Liquid crystalline networks composed of pentagonal, square, and triangular cylinders

Science

Volumn 307, Issue 5706, 2005, Pages 96-99

  Chen, Bin ^a   Zeng, Xiangbing ^b   Baumeister, Ute ^a   Ungar, Goran ^b   Tschierske, Carsten ^a  

^a MARTIN LUTHER UNIVERSITY HALLE WITTENBERG   (Germany)

^b UNIVERSITY OF SHEFFIELD   (United Kingdom)

Author keywords

[No Author keywords available]

Indexed keywords

COMPLEXATION; CYLINDERS (SHAPES); NANOSTRUCTURED MATERIALS;

CRYSTALLINE PHASES; LIQUID CRYSTALLINE NETWORKS; POLYGONS;

LIQUID CRYSTALS;

CHEMISTRY;

ARTICLE; CHEMICAL STRUCTURE; HONEY; LIQUID; PHASE TRANSITION; PREDICTION; PRIORITY JOURNAL;

EID: 11844278445     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.1105612     Document Type: Article

References (32)

1. T. C. Hales, Discrete Comput. Geom. 25, 1 (2001).
2. J. Simon, P. Bassoul, Design of Molecular Materials: Supramolecular Engineering (Wiley, Chinchester, UK, 2000).
3. D. L. D. Caspar, E. Fontano, Proc. Natl. Acad. Sci. U.S.A. 93, 14271 (1996).
4. M. Deza, P. W. Fowler, A. Rassat, K. M. Rogers, J. Chem. Inf. Comput. Sci. 40, 550 (2000).
5. A. Müller et al., Angew. Chem. Int. Ed. Engl. 37, 3359 (1999).
6. R. Penrose, Bull. Inst. Math. Appl. 10, 266 (1974).
7. R. Penrose, Eureka 39, 16 (1978).
8. B. Grünbaum, G. C. Shephard, Tilings and Patterns (Freeman, New York, 1987).
9. T. Sugimoto, T. Ogawa, Forma 15, 75 (2000).
10. B. Moulton, J. Lu, M. J. Zaworotko, J. Am. Chem. Soc. 123, 9224 (2001).
11. P. J. Collings, M. Hird, Introduction to Liquid Crystals: Chemistry and Physics (Taylor and Francis, London, 1997).
12. R. J. Bushhy, O. R. Lozman, Curr. Opin. Colloid Interface Sci. 4, 343 (2002).
13. C. Tschierske, J. Mater. Chem. 11, 2647 (2002).
14. M. Kölbel et al., J. Am. Chem. Soc. 123, 6809 (2001).
15. X. H. Cheng et al., J. Am. Chem. Soc. 125, 10977 (2003).
16. B. Chen et al., Angew. Chem. Int. Ed. Engl. 43, 4540 (2004).
17. B. Chen et al., J. Am. Chem. Soc. 116, 8608 (2004).
18. Materials and methods (synthesis, analytical data, and details of x-ray scattering) are available as supporting material on Science Online.
19. The lattice parameter is about 2.7 times the molecular length of L = 3.0 nm, as measured using molecular models (CPK models) for the most extended conformation between the two ends of the terminal alkyl chains.
20. mol), the crystal volume increments of Immirzi (21) were used.
21. A. Immirzi, B. Perini, Acta Crystallogr. Sect. A 33, 216 (1977).
22. The mesophases reported here represent ordered fluids, which implies a high degree of conformational, rotational, and translational mobility. Hence, there are no well-defined crystal-like structures, as might be suggested by the models shown. Instead, in these highly dynamic systems, there are only distinct regions with enhanced concentrations of aromatic cores, regions of the polar hydrogen bonding groups, and regions of the nonpolar segments. Depending on the degree of incompatibility between the segments, the interfaces between these segregated regions can be quite sharp or more diffuse. Also, because of this nanoscale disorder, the number of molecules within a distinct volume region is only an average value.
23. This structure corresponds to the pentagonal isohedral tiling P5-24 (8).
24. About two terphenyl units on average are arranged in the diameter of the cylinder walls.
25. There are 11 monohedral tilings of a plane with regular vertices. A vertex is called regular if the angle between each consecutive pair of edges is 2π/ν where ν is the number of edges meeting at a vertex of a tiling. These 11 tilings are often called Laves tilings after the crystallographer Fritz Laves (8).
26. There are precisely 11 distinct edge-to-edge tilings of a plane by regular polygons such that all vertices are of the same type. These tilings are called Archimedean tilings (8).
27. S. Sioula, N. Hadjichristidis, E. L. Thomas, Macromolecules 31, 8429 (1998).
28. H. Hückstädt, A. Göpfert, V. Abetz, Macromol. Chem. Phys. 201, 296 (2000).
29. K. Yamauchi et al., Macromolecules 36, 6962 (2003).
30. G. Ungar, Y. Liu, X. B. Zeng, V. Percec, W.-D. Cho, Science 299, 1208 (2003).
31. X. B. Zeng et al., Nature 428, 157 (2004).
32. This work was supported by the Deutsche Forschungsgemeinschaft (GRK 894), the Fonds der Chemischen Industrie, and the European Community (RTN LCDD). We thank A. Gleeson for helping to set up the experiment at Daresbury Synchrotron and CCLRC (Council for the Central Laboratory of the Research Councils) for granting the beamtime.