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 Electron Dynamics in Chemically Doped Complex Materials Analyzed by Time resolved Photoemission Spectroscopy written by Isabella Avigo and published by . This book was released on 2017 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Molecular Electronic Structures of Transition Metal Complexes I written by David Michael P. Mingos and published by Springer Science & Business Media. This book was released on 2012-01-13 with total page 227 pages. Available in PDF, EPUB and Kindle. Book excerpt: J.P. Dahl: Carl Johan Ballhausen (1926–2010).- J.R. Winkler and H.B. Gray: Electronic Structures of Oxo-Metal Ions.- C.D. Flint: Early Days in Kemisk Laboratorium IV and Later Studies.- J.H. Palmer: Transition Metal Corrole Coordination Chemistry. A Review Focusing on Electronic Structural Studies.- W.C. Trogler: Chemical Sensing with Semiconducting Metal Phthalocyanines.- K.M. Lancaster: Biological Outer-Sphere Coordination.- R.K. Hocking and E.I. Solomon: Ligand Field and Molecular Orbital Theories of Transition Metal X-ray Absorption Edge Transitions.- K.B. Møller and N.E. Henriksen: Time-resolved X-ray diffraction: The dynamics of the chemical bond.

Download or read book Investigations of Photoinduced Ultrafast Dynamics in Metal Coordination Complexes Using Time resolved Photoemission and Absorption Spectroscopy written by Azhr Abdulzahraa Raheem 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 Electronic and Vibronic Spectra of Transition Metal Complexes II written by Hartmut Yersin and published by Springer Science & Business Media. This book was released on 1997-07-16 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt: The unique properties and applications of transition metal compounds have long fascinated both physicists and chemists. This volume presents theoretical and experimental studies for a deeper understanding of the electronic and vibronic properties of these compounds. In particular, an introduction into properties of spin sublevels of dd*, dÂ*, and ÂÂ* states is given, and a modern ligand field theory based on the Angular Overlap Model is presented. In experimental case studies it is shown how to characterize different types of electronic transitions using modern methods of laser spectroscopy. Consequences of spin-orbit coupling, zero-field splittings, spin-lattice relaxations, chromophore-matrix interactions, Herzberg-Teller/Franck-Condon activities, and localization/delocalization properties are treated.

Download or read book Electronic Structure and Electron Transfer Dynamics at Dye Semiconductor Interfaces Studied by Means of Time Resolved XUV Photoelectron Spectroscopy written by Mario Borgwardt and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Spectral Methods in Transition Metal Complexes written by K. Sridharan and published by Elsevier. This book was released on 2016-02-13 with total page 201 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spectral Methods in Transition Metal Complexes provides a conceptual understanding on how to interpret the optical UV-vis, vibrational EPR, and NMR spectroscopy of transition metal complexes. Metal complexes have broad applications across chemistry in the areas of drug discovery, such as anticancer drugs, sensors, special materials for specific requirements, and catalysis, so a thorough knowledge in preparation and characterization of metal complexes, while niche, is critical. Accessible to both the seasoned researcher and the graduate student alike, this book provides readers with a single source of content that addresses spectral methods in transition metal complexes. Provides readers with a single reference on metal complexes and coordination compounds Contains more than 100 figures, tables, and illustrations to aid in the retention of key concepts Authored by a scientist with nearly 40 years of experience in research and instruction

Download or read book Charge Carrier Dynamics in Transition Metal Oxides Studied by Femtosecond Transient Extreme Ultraviolet Absorption Spectroscopy written by Chang-Ming Jiang and published by . This book was released on 2015 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt: With the ability to disentangle electronic transitions that occur on different elements and local electronic structures, time-resolved extreme ultraviolet (XUV) spectroscopy has emerged as a powerful tool for studying ultrafast dynamics in condensed phase systems. In this dissertation, a visible-pump/XUV-probe transient absorption apparatus with femtosecond resolution was constructed to investigate the carrier relaxation dynamics in semiconductors after photo-excitation. This includes timescales for carrier thermalization by carrier-carrier and carrier-phonon scattering. The 30 - 72 eV photon energy coverage (17 - 40 nm wavelength) generated by a table-top XUV light source is suitable for probing the 3p-to-3d core level absorptions of various transition metal oxides (TMOs) with specificities to elements and oxidation states. In Chapter 1, a brief introduction to charge carrier dynamics in semiconductor-based materials is given. In addition, fundamentals of core-level spectroscopy and the high harmonic generation (HHG) process are also addressed in this introductory chapter. Specifications of the experimental apparatus that was constructed are summarized in Chapter 2, including the design concepts and characterization of performance. Chapter 3 presents the spectral tunability of the XUV pulses generated from a semi-infinite gas cell (SIGC), as well as the data acquisition procedures. Charge carrier relaxation dynamics in Co3O4 following the charge transfer excitation pathway at 400 nm are documented in Chapter 4. In Chapter 5, various visible pump wavelengths are used to excite Co3O4 and the differences in the carrier dynamics versus excitation wavelength are considered. After selectively photoexciting a Si/TiO2 heterojunction, the resulted electron transfer process is observed and reported in Chapter 6. The concluding remarks of the dissertation are made in Chapter 7, while several ongoing time-resolved experiments are addressed in the Appendix sections.

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 Early Excited State Dynamics of Selected Transition Metal Complexes written by Elspeth Lindsay and published by . This book was released on 1993 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Primary photoprocesses of selected organometallic and coordination compounds are studied by a combination of picosecond time resolved absorption spectroscopy and quantum yield measurements in different solvents.

Download or read book Electronic Excited State Properties of Transition metal Complexes Studied by Time resolved Raman Spectroscopy and Optical Spectroscopy written by Jing-Huei Perng and published by . This book was released on 1989 with total page 472 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Study of Transition Metal Complexes by Photoelectron Spectroscopy written by Tammy C. S. Chan and published by . This book was released on 1982 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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 Time resolved THz Studies of Carrier Dynamics in Semiconductors Superconductors and Strongly correlated Electron Materials written by and published by . This book was released on 2006 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Perhaps the most important aspect of contemporary condensed matter physics involves understanding strong Coulomb interactions between the large number of electrons in a solid. Electronic correlations lead to the emergence of new system properties, such as metal-insulator transitions, superconductivity, magneto-resistance, Bose-Einstein condensation, the formation of excitonic gases, or the integer and fractional Quantum Hall effects. The discovery of high-Tc superconductivity in particular was a watershed event, leading to dramatic experimental and theoretical advances in the field of correlated-electron systems. Such materials often exhibit competition between the charge, lattice, spin, and orbital degrees of freedom, whose cause-effect relationships are difficult to ascertain. Experimental insight into the properties of solids is traditionally obtained by time-averaged probes, which measure e.g., linear optical spectra, electrical conduction properties, or the occupied band structure in thermal equilibrium. Many novel physical properties arise from excitations out of the ground state into energetically higher states by thermal, optical, or electrical means. This leads to fundamental interactions between the system's constituents, such as electron-phonon and electron-electron interactions, which occur on ultrafast timescales. While these interactions underlie the physical properties of solids, they are often only indirectly inferred from time-averaged measurements. Time-resolved spectroscopy, consequently, is playing an ever increasing role to provide insight into light-matter interaction, microscopic processes, or cause-effect relationships that determine the physics of complex materials. In the past, experiments using visible and near-infrared femtosecond pulses have been extensively employed, e.g. to follow relaxation and dephasing processes in metals and semiconductors. However, many basic excitations in strongly-correlated electron systems and nanoscale materials occur at lower energies. The terahertz (THz) regime is particularly rich in such fundamental resonances. This includes ubiquitous lattice vibrations and low-energy collective oscillations of conduction charges. In nanoscale materials, band structure quantization also yields novel infrared and THz transitions, including intersubband absorption in quantum wells. The formation of excitons in turn leads to low-energy excitations analogous to inter-level transitions in atoms. In transition-metal oxides, fundamental excitation gaps arise from charge pairing into superconducting condensates and other correlated states. This motivates the use of ultrafast THz spectroscopy as a powerful tool to study light-matter interactions and microscopic processes in nanoscale and correlated-electron materials. A distinct advantage of coherent THz pulses is that the amplitude and phase of the electric field can be measured directly, as the THz fields are coherent with the fs pulses from which they are generated. Using THz time-domain spectroscopy (THz-TDS), both the real and imaginary parts of the response functions (such as the dielectric function) are obtained directly without the need for Kramers?Kronig transforms. The THz response can also be expressed in terms of absorption and refractive index, or as the optical conductivity. The optical conductivity describes the current response of a many-body system to an electric field, an ideal tool to study conducting systems. A second important advantage is the ultrafast time resolution that results from the short temporal duration of the THz time-domain sources. In particular, optical-pump THz-probe spectroscopy enables a delicate probe of the transient THz conductivity after optical photoexcitation. These experiments can provide insight into quasiparticle interactions, phase transitions, or nonequilibrium dynamics. In this chapter we will provide many such examples. Since THz spectroscopy of solids is a quickly expanding field.

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 Electronic and Vibronic Spectra of Transition Metal Complexes II written by Hartmut Yersin and published by Springer. This book was released on 2014-03-12 with total page 262 pages. Available in PDF, EPUB and Kindle. Book excerpt: The unique properties and applications of transition metal compounds have long fascinated both physicists and chemists. This volume presents theoretical and experimental studies for a deeper understanding of the electronic and vibronic properties of these compounds. In particular, an introduction into properties of spin sublevels of dd*, dÂ*, and ÂÂ* states is given, and a modern ligand field theory based on the Angular Overlap Model is presented. In experimental case studies it is shown how to characterize different types of electronic transitions using modern methods of laser spectroscopy. Consequences of spin-orbit coupling, zero-field splittings, spin-lattice relaxations, chromophore-matrix interactions, Herzberg-Teller/Franck-Condon activities, and localization/delocalization properties are treated.

Download or read book The Photoinduced Phase Transitions of Vanadium Dioxide written by Kunal Tiwari and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: "The insulator-to-metal transition of vanadium dioxide has attracted the interest of condensed matter physicists for over half a century. In its high-temperature phase, VO2 is metallic with tetragonal rutile crystallography. In its low-temperature phase, it has correlated semiconducting electronic character and a charge-density-wave- like paired monoclinic lattice structure. Determining the relative roles of electron-electron and electron-phonon interactions in the electronic structure of the low temperature phase has been the source of the physics community's interest in VO2.Over the past two decades, it has been shown that the insulator to metal transition may be photoinduced with ultrafast laser pulses. In this thesis we present ultrafast electron diffraction and ultrafast time resolved terahertz spectroscopy measurements of this photoinduced phase transition. Our ultrafast electron diffraction results reveal, at low fluences, a novel metastable phase. This phase has the crystallography of the insulating state, but a dramatically collapsed band gap. A reorganization of valence charge density accompanies this modulated spectroscopic activity.These results have twofold significance. They show that the insulating behavior of the low temperature phase is affected primarily by electron-electron correlations, not by lattice structure. Importantly, they also show that ultrafast electron diffraction may be used to probe both electronic and lattice structure dynamics--it is sensitive to valence charge density reorganizations.Our time resolved terahertz spectroscopy results complement these ultrafast electron diffraction data. We show that, in the novel metastable monoclinic phase, the band gap does not collapse below 50 meV. We also show that dynamics in the time resolved terahertz conductivity through the full photoinduced phase transition occur on two timescales--one fast (240 femtosecond) timescale, characteristic of the coherent athermal photoinduced phase transition; and one slow (picosecond) timescale, characteristic of the astructural transition to the metastable monoclinic phase. In conjunction with our ultrafast electron diffraction measurements, these results suggest that the slow dynamics of the astructural phase transition, and the structural phase transition may be affected by the same underlying mechanism." --