In this thesis, the author investigates the chemistry and application of molecules containing urea and amide bonds. These bonds are some of the strongest known and are fundamental to biological processes. The author describes his discovery that sterically hindered ureas undergo solvolysis at room temperature under neutral conditions. This is a remarkable finding, since ureas are inert under these conditions and a general rule of chemistry is that hindered substrates are less reactive. Remarkably, the author translates these results to the correspondingly sterically hindered amides. This thesis has resulted in a number of outstanding publications in high profile journals. The unique method for breaking urea and amide bonds developed in this study is likely to have far reaching consequences for biological protein manipulation.

This book describes state-of-the-art borylation chemistry using copper(I) catalysis. Enantioselective reactions are included to afford a variety of functionalized, complex organoboronate esters, which will find wide application in asymmetric synthesis, drug discovery, and material science. Organoboron compounds are recognized as useful reagents in organic synthesis; therefore, great effort has been devoted to the development of a simple, mild, and efficient method for their preparation in the past several years. However, the synthesis of functionalized organoboron compounds remains a challenging issue because known reactions often require the use of highly reactive organometallic carbon nucleophiles. This book focuses on conceptually new, formal nucleophilic copper(I)-catalyzed borylation reactions with diboron compounds that show high selectivity and excellent functional group compatibility. Theoretical studies based on density functional theory calculations to understand the reaction mechanisms have also been described. Advances in this novel borylation chemistry will allow the rapid and efficient synthesis of complex molecules with potentially interesting properties in combination with the boron functionalization process.

Sean Ashton's doctoral thesis, which he finished at the Technical University in Munich, describes the challenge of constructing a Differential Electrochemical Mass Spectrometer instrument (DEMS). DEMS combines an electrochemical cell with mass spectrometry via a membrane interface, allowing gaseous and volatile electrochemical reaction species to be monitored online. The thesis carefully introduces the fuel cell electrocatalyst development concerns before reviewing the pertinent literature on DEMS. This is followed by the presentation and discussion of the new extended design, including a thorough characterization of the instrument. The capabilities of the new setup are demonstrated in two research studies: The methanol oxidation reaction on Pt and PtRu catalysts, and the electrochemical corrosion of fuel cell catalyst supports. Despite both topics having long since been studied, new insights can be obtained through careful investigations with the new DEMS instrument that are of great, general interest. The thesis and the instrument thus show the way for future investigations in the field.

This book introduces readers to industrially important enzymes and discusses in detail their structures and functions, as well as their manifold applications. Due to their selective biocatalytic capabilities, enzymes are used in a broad range of industries and processes. The book highlights selected enzymes and their applications in agriculture, food processing and discoloration, as well as their role in biomedicine. In turn, it discusses biochemical engineering strategies such as enzyme immobilization, metabolic engineering, and cross-linkage of enzyme aggregates, and critically weighs their pros and cons. Offering a wealth of information, and stimulating further research by presenting new concepts on enzymatic catalytic functions in basic and applied contexts, the book represents a valuable asset for researchers from academia and industry who are engaged in biochemical engineering, microbiology and biotechnology.

The subject of dioxygen activation and homogeneous catalytic oxidation by metal complexes has been in the focus of attention over the last 20 years. The widespread interest is illustrated by its recurring presence among the sessions and subject areas of important international conferences on various aspects of bioinorganic and coordination chemistry as well as catalysis. The most prominent examples are ICCC, ICBIC, EUROBIC, ISHC, and of course the ADHOC series of meetings focusing on the subject itself. Similarly, the number of original and review papers devoted to various aspects of dioxygen activation are on the rise. This trend is due obviously to the relevance of catalytic oxidation to biological processes such as dioxygen transport, and the action of oxygenase and oxidase enzymes related to metabolism. The structural and functional modeling of metalloenzymes, particularly of those containing iron and copper, by means of low-molecular complexes of iron, copper, ruthenium, cobalt, manganese, etc., have provided a wealth of indirect information helping to understand how the active centers of metalloenzymes may operate. The knowledge gained from the study of metalloenzyme models is also applicable in the design of transition metal complexes as catalytsts for specific reactions. This approach has come to be known as biomimetic or bioinspired catalysis and continues to be a fruitful and expanding area of research.

In order to meet the ever-increasing demands for enantiopure compounds, heteroge- ous, homogeneous and enzymatic catalysis evolved independently in the past. Although all three approaches have yielded industrially viable processes, the latter two are the most widely used and can be regarded as complementary in many respects. Despite the progress in structural, computational and mechanistic studies, however, to date there is no universal recipe for the optimization of catalytic processes. Thus, a trial-and-error approach remains predominant in catalyst discovery and optimization. With the aim of complementing the well-established fields of homogeneous and enzymatic catalysis, organocatalysis and artificial metalloenzymes have enjoyed a recent revival. Artificial metalloenzymes, which are the focus of this book, result from comb- ing an active but unselective organometallic moiety with a macromolecular host. Kaiser and Whitesides suggested the possibility of creating artificial metallo- zymes as long ago as the late 1970s. However, there was a widespread belief that proteins and organometallic catalysts were incompatible with each other. This severely hampered research in this area at the interface between homogeneous and enzymatic catalysis. Since 2000, however, there has been a growing interest in the field of artificial metalloenzymes for enantioselective catalysis. The current state of the art and the potential for future development are p- sented in five well-balanced chapters. G. Roelfes, B. Feringa et al. summarize research relying on DNA as a macromolecular host for enantioselective catalysis.

The activation of dioxygen by metal ions has both synthetic potential and biological relevance. Dioxygen is the cleanest oxidant for use in emission-free technologies to minimize pollution of the environment. The book gives a survey of those catalyst systems based on metal complexes which have been discovered and studied in the last decade. They activate molecular oxygen and effect the oxidation of various organic compounds under mild conditions. Much of the recent progress is due to a search for biomimetic catalysts that would duplicate the action of metalloenzymes. Mechanistic aspects are emphasized throughout the book. An introductonary chapter reviews the chemistry of transition metal dioxygen complexes, which are usually the active intermediates in the catalytic reactions discussed. Separate chapters are devoted to oxidation of saturated, unsaturated and aromatic hydrocarbons, phenols, catechols, oxo-compounds, phosphorus, sulfur and nitrogen compounds.

Multi-scale Quantum Models for Biocatalysis explores various molecular modelling techniques and their applications in providing an understanding of the detailed mechanisms at play during biocatalysis in enzyme and ribozyme systems. These areas are reviewed by an international team of experts in theoretical, computational chemistry, and biophysics.

This book presents detailed reviews concerning the development of various techniques, including ab initio molecular dynamics, density functional theory, combined QM/MM methods, solvation models, force field methods, and free-energy estimation techniques, as well as successful applications of multi-scale methods in the biocatalysis systems including several protein enzymes and ribozymes.

This book is an excellent source of information for research professionals involved in computational chemistry and physics, material science, nanotechnology, rational drug design and molecular biology and for students exposed to these research areas."

Atomically dispersed metal cations and small polyatomic cationic structures co-ordinated to the surface of porous matrices exhibit different properties from the same cationic species contained in a bulk oxide or supported on amorphous carriers. This subject is treated to an extensive review, showing how an understanding of it is essential to the development of a new generation of solid catalysts. There are also exciting opportunities to shape the catalytic properties of the transition metal cations in microporous and mesoporous matrices. The book covers both theoretical and experimental aspects, including the distribution of framework Al atoms in Si-rich zeolites, distribution and siting of charge-exchanged metal cations, electronic, adsorptive and catalytic properties of metal cations, and correlation of metal cation structure and siting with catalytic activity.

Giovanni Poli, Guillaume Prestat, Fr d ric Liron, Claire Kammerer- Pentier: Selectivity in Palladium Catalyzed Allylic Substitution.- Jonatan Kleimark and Per-Ola Norrby: Computational Insights into Palladium-mediated Allylic Substitution Reactions.- Ludovic Milhau, Patrick J. Guiry: Palladium-catalyzed enantioselective allylic substitution.- Wen-Bo Liu, Ji-Bao Xia, Shu-Li You: Iridium- Catalyzed Asymmetric Allylic Substitutions.- Christina Moberg: Molybdenum- and Tungsten-Catalyzed Enantioselective Allylic Substitutions.- Jean-Baptiste Langlois, Alexandre Alexakis: Copper-catalyzed enantioselective allylic substitution.- Jeanne- Marie Begouin, Johannes E. M. N. Klein, Daniel Weickmann, B. Plietker: Allylic Substitutions Catalyzed by Miscellaneous Metals.- Barry M. Trost, Matthew L. Crawley: Enantioselective Allylic Substitutions in Natural Product Synthesis.

Troy Townsend's thesis explores the structure, energetics and activity of three inorganic nanocrystal photocatalysts. The goal of this work is to investigate the potential of metal oxide nanocrystals for application in photocatalytic water splitting, which could one day provide us with clean hydrogen fuel derived from water and solar energy. Specifically, Townsend's work addresses the effects of co-catalyst addition to niobium oxide nanotubes for photocatalytic water reduction to hydrogen, and the first use of iron oxide 'rust' in nanocrystal suspensions for oxygen production. In addition, Townsend studies a nickel/oxide-strontium titanate nanocomposite which can be described as one of only four nanoscale water splitting photocatalysts. He also examines the charge transport for this system. Overall, this collection of studies brings relevance to the design of inorganic nanomaterials for photocatalytic water splitting while introducing new directions for solar energy conversion.

Green Chemistry is an inventive science based on fundamental research towards the development of new sustainable chemical processes. There is a great need to create a new type of chemistry focused on a new production system, in order to prepare the younger generation to get a greener future.

The globalization pushes the chemistry community to adopt ethical issues. In this prospect Green Chemistry can achieve the approval of the society by teaching students to be confident in science and at the same time by convincing people that it is possible to attain technological development with respect and care for the environment we live in. This is why it is of foremost importance that education and fundamental research remain strictly connected, so that democracy and development can grow and progress side by side.

This book has been prepared to extend the knowledge of Green Chemistry not disregarding, however, the industrial interest. It is the result of the effort to put together and share the expertise of leading practitioners in the field of Green Chemistry.

The Interuniversity Consortium 'Chemistry for the Environment' is a non-profit organisation established in 1993 in Italy. At present it includes 31 member universities and 80 research units.

The union of covalent and noncovalent chemistries manifested in the mechanical bond represents one of the great chemical triumphs of the last half century. However, until recently, the preparation of mechanically interlocked compounds has often been an inefficient and limiting process. This thesis provides a detailed account of the great strides taken to increase the synthetic accessibility of donor-acceptor mechanically interlocked molecules by the application of highly efficient and ultra mild chemical transformations during their template-directed synthesis. These new departures in synthesis have indeed played a transformative role in that more complex, higher-order, and functional architectures - once only a dream - are now comfortably within reach. Specifically, the formation of mechanical bonds in higher order rotaxanes and catenanes has become ever easier through the use of highly efficient click chemistries. The resulting mechanically interlocked compounds are functional molecular media for a host of applications including information storage, mechanical actuation, and drug release.

This book presents an in-depth study into the utility of -bond metathesis in Group 2 mediated reactivity. A comprehensive introduction defines the state of the art in both Group 2 mediated catalysis and dehydrocoupling. Structural investigations giving rise to a range of mixed s-block metal hydrides including a remarkable dodecabimetallic decahydride are then described. Subsequent extensive mechanistic work focussing on both silicon-nitrogen and boron-nitrogen dehydrocoupling gives insights into both congeneric effects down Group 2 and ligand effects centring upon magnesium. These studies show the striking effects of these factors, as well as the electronic nature of the hydridic coupling partner. Finally, the unprecedented introduction of single-electron transfer steps into Group 2 catalytic manifolds is described. The use of the stable radical TEMPO to induce single-electron transfer to substituents bound to Group 2 centres coupled with -bond metathesis allows a novel hydrogen release from silanes.

In the area of organic chemistry one major challenge we are currently faced with is how to assemble potentially useful molecules in new ways that generate molecular complexity and in sequences that are as efficient as possible. Our efforts in this regard, specifically for the preparation of amino containing compounds incorporating an aromatic ring, are described in this doctoral thesis. We discovered an interesting regioselectivity in an intramolecular Heck reaction, which we studied for a series of substrates that are unbiased in terms of the size of the newly formed ring, where very high levels of selectivity in relation to the new carbon-carbon bond are typically observed. DFT calculations were performed to attempt to shed light on the reaction sequence. This regioselective Heck reaction, combined with the reductive removal of the temporary amino-protecting group, allowed us to synthesize the Sceletium alkaloids: mesembrane, mesembranol and mesembrine.

Polyolefin is a major industry that is important for our economy and impacts every aspect of our lives. The discovery of new transition metal-based catalysts is one of the driving forces for the further advancement of this field. Whereas the classical heterogeneous Ziegler-Natta catalysts and homogeneous early transition metal metallocene catalysts remain the workhorses of the polyolefin industry, in roughly the last decade, tremendous progress has been made in developing non-metallocene-based olefin polymerization catalysts. Particularly, the discovery of late transition metal-based olefin polymerization catalysts heralds a new era for this field. These late transition metal complexes not only exhibit high activities rivaling their early metal counterparts, but more importantly they offer unique properties for polymer architectural control and copolymerization with polar olefins. In this book, the most recent major breakthroughs in the development of new olefin polymerization catalysts, including early metal metallocene and non-metallocene complexes and late transition metal complexes, are discussed by leading experts. The authors highlight the most important discoveries in catalysts and their applications in designing new polyolefin-based functional materials.

Written by a team of internationally recognized experts, this book addresses the most important types of catalytic reactions and catalysts as used in industrial practice. Both applied aspects and the essential scientific principles are described. The main topics can be summarized as follows: heterogeneous, homogeneous and biocatalysis, catalyst preparation and characterization, catalytic reaction engineering and kinetics, catalyst deactivation and industrial perspective.

The demand for selective organic reactions is growing more acute everyday. Indeed, greater product selectivity has an important impact on energy and resource utilization, in terms of reduced process energy requirements for product separation and purification, in terms of low-value by-products, and in terms of environmental acceptance and compatibility. Moreover, more and more chemicals, especially pharmaceuticals, have to be sold in an optically active form. The search for selectivity constitutes a tremendous challenge for the chemists. In the last two decades, homogeneous transition metal based catalysis has emerged as one of the most promising tools for obtaining selectivity. In connection with developments in this area, this book contains updated and expanded versions of most of the lectures presented at a Cornett course held in Trieste (Italy) in 1989 and sponsored by the European Community. A primary aim is to cultivate a deeper understanding of the parameters that govern the selectivities and stimulate a wider utilization of transition metal based catalysis in organic synthesis. All aspects of selectivity, chemo-, regio-, stereo- and enantioselectivity are considered and illustrated by applications in various fields or organic synthesis. The impact of catalysis in oxydation, reduction, carbonylation reactions, carbene chemistry, in Ni and Pd promoted dimerizations, oligomerizations as well as fonctionalisations is stressed, quite often with special emphasis laid on reaction mechanisms. In this aspect, the last chapter examplifies the interest of high pressure NMR and IR when investigating the nature of reaction intermediates in homogeneous reactions.

Since the discovery of ferrocene and the sandwich-type complexes, the development of organometallic chemistry took its course like an avalanche and became one of the scientific success stories of the second half of the twentieth century. Based on this development, the traditional boundaries between inorganic and organic chemistry gradually disappeared and a rebirth of the nowadays highly important field of homogeneous catalysis occurred. It is fair to say that despite the fact that the key discovery, which sparked it all off, was made more than 50 years ago, organometallic chemistry remains a young and lively discipline.

Homogeneous hydrogenation is one of the most thoroughly studied fields of homogeneous catalysis. The results of these studies have proved to be most important for an understanding of the underlying principles of the activation of small molecules by transition metal complexes. During the past three decades homogeneous hydrogenation has found widespread application in organic chemistry, including the production of important pharmaceuticals, especially where a sophisticated degree of selectivity is required. This volume presents a general account of the main principles and applications of homogeneous hydrogenation by transition metal complexes. Special attention is devoted to the mechanisms by which these processes occur, and the role of the recently discovered complexes of molecular hydrogen is described. Sources of hydrogen, other than H2, are also considered (transfer hydrogenation). The latest achievements in highly stereoselective hydrogenations have made possible many new applications in organic synthesis. These applications are documented by giving details of the reduction of important unsaturated substrates (alkenes, alkynes, aldehydes and ketones, nitrocompounds, etc.). Hydrogenation in biphasic and phase transfer catalyzed systems is also described. Finally, a discussion of the biochemical routes of H2 activation highlights the similarities and differences in performing hydrogenation in both natural and synthetic systems. For researchers working in the fields of homogeneous catalysis, especially in areas such as pharmaceuticals, plastics and fine chemicals.

This book shows the different molecular devices used for solar energy conversion and storage and the important characterization techniques for this kind of device. It has five chapters describing representative molecule-based solar cells, such as organic solar cells, dye-sensitized solar cells and hybrid solar cells (perovskite solar cell and quantum dots solar cells). It also includes two chapters demonstrating the use of molecular devices in the areas of solar fuel, water splitting and carbon dioxide reduction. There are further two chapters with interesting examples of solar energy storage related devices, like solar flow battery, solar capacitor and solar energy-thermal energy storage. Three chapters introduce important techniques used to characterize, investigate and evaluate the mechanism of molecular devices. The final chapter discusses the stability of perovskite solar cells. This book is relevant for a wide readership, and is particularly useful for students, researchers and industrial professionals who are working on molecular devices for solar energy utilization.

Bismuth Catalysts in Aqueous Media, by Shu Kobayashi, Masaharu Ueno and Taku Kitanosono.- Pentavalent Organobismuth Reagents in Organic Synthesis: Alkylation, Alcohol Oxidation and Cationic Photopolymerization , by Yoshihiro Matano.- Environmentally Friendly Organic Synthesis Using Bismuth(III) Compounds, by Scott W. Krabbe and Ram S. Mohan.- Bismuth-Catalyzed Addition of Silyl Nucleophiles to Carbonyl Compounds and Imines, by Thierry Ollevier.- Bismuth Salts in Catalytic Alkylation Reactions, by Magnus Rueping and Boris J. Nachtsheim.- New Applications for Bismuth(III) Salts in Organic Synthesis: From Bulk Chemicals to Steroid and Terpene Chemistry, by J. A. R. Salvador, S. M. Silvestre, R. M. A. Pinto, R. C. Santos and C. Le Roux.- Cationic Bismuth-Catalyzed Hydroamination and Direct Substitution of the Hydroxy Group in Alcohols with Amides, by Shigeki Matsunaga and Masakatsu Shibasaki.- Transition-Metal Catalyzed C-C Bond Formation Using Organobismuth Compounds, by Shigeru Shimada and Maddali L. N. Rao.- Bismuth(III) Salts as Synthetic Tools in Organic Transformations, by J. S. Yadav, Aneesh Antony and Basi V. Subba Reddy.

In response to significant developments in sensor science and technology, this book offers insight into the various extended applications and developments of N4 macrocycle complexes in biomimetic electrocatalysis. Chapters are devoted to the chemistry, electronic and electrochemical properties of porphyrin- based polymetallated supramolecular redox catalysts and their applications in analytical and photoelectrochemical molecular devices; the use of porphyrins, phthalocyanines and related complexes as electrocatalysts for the detection of a wide variety of environmentally polluting and biologically relevant molecules; and the use of electropolymerized metalloporphyrin and metallophthalocyanine films as powerful materials for analytical tools, especially for sensing biologically relevant species.

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."

The importance of solid base catalysts has come to be recognized for their environmentally benign qualities, and much significant progress has been made over the past two decades in catalytic materials and solid base-catalyzed reactions. The book is focused on the solid base. Because of the advantages over liquid bases, the use of solid base catalysts in organic synthesis is expanding. Solid bases are easier to dispose than liquid bases, separation and recovery of products, catalysts and solvents are less difficult, and they are non-corrosive. Furthermore, base-catalyzed reactions can be performed without using solvents and even in the gas phase, opening up more possibilities for discovering novel reaction systems. Using numerous examples, the present volume describes the remarkable role solid base catalysis can play, given the ever increasing worldwide importance of "green" chemistry. The reader will obtain an overall view of solid base catalysis and gain insight into the versatility of the reactions to which solid base catalysts can be utilized. The concept and significance of solid base catalysis are discussed, followed by descriptions of various methods for the characterization of solid bases, including spectroscopic methods and test reactions. The preparation and properties of base materials are presented in detail, with the two final chapters devoted to surveying the variety of reactions catalyzed by solid bases.