Liquid crystalline polyacetylene derivatives with advanced electrical and optical properties

Abstract

Herein, we review the recent progress in advanced functionalities of liquid crystalline polyacetylenes (LCPAs). We focus on properties and functionalities that include (i) electrical anisotropy, (ii) linearly polarised luminescence (LPL), and (iii) circularly polarised luminescence (CPL). In Section 2, mono-substituted LCPAs are macroscopically aligned by magnetic force, which results in enhancement of the electrical conductivity by two orders of magnitude. In Section 3, di-substituted LCPAs are macroscopically aligned using a rubbing technique to exhibit LPL with notable dichroic ratios. In Section 4, lyotropic di-substituted LCPAs are induced with chiral moieties or chiral dopants, leading to the formation of a N*-LC phase. The high degree of helical ordering in the N*-LC phase is indispensable for the generation of CPL with a large value of the dissymmetry factor in emission (g_em).