Concept of molecular design

The discovery of crown ethers by Pedersen in 1967 opened one of the largest field of research in chemistry up to 1995 <67JA7017, 88AG(E)1021>. This discovery was the spark for the emergence of the concept of molecular design introduced by Lehn <73MI 929-01 > which, by the virtue of chemist s... 

We are now in the era in which the concept of molecular design dominates in all disciplines of chemistry, including polymer science and technology. A new way of science approaching to the arts from an opposite site is now opening logical processes without supposition of black box. The new approach proceeds from the property research to the functionality research and hopefully to the sensibility research, which corresponds to the arts. 

The concept of molecular design to mimic the functional site of a protein molecule is promising. The experimental results so far have shown that, with careful and judicious... 

Testa, B., Kier, L. B. The concept of molecular structure in structure-activity relationship studies and drug design. Med. Res. Rev. 1991, 11, 35 8. 

The molecular mass has units termed daltons (Da), after the famous English chemist John Dalton (1766-1848). Eor example, the molecular mass of insulin might be said to be about 6000 daltons. However, this designation does not add much to understanding the concept of molecular size and we shall delete the dalton unit in all that follows. 

The concepts of molecular similarity (1-3) and molecular diversity (4,5) play important roles in modern approaches to computer-aided molecular design. Molecular similarity provides the simplest, and most widely used, method for virtual screening and underlies the use of clustering methods on chemical databases. Molecular diversity analysis provides a range of tools for exploring the extent to which a set of molecules spans structural space, and underlies many approaches to compound selection and to the design of combinatorial libraries. Many different similarity and diversity methods have been described in the literature, and new methods continue to appear. This raises the question of how one can compare different methods, so as to identify the most appropriate method(s) for some particular application this chapter provides an overview of the ways in which this can be carried out, illustrating such comparisons by,... 

This chapter provides a summary of concepts that molecular designers should be cognizant of when trying to minimize biological activity by manipulating physical and chemical properties of chemicals. Since the most easily accessible source of property values is often computational, the second half of the chapter provides a primer in the types of considerations and limitations that have to be appreciated when obtaining predicted property values. 

Figure 1 Concept for molecular design of switch-functionalized recognition systems.

The gap between concepts in molecular design to produce polyoxometalate integrated nanosystems or molecular-scale devices is vast due to the problem of fabrication and control of molecular orientation. Molecule-by-molecule assembly is... 

It is rarely addressed in the literature that for molecular versions of circuit elements to be useful, there has to be the possibility to connect them together in a way where their electrical characteristics — measured individually between electrodes — would be preserved in the assembled circuit. However, it has been recently shown that such a downscaling of electrical circuits within classical network theory cannot be realized due to quantum effects, which introduce additional terms into Kirchhoff s laws and let the classical concept of circuit design collapse [16]. Circuit simulations on the basis of a topological scattering matrix approach have corroborated these results [34]. 

In more recent years there is a development towards molecular recognition as a tool. Based on the increasing understanding of the weak forces between (macro) molecules we now see new concepts of material design. Chapters 1 to 3 cover three aspects of this development nanostructures that are formed by self-assembly of small molecules (chapter 1), dendritic structures (chapter 2) and polymers (chapter 3). A volume of a series like Perspectives in Supramolecular Chemistry can never claim to cover all aspects of a subject. All I can hope is that these chapters are representative of the filed of supramolecular technology. 

Below we will concentrate our attention only at the main trends of molecular design that were based upon the original concept of macrocyclic binding. From the very beginning, the strategies of numerous investigations in this field were distinctly different. 

Testa, B. and Kier, L.B. (1991). The Concept of Molecular Structure in Structure-Activity Relationship Studies and Drug Design. Med.Res.Rev., 11,35-48. 

Molecular LED Design Concept of Molecular Materials for High-Performance OLED... 

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