Why do you think your paper is highly cited?

Reddy: Bent-core liquid crystals (banana-shaped liquid crystals, see Fig. 1 for an example) represent an exciting new type of LC materials with new application properties, and therefore created significant interest. There are two key features which makes these materials different from other liquid crystals. Bent-core liquid crystals form fluid structures involving a macroscopic polar order of the molecules. This provides ferroelectric and antiferroelectric properties which are useful for many applications, such as fast-switching electrooptical devices, non-linear optics, and as materials for phase modulators.

Secondly, though the molecules themselves are achiral, their self-organization provides a new type of supramolecular chirality, which is due to the reduced symmetry provided by the special arrangement of the molecules in these self-organized soft matter structures. The chirality develops spontaneously and distinct areas with opposite chirality sense can be distinguished (spontaneous achiral symmetry breaking).

Moreover, in some materials this supermolecular chirality can be switched by means of external electric fields from racemic to homogeneous chiral and between states with opposite chirality sense by changing the sign of the external field. This provides potential applications in chiroptical switches. Fig. 2 shows a helical filament which also can be observed for some systems.

“The paper is a comprehensive review and presents a summary of recent developments in the field of bent-core liquid crystalline materials. This is an exciting new field in liquid crystal (LC) research from a fundamental scientific...”

Tschierske: In my group we recently attached silicon-containing segments into these bent-core molecules (see Fig. 1), which introduced additional options for self-organization and provided some clues for better understanding of research in this field. These silicon-containing units are incompatible with the other segments of these molecules and therefore segregate on a nanometer scale, giving rise to new soft matter structures and new application properties. For example, polar order can be changed from antiferroelectric to ferroelectric and switching of chirality can easily be tailored by variation of the size of these silicon-containing units.

Tschierske: At first it was the beauty of the textures formed by liquid crystalline phases, as they can be observed under a polarizing microscope (see for example Fig. 3), from which I began my interest in this field. Moreover, the field of LC self-assembly is a truly interdisciplinary one which includes synthetic organic chemistry, physical chemistry, physics, mathematics, and also biosciences. It is a great challenge to understand, on a molecular level, how molecular self-assembly can give rise to nature’s unique structures.

It is fascinating to realize that, in different types of matter and at different length scales, the same fundamental rules determine the self assembly. For example the rules of micro-segregation, mainly developed in polymer science, led to a whole series of new liquid crystalline phase structures based on nano-scale segregation of incompatible molecular segments.

The ground-breaking discovery of polar order in bent-core molecules by the group around Dr. Hideo Tekezoe and Dr. Junji Watanabe of the Department of Polymer Chemistry at the Tokyo Institute of Technology, immediately piqued our interest, especially concerning the question how can the unique properties of bent-core molecules be combined with the principles of multiple segregation.

Dr. R. Amaranatha Reddy graduated from the prestigious Raman Research Institute in Bangalore where, for example, discotic liquid crystals have been discovered. His research was focused on the design of new bent-core molecules by fluorination. As a "Humboldt-Research Fellow" in my Lab, the idea arose to provide a general introduction into this fascinating field, to summarize the most recent developments, and to provide some general conclusions in the light of our own research results.

Reddy: Liquid crystals influence our daily life as they are the basis of the present flat-panel displays for communication devices and mobile data processing system, which would not be possible without this technology. A major advantage of such display is their small size, low weight, and low power consumption, features which allow a sustaining of our natural resources. And bent-core liquid crystals, as new materials in this field, could lead to new applications in different areas, involving both data processing and data storage.