Compounds of formulae I and II ##STR1## wherein D is H or --OR wherein R is phenyl and R.sub.1 to R.sub.4 are H or a substituent such as phenylthio, and one of the substituents R.sub.1, R.sub.2, R.sub.3 and R.sub.4 is a group of formula III --E-CR.sub.5 =C(R.sub.6).sub.2 (III) or R is substituted by a group of formula III, wherein E is a direct bond or --X-C(O)-- wherein X is a linking group, and R.sub.5 and R.sub.6 are each independently of the other H, halogen, C.sub.1 -C.sub.12 alkyl or C.sub.6 -C.sub.10 aryl, can be polymerised to homopolymers or copolymers. The monomers and polymers are reversible photochromic systems which can be used as color indicators, as photochemically modifiable color filters, or for the optical storage of information.
化合物的
化学式I和II如下所示,其中D为H或--OR,其中R为苯基,R.sub.1至R.sub.4为H或取代基,如苯
硫基,其中R.sub.1、R.sub.2、R.sub.3和R.sub.4中的一个是
化学式III的基团--E-CR.sub.5 =C(R.sub.6).sub.2(III),或R被
化学式III的基团取代,其中E为直接键或--X-C(O)--,其中X为连接基,R.sub.5和R.sub.6分别独立地为H、卤素、C.sub.1-C.sub.12烷基或C.sub.6-C.sub.10芳基,可以聚合成均聚物或共聚物。这些单体和聚合物是可逆光致变色系统,可用作颜色指示剂,作为光
化学可改变的颜色滤光片,或用于光学信息存储。