Virtual combinatorial library VCL

The macrocyles formed depend on the overall proportions of 1 and 2, the diamine chain length and the type of cation used as the template. Of importance is the fact that the imine formation is a reversible reaction. Expressed in the DCC sense, one can say that all products, the macrocycies and the nonrepresented oligomers and polymers, are in constant equilibrium, and that all the species represented in Fig. 22 constitute a virtual combinatorial library (VCL). From this library, the high proportion of a specific macrocycle can be obtained by the use of the appropriate conditions (type of metal template, relative proportion of reactants). 

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],... 

The dynamic generation of molecular and supramolecular diversity from the reversible combination of covalently or non-covalently linked building blocks, defines a dynamic combinatorial chemistry (DCC) which gives access to dynamic combinatorial libraries, of either virtual (VCL) or real nature depending on the system and the conditions [18-20]. 

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