Organic supramolecular materials

Organic supramolecular materials may be devised on the basis of molecular components of various structures bearing recognition units [9.149, 9.235]. As shown above, liquid crystals and liquid crystalline polymers of supramolecular nature presenting various supramolecular textures are generated by the self-assembly of complementary subunits. 

Pahnans and Meijer have reported wholly organic supramolecular materials the phase segregation of benzene-1,3,5-tricarboxamide (BTA)-based helical nanorods within an amorphous polymer such as poly(ethylene butylene) (PEB) resulted in elastomeric behavior (Figure 8). The BTA motif has two binding sites (top and bottom face of the discotic), which provide the basis for both supramolecular chain extension and simultaneous cross-linking. Furthermore, hydrogen-bonding interactions and order in the nanofibers were studied via infrared (IR) spectroscopy and circular dichroism (CD). The materials are liquid crystalline at room temperature, which leads to their elastomeric properties. 

In this chapter we describe the basic principles involved in the controlled production and modification of two-dimensional protein crystals. These are synthesized in nature as the outermost cell surface layer (S-layer) of prokaryotic organisms and have been successfully applied as basic building blocks in a biomolecular construction kit. Most importantly, the constituent subunits of the S-layer lattices have the capability to recrystallize into iso-porous closed monolayers in suspension, at liquid-surface interfaces, on lipid films, on liposomes, and on solid supports (e.g., silicon wafers, metals, and polymers). The self-assembled monomolecular lattices have been utilized for the immobilization of functional biomolecules in an ordered fashion and for their controlled confinement in defined areas of nanometer dimension. Thus, S-layers fulfill key requirements for the development of new supramolecular materials and enable the design of a broad spectrum of nanoscale devices, as required in molecular nanotechnology, nanobiotechnology, and biomimetics [1-3]. 

Supramolecular organization and materials design,Cambridge University Press, Cambridge. 

Newman SP, Jones W (2001) In Jones W, Rao CNR (eds) Supramolecular Organization and Materials Design. Cambridge University Press, Cambridge Prakash AS, Kamath PV, Hegde MS (2000) Mater Res Bull 35 2189 de Roy A, Forano C, Besse JP (2001) Chapter 1 in [2]... 

Newman SP, Jones W (2001) In Rao CNR, Jones W (eds) Supramolecular Organization and Materials Design. Cambridge University Press, Cambridge UK p 295... 

In the present volume, our intention was to cover several modern approaches to phosphorus chemistry which were not, or at least not completely, covered in the previous volumes. The selected topics are expected to have broader relevance and to be interesting to a more general readership, since key aspects of phosphorus chemistry are pointed out. Indeed, several fields are investigated coordination chemistry, catalysis, supramolecular chemistry, biochemistry, hybrid organic-inorganic materials, new ambiphilic ligands, and biology. 

Bond AD, Jones W (2002) In Jones W, Rao CNR (eds) Supramolecular organization and materials design. Cambridge University Press, Cambridge, p 391... 

Stupp SI, LeBonheur V, Walker K, Li LS, Huggins KE, Keser M, Amstutz A. Supramolecular materials self-organized nanostructures. Science 1997 276 384-389. 

As far as the chemist is concerned, nanosized materials are huge macromolecules (with molecular weights of the order of 106 to 1010) constructed from millions of atoms. Atom-by-atom synthesis of nanostructures, via covalent bond formation, is a formidable task which has not as yet been achieved by synthetic chemists. Covalent polymerization is the best that chemists have done thus far [3]. Chemists have made spectacular progress, however, in forming self-organized and supramolecular materials in the size domain of nanostructures by the non-covalent bond assembly of molecules [7]. 

In spite of the potential advantages, useful organic NLO materials have not yet been developed because the necessary molecular and macroscopic characteristics have only recently begun to be understood. However, because bulk NLO properties in organic materials arise directly from the constituent molecular nonlinearities, it is possible to decouple molecular and supramolecular contributions to the NLO properties. One can then semiquantitatively predict relative macroscopic nonlinearities based on theoretical analyses of the individual molecules (7). Reliable predictions of this kind are vital for the efficiency of a program aimed towards developing new organic materials with tailored NLO properties. 

In this chapter, supramolecular chemistry related to developments in materials fabrication and functionalization at the mesoscale are discussed, with an emphasis on those systems based on organic-inorganic hybrid structures. The contents of this chapter are classified into (1) supramolecular chemistry within mesoscopic media, (2) supramolecular assembly at the mesoscale, and (3) supramolecular materials at the mesoscale. Despite this classification these topics have considerable similarities. 

---