Mixed Valency Systems Applications In Chemistry Physics And Biology

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.

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.

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.

Advances in Inorganic Chemistry presents timely and informative summaries of the current progress in a variety of subject areas within inorganic chemistry ranging from bio-inorganic to solid state studies. Thisacclaimed serial features reviews written by experts in the area and is an indispensable reference to advanced researchers. Each volume of Advances in Inorganic Chemistry contains an index, and each chapter is fully referenced.

Mössbauer Spectroscopy Unique and comprehensive overview of versatile applications of Mössbauer spectroscopy in chemistry and material sciences Mössbauer Spectroscopy provides a comprehensive overview of relevant applications of this physical analysis method in chemistry and material sciences. The book shows the versatility of Mössbauer spectroscopy in finding useful information on electronic structure, structural insights, and solid-state effects of chemical systems. A wide range of chemical applications and applied concepts are covered as well as numerous examples, selected from recent literature. To aid in reader comprehension and accessibility, contents are well-structured and divided in different sections covering energy, catalysis, coordination chemistry, spin crossover, sensing, photomagnetism. Edited by prominent scientists in the field and authored by a group of international experts, Mössbauer Spectroscopy covers sample topics such as: Li-ion batteries, catalysts, fuel cells, Fe based silicides and iron phosphates containing minerals Gold clusters and gold mixed valence complexes Molecule based magnets, photoswitchable spin crossover coordination polymers and molecular sensors for meat freshness control With comprehensive coverage of the developments in the technique, Mössbauer Spectroscopy is a beneficial resource for researchers, professionals, and academics in chemistry related fields, such as material science, sustainable environment, and molecular electronics. It can be used by newcomers as well as for educational purposes at the master and PhD levels.

The second edition of this classic book provides an updated look at crystal field theory and its applications.

Molecular magnetism is a new field of research dealing with the synthesis and study of the physical properties of molecular assemblies involving open-shell units. It is essentially interdisciplinary, joining together organic, organometallic and inorganic chemists, as well as theoreticians, physicists and materials scientists. At the core of research into molecular magnetism lie design and synthesis of new molecular assemblies exhibiting bulk properties such as long-range magnetic ordering or bistability with an hysteresis effect, which confers a memory effect on the system. In such terms, magnetism may be considered a supramolecular function. The first eight contributions to this volume present the state of the art in organic supramolecular chemistry, emphasising interlocked systems and molecular trees. The following six articles are devoted to molecular materials constructed from organic radicals and transition metal units. Molecular bistability is then focused on, followed by metal-organic and coordination magnetic materials. A new approach to nano-sized particles closes the work.