Download or read book Probing Reaction Dynamics of Transition metal Complexes in Solution Via Time resolved Soft X ray Spectroscopy written by and published by . This book was released on 2008 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report the first time-resolved soft x-ray measurements of solvated transition-metal complexes. L-edge spectroscopy directly probes dynamic changes in ligand-field splitting of 3d orbitals associated with the spin transition, and mediated by changes in ligand-bonding. We report the first time-resolved soft x-ray spectroscopy of solution-phase molecular dynamics. Changes in ligand-field splitting and spin-state populations in 3d orbitals of the Fe{sup II} complex are directly probed via transient absorption changes of the Fe L2 and L3 edges following photo-induced metal-to-ligand charge transfer. With the emergence of high-flux ultrafast soft x-ray sources, details on interplay between atomic structure, electronic states, and spin contributions will be revealed. Our experimental approach opens the door to femtosecond soft x-ray investigations of liquid phase chemistry that have previously been inaccessible.
Download or read book Probing Reaction Dynamics of Transition Metal Complexes in Solution Via Time Resolved X ray Spectroscopy written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We report measurements of the photo-induced Fe(II) spin crossover reaction dynamics in solution via time-resolved x-ray absorption spectroscopy. EXAFS measurements reveal that the iron?nitrogen bond lengthens by 0.21+-0.03 Angstrom in the high-spin transient excited state relative to the ground state. XANES measurements at the Fe L-edge show directly the influence of the structural change on the ligand-field splitting of the Fe(II) 3d orbitals associated with the spin transition.
Download or read book Ultrafast Phenomena XVI written by Paul Corkum and published by Springer Science & Business Media. This book was released on 2010-03-23 with total page 1031 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ultrafast Phenomena XVI presents the latest advances in ultrafast science, including both ultrafast optical technology and the study of ultrafast phenomena. It covers picosecond, femtosecond and attosecond processes relevant to applications in physics, chemistry, biology, and engineering. Ultrafast technology has a profound impact in a wide range of applications, amongst them biomedical imaging, chemical dynamics, frequency standards, material processing, and ultrahigh speed communications. This book summarizes the results presented at the 16th International Conference on Ultrafast Phenomena and provides an up-to-date view of this important and rapidly advancing field.
Download or read book X Ray Absorption and X Ray Emission Spectroscopy written by Jeroen A. van Bokhoven and published by John Wiley & Sons. This book was released on 2016-03-21 with total page 940 pages. Available in PDF, EPUB and Kindle. Book excerpt: During the last two decades, remarkable and often spectacular progress has been made in the methodological and instrumental aspects of x–ray absorption and emission spectroscopy. This progress includes considerable technological improvements in the design and production of detectors especially with the development and expansion of large-scale synchrotron reactors All this has resulted in improved analytical performance and new applications, as well as in the perspective of a dramatic enhancement in the potential of x–ray based analysis techniques for the near future. This comprehensive two-volume treatise features articles that explain the phenomena and describe examples of X–ray absorption and emission applications in several fields, including chemistry, biochemistry, catalysis, amorphous and liquid systems, synchrotron radiation, and surface phenomena. Contributors explain the underlying theory, how to set up X–ray absorption experiments, and how to analyze the details of the resulting spectra. X-Ray Absorption and X-ray Emission Spectroscopy: Theory and Applications: Combines the theory, instrumentation and applications of x-ray absorption and emission spectroscopies which offer unique diagnostics to study almost any object in the Universe. Is the go-to reference book in the subject for all researchers across multi-disciplines since intense beams from modern sources have revolutionized x-ray science in recent years Is relevant to students, postdocurates and researchers working on x-rays and related synchrotron sources and applications in materials, physics, medicine, environment/geology, and biomedical materials
Download or read book Time resolved X ray Absorption Spectroscopy of Transition Metal Complexes written by Wojciech Gawelda and published by . This book was released on 2006 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Luminescent and Photoactive Transition Metal Complexes as Biomolecular Probes and Cellular Reagents written by Kenneth Kam-Wing Lo and published by Springer. This book was released on 2015-06-30 with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt: The series Structure and Bonding publishes critical reviews on topics of research concerned with chemical structure and bonding. The scope of the series spans the entire Periodic Table and addresses structure and bonding issues associated with all of the elements. It also focuses attention on new and developing areas of modern structural and theoretical chemistry such as nanostructures, molecular electronics, designed molecular solids, surfaces, metal clusters and supramolecular structures. Physical and spectroscopic techniques used to determine, examine and model structures fall within the purview of Structure and Bonding to the extent that the focus is on the scientific results obtained and not on specialist information concerning the techniques themselves. Issues associated with the development of bonding models and generalizations that illuminate the reactivity pathways and rates of chemical processes are also relevant. The individual volumes in the series are thematic. The goal of each volume is to give the reader, whether at a university or in industry, a comprehensive overview of an area where new insights are emerging that are of interest to a larger scientific audience. Thus each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5 to 10 years should be presented using selected examples to illustrate the principles discussed. A description of the physical basis of the experimental techniques that have been used to provide the primary data may also be appropriate, if it has not been covered in detail elsewhere. The coverage need not be exhaustive in data, but should rather be conceptual, concentrating on the new principles being developed that will allow the reader, who is not a specialist in the area covered, to understand the data presented. Discussion of possible future research directions in the area is welcomed. Review articles for the individual volumes are invited by the volume editors. Readership: research scientists at universities or in industry, graduate students Special offer For all customers who have a standing order to the print version of Structure and Bonding, we offer free access to the electronic volumes of the Series published in the current year via SpringerLink.
Download or read book Book of Abstracts written by and published by . This book was released on 2000 with total page 778 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Charge Transfer and Dynamics in Manganese and Iron Coordination Complexes Studied with Resonant Inelastic X ray Scattering written by Drew Alan Meyer and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: X-ray spectroscopy is a powerful tool in the study of electronic structure. I have utilized resonant inelastic x-ray scattering (RIXS) to study electronic charge transfer and electronic dynamics in transition metal complexes. RIXS creates a core-hole by scanning through the x-ray absorption edge while simultaneously measuring the emitted x-ray photons as the system relaxes to a lower energy core-hole state. RIXS is analogous to Resonance Raman spectroscopy but due to the properties of hard x-ray radiation, the tool is an elemental specific probe of electronic transitions. Charge transfer is a vital property of transition metal catalysts and I am able to assign RIXS spectral features to ligand-to-metal and metal-to-ligand charge transfer resonances and clearly characterize the nature of the molecular orbitals that are involved. I have also determined the effectiveness of extracting electronic dynamics from RIXS by carefully analyzing entire 1s3p RIXS data sets. The very short lifetime of the hard x-ray excited core-hole states means the RIXS process is sensitive to ultrafast electronic dynamics. The study of both charge transfer and electronic dynamics has been complimented by theoretical techniques to further the scientific understanding. The combination of RIXS measurements and density functional calculations allows the determination of the strength of the ligand-metal electronic interaction and assignment of the Raman resonances to charge transfer transitions in several manganese and iron cyanide complexes. With x-ray excitation energies resonant with the t2g and eg pre-edge peaks derived predominantly from the Mn 3d orbitals, the observation of Raman resonances in the energy transfer range from 2 to 12 eV which result from the filling of the 1s core-hole from t1u-symmetry occupied orbitals can be assigned as ligand-to-metal charge transfers. Evidence is also presented for the observation of a transition that leaves the state with increased electronic density in a ligand orbital while creating a metal hole, representing a metal-to-ligand charge transfer. The technique is then applied to K3Fe(CN)6, K4Fe(CN)6, and RbMnFe(CN)6. The two iron cyanides show similar results to those obtained with the manganese complex and the peak positions and relative intensities are discussed in relation to the electronic structure of the complexes. The manganese K-shell RIXS for RbMnFe(CN)6 shows significant deviation from the strong field metal-cyanide centers. The demonstration of the power of the technique on well characterized model systems opens the door for RIXS to be applied to more chemically relevant systems which is necessary for RIXS to develop widespread impact. I have also explored the potential for extracting excited state electron dynamics from RIXS spectra. This has involved detailed theoretical analysis of K3Mn(CN)6 and RbMnFe(CN)6 spectra. 'Core-hole clock' resonant soft x-ray studies have been utilized in the past to determine dynamic properties for a number of systems by relying on the lifetime of the excited core-hole. Due to the shortened lifetime of the hard x-ray excited core-holes, the technique is able to probe ultrafast electronic dynamics. The standard Kramer-Heisenberg description of RIXS attributes all dynamical effects to an excitation independent 1s core-hole lifetime and a final-state dependent lifetime broadening. Thorough study of the experimental data demonstrates that the standard implementation of the Kramers-Heisenberg formula cannot fully account for the experimentally observed excited state dynamics. We have proposed an alternative approach to analyzing RIXS spectra based on a density matrix formalism developed by Mukamel. The results demonstrate that while the Kramers-Heisenberg method is able to qualitatively model the spectra, it is unable to account for all aspects of the spectral dynamics within the RIXS spectrum. While the density matrix formalism is able to more accurately describe the spectral features in the RIXS, a more detailed theoretical understanding of the dynamics involved is necessary to robustly extract a dephasing time and better understand the ultrafast electronic response to core-hole creation.
Download or read book Solute solvent Interactions written by Johannes Francois Coetzee and published by . This book was released on 1969 with total page 680 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultrafast Photoinduced Phase Transitions in Complex Materials Probed by Time resolved Resonant Soft X ray Diffraction written by and published by . This book was released on 2014 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt: In processing and data storage mainly ferromagnetic (FM) materials are being used. Approaching physical limits, new concepts have to be found for faster, smaller switches, for higher data densities and more energy efficiency. Some of the discussed new concepts involve the material classes of correlated oxides and materials with antiferromagnetic coupling. Their applicability depends critically on their switching behavior, i.e., how fast and how energy efficient material properties can be manipulated. This thesis presents investigations of ultrafast non-equilibrium phase transitions on such new materials. In transition metal oxides (TMOs) the coupling of different degrees of freedom and resulting low energy excitation spectrum often result in spectacular changes of macroscopic properties (colossal magneto resistance, superconductivity, metal-to-insulator transitions) often accompanied by nanoscale order of spins, charges, orbital occupation and by lattice distortions, which make these material attractive. Magnetite served as a prototype for functional TMOs showing a metal-to-insulator-transition (MIT) at T = 123 K. By probing the charge and orbital order as well as the structure after an optical excitation we found that the electronic order and the structural distortion, characteristics of the insulating phase in thermal equilibrium, are destroyed within the experimental resolution of 300 fs. The MIT itself occurs on a 1.5 ps timescale. It shows that MITs in functional materials are several thousand times faster than switching processes in semiconductors. Recently ferrimagnetic and antiferromagnetic (AFM) materials have become interesting. It was shown in ferrimagnetic GdFeCo, that the transfer of angular momentum between two opposed FM subsystems with different time constants leads to a switching of the magnetization after laser pulse excitation. In addition it was theoretically predicted that demagnetization dynamics in AFM should occur faster than in FM materials as no net angular momentum has to be transferred out of the spin system. We investigated two different AFM materials in order to learn more about their ultrafast dynamics. In Ho, a metallic AFM below T ≈ 130 K, we found that the AFM Ho can not only be faster but also ten times more energy efficiently destroyed as order in FM comparable metals. In EuTe, an AFM semiconductor below T ≈ 10 K, we compared the loss of magnetization and laser-induced structural distortion in one and the same experiment. Our experiment shows that they are effectively disentangled. An exception is an ultrafast release of lattice dynamics, which we assign to the release of magnetostriction. The results presented here were obtained with time-resolved resonant soft x-ray diffraction at the Femtoslicing source of the Helmholtz-Zentrum Berlin and at the free-electron laser in Stanford (LCLS). In addition the development and setup of a new UHV-diffractometer for these experiments will be reported
Download or read book Ultrafast Time resolved X ray Absorption Spectroscopic Studies of Solvated Transition Metal Complexes written by Tae-Woo Lee and published by . This book was released on 2005 with total page 214 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Probing Dynamics of Complex Ordered Phases in Colossal Magnetoresistive Transition metal Oxides Using Coherent Resonant Soft X ray Scattering written by Joshua J. Turner and published by . This book was released on 2008 with total page 414 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transition Metal and Rare Earth Compounds written by Hartmut Yersin and published by Springer. This book was released on 2003-07-01 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: There exists a large literature on the spectroscopic properties of copper(II) com- 9 pounds. This is due to the simplicity of the d electron configuration, the wide variety of stereochemistries that copper(II) compounds can adopt, and the f- xional geometric behavior that they sometimes exhibit [1]. The electronic and geometric properties of a molecule are inexorably linked and this is especially true with six-coordinate copper(II) compounds which are subject to a Jahn-T- ler effect.However,the spectral-structural correlations that are sometimes d- wn must often be viewed with caution as the information contained in a typical solution UV-Vis absorption spectrum of a copper(II) compound is limited. Meaningful spectral-structural correlations can be obtained in a related series of compounds where detailed spectroscopic data is available. In the fol- 4– lowing sections two such series are examined; the six-coordinate CuF and 6 2+ Cu(H O) ions doped as impurities in single crystal hosts.Using low tempera- 2 6 ture polarized optical spectroscopy and electron paramagnetic resonance, a very detailed picture can be drawn about the geometry of these ions in both their ground and excited electronic states. We then compare the spectrosco- cally determined structural data with that obtained from X-ray diffraction or EXAFS measurements.
Download or read book Synchrotron Light Sources and Free Electron Lasers written by Eberhard J. Jaeschke and published by Springer. This book was released on 2016-05-27 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Hardly any other discovery of the nineteenth century did have such an impact on science and technology as Wilhelm Conrad Röntgen’s seminal find of the X-rays. X-ray tubes soon made their way as excellent instruments for numerous applications in medicine, biology, materials science and testing, chemistry and public security. Developing new radiation sources with higher brilliance and much extended spectral range resulted in stunning developments like the electron synchrotron and electron storage ring and the freeelectron laser. This handbook highlights these developments in fifty chapters. The reader is given not only an inside view of exciting science areas but also of design concepts for the most advanced light sources. The theory of synchrotron radiation and of the freeelectron laser, design examples and the technology basis are presented. The handbook presents advanced concepts like seeding and harmonic generation, the booming field of Terahertz radiation sources and upcoming brilliant light sources driven by laser-plasma accelerators. The applications of the most advanced light sources and the advent of nanobeams and fully coherent x-rays allow experiments from which scientists in the past could not even dream. Examples are the diffraction with nanometer resolution, imaging with a full 3D reconstruction of the object from a diffraction pattern, measuring the disorder in liquids with high spatial and temporal resolution. The 20th century was dedicated to the development and improvement of synchrotron light sources with an ever ongoing increase of brilliance. With ultrahigh brilliance sources, the 21st century will be the century of x-ray lasers and their applications. Thus, we are already close to the dream of condensed matter and biophysics: imaging single (macro)molecules and measuring their dynamics on the femtosecond timescale to produce movies with atomic resolution.
Download or read book Nvestigation of the Excited State Dynamics of Transition Metal Complexes by Time resolved Step scan FTIR and Luminescence Spectroscopy written by Pit Jean Boden and published by . This book was released on 2022 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Time resolved X ray Absorption Spectroscopy of Trasition Metal Complexes written by Wojciech Gawelda and published by . This book was released on 2006 with total page 273 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Electronic Spectra of Transitions Metal Complexes written by Vinod Jena and published by Lulu.com. This book was released on 2015-04-12 with total page 93 pages. Available in PDF, EPUB and Kindle. Book excerpt: This books will provides a conceptual parts of Electronic spectra of various transition metal complexes, which is useful for various competitive examinations.
