Discotic liquid crystals with an inverted structure

Angewandte Chemie - International Edition

Volumn 44, Issue 18, 2005, Pages 2801-2805

  Höger, Sigurd ^a   Xiao, Hong Cheng ^c   Ramminger, Anne Désirée ^b   Enkelmann, Volker ^b   Rapp, Almut ^b,d   Mondeshki, Mihail ^b   Schnell, Ingo ^b  

^a UNIVERSITY OF KARLSRUHE   (Germany)

^b MAX PLANCK INSTITUTE FOR POLYMER RESEARCH   (Germany)

^c YUNNAN UNIVERSITY   (China)

^d University of California   (United States)

Author keywords

Liquid crystals; Macrocycles; Mesophases; Substituent effects; Supramolecular chemistry

Indexed keywords

CRYSTAL STRUCTURE; MOLECULAR STRUCTURE;

DISCOTIC LIQUID CRYSTALS; FLEXIBLE SIDE GROUPS; INTRAANNULAR POSITIONS; MACROCYCLES;

LIQUID CRYSTALS;

EID: 18844457408     PISSN: 14337851     EISSN: None     Source Type: Journal    
DOI: 10.1002/anie.200462319     Document Type: Article

References (36)

1. a) S. Chandrasekhar, B. K. Sadashiva, K. A. Suresh, Pramana 1977, 9, 471-480;
2. b) S. Chandrasekhar in Handbook of Liquid Crystals, Vol. 2B (Eds.: D. Demus, J. Goodby, G. W. Gray, H.-W. Spiess, V. Vill), Wiley-VCH, Weinheim, 1998, pp. 749-780;
3. c) R. J. Bushby, O. R. Lozman, Curr. Opin. Colloid Interface Sci. 2002, 7, 343-354.
4. a) D. Adam, P. Schuhmacher, J. Simmerer, L. Haeussling, K. Siemensmeyer, K. H. Etzbach, H. Ringsdorf. D. Haarer, Nature 1994, 371, 141-143;
5. b) N. Boden, R. J. Bushby, J. Clements, B. Movaghar, J. Mater. Chem. 1999, 9, 2081-2086;
6. c) L. Schmidt-Mende, A. Fechtenkötter, K. Müllen, E. Moons, R. H. Friend, J. D. MacKenzie, Science 2001, 293, 1119-1122.
7. a) H. Mori, Y. Itoh, Y. Nishiura, T. Nakamura, Y. Shinagawa, Jpn. J. Appl. Phys. Part 1 1997, 36, 143-147;
8. b) M. Okazaki, K. Kawata, H. Nishikawa, M. Negoro, Polym. Adv. Technol. 2000, 11, 398-403;
9. c) S. Kumar, S. K. Varshney, Angew. Chem. 2000, 112, 3270-3272;
10. Angew. Chem. Int. Ed. 2000, 39, 3140-3142.
11. a) J. P. Behr, J.-M. Lehn, A.-C. Dock, D. Moras, Nature 1982, 295, 526-527;
12. b) J.-M. Lehn, J. Malthete, A.-M. Levelut, J. Chem. Soc. Chem. Commun. 1985, 1794-1796;
13. c) J. Zhang, J. S. Moore, J. Am. Chem. Soc. 1994, 116, 2655-2656;
14. d) O. Mindyuk, M. R. Stetzer, P. A. Heiney, J. C. Nelson, J. S. Moore, Adv. Mater. 1998, 10, 1363-1366.
15. S. Höger, V. Enkelmann, K. Bonrad, C. Tschierske, Angew. Chem. 2000, 112, 3256-3258;
16. Angew. Chem. Int. Ed. 2000, 39, 2268-2270.
17. a) S. Höger, V. Enkelmann, Angew. Chem. 1995, 107, 2917-2920;
18. Angew. Chem. Int. Ed. Engl. 1995, 34, 2713-2716;
19. b) D. L. Morrison, S. Höger, Chem. Commun. 1996, 2313-2314;
20. c) S. Höger, D. L. Morrison, V. Enkelmann, J. Am. Chem. Soc. 2002, 124, 6734-6736.
21. w = 0.0901.
22. θ0 (2) These dynamic order parameters S should not be confused with the orientational order parameters that are often used for describing the degree of orientational order in liquid crystals. The two parameters are not identical, yet they are related: the dynamic order parameters are affected by both the local motions of molecular segments and the overall motions of the molecules. In contrast, only the overall molecular motions are relevant to the orientational order parameters, such that dynamic order parameters can be (and are, in our case) decreased by local segment motions relative to the orientational order of the molecules.
23. a) I. Schnell, Prog. Nucl. Magn. Reson. Spectrosc. 2004, 45, 145-207;
24. b) A. Rapp, I. Schnell, D. Sebastiani, S. P. Brown, V. Percec, H. W. Spiess, J. Am. Chem. Soc. 2003, 125, 13 284-13 297.
25. Unless otherwise stated, mesophases were assigned on the basis of their textures.
26. a) D. M. Collard, C. P. Lillya, J. Am. Chem. Soc. 1991, 113, 8577-8583;
27. b) S. Kumar, D. S. S. Rao, S. K. Prasad, J. Mater. Chem. 1999, 9, 2751-2754.
28. Thermogravimetric analysis (TGA) of 2d shows no weight loss up to 300°C. However, partial decomposition of the materials cannot be fully excluded above 230-250°C.
29. This unusual packing behavior may result from the increased ring width, which does not allow optimal space filling with all alkyl chains in the trans configuration.
30. Assuming a similar packing behavior for 2d, the smaller terminal methyl groups do not cause an interlocking of the molecules and allow mesophase formation.
31. a) S. Höger, K. Bonrad, A. Mourran, U. Beginn, M. Möller, J. Am. Chem. Soc. 2001, 123, 5651-5659;
32. b) M. Fischer, G. Lieser, A. Rapp, I. Schnell, W. Mamdouh, S. De Feyter, F. C. De Schryver, S. Höger, J. Am. Chem. Soc. 2004, 126, 214-222.
33. X. H. Cheng, S. Höger, D. Fenske, Org. Lett. 2003, 5, 2587-2589.
34. -1) to another LC phase that is not yet assigned.
35. Additionally, it can be assumed that the large polycyclic aromatic functions of the compound stabilize an orientation correlation of molecules in the mesophase: P.J. Collings, M. Hird, Introduction to Liquid Crystals, Taylor & Francis, London, 1997, p. 83. Moreover, the flexibility of the macrocyclic backbone of 5 is likely to be less than that of the other macrocycles.
36. K. Praefke, D. Blunk, D. Singer, J. W. Goodby, K. J. Toyne, M. Hird, P. Styring, W. D. J. A. Norbert, Mol. Cryst. Liq. Cryst. 1998, 323, 231-259.