Bireactive calamitic liquid crystals derived from fluorene ester linkage

Abstract

New thermotropic liquid crystalline monomer esters, containing fluorene in their mesogenic core with luminescent properties, were synthesized and characterized. The monomers studied exhibited a broad mesomorphic range and a nematic phase was identified by differential scanning calorimetry and polarized optical microscopy. Absorption and photoluminescence spectra studied in solution indicated that these compounds possess good optical stability. Linearly polarized light emission was observed in oriented thin films prepared by an in‐situ photopolymerization technique. The preparation of oriented thin films shows a preferential emission direction necessary for application in linearly polarized blue light‐emitting diodes.

Acknowledgements

The authors wish to thank Dr. R. Faria and F.Guimares for optical measurements, Dr. Boris Weiss for ¹H and ¹³C NMR at 400 MHz. This work was supported by Direction of Investigation of the Universidad de Concepción (205.024.033‐1.0). P. Sáez acknowledges a Ph.D. Scholarship from MECESUP and M. Morel acknowledges financial support for thesis for Direction of Investigation of the Universidad de Concepción.