Download or read book Infrared Multiphoton Dissociation of Three Nitroalkanes written by A. M. Wodtke and published by . This book was released on 1986 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrared multiphoton dissociation in a molecular beam has been studied in order to elucidate the collision-free thermal chemistry and dynamics of nitromethane, nitroethane, and 2-nitropropane. The isomerization of CH3NO2 to CH3ONO was observed by detecting the CH3O and NO products from the dissociation of the internally very hot, isomerized nitromethane. A novel application of RRKM theory was used to estimate the barrier height to isomerization at 55.5 kcal/mol. The barrier height determination method was tested and found to give excellent results by applying it to the determination of the barrier height to HONO elimination from nitroethane, a value which is well-known from activation energy measurements. The method was then applied to the case of HONO elimination from 2-nitropropane and it appears that there is good reason to believe that the barrier height is 3-5 kcal/mol lower in 2-nitropropane than in nitroethane. The success of this method for determining barrier heights shows how a microscopic molecular beam experiment, using infrared multiphoton dissociation where the concept of temperature has no place, can be quantitatively related to pyrolysis experiments which are conducted under collisional, thermal conditions and measure phenomenological quantities such as activation energies. The concerted HONO elimination reactions from nitroethane and 2-nitropropane were found to channel about 70 and 65% of the exit barrier into translation, respectively. This large release of translational energy is suggested to be due to the nature of the transition-state mechanical barrier which is largely made up of repulsive energy between the closed shell products and not of reactant strain energy.
Download or read book The Infrared Multiphoton Dissociation of Three Nitrolkanes written by A. M. Wodtke and published by . This book was released on 1986 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrared multiphoton dissociation in a molecular beam has been studied in order to elucidate the collision free, 'thermal' chemistry and dynamics of nitromethane, nitroethane and 2-nitropropane. The isomerization of CH3NO2 to CH3ONO was observed by detecting the CH3O and NO products from the dissociation of the very internally hot, isomerized nitromethane. A novel application of RRKM theory was used to estimate the barrier height to isomerization at 55.5 kcal/mol. The barrier height determination method was tested and found to give excellent results by applying it to the determintaion of the barrier height to HONO elimination from nitroethane, a value which is well known from activation energy measurements. The method was then applied to the case of HONO elimination from 2-nitropropane and it appears that there is good to believe that the barrier height is 3-5 kcal/mol lower in 2-nitropropane than in nitroethane. The success of this method for determining barrier heights shows how a 'microscopic' molecular beam experiment, using infrared multiphoton dissociation where the concept of temperature has no place, can be quantitatively related to pyrolysis experiments which are conducted under collisional, thermal conditions and measure phenomenological quantities such as activation energies. The concerted HONO elimination reactions from nitroethane and 2-nitropropane were found to channel about 70 and 65 percent of the exist barrier into translation, respectively.
Download or read book Energy Research Abstracts written by and published by . This book was released on 1987 with total page 616 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energetic Materials written by and published by Elsevier. This book was released on 2003-11-25 with total page 487 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume provides an overview of current research and recent advances in the area of energetic materials, focusing on decomposition, crystal and molecular properties. The contents and format reflect the fact that theory, experiment and computation are closely linked in this field. Since chemical decomposition is of fundamental importance in energetic performance, this volume begins with a survey of the decomposition processes of a variety of energetic compounds. This is followed by detailed studies of certain compounds and specific mechanisms, such as nitro/aci-nitro tautomerism. Chapter 6 covers the transition from decomposition to crystal properties, with molecular dynamics being the primary analytical tool. The next several chapters deal with different aspects of the crystalline state, again moving from the general to particular. There is also a discussion of methods for computing gas, liquid and solid phase heats of formation. Finally, the last portion of this volume looks at the potential of high-nitrogen molecules as energetic systems; this has been of considerable interest in recent years.Overall, this volume illustrates the progress that has been made in the field of energetic materials and some of the areas of current activity. It also indicates the challenges involved in characterizing and understanding the properties and behaviour of these compounds. The work is a unique state-of-the-art treatment of the subject, written by pre-eminent researchers in the field.- Overall emphasis is on theory and computation, presented in the context of relevant experimental work- Presents a unique state-of-the-art treatment of the subject- Contributors are preeminent researchers in the field
Download or read book Technical Reports Awareness Circular TRAC written by and published by . This book was released on 1987-11 with total page 588 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Infrared Multiphoton Dissociation of the Nitrobenzene Cation written by M. Moini and published by . This book was released on 1986 with total page 18 pages. Available in PDF, EPUB and Kindle. Book excerpt: Infrared multiphoton dissociation (IRMPD) of nitrobenzene cations has been shown to proceed via three pathways of ca. 1-2 eV activation energy to produce C6H5, C5H5, and NO ions. Observation of these three fragment ions and not C6H5, which has approximately the same appearance energy, suggests that they are produced from high vibrational levels of the ground electronic state of the cation, while the C6H5 either has a higher appearance energy than previously reported or is produced by dissociation from an isolated electronic state. To explain all aspects of the observed formation of C5H5 and C6H5O fragment ions from nitrobenzene cations by IRMPD two different dissociation pathways leading to C6H5O ions and one leads tro unstable C6H5O which further dissociates to C5H5.
Download or read book Theoretical and Computational Chemistry written by Peter Politzer and published by . This book was released on 1994 with total page 494 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Very High Resolution Photofragmentation translational Spectroscopy written by Alec Michael Wodtke and published by . This book was released on 1986 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Infrared Multiphoton Dissociation of Ethyl and Methyl Acetate written by Eric J. Hintsa and published by . This book was released on 1987 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: The collisionless decomposition of ethyl and methyl acetate was investigated using IR multiphoton dissociation. Ethyl acetate gave 97 percent concerted decomposition producing ethylene and acetic acid, the latter of which underwent significant secondary decomposition to ketene and water. Simple bond rupture producing ethyl radical and CH3CO2, which completely decomposed to CH3 and CO2, accounted for the remaining reaction products. Methyl acetate underwent concerted reaction to produce methanol and ketene, and simple bond rupture to form CH3 and CH3CO2, in near equal amounts. Keywords: Infrared multiphoton dissociation, Concerted unimolecular reactions, Ethyl acetate, Methyl acetate, Reaction barriers, RRKM theory, Molecular beams, Ethers. (jes).
Download or read book Dynamics of Infrared Multiphoton Dissociation of SF6 by Molecular Beam Method Nonrandomize Excitation Energy written by and published by . This book was released on 1977 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The decomposition of polyatomic molecules by infrared multiphoton absorption is a subject which is under extensive investigation in many laboratories. The process has been shown to be efficient, selective and collisionless. The physical principles which are mainly responsible for the absorption of a large number of photons by an isolated molecule under intense infrared laser radiation have been elucidated through many experimental and theoretical investigations. However, one very important question which remains to be answered is the relation between the dynamics of molecular decomposition and the degree of vibrational excitation, i.e., the question of whether the excitation energy is completely randomized before molecular decomposition. The production of electronically excited fragments in the dissociation of halogenated hydrocarbons and the observations of SF4 fragment in the decomposition of SF6 without the evidence of the formation of lower energy SF5 fragment provided some basis of speculation that the excitation energy might not be randomized before the dissociation of excited molecules. A crossed molecular beam apparatus has been adapted to study the dynamics of excitation and dissociation of polyatomic molecules in intense IR laser fields. Initial experiments have involved the study of the dissociation of SF6 by CO2 laser radiation at 10.6 .mu.m. a molecular beam of SF6 was formed by supersonic expansion using three stages of differential pumping. A grating tuned pulsed CO2 TEA laser was used as the excitation source. The laser beam was focused by a 25 cm focal length ZnSe lens, and crossed the molecular beam near its focal point. The fragments produced by multiphoton dissociation of SF6 within the small interaction region were detected as a function of recoil angle and velocity.
Download or read book Collision Dynamics of Methyl Radicals and Highly Vibrationally Excited Molecules Using Crossed Molecular Beams written by Pamela Mei-Ying Chu and published by . This book was released on 1991 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Resonant Multiphoton Ionization Detection of the NO2 Fragment from Infrared Multiphoton Dissociation of CH3NO2 written by Bennett H. Rockney and published by . This book was released on 1981 with total page 4 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Three ACT Chemistry Thesis written by Matthew P. Blackwell and published by . This book was released on 1990 with total page 134 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1987 with total page 1262 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Techniques for State selected and State to state Chemistry written by and published by . This book was released on 1993 with total page 504 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1987 with total page 792 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book American Chemical Society Directory of Graduate Research 1987 written by American Chemical Society, Committee on Professional Training Staff and published by . This book was released on 1987 with total page 1390 pages. Available in PDF, EPUB and Kindle. Book excerpt:
