Enzymes perform the executive role in growth, energy conversion, and repair of a living organism. Their activity is adjusted to their en vironment within the cell, being turned off, switched on, or finely tuned by specific metabolites according to demands at the physiologi cal level. Each enzyme discovered in the long history of enzymology has revealed its own individuality. Even closely related members of a family differ in specificity, stability or regulatory properties. Despite these, at first sight overwhelming aspects of individuality, common factors of enzymic reactions have been recognized. Enzymes are stereospecific catalysts even when a nonspecific process would yield the same product. Knowledge of the detailed stereochemistry of an enzymic reaction helps to deduce reaction mechanisms and to ob tain insight into the specific binding of substrates at the active site. This binding close to catalytically competent groups is related to the enormous speed of enzyme-catalyzed reactions. The physical ba sis of rate-enhancement is understood in principle and further exploit ed in the design of small organic receptor molecules as model enzymes. These aspects of enzyme catalysis are discussed in Session 1. Session 2 emphasizes the dynamic aspects of enzyme substrate inter action. Substrate must diffuse from solution space to the enzyme's surface. This process is influenced and can be greatly facilitated by certain electrostatic propterties of enzymes. The dynamic events during catalysis are studied by relaxation kinetics or NMR techniques."

Barry Trost: Transition metal catalyzed allylic alkylation.- Jeffrey W. Bode: Reinventing Amide Bond Formation.- Naoto Chatani and Mamoru Tobisu: Catalytic Transformations Involving the Cleavage of C-OMe Bonds.- Gregory L. Beutner and Scott E. Denmark: The Interplay of Invention, Observation and Discovery in the Development of Lewis Base Activation of Lewis Acids for Catalytic Enantioselective Synthesis.- David R. Stuart and Keith Fagnou: The Discovery and Development of a Palladium(II)-Catalyzed Oxidative Cross-Coupling of Two Unactivated Arenes.- Lukas Goossen and Kathe Goossen: Decarboxylative Cross-Coupling Reactions.- A. Stephen K. Hashmi: Gold-Catalyzed Organic Reactions.- Ben List: Developing Catalytic Asymmetric Acetalizations.- Steven M. Bischof, Brian G. Hashiguchi, Michael M. Konnick, and Roy A. Periana: The De NovoDesign of CH Bond Hydroxylation Catalysts.- Benoit Cardinal-David, Karl A. Scheidt: Carbene Catalysis: Beyond the Benzoin and Stetter Reactions.- Kenso Soai and Tsuneomi Kawasaki: Asymmetric autocatalysis of pyrimidyl alkanol.- Douglas C. Behenna and Brian M. Stoltz: Natural Products as Inspiration for Reaction Development: Catalytic Enantioselective Decarboxylative Reactions of Prochiral Enolate Equivalents. Hisashi Yamamoto: Acid Catalysis in Organic Synthesis.

Thisbookistalkingabouthowtousesupercriticalwater(SCW)torapidlyproduce micro- and nano-particles of metal oxides, inorganic salts, metals and organics. Itcoversbasicprinciples,experimentalmethodologiesandreactors,particlep- duction,characterizationsandapplicationsaswellastherecentadvancement. Fine particlescanbeproducedbybothchemicalandphysicalprecipitationofproducts from SCW. They can be used as catalysts, materials in ceramics and electronic devices andcompositematerials. Particlesareeasilyproduced continuouslyina owreactorinshortreactiontimes(0. 4s?2min)butcanalsobesynthesizedin batchreactorsforlongreactiontimes(e. g. ,12h). Theycanbeeasilystudiedin-situ microscopically(optical/IR/Raman/SR-XRD)inanopticalmicro-reactor,diamond anvilcell. Thesize,sizedistribution,crystalgrowth&structure,andmorphologyof particlescanbecontrolledbychangingtheconcentrationsofstatingmaterials,pH, pressures,temperatures,heating&coolingrates,organicmodi cations,reducingor oxidizingatmospheres, owratesandreactiontimes. Thisisthe rstbooktosystematicallyintroduceusingSCWforproductionof neparticles. Itisanidealreferencebookforengineers,researchersandgraduate studentsinmaterialscienceandengineering. vii Acknowledgments I would like to thank Drs. T. Ogi & T. Minowa (Biomass Technology Research Center,NationalInstituteofAdvancedIndustrialScienceandTechnology,Japan), and Profs. K. Arai, H. Inomata, R. L. Smith Jr. and T. Adschiri (Chemical Engineering,TohokuUniversity,Japan),whoinitiallyintroducedthehydrothermal andsupercritical uidsareastomewhenIworkedinJapanfrom1996to1999. Thanks are also due to Profs. J. A. Kozinski, R. I. L. Guthrie (Materials Engineering,McGillUniversity,Canada)andI. S. Butler(Chemistry,McGill)for theirguidanceinmyworkonhydrothermalprocessduringmyworkinCanadafrom 1999to2007. Profs. W. Bassett (Geological Sciences, Cornell University) and D. Baker (Earth&PlanetarySciences,McGill)forinstructionsregardingDAC,Dr. I-Ming Chou(U. S. GeologicalSurvey)forusefuldiscussionsofthepressurecalculation procedure. Drs. M. Watanabe and T. Sato (Research Center of Supercritical Fluid Technology, Tohoku University, Japan) for discussions about the experimental set-upofthebatchand owreactors. Drs. S. Xu,H. Assaaoudi,R. HashaikehandA. Sobhy,whoworkedwithmeat McGillinCanada. ix Contents 1 Introduction...1 1. 1 Background ...1 1. 2 RapidExpansionofSupercriticalSolution(RESS)Process ...4 1. 3 SupercriticalAntisolvent(SAS)Process ...4 1. 4 OtherPhysicalProcesses ...5 1. 5 SupercriticalWaterProcess ...5 References...8 2 Supercritical Water Process...11 2. 1 Introduction ...11 2. 2 BatchReactor ...15 2. 3 FlowReactor...18 2. 4 DiamondAnvilCell(DAC)...20 References...25 3 Metal Oxides Synthesis...29 3. 1 Introduction ...29 3. 2 Boehmite(AlOOH) ...30 3. 3 Ferrites...31 3. 4 Phosphor(YAG) ...32 3. 5 LiCoO /LiMn O ...33 2 2 4 3. 6 Ce Zr O (x =0?1)...33 1?x x 2 3. 7 PotassiumHexatitanate,PotassiumNiobateandTitania ...35 3. 8 ZincOxide...38 3. 9 Nickel,Nickel/CobaltOxide...

As we are moving ahead into the 21st century, our hunger for cost effective and environmentally friendly energy continues to grow. The Energy Information Administration of US has forecasted that only in the first two decades of the 21st century, our energy demand will increase by 60% compared to the levels at the end of the 20th century. Fossil fuels have been traditionally the major primary energy sources worldwide, and their role is expected to continue growing for the forecasted period, due to their inherent cost competitiveness compared to non-fossil fuel energy sources. However, the current fossil energy scenario is undergoing significant transformations, especially to accommodate increasingly stringent environmental challenges of contaminants like sulfur dioxide, nitrogen oxides or mercury, while still providing affordable energy. Furthermore, traditional fossil fuel utilization is inherently plagued with greenhouse gas emissions from combustion, especially carbon dioxide from stationary sources as well as from mobile sources. Should worldwide government policies dictate a reduction of greenhouse gas emissions, such as proposed by the Kyoto Protocol and the implementation of carbon taxes, fossil fuels would lose their significant competitive appeal in favor of nuclear energy and renewable energy sources. However, the current non-fossil fuel energy share of the worldwide energy market is merely below 15%, and therefore, it is more likely that fossil fuel energy producers would adapt to the new requirements by developing and implementing emission control technologies, and emission trades among other strategies."

Organic chemistry is constantly concerned with effecting reactions at a particular centre in a complex molecule, and if possible with a high and predictable level of stereoselectivity. In the light of much accumulated ex perience within organic chemistry it is usually possible to assess the likeli hood of alternative reaction pathways at least qualitatively. However, well based expectations can be falsified, and the experiments directed to the synthesis of vitamin B12 which led to Woodward's recognition of orbital symmetry control in organic chemistry are an instructive example. Our limi tations in this respect are very much accentuated in the case of hetero geneous reactions, which present additional problems, and except for very well studied instances, heterogeneous catalysis has remained a relatively empirical area of chemistry. Knowledge in this area has, however, been greatly improved by the development of transition metal complexes which replicate the catalytic properties of the metals, and are effective in a homo geneous reaction system. This development has advanced our understanding of catalysis by making it possible to interpret reactions in strictly molecular terms. In addition, these homogeneously active complexes are frequently more selective than their heterogeneous metallic counterparts either in discriminating between different functional centres in a molecule or in of fering better stereoselectivity. Homogeneous catalysts have now been devised for a number of organic chemical reactions, including hydrogenation, carbonylation, polymerisa tion, and isomerisation and dismutation of alkenes."

The field of organometallic chemistry has emerged over the last twenty-five years or so to become one of the most important areas of chemistry, and there are no signs of abatement in the intense current interest in the subject, particularly in terms of its proven and potential application in catalytic reactions involving hydrocarbons. The development of the organometallic/ catalysis area has resulted in no small way from many contributions from researchers investigating palladium systems. Even to the well-initiated, there seems a bewildering and diverse variety of organic reactions that are promoted by palladium(II) salts and complexes. Such homogeneous reactions include oxidative and nonoxidative coupling of substrates such as olefins, dienes, acetylenes, and aromatics; and various isomerization, disproportionation, hydrogenation, dehydrogenation, car bonylation and decarbonylation reactions, as well as reactions involving formation of bonds between carbon and halogen, nitrogen, sulfur, and silicon. The books by Peter M. Maitlis - The Organic Chemistry of Palladium, Volumes I, II, Academic Press, 1971 - serve to classify and identify the wide variety of reactions, and access to the vast literature is available through these volumes and more recent reviews, including those of J. Tsuji [Accounts Chem. Res. , 6, 8 (1973); Adv. in Organometal. , 17, 141 (1979)], R. F. Heck [Adv. in Catat. , 26, 323 (1977)], and ones by Henry [Accounts Chem. Res. , 6, 16 (1973); Adv. in Organometal. , 13, 363 (1975)]. F. R. Hartley's book - The Chemistry of Platinum and Palladium, App!. Sci. Pub!.

It is now IS years since the first patents in polymer supported metal complex catalysts were taken out. In the early days ion-exchange resins were used to support ionic metal complexes. Soon covalent links were developed, and after an initially slow start there was a period of explosive growth in the mid to late 1970s during which virtually every homogeneous metal complex catalyst ever reported was also studied bound to a support. Both polymers and inorganic oxides were studied as supports, although the great preponderance of workers studied polymeric supports, and of these polystyrene was by far the commonest used. This period served to show that by very careful design polymer-supported metal complex catalysts could have specific advantages over homogeneous metal complex catalysts. However the subject was a complicated one. Merely immobilising a successful metal complex catalyst to a functionalised support rarely yielded other than an inferior version of the catalyst. Amongst the many discouraging results of the 1970s, there were more than enough results that were sufficiently encouraging to demonstrate that, by careful design, supported metal complex catalysts could be prepared in which both the metal complex and the support combined together to produce an active catalyst which, due to the combination of support and complex, had advantages of activity, selectivity and specificity not found in homogeneous catalysts. Thus a new generation of catalysts was being developed.

The continually growing contribution of transition metal chemistry to synthetic organic chemistry is, of course, widely recognized. Equally well known is the difficulty in keeping up-to-date with the multifarious reactions and procedures that seem to be spawned at an ever-increasing rate. These can certainly be summarized on the basis of reviews under the headings of the individual transition metals. More useful to the bench organic chemist, however, would be the opposite type of concordance based on the structural type of the desired synthetic product. This is the approach taken in the present monograph, which presents for each structural entity a conspectus of the transition metal-mediated processes that can be employed in its production. The resulting comparative survey should be a great help in devising the optimum synthetic approach for a particular goal. It is presented from an essentially practical viewpoint, with detailed direc tions interspersed in the Houben-Weyl style. The wide scope of the volume should certainly encourage synthetic organic chemists to utilize fully the range and versatility of these transition metal-mediated processes. This will certainly be a well-thumbed reference book R. A. RAPHAEL Cambridge University v Preface In recent years an enormous amount of work has been done on the catalysis of organic reactions by various transition metal species and on the organic reactivity of organo-transition-metal compounds."

The literature contains tens of thousands of publications and patents devoted to the synthesis, characterization and processing of polymers. Despite the fact that there are more than one hundred elements, the majority of these publications and patents concern polymers with carbon backbones. Furthermore, the limited (by comparison) number of publications on polymers that contain elements other than carbon in their backbones are typically devoted to polymers based on silicon, especially those with Si-O bonds. This disparity is partially a consequence of the dearth of low cost organometallic feedstock chemicals potentially useful for polymer synthesis. It also derives from the lack of general synthetic techniques for the preparation of organometallic polymers. That is, by comparison with the numerous synthetic strategies available for the preparation of organic polymers, there are few such strategies available for synthesizing tractable, organometallic polymers. In recent years, commerical and military performance requirements have begun to challenge the performance limits of organic polymers. As such, researchers have turned to organometallic polymers as a possible means of exceeding these limits for a wide range of applications that include: (1) microelectronics processing (e.g. photoresists) [1]; (2) light weight batteries (conductors and semi-conductors) [2]; (3) non-linear optical devices [3] and, (4) high temperature structural materials (e.g. ceramic fiber processing) [4,5].

Another approach is via the peracid route [10,Il], whereby propylene is epoxidized by an organic peracid, usually peracetic acid. The latter is prepared either by reaction of acetic acid with hydrogen peroxide, or by autoxidation of acetaldehyde. - (3) - (4) ---I...MeC0 H MeCHO +02 3 /'\. (5) MeC0 H + MeCH=CH ---I ...MeCH-CH + MeC0 H 3 2 2 2 Although this method has been extensively studied [10, II] and is often the method of choice for laboratory scale preparations of epoxides, it has not been widely applied on a commercial scale. The reasons are probably to be found in the hazards associated with the handling of these explosive and corrosive peracids on an industrial scale. Nevertheless, several companies continue to groom this method for future commercialization [12]. With organic hydroperoxides becoming available as commercial chemicals, in the last decade propylene oxide process technology has seen the commercializa- tion of the hydroperoxide route. Such a process, developed by Halcon Interna- tional and Atlantic Richfield, is that often referred to as the Halcon or Oxirane process [13]. It involves the reaction of propylene with an alkyl hydroperoxide in the presence of a soluble, metal catalyst (usually a molybdenum compound). The alkyl hydroperoxide is prepared by autoxidation of an appropriate hydro- carbon. For example, tert-butyl hydroperoxide (TBHP) is prepared by autoxida- tion of isobutane. (6) Reaction with propylene gives propylene oxide and tert-butanol as a coproduct.

This book comprises the proceedings of a NATO sponsored Advanced Research Workshop held from 1st November to 6th November 1992 in the delightful Chateau de Florans, Bedoin, Vaucluse, France and entitled 'Elementary Reaction Steps in Heterogeneous Catalysis. ' The organisers are grateful to the Science Committee of NATO for their support of this meeting. This is believed to be the first wide ranging NATO ARW in the field of heterogeneous catalysis for 20 years, following a previous venture organised in Sardinia by Basolo and Burwell, of Northwestern University, Illinois, USA [1]. This volume collects the lecture presentations and reports on the lively Panel discussions. The idea for the meeting evolved from a series of International Symposia on Quantum Chemistry and Mechanism in Heterogeneous Catalysis. The first of these was held in Lyon, France in 1986, the second in Krakow, Poland in 1988 and the third in Berkeley, California in 1990. The organising committee of the present meeting was Bernard Bigot, France, Tony Farragher, Netherlands, Richard Joyner, UK, Mme. Danielle Olivier, France, and Rutger van Santen, Netherlands, (Chairman). We wish to thank all members of the committee but in particular Bernard Bigot, who undertook the very extensive work involved in the local organisation with consummate skill and made our stay in Provence a great pleasure. Bernard Bigot's secretary, Mme. Marie-Noelle Coscat and Richard Joyner's secretary, Mrs. Pat Gibbs, also deserve our considerable thanks. There were fifty-four participants from eleven countries.

Soluble catalysts are used extensively in many branches of chemistry and are indeed a vital constituent of many natural processes. They find wide application throughout the chemical industry where they assist in the production of several million tonnes of chemicals each year. Since homogeneous systems, especially those incorporating transition metals, often function effectively under milder conditions than their heterogeneous counterparts, they are becoming increasingly important at a time when the chemical industry in particular, and society in general, is seeking ways of conserving energy and of making the best possible use of available resources. My principal objective in- writing this book is to engender sufficient enthusiasm for, and knowledge of, the subject in the reader that he or she will be encouraged to begin, or continue, to make their own contribution to advancing our knowledge of homogeneous catalysis. After attempting to acquaint the reader with some of the ground rules I have tried to describe the present scope, and the future potential, of this fascinating field of chemistry by drawing both on academic and on industrial data sources. This approach stems from a personal conviction that future progress could be considerably hastened by a more meaningful dialogue between chemists working both in industrial and in academic research institutions. Wherever possible, examples of the commercial application of homogeneous catalyst systems have been included and no attempt has been made in any way to disguise the many unresolved questions and exciting challenges which still pervade this rapidly developing area.

The rate of advance in areas of science is seldom constant. Usually certain fields effloresce with activity because of the ealization that solutions are possible to long standing important problems. So it is now with asymmetric catalysis, a field which promises to change profoundly the strategic thinking of synthetic chemists. As this Report will show, reagents which can induce catalytic enantiocontrol of chemical transformations could represent the ultimate synthetic method. Nearly all synthetic strategies of complex molecules involve steps which require enantiocontrol and, in many cases, a specific catalytic transformation embodying enan tiocontrol has enormous advantages in terms of the rate and economy of the reaction. Because asymmetric catalysis is in a formative stage, workers with different backgrounds have joined the field. This Workshop had representatives with organometallic, organic, structural, kinetic, enzymatic, microbiological and industrial backgrounds. Each had his own perspective and this Report represents a consensus of this group of eleven people. The result is probably as compre hensive and balanced a view of the subject as is possible at present. It is hoped that those who have until now had but a glancing interest in asymmetric catalysis will find this Report a useful indication of its present state. We believe that asymmetric catalysis will have an increasing impact on the development of chemistry and will eventually dominate much of synthetic and industrial chemistry."

The field of petrochemicals started some years ago with the simple addition reaction of water to propylene for the production of isopropyl alcohol. Currently, the petrochemical industry has become a multi-billion dollar enterprise which encompasses a wide field of chemical products. Almost all the basic organic reactions such as hydrogenation, alkylation, substitution, polymerization, etc. are utilized for the production of these chemicals. It may not, however, have been possible to establish this huge industry without the use of different catalysts. In other words, the great advancements in the catalytic area have supported the vast developments in the petrochemical field. In this book, we have adopted the idea of discussing the petrochemical industry from the point of view of reactants' activities and susceptibilities toward different catalysts. The book is thus classified according to the reaction type. This will eriable students and other users of the book to base their understanding of the petrochemical field on the fundamental principles learned in chemistry. How ever, the first chapter is aimed at establishing some basic facts on the petro chemical industry and its major uses. It discusses, without going into details, the raw materials used, the intermediates and the downstream products. The next eight chapters discuss in some detail the main reactions and the catalysts used for the production of chemicals and polymers from petroleum. The last chapter is devoted to a discussion of some of the practical techniques used in the catalytic field."

The field of phase transfer catalysis is a tribute to the chemists involved in process development research. Phase transfer catalysis is a solution to numerous cost and yield problems encountered regularly in industrial laboratories. In fact, much of the early work in this area was conducted by industrial chemists although the work was not labelled phase transfer catalysis at the time. We certainly do not intend to minimize the contributions of academic chemists to this field, but it is an unalterable fact that much of the early understanding and many of the early advances came from industrial laboratories. A special tribute is due to Dr. Charles Starks of the Continental Oil Company. By the mid sixties, Starks had formulated the principles of phase transfer catalysis and had applied for patents on many reactions that others were later to examine in somewhat greater detail. His mechanistic model of phase transfer catalysis still stands up well today and is a model for much of the thinking in this area. It is fitting that Starks suggested the name "phase transfer catalysis" by which the whole field is now known. We wish to thank a number of people who have aided us in many ways in the preparation of this volume. We very much appreciate the helpful discussions and insights provided by Drs. Henry Stevens and Andrew Kaman of PPG Industries in Barberton, Ohio. We also thank Dr. L. A.

Metal-Ligand Interactions - Structure and Reactivity emphasizes the experimental determination of structure and dynamics, supported by the theoretical and computational approaches needed to establish the concepts and guide the experiments. Leading experts present masterly surveys of: clusters, inorganic complexes, surfaces, catalysis, ab initio theory, density functional theory, semiempirical methods, and dynamics. Besides the presentations of the fields of study themselves, the papers also bring out those aspects that impinge on, or could benefit from, progress in other disciplines. Refined in the fire of an interactive and stimulating conference, the papers presented here represent the state of the art of current research.

New Trends in Enzyme Catalysis and Biomimetic Chemical Reactions embraces modern areas of enzyme catalysis where other books in the field concentrate mainly on kinetic, bioorganic and biochemical aspects of the enzyme catalysis and do not cover biophysical and physicochemical problems. Topics covered include:

-modern physical and kinetic methods of investigation,
-contemporary theories of elementary chemical processes in enzymes,
-structure, dynamics and action mechanism of enzyme active sites,
-concept of pretransition state,
-theory of long-range electron transfer and proton translocation,
-mechanisms of "tough" biochemical reactions (dinitrogen reduction, light energy conversation, water photooxidation, hydroxilation),
-the achievements and problems of biomimetic chemical reactions.

There are only few topics in organometallic chemistry, which have stimulated research activities in as many areas, as transition-metal carbene (alkylidene) complexes. About 25 years after the first planned synthesis of a carbene complex in E.O. Fischer's laboratory in Munich the NATO Advanced Research Workshop on Transition-Metal Carbene Complexes was the first meeting which, brought together scientists from different disciplines to discuss inorganic, organic, theoretical structural catalysis-related aspects of metal carbene chemistry. The 70th birthday of Professor E.O. Fischer was a good occasion for this enterprise. The organizers of the meeting (K.D. Dotz, Marburg; F.R. KreiBl, Munchen; U. Schubert, Wurzburg) were encouraged by the fact that most of the leading scientists in this area were able to participate in the workshop. The very high standard of the contributions is reflected in this book, which contains papers from the majority of the participants. The Proceedings show the state of the art in metal carbene chemistry and will hopefully be a landmark in the development of this area of chemistry. Generous financial support for the workshop and for the preparation of this book was provided by the Scientific Affairs Division of NATO and some companies. The organizers also acknowledge the efforts of the staff of the Bildungs zentrum der Hans-Seidel-Stiftung in Wild bad Kreuth for creating a pleasant and stimulating atmosphere during the conference."

Proceedings of the NATO Advanced Study Institute on New Trends and Applications of Photoelectrochemistry and Photocatalysis for Environment Problems, Cafelu, Palermo, Italy, September 6-18, 1987

The origins of the petrochemical industry can be traced back to the 1920s when simple organic chemicals such as ethanol and isopropanol were first prepared on an industrial scale from by-products (ethylene and propylene) of oil refining. This oil-based petrochemical industry, with lower olefms and aromatics as the key building blocks, rapidly developed into the enormous industry it is today. A multitude of products that are indispensible to modern day society, from plastics to pharmaceuticals, are derived from oil and natural gas-based hydro carbons. The industry had its heyday in the '50s and '60s when predictions of future growth rates tended to be exponential curves. However, two developments that took place in the early '70s disturbed this simplistic and optimistic view of the future. Firstly, the publication of the report for the Cub of Rome on the 'Limits to Growth' emphasized the finite nature of non-renewable fossil fuel resources. Secondly, the Oil Crisis of 1973 emphasized the vulnerability of an energy and chemicals industry that is based largely on a single raw material."

Catalysts are now widely used in both laboratory and industrial-scale chemistry. Indeed, it is hard to find any complex synthesis or industrial process that does not, at some stage, utilize a catalytic reaction. The development of homogeneous transition metal catalysts on the laboratory scale has demonstrated that these systems can be far superior to the equivalent heterogeneous systems, at least in terms of selectivity. is an increasing interest in this field of research from both an Thus, there academic and industrial point of view. In connection with the rapid developments in this area, four universities from the E.E.C (Aachen, FRG; Liege, Belgium; Milan, Italy; and Lille, France) have collaborated to organise a series of seminars for high-level students and researchers. These meetings have been sponsored by the Commission of the E.E.C and state organizations. The most recent of these meetings was held in Lille in September 1985 and this book contains updated and expanded presentations of most of the lectures given there. These lectures are concerned with the field of homogeneous transition metal catalysis and its application to the synthesis of organic intermediates and fine chemicals from an academic and industrial viewpoint. The continuing petroleum crisis which began in the early 1970s has given rise to the need to develop new feedstocks for the chemical industry.

Biological nitrogen fixation provides more than 50% of the total annual input of the essential element nitrogen to world agriculture. Thus, it is of immense agronomic importance and critical to food supplies, particularly in developing countries.

This book, with chapters authored by internationally renowned experts, provides a comprehensive and detailed account of the fascinating history of the process - including the surprising discoveries of molybdenum-independent nitrogenases and superoxide-dependent nitrogenase; a review of Man's attempts to emulate the biological process - most successfully with the commercially dominant Haber-Bosch process; and the current state of the understanding art with respect to the enzymes - called nitrogenases - responsible for biological nitrogen fixation.

The initial chapters use a historical approach to the biological and industrial processes, followed by an overview of assay methodologies. The next set of chapters focuses on the classical enzyme, the molybdenum nitrogenase, and details its biosynthesis, structure, composition, and mechanism of action as well as detailing both how variants of its two component proteins are constructed by recombinant DNA technology and how computational techniques are being applied. The sophisticated chemical modelling of the metal-containing clusters in the enzyme is reviewed next, followed by a description of the two molybdenum-independent nitrogenases - first, the vanadium-containing enzyme and then the iron-only nitrogenase - together with some thoughts as to why they exist Then follows an up-to-date treatment of the clearly "non-classical" properties of the superoxide-dependent nitrogenase, which more closely resembles molybdenum-containing hydroxylases and related enzymes, like nitrate reductase, that it does the other nitrogenases. Each chapter contains an extensive list of references.

This book is the self-contained first volume of a comprehensive seven-volume series. No other available work provides the up-to-date and in-depth coverage of this series and this volume. This book is intended to serve as an indispensable reference work for all scientists working in this area, including agriculture and the closely related metals-in-biology area; to assist students to enter this challenging area of research; and to provide science administrators easy access to vital relevant information.

The development of "high-tech" materials in contemporary industries is deeply related to a detailed understanding of specific surface properties of catalysts which make particular reactions possible. But this understanding presupposes that there exists a body of theory capable of explaining situations not easily accessible to experimental methods and of relating experimental findings among themselves and with theoretical constructs. For these reasons, theoretical developments in surface physics and surface chemistry of transition metal compounds have been of paramount importance in promoting progress in catalysis, electronic devices, corrosion, etc. Although a great variety of spectroscopic methods for analyzing solids and surfaces at molecular scale have been introduced in recent years, nevertheless, many questions about the adsorption sites and intermediates, the effect of promoters, the poisoning of active sites, the nature of segregation of impurities, the process of surface reconstruction, the mechanisms of reactions, etc. have remained unanswered simply because of the great complexity of surface phenomena. It is in this sense that quantum mechanical method- combined with experimental data - may shed some light on the microscopic properties of new surface materials.