Synthesis of Novel Liquid-Crystalline Allene Derivatives with Ferroelectric Properties

Some new heterocyclic liquid‐crystalline compounds incorporating a 1,3‐disubstituted allene unit were synthesised. These axial‐chiral compounds were investigated by polarisation microscopy and differential scanning calorimetry. One of them was also synthesised in enantiomerically enriched form by enantioselective synthesis. It was found that the latter product exhibits a ferroelectric switchable chiral smectic C phase with an unexpectedly large value of the spontaneous polarisation.