Liquid crystals based on hypervalent sulfur fluorides: Part 4. [1] Pentafluorosulfanyl alkanes and olefins

New liquid crystals with a pentafluorosulfanyl function as their polar terminal group were prepared and fully characterized. The synthetic key step was the triethyl borane-catalyzed addition of SF5Br to a suitable olefin precursor, followed by dehydrobromination. The most interesting characteristic of the new materials is their combination of high polarity (Δɛ) with very low birefringence (Δn), which is of particular importance for LCDs for mobile applications.