Symmetry and Chirality in Liquid Crystals

Supermolecular Bent Configuration Composed of Achiral Flexible Liquid Crystal Trimers Exhibiting Chiral Domains with Opposite Handedness

“…Chirality in liquid crystals is recognized as influencing phase structures and electro-optical properties. 1 For the discovery of a liquid-crystalline phase in cholesterol derivatives, molecular chirality has been necessary to produce a chiral liquid-crystalline phase.…”

Spontaneous enantiomorphism in poly-phased alkaline salts of tris(oxalato)ferrate(III): crystal structure of cubic NaRb5[Fe(C2O4)3]2

“…This concept along with the related ones of chiral crystal structures and space groups is discussed by Flack (2003). Chirality is at the core (among other research areas) of the not yet understood origin of the biomolecular asymmetry of life (Meierhenrich, 2008), enantioselective chemical reactions (Knowles, 2001;Noyori, 2001;Sharpless, 2001), biological activity of pharmaceuticals (Nguyen et al, 2006) and in the design of multifunctional solid-state materials endowed with optical activity and longrange magnetic order (Coronado et al, 2003) and also in the understanding of the physical properties of chiral liquid crystals and their tailoring for applications in opto-electronic devices (Goodby, 1998;Coles, 1998).…”

Cholesteric-type cellulosic structures: from plants to applications

“…A cholesteric structure presents a reflected wavelength value (λ) which is conditioned by the length of the helical pitch (P) and the average refraction index ( n) of the material, according to de Vries expression [16] λ ¼ nPðsin θÞ (1) considering θ as the angle between the propagation of the incident light and the direction perpendicular to the cholesteric layers. Therefore, at a normal angle of incidence (θ = π/2 rad), the wavelength of the reflected light is directly proportional to the cholesteric helical pitch [17,18]. From the white disordered cotton structure, cholesteric vivid, iridescent colours can emerge if anisotropic structures are isolated and self-assembled ( Figure 1(f)).…”