Synthesis and liquid crystalline properties of several compounds with semi-fluorocarbon chains

Several molecules having long semi-fluoroalkyl chains have been synthesized , and their phase transition temperatures measured by texture observation i n a polarizing microscope and DSC. The SmC phase is particularly favoured i n this series, especially for compounds with a long semi-fluoroalkyl chain. It was found that when the terminal hydrogen atom of the semi-fluoroalkyl chain of one of the compounds (D) was substituted by a chlorine atom, the l iquid crystalline sequence and ranges did not change; however, the clearing and melting points and TI-SmA and TSmA-SmC increased by nearly 10 degreesC .