Molecular Recognition-Directed Assembly of Organized Phases

2 Molecular Recognition-Directed Assembly of Organized Phases 

It is clear that intermolecular effects strongly influence the properties of materials. The point is that one may make use of them in a controlled fashion to induce specific changes when and where desired. The self-assembly of membranes, molecular layers, films, vesicules, etc. incorporates interactions such as hydrophobic effects, hydrogen bonding, electrostatic forces and surface binding [7.1-7.13, 7.45, 7.87, 9.134-9.141], which may be used to produce specific structural and functional properties. 

This was realized with derivatives of the complementary heterocyclic groups 2,6-diaminopyridine P and uracil U bearing long aliphatic chains [9.150]. Whereas the pure compounds did not show liquid crystalline behaviour, 1 1 mixtures gave a metastable mesophase of columnar hexagonal type. The existence of the latter was attributed to the formation of a mesomorphic supermolecule 173 via association of the complementary components. 

Numerous extensions may be envisaged, such as the introduction of various central cores, in particular those already known to yield molecular liquid crystals, the incorporation of light-sensitive or electro-sensitive units, the potential use for detection devices, and the extension to various recognition components of biological nature (for biomesogens see 9.109, 9.112, 9.115, 9.146). 

Self-Organization of Supramolecular Liquid Crystalline Polymers from Complementary Components. If two (or more) complementary units e or 3 are grafted on a template T, mixing Te m with the complementary T3m may lead to the hetero-self-assembly of a linear or cross-linked, main-chain supramolecular copolymer species (Te m, Tsw), whose existence is conditioned by the molecular recognition-directed association between the e and a groups. 

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