A New Chiral Schiff Base with Ferroelectric Property

Reaction of 1,1,1,5,5,5‐hexafluoropen‐ tane‐2,4‐dione with (1 S ,2 S )‐(−)‐1,2‐diaminocyclohexane afforded a chiral Schiff base (1 Z ,4 Z )‐2,4‐bis(trifluoromethyl)‐5 a ,6,7,8,9,9 a ‐hexahydro‐3 H ‐benzo[ b ][1,4]diazepine ( 1 ). Fluorescent analysis showed its intense emission band at 488 nm when the exciting radiation was set at 437 nm. Crystallographic analysis shows that it belongs to a non‐centric space group C 2 with ferroelectric behavior. A typical ferroelectric feature of electric hysteresis loop was obtained, with remanent polarization (Pr) of ca . 0.01 µC/cm 2 and coercive field (Ec) of 0.27 kV/cm.