Synthesis and properties of photochromic liquid-crystalline polyacrylates containing a spirooxazine group

The; novel photochromic liquid-crystalline polyacrylates containing a spirooxazine group were synthesized. The photochromic polymer containing (4-pentamethyleneoxy)biphenylene moiety at the 5-position of spironaphthoxazine showed nematic phase from 122.9 to 133.8 degrees C. The photochromic polymer containing undecamethylene instead of pentamethylene showed smectic phase from 93.1 to 169 degrees C. On the other hand, the photochromic polymer containing both undecamethylene as a spacer and spironaphthoxazine-bound biphenylene moiety at 9'-position did not show any liquid crystallinity. All spirooxazine-containing liquid-crystalline polymers showed photochromism in the solid state at room temperature. Because the shape of the absorption spectra of the photochromic quenched liquid-crystalline polymer films was almost the same as those of the photochromic amorphous polymer films, the photochromic properties did not depend on the mesophase in the polymers examined. (C) 1999 John Wiley & Sons, Inc.