Organized Assemblies Of Calix 4 Arenes In The Solid State

Organized Assemblies of Calix [4] Arenes in the Solid State

Over the past thirty years synthetic receptor molecules have contributed heavily to the development of supramolecular chemistry because of their ability to bind molecular substrates by means of various intermolecular forces. Among these receptors, calixarenes have received particular attention. The cone conformation of calixarenes presents a preorganized platform that can act as a host for small substrate molecules, which may be neutral or charged. This thesis describes different approaches for the construction of organized assemblies involving derivatives of calix[4]arenes, via a self-assembly process. In this effort, 1- and 2-dimensional frameworks was obtained using the hydrogen bond capabilities of primary and secondary amides. Furthermore, the cavity of the calix[4]arene was extended by the formation of a multicomponent system. The synthesis of a coordination polymer was characterized in the solid-state. Finally, new complexes of the water soluble p -sulfunatocalix[4]arene with quaternary ammonium cation located inside the cavity of the calix[4]arene were obtained. Characterization of these complexes in the solid-state also revealed that the familiar bilayer arrangement of these water-soluble molecules is maintained.

Dissertation Abstracts International

Current Challenges on Large Supramolecular Assemblies

The objectives of the ARW were: - identifying areas and highlighting approaches by which large Supramolecular (SM) Assemblies can be synthesised - reviewing and combining methods to characterise and analyse such assemblies. The first part of the ARW is devoted to reviewing synthetic achievements in recent years for several families of SM compounds, and to bringing out principles for crystal structure design, including novel quantum mechanical methods. Synthesis pertains both to the chemical synthesis of components for SM assembly, and to the subsequent assembly process based on complementarity and non-covalent interactions. The elaboration of multiple recognition "algorithms" concurrently employed (for instance, 1t-1t and hydrogen bonds) has recently reached a high degree of sophistication in the sequence: Molecules -7 Supermolecule -7 SM array -7 Crystal or Conglomerate Novel Large Assemblies comprise synthetic entities with molecular weight as high as 15000, and hybrid SM assemblies between synthetic molecules and DNA. Further developments are foreseen at a higher level of organisation, such as between supermolecules or with electromagnetic fields in photochemical processes. Creation of 2D Assemblies is now a powerful tool for creation and study of SM interactions. Moreover, much is to be learned in going from 2D to 3D assemblies in crystal growth and other forms of organisation such as micelles or liquid crystals. On the other hand, crystal engineering based on Molecular Recognition in the Crystal State leads to novel 2D assemblies occurring within predesigned crystal structures (hydrophobic organic clays or nanoporous networks).