Download or read book On the Collision Mechanism of Bimolecular Reactions Investigations of the reaction N2 H2 D2 right arrow N2H H N2D D and CO H2 D2 right arrow COH H COD D written by A. Henglein and published by . This book was released on 1968 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Collision Mechanism of Biomolecular Reactions Part III Investigations of the Reaction N2 H2 D2 to N2H H N2D D and CO H2 D2 to COH H COD D written by K. Lacmann and published by . This book was released on 1968 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: At moderate kinetic energies up to about 50 eV of the incident ion, the velocity spectra agree with the predictions of the stripping model. At higher energies, the bands of the product ions are shifted to somewhat higher velocities. This indicates preferential forward scattering of the charged reaction product and less conversion of kinetic energy of the incident ion into internal energy of the products. As was expected, the cross sections for the transfer of an H- and D-atom are equal at the same relative kinetic energy. Over a wide range of energy, the cross section depends on the relative kinetic energy as sigma = k1 . c to the ( -k2Es) power. Reactions could still be observed at relative kinetic energies, which are larger than the dissociation energy of the product ion (up to 7 eV for N2H(+) and N2D(+) and up to 10 eV for COH(+) and COD(+)). These details of the collision mechanism are tentatively explained by two hypotheses. (Author).
Download or read book On the Collision Mechanism of Bimolecular Reactions The stripping mechanism of the reactions Ar H2 D2 right arrow ArH H ArD D at energies 20 eV written by A. Henglein and published by . This book was released on 1968 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Collision Mechanism of Bimolecular Reactions written by K. Lacmann and published by . This book was released on 1968 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Collision Mechanism of Bimolecular Reactions Theory and experimental method for the determination of the velocity spectrum of products from Simple H transfer reactions of the type X H2 right arrow XH H written by A. Henglein and published by . This book was released on 1968 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Collision Mechanism of Bimolecular Reactions written by A. Henglein and published by . This book was released on 1968 with total page 17 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple apparatus is described which allows one to measure the velocity spectrum of the XH(+) or XD(+) ions, respectively, resulting from ion-molecule reactions of the type X(+) + H2(D2) forming XH(+) + H(XD(+) + D). The secondary ions are not accelerated after their formation. The incident X(+)-ions have kinetic energies between 20 and 200 cV. Furthermore, the velocity spectra are calculated which have to be expected for different collision models. (1) Complex model: All the atoms in the reactants participate in the collision. Every kind of collision between those limiting cases is conceivable, in which the relative kinetic energy of the reactants and the heat of reaction appear as internal energy of the product ion or as kinetic energy of both products (completely inelastic and elastic collision with atomic rearrangement, respectively). (2) Stripping model: The incident X(+)-particle hits only one atom of the hydrogen molecule in a completely inelastic collision without transfer of momentum to the second hydrogen atom. It is also shown that the cross section of the reaction becomes zero above a certain energy of the incident ion. This critical energy depends on the collision mechanism. It can be measured with the apparatus described. In addition an isotope effect of the order of 2 with respect to the critical energy is expected from the transfer of an H or D atom, respectively.
Download or read book Combustion written by J. Warnatz and published by Springer Science & Business Media. This book was released on 2013-04-17 with total page 309 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides a rigorous treatment of the coupling of chemical reactions and fluid flow. Combustion-specific topics of chemistry and fluid mechanics are considered and tools described for the simulation of combustion processes. This edition is completely restructured. Mathematical Formulae and derivations as well as the space-consuming reaction mechanisms have been replaced from the text to appendix. A new chapter discusses the impact of combustion processes on the atmosphere, the chapter on auto-ignition is extended to combustion in Otto- and Diesel-engines, and the chapters on heterogeneous combustion and on soot formation are heavily revised.
Download or read book On the Collision Mechanism of Bimolecular Reactions Part I Theory and Experimental Method for the Determination of the Velocity Spectrum of Products from Simple H Transfer Reactions of the Type X H2 to XH H written by A. Henglein and published by . This book was released on 1968 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: A simple apparatus is described which allows one to measure the velocity spectrum of the XH(+) or XD(+) ions, respectively, resulting from ion-molecule reactions of the type X(+) + H2(D2) forming XH(+) + H(XD(+) + D). The secondary ions are not accelerated after their formation. The incident X(+)-ions have kinetic energies between 20 and 200 cV. Furthermore, the velocity spectra are calculated which have to be expected for different collision models. (1) Complex model: All the atoms in the reactants participate in the collision. Every kind of collision between those limiting cases is conceivable, in which the relative kinetic energy of the reactants and the heat of reaction appear as internal energy of the product ion or as kinetic energy of both products (completely inelastic and elastic collision with atomic rearrangement, respectively). (2) Stripping model: The incident X(+)-particle hits only one atom of the hydrogen molecule in a completely inelastic collision without transfer of momentum to the second hydrogen atom. It is also shown that the cross section of the reaction becomes zero above a certain energy of the incident ion. This critical energy depends on the collision mechanism. It can be measured with the apparatus described. In addition an isotope effect of the order of 2 with respect to the critical energy is expected from the transfer of an H or D atom, respectively.
Download or read book On the Collision Mechanism of Bimolecular Reactions Part II The Stripping Mechanism of the Reactions Ar H2 D2 to ArH H ArD D at Energies 20 EV written by K. Lacmann and published by . This book was released on 1968 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: The bands of ArH(+) and ArD(+) ions have been observed in the velocity spectra of the ions resulting from the interaction (chemical reaction and scattering) of Ar(+) ions with H2 and D2, respectively. The bands are practically located as it is expected from the stripping model. It is concluded that the Ar(+) ion does not collide with the whole hydrogen molecule in a completely inelastic manner as it is the case at low kinetic energies, where the polarization theory of ion-molecule reactions is applicable. The Ar(+) ion interacts only with the captured hydrogen atom without transfer of momentum to the second atom. The critical energies of the incident Ar(+) ions, above which the cross sections of the two reactions are zero, differ by a factor of about 2 and agree with the energies calculated from the stripping model. In addition, some minor deviations from the stripping model are mentioned. (Author).
Download or read book Bimolecular Collisions written by M. N. R. Ashfold and published by . This book was released on 1989 with total page 444 pages. Available in PDF, EPUB and Kindle. Book excerpt: Designed to provide an authoritative and timely review of advances in the field of gas-phase photochemistry and kinetics, this volume contains a collection of papers on biomolecular collisions. Contributors discuss collision processes, reactive processes and association reactions.
Download or read book Optical Spectroscopic and Microscopic Techniques written by Harekrushna Sahoo and published by Springer Nature. This book was released on 2022-02-25 with total page 260 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book illustrates the significance of various optical spectroscopy and microscopy techniques, including absorption spectroscopy, fluorescence spectroscopy, infrared spectroscopy, and Raman spectroscopy for deciphering the nature of biological molecules. The content of this book chiefly focuses on (1) the principle, theory, and instrumentation used in different optical spectroscopy techniques, and (2) the application of these techniques in exploring the nature of different biomolecules (e.g., proteins, nucleic acids, enzymes, and carbohydrates). It emphasizes the structural, conformational and dynamic, and kinetic including the changes in biomolecules under a range of conditions. In closing, the book summarizes recent advances in the field of optical spectroscopic and microscopic techniques.
Download or read book State to state Reaction Dynamics of H D2 and the Alignment and Orientation of Hydrogen Molecules written by Nathaniel Chung-Ming Bartlett and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This thesis details part of the ongoing experimental effort on the investigation of the dynamics of the simplest neutral bimolecular reaction system: H + D2 hydrogen exchange. A combination of molecular beam and laser-based spectroscopic techniques have been used to produce H + D2 collisions under single collision conditions, and the three-dimensional velocity distribution of state-selected HD(v', j') reaction products is captured by ion imaging. HBr and D2 are pre-mixed and co-expanded into high vacuum through a pulsed nozzle. The co-expansion produces rotationally cooled reagents with very little relative translational energy between them. The molecular beam is collimated by a skimmer before being intersected with a narrow-linewidth tunable ultraviolet laser pulse which cleaves the HBr bond, producing nearly monoenergetic H atoms which can then react with D2 molecules. Nascent HD(v', j') is state-selectively ionized via resonance-enhanced multiphoton ionization (REMPI) using radiation from another narrow-linewidth tunable ultraviolet laser pulse. This process takes place within the extraction region of a linear time-of-flight mass spectrometer fitted with an imaging detector. This configuration allows the three-dimensional velocity of individual HD(v', j') products to be recorded. Velocity distributions are analyzed and converted into center-of-mass frame scattering angle distributions or differential cross sections (DCS) using photoloc. Using these methods state-to-state differential cross sections have been measured for H + D2(v'=0, j'=0,1,2) --> HD(v'=2, j'=0,3,6,9) + D for collision energies of Ec = 1.25, 1.61, and 1.97 eV. The DCSs are compared to those calculated by Foudhil Bouakline and Stuart Althorpe after being "blurred" according to our experimental conditions. The measured DCSs are in most cases in good agreement with the calculated ones, and show the expected behavior for this reaction system which takes place via a direct recoil mechanism through a collinear transition state geometry. For a given collision energy, as the HD rotational state increases the DCSs shift from being strongly peaked in the backward scattering region to being peaked toward more sideward angles. For a given HD rotational state, as the collision energy increases the DCSs narrow and become peaked at slightly larger angles. The HD(v'=2, j'=0) state produced from reactive collisions at Ec = 1.25 eV displays unique scattering behavior in that its DCS is bimodal. This suggests that there are two competing mechanisms available for this product at this collision energy. The first is the same direct recoil mechanism responsible for product formation of all other rotational state/collision energy combinations investigated. The second is an indirect mechanism opened by a barrier resonance in which the transition state is able to rotate a fraction of a cycle before breaking apart into products. The dynamics observed here are overall similar to that found in related H + D2(v'=0, j'=0,1,2) --> HD(v'=1,3, j') reactive scattering studies performed by our group. Additionally, in a series of adjacent experiments, stimulated Raman pumping (SRP) with polarized light was used to prepare highly aligned and oriented samples of vibrationally-rotationally excited hydrogen molecules in a molecular beam expansion under collision-free conditions. Of particular significance, the (1,0) S(0) SRP line was used to prepare samples of H2(v=1, j=2, M=0) and H2(v=1, j=2, M=2) using linear or circularly polarized light, respectively. After excitation the degree of alignment was monitored using resonance-enhanced multiphoton ionization also with polarized light. This rotational level is not subject to hyperfine depolarization and we find that the samples produced retain their initial degree of alignment or orientation for up to 8 [Mu]s which makes them quite suitable for serving as aligned targets in H + H2 scattering experiments. The same SRP scheme was also used to produce aligned samples of HD(v=1, j=2, M=0) and D2(v=1, j=2, M=0) as well, both of which undergo hyperfine depolarization, through the coupling of the molecules' rotational angular momentum to the nuclear spin angular momenta. The result is that the degree of alignment becomes an oscillatory function of time, which again can be observed using REMPI. We compare the measured time-dependent alignment with a theoretical calculation for HD(v=0, j=2, M=0) and D2(v=0, j=2, M=0) and find the agreement to be within our experimental error. Thus we conclude that the hyperfine constants do not strongly vary with the vibrational state.
Download or read book Chemistry written by Thomas R. Gilbert and published by . This book was released on 2020 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "A research-based text and assessment package that helps students visualize chemistry as they solve problems. The exciting NEW Sixth Edition expands on the visualization pedagogy from coauthor Stacey Lowery Bretz and makes it even easier to implement in the classroom. Based on her chemistry education research on how students construct and interpret multiple representations, art in the book and media has been revised to be more pedagogically effective and to address student misconceptions. NEW projected visualization questions help instructors assess students' conceptual understanding in lecture or during exams. A NEW Interactive Instructor's Guide provides innovative ways to incorporate research-based active learning pedagogy into the classroom"--
Download or read book Metal Interactions with Boron Clusters written by Russell N. Grimes and published by Springer Science & Business Media. This book was released on 2013-11-11 with total page 335 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular clusters, in the broad sense that the term is commonly understood, today comprise an enormous class of species extending into virtually every important area of chemistry: "naked" metal clusters, transition metal carbonyl clusters, hydrocarbon cages such as cubane (C H ) and dodecahedrane (C H ), 8 8 20 20 organometallic cluster complexes, enzymes containing Fe S or MoFe S 4 4 3 4 cores, high polymers based on carborane units, and, of course, the many kinds of polyhedral borane species. So large is the area spanned by these diverse classes that any attempt to deal with them comprehensively in one volume would, to say the least, be ambitious-and also premature. We are presently at a stage where intriguing relationships between the various cluster families are becoming apparent (particularly in terms of bonding descriptions), and despite large dif ferences in their chemistry an underlying unity is gradually developing in the field. For example, structural changes occurring in Fe S cores as electrons are 4 4 pumped in and out, in some measure resemble those observed in boranes and carboranes. The cleavage of alkynes via incorporation into carborane cages and subsequent cage rearrangement, a sequence familiar to boron chemists, is a thermodynamically favored process which may be related to the behavior of unsaturated hydrocarbons on metal surfaces; analogies of this sort have drawn attention from theorists and experimentalists.
Download or read book Homogeneous Transition metal Catalysis written by Christopher Masters and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 284 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soluble catalysts are used extensively in many branches of chemistry and are indeed a vital constituent of many natural processes. They find wide application throughout the chemical industry where they assist in the production of several million tonnes of chemicals each year. Since homogeneous systems, especially those incorporating transition metals, often function effectively under milder conditions than their heterogeneous counterparts, they are becoming increasingly important at a time when the chemical industry in particular, and society in general, is seeking ways of conserving energy and of making the best possible use of available resources. My principal objective in- writing this book is to engender sufficient enthusiasm for, and knowledge of, the subject in the reader that he or she will be encouraged to begin, or continue, to make their own contribution to advancing our knowledge of homogeneous catalysis. After attempting to acquaint the reader with some of the ground rules I have tried to describe the present scope, and the future potential, of this fascinating field of chemistry by drawing both on academic and on industrial data sources. This approach stems from a personal conviction that future progress could be considerably hastened by a more meaningful dialogue between chemists working both in industrial and in academic research institutions. Wherever possible, examples of the commercial application of homogeneous catalyst systems have been included and no attempt has been made in any way to disguise the many unresolved questions and exciting challenges which still pervade this rapidly developing area.
Download or read book Polymers Physical Properties written by and published by Academic Press. This book was released on 1980-04-16 with total page 557 pages. Available in PDF, EPUB and Kindle. Book excerpt: Polymers Physical Properties
Download or read book Comprehensive Organometallic Chemistry II written by Richard J. Puddephatt and published by Elsevier. This book was released on 1995 with total page 670 pages. Available in PDF, EPUB and Kindle. Book excerpt:
