ABSTRACT
This introduction presents an overview of key concepts covered in this book. The book introduces liquid crystals (LC) particularly focusing on the shape of molecules and introduces a brief history of mesogens consisting of bent-shaped molecules. It is important to know how bent-shaped LCs were discovered and what the scientific background was at that time. In view of a shape, bent-shaped molecules have been believed to be unfavorable molecules for LCs, as far as the steric interaction is concerned, because of an enhanced excluded volume due to the free rotations of molecules about their long axes. Among many novel phenomena, the most important discovery is the polar LC phases and chiral phases in molecular systems consisting of nonchiral molecules. In this way, the book highlights the polarity and chirality that are the central features of bent-shaped LCs. Although intensive research on bent-core LCs started in 1996, the first mesogens were synthesized by Vorländer in the beginning of the twentieth century.
