Chapter 1 - A summary and overview of the application of self-assembled synthetic microenvironment catalysts is presented. The various clusters for which catalytic applications have been reported are introduced together, grouped by mechanism of self-assembly (i.e. hydrogen bond network or metal ligand coordination). The examples of catalysis are then discussed in the context of the nature of charge buildup in the transition state, with neutral reactions presented first, followed by reactions that develop anionic charge in the transition state, and finally reactions that develop cationic charge in the transition state. Chapter 2 - The tetrahedral [Ga4L6]12- supramolecular assembly developed in the Raymond group is shown to catalyze a bimolecular aza-Prins cyclization featuring an unexpected transannular 1,5-hydride transfer. This reaction pathway is promoted by the constrictive binding of the interior microenvironment of the cluster, and is kinetically inaccessible in bulk solution. A thorough investigation of the mechanism of this process is presented, including isotope labeling studies and kinetic analysis, indicating that the rate limiting step of the process is encapsulation of a transiently formed iminium ion and supports the proposed 1,5-hydride transfer pathway. This work represents a striking example of the enzyme-like ability of synthetic microenvironment catalysts to selectively modulate kinetic barriers in order to promote otherwise inaccessible selectivity. Chapter 3 - Catalysis of alkyl-alkyl reductive elimination from high valent transition metal complexes [such as gold(III) and platinum(IV)] by the [Ga4L6]12- Raymond cluster is described. Kinetic experiments delineate an enzyme-like Michaelis-Menten mechanism, with rate accelerations (kcat/kuncat) up to 1.9 × 107. Indirect evidence for the intermediacy of a coordinatively unsaturated encapsulated species is garnered from the observation of several persistent donor-arrested inclusion complexes, including a crystallographically characterized gold(III) cation. The catalysis of reductive elimination is further incorporated into a dual-catalytic cross coupling for which the presence of the supramolecular cluster is necessary in order to achieve efficient turnover, and the full catalytic cycle of this process is elucidated through a series of stoichiometric experiments. Chapter 4 - A novel supramolecular assembly of M4L4 stoichiometry is reported for which the addition of a guest effects an increase from S4- to T-symmetry. A mechanistic investigation of this guest-induced host isomerization revealed that the guest binding occurs by a mechanism similar to the conformational selection model for ligand binding in proteins. A comprehensive study of this simple system provides insight into analogous behavior in biophysics and enzymology, as well as important information to support future efforts in the design of more efficient self-assembled microenvironment catalysts.

Supramolecular Catalysis Provides a timely and detailed overview of the expanding field of supramolecular catalysis The subdiscpline of supramolecular catalysis has expanded in recent years, benefiting from the development of homogeneous catalysis and supramolecular chemistry. Supramolecular catalysis allows chemists to design custom-tailored metal and organic catalysts by devising non-covalent interactions between the various components of the reaction. Edited by two world-renowned researchers, Supramolecular Catalysis: New Directions and Developments summarizes the most significant developments in the dynamic, interdisciplinary field. Contributions from an international panel of more than forty experts address a broad range of topics covering both organic and metal catalysts, including emergent catalysis by self-replicating molecules, switchable catalysis using allosteric effects, supramolecular helical catalysts, and transition metal catalysis in confined spaces. This authoritative and up-to-date volume: Covers ligand-ligand interactions, assembled multi-component catalysts, ligand-substrate interactions, and supramolecular organocatalysis and non-classical interactions Presents recent work on supramolecular catalysis in water, supramolecular allosteric catalysis, and catalysis promoted by discrete cages, capsules, and other confined environments Highlights current research trends and discusses the future of supramolecular catalysis Includes full references and numerous figures, tables, and color illustrations Supramolecular Catalysis: New Directions and Developments is essential reading for catalytic chemists, complex chemists, biochemists, polymer chemists, spectroscopists, and chemists working with organometallics.

Supramolecular Catalysis Provides a timely and detailed overview of the expanding field of supramolecular catalysis The subdiscpline of supramolecular catalysis has expanded in recent years, benefiting from the development of homogeneous catalysis and supramolecular chemistry. Supramolecular catalysis allows chemists to design custom-tailored metal and organic catalysts by devising non-covalent interactions between the various components of the reaction. Edited by two world-renowned researchers, Supramolecular Catalysis: New Directions and Developments summarizes the most significant developments in the dynamic, interdisciplinary field. Contributions from an international panel of more than forty experts address a broad range of topics covering both organic and metal catalysts, including emergent catalysis by self-replicating molecules, switchable catalysis using allosteric effects, supramolecular helical catalysts, and transition metal catalysis in confined spaces. This authoritative and up-to-date volume: Covers ligand-ligand interactions, assembled multi-component catalysts, ligand-substrate interactions, and supramolecular organocatalysis and non-classical interactions Presents recent work on supramolecular catalysis in water, supramolecular allosteric catalysis, and catalysis promoted by discrete cages, capsules, and other confined environments Highlights current research trends and discusses the future of supramolecular catalysis Includes full references and numerous figures, tables, and color illustrations Supramolecular Catalysis: New Directions and Developments is essential reading for catalytic chemists, complex chemists, biochemists, polymer chemists, spectroscopists, and chemists working with organometallics.

Supramolecular catalysis is involved in assimilation or growth of biological products and it has advantages over conventional catalysis in dealing with systems beyond molecules to mimic the biological catalytic processes. Principles and Advances in Supramolecular Catalysis shows how a supramolecular catalytic reaction proceeds and how interactions among molecules provide vessels or specific binding sites to carry out chemical reactions. The utilities of such catalytic reactions in waste, hazard management, medicine, food, etc. are explained in this book. The book focuses on examples to provide a fundamental basis so that, in the future, supramolecular catalytic reactions are utilised in the field of chemical, biological, biophysical sciences and technologies. Features: Discusses fundamental and interdisciplinary aspects of supramolecular catalysis Narrates mechano-chemical and stimuli-guided supramolecular catalytic reactions Divulges the intriguing aspects of self-replications and self-assembling performed through supramolecular catalysis Incorporates supramolecular catalytic reactions of metal-organic frameworks as artificial metalloenzymes

This book describes the fundamental concepts, the latest developments and the outlook of the field of nanozymes (i.e., the catalytic nanomaterials with enzymatic characteristics). As one of today’s most exciting fields, nanozyme research lies at the interface of chemistry, biology, materials science and nanotechnology. Each of the book’s six chapters explores advances in nanozymes. Following an introduction to the rise of nanozymes research in the course of research on natural enzymes and artificial enzymes in Chapter 1, Chapters 2 through 5 discuss different nanomaterials used to mimic various natural enzymes, from carbon-based and metal-based nanomaterials to metal oxide-based nanomaterials and other nanomaterials. In each of these chapters, the nanomaterials’ enzyme mimetic activities, catalytic mechanisms and key applications are covered. In closing, Chapter 6 addresses the current challenges and outlines further directions for nanozymes. Presenting extensive information on nanozymes and supplemented with a wealth of color illustrations and tables, the book offers an ideal guide for readers from disparate areas, including analytical chemistry, materials science, nanoscience and nanotechnology, biomedical and clinical engineering, environmental science and engineering, green chemistry, and novel catalysis.

The aim of this book is to return to the biomimicry and medicinal potential that inspired many of the early supramolecular chemists and to set it in the context of current advances in the field. Following an overview of supramolecular chemistry, the first section considers the efforts made to synthesize artificial systems that mimic biological entities. The second section addresses the application of supramolecular principles to molecular diagnostics with a particular emphasis on the ‘receptor-relayreporter’ motif. Many of the examples chosen have clinical importance. The third section takes the clinical diagnostic theme further and demonstrates the therapeutic applications of supramolecular chemistry through photodynamic therapy, drug delivery, and the potential for synthetic peptides to form antibiotic tubes. The short epilogue considers the potential for supramolecular solutions to be found for further challenges in biomimetic and therapeutic chemistry.

One of the most active areas of contemporary organic chemistry involves the search for new catalysts that borrow concepts, strategies and even components from enzymes but yet are not found in nature. Such artificial enzymes not only give enormous insights into the mechanisms of enzyme catalysis but also offer the potential for catalyzing a wide range of chemical reactions with no counterpart in nature. Several approaches have been taken in the deVelopment of new catalysts, some based on biological methods and others on synthetic techniques. Site directed mutagenesis has allowed the direct replacement of amino acids in an enzyme with resulting changes in stability, selectivity and mechanism. Recent developments have shown that even non-natural amino acids can be incorporated into proteins and also that enzymes can function effectively in organic solvents. A different biological route to artificial enzymes has exploited the immune system and its ability to generate millions of antibodies to a given antigen. Novel antigens have been designed to mimic the transition states of chemical reactions. Antibodies elicited against these antigens thus contain an active site that is complementary to transition state structure and can potentially catalyze target reactions. A broad range of reactions can now be 6 catalyzed using the method with rate accelerations reaching 10 compared to the control reactions. Protein engineering and catalytic antibodies represent complex solutions to the problem of artificial enzymes. Their complexity is however their principal limitation.