Poly(9-anthrylmethyl methacrylate) ( ), poly [(10-phenyl-9-anthryl)methyl methacrylate] (PPA), and poly (9-anthrylmethyl ethenyl ether) (PAE) were prepared and their photophysics studied. The fluorescence spectra of these polymers are very dependent on the degree of anthracene crowding. The singlet energy migration constant (A,) was estimated to exceed 2 X 10~5 cm2/s for PPA but to be essentially 0 for PAE and(the latter displaying the largest fluorescence shift with respect to its monomeric model compound of all the polymers studied). Singlet-singlet annihilation was observed for PPA, which strengthens the finding that , ^0. Polymers containing ester groups were photolabile with respect to loss of anthracene groups, and especially has a strong tendency to be photoreactive.

SynopsisCopolymers of methyl methacrylate with an anthracene derivative are photodegraded in the solid state to give crosslinked material. The mechanism of insolubilization is dependent on the nature of the substituents at both the 9 and 10 positions of the anthracene chromophore. Photodimerization is the primary and most efficient cause of insolubilization if one of these positions is unsubstituted. Photodimerization does not occur if both of these positions are substituted; instead crosslinking is caused by photolysis of the endoperoxide of the parent anthracene. Bromination can sensitize the initial photooxidation and subsequent crosslinking in a copolymer where photodimerimtion does not occur. As a consequence of the crosslinking the rate of photobleaching of the anthracene chromophore by 'Ago2 is severly curtailed. Poly(methy1 methacrylate), a positive-tone polymer when exposed to UV light, is made negative acting by the incorporation of bound anthracene chromophores. EXPERIMENTAL Synthesis of Materials(1 0-Bromo-9-Anthrylmthyl Methacrylate (BAMMA) 10-Bromo-9-anthracenecarboxaldehyde was synthesized as follows; anthrone (5 g, Aldrich) was slurried in DMF (70 d) and cooled with an ice/water mixture. POBr, (5 g, Pfaltz and Bauer) was added slowly to the

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