COLUMNAR PHASES FROM COVALENT AND HYDROGEN-BONDED LIQUID-CRYSTALLINE FERROCENE DERIVATIVES

The synthesis and liquid-crystalline properties of tetracatenar covale nt and H-bonded bis-ferrocene derivatives 1 and 2, respectively, are r eported. Both compounds gave rise to enantiotropic columnar liquid-cry stalline behavior with a hexagonal molecular organization. To explore the possibility to obtain also calamitic liquid-crystalline phases fro m H-bonded ferrocene-containing liquid crystals, a rod-shaped ferrocen e mesogen 3 was synthesized, which gave rise to enantiotropic smectic C and smectic A phases. For the first time, a rational synthetic desig n at the ferrocene level led to ferrocene-based liquid-crystals with c olumnar behavior and to H-bonded metallomesogens.