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.

Connects fundamental knowledge of multivalent interactions with current practice and state-of-the-art applications Multivalency is a widespread phenomenon, with applications spanning supramolecular chemistry, materials chemistry, pharmaceutical chemistry and biochemistry. This advanced textbook provides students and junior scientists with an excellent introduction to the fundamentals of multivalent interactions, whilst expanding the knowledge of experienced researchers in the field. Multivalency: Concepts, Research & Applications is divided into three parts. Part one provides background knowledge on various aspects of multivalency and cooperativity and presents practical methods for their study. Fundamental aspects such as thermodynamics, kinetics and the principle of effective molarity are described, and characterisation methods, experimental methodologies and data treatment methods are also discussed. Parts two and three provide an overview of current systems in which multivalency plays an important role in chemistry and biology, with a focus on the design rules, underlying chemistry and the fundamental principles of multivalency. The systems covered range from chemical/materials-based ones such as dendrimers and sensors, to biological systems including cell recognition and protein binding. Examples and case studies from biochemistry/bioorganic chemistry as well as synthetic systems feature throughout the book. Introduces students and young scientists to the field of multivalent interactions and assists experienced researchers utilising the methodologies in their work Features examples and case studies from biochemistry/bioorganic chemistry, as well as synthetic systems throughout the book Edited by leading experts in the field with contributions from established scientists Multivalency: Concepts, Research & Applications is recommended for graduate students and junior scientists in supramolecular chemistry and related fields, looking for an introduction to multivalent interactions. It is also highly useful to experienced academics and scientists in industry working on research relating to multivalent and cooperative systems in supramolecular chemistry, organic chemistry, pharmaceutical chemistry, chemical biology, biochemistry, materials science and nanotechnology.

The combination of supramolecular chemistry, inorganic solids, and nanotechnology has already led to significant advances in many areas such as sensing, controlled motion, and delivery. By making possible an unprecedented tunability of the properties of nanomaterials, these techniques open up whole new areas of application for future supramolecular concepts. The Supramolecular Chemistry of Organic–Inorganic Hybrid Materials gathers current knowledge on the subject and provides an overview of the present state and upcoming challenges in this rapidly growing, highly cross- or interdisciplinary research field. The book details how these designed materials can improve existing materials or generate novel functional features such as chemical amplification, cooperative binding and signal enhancement that are difficult or not at all achievable by classical organic supramolecular chemistry. It also discusses issues related to nanofabrication or nanotechnology such as the directed and controlled assembly or disassembly, biomimetic functions and strategies, and the gating and switching of surface functions or morphology.

The work described in this thesis examines the noncovalent interactions, dynamics and structure of a self-assembled supramolecular host-guest system. The highly-charged, water soluble supramolecular assembly is able to selectively bind cationic molecules to the host interior and exterior and mediate the physical properties and chemical reactivity of bound guests. Herein, physical organic chemistry in the context of this supramolecular system is used to elucidate some of the fundamental host-guest interactions that underlie guest binding and reactivity. Chapter 1. First, an overview of different noncovalent interactions and their importance to biological systems is presented. Selected examples of synthetic supramolecular host-guest systems are then reviewed, focusing on examples that illustrate how chemists have used noncovalent interactions to construct complex host architectures and affect guest chemical reactivity. Finally, the [Ga4L6]12- supramolecular assembly, which is the topic of Chapters 2 - 5, is introduced and previous work examining the host-guest chemistry of this system is briefly reviewed. Chapter 2. Ortho-substituted benzylphosphonium guest molecules are used to quantitatively probe the steric effects of confinement within the [Ga4L6]12- host. Encapsulated guest bond rotational barriers and tumbling rates are measured in different solvents and at elevated external pressures. These studies reveal that despite the flexibility of the host assembly, guest molecules experience significant steric confinement on the host interior and their bond rotational barriers are increased by up to 6 kcal/mol. Significant solvent and pressure effects on the bond rotational rates are also observed; these suggest that the host cavity is smaller or less flexible in organic than in aqueous solution, and that internal solvent pressure is responsible for the observed changes in ligand framework flexibility. The apparently smaller cavity volumes in organic solvents are further supported by NOE distance measurements, which show shorter average host-guest distances in organic, as compared to aqueous, solutions. Chapter 3. Building on the solvent effects observed in Chapter 2, some additional, qualitative solvent effects are first presented; these show that guest binding and exchange is also sensitive to bulk solvent and that N, N-dimethylformamide can act as weakly bound guest. The second part of this chapter presents a quantitative study of the solvent effects on the thermodynamics and kinetics of guest binding and exchange in the [Ga4L6]12- host. No correlation between the guest binding or exchange parameters across different solvents are observed, illustrating the complexity of host and guest solvation in these highly-charged supramolecular systems. Chapter 4. A brief literature review of isotope effects on guest binding and exchange in supramolecular host-guest systems is first presented. The measurement of kinetic and equilibrium isotope effects on guest binding and exchange in the [Ga4L6]12- assembly are then described. Protiated guests are found to be more strongly bound to both the host interior and exterior, with significantly larger equilibrium isotope effects observed for C-H/D bonds that can participate in cation-[pi] interactions. DFT-level computations reveal that the equilibrium isotope effects arise from changes in low frequency C-H/D vibrational motions upon guest association. Kinetic isotope effects during the guest ejection process are also observed. A general model to explain both equilibrium and kinetic isotope effects, based only on changes in C-H/D vibrational force constants and zero-point energies is presented. The observation of significant isotope effects on both guest binding and exchange demonstrates the remarkable sensitivity of the [Ga4L6]12- host assembly to even the most subtle changes in guest architecture. Chapter 5. Guest molecules encapsulated in [Ga4L6]12- experience dramatic changes in their 1H nuclear magnetic resonance (NMR) chemical shifts due to the unique magnetic environment of the host interior. Gauge-independent atomic orbital NMR chemical shift calculations are carried out and compared with experiment to provide information about host-guest conformation and structure.