Chemistry supramoléculaire
The objective of the chemistry supramoléculaire is to include/understand or build buildings of nanometric size . The principle is to use molecular bricks , which once mixed in solution, under controlled conditions, is autoassemblent to give more complex buildings.
It bases for that on the establishment between already preexistent molecules of interactions known as " not covalentes" because not implying by the creation of new orbital molecular. This concept is opposed to chemistry known as " moléculaire" , which deals with the existing covalent bonds within a molecule and connecting between them its atoms. Although the new system can acquire properties which it did not have before the establishment of the aforesaid connections noncovalent, chacunes of the molecules taking share to the news " supermolécule" of anything its modified chemical integrity does not see. However, the architecture of the assembly supramoléculaire can make so that certain molecules is made more reactive by disturbance of their electronic cloud or deformation of their angles of connection. The bringing together within the entity supramoléculaire of two naturally inclined molecules to react together can as push them to react more easily as if they had been free in a solvent. One speaks then about catalysis supramoléculaire (the enzymes are the most known example of biological catalyst supramoléculaire).
Two types of approaches are considered in this branch of chemistry. One, rather observant, tries to explain, to include/understand, and to control autoassemblages observed partly, the other, rather directed towards the synthesis, tries to design molecular bricks given to obtain a given building. Certain syntheses, as specific private individuals those of Ligand S of a Metal, are obtained by assembling as a preliminary the Synthon S and metal, then by adding the reagents allowing the synthesis of the ligand itself (effect known as " template" used in the synthesis of the Cryptand S or the ethers crowns for example). The " effect; template" in the final analysis facilitate the reaction so much on the thermodynamic point of view (the receiving system/metal which results from it at the end of the synthesis moves the balance of the reaction by its great stability) that on the kinetic point of view (the presence of metal rigidifies and constrained the system at the molecular level so as to bring closer the ends which is judicious to react between them).
The interactions at the base of this chemistry can be interactions metal/ligand, ionic connections, ion/dipole, dipole/dipole, hydrogen bonds or the result of a hydrophobic effect.
Jean-Marie Lehn (Nobel Prize 1987 of Chemistry) made it possible to formalize the concepts of chemistry supramoléculaire.
Many prospects are in particular considered applications to data processing conducting buildings supramoléculaires.
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