318 Topics in Current Chemistry Editorial Board: K.N. Houk l C.A. Hunter l M.J. Krische l J M. Lehn S.V. Ley l M. Olivucci l J. Thiem l M. Venturi l P. Vogel C H. Wong l H. Wong l H. Yamamoto Topics in Current Chemistry Recently Published and Forthcoming Volumes Liquid Crystals: Materials Design and Self-Assembly Volume Editor: Carsten Tschierske Vol. 318, 2012 Fragment-Based Drug Discovery and X-Ray Crystallography Volume Editors: Thomas G. Davies, Marko Hyvo ¨ nen Vol. 317, 2012 Novel Sampling Approaches in Higher Dimensional NMR Volume Editors: Martin Billeter, Vladislav Orekhov Vol. 316, 2012 Advanced X-Ray Crystallography Volume Editor: Kari Rissanen Vol. 315, 2012 Pyrethroids: From Chrysanthemum to Modern Industrial Insecticide Volume Editors: Noritada Matsuo, Tatsuya Mori Vol. 314, 2012 Unimolecular and Supramolecular Electronics II Volume Editor: Robert M. Metzger Vol. 313, 2012 Unimolecular and Supramolecular Electronics I Volume Editor: Robert M. Metzger Vol. 312, 2012 Bismuth-Mediated Organic Reactions Volume Editor: Thierry Ollevier Vol. 311, 2012 Peptide-Based Materials Volume Editor: Timothy Deming Vol. 310, 2012 Alkaloid Synthesis Volume Editor: Hans-Joachim Kno ¨ lker Vol. 309, 2012 Fluorous Chemistry Volume Editor: Istva ´ n T. Horva ´ th Vol. 308, 2012 Multiscale Molecular Methods in Applied Chemistry Volume Editors: Barbara Kirchner, Jadran Vrabec Vol. 307, 2012 Solid State NMR Volume Editor: Jerry C. C. Chan Vol. 306, 2012 Prion Proteins Volume Editor: Jo ¨ rg Tatzelt Vol. 305, 2011 Microfluidics: Technologies and Applications Volume Editor: Bingcheng Lin Vol. 304, 2011 Photocatalysis Volume Editor: Carlo Alberto Bignozzi Vol. 303, 2011 Computational Mechanisms of Au and Pt Catalyzed Reactions Volume Editors: Elena Soriano, Jose ´ Marco-Contelles Vol. 302, 2011 Reactivity Tuning in Oligosaccharide Assembly Volume Editors: Bert Fraser-Reid, J. Cristo ´ bal Lo ´ pez Vol. 301, 2011 Luminescence Applied in Sensor Science Volume Editors: Luca Prodi, Marco Montalti, Nelsi Zaccheroni Vol. 300, 2011 Liquid Crystals Materials Design and Self-Assembly Volume Editor: Carsten Tschierske With Contributions by T. Bellini Á R. Cerbino Á X. Feng Á E. Gorecka Á T. Hegmann Á M. Kaller Á T. Kato Á S. Laschat Á M. Lehmann Á J. Mirzaei Á D. Pociecha Á Y. Sagara Á O. Stamatoiu Á H. Takezoe Á K. Tanabe Á C. Tschierske Á N. Vaupotic ˇ Á S. Yamane Á G. Zanchetta Editor Prof. Carsten Tschierske Institute of Chemistry Organic Chemistry Martin Luther University Halle-Wittenberg Kurt-Mothes Str. 2 06120 Halle/Saale Germany carsten.tschierske@chemie.uni-halle.de ISSN 0340-1022 e-ISSN 1436-5049 ISBN 978-3-642-27590-6 e-ISBN 978-3-642-27591-3 DOI 10.1007/978-3-642-27591-3 Springer Heidelberg Dordrecht London New York Library of Congress Control Number: 2011945782 # Springer-Verlag Berlin Heidelberg 2012 This work is subject to copyright. 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Houk University of California Department of Chemistry and Biochemistry 405 Hilgard Avenue Los Angeles, CA 90024-1589, USA houk@chem.ucla.edu Prof. Dr. Christopher A. Hunter Department of Chemistry University of Sheffield Sheffield S3 7HF, United Kingdom c.hunter@sheffield.ac.uk Prof. Michael J. Krische University of Texas at Austin Chemistry & Biochemistry Department 1 University Station A5300 Austin TX, 78712-0165, USA mkrische@mail.utexas.edu Prof. Dr. Jean-Marie Lehn ISIS 8, alle ´ e Gaspard Monge BP 70028 67083 Strasbourg Cedex, France lehn@isis.u-strasbg.fr Prof. Dr. Steven V. Ley University Chemical Laboratory Lensfield Road Cambridge CB2 1EW Great Britain Svl1000@cus.cam.ac.uk Prof. Dr. Massimo Olivucci Universita ` di Siena Dipartimento di Chimica Via A De Gasperi 2 53100 Siena, Italy olivucci@unisi.it Prof. Dr. Joachim Thiem Institut fu ¨ r Organische Chemie Universita ¨ t Hamburg Martin-Luther-King-Platz 6 20146 Hamburg, Germany thiem@chemie.uni-hamburg.de Prof. Dr. Margherita Venturi Dipartimento di Chimica Universita ` di Bologna via Selmi 2 40126 Bologna, Italy margherita.venturi@unibo.it Prof. Carsten Tschierske Institute of Chemistry Organic Chemistry Martin Luther University Halle-Wittenberg Kurt-Mothes Str. 2 06120 Halle/Saale Germany carsten.tschierske@chemie.uni-halle.de Prof. Dr. Pierre Vogel Laboratory of Glycochemistry and Asymmetric Synthesis EPFL – Ecole polytechnique fe ´ derale de Lausanne EPFL SB ISIC LGSA BCH 5307 (Bat.BCH) 1015 Lausanne, Switzerland pierre.vogel@epfl.ch Prof. Dr. Chi-Huey Wong Professor of Chemistry, Scripps Research Institute President of Academia Sinica Academia Sinica 128 Academia Road Section 2, Nankang Taipei 115 Taiwan chwong@gate.sinica.edu.tw Prof. Dr. Henry Wong The Chinese University of Hong Kong University Science Centre Department of Chemistry Shatin, New Territories hncwong@cuhk.edu.hk Prof. Dr. Hisashi Yamamoto Arthur Holly Compton Distinguished Professor Department of Chemistry The University of Chicago 5735 South Ellis Avenue Chicago, IL 60637 773-702-5059 USA yamamoto@uchicago.edu vi Editorial Board Topics in Current Chemistry Also Available Electronically Topics in Current Chemistry is included in Springer’s eBook package Chemistry and Materials Science. 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Aims and Scope The series Topics in Current Chemistry presents critical reviews of the present and future trends in modern chemical research. The scope includes all areas of chemical science, including the interfaces with related disciplines such as biology, medicine, and materials science. The objective of each thematic volume is to give the non-specialist reader, whether at the university or in industry, a comprehensive overview of an area where new insights of interest to a larger scientific audience are emerging. vii Thus each review within the volume critically surveys one aspect of that topic and places it within the context of the volume as a whole. The most significant developments of the last 5–10 years are presented, using selected examples to illus- trate the principles discussed. A description of the laboratory procedures involved is often useful to the reader. The coverage is not exhaustive in data, but rather conceptual, concentrating on the methodological thinking that will allow the non- specialist reader to understand the information presented. Discussion of possible future research directions in the area is welcome. Review articles for the individual volumes are invited by the volume editors. In references Topics in Current Chemistry is abbreviated Top Curr Chem and is cited as a journal. Impact Factor 2010: 2.067; Section “Chemistry, Multidisciplinary”: Rank 44 of 144 viii Topics in Current Chemistry Also Available Electronically Preface Since their discovery in 1888, liquid crystals (LCs) have developed from a scientific curiosity to an interdisciplinary research field with broad commercial applications. LC displays (LCD) represent the most obvious and successful example for the practical application of LC, well know to a broad community. The light, flat and low power-consuming LCD is one of the key components of present mobile communication and data processing devices, which have changed our lives consid- erably. Nowadays, even the TV-market is dominated by LCD which allows incred- ible screens sizes and resolutions. However, beside the well known display technology there are many other applications of liquid crystals, for example polar- ized light reflecting and photonic band gap materials and light modulators. Liquid crystalline polymers are present ly used for high strength fibres, for the encapsula- tion of microelectronic circuits and the construction of micro-electrom echanical and micro-fluidic devices. Numerous new applications of LC are also approaching, such as organic light emitting diodes, photovoltaic devices, organic field effect transistors, tuneable lasers and many others. Besides the numerous technical appli- cations there are also an increasing number of biomedical applications for drug delivery, gene delivery, sensors and as promising materials for artificial bones, tissues and actuators. In a more general sense, the combination of order and mobility in the LC state provides unique properties and is a basic requirement for self-assembly and structure formation in technical and bio-systems. However, the LC displays are still based on the simplest mode of LC organiza- tion, the nematic phase, which comprises only an orientational order of the mole- cules, new applications, as for example in organic electronics also require the directed design of positional order in one, two or three dimensions as provided by smectic, columnar and cubic phases, respectively. In this way, through molecular design and synthesis of new LC molecules, the complexity of LC phases can be increased and this is the basis for the emergence of new materials properties, paving the way to new future applications. One recent example is provided by the so-called bent-core molecules, where ferroelectricity and spontaneous achiral symmetry breaking emerge in well ordered, but still fluid system s. ix A number of fundamental aspects of liquid crystals chemistry were presented in volumes 94 and 95 of Structure and Bonding, edited by D. M. P. Mingos and published in 1999 and also in volume 128 of the same series, edited by T. Kato and published in 2008. Another monograph was published by Springer in 2007 (Thermotropic Liquid Crystals, edited by A. Ramamoorthy) and deals more with physical aspects of LC self assembly and methods of their investigation. This volume intends to shed light on a selection of different aspects of contemporary liquid crystal chemistry, focussing on molecular design carried out in order to influence the self-assembly behaviour of LC-forming molecules in a specific way. The editor has intended to avoid duplications with subjects occurring in the previous volumes of the series Structure and Bonding and to provide the read er with most update information on design and self-assembly of LC materials. This volume in the Topics in Current Chemistry series combines eight chapters from different areas, starting with reviews on the current state in the fields of LCs with perfluori- nated segments and LCs based on crown ether structures. The first one is focussed on nano-segregation as a basic tool for LC-design, leading to specific properties and new modes of self-assembly in liquid crystals. The second one provides a link to host-guest chemistry, a major area of supramolecular chemistry. The first chapter also gives a short introduction into the field of LC self-assembly and offers a brief description of the most important fundamental LC phase structures. LC phases formed by unusual molecules, namely three-arm-star molecules are reviewed in the third chapter. This is followed by a chapter presenting an overview of soft DNA- based structures, not only covering LC phases but also including other soft struc- tures based on DNA nanotechnology, which provides some examples for the importance of LC self assembly in bio-systems and for the origin of life. As already mentioned above, another contemporary field of research is related to so-called bent-core mesogens. Two chapters are devoted to this subject, one reviewing complex phases with two-dimensional order and the other one focussing on spon- taneous achiral symmetry breaking in bent-core LC and also in other LC phases. Another current research field deals with the combination of nano-particles and LCs. Nano-particles can either be combined with units promoting their mesogenity and enabling them to organize into well defined periodic LC structures, or the self assembly of nano-particles can be mediated by a LC host matrix. Finally, there is also an influence of the nano-particles on the phase structure of the LC host. The last chapter is devoted to the directed molecular design of photo-l uminescent LC. It is obvious that this volume cannot be fully comprehensive, but at least it should provide a rough overview, covering some of the important subjects in the field of liquid crystal design and self-assembly. Nevertheless, I hope the present volume will be highly informative and inspiring for chemists and physicists who are interested in developing new materials based on the unique combination of order and mobility provided by the LC state. Halle, December 2011 Carsten Tschierske x Preface [...]... diffraction 1 Introduction 1.1 Liquid Crystal Self-Assembly Liquid crystals (LC) represent truly fascinating materials in terms of their properties, their importance for the fundamental understanding of molecular selfassembly, and their tremendous success in commercial applications [1, 2] Liquid crystals can be considered as a state of matter which in a unique way combines order and mobility [3–8] The constituent... 3 Linear, Taper-Shaped, and Dendritic Molecules with RF-Chains 3.1 Smectic Phases of Liquid Crystals with One Aromatic Ring and One RF-Chain 3.2 Taper Shaped and Dendritic Molecules Leading to Curved Aggregates 4 Rod-Like Liquid Crystals with Fluorinated Chains 4.1 Rod-Like Liquid Crystals with One (Semi)Perfluorinated... November 2011 Fluorinated Liquid Crystals: Design of Soft Nanostructures and Increased Complexity of Self-Assembly by Perfluorinated Segments Carsten Tschierske Abstract The effects of perfluorinated and semiperfluorinated hydrocarbon units on the self-assembly of rod-like, disc-like, polycatenar, taper- and star-shaped, dendritic, and bent-core liquid crystalline (LC) materials is reviewed The influence of... properties, liquid crystals can be considered as anisotropic soft matter or anisotropic fluids with interesting application properties Liquid crystalline phases usually occur in a distinct temperature range between the Fluorinated Liquid Crystals: Design of Soft Nanostructures 5 crystalline solid state (Cr) and the isotropic liquid state (Iso) Therefore, such phases are also called mesophases, and the compounds... 225 Tommaso Bellini, Roberto Cerbino, and Giuliano Zanchetta Polar and Apolar Columnar Phases Made of Bent-Core Mesogens 281 ˇ N Vaupotic, D Pociecha, and E Gorecka Spontaneous Achiral Symmetry Breaking in Liquid Crystalline Phases 303 H Takezoe Nanoparticles in Liquid Crystals and Liquid Crystalline Nanoparticles ... demixing tendency of RF and RH is weaker than for hydrocarbons and water and is strongly chain length dependent The upper critical solution temperature (UCST) provides a measure for the tendency of liquids to demix and this rises with growing chain length [89, 90], as shown in Table 4 (left) Immiscibility over the complete liquid and solid state regions can be found for mixtures of alkanes and perfluoroalkanes... transitions between various liquid crystal phases with 0D, 1D, or 2D periodicity (nematic, smectic, and columnar phases) and between these liquid crystal phases and the isotropic liquid state are reversible with nearly no hysteresis However, due to the kinetic nature of crystallization, strong hysteresis can occur for the transition to solid crystalline phases (overcooling), which allows liquid crystal phases... molecular self assembly in biosystems [55] 1.2 Fluorinated Liquid Crystals Fluorination of LC provides a powerful tool for the design of new LC materials with unusual and practically important properties The specific effects of F in organic molecules result from a unique combination of high polarity and low polarizability, as well as steric and conformational effects (see next section) Fluorination...Contents Fluorinated Liquid Crystals: Design of Soft Nanostructures and Increased Complexity of Self-Assembly by Perfluorinated Segments 1 Carsten Tschierske Liquid Crystalline Crown Ethers 109 Martin Kaller and Sabine Laschat Star-Shaped Mesogens – Hekates: The Most Basic Star Structure with... (high temperature phase ¼ HT) and LC2 (low temperature phase ¼ LT) phases of C10H21–C10F21 [102] and those shown in Fig 6c,d were obtained by Monte-Carlo Fluorinated Liquid Crystals: Design of Soft Nanostructures 19 Fig 6 Structures of mesophases of semiperfluoroalkanes: (a,c) LC1 and (b,d) LC2 phases; (a,b) as suggested for C10H21–C10F21 based on experimental data [102] and (c,d) as found in simulation; . Chemistry Recently Published and Forthcoming Volumes Liquid Crystals: Materials Design and Self-Assembly Volume Editor: Carsten Tschierske Vol. 318, 2012 Fragment-Based Drug Discovery and X-Ray Crystallography Volume. of liquid crystal design and self-assembly. Nevertheless, I hope the present volume will be highly informative and inspiring for chemists and physicists who are interested in developing new materials. Takezoe Nanoparticles in Liquid Crystals and Liquid Crystalline Nanoparticles 331 Oana Stamatoiu, Javad Mirzaei, Xiang Feng, and Torsten Hegmann Stimuli-Responsive Photoluminescent Liquid Crystals 395 Shogo