Experiments showinga rapid and reversible change ofcolor s eem likemagic and are always fascinating. The process involved, photochromism, has a few real and many potential applications. Photochromic glasses thatdarken int he s unlight (protecting eyes from excessive light intensity) and bleach ind im lighta re today a part ofe v eryday life. Organic photochromic compounds in plastic ophthalmic lenses, more comfortable to wear, are now competing with silversalts in glasses, despite the longer lifetime oft he inorganic system. This successful commercial application has given a new impetus to research in the general field of photo chromism, which had its most recent revival in the early eighties. The storyo forganic photochromism with its ups anddowns, from the breakthroughs oft he pioneering periodi n the fifties, through the hardtimes dueto the drawbacks of photodegradation, tot he recent successes is in many ways a saga. The upsurges in this domain were marked by an increasing flow of articles in scientific journals andt he publication of several books (in 1971, 1990, and 1992) that have collectedt he important accumulatedknowledge. Over this period, a considerable number ofpatents have been issued. International meetings have accompanied this activity, the most recent being held in 1993 (ISOP 93 atLes Embiez Island, France) and in 1996 (ISOP 96 inClearwater, Florida). Remark ably, these meetings had good representation from both academia and industry. The next ISOP is planned for 1999 in Fukuoka, Japan.

Metal-Oxygen Clusters is the first book, providing an overview of the surface chemistry and catalytic properties of heteropoly oxometalates. After a brief look at the early knowledge of heteropoly oxometalates, the book discusses the synthesis, characterization, structure, bulk properties and stability of these materials. The remainder and the largest portion of the book explores the properties of these solids as catalysts in acid-catalyzed and oxidation processes in supported or unsupported forms. The book provides an up-to-date review of the methods for synthesizing heteropoly oxometalates of Keggin structure, techniques from spectroscopic through electrochemical to elemental analysis for their characterization and the current information on their structure, bulk properties and their stabilities at high temperatures and under acid and alkaline conditions. The book discusses the materials employed as supports for the title solid and the results of the examination of the supported materials. Methods for the identification of the nature and source of the two catalytic functions, the acidic and oxidative properties, of the heteropoly oxometalates are reviewed and discussed. The use of both the supported and unsupported heteropoly oxometalates as catalysts in acidity-requisite processes ranging from methanol conversion to hydrocarbons to ring-expansion and contraction processes and in oxidation processes from methane cyclohexane are described and related to the aforementioned properties.

In this reference, the author thoroughly reviews the current state of condensed phosphate chemistry. A unique feature of this volume is an examination of the recent developments in X-ray structural techniques, reporting on fundamental results obtained through their use. Enhanced by comprehensive tables reporting crystal data, chapters identify and characterize more than 2,000 compounds. Additional features include a concise survey of the historical development of condensed phosphate chemistry; the presently accepted classification system; a review of each family of condensed phosphates and much more.

The field of transition metal catalysis has experienced incredible growth during the past decade. The reasons for this are obvious when one considers the world's energy problems and the need for new and less energy demanding syntheses of important chemicals. Heterogeneous catalysis has played a major industrial role; however, such reactions are generally not selective and are exceedingly difficult to study. Homogeneous catalysis suffers from on-site engineering difficulties; however, such reactions usually provide the desired selectivity. For example, Monsanto's synthesis of optically-active amino acids employs a chiral homogeneous rhodium diphosphine catalyst. Industrial uses of homogeneous catalyst systems are increasing. It is not by accident that many homogeneous catalysts contain tertiary phosphine ligands. These ligands possess the correct steric and electronic properties that are necessary for catalytic reactivity and selectivity. This point will be emphasized throughout the book. Thus the stage is set for a comprehensive be treatment of the many ways in which phosphine catalyst systems can designed, synthesized, and studied."

Lead-based paint has become a national issue and will continue to be a hi- priority focus ofnational, state, and local agencies until there is no lead-based paint in the United States. Lead-based paint has become a tremendous health hazard for people and animals. Lead-based paint has been in widespread use throughout Europe and the United States. Lead has been known to be a health hazard since the time ofPliny the Elder (A. D. 23-79), but it was deemed that the advantages of lead in paint outweighed the health hazards. There has been a change in outlook, and in 1973 the U. S. Congress banned all lead paint from residential structures. A voluminous number of law suits have been initiated since, and continue to be litigated with the purpose of determining the parties responsible for the lead poisoning of children and others and to exact the indemnities. Lead-based paint is still authorized for use on bridges and nonresidential structures, and thousands of city, state, military, and federal government housing projects still contain lead-based paint. This paint must be removed if these dwellings are to be safe living quarters, especially for children. Aba- ment techniques continue to be evaluated; some have been used successfully. Lead-based paint abatement will continue into the next century, and it is hoped that this comprehensive volume will serve as a guide for those seriously interested in this important subject.

The purpose of this volume is to present the latest planetary studies of an international body of scientists concerned with the physical and chemical aspects of terrestrial planets. In recent years planetary science has developed in leaps and bounds. This is a result of the application of a broad range of scientific disciplines, particularly physical and chemical, to an understanding of the information received from manned and unmanned space exploration. The first five chapters expound on many of the past and recent observations in an attempt to develop meaningful physical-chemical models of planetary formation and evolution. For any discussion of the chemical processes in the solar nebula, it is important to understand the boundary conditions of the physical variables. In Chapter 1, Saf ranov and Vitjazev have laid down explicitly all the physical constraints and the problems of time-dependence of nebular evolutionary processes. Planetary scientists and students will find in this chapter a collection of astrophysical parameters on the transfer of angular momentum, formation of the disk and the gas envelope, nebular turbulence, physical mixing of particles of various origins and growth of planetesimals. The authors conclude their work with important information on ev olution of terrestrial planets. Although symbols are defined in the text of the article, readers who are not familiar with the many symbols and abbreviations in astrophysical literature will find it useful to consult the Appendix for explanations."

The commercial availability and decreasing cost of polyhedral oligomeric silsesquioxanes in recent years has opened up the field to everybody who wishes to apply these unique properties in their own technologies. This is the first book to provide a comprehensive overview of these applications, and covers the synthesis, characterization and history of polyhedral oligomeric silsesquioxanes, their use as metallasilsesquioxane catalysts, their effect upon polymer properties and plastics performance, and their use in superhydrophobic nanocomposites, and electronics, energy, space and biomedical applications.

"Applications of Polyhedral Oligomeric Silsesquioxanes" is a valuable reference for those working across a range of disciplines, including chemists, materials scientists, polymer physicists, plastics engineers, surface scientists, and anybody with a commercial or academic interest in plastics, composite materials, space materials, dental materials, tissue engineering, drug delivery, lithography, fuel cells, batteries, lubricants, or liquid crystal, LED, sensor, photovoltaic or biomedical devices.

The aim of this compilation has been to provide a comprehensive, non-criti cal source of information concerning organometallic compounds. The scope is limited to the compounds containing at least one carbon-metal bond. The in formation includes methods of preparation, properties, chemical reactions, and applications. The First Edition comprised the literature from 1937 to 1958. The Second Edition is completely revised and extended through 1964. The literature prior to 1937 was thoroughly covered by E. Krause and A. von Grosse in I~ie Chemie der meta11-organischen Verbindungen, " Verlag von Gebrueder Borntraeger, Berlin, 1937. Our work consists of three volumes. Volume I contains derivatives of the transition metals of Groups III through VIII of the Periodic Table. Volume II contains derivatives of germanium, tin, and lead. Volume III contains derivatives of arsenic, antimony, and bismuth. The compilation is based on searches through Chemical Abstracts. The col lection of references for 1964 was completed before the Subject Indexes to Volumes 60 and 61 of the Abstracts were available; thus some omissions in the coverage of that year are possible. We have attempted to make the coverage of the literature complete in order that the compilation may have best utility to the chemist, chemical engineer, patent attorney, and editor. In the interest of brevity, certain numerical data are omitted, but references to the original literature are given. Yield data are rounded to two significant figures. Wherever possible, tables have been used. The entries in the Bibliography section include references to Chemical Abstracts.

In the decade since the introduction of the first commercial lithium-ion battery research and development on virtually every aspect of the chemistry and engineering of these systems has proceeded at unprecedented levels. This book is a snapshot of the state-of-the-art and where the work is going in the near future. The book is intended not only for researchers, but also for engineers and users of lithium-ion batteries which are found in virtually every type of portable electronic product.

According to R.H. Crabtree, Metal Dihydrogen and sigma-Bond Complexes is described as 'the definitive account of twentieth-century work in the area of sigma complexation'. It covers not only Kubas' discovery of dihydrogen coordination and the study of its structure and general properties but also discusses both the theoretical beliefs and experimental results of bonding and activation of dihydrogen on metal centers and the coordination and activation of C-H, B-H, X-H, and X-Y bonds, giving an overview of 'one of the hottest areas in chemistry'.

Ruthenium Oxidation Complexes explores ruthenium complexes, particularly those in higher oxidation states, which function as useful and selective organic oxidation catalysts. Particular emphasis is placed on those systems which are of industrial significance. The preparation, properties and applications of the ruthenium complexes are described, followed by a presentation of their oxidative properties and summary of the different mechanisms involved in the organic oxidations (e.g. oxidations of alcohols, alkenes, arenes and alkynes, alkanes, amines, ethers, phopshines and miscellaneous substrates). Moreover, future trends and developments in the area are discussed. This monograph is aimed at inorganic, organic, industrial and catalysis chemists, especially those who wish to carry out specific organic oxidations using catalytic methods.

1.1 The Role of Silicon as a Semiconductor Silicon is unchallenged as a semiconductor base material in our present electronics indu stry. The reasons why it qualifies so strongly for this particular purpose are manyfold. The attractive combination of physical (electrical) properties of silicon and the unique properties of its native oxide layer have been the original factors for its breathtaking evolution in device technology. The majority of reasons, however, for its present status are correlated with industrial prosessing in terms of charge units ( economy), reliability (reproducibility), and flexibility, but also its availability. The latter point, in particular, plays an important role in the different long-term projects on the terrestrial application of solar cells. Practically inexhaustive resources of silicon dioxide form a sound basis even for the most pretentious programs on future alternatives to relieve the present situation in electrical power generation by photovol taics. Assuming a maximum percentage of 10% to be replaced by the year 2000 would roughly mean a cumulative annual production of 2 million metric tons of crude silicon (based on present solar cell standards) ). To illustrate the orders of magnitude that have to be discussed in pertinent programs: Today, the industrial silicon capacity of non-communistic countries (including ferrosili con and other alloys by their relative Si-content) amounts to some 2 million tons per year."

The term "carbon-functional organosilicon compound" is used for organosilicon compounds in which a functional group is bonded to an organic moiety that is in turn con nected to silicon via a Si-C bond. Thus, only Si-Cn-Y com pounds (Y designates a functional group) will be discussed in this book 1 Si-O-Cn-Y compounds will in general not be considered, although the latter group does include a large number of natural substances containing silylated hydroxyl groups. (Because of the differing importance of various Y groups, the reader will find some deviation from this restriction). Finally, compounds containing a silyl group as the functional group are not considered. An overview of the field of organosilicon chemistry would show that in the last several decades the commercial synthesis of organosilicon products has increased substan tially, both in annual production and also in the increasing variety of compounds produced. This increase in the number of commercially available carbon-functional monomers and polymers (silicone polymers) is most remarkable and is occurring because new applications are continually being found for these compounds. As might be expected, the number of publications in this field is also increasing. The important position of silicon in the periodic table - between carbon, aluminum, and phosphorus - means that an understanding of the nature of the bonds in organosilicon compounds is quite important in order to understand the bonding in these other areas."

The present book is based on the work of M.N.Bochkarev, G.S.Kalinina, L.N. zakharov and S.Ya.Khorshev. The Russian edition of that book appeared under the same title in 1989 and covered literature data up to the middle of 1986. Since that time the number of publications on this subject increased significantly. In this volume we include all the data published up to the end of 1990, as well as some of the most important relevant articles of 1991. Therefore, this book should be considered as a new book, devoted to the same problems, rather than as just a translation of the mentioned issue. This book deals with compounds of scandium, yttrium, lanthanum and lanthanoids containing direct metal-carbon bond, Le. with the real organometallic complexes of these metals. Besides, the volume includes the rare earth complexes, in which organic ligand is bonded to the metal atom via the atom of another element of the Periodic Table. In other words, the book includes all classes of rare earth organoderivatives. Carboxilates, fl-diketonates and related chelates are the exceptions, because their properties are closer to inorganic compounds and they were fully described elsewhere. It should be noted, that "rare earth elements," "rare earth metals," "lanthanoids" and related terms are used in this book for indicating scandium, yttrium, lanthanum and the following 14 elements of the Periodic Table.

The renowned theoretical physicist Victor F. Weisskopf rightly pointed out that a real understanding of natural phenomena implies a clear distinction between the essential and the peripheral. Only when we reach such an understanding - that is to say when we are able to separate the relevant from the irrelevant, will the phenomena no longer appear complex, but intelectually transparent. This statement, which is generally valid, reflects the very essence ofmodelling in the quantum theory of matter, on the molecular level in particular. Indeed, without theoretical models one would be swamped by too many details embodied in intricate accurate molecular wavefunctions. Further, physically justified simplificqtions enable studies of the otherwise intractable systems and/or phenomena. Finally, a lack of appropriate models would leave myriads of raw experimental data totally unrelated and incomprehensible. The present series ofbooks dwells on the most important models of chemical bonding and on the variety of its manifestations. In this volume the electronic structure and properties of molecules are considered in depth. Particular attention is focused on the nature of intramolecular interactions which in turn are revealed by various types ofmolecular spectroscopy. Emphasis is put on the conceptual and interpretive aspects of the theory in line with the general philosophy adopted in the series."

The second volume of the series on inorganic biochemistry and bio physics is singularly devoted to magnetic resonance on systems of high molecular complexity. Recently, there have been important advances in magnetic resonance studies of polymers; these advances touch on all aspects of magnetic resonance, both theoretical and applied. Particular emphasis is placed here on multipulse experiments. We believe such an report will be of considerable interest to the readers of our series owing to the importance of magnetic resonance techniques in the investigation of biopolymers. Ivano Bertini Harry Gray Series Editors Preface This book is a record of the Proceedings of the International Symposium on "Advanced Magnetic Resonance Techniques in Systems of High Molecular Complexity," which was held in Siena between 15 and 18 May 1985. The idea of the meeting is due to Proff. N.M. Atherton, G. Giacometti and E. Tiezzi with the aim of honouring the scientific personality of Prof. S.I. Weissman. The meeting has been organized with the assistance of a National Committee formed by R. Basosi, I. Bertini, P. Bucci, C. Corvaia, A. Gamba, G. Martini, G.F. Pedulli, P.A. Temussi, and C.A. Veracini. The invited lecturers responded enthusiastically and a comprehensive picture of the theoretical and practical aspects of magnetic resonance could be therefore provided. The book contains all the plenary lectures delivered during the meeting and also a wide selection among the huge amount of contributions collected by the organizers."

Radiocarbon After Four Decades: An Interdisciplinary Perspective commemorates the 40th anniversary of radiocarbon dating. The volume presents discussions of every aspect of this dating technique, as well as chronicles of its development and views of future advancements and applications. All of the 64 authors played major roles in establishment, development or application of this revolutionary scientific tool. The 35 chapters provide a solid foundation in the essential topics of radiocarbon dating: Historical Perspectives; The Natural Carbon Cycle; Instrumentation and Sample Preparation; Hydrology; Old World Archaeology; New World Archaeology; Earth Sciences; and Biomedical Applications.

Combined oxygen, in the form of water, metal oxides, silicates and other oxyions, accounts for about 50% by weight of the earth's crust. The chemistry of this most abundant element has two major aspects: that of water and aqueous solutions of electrolytes, and that of the solid state. The methodology and techniques appropriate for the study of these fields are sufficiently different that there have been very few points of contact between solution- and solid state chemists. One such contact, of great potential value, is provided by the extensive class of polyoxoanions formed by the transition metals of groups 5 and 6. As 'heteropoly and isopoly acids' these polyanions have been known and investigated for more than a century. The pre sent book is an attempt to survey the chemistry, structures, and applications of these species. Although the book forms part of a series in inorganic chemistry, the field of polyoxometalates deserves wider attention, for example, from organic chemists, especially those concerned with homogeneous and heterogeneous catalysis, and from biochemists, solid state- and materials scientists."

The second edition of this textbook is identical with its fourth German edi tion and it thus has the same goals: precise definition of basic phenomena, a broad survey of the whole field, integrated representation of chemistry, physics, and technology, and a balanced treatment of facts and comprehen sion. The book thus intends to bridge the gap between the often oversimpli fied introductory textbooks and the highly specialized texts and monographs that cover only parts of macromolecular science. The text intends to survey the whole field of macromolecular science. Its organization results from the following considerations. The chemical structure of macromolecular compounds should be inde pendent of the method of synthesis, at least in the ideal case. Part I is thus concerned with the chemical and physical structure of polymers. Properties depend on structure. Solution properties are thus discussed in Part 11, solid state properties in Part Ill. There are other reasons for dis cussing properties before synthesis: For example, it is difficult to understand equilibrium polymerization without knowledge of solution thermodynamics, the gel effect without knowledge of the glass transition temperature, etc. Part IV treats the principles of macromolecular syntheses and reactions."

This translation from the original Russian book outlines the production of a variety of materials by methods of self-propagating high-temperature synthesis (SHS). The types of materials discussed include: hard, refractory, corrosion and wear-resistant materials, as well as other advanced and specialty materials. The authors address the issue of optimal parameters for SHS reactions occurring during processes involving a preliminary metallothermic reduction stage, and they calculate these using thermodynamic approaches. In order to confirm the effectiveness of this approach, the authors describe experiments focusing on the synthesis of elemental crystalline boron, boron carbides and nitrides. Other parts of this brief include theoretical and experimental results on single-stage production of hard alloys on the basis of titanium and zirconium borides, as well as macro kinetics of degassing and compaction of SHS-products. This brief is suitable for academics, as well as those working in industrial manufacturing companies producing hard alloys and composites for making metal-working machinery or drilling equipment.

The chemistry of transition metal carbyne complexes has become a highly attractive field during the past twenty years. In recent years its application to aspects of catalysis and metathesis has gained considerable interest from inorganic as well as organic chemists. In addition, organic synthesis by means of metal carbon multiple bond reagents offers the most sophisticated technology currently available. In consideration of these developments some of Professor E. O. Fischer's former coworkers and colleagues felt obliged to orga nize this NATO Advanced Research Workshop on Transition Metal Carbyne Complexes in the Bavarian Alps. They have been encouraged by the fact that most of the distinguished scientists in the field of metal-carbon multiple bond chemistry had finally agreed to participate and to present stimulating lectures. The organizers of the workshop are deeply grateful to the Scientific Affairs Division of the NATO for the generous financial support of the meeting in Wildbad Kreuth and for the preparation of this book. They also feel indebted to acknowledge the generous support from Wacker-Chemie, BASF, Peroxid-Chemie, Hoechst and Bayer. Finally they thank the staff of the Hanns-Seidel-Stiftung in Wildbad Kreuth for providing a pleasant and stimu lating atmosphere during the meeting."

All existing introductory reviews of mineralogy are written accord ing to the same algorithm, sometimes called the "Dana System of Mineralogy." Even modern advanced handbooks, which are cer tainly necessary, include basic data on minerals and are essentially descriptive. When basic information on the chemistry, structure, optical and physical properties, distinguished features and para genesis of 200-400 minerals is presented, then there is practically no further space available to include new ideas and concepts based on recent mineral studies. A possible solution to this dilemma would be to present a book beginning where introductory textbooks end for those already famil iar with the elementary concepts. Such a volume would be tailored to specialists in all fields of science and industry, interested in the most recent results in mineralogy. This approach may be called Advanced Mineralogy. Here, an attempt has been made to survey the current possibilities and aims in mineral mater investigations, including the main characteristics of all the methods, the most important problems and topics of mineralogy, and related studies. The individual volumes are composed of short, condensed chap ters. Each chapter presents in a complete, albeit condensed, form specific problems, methods, theories, and directions of investigations, and estimates their importance and strategic position in science and industry."

1. G. Engelhardt, H. Koller, Stuttgart, FRG: 29Si NMR of Inorganic Solids 2. H. Pfeifer, Leizpig, FRG: NMR of Solid Surfaces 3. A. Sebald, Bayreuth, FRG: MAS and CP/MAS NMR of Less Common Spin-1/2 Nuclei 4. C. J{ger, Mainz, FRG: Satellite Transition Spectroscopy of Quadrupolar Nuclei 5. D. Brinkmann, M. Mali, Z}rich, CH: NMR-NQR Studies of High-Temperature Superconductors

In the field of plant analysis there is a confusing variety of methods and procedures, both for digestions and determinations. In many cases the digestion and the subsequent determination are interrelated. For example, a separate digestion is needed for trace elements in order to obtain determinable concentrations. The authors have chosen a design in which the digestion/extraction procedure is described in one chapter together with all determination procedures that may be carried out on that particular digest/extract. All the necessary information (such as standardizations) appears in appendices. As a consequence, several determination procedures are described two or three times, however, each based on a particular digestion or extraction method. Two types of determination procedure are described: manual and automated. Manual procedures are mainly used in research laboratories, whereas automated procedures are more frequently applied in routine laboratories. Both types of determinations can be used freely, provided that appropriate equipment is available. The determination procedures are only for inorganic components, usually elements. Besides, most procedures are designed to give a total content value of the element under consideration, regardless of the chemical structure in which it occurs in the plant. The Plant Analysis Manual is intended for the practicing (agricultural) chemist.