On Potential Application of Metallomesogen Materials in Liquid Crystal Displays

Abstract

In this work, we present a new approach for development of metallomesogen (MOM) eutectic mixtures for potential applications in liquid crystal display devices. Through molecular engineering and physical mixing techniques, we aimed to resolve the major drawbacks of MOMs including their inaccessable transition temperature and low solubility in liquid crystal hosts. Accordingly, we studied the phase diagrams of blends of model structures of rod-like MOMs based on a mono-ligand Pd alkyl/alkoxy-azobenzene complex and bi-ligand Cu, Ni and Pd salicylal-diaminate complexes. These phase diagrams indicate mesogenic miscibility, distinct eutectic points and wide mesogenic range. In addition, the phase diagrams of a eutectic MOM mixture with commercial TN10427, TNO623 and E43 liquid crystals exhibit complete mesogenic miscibility, which geneally qualifies MOMs as potential guest materials to improve the performance of commercial liquid crystal materials in display devices.

Metallomesogens as potential materials for improvement of electro-optical properties of commercial liquid crystals

“…Also, few scientific and patent literature have reported on some rod-like and discotic MOMs as dichroic dyes, non-linear optics, thermal recording, thermochromism, passive optical filters, photo-sensing, laser addressing, optical and thermal recording, polarizing flms, radiation absorbing films, ferroelectricity, ferro-magneticity, electro-conductivity, reaction catalysts, mesogenic intermediates, ink jet and security printing, medicinal and agricultural materials. [21][22][23][24][25][26][27][28][29][30] In spite of these proposed applications, until now MOM material have not been yet appeared for even simple commercial guest-host liquid crystal devices. Among the major draw backs of existing MOMs are their high transition temperatures, decomposition at high temperature, inaccessible mesophase range and low chemical stability.…”