Deterministic Synthesis and Optical Properties of Glassy Chiral-Nematic Liquid Crystals

Abstract

A new series of morphologically stable, glassy chiral-nematic liquid crystals were synthesized following three distinct deterministic approaches. A glass transition temperature from 67 to 82 °C and a clearing temperature from 175 to 225 °C were accomplished. A helical pitch length from 188 to 210 nm emerged with enantiomeric 1-phenylethylamine as the precursors, giving rise to selective reflection in the UV region. With (+)-estrone as the chiral moiety, a selective reflection in the near-infrared was observed. The concepts of high-performance circular polarizers and optical notch filters and reflectors were illustrated with a mixture of enantiomeric glassy chiral nematics. Selective reflection wavelength can be readily tuned by varying chemical composition in terms of the ratio of enantiomers or that of chiral-nematic to nematic components.

Light-Emitting Organic Materials with Variable Charge Injection and Transport Properties

“…Nematic oligomeric pendants can be chemically bonded to a volume-excluding core to form morphologically stable glassy liquid crystals for polarized OLEDs following a versatile core-pendant approach that has found general applicability. [83][84][85][86][87][88][89][90] Depicted in Chart 1 are the molecular structures of the target compounds synthesized for the present study. In addition to liquid-crystalline conjugated oligomers, shorter oligomeric pendants can be used to yield glassy-isotropic materials for unpolarized OLEDs.…”

P-170: Novel Ferroelectric Glassy Liquid Crystal and Mixtures with Wide SmC∗ Mesophase

“…Glassy liquid crystal generally shows good alignment ability with larger domain size in previous study on fused silica substrates [5][6][7]. The ITO patterned pre-made cells (2±0.5µm, from EHC) were used without any pre-treatment in this study.…”

Design and Synthesis of Chiral Nematic Liquid Crystals

“…• Color Filters and Reflectors -these applications rely on the chiral nematic phase's circular dichroic properties, that is, its ability to reflect or transmit a given circularly polarized portion of light of a particular wavelength. Clearly, it is possible to design elements to selectively reflect or transmit particular handedness by careful selection of components and dopants; stable filters are made by crosslinking polymerization of the films by use of reactive mesogen molecules [45] or by vitrifying the helical phase structure into stable glassy structure (with high T g ) [46][47][48]. These elements are of huge interest for patterned reflector surfaces to replace expensive pigmented color filter layers [49][50][51][52].…”

“…Although these materials have largely been supplanted as thermochromic materials, occasionally find application to conveniently impart chirality to a mesophase [47,180,186,[190][191][192][193][194][195]. …”