Host Guest Molecular Interactions

Composed of contributions from experts in the chemical and biological sciences, it explores host-guest molecular interactions leading to the formation of molecular assemblies containing two or more species. Exciting applications are emerging in this field and it is expected that improved understanding of the interactions in synthetic host molecule complexes will lead to a better understanding of the more complex biological systems. Topics include biomimetic chemistry, preorganization, self-assembly, template-directed synthesis, antibiotic binding to peptides and DNA, interactions between proteins and other molecules.

Composed of contributions from experts in the chemical and biological sciences, it explores host-guest molecular interactions leading to the formation of molecular assemblies containing two or more species. Exciting applications are emerging in this field and it is expected that improved understanding of the interactions in synthetic host molecule complexes will lead to a better understanding of the more complex biological systems. Topics include biomimetic chemistry, preorganization, self-assembly, template-directed synthesis, antibiotic binding to peptides and DNA, interactions between proteins and other molecules.

The scientific and practical interest in coronands (crown ethers), cryptands, podands as complexing agents for cations as well as for anions and neutral low molecular species is undeniable 1,2). The chemistry of crown compounds is steadily increasing. About 250 original papers dealing with crown chemistry appeared only in 1980. New molecules· with crown ether properties are constantly synthesized and new applications discov,?red. Owing to lack of space, only a small number of the original publications is men tioned here. Thus, in the literature compilation only some, but relevant works are selected for each chapter. Whenever possible, reference is made to reviews or review-like articles alone by means of which origin,al works can be consulted. The reviews given under ref. 1) are considered to be the most relevant. The formulae presented in the figures should be understood as representative structures outlining a specific field. 2 Classification of Oligo-/Multidentate Neutral Ligands and of their Complexes Today, a distinction is made between the classical ring oligoethers (crown ethers) and monocyclic coronands, oligocyclic spherical cryptands and the acyclic podands with respect to topological aspects 3). This classification and the topology are illustrated in Fig. 1, each figure representing the minimum number of donor atoms and chain segments characteristic of each class of compounds. Multidentate mono cyclic ligands with any type of donor atoms are called coronands ("crown compounds"), while the term crown ether should be reserved for cyclic oligoethers exclusively containing oxygen as donor atom.

In a classical approach materials science is mainly dealing with interatomic interactions within molecules, without paying much interest on weak intermolecular interactions. However, the variety of structures actually is the result of weak ordering because of noncovalent interactions. Indeed, for self-assembly to be possible in soft materials, it is evident that forces between molecules must be much weaker than covalent bonds between the atoms of a molecule. The weak intermolecular interactions responsible for molecular ordering in soft materials include hydrogen bonds, coordination bonds in ligands and complexes, ionic and dipolar interactions, van der Waals forces, and hydrophobic interactions. Recent evolutions in nanosciences and nanotechnologies provide strong arguments to support the opportunity and importance of the topics approached in this book, the fundamental and applicative aspects related to molecular interactions being of large interest in both research and innovative environments. We expect this book to have a strong impact at various education and research training levels, for young and experienced researchers from both academia and industry.

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.

This book provides a complete overview of cucurbituril chemistry, covering fundamental aspects including history, synthesis and host-guest chemistry.

Chromatographic Determination of Molecular Interactions describes the theory and practice of the measurement of molecular interactions by thin-layer, high performance liquid, and gas chromatography. Methods and various procedures used for the calculation of complex stability constants are compiled, and the stability constants of a wide variety of interactions determined by the various chromatographic techniques are included. New results of molecular interactions are covered, including those for protein-peptide and amino acid-nucleic acid bases. The book will appeal to biochemists, analytical chemists, molecular biologists, biotechnologists, biophysicists, and medicinal chemists.