Ce projet décrit la synthèse et l'étude de composés macromoléculaires liquides-cristallins à base de nanoparticules d'or (première partie) et à structures arborescentes ou dendritiques (seconde partie). Ces matériaux, à hautes valeurs ajoutées, sont intéressants d'un point de vue fondamental, pour comprendre la relation qui existe entre la structure et l'organisation supramoléculaire, et pour développer des applications dans les nanotechnologies par l'approche "bottom-up". La mise en évidence de l'influence de la structure des ces composés sur leur faculté à former des assemblages ordrés particuliers et complexes (cristaux liquides) permettra de concevoir des molécules pouvant transférer des informations de manière efficace dans l'état mesoscopique. Pour atteindre ces objectifs, des outils de synthèse modernes seront utilisés. Il est important de mentionner que ce projet est de nature multidisciplinaire et fait appel à des notions en chimie de synthèse organique, en chimie inorganique, en chimie macromoléculaire et dans la science des matériaux.


This proposal is devoted to the synthesis and study of mesomorphic supramolecular materials, the design of which is based on the combination of two elegant and effective reactions, i.e., the Huisgen 1,3-dipolar cycloaddition reaction (click reaction) and the olefin cross metathesis reaction. The two reactions will be applied is a consecutive way so that two different mesogens will be introduced into the target architectures in a controlled manner. This is a new concept in the design of mesoscopic materials. Owing to the structures that can be obtained and the information (related to the mesogens) that can be programmed within the materials, results of fundamental importance will be obtained. The first part of the proposal (Section 2.3.1.) is devoted to the synthesis and study of liquid-crystalline gold nanoparticles. Gold nanoparticles will be functionalized with thiol derivatives containing either an azido group (for the click reaction) or a terminal olefin (for the cross metathesis reaction). In a stepwise way, we will introduce two mesogens around the gold core. As it is possible to control the azido/olefin ratio, it is so possible to control the percentage of each mesogen. Therefore, by controlling the ratio, structure and nature of each mesogen, our concept will allow us to design liquid-crystalline gold nanoparticles with tailor-made properties. This is an important step in the design of organic-inorganic hybrid supramolecular materials. The second part of the proposal (Section 2.3.2.) is devoted to the synthesis and study of liquid-crystalline dendrimers, the convergent growth of which is controlled by the click and olefin cross metathesis reactions. The basic building block for the contruction of the dendrimers is a trifunctional monomer containing an azido group (for the click reaction), a terminal olefin (for the cross metathesis reaction) and a OH group (for the growth of the dendrimers). The click and olefin cross metathesis reactions will become reactions of choice for the synthesis of a great variety of liquid-crystalline dendrimers. Indeed, owing to the fact that the click and olefin cross metathesis reactions tolerate many different functional groups, a great variety of materials will be available. The design and study of liquid-crystalline dendrimers is an important research area. The design of sophisticated liquid-crystalline dendrimers which display precise properties and functions requires the use of highly perfomant chemical reactions. This part of the proposal will bring results in this direction.