RUI: Liquid Crystalline Zwitterionic Derivatives of closo-Boranes for Display Applications

Middle Tennessee State University, Murfreesboro TN

Investigators

Abstract

Non-technical Abstract With the support of the Solid State and Materials Chemistry program, this research team will take a multi-disciplinary and international approach to materials chemistry that trains undergraduate students to synthesize and characterize liquid crystals (LCs) in the context of display applications (LCD). Liquid crystalline materials are liquids or soft wax-like substances in which molecules exhibit some degree of ordering and organization; they uniquely combine fluidity of liquids and molecular ordering found in solid crystals. If molecules forming such materials are polar (have a permanent dipole moment), they can undergo realignment in an electric field resulting in switching of optical properties of the material. Such an electro-optical effect is at the heart of modern liquid crystal display industry, which demands improvements in resolution and speed of switching between screen images. This, in turn, motivates the search for new LC materials, such as those investigated in this project. Thus, a team comprised of the principal investigator (PI), co-PI, an international technical expert and undergraduate co-workers design, synthesize and fully characterize new polar liquid crystals derived from boron clusters. Among the main goals of the project is the development of extensive structure-property relationships in this class of materials, preparation of materials for practical applications, and training of undergraduate students for careers in materials chemistry. Technical Abstract This basic research project tests the hypothesis that rationally-designed zwitterionic derivatives of inorganic boron clusters, [closo-1-CB9H10]- and [closo-1-CB12H12]- anions, form liquid crystalline phases and are suitable materials for display applications. In this context, a series of zwitterions is synthesized and investigated for their spectroscopic, structural, thermal and dielectric properties using a broad selection of research tools. The experimental work is augmented with theoretical methods that allow the researchers to formulate a detailed understanding of structure-property relationships and to explain the observed results. The detailed multi-dimensional analysis of specific derivatives is expected to contribute to the understanding of the impact of the molecular structure on properties, materials performance, and to the fundamental chemistry and science of liquid crystals.