Low dimensionality is a multifarious concept which applies to very diversified materials. Thus, examples of low-dimensional systems are structures with one or several layers, single lines or patterns of lines, and small clusters isolated or dispersed in solid systems. Such low dimensional features can be produced in a wide variety of materials systems with a broad spectrum of scientific and practical interests. These features, in turn, induce specific properties and, particularly, specific transport properties. In the case of zeolites, low dimensionality appears in the network of small-diameter pores of molecular size, extending in one, two or three di mensions, that these solids exhibit as a characteristic feature and which explains the term of "molecular sieves" currently used to name these ma terials. Indeed, a large number of industrial processes for separation of gases and liquids, and for catalysis are based upon the use of this low dimensional feature in zeolites. For instance, zeolites constitute the first class of catalysts employed allover the world. Because of the peculiarity and flexibility of their structure (and composition), zeolites can be adapted to suit many specific and diversified applications. For this reason, zeolites are presently the object of a large and fast-growing interest among chemists and chemical engineers.

There are both a remote and a proximate history in the development of this book. We would like to acknowledge first the perceptiveness of the technical administrators at RCA Laboratories, Inc. during the 1970s, and in particular Dr. P. N. Yocom. Buoyed up by the financial importance of yttrium oxysulfide: europium as the red phosphor of color television tubes, they allowed us almost a decade of close cooperation aimed at understanding the performance of this phosphor. It is significant that we shared an approach to research in an industrial laboratory which allowed us to avoid the lure of "first-principles" approaches (which would have been severely premature) and freed us to formulate and to study the important issues directly. We searched for a semiquantitative understanding of the properties observed in luminescence, i. e., where energy absorption occurs, where emission occurs, and with what efficiency this conversion process takes place. We were aware that the nonradi ative transition rates found in practice vary enormously with temperature and, for a given activator, with small changes in its environment. We traced the source of this enormous variation to the magnitude of the vibrational overlap integrals, which have strong dependences on the rearrangements occurring during optical transitions and on the vibrational number of the initial electronic state. We were willing to excise from the problem the electronic aspects - the electronic wavefunctions' and their transition integrals -by treating them as parameters to be obtained from the experimental data."

Although the chemistry of boron is still relatively young, it is developing at a pace where even specific areas of research are difficult to compile into a monograph. Besides the boron hydrides, boron-nitrogen compounds are among the most fascinating derivatives of boron. Nitrogen compounds exist in a wide variety of molecular structures and display many interesting properties. The combination of nitrogen and boron, however, has some unusual features that are hard to match in any other combination of elements. This situation was first recognized by ALFRED STOCK and it seems proper to pay tribute to his outstanding work in the area of boron chemistry. One should realize that about forty years ago, STOCK and his coworkers had to develop completely new experimental techniq'\les and that no guidance for the interpreta tion of their rather unusual data had been advanced by theoretical chemists. In this monograph an attempt has been made to explore the general characteristics of structure and the principles involved in the preparation and reactions of boron-nitroge compounds. It was a somewhat difficult task to select that information which appears to be of the most interest to "inorganic and general chemistry" since the electronic relationship between a boron-nitrogen and a carbon-carbon grouping is reflected in the "organic" character of many of the reactions and compounds."

A unique selection of papers on the most recent progress in the modelling of biological molecules containing metal ions. New approaches and techniques in this field are allowing researchers to discuss structures, electronic properties and reaction mechanisms of metalloproteins on the basis of computational studies. The book discusses different approaches in the development of new force fields and their application to the computation of the structures, electronic properties and dynamics of bioinorganic compounds as well as quantum mechanical and integrated QM/MM methods for understanding the function of metalloenzymes and the calculation of electrostatic interactions.

Even brilliant colors are all bound to scatter, Who in our changing world can stay forever? From Iroha-uta, ancient Buddhistic poem of Japan For many years we have been engaged in the preparation and characterization of new metal complexes and chelates, and especially the interpretation of their electronic spectra in solutions. In the course of these studies, we have encountered a number of strange changes in color which occur upon heating, cooling or compressing the solutions, or changing the nature of the solvent. Similar effects of temperature and pressure on the color were often also observed in the solid state. Records of visual observations, spectral measurements, and their interpretations and analyses accumulated each year, until we found ourselves, quite suddenly, in the middle of a fantastic world of color changes - the world of inorganic thermochromism and related chromo tropic phenomena. This book is a result of the reviews by Sone and Prof. S. Utsuno (Kagaku no Ryoiki, 22, 222 (1968); Bunko Kenkyu, 25,123 (1976)), and a series of papers by Fukuda, Sone et al. published in the 1. Inorg. Nucl. Chern., Bull. Chern. Soc. Japan, and various other journals after 1970.

This book is devoted to nonmetal-to-metal transitions. The original ideas of Mott for such a transition in solids have been adapted to describe a broad variety of phenomena in condensed matter physics (solids, liquids, and fluids), in plasma and cluster physics, as well as in nuclear physics (nuclear matter and quark-gluon systems). The book gives a comprehensive overview of theoretical methods and experimental results of the current research on the Mott effect for this wide spectrum of topics. The fundamental problem is the transition from localized to delocalized states which describes the nonmetal-to-metal transition in these diverse systems. Based on the ideas of Mott, Hubbard, Anderson as well as Landau and Zeldovich, internationally respected scientists present the scientific challenges and highlight the enormous progress which has been achieved over the last years. The level of description is aimed to specialists in these fields as well as to young scientists who will get an overview for their own work. A common feature of all contribution is the extensive discussion of bound states," i.e. their formation and dissolution due to medium effects. This applies to atoms and molecules in plasmas, fluids, and small clusters, excitons in semiconductors, or nucleons, deuterons, and alpha-particles in nuclear matter. In this way, the transition from delocalized to localized states and vice versa can be described on a common level."

The two-word title of this book can only give an indication about its content and approach to the subject it deals with. In the course of time, the term has gradually become somewhat blurred. The reason is easy to see: similar problems are now more and more frequently studied by different branches of natural science. The term "mixed crystals" has acquired specific connotations in physics, chemistry, biology, and geology. One and the same term can now serve as a name for things which are either not quite the same or sometimes quite different. And this is precisely what happened to the two words in the title of the book. One of them, the term "crystal," for which crystallography had an un ambiguous definition, is now employed by biologists to describe the structure of cell membranes and by chemists who use it to denote degrees of polymer crystallinity. "Crystal" has thus become a broad term that can help describe any solid, or just a condensed state of a substance, if the solid has a suf ficient degree of order in the arrangement of its components. But the book is called " lixed Crystals." The other word in its title, the adjective "mixed," has also developed several meanings. It is now thought ap plicable to both homogeneous and heterogeneous systems, that is, to crystals composed of different molecules and also to solids that are a mixture of crys tals with different structures."

Each chapter of "Phosphorus Compounds: Advanced Tools in Catalysis and Material Sciences" have been carefully selected by the editors in order to represent a state-of-the-art overview of how phosphorus chemistry can provide solutions in various fields of applications.

The editors have assembled an international array of world-renowned scientists and each chapter is written by experts in the fields of synthetic chemistry, homogeneous catalysis, dendrimers, theoretical calculations, materials science, and medicinal chemistry with a special focus on the chemistry of phosphorus compounds.
"Phosphorus Compounds: Advanced Tools in Catalysis and Material Sciences" is of interest to a general readership ranging from advanced university course students to experts in academia and industry.

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.

The correlation of spectroscopic and chemical investigations in recent years has been highly beneficial of many reasons. Around 1950, no valid explanation was available of the colours of compounds of the five tran sition groups. Later, it was possible to identify the excited levels with those expected for an electron configuration with adefinite number of electrons in the partly filled shell. I t is not generally recognized that this is equivalent to determining spectroscopic oxidation states related to the preponderant electron configuration and not to estimates of the fractional atomic charges. This brings in an entirely different type of description than the formal oxidation numbers used for characterizing compounds and reaction schemes. However, it must be realized that collectively oxidized ligands, formation of cluster-complexes and catenation may prevent the oxidation state from being well-defined. The writer would like to express his gratitude to many, but first of all to DR. CLAUS SCHAFFER, University of Copenhagen, who is the most efficient group-theoretical engineer known to the writer; his comments and discussions have been highly valuable. The writer's colleague, Pro fessor FAUSTO CALDERAZZO (now going to the University of Pisa) has been most helpful in metallo-organic questions. Thanks are also due to Professors E. RANcKE-MADsEN and K. A. JENSEN for correspondence and conversations about formal oxidation numbers."

A wonderfully successful NATO Advanced Study Institute on "Sulfur-Centered Reactive Intermediates in Chemistry and Biology" was held 18-30 June, 1989, at the Hotel Villa del Mare in Maratea, Italy. Despite the beautiful setting with mountains behind us and over looking the clear blue Mediterranean Sea under a cloudless sky (and with a private beach available), the lectures were extremely well attended. While some credit can go to the seriousness of the students, more must go to the calibre of speakers and the high quality of C. Chatgilialoglu, and Co-Director, Professor K. -D. their presentations. The Director, Dr. Asmus, are to be congratulated for putting together such an outstanding scientific program. Dr. Chatgilialoglu is also to be commended for arranging an equally stimulating social pro gram which included bus, train and boat trips to many local sites of interest. It was particularly fitting that a meeting on the chemistry and biochemistry of sulfur should be held in Italy since Italian chemists have made major contributions to our under standing of the organic chemistry of sulfur, including the chemistry of its reactive inter mediates. The early Italian interest in sulfur chemistry arose from the fact that Italy, or more specifically, Sicily, was a major world producer of sulfur prior to the development and exploitation of the Frasch process in Texas and Louisiana.

This book deals with selected aspects of structural chemistry, concentrating particularly on molecular and Raman spectroscopy. The authors of the various chapters were chosen from friends, colleagues and past students of Len Woodward. It is our hope that the book will prove useful both to honours students and to research workers. We would like to thank all our contributors for their willing cooperation in this endeavour. We are also grateful to all those who have given permission for the reproduction of copyright material from other publica tions; specific acknowledgments are made in each chapter. We are par ticularly indebted to the Principal and Fellows of Jesus College, Oxford, and the artist, H. A. Freeth, R.A., for permission to reproduce the portrait of Len Woodward which forms the frontispiece. Our thanks are also due to Mrs. J. Stevenson, who undertook a great deal of the secretarial work associated with the organization of this volume, and to Mr. P. Espe who photographed the portrait. The royalties from the sale of this book will, in the first instance, go to Jesus College, Oxford, and will be used for the establishment of a prize to be associated with Len Woodward's name."

To the surprise of practically no one, research and engineering on multi polymer materials has steadily increased through the 1960s and 1970s. More and more people are remarking that we are running out of new monomers to polymerize, and that the improved polymers of the future will depend heavily on synergistic combinations of existing materials. In the era of the mid-1960s, three distinct multipolymer combinations were recognized: polymer blends, grafts, and blocks. Although inter penetrating polymer networks, lPNs, were prepared very early in polymer history, and already named by Millar in 1960, they played a relatively low-key role in polymer research developments until the late 1960s and 1970s. I would prefer to consider the IPNs as a subdivision of the graft copolymers. Yet the unique topology of the IPNs imparts properties not easily obtainable without the presence of crosslinking. One of the objectives of this book is to point out the wealth of work done on IPNs or closely related materials. Since many papers and patents actually concerned with IPNs are not so designated, this literature is significantly larger than first imagined. It may also be that many authors will meet each other for the first time on these pages and realize that they are working on a common topology. The number of applications suggested in the patent literature is large and growing. Included are impact-resistant plastics, ion exchange resins, noise-damping materials, a type of thermoplastic elastomer, and many more."

In May of 1978, several hundred of the friends, colleagues and former students of Professor Herbert C. Brown gathered on the campus of Purdue University to note his formal retirement, to honor him for his past contributions to chemistry and to wish him continued success in research. It was a time of reunion and recollection, a time for looking back and giving recognition to a lifetime of accomplishment. There was the ceremony of a banquet, presided over with inimitable wit by Professor Derek Davenport, and the dedication of the Herbert C. Brown Archives, with addresses by Dr. Alfred Bader, of Aldrich Chemicals, and Dr. Alan Schriesheim, of Exxon. There was the publi cation of a book of the personal reminiscences of students and post doctoral colleagues - "Remembering HCB." But it was also a time for looking at the present and into the future with a set of scien tific lectures, mainly by former students or associates, who des cribed their current or projected research activities. That is what this book is about. The papers, some of which are expanded versions of the lectures, fall into two broad groups - some deal with the interplay of struc ture and mechanism, the others deal with the use of organometallics in synthesis. It is, perhaps, no accident that these are the two main areas of H. C. Brown's research interest."

The first concern of scientists who are interested in synthetic polymers has always been, and still is: How are they synthesized? But right after this comes the question: What have I made, and for what is it good? This leads to the important topic of the structure-property relations to which this book is devoted. Polymers are very large and very complicated systems; their character ization has to begin with the chemical composition, configuration, and con formation of the individual molecule. The first chapter is devoted to this broad objective. The immediate physical consequences, discussed in the second chapter, form the basis for the physical nature of polymers: the supermolecular interactions and arrangements of the individual macromolecules. The third chapter deals with the important question: How are these chemical and physical structures experimentally determined? The existing methods for polymer characterization are enumerated and discussed in this chapter. The following chapters go into more detail. For most applications-textiles, films, molded or extruded objects of all kinds-the mechanical and the thermal behaviors of polymers are of pre ponderant importance, followed by optical and electric properties. Chapters 4 through 9 describe how such properties are rooted in and dependent on the chemical structure. More-detailed considerations are given to certain particularly important and critical properties such as the solubility and permeability of polymeric systems. Macromolecules are not always the final goal of the chemist-they may act as intermediates, reactants, or catalysts. This topic is presented in Chapters 10 and 11."

Almost thirty years ago the author began his studies in colloid chemistry at the laboratory of Professor Ryohei Matuura of Kyushu University. His graduate thesis was on the elimination of radioactive species from aqueous solution by foam fractionation. He has, except for a few years of absence, been at the university ever since, and many students have contributed to his subsequent work on micelle formation and related phenomena. Nearly sixty papers have been published thus far. Recently, in search of a new orientation, he decided to assemble his findings and publish them in book form for review and critique. In addition, his use of the mass action model of micelle has received much criticism, especially since the introduction of the phase separation model. Many recent reports have postulated a role for Laplace pressure in micellization. Although such a hypothesis would provide an easy explanation for micelle formation, it neglects the fact that an interfacial tension exists between two macroscopic phases. The present book cautions against too ready an acceptance of the phase separation model of micelle formation. Most references cited in this book are studies introduced in small group meetings of colloid chemists, the participants at which included Professors M. Saito, M. Manabe, S. Kaneshina, S. Miyagishi, A. Yamauchi, H. Akisada, H. Matuo, M. Sakai, and Drs. O. Shibata, N. Nishikido, and Y. Murata, to whom the author wishes to express his gratitude for useful discussions.

Biochemistry of Scandium and Yttrium gathers together existing knowledge about scandium and yttrium from a wide variety of disciplines. Part 2 addresses the biochemical aspects of these two elements, and the various medical and environmental applications. (Part 1 presents a comparative study of the physical and chemical properties of scandium and yttrium, looking at both their similarities and their differences.) While these elements are relatively rare in nature, these books will show that they have unusual physical and chemical properties, and a disproportionate number of important applications. Improved analytical techniques have revealed that scandium and yttrium are present throughout living matter, even though only a relatively limited number of species have been analyzed so far. This fact of course has far-ranging implications for biological and environmental concerns. The major impacts of scandium and yttrium in science, technology, and medicine will be of interest to a wide variety of researchers, including geochemists, inorganic and organic chemists, clinical biochemists, and those specializing in environmental protection.

The field of gas phase inorganic ion chemistry is relatively new; the early studies date back approximately twenty years, but there has been intense interest and development in the field in the last ten years. As with much of modern chemistry, the growth in gas phase inorganic ion chemistry can be traced to the development of instrumentation and new experimental methods. Studies in this area require sophisticated instruments and sample introduc tion/ ionization methods, and often these processes are complicated by the need for state-selecting (or collisionally stabilizing) the reactive species in order to assign the chemistry unequivocally. At the present level of experimental development, a wide range of experiments on diverse ionic systems are possible and many detailed aspects of the chemistry can be studied. Gas Phase Inorganic Chemistry focuses on the reactions of metal ions and metal clusters, and on the study of these species using the available modern spectroscopic methods. Three of the twelve chapters cover the chemistry of ionic monometal transition metal ions and the chemistry of these species with small diatomics and model organics. Two of the chapters focus on the studies of the chemical and physical properties of (primarily) transition metal clusters, and these chapters review experimental methods and capabilities. Two chapters also deal with the chemistry of transition metal carbonyl clusters, and these chapters address issues important to cluster growth and activation as well as the characterization of such species."

This book is about compounds such as the boron hydrides and associated metal hydrides and alkyls which acquired the label 'electron deficient' when they were thought to contain too few valence electrons to hold together. Though they are now recognized as containing the numbers of bonding electrons appropriate for their structures, the term 'electron deficient' is still commonly applied to many substances that contain too few valence electrons to provide a pair for every pair of atoms close enough to be regarded as covalently bonded. The study of such substances has contributed much to chemistry. Techniques for the vacuum manipulation of volatile substances were devised specifically for their study; developments in valence theory resulted from considerations of their bonding; and the reactivity of several (for example, diborane and complex metal hydrides, lithium and aluminium alkyls) has made them valuable reagents. The purpose of this book is to provide an introduction to the chemistry of these fascinating compounds. The experimental and spectroscopic methods by which they can be studied are outlined, the various types of structure they adopt are described and profusely illustrated, and the relative merits of extended valence bond and simple molecular orbital treatments of their bonding are discussed, with as liberal use of diagrams and as limited recourse to the Greek alphabet as possible. A recurring theme is the importance attached to considerations of molecular sym metry. Their reactions are treated in sufficient detail to show whether these reflect any deficiency of electrons."

Electronic Properties of Fullerenes and other Novel Materials gives an overview of the state-of-the-art research. It presents most recent results on preparation, experimental analysis by electron spectroscopy, infrared and Raman spectroscopy, luminescence, and nonlinear optical, as well as possible technological applications. Emphasis is also placed on the superconducting properties of Fullerenes. The introductory and advanced contributions provide a good survey of the current status of this rapidly developing field.

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."

217 2. COPOLYMERIZATION OF PROPENE OR HIGHER I-ALKENES WITH 218 CARBON MONOXIDE 2. 1. Ligands and polymerization conditions 218 2. 2. Spiroketal formation 221 2. 3. Enantioselectivity 222 2. 4. Higher I-Alkenes 226 3. COPOLYMERIZATION OF STYRENE OR ITS DERIVATIVES WITH 226 CARBON MONOXIDE 4. COPOLYMERIZATION OF OTHER OLEANS WITH CARBON MONOXIDE 230 5. ASYMMETRIC TERPOLYMERIZATION OF MORE THAN Two KINDS OF 232 OLEFINS WITH CARBON MONOXIDE 6. POLYKETONE CONFORMATION 233 7. CONCLUSION 234 Chapter 8. Chain Propagation Mechanisms 237 Ayusman Sen 1. INTRODUCTION 237 2. PALLADIUM (II) BASED SYSTEMS 238 3. NICKEL (II) BASED SYSTEMS 256 4. RHODIUM (I) BASED SYSTEMS 257 5. CONCLUSION 261 Chapter 9. Theoretical Studies on Copolymerization of Polar Monomers 265 Peter Margl, Artur Michalak, and Tom Ziegler 1. INTRODUCTION 265 2. COPOLYMERIZATION OF CARBON MONOXIDE WITH ETHYLENE 267 2. 1. Experimental and calculated rates for the insertion processes for 267 copolymerization catalysed by Pd(II) systems. 2. 2. A more detailed look at the productive and unproductive cycles 270 in copolymerization catalysed by Pd(II) complexes. 2. 2. 1. The productive cycle 270 2. 2. 2. C2H4 misinsertion into an ethylene terminated polyketone 275 chain 2. 3. Experimental and calculated rates for the insertion processes for 277 alternating copolymerization catalyzed by Ni(II) systems 3. COPOLYMERIZATION OF OLEFINS WITH POLAR MONOMERS OTHER 280 THAN CO 3. 1. Preferred binding mode of oxygen containing monomers 282 3. 2. Preferred binding mode of nitrogen containing monomers 285 3. 3.

This is a textbook of what is often called magnetochemistry. We take the point of view that magnetic phenomena are interesting because of what they tell us about chemical systems. Yet, we believe it is no longer tenable to write only about such subjects as distinguishing stereochemistry from the measurement of a magnetic susceptibility over a restricted temper ature region; that is, paramagnetism is so well-understood that little remains to explore which is of fundamental interest. The major purpose of this book is to direct chemists to some of the recent work of physicists, and in particular to a lengthy exposition of magnetic ordering phenomena. Chemists have long been interested in magnetic interactions in clusters, but many have shied away from long-range ordering phenomena. Now however more people are investigating magnetic behavior at temperatures in the liquid helium region, where ordering phenomena can scarcely be avoided. The emphasis is on complexes of the iron-series ions, for this is where most of the recent work, both experimental and theoretical, has been done. The discussion therefore is limited to insulating crystals; the nature of magnetism in metals and such materials as semiconductors is sufficiently different that a discussion of these substances is beyond our purposes. The book is directed more at the practical experimentalist than at the theoretician."

Electrochemical synthesis of inorganic compounds is a relatively unknown field. The successful, large industrial processes, such as chlorine-caustic production, are well known, but the large number of other compounds that have been synthesized electrochemically are much less appreciated, even by electrochemists and inorganic chemists. The last comprehensive book on this subject was published in the 1930's and no modern review or summary of the whole field is in existence. But the field is in no way dormant, as attested by the large number of publications, undiminished throughout the years, describing new syntheses and improvements of old ones. Indeed, it can be expected that practical applications of electrochemical inor ganic syntheses will increase in the future as an increasing portion of our energy will be available in electrical form. Electrochemical processes have important advantages over chemical routes: often the selectivity of the reaction can be better controlled through the use of potential control at the electrode, and the creation of environmen tally harmful waste material can be avoided more easily since one is using the purest reagent - the electron. In addition to development of new synthetic routes, many old ones, which were found to be un economical in the past, are worth reexamining in light of the recent considerable advances in cell design principles, materials of construc tion, and electrode and separator materials, together with our im proved understanding of electrode reactions and electrocatalysis. It is in the hope of accelerating this process that this bibliography is published."

This sourcebook is the detailed review of the chemistry, manufacturing processes, and uses of resorcinol and its derivatives. Citing over 1,900 references, the author clearly explains the chemical s complex development, discussing the many tests, techniques, and instruments used.