The weak or non-conventional hydrogen bond has been subject of intense scrutiny over recent years in several fields, in particular in structural chemistry, structural biology, and also in the pharmaceutical sciences. There is today a large body of experimental and theoretical evidenceconfirming that hydrogen bonds like C-H...O, N-H...pi, C-H...pi and even bonds like O-H...metal play distinctive roles in molecular recognition, guiding molecular association, and in determining molecular and supramolecular architectures. The relevant compound classes include organometalliccomplexes, organic and bio-organic systems, and also DNA and proteins. The book provides a comprehensive assessment of this interaction type, and is of interest to all those interested in structural and supramolecular science, including fields as crystal engineering and drug design.

Clear, concise explanation of logical development of basic crystallographic concepts. Topics include crystals and lattices, symmetry, x-ray diffraction, and more. Problems, with answers. 114 illustrations. 1969 edition.

The book presents the basic information needed to understand and to organize the huge amount of known structures of crystalline solids. Its basis is crystallographic group theory (space group theory), with special emphasis on the relations between the symmetry properties of crystals.

Crystallography may be described as the science of the structure of materi als, using this word in its widest sense, and its ramifications are apparent over a broad front of current scientific endeavor. It is not surprising, therefore, to find that most universities offer some aspects of crystallography in their undergraduate courses in the physical sciences. It is the principal aim of this book to present an introduction to structure determination by X-ray crystal lography that is appropriate mainly to both final-year undergraduate studies in crystallography, chemistry, and chemical physics, and introductory post graduate work in this area of crystallography. We believe that the book will be of interest in other disciplines, such as physics, metallurgy, biochemistry, and geology, where crystallography has an important part to play. In the space of one book, it is not possible either to cover all aspects of crystallography or to treat all the subject matter completely rigorously. In particular, certain mathematical results are assumed in order that their applications may be discussed. At the end of each chapter, a short bibliog raphy is given, which may be used to extend the scope of the treatment given here. In addition, reference is made in the text to specific sources of information. We have chosen not to discuss experimental methods extensively, as we consider that this aspect of crystallography is best learned through practical experience, but an attempt has been made to simulate the interpretive side of experimental crystallography in both examples and exercises.

Anhand verschiedener Beispiele zeigen die Autoren die Bedeutung der Kristallographie für Chemie und Biochemie auf und bieten somit eine gute Zusammenfassung der allgemeinen Prinzipien der Kristallstrukturanalyse. Zum einen sollen Interessierte, die diese Methode nicht selbst durchführen, in die Lage versetzt werden, deren Ergebnisse zu interpretieren. Zum anderen wird dem Leser deutlich gemacht, welche Bedeutung die ungeheure Datenmenge, die sich aus dieser Methode ergibt, einerseits für die Chemie sowie andererseits für die Biochemie hat. Das Buch ist verständlich geschrieben und mit zahlreichen Abbildungen versehen. Durch die Darstellung der Kristallstrukturanalyse im Vergleich zu anderen Methoden ist das Werk auch besonders für fortgeschrittene Studenten geeignet, die sich mit der Kristallographie vertraut machen wollen.

ANOXIA defines the lack of free molecular oxygen in an environment. In the presence of organic matter, anaerobic prokaryotes produce compounds such as free radicals, hydrogen sulfide, or methane that are typically toxic to aerobes. The concomitance of suppressed respiration and presence of toxic substances suggests these habitats are inhospitable to Eukaryota. Ecologists sometimes term such environments 'Death Zones'. This book presents, however, a collection of remarkable adaptations to anoxia, observed in Eukaryotes such as protists, animals, plants and fungi. Case studies provide evidence for controlled beneficial use of anoxia by, for example, modification of free radicals, use of alternative electron donors for anaerobic metabolic pathways, and employment of anaerobic symbionts. The complex, interwoven existence of oxic and anoxic conditions in space and time is also highlighted as is the idea that eukaryotic inhabitation of anoxic habitats was established early in Earth history.

Structural Biology Using Electrons and X-Rays discusses the diffraction and image-based methods used for the determination of complex biological macromolecules. The book focuses on the Fourier transform theory, which is a mathematical function that is computed to transform signals between time and frequency domain. Composed of five parts, the book examines the development of nuclear magnetic resonance (NMR), which allows the calculation of the images of a certain protein. Parts 1 to 4 provide the basic information and the applications of Fourier transforms, as well as the different methods used for image processing using X-ray crystallography and the analysis of electron micrographs. Part 5 focuses entirely on the mathematical aspect of Fourier transforms. In addition, the book examines detailed structural analyses of a specimen's symmetry (i.e., crystals, helices, polyhedral viruses and asymmetrical particles). This book is intended for the biologist or biochemist who is interested in different methods and techniques for calculating the images of proteins using nuclear magnetic resonance (NMR). It is also suitable for readers without a background in physical chemistry or mathematics. - Emphasis on common principles underlying all diffraction-based methods - Thorough grounding in theory requires understanding of only simple algebra - Visual representations and explanations of challenging content - Mathematical detail offered in short-course form to parallel the text