Download or read book Vibrational Dynamics of the Hydrogen Bond written by Simon A. Barton and published by . This book was released on 1979 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: A general treatment of non-harmonic vibrational dynamics in an isolated hydrogen bond is presented, based on an adiabatic mode separation of hydrogenic motions from those of the heavier particles. The validity of the Stepanov (adiabatic) approximation is examined by including correct non-adiabatic couplings and solving the resultant coupled eigenvalue problem for a model system (HF 2 -) in which the couplings are expected to have a maximum intrinsic strength. Convergence is demonstrated by including up to three coupled protonic states. Comparison with exact results thus obtained shows that the adiabatic approximation gives transition frequencies within 1%, and infrared relative intensities to about 10% - in cases where the coupled protonic levels are not degenerate. Cases of isolated strong coupling, arising from accidental or systematic degeneracies of proton levels, can be accommodated in the theory in a direct way, but do not arise for HF 2 -. Calculations on the HF 2 - system are based entirely on the ab initio potential energy surface of Alml^f (Ref. 24), but employ a model form with correct dissociation properties. The close agreement of computed and observed transition frequencies, and IR relative intensities, leads to a convinc ing assignment (in the adiabatic mode description) for nearly all transitions in the bifluoride spectrum (e.g. in KHF 2 (s)), on the basis of an isolated ion model.
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 Hydrogen Bonding and Transfer in the Excited State written by Ke-Li Han and published by John Wiley & Sons. This book was released on 2011-03-16 with total page 1229 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book gives an extensive description of the state-of-the-art in research on excited-state hydrogen bonding and hydrogen transfer in recent years. Initial chapters present both the experimental and theoretical investigations on the excited-state hydrogen bonding structures and dynamics of many organic and biological chromophores. Following this, several chapters describe the influences of the excited-state hydrogen bonding on various photophysical processes and photochemical reactions, for example: hydrogen bonding effects on fluorescence emission behaviors and photoisomerization; the role of hydrogen bonding in photosynthetic water splitting; photoinduced electron transfer and solvation dynamics in room temperature ionic liquids; and hydrogen bonding barrier crossing dynamics at bio-mimicking surfaces. Finally, the book examines experimental and theoretical studies on the nature and control of excited-state hydrogen transfer in various systems. Hydrogen Bonding and Transfer in the Excited State is an essential overview of this increasingly important field of study, surveying the entire field over 2 volumes, 40 chapters and 1200 pages. It will find a place on the bookshelves of researchers in photochemistry, photobiology, photophysics, physical chemistry and chemical physics.
Download or read book Visualization of Hydrogen Bond Dynamics written by Takashi Kumagai and published by Springer Science & Business Media. This book was released on 2012-09-02 with total page 139 pages. Available in PDF, EPUB and Kindle. Book excerpt: The hydrogen bond represents an important interaction between molecules, and the dynamics of hydrogen bonds in water create an ever-present question associated with the process of chemical and biological reactions. In spite of numerous studies, the process remains poorly understood at the microscopic level because hydrogen-bond dynamics, such as bond rearrangements and hydrogen/proton transfer reactions, are extremely difficult to probe. Those studies have been carried out by means of spectroscopic methods where the signal stems from the ensemble of a system and the hydrogen-bond dynamics were inferred indirectly. This book addresses the direct imaging of hydrogen-bond dynamics within water-based model systems assembled on a metal surface, using a scanning tunneling microscope (STM). The dynamics of individual hydrogen bonds in water clusters, hydroxyl clusters, and water-hydroxyl complexes are investigated in conjunction with density functional theory. In these model systems, quantum dynamics of hydrogen bonds, such as tunneling and zero-point nuclear motion, are observed in real space. Most notably, hydrogen atom relay reactions, which are frequently invoked across many fields of chemistry, are visualized and controlled by STM. This work presents a means of studying hydrogen-bond dynamics at the single-molecule level, providing an important contribution to wide fields beyond surface chemistry.
Download or read book Analysis and Control of Ultrafast Photoinduced Reactions written by Oliver Kühn and published by Springer Science & Business Media. This book was released on 2007-07-05 with total page 854 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book summarizes several years of research carried out by a collaboration of many groups on ultrafast photochemical reactions. It emphasizes the analysis and characterization of the nuclear dynamics within molecular systems in various environments induced by optical excitations and the study of the resulting molecular dynamics by further interaction with an optical field.
Download or read book Hydrogen Bonding and Transfer in the Excited State Vibrational Dynamics of the Hydrogen Bonds in Nucleic Acid Base Pairs written by and published by . This book was released on 2011 with total page 907 pages. Available in PDF, EPUB and Kindle. Book excerpt: "This book gives an extensive description of the state-of-the-art in research on excited-state hydrogen bonding and hydrogen transfer in recent years. Initial chapters present both the experimental and theoretical investigations on the excited-state hydrogen bonding structures and dynamics of many organic and biological chromophores. Following this, several chapters describe the influences of the excited-state hydrogen bonding on various photophysical processes and photochemical reactions, for example: hydrogen bonding effects on fluorescence emission behaviors and photoisomerization; the role of hydrogen bonding in photosynthetic water splitting; photoinduced electron transfer and solvation dynamics in room temperature ionic liquids; and hydrogen bonding barrier crossing dynamics at bio-mimicking surfaces. Finally, the book examines experimental and theoretical studies on the nature and control of excited-state hydrogen transfer in various systems. Hydrogen Bonding and Transfer in the Excited State is an essential overview of this increasingly important field of study, surveying the entire field over 2 volumes, 40 chapters and 1200 pages. It will find a place on the bookshelves of researchers in photochemistry, photobiology, photophysics, physical chemistry and chemical physics."--Publisher's description.
Download or read book Spectroscopy and Computation of Hydrogen Bonded Systems written by Marek J. Wójcik and published by John Wiley & Sons. This book was released on 2022-12-13 with total page 548 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spectroscopy and Computation of Hydrogen-Bonded Systems Comprehensive spectroscopic view of the state-of the-art in theoretical and experimental hydrogen bonding research Spectroscopy and Computation of Hydrogen-Bonded Systems includes diverse research efforts spanning the frontiers of hydrogen bonding as revealed through state-of-the-art spectroscopic and computational methods, covering a broad range of experimental and theoretical methodologies used to investigate and understand hydrogen bonding. The work explores the key quantitative relationships between fundamental vibrational frequencies and hydrogen-bond length/strength and provides an extensive reference for the advancement of scientific knowledge on hydrogen-bonded systems. Theoretical models of vibrational landscapes in hydrogen-bonded systems, as well as kindred studies designed to interpret intricate spectral features in gaseous complexes, liquids, crystals, ices, polymers, and nanocomposites, serve to elucidate the provenance of spectroscopic findings. Results of experimental and theoretical studies on multidimensional proton transfer are also presented. Edited by two highly qualified researchers in the field, sample topics covered in Spectroscopy and Computation of Hydrogen-Bonded Systems include: Quantum-mechanical treatments of tunneling-mediated pathways and molecular-dynamics simulations of structure and dynamics in hydrogen-bonded systems Mechanisms of multiple proton-transfer pathways in hydrogen-bonded clusters and modern spectroscopic tools with synergistic quantum-chemical analyses Mechanistic investigations of deuterium kinetic isotope effects, ab initio path integral methods, and molecular-dynamics simulations Key relationships that exist between fundamental vibrational frequencies and hydrogen-bond length/strength Analogous spectroscopic and semi-empirical computational techniques examining larger hydrogen-bonded systems Reflecting the polymorphic nature of hydrogen bonding and bringing together the latest experimental and computational work in the field, Spectroscopy and Computation of Hydrogen-Bonded Systems is an essential resource for chemists and other scientists involved in projects or research that intersects with the topics covered within.
Download or read book Vibrational Dynamics in Water from the Molecule s Perspective written by Joel David Eaves and published by . This book was released on 2005 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: (Cont.) Because electric fields drive vibrational dephasing, the frequency of the OH stretch is particularly sensitive to the microscopic details of the molecular potential. With collaborators, I have examined the accuracy of emerging fluctuating charge models for water and the role that molecular polarizability plays in the vibrational spectroscopy. In liquid water at ambient conditions, roughly 90 % of the hydrogen bonds are intact. I have examined the fates and the fundamental chemical nature of the remaining 10 % of the "broken" hydrogen bonds. We consider two reaction mechanisms that describe how hydrogen bonds change partners. In the first scenario, broken hydrogen bonds exist in stable chemical equilibrium with intact hydrogen bonds. In an alternate scenario, the broken hydrogen bond is not a meta-stable chemical state but instead a species that molecules visit during natural equilibrium fluctuations or when trading hydrogen bonding partners. I show how the methods of condensed phase reaction dynamics can be directly applied to vibrational spectroscopy of reactive systems and how experimental 2D IR spectra can distinguish between the two mechanistic scenarios. Our data support the notion that broken hydrogen bonds are an intrinsically unstable species in water and return to form hydrogen bonds on the time scale of intermolecular motions.
Download or read book Coherent Vibrational Dynamics written by Guglielmo Lanzani and published by CRC Press. This book was released on 2007-11-29 with total page 286 pages. Available in PDF, EPUB and Kindle. Book excerpt: Remarkable developments in the spectroscopy field regarding ultrashort pulse generation have led to the possibility of producing light pulses ranging from 50 to5 fs and frequency tunable from the near infrared to the ultraviolet range. Such pulses enable us to follow the coupling of vibrational motion to the electronic transitions in molecules and
Download or read book Ultrafast Hydrogen Bonding Dynamics and Proton Transfer Processes in the Condensed Phase written by Thomas Elsaesser and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 193 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hydrogen bonds represent type of molecular interaction that determines the structure and function of a large variety of molecular systems. The elementary dynamics of hydrogen bonds and related proton transfer reactions, both occurring in the ultra fast time domain between 10-14 and 10-11s, form a research topic of high current interest. In this book addressing scientists and graduate students in physics, chemistry and biology, the ultra fast dynamics of hydrogen bonds and proton transfer in the condensed phase are reviewed by leading scientists, documenting the state of the art in this exciting field from the viewpoint of theory and experiment. The nonequilibrium behavior of hydrogen-bonded liquids and intramolecular hydrogen bonds as well as photo induced hydrogen and proton transfer are covered in 7 chapters, making reference to the most recent literature.
Download or read book Advances in Molecular Vibrations and Collision Dynamics written by and published by Elsevier. This book was released on 1998-09-25 with total page 473 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume focuses on molecular clusters, bound by van der Waals interactions and hydrogen bonds. Twelve chapters review a wide range of recent theoretical and experimental advances in the areas of cluster vibrations, spectroscopy, and reaction dynamics. The authors are leading experts, who have made significant contributions to these topics. The first chapter describes exciting results and new insights in the solvent effects on the short-time photo fragmentation dynamics of small molecules, obtained by combining heteroclusters with femtosecond laser excitation. The second is on theoretical work on effects of single solvent (argon) atom on the photodissociation dynamics of the solute H2O molecule. The next two chapters cover experimental and theoretical aspects of the energetics and vibrations of small clusters. Chapter 5 describes diffusion quantum Monte Carlo calculations and non additive three-body potential terms in molecular clusters. The next six chapters deal with hydrogen-bonded clusters, reflecting the ubiquity and importance of hydrogen-bonded networks. The final chapter provides the microscopic theory of the dynamics and spectroscopy of doped helium cluster, highly quantum systems whose unusual properties have been studied extensively in the past couple of years.
Download or read book Concepts and Methods of 2D Infrared Spectroscopy written by Peter Hamm and published by Cambridge University Press. This book was released on 2011-02-24 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: 2D infrared (IR) spectroscopy is a cutting-edge technique, with applications in subjects as diverse as the energy sciences, biophysics and physical chemistry. This book introduces the essential concepts of 2D IR spectroscopy step-by-step to build an intuitive and in-depth understanding of the method. This unique book introduces the mathematical formalism in a simple manner, examines the design considerations for implementing the methods in the laboratory, and contains working computer code to simulate 2D IR spectra and exercises to illustrate involved concepts. Readers will learn how to accurately interpret 2D IR spectra, design their own spectrometer and invent their own pulse sequences. It is an excellent starting point for graduate students and researchers new to this exciting field. Computer codes and answers to the exercises can be downloaded from the authors' website, available at www.cambridge.org/9781107000056.
Download or read book Studying Ultrafast Vibrational Dynamics of Intramolecular Hydrogen Bonds Using Broadband Infrared Pump probe Spectroscopy written by Madhumitha Balasubramanain and published by . This book was released on 2018 with total page 101 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Water in Biological and Chemical Processes written by Biman Bagchi and published by Cambridge University Press. This book was released on 2013-11-14 with total page 383 pages. Available in PDF, EPUB and Kindle. Book excerpt: A unified overview of the dynamical properties of water and its unique and diverse role in biological and chemical processes.
Download or read book Hydrogen Bonding New Insights written by Slawomir Grabowski and published by Springer Science & Business Media. This book was released on 2006-10-07 with total page 536 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book uses examples from experimental studies to illustrate theoretical investigations, allowing greater understanding of hydrogen bonding phenomena. The most important topics in recent studies are covered. This volume is an invaluable resource that will be of particular interest to physical and theoretical chemists, spectroscopists, crystallographers and those involved with chemical physics.
Download or read book Ultrafast Infrared Vibrational Spectroscopy written by Michael D. Fayer and published by CRC Press. This book was released on 2013-03-04 with total page 491 pages. Available in PDF, EPUB and Kindle. Book excerpt: The advent of laser-based sources of ultrafast infrared pulses has extended the study of very fast molecular dynamics to the observation of processes manifested through their effects on the vibrations of molecules. In addition, non-linear infrared spectroscopic techniques make it possible to examine intra- and intermolecular interactions and how such interactions evolve on very fast time scales, but also in some instances on very slow time scales. Ultrafast Infrared Vibrational Spectroscopy is an advanced overview of the field of ultrafast infrared vibrational spectroscopy based on the scientific research of the leading figures in the field. The book discusses experimental and theoretical topics reflecting the latest accomplishments and understanding of ultrafast infrared vibrational spectroscopy. Each chapter provides background, details of methods, and explication of a topic of current research interest. Experimental and theoretical studies cover topics as diverse as the dynamics of water and the dynamics and structure of biological molecules. Methods covered include vibrational echo chemical exchange spectroscopy, IR-Raman spectroscopy, time resolved sum frequency generation, and 2D IR spectroscopy. Edited by a recognized leader in the field and with contributions from top researchers, including experimentalists and theoreticians, this book presents the latest research methods and results. It will serve as an excellent resource for those new to the field, experts in the field, and individuals who want to gain an understanding of particular methods and research topics.
Download or read book Vibrational Dynamics of Aqueous Hydroxide Solutions Studied Using Ultrafast Infrared Spectroscopy written by Aritra Mandal and published by . This book was released on 2015 with total page 217 pages. Available in PDF, EPUB and Kindle. Book excerpt: Liquid water possesses an extended network of hydrogen bonds that is responsible for many of its interesting properties. Mobility of hydroxide ions in aqueous solutions is much higher compared to the ions of similar size and charge density. A proton can efficiently move from a neighboring water molecule to the hydroxide ion due to the presence of hydrogen bonds, resulting fast structural diffusion of the ion. On the other hand, this hydrogen bonding network of water undergoes fluctuations on femtoseconds to picoseconds timescale, influencing the intertwined hydroxide transport process. Studying the influence of water's hydrogen bonding network on the proton transport process in aqueous hydroxide solutions is experimentally challenging, largely due to the lack of a suitable technique that is sensitive to the changes in the system on few tens of femtoseconds timescale. Vibrations in aqueous hydroxide solutions are sensitive to the strength of hydrogen bonding and hence vibrational frequencies, intensities and line shapes are closely associated with the structure and dynamics of the hydroxide ions. In this thesis, we have employed ultrafast infrared spectroscopy in conjunction with theoretical modeling to understand the nature of the vibrations and their dynamics in aqueous hydroxide solutions. The infrared spectra of aqueous solutions of NaOH and other strong bases exhibit a broad continuum absorption for frequencies between 800 and 3500 cm-1, which is attributed to the strong interactions of the hydroxide ion with its solvating water molecules. This continuum absorption has limited distinguishable features whose molecular origin holds the key in explaining the vibrational dynamics. We have performed ultrafast transient absorption and 2DIR experiments on aqueous NaOH solutions, by exciting the O-H stretch vibrations and probing the response from 1350-3800 cm-1, using a newly developed sub-70 fs broadband infrared source. By probing the entire mid-infrared continuum absorption of aqueous hydroxide solutions with ultrafast pulses, the broadband infrared source allows us to monitor time-dependent changes in this broad spectral window. These experiments, in conjunction with harmonic vibrational analysis of OH-(H2O)17 clusters, reveal that O-H stretch vibrations of aqueous hydroxides arise from coupled vibrations of multiple water molecules solvating the ion. These delocalized vibrations cannot be distinguished based on the local structure of the hydroxide ion. However, they can be classified according to the symmetry defined by the relative phase of vibrations of the O-H bonds hydrogen bonded to the ion. In general, we find the asymmetric O-H stretch vibrations to be more intense and shifted to lower frequencies compared to the symmetric ones. Analysis of transient absorption and waiting time dependent 2DIR spectroscopy shows that the vibrations in aqueous hydroxide solutions relax on 100-300 fs timescale. Alongside, the O-H stretch vibrations originating from the bulk-like water molecules as well as the asymmetric O-H stretch vibrations of the water molecules solvating the hydroxide ion lose their frequency memory within 160-180 fs. Such loss in frequency memory on similar timescales is likely to happen through migration of vibrational excitation between two types of O-H stretch vibrations. Spectral features in strongly hydrogen bonded systems like water and aqueous hydroxide solutions are very broad, particularly the induced absorption features in the transient absorption and 2DIR spectra. With the development of broadband mid-infrared pulses, we are able to detect nonlinear response of these systems in the frequency window of 1350-3800 cm-1, observing >1700 cm-1 broad induced absorption features. Qualitatively, strong coupling between intra- and intermolecular vibrations lead to such broadening. In order to explain the experimental results, we have developed a self-consistent phenomenological model that consists of an intramolecular and an intermolecular vibration, with strong nonlinear coupling between them. We find that the experimental results are reproduced when the coupling between the vibrations is strong enough to yield eigenstates with mixed intra- and intermolecular vibrational character. In such scenarios, the identities of individual intra- and intermolecular vibrational modes are lost.
