Cholesteric Solid Films Formed by Spin-Coating Solutions of Dicholesteryl Esters

Helical ordering of molecules is shown by solid films formed by spin-coating solutions of nonpolymeric, high molecular weight dicholesteryl esters (shown schematically). In these three-dimensionally organized films the axes of the helices are perpendicular to the surface of the glass plate.     

Zur Benennung von Verbindungen im Si‐Al‐O‐N‐System

Die Übersetzung basiert auf der „Terminology for Compounds in the Si‐Al‐O‐N System“ der Commission on High Temperature Materials and Solid State Chemistry der Inorganic Chemistry Division der International Union of Pure and Applied Chemistry, veröffentlicht in Pure Appl. Chem. 1999 , 71, 1765–1769. Das Original wurde von R. Metselaar, Technische Universiteit Eindhoven (Niederlande) und D. S. Yan, Academia Sinica, Shanghai (China) für die Veröffentlichung vorbereitet.     

A Columnar Liquid‐Crystal Phase Formed by Hydrogen‐Bonded Perylene Bisimide J‐Aggregates

A new perylene bisimide (PBI) dye self‐assembles through hydrogen bonds and π–π interactions into J‐aggregates that in turn self‐organize into liquid‐crystalline (LC) columnar hexagonal domains. The PBI cores are organized with the transition dipole moments parallel to the columnar axis, which is an unprecedented structural organization in π‐conjugated columnar liquid crystals. Middle and wide‐angle X‐ray analyses reveal a helical structure consisting of three self‐assembled hydrogen‐bonded PBI strands that constitute a single column of the columnar hexagonal phase. This remarkable assembly mode for columnar liquid crystals may afford new anisotropic LC materials for applications in photonics.     

Broadband Reflection in Polymer‐Stabilized Cholesteric Liquid Crystals via Thiol–Acrylate Chemistry

Thiols are prone to react with a multitude of various functional groups in high yields, which has been widely used for surface‐ and particle‐patterning, bioorganic synthesis, polymer modification, imprint nanolithography, the fabrication of optical components, hydrogel synthesis, and the curing of hard protective coatings. In this work, a chiral thiol with a high helical twisting power was synthesized through a novel synthetic route with high selectivity, yield, and cost‐effectiveness. It was then used to fabricate a liquid‐crystal composite film with ultra‐wide broadband reflection via thiol click chemistry. Cholesteric liquid‐crystal materials with broadband reflection have many potential applications for broadband polarizers, polarizer‐free displays, organic optical data storage media, smart switchable reflective windows, and continuous waveband laser protection.     

A Self‐Assembled Bicontinuous Cubic Phase with a Single‐Diamond Network

The first single‐diamond cubic phase in a liquid crystal is reported. This skeletal structure with the space group is formed by self‐assembly of bolaamphiphiles with swallow‐tailed lateral chains. It consists of bundles of π‐conjugated p‐terphenyl rods fused into an infinite network by hydrogen‐bonded spheres at tetrahedral four‐way junctions. We also present a quantitative model relating molecular architecture to the space‐filling requirements of six possible bicontinuous cubic phases, that is, the single‐ and double‐network versions of gyroid, diamond, and “plumber′s nightmare”.