Download or read book Valence trapped to Valence delocalized Mixed valence Systems by Bridge State Modification written by Kevin P. Schultz and published by . This book was released on 2008 with total page 338 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mixed Valence Systems written by Yuwu Zhong and published by John Wiley & Sons. This book was released on 2023-05-30 with total page 517 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed-Valence Systems Comprehensive overview on the advanced development of mixed-valence chemistry Mixed-Valence Systems: Fundamentals, Synthesis, Electron Transfer, and Applications covers all topics related to the theory and experimental results of mixed-valence systems, including the design, synthesis, and applications of mixed-valence compounds containing inorganic, organometallic and organic redox-active centers. The text also covers the recent advances in mixed-valence chemistry, including the development of new mixed-valence systems, transition of mixed valency, better understanding of the spectral characteristics of intervalence charge transfer, and controllable electron transfer related to molecular electronics. In Mixed-Valence Systems, readers can expect to find detailed information on sample topics such as: Characterization and evaluation of mixed-valence systems, electron paramagnetic resonance spectroscopy, and electrochemical methods Optical analysis, important issues in mixed-valence chemistry, transition of mixed valency from localized to delocalized, and solvent control of electron transfer Theoretical background, potential energy surfaces from classical two-state model, and quantum description of the potential energy surfaces Reorganization energies, electronic coupling matrix element and the transition moments, generalized Mulliken–Hush theory, and analysis of the band shape of intervalence charge transfer Strengthening the relationship of mixed-valence electron transfer and molecular electronics, Mixed-Valence Systems is of immense value to researchers and professionals working in the field of electron transfer, molecular electronics, and optoelectronics.
Download or read book The Effects of Electronic Delocalization in Highly Coupled Mixed Valence Systems written by Benjamin James Lear and published by . This book was released on 2007 with total page 146 pages. Available in PDF, EPUB and Kindle. Book excerpt: The trinuclear ruthenium cluster RuO(OAc)6L3 (where L is an ancillary ligand) is used to make a variety of mixed valence compounds in which two or more clusters are joined together by an organic bridging ligand. The magnitude of electronic coupling in the mixed valance state of these compounds is quite large and the complexes reside on the Robin-Day class II/class III borderline. The large degree of coupling in these complexes gives rise to ultrafast electron transfer whose effects are observable in the infrared (IR) spectra of these complexes. Utilizing the IR properties of the complexes we are able to arrive at thermodynamic estimates of the electronic coupling parameter (H AB) for asymmetric mixed valence compounds. These asymmetric compounds give rise to mixed valence isomers and the temperature dependence of the isomer populations is used to determine deltaH and deltaS for the electron transfer event in these complexes. The large coupling in these complexes reduces the barrier to electron transfer significantly (enabling ultrafast electron transfer). This places the rate of electron transfer under the control of the nuclear dynamics of the complex and the surrounding environment. The result is that the rate of electron transfer in these mixed valence complexes shows a strong dependence on kinetic parameters of the solvent (those that describe the movement of the nuclei of the system), but not on thermodynamic parameters of the solvent (that describe more static energetic contributions of the environment). This, in turn, leads to an unexpected temperature dependence of the electron transfer rate. It is found that the electron transfer rate dramatically increases when the solvent is frozen. This results form a decoupling of the relatively slow solvent motions from the electron transfer event allowing for the faster internal vibrational motions of the mixed valence complex to control the rate of electron transfer. The effects of the large electronic coupling in these complexes also gives rise to other surprising behaviors. The extent of the electronic coupling in the mixed valence systems is known to depend on the electron donor strength of the attached ancillary ligands. It is shown that, through supramoleuclar interactions at the ancillary ligands of these mixed valence systems, the electronic coupling may be modulated. There is a significant decrease in the resonance stabilization associated with breaking of symmetry in a mixed valence system and that this energy (together with the energy gained by restoration of symmetry) can provide substantial driving force for chemical interactions. This effect is explained in terms of both the direct stabilization of the compound through electronic coupling and in terms of resonance stabilization of the unpaired electron in the mixed valence compound. This result is then extended to molecular electronics where it is shown that changes in current effected by a chemical interaction can provide a driving force for said chemical interaction. The large magnitude of electronic coupling in these mixed valence systems is also shown to be sufficient to stabilize as the ground state what would be thought of as low-lying excited states. It is shown that an electron may transfer from a cluster to the bridging ligand and that this electron transfer gives rise to an increase in electronic coupling throughout the mixed valence state. This increase in electronic coupling is found to be sufficient to stabilize the radical state of the organic bridge. The large energy difference between uncoupled (diabatic) and coupled (adiabatic) mixed valence compounds is also exploited in order to determine whether an electron entering into the mixed valence molecule enters into a diabatic or adiabatic wavefunction. The electron transfer rate from photo-generated triplet zinc tetraphenylphorpyrin to the mixed valence compounds was observed. Comparisons of the observed electron transfer rate to the diabatic and adiabatic driving force for electron transfer are made. It is concluded that the electron enters into a diabatic wavefunciton of the mixed valence compound after which the compound evolves into the adiabatic wavefunciton. The major theme throughout this thesis is the exploitation of the huge value of electronic coupling (H AB) in order to give rise to and explain some very unique and unexpected behaviors of these mixed valence complexes.
Download or read book Mixed Valency Systems Applications in Chemistry Physics and Biology written by K. Prassides and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Mixed valency is one of various names used to describe compounds which contain ions of the same element in two different formal states of oxidation. The existence of mixed valency systems goes far back into the geological evolutionary history of the earth and other planets, while a plethora of mixed valency minerals has attracted attention since antiquity. Indeed, control of the oxidation states of Fe in its oxides (FeO, Fe304' Fe203) was elegantly used in vase painting by the ancient Greeks to produce the characteristic black and red Attic ceramics (Z. Goffer, "Archaeological Chemistry", Wiley, New York, 1980). It was, however, only 25 years ago that two reviews of mixed valency appeared in the literature almost simultaneously, signalling the first attempt to treat mixed valency systems as a separate class of compounds whose properties can be correlated with the molecular and the electronic structure of their members. Then mixed valency phenomena attracted the interest of disparate classes of scientists, ranging from synthetic chemists to solid state physicists and from biologists to geologists. This activity culminated with the NATO ASI meeting in Oxford in 1979. The 1980's saw again a continuing upsurge of interest in mixed valency. Its presence is a necessary factor in the search for highly conducting materials, including molecular metals and superconductors. The highly celebrated high T c ceramic superconducting oxides are indeed mixed valency compounds.
Download or read book Spectroscopic Properties of Inorganic and Organometallic Compounds written by G Davidson and published by Royal Society of Chemistry. This book was released on 2007-10-31 with total page 474 pages. Available in PDF, EPUB and Kindle. Book excerpt: Spectroscopic Properties of Inorganic and Organometallic Compounds provides a unique source of information on an important area of chemistry. Divided into sections mainly according to the particular spectroscopic technique used, coverage in each volume includes: NMR (with reference to stereochemistry, dynamic systems, paramagnetic complexes, solid state NMR and Groups 13-18); nuclear quadrupole resonance spectroscopy; vibrational spectroscopy of main group and transition element compounds and coordinated ligands; and electron diffraction. Reflecting the growing volume of published work in this field, researchers will find this Specialist Periodical Report an invaluable source of information on current methods and applications. Specialist Periodical Reports provide systematic and detailed review coverage in major areas of chemical research. Compiled by teams of leading experts in their specialist fields, this series is designed to help the chemistry community keep current with the latest developments in their field. Each volume in the series is published either annually or biennially and is a superb reference point for researchers. www.rsc.org/spr
Download or read book Comprehensive Coordination Chemistry II written by J. A. McCleverty and published by Elsevier Science. This book was released on 2003-12-17 with total page 874 pages. Available in PDF, EPUB and Kindle. Book excerpt: Comprehensive Coordination Chemistry II (CCC II) is the sequel to what has become a classic in the field, Comprehensive Coordination Chemistry, published in 1987. CCC II builds on the first and surveys new developments authoritatively in over 200 newly comissioned chapters, with an emphasis on current trends in biology, materials science and other areas of contemporary scientific interest.
Download or read book Electrons in Molecules written by Jean-Pierre Launay and published by Oxford University Press. This book was released on 2017-12-08 with total page 528 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book provides the reader with a unified understanding of the rapidly expanding field of molecular materials and devices: electronic structures and bonding, magnetic, electrical and photo-physical properties, and the mastering of electrons in molecular electronics. This revised edition includes updates and additions on hot topics such as molecular spintronics (the role of spin in electron transport) and molecular machines (how electrons can generate molecular motions). Chemists will discover how to understand the relations between electronic structures and properties of molecular entities and assemblies, and to design new molecules and materials. Physicists and engineers will realize how the molecular world fits in with their need for systems flexible enough to check theories or provide original solutions to exciting new scientific and technological challenges. The non-specialist will find out how molecules behave in electronics at the most minute, sub-nanosize level.
Download or read book Book of Abstracts written by and published by . This book was released on 2000 with total page 776 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Contributions written by Stanford University. Department of Chemistry and published by . This book was released on 1996 with total page 970 pages. Available in PDF, EPUB and Kindle. Book excerpt: Contains reprints of articles published by members of the department.
Download or read book Mixed Valence Compounds written by D.B. Brown and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 517 pages. Available in PDF, EPUB and Kindle. Book excerpt: It has been a decade since two seminal reviews demonstrated that mixed-valence compounds share many unique and fascinating features. The insight pro vided by those early works has promoted a great deal of both experimental and theoretical study. As a result of extensive efforts, our understanding of the bonding and properties of mixed-valence compounds has advanced substantially. There has been no compre hensive treatment of mixed-valence compounds since 1967, and the meeting convened at Oxford in September, 1979, provided a unique opportunity to examine the subject and its many ramifications. Mixed-valence compounds play an important role in many fields. Although the major impact of the subject has been in chemistry, its importance has become increasingly clear in solid state physics, geology, and biology. Extensive interest and effort in the field of molecular metals has demonstrated that mixed-valency is a prerequisite for high elec trical conductivity. The intense colors of many minerals have been shown to be due to mixed-valency, and the electron-transfer properties of certain mixed-valence metalloproteins are important in biological processes. Experts from all of these areas participated in this meeting, and the truly interdisciplinary nature of the subject made it a unique learning experience for all in attendance.
Download or read book Progress in Inorganic Chemistry Volume 8 written by F. Albert Cotton and published by John Wiley & Sons. This book was released on 2009-09-17 with total page 498 pages. Available in PDF, EPUB and Kindle. Book excerpt: This comprehensive series of volumes on inorganic chemistry provides inorganic chemists with a forum for critical, authoritative evaluations of advances in every area of the discipline. Every volume reports recent progress with a significant, up-to-date selection of papers by internationally recognized researchers, complemented by detailed discussions and complete documentation. Each volume features a complete subject index and the series includes a cumulative index as well.
Download or read book Functional Supramolecular Materials written by Rahul Banerjee and published by Royal Society of Chemistry. This book was released on 2017-05-05 with total page 476 pages. Available in PDF, EPUB and Kindle. Book excerpt: Supramolecular materials have a great number of applications due to the reversibility of their non-covalent molecular interactions, such as reversible hydrogen bonding, host–guest interactions and electrostatic interactions. This book provides a comprehensive source of information on the structure and function of organic and metal–organic supramolecular materials. The chapters of this book provide an overview of supramolecular material assembly at various scales, including the formation of 2D polymers and molecular cages. The role of intermolecular interactions in solid and solution state self-assembly is discussed, as is the role of mechanochemistry on molecular and supramolecular architectures. Finally, novel applications of these materials in molecular recognition, catalysis, light harvesting and environmental remediation are covered. Functional Supramolecular Materials will be of interest to graduate students and researchers in academia and industry in the fields of supramolecular chemistry and functional materials science.
Download or read book Handbook of Advanced Electronic and Photonic Materials and Devices High Tc superconductors and organic conductors written by Hari Singh Nalwa and published by . This book was released on 2001 with total page 428 pages. Available in PDF, EPUB and Kindle. Book excerpt: Electronic and photonic materials discussed in this handbook are the key elements of continued scientific and technological advances in the 21st century. The electronic and photonic materials comprising this handbook include semiconductors, superconductors, ferroelectrics, liquid crystals, conducting polymers, organic and superconductors, conductors, nonlinear optical and optoelectronic materials, electrochromic materials, laser materials, photoconductors, photovoltaic and electroluminescent materials, dielectric materials, nanostructured materials, supramolecular and self-asemblies, silicon and glasses, photosynthetic and respiratory proteins, etc, etc. Some of these materials have already been used and will be the most important components of the semiconductor and photonic industries, computers, internet, information processing and storage, telecommunications, satellite communications, integrated circuits, photocopiers, solar cells, batteries, light-emitting diodes, liquid crystal displays, magneto-optic memories, audio and video systems, recordable compact discs, video cameras, X-ray technology, color imaging, printing, flat-panel displays, optical waveguides, cable televisions, computer chips, molecular-sized transistors and switches, as well as other emerging cutting edge technologies. Electronic and photonic materials are expected to grow to a trillion-dollar industry in the new millennium and will be the most dominating forces in the emerging new technologies in the fields of science and engineering. This handbook is a unique source of the in-depth knowledge of synthesis, processing, fabrication, spectroscopy, physical properties and applications of electronic and photonic materials covering everything for today's and developing future technologies. This handbook consists of over one hundred state-of-the-art review chapters written by more than 200 world leading experts from 25 different countries. With more than 23,000 bibliographic citations and several thousands of figures, tables, photographs, chemical structures and equations, this handbook is an invaluable major reference source for scientists and students working in the field of materials science, solid-state physics, chemistry, electrical and optical engineering, polymer science, device engineering and computational engineering, photophysics, data storage and information technology and technocrats, everyone who is involved in science and engineering of electronic and photonic materials. Key Features * This is the first handbook ever published on electronic and photonic materials * 10 volumes summarize the advances in electronic and photonic materials made over past the two decades * This handbook is a unique source of the in-depth knowledge of synthesis, processing, spectroscopy, physical properties and applications of electronic and photonic materials * Over 100 state-of-the-art review chapters written by more than 200 leading experts from 25 different countries * About 25,000 bibliographic citations and several thousand figures, tables, photographs, chemical structures and equations * Easy access to electronic and photonic materials from a single reference * Each chapter is self-contained with cross references * Single reference having all inorganic, organic and biological materials * Witten in very clear and concise fashion for easy understanding of structure property relationships in electronic and photonic materials
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1998 with total page 878 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Resolution EPR written by Graeme Hanson and published by Springer Science & Business Media. This book was released on 2009-06-19 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: Metalloproteins comprise approximately 30% of all known proteins, and are involved in a variety of biologically important processes, including oxygen transport, biosynthesis, electron transfer, biodegradation, drug metabolism, proteolysis, and hydrolysis of amides and esters, environmental sulfur and nitrogen cycles, and disease mechanisms. EPR spectroscopy has an important role in not only the geometric structural characterization of the redox cofactors in metalloproteins but also their electronic structure, as this is crucial for their reactivity. The advent of x-ray crystallographic snapshots of the active site redox cofactors in metalloenzymes in conjunction with high-resolution EPR spectroscopy has provided detailed structural insights into their catalytic mechanisms. This volume was conceived in 2005 at the Rocky Mountain Conference on Analytical Chemistry (EPR Symposium) to highlight the importance of high-resolution EPR spectroscopy to the structural (geometric and electronic) characterization of redox active cofactors in metalloproteins. We have been fortunate to have enlisted internationally recognized experts in this joint venture to provide the scientific community with an overview of high-resolution EPR and its application to metals in biology. This volume, High-Resolution EPR: Applications to Metalloenzymes and Metals in Medicine, covers high-resolution EPR methods, iron proteins, nickel and copper enzymes, and metals in medicine. An eloquent synopsis of each chapter is provided by John Pilbrow in the Introduction. A second volume, Metals in Biology: Applications of High-Resolution EPR to Metalloenzymes, will appear later this year covering the complement of other metalloproteins. One of the pioneers in the development of pulsed EPR and its application to metalloproteins was Arthur Schweiger, whose contribution we include in this volume. Unfortunately, he passed away suddenly during the preparation of this volume. The editors and coauthors are extremely honored to dedicate this volume to the memory of Arthur Schweiger in recognition of his technical advances and insights into pulsed EPR and its application to metalloproteins. Arthur was extremely humble and treated everyone with equal respect. He was a gifted educator with an ability to explain complex phenomena in terms of simple intuitive pictures, had a delightful personality, and continues to be sadly missed by the community. It is an honor for the editors to facilitate the dissemination of these excellent contributions to the scientific community. Suggestions for future volumes are always appreciated.
Download or read book Alkoxo and Aryloxo Derivatives of Metals written by Don Bradley and published by Elsevier. This book was released on 2001-02-22 with total page 717 pages. Available in PDF, EPUB and Kindle. Book excerpt: Alkoxo and Aryloxo Derivatives of Metals gives a comprehensive account of the chemistry of metal alkoxides and metal aryloxides, including their industrial applications such as microelectronics, ceramics, nonlinear optical materials, high-temperature superconductors, specialized glasses, and other advanced novel materials. It is an invaluable reference source book. The book is an updated edition of Metal Alkoxides, published by Academic Press in 1978, with additional coverage of metal aryloxides. It reflects the enormous growth in interest in this field in recent years. Alkoxo and aryloxo derivatives are organic compounds with metals for useful industrial purposes. Alkoxo and Aryloxo Derivatives of Metals will appeal to a wide-ranging audience, including university researchers and chemistry graduate students in industrial laboratories concerned with microelectronics, ceramics, glasses and other advanced novel materials; any laboratories doing research on nonlinear optical materials, high-temperature superconductors, ceramic materials, and specialized glasses. It can also serve as a supplementary text for final year courses in advanced inorganic chemistry, e.g., metallo-organic chemistry.
Download or read book Structural Chemistry of Inorganic Actinide Compounds written by Sergey Krivovichev and published by Elsevier. This book was released on 2006-12-08 with total page 505 pages. Available in PDF, EPUB and Kindle. Book excerpt: Structural Chemistry of Inorganic Actinide Compounds is a collection of 13 reviews on structural and coordination chemistry of actinide compounds. Within the last decade, these compounds have attracted considerable attention because of their importance for radioactive waste management, catalysis, ion-exchange and absorption applications, etc. Synthetic and natural actinide compounds are also of great environmental concern as they form as a result of alteration of spent nuclear fuel and radioactive waste under Earth surface conditions, during burn-up of nuclear fuel in reactors, represent oxidation products of uranium miles and mine tailings, etc. The actinide compounds are also of considerable interest to material scientists due to the unique electronic properties of actinides that give rise to interesting physical properties controlled by the structural architecture of respective compounds. The book provides both general overview and review of recent developments in the field, including such emergent topics as nanomaterials and nanoparticles and their relevance to the transfer of actinides under environmental conditions. * Covers over 2,000 actinide compounds including materials, minerals and coordination polymers* Summarizes recent achievements in the field* Some chapters reveal (secret) advances made by the Soviet Union during the 'Cold war'
