Abstract: A series of 8-(bisphenylethynyl)-ester flexible multiple ring-containing fluoroboron pyrrole liquid crystal dyes are synthesized by introducing a diphenylethynyl rigid structure at position 8 of a boron-dipyrromethene core via a Sonogashira coupling reaction, and a flexible multiple ring such as bicyclohexane, or cholesterol is connected to the biphenylethynyl via an esterification reaction. The dye compounds all have maximum emission wavelengths in methylene chloride concentrated around 525 nm, present green fluorescence, and show good dichroic colour ratios and ordered parameters in E7 liquid crystal. The liquid crystal compounds are in a liquid crystal intermediate phase within the range of 100-280° C., and may be used for manufacturing liquid crystal display products, especially as guest dyes for guest-host mode liquid crystal displays. The response time can be improved and a rapid response effect achieved when the compounds are added to E7 liquid crystal and used for a guest-host display mode.

Abstract: A series of 8-(bisphenylethynyl)-ester flexible multiple ring-containing fluoroboron pyrrole liquid crystal dyes are synthesized by introducing a diphenylethynyl rigid structure at position 8 of a boron-dipyrromethene core via a Sonogashira coupling reaction, and a flexible multiple ring such as bicyclohexane, or cholesterol is connected to the biphenylethynyl via an esterification reaction. The dye compounds all have maximum emission wavelengths in methylene chloride concentrated around 525 nm, present green fluorescence, and show good dichroic colour ratios and ordered parameters in E7 liquid crystal. The liquid crystal compounds are in a liquid crystal intermediate phase within the range of 100-280° C., and may be used for manufacturing liquid crystal display products, especially as guest dyes for guest-host mode liquid crystal displays. The response time can be improved and a rapid response effect achieved when the compounds are added to E7 liquid crystal and used for a guest-host display mode.