Download or read book The Photodissociation and Reaction Dynamics of Vibrationally Excited Molecules Technical Progress Report written by and published by . This book was released on 1995 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: The goal of this Department of Energy sponsored research is to discover the properties, behavior, and dissociation dynamics of vibrationally energized molecules, which are crucial participants in many chemical reactions. The authors study vibrationally energized molecules by using an optical excitation scheme to prepare them and a subsequent photon to dissociate them into fragments that they detect with a spectroscopic probe. This technique, vibrationally mediated photodissociation, provides new information on vibrationally energized molecules and even provides a means of controlling the course of a molecular decomposition. During the most recent period of Department of Energy support, the authors have advanced this work in three directions: they have used vibrational overtone excitation to control the decomposition pathways in the tetra-atomic molecule isocyanic acid (HNCO) and unravelled the decomposition pathways in hydroxylamine (NH2OH), they have implemented stimulated Raman excitation as the vibrational state preparation technique in vibrationally mediated photodissociation, and they have tested the limits of transient grating spectroscopy as a means of obtaining electronic spectra of vibrationally excited molecules.
Download or read book The Photodissociation and Reaction Dynamics of Vibrationally Excited Molecules written by and published by . This book was released on 1993 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have used combined vibrational overtone excitation and laser induced fluorescence detection to study dissociation dynamics of hydroxylamine (NH[sub 2]OH), have performed our first laser induced grating experiments on water, and have begun assembling a new apparatus for preparing vibrationally excited molecules with simulated Raman excitation. We study role of vibrational excitation in photodissociation dynamics by using a vibrational state preparation technique, such as vibrational overtone excitation or stimulated Raman excitation, to create molecules with particular nuclear motions and then to excite that molecule to a dissociative electronic state.
Download or read book The Photodissociation and Reaction Dynamics of Vibrationally Excited Molecules Technical Progress Report 1993 1994 written by and published by . This book was released on 1994 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: Combined vibrational overtone excitation and laser induced fluorescence detection was used to study dissociation dynamics of hydroxylamine (NH2OH), laser induced grating experiments on water were analyzed, discovering the important role that electrostriction and thermal relaxation play, and a new apparatus for preparing vibrationally excited molecules with simulated Raman excitation was completed and the first measurements made. Role of vibrational excitation in photodissociation dynamics was studied using a vibrational state preparation technique, such as vibrational overtone excitation or stimulated Raman excitation, to create molecules with particular nuclear motions and then excite that molecule to a dissociative electronic state. Because the vibrational excitation alters the dissociation dynamics in the excited state, both by providing access to different portions of the excited state surface and by altering the motion of the system on the surface, it is usually refered to as vibrationally mediated photodissociation.
Download or read book The Photodissociation and Reaction Dynamics of Vibrationally Excited Molecules Technical Progress Report 1992 1993 written by and published by . This book was released on 1993 with total page 9 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have used combined vibrational overtone excitation and laser induced fluorescence detection to study dissociation dynamics of hydroxylamine (NH2OH), have performed our first laser induced grating experiments on water, and have begun assembling a new apparatus for preparing vibrationally excited molecules with simulated Raman excitation. We study role of vibrational excitation in photodissociation dynamics by using a vibrational state preparation technique, such as vibrational overtone excitation or stimulated Raman excitation, to create molecules with particular nuclear motions and then to excite that molecule to a dissociative electronic state.
Download or read book Spectroscopy Reaction and Photodissociation in Highly Vibrationally Excited Molecules written by and published by . This book was released on 1991 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highly vibrationally excited molecules often control the course of chemical reactions in the atmosphere, combustion, plasmas, and many other environments. The research described in this Progress Report uses laser excitation and interrogation techniques to study and control the dynamics of highly vibrationally excited molecules. In particular, they show that it is possible to unravel the details and influence the course of photodissociation and bimolecular reaction. The experiments use laser excitation of overtone vibrations to prepare highly vibrationally excited molecules, frequently with single quantum state resolution, and laser spectroscopy to monitor the subsequent behavior of the excited molecule. We have studied the vibrationally mediated photodissociation and the bond- and state-selected bimolecular reaction of highly vibrationally excited molecules. In the first process, one photon creates a highly excited molecule, a second photon from another laser dissociates it, and light from a third laser detects the population of individual product quantum states. This approach allows us to explore otherwise inaccessible regions of the ground and excited state potential energy surface and, by exciting to the proper regions of the surface, to control the breaking of a selected chemical bond. In the second process, the highly vibrationally excited molecule reacts with an atom formed either in a microwave discharge or by photolysis and another laser interrogates the products. We have used this approach to demonstrate mode- and bond-selected bimolecular reactions in which the initial excitation controls the subsequent chemistry. 30 refs., 8 figs.
Download or read book Spectroscopy Reaction and Photodissociation in Highly Vibrationally Excited Molecules Technical Progress Report written by and published by . This book was released on 1991 with total page 25 pages. Available in PDF, EPUB and Kindle. Book excerpt: Highly vibrationally excited molecules often control the course of chemical reactions in the atmosphere, combustion, plasmas, and many other environments. The research described in this Progress Report uses laser excitation and interrogation techniques to study and control the dynamics of highly vibrationally excited molecules. In particular, they show that it is possible to unravel the details and influence the course of photodissociation and bimolecular reaction. The experiments use laser excitation of overtone vibrations to prepare highly vibrationally excited molecules, frequently with single quantum state resolution, and laser spectroscopy to monitor the subsequent behavior of the excited molecule. We have studied the vibrationally mediated photodissociation and the bond- and state-selected bimolecular reaction of highly vibrationally excited molecules. In the first process, one photon creates a highly excited molecule, a second photon from another laser dissociates it, and light from a third laser detects the population of individual product quantum states. This approach allows us to explore otherwise inaccessible regions of the ground and excited state potential energy surface and, by exciting to the proper regions of the surface, to control the breaking of a selected chemical bond. In the second process, the highly vibrationally excited molecule reacts with an atom formed either in a microwave discharge or by photolysis and another laser interrogates the products. We have used this approach to demonstrate mode- and bond-selected bimolecular reactions in which the initial excitation controls the subsequent chemistry. 30 refs., 8 figs.
Download or read book The Dynamics of Vibrationally Excited Molecules written by C. B. Moore and published by . This book was released on 1985 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work studies the transfer of vibrational energy among molecular degrees of freedom and the chemical reactions of vibrationally excited molecules. By resolving the dependence of energy transfer and reaction processes on quantum numbers the mechanism of and forces involved in these processes are identified. Keywords: Photofragment spectroscopy; Vibrational energy transfer; Matrix isolation; Photodissociation; Vibrational photochemistry.
Download or read book Vibrational Dynamics Of Molecules written by Joel M Bowman and published by World Scientific. This book was released on 2022-06-14 with total page 603 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibrational Dynamics of Molecules represents the definitive concise text on the cutting-edge field of vibrational molecular chemistry. The chapter contributors are a Who's Who of world leaders in the field. The editor, Joel Bowman, is widely considered as one of the founding fathers of theoretical reaction dynamics. The included topics span the field, from fundamental theory such as collocation methods and vibrational CI methods, to interesting applications such as astrochemistry, supramolecular systems and virtual computational spectroscopy. This is a useful reference for theoretical chemists, spectroscopists, physicists, undergraduate and graduate students, lecturers and software developers.
Download or read book Advances in Chemical Reaction Dynamics written by Peter M. Rentzepis and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 608 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains the formal lectures and contributed papers presented at the NATO Advanced Study Institute on. the Advances in Chemical Reaction Dynamics. The meeting convened at the city of Iraklion, Crete, Greece on 25 August 1985 and continued to 7 September 1985. The material presented describes the fundamental and recent advances in experimental and theoretical aspects of, reaction dynamics. A large section is devoted to electronically excited states, ionic species, and free radicals, relevant to chemical sys tems. In addition recent advances in gas phase polymerization, formation of clusters, and energy release processes in energetic materials were presented. Selected papers deal with topics such as the dynamics of electric field effects in low polar solutions, high electric field perturbations and relaxation of dipole equilibria, correlation in picosecond/laser pulse scattering, and applications to fast reaction dynamics. Picosecond transient Raman spectroscopy which has been used for the elucidation of reaction dynamics and structural changes occurring during the course of ultrafast chemical reactions; propagation of turbulent flames and detonations in gaseous· energetic systems are also discussed in some detail. In addition a large portion of the program was devoted to current experimental and theoretical studies of the structure of the transition state as inferred from product state distributions; translational energy release in the photodissociation of aromatic molecules; intramolecu lar and intraionic dynamic processes.
Download or read book Molecular Reaction Dynamics written by Raphael D. Levine and published by Cambridge University Press. This book was released on 2009-06-04 with total page 574 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular reaction dynamics is the study of chemical and physical transformations of matter at the molecular level. The understanding of how chemical reactions occur and how to control them is fundamental to chemists and interdisciplinary areas such as materials and nanoscience, rational drug design, environmental and astrochemistry. This book provides a thorough foundation to this area. The first half is introductory, detailing experimental techniques for initiating and probing reaction dynamics and the essential insights that have been gained. The second part explores key areas including photoselective chemistry, stereochemistry, chemical reactions in real time and chemical reaction dynamics in solutions and interfaces. Typical of the new challenges are molecular machines, enzyme action and molecular control. With problem sets included, this book is suitable for advanced undergraduate and graduate students, as well as being supplementary to chemical kinetics, physical chemistry, biophysics and materials science courses, and as a primer for practising scientists.
Download or read book Part I Reaction Dynamics of Atomic Chlorine with Vibrationally Excited Methane Part II Oriented Photofragments in the Molecular Photodissociation written by Zee Hwan Kim and published by . This book was released on 2002 with total page 454 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time Resolved Energy Transfer and Photodissociation of Vibrationally Excited Molecules written by and published by . This book was released on 2007 with total page 10 pages. Available in PDF, EPUB and Kindle. Book excerpt: These experiments use ultrafast laser spectroscopy to study reaction and photodissociation dynamics in solution, probing both photodissociation and intramolecular energy transfer. They have observed the photodissociation dynamics of methylhypochlorite (CH3OCl) in different solvents by monitoring the disappearance of the Cl atom and have compared the flow of energy in vibrationally excited methyl iodide (CH3l) in solution and in the gas phase. This second experiment is one of the few direct comparisons of intramolecular vibrational energy flow in a solvated molecule with that in the same molecule isolated in a gas. Because of the importance of vibrational relaxation of molecules after photoisomerization, the other goal has been to probe the vibrational energy flow in both cis and trans-stilbene, a prototypical molecule for cis-trans isomerization.
Download or read book Highly Excited Molecules written by Amy S. Mullin and published by . This book was released on 1997 with total page 352 pages. Available in PDF, EPUB and Kindle. Book excerpt: Integrating both theoretical and experimental approaches, this unique book examines transition states and chemical reactivity, and will be a useful tool for anyone studying the chemical dynamics, nature, and behavior of molecules in an excited state. The subject has important applications in atmospheric chemistry, plasmas, high-temperature materials processing, combustion, photosynthesis, detonation, and explosives.
Download or read book Photodissociation Dynamics written by Reinhard Schinke and published by Cambridge University Press. This book was released on 1995-05-11 with total page 446 pages. Available in PDF, EPUB and Kindle. Book excerpt: Photodissociation induced by the absorption of single photons permits the detailed study of molecular dynamics such as the breaking of bonds, internal energy transfer and radiationless transitions. The availability of powerful lasers operating over a wide frequency range has stimulated rapid development of new experimental techniques which make it possible to analyse photodissociation processes in unprecedented detail. This text elucidates the achievements in calculating photodissociation cross-sections and fragment state distributions from first principles, starting from multi-dimensional potential energy surfaces and the Schrödinger equation of nuclear motion. Following an extended introduction in which the various types of observables are outlined, the book summarises the basic theoretical tools, namely the time-independent and the time-dependent quantum mechanical approaches as well as the classical picture of photodissociation. The discussions of absorption spectra, diffuse vibrational structures, the vibrational and rotational state distributions of the photofragments form the core of the book. More specific topics such as the dissociation of vibrationally excited molecules, emission during dissociation, or nonadiabatic effects are also discussed. It will be of interest to graduate students and senior scientists working in molecular physics, spectroscopy, molecular collisions and molecular kinetics.
Download or read book Molecular Photodissociation Dynamics written by M. N. R. Ashfold and published by CRC Press. This book was released on 1987 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: Molecular Photodissociation Dynamics was the first title to be published in this series and provides overviews of selected aspects of the subject. The experimental study of photodissociation has been revolutionized by the ready availability of intense, tunable laser sources, operational over a substantial portion of the electromagnetic spectrum, and with parallel developments in theoretical chemistry has opened the way to detailed theoretical study of the fragmentation dynamics of the excited state. This book will therefore be essential reading for those working in this area.
Download or read book Structure and Dynamics of Electronic Excited States written by Jaan Laane and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 324 pages. Available in PDF, EPUB and Kindle. Book excerpt: New developments in laser technology and theoretical modeling has allowed physicists to control chemical reactions using lasers and to attain an understanding of the underlying photochemical reaction mechanism. The book gives an up-to-date presentation of this research area, covering time-resolved spectroscopy and the dynamical behavior of electronically excited states.
Download or read book Photoisomerization Dynamics of Candidate Molecules for Vibrational Control Experiments written by and published by . This book was released on 2013 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Vibrational excitation prior to reaction can lead to efficient control of chemical reactions in isolated molecules. Extending vibrational control to the solution phase is complicated by frequent collisions between the molecule of interest and the surrounding solvent. We have shown that in the isomerization of trans-stilbene to cis-stilbene, we can preferentially promote vibrationally excited stilbene to the reactive electronic state. We find that excitation of the C-H stretch overtone and C-H stretch-bend combination band have no influence on the isomerization reaction. Our results from the stilbene system teach us about isomerization systems that may be amenable to vibrational control. We have used transient absorption techniques to determine the photoisomerization dynamics of dMe-OMe-NAIP, a biomimetic photoswitch. We find that dMe-OMe-NAIP behaves very differently from other molecules in the NAIP class after excitation and determine that these differences are due to small changes in substitution near the reactive double bond. We have also made the first measurements of the femtosecond and picosecond reaction dynamics of avobenzone, a common sunscreen component. Our measurements show the first direct evidence of a rotational isomer speculated to exist in microsecond-timescale experiments. Our experiments unify the well-studied microsecond and millisecond dynamics of avobenzone with the dynamics that occur immediately after excitation. Avobenzone is a promising candidate for vibrational control because its easily accessible C-H stretching motion may coincide with its enol to keto reaction coordinate.
