Ana Omenat, José-Luis Serrano, Teresa Sierra, David B. Amabilino, María Minguet, Elena Ramos and Jaume Veciana
Creation of helical SmC* and Ch mesophases has been achieved by means of metal ion complexation by chiral isocyanide ligands, which have already proven their ability to induce high optical activity in helical synthetic polymers. Thus, from unstable isocyanide compounds with a mesogenic core derived from phenyl benzoate, five stable complexes have been prepared. Four palladium(II) complexes have been obtained with different chiral tails and, in one case, with a three-ring mesogenic core. Their corresponding SmC* phases have been studied in terms of their ferroelectric properties. High Ps values have been found for complexes derived from (S)-octan-2-ol: 93 nC cm–2 for I2Pd(C8*)2 and 59 nC cm–2 for I2Pd(COOPhC8*)2. A gold(I) complex with (R)-2-octyl as the chiral tail is presented as the first SmC* gold(I) complex whose ferroelectric behaviour has been studied. Indeed, the complex has been used as a chiral dopant in a binary mixture, the Ps value of which has been estimated.