IUF 20 ans
 

L’année inter­na­tio­nale de la chimie : « Perspectives en Chimie : De la Chimie Supramoléculaire à la Chimie Adaptative »

Jean-Marie Lehn

Prix Nobel, Collège de France, ISIS, Université de Strasbourg

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. The design of mole­cu­lar infor­ma­tion control­led, “pro­gram­med” and func­tio­nal self-orga­ni­zing sys­tems pro­vi­des an ori­gi­nal approach to nanos­cience and nano­tech­no­logy. The spon­ta­neous but control­led gene­ra­tion of well-defi­ned, func­tio­nal mole­cu­lar and supra­mo­le­cu­lar archi­tec­tu­res of nano­me­tric size through self-orga­ni­za­tion repre­sents a means of per­for­ming pro­gram­med engi­nee­ring and pro­ces­sing of func­tio­nal nano­struc­tu­res. It offers a very power­ful alter­na­tive to nano­fa­bri­ca­tion and to nano­ma­ni­pu­la­tion for the deve­lop­ment of nano­tech­no­logy. 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 intro­du­ces a para­digm shift with res­pect to cons­ti­tu­tio­nally static che­mis­try. The latter relies on design for the gene­ra­tion of a target entity, whe­reas CDC 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. Applications of this approach in bio­lo­gi­cal sys­tems as well as in mate­rials science will be des­cri­bed. The mer­ging of the fea­tu­res : - infor­ma­tion and pro­gram­ma­bi­lity, - dyna­mics and struc­tu­ral diver­sity, -cons­ti­tu­tion and selec­tion, points towards the emer­gence of adap­tive and evo­lu­tive che­mis­try.

References

  1. Lehn, J.-M., Supramolecular Chemistry : Concepts and Perspectives, VCH Weinheim, 1995.
  2. Lehn, J.-M., Dynamic combinatorial chemistry and virtual combinatorial libraries, Chem. Eur. J., 1999, 5, 2455.
  3. Lehn, J.-M., Programmed chemical systems : Multiple subprograms and multiple processing/expression of molecular information, Chem. Eur. J., 2000, 6, 2097.
  4. Lehn, J.-M., Toward complex matter : Supramolecular chemistry and self-organization, Proc. Natl. Acad. Sci. USA, 2002, 99, 4763.
  5. Lehn, J.-M., Toward self-organization and complex matter, Science, 2002, 295, 2400.
  6. Lehn, J.-M., Dynamers : Dynamic molecular and supramolecular polymers,
  7. Prog. Polym. Sci., 2005, 30, 814.
  8. Lehn, J.-M., From supramolecular chemistry towards constitutional dynamic chemistry and adaptive chemistry, Chem. Soc. Rev., 2007, 36, 151.