Synthesis of the series of monofluoro-substituted 4-butylsulfanyl-4'-cyanobiphenyls and effect of the position of fluorine within the core on refractive indices, optical anisotropies, polarisabilities and order parameters

The syntheses and transition temperatures are reported for the series of monofluoro-substituted 4-butylsulfanyl-4'-cyanobiphenyls. The refractive indices, optical anisotropies, polarisabilities and order parameters of the compounds have been evaluated and are discussed in terms of the position of the fluoro-substituent in the core. Fluoro-substitution leads to higher polarisabilities for all positions of substitution compared to the non-fluorinated parent compound, and the order parameters of the compounds are all very similar. The results are discussed in terms of changes of the interannular torsion angle and the angle of the transition moment in relation to the position of fluoro-substitution.