Cation Binding By Macrocycles

This reference details the theory and application of cation complexation, including the design and synthesis of various cyclic systems, these materials' use as transport systems, in complexation and selectivity studies by macrocyclic systems, and methodologies for understanding these phenomena. In a

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.

Building on the pioneering work in supramolecular chemistry from the last 20 years or so, this monograph addresses new and recent approaches to anion coordination chemistry. Synthesis of receptors, biological receptors and metallareceptors, the energetics of anion binding, molecular structures of anion complexes, sensing devices are presented and computational studies addressed to aid with the understanding of the different driving forces responsible for anion complexation. The reader is promised an actual picture of the state of the art for this exciting and constantly evolving field of supramolecular anion coordination chemistry. The topics range from ion channels to selective sensors, making it attractive to all researchers and PhD students with an interest in supramolecular chemistry.

NMR is better suited than any other experimental technique for the characterization of supramolecular systems in solution. The presentations included here can be broadly divided into three classes. The first class illustrates the state of the art in the design of supramolecular systems and includes examples of different classes of supramolecular complexes: catenanes, rotaxanes, hydrogen-bonded rosettes, tubes, capsules, dendrimers, and metal-containing hosts. The second class comprises contributions to NMR methods that can be applied to address the main structural problems that arise in supramolecular chemistry. The third class includes biological supramolecular systems studied by state-of-the-art NMR techniques.

Cucurbiturils (CBs) are a young family of molecular containers, able to form stable complexes with various guests, including drug molecules, amino acids and peptides, saccharides, dyes, hydrocarbons, perfluorinated hydrocarbons, and proteins. Since the discovery of the first CB, the field has seen tremendous growth with respect to the synthesis of new homologues and derivatives, the discovery of record binding affinities of guest molecules in their hydrophobic cavity, and associated applications ranging from sensing to drug delivery. Cucurbiturils and Related Macrocycles provides a complete overview of CB chemistry, covering the fundamental aspects including its history, synthesis, host–guest chemistry and the thermodynamic basis thereof. The book will tackle specialist topics such as redox chemistry of CB complexes and CBs in the gas phase, and will address the recent trends of the application of CBs in other fields including biology and materials. Edited by a pioneer of cucurbituril chemistry, and with contributions from global experts, this title will appeal to students and researchers working in supramolecular chemistry, materials chemistry, nanotechnology, organic chemistry, biochemistry and chemical biology.