ZOOM LINK: https://kaust.zoom.us/j/92999566907
Abstract: Supramolecular chemistry is intrinsically a dynamic chemistry in view of the lability of the non-covalent interactions connecting the molecular components of a supramolecular entity and its resulting ability to exchange components. Similarly, dynamic covalent chemistry concerns molecular entities containing covalent bonds that may form and break reversibility, so as to allow a continuous modification in constitution by reorganization and exchange of building blocks. These features define a Constitutional Dynamic Chemistry (CDC) on both the molecular and supramolecular levels.
One may define constitutional dynamic materials, as materials whose components are linked through reversible covalent or non-covalent connections and which may thus undergo constitutional variation, i.e. change in constitution by assembly/deassembly processes in a given set of conditions. Because of their intrinsic ability to exchange, incorporate and rearrange their components, they may in principle select them in response to external stimuli or environmental factors and therefore behave as adaptive materials of either molecular or supramolecular nature.
Applying these considerations to polymer chemistry leads to the definition of constitutionally dynamic polymers, DYNAMERS, of both molecular and supramolecular types, possessing the capacity of adaptation by association/growth/dissociation sequences. Supramolecular materials, in particular supramolecular polymers may be generated by the polyassociation of components/monomers interconnected through complementary recognition groups. Dynamic covalent polymers result from polycondensation via reversible chemical reactions. They may undergo modifications of their properties (mechanical, optical, etc.) via incorporation, exchange and recombination of their monomeric components. These features give access to higher levels of behavior such as healing and adaptability in response to external stimuli (heat, light, medium, chemical additives, etc.).
CDC introduces a paradigm shift into the chemistry of materials and opens new perspectives in materials science. A rich variety of novel architectures, processes and properties may be expected to result from the blending of supramolecular and molecular dynamic chemistry with materials chemistry, opening perspectives towards adaptive materials and technologies.
J.-M. Lehn, Dynamic combinatorial chemistry and virtual combinatorial libraries, Chem. Eur. J., 1999, 5, 2455.
J.-M. Lehn, From supramolecular chemistry towards constitutional dynamic chemistry and adaptive chemistry, Chem. Soc. Rev., 2007, 36, 151.
J.-M. Lehn, "Dynamers: Dynamic molecular and supramolecular polymers", Aust. J. Chem. 2010, 63, 611-623.
J.-M. Lehn, Chapter 1, in Constitutional Dynamic Chemistry, ed. M. Barboiu, Topics Curr. Chem, 2012, 322, 1-32.
J.-M. Lehn, “Dynamers: From Supramolecular Polymers to Adaptive Dynamic Polymers”, in Adv. Polym. Sci., 2013, 261, 155-172.
Lehn, J.-M., Perspectives in Chemistry – Steps towards Complex Matter, Angew. Chem. Int. Ed., 2013, 52, 2836-2850.
Lehn, J.-M., Perspectives in Chemistry – Aspects of Adaptive Chemistry and Materials, Angew. Chem. Int. Ed., 2015, 54, 3276-3289.
Biography: Jean-Marie Lehn became Professor of Chemistry at the Université Louis Pasteur in Strasbourg in 1970 and from 1979 to 2010 he was Professor at the Collège de France in Paris. He is presently Professor at the University of Strasbourg Institute for Advanced Study (USIAS). He shared the Nobel Prize in Chemistry in 1987 (with Donald Cram and Charles Pedersen) for his studies on the chemical basis of “molecular recognition” (i.e. the way in which a receptor molecule recognizes and selectively binds a substrate), which also plays a fundamental role in biological processes.
Over the years his work led him to the definition of a new field of chemistry, which he has proposed calling “supramolecular chemistry” as it deals with the complex entities formed by the association of two or more chemical species held together by non-covalent intermolecular forces, whereas molecular chemistry concerns the entities constructed from atoms linked by covalent bonds. Subsequently his work developed into the chemistry of self-organization processes, based on the design of "programmed" chemical systems that undergo spontaneous assembly of suitable components into well-defined supramolecular species, directed by the supramolecular processing of molecular information. More recently, the implementation of dynamic features and of selection in both molecular and supramolecular chemistry led to the development of “constitutional dynamic chemistry”, concerning entities able to undergo reorganization in response to external stimuli, thus leading to the emergence of an “adaptive and evolutive chemistry” towards a chemistry of complex matter.
Author of more than 1000 scientific publications, Lehn is a member of many academies and institutions. He has received numerous international honours and awards.