Discrimination of Mobile Supramolecular Chirality


Book Description

This book proposes a novel concept for molecular recognition. In the field of asymmetric synthesis approaching the mature science, asymmetric discrimination and catalytic synthesis of chiral supramolecules still stand as unsolved problems. The extreme difficulty in asymmetric synthesis of such supramolecules may result from the mobile nature of supramolecular chirality. Here the author shows the first highly enantioselective synthesis of mechanically chiral supramolecules. In the presence of a chiral organocatalyst, a mechanically planar chiral rotaxane was obtained with p erfect enantiopurity (>99% ee) with an excellent selectivity. The dynamic and flexible recognition mode enabled asymmetric synthesis of supramolecules with conformational flexibility and mobility. The recognition mode of the catalyst is a contrast to the traditional static and rigid recognition mode of the typical conventional catalysts. The concept of dynamic molecular recognition will be adopted as a novel concept in a wide range of fields beyond the field of organic chemistry, including material chemistry, biochemistry, and medicinal chemistry.




Transition Metals in Supramolecular Chemistry


Book Description

Since the pioneering publications on coordination chemistry by Lehn and Pedersen in the late 1960s, coupled with the more orthodox interest from the transition metal chemists on template reactions (Busch, 1964), the field of supramolecular chemistry has grown at an astonishing rate. The use of transition metals as essential constituents of multi-component assemblies has been especially sharp in recent years, since the metals are prone to quick and reversible redox changes, and there is a wide variety of metal--ligand interactions. Such properties make supramolecular complexes of transition metal ions suitable candidates for exploration as light--energy converters and signal processors. Transition Metals in Supramolecular Chemistry focuses on the following main topics: (1) metal controlled organization of novel molecular assemblies and shapes; (2) design of molecular switches and devices operating through metal centres; (3) supramolecular catalysts that mimic metalloenzymes; (4) metal-containing sensory reagents and supramolecular recognition; and (5) molecular materials that display powerful electronic, optoelectronic and magnetic properties.







Discrimination of Mobile Supramolecular Chirality


Book Description

This book proposes a novel concept for molecular recognition. In the field of asymmetric synthesis approaching the mature science, asymmetric discrimination and catalytic synthesis of chiral supramolecules still stand as unsolved problems. The extreme difficulty in asymmetric synthesis of such supramolecules may result from the mobile nature of supramolecular chirality. Here the author shows the first highly enantioselective synthesis of mechanically chiral supramolecules. In the presence of a chiral organocatalyst, a mechanically planar chiral rotaxane was obtained with p erfect enantiopurity (>99% ee) with an excellent selectivity. The dynamic and flexible recognition mode enabled asymmetric synthesis of supramolecules with conformational flexibility and mobility. The recognition mode of the catalyst is a contrast to the traditional static and rigid recognition mode of the typical conventional catalysts. The concept of dynamic molecular recognition will be adopted as a novel concept in a wide range of fields beyond the field of organic chemistry, including material chemistry, biochemistry, and medicinal chemistry.




Advances In Chromatography


Book Description

For more than four decades, scientists and researchers have relied on the Advances in Chromatography series for the most up-to-date information on a wide range of developments in chromatographic methods and applications. Volume 44 of this authoritative series once again compiles the work of expert contributors in order to present timely and cutting




Modified Cyclodextrins: Scaffolds And Templates For Supramolecular Chemistry


Book Description

Through modification, the natural cyclodextrins are effective templates for the generation of a wide range of molecular hosts. This makes it possible to tailor a cyclodextrin host to a particular guest, to meet specific requirements in the host-guest complex, and opens the way to diverse new areas of supramolecular chemistry. Metallocyclodextrins, rotaxanes and catenanes, as well as surface monolayers of modified cyclodextrins, are readily obtained. The native cyclodextrins serve as scaffolds on which functional groups and other substituents can be assembled, with controlled geometry. This results in substantially improved molecular recognition and procedures for chemical separation, including enantiomer discrimination, through guest binding. Access to the gamut of functional groups greatly expands the utility of cyclodextrins in chemical synthesis and provides catalysts which mimic the entire range of enzymic activity. Modifications to the cyclodextrins also lead to a wide range of photochemistry of cyclodextrin complexes, through which the enhancement of guest reactivity occurs; in addition, light harvesting molecular devices and photochemical frequency switches may be constructed. In solution, modified cyclodextrins have been used to construct molecular reactors, as well as molecular, temperature and pH sensors. At surfaces, they form semipermeable membranes and sensor electrodes. Such exciting fields of chemistry, made possible only through modifications to the natural cyclodextrins, are the subject of this book.




Introduction to Supramolecular Chemistry


Book Description

A new rapidly progressing field on the crossroads among chemistry, biochemistry, physics and technology - supramolecular chemistry - has just emerged. You have to be involved, to know what's going on in this domain and to take part in the development. This book will show you in a condensed form exciting phenomena unthinkable within the realm of classical organic chemistry (for example, alkali metal anions or cyclobutadiene stable for month at room temperature) that not only provide the basis for revolutionizing numerous branches of industry but also improve our understanding of the functioning of living organisms and of the origin of life. Designing supramolecular systems with desired properties will among others make chemical industry cleaner and more safe, electronics smaller by developing devices composed of single molecule or molecular aggregate. It will also entirely change the way we use energy resources. In addition, it will also transform the pharmaceutical industry and medicine by developing new ways of drugs administration and new composite biocompatible materials which will serve as implants of new generation changing dentistry, surgery, and other branches of medicine. You cannot afford to stand apart. With its brief but comprehensive and vivid presentation including the latest development, Introduction to Supramolecular Chemistry is the best method to get into this domain. This book provides an excellent summary of information scattered across the literature. The brief but comprehensive coverage of the whole field including practically all important group of compounds forming aggregates (in particular crown ethers, cavitands, fullerenes, cyclodextrins and their complexes) provisioning full references for the discussed subjects make this book of value not only for Ph.D. students and non-specialists in this domain but also for those working in the field. The book has been found to be a particularly useful resource for students and more generally for those wanting to get the up-to-date concise account of this exciting field.




Journal of Chromatography


Book Description




Cyclodextrins and Their Complexes


Book Description

Offering comprehensive and up-to-date know-how in one compact book, an experienced editor and top authors cover every aspect of these important molecules from molecular recognition to cyclodextrins as enzyme models. Chapters include reactivity and chemistry, chromatography, X-ray, NMR plus other physicochemical methods, as well as model calculations, rotaxane and catenane structures, and applications in the pharmaceutical industry. The book also discusses other applications such as in the cosmetics, toiletries, textile and wrapping industries, agrochemistry, electrochemical sensors, and devices. A must for everyone working with these substances.




Comprehensive Supramolecular Chemistry II


Book Description

Comprehensive Supramolecular Chemistry II, Second Edition, Nine Volume Set is a ‘one-stop shop’ that covers supramolecular chemistry, a field that originated from the work of researchers in organic, inorganic and physical chemistry, with some biological influence. The original edition was structured to reflect, in part, the origin of the field. However, in the past two decades, the field has changed a great deal as reflected in this new work that covers the general principles of supramolecular chemistry and molecular recognition, experimental and computational methods in supramolecular chemistry, supramolecular receptors, dynamic supramolecular chemistry, supramolecular engineering, crystallographic (engineered) assemblies, sensors, imaging agents, devices and the latest in nanotechnology. Each section begins with an introduction by an expert in the field, who offers an initial perspective on the development of the field. Each article begins with outlining basic concepts before moving on to more advanced material. Contains content that begins with the basics before moving on to more complex concepts, making it suitable for advanced undergraduates as well as academic researchers Focuses on application of the theory in practice, with particular focus on areas that have gained increasing importance in the 21st century, including nanomedicine, nanotechnology and medicinal chemistry Fully rewritten to make a completely up-to-date reference work that covers all the major advances that have taken place since the First Edition published in 1996