Doubly cyclopalladated pyridazines: chiral liquid crystals

The mono and dicyclopalladation of new mesogenic pyridazines and subsequent reaction with β-diketones yields some novel metallomesogens. The monometallated derivatives have a flat central core. In contrast, the dimetallated derivatives have a sterically induced twist in the molecule that renders them chiral. Smectic A phases are typically exhibited by both the derivatives with transition temperatures in the region of 100–300 °C.