Pleochroic dyes with high order parameters

Abstract
The construction and performance of liquid crystal displays using the guest-host-interaction in conjunction with the cholesteric to nematic phase-change effect have been reported by White and Taylor (1974). Results are reported which extend this information and define new areas for investigation. Over 50 dichroic (pleochroic) azo-dyes have been prepared and their suitability for use in this type of display evaluated. Synthetic schemes for the preparation of these dyes are referred to briefly. Various aspects of the construction of this type of display have also been investigated with a view to optimising its appearance.