Täglich benutzen wir Schalter, um strombetriebene Geräte an- und abzuschalten und kein Compuer würde ohne sie funktionieren. Nach den gleichen Prinzipien funktionieren auch molekulare Schalter, die unter dem Einfluß ihrer Umwelt zwischen zwei definierten Zuständen wechseln können. Im Gegensatz zu den gewöhnlichen Schaltern sind molekulare Schalter aber außerordentlich klein und ihre Anwendung in der Nanotechnologie, Biomedizin und im Computerchipdesign öffnet neue Horizonte. Im vorliegenden Zweibänder berichten Herausgeber und Autoren über molekulare Schalter aus Katenanen und Rotaxanen, Fulgiden, Flüssigkristallen und Polypeptiden. Die Bandbreite der behandelten Themen reicht von chiroptischen Schaltern über multifunktionale Systeme bis hin zu molekularen logischen Schaltungen. Chemiker und Materialwissenschaftler in Industrie und Hochschule, die sich für einen der innovativsten Bereiche ihrer Wissenschaft interessieren, werden dieses Buch mit Gewinn lesen!

A comprehensive overview about the emerging field of photoswitches and their applications in materials science and biology Molecular Photoswitches guides the reader through the basic molecular structures of photochromic compounds and their applications in the area of photoresponsive materials as well as in the biological context. The initial chapters describe individual classes of molecular photoswitches, introducing their principles of photochromism, typical switching wavelengths, thermal stability of photoisomers and other key information, which is ordinarily spread in the literature. These classes comprise i.a. azobenzenes, diazocines, arylazoheterocycles, arylhydrazones, indigoids, photochromic imines, or acylhydrazones. The book also covers: Catalysis with molecular switches Applications in photochromic porous materials, liquid crystals, or nanoparticles Light-responsive molecular machines, logic devices, and molecular magnets Photomodulation of biological systems: photoswitchable biopolymers, lightmodulated antibiotics, cytotoxins, ion channel inhibitors, light-propelled artificial muscles, and computationally designed photochromic proteins This two-volume work is a valuable guide for researchers and non-experts working in the field of photochemistry, organic chemistry, catalysis, materials science, biology, and medicine.

This book provides an introduction to the important methods of chiroptical spectroscopy in general, and circular dichroism (CD) in particular, which are increasingly important in all areas of chemistry, biochemistry, and structural biology. The book can be used as a text for undergraduate and graduate students and as a reference for researchers in academia and industry. Experimental methods and instrumentation are described with topics ranging from the most widely used methods (electronic and vibrational CD) to frontier areas such as nonlinear spectroscopy and photoelectron CD, as well as the theory of chiroptical methods and techniques for simulating chiroptical properties. Applications of chiroptical spectroscopy to problems in organic stereochemistry, inorganic stereochemistry, and biochemistry and structural biology are also discussed, and each chapter is written by one or more leading authorities with extensive experience in the field.

This book details chiroptical spectroscopic methods: electronic circular dichroism (ECD), optical rotatory dispersion (ORD), vibrational circular dichroism (VCD), and vibrational Raman optical activity (VROA). For each technique, the text presents experimental methods for measurements and theoretical methods for analyzing the experimental data. It also includes a set of experiments that can be adopted for undergraduate teaching laboratories. Each chapter is written in an easy-to-follow format for novice readers, with necessary theoretical formalism in appendices for advanced readers.

In nearly all process industries, crystallization is used at some stage as a method of production, purification or recovery of solid materials. In recent years, a number of new applications have also come to rely on crystallization processes such as the crystallization of nano and amorphous materials. The articles in this book have been contributed by some of the most respected researchers in this area and cover the frontier areas of research and developments in crystallization processes. Divided into three sections, this book provides the latest research developments in many aspects of crystallization including the crystallization of biological macromolecules and pharmaceutical compounds, the crystallization of nanomaterials and the crystallization of amorphous and glassy materials. This book is of interest to both fundamental research and practicing scientists and will prove invaluable to all chemical engineers and industrial chemists in process industries, as well as crystallization workers and students in industry and academia.

The historical achievements in organic natural product synthesis can be recognized most clearly in the research accomplishments of Albert Eschenmoser. For example, his work on the chemical synthesis of vitamin B12 defined the frontier in organic natural product synthesis and profoundly influenced the science of organic chemistry. In addition to revealing the beautiful reaction pathways leading to compounds of great biochemical significance, Albert Eschenmoser has contributed innovative methods of outstanding utility for organic synthesis. Few individuals have so fundamentally influenced the science of organic chemistry as Albert Eschenmoser has. Over the years, a sizable fraction of Albert Eschenmoser′s work has been published in Helvetica Chimica Acta, hence the decision of the Editor to produce a special issue of the journal on the occasion of Albert Eschenmoser′s 75th birthday, celebrated on August 5, 2000. The highly impressive set of 67 original research papers submitted in response to the Editor′s invitation could not, for obvious technical reasons, be accommodated in a single issue and were thus divided over the August and September issues. The international reaction to this tribute has been so overwhelmingly enthusiastic that the two issues have been combined in this single volume for separate publication.

Helicenes A thorough introduction to everything there is to know about this fascinating compound class The intriguing nature of this highly interesting compound class has inspired much research over the last decade, and much of what has been produced is highly interdisciplinary, with applications found in catalysis, material science, and spectroscopy. Indeed, the field has reached maturity such that elegant synthetic methods are now available and novel applications in arenas such as enantioselective catalysis and optoelectronics are appearing. Helicenes provides not only an introduction to the synthesis of the fascinating compound class of helicenes, but also describes the properties and, most importantly, their applications. The book thoroughly explains several synthetic routes from classical to state-of-the-art methods. In addition, the different classes of helicene-based molecules – organic, organometallic, oligo-meric, and multidimensional – are covered. Helicenes readers will also find: Edited by world-leading experts in the field of chirality A comprehensive and well-structured approach that deals with every aspect of this compound class Discussions of the applications of helicenes in organic synthesis, photophysics, material science, optoelectronic devices, on-surface chemistry, and theoretical calculations A special focus on the applications of helicenes in catalysis, optoelectronics, non-linear optics, and chiroptical spectroscopy Chapters focusing on helicenes as theoretical helically chiral models Helicenes is an essential reference for organic chemists, materials scientists, spectroscopists, polymer chemists, inorganic chemists, and catalytic chemists, as well as students in these fields and libraries supplying them.