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Wedge test data for three new explosives: LAX112, 2,4-DNI, and TNAZ

Description: High pressure Pop-plots and inert Hugoniot curves have been measured for three new explosives: LAX112 (3,6-diamino-1,2,4,5-tetrazine-1,4-dioxide), 2,4-DNI (2,4-dinitroimidazole), and TNAZ (1,3,3-trinitroazetidine). LAX112 and 2,4-DNI are of interest because of their insensitivity, while TNAZ is useful for its performance and castability. The shock sensitivity of LAX112 and 2,4-DNI fall between that of pressed TNT and PBX9502, LAX112 being the less sensitive. The shock sensitivity of TNAZ falls between that of pressed PETN and PBX9501. The Pop-plot and Hugoniot data for TNAZ matches well with the lower pressure gas-gun data of Sheffield, Gustavsen, and Alcon. The inert Hugoniots for all three materials are comparable to those of other explosives.
Date: September 1, 1995
Creator: Hill, L.G.; Seitz, W.L.; Kramer, J.F.; Murk, D.M. & Medina, R.S.
Partner: UNT Libraries Government Documents Department

Coal liquefaction process streams characterization and evaluation

Description: This study demonstrated the use of the gold tube carbonization technique and reflectance microscopy analysis for the examination of process-derived materials from direct coal liquefaction. The carbonization technique, which was applied to coal liquefaction distillation resids, yields information on the amounts of gas plus distillate, pyridine-soluble resid, and pyridine-insoluble material formed when a coal liquid sample is heated to 450{degree}C for one hour at 5000 psi in an inert atmosphere. The pyridine-insolubles then are examined by reflectance microscopy to determine the type, amount, and optical texture of isotropic and anisotropic carbon formed upon carbonization. Further development of these analytical methods as process development tools may be justified on the basis of these results.
Date: December 1, 1991
Creator: Mitchell, G.; Davis, A. (Pennsylvania State Univ., University Park, PA (United States). Energy and Fuels Research Center); Burke, F.P.; Winschel, R.A. & Brandes, S.D. (Pennsylvania State Univ., University Park, PA (United States). Energy and Fuels Research Center)
Partner: UNT Libraries Government Documents Department

Visualization of drug-nucleic acid interactions at atomic resolution. IV. Structure of an aminoacridine/dinucleoside monophosphate crystalline complex, 9-aminoacridine: 5-iodocytidylyl(3'-5')guanosine

Description: 9-Aminoacridine forms a crystalline complex with the dinucleoside monophosphate, 5-iodocytidylyl(3'-5')guanosine (iodoCpG). These crystals are monoclinic, space group P2/sub 1/, with a = 13.98 A, b = 30.58 A, c = 22.47 A and ..beta.. = 113.9. The structure has been solved to atomic resolution by Patterson and Fourier methods, and refined by a combination of Fourier and sum function Fourier methods. The asymmetric unit contains four 9-aminoacridine molecules, four iodoCpG molecules and 21 water molecules, a total of 245 atoms. 9-Aminoacridine demonstrates two different intercalative binding modes and, along with these, two slightly different intercalative geometries in this model system. The first of these is very nearly symmetric, the 9-amino- group lying in the narrow groove of the intercalated base-paired nucleotide structure. The second shows grossly asymmetric binding to the dinucleotide, the 9-amino- group lying in the wide groove of the structure. Associated with these two different intercalative binding modes is a difference in geometries in the structures. Although both structures demonstrate C3' endo (3'-5') C2' endo mixed sugar puckering patterns, with corresponding twist angles between base-pairs of about 10/sup 0/, they differ in the magnitude of the helical screw axis dislocation accompanying intercalation. In the pseudosymmetric intercalative structure, this value is about +0.5 A, whereas in the asymmetric intercalative structure this value is about +2.7 A. These conformational differences can be best described as a sliding of base-pairs on the intercalated acridine molecule.
Date: January 1, 1979
Creator: Sakore, T.D.; Reddy, B.S. & Sobell, H.M.
Partner: UNT Libraries Government Documents Department

Photoinduced charge separation in linked donor-chromophore-acceptor systems

Description: Focus has been mainly on preparation and characterization of triply bridged dinuclear complexes containing a tris-2-2'- bipyridineruthenium chromophore and a second tris-bipyridine metal complex which is to serve as electron donor or acceptor, and of linked RuL[sub 3]-containing D-C-A complexes where D is a phenothiazine donor and A is a diquat type acceptor. (DLC)
Date: June 1, 1993
Creator: Elliott, C.M.
Partner: UNT Libraries Government Documents Department

Ionization probes of molecular structure and chemistry. Progress report, January 15, 1992--January 14, 1993

Description: Development of laser ionization tools toward study of spectroscopy and dynamics of molecules relevant to combustion processes. Ionization versus dissociation was studied in CO{sub 2}; the intensity dependence of vibrational structure in photoelectron spectra had no changes over almost a 2{times} factor, indicating that the CO{sub 2} multiphoton ionization through its Rydberg states proceeds by autoionization of bound, neutral dissociative states at the four photon level. Variants of threshold ionization spectroscopy were used for studying ions, aromatics, diazines, azines, etc. In collaboration with BNL people, rotational structure of the combustion radicals trans-HOCO and DOCO, and vacuum uv photodissociation of three chlorofluoromethanes were studied.
Date: January 1, 1993
Creator: Johnson, P. M.
Partner: UNT Libraries Government Documents Department

Computational analysis of azine-N-oxides as energetic materials

Description: A BKW equation of state in a 1-dimensional hydrodynamic simulation of the cylinder test can be used to estimate the performance of explosives. Using this approach, the novel explosive 1,4-diamino-2,3,5,6-tetrazine-2,5-dioxide (TZX) was analyzed. Despite a high detonation velocity and a predicted CJ pressure comparable to that of RDX, TZX performs relatively poorly in the cylinder test. Theoretical and computational analysis shows this to be the result of a low heat of detonation. A conceptual strategy is proposed to remedy this problem. In order to predict the required heats of formation, new ab initio group equivalents were developed. Crystal structure calculations are also described that show hydrogen-bonding is important in determining the density of TZX and related compounds.
Date: May 1, 1994
Creator: Ritchie, J. P.
Partner: UNT Libraries Government Documents Department

Pulsed laser kinetic studies of liquids under high pressure

Description: A high pressure apparatus constructed for measuring the rates of reactions in liquids under pressures ranging from 1 atm to 2000 atm has been used to measure the complexation kinetics of molybdenum hexacarbonyl reacting with 2,2-bipyridine, 4,4{prime}-dimethyl-2-2{prime}-bipyridine and 4,4{prime}-diphenyl-2-2{prime} bipyridine in toluene. Pentacarbonyl reaction intermediates are created by a 10 nsec flash of frequency tripled Nd:YAG laser light. Measured activation volumes for chelate ligand ring closure indicate a change in mechanism from associative interchange to dissociative interchange as steric hindrance increases. A similar high pressure kinetics study of molybdenum carbonyl complexation by several substituted phenanthrolines is now well advanced that indicates that with the more rigid phenanthroline ligands steric effects from bulky substituents have less effect on the ring closure mechanism than in the case of the bipyridine ligands. An experimental concentration dependence of the fluorescence quantum yield of cresyl violet has been harmonized with previously published contradictory reports. Fluorescence of cresyl violet in various solvents and in micellar systems has also been systematically explored.
Date: November 25, 1991
Creator: Eyring, E.M.
Partner: UNT Libraries Government Documents Department

Influence of phase boundaries on photo-induced electron transfer reactions. Final report, July 1, 1977-August 31, 1979

Description: A summary is presented of results of research which was conducted on bipyridyl complexes of ruthenium, with the objective of storing visible light energy. The research covered analytical techniques, synthesis, properties of Ru complexes in monolayers and micelles, and luminescence quenching. 23 references. (DLC)
Date: August 1, 1979
Partner: UNT Libraries Government Documents Department

Chelating extractants of improved selectivity. Progress report, August 1, 1978-July 31, 1979

Description: During the current contract period, the variation of coordination number of tervalent lanthanides observed earlier with 8-quinolinol extraction systems was exploited in the development of mixed ligand (so-called synergistic) extraction systems involving 1, 10-phenanthroline (phen) and 8-quinolinol (HOx). Using a mixture of HOx and phen significantly enhanced the difference between adjacent lanthanide ions and facilitated their separation.
Date: August 1, 1979
Partner: UNT Libraries Government Documents Department

Thermodynamics of the solvent swelling of coal

Description: Sorption of benzene by the pyridine-extracts of premium Argonne Illinois {number sign}6 coal was studied at several relative vapor pressures at 50{degrees}C and 70{degrees}C. The amount of benzene sorbed by the extract increases linearly or nearly linearly with benzene vapor pressure. The extrapolated lines do not pass through the origin. At low pressures, a dual-mode sorption mechanism is proposed, whereby benzene concurrently fills holes (microvoids) and dissolves into the extract. At higher pressures, we propose that the holes are saturated and that only dissolution is occurring. Dissolution thus increases linearly with pressure of benzene. The heat of dilution, calculated from the change in slope of the curve with temperature, is positive, indicating a endothermic process. This result is in distinct contrast to results obtained previously using pyridine as solvent. The O-methylated extract absorbs considerably more benzene at 50{degrees}C compared to the extract. Again, the sorption curve is linearly, with a slope 1.5 times that of the extract. The increase in slope is consistent with the disruption of hydrogen bonds by O-methylation. 3 refs., 2 figs., 1 tab.
Date: October 10, 1991
Creator: Green, T.K.
Partner: UNT Libraries Government Documents Department

Advanced soluble hydroliquefaction and hydrotreating catalysts

Description: The purpose of the present program is to develop soluble analogs of surface confined catalysts that can be impregnated directly into the coal structure at low temperatures. This approach should avoid problems related to surface area dependence, a two phase (surface- liquid) reaction system and, mass transport limitations.
Date: January 31, 1992
Creator: Laine, R.M. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Materials Science and Engineering) & Stoebe, T. (Washington Univ., Seattle, WA (United States). Dept. of Materials Science and Engineering)
Partner: UNT Libraries Government Documents Department

Advanced soluble hydroliquefaction and hydrotreating catalysts

Description: The purpose of the present program is to develop soluble analogs of surface confined catalysts that can be impregnated directly into the coal structure at low temperatures. This approach should avoid problems related to surface area dependence, a two phase (surface-liquid) reaction system and, mass transport limitations.
Date: November 22, 1991
Creator: Laine, R.M. (Michigan Univ., Ann Arbor, MI (United States). Dept. of Materials Science and Engineering) & Stoebe, T. (Washington Univ., Seattle, WA (United States). Dept. of Materials Science and Engineering)
Partner: UNT Libraries Government Documents Department

Excited state processes in transition metal complexes: Redox splitting in soluble polymers

Description: In our research there were two major themes. The first was the continued development of excited states as sensitizers. In one sequence of experiments the synthetic aspects of this area were developed in further detail both by extending the chemistry of the polypyridyl-accepting ligands associated with the excited state and by developing a new procedure for the preparation of unsymmetrical tris-chelate complexes. The second important aspect of this work was the continued investigation of the molecular and electronic structure characteristics of this class of excited states and how those factors determine such properties as photostability and excited state decay. This effort was extended to complexes of Re(I) and an examination of their excited state characteristics, the role of hydride ligand in determining the properties of excited states, the calculation of relative nonradiative decay rate constants for a series of complexes of Ru(II), the participation of higher lying excited states in decay in complexes of Ru(II) and Os(II), and the application of the transient infrared technique to the elucidation of a photochemical intermediate following laser flash excitation. The second area of study involved excited states in soluble polymers to investigate photoinduced electron and energy transfer in multi-component assemblies. This work was based on chemically derivatized polystyrene polymers which contain combinations of chromophores and electron or energy transfer quenchers.
Date: March 1, 1992
Creator: Meyer, T.J.
Partner: UNT Libraries Government Documents Department

Catalysis and co-catalysis of bond cleavages in coal and coal analogs. [N,N-Dimethylaniline]

Description: Catalytic hydrogenolysis and thermal fragmentation of coal-related compounds are covered in this report. Data are tabulated for the following processes: (1) Transfer Hydrogenolysis in Tetralin at 450{degrees}C in Stainless Steel Reactors; (2) Effects of Diphenylamine on Fragmentation of 1,1-Dibenzyl-1,4-dihydronaphthalene at 150{degrees}C; (3) Effect of Diphenylamine on Rate of Fragmentation of 1,1-Di-p-tolyl-1,4-dihydronaphthalene at 150{degrees}C; (4) Fragmentation of 1,1-Di-(4-chlorobenzyl)-1,4-dihydronaphthalene at 150{degrees}C. (VC)
Date: January 1, 1992
Creator: Miller, B.
Partner: UNT Libraries Government Documents Department

The single electron chemistry of coals, July 1, 1991--September 30, 1991

Description: The objectives of this work are to investigate and characterize the single electron reactions of alkyl and alkoxy aromatic compounds in order to determine the role these reactions play in the chemistry of coal. (1) Attempts will be made to demonstrate that the radicals from inertinite maceral group will initiate the polymerization of 4-vinylpyridine. (2) The molecule, N, N-diphenyl-phenylendiamine, will be deposited in coals to characterize their native free radicals. (3) Tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) will be used to characterize the numbers and strengths of single electron donors in coals.
Date: January 1, 1991
Creator: Larsen, J.W. & Eskay, T.P.
Partner: UNT Libraries Government Documents Department

Electron transfer reactions of excited dyes with metal complexes. Progress report, March 1, 1978-February 28, 1979. [Iron-methylene blue]

Description: An intense absorption band of /sup 3/MBH/sup 2 +/ at 700nm was characterized in several media and its pK/sub A/ was measured to be 7.17 +- .1 in water. Flash photolysis show that semiethylene blue, MBH/sup +/, formed by quenching /sup 3/MBH/sup 2 +/ with Fe/sub II/(H/sub 2/O)/sub 6//sup 2 +/, decays by disproportionation at a diffusion-controlled rate. Rates of decay of the photostationary state of solutions of MB/sup +/ and Fe/sup II/(H/sub 2/O)/sub 6//sup 2 +/ in acidic media were measured using crossed beams to yield specific rates of oxidation of leucomethylene blue (MBH/sub 3//sup 2 +/) by MB/sup +/ (synproportionation) and by Fe(III). Laser flash-photolysis shows that quenching of MB/sup +/(S/sub 1/) by Fe(H/sub 2/O)/sub 6//sup 2 +/ can result in electron transfer to give MBH/sup +/. Profound differences between processes initiated by quenching triplet methylene blue with Fe(H/sub 2/O)/sub 6//sup 2 +/ and with stable coordination complexes of Fe(II) were found. Quenchers included (Fe/sup II/(CN)/sub 6/)/sup 4 -/, (Fe/sup II/(CN)/sub 4/(bpy)/sub 2/)/sup 2 -/, (Fe/sup II/(CN)/sub 2/(bpy))/sup 0/, and (Fe/sup II/(bpy)/sub 3/)/sup 2 +/. Measurements were made in aqueous and aqueous-alcoholic solutions at pH 2, 4.4, and 8.2. Quenching of /sup 3/MBH/sup 2 +/ or /sup 3/MB/sup +/ by a stable complex of Fe(II) is diffusion-controlled and 10/sup 2/ to 10/sup 3/ times the rate at which Fe(H/sub 2/O)/sub 6//sup 2 +/ quenches /sup 3/MBH/sup 2 +/. Net electron transfer accounts for less than 1/3 of total quenching by complexed Fe(II). In contrast, quenching by Fe(H/sub 2/O)/sub 6//sup 2 +/ goes essentially entirely with net electron transfer. It is concluded that quenching of triplet methylene blue by complexes proceeds via electron transfer which is reversible in the encounter complex. The MBH/sup +/ which results from net electron transfer from complexes of Fe(II) decays essentially entirely to MB/sup ...
Date: March 15, 1979
Creator: Lichtin, N.N.
Partner: UNT Libraries Government Documents Department

The single electron chemistry of coals

Description: The objective of this work is to investigate and characterize the single electron reactions of alkyl and alkoxy aromatic compounds in order to determine the role these reactions play in the chemistry of coal. Activities carried out in this reporting period are as follows: (1) attempts will be made to demonstrate that the radicals from inertinite maceral group will initiate the polymerization of 4-vinylpyridine; (2) the molecule, N,N-diphenyl-phenylenediamine, will be deposited in coals to characterize their native free radicals; (3) tetracyanoquinodimethane (TCNQ) and tetracyanoethylene (TCNE) will be used to characterize the numbers and strengths of single electron donors in coals. 7 refs., 4 tabs.
Date: January 1, 1991
Creator: Larsen, J.W. & Eskay, T.
Partner: UNT Libraries Government Documents Department

Photochemistry and charge transfer chemistry of the platinum group elements

Description: Significant progress has been made on the photochemistry and photophysics of platinum group element dithiolate complexes. The specific systems under investigation are square planar complexes of Pt(II) containing a dithiolate chelate and two other donor groups to complete the coordination sphere. The donor groups may be amines, imines, phosphines, phosphites or olefins, and they can be either monodentate or joined together as part of a chelate ring.
Date: December 1, 1991
Creator: Eisenberg, R.
Partner: UNT Libraries Government Documents Department

Development of a practical photochemical energy storage system. Quarterly report

Description: A study of a series of copper(I) compounds which contain a strongly absorbing chromophore (e.g., CuBr(PPh/sub 3/)-(2,2'-bipyridine)) for use as sensitizers in photochemical energy storage systems is described. The generally low sensitization efficiencies of these compounds preclude their use as sensitizers in a practical photochemical energy storage system. Nevertheless, some interesting mechanistic information has emerged from this study, the full details of which are being written for publication. Also, the related compound, Ru(bipy)/sub 2/(NBD)/sup +2/, which features a norbornadiene molecule coordinated directly to a strongly absorbing metal containing fragment was examined. The original rationale for studying this compound was the expectation that the absorption of visible light would result in the population of an electronically excited state in which the electron density of the NBD is considerably perturbed. Relaxation of this state could then occur by a pathway which leads to the rearranged product, quadricyclene. It was found, however, that the sensitization efficiency of this compound is quite low. A comprehensive study of the factors which affect the sensitization efficiencies of Ir(bipy)/sub 2/(bipy')OH/sub 2//sup +3/ is unerway. In order to elucidate the mechanism(s) by which organic sensitizers affect the conversion of norbornadiene to quadricyclene, a study to measure the actual rate constant for the sensitization process is underway. The status of the project is discussed.
Date: September 15, 1978
Creator: Hautala, R.R. & Kutal, C.R.
Partner: UNT Libraries Government Documents Department

Photoinduced charge separation by polymer-bound chromophores

Description: This project has examined the photodynamic behavior of water-soluble polymers that have covalently linked hydrophobic chromophores spaced along the chains. These polymeric systems have been examined for photoinduced charge separation with electron-accepting ions having different total charge. Focus has been on the excited singlet (S{sub 1}) state formed by laser flash absorption. The effects of pH and ionic strength -- factors that govern the conformational nature of the polymer in solution -- have been studied. A second major effort has been to study photoinduced redox processes involving excited states of water-soluble variants of anthracene and acridine. 27 refs., 16 figs., 2 tabs.
Date: September 1, 1991
Creator: Rodgers, M.A.J.
Partner: UNT Libraries Government Documents Department