Download or read book Ultrafast Dynamics of Transition Metal Complexes written by George Farrow and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultrafast Electron Dynamics in Transition Metal Complexes Studied in Solution by Means of Time Resolved XUV Photoemission Spectroscopy written by Alexandre Moguilevski and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ultrafast Photophysical and Photochemical Dynamics of Polyhalogenated Alkanes Cycloalkanes and Transition Metal Complexes written by Darya S Budkina and published by . This book was released on 2019 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work aims at deeper understanding of chemical reaction dynamics, ultrafast photochemical and photophysical relaxation pathways, and energy redistribution and dissipation in the liquid phase on a femto-to-picosecond timescale. Breaking and making of chemical bonds, structural reorganization, and energy flow are all the essence of chemistry, and all occur on the time scale of molecular vibrations (tens of femtoseconds). Important insights about the structure of evolving molecules, relaxation phenomena, and ultrafast photochemical and photophysical population dynamics can be obtained using sub-50-fs time-resolved transient absorption spectroscopy. As a result, highly viable and/or unique information about the mechanism of relaxation dynamics and the nature of short-lived intermediates can be gained. Furthermore, ultrashort laser pulses with duration of 100 fs or shorter can help set up and detect coherent motion in vibronic excited and ground states. Coherence observed in product states provides the knowledge about electronic and nuclear motion along the relaxation path. This yields the information about the potential energy surfaces involved in the photochemical or photophysical process that occurs. The knowledge acquired from such experiments can be used as an entry point for control of femtochemical processes in solution. The technical aspect of this work focuses on developing and optimizing the ultrafast transient absorption setup for studying ultra-rapid photochemical relaxation dynamics in the molecules of interest, namely, geminal dibromocycloalkanes and halogen-containing transition metal complexes. Excitation pulses from deep-UV to near-IR were temporally compressed using prisms compressors to generate sub-40 fs laser pulses. Also, stable white-light continuum pulses used for probing were generated in the wide spectral range of 280 - 760 nm. This thesis is divided into two main parts. The first part provides information about ultrafast dynamics (10-fs time resolution after deconvolution) of geminal dibromocycloalkanes. The second part covers ultrafast radiationless relaxation dynamics of halogen-containing transition metal complexes (IrBr62-, IrCl62-, etc.). A particular focus in this part is on excitation into several vibronic states of the different nature (ligand-to-metal charge-transfer (LMCT) and intraconfigurational), where the lowest-excited intraconfigurational state is accessed via direct femtosecond near-IR (2000 nm) excitation.
Download or read book Exploring the Ultrafast Excited state Dynamics of Transition Metal Complexes with Ab inito Multiple Spawning written by Julia Preiß and published by . This book was released on 2019 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Seit ihrer Entstehung im letzten Jahrhundert hat sich die Quantenchemie weitverbreitet, mit der bereits routinemäßig eine Vielzahl von Spektren berechnet werden können. Im Gegensatz dazu ist die Modellierung von ultraschnellen photochemischen Prozessen heute noch sehr anspruchsvoll und limitiert auf kleine und mittelgroße Moleküle. Die stetig steigende Computerleistung ermöglicht nun die Berechnung großer Übergangsmetallkomplexe. Aufgrund ihrer hohen Anzahl an elektronischen Zuständen und Atomen bergen diese jedoch einige Herausforderungen für die quantenmechanischen Methoden zur Modellierung von ultraschnellen Prozessen. Daher ist es Ziel dieser Arbeit Methoden zu identifizieren, mit denen diese Herausforderungen bewältigt werden können. Dafür wurde zunächst die Methode ab-initio multiple spawning (AIMS) zur Berechnung der Atomkerndynamik basierend auf einem Vergleich von zwei vielversprechenden Methoden ausgesucht. Anschließend wurde die zeitabhängige Dichtefunktionaltheorie (TDDFT) für die Beschreibung der elektronischen Struktur ausgewählt, da diese Methode einen guten Kompromiss zwischen Genauigkeit und Rechenaufwand ermöglicht. Dabei wurden anhand des Beispielkomplexes Eisenpentacarbonyl auch die Grenzen der Methode aufgezeigt. Mit den ausgewählten Methoden wurden 500 fs der Dynamik eines Übergangsmetallkomplexes mit mehr als 100 Atomen simuliert, was die bisher größte AIMS Berechnung für einen Übergangsmetallkomplex darstellt. Durch einen Vergleich mit experimentellen Ergebnissen konnte die Simulation validiert werden und weitere Erkenntnisse über den Reaktionsmechanismus des Komplexes konnten gewonnen werden. Außerdem wurde die Dynamik der angeregten Zustände eines experimentell bisher kaum untersuchten Übergangsmetallkomplexes vorhergesagt, um das Potential der hier ausgewählten Methoden aufzuzeigen. Zusammenfassend wurde damit gezeigt, dass die Kombination von AIMS und TDDFT eine effiziente Berechnung der Dynamik von Übergangsmetallkomplexen ermöglicht.
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 Photoinduced Molecular Dynamics in Solution written by Gianluca Levi and published by Springer Nature. This book was released on 2019-09-03 with total page 208 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book explores novel computational strategies for simulating excess energy dissipation alongside transient structural changes in photoexcited molecules, and accompanying solvent rearrangements. It also demonstrates in detail the synergy between theoretical modelling and ultrafast experiments in unravelling various aspects of the reaction dynamics of solvated photocatalytic metal complexes. Transition metal complexes play an important role as photocatalysts in solar energy conversion, and the rational design of metal-based photocatalytic systems with improved efficiency hinges on the fundamental understanding of the mechanisms behind light-induced chemical reactions in solution. Theory and atomistic modelling hold the key to uncovering these ultrafast processes. Linking atomistic simulations and modern X-ray scattering experiments with femtosecond time resolution, the book highlights previously unexplored dynamical changes in molecules, and discusses the development of theoretical and computational frameworks capable of interpreting the underlying ultrafast phenomena.
Download or read book Ultrafast Electron Dynamics in Molecules Within Density matrix based Configuration Interaction Framework written by Vladislav Kochetov and published by . This book was released on 2023 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The main goal of this thesis is to present the results of work concerning photon-induced ultrafast spin dynamics being theoretically modeled within the framework of ab-initio calculations. The effect of chemical structure on the ultrafast spin-flip dynamics in core-excited states of transition metal complexes has been studied. Detailed analysis of spin-orbit coupling-driven dynamics in core-excited states, based on the preselection of states and utilizing the Wigner-Eckart theorem, is conducted. A general framework to numerically simulate the ultrafast electron dynamics was developed.eng
Download or read book Transition Metals in Coordination Environments written by Ewa Broclawik and published by Springer. This book was released on 2019-03-16 with total page 532 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book focuses on the electronic properties of transition metals in coordination environments. These properties are responsible for the unique and intricate activity of transition metal sites in bio- and inorganic catalysis, but also pose challenges for both theoretical and experimental studies. Written by an international group of recognized experts, the book reviews recent advances in computational modeling and discusses their interplay using experiments. It covers a broad range of topics, including advanced computational methods for transition metal systems; spectroscopic, electrochemical and catalytic properties of transition metals in coordination environments; metalloenzymes and biomimetic compounds; and spin-related phenomena. As such, the book offers an invaluable resource for all researchers and postgraduate students interested in both fundamental and application-oriented research in the field of transition metal systems.
Download or read book Ultrafast Dyanmics i e Dynamics Associated with Transition Metal based Sensitizers for Titanium Dioxide Based Solar Cells written by Amanda Lea Smeigh and published by . This book was released on 2007 with total page 334 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Photochemistry and Photophysics of Earth Abundant Transition Metal Complexes written by and published by Elsevier. This book was released on 2024-05-28 with total page 332 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Inorganic Chemstry serial highlights new advances in the field with this new volume presenting interesting chapters. Each chapter is written by an international board of authors. Provides the authority and expertise of leading contributors from an international board of authors Presents the latest release in Advances in Inorganic Chemistry serials Updated release includes the latest information on Photochemistry and Photophysics of Earth-Abundant Transition Metal Complexes
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 Femtosecond Soft X ray Spectroscopy of Solvated Transition Metal Complexes written by and published by . This book was released on 2011 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We present the first implementation of femtosecond soft X-ray spectroscopy as an ultrafast direct probe of the excited-state valence orbitals in solution-phase molecules. This method is applied to photoinduced spin crossover of [Fe(tren(py)3)]2+, where the ultrafast spinstate conversion of the metal ion, initiated by metal-to-ligand charge-transfer excitation, is directly measured using the intrinsic spin-state selectivity of the soft X-ray L-edge transitions. Our results provide important experimental data concerning the mechanism of ultrafast spin-state conversion and subsequent electronic and structural dynamics, highlighting the potential of this technique to study ultrafast phenomena in the solution phase.
Download or read book Ultrafast Dynamics and Interfacial Structural Orientation Investigated with Multidimensional Vibrational Spectroscopy written by Jiaxi Wang and published by . This book was released on 2019 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: In this thesis, two multidimensional spectroscopic methods--two-dimensional infrared (2D IR) spectroscopy and heterodyne 2D sum frequency generation (HD 2D SFG) spectroscopy--are applied to investigate ultrafast chemical exchange of organometallics in bulk solution and structural orientation of surface catalysts at interface, respectively. 2D IR spectroscopy is used to study the ultrafast chemical exchange of two organometallics compound ( Ru(S2C2(CF3)2)(CO)(PPh3)2 and Co(CNArMes2)4 ) occurring on the picosecond time scale. Combined with DFT simulation results, 2D IR provides direct evidence of the existence of various isomers. For the five-coordinate Ru complex, one isomers that serves as the intermediate of the axial-equatorial exchange was observed for the first time. Furthermore, our 2D IR works find the kinetic barriers of dynamic exchange between multiple isomers surprisingly low, consider both of the transition metal complexes under study have relatively large ligands. The low kinetic barriers are attributed to the small core-angle movement involved in the chemical exchange. 2D IR is also applied to W(CO)6/dual cavity system to observe ultrafast intercavity nonlinear polariton interactions. Combined with a newly developed theory model, we show that the nonlinear interaction is realized by shared molecular anharmonicities among cavity modes, e.g. through mode delocalization, some molecules (with anharmonicity) are coupled by cavity modes adjacent to each other. HD 2D SFG spectroscopy is used to study a model CO2 reduction catalyst, Re(diCNbpy)(CO)3Cl, as a monolayer on a gold surface. We show that short-range interactions with the surface can cause substantial line-shape differences between vibrational bands from the same molecules. This interaction can be explained as the result of couplings between CO vibrational modes of the catalyst molecules and the image dipoles on gold surface, which are sensitive to the relative distance between the molecule and the surface. Thus, by analysis of HD 2D SFG lineshape differences and polarization dependences of IR spectra, the ensemble-averaged orientation of the molecules on the surface can be determined unambiguously. The high sensitivity of HD 2D SFG spectra to short-range interactions can be applied to many other adsorbate-substrate interactions and therefore serve as a unique tool to determine adsorbate orientations on surfaces. Meanwhile, surface molecules of the monolayers can adopt conformations with many different orientations. Thus, it is necessary to describe the orientations of surface molecular monolayers using both mean tilt angle and orientational distribution, which together we refer to as orientation heterogeneity. Orientation heterogeneity is difficult to measure. In most cases, in order to calculate the mean tilt angle, it is assumed that the orientational distribution is narrow. This assumption causes ambiguities in determining the mean tilt angle and loss of orientational distribution information, which is known as the "magic angle" challenge. Using HD 2D SFG spectroscopy, we report a novel method to solve the "magic angle" challenge, by simultaneously measuring mean tilt angle and orientational distribution of molecular monolayers. Although applied to a specific system, this method is a general way to determine the orientation heterogeneity of an ensemble-averaged molecular interface.
Download or read book Ultrafast Optics And Spectroscopy In Physical Chemistry written by Atanu Bhattacharya and published by World Scientific. This book was released on 2017-12-28 with total page 291 pages. Available in PDF, EPUB and Kindle. Book excerpt: The primary goal of this text book is to ensure that any physical science student, even one who has never heard of the subject, should be able to learn what ultrafast spectroscopy is, why optics related to the subject requires special attention, how to use the basic ideas of the subject in laboratory-based ultrafast spectroscopy experiments, how to interpret the experimental observations and so on. This book gives a more than adequate introduction to mathematical representation of an ultrafast pulse, chirp, time-band width product, nonlinear optical effects, dispersion effects, construction of ultrafast laser, ultrafast measurement techniques and different ultrafast processes of chemical interest.
Download or read book Laser driven Electron and Spin state Quantum Dynamics in Transition Metal Complexes written by Huihui Wang and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent advances in attosecond spectroscopy open the door to the understanding correlated motion of valence and core electrons in molecular systems. In this thesis, the density matrix-based TD-RASCI method is used to study the electron and spin-flip dynamics. The dephasing effect of nuclear vibrations is incorporated implicitly making use of an electronic system/vibrational bath partitioning. We theoretically addressed the ultrafast spin-flip dynamics in a transition metal complex which is triggered by isolated sub-fs soft-X-ray pulses as well as X-ray pulse trains.eng
Download or read book Ultrafast Phenomena XI written by Thomas Elsässer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 706 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume contains papers presented at the Eleventh International Conference on Ultrafast Phenomena held at Garmisch-Partenkirchen, Germany, from July 12 to 17, 1998. The biannual Ultrafast Phenomena Conferences provide a forum for dis cussion of the latest advances in ultrafast optics and their applications in science and engineering. The Garmisch conference brought together a multidisciplinary group of 440 participants from 27 countries, including 127 students. The enthu siasm of this large number of Participants, the high quality of the papers they presented and the magnificent conference site resulted in a successful and pleasant conference. Progress was reported in the technology of generating ultrashort pulses, in cluding new techniques for improving laser-pulse duration, tunability over broad wavelength ranges, output power and peak intensity. Ultrafast spectroscopy con tinues to provide new insight into fundamental processes in physics, chemistry, biology, and engineering. In addition to analyzing ultrafast phenomena, control of ultrafast dynamics now represents an important topic. Ultrafast concepts and tech niques are being applied in imaging and microscopy, high speed optoelectronics, mat~rial diagnostics and processing, reflecting the maturing of the field. Acknowledgements. Many people contributed to the success of the conference.
Download or read book The Ultrafast Dynamics of Chromium III Coordination Complexes written by Eric Anderson Juban and published by . This book was released on 2006 with total page 340 pages. Available in PDF, EPUB and Kindle. Book excerpt:
