Download or read book Molecular Beam Studies of Atom and Free Radical Reactions written by Grant Logan Duncan and published by . This book was released on 1982 with total page 151 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crossed Molecular Beam Study of the Reactions of Oxygen Atoms and Free Radicals written by Yuan Tseh Lee and published by . This book was released on 1975 with total page 11 pages. Available in PDF, EPUB and Kindle. Book excerpt: The development of rare gas seeded fluorine atom beam source and reactions studied by this new source are main subject of this brief final report. F+CH3I to IF + CH3 reaction has been studied.
Download or read book Molecular Beam Study of Polyatomic Free Radical Reactions written by David Lee McFadden and published by . This book was released on 1972 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The polyatomic free radicals CH3 and C2H5(R) were produced by thermal dissociation (1500K) of R2Cd or R2Zn. A molecular beam containing about 7 - 20% free radicals emerged from the source and collided with a hydrodynamic (nozzle) beam of halogen molecules. Angular distributions of the alkyl halide product were measured with a quadrupole mass spectrometer for the reactions CH3 + Cl2, Br2, I2, ICl (both products), and C2H5 + Br2. The reactive scattering is predominantly backwards in the c.m. system and the reaction cross sections, estimated within a factor of three, are small, about 0.5 to 5A squared. There is much similarity between these polyatomic free radical reactions and corresponding D atom reactions, except that there is much less forward scattering in the CH3 cases. The angular distribution of C2H5Br is peaked backwards and is remarkably narrow. (Author).
Download or read book Frontiers of Free Radical Chemistry written by William Pryor and published by Elsevier. This book was released on 2012-12-02 with total page 400 pages. Available in PDF, EPUB and Kindle. Book excerpt: Frontiers of Free Radical Chemistry covers the proceedings of the 1979 symposium on Frontiers of Free Radical Chemistry, held in Louisiana State University Chemistry Department, supported by the Exxon Education Foundation. The contributors discuss the mechanisms of hydrocarbon cracking; oxidation processes; inhibition; and the theory of organic radical reactions, halogenations, and organic peroxide chemistry. This book is organized into three parts encompassing 15 chapters. Part I deals with the understanding of molecular and free radical mechanisms in predicting thermochemical data for radicals and molecules. This part also describes the relationship between distortions of organic molecules and the reactions of pericyclic, ionic, and radical molecules. Part II presents quantitative evaluations of gas phase reactions or carbynes and hydrocarbon pyrolysis and cracking. Discussions on the reactions of free atoms and radicals in the chemistry of the stratosphere and natural troposphere, with an emphasis on the ozone layer and its potential depletion by artificial pollutants, are included in this part. Part III explores the pertinent free radical reactions related to fuel research. Petroleum chemists, researchers, and engineers will find this book invaluable.
Download or read book Molecular Beam Studies of Oxygen Atom Reactions with Unsaturated Hydrocarbons written by Annemarie Schmoltner and published by . This book was released on 1989 with total page 628 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reactions of Atoms and Radicals in Pulsed Molecular Beams written by H. Reisler and published by . This book was released on 2004 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The final report describes studies of unimolecular reactions of transient species and radicals relevant to combustion processes. Specifically, the dynamics of predissociation of free radicals for which multiple pathways, including molecular rearrangements, compete. These small, prototypical, systems are amenable to treatment by high level theory, and close collaboration with theory continues to be a cornerstone of the program. The chemistry of hydroxyalkyl radicals is important in atmospheric and combustion environments, because cleavage of the C-H and O-H bonds is implicated in the reactions of several atoms and radicals with alcohols and alkanes. In particular, the hydroxymethyl radical affords many opportunities to study both isomerization and dissociation on the ground and excited potential energy surfaces. During this funding period, high vibrational levels of the ground electronic state of the hydroxymethyl radicals were accessed in two ways: (1) by using internal conversion from the lowest excited electronic state, the 3s Rydberg state; and (2) via direct vibrational excitation of the hydroxymethyl radical accessed by pumping OH overtones as ''bright'' states. In the former method, levels that are {approx} 3 eV above the H + formaldehyde asymptote are reached. In the latter, the region of the dissociation barrier is gradually approached from below, while examining the role of energy flow from OH overtones to other vibrational levels. The first task was to characterize the electronic absorption of the radical, in order to develop diagnostics and reach the ground state via excitation of the lowest-lying state, the 3s Rydberg state. To this end, excitations to the three lowest 3s and 3p Rydberg states were studied and the dissociation channels identified. These were predominantly O-H and C-H fission, while isomerization to the methoxy radical was not observed. Collaborations with theory identified the molecular dynamics on the excited electronic potential energy surfaces and how the ground state is reached via nonadiabatic transitions. Establishing the relevant dissociation and isomerization pathways on the ground electronic state requires studying energy flow patterns with increasing internal energy. Two energy regimes corresponding to distinct unimolecular dynamics were reached: (1) low energy spectroscopic studies of IR transitions in the region of the fundamental and first overtone of the OH-stretch, where intramolecular dynamics is likely to be weak and first manifested; (2) Studies of the region near the dissociation barrier, i.e. the third OH-stretch overtone, where dissociation occurs mostly by tunneling. The experimental approach relies on pulsed molecular beams, state-selective reactant preparation and product detection, and good resolution in both frequency and velocity domains. Radicals are prepared in molecular beams by using photoinitiated bimolecular reactions in a quartz tube attachment to the pulsed valve. Excitation is achieved using either overtone pumping of OH stretch vibrations, or excitation to an electrically excited state followed by radiationless transitions. Detection relies on time-of-flight methods with core sampling, which provide kinetic energy and angular distribution.
Download or read book Molecular Beam Studies of Reaction Dynamics written by and published by . This book was released on 1993 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Thrust was to elucidate simple elementary reactions and to unravel mechanism of complex/photochemical reactions. Molecular beams are used to study reactions between molecules or to monitor photodissociation events in a collision-free environment. Recent activities centered on reactions involving oxygen atoms with unsaturated hydrocarbons, endothermic substitution reactions, dependence of reactivity of excited atoms on alignment of excited orbitals, photochemical reactions of polyatomic, energy transfer, free radicals in combustion processes, infrared absorption spectra of carbonium ions and hydrated hydronium ions, and bond-selective photodissociation.
Download or read book Reactions of Ions with Atomic and Molecular Free Radicals Progress Report May 1 1978 April 30 1979 Summaries of Research Activities at Univ of Minnesota written by and published by . This book was released on 1979 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: A program of research was undertaken to study the dynamics of the reactions of ions with atomic and molecular free radicals, using a merged molecular beam technique. The objectives of this research are to obtain fundamental information on reaction mechanisms in reactions of species having open-shell electronic configurations, and to investigate the importance of electronic nonadiabaticity in chemical reactions. During the present contract year work was done on completing studies of the reaction D2 + F(2P) .-->. FD+ + D and of the complementary reactions D2+ + HF .-->. FD22 + H, D2+ + HF .-->. FHD+ + D, and D2+ + HF .-->. FD+ + HD. Also some experiments were carried out on the reaction C+ + D2 .-->. CD+ + D to complement our previous work on the opposite initial charge state of the system, D2+ + C .-->. CD+ + D. Finally, as an aid in interpreting our merged-beam data at kinetic energies as low as 0.002 eV. A theoretical analysis was performed of the differential cross sections for ion-dipole capture collisions followed by direct-mode reactions. The results indicate that shifts in the product angular distribution with a change in the reactant kinetic energy do not necessarily imply a change in the short-range reaction mechanism. A list of publications is included.
Download or read book Dynamics Studies of Free Radical Reactions Using Hydrogen Rydberg Time of flight Spectroscopy written by Mariví Ortiz-Suárez and published by . This book was released on 2007 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Atomic and Molecular Beams written by Cyril Bernard Lucas and published by CRC Press. This book was released on 2013-12-13 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt: Atomic and molecular beams are employed in physics and chemistry experiments and, to a lesser extent, in the biological sciences. These beams enable atoms to be studied under collision-free conditions and allow the study of their interaction with other atoms, charged particles, radiation, and surfaces. Atomic and Molecular Beams: Production and Collimation explores the latest techniques for producing a beam from any substance as well as from the dissociation of hydrogen, oxygen, nitrogen, and the halogens. The book not only provides the basic expressions essential to beam design but also offers in-depth coverage of: Design of ovens and furnaces for atomic beam production Creation of atomic beams that require higher evaporation temperatures Theory of beam formation including the Clausing equation and the transmission probability Construction of collimating arrays in metals, plastics, glass, and other materials Optimization of the design of atomic beam collimators While many review articles and books discuss the application of atomic beams, few give technical details of their production. Focusing on practical application in the laboratory, the author critically reviews over 800 references to compare the atomic and molecular beam formation theories with actual experiments. Atomic and Molecular Beams: Production and Collimation is a comprehensive source of material for experimentalists facing the design of any atomic or molecular beam and theoreticians wishing to extend the theory.
Download or read book Molecular Beams in Physics and Chemistry written by Bretislav Friedrich and published by Springer Nature. This book was released on 2021-06-19 with total page 639 pages. Available in PDF, EPUB and Kindle. Book excerpt: This Open Access book gives a comprehensive account of both the history and current achievements of molecular beam research. In 1919, Otto Stern launched the revolutionary molecular beam technique. This technique made it possible to send atoms and molecules with well-defined momentum through vacuum and to measure with high accuracy the deflections they underwent when acted upon by transversal forces. These measurements revealed unforeseen quantum properties of nuclei, atoms, and molecules that became the basis for our current understanding of quantum matter. This volume shows that many key areas of modern physics and chemistry owe their beginnings to the seminal molecular beam work of Otto Stern and his school. Written by internationally recognized experts, the contributions in this volume will help experienced researchers and incoming graduate students alike to keep abreast of current developments in molecular beam research as well as to appreciate the history and evolution of this powerful method and the knowledge it reveals.
Download or read book Radical Reactions written by Nathan Price and published by American Chemical Society. This book was released on 2023-03-31 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radical Reactions provides the reader a brief overview of radical reactions, an overview overlooked in most undergraduate chemistry curriculums. Most of the exciting developments in the field of radical and radical ion chemistry came about because someone understood the fundamentals and was able to design new chemistry based upon that understanding. The target audience is individuals who have had at least one semester of organic chemistry.
Download or read book Atomic and Free Radical Reactions written by Edgar William Richard Steacie and published by . This book was released on 1954 with total page 506 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Application of a Hydrogen Atom Discharge to Crossed Molecular Beam Free Radical Studies written by Robert Chadwick Kuns and published by . This book was released on 1967 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Chemistry of Free Radicals written by Rayson L. Huang and published by Hodder Education. This book was released on 1974 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Crossed Molecular Beam Study of the Reactions of Oxygen and Fluorine Atoms written by Yuan T. Lee and published by . This book was released on 1978 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: Rapid developments in the study of oxygen reaction chemistry occurred as it is succeeded in obtaining an O(1D) beam source and commenced investigating the dynamics of several important reactions of O(3P) and O(1D). In the reaction of O(3P) with C6H6 and C6D6, two competing channels, one producing a stabilized addition complex and the other forming radical products C6H50 + H has been identified. Studies of the effects of collision energy and of deuteration were used to clarify the reaction mechanism. The reaction of O(3P) with another aromatic hydrocarbon toluene, results in competition between two substitution channels, loss of H atom and loss of CH3. In contrast to the 0 + C6H6 reaction, no stabilized oxygen-toluene adduct was observed.
Download or read book Atomic and Free Radical Reactions written by Edgar William Richard Steacie and published by . This book was released on 1946 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt:
