The art and science of macromolecular architecture is based on synthesis, analysis, processing, and evaluation of physical properties of polymers. The growing specificity of available synthetic methods and the increasing refinement of analytical and physical analysis are gradually providing a deeper insight into structure-property relationships of polymers, upon which many applications can be based. This book deals with recent methods for polymer synthesis. Those that lead to specific structures have been selected especially. Background, mechanism scope and limitations, and illustrative procedures are given for each method. With this layout the editor hopes that the book will provide a practical guideline, for the synthetic polymer chemist in industry or at a university graduate school, on how to apply the methods in the design of new polymer structures. The editor is grateful to the authors not only for their contributions containing interesting new developments in polymer synthesis, but also for the way they have fitted their text into the general framework of the book. The elegant chemistry described in the following chapters will, it is hoped, inspire more organic chemists to apply their skills to polymer synthesis, where the beauty of organic chemistry in terms of structural control and reactivity may be even more apparent than in the low molecular field.

Many chemical processes that are important to society take place at boundaries between phases. Understanding these processes is critical in order for them to be subject to human control. The building of theoretical or computational models of them puts them into a theoretical framework in terms of which the behavior of the system can be understood on a detailed level. Theoretical and computational models are often capable of giving descriptions of interfacial phenomena that are more detailed, on a molecular level, than can be obtained through experimental observation. Advances in computer hardware have also made possible the treatment of larger and chemically more interesting systems. The study of interfacial phenomena is a multi-disciplinary endeavor which requires collaboration and communication among researchers in different fields and across different types of institutions. Because there are many important problems in this field much effort is being expended to understand these processes by industrial laboratories as well as by groups at universities. Our conference titled "Theoretical and Computational Approaches to Interface Phenomena" held at South Dakota State University, August 2-4, 1993 brought together over thirty scientists from industry and academia and three countries in the western hemisphere to discuss the modeling of interfacial phenomena.

Polyoxometalates are discrete early transition metal-oxide cluster anions and comprise a class of inorganic complexes of unrivaled versatility and structural variation in both symmetry and size, with applications in many fields of science. Recent findings of both electron-transfer processes and magnetic exchange-interactions in polyoxometalates with increasing nuclearities, topologies, and dimensionalities, and with combinations of different magnetic metal ions and/or organic moieties in the same lattice attract strong attention towards the design of nano-composites, since the assemblies of metal-oxide lattices ranging from insulators to superconductors form the basis of electronic devices and machines in present-day industries. The editors organized the symposium, "Polyoxometalate Chemistry for Nano-Composite Design" at the Pacifichem 2000 Congress, held in Honolulu on December 17-19, 2000. Chemists from several international polyoxometalate research groups discussed recent results, including: controlled self-organization processes for the preparation of nano-composites; electronic interactions in magnetic mixed-valence cryptands and coronands; synthesis of the novel polyoxometalates with topological or biological significance; systematic investigations in acid-base and/or redox catalysis for organic transformations; and electronic properties in materials science. It became evident during the symposium that the rapidly growing field of polyoxometalates has important properties pertinent to nano-composites. It is therefore easy for polyoxometalate chemists to envisage a "bottom-up" approach for their design starting from individual small-size molecules and moieties which possess their own functionalities relevant to electronic/magnetic devices (ferromagnetism, semiconductivity, prot- conductivity, and display), medicine (antitumoral, antiviral, and antimicrobacterial activities), and catalysis.

This treatise is a compendium of refereed papers based on invited talks presented at the American Chemical Society Symposium on Electrorheological (ER) Materials and Fluids. ER fluids were first investigated 50+ years ago. These fluids, which change rheology when placed in an electric field, were recognized, from the beginning, for allowing an extremely efficient interface between electrical control and mechanical devices. Critical problems, however, existed with the initial fluids, which prevented them from serious consideration for large-scale applications. While over time some of the critical problems have been solved and activity in ER technology has increased, commercial success has remained elusive. A recent Department of Energy report concluded that a primary reason for the failure to commercialize this promising technology is due to a lack in understanding the physics and chemistry of how the materials work. The goal of the symposium was to address the issue of understanding how ER materials work and how they can be used. One of the outcomes of the symposium, which we hope is conveyed in this book, is a feeling that if the mechanism of ER is to be fully understood and improved, expertise from diverse fields must be applied to the problem.

This volume chronicles the proceedings of the Symposium on Metallized Plastics: Fundamental and Applied Aspects held under the auspices of the Dielectrics and Insulation Division of the Electrochemical Society in Chicago, October 10-12, 1988. This was the premier symposium on this topic and if the comments from the attendees are any barometer of the success of a symposium then it was a grand success. Concomitantly, it has been decided to hold it on a regular basis (at intervals of 18 months) and the second event in this series is planned as a part of the Electrochemical Society meeting in Montreal, Canada, May 6-10, 1990. Metallized plastics find a legion of applications ranging from mundane to very sophisticated. A complete catalog of the various technological applications of metallized plastics will be prohibitively long, so here some eclectic examples should suffice to show why there is such high tempo of R&D activity in the arena of metallized plastics, and all signals indicate that this high tempo will continue unabated. For example, polymeric films are metallized for packaging (food and other products) purposes, and the applications of metallized plastics in the automotive industry are quite obvious. In the field of microelectronics and computer technology, insulators are metallized for interconnection and other functional purposes. Also plastics are metallized to provide electromagnetic shielding.

Molecular similarity has always been an important conceptual tool of chemists, yet systematic approaches to molecular similarity problems have only recently been recognized as a major contributor to our understanding of molecular properties. Advanced approaches to molecular similarity analysis have their foundation in quantum similarity measures, and are important direct or indirect contributors to some of the predictive theoretical, computational, and also experimental methods of modern chemistry. This volume provides a survey of the foundations and the contemporary mathematical and computational methodologies of molecular similarity approaches, where special emphasis is given to applications of similarity studies to a range of practical and industrially significant fields, such as pharmaceutical drug design. The authors of individual chapters are leading experts in various sub-fields of molecular similarity analysis and the related fundamental theoretical chemistry topics, as well as the relevant computational and experimental methodologies. Whereas in each chapter the emphasis is placed on a different area, nevertheless, the overall coverage and the wide scope of the book provides the reader with a general yet sufficiently detailed description that may serve as a good starting point for new studies and applications of molecular similarity approaches. The editors of this volume are grateful to the authors for their contributions, and hope that the readers will find this book a useful and motivating source of information in the rapidly growing field of molecular similarity analysis.

* Much progress has been made in the last 8 years in understanding the theory and practice of silane coupling agents. A major advance in this direction was the measurement of true equilibrium constants for the hydroly sis and formation of siloxane bonds. Equilibrium constants for bond reten tion are so favorable that a silane coupling agent on silica has a thousandfold advantage for bond retention in the presence of water over an alkoxysilane bond formed from hydroxy-functional polymers and silica. In practice, the bonds of certain epoxies to silane-primed glass resist debonding by water about a thousand times as long as the epoxy bond to unprimed glass. Oxane bonds of silane coupling agents to metal oxides seem to follow the same mechanism of equilibrium hydrolysis and rebonding, although equilibrium constants have not been measured for individual metal-oxygen silicon bonds. This suggests, however, that methods of improving bond retention to glass will also improve the water resistance of bonds to metals. of standard coupling agents with a hydrophobic silane or one Modification with extra siloxane cross-linking have improved the water resistance of bonds to glass and metals another hundredfold over that obtained with single coupling agents."

This book documents the proceedings of the symposium, "Mineral Scale Formation and Inhibition," held at the American Chemical Society Annual Meeting August 21 to 26, 1994, in Washington, D. C. The symposium, sponsored by the Division of Colloid and Surface Chemistry, was held in honor of Professor George H. Nancollas for his pioneering work in the field of crystal growth from solution. A total of 30 papers were presented by a wide spectrum of scientists. This book also includes papers that were not presented but were in the symposium program. The separation of a solid by crystallization is one of the oldest and perhaps the most frequently used operations in chemistry. Because of its widespread applicability, in recent years there has been considerable interest exhibited by academic and industrial scientists in understanding the mechanisms of crystallization of sparingly soluble salts. The salt systems of great interest in industrial water treatment area (i. e., cooling and boiler) include carbon ates, sulfates, phosphates, and phosphonates of alkaline earth metals. Although not as common as calcium carbonate and calcium sulfate, barium and strontium sulfates have long plagued oil field and gas production operations. The build-up of these sparingly soluble salts on equipment surfaces results in lower heat transfer efficiency, increased corrosion rates, increased pumping costs, etc. In the laundry application, insoluble calcium carbonate tends to accumulate on washed fabrics and washing equipment parts, resulting in undesirable fabric-encrustation or scaling."

Science is not a mere collection of facts. It is the correlation of facts, the interpretative synthesis of the available knowledge and its application that excite the imagination of a scientist. Even in these days of modern technology, the need for quick and accurate dissemination of new information and current concepts still exists. Conferences and Symposia offer one direct method of communication. The Summer Schools are another approach. The success of a Summer School is mainly due to that human factor and under standing that goes with it and allows for extensive and often time-unrestricted discussions. During the course of the past 20 years, one of the most in tensively studied groups of elements in the Periodic Table is the Lanthanides. In this period, we have increased our knowledge on these once exotic elements, which were once considered to be a part of a lean and hungry industry, many-fold due to the involve ment of scientists from various disciplines. The purpose of our Summer School was to bring a group of ex perts and participants together for the exchange of ideas and in formation in an informal setting and to promote interdisciplinary interactions. Out of many conceivable topics, we selected the following five as the main basis to broaden our knowledge and understanding I) Systematics 2) Structure 3) Electronic and Magnetic Proper ties 4) Spectroscopic Properties and 5) Lanthanide Geochemistry."

P.J. van der Put offers students an original introduction to materials chemistry that integrates the full range of inorganic chemistry. Technologists who need specific chemical facts to manipulate matter will also find this work invaluable as an easy-to-use reference. The text includes practical subjects of immediate use for materials such as bonding, morphogenesis, and design that more orthodox materials science volumes often leave out.

Phosphate Fibers is a singular detailed account of the discovery, chemistry, synthesis, properties, manufacture, toxicology, and uses of calcium and sodium calcium polyphosphate fibers. Author Edward J. Griffith-the inventor and developer of this safe, biodegradable material-takes a multidisciplinary approach to this subject, considering the social, legal, medical, and industrial issues surrounding the use of asbestos and other mineral fibers. This compelling study is a beneficial resource to both readers interested in mineral fibers as well as those who want to understand the complexities of bringing new substances into the modern marketplace.

This book is about how to avoid the accidents and injuries that may occur when batteries are abused or mishandled. It is the first book to deal specifically with this subject in a reasonably comprehensive manner accessible to readers ranging from regular consumers to technical specialists. Batteries and battery processes are described in sufficient detail to enable readers to understand why and how batteries cause accidents and what can be done to prevent them. Each year in the United States alone, thousands of individuals are injured by battery accidents, some of which are severely disabling. The tragedy is that such accidents need not occur. The book is intended to satisfy the needs of a varied group of readers: battery users in general, battery engineers, and designers of battery-operated equipment and consumer electronics. Since the book is a reference source of information on batteries and battery chemicals, we believe it may also be useful to those studying the environment as well as to medical personnel called upon to treat battery injuries. There are no prerequisites for an under standing of the text other than an interest in batteries and their safe usage.

Twenty years ago Tanabe and Sugano published the first ligand field energy diagrarns which are applicable to dN electronic configurations. These diagrams are limited in scope in that they can be used only for octahedral symmetry and for a limited number of terms. The present volume is an attempt to fill the gap by providing a reasonable nurober of complete and accurate ligand field energy diagrarns for dN configurations in the most commonly encountered symmetries. Despite their limited nature, the diagrarns of Tanabe and Sugano were exten sively used in the past in order to rationalize optical and luminescence spectra and to discuss various electronic properties of transition metal ions, their coordination compounds and solids. Moreover, Tanabe-Sugano diagrams have an established place in the theory of transition metal compounds and are included in most textbooks of inorganic and coordination chemistry. It is expected that the present diagrarns will be found useful for a similar purpose."

The development of "tailormade" electrode surfaces using electroactive polymer films has been one of the most active and exciting areas of electrochemistry over the last 15 years. The properties of these materials have been examined by a wide range of scientists from a variety of perspectives, and now electroactive polymer research is considered to be a reasonably mature area of research endeavor. Much is now understood about the fundamental mechanism of conduction in these materials. A wide range of electrochemical techniques may be used to probe the conductivity processes in these materials, and more recently, a number of in situ spectroscopic techniques have been used to further elucidate the structure of these materials. The in situ spectroscopies and allied techniques have also been used to obtain correlations between structure and redox activity. The applications found for electroactive polymers are many and varied, and range from thin film amperometric chemical and biological sensors, electrocatalytic systems, drug delivery devices, and advanced battery systems through to molecular electronic devices. The research literature on electroactive polymers is truly enormous and can daunt even the most hardened researcher. The vast quantity of material reported in the literature can also intimidate beginning graduate students. Hence the present book. The original idea for this book arose as a result of a series of lectures on chemically modified eiectrodes and electroactive polymers given by the writer to final-year undergraduates at Trinity College Dublin.

Water-based technology has undergone revolutionary changes during the past two decades. Interest in the properties and uses of water-based coatings, paints and inks has continued to grow since the establishment of the Clean Air Act of 1970. The present book is devoted to recent developments and trends in water-based coating and ink technology. This volume is divided in three broad catagories: (1) Additives and Water-based Coating/Ink Systems, (2) Surface Modifications and Wettability, and (3) Ink/Coating Formulations and Their characterization. The role of various additives to improve the performance and properties of water-based coatings with special reference to surface phenomena such as wettability, adhesion, surface energies, dispersion stability, particle size and size distribution are presented in these sections. This volume documents the proceedings of the International symposium on Surface Phenomena and Additives in Water-Based Coatings and Printing Technology sponsored by the 21st Annual Meeting of the Fine Particle Society (FPS). This meeting was held in San Diego, california, AUgust 21-25, 1990. The symposium upon which this volume is based was organized in four sessions emphasizing several basic and applied aspects of water-based coatings and printing technology. Major topics discussed include advances in water-based technology, water-based flexo and gravure inks, hydrophobically-modified cellulosic thickeners, organosilicones, uv curable silicone release coatings, surface characterization of Ti02 pigments, polymer substrates, flexographic plates and coating films, pigment wetting and dispersing agents, hydrotrope effect in emulsion polymers, film thickness control, particle size measurements, rheological properties, and statistically designed mixtures for ink formulations.

When we see a jumbo jet at the airport, we sometimes wonder how such a huge, heavy plane can fly high in the sky. To the extent that we think in a static way, it is certainly not understandable. In such a manner, dynamics yields behavior quite different from statics. When we want to prepare an iron nitride, for example, one of the most orthodox ways is to put iron in a nitrogen atmosphere under pressures higher than the dissociation pressure of the iron nitride at temperatures sufficiently high to let the nitrogen penetrate into the bulk iron. This is the way thermodynamics tells us to proceed, which requires an elaborate, expensive high-pressure apparatus, sophisticated techniques, and great efforts. However, if we flow ammonia over the iron, even under low pressures, we can easily prepare the nitride-provided the hydrogen pressure is sufficiently low. Since the nitrogen desorption rate is the determining step of the ammonia decomposition on the iron surface, the virtual pressure of nitrogen at the surface can reach an extremely high level (as is generally accepted) because, in such a dynamic system, the driving force of the ammonia decomposition reaction pushes the nitrogen into the bulk iron to form the nitride. Thus, dynamics is an approach considerably different from statics.

Molecular clusters, in the broad sense that the term is commonly understood, today comprise an enormous class of species extending into virtually every important area of chemistry: "naked" metal clusters, transition metal carbonyl clusters, hydrocarbon cages such as cubane (C H ) and dodecahedrane (C H ), 8 8 20 20 organometallic cluster complexes, enzymes containing Fe S or MoFe S 4 4 3 4 cores, high polymers based on carborane units, and, of course, the many kinds of polyhedral borane species. So large is the area spanned by these diverse classes that any attempt to deal with them comprehensively in one volume would, to say the least, be ambitious-and also premature. We are presently at a stage where intriguing relationships between the various cluster families are becoming apparent (particularly in terms of bonding descriptions), and despite large dif ferences in their chemistry an underlying unity is gradually developing in the field. For example, structural changes occurring in Fe S cores as electrons are 4 4 pumped in and out, in some measure resemble those observed in boranes and carboranes. The cleavage of alkynes via incorporation into carborane cages and subsequent cage rearrangement, a sequence familiar to boron chemists, is a thermodynamically favored process which may be related to the behavior of unsaturated hydrocarbons on metal surfaces; analogies of this sort have drawn attention from theorists and experimentalists."

The Plenum Press series, Monographs in Inorganic Chemistry, is intended to fill an obvious need for high-level surveys of recent research in that area, particularly in matters which go beyond the traditional or classical bound aries of the subject. The study of n-bonding of hydrocarbon groups (and their derivatives) to metals is exactly that kind of subject, for it provides a new way of understanding the behavior of metals (which constitute four-fifths of all the chemical elements). In addition, n-bonding has expanded the intriguing area of organometallic chemistry threefold, bringing in all the transition metals, the lanthanides, and the actinides. So much has been discovered and developed in the area of n-bonded "complexes" of the metals that important new industrial processes based on such substances have been developed. A truly comprehensive review of all n-bonded compounds of the metals would now result in an impossibly large and expensive volume, and would require monthly revision. Instead, the present authors have wisely decided to write a survey which outlines the general aspects of preparation, properties, structure, reactions, and uses of such compounds-a survey which can serve as a textbook, but which can also lead the more experienced practitioner to the most advanced literature on the subject. They have clarified and condensed the subject by means of good organization and a liberal use of diagrams-features which will please the general reader."

This series of books, which is published at the rate of about one per year, addresses fundamental problems in materials science. The contents cover a broad range of topics from small clusters of atoms to engineering materials and involve chemistry, physics, and engineering, with length scales ranging from Angstromsup to millimeters. The emphasis is on basic science rather than on applications. Each book focuses on a single area ofcurrent interest and brings together leading experts to give an up-to-date discussion of their work and the work ofothers. Each article contains enough references that the interested reader can accesstherelevant literature. Thanks aregiven to the Center forFundamental Materials Research atMichigan State University forsupportingthis series. M.F. Thorpe, Series Editor E-mail: [email protected] EastLansing, Michigan, September, 1995 PREFACE This book records selected papers given at an interdisciplinary Symposium on Access in Nanoporous Materials held in Lansing, Michigan, on June 7-9, 1995. Broad interest in the synthesis of ordered materials with pore sizes in the 1.0-10 nm range was clearly manifested in the 64 invited and contributed papers presented by workers in the formal fields of chemistry, physics, and engineering. The intent of the symposium was to bring together a small number ofleading researchers within complementary disciplines to share in the diversity of approaches to nanoporous materials synthesis and characterization."

This volume documents the proceedings of the Second Symposium on Metallized Plastics: Fundamental and Applied Aspects held under the aegis of the Dielectric Science and Technology Division of the Electrochemical Society in Montreal, Canada, May 7-10, 1990. The first symposium on this topic was held in Chicago, October 10-12, 1988 and the proceedings of l which have been chronicled in a hard-bound volume l As pointed out in the Preface to the proceedings of the first symposium the metallized plastics find scores of applications ranging from very mundane to very sophisticated. Even a cursory look at the literature will convince that this field has sprouted; and there is every reason to believe that with all the research and development activities taking place, new and exciting applications of metallized plastics will emerge. The program for the second symposium was very comprehensive as it included 46 papers covering many aspects of metallized plastics. This symposium was a testimonial to the brisk research activity and keen interest in the topic of metallized plastics. The success of this symposium reinforced our earlier belief that there was a definite need to hold symposia on this topic on a regular basis. Concomitantly, the third symposium in this vein was held in Phoenix, Arizona, October 13-18, 1991 and the fourth is planned for May 16-21, 1993 in Honolulu, Hawaii. As regards the present volume, it contains a total of 35 papers covering a variety of topics ranging from very fundamental to very applied.

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."

During the past fifteen years commercial interest in compounds containing carbon fluorine bonds has burgeoned beyond all expectations, mainly owing to business opportunities arising from work on biologically active fluoroorganics-particularly agrochemicals, the relentless search for new markets for fluoropolymers and fluoro carbon fluids, developments in the field of medical diagnostics, and the drive to find replacements for ozone-depleting CFCs and Halon fire-extinguishing agents. Judging the situation to warrant the publication of a comprehensive collection of up-to-date reviews dealing with commercial organofluorine compounds within a single volume of manageable size (and hence reasonable cost), we were delighted to be invited by Plenum Publishing Corporation to produce a suitable book. In order to provide an authentic and wide-ranging account of current commercial applications of fluoroorganic materials, it clearly was necessary to assemble a sizeable team of knowledgeable contributing authors selected almost entirely from industry. Through their efforts we have been able to produce an almost complete coverage of the modem organofluorochemicals business in a manner designed to attract a reader ship ranging from experts in the field, through chemists and technologists currently unaware of the extent of industrial involvement with fluoroorganics, to students of applied chemistry. Promised chapters dedicated to perfluoroolefin oxides and 18F labeling of radiopharmaceuticals failed to materialize. This is somewhat unfortunate in view of our aim to achieve comprehensive coverage of the subject.

Hydroxyapatite is the structural prototype of the main inorganic constituent of bone and teeth and, together with fluorapatite, is also one of the principal minerals in commercial phosphate ores. The adsorption characteristics and surface chemistry of hydroxyapatite are important in understanding the growth, dissolution and adhesion mechanisms of bone and tooth tissues and in elucidating the factors in mineral beneficiation such as floation and flocculation. This volume essentially documents the proceedings of the symposium on the same topic held at the American Chemical Society Meeting in Kansas City, MO, September 12-17, 1982. It includes a few papers which were not presented at the symposium but does not comprise the entire program. This volume provides, on a limited scale, a multidisciplinary overview of current work in the field of adsorptive behavior and surface chemistry of hydroxyapatite and includes certain review articles. There are two papers each on adsorption, adsorption and its effects on crystal growth or dissolution kinetics, effects of electrochemical parameters on solubility and adsorption, and newer physical methods (exoemission and high-resolution NMR) of examining hydroxyapatite surface. There is one paper each on structure modelling of apatite surface based on octacalcium phosphate interface and on biodegradation of sintered hydroxyapatite.

Organometallic chemistry belongs to the most rapidly developing area of chemistry today. This is due to the fact that research dealing with the structure of compounds and chemical bonding has been greatly intensified in recent years. Additionally, organometallic compounds have been widely utilized in catalysis, organic synthesis, electronics, etc. This book is based on my lectures concerning basic organometallic chemistry for fourth and fifth year chemistry students and on my lectures concerning advanced organometallic chemistry and homogeneous catalysis for Ph.D. graduate students. Many recent developments in the area of organometallic chemistry as weIl as homogeneous catalysis are presented. Essential research results dealing with a given class of organometallic compounds are discussed briefly. Results of physicochemical research methods of various organometallic compounds as weIl as their synthesis, properties, structures, reactivities, and applications are discussed more thoroughly. The selection of tabulated data is arbitrary because, often, it has been impossible to avoid omissions. Nevertheless, these data can be very helpful in understanding properties of organometaIlic compounds and their reactivities. All physical data are given in SI units; the interatomic distances are given in pm units in figures and tables. I am indebted to Professor S. A. Duraj for translating and editing this book. His remarks, discussions, and suggestions are greatly appreciated. I also express gratitude to Virginia E. Duraj for editing and proofreading.

to the Fundamental and Applied Catalysis Series Catalysis is important academically and industrially. It plays an essential role in the manufacture of a wide range of products, from gasoline and plastics to fertilizers and herbicides, which would otherwise be unobtainable or prohibitively expensive. There are few chemical-or oil-based material items in modem society that do not depend in some way on a catalytic stage in their manufacture. Apart from manu facturing processes, catalysis is finding other important and ever-increasing uses; for example, successful applications of catalysis in the control of pollution and its use in environmental control are certain to increase in the future. The commercial importance of catalysis and the diverse intellectual challenges of catalytic phenomena have stimulated study by a broad spectrum of scientists, including chemists, physicists, chemical engineers, and material scientists. Increas ing research activity over the years has brought deeper levels of understanding, and these have been associated with a continually growing amount of published material. As recently as sixty years ago, Rideal and Taylor could still treat the subject comprehensively in a single volume, but by the 1950s Emmett required six volumes, and no conventional multivolume text could now cover the whole of catalysis in any depth. In view of this situation, we felt there was a need for a collection of monographs, each one of which would deal at an advanced level with a selected topic, so as to build a catalysis reference library.