Basic Concepts in Supramolecular Chemistry

The following sections discuss some fundamental concepts in supramolecular chemistry. The list is certainly not comprehensive and the reader is referred to textbooks for a broader scope of examples. However, the selection reveals that supramolecular research developed from its heart, i.e. the examination and understanding of the noncovalent bond, to more advanced topics which make use of that 

Clearly, molecular recognition processes are the prototypical supramolecular reactions on which the other aspects are based. Without molecular recognition, there are no template effects, no self-assembly, and certainly no self-replication. In contrast to opinions sometimes encountered among chemists from other areas, supramolecular chemistry did not come to a halt with the examination of hosts and guests and their interactions. Sophisticated molecular devices are available which not only are based on, but go far beyond mere molecular recognition. 

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Steed, J.W., Turner, D.R. and Wallace, K. (2007) Core Concepts in Supramolecular Chemistry and Nanochemistry, John Wiley Sons, Ltd, Chichester, UK. Fundamentals of the frontier research fields of supramolecular chemistry and nanochemistry are covered in a fairly concise manner, explaining the evolution of the fields from more basic foundations suitable for students who want a clear and accessible introduction to these areas. 

At the most basic level, mechanical properties are necessarily a matter of action and reaction, stimulus and response. The actor—a mechanical stress—is a familiar part of everyday life, but efforts to understand its molecular consequences are only recently coming to the fore in supramolecular chemistry. We next consider examples of how covalent polymers respond to a mechanical stress, and then we extend that examination to the case of SPs. This discussion is not intended to capture all of the details of a thermodynamically rigorous treatment but is instead focused on providing a useful conceptual framework for key concepts related to the mechanics of SPs. 

MPs and MPcs show very similar physical and chemical properties and they are structurally related to biological catalysts like cytochrome c and hemoglobin. The basic difference between their structures is shown (Fig. 7.1). As it will be discussed in details later, the properties of these complexes are very dependent on the type of central metal (M) and on the nature of substituents on the ligand. It is important to remark that the choice of substituents for the macrocyclic ligands is inexhaustible which leaves plenty of room for tailoring their properties. For example, the properties of metaUoporphyrins may be varied widely by means of substitution groups at the p and meso-positions of the ring (Fig. 7.1a). Furthermore, the concepts of supramolecular chemistry and molecular self-assembly offer additional possibilities to vary the properties of metallomacrocyclic [22-24]. 

Supramolecular chemistry provides very different insights into chemical events, particularly at nano- and meso-scale levels. In addition, application of supramolecular chemistry to materials science has recently developed significantly to give a variety of highly functionalized sensors, molecular devices, and polymeric materials. An up-to-date survey of recent progress in this field. Synergy in Supramolecular Chemistry introduces basic concepts and examples of supramolecular chemistry in terms of cooperativity and synergy. 

Supramolecular chemistry has been described as chemistry beyond the molecule. Although a very broad statement, it does generally summarize the basic concept, which is the study of how molecules can interact and associate with each other to generate more complex structures with more sophisticated functions. The original supramolecular chemist is Mother Nature, who has created the greatest achievements in supramolecular chemistry. A good example of supramolecular chemistry in nature is viruses. You probably know viruses more for their ability to cause diseases, like the common cold. But if you take a closer look at a virus, what you see is one of the most spectacular examples of supramolecular chemistry. 

The concept of supermolecular chemistry, chemistry of very large molecules, is also of great current interest and is relevant to both crystal engineering and supramolecular chemistry. When one considers the development of supermolecules , the 1990s will probably be regarded as the key time period in which the basic concepts were delineated and experimental results were forthcoming. Indeed, we have witnessed synthesis and characterization of the largest hydrocar-... 

Before going into detail with respect to the analytical methods that are applied in contemporary supramolecular chemistry, this brief introduction to some basic concepts and research topics within supramolecular chemistry is intended to provide the reader with some background. Of course, it is not possible to give a comprehensive overview. It is not even achievable to review the last 40 or so years of supramolecular research in a concise manner. For a more in-depth discussion, the reader is thus referred to some excellent text books on supramolecular chemistry [7]. 

Other photoisomerizable molecules including azobenzene-capped /1-cyclodex-trins, dendrimers, aza-crown and calixarene compounds have been reported [14,160,161] and, though they are not used for studying biomolecules, they open up new perspectives in the field of supramolecular chemistry and help to understand basic concepts that have been validated in biochemistry. 

It is clear that the time is ripe for an Encyclopedia of Supramolecular Chemistry, presenting its basic concepts, its various objects, and processes as well as its relations to other areas of basic and applied science. It will be of great value to the many practitioners in the field as well as to those, perhaps even more numerous newcomers, who wish to get acquainted with it end may wish to join the family and become part of the adventure ... 

However, amongst the chemical foundations on which the pioneers of supramolecular chemistry were building, although sometimes without acknowledgment, were the basic principles of colloid science. Colloid chemistry had been long established by the time of the initial development of supramolecular chemistry, and had also focused on the behavior of ensembles of molecules—typically mediated through noncovalent interactions. Indeed, the concept of self-assembly is fundamental in the study and manipulation of colloidal materials. By definition, colloids consist of a dispersed phase (or discontinuous phase) distributed... 

Supramolecular chemistry thus has a direct relationship with the highly active area of combinatorial chemistry, however in a very specific fashion. Indeed, reversibility being a basic and crucial feature of supramolecular systems, the dynamic generation of supramolecular diversity from the reversible combination of noncovalently linked building blocks falls within the realm of the emerging area of dynamic combinatorial chemistry (DCC) which involves dynamic combinatorial libraries, of either virtual (VCL) or real nature depending on the system and the conditions [45,46], The concepts and perspectives of the DCCA CL approach have been outlined, inter alia with respect to supramolecular polymers [45],... 

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