmospheric photochemical reactions, and is synthesized for military, aerospace, and industrial applications. Nitrate-enriched soils of the Atacama Desert (Chile) contain high concentrations of natural ClO{sub 4}{sup -}; nitrate produced from these soils has been exported worldwide since the mid-1800's for use in agriculture. The widespread introduction of synthetic and agricultural ClO{sub 4}{sup -} into the environment has complicated attempts to understand the geochemical cycle of ClO{sub 4}{sup -}. Natural ClO{sub 4}{sup -} samples from the southwestern United States have relatively high {sup 36}Cl abundances ({sup 36}Cl/Cl = 3,100 x 10{sup -15} to 28,800 x 10{sup -15}), compared with samples of synthetic ({sup 36}Cl/Cl = 0.0 x 10{sup -15} to 40 x 10{sup -15}) and Atacama Desert ({sup 36}Cl/Cl = 0.9 x 10{sup -15} to 590 x 10{sup -15}) ClO{sub 4}{sup -}. These data give a lower limit for the initial {sup 36}Cl abundance of natural ClO{sub 4}{sup -} and provide temporal and other constraints on its geochemical cycle.
Date: January 1, 2009
Creator: Heikoop, Jeffrey M; Dale, M; Sturchio, Neil C; Caffee, M; Belosa, A D; Heraty, Jr., L J et al.
Partner: UNT Libraries Government Documents Department

High-Temperature Fast-Flow Reactor Kinetics Studies of the Reactions of Al with Cl₂, Al with HCl, and AlCl, with Cl₂ over Wide Temperature Ranges

Description: Article on high-temperature fast-flow reactor kinetics studies of the reactions of aluminum with chlorine, aluminum with hydrogen chloride and aluminum monochloride with chlorine over wide temperature ranges.
Date: April 12, 1988
Creator: Rogowski, Donald F.; Marshall, Paul & Fontijn, A. (Arthur)
Partner: UNT College of Arts and Sciences