Preparation of photochromic polymers by stereospecific copolymerization of trans-4-methacryloxyethylenoxyazobenzene and (-)-menthyl methacrylate

The synthesis is reported of a new photochromic monomer, trans-4-(2-methacryloxyethyloxy) azobenzene (MEAB), where the azobenzene chromophore is separated from the ester group by an ethylenoxy spacer arm. Comparative experiments show that trans-4-methacryloxyazobenzene (MAB), having the azobenzene group directly attached to the ester functionality, does not homopolymerize or copolymerize with (−)-menthyl methacrylate (MnMA) in the presence of different anionic initiators, whereas isotactic homopolymers and copolymers of MEAB can be obtained: the microstructure is described with reference to analogous atactic macromolecules.