Synthesis and liquid crystalline studies of biphenylyl-1,3,4-thiadiazoles and diphenyl-1,3,4-thiadiazoles: influence of side chain semifluorination and lateral ring fluorination

Four series of 1,3,4-thiadiazole based compounds (Series I–IV) were synthesised, and their liquid crystalline properties were studied. Series I compounds are two tailed biphenylyl-1,3,4-thiadiazoles (seven new compounds). Series II is a set of new diphenyl-1,3,4-thiadiazoles with perhydrogenated and semifluorinated tails (eight new compounds). Series III compounds are symmetrical semifluorinated diphenyl-1,3,4-thiadiazoles (five new compounds). Two laterally fluorinated diphenyl-1,3,4-thiadiazoles along with their parent nonfluorinated compound were also synthesised (Series IV). In all of the four series SmA and/or SmC phases are observed.