Author: Georges H. Wagnière Publisher: John Wiley & Sons ISBN: 3906390608 Category : Science Languages : en Pages : 256
Book Description
Until half a century ago, it was assumed that the forces of nature were symmetric and that they did not distinguish between right and left, between image and mirror image. The discovery of the violation of parity in 1956 was more than a sensation, for some it was a shock. It implied that the universe displays handedness, or chirality, and that it is fundamentally asymmetric. Remarkably, a most striking asymmetry is encountered in the realm of biology. Living organisms contain proteins built almost exclusively from L-amino acids, and nucleic acids derived from D-sugars only. Yet a mirror-image biochemistry, based on D-amino acids and L-sugars is, from a purely chemical standpoint, entirely conceivable. Where, then, does this extraordinary natural selectivity come from? Is it directly, or indirectly, connected to the universal violation of parity? This book is meant as a brief review of the various manifestations of handedness, or chirality, in the universe. It does not attempt to present a solution to basic questions which perhaps will never be unambiguously and conclusively answered. Rather, it is an excursion through nature, to observe and recognize how the chirality manifests itself at different structural levels. The excursion starts in the chemistry and physics laboratory. Then a journey into outer space and back in time is undertaken. After a return to our planet Earth, the focus is on the development of living organisms. The text should be accessible to anyone having the equivalent of a first-year university instruction in physics and chemistry. It is also hoped that a layperson with a more modest scientific formation may gain a general impression of the basic asymmetry in nature and of the fundamental significance of chirality. Mathematical expressions, wherever they occur, may then be overlooked. Some more difficult sections may be skipped. A Glossary preceding the Subject Index should be helpful.
Author: Robert E. Gawley Publisher: Elsevier ISBN: 0080914136 Category : Science Languages : en Pages : 569
Book Description
The world is chiral. Most of the molecules in it are chiral, and asymmetric synthesis is an important means by which enantiopure chiral molecules may be obtained for study and sale. Using examples from the literature of asymmetric synthesis, this book presents a detailed analysis of the factors that govern stereoselectivity in organic reactions. After an explanation of the basic physical-organic principles governing stereoselective reactions, the authors provide a detailed, annotated glossary of stereochemical terms. A chapter on "Practical Aspects of Asymmetric Synthesis" provides a critical overview of the most common methods for the preparation of enantiomerically pure compounds, techniques for analysis of stereoisomers using chromatographic, spectroscopic, and chiroptical methods. The authors then present an overview of the most important methods in contemporary asymmetric synthesis organized by reaction type. Thus, there are four chapters on carbon-carbon bond forming reactions, one chapter on reductions, and one on oxidations (carbon-oxygen and carbon-nitrogen bond forming reactions). This organization allows the reader to compare the leading methods for asymmetric synthesis in an appropriate context. A highlight of the book is the presentation and discussion of transition states at the current level of understanding, for important reaction types. In addition, extensive tables of examples are used to give the reader an appreciation for the scope of each reaction. Finally, leading references are provided to natural product synthesis that has been accomplished using a given reaction as a key step. - Authoritative glossary to aid understanding of stereochemical terminology - Explanations of the key factors influencing stereoselectivity with numerous examples, organized by reaction type - A handy reference guide to the literature of asymmetric synthesis for practitioners in the field
Author: Michiya Fujiki Publisher: Buy this from MDPI Books ISBN: 3039217224 Category : Science Languages : en Pages : 318
Book Description
In 1978, Fred Hoyle proposed that interstellar comets carrying several viruses landed on Earth as part of the panspermia hypotheses. With respect to life, the origin of homochirality on Earth has been the greatest mystery because life cannot exist without molecular asymmetry. Many scientists have proposed several possible hypotheses to answer this long-standing L-D question. Previously, Martin Gardner raised the question about mirror symmetry and broken mirror symmetry in terms of the homochirality question in his monographs (1964 and 1990). Possible scenarios for the L-D issue can be categorized into (i) Earth and exoterrestrial origins, (ii) by-chance and necessity mechanisms, and (iii) mirror-symmetrical and non-mirror-symmetrical forces as physical and chemical origins. These scenarios should involve further great amplification mechanisms, enabling a pure L- or D-world.
Author: Roberto Purrello Publisher: World Scientific ISBN: 1800610262 Category : Science Languages : en Pages : 225
Book Description
Fundamentals of Supramolecular Chirality is a critical description of the start and advancement of supramolecular chirality. This book focuses on the noncovalent approach with some supplementary examples of covalent supramolecular chirality.This contribution to supramolecular chirality is not intended to be a mere catalogue and description of the work done. It also traces a philosophical path following the development and possible perspectives of this topic, providing not a review but a critical examination of the field.
Author: F. Richard Keene Publisher: John Wiley & Sons ISBN: 1118867319 Category : Science Languages : en Pages : 722
Book Description
Supramolecular chemistry deals with the organisation of molecules into defined assemblies using non-covalent interactions, including weaker and reversible interactions such as hydrogen bonds, and metal-ligand interactions. The aspect of stereochemistry within such chemical architectures, and in particular chirality, is of special interest as it impacts on considerations of molecular recognition, the development of functional materials, the vexed question of homochirality, nanoscale effects of interactions at interfaces, biocatalysis and enzymatic catalysis, and applications in organic synthesis. Chirality in Supramolecular Assemblies addresses many of these aspects, presenting a broad overview of this important and rapidly developing interdisciplinary field. Topics covered include: Origins of molecular and topological chirality Homochirogenesis Chirality in crystallinity Host-guest behavior Chiral influences in functional materials Chirality in network solids and coordination solids Aspects of chirality at interfaces Chirality in organic assemblies Chirality related to biocatalysis and enzymes in organic synthesis. This book is a valuable reference for researchers in the molecular sciences, materials science and biological science working with chiral supramolecular systems. It provides summaries and special insights by acknowledged international experts in the various fields.
Author: Tomas Torres Publisher: John Wiley & Sons ISBN: 1118354362 Category : Science Languages : en Pages : 636
Book Description
Discover a new generation of organic nanomaterials and their applications Recent developments in nanoscience and nanotechnology have given rise to a new generation of functional organic nanomaterials with controlled morphology and well-defined properties, which enable a broad range of useful applications. This book explores some of the most important of these organic nanomaterials, describing how they are synthesized and characterized. Moreover, the book explains how researchers have incorporated organic nanomaterials into devices for real-world applications. Featuring contributions from an international team of leading nanoscientists, Organic Nanomaterials is divided into five parts: Part One introduces the fundamentals of nanomaterials and self-assembled nanostructures Part Two examines carbon nanostructures from fullerenes to carbon nanotubes to graphene reporting on properties, theoretical studies, and applications Part Three investigates key aspects of some inorganic materials, self-assembled monolayers, organic field effect transistors, and molecular self-assembly at solid surfaces Part Four explores topics that involve both biological aspects and nanomaterials such as biofunctionalized surfaces Part Five offers detailed examples of how organic nanomaterials enhance sensors and molecular photovoltaics Most of the chapters end with a summary highlighting the key points. References at the end of each chapter guide readers to the growing body of original research reports and reviews in the field. Reflecting the interdisciplinary nature of organic nanomaterials, this book is recommended for researchers in chemistry, physics, materials science, polymer science, and chemical and materials engineering. All readers will learn the principles of synthesizing and characterizing new organic nanomaterials in order to support a broad range of exciting new applications.
Author: David B. Amabilino Publisher: John Wiley & Sons ISBN: 3527625356 Category : Technology & Engineering Languages : en Pages : 442
Book Description
The only standard reference in this exciting new field combines the physical, chemical and material science perspectives in a synergic way. This monograph traces the development of the preparative methods employed to create nanostructures, in addition to the experimental techniques used to characterize them, as well as some of the surprising physical effects. The chapters cover every category of material, from organic to coordination compounds, metals and composites, in zero, one, two and three dimensions. The book also reviews structural, chemical, optical, and other physical properties, finishing with a look at the future for chiral nanosystems.
Author: Albert Guijarro Publisher: Royal Society of Chemistry ISBN: 1839163690 Category : Science Languages : en Pages : 207
Book Description
This book provides an interdisciplinary review of one of the great unsolved mysteries that has fascinated scientists for over 150 years: the origin of chirality in biomolecules. Current advances in fields as diverse as space exploration, prebiotic chemistry and high-energy physics may help to provide an answer. Important pieces of information will come from observations at the two frontiers of science: outer space and the subatomic world. Observation of distant planets, galaxies, and even actual sampling of celestial objects from beyond the solar system are projects currently underway. At the other end of the spectrum, there are experiments that study the elemental properties of matter, such as symmetry, and interactions with the fundamental forces. Completely revised and updated this new edition once again unifies all the theories of the origin of biomolecular homochirality together in a single source. This complete, interdisciplinary review of an intriguing subject condenses a large and disparate range of contributions from journals in almost every scientific field. The various theories have been organized, interrelated and explained in a unified way. It is fundamental, comprehensive and structured to be accessible for educational purposes.
Author: Zhiyong Tang Publisher: John Wiley & Sons ISBN: 3527337571 Category : Technology & Engineering Languages : en Pages : 300
Book Description
Thorough and up-to-date, this book presents recent developments in this exciting research field. To begin with, the text covers the fabrication of chiral nanomaterials via various synthesis methods, including electron beam lithography, ion beam etching, chemical synthesis and biological DNA directed assembly. This is followed by the relevant theory and reaction mechanisms, with a discussion of the characterization of chiral nanomaterials according to the optical properties of metal nanoparticles, semiconductor nanocrystals, and nanoclusters. The whole is rounded off by a summary of applications in the field of catalysis, sensors, and biomedicine. With its comprehensive yet concise coverage of the whole spectrum of research, this is invaluable reading for senior researchers and entrants to the field of nanoscience and materials science.
Author: Kazuo Akagi Publisher: John Wiley & Sons ISBN: 3527841091 Category : Science Languages : en Pages : 1201
Book Description
Comprehensive resource illustrating the latest stage and development of chiral luminescence in science and technology, from fundamentals to applications Chiral Luminescence imparts a comprehensive understanding for chiral materials bearing circularly polarized luminescence (CPL) functions, including molecules, oligomers, polymers, chiral metal organic complexes, and chiral biochemical materials, with guidance on how to promote and control this kind of luminescence towards the development of advanced photonic materials and devices such as chiroptical and electronic devices, next-generation displays, and others. The book covers detailed information on the molecular design, synthesis, and polymerization methods of chiral luminescent materials, the evaluation of chiroptical properties represented by CPL, novel spectroscopic instruments and techniques, the fabrication of chiral luminescent devices such CPL-OLED, a theoretical evaluation, and potential applications. With insight from leading academics and industrial researchers in the field, Chiral Luminescence includes information on: Optical resolution and chiroptical properties of partially overlapping carbazolophanes and developments in CPL research using cyclodextrins Synthesis and chiroptical properties of helical, conjugated polymers and twisted molecules, and chiroptical and magnetooptical properties of porphyrin compounds Principles of CPL measurement systems and advances in measurement methods, and intense and sign-invertible CPL Development of organic light-emitting diodes using aggregation-induced enhanced CPL perylene diimides Binding constants as fundamental physical properties for quantitative treatments of sensing processes in supramolecular systems Providing far-reaching coverage of chiral luminescence and its many applications, Chiral Luminescence is a must-read resource for a variety of chemists and engineers who wish to understand the state-of-the-art development in this optical science.
Author: Georges H. Wagnière
Author: Robert E. Gawley
Author: Michiya Fujiki
Author: Roberto Purrello
Author: F. Richard Keene
Author: Tomas Torres
Author: David B. Amabilino
Author: Albert Guijarro
Author: Zhiyong Tang
Author: Kazuo Akagi