Smectic C Mesogens with Terminal Perfluoroalkyl Chains

Abstract

The fluorocarbon derivatives were synthesized. Liquid crystalline states were studied by DSC and microscopic observation. TNI of those compounds were from 161.2°C to 191.7°C, which represented those compounds had very good liquid crystalline stability. Smectic C temperature range was 91.7°C for F8H2OPMB, 54.9°C for F8H2OPCB, 41.1°C for F8H2OPMB-F, 36.2°C for F8H2OMB, 27.4°C for F8H2OPCB-F, and 10.8°C for F6H2OMB. The structures of F8H2OPCB and F8H2OPCB-F at room temperature were tilted herringbone packing of two aromatic ring ester cores (smectic K phase) and perfluoroalkyl chains were located up and down alternatively. Smectic K was proved by high intensity of 003 and 004 reflections in X-ray diffraction.