Download or read book Gas phase Kinetic Studies of the OH and NH2 Self reactions and the Reactions of OH with CH3 C2H5 and NH2 written by Kjell Fagerström and published by . This book was released on 1995 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetics of OH Reactions with N2H4 CH3NHNH2 and CH3 2NNH2 in the Gas Phase written by and published by . This book was released on 2000 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The gas phase reaction kinetics of OH with three di-amine rocket fuels; N(2)H(4), CH(3)NHNH(2) and (CH3)2NNH2 was studied in a discharge flow-tube apparatus and a pulsed- photolysfs reactor under pseudo-first-order conditions in OH. Direct laser-induced fluorescence monitoring 9f the OH temporal profiles in a known excess of the DI-AMINE yielded the following absolute second-order OH rate coefficient expressions; k(I) = (2.17 plus or minus 0.39) x 10(exp -11) e(160 plus or minus 30)/T, k(2) = (4.59 plus or minus 0.83) x 10(exp -11) e(85 plus or minus 35)/T and k(3) = (3.35 plus or minus 0.60) x 10(exp -11) e(175 plus or minus 25)/T cu cm molec-1 s( -1), respectively, for reactions with N(2)H(4), CH(3)NHNH(2) and (CH3)(2)NNH(2) in the temperature range 232-637 K. All three reactions did not show any discemable pressure dependence on He or N(2) buffer gas pressure of up to 530 torr. The magnitude, and the weak temperature and the lack of pressure effects of the OH + N(2)H(4) reaction rate coefficient suggests that a simple direct metathesis of H-atom may not be important compared to addition of the OH to one of the N-centers of the di-amine skeleton, followed by rapid dissociation of the intermediate into products. Our findings on this reaction are qualitatively consistent with a previous ab-initio study Armstrong et al. J Phys Chem A 1997, 101, 4761. However, in the alkylated di-amines, direct H-abstraction from the methyl moiety can not be completely ruled out.
Download or read book Kinetics and Dynamics of Elementary Gas Reactions written by Ian W. M. Smith and published by Butterworth-Heinemann. This book was released on 2013-10-22 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Kinetics and Dynamics of Elementary Gas Reactions surveys the state of modern knowledge on elementary gas reactions to understand natural phenomena in terms of molecular behavior. Part 1 of this book describes the theoretical and conceptual background of elementary gas-phase reactions, emphasizing the assumptions and limitations of each theoretical approach, as well as its strengths. In Part 2, selected experimental results are considered to demonstrate the scope of present day techniques and illustrate the application of the theoretical ideas introduced in Part 1. This publication is intended primarily for working kineticists and chemists, but is also beneficial to graduate students.
Download or read book Gas Phase Reactions in Organic Synthesis written by Yannick Vallee and published by CRC Press. This book was released on 1998-01-29 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Flash Vacuum Thermolysis (FVT) techniques have become well-established methods and occupy an increasingly important place in synthesis. Gas Phase Reactions in Organic Synthesis is a complete review of the applications of flash vacuum thermolysis in organic chemistry; it features new developments in FVT, flow thermolysis and vacuum gas-solid reactions which have appeared in scientific literature since 1980.
Download or read book Gas phase Reactions written by Viktor Nikolaevich Kondratʹev and published by Springer. This book was released on 1981 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Phase Reaction Kinetics of O Atoms with CH3 2NNH2 CH3NHNH2 and N2H4 and Branching Ratios of the OH Product written by and published by . This book was released on 2001 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The gas phase reaction kinetics of O-atoms with the two alkylated di-amine rocket fuels (CH3)2NNH2 and CH3NHNH2 was studied in a discharge flow-tube apparatus under pseudo first-order conditions in O-atom. Direct vuv cw-resonance fluorescence monitoring of the O-atom temporal profiles in a known excess of the DI-AMINE yielded the following absolute second-order O-atom rate coefficient expressions; k(sub j) = (1.94 + or - 0.34) x 10(exp -11) e(25 + or - 25)/T and k2 = (2.29 + or - 0.40) x 10(exp -11) e( -145 + or - 40)/T cu cm molec(exp -1) s(exp -1), respectively, for reactions with (CH3)2NNH2 and CH3NHNH2 in the temperature range 232-644 K and in He pressure of 2.0 torr. The total yields of OH in the reactions were measured to be (0.12 + or - 0.09) and (0.14 + or - 0.10) at 298 K and in 2.0 torr He pressure. Close to approx. 53% and approx. 59% of the OH produced was estimated to be vibrationally excited. A pulsed-photolysis reactor was used to extend our measurements on the O-atom reaction kinetics with the unsubstituted rocket fuel N2H4 that we had previously studied in the flow-tube apparatus. At 298 K, both the rate coefficient, k3 = (0.59 = or - 0.12) x 10(exp -11) cu cm/ molec s and the total OH yield = (0.35 + or - 0.14) did not show any discernable dependence on He or N2 buffer gas pressures of up to 404 torr. The magnitude of the weak temperature dependence and the lack of pressure effects in the O + N2H4 reaction rate coefficient suggests that simple direct metathesis of H-atom may not be important compared to initial addition of the O-atom to the di-amine, followed by rapid dissociation of the intermediate into a variety of products.
Download or read book Physical Chemistry of Fast Reactions written by B. Levitt and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 342 pages. Available in PDF, EPUB and Kindle. Book excerpt: The chapters in this book are devoted to the elementary reactions of small molecules in the gas phase, with some emphasis on reactions important in combustion. The first three chapters cover experimental measurements made at high temperatures, mainly using shock waves and flames; the final chapter describes discharge flow methods near room temperature. The authors-all active in the fields they describe were asked to aim at a level intermediate between a textbook and a review, designed for readers not already familiar with this branch of chemical kinetics. We hope the book will prove especially useful to research workers in related subjects, to research students, and perhaps as source material for the preparation of lectures. The examples have been chosen to illustrate the theoretical basis of the topics rather than attempt a complete coverage. Professors Wagner and Troe describe the remarkable progress made in recent years in measuring dissociation rates for small molecules. Tests ofunimolecular reaction theories are usually made in the 'fall-off' region of pressure: the kinetics change from first order to second order as the pressure is reduced. For large molecules this region lies below atmospheric pressure and is relatively easily accessible. For molecules with four or less atoms, however, the fall-off region lies well above atmospheric pressure: it has been explored using the high pressure shock tube techniques developed by the authors.
Download or read book Gas Phase Reaction Rate Theory written by Harold S. Johnston and published by . This book was released on 1966 with total page 390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Temperature Kinetic Study of the Reactions H O2 Oh O and O H2 Oh H in H2 O2 System by Shock Tube Laser Absorption Spectroscopy written by National Aeronautics and Space Adm Nasa and published by . This book was released on 2018-11-13 with total page 128 pages. Available in PDF, EPUB and Kindle. Book excerpt: The reactions: (1) H + O2 = OH + O; and (2) O + H2 = OH + H are the most important elementary reactions in gas phase combustion. They are the main chain-branching reaction in the oxidation of H2 and hydrocarbon fuels. In this study, rate coefficients of the reactions and have been measured over a wide range of composition, pressure, density and temperature behind the reflected shock waves. The experiments were performed using the shock tube - laser absorption spectroscopic technique to monitor OH radicals formed in the shock-heated H2/O2/Ar mixtures. The OH radicals were detected using the P(1)(5) line of (0,0) band of the A(exp 2) Sigma(+) from X(exp 2) Pi transition of OH at 310.023 nm (air). The data were analyzed with the aid of computer modeling. In the experiments great care was exercised to obtain high time resolution, linearity and signal-to-noise. The results are well represented by the Arrhenius expressions. The rate coefficient expression for reaction (1) obtained in this study is k(1) = (7.13 +/- 0.31) x 10(exp 13) exp(-6957+/- 30 K/T) cu cm/mol/s (1050 K less than or equal to T less than or equal to 2500 K) and a consensus expression for k(1) from a critical review of the most recent evaluations of k(1) (including our own) is k(1) = 7.82 x 10(exp 13) exp(-7105 K/T) cu cm/mol/s (960 K less than or equal to T less than or equal to 5300 K). The rate coefficient expression of k(2) is given by k(2) = (1.88 +/- 0.07) x 10(exp 14) exp(-6897 +/- 53 K/T) cu cm/mol/s (1424 K less than or equal to T less than or equal to 2427 K). For k(1), the temperature dependent A-factor and the correlation between the values of k(1) and the inverse reactant densities were not found. In the temperature range of this study, non-Arrhenius expression of k(2) which shows the upward curvature was not supported. Ryu, Si-Ok and Hwang, Soon Muk and Dewitt, Kenneth J. Unspecified Center ABSORPTION SPECTROSCOPY; COMBUSTION CHEMISTRY; GAS MIXTURES; HIGH TEMPERATURE TESTS; HYDROGEN; HYDROX...
Download or read book Gas Phase Combustion Chemistry written by W.C., Jr. Gardiner and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 553 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superseding Gardiner's "Combustion Chemistry", this is an updated, comprehensive coverage of those aspects of combustion chemistry relevant to gas-phase combustion of hydrocarbons. The book includes an extended discussion of air pollutant chemistry and aspects of combustion, and reviews elementary reactions of nitrogen, sulfur and chlorine compounds that are relevant to combustion. Methods of combustion modeling and rate coefficient estimation are presented, as well as access to databases for combustion thermochemistry and modeling.
Download or read book Gas Phase Kinetic Studies of the Unimolecular Reactions written by John Metcalfe and published by . This book was released on 1970 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Elementary Reactions of NH2 radicals in the Gas Phase III written by W. Hack and published by . This book was released on 1983 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Gas Phase Kinetic Studies of the Thermal Unimolecular Reactions of Some Cyclic Hydrocarbons written by Richard Graham Hopkins and published by . This book was released on 1971 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reaction Kinetics of O 3P and OH With Diamine Rocket Fuels written by and published by . This book was released on 1998 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt: The gas phase kinetics of O((sup 3)P) and OH reactions with the three diamine fuels; N2H4, CH3NHNH2 and (CH3)2NNH2 has been studied in a discharge flow-tube apparatus. The reactions were studied in 2 torr of He under pseudo-first-order conditions in the transient species concentration with a known excess of diamine concentration. The steady-state concentration temporal profiles of the transient species were directly monitored by fluorescence techniques to deduce the absolute second-order reaction rate coefficients. The Arrhenius expressions; (7.35 +/- 2.16) x 10(exp -13) e(640 +/- 60)/T, (2.71 +/- 0.04) x 10(exp -11) e-(190 +/- 50)/T and (1.96 +/- 0.29) x 10(exp -11) e(20 +/- 40)/T cu cm/molec/s in the temperature range 252-640 K were obtained for reactions of O((sup 3)P) with N2H4, CH3NHNH2 and (CH3)2NNH2, respectively. The corresponding expressions; (1.25 +/- 0.19) x 10 (exp -11) e(315 +/- 55)/T, (2.88 +/- 0.04) x 10(exp -11) e(210 +/- 55)/T and (2.00 +/- 0.30) x 10(exp -11) e(330 +/- 80)/T cu cm/molec/s in the range 232-374 K were determined for the OH reactions. Our recent measurement of the total yield of OH(X(sup 2)II) formation in the O +/- N2H4 reaction of (0.15 +/- 0.05) at 298 K (of which ^50% was found to be produced hot with vibrational excitation up to the limit of reaction exothermicity) and the present observed experimental kinetic trends suggest that the initial addition of O((sup 3)P) and OH to the hydrazine molecule followed by rapid dissociation to products is an important process. Alkylation in the diamine molecule also allows direct H-abstraction mechanism to operate in these reaction systems.
Download or read book International Aerospace Abstracts written by and published by . This book was released on 1998 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1973-11 with total page 1100 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Phase Combustion Chemistry written by W.C., Jr. Gardiner and published by Springer Science & Business Media. This book was released on 1999-12-10 with total page 564 pages. Available in PDF, EPUB and Kindle. Book excerpt: Superseding Gardiner's "Combustion Chemistry", this is an updated, comprehensive coverage of those aspects of combustion chemistry relevant to gas-phase combustion of hydrocarbons. The book includes an extended discussion of air pollutant chemistry and aspects of combustion, and reviews elementary reactions of nitrogen, sulfur and chlorine compounds that are relevant to combustion. Methods of combustion modeling and rate coefficient estimation are presented, as well as access to databases for combustion thermochemistry and modeling.
