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'.

Phosphorus is essential to all life. A critical component of fertilizers, Phosphorus currently has no known substitute in agriculture. Without it, crops cannot grow. With too much of it, waterways are polluted. Across the globe, social, political, and economic pressures are influencing the biogeochemical cycle of phosphorus. A better understanding of this non-renewable resource and its impacts on the environment is critical to conserving our global supply and increasing agricultural productivity. Most of the phosphorus-focused discussion within the academic community is highly fragmented. Phosphorus, Food, and Our Future will bring together the necessary multi-disciplinary perspectives to build a cohesive knowledge base of phosphorus sustainability. The book is a direct continuation of processes associated with the first international conference on sustainable phosphorus held in the United States, the Frontiers in Life Sciences: Sustainable Phosphorus Summit, though it is not a book of conference proceedings; rather, the book is part of an integrated, coordinated process that builds on the momentum of the Summit. The first chapter will introduce the biological and chemical necessity of phosphorus. The subsequent ten chapters will explore different facets of phosphorus sustainability and the role of policy on future global phosphorus supplies. The final chapter will synthesize all of the emerging views contained in the book, drawing out the leading dilemmas and opportunities for phosphorus sustainability.

D. Santamaria-Perez and F. Liebau : Structural relationships between intermetallic clathrates, porous tectosilicates and clathrates hydrates Vladislav A. Blatov: Crystal structures of inorganic oxoacid salts perceived as cation arrays: a periodic graph approach Angel Vegas: FeLiPO4: Dissection of a crystal structure. The parts and the whole D. J. M. Bevan, R. L. Martin, Angel Vegas: Rationalisation of the substructures derived from the three fluorite-related [Li6(MVLi)N4] polymorphs: An analysis in terms of the "Barnighausen Trees" and of the "Extended Zintl-Klemm Concept" Angel Vegas: Concurrent pathways in the phase transitions of alloys and oxides: Towards an Unified Vision of Inorganic Solids

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.

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 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 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."

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."

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."

Theoretical and numerical details of an optimized LCAO (linear combination of atomic orbitals) method for the calculation of self-consistent bandstructures are given together with a variety of examples. The method will be a valuable tool both for researchers engaged in calculations and for scientists looking for numerical results of self-consistent bandstructure calculations. The presentation starts with an introduction to the modern many-body theory of electronic bandstructure. The essentials of the representation with a non-orthogonal basis and the usual tight-binding variants are critically reviewed. A variational approach to the optimization of atom-like basis orbitals is described together with an SCF procedure for band calculations. Complete numerical and graphic results for all elementary metals from lithium to zinc are given.

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.

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.

In the early 1980s capillary liquid chromatography was being established; it was a period in which only a few research groups published a relatively small number of papers on the subject. In terest has since taken off, and a period of intense development, to which no end is yet in sight, is now upon us. More investiga tors and instrument-making firms are now entering the field. This greater interest has resulted in the rapid appearance of two collec tions [1, 2] and a series of topical reviews [3-6]. However, it could hardly be said that all the problems in this area have been formulated, let alone solved. The preparation of very efficient - open tubular or packed - microbore columns, for example, remains more an art than a science, while the relation ship between radial and longitudinal mass transfer, and the effect of transcolumn velocity profiles on chromatographic efficiency, have been very poorly studied. Indeed, recent publications on these subjects have sometimes, far from clarifying matters, only muddied them further. Many instrument-making firms are trying to unify their equip ment so that it is suitable for microbore, conventional (analytical), and preparative liquid chromatography. This approach has not real ized the full potential of capillary chromatography, and there also remains room for improving the performance of capillary columns.

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

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."

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."

Determining the structure of molecules is a fundamental skill that all chemists must learn. "Structural Methods in Molecular Inorganic Chemistry" is designed to help readers interpret experimental data, understand the material published in modern journals of inorganic chemistry, and make decisions about what techniques will be the most useful in solving particular structural problems.

Following a general introduction to the tools and concepts in structural chemistry, the following topics are covered in detail:

- computational chemistry- nuclear magnetic resonance spectroscopy - electron paramagnetic resonance spectroscopy - Mossbauer spectroscopy - rotational spectra and rotational structure - vibrational spectroscopy - electronic characterization techniques- diffraction methods - mass spectrometry

The final chapter presents a series of case histories, illustrating how chemists have applied a broad range of structural techniques to interpret and understand chemical systems.

Throughout the textbook a strong connection is made between theoretical topics and the real world of practicing chemists. Each chapter concludes with problems and discussion questions, and a supporting website contains additional advanced material.

"Structural Methods in Molecular Inorganic Chemistry" is an extensive update and sequel to the successful textbook "Structural Methods in Inorganic Chemistry" by Ebsworth, Rankin and Cradock. It is essential reading for all advanced students of chemistry, and a handy reference source for the professional chemist.

Rapid advances are taking place in the application of density functional theory (DFT) to describe complex electronic structures, to accurately treat large systems and to predict physical and chemical properties. Both theoretical content and computational methodology are developing at a pace which offers researchers new opportunities in areas such as quantum chemistry, cluster science, and solid state physics. This volume contains ten contributions by leading scientists in the field and provides an authoritative overview of the most important developments. The book focuses on the following themes: determining adequate approximations for the many-body problem of electronic correlations; how to transform these approximations into computational algorithms; applications to discover and predict properties of electronic systems; and developing the theory. For researchers in surface chemistry, catalysis, ceramics and inorganic chemistry.

Modular Chemistry: the First Steps In recent years, there has been increasing interest among chemists, physicists, materials scientists, biologists, engineers, and others in the assembly of well defmed, relatively large functional structures from repetitive units that themselves are molecules of some complexity. Using the dictionary defmition of a module (a detachable section, compartment, or unit with a specific purpose or function, and in electronics, a compact assembly functioning as a component of a larger unit) [1], we feel that this newly emerging field of endeavor could be called "modular chemistry" [2]. The NATO Advanced Research Workshop on Modular Chemistry that was held on September 9 to 12, 1995, at Aspen Lodge near Estes Park, Colorado, was meant to bring together prominent contributors to modular chemistry as it is being born, and to examine the associated birth pangs. It was concluded that although real, these are not nearly as bad as giving birth to a hedgehog tail first, and that the ultimate rewards were likely to be far more satisfying in terms of new ideas and enabling methodology. The level of excitement about the possibilities that are opening up for modular chemists, and also the challenge involved, are perhaps best documented by noting that the planned discussion periods at the workshop were as long as the oral presentation periods, and yet, each discussion ran over the allocated time.

Modern Synthetic and Application Aspects of Polysilanes: An Underestimated Class of Materials?, by A. Feigl, A. Bockholt, J. Weis, and B. Rieger;
*
Conjugated Organosilicon Materials for Organic Electronics and Photonics, by Sergei A. Ponomarenko and Stephan Kirchmeyer;
*
Polycarbosilanes Based on Silicon-Carbon Cyclic Monomers, by E.Sh. Finkelshtein, N.V. Ushakov, and M.L. Gringolts;
*
New Synthetic Strategies for Structured Silicones Using B(C6F5)3, by Michael A. Brook, John B. Grande, and Francois Ganachaud;
*
Polyhedral Oligomeric Silsesquioxanes with Controlled Structure: Formation and Application in New Si-Based Polymer Systems, by Yusuke Kawakami, Yuriko Kakihana, Akio Miyazato, Seiji Tateyama, and Md. Asadul Hoque;"

This book represents the proceedings of the First International Conference on Frontiers of Polymer Research held in New Delhi, India during January 20-25, 1991. Polymers have usually been perceived as substances to be used in insulations, coatings, fabrics, and structural materials. Defying this classical view, polymers are emerging as a new class of materials with potential applications in many new technologies. They also offer challenging opportunities for fundamental research. Recognizing a tremendous growth in world wide interest in polymer research and technology, a truly global "1st International Conference on Frontiers of Polymer Research" was organized by P. N. Prasad (SUNY at Buffalo), F. E. Karasz (University of Massachusetts) and J. K. Nigam (Shriram Institute for Industrial Research, India). The 225 participants represented 25 countries and a wide variety of academic, industrial and government groups. The conference was inaugurated by the Prime Minister of India, Mr. Chandra Shekhar and had a high level media coverage. The focus of the conference was on three frontier areas of polymer research: (i) Polymers for photonics, where nonlinear optical properties of polymers show great promise, (ii) Polymers for electronics, where new conduction mechanisms and photophysics have generated considerable enthusiasm and (iii) High performance polymers as new advanced polymers have exhibited exceptionally high mechanical strength coupled with light weight.

Environmental pollution is one of the main problems to confront humanity, with the heavy metals occupying a leading role among the most pernicious pollutants. The metals cause cancer and other sicknesses. Their cytotoxic, mutagenic and carcinogenic potentials are not fully understood, and any thorough investigation demands the combined efforts of scientists drawn from many different disciplines. But the effects of heavy metals are not all negative: some, like cis-DDP, and some ruthenium and tin complexes, have antitumour activity. The idea underlying the present work is therefore to present a multidisciplinary perspective on heavy metals in the environment, affording a better understanding of their action on human organisms and health, aiming to make them less polluting and more environmentally friendly.