Flüssigkristalline Architekturen Wege zur Komplexität in chemischen Systemen. C. Tschierske

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1 Flüssigkristalline Architekturen Wege zur Komplexität in chemischen Systemen C. Tschierske Institute of Chemistry, rganic Chemistry, Martin-Luther- University Halle-Wittenberg

2 Complexity in Chemistry Complexity. is a word rich with ambiguity and highly dependent on context. Information Science Complex systems require more information to describe them than simple systems Chemistry is an inherently complex science - Experimental science; when predictions are made from theory they always need to be verified in the Lab. Complexity in chemistry - Finding a synthetic route to a desired molecule - Chemical reactions (catalysis, autocatalysis, self-replication, dynamic self regulating molecular networks) - Structural complexity (molecules, supramolecular aggregates, crystal structures)

3 Structural Complexity in Molecular Chemistry 115 C-atoms 64 stereogenic centers 7 double bonds 2 64 stereoisomers = 1.8 x Synthesis: 1994 Kishi

4 Structural Complexity in Supramolecular Chemistry Self-assembled dodecahedra S. R. Seidel, P. J. Stang. Acc. Chem. Res. 2002,

5 Structural Complexity in Solid State and Surface Chemistry Coordination Polymers, MFs Self-assembled Grids on surfaces Ag(111) Co + M. Fujita et al. Chem. Commun. 2004, 1586 Stepanow et al. Chem. Commun. 2005, 1681, Angew. Chem., 2007, 46, 710.

6 Complexity in Biological Systems Soft Self-organized Matter - rder formed in self-assembly process - Softness and Mobility: ability to respond on external stimuli

7 Structural Complexity in Soft Matter (Complex Fluids) Bottom-up approach - Creation of complex soft matter systems from simple components (small molecules) - Introduction: Self assembly of classical (binary) amphiphiles and liquid crystals - Self assembly of polyphilic (triphilic) molecules - Complex multicolor tiling patterns (tetraphilic molecules)

8 Amphiphiles: Soft Self-assembly by Segregation Amphiphiles + solvent: lyotropic systems Spheroids Columns Interface curvature Layers

9 Amphiphiles: Soft Self-assembly by Segregation Homogeneous Systems (no solvents = thermotropic) Spheroids Columns Interface curvature Branched Columns Layers

10 Amphiphiles: Soft Self-assembly by Segregation Homogeneous Systems (no solvents = thermotropic) R F R F R F R F R F R F R F R F = C n F 2n+1 R F R F R F R F R F R F R F Spheroids Columns Interface curvature R F R F R F R F R F R F Branched Columns R F R F Layers R F R F X. H. Cheng, S. Diele, C. Tschierske, Angew. Chem. Int. Ed. 2000, 39, 592.

11 Liquid Crystals: Soft Self-assembly by Shape Rod-like (calamitic) Disc-like (discotic) n rientational order n - Minimizing the excluded volume - Maximizing van der Waals interactions b N D a Layers + positional order Columns

12 Combination of Amphiphilic and Shape-dependent Self-assembly: Polyphilic Blockmolecules Amphiphile + Rod-like unit - Polyphilicity - Competition - Attraction Linear triblockmesogens Laterally substituted bolaamphiphile Facial amphiphile

13 T-Shaped Ternary Bolaamphiphiles H Rigid core structures H H H R R H H H H H R R Flexible lateral chains R H H H H H H H S R S S S R S H H H H Si Si Si C n F 2n+1 Si Si Si Si Si C n F 2n+1 R R

14 Supramolecular Synthesis: Soft Self-Assembly SmA Col hex # 3 SmA + Cub Lam Iso Col rec /c2mm 4 Col squ /p4mm Lam N 4 Col squ /p4gm Col hex Col rec /c2mm Lam Sm 4 p2mm 5 p2gg 5 6 c2mm C. Tschierske Chem. Soc. Rev. 36, (2007) 10 p2gg 12 p6mm

15 Hexagonal Honeycombs H H H H C 12 H C 12 H 25 M. Kölbel, T. Beyersdorff, X.H. Cheng, C. Tschierske, J. Kain, S. Diele, J. Am. Chem. Soc. 2001, 123, 6809.

16 Phase Sequence of T-Shaped Bolaamphiphiles SmA H H H H SmA + Area to circumference ratio C n H 2n+1 Col rec /c2mm n = 0-5: SmA/SmA + 4 Col squ /p4mm n = Col squ /p4gm Col hex n = n = C. Tschierske Chem. Soc. Rev. 36, (2007)

17 Phase Sequence of T-Shaped Bolaamphiphiles SmA H H H H SmA + Area to circumference ratio 6 C 11 H 23 4 Col rec /c2mm Col squ /p4mm Col hex /p6mm 4 Col squ /p4gm Col hex H H H H C 11 H 23 4 p2mm 5 p2gg 5 6 c2mm 4 6 Col squ /p2mm C. Tschierske Chem. Soc. Rev. 36, (2007) 4 Col squ /p4mm

18 Polarizing Microscopy Polarizing microscopy - Birefringence - Textures as typical for columnar phases 4 Polarizing microscopy with λ-retarder plate π-conjugated rods Columns (cylinders) Indicatrix orientation in fans 5 4 Indicatrix orientation in compensator - Negative birefringence - Conjugated aromatic rods are perpendicular to the column long axis 6

19 Periodic rganization of Pentagonal Cylinders! H H H p2gg H C4F9 a = 5.4 nm; b = 5.8 nm a,b ~ 2.5 L; L = 2.1 nm X. H. Cheng, M. Prehm, M. K. Das, J. Kain, U. Baumeister, S. Diele, D. Leine, A. Blume, C. Tschierske J. Am. Chem. Soc. 2003, 125,

20 Phase Sequence of T-Shaped Bolaamphiphiles SmA Col hex # SmA + Cub 3 Lam Iso Col rec /c2mm 4 Col squ /p4mm Lam N 4 Col squ /p4gm Col hex Col rec /c2mm Lam Sm 4 p2mm 5 p2gg 5 6 c2mm C. Tschierske Chem. Soc. Rev. 36, (2007) 10 p2gg 12 p6mm

21 Multi-color Tilings Ternary ampiphiles: simple tilings Quaternary amphiphiles: multi-colour tilings C n F 2n+1 C n H 2n+1

22 T-Shaped vs. X-Shaped Bolaamphiphiles C 8 F 17 -(CH 2 ) 6 H T H H X H R R = H R = (CH 2 ) 6 -C 8 F 17 Cr 87 Col hex 229 Iso a hex = 4.24 nm, n cell = 6.43, n wall = 2.1 Cr 44 Col hex 106 Lam Iso 116 Iso a hex = 4.01 nm, n cell = 3.91, n wall = 1.3 R. Kieffer, M. Prehm, B. Glettner, K. Pelz, U. Baumeister, F. Liu, X. Zeng, G. Ungar, C. Tschierske, Chem. Commun., 2008, 3861.

23 T-Shaped vs. X-Shaped Bolaamphiphiles C 8 F 17 -(CH 2 ) 6 H T H H X H R R = H R = (CH 2 ) 6 -C 8 F 17 Cr 87 Col hex 229 Iso a hex = 4.24 nm, n cell = 6.43, n wall = 2.1 Cr 44 Col hex 106 Lam Iso 116 Iso a hex = 4.01 nm, n cell = 3.91, n wall = 1.3 Double walls Single walls R. Kieffer, M. Prehm, B. Glettner, K. Pelz, U. Baumeister, F. Liu, X. Zeng, G. Ungar, C. Tschierske, Chem. Commun., 2008, 3861.

24 Ternary vs. Qarternary X-Shaped Bolaamphiphiles C 8 F 17 -(CH 2 ) 6 H X H H X H R R = C 14 H 29 R = (CH 2 ) 6 -C 8 F 17 Cr 49 Col hex 102 Iso ( C) a hex = 3.84 nm, n cell = 3.86, n wall = 1.3 Cr 44 Col hex 106 Lam Iso 116 Iso ( C) a hex = 4.01 nm, n cell = 3.91, n wall = 1.3 Staggered single walls

25 Intracolumnar Segregation: Core-Shell Structures 460 C 8 F 17 -(CH 2 ) 6 H H H H L = 2.3 nm C 14 H a hex = 1.73 L : a hex = nm Cr 49 Col hex 102 Iso ( C) a hex = 3.84 nm n wall = 1.3 Packing density in liquids is 0.55 Core-shell structures

26 The Kagome Motif Solid state Structures jpn.: kago = basket; me = hole, eye A.K. Powell,et. al. J. Phys Chem. Solids 2004, 65, 667 Geometrically frustrated magnetism

27 Liquid Crystalline Kagome 560 Å 3 H C 12 F 25 -(CH 2 ) 4 H H H C 10 H Å 3 Cr 70 Col x 88 Col hex /p6mm 117 Iso ( C) a hex = 5.8 nm L = 2.8 nm 2.8 x 2.0 = 5.6 nm Kagome with two colour tiling

28 Liquid Crystal Kagome H C 12 F 25 -(CH 2 ) 4 H H H a = 5.8 nm n cell = 6.9, n wall = 1.2 C 10 H 21 Cr 70 Col x 88 Col hex /p6mm 117 Iso ( C) Low High B. Glettner, F. Liu, X. B. Zeng, M. Prehm, U. Baumeister, M. A. Bates, M. Walker, P. Boesecke, G. Ungar, C. Tschierske, Angew. Chem., Int. Ed. 2008, 47, 9063.

29 Conclusions Classical (organic) chemistry Supramolecular soft matter engineering Bio-systems (Proteins) XH 2 C CH 2 H H 2 N CH R C H H H H α-helix N N H H N H N H H β-sheet N N Loops, coils

30 Acknowledgements Syntheses: R. Kieffer, B. Glettner, C. Nürnberger, H. Ebert (Uni Halle) SNS II Self rganised Nanostructures Carbosilanes: H. Lang, H. Hahn (TU Chemnitz) X-Ray: K. Pelz, M. Prehm (Uni Halle) G. Ungar, X. Zeng, F. Liu (Uni Sheffield) AFM: C. H. M. Weber. J. K. Hobbs (Uni Sheffield) DFG, FCI

31 References: Design of Liquid Crystalline Block-Molecules with Non-Conventional Mesophase Morphologies: Calamitic Bolaamphiphiles with Lateral Alkyl Chains, M. Kölbel, T. Beyersdorff, X.-H. Cheng, C. Tschierske, J. Kain, S. Diele, J. Am. Chem. Soc, 123, (2001). New Liquid Crystalline Phases with Layerlike rganization, M. Prehm, X. H. Cheng, S. Diele, M. K. Das, C. Tschierske, J. Am. Chem. Soc., 124, (2002). Novel Liquid Crystalline Phases with Layerlike rganization, X. H. Cheng, M. K. Das, S. Diele, C. Tschierske, Angew. Chem. 114, (2002) Angew. Chem. Int. Ed. 41, (2002) Correlated Layer Structures- A Novel Type of Liquid Crystalline Phases with 2D-Lattice M. Prehm, S. Diele, M.K. Das, C. Tschierske, J. Am. Chem. Soc., 125, (2003). Calamitic Bolaamphiphiles with (Semi)Perfluorinated Lateral Chains: Polyphilic Block Molecules with New Liquid Crystalline Phase Structures X.-H. Cheng, M. Prehm, M. K. Das, J. Kain, U. Baumeister, S. Diele, D. Leine, A. Blume, C. Tschierske, J.Am. Chem. Soc., 125, (2003). A new type of square columnar liquid crystalline phases formed by facial amphiphilic block molecules B. Chen, U. Baumeister, S. Diele, M. K. Das, X. Zeng, G. Ungar, C. Tschierske, J. Am. Chem. Soc., 126, (2004). Liquid crystals with novel complex superstructures; B. Chen, X. Zeng, U. Baumeister, S. Diele, G. Ungar, C. Tschierske Angew. Chem.Int. Ed., 43, (2004). Liquid Crystalline Bolaamphiphiles with Semiperfluorinated Lateral Chains: Competition Between Layerlike and Honeycomb-Like rganization,.cheng, M. K. Das, U. Baumeister, S. Diele, C. Tschierske, J. Am. Chem. Soc. 126, (2004). Liquid Crystals composed of pentagonal, square and trigonal column; B. Chen, X. Zeng, U. Baumeister, G. Ungar, C. Tschierske Science, 307, (2005). Supramolecular Dendrimers: Unusual mesophases of ionic liquid crystals derived from protonation of DAB dendrimers with facial amphiphilic carboxylic acids A. G. Cook, U. Baumeister, C. Tschierske J. Mater. Chem., 15, (2005) Carbohydrate-Rod-Conjugates Ternary Rod-Coil Block Molecules Forming Complex Liquid Crystal Structures B. Chen, U. Baumeister, G. Pelzl, M. K. Das, X, Zeng, G. Ungar, C. Tschierske J. Am. Chem. Soc, 127, (2005) The Triangular Cylider Phase: A New Mode of Self-Assembly in Liquid-Crystalline Soft Matter; F. Liu, B. Chen, U. Baumeister, X. B. Zeng, G. Ungar, C. Tschierske, J. Am. Chem. Soc.. 129, (2007).

32 Complex Liquid-Crystallline Superstructure of a p-conjugated ligothiophenes; Marko Prehm, Günther Götz, Peter Bäuerle, Feng Liu, Goran Ungar and Carsten Tschierske, Angew. Chem. 119, ; Angew. Chem. Int. Ed. 46, (2007). The Giant-Hexagon Cylinder Network-A Liquid Crystalline rganization Formed by T-Shaped Quaternatry Amphiphiles; Marko Prehm, Feng Liu, Xiangbin Zeng, Goran Ungar and Carsten Tschierske, Angew. Chem. 119, ; Angew. Chem. Int. Ed. 46, (2007). Review: Liquid crystal engineering new complex mesophase structures and their relation to polymer morphologies, nanoscale patterning and crystal engineering; Carsten Tschierske, Chem. Soc. Rev. 36, (2007). Distinct Columnar and Lamellar Liquid Crystalline Phases Formed by New Bolaamphiphiles with Linear and Branched Lateral Hydrocarbon Chains; M. Prehm, C. Enders, M. Y. Anzahaee, B. Glettner, U. Baumeister, C. Tschierske, Chem. Eur. J., 14, (2008). X-shaped polyphilics: Liquid crystal honeycombs with single-molecule walls; Robert Kieffer, Marko Prehm, Benjamin Glettner, Karsten Pelz, Ute Baumeister, Feng Liu, Xiangbing Zeng, Goran Ungar, Carsten Tschierske, Chem. Commun., 2008, Polygonal Cylinder Phases of 3-Alkyl-2,5-diphenylthiophene Based Bolaamphiphiles: Changing Symmetry by Retaining Net Topology; Xiaohong Cheng, Xing Dong, Rong Huang, Xiangbing Zeng, Goran Ungar, Marko Prehm, Carsten Tschierske, Chem. Mater., 20, (2008). Liquid crystal engineering with anchor-shaped molecules: Honeycombs with hexagonal and trigonal symmetries formed by polyphilic bent-core molecules; Benjamin Glettner, Feng Liu, Xiangbing Zeng, Marko Prehm, Ute Baumeister, Goran Ungar, Carsten Tschierske, Angew. Chem., 120, ; 2008, Angew. Chem. Int. Ed. 47, (2008). The Trapezoid Cylinder Phase: A New Mode of Self-Assembly in Liquid-Crystalline Soft Matter; Feng Liu, Bin Chen, Benjamin Glettner, Marko Prehm, Malay Kumar Das, Ute Baumeister, Xiangbing Zeng, Goran Ungar, Carsten Tschierske, J. Am. Chem. Soc., 130, (2008). Liquid Crystalline Kagome; Benjamin Glettner, Feng Liu, Xiangbing Zeng, Marko Prehm, Ute Baumeister, Martin A. Bates, Martin Walker, Peter Boesecke, Goran Ungar, Carsten Tschierske, Angew. Chem. Int. Ed. 47, ; Angew. Chem. 120, (2008). 2D and 3D rdered Columnar Liquid Crystalline Phases by Bundles of Bolaamphiphilies with Swallow tailed Side-Chains; M. Prehm, F. Liu, X. B. Zeng, G. Ungar, C. Tschierske, J. Am. Chem. Soc., 130, (2008). Liquid-Crystalline Triangle Honeycomb Formed by a Dithiophene-Based X-Shaped Bolaamphiphile; X. H. Cheng, X. Dong, G. Wie, M. Prehm, C. Tschierske, Angew. Chem. 121, ; Angew. Chem. Int. Ed. 48, (2009). Reversible aggregation of X-Shaped bolaamphiphiles with partially fluorinated lateral chains at the air/water interface; Patrycja Niton, Andrzej Zywocinski, Robert Hoyst, Robert Kieffer, Carsten Tschierske, Jan Paczesny, Damian Pociecha and Ewa Górecka, Chem. Commun., 46, (2010)