From Supramolecular Chemistry Towards Adaptive Chemistry
Supramolecular chemistry lies beyond molecular chemistry. It aims at implementing highly complex chemical systems from molecular components held together by non-covalent intermolecular forces and effecting molecular recognition, catalysis and transport processes. A further step consists in the design of systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, thus behaving as programmed chemical systems.
Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the interactions connecting the molecular components of a supramolecular entity and the resulting ability of supramolecular species to exchange their components. The same holds for molecular chemistry when the molecular entity contains covalent bonds that may form and break reversibility, so as to allow a continuous change in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.
CDC takes advantage of dynamic constitutional diversity to allow for variation and selection in response to either internal or external factors to achieve adaptation.
The implementation of selection in chemistry introduces a fundamental change in outlook with respect to the usual molecular chemistry. The combination of dynamics and reversibility with constitutional and structural diversity points towards the emergence of Adaptive and Evolutive Chemistry.
Illustrations from applications of this approach to biochemical systems will be given.