A series of novel liquid crystalline monomers and polymers incorporating phenylbenzoate or phenylcinnamate segments as mesogenic cores have been synthesized to investigate the sensitivity of the photochromic cinnamoyl derivatives and to overcome the defects of the thermal instability of azobenzene. Their liquid crystalline, thermal, and photoinduced properties of all monomers and polymers were characterized. The polymers showed excellent solubility in common organic solvents such as CHCl3, toluene, and DMF and exhibited good thermal stability with decomposition temperatures (T-d) at 5% weight loss greater than 340 degrees C and about 50% weight loss occurred beyond 430 degrees C under nitrogen atmosphere. The pitch length (about 574 nm) of the synthesized cholesteric polymeric film (CP2) was estimated using scanning electron microscopy. These photochromic polymers exhibited strong UV-vis absorption maxima at about 264 or 320 nm. Moreover, photo induced configurational E/Z isomerization further changed the pi-electron conjugation systems leading to a decrease at the pi-pi* transition and an increase in the range of 300 mn to 400 mn for photochromic copolymers. The thermal stability of the Z-structural segment was confirmed by heating the polymer at 50 degrees C for over 5 h. (C) 2008 Wiley Periodicals, Inc.