ECCS '12 Brussels - European Conference on Complex Systems ECCS'12 Complex Systems Society





Springer Complexity Lecture

Jean-Marie Lehn
ISIS, Université de Strasbourg, France

Jean-Marie Lehn is Honorary Professor at Collège de France and Professor Emeritus at Université de Strasbourg, where he heads the Laboratoire de Chimie Supramoléculaire. In 1987, he was awarded the Nobel Prize, alongside Donald Cram and Charles Pedersen, for his works on the chemical basis of molecular recognition (i.e. the way in which a receptor molecule recognizes and selectively binds a substrate), a process which also plays a fundamental role in biology. Lehn is a pioneer in the chemistry of recognition-directed molecular assemblies based on selective intermolecular interactions, which he termed supramolecular chemistry. It has subsequently evolved into the chemistry of self-organizing processes and more recently into constitutional dynamic chemistry and adaptive chemistry.

Towards Complex Matter:
From Supramolecular Chemistry to Adaptive Chemistry

Supramolecular chemistry lies beyond molecular chemistry and aims at constructing highly complex chemical systems from components held together by non-covalent intermolecular forces.

Beyond pre-organization, supramolecular chemistry is actively exploring systems undergoing self-organization, i.e. systems capable of spontaneously generating well-defined functional supramolecular architectures by self-assembly from their components, on the basis of the molecular information stored in the covalent framework of the components and read out at the supramolecular level through specific non-covalent interactional algorithms, thus behaving as programmed chemical systems. Chemistry may therefore also be considered as an information science, the science of informed matter.

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 constituents. 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 introduces a paradigm shift with respect to constitutionally static chemistry. It takes advantage of dynamic diversity to allow variation and selection. The implementation of selection in chemistry introduces a fundamental change in outlook. Whereas self-organization by design strives to achieve full control over the output molecular or supramolecular entity by explicit programming, self-organization with selection operates on dynamic constitutional diversity in response to either internal or external factors to achieve adaptation.

The merging of the features---information and programmability, dynamics and reversibility, constitution and structural diversity---points to the emergence of adaptive and evolutive chemistry. In combination with the corresponding fields of physics and biology, chemistry thus plays a major role in the progressive elaboration of a science of informed, organized, evolutive matter, a science of complex matter.