Towards a new class of ferroelectric liquid crystal molecules for nonlinear optical applications

The synthesis of a new molecule specifically designed to exhibit both ferroelectric and nonlinear optical properties is presented. This molecule possesses an optically active phenyl sulphinic group, which introduces a dipole moment directly linked to the chromophore group, with a nitro group in the meta -position. The rest of the molecule comprises a tolane and a benzoate group. Such a structure results in an enantiotropic smectic C*-smectic A phase sequence in its polymorphism. A first measurement of the spontaneous polarization shows a high value. The polymorphism of the racemic homologous molecule possessing the nitro group in the ortho-position is also presented, and also shows the smectic C-smectic A phase sequence.