Supramolecular liquid crystalline polymers

Fouquey, C. Lehn, J.-M. Levelut, A.-M. Molecular recognition directed self-assembly of supramolecular liquid crystalline polymers from complementary chiral components. Adv. Mater. 1990, 2, 254-257. 

Gulikkrzywicki T, Fouquey C, Lehn JM. Electron-microscopic study of supramolecular liquid-crystalline polymers formed by molecular-recognition-directed self-assembly from complementary chiral components. Proc Natl Acad Sci USA 1993 90 163-167. 

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. 

It is reasonable to assume that the complementary units form the expected triply hydrogen bonded pairs, so that the entirely different behaviour of the pure compounds and of the 1 1 mixtures may be attributed to the spontaneous association of the complementary components into a polymolecular entity based on hydrogen bonding. The overall process may then be described as the self-assembly of a supramolecular liquid-crystalline polymer based on molecular recognition (Figure 40). The resulting species (TP2, TU2) is represented schematically by structure 174. 

Molecular recognition directed self-assembling of organized phases has been described recently in the formation 1) of mesophases by association of complementary molecular component, as in 13 (23) 2) of supramolecular liquid crystalline polymers of type 14 (24) and 3) of ordered solid state structures, such as that represented by 15 (25). In all these cases, the incorporation of NLO active groups may be expected to produce materials whose SHG properties would depend on molecular recognition induced self-organization. 

T. Gulik-Krzywicki, C. Fouquey, J.-M. Lehn, Electron Microscopic Study of Supramolecular Liquid Crystalline Polymers Formed by Molecular-Recognition-Directed Self-Assembly from Complementary Chiral Components , Proc. Natl. Acad. Sci. USA, 90, 163 (1993)... 

Fig. 2 A selection of early examples of supramolecular liquid crystalline polymers designed by Frechet and Kato [42-45], Lehn [46-50] and Griffin [51-54]...

Fig. 3 Schematic representations of some possible supramolecular liquid crystalline polymer architectures, a-e Different classes of main-chain structures, f-i Different side chain polymers, j-m Different types of networks...

Fig. 9 A halogen-bond mediated main-chain supramolecular liquid crystalline polymer 11-4...

The topic of hydrogen bonded liquid crystalline materials has been reviewed by several groups [2,27,29-31]. Herein only the important and recent development on hydrogen bonded supramolecular low molecular weight LCs will be introduced. Supramolecular liquid crystalline polymers will not be included in this chapter. 

Zettsu N, Ogasawara T, Mizoshita N, Nagano S, Seki T. 2008. Photo triggered surface relief grating formation in supramolecular liquid crystalline polymer systems with detachable azobenzene unit. Adv Mater 20 516 521. 

Zettsu, N. Ogasawara, T. Mizoshita, N. Nagano, S. Seki, T. (2008). Photo-Triggered Surface Relief Grating Formation in Supramolecular Liquid Crystalline Polymer Systems with Detachable Azobenzene Units. Adv. Mater., 2008, 20, 516-521. 

MOLECULAR RECOGNITION DIRECTED SELF-ASSEMBLY OF SUPRAMOLECULAR LIQUID CRYSTALLINE POLYMERS... 

Scheme 7. Generation of a supramolecular liquid crystalline polymer.

B. Generation of Supramolecular Liquid-Crystalline Polymers and Fibers... 

The racemic mixture of all four components LP2, LU2, DP2, and DU2 yielded long superhelices of opposite handedness that coexisted in the same sample, pointing to the occurrence of spontaneous resolution through chiral selection in molecular recognition-directed self-assembly of supramolecular liquid-crystalline polymers. Such chiral selection features of self-organized entities are of general significance in connection with the questions of spontaneous resolution and of chirality amplification. This was confirmed by subsequent studies on a variety of helical supramolecular polymers (see Chapters 2, 3, and 6). 

Rgure24 Supramolecular liquid-crystalline polymers 32 and 33 without aromatic mesogens. 

C. Examples of Multiply Hydrogen-Bonding Building Blocks Hydrogen-Bonded, Supramolecular Liquid-Crystalline Polymers... 

Last but not least, it is remarkable that mesophases and living systems are closely connected. One aspect of this relation is the formation of bilayers, micelles, and other organized structures by amphiphilic molecules. These supermolecular structures can form lyotropic mesophases (Chapter 14) and vesicles [81]. In addition, Lehn and coworkers [82] have demonstrated a self-assembly of supramolecular liquid crystalline polymers (Figure 1.17) which is very reminiscent of the supermolecular structure of biochemical macromolecules (Figure 1.5). Tartaric acid-based molecules bearing complemen-... 

Supramolecular liquid crystalline polymers containing pyridine moieties... 

Fouquey C., Lehn J.-M andLevelut A.-M. (1990), Molecular Recognition Directed Self-Assembly of Supramolecular Liquid Crystalline Polymers from Complementary Chiral Components , Mater., 2,254-7. 

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