Download or read book Electron Photodetachment from Gas phase Molecular Anions written by Bruce Kenneth Janousek and published by . This book was released on 1979 with total page 462 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigations of Gas Phase Molecular Anions and Radicals Using Electron Photodetachment Spectroscopy written by Donna Marlene Wetzel and published by . This book was released on 1988 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Kinetics of Gas Phase Ion molecule Reactions written by James Alfred Dodd and published by . This book was released on 1985 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photodetachment of Gas Phase Anions written by Paul Stephen Drzaic and published by . This book was released on 1983 with total page 732 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photodetachment and Photodissociation of Negative Molecular Ions in the Gas Phase written by Jeffery Howard Richardson and published by . This book was released on 1974 with total page 366 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dynamics of Gas phase Transient Species Studied by Dissociative Photodetachment of Molecular Anions written by Zhou Lu and published by . This book was released on 2007 with total page 177 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gas Phase Ion Chemistry written by Michael T. Bowers and published by Academic Press. This book was released on 2013-10-22 with total page 363 pages. Available in PDF, EPUB and Kindle. Book excerpt: Gas Phase Ion Chemistry, Volume 2 covers the advances in gas phase ion chemistry. The book discusses the stabilities of positive ions from equilibrium gas-phase basicity measurements; the experimental methods used to determine molecular electron affinities, specifically photoelectron spectroscopy, photodetachment spectroscopy, charge transfer, and collisional ionization; and the gas-phase acidity scale. The text also describes the basis of the technique of chemical ionization mass spectrometry; the energetics and mechanisms of unimolecular reactions of positive ions; and the photodissociation of gas-phase ions. The applications of molecular beam techniques to the study of ion-molecule collisions; as well as the variational treatment of charge transfer reactions are also encompassed. Chemists and biochemists will find the book invaluable.
Download or read book Gaseous Molecular Ions written by Eugen Illenberger and published by Springer Science & Business Media. This book was released on 2013-03-09 with total page 357 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the matter in our solar system, and, probably, within the whole universe, exists in the form of ionized particles. On the other hand, in our natural environ ment, gaseous matter generally consists of neutral atoms and molecules. Only under certain conditions, such as within the path oflightning or in several technical devices (e. g. gas discharges, rocket engines, etc. ) will some of the atoms and molecules be ionized. It is also believed that the chemistry of the earth's troposphere predomi nantly proceeds via reactions between neutral particles. (The complex system of atmospheric chemistry will be treated in one of the forthcoming volumes to this series. ) Why, then, are ions considered so important that hundreds oflaboratories all over the world (including some of the most prestigious) are involved in research pro grams on ions, covering many different facets, from biochemistry to physics? One may obtain as many different answers as there are research groups busy in this field. There is, however, one simple, common feature which makes it attractive to work with ions: since they carry one or more net elementary charges, they can easily be gui ded, focused or separated by appropriate electric and magnetic fields, and, last but not least, they can easily be detected. Apart from these advantages, which are welcome and appreciated by the researcher, the study of molecular ions can provide insight into very fundamental aspects of the general behavior of molecules.
Download or read book Electron Binding Energy and Electronic Charge Distribution in Negative Molecular Ions Determined by Photodetachment Spectroscopy written by Kenneth Joseph Reed and published by . This book was released on 1975 with total page 586 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photoionization And Photodetachment In 2 Parts written by Cheuk-yiu Ng and published by World Scientific. This book was released on 2000-06-30 with total page 684 pages. Available in PDF, EPUB and Kindle. Book excerpt: Owing to the advances of vacuum ultraviolet and ultrafast lasers and third generation synchrotron sources, the research on photoionization, photoelectrons, and photodetachment has gained much vitality in recent years. These new light sources, together with ingenious experimental techniques, such as the coincidence imaging, molecular beam, pulsed field ionization photoelectron, mass-analyzed threshold ion, and pulsed field ion pair schemes, have allowed spectroscopic, dynamic, and energetic studies of gaseous species to a new level of detail and accuracy. Profitable applications of these methods to liquids are emerging.This invaluable two-volume review consists of twenty-two chapters, focusing on recent developments in photoionization and photodetachment studies of atoms; molecules, transient species, clusters, and liquids.
Download or read book Gas Phase Studies of Polyatomic Negative Ion Spectroscopy by Electron Photodetachment written by Robert Lloyd Jackson and published by . This book was released on 1980 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Photoelectron Spectroscopy of Gas Phase Anions written by Sean Michael Casey and published by . This book was released on 1993 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photodetachment Studies of the Orbital Structure and Electronic Spectroscopy of Delocalized Negative Ions in the Gas Phase written by Albert H. Zimmerman and published by . This book was released on 1977 with total page 502 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Gaseous Molecular Ions written by Eugen Illenberger and published by Springer Science & Business Media. This book was released on 1992-05-26 with total page 944 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most of the matter in our solar system, and, probably, within the whole universe, exists in the form of ionized particles. On the other hand, in our natural environ ment, gaseous matter generally consists of neutral atoms and molecules. Only under certain conditions, such as within the path oflightning or in several technical devices (e. g. gas discharges, rocket engines, etc. ) will some of the atoms and molecules be ionized. It is also believed that the chemistry of the earth's troposphere predomi nantly proceeds via reactions between neutral particles. (The complex system of atmospheric chemistry will be treated in one of the forthcoming volumes to this series. ) Why, then, are ions considered so important that hundreds oflaboratories all over the world (including some of the most prestigious) are involved in research pro grams on ions, covering many different facets, from biochemistry to physics? One may obtain as many different answers as there are research groups busy in this field. There is, however, one simple, common feature which makes it attractive to work with ions: since they carry one or more net elementary charges, they can easily be gui ded, focused or separated by appropriate electric and magnetic fields, and, last but not least, they can easily be detected. Apart from these advantages, which are welcome and appreciated by the researcher, the study of molecular ions can provide insight into very fundamental aspects of the general behavior of molecules.
Download or read book Nearly Symmetrical Hydrogen Bonds in the Gas Phase written by Geo Geov Gatev and published by . This book was released on 1997 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time resolved Radiation Chemistry written by Sarah Bailey King and published by . This book was released on 2015 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt: Time-resolved photoelectron imaging is used to investigate the dynamics of electron attachment and electron interaction with the molecules uracil (U), thymine (T), adenine (A) and imidazole (Im). In this technique, the molecule of interest is clustered with an iodide atom, and a tunable UV photon induces ultrafast electron transfer from iodide to the molecule, forming a transient negative ion with femtosecond time resolution. After a known time delay, a second photon detaches the transient negative ion and the resulting photoelectrons are detected using velocity map imaging. This experimental method allows for insight into how biologically relevant molecules in the gas phase interact with, and accommodate, an excess electron, an important question in radiation biology. Uracil and thymine interact similarly with excess electrons. We observe two different electron attachment motifs, dependent on the pump pulse excitation energy that induces charge transfer from the iodide atom. The vertical detachment energy (VDE) of the iodide-uracil cluster is 4.11 " 0.05 eV and 4.05 " 0.05 eV for the iodide-thymine cluster. Excitation of the clusters with photon energies of approximately 500-700 meV above the I-U and I-T VDEs results in electrons with approximately 500-700 meV of kinetic energy that scatter directly into the valence-bound orbitals of uracil and thymine, forming the valence bound anion. Using lower excitation energies, between 120 meV below the VDE and 110 meV above the I-U and I-T VDEs, the I-T anion ground state is photoexcited to an anion state where the excess electron is bound in a dipole-bound (DB) anion state by the dipole moment of the cluster. Due to a changing photodetachment cross-section of the uracil and thymine DB anion from geometry relaxation at early times, the DB photoelectron signal has a rise-time longer than the cross-correlation of the pump and probe pulses. Subsequently, a small population of the uracil and thymine DB anions transition to the valence-bound (VB) anions, in agreement with theoretical predictions. However, no participation of the uracil or thymine DB anion is observed in the formation of the respective VB anion at excitation energies 500-700 meV above the I-U/T VDEs, contrary to experiments that invoked participation of the dipole-bound anions to explain features in the dissociative electron attachment spectra. The uracil and thymine DB and VB anions ultimately decay through a variety of mechanisms. In the lower excitation energy region, both the DB and VB anions of uracil and thymine decay bi-exponentially at all of the excitation energies studied. The decay lifetimes range between 2 to 25 ps for the short decay lifetime and 30-2000 ps for the long decay lifetime, depending on excitation energy and anion state. In the higher excitation energy region, the thymine VB anion signal decays completely by 10 ps, unlike uracil that has a bi-exponential long-time lifetime that persists until at least 100 ps. The bi-exponential decays for the DB and VB anions of uracil and thymine are attributed to various mechanisms depending on the molecule and excitation energy including: different rates of autodetachment prior and subsequent to iodine loss, and non-statistical autodetachment versus statistical autodetachment. Experiments investigating the electron attachment dynamics to adenine show evidence of multiple tautomers of adenine participating in the dynamics. Excitation from the ground state I-A anion cluster to the iodine-adenine DB anion, is induced with excitation energies near the 3.96 " 0.05 eV VDE of the I-A9 canonical tautomer. The DB anion of adenine is initially formed with a ~250 fs rise-time due to a changing photodetachment cross-section correlated with relaxation of the cluster geometry from the Franck-Condon region, as is observed in uracil and thymine. The DB anion undergoes a complete ultrafast transition to the VB anion at some excitation energies, and a partial transition at other excitation energies. However, electronic structure calculations do not predict a stable valence bound anion of the A9 canonical tautomer of adenine, and the relative intensities of the dipole-bound and valence-bound anions and the dipole-bound anion decay lifetimes display non-monotonic trends. These dynamics are consistent with two tautomers present in the ion beam clustered to iodide, the A9 canonical tautomer and the A3 non-canonical tautomer. The DB to VB transition is due to the A3 tautomer. The A3 tautomer is calculated to support a VB anion with an exothermic transition from the DB to VB state. The A9 canonical tautomer however only supports an excess electron in a DB orbital and the DB anion is formed in a narrower excitation energy range than the A3 tautomer, causing the non-monotonic trends in the dipole-bound and valence-bound anion intensity ratios and dipole-bound anion decay lifetimes. Imidazole, like the A9 tautomer of adenine, only supports an excess electron in a DB orbital. The VDE of the iodide-imidazole binary cluster is 3.90 " 0.05 eV. With excitation energies just below 3.90 eV, the ground state I-Im cluster is excited to the I Im-(DB) anionic excited state with an ultrafast rise-time due to geometry changes in the [I Im]- cluster. The DB state decays multi-exponentially with decay dynamics that change rapidly with small changes in the excitation energy. These dynamics suggest that the degree of vibrational excitation in the dipole-bound cluster considerably effects the decay dynamics of the transient [I Im]- ion. Overall, the systems studied provide a wide picture of the various ways that biologically relevant molecules can interact with, and accommodate, excess charge in dipole- and valence-bound anion states, and the various ways that iodide(iodine) can influence the observed dynamics, through the rise time of the dipole-bound state and the decay of both dipole- and valence-bound anions. A detailed understanding of the electron kinetic energy dependent mechanisms of electron attachment in nucleobases, and any subsequent dipole-bound anion to valence-bound anion transition, is crucial for understanding the various mechanisms of low-energy electron damage to DNA.
Download or read book Physical Chemistry of Cold Gas Phase Functional Molecules and Clusters written by Takayuki Ebata and published by Springer. This book was released on 2019-08-02 with total page 395 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes advanced research on the structures and photochemical properties of polyatomic molecules and molecular clusters having various functionalities under cold gas-phase conditions. Target molecules are crown ethers, polypeptides, large size protonated clusters, metal clusters, and other complex polyatomic molecules of special interest. A variety of advanced frequency and time-domain laser spectroscopic methods are applied. The book begins with the principle of an experimental setup for cold gas-phase molecules and various laser spectroscopic methods, followed by chapters on investigation of specific molecular systems. Through a molecular-level approach and analysis by quantum chemical calculation, it is possible to learn how atomic and molecular-level interactions (van der Waals, hydrogen-bonding, and others) control the specific properties of molecules and clusters. Those properties include molecular recognition, induced fitting, chirality, proton and hydrogen transfer, isomerization, and catalytic reaction. The information will be applicable to the design of new types of functional molecules and nanoparticles in the broad area that includes applied chemistry, drug delivery systems, and catalysts.
